JP2004224632A

JP2004224632A - Direct reforming composite system for low-grade hydrocarbon

Info

Publication number: JP2004224632A
Application number: JP2003014049A
Authority: JP
Inventors: Masaru Ichikawa; 勝市川
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-01-22
Filing date: 2003-01-22
Publication date: 2004-08-12
Anticipated expiration: 2023-01-22
Also published as: JP4297478B2

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently produce and supply hydrogen and an organic hydride, which is used as a hydrogen storing/supplying agent, for a fuel cell by using low-grade hydrocarbon resources such as natural gas. <P>SOLUTION: The direct reforming composite system for a low-grade hydrocarbon is made combining a direct reforming device for a low-grade hydrocarbon, a combustion apparatus such as a gas turbine, and a hydrogenation reactor for an aromatic hydrocarbon. The composite system reforms a raw material gas, whose main component is a low-grade hydrocarbon such as natural gas, in the presence of a low-grade hydrocarbon direct reform catalyst by using a high-temperature exhaust gas supplied from the combustion apparatus so as to generate hydrogen and an aromatic hydrocarbon, and also generates an organic hydride from the generated hydrogen and aromatic hydrocarbon. Further, the composite system provides the generated hydrogen and hydrogen-containing gas as a fuel for the combustion apparatus. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】本発明は、低級炭化水素直接改質器と燃焼装置と芳香族炭化水素水素化反応器とを組み合わせてなる、低級炭化水素を原料とした有機ハイドライド、水素、芳香族炭化水素又は／及び電力を併産する複合装置に関する。
【０００２】
【従来の技術】
天然ガス、バイオガス、コークス炉オフガス等のメタン等の２〜５炭素原子を分子内に含む低級炭化水素含有原料を、金属坦持メタロシリケート触媒の存在下で直接改質を行い、水素およびベンゼン、ナフタレン等芳香族炭化水素を併産する方法は、特開平１０−２７０３６６号公報、特開平１１−４７６０６号公報、特開平１１−６０５１４号公報、特許開２００１−３３４１５１号公報、特開２００１−３３４１５２号公報、特開２００２−３３６７０４号公報で知られている。
【０００３】
上記の低級炭化水素含有原料の直接改質は、固定床、移動床又は流動床等の流通式反応形式により、低級炭化水素含有原料を金属坦持メタロシリケート触媒に３００〜８００℃、好ましくは４５０〜７７５℃、より好ましくは７０５〜７５０℃の高温下で接触させて行うものであるが、常に高温の反応熱を該触媒及び反応装置に供給する必要があり、装置規模に応じて多量の熱をどう供給するかが実用上の課題となっていた。
【０００４】
これに対し、本願発明者は、特開２００３−００７３２１号公報に開示されるＳＯＦＣ（固体酸化物形燃料電池）を低級炭化水素直接改質器と複合化して、ＳＯＦＣの高温排ガスを原料ガスに混合するとともに、ＳＯＦＣと直接改質器を同一の断熱容器内に配置して伝熱により直接改質反応の反応熱に供給する方式を開発し、引き続きその実用化に向けた研究開発を進めている。しかし、ＳＯＦＣ本体の研究開発が各方面で現在鋭意進行中であるとともに、ＳＯＦＣと低級炭化水素直接改質器を同一断熱容器内に配置して伝熱により反応熱を供給するときに、コーキング（炭素析出）が発生したり、ＳＯＦＣや直接改質器本体の熱耐性の問題など解決されなければならない問題が多く、実用化までにさらなる技術開発を要する状況にあった。
【０００５】
一方、燃焼装置の高温熱をより高度に利用し、投入する１次エネルギーの利用効率を向上するために、各方面において燃焼装置と発電装置等との複合化の研究開発が取り組まれており、熱と電気を併産するコージェネレーション装置が実用化されつつある。とりわけ、高いエネルギー効率を有するガスタービン機関を活用した装置では、所謂マイクロガスタービンといわれる高回転型小型ガスタービンが、精密加工技術、高速軸受技術、材料技術の進展により実用化段階を迎えており、マイクロガスタービン・コージェネレーションシステムでは、７０％を越える総合エネルギー効率を発揮するものも登場している。
【０００６】
また、ガスタービン機関とＳＯＦＣ等の高温型燃料電池との複合化によるコージェネレーション装置の研究開発が進められてきており、メタン等の低級炭化水素を含有する燃料が利用して、前処理として該燃料を水蒸気改質器により水素及び一酸化炭素に改質し、その上でガスタービンの燃料として利用することが多い。ガスタービンと燃料電池の複合システムに関しては、特開２００１−２６６９２４号公報等が開示されている。
【０００７】
しかし、ガスタービンと燃料電池の複合装置では、水蒸気改質による予備改質を経た水素及び一酸化炭素を燃料とした場合、実際上はガスタービン自体及び組み合わせられる各種機関の各部でカーボンの析出現象が発生するため発電性能の低下が生じる懸念が解消いないとともに、ガスタービンの高温オフガスとガスタービンを組み合わせたコージェネレーションシステムでは、水素の酸化により生じる多量の水分を含んだ高温オフガスと整合した専用のガスタービン設計が必要であったり、電気化学反応による早い系とオフガスの熱機関への利用に伴う遅い系を組み合わせるため運転制限を受けたりするなどの問題があった。
【０００８】
【発明が解決しようとする課題】
本発明は、かかる低級炭化水素改質プロセス及びガスタービン複合システムに関する従来技術がそれぞれ有する問題点に鑑み、ガスタービンからの高温のオフガスを低級炭化水素改質プロセスが要する高温の反応熱の供給に利用するとともに、低級炭化水素改質プロセスにより生成する水素や未反応原料の一部又は全部をガスタービンの燃料として供給し、これらの熱及び、水素及び芳香族炭化水素の生産の均衡を図り、同時に、低級炭化水素改質プロセスにより生成する水素と芳香族を利用して、燃料電池用の水素貯蔵物質となる有機ハイドライド（芳香族炭化水素水素化物）を生産する低級炭化水素改質複合装置を提供することを目的とする。
【０００９】
【課題を解決するための手段】
本願請求項１の発明は、低級炭化水素直接改質器１０と、芳香族炭化水素水素化反応器６０と、燃焼装置５０からなる低級炭化水素直接改質複合装置であって、低級炭化水素直接改質器１０は、低級炭化水素直接改質触媒１５の存在下で反応熱を供給されて、系外より取り入れた低級炭化水素含有原料ガスを水素及び芳香族炭化水素に改質し、水素及び芳香族炭化水素と、未反応の低級炭化水素含有原料ガスとの混合ガスを生成し、芳香族炭化水素水素化反応器６０は、低級炭化水素直接改質器１０から混合ガスが送給されて、芳香族炭化水素水素化触媒６５の存在下で、芳香族炭化水素が水素化されて有機ハイドライドを生成し、燃焼装置５０は、系外より取り入れた低級炭化水素含有原料ガス、低級炭化水素直接改質器１０で生成される混合ガスの一部あるいは該混合ガスより分離される水素又は／及び低級炭化水素、のいずれかのガス又はそれらの混合ガスを燃料として燃焼して高温の熱を発生し、低級炭化水素直接改質器１０に供給される低級炭化水素含有原料ガスを予熱するとともに低級炭化水素直接改質器１０に反応熱することを特徴とする低級炭化水素直接改質複合装置を提供する。
【００１０】
本願請求項２の発明は、前記燃焼装置５０は、ガスタービン発電機５５であり、反応熱とともに電力が得られることを特徴とする請求項１に記載の低級炭化水素直接改質複合装置を提供する。
【００１１】
本願請求項３の発明は、前記芳香族炭化水素水素化反応器６０は、低級炭化水素直接改質器１０から送給される混合ガスから芳香族炭化水素を分離する芳香族抽出器２０又は該混合ガスから水素を分離する水素分離装置３０のいずれか又は両方をさらに具備していることを特徴とする請求項１又は請求項２に記載の低級炭化水素直接改質複合装置を提供する。
【００１２】
本願請求項４の発明は、前記芳香族抽出器２０により芳香族炭化水素が分離され生成する水素含有ガスの一部又は水素分離装置３０により分離された水素の一部は、低級炭化水素直接改質器１０に送給され、低級炭化水素直接改質触媒１５に析出した炭素をメタン等に還元し触媒を賦活化させることを特徴とする請求項３に記載の低級炭化水素改質複合装置を提供する。
【００１３】
本願請求項５の発明は、芳香族炭化水素水素化反応器６０により生成する有機ハイドライドを、精製する蒸留装置８０をさらに具備することを特徴とする請求項１から請求項４のいずれかに記載の低級炭化水素改質複合装置を提供する。
【００１４】
本願請求項６の発明は、低級炭化水素直接改質器１０又は／及び燃焼装置５０に供給される低級炭化水素含有原料ガスが、天然ガス、メタンガス、メタンハイドレート、コークス炉ガスＣＯＧ、し尿や生ゴミ等を発酵処理して得られるバイオガス（発酵メタンガスを含む。）、木材等の有機物等を乾留処理して得られるを乾溜ガスによって構成される群から選定された１又は２以上であることを特徴とする請求項１から請求項５のいずれかに記載の低級炭化水素直接改質複合装置を提供する。
【００１５】
本願請求項７の発明は、低級炭化水素含有原料ガスは圧力変動吸着（ＰＳＡ）装置９０によりガス成分調整精製を行うことを特徴とする請求項１から請求項６のいずれかに記載の低級炭化水素直接改質複合装置を提供する。
【００１６】
本願請求項８の発明は、低級炭化水素直接改質触媒１５が、金属担持ゼオライト触媒であることを特徴とする請求項１から請求項７のいずれかに記載の低級炭化水素直接改質複合装置を提供する。
【００１７】
本願請求項９の発明は、芳香族炭化水素水素化反応器６０は、芳香族炭化水素水素化触媒６５を有機ハイドライド脱水素触媒として利用して、反応熱が供給されて、有機ハイドライドを脱水素化反応させて水素と芳香族炭化水素を生成する有機ハイドライド脱水素反応器を兼用することを特徴とする請求項１から請求項８のいずれかに記載の低級炭化水素直接改質複合装置を提供する。
【００１８】
【発明の実施の形態】
図１は、本願発明の低級炭化水素直接改質複合装置の１実施例の構成を示す。本実施例では、本願請求項２の発明のとおり、燃焼装置５０としてガスタービン発電機５５（以下「ガスタービン」という）を活用し、ガスタービン発電機５５の出口温度概７５０〜１２００℃の排出ガスを利用して、系外から取り入れる低級炭化水素原料ガス（以下「原料ガス」という）を熱交換部（図示せず）で熱交換して予熱するとともに、低級炭化水素直接改質器１０（以下「直接改質器」という）を熱交換部（図示せず）により概７５０℃に保持した後、該原料ガスを直接改質器１０に供給して水素及び芳香族化合物を生成し、該生成した水素は及び未反応の原料ガスは芳香族炭化水素と分離されて、芳香族炭化水素水素化反応器６０（以下「水素化反応器」という）に供給されるとともに、その一部がガスタービン５５の燃料として供給される低級炭化水素直接改質複合装置である。
【００１９】
原料ガスは、本願請求項７の発明により、ＰＳＡ装置９０により原料ガスの成分の調整精製が行われ、直接改質器１０の入り口でメタン９０％、二酸化炭素５％の濃度に調整されるようになっている。
【００２０】
直接改質器１０においては、予熱された原料ガスが供給され、低級炭化水素直接改質触媒１５（以下「改質触媒」という）に接触されて、水素及びベンゼン、ナフタレン、トルエン、キシレン、メチルナフタレン等からなる芳香族炭化水素を生成する。また、熱交換部（図示せず）によりガスタービン５５の高温オフガスの顕熱を利用して直接改質器１０内が概７５０℃の温度雰囲気とするようになっており、原料ガス（成分調整後）は約２０％の転化率により水素および芳香族炭化水素への転化が進行し、未反応の原料ガスとともに混合ガスとなって水素化反応器６０の原料として送出される。
【００２１】
改質触媒２１としては特に制限はなく、特開平１０−２７０３６６号公報、特開平１１−４７６０６号公報、特開平１１−６０５１４号公報、特許開２００１−３３４１５１号公報、特開２００１−３３４１５２号公報、特開２００２−３３６７０４号公報で知られている公知の触媒の中から、任意のものを適宜選択して用いることができる。
【００２２】
直接改質器１０は、固定床触媒反応形式又は流動層触媒反応形式であることが好ましいが、原料ガスを改質触媒２１に十分に接触させることができるならばどの触媒反応形式でもよい。流動層反応形式の場合は、変換反応後の水素、芳香族化合物及び未転化原料ガスの混合ガス中に含まれる固体触媒微粒子を捕集するサイクロンを出口に付設することが好ましい。
【００２３】
いすれの反応形式によるときも、公知の従来技術に基づき、原料ガスに一酸化炭素又は／及び二酸化炭素を０．０１〜３０容量％、好ましくは０．１〜２５容量％添加して低級炭化水素の反応転化率を向上してもよい。また、バイオガス等、原料ガス中に二酸化炭素を概３０容量％以上含むときは、ＰＳＡ装置９０により、二酸化炭素容量％の調整を施すことが必要となる。
【００２４】
改質触媒２１では反応時間の経過に伴い炭素の析出による触媒性能の低下が生じるため、本願請求項４の発明のとおり、直接改質器１０には、芳香族抽出器２０や水素分離装置３０により分離された水素又は水素含有ガスが、循環ガスとして送給されており、析出した炭素をメタン等に還元し触媒を活性化するようになっている。また、図１には示されていないが、改質触媒２１に析出した炭素は、酸素等により燃焼し再生する触媒再生過程を施すようにしてもよい。
【００２５】
水素ガスによる触媒賦活過程は、低級炭化水素の変換反応過程と交互に連続して施してもよいし、適宜間歇的に施してもよい。また、水素による触媒賦活過程は、改質触媒２１を適宜循環させて逐次再生するなど、低級炭化水素の変換反応過程と並列的に施してもよい。
【００２６】
直接改質器１０から送出される水素、芳香族炭化水素及び未転化原料ガスとの混合ガスは、まず、芳香族抽出器２０により水素と未転化原料の気体と液体状の芳香族炭化水素に気液分離される。液体状の芳香族炭化水素は貯蔵部（図示せず）に貯蔵され、分離された水素及び未転化原料ガスは水素分離装置３０に導入され、水素が選択的に分離される。
【００２７】
芳香族抽出器２０は、水素、芳香族炭化水素及び未転化原料ガスとの混合ガスを、芳香族炭化水素の沸点以下の温度の冷却部に接触させる凝縮分離方式や、デカリンやメチルナフタレン等の液体溶剤中にバブリングし、芳香族炭化水素を溶解し分離する本願発明者の既存出願発明（現時点で未開時）による方式など任意の分離方式を適宜選択することができる。図１の実施例では、液体溶剤中へのバブリングによる抽出器本体が分離した液体状の芳香族炭化水素の貯蔵部となるようになっている。
【００２８】
水素分離装置３０又は芳香族抽出器２０により水素又は芳香族炭化水素と分離された残留の未転化原料ガスは、ガスタービン５５に導入される。また、水素分離装置３０により分離された水素は、水素保持部４０に導入されて貯蔵されたり、ガスタービン５５に燃料として供給されたり、水素化反応器６０へ供給される。また、図１の実施例では、水素分離装置３０で分離された水素の一部は直接改質器１０の原料ガス入り口から供給され、改質触媒２１を活性化させるようになっている。水素の水素保持部４０への貯蔵、ガスタービン５５への供給、または水素化反応器６０への供給は、弁及び制御装置（図示せず）により制御されている。
【００２９】
水素分離装置３０の分離材料としては、１ｎｍ〜１０μｍの膜厚で特徴付けられるＰｄ膜、ＰｄとＡｇの合金膜（Ａｇ−Ｐｄ膜）、１ｎｍ〜１００μｍの膜厚で特徴付けられるゼオライト膜や多孔質シリカ膜等のような水素分離膜、ゼオライト、メソ多孔質材、フェルト状活性炭、ハニカム状活性炭、カーボンナノチューブ等の水素吸着作用で水素と分離する吸着材のうち１つ以上を選択することが好ましいが、特に限定されることなく公知の分離材料から選択することができる。
【００３０】
水素保持部４０は、水素貯蔵タンクや水素貯蔵合金等の公知の水素貯蔵体と水素の貯蔵及び放出の装置を具備しており、所定量の水素を保持するとともに、水素を系外に導出する場合の水素供給装置となっている。また、ガスタービン５５が原料ガスを燃料としないときは、水素保持部４０に貯蔵された水素が、本願発明の低級炭化水素直接改質複合装置の起動時にガスタービン５５に供給されるようになっている。
【００３１】
水素化反応器６０においては、水素雰囲気下で所定の反応温度に保持した芳香族炭化水素水素化触媒６５（以下「水素化触媒」という）に貯蔵された芳香族炭化水素を接触させ、シクロヘキサン、デカリン等の有機ハイドライドに改質し、有機ハイドライド貯蔵部７０に貯蔵される。
【００３２】
水素化反応器６０は、直接改質器１０を加熱した後のガスタービン５５のオフガスの顕熱を利用して約２５〜約４００℃、好ましくは約５０〜約３００℃の温度と、約０．１〜約１０気圧、好ましくは約１〜約５気圧の圧力に保たれ、水素分離装置３０から直接に、あるいは水素保持部４０から供給される水素雰囲気の中で、液体状の芳香族炭化水素が供給され水素化触媒６５に接触されて、シクロヘキサン、デカリン等の有機ハイドライドを生成する。
【００３３】
水素化触媒６５としては特に制限はなく、特開２００１−１１０４３７号公報、特開２００１−１９８４６９号公報、特開２００２−１３４１４１号公報、特開２００２−１８４４３６号公報、特開２００２−１８７７０２号公報等で知られている公知の触媒の中から、任意のものを適宜選択して用いることができる。
【００３４】
水素化反応器６０は、上述公知の発明に基づく反応方式をはじめとして水素化触媒６５に芳香族炭化水素を接触させることができるいずれの触媒反応方式でもよいが、水素雰囲気下で液体状の芳香族炭化水素を水素化触媒６５に前記の公知の出願発明のごとく噴霧又はシャワー状にて供給して、概触媒表面に液膜状の濡れを形成し反応させる方式が好ましい。
【００３５】
水素化反応器６０では、水素雰囲気下で水素化触媒６５と高温化で芳香族炭化水素が接触して有機ハイドライドと未反応の水素及び芳香族炭化水素の混合ガスが生成する。該混合ガスは冷却器などにより気液分離され、有機ハイドライド貯蔵部７０に導出される。
【００３６】
有機ハイドライド貯蔵部７０の有機ハイドライドと芳香族炭化水素の混合物質は、本願請求項５の発明のように、蒸留装置８０による分留など処理により容易にそれぞれの物質に分離することでき、利用することができる。
【００３７】
このように、図１の本願発明の実施例では、ガスタービン５５と直接改質器１０及び水素化反応器６０とを、生成物質的及び熱エネルギーの観点から非常に効率的に複合化させた装置として実現することができるものとなる。ガスタービン５５での発電と、ガスタービン出口のオフガスの温度は、半比例的な関係となるため、実用上、電力、水素、有機ハイドライドの需要量や市場価格の動向に応じて生産量を好適に調整することは有効であり、とりわけ貯蔵の困難な電力を調整できることは大きな意義を有する。
【００３８】
本発明は、以上の発明の実施の形態に限定されることなく、特許請求の範囲に記載された発明の範囲内で、種々の変更が可能であり、それらも本発明の範囲内に包含されるものであることはいうまでもない。
【００３９】
【発明の効果】
本発明の低級炭化水素改質複合装置よれば、ガスタービン５５等の燃焼装置５０による高温排熱を利用して低級炭化水素含有原料ガスから、燃料電池用水素貯蔵物質として期待されるシクロヘキサン、デカリン等の有機ハイドライドや水素を特に効率的に製造することができる。また、生成水素をガスタービン５５の燃料や直接改質器１０の活性化のために供給することができ、装置全体の運転を特に高効率かつ安定的に行うことができる。このため、電力、水素、有機ハイドライドのいずれかを単独で生産する従来システムよりも、エネルギー効率上及び経済計算上の飛躍的な効率化を図ることができる。
【図面の簡単な説明】
【図１】本願発明の低級炭化水素直接改質複合装置の１実施例を示した図。
【符号の説明】
１０：低級炭化水素直接改質器
１５：低級炭化水素直接改質触媒
２０：芳香族抽出器
３０：水素分離装置
４０：水素保持部
５０：燃焼装置
５５：ガスタービン発電機
６０：芳香族炭化水素水素化反応器
６５：芳香族炭化水素水素化触媒
７０：有機ハイドライド貯蔵部
８０：蒸留装置
９０：圧力変動吸着（ＰＳＡ）装置[0001]
[0001] The present invention relates to an organic hydride, hydrogen, aromatic, and the like obtained from a lower hydrocarbon as a raw material by combining a lower hydrocarbon direct reformer, a combustion device, and an aromatic hydrocarbon hydrogenation reactor. The present invention relates to a combined device that produces hydrocarbons and / or electric power.
[0002]
[Prior art]
Natural gas, biogas, coke oven off-gas, and other lower hydrocarbon-containing raw materials containing 2 to 5 carbon atoms in the molecule, such as methane, are directly reformed in the presence of a metal-supported metallosilicate catalyst to produce hydrogen and benzene. Methods for co-producing aromatic hydrocarbons such as naphthalene are disclosed in JP-A-10-270366, JP-A-11-47606, JP-A-11-60514, JP-A-2001-334151, and JP-A-2001-334151. This is known from JP-A-334152 and JP-A-2002-336704.
[0003]
In the direct reforming of the lower hydrocarbon-containing raw material, the lower hydrocarbon-containing raw material is converted to a metal-supported metallosilicate catalyst at 300 to 800 ° C., preferably 450 ° C. by a flow-type reaction system such as a fixed bed, a moving bed or a fluidized bed. To 775 ° C., more preferably 705 to 750 ° C., but it is necessary to always supply high-temperature reaction heat to the catalyst and the reactor, and a large amount of heat depends on the scale of the apparatus. How to supply them has been a practical issue.
[0004]
On the other hand, the present inventor has combined the SOFC (Solid Oxide Fuel Cell) disclosed in Japanese Patent Application Laid-Open No. 2003-007321 with a lower hydrocarbon direct reformer to convert the high-temperature exhaust gas of the SOFC into a raw material gas. In addition to mixing, the SOFC and the direct reformer were placed in the same adiabatic container to develop a method of supplying heat to the reaction heat of the direct reforming reaction by heat transfer, and continued to pursue R & D for its practical use. I have. However, research and development of the SOFC main body is currently intensely progressing in various fields, and when the SOFC and the lower hydrocarbon direct reformer are arranged in the same insulated container to supply reaction heat by heat transfer, coking ( There are many problems that need to be solved, such as the occurrence of carbon deposition) and the heat resistance of the SOFC and the main body of the direct reformer, and further technological development was required before practical use.
[0005]
On the other hand, in order to utilize the high-temperature heat of the combustion device to a higher degree and to improve the utilization efficiency of the primary energy to be input, research and development of the combination of the combustion device and the power generation device in various fields are underway. Cogeneration equipment that produces both heat and electricity is being put to practical use. In particular, in equipment utilizing a gas turbine engine with high energy efficiency, a high-rotation small gas turbine called a so-called micro gas turbine has reached the stage of practical application due to advances in precision machining technology, high-speed bearing technology, and material technology. Some micro gas turbine cogeneration systems exhibit overall energy efficiency of over 70%.
[0006]
Also, research and development of a cogeneration system by combining a gas turbine engine with a high-temperature fuel cell such as an SOFC have been advanced, and a fuel containing a lower hydrocarbon such as methane is used as a pretreatment. The fuel is often reformed into hydrogen and carbon monoxide by a steam reformer, and then used as a fuel for a gas turbine. Japanese Patent Application Laid-Open No. 2001-266924 discloses a combined system of a gas turbine and a fuel cell.
[0007]
However, in a combined gas turbine and fuel cell system, when hydrogen and carbon monoxide that have undergone preliminary reforming by steam reforming are used as fuel, in practice, the carbon deposition phenomenon occurs in the gas turbine itself and in various parts of various combined engines. The concern that the power generation performance will decrease due to the generation of gas will not be eliminated, and the cogeneration system that combines the gas turbine's high-temperature offgas and the gas turbine will require a dedicated high-temperature offgas that contains a large amount of moisture generated by the oxidation of hydrogen. There have been problems such as the necessity of gas turbine design and the restriction of operation due to the combination of a fast system by electrochemical reaction and a slow system associated with the use of off-gas for a heat engine.
[0008]
[Problems to be solved by the invention]
The present invention has been made in view of the problems of the prior art relating to the lower hydrocarbon reforming process and the gas turbine combined system, respectively, and is intended to supply the high-temperature off-gas from the gas turbine to the supply of high-temperature reaction heat required by the lower hydrocarbon reforming process. In addition to utilizing, part or all of the hydrogen and unreacted raw materials generated by the lower hydrocarbon reforming process are supplied as fuel for the gas turbine, and the heat and the production of hydrogen and aromatic hydrocarbons are balanced. At the same time, a combined lower hydrocarbon reforming device that uses hydrogen and aromatics generated by the lower hydrocarbon reforming process to produce organic hydrides (aromatic hydrocarbon hydrides) that will be used as hydrogen storage materials for fuel cells The purpose is to provide.
[0009]
[Means for Solving the Problems]
The invention of claim 1 of the present application is a combined lower hydrocarbon direct reforming apparatus comprising a lower hydrocarbon direct reformer 10, an aromatic hydrocarbon hydrogenation reactor 60, and a combustion device 50, The reformer 10 is supplied with the heat of reaction in the presence of the lower hydrocarbon direct reforming catalyst 15 to reform the lower hydrocarbon-containing raw material gas taken in from outside the system into hydrogen and aromatic hydrocarbons. A mixed gas of the aromatic hydrocarbon and the unreacted lower hydrocarbon-containing raw material gas is generated, and the mixed gas is supplied to the aromatic hydrocarbon hydrogenation reactor 60 from the lower hydrocarbon direct reformer 10. In the presence of the aromatic hydrocarbon hydrogenation catalyst 65, the aromatic hydrocarbon is hydrogenated to produce an organic hydride, and the combustion device 50 uses the lower hydrocarbon-containing raw material gas, the lower hydrocarbon directly Generated in the reformer 10 Combustion using either a part of the combined gas or hydrogen and / or lower hydrocarbons separated from the mixed gas or a mixed gas thereof as fuel to generate high-temperature heat and directly reform lower hydrocarbons A lower hydrocarbon direct reforming combined apparatus characterized in that a lower hydrocarbon-containing raw material gas supplied to a reactor (10) is preheated and reacts to the lower hydrocarbon direct reformer (10).
[0010]
The invention of claim 2 of the present application provides the lower hydrocarbon direct reforming combined device according to claim 1, wherein the combustion device 50 is a gas turbine generator 55, and electric power is obtained together with reaction heat. I do.
[0011]
The invention of claim 3 of the present application is directed to the aromatic hydrocarbon hydrogenation reactor 60, wherein the aromatic extractor 20 or the aromatic extractor 20 for separating aromatic hydrocarbons from the mixed gas supplied from the lower hydrocarbon direct reformer 10. The low-grade hydrocarbon direct reforming combined device according to claim 1 or 2, further comprising one or both of a hydrogen separation device 30 for separating hydrogen from the mixed gas.
[0012]
The invention of claim 4 of the present application is directed to a method for directly converting a lower hydrocarbon into a part of a hydrogen-containing gas generated by the aromatic extractor 20 and a part of the hydrogen separated by the hydrogen separator 30. 4. The combined lower hydrocarbon reforming apparatus according to claim 3, wherein the carbon fed to the reformer 10 and precipitated on the lower hydrocarbon direct reforming catalyst 15 is reduced to methane or the like to activate the catalyst. provide.
[0013]
The invention according to claim 5 of the present application is further provided with a distillation device 80 for purifying an organic hydride generated by the aromatic hydrocarbon hydrogenation reactor 60, wherein the distillation device 80 is further provided. And a low-grade hydrocarbon reforming combined device.
[0014]
In the invention of claim 6 of the present application, the lower hydrocarbon-containing raw material gas supplied to the lower hydrocarbon direct reformer 10 and / or the combustion device 50 is natural gas, methane gas, methane hydrate, coke oven gas COG, human waste, Biogas (including fermented methane gas) obtained by fermenting garbage and the like, and one or more selected from the group consisting of dry-distilled gas obtained by dry-distilling organic matter such as wood. A low hydrocarbon direct reforming combined apparatus according to any one of claims 1 to 5, characterized in that:
[0015]
The invention according to claim 7 of the present application is characterized in that the lower hydrocarbon-containing raw material gas is subjected to gas component adjustment purification by a pressure swing adsorption (PSA) device 90. Provide a combined hydrogen direct reforming apparatus.
[0016]
The invention of claim 8 of the present application, wherein the lower hydrocarbon direct reforming catalyst 15 is a metal-supported zeolite catalyst, wherein the combined lower hydrocarbon direct reforming apparatus according to any one of claims 1 to 7 is used. I will provide a.
[0017]
In the invention of claim 9 of the present application, the aromatic hydrocarbon hydrogenation reactor 60 uses the aromatic hydrocarbon hydrogenation catalyst 65 as an organic hydride dehydrogenation catalyst, and is supplied with heat of reaction to dehydrogenate the organic hydride. An apparatus for direct reforming of lower hydrocarbons according to any one of claims 1 to 8, wherein the apparatus also serves as an organic hydride dehydrogenation reactor for producing hydrogen and aromatic hydrocarbons through a hydrogenation reaction. I do.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows a configuration of an embodiment of a low hydrocarbon direct reforming combined apparatus of the present invention. In the present embodiment, a gas turbine generator 55 (hereinafter, referred to as “gas turbine”) is used as the combustion device 50 as in the second embodiment of the present invention, and the outlet temperature of the gas turbine generator 55 is approximately 750 to 1200 ° C. Using a gas, a lower hydrocarbon raw material gas (hereinafter referred to as “raw material gas”) taken in from outside the system is pre-heated by heat exchange in a heat exchange unit (not shown), and the lower hydrocarbon direct reformer 10 ( (Hereinafter, referred to as “direct reformer”) is maintained at about 750 ° C. by a heat exchange unit (not shown), and then the raw material gas is directly supplied to the reformer 10 to generate hydrogen and an aromatic compound. The generated hydrogen and the unreacted raw material gas are separated from the aromatic hydrocarbon and supplied to an aromatic hydrocarbon hydrogenation reactor 60 (hereinafter, referred to as “hydrogenation reactor”), and a part of the gas is supplied to the reactor. With the fuel of the turbine 55 It is a lower hydrocarbon directly reformer composite device supplied Te.
[0019]
According to the seventh aspect of the present invention, the raw material gas is subjected to the adjustment and purification of the raw material gas by the PSA device 90, and is adjusted to a concentration of 90% methane and 5% carbon dioxide directly at the inlet of the reformer 10. It has become.
[0020]
In the direct reformer 10, a preheated raw material gas is supplied and brought into contact with a lower hydrocarbon direct reforming catalyst 15 (hereinafter, referred to as a "reforming catalyst"), and hydrogen and benzene, naphthalene, toluene, xylene, methyl Generates aromatic hydrocarbons such as naphthalene. The heat exchange unit (not shown) uses the sensible heat of the high-temperature off-gas of the gas turbine 55 to directly bring the inside of the reformer 10 to a temperature atmosphere of about 750 ° C. In (after), the conversion to hydrogen and aromatic hydrocarbons proceeds at a conversion rate of about 20%, and the mixed gas is sent out as a raw material of the hydrogenation reactor 60 together with unreacted raw material gas.
[0021]
The reforming catalyst 21 is not particularly limited, and is disclosed in JP-A-10-270366, JP-A-11-47606, JP-A-11-60514, JP-A-2001-334151, and JP-A-2001-334152. Any of the known catalysts described in JP-A-2002-336704 can be appropriately selected and used.
[0022]
The direct reformer 10 is preferably of a fixed bed catalytic reaction type or a fluidized bed catalytic reaction type, but may be of any catalytic reaction type as long as the raw material gas can sufficiently contact the reforming catalyst 21. In the case of a fluidized bed reaction type, a cyclone for collecting solid catalyst fine particles contained in a mixed gas of hydrogen, aromatic compound and unconverted raw material gas after the conversion reaction is preferably provided at the outlet.
[0023]
In any of the reaction types, lower carbonization is performed by adding 0.01 to 30% by volume, preferably 0.1 to 25% by volume of carbon monoxide and / or carbon dioxide to the raw material gas based on a known conventional technique. The reaction conversion of hydrogen may be improved. When the raw material gas such as biogas contains about 30% by volume or more of carbon dioxide, it is necessary to adjust the volume of carbon dioxide by the PSA device 90.
[0024]
Since the catalytic performance of the reforming catalyst 21 decreases due to the precipitation of carbon as the reaction time elapses, the direct reformer 10 includes the aromatic extractor 20 and the hydrogen separator 30 as described in the fourth aspect of the present invention. Is supplied as a circulating gas, and the deposited carbon is reduced to methane or the like to activate the catalyst. Although not shown in FIG. 1, a catalyst regeneration process in which carbon deposited on the reforming catalyst 21 is burned by oxygen or the like and regenerated may be performed.
[0025]
The catalyst activation process using hydrogen gas may be performed alternately and continuously with the lower hydrocarbon conversion reaction process, or may be performed intermittently as appropriate. In addition, the catalyst activation process using hydrogen may be performed in parallel with the lower hydrocarbon conversion reaction process, such as successively regenerating the reforming catalyst 21 by circulating it as appropriate.
[0026]
The mixed gas of hydrogen, aromatic hydrocarbon and unconverted raw material gas sent from the direct reformer 10 is first converted into hydrogen, unconverted raw material gas and liquid aromatic hydrocarbon by the aromatic extractor 20. Gas-liquid separation. The liquid aromatic hydrocarbon is stored in a storage unit (not shown), and the separated hydrogen and the unconverted raw material gas are introduced into a hydrogen separator 30 to selectively separate hydrogen.
[0027]
The aromatic extractor 20 includes a condensing / separating method in which a mixed gas of hydrogen, aromatic hydrocarbon and unconverted raw material gas is brought into contact with a cooling unit having a temperature equal to or lower than the boiling point of aromatic hydrocarbon, or a method such as decalin or methylnaphthalene. An arbitrary separation method such as a method according to the existing application invention of the present inventor (when not yet opened) for bubbling in a liquid solvent to dissolve and separate an aromatic hydrocarbon can be appropriately selected. In the embodiment of FIG. 1, the extractor body by bubbling into a liquid solvent serves as a storage for the separated liquid aromatic hydrocarbons.
[0028]
The remaining unconverted raw material gas separated from the hydrogen or the aromatic hydrocarbon by the hydrogen separator 30 or the aromatic extractor 20 is introduced into the gas turbine 55. Further, the hydrogen separated by the hydrogen separation device 30 is introduced into the hydrogen holding unit 40 and stored, supplied to the gas turbine 55 as fuel, or supplied to the hydrogenation reactor 60. In the embodiment of FIG. 1, a part of the hydrogen separated by the hydrogen separation device 30 is supplied directly from the raw material gas inlet of the reformer 10 to activate the reforming catalyst 21. The storage of hydrogen in the hydrogen holding unit 40, the supply to the gas turbine 55, or the supply to the hydrogenation reactor 60 is controlled by a valve and a control device (not shown).
[0029]
As a separation material of the hydrogen separation device 30, a Pd film characterized by a film thickness of 1 nm to 10 μm, an alloy film of Pd and Ag (Ag-Pd film), a zeolite film characterized by a film thickness of 1 nm to 100 μm, or a porous material One or more adsorbents that separate from hydrogen by hydrogen adsorption such as hydrogen separation membrane such as porous silica membrane, zeolite, mesoporous material, felt activated carbon, honeycomb activated carbon, carbon nanotube, etc. Although preferred, it can be selected from known separation materials without any particular limitation.
[0030]
The hydrogen holding unit 40 includes a known hydrogen storage unit such as a hydrogen storage tank or a hydrogen storage alloy, and a device for storing and releasing hydrogen. The hydrogen holding unit 40 holds a predetermined amount of hydrogen and guides the hydrogen out of the system. In this case, it is a hydrogen supply device. Further, when the gas turbine 55 does not use the raw material gas as fuel, the hydrogen stored in the hydrogen holding unit 40 is supplied to the gas turbine 55 at the time of starting up the low hydrocarbon direct reforming combined apparatus of the present invention. ing.
[0031]
In the hydrogenation reactor 60, an aromatic hydrocarbon stored in an aromatic hydrocarbon hydrogenation catalyst 65 (hereinafter, referred to as “hydrogenation catalyst”) maintained at a predetermined reaction temperature under a hydrogen atmosphere is brought into contact with cyclohexane, It is reformed into organic hydride such as decalin and stored in the organic hydride storage unit 70.
[0032]
The hydrogenation reactor 60 utilizes the sensible heat of the off-gas of the gas turbine 55 after directly heating the reformer 10 to a temperature of about 25 to about 400 ° C., preferably about 50 to about 300 ° C., and about 0 to about 300 ° C. Is maintained at a pressure of from about 1 to about 10 atm, preferably from about 1 to about 5 atm, in a hydrogen atmosphere supplied directly from the hydrogen separator 30 or in a hydrogen atmosphere supplied from the hydrogen holding section 40. Hydrogen is supplied and brought into contact with the hydrogenation catalyst 65 to generate an organic hydride such as cyclohexane or decalin.
[0033]
The hydrogenation catalyst 65 is not particularly limited, and is disclosed in JP-A-2001-110439, JP-A-2001-198469, JP-A-2002-134141, JP-A-2002-184436, and JP-A-2002-187702. Any of the known catalysts known as, for example, can be appropriately selected and used.
[0034]
The hydrogenation reactor 60 may be any type of catalyst reaction type capable of bringing an aromatic hydrocarbon into contact with the hydrogenation catalyst 65, such as the reaction type based on the above-mentioned known invention, but may be a liquid type under a hydrogen atmosphere. It is preferable that the aromatic hydrocarbon is supplied to the hydrogenation catalyst 65 in the form of a spray or a shower as in the above-described known invention, and a liquid film is formed on the surface of the catalyst to cause a reaction.
[0035]
In the hydrogenation reactor 60, the hydrogenation catalyst 65 and the aromatic hydrocarbon are brought into contact with each other at a high temperature in a hydrogen atmosphere to produce a mixed gas of the organic hydride, unreacted hydrogen and aromatic hydrocarbon. The mixed gas is separated into gas and liquid by a cooler or the like, and is led to the organic hydride storage unit 70.
[0036]
The mixed substance of the organic hydride and the aromatic hydrocarbon in the organic hydride storage unit 70 can be easily separated into respective substances by a treatment such as fractional distillation by the distillation apparatus 80 as in the invention of claim 5 of the present application, and is used. be able to.
[0037]
As described above, in the embodiment of the present invention shown in FIG. 1, the gas turbine 55, the direct reformer 10 and the hydrogenation reactor 60 are very efficiently combined from the viewpoint of the generated material and heat energy. It can be realized as a device. Since the power generation in the gas turbine 55 and the temperature of the off-gas at the gas turbine outlet are in a semi-proportional relationship, the production amount is practically suitable in accordance with the demands of electric power, hydrogen, organic hydride and market price trends. It is effective to adjust the power, and it is particularly significant that the power that is difficult to store can be adjusted.
[0038]
The present invention is not limited to the above embodiments of the invention, and various modifications can be made within the scope of the invention described in the claims, which are also included in the scope of the invention. Needless to say, it is.
[0039]
【The invention's effect】
According to the combined lower hydrocarbon reforming apparatus of the present invention, cyclohexane and decalin, which are expected as hydrogen storage materials for fuel cells, from lower hydrocarbon-containing raw material gas by utilizing high-temperature exhaust heat from the combustion device 50 such as the gas turbine 55 And organic hydrides and hydrogen can be produced particularly efficiently. Further, the generated hydrogen can be supplied for activating the fuel of the gas turbine 55 or the direct reformer 10, and the operation of the entire apparatus can be performed particularly efficiently and stably. For this reason, it is possible to achieve a dramatic increase in energy efficiency and economic calculation as compared with a conventional system that independently produces any of electric power, hydrogen, and organic hydride.
[Brief description of the drawings]
FIG. 1 is a view showing one embodiment of a low-grade hydrocarbon direct reforming combined apparatus of the present invention.
[Explanation of symbols]
10: Lower hydrocarbon direct reformer 15: Lower hydrocarbon direct reforming catalyst 20: Aromatic extractor 30: Hydrogen separator 40: Hydrogen holding unit 50: Combustion device 55: Gas turbine generator 60: Aromatic hydrocarbon Hydrogenation reactor 65: Aromatic hydrocarbon hydrogenation catalyst 70: Organic hydride storage unit 80: Distillation unit 90: Pressure swing adsorption (PSA) unit

Claims

A combined lower hydrocarbon direct reformer comprising a lower hydrocarbon direct reformer (10), an aromatic hydrocarbon reactor (60), and a combustion device (50),
The lower hydrocarbon direct reformer (10) is supplied with heat of reaction in the presence of the lower hydrocarbon direct reforming catalyst (15), and converts the lower hydrocarbon-containing raw material gas taken from outside the system into hydrogen and aromatic hydrocarbon. Reforms to hydrogen to produce a mixed gas of hydrogen and aromatic hydrocarbons and unreacted lower hydrocarbon-containing raw material gas,
The aromatic hydrocarbon hydrogenation reactor (60) is supplied with the mixed gas from the lower hydrocarbon direct reformer (10), and reacts with the aromatic hydrocarbon in the presence of the aromatic hydrocarbon hydrogenation catalyst (65). Hydrogen is hydrogenated to produce organic hydride,
The combustion device (50) is provided with a lower hydrocarbon-containing raw material gas taken in from outside the system, a part of the mixed gas generated in the lower hydrocarbon direct reformer (10), or hydrogen separated from the mixed gas and / or Combustion of any of the lower hydrocarbons or a gas mixture thereof as a fuel to generate high-temperature heat to preheat the lower hydrocarbon-containing raw material gas supplied to the lower hydrocarbon direct reformer (10). Combined with a lower hydrocarbon direct reformer (10).

The combined lower hydrocarbon direct reforming device according to claim 1, wherein the combustion device (50) is a gas turbine generator (55), and electric power is obtained together with reaction heat.

The aromatic hydrocarbon hydrogenation reactor (60) is an aromatic extractor (20) for separating aromatic hydrocarbons from a mixed gas fed from a lower hydrocarbon direct reformer (10) or the mixed gas. The combined direct reformer for lower hydrocarbons according to claim 1 or 2, further comprising one or both of a hydrogen separator (30) for separating hydrogen from the hydrogen.

Part of the hydrogen-containing gas generated by the separation of the aromatic hydrocarbons by the aromatic extractor (20) or part of the hydrogen separated by the hydrogen separation device (30) is converted to a lower hydrocarbon direct reformer (10). 4.) The combined lower hydrocarbon reforming apparatus according to claim 3, wherein the carbon fed to the lower hydrocarbon direct reforming catalyst (15) is reduced to methane or the like to activate the catalyst.

The lower hydrocarbon according to any one of claims 1 to 4, further comprising a distillation device (80) for purifying an organic hydride produced by the aromatic hydrocarbon hydrogenation reactor (60). Combined reforming equipment.

The lower hydrocarbon-containing raw material gas supplied to the lower hydrocarbon direct reformer 10 and / or the combustion device (50) is natural gas, methane gas, methane hydrate, coke oven gas (COG), night soil, garbage and the like. Biogas (including fermented methane gas) obtained by fermentation treatment, and one or more selected from the group consisting of dry distillation gas obtained by carbonization of organic substances such as wood. The combined lower hydrocarbon direct reforming apparatus according to any one of claims 1 to 5.

The low hydrocarbon direct reforming combined apparatus according to any one of claims 1 to 6, wherein the lower hydrocarbon-containing raw material gas is subjected to gas component adjustment purification by a pressure fluctuation adsorption (PSA) apparatus (90). .

The combined lower hydrocarbon direct reforming apparatus according to any one of claims 1 to 7, wherein the lower hydrocarbon direct reforming catalyst (15) is a metal-supported zeolite catalyst.

The aromatic hydrocarbon hydrogenation reactor (60) uses the aromatic hydrocarbon hydrogenation catalyst (65) as an organic hydride dehydrogenation catalyst, is supplied with reaction heat, and causes the organic hydride to undergo a dehydrogenation reaction. The combined lower hydrocarbon direct reforming apparatus according to any one of claims 1 to 8, wherein the apparatus also serves as an organic hydride dehydrogenation reactor that generates hydrogen and aromatic hydrocarbons.