ZA200607240B

ZA200607240B - Natural gas liquefaction

Info

Publication number: ZA200607240B
Application number: ZA2006/07240A
Authority: ZA
Inventors: John D Wilkinson; Hank M Hudson; Kyle T Cuellar
Original assignee: Ortloff Engineers Ltd
Priority date: 2004-04-26
Filing date: 2006-08-30
Publication date: 2008-03-26
Also published as: EA010538B1; BRPI0418780A; MXPA06011644A; CN100473927C; AU2004319953A1; CA2562323A1; PE20051002A1; EA200601989A1; SA05260083B1; AU2004319953B2; KR20070012814A; BRPI0418780B1; CN1946979A; EP1740897A4; EG25056A; KR101118830B1; WO2005114076A1; JP2007534923A; AR046607A1; NO20065055L

Description

03137.000226.

TO ALL WHOM IT MAY CONCERN:

Be it known that WE, JOHN D. WILKINSON and HANK M. HUDSON, both citizens of the Uniteci States, all residing in Midland, Coumnty of Midland, State of

Texas, whose post office addresses are 2800 W. Dengar, Midland, Texas 79705 and 2508

W. Sinclair, Midland, Texas 79705, respectively, and KYLE T .CUEBLLAR, a citizen of the United States, residing in Katy, County of Fort Bend, State of Texas, whose post office address is 1611 Cottage Point, Katy, Texas 77494, have invented an improvement m

NATURAL GAS LIQUEFACTION of which the followingis a " : SPECIFICATION

B ACKGROUND OF THE INVENTION

[0001] This invention relates to a process for processin_g natural gas or other } methane-rich gas streams to produce a liquefied natural gas (LING) stream that has a high methane purity and a liquid stream containing predominantly hw ydrocarbons heavier than methane. . [0002] Natural gas is typically recovered from wells dr3lled into underground reservoirs. It usually has a major proportion of methane, i.e., methane comprises at least : 50 mole percent of the gas. Depending on the particular under ground reservoir, the natural gas also contains relatively lesser amounts of heavier hydrocarbons such as

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ethane, propame, butanes, pentanes and the like, as well as water, hydrogen, nitrozgen, carbon dioxid_e, and other gases. ‘

[0003] Most natural gas is handled in gaseous form. The most common mmeans for transportimng natural gas from the wellhead to gas processing plants and thenc eto the natural gas consumers is in high pressure gas transom ission pipelines. In a number of circumstance s, however, it has been found necessary and/or desirable to liquefy the natural gas ei ther for transport or for use. In remote locations, for instance, there is often no pipeline ixafrastructure that would allow for convenient transportation of the rmatural gas to market. In such cases, the much lower specific volume of LNG relative to natural gas in the gasseous state can greatly reduce transport-ation costs by allowing delivery of the LNG usirg cargo ships and transport trucks.

[0004] Another circumstance that favors thes liquefaction of natural gas i_s for its use as a moteor vehicle fuel. In large metropolitan areas, there are fleets of busess, taxi cabs, and trucks that could be powered by LNG if there were an economic source of LNG available. S=uch LNG-fueled vehicles produce cons iderably less air pollution dume to the clean-burnim g nature of natural gas when compared. to similar vehicles powered by gasoline andk diese! engines which combust higher rmolecular weight hydrocarbons. In addition, if the LNG is of high purity (i.e., with a methane purity of 95 mole percent or higher), the amount of carbon dioxide (a “greenhouse gas") produced is considesrably less due to the lower carbon:hydrogen ratio for methane compared to all other hydrocarbon fucls.

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[0005] Th _e present invention is generally comncemed with the liquefaction Of natural gas while —producing as a co-product a liquid stream consisting primarily off hydrocarbons heavier than methane, such as natural gas liquids (NGL) composed eof ethane, propane, boutanes, and heavier hydrocarbon components, liquefied petrolexam gas (LPG) composed of propane, butanes, and heavier Enydrocarbon components, or condensate comp osed of butanes and heavier hydrocarbon components. Producin_g the co-product liquid _ stream has two important benefitss: the LNG produced has a highh methane purity, aand the co-product liquid is a valu=able product that may be used For many other purposes. A typical analysis of a natural gas stream to be processed ima accordance with —this invention would be, in approx-imate mole percent, 84.2% me=thane, } 7.9% ethane and other C, components, 4.9% propane and other C; components, 1 .0% iso-butane, 1.1% normal butane, 0.8% pentanes phs, with the balance made up of nitrogen and cartoon dioxide. Sulfur containing gasses are also sometimes present.

[0006] There are a number of methods kno—wn for liquefying natural gas. For instance, see Finmn, Adrian J, Grant L. Johnson, ancl Terry R. Tomlinson, "LNG

Technology for Offshore and Mid-Scale Plants", P_xoceedings of the Seventy-Ninuth

Annual ConventHion of the Gas Processors Association, pp. 429-450, Atlanta, Geowrgia,

March 13-15, 20 00 and Kikkawa, Yoshitsugi, Mas= aaki Ohishi, and Noriyoshi No=zawa, "Optimize the Power System of Baseload LNG Plant", Proceedings of the Eightieth

Annual Convent=ion of the Gas Processors Association, San Antonio, Texas,

March 12-14, 20801 for surveys of a number of suc_h processes. U.S. Pat. Nos. 4,4345,917, 4,525,185; 4,545,795; 4,755,200; 5,291,736; 5,3638,655; 5,365,740; 5,600,969; 5, 615,501,

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VWO 2005/114076 PCI/US2004/012792 5,651,269; 5,755,114; 5,893,274; 6,014,869; 6,062,041; 6,119,479; 6,125,653; 6 ,250,105 B1; 6,269,655 B1; 6,272,882 B1; 6,308,531 Bl; 6,324,867 B1 ; 6,347,532 Bl; amd our co-pending U.S. Patent Application Serial No. 10/161,780 filed Bune 4, 2002 also d-escribe relevant processes. These methods generally include steps in which the natural gas is purified (by removing water and troublesome compounds such as carbon dioxide amd sulfur compounds), cooled, condensed, and expanded. Cooling and econdensation of tie natural gas can be accomplished in many different manners. "Cascadlle refrigeration” employs heat exchange of the natural gas with several refrigerants having successively . lower boiling points, such as propane, cthame, and methane. As an alternative, this heat emchange can be accomplished using a single refrigerant by evaporating the refrigerant at several different pressure levels. "Multi-component refrigeration” emplo_ys heat exchange of the natural gas with one or more refrigerant fluids composed. of several re=frigerant components in lieu of multiple single-component refrigerants. Expansion of th_e natural gas can be accomplished both is enthalpically (using Joule-Thoomson exzpansion, for instance) and isentropically (using a work-expansion turbire, for instance). [0=007] Regardless of the method used to liquefy the natural gas staream, it is co mmon to require removal of a significant fraction of the hydrocarbons Imeavier than methane before the methane-rich stream is liquefied. The reasons for this hydrocarbon rex-noval step are numerous, including the need to control the heating values of the LNG stream, and the value of these heavier hydrocarbon components as products in their own right. Unfortunately, little attention has beem focused heretofore on the ef#ificiency of the hydrocarbon removal step.

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[0008] In accordance with the present in—vention, it has been found that careful integration off the hydrocarbon removal step into= the LNG liquefaction process can produce both LNG and a separate heavier hydroecarbon liquid product using sigenificantly less energy than prior art processes. The present invention, although applicable at lower pressures, is particularly advantageous when promcessing feed gases in the ranges of 400 to 1500 psia [2,758 to 10,342 kPa(a)] or higher. -

[0009] For a better understanding of the gpresent invention, reference is “made to the following examples and drawings. Referring to the drawings: 0010} FIG. 1 is a flow diagram of a natumral gas liquefaction plant adapted for co-productiora of LPG in accordance with the present invention;

[0011] FIGS. 2 and 3 are diagrams of altemative fractionation systems which may be employed in the process of the present invention;

[0012] FIG. 4 is a pressure-enthalpy phasse diagram for methane used to illustrate the advantage=s of the present invention over prior art processes; and

[0013] FIGS. 5, 6, 7, 8, 9, and 10 are flov= diagrams of alternative naturzal gas liquefaction p Tants adapted for co-production of =a liquid stream in accordance with the present invent=ion.

[0014] In the following explanation of the above figures, tables are provided summarizing Slow rates calculated for representative process conditions. In the “tables appearing herein, the values for flow rates (in mo les per hour) have been rounde=d to the nearest whole number for convenience. The total. stream rates shown in the tables include all nor-hydrocarbon components and hen-ce are generally larger than thes sum of

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the stoream flow rates for the hydrocarbom. components. Temperatures inedicated are approximate values rounded to the nearest degree. It should also be note=d that the processs design calculations performed fo x the purpose of comparing the processes depicted in the figures are based on the assumption of no heat leak from (or to) the surrosundings to (or from) the process. The quality of commercially avai lable insulating mate=rials makes this a very reasonable assumption and one that is typically made by those skilled in the art. {0015s} For convenience, process parameters are reported in both the traditional

Briti_sh units and in the units of the Intermational System of Units (SI). —The molar flow ratess given in the tables may be interpreted as either pound moles per hour or kilogram moles per hour. The energy consumptionns reported as horsepower (HPD) and/or thousand

British Thermal Units per hour (MBTU/ Hr) correspond to the stated molar flow rates in pournd moles per hour. The energy cons umptions reported as kilowatts (kW) correspond . to thme stated molar flow rates in kilograrm moles per hour. The production rates reported as pounds per hour (Lb/Hr) correspond #o the stated molar flow rates in_ pound moles per houm. The production rates reported as kilograms per hour (kg/Hr) corr espond to the stateed molar flow rates in kilogram moles per hour.

DESCRIPTIOIN OF THE INVENTION

[001_6} Referring now to FIG. 1, we begin with an illustration o—fa process in accordance with the present invention where it is desired to produce an LPG co-product containing the majority of the propane and heavier components in the ratural gas feed stre am. In this simulation of the present invention, inlet gas enters the —plant at 90°F

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[32°C] and 1285 psia [8,8 60 kPa(a)] as stream 31. If the inlet gas =contains a concentration of carbon di oxide and/or sulfur compounds which w~ould prevent the product streams from meeting specifications, these compounds are= removed by appropriate pretreatment of the feed gas (not illustrated). In additi=on, the feed stream is usually dehydrated to prevent hydrate (ice) formation under cryogesnic conditions. Solid desiccant has typically been used for this purpose.

[0017] The feed stream 31 is cooled in heat exchanger 10 y heat exchange with refrigerant streams and flashed separator liquids at -14°F [-26°C] (stream 40a). Note that in all cases heat exchanger 10 is representative of either a multitude of individual heat exchangers or a single multi-pass heat exchanger, or any combination thereof. (The decision as to whether to vase more than one heat exchanger for the- indicated cooling services will depend on a umber of factors including, but not limi ted to, inlet gas flow rate, heat exchanger size, stream temperatures, etc.) The cooled staream 31a enters separator 11 at 23°F [-5°C] and 1278 psia [8,812 kPa(a)] where thes vapor (stream 32) is separated from the condensed liquid (stream 33).

[0018] The vapor (stream 32) from separator 11 is divided “into two streams, 34 and 36, with stream 34 corataining about 42% of the total vapor. Scme circumstances may favor combining stream 34 with some portion of the condense=d liquid (stream 39) to form stream 35, but in this simulation there is no flow in stream 39 . Combined stream 35 passes through heat exchanger 13 in heat exchange relation with re frigerant stream 71e, resulting in cooling and substantial condensation of stream 35a. Thhe substantially condensed stream 35a at 90°F [-68°C] is then flash expanded throwugh an appropriate

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expansion device, such as expansion valve 14, to slightly above the cmperating pressure (approximately 450 psia [3,103 kPaqa)]) of fractionation tower 19. During expansion a portion of the stream is vaporized, resulting in cooling of the total str—eatn. In the process illustrated in FIG. 1, the expanded stream 35b leaving expansion val=ve 14 reaches a temperature of -123°F [-86°C]. The expanded stream 35b is warmed to -78°F [-61°C] and further vaporized in heat exchanger 21 as it provides cooling anc partial condensation of vapor distillation stream 37 rising from the fractionamtion stages of ‘ fractionation tower 19. The warmed stream 35c is then supplied at a_n upper mid-point feed position in deethanizing section 19b of fractionation tower 19.

[0019] The remaining 58% of the vapor from separator 11 (stream 36) enters a work expansion machine 15 in which mechanical energy is extractecq from this portion of the high pressure feed. The machin e 15 expands the vapor substanti=ally isentropically from a pressure of about 1278 psia [ 8,812 kPa(a)] to the tower opera . ting pressure, with the work expansion cooling the exp anded stream 36a to a temperatumre of approximately -57°F [49°C]. The typical commercially available expanders are ca—pable of recovering on the order of 80-85% of the work theoretically available in an idea_l isentropic expansion. The work recovered is often used to drive a centrifugal ccompressor (such as item 16) that can be used to re-compress the tower overhead gas (straeam 49), for example. The expanded and partial ly condensed stream 36a is suppBlied as feed to distillation column 19 at a lower mi d-column feed point. Stream 40, the remaining portion of the separator liquid (streaxm 33) is flash expanded to slightly above the operating pressure of deethanizer 19 by expansion valve 12, cooling stream 40 to -14°F

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[26°C] (stream 40a) before it provides cooling to the incoming feed gas as described earlier, Stream 40b, now at 75°F [24°C], then enters decthanizesr 19 at a second lower mid-column feed point.

[0020] The deethani zer in fractionation tower 19 is a coraventional distillation column containing a plurality of vertically spaced trays, one or rmore packed beds, or some combination of trays and packing. As is often the case in matural gas processing plants, the fractionation tower may consist of two sections. The upper section 19a is a separator wherein the top feed is divided into its respective vapor and liquid portions, and wherein the vapor rising from the lower distillation or decthanizling section 19b is combined with the vapor poxtion (if any) of the top feed to form the deethanizer overhead vapor (stream 37) which exi ts the top of the tower. The lower, d_ecthanizing section 19b contains the trays and/or packing and provides the necessary comtact between the liquids falling downward and the vapors rising upward. The deethanizirag section also includes one or more reboilers (such as reboiler 20) which heat and vaporize a portion of the liquids flowing down the column to provide the stripping vapors which flow up the column. The liquid product stream 41 exits the bottom of the tovver at 213°F [101°C], based on a typical specification of an ethane to propane ratio of .020:1 on a molar basis in the bottom product.

[0021] The overhead distillation stream 37 leaves deetharizer 19 at -73°F [-59°C] and is cooled and partially condensed in reflux condenser 21 as described earlier. The partially condensed stream 37a enters reflux drum 22 at -94°F [-770°C] where the condensed liquid (stream 44) is separated from the uncondensed wapor (stream 43). The

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condensed liquid (stream 44) is goumped by pump 23 to a top feed point on deethanizer 19 as reflux stream 44a.

[0022] When the deetharizing section forms the lower gportion of a fractionation tower, reflux condenser 21 may “be located inside the tower abcave column 19 as shown in

FIG. 2. This eliminates the need for reflux drum 22 and reflux pump 23 because the distillation stream is then both cooled and separated in the tower above the fractionation stages of the column. Alternatively, use of a dephlegmator (such as dephlegmator 21 in

FIG. 3) in place of reflux conderaser 21 in FIG. 1 eliminates the= reflux drum and reflux pump and also provides concurrent fractionation stages to replamce those in the upper section of the deethanizer column. If the dephlegmator is posit ioned in a plant at grade level, it is connected to a vapor/l-iquid separator and the liquid collected in the separator is pumped to the top of the distillat ion column. The decision as tc whether to include the reflux condenser inside the colurmn or to use a dephlegmator us ually depends on plant size and heat exchanger surface requirements.

[0023] The uncondensed vapor (stream 43) from reflux drum 22 is warmed to 93°F [34°C] in heat exchanger 2<4, and a portion (stream 48) is ®hen withdrawn to serve as fuel gas for the plant. (The amouvant of fuel gas that must be witBhdrawn is largely determined by the fuel required for the engines and/or turbines clriving the gas compressors in the plant, such as refrigerant compressors 64, 66», and 68 in this example.)

The remainder of the warmed vapor (stream 49) is compressed ¥by compressor 16 driven by expansion machines 15, 61, arad 63. After cooling to 100°F [38°C] in discharge cooler

NY(2:408682.3 -10-

25, stream 49b is further ¢ ooled to -83°F [-64°C] in heat excharager 24 by cross exchange with the cold vapor, stream 43.

[0024] Stream 49¢ then enters heat exchanger 60 and is further cooled by refrigerant stream 71d to -2255°F [-160°C] to condense and subc ool it, whereupon it enters a work expansion mmachine 61 in which mechanical energy is extracted from the stream. The machine 61 expands liquid stream 49d substantially isentropically from a pressure of about 593 psia [4,085 kPa(a)] to the LNG storage pressure (15.5 psia [107 kPa(a)]), slightly abowe atmospheric pressure. The work expansion cools the expanded stream 49e to a t emperature of approximately -256°F f-160°C], whereupon it is then directed to the LNG s#torage tank 62 which holds the LNG poroduct (stream 50).

[0025] All of the cooling for streams 35 and 49c¢ is provi ded by a closed cycle refrigeration loop. The wo king fluid for this cycle is a mixture of hydrocarbons and nitrogen, with the composition of the mixture adjusted as needed to provide the required refrigerant temperature whilile condensing at a reasonable pressur-e using the available cooling medium. In this ca se, condensing with cooling water has been assumed, so a _ refrigerant mixture compos ed of nitrogen, methane, ethane, prop ane, and heavier hydrocarbons is used in the simulation of the FIG. 1 process. Thee composition of the stream, in approximate mol e percent, is 8.7% nitrogen, 31.7% methane, 47.0% ethane, and 8.6% propane, with the balance made up of heavier hydrocarbons. {0026) The refrigereant stream 71 leaves discharge cooler 69 at 100°F [38°C] and 607 psia [4,185 kPa(a)]. It enters heat exchanger 10 and is cooled to -34°F [-37°C] and partially condensed by the partially warmed expanded refrigerant: stream 71f and by other

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refrigerant streams. For the FICS. 1 simulation, it has been assumedh that these other refrigerant streams are commercial-quality propane refrigerant at tiaree different temperature and pressure levels . The partially condensed refrigeramt stream 71a then enters heat exchanger 13 for further cooling to -90°F [-68°C] by pa_ttially warmed expanded refrigerant stream 71, further condensing the refrigerant= (stream 71b). The refrigerant is condensed and thesn subcooled to -255°F [-160°C] in “heat exchanger 60 by expanded refrigerant stream 71a&l. The subcooled liquid stream 71 c= enters a work expansion machine 63 in which. mechanical energy is extracted frorxu the stream as it is expanded substantially isentrop ically from a pressure of about 586 psia [4,040 kPa(a)] to about 34 psia [234 kPa(a)]. During expansion a portion of the stre=am is vaporized, resulting in cooling of the total stream to -264°F [-164°C] (stream ~71d). The expanded stream 71d then reenters heat exchangers 69, 13, and 10 where it p—1ovides cooling to stream 49c, stream 35, and the mefrigerant (streams 71, 71a, and 71 b) as it is vaporized and superheated.

[0027] The superheated refrigerant vapor (stream 71g) leav=es heat exchanger 10 at 90°F [32°C] and is compressed in three stages to 617 psia [4,254 kPa(a)]. Each of the three compression stages (refrigerant compressors 64, 66, and 68) ms driven by a supplemental power source andl is followed by a cooler (discharge coolers 65, 67, and 69) to remove the heat of compression. The compressed stream 71 from discharge cooler 69 returns to heat exchanger 10 to complete the cycle.

[0028] A summary of stream flow rates and energy consun—iption for the process illustrated in FIG. 1 1s set forth in the following table:

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Table I (FIG. 1)

Stream Flow Summary - Lb. Moles/Fr [kg moles/Hr]

Stream Methane Ethane Proparme Butanes+ Tot=al 31 4Q977 3,861 2,408 1,404 48,65 6 32 40,193 3,667 2,171 1,087 47,123 33 784 x 194 237 317 1,53 3 34 16,680 1,522 9m 1 451] 19,55 6 36 23,513 2,145 1,270 636 27,56=7 37 4.4843 7,065 12.0 0 52,03 § 40 784 194 237 317 1,53 3 4] 0 48 2,385 1,404 3,83 7 43 44,977 3,813 23 0 44.81 9 44 3,866 3,252 97 0 721 6 48 2,527 235 1 0 2,76 5 50 3 8,450 3,578 22 0 42,054

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Recoveries in 1PG*

Proparae 99.05%

Butaness+t 100.00%

Producction Rate 197,031 Lb/Hr [ 197, 031 kg/Hr]

LNG Product

Production Rate 725,522 Lb/Mr [ 725.522 kg/Mr]

Purity~* 91.43%

Lower Heating Value 970.4 BTU/SCF [ 36.16 MJ/m®]

Power

Refrigerant Compression 90,714- HP [ 149 ,132 kW]

Propane Compression 36,49% HP [ 59994 kW]

Total Compression 127,207 HP [ 209%,126 kW]

Utility Heat

Deme=thanizer Reboiler 58,003 MBTUMr [ 37470 kW) * (Based on un-r—ounded flow rates)

[0029] T he efficiency of LNG production orocesses is typically compared using the "specific poser consumption” required, which is the ratio of the total refrigeration compression po=wer to the total liquid production rz=zte. Published informat—ion on the specific power cconsumption for prior art processes: for producing LNG incHicates a range of 0.168 HP-Hr./Lb [0.276 kW-Hr/kg] to 0.182 HP=-Hr/Lb {0.300 kW-Hr/k=g], which is believed to be bwased on an on-stream factor of 3408 days per year for the L-NG production plant. On this ssame basis, the specific power conssumption for the FIG. 1 «embodiment of

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the present invention is Q.148 HP-Hr/Lb [0.243 kW-Hr/kg], which seives an efficiency improvement of 14-23% over the prior art processes.

[0030] There are two primary factors that account for the immproved efficiency of the present invention. The first factor can be understood by examiring the thermodynamics of the liquefaction process when applied to a higlm pressure gas stream such as that considered in this example. Since the primary constini=ent of this stream is methane, the thermodynamic properties of methane can be used foxx the purposes of comparing the liquefaction cycle employed in the prior art process es versus the cycle used in the present invention. FIG. 4 contains a pressure-enthalpy phase diagram for methane. In most of thee prior art liquefaction cycles, all cooling o fthe gas stream is accomplished while the stream is at high pressure (path A-B), whereupon the stream is then expanded (path B—C) to the pressure of the LNG storage vess-¢l (slightly above atmospheric pressure). This expansion step may employ a work expansion machine, which is typically capable of recovering on the order of 75-80% ofthe work theoretically available in an ideal isentropic expansion. In the interest of simpl icity, fully isentropic expansion is displayed in FIG. 4 for path B-C. Even so, the entha_lIpy reduction provided by this work expansion is quite small, because the lines of constart entropy are nearly vertical in the liquid region of the phase diagram.

[0031] Contrast this now with the liquefaction cycle of thes present invention.

After partial cooling at high pressure (path A-A'"), the gas stream 3s work expanded (path

A“A") to an intermediate pressure. (Again, fully isentropic expamnsion is displayed in the interest of simplicity.) The remainder of the cooling is accomplished at the intermediate

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pressure (path A"—B"), and the stream is then expande=d (path B'-C) to the pressure of the

LNG storage vess el. Since the lines of constant entropy slope less steeply in the vapor region of the phase diagram, a significantly larger en-thalpy reduction is provided by~ the first work expansion step (path AA") of the present invention. Thus, the total amo-unt of cooling required For the present invention (the sum o-f paths A-A' and A"-B') is less than the cooling required for the prior art processes (path A-B), reducing the refrigeratiomn (and hence the refrigeration compression) required to liqumefy the gas stream.

[0032] Thae second factor accounting for the —improved efficiency of the present invention is the smiperior performance of hydrocarbomn distillation systems at lower operating pressures. The hydrocarbon removal step in most of the prior art processes is performed at high pressure, typically using a scrub c:olumn that employs a cold hydrocarbon liqu id as the absorbent stream to remove the heavier hydrocarbons froam the incoming gas stream. Operating the scrub column a—t high pressure is not very efficient, as it results in thes co-absorption of a significant fraction of the methane and ethane from the gas stream, wrhich must subsequently be strippec3 from the absorbent liquid and cooled to become part o£ the LNG product. In the present invention, the hydrocarbon rem«oval step is conducted at the intermediate pressure where= the vapor-liquid equilibrium is much more favorable, wesulting in very efficient recovery =of the desired heavier hydrocarbons in the co-product liquid stream.

Other Embodimesnts

[0033] Ose skilled in the art will recognize shat the present invention can b € adapted for use with all types of LNG liquefaction polants to allow co-production off an

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NGL stream, an LPG stream, or a condensate strearm, as best suits the needs at za given plant locatior. Further, it will be reco gnized that a ~variety of process configurastions may be employed for recovering the liquid co-product stream. The present inventior can be adapted to re«cover an NGL stream containing a sigmnificant fraction of the C; co-mponents present in thes feed gas, or to recover a condensate sstream containing only the C 4 and heavier components present in the feed gas, rather Shan producing an LPG co-p-roduct as described eaxclier.

[0034] FIG. 1 represents the preferred embsodiment of the present invermtion for the processirmg conditions indicated. FIGS. 5 throu gh 10 depict alternative emt>odiments of the presermt invention that may be considered for a particular application. Depending on the quantity of heavier hydrocarbons in the feed gas and the feed gas pressure, the cooled feed stream 31a leaving heat exchanger 10 -xnay not contain any liquid (because it is above its cdewpoint, or because it is above its criccondenbar), so that separator= 11 shown in FIGS. 1 amd 6 through 10 is not required, and th _e cooled feed stream can flow directly to an approperiate expansion device, such as work expansion machine 15. In in stances where the in let gas is richer than that heretofore de=scribed, an embodiment of t he present invention such as that shown in FIG. 5 may be emgployed. Condensed liquid stream 33 flows througzh heat exchanger 18 and is subcooled,_. then divided into two porticons. The first portion (stream 40) flows through expansion =walve 12 where it undergoes expansion for flash vaporization as the pressure is reduced to about the pressure of distillation column 19. The cold stream 40a from expansion =walve 12 then flows through heat exchanger 1. 8 where it is partially warmed as it is v1sed to subcool stream 33 as described

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earlier. Partially warme=d stream 40b is then further warmed ion heat exchanger 10 and flows to a lower mid-po int feed location on fractionation colummn 19. The second liquid portion (stream 39), still at high pressure, is (1) combined witt portion 34 of the vapor stream from separator 11, or (2) combined with substantially condensed stream 35a, or (3) expanded in expansion valve 17 and thereafter either supplied to fractionation column 19 at an upper mid-point feed location or combined with exparided stream 35b.

Alternatively, portions of stream 39 may follow any or all of the flow paths herctofore described and depicted im FIG. 5.

[0035] The disposition of the gas stream remaining after recovery of the liquid co-product stream (streamm 43 in FIGS. 1 and 6 through 10) bef ore it is supplied to heat exchanger 60 for conden sing and subcooling may be accomplisshed in many ways. In the process of FIG. 1, the stream is heated, compressed to higher p xessure using energy derived from one or more work expansion machines, partially cooled in a discharge cooler, then further coolesd by cross exchange with the original stream. As shown in

FIG. 6, some applications may favor compressing the stream tow higher pressure, using supplemental compressor: 59 driven by an external power sourc e for example. As shown . by the dashed equipment (heat exchanger 24 and discharge coo ler 25) in FIG. 1, some circumstances may favor reducing the capital cost of the facilits by reducing or eliminating the pre-coolirg of the compressed stream before it enters heat exchanger 60 (at the expense of increas ing the cooling load on heat exchangem 60 and increasing the power consumption of refrigerant compressors 64, 66, and 68). In such cases, stream 49a leaving the compressor may flow directly to heat exchanger 24 zs shown in FIG. 7, or

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‘flow directly to heat exchanger 60 as shown i n FIG. 8. If work expansion nmachines are not tased for expansion of any portions of the high pressure feed gas, a comp xessor driven by am external power source, such as compresssor 59 shown in FIG. 9, may b e used in lieu of compressor 16. Other circumstances may mot justify any compression of the stream at all, sso that the stream flows directly to heat exchanger 60 as shown in FIG. 1 0 and by the dash ed equipment (heat exchanger 24, compressor 16, and discharge cooler 225) in FIG. 1.

If he at exchanger 24 is not included to heat th_e stream before the plant fuel gas (stream 48) i s withdrawn, a supplemental heater 58 m_ay be needed to warm the fuel gas before it is consumed, using a utility stream or another process stream to supply the necessary heat, as shown in FIGS. 8 through 10. Choices such as these must generally be evaluated for each application, as factors such as gas commnposition, plant size, desired ce-product strea-m recovery level, and available equipment must all be considered.

[0036] In accordance with the present invention, the cooling of the irmlet gas stream and the feed stream to the LNG production section may be accomplished in many wayss. In the processes of FIGS. 1 and 5 throumgh 10, inlet gas stream 31 is cooled and cond_ensed by external refrigerant streams and flashed separator liquids. Howvever, the cold process streams could also be used to supply some of the cooling to the high presssure refrigerant (stream 71a). Further, an-y stream at a temperature colder than the : streasm(s) being cooled may be utilized. For ixastance, a side draw of vapor firom fractionation tower 19 could be withdrawn ane used for cooling. The use and distribution of tower liquids and/or vapors for process hea-t exchange, and the particular arrangement of he=at exchangers for inlet gas and feed gas cooling, must be evaluated for each

NY02:<408682.3 -19»-

particulas application, as well as the choice «of process streams for specific hesat exchange services. The selection of a source of coolirag will depend on a number of fa_ctors including, but not limited to, feed gas composition and conditions, plant size _ heat exchange: size, potential cooling source term perature, etc. One skilled in the art will also recognize= that any combination of the above cooling sources or methods of c ooling may be employed in combination to achieve the dllesired feed stream temperature(ss).

[0037] Further, the supplemental extemal refrigeration that is suppliead to the inlet gas stream and the feed stream to the LNG production section may also be accomplished "in many d=ifferent ways. In FIGS. 1 and 6 through 10, boiling single-componesnt refrigerant has been assumed for the high lev-el external refrigeration and vaporizing multi-component refrigerant has been assume=d for the low level external refri_geration, with the single-component refrigerant used tc» pre-cool the multi-component refrigerant stream. AXternatively, both the high level cooling and the low level cooling could be accomplisinied using single-component refrigerants with successively lower bo iling points (i.e., "cascaade refrigeration"), or one single-component refrigerant at successively lower evaporatiom pressures. As another alternative , both the high level cooling and the low level coolirag could be accomplished using multi-component refrigerant streams with their respecstive compositions adjusted to prov-ide the necessary cooling temperatures.

The selecticon of the method for providing extemal refrigeration will depend orm 2 number of factors iracluding, but not limited to, feed gas composition and conditions, pant size, compressor driver size, heat exchanger size, arnbient heat sink temperature, etc . One skilled in thwe art will also recognize that any combination of the methods for providing

NY02:408682.3 20—

external refrig eration described above may be employed in combination to aechieve the desired feed stream temperature(s).

[0038] Subcooling of the condensed liquicE stream leaving heat excha-nger 60 (stream 49d in_ FIG. 1, stream 49e in FIG. 6, strearm 49c¢ in FIG. 7, stream 491 in FIGS. 8 and 9, and strezam 49a in FIG. 10) reduces or elimi nates the quantity of flash vapor that may be generasted during expansion of the stream t o the operating pressure of= LNG storage tank 62. This generally reduces the specific power consumption for (oroducing ’ the LNG by eliminating the need for flash gas com pression. However, some circumstances mmay favor reducing the capital cost «of the facility by reducing wthe size of heat exchanger 60 and using flash gas compressiome or other means to dispose of any flash gas that may be= generated.

[0039] Although individual stream expansion is depicted in particular expansion devices, alternative expansion means may be employed where appropriate. Foor example, conditions may warrant work expansion of the subs-tantially condensed feed stream (stream 35a in EXIGS. 1 and 5 through 10). Further, isenthalpic flash expansiom: may be used in lieu of vwork expansion for the subcooled ligguid stream leaving heat ex changer 60 (stream 49d in FIG. 1, stream 49e in FIG. 6, stream 49¢ in FIG. 7, stream 49b in FIGS. 8 and 9, and strearn 49a in FIG. 10), but will necessitate either more subcooling _in heat exchanger 60 to avoid forming flash vapor in the expansion, or else adding flassh vapor compression or other means for disposing of the flassh vapor that results. Simil arly, isenthalpic flash expansion may be used in lieu of w-ork expansion for the subceooled high pressure refrigerant stream leaving heat exchanger 6%0 (stream 71¢ in FIGS. 1 amnd 6

NY02:408682.3 21-

through 10), with the resultant increase in the power consumption for compression of the . refrigerant=.

[0040] While there have been describesd what are believed to be preferred : embodimemnts of the invention, those skilled ir the art will recognize that other— and further modifications may be made thereto, e.g. to adapt the invention to various conditions, types of feed, or other requirements without departing from the spirit of the pressent invention a_s defined by the following claims.

NY02:408682.3 -22-

Claims

WE CLAIM:

1. Ina process for liqucfying a natural gas stream containing methmane and heavier hydrocarbon components wherein (a) said natural gas strcam is coeoled under pressure to condense at least a portion of it and form a condensed stream; and (b) said condensed stream is expanded to lower pressure to #orm said liquefied naturaal gas stream; the improvement wherein (1) said natural gas stream is treated in one or more cooling steps; (2) said cooled natural gas strearm is divided into at least a fir=st gaseous stream and a second gaseous stream; (3) said first gaseous stream is comoled to condense substantially all of it and thereafter expanded to an intermediate pressure; (4) said expanded substantially condensed first gaseous strearn is directed in heat exch ange relation with a more volatile v apor distillation streamn which rises from fractionati on stages of a distillation column ard is thereby warmed: (5) said second gaseous stream is expanded to said intermedia_te pressure; (6) said warmed expanded first gaseous stream and said expanded second gaseous strearn are directed into said distillation column wherein said streamss are separated into said moore volatile vapor distillation stream_ and a relatively less volatile fraction containing a rugjor portion of said heavier hydrocarbon components; NY02:408682.3 -23-

(7) said more volatile vapor distillatio~n stream is cooled by said expanded substantially cormdensed first gaseous stream sufficziently to partially condense i and is thereafter separated to form a volatile residue gas fraction containing a major portion of said methane an _d lighter components and a reflux stream; (8) =said reflux stream is directed into said distillation column as a top feed thereto; and ‘ (9) said volatile residue gas fraction i_s cooled under pressure to condense at least a portiora of it and form thereby said cande=nsed stream.

2. In a process for liquefying a natural gas sSstream containing methane and heavier hydrocarbon ccomponents wherein ) (a) said natural gas stream is cooled munder pressure to condense at: least a portion of it and foam a condensed stream; and \ (b) said condensed stream is expande=d to lower pressure to form said liquefied natural gas stream, i the improvement wherein (1) said natural gas stream is treated in one or more cooling steps to partially condense it; (2) said partially condensed natural gas stream is separated to provide thereby a vapor s tream and a liquid stream; (3) said vapor stream is divided into at least a first gaseous streanm and a second gaseous stream; NY02:408682.3 -24-

(4) said first gaseous stream is cooled to condensse substantially all osfit and thereafter expanded to an intermediate pressure;

(5) said expandled substantially condensed first ggaseous stream is

Alrected in heat exchange relation with a more volatile vapor distillation stream which rises from fractionation stages of a distillation column and is thereby w=armed;

(6) said second gaseous stream is expanded to s=aid intermediate

[oressure; (7) said liquid stream is expanded to said intermediate pressure; (8) said warmed expanded first gaseous stream, said expanded =second gaseous stream, and said expanded liquid stream are directed irnto said distillation ecolumn wherein said streams are sep arated into said more volatile vapcor distillation =stream and a relatively less volatile fraction containing a major portior of said heavier “hydrocarbon components;

(9) said more volatile vapor distillation stream i_s cooled by said expanded substantially condensed first gaseous stream sufficiently to oartially condense it and is thereafter separated to form a volatile residue gas fraction conta ining a major portion of said methane and lighter components and a reflux stream;

(10) said reflux stream is directed into said distillation column as a top feed thereto, and

(11) said volatile residue gas fraction is coole=d under pressure to condense at least a portion of it and form thereby said condensed streaam.

NY02:408682.3 -25-

Wd 2005/114076 PCT/US22004/012792

3. In a process for liquefy ing a natural gas stream containing methane an-d heavier hydrocarbon components wherein (a) said natural gas stream is cooled under pressure to condense at lezast a portion of it and form a condensed. stream; and SE (b) said condensed. stream is expanded to lower pressu_re to form said liquefied natural gas stream; the improvement wherein (1) said natural gas stream is treated in one or more comoling steps tom partially condense it; (2) said partially c ondensed natural gas stream is sepa rated to pmovide thereby a vapor stream and a liquid stream; (3) said vapor stream is divided into at lcast a first gaseous stream amd a second gaseous stream; (4) said first gaseous stream is combined with at least a portion of s-aid liquid stream, forming thereby a cosmbined stream; (5) said combined stream is cooled to condense subst antially all of i~t and thereafter expanded to an intermediate pressure; (6) said expanded substantially condensed combined stream is directed in heat exchange relation with a more volatile vapor distillation stresam which xises from fractionation stages of a disti Tation column and is thereby warmed; (7) said second gaseous stream is expanded to said irtermediate Foressure; ~NY02:408682.3 -26-

(8) any reemaining portion of said liquid stream is expanded to said intermediate pressure; 9) said warmed expanded combined stream, said expanded second gaseous stream, and said expanded remaining portion of said 1 iquid stream are directe=d into said distillation column wkaerein said streams are separated into said more volatile vapor distillation stream and a relatively less volatile fraction ~containing a major portion of said heavier hydrocarbon caempaonents; (10) said more volatile vapor distillation stream is cooled bys said expanded substantially condensed combined stream suffi_ciently to partially concdense it and is thereafter separated to form a volatile residue gas fraction containing a major portion of said methane and li gshter components and a reflux stream; (11) said reflux stream is directed imto said distillation colummn as a top feed thereto; and (12) said volatile residue gas fractiomn is cooled under pressmure to condense at least a portion of it and form thereby said condernsed stream.

4. In a processs for liquefying a natural gas stream containing methame and heavier hydrocarbon components wherein (a) sai«d natural gas stream is cooled under pressure to conderse at least a portion of it and form a condensed stream; and (b) sai d condensed stream is expande d to lower pressure to fom said liquefied natural gas stream, the imeprovement wherein NY02:408682.3 -27-

(1) said natural gass stream is treated in one or more cooling steps to partially condense it; (2) said partially c ondensed natural gas stream is separated to provide thereby a vapor stream and a liquid stream;

(3) said vapor stre am js divided into at least a first g=aseous stream and a second gaseous stream;

(4) said first gaseOus stream is cooled to condense smibstantially all of it and thereafter expanded to an intermediate pressure;

(5) said expanded. substantially condensed first gase-ous stream is directed in heat exchange relation with a more volatile vapor distillation st-ream which rises from fractionation stages of a distil lation column and is thereby warned;

(6) said second gaseous stream is expanded to said Hntermediate ) pressure; :

(7) said liquid stresam is cooled and thereafter dividesd into at least a first portion and a second portion;

(8) said first portion is expanded to said intermediate pressure and thereafter warmed;

(9) said second portion is expanded to said intermecliate pressure; (10) said warmed expanded first gaseous stream, said expanded second gaseous stream, said warmed expanded first portion, and said expanded second portion are directed into said distillatiors column wherein said streams are separated into NY02:408682.3 -28-

said more volatile vapor distill ation stream and a relatively lesss volatile fraction containing a major portion of said heavier hydrocarbon compoments; (11) said more volatile vapor distillatmon stream is cooled by said expanded substantially condensed first gaseous stream sufficiently to partially condense it and is thereafter separated to form a volatile residume gas fraction containing a major portion of said methane: and lighter components and a reflux stream; (12) said reflux stream is directed int=o said distillation column as a top feed thereto; and ’ (13) said volatile residue gas fractiomm is cooled under pressure to condense at least a portion of it and form thereby said condenssed stream.

5. In aprocess for liquefying a natural gas stream containing methane and heavier hydrocarbon components wherein (a) said natural gas stream is cooled un_der pressure to condense at least a portion of it and form a condensed stream; and (b) said condensed stream is expanded to lower pressure to form said liquefied natural gas stre am; the improvement wherein (1) said natural gas stream is treated in_ one or more cooling steps to partially condense it; (2) sai_d partially condensed natural gass stream is separated to provide thereby a vapor stream and a liquid stream; NY02:408682.3 -29-

(3) said vapor stream 1s divided into at lea st a first gaseous stream and a second gaseous stream;

(4) said fix-st gaseous strcam is cooled to czondense substantially all of it;

(5) said liquid stream is cooled and thereafter divided into at least a first portion and a second porti on;

(6) said fi rst portion is expanded to an instermediate pressure and thereafter warmed;

(7) said second portion is combined withm said substantially condensed first gaseous stream, forming thereby a combined stmream, whereupon said combined stream is expanded to said intermediate pressure;

(8) said expanded combined stream is directed in heat exchange relation with a more volatile vapor distillation stream which risses from fractionation stages of a distillation column mand is thereby warmed,

(9) said second gaseous stream is expan_ded to said intermediate pressure;

(10) s aid warmed expanded combine~d stream, said expanded second gaseous stream, and sai d warmed expanded first portiosn are directed into said distillation column wherein sai d streams are separated into said more volatile vapor distillation stream and a relativ=ely less volatile fraction containing a major portion of sa=3d heavier hydrocarbon componemts;

NY02:408682.3 -30-

(11) said more volatile vapor distillation stream is cooled by said expanded combined stream sufficiently to partially condense it and is thereafter separated to fosrm a volatile residue gas fraction containing a major portion of said methane and 1=ighter components and a reflux stream; (12) said reflux stream is directed into said distillation columm as a top feed thereto; and (13) said volatile residue gas fraction is cooled under pressure to condense at least a portion of it and form thereby saied condensed stream.

6. The improvement according to claim 1 wherein said distillation column is 2 1 ower section of a fractionation tower arad wherein said more volatile vap=or distillation stream is cooled sufficiently to partially condense it in a portion of said to wer above said d_istillation column and concurrently separated to form said volatile residume gas fraction and said reflux stream, whereupon said reflux stream flows to the top fractionation stage of said distillation column.

7. The improvement according to claim 2 wherein said distillation column is a_ lower section of a fractionation tower aand wherein said more volatile va_por distillation stream is cooled sufficiently to partially~ condense itin a portion of said tower above said distillation column and concurrently separated to form said volatile residue gas fractiom and said reflux stream, whereupon said reflux stream flows to the top fractionation stage of said distillation column.

8. The improvement according to claim 3 wherein said distillation column is alower section of a fractionation tower and wherein said more volatile vapor NY02:408682..3 -31-

distillation stream is Cooled sufficiently to partially conden se it in a portion of said towwer above said distillatior column and concurrently separated to form said volatile residue gas fraction and said reflux stream, whereupon said reflux stream flows to the top : fractionation stage of said distillation column. .

9. Time improvement according to claim 4 wherein said distillation column is a lower section of a fractionation tower and whe rein said more volatile vap or distillation stream is ecooled sufficiently to partially condemmse it in a portion of said to~wer above said distillatior=1 column and concurrently separated #&o form said volatile residue gas fraction and said reflux stream, whereupon said reflux stream flows to the top fractionation stage of said distillation column.

10. The improvement according to claim 5 =wherein said distillation column is a lower section of a fractionation tower and whe=rein said more volatile vap-or distillation stream is «cooled sufficiently to partially condemmse it in a portion of said to—wer above said distillatiomn column and concurrently separated ®o form said volatile residu=e gas fraction and said reflux stream, whereupon said reflux stream flows to the top : fractionation stage of= said distillation column.

11. The improvement according to claim 1 =wherein said more volatile vapor distillation stre=am is cooled sufficiently to partially condense it in a dephlegma—tor and concurrently sepaarated to form said volatile residuc ga s fraction and said reflux stream, whereupon said reflux stream flows from the dephTlegmator to the top fractionation stage off said distillation column. NY02:408682.3 -32-

12. The improvement according to claim 2 wherein said more voslatile vapor distillation stream is cooled sufficiently to partially condense it in a dephMegmator andl concurrently separated to form said volatile residue gas fraction and said re flux stream, whereupon said reflux stream flows from the dephlegmator to the top fractionation stage of said distillation colurnn.

13. The improvement accordin g to claim 3 wherein said more volatile vapor distillation stream is cooled sufficiently” to partially condense it in a deph legmator an d concurrently separated to form said volati le residue gas fraction and said re=flux stream, whereupon said reflux stream flows from the dephlegmator to the top fractionation stage of said distillation column.

14. The improvement accordin g to claim 4 wherein said more volatile va por distillation stream is cooled sufficiently” to partially condense it in a deph_legmator ame d concurrently separated to form said volatile residue gas fraction and said reflux stream, whereupon said reflux stream flows firom the dephlegmator to the top fraxctionation stage of said distillation column _

15. The improvement accordimg to claim 5 wherein said more veolatile vapor distillation stream is cooled sufficiently” to partially condense it in a dephmlegmator arad concurrently separated to form said volatile residue gas fraction and said reflux stream, whereupon said reflux stream flows firom the dephlegmator to the top fractionation stage of said distillation column .

16. The improvement accordiragto claim 1,2, 3,4, 5,6, 7, 8,9, 10,11, 12, 13, 14, or 15 wherein said volatile residue gas fraction) is compressed and there=after N'w02:408682.3 33.

cooled under pressure to cosndense at least a portion of it and fomm thereby said condensed stream.

17. The imp rovement according to claim 1,2,3, 4,5,6,7,8,9,10,11, 12, 13, 14, or 15 wherein said wolatile residue gas fraction is heated, compressed, and thereafter cooled under pre-ssure to condense at least a portion of it and form thereby said "condensed stream.

18. The improvement according to claim1,2,3.4,5,6,7,8,9,10,11, 12, 13, 14, or 15 wherein said volatile residue gas fraction contains a major portion of said methane, lighter components, and Cz components.

19. The improvement according to claim 16 wheerein said volatile residue gas fraction contains a maj or portion of said methane, lighter components, and C; components.

20. The imporoyement according to claim 17 wh.erein said volatile residue gas fraction contains a mag or portion of said methane, lighter components, and C;

. components.

21. The imgorovement according to claim 1, 2,3,4,5,6,7,8,9,10, 11, 12, 13, 14, or 15 wherein said volatile residue gas fraction contains a major portion of said methane, lighter componemts, C, components, and Cy componeats.

22. The imgprovement according to claim 16 wihnerein said volatile residue gas fraction contains a major portion of said methane, lighter ccomponents, Cp components, and C3 compwonents. NY02:408682.3 -34-

23.The improvement according to claim 17 wherein said voRatile residue gas fr-action contains a major portion of said methane, lighter components, (_; comp onents, and C3 components.

24. An apparatus for the liquefaction of a natural gas stream containing methane and heavier hydrocarbon components, which includes © (1) one or more first heat exchange means to receives said natural gas s=tream and cool it under pressure; (2) dividing means connected to said first heat exch=ange means to receive said cooled natural gas stream and divide it into at least a first gase=ous stream and a seccond gaseous stream; | ] (3) second heat exchange means connected to said dividing means to resceive said first gaseous stream and to cool it sufficiently to substantia_lly condense it; (4) first expansion means connected to said second heat exchange means to receive said substantially condensed first gaseous stream and expand it to an intesrmediate pressure; (5) third heat exchange means connected to - fixr—st expansion means to receive said expanded substantially condensed first gaseous sire=am and heat it, sai third heat exchange means being further connected to a distillation ceolumn to receive a more volatile vapor distillation stream rising from fractionation stages Of said dis tillation column and cool it sufficiently to partially condense it; (6) second expansion means connected to said dividing means to receive said second gaseous stream and expand it to said intermediate precssure; NY 02:408682.3 -35-

(7) said distillation column being further connected to said third heat exchange re eans and said second expansion means to receive said heated expande~d first gaseous strezam and said expanded second gaseous stream, with said distillation column adapted to separate said streams into said more —volatile vapor distillation streamm and a relatively Bess volatile fraction containing a major portion of said heavier hydrocarbon cormaponents;

(8) separation means connected teo said third heat exchange means to receive said cooled partially condensed distillation staream and separate it into a vola_tile residue gas fraction containing a major portion of said nethane and lighter componentss and a reflux strezam, said separation means being further connected to said distillation column to direct said reflux stream into said distillation column as a top feed thereto;

(9) fourth heat exchange means c¢ onnected to said separation means to receives said volatile residue gas fraction, with said fourth heat exchange meamns adapted to cool said volatile residue gas fraction under pressure to condense at leasta portion of it and form thereby a condensed stream;

(10) third expansion means cormected to said fourth heat exchange means to receive said condensed stream and expand it to lower pressure to fom said liquefied na-tural gas stream; and

(11) control means adapted to megulate the quantities and temperatures of ssaid feed streams to said distillation colwimn to maintain the overhead temperature of szid distillation column at a temperature “whereby the major portion of said heavier hydrocarbon components is recovered in said relatively less volatile fraction.

NY02:408682.3 -36-

25s.

An apparatus for the liquefactior of a natural gas stream c-ontaining methane and heavier hydrocarbon components, which includes

(1) one or more first heat exchange means to receive ssaid natural gas stream and ccool it under pressure sufficiently to partially condense it;

(2) first separation means cosnnected to said first heat -exchange Tneans to receive said partially condensed natural gzas stream and separate it Tinto a vapor stream and a liqumid stream;

(3) dividing means connected to said first separation neans to receive said vapor stream and divide it into at least a first gaseous stream aned a second gaseous stream; :

(4) second heat exchange m-eans connected to said diwiding means to receive said fi rst gaseous stream and to cool it suafficiently to substantially condense it;

(5) first expansion means connected to said second he=at exchange means to receive= said substantially condensed first gaseous stream and expand it to an intermediate pre=ssure;

(6) third heat exchange mea ns connected to said first expansion means to receives said expanded substantially cond ensed first gaseous strean— and heat it,

: said third heat e=xchange means being further connected to a distillation colummn to receive a more volatile \apor distillation stream rising frorm fractionation stages of ssaid distillation colur-nn and cool it sufficiently to partially condense it;

(7) second expansion means connected to said dividimng means to receive said second gaseous stream and expand it #0 said intermediate pressmure; NY02:408682.3 -37-

(8) third expan sion means connected to said firsst separation means to receive said liquid stream and expand it to said intermediate pressume;

(9) said distillation column being further connected to said third heat cxchange means, said second expansion means, and said third expansion means to receive said heated expanded first gas eous stream, said expanded seco nd gaseous stream, and said expanded liquid stream, with. said distillation column adapted® to separate said streams into said more volatile vapor distillation stream and a relatively less volatile fraction containing a major portion of said heavier hydrocarbon compOnents;

(10) second separation means connected to said third heat exchange means to receive said cooled partially condensed distillation stream and separate it into a volatile residue gas faraction containing a major portio=n of said methane =and lighter components and a reflux stream, said second separation me=ans being further econnected to said distillation column to direct said reflux stream into s=aid distillation

«olumn as a top feed thereto;

(11) fourth heat exchange means connected to said second separation means to receive said volati le residue gas fraction, with said_ fourth heat : B exchange means adapted to cool said volatile residue gas fraction undem pressure to condense at least a portion of it and form thereby a condensed stream;

(12) fourth expansion means connected to said fourth heat exchange means to receive said conderased stream and expand it to loweer pressure to form ssaid liquefied natural gas stream; and NIY02:408682.3 -38-

WOB 2005/114076 PCT/US2004/012792 (13) control means adapted to regulate the quantities and tem peratures of said feed streams to sa-id distillation column to maint:ain the overhead tem perature of said distillation column at a temperature whereby the “major portion of said heavier hydrocarbon components fis recovered in said relatively Bess volatile fraction.

26. An apparatus for thes liquefaction of a natural gas sstream containing methane and heavier hydrocarbon components, which includes (1) one or more first heat exchange means to receive said natural gas stream and cool it under pressure stafficiently to partially condens= ¢ it; (2) first separation means connected to said firast heat exchange means {o receive said partially condens ed natural gas stream and sepamrate it into a vapor strezam and a liquid stream; (3) dividing means connected to said first sepamration means to rece ive said vapor stream and divide it #Ento at least a first gaseous stre=am and a second gase=ous stream; (4) combining meeans connected to said dividin-g means and to said first separation means to receive said fir-st gaseous stream and at least a portion of said liqui_d stream and form thereby a combimed stream; (5) second heat exchange means connected to s-aid combining meams to receive said combined stream and to cool it sufficiently to sumbstantially condlense it; NY02:<408682.3 -39-

(6) first expansion means connected to said second heat exchange means to receive said subsstantially condensed combined stream and expand it to an intermediate pressure; (7p third heat exchange means connected to said first expansion means to receive said expanded substantially condensed combined stream and heat it, said third heat exchange mmeans being further connected to a distillation column to receive a more volatile vapor distillation stream rising from fractionation stages of said distillation column and cool it sufficiently to partially condense it;

(8) second expansion means connected to said dividing means to receive said second gasecus siream and expand it to said intermediate pressure;

© (9) third expansion means connected to said first separation means to receive any remaining portion of said liquid stream and expand it to said intermediate pressure;

(10) said distillation column being further connected to said third heat exchange meas, said second expansion means, and said third expansion means to receive said heated exppanded combined stream, said expanded second gaseous stream, and said expanded remairaing portion of said liquid stream, with said distillation column

’ adapted to separate said streams into said more volatile vapor distillation stream and a relatively less volatile fraction containing a major portion of said heavier hydrocarbon components;

(11) second separation means connected to said third heat exchange means to receive said cooled partially condensed distil3ation stream and NY02:408682.3 -40-

separate it into a volatile residue gas fraction containing a major portion of said methane and lighter components and a reflux stream, said second separation meamns being further connected to said distillation column t-o direct said reflux stream into said distillation column as a top feed thereto; (12) fourth meat exchange means connected to said second separation means to receive said volatile residue gas fraction, with said —fourth heat exchange means adapted to cool said volatile residue gas fraction under pressure to condense at least a portion of it and form thereby a condensed stream; (13) fourth expansion means connected to saidl fourth heat exchange means to receive said condensed stream and expand it to lower pressure to form said liquefied natural gas siream; and (14) control means adapted to regulate the qua ntities and temperatures of said feed streams to said distillation column to maintairm the overhead temperature of said distillation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered in said relatively les s volatile fraction.

27. An apparatus for the liquefaction of a natural gas stream containing methane and heavier hydrocarbon commponents, which includes (1) one or mor e first heat exchange means to recesive said natural gas stream and cool it under pressure sufficiently to partially condense it; (2) first separa tion means connected to said first heat exchange means to receive said partially condemsed natural gas stream and separamte it into a vapor strearn and a liquid stream; NY02:408682.3 -41-

wWVO 2005/114076 PCT/US 2004/012792

(3) second heat exchange means connected to said firs€ separation means to receive said liquid stream and cool it;

(4) first dividing means connected to said second heat exchange neans to receive said cooled liquid stream and divide it into at least a first poTtion and a second portion;

(5) first expansion means connected to said first dividing means to resceive said first portion and expand it ®o an intermediate pressure, said first exparnsion means being further connected to supply said expanded first portion to said second heat exchange means, thereby heating said expanded first portion while cooling said liquid s dream;

(6) second dividing means connected to said first sepaxation means to receive said vapor stream and divide it into at least a first gaseous stream and a second gzaseous stream,

(7) third heat exchange means connected to said second dividing means to receive said first gaseous stream and to cool it sufficiently to substantially c-ondense it;

(8) second expansion means connected to said third hesat exchange means to receive said substantially conclensed first gaseous stream and expamd it to said imntermediate pressure;

(9) third expansi on means connected to said second dividing means to receive said second gaseous stream and expand it to said intermediate pressure; NIY02:408682.3 -42-

(10) fourth expansion means connected to said first dividingg, means to receives said second portion and expand it to said intermediate pressure;

(11) fourth heat exchange me=ans connected to said second expansion meanss to receive said expanded substantial ‘1y condensed first gaseous stream and heat it, said fourth heat exchange means being further connected to a distillation

: column to receive a more volatile vapor distillation stmream rising from fractionation / stages of said distillation column and cool it sufficiently to partially condense it;

(12) said distillation column being further connected to said fourth heat exchange means, said third expansion meamns, said fourth expansion mears, and said second Theat exchange means to receive said Eneated expanded first gaseous stream, said expanded second gaseous stream, said expanded second portion, and sai d heated expanded first portion, with said distillation co lumn adapted to separate said streams into saidl more volatile vapor distillation streamn and a relatively less volatile fraction containing a major portion of said heavier hycirocarbon components;

(13) second separation mean s connected to said fourth heat exchange means to receive said cooled partially condensed distillation stream and separate it into a volatile residue gas fraction containizag a major portion of said meth_ane and lighter components and a reflux stream, said secomnd separation means being furtliner connected to saicd distillation column to direct said ref Aux stream into said distillation column as a top feed thereto;

(14) fifth beat exchange mea ns connected fo said second separation means to receive said volatile residue gas faraction, with said fifth heat NY02:408682.3 43-

exchange mmeans adapted to cool said volatile residue gas fraction under pressure to condense at least a portion of it and form therezby a condensed stream; (15) fifth expansion mmeans connected to said fifth heat «xchange means to receive said condensed stream and expand it to lower pressure to form said liquefied natural gas stream; and (16) control means adapted to regulate the quantities armd temperatumres of said feed streams to said disti lation column to maintain the ovemrhead temperatumre of said distillation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered in said relatively less volatiles fraction.

28. An apparatus for the liquefaction of a natural gas stream containing methane =and heavier hydrocarbon component=s, which includes (1) one or more first heat exchange means to receive said natural gas strearm and cool it under pressure sufficiemntly to partially condense it; (2) first separation means connected to said first heat exchange means to receive said partially condensed natural gas stream and separate it into a vapor stream amd a liquid stream; : (3) second heat excharage means connected to said first separation means to receive said liquid stream and cool It; (4) first dividing meams connected to said second heat ex«change means to receive said cooled liquid stream ard divide it into at least a first portion and a second portion; © NY02:40868 2.3 4-4 receive said first portion and expand it to an intermediate pressure, saied first expansion mezans being further connected to supply said expanded first portion to- said second heat exchhange means, thereby heating said expanded first portion while cooling said liquid stream; :

(6) second dividing means connected to said firsst separation means to receive said vapor stream and divide it into at least a first gaseous stmream and a second gase=ous stream,

(7) third heat exchange means connected to said second dividing means to receive said first gaseous sireadm and to cool it sufficiently to substantially condense it;

(8) combining means connected to said third heat exchange means : and t=o said first dividing means to receivre said substantially condensed first gaseous strea—m and said second portion and formu thereby a combined stream;

(9) second expansion means connected to said co=mbining means to recei—ve said combined stream and expand it to said intermediate pressure;

(10) third exparasion means connected to said s econd dividing meanas to receive said second gaseous stream and expand it to said interrmediate pressure;

(11) fourth heat exchange means connected to ssaid second exparsion meaus to receive said expanded combined stream and heat it, said fourth heat exchamnge means being further connected to a distillation column to recei_ve a more NY(2:4C08682.3 45-

volatile vapor distillation stream rising from fractionation stages of said distillation ‘column and cool it stafficiently to partially condense it;

(12) said distillation column berg further connected to said fourth heat exchange= means, said third expansion means, and said second heat exchange means to reccive saicl heated expanded combined stream, said expanded second gaseous strcam, and said heatzed expanded first portion, with said clistillation column adapted to separate said streamss into said more volatile vapor distillation stream and a relatively less volatile fraction cont aining a major portion of said heaviex hydrocarbon components;

(13) second separation means co-mnected to said fourth heat exchange means to receive said cooled partially condense d distillation stream and separate it into a volzatile residue gas fraction containing a major portion of said methane and lighter componemnts and a reflux stream, said second s eparation means being further connected to said dis tillation column to direct said reflux stream into said distillation column as a top feed thereto;

(14) fifth heat exchange means connected to said second separation means to receive said volatile residue gas fraction, with said fifth heat exchange means adagpoted to cool said volatile residue gas fraction under pressure to condense at least a portion of it and form thereby a condersed stream;

(15) fourth expansion means coranected to said first fifth exchange means to receive said condensed stream and expand it to lower pressure to form said liquefied natural. gas stream; and NY02:408682.3 -46-

(16) control means adapted to regulate the quantities and temperatures of said feed streams to said distillation =column to maintain the over=head temperature of said distillation column at a temperature whereby the major portion of said heavier hydroca-rbon components is recovered ir said relatively less volatile fraction.

29. Tne apparatus according to claim 24 wherein (1) said distillation column is —a lower section of a fractionation tower and wherein said more volatile vapor distillation stream is cooled sufficien tly to partially condense it in a section of said fractionatiorm tower above said distillatiom column and concurre=ntly separated to form said vola=tile residue gas fraction and =said reflux stream, wherewupon said reflux stream flows to the top fractionation stage of said - distillation column; sand (2) said fourth heat exchange rmeans is connected to said fractionation tower to receive said volatile residue gas fraction, with said fourth ha eat exchange means adapted to cool said volatile residue gas fraction under pressure to condense at least a portion of it and form thereby said condensed stream.

30. Thme apparatus according to claim 25 wherein (1) said distillation column is = lower section of a fractionation tower and wherein sa—id more volatile vapor distillatiomn stream is cooled sufficiently to partially condense it i na section of said fractionation tower above said distillatiorm column and concurremtly separated to form said volat -le residue gas fraction and ssaid reflux stream, whereumpon said reflux stream flows to the top fractionation stage of said distillation column; amnd NY02:408682.3 -47-

(2) said fourth heat exchange means is connected to said fractionation tower to receive said volatile residue gas fi-action, with said fourth heat exchange mcans adapted to cool said volatile residue gass fraction under pressure to condense at least a portion of it and form thereby said cosndensed stream.

31. "The apparatus according to claim 26 wherein : (1) said distillation column is a lower section of a fractionation tower and wherein said more volatile vapor distillation stream is cooled sufficiently to partially condense Xt in a section of said fractionation tovver above said distillation column and concurrently separated to form said volatile —residue gas fraction and said reflux stream, whereupon said reflux stream flows to the top fractionation stage of said distillation columns and (2) said fourth heat exchange means is connected to said fractionation tower to receive said volatile residue gas fraction, with said fourth heat exchange means ad apted to cool said volatile residue gass fraction under pressure to condense at least a portion of it and form thereby said coondensed stream.

32. The apparatus according to claim 27 wherein (1) said distillation column is a lower section of a fractionation tower and wherein said more volatile vapor distillation stream is cooled sufficiently to partially condense it in a section of said fractionation tower above said distillation column and concurrently separated to form said volatile residue gas fraction and said reflux stream, whereupon said reflux stream flows to the top fractionation stage of said distillation column; and NY02:408682.3 -48-

(2) said fifth heat exchange means is conanected to said fractionation tower to receive s=aid volatile residue gas fraction, with said fifth heat exchange means adapted to cool said volatile residue gas fracticon under pressure to condense at least a portion of it: and form thereby said condensed stream.

33. The apparatwis according to claim 28 whereixa (1) said -distillation column is a lower seaction of a fractionation tower and wherein said more v olatile vapor distillation stream ms cooled sufficiently to partially condense it in a section of said fractionation tower above said distillation column and concurrently separated to form said volatile residuee gas fraction and said reflux stream, whereupon said reflux stream flows to the top fractionation stage of said distillation column; and (2) said fifth heat exchange means is comnnected to said fractionation tower to receive said volatile residue gas fraction_, with said fifth heat exchange means adapted to coeol said volatile residue gas fracti_on under pressure to - condense at least a portion of i t and form thereby said condens-ed stream.

34. The apparatus according to claim 24 wherei said apparatus includes (1) a dephlegmator connected to said first expansion means to receive said expanded substantially condensed first gaseous str—eam and heat it, said * dephlegmator being further co nnected fo said distillation colurmn to receive said more volatile vapor distillation strezmm and cool it sufficiently to par@ially condense it and concurrently separate it to fortm said volatile residue gas fractieon and said reflux stream, said dephlegmator being furth er connected to said distillation ecolumn to supply said NY02:408682.3 49.

heated expanded first gaseous stream as a feed thereto and said reflux stream as a top feed thereto; and (2) said fourth heal exchange means con nected to said - dephlegmator to receive said volatile residue gas fraction, with said fourth heat exchange means adapted to cool said volatile residue gas fraction under pressure to condense at least a portion of it and Horm thereby said condensed stream.

35. The apparatus according to claim 25 whereim said apparatus includes (1) a dephlegmator connected to said first expansion means to receive said expanded swibstantially condensed first gaseous str eam and heat it, said dephlegmator being furt-her connected to said distillation colunan to receive said more volatile vapor distillation stream and cool it sufficiently to partially condense it and concurrently separate it to form said volatile residue gas fracticen and said reflux stream, said dephlegmator being further connected to said distillation column to supply said heated expanded first gaseous stream as a feed thereto and said. reflux stream as a top feed thereto; and ] (22) said fourth heat exchange means comnected to said dephlegmator to receives said volatile residue gas fraction, with said fourth heat exchange means adapted to cool s aid volatile residue gas fraction under pressure to condense at least a portion of it and form thereby said condensed stream.

36. The apparatus according to claim 26 whereim said apparatus includes (1) a dephlegmator connected to said firsst expansion means to receive said expanded swbstantially condensed combined strearn and heat it, said NY02:408682.3 -50-

dephlegma tor being further connected to said distillation column to receive sad more volatile vagpor distillation stream and cool it su fficiently to partially condense Et and concurrent ly separate it to form said volatile residue gas fraction and said refhiax stream, said dephlesgmator being further connected to said distillation column to supply said : heated exp anded combined stream as a feed thereto and said reflux stream as = top feed thereto; an-d (2) said fourth heat exchange means connected to said dephlegmamtor to receive said volatile residue g=as fraction, with said fourth heant exchange means adagpted to cool said volatile residue gass fraction under pressure to conciense at least a porttion of it and form thereby said conclensed stream.

37. The apparatus according to claim 27 wherein said apparatus includes (1) a dephlegmator connected to said second expansion means to : receive sai-d expanded substantially condensed. first gaseous strearn and heat it_, said dephlegmamtor being further connected to said clistillation column to receive samd more volatile vagpor distillation stream and cool it sufficiently to partially condense i_t and concurrent ly separate it to form said volatile ressidue gas fraction and said reflumx stream, said dephlesgmator being further connected to ssaid distillation column to supply said heated exp anded first gaseous stream as a feed thereto and said reflux stream asa top feed thereteo; and (2) said fifth heat exchaxge means connected to said degohlegmator to receive ssaid volatile residue gas fraction, with said fifth heat exchange mearns adapted NY02:408682.3 -51—

to cool saicl volatile residue gas fraction under presssure to condense at least a portion of it and form thereby said condensed stream.

38. The apparatus according to claimm 28 wherein said apparatus includes (1) a dephlegmator connected to said second expaunsiomn means {o receive saied expanded combined stream and heat int, said dephlegmator being further connected to said distillation column to receive said more volatile vapor disti lation stream and. cool it sufficiently to partially condensee it and concurrently separzate it to form said volatile residue gas fraction and said reflux stmream, said dephlegmator be=ing further connected to said distillation column to supply saied heated expanded combineed stream as a feed theresto and said reflux stream as a top feed sthereto; and (2) said fifth heat exchange means connected to said deephlegmator to receive said volatile residue gas fraction, with szaid fifth heat exchange means adapted to cool sail volatile residue gas fraction under presssure to condensc at least a portion of it and form thereby said condensed stream.

39. The apparatus according to claimm 24 wherein said apparatias includes (1) compressing means conmaected to said separating means to receive said volatile residue gas fraction and comp ress it; and (2) said fourth heat exchang_e means connected to said compressirg means to receive said compressed voMatile residue gas fraction, \vith said fourth heat exchange means adapted to cool said coompressed volatile residue gas fraction under pressure to condense at least a portion of it a_nd form thereby said condensed stream. NY02:408682.3 -52-

40_ The apparatus according to claim. 25 or 26 wherein said apparatus includes (1) compressing means conne=cted to said second separating mraeans to receive said vo latile residue gas fraction and compress it; and (2) said fourth heat exchange= means connected to said compressing mea_1s to receive said compressed volatile residue gas fraction, with sa®d fourth heat excha nge means adapted to cool said compressed volatile residue gas fra ction under pressure to condense at least a portion of it arad form thereby said condensed stream.

41_. The apparatus according to clair 27 or 28 wherein said apparatus includes (1) compressing means conn ected to said second separating maeans to receive said volatile residue gas fraction and compress it; and (2) said fifth heat exchange rmeans connected to said compressing means to receive said compressed volatile residue gzas fraction, with said fifth heat exchange means adapted to cool said compressed volatile residue gas fraction under pressure to condeense at least a portion of it and forrn thereby said condensed stream. .

422. The apparatus according to clairm 29, 30, or 31 wherein said appaaratus includes (1) compressing means contested to said fractionation tower to receive said volaatile residue gas fraction and comparess it; and : NY02:408682.3 -53-

(2) said fourth heat exchange means connected tos said compre=ssing means to receive said compressed volatile residue gas fraciion, with said fourth Ineat exchange means adapted to cool said compressed volatile ressidue gas fraction under poressure to condense at least a portion of it and form thereby said condensed stream. .

43. The apparatus accordimng to claim 32 or 33 wherein said apparatus include=s (1) compressing means connected to said fractiormation tower to receives said volatile residue gas fraction sand compress it; and (2) said fifth heat eexchange means connected to s aid compressing means “to receive said compressed volatiles residue gas fraction, with sai fifth heat exchan_ge means adapted to cool said compressed volatile residue gas freaction under pressur—e to condense at least a portion of it and form thereby said condemnsed stream.

44. The apparatus accordixg to claim 34, 35, or 36 where=in said apparatus includess (1) compressing mm eans connected to said dephleg=mator to receive said volatile residue gas fraction and commypress it; and (2) said fourth heat exchange means connected to said compressing means to receive said compressed volatile residue gas fraction, with said ‘ fourth 1 aeat exchange means adapted to coool said compressed volatile residue gas fraction under peressure to condense at least a portion of it and form thereby said condensed streain. NY02:408a6582.3 -54-

45. The apparatus according to claim 37 or 38 wherein sail apparatus includes (1) compressing means connected to said dephlegnator to receive said volatile residue gas fraction and compress it; and (2) said fifth heat exchange means connected to sa®d compressing means to receive said compressed volatile residue gas fraction, with said fifth heat exchange means adapted to cool said compressed volatile residue gas fraction under pressure to condense at least a portion of it and form thereby said conden_sed stream.

46. The apparatus according to claim 24 wherein said apparatus includes (1) heating means connected to said separation me=ans to receive said volatile residue gas fraction and heat it; (2) compressing means connected to said heating mmeans to receive said heated volatile residue gas fraction and compress it; and (3) said fourth heat exchange means connected to said compressing means to receive said compressed heated volatile residue gaas fraction, with said fourth heat exchange means adapted to cool said compressed heated volatile residue - gas fraction under pressure to condense at least a portion of it and form thereby said condensed stream.

47. The apparatus according to claim 25 or 26 wherein samid apparatus includes (1) heating means connected to said second separation means to receive said volatile residue gas fraction and heat it; NY02:408682.3 -55-

(2) compressing means conneected to said heating means to receive said heated volati le residue gas fraction and compre=ss it; and (3) said fourth heat exchange= means connected to said compressing meamns to receive said compressed heated volatile residue gas fracCion, with said fourth heat em<change means adapted to cool said compressed heated volatile residue gas fraction under— pressure to condense at least a po=rtion of it and form thereby said condensed stream .

48. The apparatus according to claim 27 or 28 wherein said appamratus includes (1) heating means connected so said second separation m eans to receive said volati le residue gas fraction and heat it; (2) compressing means conne cted to said heating means €o receive said heated volatilee residuc gas fraction and compresss it; and (3) said fifth heat exchange means connected to said compressing means to receive s=aid compressed heated volatile res ddue gas fraction, with said fifth heat exchange means aclapted to cool said compressed hezated volatile residue gas fraction under pressure to c=ondense at least a portion of it andl form thereby said condensed stream.

49. "The apparatus according to claim 229, 30, or 31 wherein said agpparatus includes (1) heating means connected tO said fractionation tower to receive said volatile residues gas fraction and heat it; NY02:408682.3 -56- )

(2) compressing means connected to said heating means to receive said heated volatile residue gas fraction and compress it; and (3) said fourth heat excharage means connected to said compressin_g means to receive said compressed heated volatile residue gas fraction, with said fourth heat exchange means adapted to cool said compressed heated volatile _residue gas fractiorm under pressure to condense at least a portion of it and form thereby said condensed stream.

50. The apparatus according to clawim 32 or 33 wherein said appara tus includes (1) heating means connected to said fractionation tower to mreceive said volatiles residue gas fraction and heat it; (2) compressing means coranected to said heating means to receive said heated volatile residue gas fraction and compress it; and (3) said fifth heat exchanges means connected to said compr-essing means to receive said compressed heated volatile residue gas fraction, with said fisfth heat exchange m_eans adapted to cool said compressed heated volatile residue gas fracti_on : under pressure to condense at least a portion of it -and form thereby said condensed stream. | .

51. The apparatus according to claim 34, 35, or 36 wherein said apparatus includes (1) beating means connected to said dephlegmator to receives said volatile resiciue gas fraction and heat it; NY02:408682.3 -57-

(2) compressing means commnected to said heating meeans to receive said heated volatile residue gas fraction and compress it; and (3) said fourth heat excharmge means connected to samid compressirag means to receive said compressed heated volatile residue gas fraction, with said fourth heat exchange means adapted to cool said compressed heated volatile residue gas fractiomn under pressure to condense at least a portion of it and form the=reby said condensed stream.

52. The apparatus according to claim 37 or 38 wherein said apparatus includes (1) heating means connecte=d to said dephlegmator tO receive said volatile res idue gas fraction and heat it; (2) compressing means corinected to said heating me=ans to receive said heated volatile residue gas fraction and compress it; and (3) said fifth heat exchange means connected to said. compressing means to re=ceive said compressed heated volatile residue gas fraction, with said fifth heat exchange means adapted to cool said compressed heated volatile residue gams fraction under presssure to condense at least a portion of it and form thereby said corndensed stream.

53. The apparatus according to claim 24, 25, 26, 27, 28, 29, 230, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 46 wherein said volatile residue gas fraction conta ins a major portion of s=aid methane, lighter components, and &C; components. NY02:408682.3 _58-

54. The apparatus according to clazim 40 wherein said volatile resiclue gas fraction contains a major portion of said methane ,, lighter components, and C,; COMpODErnts.

55. The apparatus according to clamim 41 wherein said volatile resisdue gas fraction contains a major portion of said methane=, lighter components, and C; componerts.

56. The apparatus according to claim 42 wherein said volatile resi due gas fraction ceontains a major portion of said methane, lighter components, and Cz componerts.

57. The apparatus according to cleaim 43 wherein said volatile resi due gas fraction c-ontains a major portion of said methane, lighter components, and C, componemts.

58. The apparatus according to claim 44 wherein said volatile resmdue gas fraction ¢ ontains a major portion of said methane, lighter components, and C; componemts.

59. The apparatus according to claim 45 wherein said volatile residue gas - fraction c-ontains a major portion of said methane, lighter components, and C; componcts.

G60. The apparatus according to claim 47 wherein said volatile residue gas fraction ccontains a major portion of said methanes, lighter components, and C; compone=nts. NY02:40868=2.3 -59-

61. The apparatus according to claim 48 wherein said volawtile residue gas fraction contains a major portion of said meth ane, lighter components, aned C; compone=nis. }

62. The apparatus according to claim 49 wherein said volatile residuc gas fraction econtains a major portion of said methane, lighter components, ancl Cz components.

63. The apparatus according to claim 50 wherein said volatile residue gas fraction contains a major portion of said methane, lighter components, anc C; compone=nts.

64. The apparatus according to claim 51 wherein said volat-ile residue gas fraction contains a major portion of said metheare, lighter components, andl C, compone=nts.

65. The apparatus according to «claim 52 wherein said volatmile residue gas fraction contains a major portion of said metha ne, lighter components, and C; components.

66. The apparatus according to claim 24, 25, 26, 27, 28,29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 46 wherein said volatsle residue gas fraction cont=ains a major portion oF said methane, lighter components, C 5 components, and C; comp onents.

67. The apparatus according to claim 40 wherein said volatile residue gas fraction ceontains a major portion of said methame, lighter components, C, ccomponents, and Cs components. NY02:408682. 3 -60-

68. The apparatus according to clain—1 41 wherein said volatile residue gas fraction contains a major portion of said methane, 1-ighter components, C; compone=nts, and C3 components. ’ 69. The apparatus according to clainra 42 wherein said volatile residiac gas fraction contains a major portion of said methane, lighter components, C; components, and C3 components.

70. The apparatus according to claim 43 wherein said volatile residue gas fraction contains a major portion of said methane, 1i_ ghter components, C; compone=nts, \ and C3; components.

71. The apparatus according to claim 44 wherein said volatile residue gas fraction contains a major portion of said methane, li_ghter components, C; components, and C; components.

72. The apparatus according to claim 45 wherein said volatile residue gas fraction contains a major portion of said methane, lighter components, C; componemnts, and Cs; co mponents.

73. The apparatus according to claim 47 wherein said volatile residues gas fraction contains a major portion of said methane, lighter components, C; componerts, and C; coanponents.

74. The apparatus according to claim 48 wherein said volatile residue gas fraction contains a major portion of said methane, ligehter components, C; componemts, and C3 cormponents. NY02:408682.3 61-

75. Thee apparatus according to claim 4% wherein said volatile residume gas fraction contains a major portion of said methane, lighater components, C; compone=nts, and C; components.

76. Th_e apparatus according to claim 5%0 wherein said volatile residue gas fraction contains a maajor portion of said methane, lighmter components, C; components, and Cs components.

77. Thee apparatus according to claim 5 1 wherein said volatile residue gas fraction contains a major portion of said methane, Lighmter components, C2 componests, and C; components.

78. Th_e apparatus according to claim 572 wherein said volatile reside gas fraction contains a major portion of said methane, lighmter components, C, components, and C3; components. NY02:408682.3 -62-