JP2004530858A - Natural gas liquefaction - Google Patents

Abstract

Disclosed is a process for producing a liquid stream (41) comprising primarily hydrocarbons heavier than methane while simultaneously liquefying (50) natural gas. In this process, the natural gas stream (31) to be liquefied is partially cooled, expanded to an intermediate pressure (14, 15) and fed to a distillation column (19). The bottom product (41) from this distillation column preferably contains the majority of all hydrocarbons heavier than methane, which may reduce the purity of the liquefied natural gas (50). The residual gas stream (37) from the distillation column (19) is compressed to a high intermediate pressure (16), cooled and condensed under pressure (60), and expanded to a low pressure to form a liquefied natural gas stream .

Description

【００２３】
LNG製造プロセス効率は、通常、全冷却圧縮動力対全液体製造速度の比である、必要な「比動力消費(specific power consumption)」を使用して比較する。LNGを製造するための従来プロセスに関し比動力消費の公開情報では、0.168HP-Hr/Lb[0.276kW/-時間/kg]〜0.182HP-Hr/Lb[0.300kW/-時間/kg]の範囲を示しており、これはLNG製造プラントの年間340日の操業因子に基づくものと考えられる。これと同一ベースで、本発明の図１の態様の比動力消費は0.161HP-Hr/Lb[0.265kW/-時間/kg]であり、これは従来プロセスよりも４〜13%も効率が改良している。さらに、従来プロセスの比動力消費は、本発明のこの実施例で示されているようにNGL(C₂及び重質炭化水素)液体ストリームではなく、比較的低い回収レベルでLPG(C₃及び重質炭化水素)または凝縮物(C₄及び重質炭化水素）液体ストリームだけを同時に製造することをベースとしていることに留意しなければならない。従来プロセスは、LPGストリームまたは凝縮物ストリームの代わりにNGLストリームを同時に製造するためにかなりの冷却動力が必要である。
【００２４】
本発明の優れた効率の原因となる二つの主な因子がある。第一の因子は、この実施例で検討されたような高圧ガスストリームに適用した際に、液化プロセスの熱力学を調べることによって理解することができる。このストリームの主構成成分はメタンであるので、メタンの熱力学的特性は、従来プロセスで使用した液化プロセスと本発明で使用したサイクルとを比較する目的のために使用することができる。図２は、メタンに関する圧力−エンタルピー相図を含む。殆どの従来法の液化サイクルでは、ガスストリームは全て冷却され、同時にストリームは高圧(パスA-B)であり、次いでストリームは膨張(パスB-C)して、LNG貯蔵容器の圧力(大気圧よりやや上)になる。この膨張段階では膨張仕事機械を使用することができ、これは通常、理想の等エントロピー膨張で理論的に利用可能な仕事の75〜80%のオーダーで回復することができる。簡単にするために、パスB-Cに関し、図２に完全等エントロピー膨張を示す。それにしても、一定のエントロピーラインが相図の液体領域で殆ど垂直であるため、この膨張仕事によって提供されたエンタルピー減少はかなり小さい。
【００２５】
これと、本発明の液化サイクルとを対照させる。高圧で一部冷却した後(パスA-A')、このガスストリームを膨張仕事させて中間圧力とする(パスA'-A")。（再び、簡単にするために、完全等エントロピー膨張を示す）残りの冷却は中間圧力で実施し(パスA"-B')、次いでストリームをLNG貯蔵容器の圧力に膨張させる(パスB'-C)。一定エントロピースロープのラインは、相図の気相領域によって提供されるので、本発明の第一の膨張仕事段階(パスA'-A")によってかなり大きなエンタルピー減少が提供される。かくして、本発明で必要な全冷却量(パスA-A'とA"-B'の和)は、従来プロセスで必要な冷却(パスA-B)よりも少なく、ガスストリームに液化するのに必要な冷却力が少ない。
【００２６】
本発明の優れた効率の原因となる第二の因子は、低い操作圧力で炭化水素蒸留系をうまく実施するということである。殆どの従来プロセスでの炭化水素除去段階は、通常、入ってくるガスストリームから重質炭化水素を除去するための吸着ストリームとして冷炭化水素液体を使用するスクラブカラムを使用して、高圧で実施する。ガスストリームからメタンとエタンのかなりの画分を同時吸着させてしまい、続いてこれを吸着液体からストリッピングし、冷却して、LNG生成物の一部としなければならないので、高圧でスクラブカラムを操作するのは非常に効率的ではない。本発明において、炭化水素除去段階は中間圧力で実施し、ここでは気−液平衡がずっと都合がよく、副生成物の液体ストリームに所望の重質炭化水素を非常に効率的に回収できる。
実施例２
LNG生成物に関する規格によって、供給材料ガスに含まれるより多くのエタンをLNG生成物中に回収できれば、本発明の簡便な態様を使用することができる。図３は、そのような別の態様を示す。図３に示されるプロセスで考えられる入口ガス組成と条件とは、図１のものと同一である。従って、図３のプロセスは、図１に示された態様と比較することができる。
【００２７】
図３のプロセスのシミュレーションでは、NGL回収区画に関する入口ガス冷却、分離及び膨張スキームは、図１で使用したものと本質的に同一である。入口ガスはストリーム31として90゜F[32℃]及び1285psia[8,860kPa(a)]でプラントに入り、−35゜F[−37℃]で冷媒ストリームとデメタナイザー・サイド・リボイラー液体（ストリーム40)との熱交換により冷却される。この冷却ストリーム31aは−30゜F[−34℃]及び1278psia[8,812kPa(a)]で分離器11に入り、ここで蒸気(ストリーム32)は凝縮液体(ストリーム33)から分離される。
【００２８】
分離器11からの蒸気(ストリーム32)を二つのストリーム34と36とに分割する。全蒸気の約20%を含有するストリーム34を凝縮液体のストリーム33と混合してストリーム35を形成する。混合ストリーム35を、冷媒ストリーム71eを使う熱交換関係にある熱交換器13を通して冷却し、実質的にストリーム35aに凝縮させる。この実質的に凝縮されたストリーム35aは−120゜F[−85℃]で、膨張弁14などの適当な膨張デバイス内を通して、分留塔19の操作圧力(約465psia[3,206kPa(a)])にフラッシュ膨張させる。膨張の間にストリームの一部が気化してストリーム全体が冷却される。図３に示されているプロセスでは、膨張弁14を離れる膨張ストリーム35bは−122゜F[−86℃]の温度に到達し、分留塔19の上部領域の分離器区画に供給される。この中で分離された液体は、分留塔19の下部領域の脱メタン化区画への上部供給材料になる。
【００２９】
分離器11からの蒸気の残りの80%(ストリーム36)は膨張仕事機械15に入り、ここで機械的エネルギーが高圧供給材料のこの部分から取り出される。この機械15は約1278psia[8,812kPa(a)]の圧力から塔の操作圧力に蒸気を実質的に等エントロピー的に膨張させ、膨張仕事によって膨張ストリーム36aを約−103゜F[−75℃]の温度に冷却する。この膨張し、一部凝縮させたストリーム36aを供給材料として、中間カラム供給点で蒸留カラム19に供給する。
【００３０】
冷デメタナイザー塔頂部蒸気(ストリーム37)は−123゜F[−86℃]で分留塔19の上部を出る。液体生成物ストリーム41は、底部生成物のモルベースでメタン対エタン比0.020：１の典型的な規格をベースとして、118゜F[48℃]で塔の底部を出る。
【００３１】
デメタナイザー塔頂部蒸気(ストリーム37)を熱交換器24で90゜F[32℃]に温め、次いで一部(ストリーム48)を抜き出してプラント用燃料ガスとして利用する。温暖デメタナイザー塔頂部蒸気の残余(ストリーム49)を圧縮機16により圧縮する。流出冷却器(discharge cooler)で100゜F[38℃]に冷却した後、冷デメタナイザー塔頂部蒸気、ストリーム37と相互交換により熱交換器24内でストリーム49bをさらに−112゜F[−80℃]に冷却する。
【００３２】
次いでストリーム49cは熱交換器60に入り、冷媒ストリーム71dでさらに−257゜F[−160℃]に冷却して、このストリームを凝縮させ、過冷却し、そしてストリームは膨張仕事機械61に入り、ここで機械的エネルギーがストリームから取り出される。機械61は液体ストリーム49dを、約583psia[4,021kPa(a)]から大気圧よりやや上のLNG貯蔵圧力(15.5psia[107kPa(a)])に実質的に等エントロピー的に膨張させる。この膨張仕事によって膨張ストリーム49eを約−258゜F[−161℃]に冷却し、LNG貯蔵タンク62に向け(ストリーム50)、そこでLNG製品ストリーム50を保持する。
【００３３】
図１のプロセスと同様に、ストリーム35と49cの冷却は全て、閉鎖系冷却ループによって提供される。図３のプロセスのサイクルで作動流体として使用したストリームの組成は、おおよそのモルパーセントで7.5%窒素、40.0%メタン、42.5%エタンと10.0%プロパンで、残余は重質炭化水素であった。冷媒ストリーム71は100゜F[38℃]及び607psia[4,185kPa(a)]で流出冷却器69を離れる。これは熱交換器10に入り、−31゜F[−35℃]に冷却され、部分的に温められた膨張冷媒ストリーム71fにより及び他の冷媒ストリームによって部分的に凝縮される。図３のシミュレーションに関しては、これら他の冷媒ストリームは種々の温度及び圧力レベルにける市販品質のプロパン冷媒であると想定された。次いで部分的に凝縮された冷媒ストリーム71aは、部分的に温められた膨張冷媒ストリーム71eによってさらに−121゜F[−85℃]に冷却されて、凝縮させ、冷媒(ストリーム71b)を過冷却する。この冷媒は、膨張冷媒ストリーム71dにより熱交換器60内で−257゜F[−160℃]にさらに過冷却される。この過冷却液体ストリーム71cは膨張仕事機械63に入り、ここで約586psia[4,040kPa(a)]から約34psia[234kPa(a)]の圧力に実質的に等エントロピー的に膨張するにつれて、機械的エネルギーがストリームから取り出される。膨張の間に、ストリームの一部が気化し、ストリーム全体を−263゜F[−164℃]に冷却する(ストリーム71d)。次いでこの膨張ストリーム71dは熱交換器60、13及び10に入り、ここで気化し過熱されるにつれて、ストリーム49c、ストリーム35及び冷媒(ストリーム71、71a及び71b)を冷却する。
【００３４】
過熱冷媒蒸気(ストリーム71g)は93゜F[34℃]で熱交換器10を離れ、三段階で617psia[4,254kPa(9)]に圧縮される。三つの圧縮段階(冷媒圧縮機64、66及び68)はそれぞれ追加の電源によって駆動され、冷却器(流出冷却器65、67及び69)に続いて圧縮熱を除去する。流出冷却器69からのこの圧縮ストリームは熱交換器10に戻って系は完了する。
【００３５】
図３に示したプロセスのストリーム流速及びエネルギー消費の概要を以下の表に示す。
【００３６】
【表２】

【００３７】
LNG製造プラントが１年に340日の操業因子と仮定すると、本発明の図３の態様の比動力消費は0.153HP-Hr/Lb[0.251kW-Hr/Kg]である。従来プロセスと比較して、改善効率は図３の態様に関しては10〜20%である。図１の態様で既に述べたように、従来プロセスにより製造された凝縮副生成物またはLPGよりもむしろNGL副生成物が生成されるのに、この改善効率は本発明に関して可能である。
【００３８】
図１の態様と比較して、本発明の図３の態様は生成した液体の単位当たり約５%低い動力が必要である。かくして、利用可能な圧縮動力の所定量に関しては図３の態様は、NGL副生成物中にC₂及び重質炭化水素をあまり回収できないので、図１の態様よりも約５%多い天然ガスを液化できるだろう。特定の適用に関して本発明の図１の態様と図３の態様との選択は、(図１の態様によって生成したLNGの発熱量は図３の態様によって生成したものよりも低いので)通常、NGL生成物中の重質炭化水素の金銭的価値対LNG生成物中のその対応する値により、またはLNG生成物に関する発熱量規格により決定される。
実施例３
LNG生成物に関する規格によって供給ガス中に含まれるエタンが全てLNG生成物中に回収できるならば、またはエタンを含有する液体副生成物の市場がないならば、図４に示されているような本発明の別の態様を使用してLPG副生成物ストリームを製造することができる。図４に示されているプロセスで検討された入口ガス組成及び条件は、図1及び３のものと同一である。従って図４のプロセスは、図１及び３に示された態様と比較することができる。
【００３９】
図４のプロセスのシミュレーションにおいて、入口ガスはストリーム31として90゜F[32℃]及び1285psia[8,860kPa(a)]でプラントに入り、−46゜F[−43℃]で冷媒ストリーム及びフラッシュ分離器液体と熱交換により熱交換器10で冷却される(ストリーム33a)。この冷却ストリーム31aは−１゜F[−18℃]及び1278psia[8,812kPa(a)]で分離器11に入り、ここで蒸気(ストリーム32)を凝縮液体(ストリーム33)から分離する。
【００４０】
分離器11からの蒸気(ストリーム32)は膨張仕事機械15に入り、ここで機械的エネルギーが高圧供給材料のこの部分から取り出される。この機械15は約1278psia[8,812kPa(a)]の圧力から約440psia[3,034kPa(a)]の圧力(分離器/吸着塔18の操作圧力)へ蒸気を実質的に等エントロピー的に膨張させ、膨張仕事によって膨張ストリーム32aを約−81゜F[−63℃]の温度に冷却する。膨張し部分的に凝縮されたストリーム32aは、分離器/吸着塔18の下部領域の吸着区画18bに供給される。膨張ストリームの液体部分は、吸着区画から下降する液体と混ざって、混合液体ストリーム40は分離器/吸着塔18の底部を−86゜F[−66℃]で出る。膨張ストリームの蒸気部分は吸着区画を通って上昇し、下降する冷液体と接触してC₃成分と重質成分とを凝縮且つ吸収する。
【００４１】
分離器/吸着塔18は、垂直に間隔を開けた複数のトレーと、一つ以上の充填床と、またはトレーと充填材との組合せを含む慣用の蒸留カラムである。天然ガス処理プラントでよく見られることであるが、分離器/吸着塔は二つの区画からなっていてもよい。上部区画18aは分離器であり、ここで上部供給材料中に含まれる全ての蒸気がその対応する液体部分から分離され、ここで下部蒸留または吸着区画18bから上昇する蒸気は上部供給材料の蒸気部分(もしあれば）と混合して冷蒸留ストリーム37を形成し、これは塔の上部を出る。下部の吸着区画18bはトレー及び／または充填材を含み、下降する液体と上昇する蒸気との間に必要な接触を提供して、C₃成分と重質成分とを凝縮且つ吸着する。
【００４２】
分離器/吸着塔18の底部からの混合液体ストリーム40をポンプ26によって熱交換器13に輸送し、そこでデエタナイザー(deethanizer)塔頂部(ストリーム42)と冷媒(ストリーム71a)とを冷却するに連れて、それ(ストリーム40a)は加熱される。混合液体ストリームは−24゜F[−31℃]に加熱され、部分的にストリーム40bを気化したあと、中間カラム供給材料としてデエタナイザー19に供給される。分離器液体(ストリーム33)を膨張弁12によってデエタナイザー19の操作圧力よりもやや上にフラッシュ膨張させ、ストリーム33を−46゜F[−43℃]に冷却してから、上記の如く入ってくる供給材料ガスを冷却する。いまは85゜F[29℃]のストリーム33bは下方の中間カラム供給点でデエタナイザー19に入る。デエタナイザーでは、ストリーム40bと33bはそのメタンとC₂成分とがストリッピングされる。約453psia[3,123kPa(a)]で操作する塔19のデエタナイザーは、垂直に間隔を開けた複数のトレー、一つ以上の充填床、またはトレーと充填材との組合せを含む慣用の蒸留カラムでもある。このデエタナイザー塔は上部の分離器区画19aと下部の脱エタン化区画19bとからなっていてもよく、上部の分離器区画19aでは、上部供給材料中に含まれる全ての蒸気をその対応する液体部分から除去し、下部蒸留または脱エタン化区画19bから上がってくる蒸気を上部供給材料の(もしあれば)蒸気部分と混合して、塔の上部を出る蒸留ストリーム42を形成する；下部の脱エタン化区画19はトレー及び／または充填材を含み、下降する液体と上昇する蒸気との間に必要な接触を提供する。脱エタン化区画19bは、一つ以上のリボイラ(たとえばリボイラ20)も含み、これはカラム底部で液体の一部を加熱且つ気化させて、ストリッピング蒸気を提供し、これはカラムを昇流してメタンとC₂成分との液体生成物、ストリーム41をストリッピングする。底部液体生成物の典型的な規格は、モルベースでエタン対プロパン比0.020：１である。液体生成物ストリーム41は214゜F[101℃]でデエタナイザーの底部を出る。
【００４３】
デエタナイザー19内の操作圧力は、分離器/吸着塔18の操作圧力よりもやや上に保持する。これによってデエタナイザー塔頂部蒸気(ストリーム42)が熱交換器13内を、次いで分離器/吸着塔18の上部区画に流れることができる。熱交換器13では、−19゜F[−28℃]でデエタナイザー塔頂部は分離器/吸着塔18の底部からの混合液体ストリーム(ストリーム40a)と熱交換関係に導かれ、冷媒ストリーム71eをフラッシュし、ストリームを−89゜F[−67℃]に冷却し(ストリーム42a)、部分的に凝縮させる。この部分的に凝縮させたストリームは還流ドラム22に入り、ここで凝縮液体(ストリーム44)は未凝縮蒸気(ストリーム43)から分離される。ストリーム43は分離器/吸着器の上部領域を離れる蒸留蒸気ストリーム(ストリーム37)と混合して、冷残渣ガスストリーム47を形成する。凝縮液体(ストリーム44)はポンプ23によって高圧に汲み上げられ、同時にストリームは二つの部分に分割される。一方の部分ストリーム45は分離器/吸着塔18の上部分離器区画に輸送されて、吸着区画内を上昇する蒸気と接触する冷液体として機能する。もう一方は還流ストリーム46としてデエタナイザー19に供給されて、−89゜F[−67℃]で上部供給点に流れる。
【００４４】
冷残渣ガス(ストリーム47)は熱交換器24内で−94゜F[−70℃]から94゜F[34℃]に温められ、一部(ストリーム48)が抜き出されてプラント用燃料ガスとして機能する。温暖残渣ガスの残余(ストリーム49)は圧縮機16によって圧縮される。流出冷却器25内で100゜F[38℃]に冷却された後、ストリーム49bを熱交換器24内で冷残渣ガス、ストリーム47で相互交換によりさらに−78゜F[−61℃]に冷却する。
【００４５】
次いでストリーム49cは熱交換器60に入り、冷媒ストリーム71dにより−255゜F[−160℃]にさらに冷却されて、ストリームを凝縮且つ過冷却し、それでストリームは膨張仕事機械61に入り、そこで機械的エネルギーがストリームから取り出される。この機械61は液体ストリーム49dを約648psia[4,465kPa(a)]の圧力から、大気圧よりもやや上のLNG貯蔵圧力(15.5psia[107kPa(a)])に実質的に等エントロピー的に膨張させる。この膨張仕事によって膨張ストリーム49cを約−256゜F[−160℃]の温度に冷却し、LNG生成物(ストリーム50)を保持するLNG貯蔵タンク62に向ける。
【００４６】
図１及び図３のプロセスと同様に、閉鎖サイクル冷却ループによって、ストリーム42の冷却の大部分とストリーム49cの冷却の全てが提供される。図４のプロセスに関するサイクルで作動流体として使用したストリームの組成は、おおよそのモルパーセントで、8.7%窒素、30.0%メタン、45.8%エタン及び11.0%プロパンで、残余は重質炭化水素である。冷媒ストリーム71は100゜F[38℃]及び607psia[4,185kPa(a)]で流出冷却器69を離れる。これは熱交換器10に入り、−17゜F[−27℃]に冷却され、部分的に温められた膨張冷媒71fにより及び他の冷媒ストリームによって部分的に凝縮される。図４のシミュレーションに関しては、これら他の冷媒ストリームは三つの異なる温度及び圧力レベルで市販品質のプロパン冷媒であると仮定される。次いで部分的に凝縮された冷媒ストリーム71aは熱交換器13に入り、部分的に温められた膨張冷媒ストリーム71eによってさらに−89゜F[−67℃]に冷却され、さらに冷媒を凝縮させる(ストリーム71b)。この冷媒は完全に凝縮され、膨張冷媒ストリーム71dによって熱交換器60内で−255゜F[−160℃]に過冷却される。過冷却液体ストリーム71cは膨張仕事機械63に入り、そこで約586psia[4,040kPa(a)]から約34psia[234kPa(a)]の圧力に実質的に等エンタルピー的に膨張するに連れて、機械的エネルギーがストリームから取り出される。膨張の間に、ストリームの一部が気化し、ストリーム全体を−264゜F[−164℃]に冷却する(ストリーム71d)。次いで膨張ストリーム71dは熱交換器60、13及び10に再び入って、気化且つ過熱されるにつれて、ストリーム49c、ストリーム42及び冷媒(ストリーム71、71a及び71b)を冷却する。
【００４７】
過熱冷媒蒸気(ストリーム71g)は90゜F[32℃]で熱交換器10を離れ、三段階で617psia[4,254kPa(a)]に圧縮される。三つの圧縮段階(冷媒圧縮機64、66及び68)はそれぞれ追加の電源により駆動され、冷却器(流出冷却器65、67及び69)に続き圧縮熱を除去する。流出冷却器69からの圧縮ストリーム71は熱交換器10に戻って系は完了する。
【００４８】
図４に示したプロセスのストリーム流速及びエネルギー消費の概要を以下の表に示す。
【００４９】
【表３】

【００５０】
LNG製造プラントが１年に340日の操業因子と仮定すると、本発明の図４の態様の比動力消費は0.143HP-Hr/Lb[0.236kW-Hr/Kg]である。従来プロセスと比較して、改善効率は図４の態様に関しては17〜27%である。
【００５１】
図１及び図３の態様と比較して、本発明の図４の態様は生成した液体の単位当たり６%〜11%低い動力が必要である。かくして、利用可能な圧縮動力の所定量に関しては図４の態様は、LPG副生成物としてC₃及び重質炭化水素を回収することにより、図１の態様よりも約６%多い天然ガス、または図３の態様よりも約11%多い天然ガスを液化することができる。特定の適用に関して本発明の図４の態様と図１または図３の態様との選択は、(図１と図３の態様によって生成したLNGの発熱量は図４の態様によって生成したものよりも低いので)通常、NGL生成物中の重質炭化水素の金銭的価値対LNG生成物中のその対応する値により、またはLNG生成物に関する発熱量規格により決定される。
実施例４
LNG生成物に関する規格によって供給ガス中に含まれるエタンとプロパンが全てLNG生成物中に回収できるならば、またはエタンとプロパンとを含有する液体副生成物の市場がないならば、図５に示されているような本発明の別の態様を使用して凝縮物副生成物ストリームを製造することができる。図５に示されているプロセスで検討された入口ガス組成及び条件は、図1、３及び４のものと同一である。従って図５のプロセスは、図１、３及び４に示された態様と比較することができる。
【００５２】
図５のプロセスのシミュレーションにおいて、入口ガスはストリーム31として90゜F[32℃]及び1285psia[8,860kPa(a)]でプラントに入り、冷媒ストリームにより熱交換器10で冷却され、−37゜F[−38℃]で高圧分離器液体をフラッシュし(ストリーム33b)、−37゜F[−38℃]で中間圧力分離器液体をフラッシュする。この冷却ストリーム31aは−30゜F[−34℃]及び1278psia[8,812kPa(a)]で分離器11に入り、ここで蒸気(ストリーム32)は凝縮液体(ストリーム33)から分離される。
【００５３】
分離器11からの蒸気(ストリーム32)は膨張仕事機械15に入り、ここで機械的エネルギーが高圧供給材料のこの部分から取り出される。この機械15は約1278psia[8,812kPa(a)]の圧力から約635psia[4,378kPa(a)]の圧力へ蒸気を実質的に等エントロピー的に膨張させ、膨張仕事によって膨張させたストリーム32aを約−83゜F[−64℃]の温度に冷却する。膨張し部分的に凝縮されたストリーム32aは、分離器18に入り、ここで蒸気(ストリーム42)は凝縮液体(ストリーム39)から分離される。中間圧力分離器液体(ストリーム39)を、膨張弁17によってデプロパナイザー(depropanizer)19の操作圧力よりやや上にフラッシュ膨張させ、ストリーム39を−108゜F[−78℃]に冷却(ストリーム49a)し、その後ストリームは熱交換器13に入り、上記の如く残渣ガスストリーム49と冷媒ストリーム71a、熱交換器10を冷却して、入ってくる供給材料ガスを冷却するに連れて加熱される。−15゜F[−26℃]のストリーム39cは、上部中間カラム供給点でデプロパナイザー19に入る。
【００５４】
高圧分離器11からの凝縮液体、ストリーム33を、膨張弁12によってデプロパナイザー19の操作圧力よりやや上にフラッシュ膨張させ、ストリーム33を−93゜F[−70℃]に冷却してから(ストリーム33a)、ストリームは熱交換器13に入り、上記の如く残渣ガスストリーム49と冷媒ストリーム71a、熱交換器を冷却し、入ってくる供給材料ガスを冷却するに連れて加熱される。50゜F[10℃]のストリーム33cは、下部中間カラム供給点でデプロパナイザー19に入る。デプロパナイザーでは、ストリーム39cと33cをメタン、C₂成分及びC₃成分にストリッピングする。約385psia[2,654kPa(a)]で操作するデプロパナイザー塔19は、垂直に間隔を開けた複数のトレー、一つ以上の充填床、またはトレーと充填材との組合せとを含む慣用の蒸留カラムである。このデプロパナイザー塔は上部分離器区画19aと下部脱プロパン化区画19bの二つの区画から構成されていてもよい。上部分離器区画19aでは、上部供給材料に含まれる全ての上記がその対応する液体部分から分離され、下部蒸留または脱プロパン化区画19bから上昇する蒸気が上部供給材料の(もしあれば)蒸気部分と混合されて、塔の上部を出る蒸留ストリーム37を形成する。下部の脱プロパン化区画19bはトレー及び／または充填材を含み、下降する液体と上昇する蒸気との間に必要な接触を提供する。この脱プロパン化区画19bは一つ以上のリボイラ(たとえばリボイラ20)も含み、これはカラムの底部で液体の一部を加熱且つ気化して、メタン、C₂成分及びC₃成分の液体生成物、ストリーム41をストリッピングするためのカラムを昇流するストリッピング蒸気を提供する。底部液体生成物の典型的な規格は、容積ベースでプロパン対ブタン比0.020：１である。液体生成物ストリーム41は286゜F[141℃]でデエタナイザー底部を出る。
【００５５】
塔頂部蒸留ストリーム37は36゜F[２℃]でデプロパナイザー19を出て、還流コンデンサ21で市販品質のプロパン冷媒によって冷却且つ部分的に凝縮される。部分的に凝縮されたストリーム37aは２゜F[−17℃]で還流ドラム22を出て、そこで凝縮液体(ストリーム44)は未凝縮蒸気(ストリーム43)から分離される。凝縮液体(ストリーム44)は還流ストリーム44aとしてデプロパナイザー19の上部供給点へポンプにより汲み上げられる。
【００５６】
還流ドラム22からの未凝縮蒸気(ストリーム43)を熱交換器24で94゜F[34℃]に温め、次いで一部(ストリーム48)をプラント用燃料ガスとするために抜き出す。温暖蒸気の残余(ストリーム38)は圧縮機16により圧縮する。流出冷却器25内で100゜F[38℃]に冷却した後、ストリーム38bは、冷蒸気、ストリーム43との相互交換により熱交換器24内で15゜F[−９℃]にさらに冷却される。
【００５７】
次いでストリーム38cを中間圧力分離器蒸気(ストリーム42)と混合して、冷残渣ガスストリーム49を形成する。ストリーム49は熱交換器13に入り、上記の如く分離器液体(ストリーム39a及び33a)により、及び冷媒ストリーム71eにより−38゜F[−39℃]から−102゜F[−74℃]に冷却される。次いで部分的に凝縮させたストリーム49aは熱交換器60に入り、冷媒ストリーム75dによりさらに−254゜F[−159℃]に冷却されて凝縮且つ過冷却し、その後ストリームは膨張仕事機械61に入り、そこで機械的エネルギーはストリームから取り出される。機械61は液体ストリーム49bを、約621psia[4,282kPa(a)]から大気圧をやや超えるLNG貯蔵圧力(15.5psia[107kPa(a)])に実質的に等エントロピー的に膨張させる。膨張仕事によって膨張ストリーム49cを約−255゜F[−159℃]の温度に冷却し、次いでLNG貯蔵タンクに方向付け(ストリーム50)、LNG生成物を保持する。
【００５８】
図１、図３及び図４のプロセスと同様に、ストリーム49を冷却する大部分とストリーム49aの冷却の全ては、閉鎖循環式冷却ループによって提供する。図５のプロセスに関するサイクル中の作動流体として使用したストリームの組成は、おおよそのモルパーセントで、8.9%窒素、34.3%メタン、41.3%エタン及び11.0%プロパンで、残余は重質炭化水素である。冷媒ストリーム71は100゜F[38℃]及び607psia[4,185kPa(a)]で流出冷却器69を離れる。このストリームは熱交換器10に入り、−30゜F[−34℃]に冷却され、部分的に温められた膨張冷媒ストリーム71fにより及び他の冷媒ストリームにより部分的に凝縮される。図５のシミュレーションに関しては、これら他の冷媒ストリームは、三つの異なる温度及び圧力レベルで市販品質のプロパン冷媒であると仮定された。次いで部分的に凝縮された冷媒ストリーム71aは熱交換器13に入り、部分的に温められた膨張冷媒ストリーム71eによってさらに−102゜F[−74℃]に冷却され、さらに冷媒を凝縮させる(ストリーム71b)。この冷媒は、完全に凝縮され、次いで膨張冷媒ストリーム71dによって熱交換器60により−254゜F[−159℃]に過冷却される。この過冷却液体ストリーム71cは膨張仕事機械63に入り、約586psia[4,040kPa(a)]から約34psia[234kPa(a)]の圧力に実質的に等エントロピー的に膨張するに連れて、機械的エネルギーがストリームから取り出される。膨張の間、ストリームの一部が気化し、ストリーム全体が−264゜F[−164℃]に冷却される(ストリーム71d)。次いで膨張ストリーム71dは熱交換器60、13及び10に入り、気化及び過熱されるにつれて、ストリーム49a、ストリーム49及び冷媒(ストリーム71、71a及び71b)を冷却する。
【００５９】
過熱冷媒蒸気(ストリーム71g)は93゜F[34℃]で熱交換器10を離れ、三段階で617psia[4,254kPa(a)]に圧縮される。三つの圧縮段階(冷媒圧縮機64、66及び68)はそれぞれ追加の電源により駆動され、圧縮熱を除去するために冷却器(流出冷却器65、67及び69)に続く。流出冷却器69からの圧縮ストリーム71は熱交換器10に戻ってサイクルは完了する。
【００６０】
図５に示されたプロセスのストリーム流速とエネルギー消費の概要を以下の表に示す。
【００６１】
【表４】

【００６２】
LNG製造プラントが１年に340日の操業因子と仮定すると、本発明の図５の態様の比動力消費は0.145HP-Hr/Lb[0.238kW-Hr/Kg]である。従来プロセスと比較して、改善効率は図５の態様に関しては16〜26%である。
【００６３】
図１及び図３の態様と比較して、本発明の図５の態様は生成した液体の単位当たり５%〜10%低い動力が必要である。かくして、利用可能な圧縮動力の所定量に関しては図５の態様は、凝縮物副生成物としてC₄及び重質炭化水素を回収することにより、図１の態様よりも約５%多い天然ガス、または図３の態様よりも約10%多い天然ガス、または図４の態様と大体同量の天然ガスを液化することができる。特定の適用に関して本発明の図５の態様と図１、図３または図４の態様との選択は、(図１、図３及び図４の態様によって生成したLNGの発熱量は図５の態様によって生成したものよりも低いので)通常、NGLまたはLPG生成物中のエタン及びプロパンの金銭的価値対LNG生成物中のその対応する値により、またはLNG生成物に関する発熱量規格により決定される。
他の態様
当業者は、所定のプラントの場所での需要に最も合うように、NGLストリーム、LPGストリームまたは凝縮物ストリームを同時に製造できるように全てのタイプのLNG液化プラントで使用するために本発明を適合させ得ることを理解するだろう。さらに、液体副生成物ストリームを回収するために、種々のプロセス配置を使用できることを理解するだろう。たとえば図１及び図３の態様は、実施例１及び２に記載したようなNGLストリームよりもむしろ、液体副生成物ストリームとしてLPGストリームまたは凝縮物ストリームを回収するために適合させることができる。図４の態様は、実施例３に記載の如くLPG副生成物を製造するよりも供給材料ガスに含まれるC₂成分のかなりの画分を含むNGLストリームを回収するため、または供給材料ガス中に含まれるC₄及び重質成分だけを含有する凝縮物ストリームを回収するために適合させることができる。図５の態様は、実施例４に記載の如く凝縮物副生成物を製造するよりも供給材料ガスに含まれるC₂成分のかなりの画分を含むNGLストリームを回収するため、または供給材料中に含まれるC₃成分のかなりの画分を含有するLPGストリームを回収するために適合させることができる。
【００６４】
図１、３、４及び５は、示された処理条件に関する本発明の好ましい態様を示す。図６〜図２１は、特定の適用に関して検討され得る本発明の別の態様を表す。図６及び７に示されているように、分離器11からの凝縮液体(ストリーム33)の全てまたは一部を、熱交換器13に流れる分離器蒸気(ストリーム34)の一部と一緒に混合するよりも、むしろ別々に下部中間カラム供給材料位置で分留塔19に供給することができる。図８は、その比動力消費が幾らか高いが、図１及び図６の態様よりも装置が少なくてよい本発明の別の態様を示す。同様に、図９は、高い比動力消費を犠牲にして図３及び図７の態様よりも装置が少なくてよい本発明の別の態様を示す。図10〜14は、その比動力消費が高いが、図４の態様よりも装置が少なくてよい本発明の別の態様を示す。(図10〜図14に示されているように、たとえばデエタナイザー19などの蒸留カラムまたは系は、再沸騰吸着材塔デザインと還流再沸騰塔デザインの両方を含むことに留意されたい)図15及び図16は、図４と図10〜図14の分離器/吸着材塔18とデエタナイザー19の機能を一つの分留カラム19に組み合わせる本発明の別の態様を示す。供給材料ガス中の重質炭化水素の質と供給材料ガス圧とに依存して、熱交換器10を離れる冷却供給材料ストリーム31aは全く液体を含んでいないので[露点より上であるか、またはクリコンデンバー(criocondenbar)を超えているので]、図１及び３〜16に示されている分離器11は必要ではなく、冷却供給材料ストリームは膨張仕事機械15などの適当な膨張デバイスに直接流れることができる。
【００６５】
凝縮及び過冷却用に熱交換器60に供給する前に、液体副生成物ストリーム(図１、３、６〜11、13及び14のストリーム37、図４、12、15及び16のストリーム47、並びに図５のストリーム43)を回収した後に残存するガスストリームの処置は多くの方法で実施することができる。図１及び３〜16のプロセスにおいて、ストリームは加熱され、一つ以上の膨張仕事機械から誘導されたエネルギーを使用して高圧に圧縮され、流出冷却器で部分的に冷却され、次いで元のストリームとの相互交換によりさらに冷却される。図１７に示されているように、幾つかの応用では、たとえば外部電源により駆動される追加の圧縮機59を使用して、ストリームを高圧に圧縮するのが好ましい。図１及び３〜16の破線の装置(熱交換器24及び流出冷却器25)により示されているように、状況によっては、熱交換器60に入る前に(冷媒圧縮機64、66及び68の動力消費が増加し、熱交換器60の冷却負荷が多くなるのを犠牲にして)圧縮ストリームの予備冷却を減らしたり、省略することによって設備の資本コストを軽減させることが好ましい。そのような場合、圧縮機を離れるストリーム49aは、図18に示されるように熱交換器24に直接流れるか、または図19に示されているように熱交換器60に直接流れることができる。膨張仕事機械を高圧供給材料ガスのどの部分の膨張にも使用しない場合、図20により示されている圧縮機59などの外部電源により駆動される圧縮機を圧縮機16の代わりに使用することができる。他の場合ではストリームの圧縮を全く妥当と考えられないので、ストリームは図21に示されている熱交換器60並びに図１及び３〜16に示されている破線の装置(熱交換器24、圧縮機16及び流出冷却器25)に直接流れる。プラント燃料ガス(ストリーム48)が抜き出される前にストリームを加熱するために熱交換器24が備えられない場合、図19〜21に示されているように、必要な熱を供給するためにユーティリティーストリーム(utility stream)またはもう一つのプロセスストリームを使用して、燃料ガスを消費する前に燃料ガスを温めるために追加のヒーター58が必要かもしれない。ガス組成、プラントのサイズ、所望の副生成物ストリーム回収率レベル、及び利用可能な装置などの因子を全て考慮に入れなければならないので、これらのような選択は通常、適用毎に評価しなければならない。
【００６６】
本発明に従って、LNG製造区画への供給材料ストリーム及び入口ガスストリームの冷却は多くの方法で実施することができる。図１、３及び６〜９のプロセスでは、入口ガスストリーム31は、分留塔19からの塔液体と外部冷媒ストリームにより冷却且つ凝縮される。図４、５及び10〜14では、フラッシュ分離器液体を外部冷媒ストリームと一緒にこの目的に関して使用する。図15及び16では、外部冷媒ストリームと一緒にこの目的に関して塔液体及びフラッシュ化分離器液体を使用する。図17〜21では、外部冷媒ストリームのみを使用して入口ガスストリーム31を冷却する。しかしながら、図４、５、10及び１１に示されているように、冷プロセスストリームを使用して高圧冷媒(ストリーム71a)を幾らか冷却することもできよう。さらに、単数または複数のストリームよりも冷たい任意のストリームを使用することができる。たとえば、分離器/吸着塔19または分留塔19からの蒸気側流(side draw)を冷却用に抜き出し使用することができよう。プロセス熱交換用の塔の液体及び／または蒸気の使用及び分配、並びに入口ガス及び供給材料ガス冷却用の熱交換器の特定の配置は、それぞれ特定の用途に関して、並びに具体的な熱交換操作用のプロセスストリームの選択に関して評価しなければならない。冷却源の選択は、供給ガス組成及び条件、プラントのサイズ、熱交換器のサイズ、潜在的冷却源温度などを含む多数の因子に依存しようが、これらに限定されない。当業者は、上記冷却源または冷却方法の任意の組合せを使用して、単数または複数の所望の供給材料ストリーム温度を得ることができる。
【００６７】
さらに、LNG製造区画に入口ガスストリーム及び供給材料ストリームを供給する追加の外部冷却は、種々の方法で実施することもできる。図１及び３〜21では、高レベルの外部冷却に関しては単一成分の冷媒の沸騰が想定され、低レベルの外部冷却に関しては多成分の冷媒の沸騰が想定され、単一成分の冷媒を使用して多成分冷媒ストリームを予備冷却する。あるいは高レベル冷却と低レベル冷却のいずれをも、順に低い沸点をもつ単一成分冷媒(則ちカスケード冷却)または、順に低い蒸発圧力で単一成分冷媒を使用して実施することができる。もう一つには、高レベル冷却と低レベル冷却のいずれをも使用して、必要な冷却温度を提供するように調節されたそれぞれの組成をもつ多成分冷媒ストリームを使用して実施することができる。外部冷却を提供するための方法の選択は、供給ガス組成及び条件、プラントのサイズ、圧縮機ドライバーのサイズ、熱交換器のサイズ、周囲ヒートシンク温度などの多くの因子に依存しようが、これらに限定されない。当業者は、上記の外部冷却を提供するための方法の任意の組合せを使用して、単数または複数の所望の供給材料ストリーム温度を得ることができる。
【００６８】
熱交換器60を離れる凝縮液体ストリーム(図１、６及び８のストリーム49、図３、４、７及び９〜16のストリーム49d、図５、19及び20のストリーム49b、図17のストリーム49e、図18のストリーム49c並びに図21のストリーム49a)の過冷却によって、LNG貯蔵タンク62の操作圧力にストリームを膨張させる間に発生し得るフラッシュ蒸気の量を軽減または省略する。これは通常、フラッシュガス圧縮の必要性を省略することによってLNGを製造するための比動力消費を軽減する。しかしながら、状況によっては、発生し得る全てのフラッシュガスを処分するためにフラッシュガス圧縮または他の手段を使用して、及び熱交換器60のサイズを小さくすることによって設備の資本コストを軽減するのが好ましい。
【００６９】
個々のストリーム膨張を特定の膨張デバイスで表現したが、それぞれの場合に応じて別の膨張手段を使用することができる。たとえば、条件によっては実質的に凝縮された供給材料ストリーム(図１、３、６及び７のストリーム35a)または中間圧力還流ストリーム(図１、６及び８のストリーム39)の膨張仕事を保証することができる。さらに、熱交換器60を離れる過冷却液体ストリーム(図１、６及び８のストリーム49、図３、４、７及び９〜16のストリーム49d、図５、19及び20のストリーム49b、図17のストリーム49e、図18のストリーム49c並びに図21のストリーム49a)の膨張仕事の代わりに等エンタルピー的フラッシュ膨張を使用することができるが、膨張の間にフラッシュ蒸気が形成するのを防ぐために熱交換器60内でもっと過冷却するか、または発生したフラッシュ蒸気を処理するためにフラッシュ蒸気圧縮または他の手段を加えることが必要であろう。同様に、熱交換器60を離れる過冷却高圧冷媒ストリーム(図１及び３〜21のストリーム71c)の膨張仕事の代わりに等エンタルピー的フラッシュ膨張を使用することができ、これによって冷媒を圧縮するために動力消費が増大する。
【００７０】
本発明の好ましい態様と考えられるものについて記載してきたが、当業者は、付記請求の範囲に限定された本発明の趣旨から逸脱することなく、これらに他のまたはさらなる変形を加えて、本発明を種々の条件、供給材料のタイプまたは他の要件に適合させることができよう。
【図面の簡単な説明】
【００７１】
【図１】図１は、本発明に従ったNGLを同時に製造するために適合させた天然ガス液化プラントのフローチャートである。
【図２】図２は、従来プロセスより本発明の好都合な点を説明するために使用したメタン用の圧力−エンタルピー相図である。
【図３】図３は、本発明に従ったNGLを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図４】図４は、本発明に従ったLPGを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図５】図５は、本発明に従った凝縮物を同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図６】図６は、本発明に従った液体ストリームを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図７】図７は、本発明に従った液体ストリームを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図８】図８は、本発明に従った液体ストリームを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図９】図９は、本発明に従った液体ストリームを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図１０】図１０は、本発明に従った液体ストリームを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図１１】図１１は、本発明に従った液体ストリームを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図１２】図１２は、本発明に従った液体ストリームを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図１３】図１３は、本発明に従った液体ストリームを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図１４】図１４は、本発明に従った液体ストリームを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図１５】図１５は、本発明に従った液体ストリームを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図１６】図１６は、本発明に従った液体ストリームを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図１７】図１７は、本発明に従った液体ストリームを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図１８】図１８は、本発明に従った液体ストリームを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図１９】図１９は、本発明に従った液体ストリームを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図２０】図２０は、本発明に従った液体ストリームを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。
【図２１】図２１は、本発明に従った液体ストリームを同時に製造するために適合させた別の天然ガス液化プラントのフローチャートである。[Background Art]
[0001]
Background of the Invention
The present invention relates to a method for processing natural gas or other methane-rich gas stream to produce a liquid stream mainly containing liquefied natural gas (LNG) stream and hydrocarbons heavier than methane high purity methane.
[0002]
Natural gas is typically recovered from wells drilled into underground reservoirs. Usually, natural gas is mostly methane, Sokuchi methane comprises at least 50 mole percent of the natural gas. Depending on the particular underground reservoir, the natural gas is ethane, propane, butane, relatively small amounts of heavier hydrocarbons such as pentane, as well as water, contains hydrogen, nitrogen, and carbon dioxide and other gases.
[0003]
Most natural gas is handled in gaseous form. The most common means of transporting natural gas from a source to a gas processing plant and from there to a natural gas consumer is a high pressure gas transport pipeline. However, it has often been deemed necessary and / or desirable to liquefy natural gas for transport or use. In remote areas, often there is no pipeline equipment, for example, natural gas was considered to be easily transported to the market. In such a case, since the natural gas in a gas state to LNG is a very low specific volume, it is possible to greatly reduce transportation costs by transporting LNG using cargo ships and transport trucks.
[0004]
For natural gas liquefaction is the preferred alternative, it is when used as an automotive fuel. In metropolitan areas, many buses, taxis and trucks could have been powered by LNG if economical LNG sources were available. Vehicles fueled with such LNG emit less natural gas fuel than similar vehicles powered by gasoline and diesel engines that burn high molecular weight hydrocarbons, resulting in lower air pollution. considerably less. In addition, if LNG is of high purity (Sokuchi methane purity of 95% or more), methane compared to all other hydrocarbon fuels carbon: since hydrogen ratio is low, the carbon dioxide (greenhouse gas) to produce the amount is considerably less.
[0005]
The present invention is generally at the same time to liquefy the natural gas, a liquid stream consisting primarily of heavier than methane hydrocarbons, such as ethane, propane, natural gas liquid composed of butanes and heavier hydrocarbon components (NGL), propane Liquefied petroleum gas (LPG) composed of butane and heavy hydrocarbon components, or condensate composed of butane and heavy hydrocarbon components, etc. as a by-product. The production of by-products of the liquid stream two important advantages: it generated LNG is high methane purity, and the liquid by-product, that it is a useful product which can be used in the context of many other purposes there is. A typical analytical result of a natural gas stream to be processed according to the present invention is, on a mole% basis, about 84.2% methane, 7.9% ethane and other C_TwoComponents, 4.9% propane and other C_ThreeThe components, 1.0% isobutane, 1.1% normal butane, 0.8% pentane, with the balance being nitrogen and carbon dioxide. Gases containing sulfur may also be included.
[0006]
Many methods are known for the liquefaction of natural gas. See, for example, Finn, Adrian J., Grant L. Johnson and Terry R. Tomlinson, "LNG Technology for Offshore and Mid-Scale Plants", Proceedings of the Seventy-Ninth Annual Convention of the Gas Processors Association, pp. 429-450, Atlanta, Georgia, March 13-15, 2000 and Kikkawa, Yoshitsugi, Masaaki Ohnishi, and Noriyoshi Nozawa, "Optimize the Power System of Baseload LNG Plant", Proceedings of the Eightieth Annual See Convention of the Gas Process Association, San Antonio, Texas, March 12-14, 2001. U.S. Patent Nos. 4,445,917; 4,525,185; 4,545,795; 4,755,200; 5,291,736; 5,363,655; 5,365,740; 5,600,969; 5,615,561; and 5,651,269. No. 5,755,114; No. 5,893,274; No. 6,014,869; No. 6,062,041; No. 6,119,479; No. 6,125,653; No. 6,250, 105B1; No. 6,269,655B1; No. 6,272,882B1; Nos. 6,308,531B1; 6,324,867B1 and 6,347,532B1 also describe related processes. These methods typically include natural gas (and water, by removing the compound laborious, such as carbon dioxide and sulfur compounds) was purified, cooled and condensed, the step of expanding. Cooling and condensation of natural gas can be achieved by various methods. "Cascade refrigeration Method: cascade Refrigeration" At, utilizing heat exchange propane, in this order, such as ethane and methane and several refrigerant having a low boiling point (Refrigerant) and natural gas. Alternatively, this heat exchange can be performed using one type of refrigerant by evaporating the refrigerant at several different pressure levels. "Multi-component refrigeration" utilizes heat exchange between natural gas and one or more refrigerant fluids composed of several refrigerant components instead of various single refrigerant components. Expansion of natural gas, (e.g. Joule - Thomson expansion to use) can be carried out [Use example expansion work turbine (work-expansion turbine)] isenthalpic and any such entropic of.
[0007]
Despite the method used to liquefy the natural gas stream prior to liquefaction of methane-rich stream, usually it must be removed most of the hydrocarbons heavier than methane. The reasons for this hydrocarbon removal stage are numerous, including the need to control the calorific value of the LNG stream and the value of the heavy hydrocarbon component as a product per se. Surprisingly, not been little attention for the efficiency of the hydrocarbon removal stage to date.
[0008]
In accordance with the present invention, by careful aggregate hydrocarbon removal stage LNG liquefaction process can produce LNG and and individual heavy hydrocarbon liquid product with significantly less energy than conventional processes. Although applicable at low pressures, the present invention is particularly advantageous if the feed gas is treated in the range of 400 to 1500 psia [2,758 to 10,342 kPa (a)] or more.
[0009]
For a better understanding of the present invention, reference is made to the following examples and drawings.
In the description of the drawings, it provides a table summarizing the calculated flow rate with respect to representative process conditions. In this table, the flow rate values (mol / hr) have been rounded to the nearest integer for convenience. The total stream velocity shown in the table includes all non-hydrocarbon components and is therefore typically greater than the sum of the hydrocarbon component stream flow rates. The displayed temperature is an approximate value rounded to the nearest temperature. Process design calculations performed for the purpose of comparing the illustrated processes are based on the assumption that there is no heat loss from the environment to the process or from the process to the environment. It is assumed that the quality of the commercially available insulation material makes this assumption a very reasonable assumption and can normally be carried out by a person skilled in the art.
[0010]
For convenience, process parameters are reported in both traditional British Standard units and International System of Units (SI) units. Molar flow rate in the table, can be interpreted as a pound moles / hour or kilogram moles / hr. Energy consumption, reported as horsepower (HP) and / or 1000 British thermal units per hour (MBTU / Hr), corresponds to a specified molar flow rate in pounds-mole / hour. Energy consumption reported as kilowatts (kW) corresponds to a specified molar flow rate in kilogram moles / hour. The production rate reported as pounds per hour (Lb / Hr) corresponds to the specified molar flow rate in pounds per hour. The production rate reported as kilograms / hour (kg / Hr) corresponds to the specified molar flow rate in kilogram moles / hour.
DETAILED DESCRIPTION OF THE INVENTION
Example 1
With reference to FIG. 1, we start with a description of the process according to the invention. In this figure, it is desirable to produce an NGL by-product containing most of the ethane and heavy components in the natural gas feed stream. In this simulation of the invention, the inlet gas enters the plant as stream 31 at 90 ° F. [32 ° C.] and 1285 psia [8,860 kPa (a)]. If the inlet gas contains carbon dioxide and / or sulfur compounds is concentration to prevent suit preventing the product stream specifications, these compounds, suitably pretreated feed gas (not shown) It is removed by. In addition, this feed stream is usually dehydrated under cryogenic conditions so that hydrates (ice) do not form. Solid desiccants have usually been used for this purpose.
[0011]
The feed stream 31 is cooled in heat exchanger 10 by heat exchange with -68 ° F refrigerant stream and demethanizer side reboiler at [-55 ℃] (demethanizer side reboiler) solution. Note that in all cases, the heat exchanger 10 is a group of individual heat exchangers, or is representative of a single multi-pass heat exchanger, or any combination thereof. (Display of the cooling equipment relates two or more heat exchangers to whether to use judgment, inlet gas flow rate, the size of the heat exchanger, is dependent on many factors, including the stream temperature, but not limited to) cooling stream 31a enters separator 11 at -30 ° F [-34 ° C.] and 1278psia [8,812kPa (a)], where the vapor (stream 32) is separated from the condensed liquid (stream 33).
[0012]
Dividing the vapor from separator 11 (stream 32) into two streams 34 and 36. Condensed liquid stream 34 containing about 20% of the total vapor, is mixed with stream 33 to form stream 35. The mixed stream 35 passes through a heat exchanger 13 in heat exchange with the refrigerant stream 71e to cool and substantially condense the stream 35a. The substantially condensed stream 35a is then flash-expanded at -120 ° F [-85 ° C] through a suitable expansion device such as expansion valve 14 to operate at the operating pressure of fractionation tower 19 (about 465 psia [3,206 pKa (a to)]). While inflated, the stream is vaporized part, the entire stream is cooled. In the process illustrated in FIG. 1, the expansion stream 35b leaving expansion valve 14 reaches a temperature of -122 ° F [-86 ° C.], supplied to an intermediate position of supplying the demethanizer zone 19b fractionator 19 It is.
[0013]
The remaining 80% of the vapor from separator 11 (stream 36) enters expansion work machine 15, where mechanical energy is extracted from this portion of the high pressure feed. Machine 15 expansion work of steam about 1278psia substantially isentropically inflated from [8,812kPa (a)] to the operating pressure of the column, the expansion stream 36a to a temperature of about -103 ° F [-75 ° C.] by cooling. Normally available expanders can recover on the order of 80-85% of the theoretically available work with ideal isentropic expansion. The recovered work is often used to drive a stretch compressor (eg, item 16) that can be used, for example, to recompress the overhead gas (stream 38). The expanded, partially condensed stream 36a is fed as a feed to distillation column 19 at the lower intermediate column feed point.
[0014]
Demethanizer in fractionation tower 19 is a distillation column of conventional, including a combination of a plurality of vertically arranged trays, one or more packed beds or trays, and the filler. As is common in natural gas processing plants, this fractionation tower may be composed of two compartments. The upper section 19a is a separator wherein dividing the upper feed respectively the vapor and liquid portions, the vapor rising from the lower distillation zone or demethanizer zone 19b (if any) vapor portion of the upper feed And form a cold demethanizer overhead vapor (stream 37), which exits at -135 ° F [-93 ° C]. The lower demethanization section 19b contains trays and / or packing to provide the necessary contact between the descending liquid and the rising vapor. The demethanizing section also includes one or more reboilers (such as reboiler 20), which by heating and vaporizing a portion of the liquid downcomer column to provide stripping vapor upflow column. Liquid product stream 41, of methane on a molar basis in the bottom product: ethane ratio of 0.020: 1 typical standard (specification) as the base, leaving the bottom of the column at 115 ° F [46 ℃].
[0015]
The demethanizer overhead vapor (stream 37) is warmed to 90 ° F. [32 ° C.] in the heat exchanger 24, and a portion of the warm demethanizer overhead vapor is withdrawn and supplied as plant fuel gas (stream 48). (Amount of fuel gas that must be withdrawn is largely determined by the fuel required for example to the engine and / or turbine driving a gas compressor plant of the refrigerant such as compressors 64, 66 and 68 in this embodiment The remainder of the warm demethanizer overhead vapor (stream 38) is compressed by a compressor 16 driven by expansion machines 15, 61 and 63. After cooling to 100 ° F. [38 ° C.] in a discharge cooler 25, stream 38b was cooled to −123 ° F. in a heat exchanger 24 by cross-exchange with a cold demethanizer top stream, stream 37. It is cooled to -86 ℃].
[0016]
Then stream 38c enters the heat exchanger 60 is further cooled by a refrigerant stream 71d. After cooling to an intermediate temperature, stream 38c is split into two parts. The first portion, stream 49 is condensed and further cooled to in a heat exchanger 60 -257 ° F [-160 ° C.] by supercooling, wherein the stream enters work expansion machine 61, where mechanical energy There is taken out from the stream. This machine 61 causes the liquid stream 49 to expand substantially isentropically from a pressure of about 562 spia [3,878 kPa (a)] to an LNG storage pressure (15.5 spia [107 kPa (a)]), slightly above atmospheric pressure. Cooled to a temperature of the stream 49a inflated about -258 ° F [-161 ° C.] by the expansion work, directed to LNG storage tank 62, holds the LNG product (stream 50).
[0017]
Stream 39, extracted from the heat exchanger to another part of the stream 38c in -160 ° F [-107 ° C.], to flush it expanded to the operating pressure of fractionation tower 19 at an appropriate expansion device, such as expansion valve 17. In the process illustrated in FIG. 1, since the expansion in stream 39a evaporation is not, the temperature drops to little -161 ° F [-107 ° C.], it exits the expansion valve 17. Then supplying inflation stream 39a to separator section 19a in the upper region of fractionation tower 19. Therefore separated liquid is at the top feed to demethanizing section 19b.
[0018]
All cooling of stream 35 and 38c is provided by a closed circuit cooling loop. The working fluid for this cycle (working fluid) is a mixture of hydrocarbons and nitrogen, the composition of this mixture provides a coolant temperature necessary while condensed at the proper pressure using a cooling medium available It is adjusted as necessary to. In this case, because it was assumed to be condensed using cooling water, nitrogen, methane, ethane, are used in the simulation of the process of FIG. 1 a composed refrigerant mixture from propane and heavier hydrocarbons. The composition of the stream is approximately mole percent, 7.5% nitrogen, 41.0% methane, 41.5% ethane and 10.0% propane, with the balance being heavy hydrocarbons.
[0019]
Refrigerant stream 71 leaves effluent cooler 69 at 100 ° F [38 ° C] and 607 psia [4,185 kPa (a)]. This stream enters heat exchanger 10, is cooled to -31 ° F [-35 ° C], and is partially condensed by the partially warmed expanded refrigerant stream 71f and other refrigerant streams. For the simulation of FIG. 1, it was assumed that these other refrigerant streams were commercial quality propane refrigerants at various temperatures and pressure levels. Then, partially condensed refrigerant stream 71a is further cooled to -114 ° F [81 ° C.] by partially warmed expanded refrigerant stream 71e, condensed, partially over the refrigerant (stream 71b) It enters the heat exchanger 13 for cooling. This refrigerant is further subcooled to -257 ° F [-160 ° C] in the heat exchanger 60 by the expanded refrigerant stream 71d. This subcooled liquid stream 71c enters the expansion work machine 63, where it expands substantially mechanically isentropically to a pressure of about 586 psia [4,040 kPa (a)] to about 34 psia [234 kPa (a)]. energy is extracted from the stream. During expansion, a portion of the stream evaporates, cooling the entire stream to -263 ° F [-164 ° C] (stream 71d). Then expanded stream 71d enters heat exchanger 60,13 and 10, as where it is vaporized to overheat and cooled stream 38c, stream 35 and the refrigerant (streams 71,71a and 71b).
[0020]
The superheated refrigerant vapor (stream 71g) leaves heat exchanger 10 at 93 ° F [34 ° C] and is compressed to 617 psia [4,254 kPa (a)] in three stages. Each of the three compression stages (refrigerant compressors 64, 66 and 68) is driven by a backup power supply and goes to a cooler (outflow coolers 65, 67 and 69) to remove the heat of compression. Compressed stream 71 from the outflow cooler 69 returns to heat exchanger 10, completing the cycle.
[0021]
Description of stream flow rates and energy consumption of the process shown in FIG. 1 shown in the following table.
[0022]
[Table 1]

[0023]
LNG production process efficiencies are compared using the required "specific power consumption", which is typically the ratio of total cooling compression power to total liquid production rate. Published information on specific power consumption for conventional processes for producing LNG ranges from 0.168HP-Hr / Lb [0.276kW / -hour / kg] to 0.182HP-Hr / Lb [0.300kW / -hour / kg] the shows, which is believed to be based on operational factors year 340 days LNG production plant. The same base and this, specific power consumption of the embodiment of FIG 1 of the present invention is 0.161HP-Hr / Lb - a [0.265kW / Time / kg], which is the efficiency improvements 4-13% than the conventional process are doing. Further, specific power consumption of the conventional process, as shown in this embodiment of the present invention NGL (C_TwoAnd heavy hydrocarbons) rather than a liquid stream, at a relatively low recovery levels LPG (C_ThreeAnd heavier hydrocarbons) or condensate (C_FourAnd it should be noted that it is based on to produce heavy hydrocarbons) liquid stream by the same time. Conventional processes require significant cooling power to simultaneously produce an NGL stream instead of an LPG or condensate stream.
[0024]
There are two main factors responsible for the excellent efficiency of the present invention. The first factor can be understood by examining the thermodynamics of the liquefaction process when applied to a high pressure gas stream as discussed in this example. Since the main components of this stream is methane, the thermodynamic properties of methane can be used for the purpose of comparing the cycle used in the liquefaction process and the present invention used in conventional processes. FIG. 2 contains a pressure-enthalpy phase diagram for methane. In most of the prior art liquefaction cycles, gas stream is all cool, at the same time the stream is a high pressure (path AB), then the stream is expanded (path BC), the pressure of the LNG storage vessel (slightly above atmospheric pressure) become. An expansion work machine can be used in this expansion phase, which can typically recover on the order of 75-80% of the theoretically available work with ideal isentropic expansion. For simplicity, it relates the path B-C, shows a fully isentropic expansion in FIG. Nevertheless, the enthalpy reduction provided by this expansion work is quite small, since the constant entropy line is almost vertical in the liquid region of the phase diagram.
[0025]
This contrasts with the liquefaction cycle of the present invention. After some cooling at high pressure (path A-A '), the gas stream is expansion work to an intermediate pressure (path A'-A "). (Again, for simplicity, a fully isentropic expansion The remaining cooling is performed at intermediate pressure (shown) (pass A "-B '), and then the stream is expanded to the pressure of the LNG storage vessel (pass B'-C). Since the line of constant entropy rope is provided by the gas phase region of the phase diagram, the first expansion work phase of the present invention (pass A'-A ") provides a significant reduction in enthalpy. Requires less total cooling (pass A-A 'and A "-B') than the cooling required by conventional processes (pass AB) and requires less cooling power to liquefy into a gas stream .
[0026]
A second factor responsible for the excellent efficiency of the present invention is the successful operation of the hydrocarbon distillation system at low operating pressures. Hydrocarbon removal step in most conventional processes, typically using a scrub column using cold hydrocarbon liquid as the suction stream to remove heavy hydrocarbons from the incoming gas stream is carried out at a high pressure . Will by coadsorption significant fraction of methane and ethane from a gas stream, which is subsequently stripped from the adsorption liquid, cooled, since they must be part of the LNG product, the scrub column at high pressure operation to the is not very efficient. In the present invention, the hydrocarbon removal step is carried out at an intermediate pressure, wherein the gas - convenient liquid equilibrium is much well, be highly efficient recovery of desired heavy hydrocarbon in the liquid stream of by-products.
Example 2
If the specifications for LNG products allow more ethane to be contained in the feed gas in the LNG product, then a simple embodiment of the present invention can be used. FIG. 3 illustrates such another embodiment. The inlet gas composition and conditions considered in the process shown in FIG. 3, is identical to that of FIG. Thus, the process of FIG. 3, can be compared to the embodiment shown in Figure 1.
[0027]
In the simulation of the process of FIG. 3, the inlet gas cooling, separation and expansion scheme for the NGL recovery section is essentially the same as that used in FIG. Inlet gas enters the plant at 90 ° F. [32 ° C.] and 1285 psia [8,860 kPa (a)] as stream 31 and at −35 ° F. [−37 ° C.] refrigerant stream and demethanizer side reboiler liquid (stream 40) It is cooled by heat exchange with. The cooling stream 31a enters separator 11 at -30 ° F [-34 ° C.] and 1278psia [8,812kPa (a)], where the vapor (stream 32) is separated from the condensed liquid (stream 33).
[0028]
Dividing the vapor from separator 11 (stream 32) into two streams 34 and 36 and. The stream 34 containing about 20% of the total vapor is mixed with the stream 33 of the condensed liquid to form a stream 35. The mixed stream 35 is cooled through the heat exchanger 13 in heat exchange relationship with the refrigerant stream 71e and substantially condensed into stream 35a. This substantially condensed stream 35a is passed through a suitable expansion device such as expansion valve 14 at -120 ° F [-85 ° C] and the operating pressure of fractionation tower 19 (about 465 psia [3,206 kPa (a)]). ) in order to flash expansion. During expansion, a portion of the stream is vaporized and the entire stream is cooled. In the process shown in FIG. 3, the expansion stream 35b leaving expansion valve 14 reaches a temperature of -122 ° F [-86 ° C.], it is supplied to the separator section in the upper region of fractionation tower 19. The liquid separated therein becomes the upper feed material to the demethanization section in the lower region of the fractionation tower 19.
[0029]
The remaining 80% of the vapor from separator 11 (stream 36) enters expansion work machine 15, where mechanical energy is extracted from this portion of the high pressure feed. This machine 15 expands the steam substantially isentropically from a pressure of about 1278 psia [8,812 kPa (a)] to the operating pressure of the tower, and expands the expansion stream 36a to about -103 ° F [-75 ° C] by expansion work. It is cooled to the temperature. The expanded, as a feed stream 36a, which is partially condensed, fed to a distillation column 19 at an intermediate column feed point.
[0030]
The cold demethanizer top vapor (stream 37) exits the top of fractionation tower 19 at -123 ° F [-86 ° C]. Liquid product stream 41 exits the bottom of the column at 118 ° F. [48 ° C.] based on typical specifications of a 0.020: 1 methane to ethane ratio on a molar basis of the bottom product.
[0031]
Warm demethanizer column top vapor (stream 37) to the heat exchanger 24 90 ° F [32 ℃], then used as plant fuel gas by extracting a portion (stream 48). Compressed by the compressor 16 a residual (stream 49) of the warm demethanizer column top vapor. After cooling to 100 ° F [38 ° C.] in the outflow cooler (Discharge cooler), the cold demethanizer column top vapor, further -112 ° F [-80 ° C. The stream 49b in stream 37 and heat exchanger within 24 by cross exchange ] to cool.
[0032]
Then stream 49c enters the heat exchanger 60, and further cooled to -257 ° F [-160 ° C.] by the refrigerant stream 71d, to condense this stream, subcooled, and stream enters work expansion machine 61, here mechanical energy is extracted from the stream. Machine 61 expands liquid stream 49d substantially isentropically from about 583 psia [4,021 kPa (a)] to an LNG storage pressure slightly above atmospheric pressure (15.5 psia [107 kPa (a)]). This expansion work cools expansion stream 49e to about -258 ° F [-161 ° C] and directs it to LNG storage tank 62 (stream 50), where LNG product stream 50 is retained.
[0033]
Similar to the process of FIG. 1, the cooling stream 35 and 49c are all provided by the closed system cooling loop. The composition of the streams used as the working fluid in the process cycle of Figure 3, 7.5% nitrogen approximate mole percent, with 40.0% methane, 42.5% ethane and 10.0% propane, the balance was heavy hydrocarbons. Refrigerant stream 71 leaves effluent cooler 69 at 100 ° F [38 ° C] and 607 psia [4,185 kPa (a)]. It enters heat exchanger 10, cooled to -31 ° F [-35 ° C.], is partially condensed by and by other refrigerant streams partially warmed expanded refrigerant stream 71f. For the simulation of FIG. 3, these other refrigerant streams were assumed to be commercial quality propane refrigerants at various temperature and pressure levels. Then partially condensed refrigerant stream 71a is cooled further -121 ° F [-85 ° C.] by partially warmed expanded refrigerant stream 71e, is condensed and subcooled refrigerant (stream 71b) . This refrigerant is further subcooled to -257 ° F [-160 ° C] in the heat exchanger 60 by the expanded refrigerant stream 71d. This supercooled liquid stream 71c enters the expansion work machine 63, where it expands mechanically as it expands substantially isentropically to a pressure of about 586 psia [4,040 kPa (a)] to about 34 psia [234 kPa (a)]. energy is extracted from the stream. During expansion, a portion of the stream evaporates, cooling the entire stream to -263 ° F [-164 ° C] (stream 71d). Then the inflated stream 71d enters heat exchanger 60,13 and 10, as here vaporized is overheated, cooling stream 49c, stream 35 and the refrigerant (streams 71,71a and 71b).
[0034]
The superheated refrigerant vapor (stream 71g) leaves heat exchanger 10 at 93 ° F [34 ° C] and is compressed to 617 psia [4,254 kPa (9)] in three stages. The three compression stages (refrigerant compressors 64, 66 and 68) are each driven by an additional power supply and remove the heat of compression following the coolers (outlet coolers 65, 67 and 69). The compressed stream from the effluent cooler 69 returns to heat exchanger 10 system is completed.
[0035]
Description of stream flow rates and energy consumption for the process illustrated in FIG. 3 shown in the following table.
[0036]
[Table 2]

[0037]
When LNG production plant is assumed to operate factors 340 days a year, specific power consumption of the embodiment of FIG 3 of the present invention is 0.153HP-Hr / Lb [0.251kW-Hr / Kg]. Compared to conventional processes, improved efficiency is 10-20% with respect to the embodiment of FIG. 3. As already mentioned in the embodiment of FIG. 1, to a conventional condensate by-product produced by the process or NGL byproducts rather than LPG is produced, the improvement efficiency is possible with the present invention.
[0038]
Compared to the embodiment of FIG. 1, the embodiment of FIG. 3 of the present invention requires approximately 5% less power per unit of produced fluid. Thus, the embodiment of FIG. 3 is for a given amount of available compression power is, C in NGL-products_TwoAnd so heavy not make much recover hydrocarbons, it could be liquefied about 5% more natural gas than the embodiment of Figure 1. The choice between the embodiment of FIG. 1 and the embodiment of FIG. 3 of the present invention for a particular application is usually due to the fact that the calorific value of the LNG generated by the embodiment of FIG. 1 is lower than that generated by the embodiment of FIG. the heavy their corresponding values in the monetary value pairs LNG product hydrocarbons in the product, or is determined by the amount of heat generation standards for LNG product.
Example 3
If all the ethane contained in the feed gas can be recovered in the LNG product according to the specifications for the LNG product, or if there is no market for liquid by-products containing ethane, as shown in FIG. it can be produced LPG byproduct stream using another aspect of the present invention. Inlet gas composition and conditions that are considered in the process shown in FIG. 4 is identical to that of FIGS. 1 and 3. Thus, the process of FIG. 4 can be compared to the embodiment shown in FIGS.
[0039]
In the simulation of the process of FIG. 4, the inlet gas enters the plant at 90 ° F. [32 ° C.] and 1285 psia [8,860 kPa (a)] as stream 31 and the refrigerant stream and flash separation at −46 ° F. [−43 ° C.] The liquid is cooled in the heat exchanger 10 by heat exchange with the liquid (stream 33a). This cooling stream 31a enters separator 11 at -1 ° F [-18 ° C] and 1278 psia [8,812 kPa (a)] where vapor (stream 32) is separated from condensed liquid (stream 33).
[0040]
Vapor from separator 11 (stream 32) enters a work expansion machine 15, where mechanical energy is extracted from this portion of the high pressure feed. This machine 15 expands the vapor substantially isentropically from a pressure of about 1278 psia [8,812 kPa (a)] to a pressure of about 440 psia [3,034 kPa (a)] (operating pressure of the separator / adsorption column 18). It is cooled to a temperature of the expansion stream 32a approximately -81 ° F [-63 ° C.] by the expansion work. Expanded and partially condensed stream 32a is supplied to the suction compartment 18b in the lower region of the separator / adsorption tower 18. The liquid portion of the expansion stream mixes with liquid descending from the adsorption section, and the mixed liquid stream 40 exits the bottom of the separator / adsorption tower 18 at -86 ° F [-66 ° C]. Vapor portion of the expanded stream is in contact with the cold liquid to rise through the adsorption zone, the descending C_ThreeComponents and heavy components are condensed and absorbed.
[0041]
Separator / adsorption tower 18 is a conventional distillation column that includes a plurality of vertically spaced trays, one or more packed beds, or a combination of trays and packing. It is to be common in natural gas processing plants, the separator / adsorption tower may consist of two compartments. The upper section 18a is a separator where all the vapor contained in the upper feed is separated from its corresponding liquid portion, where the vapor rising from the lower distillation or adsorption section 18b is the vapor portion of the upper feed. (if any) mixed to form a to form a cold distillation stream 37, which exits the top of the column. Adsorption section 18b of the bottom comprises a tray and / or fillers, to provide a necessary contact between the vapors rising and descending liquid, C_ThreeComponents and heavy components are condensed and adsorbed.
[0042]
The mixed liquid stream 40 from the bottom of the separator / adsorption column 18 is transported by the pump 26 to the heat exchanger 13 where it cools the deethanizer top (stream 42) and refrigerant (stream 71a). , It (stream 40a) is heated. The mixed liquid stream is heated to −24 ° F. [−31 ° C.] and, after partially vaporizing stream 40b, is supplied to deethanizer 19 as an intermediate column feed. The separator liquid (stream 33) is flash-expanded slightly above the operating pressure of the deethanizer 19 by the expansion valve 12 to cool the stream 33 to -46 ° F [-43 ° C] before entering as described above. Cool the feed gas. Stream 33b of 85 ° F [29 ° C.] now enters deethanizer 19 at a mid column feed point downward. In the deethanizer, streams 40b and 33b are methane and C_TwoThe components are stripped. Operating at about 453 psia [3,123 kPa (a)], the deethanizer in tower 19 can be used in conventional distillation columns containing multiple vertically spaced trays, one or more packed beds, or a combination of trays and packing. is there. This deethanizer tower may consist of an upper separator section 19a and a lower deethanizer section 19b, in which all vapors contained in the upper feed are converted to their corresponding liquid fractions. From the lower distillation or deethanization section 19b and mix with the vapor portion (if any) of the upper feed to form a distillation stream 42 exiting the top of the column; the reduction zone 19 comprises a tray and / or fillers, to provide a necessary contact between the vapors rising and descending liquid. The deethanization section 19b also includes one or more reboilers (e.g., reboiler 20), which heat and vaporize a portion of the liquid at the bottom of the column to provide stripping vapor, which rises up the column. Methane and C_TwoThe liquid product with components, stream 41, is stripped. Typical standards of the bottom liquid product, ethane-to-propane ratio on a molar basis 0.020: 1. Liquid product stream 41 exits the bottom of the deethanizer at 214 ° F [101 ℃].
[0043]
The operating pressure in deethanizer 19. holds the upper slightly than the operating pressure of separator / adsorption tower 18. This makes it possible to deethanizer column top vapor (stream 42) through the heat exchanger 13 and then flows into the upper section of the separator / adsorption tower 18. In the heat exchanger 13, at −19 ° F. [−28 ° C.], the top of the deethanizer is introduced into a heat exchange relationship with the mixed liquid stream (stream 40a) from the bottom of the separator / adsorption tower 18 to flush the refrigerant stream 71e. and, cooling the stream to -89 ° F [-67 ℃] (stream 42a), it is partially condensed. This partial stream which were condensed enters the reflux drum 22, where the condensed liquid (stream 44) is separated from the uncondensed vapor (stream 43). Stream 43 is mixed with distilled vapor stream leaving the upper region of the separator / absorber (stream 37) to form a Hiyazan渣 gas stream 47. Condensed liquid (stream 44) is pumped to high pressure by the pump 23 is split stream into two parts at the same time. One part stream 45 is transported to the upper separator section in separator / adsorption tower 18, which functions as a cooling liquid in contact with the vapor ascending adsorption compartment. The other is supplied to deethanizer 19 as reflux stream 46, flows to the upper supply point -89 ° F [-67 ℃].
[0044]
The cold residue gas (stream 47) is heated from -94 ° F [-70 ° C] to 94 ° F [34 ° C] in the heat exchanger 24, and a part (stream 48) is extracted and the plant fuel gas Function as The remainder of the warm residue gas (stream 49) is compressed by the compressor 16. After being cooled to 100 ° F. [38 ° C.] in the outflow cooler 25, the stream 49b is further cooled to −78 ° F. [−61 ° C.] by interchanging the cold residue gas in the heat exchanger 24 and the stream 47. I do.
[0045]
Stream 49c then enters heat exchanger 60 and is further cooled to −255 ° F. [−160 ° C.] by refrigerant stream 71d to condense and subcool the stream, so that the stream enters expansion work machine 61, where it Energy is extracted from the stream. This machine 61 expands the liquid stream 49d from a pressure of about 648 psia [4,465 kPa (a)] to an LNG storage pressure slightly above atmospheric pressure (15.5 psia [107 kPa (a)]) substantially isentropically Let it. This expansion work cools expansion stream 49c to a temperature of about -256 ° F [-160 ° C] and directs it to LNG storage tank 62, which holds the LNG product (stream 50).
[0046]
Similar to the process of FIGS. 1 and 3, by the closing cycle cooling loop, all cooling of the majority and stream 49c of the cooling stream 42 is provided. The composition of the stream used as the working fluid in the cycle for the process of FIG. 4 is approximately 8.7% nitrogen, 30.0% methane, 45.8% ethane and 11.0% propane, with the balance being heavy hydrocarbons. The refrigerant stream 71 leaves the outflow cooler 69 at 100 ° F [38 ° C.] and 607psia [4,185kPa (a)]. It enters the heat exchanger 10 and is cooled to -17 ° F [-27 ° C] and partially condensed by the partially warmed expanding refrigerant 71f and by other refrigerant streams. For the simulation of FIG. 4, these other refrigerant streams are assumed to be propane refrigerant commercial quality at three different temperature and pressure levels. The partially condensed refrigerant stream 71a then enters the heat exchanger 13 and is further cooled to -89 ° F [-67 ° C] by the partially warmed expanded refrigerant stream 71e to further condense the refrigerant (stream 71b). The refrigerant is completely condensed and subcooled in heat exchanger 60 to -255 ° F [-160 ° C.] by expansion refrigerant stream 71d. The supercooled liquid stream 71c enters the expansion work machine 63, where it expands mechanically as it is substantially isenthalpically expanded to a pressure of about 586 psia [4,040 kPa (a)] to about 34 psia [234 kPa (a)]. Energy is extracted from the stream. During the expansion, part of the stream is vaporized, cooling the entire stream to -264 ° F [-164 ℃] (stream 71d). Expansion stream 71d then reenters heat exchangers 60, 13 and 10 to cool stream 49c, stream 42 and the refrigerant (streams 71, 71a and 71b) as they evaporate and superheat.
[0047]
The superheated refrigerant vapor (stream 71g) leaves heat exchanger 10 at 90 ° F [32 ° C] and is compressed to 617 psia [4,254 kPa (a)] in three stages. Three compression stages (refrigerant compressors 64, 66 and 68) are driven by additional power respectively, to remove more heat of compression in cooler (outflow cooler 65, 67 and 69). Compressed stream 71 from the outflow cooler 69 returns to heat exchanger 10 system is completed.
[0048]
A summary of the stream flow rates and energy consumption of the process shown in FIG. 4 is provided in the table below.
[0049]
[Table 3]

[0050]
Assuming that the LNG production plant is operating at 340 days per year, the specific power consumption for the embodiment of FIG. 4 of the present invention is 0.143 HP-Hr / Lb [0.236 kW-Hr / Kg]. Compared to conventional processes, improved efficiency is 17-27% with respect to the embodiment of FIG. 4.
[0051]
Compared to the embodiment of FIG. 1 and FIG. 3, the embodiment of FIG. 4 of the present invention requires 6% to 11% per unit of produced liquid low power. Thus, the embodiment of FIG. 4 for a given amount of available compression power is, C as LPG byproduct_ThreeAnd by recovering the heavy hydrocarbons, it is possible to liquefy even about 11% more natural gas than aspects of about 6% more natural gas than the embodiment of FIG. 1 or FIG, 3. The choice between the embodiment of FIG. 4 and the embodiment of FIG. 1 or 3 of the present invention for a particular application is such that the heating value of the LNG generated by the embodiment of FIGS. 1 and 3 is higher than that generated by the embodiment of FIG. It is usually determined by the monetary value of the heavy hydrocarbon in the NGL product versus its corresponding value in the LNG product, or by the calorific value specification for the LNG product.
Example 4
If the specifications for LNG products allow all of the ethane and propane contained in the feed gas to be recovered in the LNG product, or if there is no market for liquid by-products containing ethane and propane, then the diagram shown in FIG. it is another aspect of the present invention as it is possible to produce a condensate by-product stream using. Inlet gas composition and conditions that are considered in the process shown in FIG. 5 are identical to those in FIGS. 1, 3 and 4. Thus the process of Figure 5 can be compared with the embodiment shown in FIGS. 1, 3 and 4.
[0052]
In the simulation of the process of FIG. 5, inlet gas enters the plant at 90 ° F [32 ° C.] and 1285psia as a stream 31 [8,860kPa (a)], is cooled in heat exchanger 10 by the refrigerant stream, -37 ° F Flush the high pressure separator liquid at [−38 ° C.] (stream 33b) and flush the intermediate pressure separator liquid at −37 ° F. [−38 ° C.]. The cooling stream 31a enters separator 11 at -30 ° F [-34 ° C.] and 1278psia [8,812kPa (a)], where the vapor (stream 32) is separated from the condensed liquid (stream 33).
[0053]
Vapor from separator 11 (stream 32) enters a work expansion machine 15, where mechanical energy is extracted from this portion of the high pressure feed. The machine 15 is substantially isentropically expands the vapor from a pressure of about 1278psia [8,812kPa (a)] to a pressure of about 635psia [4,378kPa (a)], about the streams 32a inflated by the expansion work -83 to cool to a temperature of ° F [-64 ℃]. The expanded and partially condensed stream 32a enters the separator 18, where the vapor (stream 42) is separated from the condensed liquid (stream 39). The intermediate pressure separator liquid (stream 39) is flash expanded slightly above the operating pressure of the depropanizer 19 by the expansion valve 17 to cool the stream 39 to -108 ° F [-78 ° C] (stream 49a The stream then enters the heat exchanger 13 where it is heated as it cools the residual gas stream 49, the refrigerant stream 71a, and the heat exchanger 10 as described above, and cools the incoming feed gas. The stream 39c at −15 ° F. [−26 ° C.] enters the depropanizer 19 at the upper middle column feed point.
[0054]
The condensed liquid from the high-pressure separator 11, the stream 33, is flash-expanded slightly above the operating pressure of the depropanizer 19 by the expansion valve 12, and the stream 33 is cooled to −93 ° F. [−70 ° C.] Stream 33a), the stream enters the heat exchanger 13 and is heated as described above to cool the residue gas stream 49 and the refrigerant stream 71a, the heat exchanger, and to cool the incoming feed gas. Stream 33c of 50 ° F [10 ° C.] enters the depropanizer 19 at a lower mid column feed point. The depropanizer, methane streams 39c and 33c, C_TwoComponent and C_ThreeStrip to ingredients. Depropanizer tower 19 operating at about 385psia [2,654kPa (a)], a plurality of trays spaced vertically spacing, conventional distillation comprising a combination of one or more packed beds or trays, and the filler It is a column. This depropanizer tower may be composed of two sections, an upper separator section 19a and a lower depropanization section 19b. In the upper separator section 19a, all of the above contained in the upper feed is separated from its corresponding liquid portion, and the vapor rising from the lower distillation or depropanation section 19b is converted to the vapor portion (if any) of the upper feed. It is mixed with, to form a distillation stream 37 leaving the top of the column. The lower depropanization section 19b contains trays and / or packing to provide the necessary contact between the descending liquid and the rising vapor. The depropanizer zone 19b also includes one or more reboilers (such as reboiler 20), which is heated and vaporized part of the liquid at the bottom of the column, methane, C_TwoComponent and C_ThreeLiquid product component, provides a stripping vapor upflow column to the stream 41 to stripping. Typical standards of the bottom liquid product, propane-to-butane ratio by volume based 0.020: 1. Liquid product stream 41 exits the deethanizer bottoms at 286 ° F [141 ℃].
[0055]
The overhead distillation stream 37 exits the depropanizer 19 at 36 ° F. [2 ° C.] and is cooled and partially condensed in the reflux condenser 21 with commercially available propane refrigerant. Partially condensed stream 37a exits reflux drum 22 at 2 ° F. [-17 ° C.], where condensed liquid (stream 44) is separated from uncondensed vapor (stream 43). The condensed liquid (stream 44) is pumped as a reflux stream 44a to the upper feed point of the depropanizer 19.
[0056]
The uncondensed vapor (stream 43) from reflux drum 22 is warmed to 94 ° F. [34 ° C.] in heat exchanger 24 and then a portion (stream 48) is withdrawn for use as plant fuel gas. Remaining warm vapor (stream 38) is compressed by the compressor 16. After cooling to 100 ° F [38 ° C] in the outflow cooler 25, the stream 38b is further cooled to 15 ° F [-9 ° C] in the heat exchanger 24 by interchange with cold steam, stream 43. You.
[0057]
Then mixed stream 38c and the intermediate pressure separator vapor (stream 42) to form a Hiyazan渣 gas stream 49. Stream 49 enters the heat exchanger 13, cooling the above as separator liquid by (stream 39a and 33a), and -102 ° F [-74 ° C.] from -38 ° F [-39 ° C.] by a refrigerant stream 71e Is done. The partially condensed stream 49a then enters heat exchanger 60, where it is further cooled to -254 ° F [-159 ° C] by refrigerant stream 75d to condense and supercool, after which the stream enters expansion work machine 61. Where mechanical energy is extracted from the stream. Machine 61 the liquid stream 49b, is expanded about 621psia [4,282kPa (a)] slightly above atmospheric pressure from the LNG storage pressure (15.5psia [107kPa (a)]) in substantially isentropically. By work expansion cooling to a temperature of the expansion stream 49c about -255 ° F [-159 ° C.], then directed to the LNG storage tank (stream 50), holds the LNG product.
[0058]
Similar to the processes of FIGS. 1, 3 and 4, most of the cooling of stream 49 and all of the cooling of stream 49a is provided by a closed circulation cooling loop. The composition of the streams used as working fluid in the cycle for the process of Figure 5, in approximate mole percent, 8.9 percent nitrogen, 34.3% methane, at 41.3% ethane and 11.0% propane, the remainder being heavier hydrocarbons. The refrigerant stream 71 leaves the outflow cooler 69 at 100 ° F [38 ° C.] and 607psia [4,185kPa (a)]. This stream enters heat exchanger 10, is cooled to -30 ° F [-34 ° C], and is partially condensed by partially warmed expanded refrigerant stream 71f and by other refrigerant streams. For the simulation of FIG. 5, these other refrigerant streams were assumed to be commercial quality propane refrigerant at three different temperature and pressure levels. Partially condensed refrigerant stream 71a then enters heat exchanger 13, is cooled further -102 ° F [-74 ° C.] by partially warmed expanded refrigerant stream 71e, further condensing the refrigerant (stream 71b). This refrigerant is completely condensed and then subcooled by the heat exchanger 60 to -254 ° F [-159 ° C] by the expanding refrigerant stream 71d. The supercooled liquid stream 71c enters a work expansion machine 63, as the inflated about 586psia [4,040kPa (a)] about 34psia [234kPa (a)] of substantially isentropically to a pressure, mechanical Energy is extracted from the stream. During expansion, a portion of the stream is vaporized and the entire stream is cooled to -264 ° F [-164 ° C] (stream 71d). Then expanded stream 71d enters heat exchanger 60,13 and 10, as is vaporized and superheated, cooling stream 49a, stream 49 and the refrigerant (streams 71,71a and 71b).
[0059]
The superheated refrigerant vapor (stream 71g) leaves heat exchanger 10 at 93 ° F [34 ° C] and is compressed to 617 psia [4,254 kPa (a)] in three stages. The three compression stages (refrigerant compressors 64, 66 and 68) are each driven by an additional power supply and follow a cooler (outlet coolers 65, 67 and 69) to remove the heat of compression. Cycle compressed stream 71 from the outflow cooler 69 returns to heat exchanger 10 is completed.
[0060]
Description of stream flow rates and energy consumption for the specified process 5 shown in the following table.
[0061]
[Table 4]

[0062]
When LNG production plant is assumed to operate factors 340 days a year, specific power consumption of the embodiment of FIG 5 of the present invention is 0.145HP-Hr / Lb [0.238kW-Hr / Kg]. Compared to conventional processes, improved efficiency is 16-26% with respect to the embodiment of FIG. 5.
[0063]
Compared to the embodiments of FIGS. 1 and 3, the embodiment of FIG. 5 of the present invention requires 5% to 10% less power per unit of liquid produced. Thus, the embodiment of FIG. 5 for a given amount of available compression power is, C as condensate by-products_FourAnd by recovering the heavy hydrocarbons, about 5% more natural gas than the embodiment of FIG. 1 or about 10% more natural gas than the embodiment of Figure 3, or aspects and roughly the same amount of natural gas in Fig. 4, Can be liquefied. The choice between the embodiment of FIG. 5 and the embodiment of FIG. 1, 3 or 4 of the present invention for a particular application is based on the fact that the calorific value of the LNG produced by the embodiment of FIG. 1, FIG. 3 and FIG. It is lower than those produced by) usually determined by the calorific value specifications for that by a corresponding value or LNG product, the NGL or LPG product ethane and monetary value pairs LNG product of propane in.
Other aspects
Those skilled in the art to best fit the demand in place of a given plant, to adapt the present invention for use in all types of LNG liquefaction plant to allow production NGL stream, an LPG stream or distillate stream simultaneously You will understand what you get. Furthermore, in order to recover the liquid by-product stream will appreciate the ability to use a variety of process placement. For example, the embodiments of FIGS. 1 and 3 can be adapted to recover an LPG or condensate stream as a liquid by-product stream, rather than an NGL stream as described in Examples 1 and 2. The embodiment of FIG. 4 has a higher C content in the feed gas than producing the LPG by-product as described in Example 3._TwoTo recover the NGL stream containing a significant fraction of the components, or C contained in the feed gas_FourAnd it can be adapted to recover the condensate stream containing only the heavier components. The embodiment of FIG. 5 has a higher C content in the feed gas than producing a condensate by-product as described in Example 4._TwoTo recover the NGL stream containing a significant fraction of the components, or C contained in the feed_ThreeIt can be adapted to recover LPG stream containing a substantial fraction of component.
[0064]
1, 3, 4 and 5 show a preferred embodiment of the present invention relates to the indicated treatment conditions. 6 to 21 represent another aspect of the present invention that may be considered for certain applications. As shown in FIGS. 6 and 7, mixing all or a portion of the condensed liquid (stream 33) from separator 11, together with a portion of the separator vapor flowing through the heat exchanger 13 (stream 34) than it can be supplied to fractionation tower 19 at a lower intermediate column feed position rather differently. FIG. 8 shows another embodiment of the invention, the specific power consumption of which is somewhat higher, but which may require less equipment than the embodiments of FIGS. Similarly, FIG. 9 illustrates another embodiment of the present invention that may require less equipment than the embodiments of FIGS. 3 and 7 at the expense of high specific power consumption. 10 to 14 show another embodiment of the invention, whose specific power consumption is high, but which may require less equipment than the embodiment of FIG. (As shown in FIGS. 10 14, for example, a distillation column or system, such as the deethanizer 19 is noted to include both the reflux reboiled tower design and reboiled adsorbent tower design) 15 and Figure 16 shows another embodiment of the present invention to combine into a single fractionation column 19 the function of separator / adsorbent column 18 and deethanizer 19 in FIG. 4 and FIGS. 10 to 14. Depending on the quality of the heavy hydrocarbons in the feed gas and the feed gas pressure, the cooling feed stream 31a leaving the heat exchanger 10 contains no liquid [above the dew point or 1 and 3-16, the cooling feed stream may flow directly to a suitable expansion device, such as expansion work machine 15. Can be.
[0065]
Prior to feeding to heat exchanger 60 for condensation and subcooling, the liquid by-product stream (stream 37 in FIGS. 1, 3, 6-11, 13 and 14; stream 47 in FIGS. 4, 12, 15 and 16; and treatment of the gas stream remaining after recovery of the stream 43) of Figure 5 can be implemented in many ways. In the process of FIGS. 1 and 3-16, the stream is heated, compressed to high pressure using energy derived from one or more expansion work machines, partially cooled in an outlet cooler, and then returned to the original stream. Further cooling by interchanging with As shown in FIG. 17, in some applications, it is preferable to compress the stream to high pressure, for example, using an additional compressor 59 driven by an external power source. As indicated by the dashed devices (heat exchanger 24 and effluent cooler 25) in FIGS. 1 and 3-16, in some situations, prior to entering heat exchanger 60 (refrigerant compressors 64, 66 and 68). It is preferred to reduce capital costs of the equipment by reducing or omitting pre-cooling of the compression stream (at the expense of increased power consumption and increased cooling load of heat exchanger 60). In such a case, the stream 49a leaving the compressor may flow directly to the heat exchanger 24 as shown in FIG. 18 or may flow directly to the heat exchanger 60 as shown in FIG. If the work expansion machine does not use the expansion of any portion of the high pressure feed gas, the use of a compressor driven by an external power source, such as compressor 59 shown by FIG. 20 in place of the compressor 16 it can. In other cases, the compression of the stream would not be considered justified at all, so the stream could be replaced by the heat exchanger 60 shown in FIG. 21 and the dashed devices shown in FIGS. 1 and 3-16 (heat exchanger 24, flow compressor 16 and the outflow cooler 25) directly. If the heat exchanger 24 is not provided to heat the stream before the plant fuel gas (stream 48) is withdrawn, a utility to supply the necessary heat, as shown in FIGS. Using a utility stream or another process stream, an additional heater 58 may be required to warm the fuel gas before consuming it. Since factors such as gas composition, plant size, desired by-product stream recovery levels, and available equipment must all be taken into account, choices such as these generally must be evaluated for each application. No.
[0066]
In accordance with the present invention, cooling of the feed and inlet gas streams to the LNG production section can be performed in a number of ways. 1, 3 and 6-9, the inlet gas stream 31 is cooled and condensed by the column liquid from the fractionation tower 19 and an external refrigerant stream. In Figure 4, 5 and 10-14, used for this purpose a flash separator liquid with external refrigerant stream. In Figure 15 and 16, using a column liquid and flash of separator liquid for this purpose together with the external refrigerant stream. In Figure 17-21, to cool the inlet gas stream 31 by using only the external refrigerant stream. However, a cold process stream could be used to cool the high pressure refrigerant (stream 71a) somewhat, as shown in FIGS. Furthermore, it is possible to use any stream cooler than one or more streams. For example, a vapor side draw from separator / adsorption tower 19 or fractionation tower 19 could be withdrawn and used for cooling. The use and distribution of liquids and / or steam in the tower for process heat exchange, and the particular arrangement of heat exchangers for inlet gas and feed gas cooling are each for specific applications and for specific heat exchange operations. Must be evaluated for the selection of the process stream. The choice of cooling source will depend on a number of factors including, but not limited to, feed gas composition and conditions, plant size, heat exchanger size, potential cooling source temperatures, and the like. One of ordinary skill in the art can use any combination of the above cooling sources or methods to obtain one or more desired feed stream temperatures.
[0067]
Further, additional external cooling to supply the inlet gas stream and the feed stream to the LNG production section may be performed in various ways. In FIGS. 1 and 3-21, a single component refrigerant is assumed for high level external cooling, a multi-component refrigerant is assumed for low level external cooling, and a single component refrigerant is used. To pre-cool the multi-component refrigerant stream. Alternatively, both the high-level cooling and the low-level cooling can be performed using a single-component refrigerant having a sequentially lower boiling point (that is, cascade cooling) or a single-component refrigerant having a sequentially lower evaporation pressure. The other, that also use any of the high level cooling and the low level cooling is performed using a multi-component refrigerant streams with their respective compositions adjusted to provide the cooling temperature required it can. The choice of method for providing external cooling will depend on many factors such as, but not limited to, feed gas composition and conditions, plant size, compressor driver size, heat exchanger size, ambient heat sink temperature, etc. Not done. One of ordinary skill in the art can use any combination of the methods for providing external cooling described above to obtain the desired feed or stream temperatures.
[0068]
Stream 49 of the condensed liquid stream (Fig. 1, 6 and 8 which leaves the heat exchanger 60, FIG. 3, 4, 7 and 9 to 16 of the stream 49d, stream 49b in FIGS. 5 and 19 and 20, stream 49e in FIG. 17, Subcooling of stream 49c of FIG. 18 as well as stream 49a) of FIG. 21 reduces or eliminates the amount of flash vapor that may be generated during expansion of the stream to the operating pressure of LNG storage tank 62. This typically reduces the specific power consumption for producing LNG by eliminating the need for flash gas compression. However, in some situations, the use of flash gas compression or other means to dispose of any possible flash gas and reducing the capital cost of the facility by reducing the size of the heat exchanger 60 can be reduced. Is preferred.
[0069]
Although the individual stream inflation has been represented by a particular inflation device, different inflation means may be used in each case. For example, to ensure expansion work of substantially condensed feed stream (stream 35a in FIGS. 1, 3, 6 and 7) or intermediate pressure reflux stream (stream 39 in FIGS. 1, 6 and 8) depending on conditions Can be. Furthermore, a supercooled liquid stream leaving the heat exchanger 60 (stream 49 in FIGS. 1, 6 and 8, the stream 49d in FIGS. 3, 4, 7 and 9 to 16, stream 49b in FIGS. 5 and 19 and 20, in FIG. 17 stream 49e, may be used, isenthalpic flash expansion instead of expansion work stream 49a) stream 49c and 21 in FIG. 18, the heat exchanger to prevent the flash vapor formed during the expansion It may be necessary to undercool more within 60 or to add flash vapor compression or other means to handle the flash vapor generated. Similarly, it is possible to use the isenthalpic flash expansion instead of expansion work of the subcooling pressure refrigerant stream leaving heat exchanger 60 (stream 71c in FIGS. 1 and 3 to 21), thereby to compress the refrigerant Power consumption increases.
[0070]
Having described what is considered to be the preferred embodiments of the invention, those skilled in the art will recognize that, without departing from the spirit of the invention as defined by the appended claims, other or further modifications thereof may be made without departing from the spirit and scope of the invention. various conditions could be adapted to the type or other requirements of the feed material.
[Brief description of the drawings]
[0071]
FIG. 1 is a flow chart of a natural gas liquefaction plant adapted for simultaneously producing NGL according to the present invention.
FIG. 2 is a pressure-enthalpy phase diagram for methane used to illustrate the advantages of the present invention over conventional processes.
FIG. 3 is a flow chart of another natural gas liquefaction plant adapted for simultaneously producing NGL according to the present invention.
FIG. 4 is a flow chart of another natural gas liquefaction plant adapted for simultaneously producing LPG according to the present invention.
FIG. 5 is a flow chart of another natural gas liquefaction plant adapted for simultaneously producing condensate according to the present invention.
FIG. 6 is a flow chart of another natural gas liquefaction plant adapted for simultaneously producing a liquid stream according to the present invention.
FIG. 7 is a flow chart of another natural gas liquefaction plant adapted for simultaneously producing a liquid stream according to the present invention.
FIG. 8 is a flow chart of another natural gas liquefaction plant adapted for simultaneously producing a liquid stream according to the present invention.
FIG. 9 is a flow chart of another natural gas liquefaction plant adapted to simultaneously produce a liquid stream according to the present invention.
FIG. 10 is a flow chart of another natural gas liquefaction plant adapted to simultaneously produce a liquid stream according to the present invention.
FIG. 11 is a flow chart of another natural gas liquefaction plant adapted to simultaneously produce a liquid stream according to the present invention.
FIG. 12 is a flow chart of another natural gas liquefaction plant adapted to simultaneously produce a liquid stream according to the present invention.
FIG. 13 is a flow chart of another natural gas liquefaction plant adapted for simultaneously producing a liquid stream according to the present invention.
FIG. 14 is a flow chart of another natural gas liquefaction plant adapted to simultaneously produce a liquid stream according to the present invention.
FIG. 15 is a flow chart of another natural gas liquefaction plant adapted to simultaneously produce a liquid stream according to the present invention.
FIG. 16 is a flow chart of another natural gas liquefaction plant adapted to simultaneously produce a liquid stream according to the present invention.
FIG. 17 is a flow chart of another natural gas liquefaction plant adapted to simultaneously produce a liquid stream according to the present invention.
FIG. 18 is a flow chart of another natural gas liquefaction plant adapted to simultaneously produce a liquid stream according to the present invention.
FIG. 19 is a flow chart of another natural gas liquefaction plant adapted to simultaneously produce a liquid stream according to the present invention.
FIG. 20 is a flow chart of another natural gas liquefaction plant adapted to simultaneously produce a liquid stream according to the present invention.
FIG. 21 is a flowchart of another natural gas liquefaction plant adapted for simultaneously producing a liquid stream according to the present invention.

Claims (108)

A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) is treated with one or more cooling stages the natural gas stream;
(2) the inflating cooling of the natural gas stream and said intermediate pressure;
(3) directing the expanded cooling of the natural gas stream was in the distillation column, and wherein the volatile residue gas fraction of the stream containing a majority and lighter components of the methane, the heavy hydrocarbon It is separated into a relatively less volatile fraction containing a majority of components partial;
(4) cooling the volatile residue gas fraction under pressure to condense at least a portion thereof;
(5) dividing the condensed portion into at least two portions to form the condensed stream and the liquid stream; and
(6) An improvement is directed to directing the liquid stream into the distillation column as a top feed to the distillation column. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) treating and partially condensing the natural gas stream in one or more cooling stages;
(2) separating the partially condensed natural gas stream to provide at least one vapor stream and a first liquid stream;
(3) expanding the vapor stream to the intermediate pressure;
(4) expanding the first liquid stream to the intermediate pressure;
(5) directing at least the expanded vapor stream and the expanded first stream into a distillation column, wherein the stream comprises a volatile residue gas fraction containing a majority of the methane and light components. And a relatively less volatile fraction containing most of the heavy hydrocarbon components;
(6) cooling the volatile residue gas fraction under pressure to condense at least a portion thereof;
(7) dividing the condensing portion into at least two portions to form the condensing stream and a second liquid stream; and
(8) The improvement comprises directing the second liquid stream into the distillation column as a top feed to the distillation column. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) is treated with one or more cooling stages the natural gas stream;
(2) splitting the cooled natural gas stream into at least a first gas stream and a second gas stream;
(3) cooling the first gas stream to condense substantially all of it and then expanding to an intermediate pressure;
(4) expanding the second gas stream to the intermediate pressure;
(5) directing the expanded first stream of substantially condensed gas and the second stream of expanded gas into a distillation column, wherein the stream comprises a major portion of the methane and light components. And a relatively less volatile fraction containing most of the heavy hydrocarbon components; and
(6) The improvement comprises cooling the volatile residue gas fraction under pressure and condensing at least a portion thereof to form the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) treating and partially condensing the natural gas stream in one or more cooling stages;
(2) separating the partially condensed natural gas stream to provide a vapor stream and a liquid stream;
(3) splitting the vapor stream into at least a first gas stream and a second gas stream;
(4) cooling the first gas stream to condense substantially all of it and then expanding to an intermediate pressure;
(5) expanding the second gas stream to the intermediate pressure;
(6) expanding the liquid stream to the intermediate pressure;
(7) directing the expanded first stream of substantially condensed gas, the second stream of expanded gas, and the expanded liquid stream into a distillation column, wherein the stream is Separating a volatile residue gas fraction containing most of the methane and light components and a relatively less volatile fraction containing most of the heavy hydrocarbon components; and
(8) The improvement comprises cooling the volatile residue gas fraction under pressure to condense at least a portion thereof to form the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(A) condensing the at least partially cooling the natural gas under pressure to form a condensed stream; and
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) treating and partially condensing the natural gas stream in one or more cooling stages;
(2) providing a vapor stream and a liquid stream to separate natural gas streams this partially condensed;
(3) splitting the vapor stream into at least a first gas stream and a second gas stream;
(4) the first gas stream is mixed with at least a portion of said liquid stream to form a mixed stream;
(5) the mixture to condense substantially all of the cooling stream, was subsequently expanded to an intermediate pressure;
(6) by expanding the second gas stream and said intermediate pressure;
(7) by any expanding the remaining portion of said liquid stream and said intermediate pressure;
(8) expanded substantially condensed of mixed streams were, a second stream of expanded so gas, the directing and the remainder of the liquid stream to the distillation column, the stream where large of the methane A volatile residue gas fraction containing a fraction and light components and a relatively less volatile fraction containing a majority of said heavy hydrocarbon components; and
(9) The improvement comprises cooling the volatile residue gas fraction under pressure and condensing at least a portion thereof to form the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) is treated with one or more cooling stages the natural gas stream;
(2) splitting the cooled natural gas stream into at least a first gas stream and a second gas stream;
(3) cooling the first gas stream to condense substantially all of it and then expanding to an intermediate pressure;
(4) expanding the second gas stream to the intermediate pressure;
(5) directing the expanded first stream of substantially condensed gas and the second stream of expanded gas into a distillation column, wherein the stream comprises a major portion of the methane and light components. Separating into a volatile residue gas fraction containing and a relatively less volatile fraction containing most of said heavy hydrocarbon components;
(6) cooling the volatile residue gas fraction under pressure to condense at least a portion thereof;
(7) dividing the condensing portion into at least two portions to form the condensing stream and the liquid stream; and
(8) The improvement is to direct the liquid stream into the distillation column as a top feed to the distillation column. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) treating and partially condensing the natural gas stream in one or more cooling stages;
(2) separating the partially condensed natural gas stream to provide a vapor stream and a first liquid stream;
(3) splitting the gas stream into at least a first gas stream and a second gas stream;
(4) cooling the first gas stream to condense substantially all of it and then expanding to an intermediate pressure;
(5) expanding the second gas stream to the intermediate pressure;
(6) expanding the first liquid stream to the intermediate pressure;
(7) directing the expanded first stream of substantially condensed gas, the second stream of expanded gas, and the expanded first liquid stream into a distillation column, wherein: Separating the stream into a volatile residue gas fraction containing most of the methane and light components and a relatively less volatile fraction containing most of the heavy hydrocarbon components;
(8) cooling the volatile residue gas fraction under pressure to condense at least a portion thereof;
(9) dividing the condensed portion into at least two portions to form the condensed stream and a second liquid stream; and
(10) An improvement is directed to directing the second liquid stream into the distillation column as a top feed to the distillation column. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(A) condensing the at least partially cooling the natural gas under pressure to form a condensed stream; and
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) treating and partially condensing the natural gas stream in one or more cooling stages;
(2) separating the partially condensed natural gas stream to provide a vapor stream and a first liquid stream;
(3) splitting the vapor stream into at least a first gas stream and a second gas stream;
(4) mixing the first gas stream with at least a portion of the first liquid stream to form a mixed stream;
(5) cooling the mixed stream to condense substantially all of it and then expanding to an intermediate pressure;
(6) by expanding the second gas stream and said intermediate pressure;
(7) expanding the remaining portion of the first liquid stream to the intermediate pressure;
(8) directing the expanded substantially condensed mixed stream, the second stream of expanded gas, and the remainder of the first liquid stream into a distillation column, wherein the stream is Separating into a volatile residue gas fraction containing most of the methane and light components and a relatively less volatile fraction containing most of the heavy hydrocarbon components;
(9) cooling the volatile residue gas fraction under pressure to condense at least a portion thereof;
(10) dividing the condensing portion into at least two portions to form the condensing stream and a second liquid stream; and
(11) An improvement is directed to directing the second liquid stream into the distillation column as a top feed to the distillation column. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) is treated with one or more cooling stages the natural gas stream;
(2) the inflating cooling of the natural gas stream and said intermediate pressure;
(3) separating the expanded cooled natural gas stream to provide a vapor stream and a liquid stream;
(4) expanding the liquid stream to a low intermediate pressure;
(5) directing the expanded liquid stream into a distillation column, wherein the stream is a more volatile vapor distillation stream and a relatively less volatile containing a majority of the heavy hydrocarbon components. Separated into fractions;
(6) mixing the more volatile distillation stream with the vapor stream to form a volatile residue gas fraction containing a majority of the methane and light components;
(7) The improvement comprises cooling the volatile residue gas fraction under pressure and condensing at least a portion thereof to form the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) treating and partially condensing the natural gas stream in one or more cooling stages;
(2) separating the partially condensed natural gas stream to provide a first vapor stream and a first liquid stream;
(3) expanding the first vapor stream to an intermediate pressure;
(4) separating the expanded first vapor stream to provide a second vapor stream and a second liquid stream;
(5) expanding the second liquid stream to a low intermediate pressure;
(6) expanding the first liquid stream to the low intermediate pressure;
(7) directing the expanded second liquid stream and the expanded first liquid stream into a distillation column, wherein the streams are more volatile distillation streams and the heavy carbonized Separating into a relatively less volatile fraction containing most of the hydrogen component;
(8) mixing the more volatile steam distillation stream with the second steam stream to form a volatile residue gas fraction containing a majority of the methane and light components; and
(9) The improvement comprises cooling the volatile residue gas fraction under pressure and condensing at least a portion thereof to form the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) is treated with one or more cooling stages the natural gas stream;
(2) expanding the cooled natural gas stream to an intermediate pressure, and then directing it to a contact device, whereby a volatile residue gas fraction containing a majority of the methane and light components; and a first liquid. Form a stream with
(3) directing the first liquid stream into a distillation column, wherein the stream is combined with a more volatile steam distillation stream and a relatively volatile stream containing a majority of the heavy hydrocarbon components. Separates into lower fractions;
(4) cooling the more volatile steam distillation stream sufficiently to condense at least a portion thereof, thereby forming a second liquid stream;
(5) bringing at least a portion of the expanded cooled natural gas stream into complete contact with at least a portion of the second liquid stream in the contacting device; and
(6) The improvement comprises cooling the volatile residue gas fraction under pressure and condensing at least a portion thereof to form the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to a low pressure to form the liquefied natural gas stream;
(1) treating and partially condensing the natural gas stream in one or more cooling stages;
(2) separating the partially condensed natural gas stream to provide a vapor stream and a first liquid stream;
(3) expanding the vapor stream to an intermediate pressure, and then directing it to a contact device, whereby a volatile residue gas fraction containing most of the methane and light components and a second liquid stream. Form;
(4) expanding the first liquid stream to the intermediate pressure;
(5) directing the second liquid stream and the expanded first liquid stream to a distillation column, wherein the stream is more volatile, a steam distillation stream, and a large fraction of the heavy hydrocarbon component. Separated into a relatively less volatile fraction containing
(6) cooling the more volatile steam distillation stream sufficiently to condense at least a portion thereof, thereby forming a third liquid stream;
(7) bringing at least a portion of the expanded vapor stream into complete contact with at least a portion of the third liquid stream in the contact device;
(8) The improvement comprises cooling the volatile residual gas fraction under pressure to condense at least a portion thereof, thereby forming the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) is treated with one or more cooling stages the natural gas stream;
(2) expanding the cooled natural gas stream to an intermediate pressure, and then directing it to a contact device, thereby forming a first vapor stream and a first liquid stream;
(3) directing the first liquid stream to a distillation column, wherein the stream is a more volatile steam distillation stream and a relatively less volatile containing a majority of the heavy hydrocarbon components. Separated into fractions;
(4) cooling the more volatile vapor distillation stream sufficiently to condense at least a portion thereof, thereby forming a second vapor stream and a second liquid stream;
(5) directing a portion of the second liquid stream to the distillation column as a top feed to the distillation column; and
(6) bringing at least a portion of the expanded cooled natural gas stream into complete contact with at least a portion of the remaining portion of the second liquid stream in the contact device;
(7) mixing the first vapor stream with the second vapor stream to form a volatile residue gas fraction containing a majority of the methane and light components; and
(8) The improvement comprises cooling the volatile residue gas fraction under pressure and condensing at least a portion thereof to form the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) treating and partially condensing the natural gas stream in one or more cooling stages;
(2) separating the partially condensed natural gas stream to provide a first vapor stream and a first liquid stream;
(3) expanding the first vapor stream to an intermediate pressure, and then directing it to a contact device, thereby forming a second vapor stream and a second liquid stream;
(4) expanding the first liquid stream to the intermediate pressure;
(5) directing the second liquid stream and the expanded first liquid stream to a distillation column, wherein the stream is more volatile, a steam distillation stream, and a large fraction of the heavy hydrocarbon component. Separated into a relatively less volatile fraction containing
(6) cooling the more volatile vapor distillation stream sufficiently to condense at least a portion thereof, thereby forming a third vapor stream and a third liquid stream;
(7) directing a portion of the third liquid stream to the distillation column as a top feed to the distillation column;
(8) bringing at least a portion of the expanded first vapor stream into complete contact with at least a portion of the remaining portion of the third liquid stream in the contact device;
(9) mixing the second vapor stream with the third vapor stream to form a volatile residue gas fraction containing a majority of the methane and light components; and
(10) The improvement comprises cooling the volatile residual gas fraction under pressure to condense at least a portion thereof, thereby forming the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) is treated with one or more cooling stages the natural gas stream;
(2) expanding the cooled natural gas stream to an intermediate pressure, and then directing it to a contact device, whereby a volatile residue gas fraction containing a majority of the methane and light components; and a first liquid. Form a stream with
(3) the heated first liquid stream, then directed to a distillation column, the stream where a more volatile vapor distillation stream, relatively containing most of the heavier hydrocarbon components Separates into less volatile fractions;
(4) cooling the more volatile steam distillation stream sufficiently to condense at least a portion thereof, thereby forming a second liquid stream;
(5) bringing at least a portion of the expanded cooled natural gas stream into complete contact with at least a portion of the second liquid stream in the contact device;
(6) The improvement comprises cooling the volatile residue gas fraction under pressure and condensing at least a portion thereof to form the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) treating and partially condensing the natural gas stream in one or more cooling stages;
(2) separating the partially condensed natural gas stream to provide a vapor stream and a first liquid stream;
(3) expanding the vapor stream to an intermediate pressure, and then directing it to a contact device, whereby a volatile residue gas fraction containing most of the methane and light components and a second liquid stream. Form;
(4) heating the second liquid stream;
(5) expanding the first liquid stream to the intermediate pressure;
(6) the said heated with a second liquid stream directing the first liquid stream is expanded to a distillation column, where the more volatile vapor distillation stream to the stream, the heavy hydrocarbon Separates into a relatively less volatile fraction containing most of the components;
(7) cooling the more volatile steam distillation stream sufficiently to condense at least a portion thereof, thereby forming a third liquid stream;
(8) bringing at least a portion of the expanded vapor stream into complete contact with at least a portion of the third liquid stream in the contact device; and
(9) The improvement comprises cooling the volatile residue gas fraction under pressure to condense at least a portion thereof, thereby forming the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) is treated with one or more cooling stages the natural gas stream;
(2) expanding the chilled natural gas stream to an intermediate pressure, and then directing it to a contact device, thereby forming the first vapor stream and the first liquid stream;
(3) the heated first liquid stream, then directed to a distillation column, the stream where a more volatile vapor distillation stream, relatively containing most of the heavier hydrocarbon components Separates into less volatile fractions;
(4) cooling the more volatile vapor distillation stream sufficiently to condense at least a portion thereof, thereby forming a second vapor stream and a second liquid stream;
(5) directing a portion of the second liquid stream to the distillation column as a top feed to the distillation column;
(6) bringing at least a portion of the expanded cooled natural gas stream into complete contact with at least a portion of the remaining portion of the second liquid stream in the contact device;
(7) mixing the first vapor stream with the second vapor stream to form a volatile residue gas fraction containing a majority of the methane and light components; and
(8) The improvement comprises cooling the volatile residual gas fraction under pressure to condense at least a portion thereof, thereby forming the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) treating the natural gas stream in one or more cooling stages to partially condense;
(2) separating the partially condensed natural gas stream to provide a first vapor stream and a first liquid stream;
(3) expanding the first gas stream to an intermediate pressure and then directing it to a contact device, thereby forming a second vapor stream and a second liquid stream;
(4) heating the second liquid stream;
(5) expanding the first liquid stream to the intermediate pressure;
(6) directing the heated second liquid stream and the expanded first liquid stream to a distillation column, wherein the stream is more volatile, a steam distillation stream, and the heavy hydrocarbon component. To a relatively less volatile fraction containing most of
(7) cooling the more volatile vapor distillation stream sufficiently to condense at least a portion thereof, thereby forming a third vapor stream and a third liquid stream;
(8) directing into said distillation column a portion of said third liquid stream as a top feed to the distillation column;
(9) bringing at least a portion of the expanded first vapor stream into complete contact with at least a portion of the remaining portion of the third liquid stream in the contact device;
(10) mixing the second vapor stream with the third vapor stream to form a volatile residue gas fraction containing a majority of the methane and light components; and
(11) The improvement comprises cooling the volatile residue gas fraction under pressure to condense at least a portion thereof, thereby forming the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) is treated with one or more cooling stages the natural gas stream;
(2) expanding the chilled natural gas stream to an intermediate pressure, and then directing the stream to an intermediate column feed location on a distillation column, wherein the stream is combined with a more volatile steam distillation stream; Separates into a relatively less volatile fraction containing most of the hydrocarbon components;
(3) A vapor distillation stream is withdrawn from the distillation column area below the expanded cooled natural gas stream and cooled sufficiently to condense at least a portion thereof, thereby separating the vapor and liquid streams. Form;
(4) bringing at least a portion of the expanded cooled natural gas stream into complete contact with at least a portion of the liquid stream in the distillation column;
(5) mixing the vapor stream with the more volatile vapor distillation stream to form a volatile residue gas fraction containing a majority of the methane and lighter components; and
(6) The improvement comprises cooling the volatile residue gas fraction under pressure and condensing at least a portion thereof to form the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) treating and partially condensing the natural gas stream in one or more cooling stages;
(2) separating the partially condensed natural gas stream to provide a first vapor stream and a first liquid stream;
(3) expanding the first vapor stream and the first liquid stream to an intermediate pressure;
(4) the a first liquid stream and first vapor stream is expanded the inflated oriented intermediate column feed position on the distillation column, wherein the more volatile vapor distillation stream stream And a relatively less volatile fraction containing most of the heavy hydrocarbons;
(5) a vapor distillation stream, withdrawn from a region of said distillation column below the first vapor stream is said inflation, and at least a portion thereof cooled sufficiently to condense, whereby the second vapor stream forming a second liquid stream;
(6) bringing at least a portion of the expanded first vapor stream into complete contact with at least a portion of the second liquid stream in the distillation column;
(7) said second vapor stream is mixed with the high vapor distillation stream volatile than said, to form a volatile residue gas fraction containing a large portion and lighter components of said methane; and
(8) The improvement comprises cooling the volatile residual gas fraction under pressure to condense at least a portion thereof, thereby forming the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) is treated with one or more cooling stages the natural gas stream;
(2) expanding the cooled natural gas stream to an intermediate pressure and then directing it to an intermediate column feed location of a distillation column, wherein the stream comprises a more volatile steam distillation stream and the heavy carbonized stream. Separating into a relatively less volatile fraction containing most of the hydrogen component;
(3) withdrawing a steam distillation stream from the distillation region of the expanded cooled natural gas stream and cooling it at least partially to condense, thereby forming a vapor stream and a liquid stream;
(4) feeding a portion of the liquid stream to the distillation column as another feed to the distillation column at a feed location in substantially the same area as the vapor distillation stream is withdrawn;
(5) bringing at least a portion of the expanded cooled natural gas stream into complete contact with at least a portion of the remainder of the liquid stream in the distillation column; and
(6) mixing the steam stream with the more volatile steam distillation stream to form a volatile residue gas fraction containing a majority of the methane and lighter components; and
(7) The improvement comprises cooling the volatile residue gas fraction under pressure and condensing at least a portion thereof to form the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) treating and partially condensing the natural gas stream in one or more cooling stages;
(2) separating the partially condensed natural gas stream to provide a first vapor stream and a first liquid stream;
(3) expanding the first vapor stream and the first liquid stream to an intermediate pressure;
(4) said directing a first liquid stream and first vapor stream is expanded the inflated in the middle column feed position of the distillation column, where the more volatile vapor distillation stream the stream Separating into a relatively less volatile fraction containing most of said heavy hydrocarbon components;
(5) steam distillation stream, withdrawn from a region of said distillation column below the first vapor stream is said inflation was sufficiently cooled to condense a part, whereby a second steam stream first Form a second liquid stream;
(6) feeding a portion of the liquid stream to the distillation column as another feed to the distillation column at a feed location in substantially the same area as withdrawing the steam distillation stream;
(7) bringing at least a portion of the expanded first vapor stream into complete contact with at least a portion of the remaining portion of the second liquid stream in the distillation column;
(8) said second vapor stream is mixed with the high vapor distillation stream volatile than said, to form a volatile residue gas fraction containing a large portion and lighter components of said methane; and
(9) The improvement comprises cooling the volatile residue gas fraction under pressure to condense at least a portion thereof, thereby forming the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) is treated with one or more cooling stages the natural gas stream;
(2) expanding the chilled natural gas stream to an intermediate pressure, and then directing the stream to an intermediate column feed location of a distillation column, where the stream is combined with a more volatile steam distillation stream and the heavy carbonized stream. Separating into a relatively less volatile fraction containing most of the hydrogen component;
(3) Withdrawing a steam distillation stream from the distillation zone below the expanded cooled natural gas stream and cooling it at least partially enough to condense, thereby forming a vapor stream and a liquid stream. ;
(4) bringing at least a portion of the expanded cooled natural gas stream into complete contact with at least a portion of the liquid stream in the distillation column;
(5) withdrawing the liquid distillation stream from the distillation column at a location above the region, wherein the vapor distillation stream is withdrawn, where the liquid distillation stream is heated, and then below the region where the vapor distillation stream is withdrawn. Directing the distillation column as another feed to the distillation column at a location of
(6) mixing the steam stream with the more volatile steam distillation stream to form a volatile residue gas fraction containing a majority of the methane and lighter components; and
(7) The improvement comprises cooling the volatile residue gas fraction under pressure and condensing at least a portion thereof to form the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) treating and partially condensing the natural gas stream in one or more cooling stages;
(2) separating the partially condensed natural gas stream to provide a first vapor stream and a first liquid stream;
(3) expanding the first vapor stream and the first liquid stream to an intermediate pressure;
(4) directing the expanded first vapor stream and the expanded first liquid stream to an intermediate column feed location in a distillation column, wherein the streams are combined with a more volatile steam distillation stream. separates the in the heavy relatively less volatile fraction containing a major portion of the hydrocarbon components;
(5) Withdrawing the steam distillation stream from the area of the distillation column below the expanded first steam stream and cooling it sufficiently to condense at least a portion thereof, thereby forming a second steam stream. Forming a second liquid stream;
(6) bringing at least a portion of the expanded first vapor stream into complete contact with at least a portion of the second liquid stream in the distillation column;
(7) Withdrawing the liquid distillation stream from the distillation column at a position above the area where the steam distillation stream is withdrawn, wherein the liquid distillation stream is heated and then at a position below the area where the steam distillation stream is withdrawn. directing another distillation column as a feed to the distillation column;
(8) said second vapor stream is mixed with the high vapor distillation stream volatile than said, to form a volatile residue gas fraction containing a large portion and lighter components of said methane; and
(9) The improvement comprises cooling the volatile residue gas fraction under pressure to condense at least a portion thereof, thereby forming the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) is treated with one or more cooling stages the natural gas stream;
(2) expanding the cooled natural gas stream to an intermediate pressure and then directing it to an intermediate column feed location of a distillation column, wherein the stream comprises a more volatile steam distillation stream and the heavy carbonized stream. Separating into a relatively less volatile fraction containing most of the hydrogen component;
(3) the extracted steam distillation stream from a region of said distillation column below the expansion cooling of the natural gas stream was, at least partially cooled sufficiently to condense and it by the vapor stream and liquid stream Form;
(4) feeding a portion of the liquid stream to the distillation column as another feed to the distillation column at a feed location in substantially the same area as the vapor distillation stream is withdrawn;
(5) bringing at least a portion of the expanded cooled natural gas stream into complete contact with at least a portion of the remainder of the liquid stream in the distillation column;
(6) the withdrawn vapor stream from the distillation column at a location above the region where vapor distillation stream is withdrawn, where heating said liquid distillation stream, a position below the area where subsequently the steam distillation stream is withdrawn Directing the distillation column as another feed to the distillation column at
(7) mixing the vapor stream with the more volatile steam distillation stream to form a volatile residue gas fraction containing a majority of the methane and lighter components; and
(8) The improvement comprises cooling the volatile residue gas fraction under pressure and condensing at least a portion thereof to form the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) treating and partially condensing the natural gas stream in one or more cooling stages;
(2) separating the partially condensed natural gas stream to provide a first vapor stream and a first liquid stream;
(3) expanding the first vapor stream and the first liquid stream to an intermediate pressure;
(4) directing the expanded first vapor stream and the expanded first liquid stream in a distillation column to an intermediate column feed location, wherein the stream is a more volatile steam distillation stream. And a relatively less volatile fraction containing most of the heavy hydrocarbon components;
(5) Withdrawing the steam distillation stream from the area of the distillation column below the expanded first steam stream and cooling it sufficiently to condense at least a portion thereof, thereby forming a second steam stream and a second steam stream. Form a second liquid stream;
(6) feeding a portion of the second liquid stream to the distillation column as another feed to the distillation column at a feed location in substantially the same area as withdrawing the steam distillation stream;
(7) bringing at least a portion of the expanded first vapor stream into complete contact with at least a portion of the remaining portion of the second liquid stream in the distillation column;
(8) Withdrawing the liquid distillation stream from the distillation column at a position above the area where the steam distillation stream is withdrawn, where the liquid distillation stream is heated, and then at a position below the area where the steam distillation stream is withdrawn. To the distillation column as another feed to the distillation column;
(9) mixing the second vapor stream with the more volatile vapor distillation stream to form a volatile residue gas fraction containing a majority of the methane and light components; and
(10) The improvement comprises cooling the volatile residue gas fraction under pressure and condensing at least a portion thereof, thereby forming the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) is treated with one or more cooling stages the natural gas stream;
(2) the inflating cooling of the natural gas stream and said intermediate pressure;
(3) directing the expanded chilled natural gas stream to a distillation column, wherein the stream comprises a volatile residue gas fraction containing most of the methane and light components, and a heavy hydrocarbon component. Separated into a relatively less volatile fraction containing most of
(4) The improvement comprises cooling the volatile residue gas fraction under pressure and condensing at least a portion thereof to form the condensed stream. A method of liquefying a natural gas stream containing methane and heavier hydrocarbon components,
(a) cooling the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) expanding the condensed stream to low pressure to form the liquefied natural gas stream, wherein
(1) treating and partially condensing the natural gas stream in one or more cooling stages;
(2) separating the natural gas stream wherein the partially condensed, providing at least a vapor stream and a liquid;
(3) expanding the vapor stream to an intermediate pressure;
(4) expanding the liquid stream to an intermediate pressure;
(5) directing at least the expanded vapor stream and the expanded liquid stream to a distillation column, wherein the stream is combined with a volatile residue gas fraction containing a majority of the methane and light components. separates the in the heavy relatively less volatile fraction containing a major portion of the hydrocarbon moiety; and
(6) The improvement comprises essentially consisting of each processing step, wherein the volatile residue gas fraction is cooled under pressure to condense at least a portion thereof, thereby forming a condensed stream. 15. The volatile residue gas fraction is compressed, and then cooled under pressure to condense at least a portion thereof, thereby forming the condensed stream. , 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, and 28. (1) compressing the volatile residue gas fraction and then cooling it under pressure to condense at least a portion thereof; and
7. The improvement of claims 1 and 6, wherein the condensing portion is divided into at least two portions, thereby forming the condensing stream and the liquid stream. (1) compressing the volatile residue gas fraction and then cooling it under pressure to condense at least a portion thereof; and
The improvement of claims 2, 7 and 8 wherein (2) the condensing portion is split into at least two portions, thereby forming the condensing stream and a second liquid stream. 10. The improvement of claim 9, wherein the more volatile steam distillation stream is compressed and subsequently mixed with the steam stream to form a volatile residue gas fraction containing a majority of the methane and light components. point. 11. The method of claim 10, wherein the more volatile vapor distillation stream is compressed and then mixed with the second vapor stream to form a volatile residue gas fraction containing a majority of the methane and light components. Improvements described in. 13. The method of claim 3, 4, 5, 11, 11, 12, wherein the volatile residue gas fraction is heated, compressed, and then cooled under pressure to condense at least a portion thereof, thereby forming the condensed stream. Improvements according to 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 and 28. (1) heating, compressing, and then cooling under pressure to condense at least a portion of the volatile residue gas fraction; and
7. The improvement of claims 1 and 6, wherein the condensing portion is divided into at least two portions, thereby forming the condensing stream and the liquid stream. (1) heating, compressing, and then cooling under pressure to condense at least a portion of the volatile residue gas fraction; and
The improvement of claim 2, 7 or 8, wherein (2) the condensing portion is divided into at least two portions, thereby forming the condensing stream and the liquid stream. Heating, compressing, cooling, and then mixing the more volatile steam distillation stream with the steam stream to form the volatile residue gas component containing a majority of the methane and light components; An improvement according to claim 9. The more volatile steam distillation stream is heated, compressed, cooled, and then mixed with the second steam stream to remove the volatile residue gas component containing a majority of the methane and light components. 12. The improvement of claim 10, wherein forming. Said volatile residue gas fraction contains a major portion, light components and C ₂ components of the methane, claims 1,2,3,4,5,6,7,8,9,10,11,12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37 and 38. The improvement according to item 38. The majority of the volatile residue gas fraction the methane, lighter components, containing C ₂ components and C ₃ components, claim 1,2,3,4,5,6,7,8,9,10, 11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35, Improvements described in 36, 37 and 38. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means receiving the natural gas stream and cooperatively coupled for cooling under pressure;
(2) second expansion means coupled to the second heat exchange means for receiving and expanding the cooled natural gas stream to the intermediate pressure;
(3) a distillation column connected to receive the expanded cooled natural gas stream, the distillation column comprising a volatile residue gas fraction containing most of the methane and light components; Adapted to separate the stream into a relatively less volatile fraction containing most of the high quality hydrocarbons;
(4) the first heat exchange means connected to the distillation column to receive the volatile residue gas fraction, the first heat exchange means cooling the residue gas fraction under pressure It is adapted to the condense at least a portion;
(5) splitting means for receiving the condensing portion and splitting it into at least two portions, thereby connecting to the first heat exchange means for forming the condensed stream and the liquid stream; Means are further connected to the distillation column to direct the liquid stream to the distillation column as a top feed to the distillation column; and
(6) control means adapted to maintain the overhead temperature of the distillation column at a temperature controlling the amount and temperature of the feed stream to the distillation column, whereby the heavy hydrocarbon component and improvement in that it comprises the majority is recovered in a relatively low volatility fraction. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) in the apparatus, wherein there is a first expansion means connected to the first heat exchange means to receive and expand the condensed stream to a low pressure to form the liquefied natural gas stream;
(1) one or more second heat exchange means cooperatively connected to receive the natural gas stream and cool it under pressure sufficiently to partially condense it;
(2) second expansion means coupled to said second heat exchange means for receiving said partially condensed natural gas stream and separating it into a vapor stream and a first liquid stream;
(3) said vapor stream receiving, second expansion means wherein ligated to a separation means to an intermediate pressure by expanding it;
(4) third inflation means coupled to the separation means for receiving the first liquid stream and inflating it to the intermediate pressure;
(5) a distillation column coupled to receive the expanded vapor stream and the expanded first liquid stream, wherein the distillation column is a volatile residue containing most of the methane and light components. Adapted to separate the stream into a gaseous fraction and a relatively less volatile fraction containing a majority of the heavy hydrocarbon component; and
(6) the first heat exchange means connected to the distillation column to receive the volatile residue gas fraction, wherein the first heat exchange means cools the volatile residue gas fraction under pressure And condensing at least a portion thereof.
(7) dividing means coupled to the first heat exchange means for receiving and dividing the condensed part into at least two parts, thereby forming the condensed stream and the liquid stream; further it is connected to said distillation column to direct to the distillation column the second liquid stream as a top feed to the distillation column; and
(8) controlling the amount and temperature of the feed stream to the distillation column to maintain the overhead temperature of the distillation column at a certain temperature, thereby removing most of the heavy hydrocarbon component to the relatively and improvement in that it comprises an adapted control means to recover the low volatility fraction. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) wherein the apparatus has a first expansion means connected to the first heat exchange means to receive and expand the condensed stream to a low pressure and form the liquefied natural gas stream; :
(1) one or more second heat exchange means receiving the natural gas stream and cooperatively coupled for cooling under pressure;
(2) splitting means coupled to said second heat exchange means for receiving said cooled natural gas stream and splitting it at least into a first gas stream and a second gas stream;
(3) third heat exchange means coupled to the splitting means for receiving the first gas stream and cooling it sufficiently to substantially condense it;
(4) a second expansion means coupled to the third heat exchange means for receiving the substantially condensed first gas stream and expanding it to an intermediate pressure;
(5) third inflation means coupled to the dividing means for receiving the second gas stream and inflating it to an intermediate pressure;
(6) a distillation column coupled to receive the expanded substantially condensed first gas stream and the expanded second gas stream, wherein the distillation column converts the stream to the methane; Adapted to separate into a volatile residue gas fraction containing most and light components and a relatively less volatile fraction containing most of said heavy hydrocarbon components;
(7) the first heat exchange means connected to the distillation column to receive the volatile residue gas fraction, wherein the first heat exchange means cools the volatile residue gas fraction under pressure And condensing at least a portion thereof, thereby forming said condensed stream; and
(8) controlling the amount and temperature of the feed stream to the distillation column to maintain the top temperature of the distillation column at a certain temperature to remove most of the heavy hydrocarbon component from the volatiles; It is an improvement to include a control means adapted to recover to a relatively low fraction of the oil. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) in the apparatus, wherein there is a first expansion means connected to the first heat exchange means to receive and expand the condensed stream to a low pressure to form the liquefied natural gas stream;
(1) one or more second heat exchange means cooperatively coupled to cool and cool the natural gas stream under pressure sufficient to partially condense;
(2) separation means coupled to said second heat exchange means for receiving said partially condensed natural gas stream and separating it into a vapor stream and a liquid stream;
(3) splitting means coupled to the separating means for receiving the vapor stream and splitting it into at least a first gas stream and a second gas stream;
(4) third heat exchange means coupled to the dividing means for receiving and cooling the first gas stream sufficiently to substantially condense it;
(5) a second expansion means coupled to the third heat exchange means for receiving the substantially condensed first gas stream and expanding it to an intermediate pressure;
(6) third inflation means coupled to the dividing means for receiving the second gas stream and inflating it to the intermediate pressure;
(7) fourth expansion means connected to the separation means for receiving the liquid stream and expanding it to the intermediate pressure;
(8) the first gas substantially condenses reduction inflated, a second gas stream is the expansion, distillation column and ligated for receiving said inflation fluid stream, said distillation column wherein the stream and a volatile residue gas fraction containing a major portion and a light component of the methane, is adapted to separate the in the heavy relatively less volatile fraction containing a major portion of the hydrocarbon components ing;
(9) said volatile residue gas fraction the first heat exchange means is connected to said distillation column for receiving said first heat exchange means, said volatile residue gas fraction under pressure Adapted to cool and condense at least a portion thereof, thereby forming said condensed stream; and
(10) wherein the amount of the feed stream to the distillation column and by controlling the temperature held at a temperature in the column head temperature of the distillation column, the relatively volatile most of the heavier hydrocarbon components by this Control means adapted to collect the less likely fraction are improvements. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) said natural gas stream to receive one or more second heat exchange means which is connected to the cooperatively to cool enough pressure to cause partially condensed;
(2) the receiving partially natural gas stream is condensed, separating means which was connected to the second heat exchange means for separation into a vapor stream and a liquid stream;
(3) splitting means coupled to the separating means for receiving the vapor stream and splitting it into a first gas stream and a second gas stream;
(4) the the first gas stream, wherein the receiving the at least a portion of the liquid stream to form a mixed stream by mixing these, the dividing means and the mixing means is coupled to said separating means ;
(5) third heat exchange means coupled to the mixing means for receiving the mixed stream and cooling it sufficiently to substantially condense it;
(6) The receiving substantially mixed stream is condensed, the second expansion means is expanded it is connected to the third heat exchange means to an intermediate pressure;
(7) third inflation means coupled to the dividing means for receiving the second gas stream and inflating it to the intermediate pressure;
(8) fourth inflation means coupled to the separation means for receiving all remaining portions of the liquid stream and inflating it to the intermediate pressure;
(9) said expanded substantially condensed of mixed streams were, distillation column and ligated to receive a-expanded residual portion of the second gas stream and the liquid stream obtained by the expansion, the distillation column , a volatile residue gas fraction containing a major portion and a light component of the methane, in order to separate the streams the in the heavy relatively less volatile fraction containing a major portion of the hydrocarbon components Adapted;
(10) The ligated to the distillation column for receiving a volatile residue gas fraction the first heat exchange means, said first heat exchange means, said volatile residue gas fraction under pressure Adapted to cool and condense at least a portion thereof, thereby forming said condensed stream; and
(11) said amount of said feed stream to the distillation column and by controlling the temperature held at a temperature in the column head temperature of the distillation column, the volatile most of it by the heavier hydrocarbon components It is an improvement to include a control means adapted to recover to a relatively low fraction of the oil. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means receiving the natural gas stream and cooperatively coupled for cooling under pressure;
(2) first splitting means coupled to the second heat exchange means for receiving the cooled natural gas stream and splitting it into at least a first gas stream and a second gas stream;
(3) third heat exchange means coupled to the first splitting means for receiving the first gas stream and cooling it sufficiently to substantially condense it;
(4) a second expansion means coupled to the third heat exchange means for receiving the substantially condensed first gas stream and expanding it to an intermediate pressure;
(5) third inflation means coupled to the first dividing means for receiving the second gas stream and inflating it to the intermediate pressure;
(6) a distillation column connected to receive the expanded substantially condensed first gas stream and the expanded second gas stream; A volatile residue gas fraction containing the component and a relatively less volatile fraction containing a majority of the heavy hydrocarbon component;
(7) the first heat exchange means connected to the distillation column to receive the volatile residue gas fraction, wherein the first heat exchange means pressurizes the volatile residue gas fraction under pressure Adapted to cool and condense at least a portion thereof;
(8) a second split receiving the condensing portion and splitting it into at least two portions, thereby connecting to the first heat exchange means to form the condensing stream and the liquid stream Means, the second splitting means is further connected to the distillation column to direct the liquid stream to the distillation column as a top feed to the distillation column; and
(9) controlling the amount and temperature of the feed stream to the distillation column to maintain the overhead temperature of the distillation column at a certain temperature, thereby removing most of the heavy hydrocarbon components to the volatiles; It is an improvement to include a control means adapted to recover to a relatively low fraction of the oil. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream;
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) said natural gas stream to receive one or more second heat exchange means which is connected to the cooperatively to cool enough pressure to cause partially condensed;
(2) the receiving partially natural gas stream is condensed, separating means which was connected to the second heat exchange means for separation into a vapor stream and a liquid stream;
(3) first splitting means coupled to the separating means for receiving the vapor stream and splitting it into a first gas stream and a second gas stream;
(4) third heat exchange means connected to the first splitting means for receiving the first gas stream and cooling it sufficiently to condense it effectively;
(5) a second expansion means coupled to the third heat exchange means for receiving the substantially condensed first gas stream and expanding it to an intermediate pressure;
(6) third inflation means coupled to the first splitting means for receiving the second gas stream and inflating it to the intermediate pressure;
(7) fourth expansion means coupled to the separation means for receiving the first liquid stream and expanding it to the intermediate pressure;
(8) a distillation column coupled to receive the expanded substantially condensed first gas stream, the expanded second gas stream, and the expanded first liquid stream; A column separates the stream into a volatile residue gas fraction containing most of the methane and light components and a relatively less volatile fraction containing most of the heavy hydrocarbon components. Adapted for;
(9) the first heat exchange means connected to the distillation column to receive the volatile residue gas fraction, wherein the first heat exchange means pressurizes the volatile residue gas fraction under pressure Adapted to cool and condense at least a portion thereof;
(10) a second receiving the condensing portion and dividing it into at least two portions, thereby connecting to the first heat exchange means to form the condensing stream and the liquid stream A splitting means, the second splitting means being further connected to the distillation column for directing the second liquid stream to the distillation column as a top feed to the distillation column; and
(11) said amount of said feed stream to the distillation column and by controlling the temperature held at a temperature in the column head temperature of the distillation column, the volatile most of it by the heavier hydrocarbon components It is an improvement to include a control means adapted to recover to a relatively low fraction of the oil. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) said natural gas stream to receive one or more second heat exchange means which is connected to the cooperatively to cool enough pressure to cause partially condensed;
(2) the receiving partially natural gas stream is condensed, separating means which was connected to the second heat exchange means for separation into a vapor stream and a liquid stream;
(3) first splitting means coupled to the separating means for receiving the vapor stream and splitting it into a first gas stream and a second gas stream;
(4) receiving at least a portion of the first gas stream and the first liquid stream, and connecting the first gas stream and the first liquid stream to the first splitting means and the separating means to mix them into a mixed stream. Mixing means;
(5) third heat exchange means coupled to the mixing means for receiving the mixed stream and cooling it sufficiently to substantially condense it;
(6) second expansion means coupled to the third heat exchanger for receiving the substantially condensed mixed stream and expanding it to an intermediate pressure;
(7) third inflation means coupled to the first dividing means for receiving the second gas stream and inflating it to the intermediate pressure;
(8) fourth inflation means coupled to the separation means for receiving any remaining portion of the first liquid stream and inflating it to the intermediate pressure;
(9) a distillation column coupled to receive the expanded substantially condensed mixed stream, the expanded second gas stream, and the expanded remaining portion of the first liquid stream; The distillation column converts the stream into a volatile residue gas fraction containing most of the methane and light components and a relatively less volatile fraction containing most of the heavy hydrocarbon components. Adapted for separation;
(10) the first heat exchange means connected to the distillation column to receive the volatile residue gas fraction, wherein the first heat exchange means cools the volatile residue gas fraction under pressure Adapted to condense at least part of it;
(11) receiving the condensed portion and dividing it into at least two portions, thereby connecting to the first heat exchange means to form the condensed stream and the second liquid stream. A second splitting means, the second splitting means further connected to the distillation column to direct the second liquid stream to the distillation column as a top feed to the distillation column; and
(12) controlling the amount and temperature of the feed stream to the distillation column to maintain the overhead temperature of the distillation column at a certain temperature, thereby predominantly removing the heavy hydrocarbon component from the relatively volatile It is an improvement to include control means adapted to collect in less likely fractions. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means receiving the natural gas stream and cooperatively coupled to cool it under pressure;
(2) second expansion means coupled to the second heat exchange means for receiving and expanding the cooled natural gas stream to an intermediate pressure;
(3) separation means for receiving the expanded cooled natural gas stream and coupled to the second expansion means for separating it into a vapor stream and a liquid trim;
(4) third expansion means connected to the separation means for receiving the liquid stream and expanding it to a low intermediate pressure;
(5) a distillation column connected to receive the expanded liquid stream, wherein the distillation column is a more volatile vapor distillation stream and a relatively volatile stream containing a majority of the heavy hydrocarbon components; Adapted to separate said stream into a lower fraction of
(6) receiving the vapor stream and the more volatile vapor distillation stream and mixing them to form a volatile residue gas fraction containing a majority of the methane and light components. Mixing means connected to the separation means and the distillation column;
(7) the first heat exchange means connected to the mixing means to receive the volatile residue gas fraction, the first heat exchange means converts the volatile residue gas fraction under pressure cooling the condensing at least partially, thereby being adapted to form the condensation stream; and
(8) controlling the amount and temperature of the feed stream to the distillation column to maintain a temperature at the top of the distillation column at a certain temperature, thereby removing most of the heavy hydrocarbon components to the relatively volatile and improvement in that it comprises control means adapted to recover sexual low fractions. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) said natural gas stream to receive one or more second heat exchange means which is connected to the cooperatively to cool enough pressure to cause partially condensed;
(2) a first gas receiving the partially condensed natural gas stream and coupled to the second heat exchange means for separating it into a first vapor stream and a first liquid stream; Separation means;
(3) said first vapor stream receiving, second expansion means is expanded by connecting to said first separating means to the intermediate pressure it;
(4) a second separation means coupled to the second expansion means for receiving the expanded first vapor stream and separating it into a second vapor stream and a second liquid stream; ;
(5) the second liquid stream receiving a third expansion means is connected to said second separating means to the lower intermediate pressure by expanding it;
(6) said first liquid stream receiving, fourth expansion means is connected to said first separation means to said lower intermediate pressure by expanding it;
(7) a distillation column coupled to receive the expanded second liquid stream and the expanded first liquid stream, the distillation column comprising a more volatile vapor distillation stream; Adapted to separate the stream into a relatively less volatile fraction containing a majority of heavy hydrocarbon components;
(8) receiving the second steam stream and the more volatile steam distillation stream and mixing them to form a volatile residue gas fraction containing most of the methane and light components Mixing means coupled to the second separation means and the distillation column to perform
(9) the first heat exchange means connected to the mixing means to receive the volatile residue gas fraction, wherein the first heat exchange means pressurizes the volatile residue gas fraction under pressure; Adapted to cool and condense at least a portion thereof, thereby forming said condensed stream; and
(10) controlling the amount and temperature of the feed stream to the distillation column to maintain the overhead temperature of the distillation column at a certain temperature, thereby removing most of the heavy hydrocarbon components to the relatively It is an improvement to include control means adapted to collect in the less volatile fraction. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means receiving the natural gas stream and cooperatively coupled to cool it under pressure;
(2) second expansion means connected to said second heat exchange means for receiving said cooled natural gas stream and expanding it to an intermediate pressure;
(3) contacting and separating means coupled to receive the expanded cooled natural gas stream, wherein the contacting and separating means comprises at least one contacting device for mixing liquid and vapor; Separation means for later separating said vapor and liquid to form a volatile residue gas fraction containing a majority of said methane and light components and a first liquid stream;
(4) a distillation column coupled to receive the first liquid stream, wherein the distillation column contains a more volatile vapor distillation stream of the stream and a majority of the heavy hydrocarbon component; It is adapted to separate the relatively less volatile fraction;
(5) receiving the more volatile vapor distillation stream and cooling it sufficiently to condense at least a portion thereof, thereby connecting to the distillation column to form a second liquid stream. third heat exchange means;
(6) receiving the second liquid stream, such that at least a portion of the expanded cooled natural gas stream is in complete contact with at least a portion of the second liquid stream in the contact device. It said contact and separation means further is connected to the third heat exchange means;
(7) the first heat exchange means connected to the contacting and separating means so as to receive the volatile residue gas fraction, the first heat exchange means comprising: Cooling the minute to condense at least a portion thereof, thereby forming said condensed stream; and
(8) the contact and controls the the separation means the amount and temperature of the feed to the distillation column, maintaining the temperature in the column head temperature of the distillation column and the contact and separation unit, whereby said heavy It is an improvement to include control means adapted to recover a majority of the high hydrocarbon component to the relatively less volatile fraction. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means cooperatively connected to receive the natural gas stream and cool it under pressure sufficiently to partially condense it;
(2) the receiving partially natural gas stream is condensed, separating means which was connected to the second heat exchange means for separation into a vapor stream and a first liquid stream;
(3) said vapor stream receiving, second expansion means wherein ligated to a separation means to an intermediate pressure by expanding it;
(4) linked thereby contact and separation means to receive said vapor stream is expanded, the contact and separation means comprises at least one contact device for mixing a liquid and a vapor, after mixing wherein the vapor and liquid are separated, comprising a volatile residue gas fraction containing a major portion and a light component of the methane, a separation means for forming a second liquid stream;
(5) third inflation means coupled to the separation means for receiving the first liquid stream and inflating it to the intermediate pressure;
(6) the second distillation column is connected to receive a first liquid stream and a liquid stream wherein the inflated, the distillation column is more and highly volatile distillation stream, wherein the heavy hydrocarbon Adapted to separate the stream into a relatively less volatile fraction containing most of the components;
(7) the aforementioned than receiving a high vapor distillation stream volatile, the at least a portion of the cooled sufficiently to condense and thereby is connected to the distillation column to form a third liquid stream third heat exchange means;
(8) said third liquid stream receiving, its expanded so vapor stream at least a portion of the third in the contact device of the liquid stream at least a portion full contact to the third, as Said contacting and separating means further connected to a heat exchange means;
(9) said contacting and said ligated to a separation means volatile residue gas fraction for receiving the first heat exchange means, said first heat exchange means, said volatile residue gas fraction under pressure Cooling the minute to condense at least a portion thereof, thereby forming said condensed stream; and
(10) the contact and by controlling the amount and temperature of the feed stream to the separating means to the distillation column, maintaining the temperature in the column head temperature of the distillation column and the contact and separation means, said by it It is an improvement to include control means adapted to recover a majority of the heavy hydrocarbon components to the less volatile fraction. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means receiving the natural gas stream and cooperatively coupled to cool it under pressure;
(2) second expansion means connected to said second heat exchange means for receiving said cooled natural gas stream and expanding it to an intermediate pressure;
(3) contacting and separating means was ligated to receive the cooling of the natural gas stream is the expansion, the contact and separation means comprises at least one contact device for mixing a liquid and a vapor, mixed Separating means for later separating said vapor and liquid to form said first vapor stream and said liquid stream;
(4) the first distillation column is connected to receive a liquid stream, said distillation column includes a vapor distillation stream having higher volatility of the stream, containing most of the heavier hydrocarbon components Adapted for separation into relatively less volatile fractions;
(5) receiving the high vapor distillation stream volatile than said, at least a portion to adequately cool this to condense, the third heat exchange means is connected to said distillation column;
(6) the cooled high vapor distillation stream volatile than was receiving, which second vapor stream and a second separation means is connected to the third heat exchange means to separate into a liquid stream ;
(7) to receive said second liquid stream, dividing means is connected to said separating means to divide it into at least a first portion and a second portion, said dividing means further to the distillation column Connected to supply a first portion of the second liquid stream to a distillation column as a top feed to the distillation column;
(8) said second portion of the second liquid stream receiving, in said contacting device at least a portion of the cooling of the natural gas stream is expanded, at least one second portion of said second liquid stream Said contacting and separating means further connected to said dividing means for complete contact with the part;
(9) said first receiving and said second steam stream and vapor stream, and mixing them to form a volatile residue gas fraction containing a major portion and a light component of the methane Mixing means coupled to said contacting and separating means and said separating means;
(10) The ligated with the mixing means for receiving a volatile residue gas fraction the first heat exchange means, said first heat exchange means, said volatile residue gas fraction under pressure Cooling and condensing at least a portion thereof to form the condensed stream; and
(11) the contact and by controlling the amount and temperature of the feed stream to the separating means to the distillation column, maintaining the temperature in the column head temperature of the distillation column and the contact and separation unit, the thereby It is an improvement to include control means adapted to recover a majority of the heavy hydrocarbon components into the relatively less volatile fraction. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) said natural gas stream to receive one or more second heat exchange means which is connected to the cooperatively to cool enough pressure to cause partially condensed;
(2) receiving the partially condensed cooled natural gas stream and connecting it to the second heat exchange means to separate it into a first vapor stream and a first liquid stream. one separating means;
(3) said first vapor stream receiving, second expansion means is connected to the first separation means to the intermediate pressure by expanding it;
(4) contacting and separating means coupled to receive the expanded first vapor stream, wherein the contacting and separating means comprises at least one contacting device for mixing liquid and vapor; Including separating means for separating the vapor and the liquid after mixing to form a second vapor stream and a second liquid stream;
(5) third inflation means coupled to the separation means for receiving the first liquid stream and inflating it to the intermediate pressure;
(6) a distillation column coupled to receive the second liquid stream and the expanded first liquid stream, the distillation column comprising a more volatile vapor distillation stream; and the heavy hydrocarbons. Adapted to separate said stream into a relatively less volatile fraction containing a majority of
(7) third heat exchange means coupled to the distillation column for receiving the more volatile vapor distillation stream and cooling it at least partially to condense it;
(8) a second coupled to the third heat exchange means for receiving the cooled more volatile vapor distillation stream and separating it into a third vapor stream and a third liquid stream. separating means;
(9) receiving the third liquid stream, dividing means coupled to the second separating means to divide it into at least a first part and a second part, the dividing means further comprising: It is connected to the distillation column to provide a first portion of said third liquid stream to said distillation column as a top feed to the distillation column;
(10) Further receiving a second portion of the third liquid stream, at least a portion of the expanded first vapor stream in the contacting device, at least a portion of the second portion of the third liquid stream. It said contact and separation means was connected to the dividing means in order to full contact with the part;
(11) receiving the second vapor stream and the third vapor stream and mixing them to form a volatile residue gas fraction containing a majority of the methane and light components. , mixing means is coupled to said separating means and the contact and separation means;
(12) the first heat exchange means connected to the mixing means to receive the volatile residue gas fraction, the first heat exchange means, under pressure the volatile residue gas fraction Adapted to cool to condense at least a portion thereof, thereby forming said condensed stream; and
(13) controlling the amount and temperature of the feed stream to the contacting and separating means and the distillation column to maintain the temperature at the top of the contacting and separating means and the distillation column at a certain temperature; It is an improvement to include control means adapted to recover the majority of the high hydrocarbon components into a relatively less volatile fraction. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means receiving the natural gas stream and cooperatively coupled to cool it under pressure;
(2) second expansion means connected to said second heat exchange means for receiving said cooled natural gas stream and expanding it to an intermediate pressure;
(3) contacting and separating means coupled to receive the expanded cooled natural gas stream, wherein the contacting and separating means comprises at least one contacting device for mixing liquid and vapor; Separation means for later separating said vapor and liquid to form a volatile residue gas fraction containing a majority of said methane and light components and a first liquid stream;
(4) third heat exchange means coupled to the contacting and separating means for receiving the first liquid stream;
(5) a distillation column coupled to receive the heated first liquid stream, the distillation column comprising a stream of a more volatile vapor distillation stream and a majority of the heavy hydrocarbon component; It is adapted to separate low fractions of relatively volatile containing;
(6) receiving the more volatile vapor distillation stream, cooling the at least a portion thereof sufficiently to condense, and thereby connecting to the distillation column to form a second liquid stream. fourth heat exchange means;
(7) further receiving the second liquid stream, wherein the expanded natural gas stream is at least partially contacted with at least a portion of the second liquid stream in the contact device; It said contact and separation means was ligated into the fourth heat exchange means;
(8) the first heat exchange means connected to the contacting and separating means for receiving the volatile residue gas fraction, the first heat exchange means applying the volatile residue gas fraction Cooling under pressure and condensing at least a portion thereof, thereby forming said condensed stream; and
(9) controlling the amount and temperature of the feed stream to the contact and separation means and the distillation column to maintain a temperature at the top of the contact and separation means and the distillation column at a certain temperature; It is an improvement to include control means adapted to recover a majority of the heavy hydrocarbon components into a relatively less volatile fraction. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) said natural gas stream to receive one or more second heat exchange means which is connected to the cooperatively to cool enough pressure to cause partially condensed;
(2) a separation coupled to the second heat exchange means for receiving the partially condensed cooled natural gas stream and separating it into a first vapor stream and a first liquid stream; means;
(3) said first vapor stream receiving, second expansion means is expanded by connecting to said first separating means to the intermediate pressure it;
(4) contacting and separating means coupled to receive the expanded first vapor stream, wherein the contacting and separating means comprises at least one contacting device for mixing liquid and vapor; Separation means for separating the vapor and liquid after mixing to form a volatile liquid gas fraction containing a majority of the methane and light components and a second liquid stream;
(5) third heat exchange means coupled to the contacting and separating means for receiving and heating the second liquid stream;
(6) third inflation means coupled to the separation means for receiving the first liquid stream and inflating it to the intermediate pressure;
(7) a distillation column coupled to receive a heated second liquid stream and an expanded first liquid stream, wherein the distillation column further comprises: Adapted to separate into a less volatile fraction containing most of the heavy hydrocarbon components;
(8) receiving the more volatile vapor distillation stream and cooling it at least partially to condense it, thereby connecting to the distillation column to form a third liquid stream. fourth heat exchange means;
(9) Further receiving the third liquid stream and bringing at least a portion of the expanded first vapor stream into complete contact with at least a portion of the third liquid stream in the contact device. It said contact and separation means was connected to the fourth heat exchange means to;
(10) The first heat exchange means connected to the contacting and separating means for receiving the volatile residue gas fraction, the first heat exchange means applying the volatile residue gas fraction Cooling under pressure and condensing at least a portion thereof, thereby forming said condensed stream;
(11) controlling the amount and temperature of the feed stream to the contacting and separating means and the distillation column to maintain a temperature at the top of the contacting and separating means and the distillation column at a certain temperature; It is an improvement to include control means adapted to recover a majority of the heavy hydrocarbon components into the relatively less volatile fraction. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means receiving the natural gas stream and cooperatively coupled to cool it under pressure;
(2) second expansion means connected to said second heat exchange means for receiving said cooled natural gas stream and expanding it to an intermediate pressure;
(3) contact and separation means coupled to receive the expanded cooled natural gas stream, the contact and separation means comprising at least one contact device for mixing liquid and vapor; Including separating means for separating the vapor and liquid after mixing to form a first vapor stream and a first liquid stream;
(4) third heat exchange means connected to the contacting and separating means for receiving and heating the first liquid stream;
(5) distillation column and ligated to receive said first liquid stream is heated, the distillation column is more and more volatile vapor distillation stream, relatively containing most of the heavy hydrocarbon Adapted to separate the stream into a less volatile fraction;
(6) fourth heat exchange means coupled to the distillation column for receiving the more volatile vapor distillation stream and cooling it sufficiently to condense at least a portion thereof;
(7) the cooled high vapor distillation stream volatile than was receiving, which second vapor stream and a second separation means is connected to the fourth heat exchange means to separate into a liquid stream ;
(8) receiving the second liquid stream, dividing means connected to the separating means so as to divide it into at least a first part and a second part, the dividing means further comprising: Connected to the distillation column to supply a first portion of the second liquid stream to the distillation column as an upper feed of the distillation column;
(9) further receiving a second portion of the second liquid stream, at least a portion of the expanded cooled natural gas stream in the contacting device, at least a portion of the second portion of the second liquid stream; Said contacting and separating means connected to said dividing means for complete contact with a part;
(10) the first receiving and said second steam stream and vapor stream, and mixing them to form a volatile residue gas fraction containing a major portion and a light component of the methane Mixing means connected to the contacting and separating means and the separating means;
(11) said volatile residue gas fraction was ligated into the mixing means for receiving the first heat exchange means, said first heat exchange means, said volatile residue gas fraction under pressure Adapted to cool to condense at least a portion thereof, thereby forming said condensed stream; and
(12) the contact and controls the the separation means the amount and temperature of the feed stream to the distillation column, maintaining the temperature in the column head temperature of the distillation column and the contact and separation unit, whereby said heavy It is an improvement to include control means adapted to recover the majority of the high hydrocarbon components into a relatively less volatile fraction. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) said natural gas stream to receive one or more second heat exchange means which is connected to the cooperatively to cool enough pressure to cause partially condensed;
(2) receiving the partially condensed cooled natural gas stream and connecting it to the second heat exchange means to separate it into a first vapor stream and a first liquid stream. one separating means;
(3) said first vapor stream receiving, second expansion means is connected to the first separation means to the intermediate pressure by expanding it;
(4) contacting and separating means coupled to receive the expanded first vapor stream, wherein the contacting and separating means comprises at least one contacting device for mixing liquid and vapor; Including separating means for separating the vapor and the liquid after mixing to form a second vapor stream and a second liquid stream;
(5) third heat exchange means connected to the contacting and separating means for receiving and heating the second liquid stream;
(6) third inflation means coupled to receive and inflate the first liquid stream to an intermediate pressure;
(7) a distillation column coupled to receive the heated second liquid stream and the expanded first liquid stream, the distillation column comprising a more volatile vapor distillation stream, Adapted to separate the stream into a relatively less volatile fraction containing most of the high quality hydrocarbons;
(8) fourth heat exchange means coupled to the distillation column for receiving the more volatile vapor distillation stream and cooling it sufficiently to condense at least a portion thereof;
(9) a second coupled to the fourth heat exchange means for receiving the cooled more volatile vapor distillation stream and separating it into a third vapor stream and a third liquid stream; Separation means;
(10) receiving the third liquid stream, dividing means connected to the second separating means so as to divide it into at least a first part and a second part, the dividing means further comprises: Connected to the distillation column to supply a first portion of the third liquid stream to the distillation column as a top feed to the distillation column;
(11) further receiving a second portion of the third liquid stream, at least a portion of the expanded first vapor stream in the contacting device, at least a portion of the second portion of the third liquid stream; Said contacting and separating means connected to said dividing means for complete contact with a part;
(12) receiving the second vapor stream and the third vapor stream and mixing them to form a volatile residue gas fraction containing a majority of the methane and light components; Mixing means connected to the contacting and separating means and the separating means;
(13) the first heat exchange means connected to the mixing means to receive the volatile residue gas fraction, wherein the first heat exchange means pressurizes the volatile residue gas fraction under pressure Adapted to cool to condense at least a portion thereof, thereby forming said condensed stream; and
(14) controlling the amount and temperature of the feed stream to the contacting and separating means and the distillation column to maintain the temperature at the top of the contacting and separating means and the distillation column at a certain temperature; It is an improvement to include control means adapted to recover the majority of the high hydrocarbon components into a relatively less volatile fraction. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means receiving the natural gas stream and cooperatively coupled to cool it under pressure;
(2) second expansion means connected to said second heat exchange means for receiving said cooled natural gas stream and expanding it to an intermediate pressure;
(3) a distillation column coupled to receive the expanded chilled natural gas stream, wherein the distillation column is more volatile and contains a majority of the heavy hydrocarbons; Adapted to separate the stream into a less volatile fraction;
(4) the for receiving a vapor distillation stream from a region of said distillation column below the expansion cooling of the natural gas stream was, extracted steam was ligated into the distillation column means;
(5) the receiving steam distillation stream, a third heat exchanger means said linked to vapor extraction means to sufficiently cooled to cause condensing at least a portion;
(6) said cooling of steam distillation stream receiving, separation means which was connected to the third heat exchange means for separation into a vapor stream and a liquid stream;
(7) the receiving liquid stream, at least a portion of the cooling of the natural gas stream is said inflation in the distillation column, is connected to the separating means in order to complete contact at least a portion of the liquid stream Said distillation column;
(8) receiving the more volatile steam distillation stream and the vapor stream and mixing them to form a volatile residue gas fraction containing a majority of the methane and light components. Mixing means connected to the distillation column and the separation means;
(9) the first heat exchange means connected to the mixing means so as to receive the volatile residue gas fraction, the first heat exchange means pressurizing the volatile residue gas fraction And condensing at least a portion thereof, thereby forming said condensed stream; and
(10) by controlling the amount and temperature of the feed stream to the distillation column, maintaining the temperature in the column head temperature of the distillation column, whereby a relatively volatile most of the heavier hydrocarbon components It is an improvement to include a control means adapted to collect in low fractions. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means cooperatively connected to receive the natural gas stream and cool it under pressure sufficiently to partially condense it;
(2) a first gas receiving the partially condensed natural gas stream and coupled to the second heat exchange means for separating it into a first vapor stream and a first liquid stream; Separation means;
(3) said first vapor stream receiving, second expansion means is expanded by connecting to said first separating means to the intermediate pressure it;
(4) third inflation means coupled to the first separation means for receiving the first liquid stream and inflating it to the intermediate pressure;
(5) a distillation column coupled to receive the expanded first vapor stream and the expanded first liquid stream, the distillation column comprising a more volatile steam distillation stream; Adapted to separate said stream into a relatively less volatile fraction containing a majority of heavy hydrocarbon components;
(6) vapor extraction means coupled to the distillation column for receiving the steam distillation stream from a region of the distillation column below the expanded first vapor stream;
(7) third heat exchange means coupled to the vapor withdrawal means for receiving the distillation stream and cooling it sufficiently to condense at least a portion thereof;
(8) a second separation means coupled to the third heat exchange means for receiving the cooled vapor distillation stream and separating it into a second vapor stream and a second liquid stream;
(9) receiving said second liquid stream, said at least a portion of the expanded first vapor stream in said distillation column to completely contact at least a portion of said second liquid stream; the distillation column was further connected to a second separation means;
(10) receiving the more volatile vapor distillation stream and the second vapor stream and mixing them to form a volatile residue gas fraction containing a majority of the methane and light components. Mixing means connected to the distillation column and the second separation means for
(11) the first heat exchange means connected to the mixing means to receive the volatile residue gas fraction, the first heat exchange means, the volatile residue gas fraction under pressure Cooling and condensing at least a portion thereof, thereby forming said condensed stream; and
(12) wherein the amount of the feed stream to the distillation column and by controlling the temperature of the distillation column top section temperature was maintained at a temperature in the, whereby most of the volatile of said heavier hydrocarbon components and improvement in that it comprises control means adapted to recover to a relatively low fractions. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means receiving the natural gas stream and cooperatively coupled to cool it under pressure;
(2) second expansion means connected to said second heat exchange means for receiving said cooled natural gas stream and expanding it to an intermediate pressure;
(3) a distillation column coupled to receive the expanded chilled natural gas stream, wherein the distillation column is more volatile and contains a majority of the heavy hydrocarbons; Adapted to separate the stream into a less volatile fraction;
(4) the for receiving a vapor distillation stream from a region of said distillation column below the expansion cooling of the natural gas stream was, extracted steam was ligated into the distillation column means;
(5) third heat exchange means coupled to the vapor extraction means for receiving the vapor distillation stream and cooling it sufficiently to condense at least a portion thereof;
(6) said cooling of steam distillation stream receiving, separation means which was connected to the third heat exchange means for separation into a vapor stream and a liquid stream;
(7) said liquid stream receiving, which at least a first portion and a second portion and dividing means is connected to said separating means to divide the said dividing means further said vapor distillation stream vent Connected to the distillation column to supply a first portion of the liquid stream to the distillation column at substantially the same area of the feed location as is discharged;
(8) receiving a second portion of the liquid stream to completely convert at least a portion of the expanded cooled natural gas stream with at least a portion of the second portion of the liquid stream in the distillation column. Said distillation column further connected to said dividing means for contacting;
(9) receiving the more volatile steam distillation stream and the vapor stream and mixing them to form a volatile residue gas fraction containing a majority of the methane and light components; Mixing means connected to the distillation column and the separation means;
(10) the first heat exchange means connected to the mixing means to receive the volatile residue gas fraction, wherein the first heat exchange means cools the volatile residue gas fraction under pressure And condensing at least a portion thereof, thereby forming said condensed stream; and
(11) by controlling the amount and temperature of the feed stream to the distillation column, maintaining the temperature in the column head temperature of the distillation column, whereby a relatively volatile most of the heavier hydrocarbon components and improvement in that it comprises an adapted control means to recover the low fractions. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means cooperatively coupled to receive and cool under pressure sufficient to receive and partially condense the natural gas stream;
(2) a first gas receiving the partially condensed natural gas stream and coupled to the second heat exchange means for separating it into a first vapor stream and a first liquid stream; Separation means;
(3) said first vapor stream receiving, second expansion means is expanded by connecting to said first separating means to the intermediate pressure it;
(4) third inflation means coupled to the first separation means for receiving the first liquid stream and inflating it to the intermediate pressure;
(5) a distillation column coupled to receive the expanded first vapor stream and the expanded first liquid stream, the distillation column comprising a more volatile steam distillation stream; Adapted to separate said stream into a relatively less volatile fraction containing a majority of heavy hydrocarbon components;
(6) vapor extraction means coupled to the distillation column for receiving a vapor distillation stream from a region of the distillation column below the expanded vapor stream;
(7) third heat exchange means coupled to the vapor withdrawal means for receiving the vapor distillation stream and cooling it at least partially to condense it;
(8) a second separation means coupled to the third heat exchange means for receiving the cooled vapor distillation stream and separating it into a second vapor stream and a second liquid stream;
(9) receiving the second liquid stream, dividing means coupled to the second separating means to divide it into at least a first part and a second part, the dividing means further comprising: It said vapor distillation stream is connected to said distillation column to supply a first portion of said second liquid stream to the distillation column at feed position of substantially the same area and from being withdrawn;
(10) receiving a second portion of the second liquid stream and expanding at least a portion of the expanded first vapor stream into the distillation column in the second portion of the second liquid stream; Said distillation column further connected to said dividing means for complete contact with at least a portion of
(11) receiving the more volatile vapor distillation stream and the second vapor stream and mixing them to form a volatile residue gas fraction containing a majority of the methane and light components. Mixing means connected to the distillation column and the separating means for
(12) the first heat exchange means connected to the mixing means to receive the volatile residue gas fraction, the first heat exchange means, under pressure the volatile residue gas fraction Adapted to cool and condense at least a portion thereof, thereby forming said condensed stream; and
(13) controlling the amount and temperature of the feed stream to the distillation column to maintain the overhead temperature of the distillation column at a certain temperature, thereby removing most of the heavy hydrocarbon components to the relatively and improvement in that it comprises an adapted control means to recover the low volatility fraction. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means receiving the natural gas stream and cooperatively coupled to cool it under pressure;
(2) a second expansion means coupled to the second heat exchange means for receiving the partially condensed natural gas stream and expanding it to an intermediate pressure;
(3) a distillation column coupled to receive the expanded cooled natural gas stream, the distillation column containing a more volatile steam distillation stream and a majority of the heavy hydrocarbon component; It is adapted to separate said stream into a relatively less volatile fraction;
(4) vapor extraction means coupled to the distillation column for receiving a steam distillation stream from a region of the distillation column below the expanded cooled natural gas stream;
(5) third heat exchange means coupled to the vapor extraction means for receiving the vapor distillation stream and cooling it sufficiently to condense at least a portion thereof;
(6) said cooling of steam distillation stream receiving, separation means which was connected to the third heat exchange means for separation into a vapor stream and a liquid stream;
(7) receiving the liquid stream, further comprising at least a portion of the expanded cooled natural gas stream in the distillation column, wherein the separation means further comprises at least a portion of the liquid stream. the distillation column is connected;
(8) liquid withdrawal means coupled to the distillation column for receiving a liquid distillation stream from a region of the distillation column above the vapor withdrawal means;
(9) a fourth heat exchange means coupled to the liquid withdrawal means for receiving the liquid stream and heating it, wherein the fourth heat exchange means is further below the vapor withdrawal means; is connected to the distillation column to supply said heated liquid distillation stream into said distillation column;
(10) receiving the more volatile vapor distillation stream and the vapor stream and mixing them to form a volatile residue gas fraction containing a majority of the methane and light components. distillation column and the mixing means is coupled to said separating means;
(11) the first heat exchange means connected to the mixing means to receive the volatile residue gas fraction, the first heat exchange means, the volatile residue gas fraction under pressure Adapted to cool and condense at least a portion thereof, thereby forming said condensed stream; and
(12) controlling the amount and temperature of the feed stream to the distillation column to maintain the overhead temperature of the distillation column at a certain temperature, thereby removing most of the heavy hydrocarbon component to the relatively and improvement in that it comprises an adapted control means to recover the low volatility fraction. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means cooperatively connected to receive the natural gas stream and cool it under pressure sufficiently to partially condense it;
(2) a first gas receiving the partially condensed natural gas stream and coupled to the second heat exchange means for separating it into a first vapor stream and a first liquid stream; Separation means;
(3) said first vapor stream receiving, second expansion means is expanded by connecting to said first separating means to the intermediate pressure it;
(4) third inflation means coupled to the first separation means for receiving the first liquid stream and inflating it to the intermediate pressure;
(5) a distillation column coupled to receive the expanded first vapor stream and the expanded first liquid stream, the distillation column comprising a more volatile steam distillation stream; Adapted to separate said stream into a relatively less volatile fraction containing a majority of heavy hydrocarbon components;
(6) vapor extraction means coupled to the distillation column for receiving a vapor distillation stream from a region of the distillation column below the expanded first vapor stream;
(7) third heat exchange means coupled to the vapor withdrawal means for receiving the vapor distillation stream and cooling it at least partially to condense it;
(8) a second separation means coupled to the third heat exchange means for receiving the cooled vapor distillation stream and separating it into a second vapor stream and a second liquid stream;
(9) further comprising receiving the second liquid stream and bringing at least a portion of the expanded first vapor stream into full contact with at least a portion of the second liquid stream in the distillation column. the distillation column is connected to the second separation means;
(10) liquid withdrawal means coupled to the distillation column for receiving a liquid distillation stream from a region of the distillation column above the vapor withdrawal means;
(11) a fourth heat exchange means connected to the liquid withdrawal means for receiving the liquid distillation stream and heating it, the fourth heat exchange means further comprising a position below the vapor withdrawal means; in being connected to said distillation column to supply said heated liquid distillation stream into said distillation column;
(12) receiving the more volatile vapor distillation stream and the second vapor stream and mixing them to form a volatile residual gas fraction containing a majority of the methane and light components. mixing means connected to said distillation column and said second separation means to;
(13) The first heat exchange means connected to the mixing means to receive the volatile residue gas component, wherein the first heat exchange means cools the volatile residue gas fraction under pressure. as condensing at least a portion Te, thereby being adapted to form the condensation stream; and
(14) controlling the amount and temperature of the feed stream to the distillation column to maintain the overhead temperature of the distillation column at a certain temperature, thereby removing most of the heavy hydrocarbon component to the relatively and improvement in that it comprises an adapted control means to recover the low volatility fraction. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means receiving the natural gas stream and cooperatively coupled for cooling under pressure;
(2) second heat exchange means coupled to said second heat exchange means for receiving said cooled natural gas stream and expanding it to an intermediate pressure;
(3) a distillation column connected to receive the expanded cooled natural gas stream, the distillation column containing a more volatile steam distillation stream and a majority of the heavy hydrocarbon component; It is adapted to separate said stream into a relatively less volatile fraction;
(4) vapor extraction means coupled to the distillation column for receiving a steam distillation stream from a region of the distillation column below the expanded chilled natural gas stream;
(5) third heat exchange means coupled to the vapor extraction means for receiving the vapor distillation stream and cooling it sufficiently to condense at least a portion thereof;
(6) said cooling of steam distillation stream receiving, separation means which was connected to the third heat exchange means for separation into a vapor stream and a liquid stream;
(7) said liquid stream receiving, which at least a first portion and a second portion and dividing means is connected to said separating means to divide the said dividing means further said vapor distillation stream vent Connected to the distillation column to supply a first portion of the liquid stream to the distillation column at substantially the same area of feed location as is discharged;
(8) the distillation column receives a second portion of the liquid stream and converts at least a portion of the expanded cooled natural gas stream into at least a portion of the second portion of the liquid stream in the distillation column. Further connected to said dividing means for complete contact with a part;
(9) liquid withdrawal means coupled to the distillation column for receiving a liquid distillation stream from a region of the distillation column above the vapor withdrawal means;
(10); fourth heat exchange means connected to the liquid withdrawal means for receiving and heating the liquid distillation stream, wherein the fourth heat exchange means is at a position below the vapor withdrawal means. is further connected to said distillation column to supply said heated liquid distillation stream into said distillation column;
(11) receiving the more volatile vapor distillation stream and the vapor stream and mixing them to form a volatile residue gas fraction containing a majority of the methane and light components. distillation column and the mixing means is coupled to said separating means;
(12) the first heat exchange means connected to the mixing means to receive the volatile residue gas fraction, the first heat exchange means, under pressure the volatile residue gas fraction cooling the condensing at least partially, thereby being adapted to form the condensation stream; and
(13) controlling the amount and temperature of the feed stream to the distillation column to maintain the overhead temperature of the distillation column at a certain temperature, thereby removing most of the heavy hydrocarbon components to the relatively and improvement in that it comprises an adapted control means to recover the low volatility fraction. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means cooperatively coupled to receive and cool under pressure sufficient to receive and partially condense the natural gas stream;
(2) a first gas receiving the partially condensed natural gas stream and coupled to the second heat exchange means for separating it into a first vapor stream and a first liquid stream; Separation means;
(3) said first vapor stream receiving, second expansion means is expanded by connecting to said first separating means to the intermediate pressure it;
(4) third inflation means coupled to the first separation means for receiving the first liquid stream and inflating it to the intermediate pressure;
(5) a distillation column coupled to receive the expanded first vapor stream and the expanded first liquid stream, the distillation column comprising a more volatile steam distillation stream; Adapted to separate said stream into a relatively less volatile fraction containing a majority of heavy hydrocarbon components;
(6) vapor extraction means coupled to the distillation column for receiving a vapor distillation stream from a region of the distillation column below the expanded first vapor stream;
(7) third heat exchange means coupled to the vapor withdrawal means for receiving the vapor distillation stream and cooling it at least partially to condense it;
(8) a second separation means coupled to the third heat exchange means for receiving the cooled vapor distillation stream and separating it into a second vapor stream and a second liquid stream;
(9) receiving the second liquid stream, dividing means coupled to the second separating means to divide it into at least a first part and a second part, the dividing means further comprising: It said vapor distillation stream is connected to said distillation column to supply a first portion of said second liquid stream to the distillation column at feed position of substantially the same area and from being withdrawn;
(10) receiving a second portion of the second liquid stream and expanding at least a portion of the expanded first vapor stream into the distillation column in the second portion of the second liquid stream; Said distillation column further connected to said dividing means for complete contact with at least a portion of
(11) liquid withdrawal means coupled to said distillation column for receiving a liquid distillation stream from a region of the vapor column above said vapor withdrawal means;
(12) a fourth heat exchange means connected to the liquid withdrawal means for receiving and heating the liquid distillation stream, wherein the fourth heat exchange means is at a position below the vapor withdrawal means; further to the distillation column to supply said heated liquid distillation stream to a distillation column is connected;
(13) receiving the more volatile vapor distillation stream and the second vapor stream and mixing them to form a volatile residue gas fraction containing a majority of the methane and light components. Mixing means connected to the distillation column and the separating means for
(14) the first heat exchange means connected to the mixing means to receive the volatile residue gas fraction, wherein the first heat exchange means pressurizes the volatile residue gas fraction under pressure; Adapted to cool and condense at least a portion thereof, thereby forming said condensed stream; and
(15) controlling the amount and temperature of the feed stream to the distillation column to maintain the overhead temperature of the distillation column at a certain temperature, thereby removing most of the heavy hydrocarbon component to the relatively and improvement in that it comprises an adapted control means to recover the low volatility fraction. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means receiving the natural gas stream and cooperatively coupled for cooling under pressure;
(2) second expansion means connected to said second heat exchange means for receiving said cooled natural gas stream and expanding it to an intermediate pressure;
(3) a distillation column connected to receive the expanded cooled natural gas stream, the distillation column comprising a volatile residue gas fraction containing most of the methane and light components; Adapted to separate the stream into a relatively less volatile fraction containing a majority of the heavy hydrocarbon components;
(4) the first heat exchange means connected to the second distillation means to receive the volatile residue gas fraction, wherein the first heat exchange means pressurizes the volatile residue gas fraction in cooling the condensing at least partially, thereby being adapted to form the condensation stream; and
(5) controlling the amount and temperature of the feed stream to the distillation column to maintain the overhead temperature of the distillation column at a certain temperature, thereby removing most of the heavy hydrocarbon components to the relatively and improvement in that it comprises an adapted control means to recover the low volatility fraction. A liquefier natural gas stream containing methane and heavier hydrocarbon components,
(a) one or more first heat exchange means cooperating to receive and cool the natural gas stream under pressure to condense at least a portion thereof to form a condensed stream; ;as well as
(b) wherein the apparatus has a first expansion means for receiving and expanding the condensed stream to a low pressure and connected to the first heat exchange means to form the liquefied natural gas stream; Equipment:
(1) one or more second heat exchange means cooperatively coupled to receive and cool under pressure sufficient to receive and partially condense the natural gas stream;
(2) the receiving partially natural gas stream is condensed, separating means which was connected to the second heat exchange means for separation into a vapor stream and a liquid stream;
(3) the first vapor stream receiving, second expansion means is coupled to said separating means to the intermediate pressure by expanding it;
(4) the liquid stream receiving, third expansion means the ligated to a separation means to said intermediate pressure by expanding it;
(5) a distillation column coupled to receive the expanded vapor stream and the expanded liquid stream, the distillation column comprising a volatile residue gas fraction containing most of the methane and light components; min, wherein is adapted for a heavy relatively less volatile fraction containing a major portion of the hydrocarbon components in order to separate the stream;
(6) the first heat exchange means connected to the distillation column to receive the volatile residue gas fraction, wherein the first heat exchange means cools the volatile residue gas fraction under pressure And condensing at least a portion thereof, thereby forming said condensed stream; and
(7) controlling the amount and temperature of the feed stream to the distillation column to maintain the overhead temperature of the distillation column at a certain temperature, thereby removing most of the heavy hydrocarbon component to the relatively and improvement that consists essentially adapted control means to recover the low volatility fraction. 69. The improvement of claims 43, 44, 45, 67 and 68 wherein the device comprises:
(1) compression means coupled to the distillation column for receiving and compressing the volatile residue gas fraction; and
(2) the said linked to the compression means the compacting volatile residue gas fraction for receiving the first heat exchange means, said first heat exchange means, said compacting volatile residue gas fraction Is cooled under pressure to condense at least a portion thereof, thereby forming said condensed stream. 42. The improvement of claim 41, wherein the device comprises:
(1) the volatile gas fraction receiving, compressing means is connected to said distillation column to compress it;
(2) the first heat exchange means connected to the compression means for receiving the compressed volatile residue gas fraction, wherein the first heat exchange means comprises a compressed volatile residue gas fraction; cooled minute under pressure being adapted to condense at least a portion; and
(3) the splitting means receiving the condensed portion and dividing it into at least two portions, thereby connecting to the first heat exchange means to form the condensed stream and the liquid stream The splitting means is further connected to the distillation column for directing the liquid stream to the distillation column as a top feed to the distillation column. 43. The improvement of claim 42, wherein said device comprises:
(1) the volatile gas fraction receiving, compressing means is connected to said distillation column to compress it;
(2) the first heat exchange means connected to the compression means for receiving the compressed volatile residue gas fraction, wherein the first heat exchange means comprises a compressed volatile residue gas fraction; cooled minute under pressure being adapted to condense at least a portion; and
(3) receiving the condensed portion and dividing it into at least two portions, thereby connecting to the first heat exchange means to form the condensed stream and the second liquid stream. The dividing means is further connected to the distillation column for directing the second liquid stream to the distillation column as a top feed to the distillation column. 47. The improvement of claim 46, wherein the device comprises:
(1) a compression means connected to the distillation column for receiving the volatile residue gas fraction and compressing the same;
(2) the compression of volatile residue gas fraction the compression means the first heat exchange means is connected to in order to receive the said first heat exchange means is the compression of volatile residue gas fraction It cooled under pressure being adapted to condense at least a portion; and
(3) receiving said condensed portion and dividing it into at least two portions, thereby connecting said second heat exchange means to said first heat exchange means to form said condensed stream and said liquid stream; And the second splitting means are further connected to the distillation column for directing the liquid stream to the distillation column as a top feed to the distillation column. 49. The improvement according to claims 47 and 48, wherein said device comprises:
(1) compression means connected to the distillation column for receiving the volatile gas fraction and compressing it;
(2) the first heat exchange means connected to the compression means for receiving the compressed volatile residue gas fraction, wherein the first heat exchange means comprises a compressed volatile residue gas fraction; Adapted to cool the minute under pressure to condense at least a portion thereof; and
(3) receiving said condensing portion, which is divided into at least two parts, and thereby is connected to the first heat exchange means to form and said second liquid stream and the condensing stream The second splitting means, the second splitting means is further connected to the distillation column for directing the second liquid stream to the distillation column as a top feed to the distillation column. 50. The improvement of claim 49, wherein the device comprises:
(1) receiving the volatile vapor distillation stream from said compression means was connected to the distillation column in order to compress it; and
(2) receiving the vapor stream and the compressed more volatile vapor distillation stream and mixing them to form the volatile residue gas fraction containing a majority of the methane and light components. The mixing means connected to the separating means and the compressing means. 51. The improvement of claim 50, wherein the device comprises:
(1) receiving a high vapor distillation stream volatile than the compression means was connected to the distillation column in order to compress it; and
(2) receiving the second vapor stream and the compressed more volatile vapor distillation stream and mixing them to form the volatile residue gas fraction containing a majority of the methane and light components. to form the said mixing means which is connected to said compressing means and said separating means. Improvement of claim 51, 52, 55 and 56 wherein the device comprises:
(1) a compression means for receiving the volatile gas fraction and connected to the contacting and separating means for compressing it; and
(2) the said ligated to the compression means for receiving compressed volatile residue gas fraction first heat exchange means, said first heat exchange means, the compression of volatile residue gas fraction Adapted to cool under pressure to condense at least a portion thereof, thereby forming said condensed stream. Improvement of claim 53,54,57,58,59,60,61,62,63,64,65 and 66 wherein the device comprises:
(1) compression means connected to the mixing means for receiving the volatile gas fraction and compressing it; and
(2) the said linked to the compression means the compacting volatile residue gas fraction for receiving the first heat exchange means, said first heat exchange means, said compacting volatile residue gas fraction Is cooled under pressure to condense at least a portion thereof, thereby forming said condensed stream. 69. The improvement of claims 43, 44, 45, 67 and 68 wherein the device comprises:
(1) the volatile gas fraction receiving, heating means said ligated to the distillation column in order to heat it;
(2) said heated volatile residue receive the gas fraction, compression means were connected to the heating means to compress it; and
(3) the first heat exchange means connected to the compression means for receiving the compressed heat volatile residue gas fraction, wherein the first heat exchange means comprises the compressed heat volatile residue gas fraction; the residue gas fraction is cooled under pressure that is condensed at least partially, thereby being adapted to form the condensation stream. 42. The improvement of claim 41, wherein the device comprises:
(1) heating means connected to the distillation column for receiving the volatile gas fraction and heating it;
(2) said heated volatile residue receive the gas fraction, compression means is connected to said heating means to compress it;
(3) the first heat exchange means connected to the compression means for receiving the compressed heat volatile residue gas fraction, wherein the first heat exchange means comprises the compressed heat volatile residue gas fraction; Adapted to cool the residual gas fraction under pressure to condense at least a portion thereof; and
(4) said dividing means for receiving said condensing part and dividing it into at least two parts, thereby being connected to said first heat exchange means to form said condensed stream and said liquid stream; It said dividing means further wherein is coupled to a distillation column to direct said liquid stream to the distillation column as a top feed to the distillation column. 43. The improvement of claim 42, wherein said device comprises:
(1) the volatile gas fraction receiving, heating means said ligated to the distillation column in order to heat it;
(2) said heated volatile residue receive the gas fraction, compression means is connected to said heating means to compress it;
(3) the first heat exchange means connected to the compression means for receiving the compressed heat volatile residue gas fraction, wherein the first heat exchange means comprises the compressed heat volatile residue gas fraction; cooling the residue gas fraction under pressure being adapted to condense at least a portion; and
(4) said dividing means for receiving said condensing part and dividing it into at least two parts, thereby being connected to said first heat exchange means to form said condensed stream and said liquid stream; The dividing means is further connected to the distillation column for directing the second liquid stream to the distillation column as a top feed to the distillation column. 47. The improvement of claim 46, wherein the device comprises:
(1) the volatile gas fraction receiving, heating means said ligated to the distillation column in order to heat it;
(2) said heated volatile residue receive the gas fraction, compression means is connected to said heating means to compress it;
(3) the first heat exchange means connected to the compression means for receiving the compressed heat volatile residue gas fraction, wherein the first heat exchange means comprises the compressed heat volatile residue gas fraction; Adapted to cool the residual gas fraction under pressure to condense at least a portion thereof; and
(4) said dividing means for receiving said condensing part and dividing it into at least two parts, thereby being connected to said first heat exchange means to form said condensed stream and said liquid stream; It said dividing means further wherein is coupled to a distillation column to direct said liquid stream to the distillation column as a top feed to the distillation column. 49. The improvement according to claims 47 and 48, wherein said device comprises:
(1) the volatile gas fraction receiving, heating means said ligated to the distillation column in order to heat it;
(2) said heated volatile residue receive the gas fraction, compression means is connected to said heating means to compress it;
(3) the first heat exchange means connected to the compression means for receiving the compressed heat volatile residue gas fraction, wherein the first heat exchange means comprises the compressed heat volatile residue gas fraction; Adapted to cool the residual gas fraction under pressure to condense at least a portion thereof; and
(4) said dividing means for receiving said condensing part and dividing it into at least two parts, thereby being connected to said first heat exchange means to form said condensed stream and said liquid stream; The dividing means is further connected to the distillation column for directing the second liquid stream to the distillation column as a top feed to the distillation column. 50. The improvement of claim 49, wherein the device comprises:
(1) receiving a high vapor distillation stream volatile than said heating means wherein ligated to the distillation column in order to heat it;
2 wherein the high vapor distillation stream volatile than the heated receiving, compressing means is connected to said heating means to compress it;
(3) cooling means coupled to the compression means for receiving and cooling the compressed heated more volatile steam distillation stream;
(4) receiving the vapor stream and the cooled and compressed more volatile vapor distillation stream and mixing them to form a volatile residue gas fraction containing most of the methane and light components. Said mixing means being connected to said separating means and said cooling means to form. 51. The improvement of claim 50, wherein the device comprises:
(1) receiving a high vapor distillation stream volatile than said heating means wherein ligated to the distillation column in order to heat it;
(2) compression means connected to the heating means for receiving the heated more volatile steam distillation stream and compressing it;
(3) cooling means coupled to the compression means for receiving and cooling the compressed heated more volatile steam distillation stream;
(4) receiving the second vapor stream and the cooled and compressed more volatile vapor distillation stream, mixing them to form a volatile residue gas containing most of the methane and light components; The mixing means connected to the separation means and the cooling means to form a fraction. Improvement of claim 51, 52, 55 and 56 wherein the device comprises:
(1) heating means connected to the contacting and separating means for receiving the volatile residue gas fraction and heating it;
(2) said heated volatile residue receive the gas fraction, compression means were connected to the heating means to compress it; and
(3) the first heat exchange means connected to the compression means to receive the compressed and heated volatile residue gas fraction, wherein the first heat exchange means comprises the compressed and heated The volatile residue gas fraction is adapted to be cooled under pressure to condense at least a portion thereof, thereby forming said condensed stream. Improvement of claim 53,54,57,58,59,60,61,62,63,64,65 and 66 wherein the device comprises:
(1) heating means connected to the mixing means for receiving the volatile residue gas fraction and heating it;
(2) said heated volatile residue receive the gas fraction, compression means were connected to the heating means to compress it; and
(3) the first heat exchange means connected to the compression means to receive the compressed and heated volatile residue gas fraction, wherein the first heat exchange means comprises the compressed and heated The volatile residue gas fraction is adapted to be cooled under pressure to condense at least a portion thereof, thereby forming said condensed stream. Said volatile residue gas fraction, most of the methane, containing the lighter components and C ₂ components, according to claim 41,42,43,44,45,46,47,48,49,50,51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85 and 86. Said volatile residue gas fraction, most of the methane, lighter components, containing a C ₂ component and the C ₃ components, claim 41,42,43,44,45,46,47,48,49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85 and 86. It said volatile residue gas fraction, most of the methane, containing the lighter components and C ₂ components, improvement of claim 29. It said volatile residue gas fraction, most of the methane, containing the lighter components and C ₂ components, improvement of claim 30. It said volatile residue gas fraction, most of the methane, containing the lighter components and C ₂ components, improvement of claim 31. It said volatile residue gas fraction, most of the methane, containing the lighter components and C ₂ components, improvement of claim 34. It said volatile residue gas fraction, most of the methane, containing the lighter components and C ₂ components, improvement of claim 35. It said volatile residue gas fraction, most of the methane, containing the lighter components and C ₂ components, improvement of claim 36. It said volatile residue gas fraction, most of the methane, lighter components, improvement of claim 29 containing a C ₂ component and the C ₃ components. It said volatile residue gas fraction, most of the methane, lighter components, containing a C ₂ component and the C ₃ components, improvement of claim 30. It said volatile residue gas fraction, most of the methane, lighter components, containing a C ₂ component and the C ₃ components, improvement of claim 31. It said volatile residue gas fraction, most of the methane, lighter components, containing a C ₂ component and the C ₃ components, improvement of claim 34. It said volatile residue gas fraction, most of the methane, lighter components, containing a C ₂ component and the C ₃ components, improvement of claim 35. It said volatile residue gas fraction, most of the methane, lighter components, containing a C ₂ component and the C ₃ components, improvement of claim 36. It said volatile residue gas fraction, most of the methane, containing the lighter components and C ₂ components, improvement of claim 69. It said volatile residue gas fraction, most of the methane, containing the lighter components and C ₂ components, improvement of claim 73. It said volatile residue gas fraction, most of the methane, containing the lighter components and C ₂ components, improvement of claim 75. It said volatile residue gas fraction, most of the methane, containing the lighter components and C ₂ components, improvement of claim 77. It said volatile residue gas fraction, most of the methane, containing the lighter components and C ₂ components, improvement of claim 78. It said volatile residue gas fraction, most of the methane, containing the lighter components and C ₂ components, improvement of claim 82. It said volatile residue gas fraction, most of the methane, containing the lighter components and C ₂ components, improvement of claim 85. It said volatile residue gas fraction, most of the methane, containing the lighter components and C ₂ components, improvement of claim 86.

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