SA02230280B1 - Liquefaction Natural gas - Google Patents

Abstract

Abstract: The present invention relates to a process for the liquefaction of natural gas in combination with the production of a liquid stream that predominantly contains hydrocarbons heavier than methane. In the process, the natural gas stream to be liquefied is partially cooled, expanded to medium pressure and fed to a distillation column. The bottom product of this distillation column should preferably contain the largest amount of any hydrocarbons heavier than methane that might otherwise reduce the purity of the LNG. The remaining gas in the distillation column is compressed to a higher intermediate pressure, cooled under pressure to condense, and then expanded to a lower pressure to form the LNG stream.

Description

Y

Naturali j= Liquified Natural Gas Full Description This invention relates to a process for processing natural gas or other gaseous streams rich in methane containing high purity methane and liquefied natural gas (LNG) stream to produce liquid natural gas It predominantly contains hydrocarbons heavier than methane. The applicants of this application claim (e) 116 to the US Code of Law; Paragraph YO with the benefits stated in Title No. 0 of the provisional US patent application serial number 10/797,8544 filed on the 8th pVer) of June of

Sle Natural gas is usually extracted from wells drilled in underground reservoirs. It contains a large percentage of methane. That is, the mechane constitutes at least 750 moles of gas. Depending on the specific underground reservoir; Natural gas also contains relatively lower amounts of 0; butanes; propane compounds; propane ethane ethane Jie Ja hydrocarbons ; Nitrogen hydrogen and the like in addition to water ¢ hydrogen pentanes pentane compounds and other gases. carbon dioxide carbon dioxide ¢ nitrogen Most of the natural gas is used in the gaseous state. The most widely used means of transporting natural gas from the main source to the gas processing units and then to the natural gas consumers1 is the high-pressure gas transmission pipelines. However, it was found in several cases that it was natural gas, either for transportation or use. And very little is found in the necessary and/or desirable AL. Remote locations eg pipeline infrastructure that allows convenient transportation of natural gas to market Very low specific volume of liquefied natural gas dail In cases like this compared to natural gas in the gaseous state can reduce transportation costs by enabling the transportation of natural gas Liquefied _- “0 using cargo ships and transport trucks. In another case; It is preferable to liquefy natural gas for use as fuel for cars. And in the major metropolitan areas; There are convoys of buses; Taxis and trucks that can

. Jai by liquefied natural gas if an economic source of liquefied natural gas is available. Such LNG-fueled vehicles generate much less air pollution due to the clean-burning property of natural gas compared to similar vehicles with gasoline and diesel engines that burn higher molecular weight hydrocarbons0 In addition; if 0 is high purity natural gas (i.e. a methane purity of 798 moles or higher); The amount of carbon dioxide produced (“JF gas (ds”) is much the result of the lower carbon to hydrogen ratio of methane than that of all other hydrocarbon fuels. General description of the invention The present invention generally relates to the liquefaction of natural gas with the production of a liquid stream containing primarily 0 Hydrocarbons heavier than methane as a co-product such as natural gas liquids (NGL) consisting of ethane; propane; butane compounds and hydrocarbon components heavier liquefied petroleum gas (LPG) liquefied petroleum gas consisting of propane; butane compounds and hydrocarbon components Ji or a flaky substance consisting of butane compounds and hydrocarbon components aay is more difficult to produce a liquid-stream co-product with two important benefits: the high methane-0 purity of the resulting LNG and the value of the liquid co-product as it can be used for other purposes An approximate molar percentage of a natural gas stream to be treated according to the present invention is represented by an approximate molar percentage of 785.7 for methane, 797.9 for ethane and other ©2carbonate components, and 76.4 for propane and other ©3carbonate components; 71.0 for isobutane; 72100 “iso-butane for ordinary butane; 70.8 for pentane compounds and compounds of higher molecular weight Yo ; With nitrogen and carbon dioxide representing the remainder of the percentage. Sometimes there are sulfur-containing gases. There are many known ways to liquefy natural gas. See, for example, Adrian J. Finn + Grant L. Johnson.

Johnson and Terry R. Tomlinson Terry 1. in a paper titled 'LNG Technology for Offshore and Midstream Industrial Units Yo Gall' Presented in Minutes of the 79th Annual Conference of the Gas Processors Association + 00-471 Atlanta Atlanta, Georgia, Ga, in the period between March 11 and 15 of the year 1000 A.D. What was reported by Kikkawa ¢ Yoshitsugi ¢ Masaaki Yoyo

¢

Masaaki Ohishi and Noriyoshi Nozawa in a paper entitled “Power Grid Optimization for an AL ene-based LNG Unit”; Presented in the minutes of the sessions of the 80th Annual Conference of the Gas Handlers Association; San Antonio 580; Texas in the paragraph between March 11 to VE of the year 1100 AD to review a number of these 0 operations. as cel pa ai US Patent Nos. 6,446,511 ¢£,0Y0,1A0 6 bar armfaar; 1l (¢0,Y4), mf 1 aram tarm 0,144,479 (0,T0),Y14 ¢0,110,01) amard €,A19 €0,AAF,YVE 61,01 not below (a) T,YVY,AAY ec) 1,Y14,100 sq) Ye Yee 1,170,108 4 FAO) ab; LYYEATY APP and 2,757,077 APP related operations. These Ve methods generally involve steps in which natural gas is purified (by removing water and irritating compounds such as carbon dioxide and sulfur compounds), cooled, condensed and expanded. The steps of cooling and condensation of natural gas can be accomplished by several different methods. The "cascade cooling" method uses the heat exchange of natural gas with several refrigerants with lower boiling points in the form of alate, such as propane; Ichan and methane. Yay from that; This heat exchange can be accomplished by using a single Ve refrigerant vaporized at different Bae values of pressure. The "multicomponent refrigeration" method uses the heat exchange of natural gas with one or more refrigerants consisting of several Gla refrigerants instead of Bae single component refrigerants. Expansion of natural gas can be done by enthalpy constants (for example using the Joule-Thomson expansion and the

thermal inertia (Sie) using an operational expansion turbine).

a Regardless of the method used UY the natural gas stream; A large fraction of the hydrocarbons heavier than methane usually needs to be removed before the Al mechane-rich stream. The reasons for this hydrocarbon removal step are many, including the need to control the calorific value of the LNG stream and the value of these heavier hydrocarbon components as any products themselves. Unfortunately, so far little attention has been paid to Aled's hydrocarbon removal step. Ye

0 It has been found according to the present invention that liquefied natural gas and a separate heavy liquid hydrocarbon product can be produced using much less energy than that used in the processes of the previous technology; By accurately including the hydrocarbon removal step in the natural gas liquefaction process. Although the present invention is suitable for application at low pressures; However, it is particularly useful for processing feed gases at absolute pressures from 7758 to 7 kPa (absolute) 01400 od to toes psi'] or higher. For a better understanding of the present invention, Jay refers to the following examples and drawings: Figure []. : represents a flow diagram of a natural gas liquefaction unit SL se 1 for the contribution production of NGLs according to the present invention; Figure [Y] : represents a plot of the pressures at which phase transitions of used methane occur as a function of enthalpy to illustrate the advantages of the present invention over prior technology processes; Figure [©]. : represents a flow diagram of an alternative natural gas liquefaction unit configured yo to contribute NGLs according to the present invention; Figure [8]: represents a schematic diagram of the process flow of an alternative natural gas liquefaction unit configured to produce liquefied petroleum gas in a contribution form according to the present invention; Figure [0]: represents a flow diagram of an alternative natural gas liquefaction unit configured to produce condensate in a contribution form according to the present invention; vo Figure [1]: Lewy is a schematic representation of the process flow in a natural gas liquefaction unit, Ly, configured to produce a liquid stream in a contributory form according to the present invention; Figure [V] : represents a flow diagram of an alternative natural gas liquefaction unit configured to produce a liquid stream in a contribution form according to the present invention; Figure [A] : represents a flow diagram of an AL vo natural gas liquefaction unit configured to produce a liquid stream in a contribution form according to the present invention;

Figure [4]: represents a flow diagram of an Any natural gas liquefaction unit configured to produce a liquid stream in a contribution form according to the present invention; Figure [01]: Lewy is a schematic representation of the process flow in an AL unit Natural gas Lay prepared to produce a liquid stream in a contributory form according to the present invention; 0 Figure [DV] : represents a flow diagram of an alternative natural gas liquefaction unit configured to produce a liquid stream in a contribution form according to the present invention; Figure [DY] : represents a process flow diagram of an alternative natural gas liquefaction unit iL se for the production of a liquid stream in contribution form according to the present invention; Figure [VY] : represents a flow diagram of an alternative natural gas liquefaction unit 0 configured to produce a liquid stream in a contribution form according to the present invention; JS [1] : represents a flow diagram of an alternative natural gas liquefaction unit configured to produce a liquid stream in a contribution form according to the present invention; Figure [10] includes a flow diagram of an alternative natural gas liquefaction unit configured to produce a liquid stream in a contribution form according to the present invention; 0 Figure [11]: represents a schematic diagram of the process flow of an Al natural gas alternative unit prepared to produce a liquid stream in a contributory form according to the present invention; Figure [IV] : represents a flow diagram of an alternative natural gas AL unit configured to produce a liquid stream in contribution form according to the present invention; Figure [VA] : represents a flow diagram of an alternative natural gas liquefaction unit, see Y., to produce a liquid stream in a contribution form according to the present invention; [V4] Js : Lowy represents a flow schematic of a natural gas liquefaction unit Lay configured to produce a liquid stream in a contribution form according to the present invention; Figure [Ye] : represents a flow diagram of an alternative natural gas liquefaction unit configured to produce a liquid stream in a contribution form according to the present invention; ve Figure [MN] : includes a flow diagram of an alternative natural gas liquefaction unit configured to produce a liquid stream in a contribution form according to the present invention.

Detailed Description: In the following illustration of the above figures; 3555 pa AL Tables Calculated flow rates relative to typical process conditions. And in the tables shown in this statement; Round the flow rate values (in moles per hour) to the nearest whole number for convenience. The total current flow rates shown in the tables include all non-hydrocarbon components and are therefore generally greater than the sum of the current flow rates for the hydrocarbon components. The indicated temperatures are approximate values rounded to the nearest degree. It should also be noted that the process design calculations made for the purpose of: Comparing the processes depicted in the figures are based on the assumption that there is no heat leakage from the surrounding media to the curing process or vice versa. The quality of commercially available insulating materials makes this assumption very reasonable and usually achievable by those skilled in the technique. and for ease; The process variables are shown in traditional British units and SI units (81). The particle flow rates given in the tables can be expressed in pounds-moles per hour or kilogram-moles per hour. The energy consumption rates are similar to Lge in units of horsepower and/or thousand Btu particle flow rates expressed as Vo are expressed in psi psi Energy consumption rates in kW are the same as molecular flow rates in kg mole per hour Production rates in psi are the same as molecular flow rates mentioned in pounds-mole per hour The production rates, in terms of mall, in kilograms per hour, are identical to the molecular flow rates referred to in kilograms-mol per hour. ; illustrates a process according to the present invention where it is desired to produce a NGL co-product containing the largest amount of ethane and Ji components in the natural gas feedstream 0 and in this simulation of the process according to the present invention; Se Ye enters the unit entry At a temperature of 10°F [77°C] and an absolute pressure of 17485 psi" AAT [kPa] as FY . And if Yoyo

A

The inlet gas contained a concentration of carbon dioxide and/or sulfur compounds that would prevent the produced streams from meeting the required specifications; These compounds are removed with a suitable pretreatment to avoid the formation of aqueous bale of the feed gas (not shown). It also removes water from the feed stream (snow) in arid conditions. A solid desiccant is usually used for this purpose. uy o Feed stream (©0) in heat exchanger (V+) heat exchange with refrigerant streams and demethanation side reboiling boiler fluids at (-8°F (minus Fahrenheit) (p00) (minus zero degrees Celsius) (current £0) It is noted that in all cases the heat exchanger (01) is represented by either several single heat exchangers or a single multi-pass heat exchanger or any combination thereof. (It depends The decision to use more than 0 heat exchanger for the aforementioned refrigeration services depends on several factors, including, but not limited to, the inlet gas flow rate; the size of the heat exchanger; the stream temperatures (Ad. ) at a temperature [TE] GY and an absolute pressure of 1778 psi” [8877 kPa (Abt)] where the vapor (stream (TY) separates from the condensate liquid (APY stream CF) ( TE) into two streams (11) leaving from the separator (YY) and the steam (stream Yo ci; which contains about 770 total vapor; is divided with liquid (FE) and the stream (VF) is mixed to form Stream (70). The mixed stream (5©) passes through the heat exchanger (YY) stream where it exchanges heat with the refrigerant stream (1Ah); This results in the stream (170) being cooled and condensed [-5+m] through Yam substantially. The exposed current is then substantially expanded (170) at 00 sd by extending a suitable Jie expansion valve (06). ¢ to the operating pressure (about £10 psi'absolute TY [kPa (absolute)] of the fractionation tower (18). During expansion aay part of the stream cools the total stream. In the process shown in Figure [ 1]; the expanding stream (FE) from the expansion valve (TE) has a temperature of -177°F (-1 mm) and is supplied to a feed position in the middle of the methane section (9) of the fractionation tower (V4) Yo The remaining amount of steam escaping from separator (1) (780 of the total steam) (stream 11) enters an operational expansion machine (V0) where the mechanical energy is extracted from this part of the stream.

; High pressure feeding. The machine (10) expands the steam in a substantially inertial fashion from an absolute pressure of about 1778 psi [AMY [kPa (ab)] to the operating pressure of the tower so that the operational expansion cools the expanding stream ( v=) to a temperature of about [Ve] Gers Typical commercially available 0 expansion tools can recover 80 to 785 percent of the theoretically available work in a typical inertial expansion The work recovered is often used to operate a compressor Expellers (eg tool 11) can be used to recompress the upper gas of the tower (eg stream (FA). The expanded and partially condensed stream (IT) is supplied as feed stream to distillation column (14) at the Jind feed point mid-column 01. The fractionation tower demethane (V4) is a conventional distillation column containing vertically spaced sae trays; one or more stuffed layers or a combination of one or more trays and packings. Natural gas processing units: The fractionation tower includes two sections, the upper section (119), which is a separator where the ad feed stream is divided into its respective steam and liquid parts; Whereas, Jala Ty, the steam rising from the lower ve distillation or methane removal section (19) with the upper feed stream steam part (if any) to form the upper cold steam Ae HU methane (VY stream) which exits from the top of the tower at - F [-17°C] The lower de-methane section (91B) contains trays and/or gaskets and ensures the necessary contact between the downward flowing liquids and the upwards vapors The demethane section also includes one or more gle re-boilers (eg TS re-boiling boiler) 01 works to heat and vaporize part of the liquids flowing down the column to supply the extraction vapors flowing lef the column.The liquid product stream (41) exits from the bottom of the tower at 7111 F [47 m]; Based on a typical methane to ethane ratio of .070:1; on a molecular basis in bottom product. ia top steam of demethanation (A)©) to 00F [FY] in a YO heat exchanger (YE A portion of the upper (lad) steam is drawn from the demethane to act as a fuel catalyst (stream 44) for the unit. (In general, the amount of fuel gas that must be withdrawn is determined by the fuel required for the engines and/or turbines that run the gas compressors in the unit, such as the Yoyo compressors.

0 refrigerant (NE 175 and 18 in this example). The remainder of the upper andl steam is compressed

for demethanation (YA) by compressor (V1) driven by graters (V0) (11) and

(17). and after cooling to 100'F [78°C] in the Saal Tafrifi (YO); the stream cools down (*?b)

Further to [TAT] GY in the heat exchanger (?7) by means of the coupling (PY) transversal with the upper cold steam of the deflector (current 0

Then the stream (TA) enters the heat exchanger (10) yu further by means of a material stream

Refrigeration (1d). After cooling to an average temperature of 0, the current (4 “C) is divided into two parts.

Dus part one; current (£9); further in the heat exchanger (+1) to -857 F

ARTE to condensate and sub-cool (below BSH) where Jay is then an operational expansion machine

Cua (11) 0 - The mechanical energy is extracted from the stream. The machine (11) intrinsically expands the liquid stream (9£) from a pressure of about ONY lbs/in'AVA [kPa (absolute)] to LNG storage pressure

) 1000 psi'017 [kPa (absolute)] ; slightly higher atmospheric pressure.

The operational expansion cools the expanding stream (189) to a temperature of about -

M mmf 0 5 YI], which is then directed to the LNG tank (17) which contains

| Liquefied Natural Gas (NER) producer

current is withdrawn (4); The other part of the current (aT) is from the heat exchanger

(14) at a temperature of -166 F 017-[C] and it expands and flashes through an extension tool

suitable; ie expansion valve (VY) to (V4) Wall tower operating pressure. And in the process

Xe >< 0 shown in Figure [1] ; Expansion stream (14) does not evaporate so its temperature is reduced only slightly to -0161 F [-710C] leaving the expansion valve (OY) and then the stream is supplied

Expanding (179) to the separation section (119) in the upper area of the retail tower (19).

Separated inside it to the de-methane section (V4) as an upper feed stream in relation to it.

Complete cooling of the (©) and (—aTA) streams is provided by means of a closed circuit cooling loop.

YO The working fluid intended for this cycle is a mixture of hydrocarbons and nitrogen ¢ provided that the composition of the mixture is adjusted if necessary to provide the required coolant temperature while the

Condensation at moderate pressure using the available refrigerant medium. In this case; Assume forced

Yio

1 condensation using cooling water; So that a mixture of refrigerants consisting of nitrogen is used, in simulating the process according to the Ji form, and propane hydrocarbons in the form of ethane; Propane 741.0 » The current composition is represented by an approximate molar percentage as follows: 797.08 for nitrogen. [1] for propane; so that heavy hydrocarbons make up the remainder of 21001 for methane; 741.5 for ethane and composition.‎ 0

The refrigerant stream (VV) is discharged from a vacuum cooler (19) at a temperature of q

. kPa (Absolute)] VAC] and at an absolute pressure of 7097 psi” [YA] Gaver partly by 3 stream [TO] V-70 and cooled to (01) enters the heat exchanger ,

Partially heated expanded refrigerant (17F) and by other streams of refrigerant.

B 0 To simulate the process according to JCal [1], assume that this other refrigerant stream is a commercial grade propane refrigerant at different values of temperatures and pressures. Then he enters

Partially condensed refrigerant stream (V1) heat exchanger (VF) to further cool it to -

4V [AY] by means of a partially heated and expanded refrigerant stream (1lah);

To condense the refrigerant and partially cool it down (current 1lab). The refrigerant cools down

ve is added to Yes [-010°C] in the heat exchanger (10) by means of an expanding refrigerant stream (VY). The inferiorly cooled liquid stream (av) enters the operational expansion machine (17) where it is extracted

The mechanical energy of the machine from the stream when it expands statically intrinsic thermal inertia at a pressure of about OA psi'at [40 50 kPa (At)]

to about YE psi'absolute [YE kPa (absolute)]. and while stretching; Part of it evaporates

0 current; This cools the total stream to -777 V [VES] (current 1 lad). Then the expanding stream (17d) enters the heat exchangers (0) (VF) and (01) again Cus providing cooling to the tipsar (—aTA) (Yo stream) and the refrigerant (streams Laie (in 1 dV) 71 evaporates and heats up dramatically

excessive. The overheated refrigerant vapor (stream (OY) is discharged from the heat exchanger (01) 7

£Y01] NY pounds/inch absolute at 47 F [4 7 C] and pressurized to Yo kPa] in three stages. Each of the three stages of compression is managed

hil guia) refrigerant AE 17 and 18) by an auxiliary power supply and attached to a refrigerant(s

Yoyo

\Y | vacuum TY lo and 14) to remove the heat of compression. The compressed current (VV) exhausted from the vacuum cooler (14) returns to the heat exchanger (01) to complete the cycle. In the following table is a summary of the current flow rates and power consumption for the process shown in Figure [1]. 1(Js) 0) Summary of current flow rates - lb mol/hr [kg mol/h] Current Methane | YY AR ER! Safar Safar EA TAY ra LG Safar Safar 190 YE 8 YEA rv.vv 3 parameters M FATA Safar Safar km 0 Lakh a Safar Jia m recovery rates in natural gas liquids gas * ethane ethane ve propane propane fer butane compounds and higher molecular weight compounds FY eyes Production rate 18 lbs/hr 80 EY [kg/hr] Hall's liquefied natural product natural gas liquefaction production rate AVY (1 lb/hr [AVY 11 kg/hr] 0 Purity* °C

VY

MJ/m"] FF, 88] Minimum calorific value .917.7 BTU/ft" Standard kW [VV ede] Horsepower 0101 Refrigerant Compression Horsepower [00041 kW ] TFAYO \ propane [77495? glans kW Capacity 7/17 Total pressure 0 Utility heat

[VAG] Demethchan Reboiler 79914 thousand BTU/hour l kW] (depending on unrounded flow rates) * using specific consumption sale and comparing the efficiency of LNG production processes ye For the required capacity, which is the ratio of the total capacity of the refrigerant compression to the total production rate of the liquid, and the published information shows the specific consumption of the capacity for the previous technology processes to produce [kilowatt-hours/kJ [+, YVR] horsepower-hours/ lbs +, VIA LNG ranges from over a diay [kWh/kg] ; thought to be [Fe] horsepower-hours/lb [VAY] to days per year per unit of natural gas production Liquefied. Based on this same Yoo has an operating factor of V0

cnty] baseline; The specific power consumption according to the embodiment of the present invention is in the form [kWh/kg] ; This value provides an improvement in efficiency of [1,775 horsepower-hours/lbs.] ranging from ; to 717 compared to previous technical operations. In addition, it should be noted that the specific capacity consumption of the previous technology processes depends on the co-production only of a liquid stream of LPG (tricarbonate© and heavier hydrocarbons) or condensate 1tetracarbonate© and heavier hydrocarbons) at Relatively low recovery levels and not a stream ( liquid from NGLs (bicarbonate© and heavier hydrocarbons) as shown for this example according to the present invention. The prior technology processes required much more cooling capacity to co-produce a NGL stream rather than A liquefied petroleum gas stream or a condensate stream There are two main factors to which the improved efficiency of the present invention is attributed.

Yoyo

A high pressure V¢ such as the one considered in this example. And given gas on a gaseous stream; The dynamic properties of methane can be used because the main constituent of this stream is methane, the thermodynamics of methane, for the purposes of comparing the liquefaction cycle used in the processes of the previous technology against a graph of the pressures that conduct [Y] the cycle used in the present invention. The figure then shows the phase transformations of methane as a function of enthalpy. And in most of the 0 liquefaction cycles of the previous technology; All cooling of the gaseous stream takes place when the stream is at high pressure (path A-B); Where the stream extends later (path B-C) to the pressure of the LNG storage vessel (pressure slightly above atmospheric pressure). This expansion step can use a machine to recover the work theoretically available in the expansion of the inertial constant ale an operational expansion capable of expanding the constant of inertia my and for the sake of simplification SAY VO ideally by a ratio of about 0 for path b -c. However ; The decrease in [1] heat content entirely in thermal form provided by this operational expansion is quite small; Due to the fact that the fixed thermal inertia lines are almost vertical in the liquid region in the phase diagram. This can be contrasted with the liquefaction cycle according to the present invention. Where the gaseous stream expands to medium pressure after partial cooling at elevated pressure (Tad) by operational expansion ve fully expands the entropic constant to assume sn (again; IHF (simplified path) The rest of the cooling takes place at intermediate pressure (path A”-B), and then the stream is extended (path B’-C) to the pressure of the LNG storage vessel. vapors of the phases scheme; provides a reduction in enthalpy much greater than the first operational expansion step (route 1) according to Te and TT of the present invention. Therefore, the total amount of cooling required of the present invention (the sum of the two paths) is less than the necessary for the previous technology processes (path A-B); which reduces the cooling (and thus (cooling pressure) required to liquefy the gaseous stream-Z). The second factor attributing the improved efficiency of the present invention is the superior performance of hydrocarbon distillation systems at The hydrocarbon removal step in most prior technology processes is carried out at high pressure, usually with a vo column wash that uses a cold hydrocarbon liquid as the sorbent stream to remove heavier hydrocarbons than leads to the incoming gaseous stream AN. Operation of the scrubber at high pressure is not considered very efficient; co-absorption of a large fraction of methane and ethane from the gaseous stream; From which the absorbent liquid should be removed and cooled to become part of the liquefied natural gas product later. In the present invention; The hydrocarbon removal step takes place at medium pressure where the vapor-liquid equilibrium 0 is much more desirable, leading to a very efficient recovery of the desired heavier hydrocarbons in the contributory product than the liquid stream. If the LNG product would allow a greater amount of the ethane present in the feed gas to be recovered in the LNG product, a simpler embodiment 0 of the present invention may be used. An alternative such embodiment is shown in Figure [©]. The inputs considered in the process represented in Fig. [©] are identical to those in Fig. [1]. Therefore, the process described in Fig. [©] can be compared with the embodiment shown in Fig. [1] and in a simulation of the process described in Fig. [1]. Figure [?]” The entry gas cooling, separation and expansion scheme of the NGL recovery section is essentially the same as that used in Figure - 88710 [lbs/in” Absolute 1786 52 FY] and the inlet gas enters the unit at 8 F. [1] by exchanging (01) and cooling in a heat exchanger (91) kPa (absolute)] in the form of heat stream with refrigerant streams and boiler fluids side reboiling of demethane at -35 F ,

SLATE]. lbs/inch' absolute 17726 00

TY condenses (stream) and (FT) and (TE) are mixed into two streams (11) resulting from the separator (TY) and the steam (stream is divided into stream (74); which contains about 7780 The total vapor with the exposed liquid through an exchanger (FO) to form a stream (70). The mixed stream (YF) passes the condensed stream leading to cooling and condensation (VY) in a heat exchange relationship with Refrigerant stream (1) thermal YO V [hmmm] VY = at (YO) intrinsically ESI and then extends the current 0 (ire) intrinsic to the stream

1 expansion valve (?1); to the operating pressure (which is ia (through a suitable expander; Laas kPa (absolute) approx.]) of a fragmentation tower (14). During expansion TY +7 [lbs/in] absolute £70

J Part of the stream evaporates; This leads to cooling of the total stream. and in the process described in - which leaves the expansion valve (?1) to a temperature of (FO) [?]; The expanding stream [m] ¢ reaches and is supplied to the separating section in the upper area of the fractionation tower (14). The liquids separated [AT] f 1” oe are the upper feed stream of the dewatering section in the lower area (19 0 0). of the fractionation tower to an expanding machine (FT) (stream (VY) and the remaining 780 steam from the operational separator (10) enters where the mechanical energy is extracted from this part of the high-pressure feed stream. Machine (10) extends the steam in an intrinsic intrinsic constant from a pressure of 0 kPa [absolute] to the turret operating pressure with AMY [lbs/in] absolute 1,717,748 of approximately [Vor] Gi) em By operational expansion to a temperature of approximately (771) saad the stream is cooled. The partially condensed and expanded stream (71) is supplied as a feed stream to a distillation column at a feed point in the middle of the column. (V4) (V4) From the top of the fractionation tower (FV) the cold upper vapor of the fumigator (V 118 stream) exits at -177 F [hkm]. The liquid product stream (£1) exits from the bottom of the tower at On the basis of the typical specification for the ratio of faeces to ethane which amounts to 1:0.078 on a 0 [» tA] p molecular basis in the lower product. p [7 m] in heat exchanger 90 (TY) top steam for demethanation (lag stream (74); Then part (4£ stream) is calculated to serve as fuel gas for the unit. The remaining T° part of the upper demethanation steam (stream 49) is compressed using a compressor (11). After cooling to -117 F additional to JS stream (4;b) (YO) is cooled in a vacuum cooler [YA V0 by cross exchange with the cold upper vapor of a dehydrator (VE) M] in a heat exchanger [A+] (TY) methane; stream and then a stream (49;c) enters a heat exchanger (10) and is further cooled by [Yo m] to condensate and cool it down » and then enters 11am] F YOV= to ( VY) refrigerant stream

Yoyo

And an operational expansion machine (11) where the mechanical energy is extracted from the current. The machine (1) extends a liquid stream (389) in an intrinsically inertial manner from a pressure of about 881 psi” absolute [071 kPa (ab)] to an LNG storage pressure of 10.0 psi” absolute 017 [kPa (absolute)!) which is greater than SB above atmospheric pressure © Operational expansion cools the expanding stream (59 H) to a temperature of approximately -104 F 1-1131 C] where it is then directed to An LNG storage tank (17) that holds the LNG product (stream 0 *), similar to the process shown in Fig. [1] All cooling is supplied to streams (10) and (5;c) via a loop Encapsulated cycle cooling The composition of the stream used as the working fluid is 0 > in the process cycle shown in the figure [©]; as an approximate molar ratio, it is nitrogen with a ratio of 7450.0 methane, ethane with a ratio of 747.8, and propane with a ratio of AN aye, where it forms Heavier hydrocarbons remain the percentage. The refrigerant stream (V1) leaves a vacuum cooler (18) at 100 F TAL m] and 107 psi'vat [£100 kPa (Absolute)]. It enters the heat exchanger (01) and cooled to -70 F [Yo] and partially condensed by the heated expanding ve refrigerant stream (SV) Los and by other refrigerant streams. For the process simulation shown in Figure [©]; It was assumed that the other refrigerant streams were commercial grade propane refrigerant at three different levels of temperature and pressure. The partially condensed refrigerant stream (V1) then enters the heat exchanger (VF) for the purpose of further cooling to 1171-F [a AO] via the partially heated expanded refrigerant stream 1 (1Lah) E ; This leads to the condensation and partial cooling of the refrigerant (the father's coil). The refrigerant is further downstream to YoV=V-01 [p] in the heat exchanger (+1) via the expanding refrigerant stream (V1). The downstream liquid stream (1L/1c) enters the Machine - Operational Expansion (TF) in which mechanical energy from the stream when statically expanded extracts intrinsic thermal inertia from a pressure of about 587 psi' absolute [£080 kPa (Ge) YO to about TE psi [Absolute YY] kPa (Absolute)]. During expansion, part of the stream evaporates, causing the total stream to cool down to [VE] Yr (Yoyo stream |

A 1 Lad). Hence Jay extends stream (VY) back to heat exchangers (10) » (VF) and (01) where it supplies cooling to stream (4;c) – stream (70) and refrigerant (streams IVY VY and (QV) when evaporated and overheated. 0 and the overheated refrigerant vapor (current 1las) leaves the heat exchanger (01) at [LYelaar oo] and is compressed in three stages to 7017 lbs/in” absolute [£Y0¢] kPa (absolute)]. Each of the three compression stages (refrigerant 69 664 and TA compressors) is driven by an auxiliary power source and each stage is followed by a vacuum cooler(s). 10 47 and 19) to remove the heat of compression. The compressed stream (VY) returns from the vacuum cooler (194) to the heat exchanger (01) to complete the cycle. ye A summary of the current flow rates and energy consumption for the process shown in Fig. [©] in the following table Table (7) (Fig. [©]) Summary of current flow rates - lbmol/hr [kgmol/hr] al methane ethane propane butane compounds total propane ethane methane and higher compounds Molecularly bs 2 Alak 0 YE A FANN 1" 17m YY Bk VY. 4 Voy y€14 Yive VEY A: 94 WAT ANY rr Yai ovo Evy ve 4 717 Yaviv 541 VIVO Yi.

YOAAA 1 ba 6 f 7+ 7 07 mia TYA wv 1 0 and ray £149 Yo Y414 2 1 zero m oA 5 7161 EX for 97.7 Yeo

Retrieval ratios in natural gas liquids * ethane no RLA / propane L: butane compounds and compounds with a higher weight Ue 744.47 Production rate 5? lb/hr [° 1717 kghr] LNG product natural gas liquefaction Production rate Yo) OY lb/hr [75157 kghr] JAA Co Fall Min Calorific Value VAY BTU/ft" Standard [YE,YV] MJ/m"] Capacity Refrigerant Compressibility 1006 HP [Ll lS YoAVEY] Propane Pressure YEVY Statistics OV AT [kW] Total Compression 12174840 HP [YVOAY] kW] facility heat [guy] demethanation reboiling phases 1717 kbtu/hr [1771 kW]* (based on unrounded flow rates) and assuming an operating factor of TE days per year per gas production unit liquefied natural; The specific power consumption for the embodiment of the present invention according to the form [©] LOY ly is horsepower-hour/lb YO] + kWh/kg]. And compared to the previous technical processes; The percentage improvement in efficiency ranges from 01 to 778 for rendering according to Figure ©] . 0 As previously noted for the embodiment according to Figure [1] ; This improvement in efficiency is possible by using the present invention even if a co-product of natural gas liquids is produced instead of the co-product of liquefied petroleum gas or the condensate produced using the previous technology processes. Yoo

1 [3] The embodiment of the present invention according to Figure 1 [1] of Figure Gy and in comparison with the embodiment requires about 75 less capacity per unit of liquid produced. And so on ; For a given amount of 75 compression power is available; According to the embodiment of the figure [©], a greater amount of natural gas can be liquefied by about

C, Sl carbonates due to the recovery of a smaller amount of constituents [1] compared to the embodiment by form and heavier hydrocarbons in the NGL contribution product. The choice between the Bale value embodiment [1] and embodiment [©] according to the present invention will depend on a particular application of the monetary heavier hydrocarbons in the NGL product against their corresponding values in the NGL product. LNG or on the specification of the calorific value of the LNG product (since it is less than that [1] calorific value of the LNG produced by embodiment according to Figure 0

IY] produced by embodiment according to Figure 0 (©) Example If the LNG product specification will allow all the ethane in the feed gas to be recovered in the LNG product or if there is no market for a liquid co-product contains ethane, an alternative embodiment of the present invention such as that shown in 0

Sle Figure [4] to produce a co-product stream of liquefied petroleum gas. The conditions and composition of ve and [1] entries taken into account in the process represented in Figure [;] are identical to those in Figures [;] and accordingly the process shown in Figure [;] can be compared with the embodiments shown in Figures . [©]. [1] and [1] In a simulation of the process shown in the figure [€] ; An inlet gas enters the unit at lbs/in" Absolute 88501 kPa (Absolute)] as a stream of 1785 [27 m EST] by exchanging heat with refrigerant streams; (01) and cooled in a heat exchanger (TY) and the refrigerant stream (1?A) enters (IY) [-47Am] GE and fluids from a flash separator at AMY kPa] psi” Absolute 1778 [VAS] At -1 F (VY) separator (FY LL) from the condensed liquid (TY (absolute)] where the vapor separates (stream where (V0) operational expansion Al to 11) The output from the separator (FY) and the steam enters (the Yo stream) and the machine operates. The mechanical energy is extracted from this part of the pressure feed stream

(10) to steadily expand the vapor is intrinsically inertial from a pressure of about 1778 lb/in' absolute [AAVY] kPa (At)] to a pressure of about 6 ; lb/in' absolute [E] 907 kPa (At ] (pressure separation/absorption (VA) tower operation with the expansion current (Ivy) cooled by operational expansion to a temperature of approximately [I] GAY. The partially condensed and expanded © (TY) supplies the absorption section (A) In the lowest area of the tower

Separation/absorption (18). The liquid part of the expanding stream mixes with the downstream liquids from the absorption section and the admixed liquid stream (£1) exits from the bottom of the separation/absorption tower

(VA) at HV [=] 0 and the vapor portion of the expanding stream ascends upward through

The absorption section comes into contact with the cold liquid falling towards the bottom to intensify and reduce it

INGREDIENTS: Tricarbonate© and heavier ingredients.‎ 0

The separation/absorption (VA) tower is a conventional distillation column containing several

vertically spaced trays; One or more stuffed layers or a certain combination of sandwiches and fillings. As is often the case in natural gas processing units; The separation/absorption tower can consist of two parts. The upper section (114) is a comma separating any

NO vapor present in the feed stream satel than the corresponding liquid portion and where the vapor rising from the distillation or lower absorption section (VA) mixes with the vapor portion (if any) of the stream

The upper feed to form the cold distillation stream (YY) that exits from the top of the tower. The lower absorption section (81b) contains the trays and/or gaskets and provides the necessary contact between the falling liquids and the upwards vapors for condensation and absorption of the Cr tricarbonate components.

0 and heavier components.

The mixed liquid stream (40) is directed from the bottom of the separation/absorption (VA) tower to an exchanger

0 <<< thermocouple (V1) via a pump (Y1) where it heats up (current 160) when the upper steam cools down

of demethanation (stream (£Y) and refrigerant (stream (IVY). The mixed liquid stream is heated to -

F [-71m]; which partially discharges current (10;b) before it is supplied to a feed point in the middle

YO deethane column (14). The separator fluid (current (FF) is extended and flashed to a pressure of

Yoyo

YY

; Which cools the stream (V1) slightly more than the operating pressure of the deethanizer (18) through an expansion valve before the incoming feed gas is cooled as previously described + and from ITY (stream [» v=] to - 17 F (YY) F [-5?m]; to deethanase (14) at point Ae and then enters a stream (??”b); presently present at a feed lower in the middle of the column. De-methane and bicarbonate components, which operate at (19) and are de-ethane in the tower (FY) from the streams (00;b) and ©6 kPa (absolute)]; also a distillation column [¥IYT] about £07 lb/in' Conventional shooter containing several trays spaced vertically; one or more filled layers or a particular combination (also: Cand section of BN) of trays and fillings. A dewatering tower may be formed where any vapor present in the upper feed stream is separated from the corresponding liquid part (Iva) and where the rising vapor from the lower distillation or deethanation section (9) mixes with the part 0 exiting from the top (EY). upper section to form a BA steam distillation stream (if any) from the tower stream; and a lower section for de-ethane (913) containing trays and/or gaskets to provide the necessary contact between the downward-falling liquids and the upward-rising vapors. The de-ethane (+ Jia reboiler) section (219) also includes one or more reboilers which heat and vaporize a portion of the liquid at the bottom of the column to supply the stripping vapors which flow to the 0 (£1 stream From the top of the column to remove methane and the bicarbonate© components from the product. Typical specifications for the bottom liquid product. Obtaining a ratio of ethane to propane on a molecular basis. A liquid product stream (£1) exits from the bottom of the deethanizer. At Ye .[0101m] 4V the working pressure of SLi and maintains the working pressure of the deethane (19) so that the veo increases and this allows the upper vapor flow of the deethane (current £7) under (VA) Separation/absorption tower and then to the upper section of the (VF) tower pressurized through the heat exchanger; the upper steam is directed to the de-ethane (OF) and into the heat exchanger (VA) separation/absorption m ] In a heat exchange relationship with the admixed liquid stream (stream 16) from the bottom of the YA at -19 V - and the flash refrigerant stream (1/AH) which cools the stream to (VA) the separation/absorption tower YO

Yoo

[pV] i AA (47a threat) is condensed by Ln and the condensate stream partially enters a cylindrical reflux vessel (YY) where the condensate (6£ stream) is separated from the non-Sal vapor (EY stream The stream (£7) mixes with the steam distillation stream (FY stream) leaving the upper region of the separation/absorption tower (VA) to form a cool residual gaseous stream (£Y). The liquid GG© (stream 44) to lel pressure by means of a pump (YT) and then the stream (44)) is divided into two parts. As the cold liquid that comes into contact with the vapors rising to the top through the absorption section, the other part is supplied to the deethanerate (VA) in the form of a return stream (£71) Gay to an upper feed point in the deethanerate (19) at ‎ CLE GA yo and the cold residual gas (stream 7?) is warmed from atm P [Ve] to aE [7m] in a heat exchanger (VE); and then part (stream £4) to make JAS fuel for the unit. The rest of the heated remaining gas (stream 89) is compressed through a compressor (01) and after cooling to 1001 F YA [m] in a vacuum cooler (YO) the stream (49 b) further to the [T=] ally in the heat exchanger (TE) by means of cross exchange with the cold residual gas; Stream (EY) Then stream (49;c) enters heat exchanger (10) and is further cooled by means of refrigerant stream (V1) to Yoo F-001 [m] to condense and cool it Liga; and later enters into an operational expansion (VY) where mechanical energy is extracted from the stream The machine (VY) expands a fluid stream (4;d) intrinsically inertial constant from a pressure of about TEA psi” absolute [e 7 kPa (absolute)] to LNG storage pressure (N00 Ye psi” absolute 01 kPa (absolute)]); which is slightly greater than atmospheric pressure. Operational extension cools the residual current (9;e) to a temperature of approximately -0 000 [1 C]; It is then directed to the LNG storage tank (17) which holds the LNG product (stream 0 #). In the Blas form of operations as per Figure [1] and Figure [©]; supplies most of the cooling to the stream (£). 7) Ye and all cooling of the stream (29) by means of a closed circuit cooling loop. The composition of the stream used is Yoyo

Y¢ as the working fluid in the process cycle according to Figure [4]; as an approximate molar ratio; It is nitrogen by 749.8, propane by 11t GLB, methane by 77050; JAY by refrigerant (V1), and the heavier hydrocarbons make up the rest of the percentage. The refrigerant stream leaves. q [78 m] and 7607 lb/in’ absolute [4185 kPa (absolute)] 001 vacuum (14) at GS [YY] GV is partially cooled to (01) and enters the heat exchanger © Partially (1or) and through other refrigerant streams Badly Expansion Cooling sale by stream: For the simulation of the process shown in Figure [4], it was assumed that these other refrigerant streams are a refrigerant From propane of commercial quality at three different levels of temperature and pressure to the exchanger (V1), then the condensing refrigerant stream enters the thermal part (0) for additional cooling to -84 F [-7 “C] from By means of an expanded and heated refrigerant stream 0 material Ci Gy. In addition (YY A: Partially (1 lah) which keeps the refrigerant (heat exchanger stream (+1)) from [VT] Yoon completely cooled Then it cools down to machine (a) and the liquid stream enters the cooler downstream (VY) through the expanding refrigerant stream, an operational extension (17), where the mechanical energy is extracted from the stream when it expands in a constant inertia. lb/in' absolute [£1 £1 kPa (absolute)] intrinsically thermal OAT from a pressure of about Ne

CYNE; Which leads to the cooling of the total stream, Jill, and during the expansion, part of the evaporates, and then the expanding stream (1 "d) enters again into the heat exchangers (VY (current [» 116] and the refrigerant (streams) (£Y) where it provides cooling to the current (£3) of the current (01) and (VF) » (1): when it evaporates and gets excessively heated. (Ve) Overheated refrigerant (1g current) heat exchanger Bale and Ye steam leaves [£Y0£]kPa [lb/in] Absolute +117 and compresses in three stages to [YY]V and VE (absolute)]. Each of the three compression stages (refrigerant compressors (VA TV 26) is managed by an auxiliary power source, and each stage is followed by a cooler(s) (18) from a vacuum cooler (14). ) to the exchanger (V1) to remove the heat of compression. The compressed stream returns to complete the thermal cycle. (01) Ye

Yio

Yo The summary of current flow rates and energy consumption for the process shown in Fig. [;] is shown in the following table: (¥) Table ([€] (Fig. Summary of current flow rates - lbmol/hr [kg mol/h] ° prod ethane compounds dud gE dad JE and higher compounds butanes propane ethane methane

Loe weight dt YEA FAT avy A m kh 66 AX” YAYY 11 67 vy 75111 oA¢ ov o¢t 1 YY £401 yy 4 zero 16 AY” 00 rad 079 Eo YAYY YRA YYAR tA zero 3 14 zero VHA May 0111 31 231 AD ey 3 zero what ¢£ count 0 015 zero 1 VY zero av vere YoAo go 76 0 TA Yyva Yea) £7 1 4 0 YY YAY Alak ty 91412 0 1 YYA Y,toYV m 1 0 AR YoAo Qom 0 Os 0. a

Recoveries in liquefied petroleum gas *natural gas A propane ,744 Butane compounds and higher compounds 7000000 Molecular Weight 970511 lbs/hr - [197051 kg/hr] Production Rate Jali Natural Gas Product 1 | Production rate 7794 lb/hr [7717918 kg/hr] Purity * 7a, min calorific value 8 BTU/ft' standard [€ YU) : | MJ/m”] Refrigerant Compression 4 Power 10 8977 [ Lilian kW] Propane Compression +0 HP [£3174 kW] Total Compression YY EAS Statistical Capacity Yo ¥en [kW] Utilization Heat Reboiler Reboiler © 0070 0070 thousand Btu/hr [Yoove methane kW] * (based on unrounded flow rates) and assuming an operating factor of Loss TE aly per year for an LNG production unit, the consumption rate The specific power for the embodiment of the present invention according to Figure [6] VEY is 0 horsepower-hour/lb [YT] [kWh/kg]. from 777-117 №" and in comparison with the two incarnations according to Fig. [1] and [©]; An embodiment of the present invention according to Figure [£] requires a Jil capacity of 7276 to 711 per unit of liquid produced. And so on ; For a given amount of compressive capacity provided; According to the embodiment of [;] AL, more quantity of 0 > natural gas can be obtained by about 77 compared to the embodiment of [1] or more natural gas by 0.6

XY

7211 compared to the [V] embodiment thanks to the recovery of Cy hydrocarbons and Jil hydrocarbons only as a co-product of LPG. In general, the choice between embodying Fig. [4] and embodying Fig. [1] or embodying [©] according to the current SOU for a given application depends either on the monetary value of the ethane as part of the natural gas liquefaction product© versus its corresponding value in the LNG product, or on the specification Calorific value of LNG product (Since calorific value of LNG produced “m by embodiment of Fig. [1] and embodiment of Fig. [1] is less than that produced by embodiment of Fig. [1]]. Example (£) z 0 if The specification of the LNG product would allow all the ethane and propane contained in the feed gas to be recovered in the LNG product or if there is no market for a liquid stock product containing ethane and propane » an alternative embodiment of the present invention such as that shown in Figure [0] could be used to produce The conditions and composition of the inlet gas considered in the process represented in Figure [0] are similar to those in Figures 0 [©] and [6]. Accordingly, the process of Figure [0] can be compared with the embodiments shown in Figures E]1[0 fe] [?] and DV] In a simulation of process Ty of figure [0] an entry gas enters the unit at Gar [m] and 1785 psi'absolute AAT [kPa (absolute)] as stream (F3) and cooled in heat exchanger (01) by heat exchange with 0 refrigerant streams and liquids 0 00” high flash separator all Muffle at -7” P [PA] (FF) and liquids from a medium pressure flash separator at GTY= [-78 m] (4**B). The refrigerant stream (171) enters a high-pressure separator (11) at Gao [-4 7 m] and VIVA psi’ [AVY [absolute] kPa] where it separates the vapor (stream (TY) of the compressed fluid (FT ll) and the vapor (stream (VY) from the high-pressure separator (11) enters into an operational expansion machine (VO) YO where mechanical energy is extracted from this portion of the feed stream High-pressure The machine (V0) expands steam intrinsically inertial constant from a pressure of Yoyo

XA

We kPa (absolute)] to a pressure of approximately AMY] psi'absolute VIVA in operational expansion to (VY) psi absolute [//7; kPa (absolute)] and the cooling of the expanding stream (77) has a temperature of approximately -87 F [-4 1 C]. The expanding and partially unfolded stream enters where the vapor (stream “;”) is separated from the condensed liquid (stream (VA) into a medium-pressure separator, and the liquid produced from the medium-pressure separator (stream 74) expands and expands to a pressure). ©4 0 slightly above the depropane operating pressure (19) by an expansion valve (17); which then cools (VF) before entering the heat exchanger IVa (stream [VAS] GAs (stream 34) Then, when cooled, it enters the exchanger (V1) for the residual lazi stream (18) and the OSs refrigerant stream as previously described. It enters (stream 4*#G)- Jalal to cool the feed gas (01). to the propane dehydrogenase (19) at the feed point of [pe] Yo present. At this point at 0 above the middle of the column. By extension (11); resulting from the high pressure separator ( FF and the condensate liquid expands the stream to a pressure slightly higher than the working pressure of the propane propane (14) by an expansion valve before entering the exchanger ITY (stream [Y=] which cools the stream (7© ) to -47 F (VY) then (71) then triturated when cooled to residual gaseous stream (£9) and refrigerant stream (IF) enthalpy 0 as previously described. And the Jalal stream to cool the feed gas (01) enters the heat exchanger at (V4) at [10 m] to the propane dehydrator © 0 (7c), which is present at this point at the feed point. Lower than the middle of the column In the propane dehydrator, methane is removed Components of streams (#1c) and (7c) C3 carbonate © and tricarbonate components 1 + 6 [4 lbs / inch] Absolute YAO The propane dehydrator in the tower (14) which operates at about -0 kPa (absolute)]; is a conventional distillation column containing several vertically spaced trays; one or more packed layers or a certain combination of trays and packings. The propane stripper tower consists of two parts: an upper separation section (119) where the vapor present in the upper feed stream is separated from the corresponding liquid part, and where the steam rising from the distillation or lower propane removal section (17) mixes with the steam part (if and Gbd) from the upper feed Yo stream to form the distillation stream (7?) which exits from the top of the tower; and a lower section to remove 0

95° Propane (219) contains trays and/or gaskets to provide the necessary contact between the downward-falling liquids and the upward-rising vapors. The propane removal section (91b) also includes one or more reboilers (such as a reboiler)) 01) which drains and evaporates part of the liquid at the bottom of the column to supply stripping vapors that flow to the top of the column 0 to remove the liquid product; (stream 41) consisting of methane; © dicarbonate and tricarbonate © components. Typical specifications for the lower liquid product Obtaining a ratio of propane to butane compounds of 0.07:1 on a volumetric basis The liquid product stream (41) exits from the bottom of the propane extractor at 787 °F [LV] and the upper distillation stream (TY) leaves Propane dehydrator (V4) at 77 F [7 C] Fy ay Woe cGy 0 by commercial grade propane refrigerant in rewind accelerator (YY). Cylindrical return (YY) at “V [VV] where the liquid Cia (stream ;;) is separated from the non-condensing vapor (stream L). The condensate liquid (stream £6) is pumped by pump (YT) to Top feed point into propane extractor (V9) as reference stream (44A). ly 00 non-condensing steam J (£7) leaving the cylindrical reflux vessel (VY) to 4F [;7m] in heat exchanger (TE) draws part (EA J) to operate iS is fuel in the industrial unit. The remainder of the vapor (Gaal) (stream (PA) is compressed by means of a compressor (11). After cooling to 100 F TA [m] in a vacuum cooler (©?); the stream is cooled. (GFA) is further added to ae | 4-1[ in the heat exchanger (YE) by cross-exchanging with cold steam 0 (current ? L¢) then mixing (current +c) with the steam produced from the medium pressure separator (7£ stream) to form a cold residual gaseous stream (9£) and the stream (9£) enters the heat exchanger Say (VF) from -V [-3] to 01"-V [- Lam] by the separator fluids (currents (IPR and IF) as described by Sel and by means of the refrigerant stream (1/Ah). Then the partially condensing stream (13) to the Ye heat exchanger wy (Jay) 11) additionally by refrigerant stream (V1) to t= 75 pL

Ye operational expansion (1) where AT m] to condensate and partially cool it; and then enters into 1-14 mechanical energy is extracted from the stream. The machine (11) extends the liquid stream (4 b) lbs. /in absolute +71 consistently intrinsic thermal inertia from a pressure of about kPa [absolute]] to the LNG storage pressure (10.0 psi [EY AY] kPa [absolute]) which is slightly higher than Atmospheric pressure . Operational expansion operates at [0 017] and then [100] Yoo Cooling of the expanding stream (289) to a temperature of approx. which keeps the LNG product (VY) is directed to the LNG storage tank ( er (stream; Fig. [©] and Fig. [;]; most of the cooling [1] is provided for the processes according to Figure Blas and in the form of the stream (49) and all the cooling for the stream (49a) by means of a closed-loop refrigeration. The composition of the stream 0 is the 0 z used as the working fluid in the process cycle according to Figure [0]; as an approximate molar ratio

CTY 78.9% nitrogen; methane by 775,3; Ethane by 741, and propane by refrigerant (V9) the rest of the percentage. The refrigerant stream leaves (JY) and hydrocarbons form: . kPa (Absolute) £1 AO] lb/in TeV [a WA] VA 001 vacuum (14) at partly by current ay [FE] Ye and cooled to (01) and enters Heat exchanger 00 Expanded and partially heated refrigerant (1L) and by other refrigerant streams For the simulation process of Figure [0] suppose that these other refrigerant streams are propane refrigerants of commercial quality at three different levels From the temperature and pressure, then to the heat exchanger (17) for additional cooling (IVY) indicates the partly condensed refrigerant stream:

Lan (VY) by partly heated defrosted refrigerant stream [Ve] aver 0 additionally. The refrigerant is completely condensed, then (YY) the refrigerant (stream in the heat exchanger (10) is condensed by a [2 1ea-] stream partially to -164F Sd extension dl partially cooled ( ) =( to Sd and the stream enters 0d1) Expansion Cooling where mechanical energy is extracted from the stream when it is statically expanded Operational Thermal Inertia (VF) lb/in’Absolute 61 £0 kPa (Absolute)] OAT substantially from a pressure of about T° psi absolute [;7 kPa (Absolute)]. During expansion the YE fraction vaporizes to about

Yoyo

of the stream which cools the total stream to -774 F [ve] (stream (WY). Then the expanding stream (1 Lad) enters the heat exchangers (01) (VF) (10) where it provides cooling to stream (19); current (£4) and refrigerant (currents 71 17a; and (QV) causing it to evaporate and overheat. ° and the overheated refrigerant vapor (current 1las) leaves the heat exchanger (01) at F [Ye] and compresses in three stages to +17 lbs/in'absolute [£Y0£] kPa (Absolute)) Each of the three stages of compression (Lgl gum) is administered refrigerant cE 15 and VA by an auxiliary power source and each stage is followed by a cooler (vacuum coolers 10 AY 14) to remove the compression heat. The compressed current (V1) from the vacuum cooler (14) returns to Ye A Heat exchanger (01) to complete the cycle. Table (4) (Fig. ([e] Summary of current flows-lb mol/hr [kg mol/hr]: oy dad UW propane > butane morcate pred propane ethane methane 8 and higher compounds with molecular weight vy etc <0 1 YAY 0 YY mM 14 MB Voy V 4 m vy 1 971 VY EEY Vay DM 1710 YY 161 ‎AYAA > 7 16 at v4 | | 3 zero zero \YVo 7 YY yay 011 SERN 3 pal 1/71 Yo YAS YAY 181 ¢v yi m ma 71 YYo. v YEA YAYA Yo.

Yayas 8 £4 (£0.41) Recovery ratios in ta sd vehicles:

Butane compounds Olin pentanes and lef compounds 794:57 Molecular weight ATA. lb/hr AYA [kg/hr] Production rate Production rate 47 47 lb/hr [4 87 kg/hr] ] Purity * lac / Minimum Calorific Value 0014 BTU/ft” Standard [PAY] ‘MJ/m’] Capacity Z Refrigerant Compression 4 Fea [Olan 1 kW] Propane Compression 4 Static Capacity ‎ VEATY [kW] : Total Pressure 14 HP [0 0 kW Utility Heat Methane Reboiler © 7917 thousand BTU/hr AY (YE] kW] * (based on non flow rates rounded) and assuming an operating factor of Log Vo per unit LNG production year, the specific power consumption rate for the embodiment of the present invention in accordance with Figure [0] il : 5 horsepower-hours/lb oY YA] kW -h/kg] In comparison with the previous _© < 0 < > technology processes, the percentage of improvement in efficiency varies according to the embodiment of Figure [0] from TXT 0 >> and compared with the two embodiments according to Figure [1] and Figure [© ] ; the embodiment of the present invention according to form [fo] requires 78 to 701 less capacity per unit of liquid produced. In comparison with the embodiment [0 [Fig. And so on ; For a given amount of available compressibility ¢ the Ty embodiment of Fig. [0] can liquefy about 75 more natural gas than the embodiment of Fig. 0 [1]; and about 701 more natural gas than the embodiment of Fig. [©] or approximately the same 0.5 vy the amount of natural gas as in the embodiment of the figure [£] ; Thanks to the recovery of hydrocarbons, in general, selection 0 is supported only in the form of Jil and hydrocarbons © ; Figure [©] or Figure [;] [1] between the embodiment of Figure [0] and embodiments of the present invention according to the figure and propane as part of a liquefied natural gas product or OB of a particular application on LPG monetary values vs. Corresponding in the LNG product or on specification 0 Calorific value of the LNG product (since the calorific value of the produced LNG is that produced by embodiment according to Figure OFF [4] by embodiments according to Figures [1]); [©] and : ([°] Other Embodiments and those familiar with the technique will realize that the present invention can be adapted for use with all types of Ae NGL liquefaction units to enable co-production of a natural gas liquid stream; a liquefied petroleum gas stream or An acculturated stream, as best suited to the needs at a specific location of the unit.It will also: Realize that different configurations of the process can be used to recover the liquid co-product stream. Or a condensed product stream in the form of a liquid feedstock stream instead of a natural gas liquid stream as 1 and (1) and the embodiment of the form [?] can be configured to retrieve a gas liquid stream (1) previously described in the existing feed examples In the natural C feed gas containing a large portion of the bicarbonate components and the lighter components Cy or to recover a condensation product stream that contains only the tetracarbonate components of the feed gas instead of producing a contribution product of liquefied petroleum gas as previously described in ‎ Bases _Example (©). The embodiment can be configured according to Figure [0] to recover a natural gas liquid stream containing ©

Sle a significant portion of the N,© bicarbonate components present in the feed gas or to recover a liquefied petroleum stream containing a large portion of the N,© tricarbonate components present in the feed gas (4) instead of producing an unearthed share product as previously described. In the example [?]; [€] and [0] are preferred embodiments of the present invention for conditions 1 and the figures represent alternative embodiments of the present invention that can be taken [VV] the treatment shown. Figures [7] to YO are depicted into consideration for a specific application.As shown in Figures [7] and [7], all or part of a

Ye at a feed site (V4) to a fractionation tower (11) of the separator (VF) of the condensate liquid (ve) separated down the middle of the column instead of mixing with a portion of the separator vapor (ve) An alternative embodiment of the present invention requiring [A] flowing to the heat exchanger and [1] is depicted in Fig. (V1), though having a higher SAR [1] less equipment than the two embodiments in accordance with Fig. Similarly, Figure [4] depicts an alternative embodiment of the present invention that requires equipment less than 0 also at the expense of increasing the specific consumption rate « [V] The two embodiments according to the figure [©] and the figure to [€ 1] embodiments An alternative of the present invention that requires [01] equipment [0] for capacity, and visualization of figures, is lower than the embodiment according to Figure [4], although specific capacity consumption rates are higher. [01] shown in Figs. LS (noting that on designs for a boiling-reactive absorption tower and designs for a decanter reflux tower (V9) in a boiling-0). [Two alternative embodiments of the present invention combining Say in embodiments of form [;] and forms (V4) and deethane (VA) functions of separation/adsorption tower in gas J single fractionation column (19) and depending on the amount of hydrocarbons ADE SD] that leaves the heat exchanger (©1) feed and feed gas pressure; The refrigerant feed stream at AN may not contain any liquid (because it is present at a point higher than its dew point or (01) 0 [1] shown in Figure (11) a pressure higher than its coexisting pressure ); Therefore, the separator does not need the AT extension and the figures [¥] to [17]; The cooled feed stream may flow directly to a suitable expanding device such as (10) op and the residual gaseous stream may be eliminated after recovery of the liquid contribution stream forms ev (stream [VE] and DTT to [1[ ][ J] in Figs. (ry ay) 0 (60) and (current £7) in Fig. [0](before being supplied to heat exchanger D3] and Del DY] (a And the shapes [©] to [1] for condensation and partial cooling in several ways.In the processes according to the form, the extension of AT using the energy reached by lef, the current is heated and then compressed to the pressure of «VT]: one or more units and partially cooled in a vacuum cooler and then further cooled by cross-exchange with the original stream, as shown in Figure [17]; in some applications it may be preferable to use an auxiliary compressor (09) driven, for example, by a source ef pressure current to a pressure of 00

Yo (Y£) is an external power. As shown by the equipment plotted with dashed lines (for the heat exchanger 1 [11], the shapes [©] to DY], and the vacuum cooler (©1)) in Fig. Reducing or eliminating the pre-cooling of the compressed stream before entering the heat exchanger (10) (at the expense of increasing the cooling load on the heat exchanger and in this (TA) and increasing the rate of power consumption in refrigerant compressors (14) » ( 17) and (10) 0 As is (Ye) cases; the current (1£9) leaving the compressor may flow directly to the heat exchanger as shown in Figure (01) shown in Figure [18 [ ] ; or it flows directly into the heat exchanger ` 0 and if operational expansion machines are not used to expand any of the parts of the high pressure feed gas ; [ 1 a ] by means of an external power source + such as the compressor (08) shown Jay The use of a compressor and it is not justified in other cases to make any compression of the Yao [Ye] in Figure 0 (V1) of the compressor at all, so the current flows directly to the heat exchanger (10) as shown in Compressor 16; “YE”; and by equipment plotted with broken lines (heat exchanger [TV] Fig. may need EA to preheat the stream before unit fuel gas is drawn (stream (YE) heat exchanger: before it is consumed; using utility stream fuel gas to warm additional fuel gas (0A) da NO to [V4] or other process stream to supply necessary heat; As shown in the figures from where consideration should be given to Baka evaluating choices of such for each sale and should. [YY] Factors such as gas composition; unit size; The desired input product stream recovery level

1 and available equipment.

x and according to the present invention; The inlet gas stream and the feed stream to the LNG production section can be cooled in several ways. In operations according to Figures I [IPTV] to 81]; om the inlet gas stream (11) and condensed by external refrigerant streams and liquids from the fractionation tower

As. (V4) - Figures [01[ slo] fg] to [VE] use flash separator fluids for this purpose with external refrigerant streams. and in figures [10] and [11]; Fluids from the ve tower and flash separator fluids are used for this purpose with external refrigerant streams. and in figures DV] to [1?] only external refrigerant streams are used to cool the inlet gas stream

Yoyo

(TY) However, cold process streams can also be used to supply some cooling to the high-pressure refrigerant (Ivy stream; such as those shown in Figures [4] [01] + [©] 0 and [11] Any stream at a cooler temperature than the stream(s) being cooled can also be used, for example a side stream of steam can be drawn from a separation/absorption tower (VA) or fractionation tower (11)e and used for cooling. Evaluation of the use and distribution of fluids and/or vapors from the tower to conduct heat exchange The particular arrangement of heat exchangers for inlet gas and feed gas cooling for each specific application As well as the selection of process streams for specific heat exchange services The choice of a cooling source depends on several factors, including For example, but not limited to, conditions and composition of the feed gas, unit size, heat exchanger size, temperature of the potential refrigerant source 0 0 ... etc. A MM in the technology will also realize that any combination of the above refrigerant sources or refrigeration methods can be used. To obtain the desired feed stream temperature(s) Furthermore, additional external cooling provided to the inlet gas stream and the feed stream to the LNG production section can also be achieved in several different ways. In Figure [1] and Figures IY] to [VV] it is assumed that the single-component refrigerant is boiled for high external cooling “0 | level” and the multi-component refrigerant is assumed to be evaporated for low-level external cooling so that the single-component refrigerant is used Alternatively both high-level cooling and low-level cooling can be achieved by using single-component refrigerants with low boiling points in series (“cascade cooling”) or a single single-component refrigerant at low evaporation pressures in series . As another alternative, high-level cooling and low-level cooling can be achieved by using multi-component refrigerant streams that adjust their own compositions to supply the necessary cooling temperatures. The choice of external cooling supply method depends on several factors including, but not limited to; feed gas conditions and composition unit size ay compressor drive size heat exchanger enclosed heat sink temperature etc. An expert in Yo technology will also realize that any combination of external cooling supply methods described above can be used to obtain On: The temperature(s) of the desired feed stream.

YY

Partial cooling of the condensate liquid stream leaving the heat exchanger (60) ((stream

V1] and [19 to IVT [4[ ofr] (stream 4;d) in Figs. [A] and [1] (DY in Figs. 4) (stream 44;c)] 17] (current 4;e) in Fig. [01] and [ral eel in Figs. fd (current) indicates the reduction or elimination of the amount of flashing vapor (In) and (current 49a). ) in the form [VA] in the form that may be formed during the extension of the stream to the operating pressure of the LNG storage tank 0 and this generally reduces the specific consumption rate of the capacity for the production of LNG (7) by disposing of The need for flash gas compression However, in some cases it may be preferable to reduce the capital cost of the facility by reducing the size of the heat exchanger (10) and using a means of compressing the flash gas or other means to get rid of any flash gas that may form. It is not possible to separate current extension in certain extension devices, however, alternative means of extension Vo may be used as appropriate. For example, conditions may permit operational extension of feed current or return current (V1 and [7] dv] » [1] in forms (ro substantially receding) ((current) and flash dilation ([A] and [7] [1]] can be used in forms (VS average pressure)) Partial current leaving ad IL from operational expansion of current Yay enthalpy constant qr] heat exchanger (10) ((current £8) in figures []; [1] and [+]; (stream 9;d) in Figs 0 (stream 4;e) in [01] sa] [eo] and [1] to [11]; (stream 4b) in Figures IVT [?] and (stream 169 (in Figure [1?]) ; but it would require either [YA] (stream 4c) in Figure (Hv) Fig. Gas and flash in the Ol SS process Further partial cooling in the heat exchanger (11) is required to avoid sintering and either to increase the compression of the flash vapor or other methods to eliminate the resulting scalding vapor. Likewise, constant enthalpy flash expansion can be used instead From the operational expansion “0” of the partially cooled high-pressure refrigerant stream leaving the heat exchanger with the result being an increase in the rate of ([1] and figures [©] to [1] ((the refrigerant stream) in Fig. (ve) the power consumption required for the compression of the refrigerant. While describing what are believed to be the preferred embodiments of the invention, those versed in the technique will recognize that further and additional modifications may be made to it, for example to adapt the invention to the conditions of 7.6

Ya

The present invention also provides for feed streams or other requirements without deviating from 3 days ¢ for types of streams without the following protections.” In the following claims is defined Ver

Claims (1)

Claims of protection 1-1 An improved process for liquefaction of 8 natural gas stream containing methane Y and hydrocarbon components Ji hydrocarbon where Y (a) said natural gas stream is cooled under pressure to condense at least part of it £ and form condensed stream PEL and (b) extend said condensed stream to pressure Ji to form said natural gas LNG stream; v where the optimization includes steps Cal z A 0) treats said natural gas stream in one or more cooling steps; (Y) 4 extends said natural gas stream to Medium pressure and then veo is directed to a feeding site in the middle of the distillation column, where it separates the aforementioned stream 11 into a more volatile vapor distillation stream and a relatively less volatile VY that contains a large part of the hydrocarbon components. VY the said heavier; Ve (¥) a steam distillation stream draws from an area in the said distillation column below the site yo feeding the said natural gas said expanded refrigerant stream and cools 1 sufficiently to condense at least part of it; thus A vapor stream and a liquid stream ¢stream VY ||Co m z (¢) form that substantially touches at least part of said said natural gas expanded cooled 1 stream with at least part of the stream said liquid stream 2 in said distillation column; 71 (0) said vapor distillation SLA is mixed with said more volatile vapor distillation stream YY to form a volatile fraction of residue gas containing YY contains a large portion of said methane and lighter components; And ve (1) The volatile fraction of said residue gas is cooled under pressure Yo to condense at least part of it and form said condensed stream 7. 1 “- an improved process for the liquefaction of a natural gas stream Gas contains methane Y and hydrocarbon components Ashkel Cus and 0 The aforementioned said natural gas stream cools under pressure can AS Part of it is at least 1 and forms a condensed stream Ci he; and ° (b) the said condensed stream is expanded to a lower pressure to form the said natural gas stream 1, where the improvement includes the following steps: (1) 0 A treats the natural gas stream said natural gas said in one or 4 more cooling steps to partially condense; (V) “expands said first vapor stream and said first liquid stream 0 to medium pressure; 0 (2) directs said first expanding vapor stream and said expanding first liquid stream M to two feed locations in the middle Distillation column where the aforementioned two streams are separated into a more volatile steam distillation stream and a relatively less volatile fraction containing a large portion of the aforementioned heavier hydrocarbon components; VA (©) A steam distillation stream is drawn from an area in said distillation column below the feed position of said first expanding steam stream 4 and cooled sufficiently to condense part of it on Y. the least », thus forming a second vapor stream and a second liquid stream; (7) At least part of said first expanding vapor stream YY is substantially in contact with at least part of said second liquid stream wo in said distillation column; (VY) i Said second vapor stream is mixed with said more volatile steam distillation stream, said Yo, to form a residue gas volatile fraction containing 1 large part of said methane and lighter components; and (A) 7 the volatile fraction of said residue gas is cooled under pressure YA to condense at least part of it and form said condensed stream. ~Y 1 Improved process for liquefaction of a natural gas stream containing methane Y and hydrocarbon components Cus Jai hydrocarbon ¥ 00 (The said natural gas stream is cooled under pressure to condense part of it to 1 least and form condensed stream ¢ and 03 o (b) extend said condensed stream to a lower pressure to form said 1 JG natural liquefied gas; Cua v improvement includes (1) 0 A treats said natural gas stream in one or more cooling steps; (Y) 4 Expands said natural gas stream said cooled natural gas to medium pressure and then Aan 1 to a feeding site in the middle of the distillation column, where the aforementioned stream is separated into 111 vapor distillation streams that are more volatile and a relatively less volatile fraction 7 that contains a large part of the aforementioned Ji hydrocarbon Wwe components. : VE (9) draws a vapor distillation stream from an area in said distillation column yo below the feed site of said expanding cooled natural gas stream 1 and cools sufficiently to condense at least part of it ; This forms a vapor stream 11 and a liquid stream ¢ 'A (0) that supplies part of the said liquid stream to the said distillation column as another feed stream 4 with respect to it at a feed site in the same area con Among them is the aforementioned vapor distillation stream, essentially; 9 (©) At least part of the natural gas stream of said expanding refrigerant YY substantially touches with at least part of the residue gas of said liquid stream YY in said distillation column ; L (1) The aforementioned vapor stream is mixed with the said more volatile (Goad) vapor distillation stream Yo to form a volatile fraction of 7 residue gas containing a large part of the aforementioned methane for lighter components; and YA 791 cools the volatile fraction of said residue gas under pressure Yq to condense at least part of it and form said condensed stream 7 (5S). Z 1 ;- An improved process for liquefying a natural gas stream said natural gas containing methane Y and hydrocarbon components Cus Jif hydrocarbon roo (1) The said natural gas stream is cooled under pressure to condensate part of it at least 1 and form a condensed stream ¢ and o (b) extend said condensed stream to a lower pressure to form said natural gas LNG stream 1 where the optimization includes the following steps : (1) A | said natural gas stream is treated in one or more cooling steps q to partially condensate; (Y) Ve separates said partially condensed natural gas stream to supply a steam stream vapor stream 11 first and first liquid stream; (Y) "7 | expands said first vapor stream and first said liquid stream L to medium pressure; ¢\(;) directs the vapor stream said first expanding vapor stream and said first expanding liquid stream to two feed locations in the middle of a distillation column where the two streams separate LY aforementioned to a more volatile steam distillation stream and a relatively less volatile fraction containing 8" of the aforementioned heavier; VA Feed said first expanding vapor stream and cool enough to condense part of it on 4 second; lower liquid stream, thus forming a second vapor stream and said second liquid stream Y. to distillation column liquid stream supplies part of the stream The liquid (1) (7) at a feed site in the same Ad) mentioned as another feed stream with respect to the Yy vapor distillation stream the area from which the mentioned YY vapor distillation stream is drawn substantially; Yt touches at least part of Said first expanding vapor stream substantially (V) Yo second said liquid stream with at least part of the remaining part of the liquid stream 7 L in said distillation column; said second vapor stream mixed with steam distillation stream (A) The said most volatile YA to form a volatile fraction of the said vapor distillation stream Yq and methane constituents containing a large portion of residue gas v. lighter And the aforementioned i is under pressure (residue gas) The volatile fraction of the residual gas (2) vy the aforementioned condensed stream Ca Sad) is cooled to condensate at least part of it and form a stream vy methane containing methane natural gas For liquefaction of natural gas streams Lina ile —0 \ heavier where hydrocarbon and hydrocarbon components Y mentioned under pressure to condensate part of it natural gas cool natural gas stream (0 v and ¢ condensed stream Ci Sha at least And the formation of the said ¢ stream to a lower pressure to form the natural gas stream ai (b) extends the said liquefied natural gas stream; natural gas Treats the natural gas stream (1) A 0110 A: tt said refrigerant to medium pressure 8 natural gas extends the natural gas stream (Y) q to a feed site in the middle of the distillation aan where it separates Aan Hence a more volatile Vs vapor distillation stream said stream into a steam distillation stream 11 and a relatively less volatile fraction containing a large portion of the hydrocarbon components “1 Ashqel mentioned; hydrocarbon 7 a steam distillation stream is drawn from the area In the distillation column mentioned below (( \¢ said natural gas expanding coolant to the feed site of the natural gas stream and cool enough to condense at least part of it ; Which forms a vapor stream 11 ¢ liquid stream and a vapor stream VY The expanding coolant said natural gas At least part of the natural gas stream (4) 1A liquid stream mentioned substantially touches with at least part of the liquid stream 4 mentioned in the said distillation column; Y. A liquid distillation stream is drawn from the said distillation column at a location above the mentioned (©) 71 area where the vapor distillation stream is heated from which the steam distillation stream YY is drawn A Said liquid distillation stream thereafter and then directed again to the said distillation column as another feed stream with respect to it at a location below the area from which Yi the said steam distillation stream is drawn; Yo the said steam stream is mixed with the more steam distillation stream Said volatile (1) 7 contains a large portion of residue gas A: L to form a volatile fraction of said residual gas and lighter components; and methane said methane YA under pressure residue gas The volatile fraction cools From the remaining gas (71 Yq condensed stream) to condense at least part of it and form the aforementioned condensed stream. l and hydrocarbon components £0 v (a) cools said said natural gas stream under pressure to condensate at least 1 part of it and form condensed stream Ci ¢ and ° (b) expands said condensed stream Gad to a lower pressure To form the aforementioned liquefied natural gas stream 1; Where the optimization includes the following steps: (1) A treats said said natural gas stream in one or 4 more cooling steps to partially condense it; (1) (7) separates said natural gas stream condensed partially said to supply 1 first vapor stream and 1st liquid stream; (1) extend said 1st vapor stream and said 1st liquid stream 1 to medium pressure; vi (2) directs The aforementioned first expanding vapor stream and the aforementioned first expanding liquid stream to two feeding sites in the middle of a distillation column where the aforementioned 5 streams separate into a more volatile steam distillation stream and a relatively less volatile fraction containing a large portion of hydrocarbon components. The aforementioned heavier; VA (©) draws a stream of steam distillation from an area in the said distillation column below the location 4 of feeding the said first expanded vapor stream and cools sufficiently to condense at least 7 part thereof, thus forming a second vapor stream and a liquid stream a second liquid stream: 1 (7) at least part of said first expanding vapor stream YY is substantially in contact with at least part of said second liquid stream 18,11 L in said distillation column; Y¢ () a liquid distillation stream is drawn from said distillation column at a location above the region Yo from which said vapor distillation stream is drawn ¢ where 5 the said liquid distillation stream is then heated and then is not directed again to said distillation column as another feed stream with respect to it YA at a location below the zone from which said vapor distillation stream Yq is withdrawn; £1 (A) 7 The said second steam stream is mixed with the steam distillation stream vapor distillation stream 71 The most volatile denatured to form a volatile distillate of YY residue gas Bie contains a large portion of the aforementioned methane vy and lighter components; and z Ye (9) The volatile fraction of said residue gas is cooled under pressure Yo to condense part of it on J and form said condensed stream Gal v1. methane contains methane natural gas improved natural gas stream liquefaction process 17 1 Cua Jil hydrocarbon and Y hydrocarbon components Y 0) The aforementioned natural gas stream is cooled under pressure to condense part of it on Least £ and configuration of condensed stream Ch Kia ¢ f 0 (9) The said condensed stream Ca al) is expanded to a lower pressure to form a stream il natural gas said liquefied natural gas mentioned; The improvement includes the following steps: (1) A treats said natural gas stream in one or more cooling steps; (Y ) q The natural gas stream extends said coolant natural gas to medium pressure and then Aa 1 to a feed site in the middle of the distillation column where said stream 11 separates into a more volatile vapor distillation stream And a less volatile cut Ji 91 hydrocarbon comparatively contains a large portion of the aforementioned 1 hydrocarbon constituents; VY a steam distillation stream is drawn from an area in the said distillation column below the said vy V site and cooled naturally natural gas feeding the natural gas stream yo vapor stream is enough to intensify at least part of it; Which forms a steam stream “an ¢ liquid stream” and a liquid stream mentioned to the mentioned distillation column, a liquid stream that supplies part of the liquid stream (£) YA as another feed stream for it at a feed site in the same area that “oo And Y. The aforementioned vapor distillation stream is drawn from it in a substantial Co capacity; oh (° ) YY at least part of said cooled expanding natural gas stream Yr substantially with at least part of the remainder of said liquid stream in said distillation column Ys; Yo (1) A liquid distillation stream is drawn from the aforementioned distillation column at a location above the area from which the aforementioned steam distillation stream Ya is drawn, where the aforementioned liquid distillation stream is then heated and then directed again to the aforementioned distillation column as ‘Yo’ A another feed stream with respect to it at a location below the area from which said vapor distillation stream Y4 withdraws; and (V) said vapor distillation stream mixes with the more volatile mother vapor distillation stream said to form volatile fraction of said residue gas containing, YY, a large portion of said methane and lighter components; and (A) vy cools the volatile fraction of said residue gas under pressure, Yi to condense at least part of it and form the aforementioned condensed stream. The aforementioned natural gas stream is cooled under pressure to condensate at least part of it and form a condensed stream “a Sa eg ¢ and (9°) the aforementioned condensed stream Cad) is expanded to a lower pressure to form a stream 1 natural gas, the aforementioned liquefied natural gas; Where the optimization includes the following steps: (1) A treats said natural gas stream in one or more cooling step 9 to partially condense it; (7) Ve (7) separates said partially condensed natural gas stream to supply an 11 Js vapor stream and a first liquid stream; m VY (7) expands said first vapor stream and said first liquid stream L to medium pressure; 1 ¢) Said first expanding vapor stream and said first expanding liquid stream yo are directed to two feed locations in the middle of a distillation column where said two streams 8 separate into a more volatile and relatively less volatile steam distillation stream containing 7 large fraction of the aforementioned heavier hydrocarbon components; m (©) a steam distillation stream is drawn from an area in the aforementioned distillation column below 4 the feed site of the aforementioned first expanding vapor stream and cools down Y. Sufficient to accommodate at least part of it; Which forms a second vapor stream and a 71 tb liquid stream oy (7) that supplies part of the said second liquid stream to the said distillation column as wo a second feed stream with respect to it; at a feed site within the same area from which the said vapor distillation stream, Yt, is drawn; (V) Yo at least part of said first expanding vapor stream v1 is substantially in contact with at least part of the remainder of said second liquid stream YY in said distillation column; (A) YA a liquid distillation stream is drawn from said distillation column Yq at a location above the area from which said steam distillation stream is drawn; Where 7 the aforementioned liquid distillation stream is then heated and then directed again to the aforementioned distillation column oo as another feed stream in relation to it at a location below the area B from which the aforementioned vapor distillation stream is drawn; vy (2) said second vapor stream is mixed with said more volatile vapor distillation stream ve to form a volatile fraction of residual 1 vo gas containing a large portion of said methane and 7 components lighter; and (V+) vy the volatile fraction of said residue gas is cooled under pressure vA to condense at least part of it and form said condensed stream. . lee - 1 improved to liquefy natural gas stream said natural gas contains methane Y and hydrocarbon components Cua Jil hydrocarbon y 0 ( said natural gas stream is cooled under pressure to condense part of it at least ¢ and form a condensed stream ¢ and ° (b) the said condensed stream Ci ad is extended to a lower pressure to form said stream: natural gas liquefied natural gas; no where improvement mainly includes treatment steps the following: (a) (1) treats said natural gas stream in one or more cooling steps q; (Y) 0 expands said natural gas stream to medium pressure; ( Y) 1) Said cooled and expanded natural gas stream is directed to a distillation column where 1 separates said stream into a volatile residue of residue gas containing VY. Relatively less volatile containing a large portion of the hydrocarbon constituents yo the aforementioned ashqal; and 4” (£) the volatile fraction of the aforementioned residue gas is cooled under pressure 7l to condense at least part of it and form a condensed stream the mentioned stream. alee -0 -1 improved for liquefaction of natural gas stream said natural gas contains methane Y and hydrocarbon components lighter as v 0 the said natural gas stream cools under pressure to condense part of it at least £ and form a condensed stream ¢ and (b) extend said condensed stream Ci Saal to a lower pressure to form said said natural gas liquefied stream; v where optimization mainly comprises the following treatment steps: (1) A said natural gas stream is treated in one or more cooling steps q to be partially condensed; : (Y) 1 partially separates the said Sh natural gas stream to provide at least 11 vapor stream and one liquid stream; 1" (7) said vapor stream is expanded to said medium pressure; - (£) said liquid stream is expanded to said medium pressure; ay (©) Vt expanding vapor stream said and said expanding liquid stream at least to a distillation column where the said two streams separate into ie 11 volatile residue gas ke containing a large portion of said methane VY methane and lighter components and a relatively less volatile fraction containing a portion of: the said Jay hydrocarbon constituents; and 4 (7) the volatile fraction of said residue gas is cooled under pressure Y. To condense at least part of it and form the aforementioned condensed stream. -11 1 | improvement according to protection requirement AY 10 ef oF 7 1 1 or 01 wherein the volatile fraction of said residue gas Y is compressed and then cooled under pressure v to condense part of it on least and configure the condensed stream Ci aa mentioned. 1?1- improvement according to Claim 01 AY 1 68 4 FY 01 where heated: the volatile fraction of said residue gas; It is compressed and then cooled under v pressure to condense at least part of it and form the aforementioned condensed stream. VY Gay improvement of protection claim 01 A AY 01 6 4 0 7 60 wherein the volatile fraction of said residue gas contains a large portion of said methane v; The lighter components, Cp bicarbonate components, and Dh components ¢ Cy carbonates mentioned: =VE 1 Gay improvement of protection requirement 01 fA AY © 64 FY where it contains Y. The volatile fraction of the aforementioned residue gas over a large part of the methchan. 0.0 011 the aforementioned methane Cy; lighter ingredients; Dicarbonate components: © and tricarbonate components in 1 carbonate, Cs. - residual gas; Where the remaining gaseous extract contains 11 improvement according to the protection requirement -10© 0 mentioned; The lighter components mentioned volatile methane contain a large part of the aforementioned v methane. Cp and bicarbonate components v residual gas; Where the residual gaseous extract 07 contains the improvement according to the said protection requirement 11-0 ay 1 ; Components The aforementioned volatile methane contains a large part of the aforementioned v methane. Cp and bicarbonate v components residue gas wherein the remaining gaseous fraction contains 1 1 improvement per claim 11-1 said + lighter components; methane of said volatile methane aS on the part of said. ; and tricarbonate components v ——Y A 1 | Improvement pursuant to Claim 1 1 wherein the residual gas fraction said residue gas lady contains a significant portion of said methane; lighter ingredients; v components of Cp bicarbonate ; and the components of the aforementioned D-tricarbonate.