MXPA03011267A

MXPA03011267A - Natural gas liquefaction.

Info

Publication number: MXPA03011267A
Application number: MXPA03011267A
Authority: MX
Inventors: T Cuellar Kyle
Original assignee: Elk Corp
Priority date: 2001-06-08
Filing date: 2002-06-04
Publication date: 2004-10-28
Also published as: HK1071423A1; CN1592836A; MY138353A; ZA200309504B; JP2004530858A; JP5041650B2; CA2746624A1; AR034457A1; CA2448884A1; JP2012189315A; BR0210928A; NO20035423D0; UA76750C2; NZ529941A; JP2015166670A; EA200400014A1; SA02230280B1; WO2002101307A1; EA005326B1; KR100877029B1

Abstract

A process for liquefying natural gas (50) in conjunction with producing a liquid stream containing predominantly hydrocarbons heavier than methane (41) is disclosed. In the process, the natural gas stream to be liquefied (31) is partially cooled, expanded to an intermediate pressure (14,15), and supplied to a distillation column (19). The bottom product (41) from this distillation column preferentially contains the majority of any hydrocarbons heavier than methane that would otherwise reduce the purity of the liquefied natural gas (50). The residual gas stream (37) from the distillation column (19) is compressed (16) to a higher intermediate pressure, cooled under pressure (60) to condense it, and then expanded (61) to low pressure to form the liquefied natural gas stream.

Description

LICENFACTION OF NATURAL GAS BACKGROUND OF THE INVENTION This invention relates to a process for processing natural gas or other methane-rich gas flows to produce a flow of liquefied natural gas (LNG) having a high methane purity and a liquid flow having predominantly hydrocarbons heavier than methane. Applications claiming benefit under Title 35, United States Code, Section 119 (e) of the provisional application of the United States of America, former Serial Number 60 / 296,848, which was filed on June 8, 2001. Natural Gas it is typically recovered from wells drilled in underground reservoirs. This usually has a larger portion of methane, that is, the methane comprises at least 50 mole percent of the gas. Depending on the particular underground reservoir, natural gas also contains relatively less quantities of heavy hydrocarbons such as ethane, propane, butanes, pentanes and the like, as well as water, hydrogen, nitrogen, carbon dioxide and other gases. Most natural gas is handled in a gaseous form. Most common means of transporting natural gas from the wellhead to the gas processing plants without consequence to natural gas consumers is Ref: 152395 in gas transmission pipelines at high pressure. In a number of circumstances, however, it has been found necessary and / or desirable to owe the natural gas either to transport it or to use it. In remote locations, for example, there is often no pipeline infrastructure that allows convenient transportation of natural gas to the market. In those cases, the much lower specific volume of LNG relative to natural gas in the gaseous state can greatly reduce transportation costs by allowing delivery of LNG using cargo ships and transport trucks. Another circumstance that favors the liquefaction of natural gas is its use as a fuel for motor vehicles. In large metropolitan areas, there are bus fleets, taxis, and trucks that could be driven by LNG if there is an economic source of LNG available. Those vehicles powered by LNG produce considerably less air pollution due to the nature of the clean combustion of natural gas when compared to similar vehicles powered by gasoline and diesel engines, which burn higher molecular weight hydrocarbons. In addition, if the LNG is of high purity (ie, with a methane purity of 95 mole percent or more), the amount of carbon dioxide (a "greenhouse gas") produced is considerably lower due to the ratio of carbon: lower hydrogen for methane compared to all other hydrocarbon fuels. The present invention relates generally to the liquefaction of natural gas, as well as to the production of gas as a co-product of a liquid flow consisting mainly of hydrocarbons heavier than methane, such as natural gas liquids (NGL). composed of ethane, propane, butanes, and heavier hydrocarbon components, liquefied petroleum gas (LPG) composed of propane, butanes, and heavier hydrocarbon components, or condensate composed of butanes and heavier hydrocarbon components. The production of the co-produced liquid or liquid has two important benefits: the LNG produced has a higher purity of methane, and the liquid co-product is a valuable product that can be used for many other purposes. A typical analysis of n flow of natural gas to be processed in accordance with this invention would be, in mol percent, approximately 84.2 percent methane, 7.1% ethane and other C2 components, 4.9% propane and other C3 components , 1.0% isobutane, 1.1% normal butane, 0.8% additional pentanes, with the rest constituted by nitrogen and carbon dioxide. Sulfur containing gases are also sometimes present. There are numerous known methods for liquefying natural gas. For example, see Finn, Adrián J., Grant L. Johnson and Terry R. Tomlinson, "LNG Technology for Offshore and Mid-Scale Plants," Proceedings of the Seventy-ninth Annual Convention of the Gas Processors Association, p. 429-450, Atlanta Georgia, March 13-15, 2000 and Kikkawa, Yoshitsugi, Masaaki Ohishi and Noriyoshi Nozawa, "Optimize the Power System of Baseload LNG Plant," Proceedings of the Eightieth Annual Convention of the Gas Processors Association, San Antonio, Texas, March 12-14, 2001 the same for the study of the number of those processes. US Patents Nos. 4,445,917; 4,525,185; 4,545,795; 4,755,200; 5,291,736; 5,363,655; 5,365,740; 5,600,969; 5,615,561; 5,651,269; 5,755,114; 5,893,274; 6,014,869; 6,062,041; 6,119,479; 6,125,653; 6,250,105 Bl; 6,269,655 Bl; 6,272,882 Bl; 6,308,531 Bl; 6,324,867 Bl; and 6,347,532 Bl also describe relevant processes. These methods include, in general, steps in which natural gas is purified (removing water and problematic compounds such as carbon dioxide and sulfur compounds), cooled, condensed and expanded. The cooling and condensation of natural gas can be effected in many different ways. "Cascade cooling" uses the heat exchange of natural gas with several refrigerants that have, in turn, lower boiling temperatures, such as propane, ethane and methane. As an alternative, this heat exchange can be effected using a single refrigerant, by evaporating the refrigerant at several different pressure levels. "Multi-component refrigeration" uses the heat exchange of natural gas with one or more refrigerant fluids composed of several refrigerant components instead of multiple single-component refrigerants. The expansion of natural gas can be carried out both isenthenically (using the Joule-Thomson expansion, for example) and isentropically (using an expansion work turbine, for example). Regardless of the method used to liquefy the flow of natural gas, it is common to require the removal of a significant fraction of the heavier hydrocarbons than methane before the methane-rich flow is liquefied. The reasons for this step of hydrocarbon removal are numerous, including the need to control the heating value of the LNG flow, and the value of those heavier hydrocarbon components as products in their own right. Unfortunately, little attention has been focused so far on the efficiency of the hydrocarbon removal step. In accordance with the present invention, it has been found that careful integration of the hydrocarbon removal step in the LNG liquefaction process can produce LNG and a separate heavier hydrocarbon liquid product using significantly less energy than the processes of the prior art. The present invention, although applicable at lower pressures, is particularly advantageous when feeding gases in the range of 400 to 1500 psia [2,758 to 10,342 kPa (a)] or greater are processed. For a better understanding of the present invention, reference is made to the following examples and drawings. Referring to the drawings: FIGURE. 1 is a flow diagram of a natural gas liquefaction plant adapted for the co-production of NGL in accordance with the present invention; FIGURE 2 is a pressure-enthalpy phase diagram for methane, used to illustrate the advantages of the present invention over the processes of the prior art; FIGURE 3 is a flow diagram of an alternative natural gas liquefaction plant adapted for the co-production of NGL in accordance with the present invention; FIGURE 4 is a flow chart of an alternative natural gas liquefaction plant adapted for the co-production of LPG in accordance with the present invention; FIGURE 5 is a flowchart of an alternative natural gas liquefaction plant adapted for co-production of condensate according to the present invention; FIGURE 6 is a flow diagram of an alternative natural gas liquefaction plant adapted for the coproduction of a liquid flow according to the present invention; FIGURE 7 is a flowchart of an alternative natural gas liquefaction plant adapted for the coproduction of a liquid flow according to the present invention; FIGURE 8 is a diagram of. flow of an alternative natural gas liquefaction plant adapted for the coproduction of a liquid flow according to the present invention; FIGURE 9 is a flow diagram of an alternative natural gas liquefaction plant adapted for the coproduction of a liquid flow according to the present invention; FIGURE 10 is a flow chart of an alternative natural gas liquefaction plant adapted for the coproduction of a liquid flow according to the present invention; FIGURE 11 is a flowchart of an alternative natural gas liquefaction plant adapted for the coproduction of a liquid flow according to the present invention; FIGURE 12 is a flow chart of an alternative natural gas liquefaction plant adapted for the coproduction of a liquid flow according to the present invention; FIGURE 13 is a flow chart of an alternative natural gas liquefaction plant adapted for the co-production of a liquid flow according to the present invention; FIGURE 14 is a flow diagram of an alternative natural gas liquefaction plant adapted for the coproduction of a liquid flow according to the present invention; FIGURE 15 is a flow diagram of an alternative natural gas liquefaction plant adapted for the coproduction of a liquid flow according to the present invention; FIGURE 16 is a flowchart of an alternative natural gas liquefaction plant adapted for the coproduction of a liquid flow according to the present invention; FIGURE 17 is a flow diagram of an alternative natural gas liquefaction plant adapted for the co-production of a liquid flow according to the present invention; FIGURE 18 is a flow diagram of an alternative natural gas liquefaction plant adapted for the coproduction of a liquid flow according to the present invention; FIGURE 19 is a flow diagram of an alternative natural gas liquefaction plant adapted for the coproduction of a liquid flow according to the present invention; FIGURE 20 is a flow diagram of an alternative natural gas liquefaction plant adapted for the coproduction of a liquid flow according to the present invention; and FIGURE 21 is a flow diagram of an alternative natural gas liquefaction plant adapted for the coproduction of a liquid flow according to the present invention; In the following explanation of the previous figures, tables are provided that summarize the calculated flow rates for representative process conditions. In the tables that appear here, the values for the flow rates (in moles per hour) have been rounded to the nearest whole number for convenience. The total flow rates shown in the tables include all non-hydrocarbon components and are therefore generally larger than the sum of the flow rates of the streams or streams 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 described in the figures are based on the assumption that there is no heat leakage from (or into) the surroundings to (or from) the process. The quality of the commercially available insulating materials makes this very reasonable assumption and one that is typically made by those skilled in the art. For convenience, process parameters are reported in both the traditional British units and the Units of the International System of Units (SI). The molar flow rates in the tables can be interpreted as mol pounds per hour or kilograms mol per hour. The energy consumptions reported as horsepower (hp) and / or thousands of British Thermal Units (MBTU / Hr) correspond to the molar flow rates established in mol pounds per hour. The energy consumptions reported as kilowatts (kW) correspond to the molar flow rates established in kilograms mol per hour. The production rates reported as pounds per hour (Lb / Hr) correspond to the molar flow rates established in mol pounds per hour. The production speeds reported as kilograms per hour (kg / hr) correspond to the molar flow rates established in kilograms mol per hour. DETAILED DESCRIPTION OF THE INVENTION Example 1 Referring now to FIGURE 1, we begin with an illustration of a process according to the present invention, where it is desired to produce an NGL co-product containing the majority of the ethane and the heavier components in the natural gas feed flow. In this simulation of the present invention, the inlet gas enters the plant at 90 ° F [32 ° C] and 1285 psia [8.860 kPa (a)] as flow 31. If the inlet gas contains a dioxide concentration of carbon and / or sulfur compounds that could prevent product flows from satisfying the specifications, those compounds are removed by the appropriate pretreatment of the feed gas (not shown). In addition, the feed flow is usually dehydrated to prevent the formation of hydrate (ice) under cryogenic conditions. Typically, a solid desiccant has been used for this purpose. The feed flow 31 is cooled in the heat exchanger 10 by heat exchange with coolant flows and de-tailed side-boiler fluids at -68 ° F [-55 ° C] (flow 40). Note that in all cases the heat exchanger 10 is representative of any one of a multitude of individual heat exchangers or a single multi-pass heat exchanger, or any combination thereof. (The decision to use more than one heat exchanger for the indicated cooling · services will depend on numerous factors including, but not limited to, the flow velocity of the inlet gas, the size of the heat exchanger, the flow, etc.). The cooled flow 31a enters the separator 11 at -30 ° F [-34 ° C] and 1278 psia [8,812 kPa (a)], where the vapor (flow 32) is separated from the condensed liquid (flow 33). The vapor (flow 32) of the separator 11 is divided into two streams, 34 and 36. The stream 34, which contains about 20% of the total vapor, is combined with the condensed liquid, the stream 33, to form the stream 35. combined flow 35 passes through heat exchanger 13 in relation to heat exchange with coolant flow 71e, resulting in substantial cooling and condensation of flow 35a. The substantially condensed flow 35a to -120 ° F [-85 ° C] is then rapidly expanded through an appropriate expansion device, such as the expansion valve 14, to the operating pressure (approximately 465 psia - [3.206 kPa ( a)]) of the fractionation tower 19. During expansion a portion of the flow is evaporated, resulting in the cooling of the total flow. In the process illustrated in FIGURE 1, the expanded flow 35b leaving the expansion valve 14 reaches a temperature of -122 ° F [-86 ° C], and is supplied to a feeding position at the midpoint in the section demethanizer 19b from the fractionation tower 19. The remaining 80% of the steam from the separator 11 (flow 36) enters an expansion work machine 15 in which the mechanical energy is extracted from this portion of the high pressure feed. The machine 15 expands the vapor in a substantially isentropic manner from a pressure of about 1278 psia [8,812 kPa (a)] to the operating pressure of the tower, with the work of an expansion cooling the expanded flow 36a to a temperature of about - 103 ° F [-75 ° C]. Typical commercially available expanders are capable of recovering in the order of 80-85% of the theoretically available work in an ideal isentropic expansion. The recovered work is often used to drive a centrifugal compressor (such as element 16) that can be used to recompress the gas at the top of the tower (flow 38), for example. The expanded and partially condensed flow 36a is supplied as feed to the distillation column 19 at a feed point in the middle of the lower column. The demethanizer in the fractionating tower 19 is a conventional distillation column containing a plurality of vertically spaced trays, one or more packed beds, or some combination of trays and gaskets. As is often the case in natural gas processing plants, the fractionation tower can consist of two sections. The upper section 19a is a separator where the upper feed is divided into its respective vapor and liquid portions, and where the steam rising from the distillation or demethanization section 19b is combined with the steam portion (if any) the upper feed to form the vapor of the cold demethanized top (flow 37), which leaves the top of the tower at -135 ° F [-93 ° C]. The demethanization section, lower, 19b contains the trays and / or gaskets and provides necessary contact between the liquids falling down and the vapors ascending upwards. The demethanization section also includes one or more boilers (such as boiler 20) which heat and evaporate a portion of the liquid flowing down the column to provide separation of the vapors flowing up the column. The liquid product flow 41 exits the bottom of the tower at 115 ° F [46 ° C], based on a typical specification of a methane to ethane ratio of 0.020: 1 on a molar basis in the bottom product . The demethanized vapor from the top (flow 37) is heated to 90 ° F [32 ° C] in the heat exchanger 24, and a portion of the hot demethanized steam from the top is withdrawn to serve as fuel gas (flow 48). ) for the plant. (The amount of fuel gas that must be removed is determined to a large extent by the fuel required by the machines and / or turbines that drive the gas compressors in the plant, such as refrigerant compressors 64, 66 and 68 in this example). The hot demethanized vapor from the remaining top (flow 38) is compressed by the compressor 16 operated by the expansion machines 15, 61 and 63. After cooling to 100 ° F [38 ° C] in the discharge chiller 25 the flow 38b is further cooled to -123 ° F [-86 ° C] in heat exchanger 24 by cross-exchange with cold demethanized vapor from top, flow 37. Flow 38c then enters heat exchanger 60 and it is further cooled by the coolant flow 71d. After cooling to an intermediate temperature, the flow 38c is divided into two portions. The first portion, flow 49, is further cooled in the heat exchanger 60 to -257 ° F [-160 ° F] to condense and subcool it, after which it enters an expansion work machine 61 in which the mechanical energy of the flow is extracted. The machine 61 expands the liquid flow 49 substantially isentropically from a pressure of about 562 psia [3,878. kPa (a)] at the storage pressure of the LNG (15.5 psia [107 kPa (a)], slightly above the atmospheric pressure The expansion work cools the expanded flow 49a to a temperature of approximately -258 ° F [ -161 ° C], after which it is then directed to the LNG storage tank 62 which houses the LNG product (flow 50) The flow 39, the other portion of the flow 38c, is removed from the heat exchanger 60 at -160 ° F [-107 ° C] and rapidly expanded through an appropriate expansion device, such as the expansion valve 17, to the operating pressure of the fractionation tower 19. In the process illustrated in FIGURE 1 , there is no evaporation in the expanded flow 39a, so that its temperature falls only slightly to -161 ° F [-107 ° C] leaving the expansion valve 17. The expanded flow 39a is then supplied to the a separating section 19a in the upper region of the fractionation tower 19. Liquids eparados in it become the food superior to the demethanization section 19b. All cooling for flows 35 and 38c is provided by the closed-cycle cooling circuit. The working fluid for this cycle is a mixture of hydrocarbons and nitrogen, with the composition of the mixture adjusted as necessary to provide the required coolant temperature, condensing at the same time at a reasonable pressure using the available cooling medium. In this case, the condensation with cooling water has been considered, so a refrigerant mixture composed of nitrogen, methane, ethane, propane and heavier hydrocarbons is used in the simulation of the process of FIGURE 1. The composition of the flow, in mol percent, it is 7.5% nitrogen, 41.0% methane, 41.5% ethane, and 10.0% propane, with the rest constituted by heavier hydrocarbons. The coolant flow 71 leaves the discharge cooler 69 at 100 ° F [38 ° C] and 607 psia [4.185 kPa (a)]. This enters the heat exchanger 10 and is cooled to -331F [-35 ° C] and partially condensed by the partially heated expanded coolant flow 71f and by other coolant flows. For the simulation of FIGURE 1, it has been assumed that these other coolant flows are commercial grade propane coolant at three different temperatures and pressure levels. The partially condensed refrigerant flow 71a then enters heat exchanger 13 to further cool to -114 ° F [-81 ° C] by the partially heated expanded coolant flow 71e, which partially condenses and subcool to the refrigerant (flow 71b) . The refrigerant is subcooled to -257 ° F [-160 ° C] in the heat exchanger 60 by the expanded coolant flow 71d. The flow of subcooled liquid 71c enters an expansion work machine 63 in which the mechanical energy of the flow is extracted as it expands substantially isentropically from a pressure of about 586 psia [4.040 kPa (a)] to approximately 34 psia [234 kPa (a)]. During expansion a portion of the flow is evaporated, resulting in cooling of the total flow to -263 ° F [-164 ° C] (flow 71d). The expanded flow 71d then enters the heat interreactors 60, 13 and 10 where it provides cooling to the flow 38c, the flow 35, and the refrigerant (flow 71, 71a and 71b) when it evaporates and overheats. The superheated refrigerant (flow 71g) leaves the heat exchanger 10 at 93 ° F [34 ° C] and is compressed in three stages at 617 psia [4,254 kPa (a)]. Each of the three compression stages (refrigerant compressors 64, 66 and 68) is driven by one. source of supplementary energy and is followed by a cooling (discharge chillers 65, 67 and 69) to remove the heat of compression. The compressed flow 71 of the discharge cooler 69 returns to the heat exchanger 10 to complete the cycle. A summary of the flow rates of the flow or current and the energy consumption for the process illustrated in FIGURE 1 is presented in the following table: Table I (FIGURE 1) Summary of Current Flow-Lb. Moles / Hr [kg moles / Hr] Flow Methane Ethane Propane Butane + Total 31 40,977 3, 861 2, 408 1, 404 48, 656 32 32,360 '2, 675 1, 469 701 37,209 33 8, 617 1, 186 939 703 11,447 34 6, 472 535 294 140 7,442 36 25,888 2, 140 1,175 561 29,767 37 47, 771 223 0 0 48, 000 39 6, 867 32 0 0 6, 900 41 73 3, 670 2, 408 1, 404 7,556 48 3, 168 15 0 0 3,184 50 37,736 176 0 0 37, 916 Recoveries in LGN * Ethane 95.06% Propane 100.00%. Butane + 100.00% Production Speed 308.147 L / Hr [308.147 kg / Hr] LNG Product Production Speed 610.813 Lb / Hr [610.813 kg / Hr] Purity * 99.52% Heating value 912.3 BTÜ / SCF [33.99 MJ / m3] Lower Power Compressor Coolant 103,957 HP [170,904 kW] Compression Propane 33,815 HP [55,591 kW] Total Compression 137,772 HP [226,495 kW] Heat Useful Demetanizer boiler 29,364 MBTU / Hr [18,969 kW] * (Based on unrounded rounds) The efficiency of the GLN production processes is typically compared using the "specific energy consumption" required, which is the ratio of the total cooling compression power to the total liquid production rate. The published information on the specific energy consumption for prior art processes to produce GLN indicates a range of 0.168 HP / hr [0.276 kW-Hr / kg] to 0.182 HP-Hr / Lb [0.300 khr / kg], which is believed to be based on a factor on the flow of 340 days per year for the GLN production plant. On this same basis, the specific energy consumption for the embodiment of FIGURE 1 of the present invention is 0.161 HP-Hr / Lb [0.265 kW-Hr / kg], which gives an improvement in the efficiency of 4-13. % on the processes of the prior art. Furthermore, it should be noted that the specific energy consumption for the prior art processes is based on the coproduction of only one GPL stream (C3 and heavier hydrocarbons) or condensed liquid (C4 and heavier hydrocarbons) at levels of Relatively low recovery, a liquid flow of NGL (C2 and heavier hydrocarbons) as shown for this example of the present invention. The prior art processes require considerably more cooling energy to co-produce a GLN energy flow instead of a GPL flow or a condensed flow. There are two main factors that contribute to the improved efficiency of the present invention. The first factor can be understood by examining the thermodynamics of the liquefaction process when applied to a high pressure gas flow as considered in this example. Since the principal constituent of this flow is methane, the thermodynamic properties of methane can be used for purposes of comparing the liquefaction cycle employed in the prior art processes against the cycle used in the present invention. FIGURE 2 contains a pressure-enthalpy phase diagram for methane. Most of the prior art liquefaction cycles, all the cooling of the gas flow is effected while the flow is at high pressure (path AB), after which the flow is then expanded (path BC) to the pressure of the GLN storage vessel (slightly above atmospheric pressure). This expansion step can employ an expansion work machine, which is typically capable of recovering in the order of 75-80% of the work theoretically available in an ideal isentropic expansion. For the purpose of simplification, the fully isentropic expansion is presented in FIGURE 2 for path B-C. Even so, the enthalpy reduction provided by this expansion work is very small, because the constant entropy lines are almost vertical in the liquid region of the phase diagram. This now contrasts with the liquefaction cycle of the present invention. After partial cooling at high pressure (path A-A ') / the gas flow is expanded by work (path A' -A ") at an intermediate pressure., the completely isentropic expansion is presented with the interest of simplifying). The rest of the cooling is effected at the intermediate pressure (path A "-B"), and the flow is then expanded (path B'-C) to the pressure of the GLN storage vessel. Since the constant entropy lines are inclined at least gradually in the vapor region of the phase diagram, a significantly greater enthalpy reduction is provided by the first expansion work step (path A '-A ") of the present invention. Thus, the total amount of cooling required by the present invention (the sum of the trajectories AA 'and A "-B') is less than the cooling required by the prior art process (trajectory AB), reducing the cooling (and consequently cooling compression) required to liquefy the gas flow. The second factor that contributes to the best efficiency of the present invention is the superior performance of hydrocarbon distillation systems at lower operating pressures. The hydrocarbon removal step and most of the processes of the prior art is carried out at high pressure, typically using a scrubbing column that employs a cold hydrocarbon liquid as the absorbent flow to remove the heavier hydrocarbons from the incoming gas flow. . The operation of the high pressure scrubbing column is very efficient, since it results in the coabsorption of a significant fraction of methane and ethane from the gas flow, which must be subsequently separated from the absorbent liquid and cooled to become part of the product. of GLN. In the present invention, the hydrocarbon removal step is conducted at the intermediate pressure where the vapor-liquid equilibrium is much more favorable, where as a result it gives a very efficient recovery of the heavier hydrocarbons desired in the co-product liquid flow. Example 2 If the specification of the GLN product allows it to be recovered more from the ethane contained in the feed gas in the GLN product, a simpler embodiment of the present invention may be employed. FIGURE 3 illustrates that alternative modality. The composition of the incoming gas and the conditions considered in the process presented in FIGURE 3 are the same as those in FIGURE 1. Consequently, the process of FIGURE 3 can be compared with the modality presented in FIGURE 1. In the simulation of the process of FIGURE 3, the cooling, expansion, and expansion scheme of the inlet gas for the NGL recovery section is essentially the same as that used in FIGURE 1. The inlet gas enters the plant at 90 ° F [32 ° C] and 1285 psia [8,860 kPa (a)] as flow 31 and is cooled in heat exchanger 10 by heat exchange with coolant flows and liquids from demetallizing side boiler to -35 ° F [- 37 ° C] (flow 40). The cooled flow 31a enters the separator 11 at -30 ° F [~ 34 ° C] and 1278 psia [8,812 kPa (a)], where the steam (flow 32) is separated from the condensed liquid (flow 33). The vapor (flow 32) of the separator 11 is divided into two flows, 34 and 36. The flow 34, which contains about 20% of the total vapor, is combined with the condensed liquid, flow 33, to form the flow 35. The flow combined 35 passes through the heat exchanger 13 in relation to the heat exchange with the coolant flow 7le, resulting in substantial cooling and condensation of the flow 35a. The substantially condensed flow 35a to -120 ° F [-85 ° C] is then rapidly expanded through an appropriate expansion device, such as expansion valve 14 at operating pressure (approximately 465 psia [3,206 kPa (a)) ]) of the fractionation tower 19. During expansion a portion of the flow evaporates, resulting in the cooling of the total flow. In the process illustrated in FIGURE 3, the expanded flow 35b leaving the expansion valve 14 reaches a temperature of -122 ° F [-86 ° C], and is supplied to the separating section in the upper region of the fractionation tower 19. The liquids separated therein are convert the top feed to the demetaminating section in the lower region of the fractionation tower 19. The remaining 80% of the steam from the separator 11 (flow 36) enters an expansion work machine 15 in which the mechanical energy is extracted of this portion of the high pressure feed. The machine 15 expands the vapor in a substantially isentropic manner from a pressure of about 1278 psi [8,812 kPa (a)] to the operating pressure of the tower, with the expansion work cooling the expanded flow 36a to a temperature of about -103. ° F [-75 ° C]. The expanded and partially condensed flow 36a is supplied as feed to the distillation column 19 at the feed point in the middle part of the column. Cold demethanized vapor from the top (flow 37) leaves the top. from the fractionation tower 19 to -123 ° F [-86 ° C]. The liquid product flow 41 exits the bottom of the tower at 118 ° F [48 ° C], based on the typical specification of a methane to ethane ratio of 0.020: 1 on a molar basis in the bottom product. The demethanized vapor from the top (flow 37) is heated to 90 ° F [32 ° C] in the heat exchanger 24, and a portion (flow 48) is then removed to serve as a fuel gas for the plant. The remainder of the demethanized hot steam from the top (flow 49) is compressed by the compressor 16. After cooling to 100 ° F [38 ° C] in the discharge chiller 25, the flow 49b is further cooled to -112. ° F [-80 ° C] in the heat exchanger 24 by cross-exchange with the cold demethanized vapor from the top, flow 37. The flow 49c then enters the heat exchanger 60 and is further cooled by the flow of refrigerant 71d at -257 ° F [-160 ° C] to condense and subcool it, after which an expansion work machine 61 enters in which the mechanical energy of the flow is extracted. The machine 61 expands the flow of liquid 49d substantially isentropically from a pressure of about 583 psia [4.021 kPa (a)] to the storage pressure of GLN (15.5 psia [107 kPa (a)]), slightly above the atmospheric pressure. The expansion work cools the expanded flow 49e to a temperature of about -258 ° F [-161 ° C], after which it is then directed to the GLN storage tank 62 which contains a GLN product (flow 50) . Similar to the process of FIGURE 1, all cooling for flow 35 and 49c is provided by a closed cycle refrigeration circuit. The flow composition used as a working fluid in the cycle for the process of FIGURE 3, at approximately one mole percent, is 7.5% nitrogen, 40.0% methane, 42.5% ethane and 10.0% propane, with the rest consisting of hydrocarbons more heavy. The coolant flow 71 leaves the discharge cooler 69 at 100 ° F [38 ° C] and 607 psia [4.185 kPa (a)]. This enters the heat exchanger 10 and is cooled to -31 ° F [-35 ° C] and partially condensed by partially heated expanded coolant flow 71f and by other coolant flows. For the simulation of FIGURE 3, it has been assumed that these other refrigerant streams are commercial quality propane refrigerant at three different temperature and pressure levels. The partially condensed refrigerant flow 71a then enters the heat exchanger 13 to further cool to -121 ° F [-85 ° C] by the partially heated expanded coolant flow 7le, partially condensed and subcooled the refrigerant (flow 71b). The refrigerant is subcooled further to -257 ° F [-160 ° C] in the heat exchanger 60 by the expanded refrigerant flow 71d. The subcooled liquid flow 71c enters an expansion work machine 63 in which the mechanical energy of the flow is extracted when it expands substantially isentropically from a pressure of about 586 psia [4.040 kPa (a)] to about 34 psia [234 kPa (a)]. During expansion a portion of the flow evaporates, resulting in cooling of the total flow to -263 ° F [-l'64 ° C] (flow 71d). The expanded flow 7Id then again enters the heat exchangers 60, 13 and 10 where it provides cooling to the flow 49c, flow 35, and the refrigerant (flows 71, 71a and 71b) when it is evaporated and superheated. The superheated refrigerant vapor (flow 71g) leaves the heat exchanger 10 at 93 ° F [34 ° C] and is compressed in three stages at 617 psia [4,254 kPa (a)]. Each of the three compression stages (refrigerant compressors 64, 66 and 68) is activated by a supplementary energy source and is followed by a cooler (discharge chillers 65, 67 and 69) to remove the compression heat. The compressed flow 71 of the discharge cooler 69 returns to the heat exchanger 10 to complete the cycle. A summary of the flow rates of the flow or current of energy consumption for the process illustrated in FIGURE 3 is presented in the following table: Table II (FIGURE 3) Summary of Current Flow-Lb. Moles / Hr [kg moles / Hr] Flu or Methane Ethane Propane Butane + Total 31 40, 977 3, 861 2,408 1,404 48, 656 32 32, 360 2, 675 1, 469 701 37,209 33 8, 617 1, 186 939 703 11, 447 34 6, 472 535 294 140 7,442 36 25, 888 2, 140 1, 175 561 29,767 37 40, 910 480 62 7 41, 465 41 67 3, 381 2, 346 1,397 7,191 48 2, 969 35 4 0 3,009 50 37, 41 445 58 7 38, 456 Recoveries in NGL * Ethane 87.57% Propane 97.41% Butane + 99.47% Production Speed 296.175 L / Hr [296.175 kg / Hr] LNG Product Production Speed 625,152 Lb / Hr [625,152 kg / Hr] Purity * 98.66% Heating value 919.7 BTU / SCF [34.27 MJ / m3] Lower Power Compression of Refrigerant 96,560 HP [158,743 kW] Compression of Propane 34,724 HP [57,086 kW] Total compression 131,284 HP [215,829 kW] Heat Util Demetanizer Boiler 22,177 MBTU / Hr [14,326 kW] * (Based on unrounded rounds) Assuming a factor in flow of 340 days per year for the NGL production plant, the specific power consumption for the modality of FIGURE 3 of the present invention is 0.153 HP-Hr / Lb [0.251 k-Hr / Kg] . In comparison with the processes of the prior art, the improvement in efficiency is 10-20% for the FIGURE modality. 3. As noted at the beginning for the embodiment of FIGURE 1, this improves the efficiency that is possible with the present invention even when a NGL co-product is produced instead of the GPL or condensate co-product produced by the processes of the art. previous. In comparison with the embodiment of FIGURE 1, the embodiment of FIGURE 3 of the present invention requires approximately 5% less power per unit of liquid produced. Thus, for a given amount of available compression power, the modality of FIGURE 3 could liquefy approximately 5% more natural gas than the modality of FIGURE 1 by virtue of the lower recovery of C2 hydrocarbons and heavier in the NGL co-product. The choice between the modalities of FIGURE 1 and FIGURE 3 of the present invention for a particular application will be dictated, generally, by the monetary value of the heavier hydrocarbons in the LNG product - against its corresponding value of the product of LNG, or by the specification of the heating index for the GLN- product (since the GLN heating rate produced by the modality of FIGURE 1 is less than that produced by the modality of FIGURE 3).

Example 3 If the specifications for a GL product allow all the ethane contained in the fed gas to be recovered in the LNG product, or if there is no market for a liquid co-product containing ethane, an alternative mode of the product may be used. present invention as shown in FIGURE 4 to produce a co-product flow of LPG. The composition of the inlet gas and the conditions considered in the process presented in FIGURE 4 are the same as those of FIGURES 1 to 3. Accordingly, the process of FIGURE 4 can be compared with the embodiments presented in FIGURES 1 and 3. In the process simulation of Figure 4, the inlet gas enters the plant at 90 ° F [32 ° C] and 1285 psia [8,860 kPa (a)] as flow 31 and is cooled in the heat exchanger. heat 10 by heat exchange by the coolant streams and the separator liquids evaporated instantaneously at -46 ° F (-43 ° C) (flow 33a). The cooled flow 31a enters the separator 11 at -1 ° C [-18 ° C] and 1278 psia [8,812 kPa (a)] where the vapor (flow 32) is separated from the condensed liquid (flow 33). The steam (flow 32) of the separator 11 enters the expansion work machine 15 in which the mechanical energy of this portion of the high pressure supply is extracted. The machine 15 expands the vapor in a substantially isentropic manner from a pressure of about 1278 psia [8,812 kPa (a)] to a pressure of about 440 psia [3,034 kPa (a)] (the operating pressure of the separating / absorbing tower). ), with the expansion work cooling the expanded flow 32a to a temperature of approximately -81 ° F [-63 ° C]. The expanded and partially condensed flow 32a is supplied to the absorbent section 18b in a lower region of the separator / absorbent tower 18. The liquid portion of the expanded flow is mixed with the liquids that fall down from the absorbent section and the liquid flow combined 40 leaves the bottom of the separating / absorbing tower 18 at -86 ° F [-66 ° C]. The expanded flow steam portion rises upward through the absorbent section and comes in contact with the cold liquid that falls down to condense and absorb the C3 components and heavier components. The separator / absorbent tower 18 is a conventional distillation column containing a plurality of vertically spaced trays, one or more packed beds or some combination of trays and packages. As is often the case in natural gas processing plants, the separating / absorbing tower may consist of two sections. The upper section 18a is a separator where any vapor contained in the upper feed is separated from its corresponding liquid portion, and where the steam rising or arising from the lower distillation or absorption section 18b is combined with the steam portion (if there is) of the upper feed to form the cold distillation flow 37, which leaves the top of the tower. The lower absorption section 18b contains the trays and / or packages and provides the necessary contact between the liquids falling down and the vapors rising upwards to condense and absorb the components of C3 and heavier components. The combined liquid flow 40 from the bottom of the separator / absorber tower 18 is routed to the heat exchanger 13 by the pump 26 where it (the flow 40a) is heated since it is provided with the cooling of the top of the deethanizer (flow 42) and the refrigerant (flow 71a). The combined liquid flow is heated to -24 ° F [-31 ° C], partially evaporating the flow 40b before it is supplied as a feed to the middle part of the deethanizer column 19. The separator liquid (flow 33) ) is instantaneously expanded slightly above the operating pressure of the deethanizer 19 by the expansion valve 12, cooling the flow 33 to -46 ° F [-43 ° C] (flow 33a) before it provides cooling to the feed gas incoming as described at the beginning. The flow 33b, now at 85 ° F [29 ° C], then enters the deethanizer 19 at the middle feed point of the lower air column. In the deethanizer, the flows 40b and 33b are separated from their methane and C2 components. The deethanizer of tower 19, which operates at about 453 psia [3,123 kPa (a)], is also a conventional distillation column containing a plurality of vertically separated trays, one or more packed beds, or some combination of trays and packages . The deethanizer tower may also consist of two sections: an upper separating section 19a where any vapor contained in the upper feed is separated from its corresponding liquid portion, and where the steam rising from the lower distillation or destannation section 19b is combined with the steam portion (if any) of the upper feed to form the distillation flow 42 which leaves the top of the tower; and a lower, desetanization section 19b containing the trays and / or packages to provide the necessary contact between the liquids falling down and the vapor rising upwards. The detanning section 19b also includes one or more boilers (such as boiler 20) which heat and evaporate a portion of liquid at the bottom of the column to provide separation vapors flowing up the column to separate the liquid product, flow 41, of the methane and C2 components. A typical specification for the bottom liquid product is that it has an ethane to propane ratio of 0.020: 1 on a molar basis. The liquid product flow 41 exits the deethanizer bottom at 214 ° F [101 ° C]. The operating pressure in the deethanizer 19 is maintained slightly above the operating pressure of the separator / absorbent tower 18. This allows steam from the top of the deethanizer (flow 42) to flow through the heat exchanger 13 and consequently towards the upper section of the separator / absorbent tower 18. In the heat exchanger 13, the top of the deethanizer at -19 ° F [-28 ° C] is' directed in heat exchange relationship with the flow of combined liquid (flow 40a) from the bottom of the separating / absorbing tower 18 and the flow of evaporated evaporator 71e instantly, cooling the flow to -89 ° F [-67 ° C] (flow 42a) and condensing this partially. The partially condensed stream enters the reflux drum 22 where the condensed liquid (stream 44) is separated from the non-condensed vapor (stream 43). The flow 43 is combined with the distillation steam flow (flow 37) leaving the upper region of the separating / absorbing tower 18 to form the cold waste gas flow 47. The condensed liquid (flow 44) is pumped at a higher pressure by the pump 23, after which the flow 44a is divided into two portions. A portion, the flow 45 is routed to the upper separating section of the separator / absorbent tower 18 to serve as the cold liquid that comes in contact with vapors that rise upwardly through the absorbent section. The other portion is supplied to deethanizer 19 as reflux flow 46, which flows to an upper feed point on deethanizer 19 at -89 ° F [-67 ° C]. The cold waste gas (flow 47) is heated to at least -94 ° F [-70 ° C] to 94 ° F [34 ° C] in the heat exchanger 24, and a portion (flow 48) is then removed to serve as fuel gas for the plant. The remainder of the heated waste gas (flow 49) is compressed by the compressor 16. After cooling to 100 ° F [38 ° C] in the discharge cooler 25, the flow 49b is further cooled to -78 ° F [- 61 ° C] in the heat exchanger 24 by cross-exchange with the cold waste gas, the flow 47. The flow 49c then enters the heat exchanger 60 and is further cooled by the flow of the refrigerant 71d to -255 ° F [ -1G0 ° C] to condense and subcool this, after which it enters an expansion work machine 61 in which the mechanical energy of the flow is extracted. The machine 61 expands the liquid flow 49d substantially isentropically from a pressure of about 648 psia [4.465 kPa (a)] to the storage pressure of LNG (15.5 psia [107 kPa (a)]), slightly above the atmospheric pressure. The expansion work cools the expanded flow 49e to a temperature of about -256 ° F [-160 ° C], after which it is then directed to the LNG storage tank 62 which contains the product, of LNG (flow fifty) . Similar to the processes of Figure 1 and Figure 3, much of the cooling of the flow 42 and all of the cooling of the flow 49c is provided by a closed-cycle cooling circuit. The composition of the flow used as working fluid in the cycle for the process of Figure 4, in mol approximate percent, it is 8.7% nitrogen, 30.0% methane, 45.8% ethane and 11.0% propane, with the rest consisting of heavier hydrocarbons. The coolant from flow 71 leaves the discharge cooler 69 at 100 ° F [38 ° C] and 607 psia [4.185 kPa (a)]. It enters heat exchanger 10 and is cooled to -17 ° F [-27 ° C] and partially condensed by the partially heated expanded coolant flow 71f and by other reflower flows. For the simulation of Figure 4, it has been assumed that these other refrigerant flows are of commercial quality propane refrigerant at three different temperature and pressure levels. The partially condensed refrigerant flow 71a then enters the heat exchanger 13 to be further cooled to -89 ° C [-67 ° C] by the partially heated expanded coolant flow 71e further condensing the refrigerant (flow 71b). The refrigerant is fully condensed and then subcooled to -255 ° F [-160 ° C] in the heat exchanger 60 by the flow of the expanded refrigerant 71d. The flow of the subcooled liquid 71c enters an expansion work machine 63 in which the mechanical energy of the flow is extracted when it is substantially isentropically expanded from a pressure of about 586 psia [4.040 kPa (a)] to about 34 psia [234 kPa (a)]. During expansion a portion of the flow evaporates, resulting in cooling of the total flow to -264 ° F [-164 ° C] (flow 71d). The expanded flow 7Id then again enters the heat interreactors 60, 13 and 10 where it provides cooling to the flow 49c, the flow 42, and the refrigerant (flows 71, 71a and 71b) when it is evaporated and superheated. The superheated refrigerant vapor (flow 71g) leaves the heat exchanger 10 at 90 ° F [32 ° C] and is compressed in three stages at 617 psia [4,254 kPa (a)]. Each of the three compression stages (refrigerant compressors 64, 66 and 68) is operated by a supplementary energy source and followed by a cooler (discharge chillers 65, 67 and 69) to remove the compression heat. The compressed flow 71 of the discharge cooler 69 returns to the heat exchanger 10 to complete the cycle. A summary of the flow rates of flow and energy consumption for the process illustrated in Figure 4 is presented in the following table: Table III (Figure 4) Summary of Flow Flow - Lb.Moles / Hr [kg moles / Hr ] Flu or Me-Bath Ebony Propane Butanes + Total 31 40, 977 3,861- 2,408 1,404 48, 656 32 38, 431 3,317 1,832 820 44, 405 33 2,546 544 576 584 4,251 37 36, 692 3,350 19 0 40, 066 40 5,324 3,386 1,910 820 11, 440 41 0 48 2, 386 1, 404 3, 837 42 10, 361 6,258 168 0 16,789 43 4,285 463 3 0 4,753 44 6, 076 5,795 165 0 12, 036 45 3,585 3,419 97 0 7,101 46 2, 491 2,376 68 0 4,935 47 40, 977 3, 813 22 0 44, 819 48 2, 453 228 1 0 2, 684 50 38, 524 3, 585 21 0 42,135 Recoveries in PGL * Propane 99.08% Butaños + 100.00% Production Speed 197,051 Lb / Hr [197,051 kg / Hr] LNG Product Production Speed 726,918 Lb / Hr [726,918 kg / Hr] Purity * 91.43% Lower Heating Value 969.9 BTU / SCF [36.14 MJ / m3] Power Coolant Compression 95.424 HP [156.876 kW] Propane Compression 28.060 HP [46.130 kW] Total Compression 123.484 HP [203.006 kW] Heat Utilizer Demetanizer Boiler 55.070 MBTU / Hr [35,575 kW] * (Based on non-rounded flow rates) Assuming a factor on the flow of 340 days per year for the LNG production plant, the specific energy consumption for the modality of Figure 4 of the present invention is 0.143 HP- Hr / Lb [0.236 kW-Hr / kg]. Compared with the processes of the prior art, the improvement in efficiency is 17-27% for the modality of Figure 4.

Compared with the embodiments of Figure 1 and Figure 3, the embodiment of Figure 4 of the present invention requires from 6% to 11% less energy per unit of liquid produced. Thus, for a given amount of available compression power, the embodiment of Figure 4 could liquefy approximately 6% more natural gas than the embodiment of Figure 1 or approximately 11% more natural gas than the embodiment of Figure 3 by virtue of recovering only the C3 hydrocarbons and heavier as a GPL coproduct. The choice between the embodiment of Figure 4 against any of the embodiments of Figure 1 or Figure 3 of the present invention for a particular application will generally be dictated by the monetary value of the ethane as part of a NGL product against its corresponding value in the product of GL, or by the specification of the value of the heating index for the LNG product (since LNG heating rate produced by one modality of Figure 1 and Figure 3 is smaller than that produced by the modality of Figure 4). Example 4 If the specifications for the LNG product allowed all the ethane and propane contained in the fed gas to be recovered in the LNG product, if there was no market for a liquid co-product containing ethane and propane, an alternative mode may be used of the present invention as shown in Figure 5 to produce a condensed co-product stream. The composition of the inlet gas and the conditions considered in the process presented in Figure 5 are the same as those of Figures 1, 2 and 3. Consequently, the process of Figure 5 can be compared with the modalities presented in the Figures 1, 3 and 4. In the simulation of the process of Figure 5, the inlet gas enters the plant at 90 ° F [32 ° C] and 1285 psia [8,860 kPa (a)] as the flow 31 and is cooled in heat exchanger 10 by heat exchange with coolant flows, high pressure liquid separator evaporated instantaneously at -37 ° C [-38 ° C] (flow 33b), and intermediate pressure separator liquids evaporated instantaneously at -37 ° F [-38 ° C] (flow 39b). The cooled flow 31a enters the high pressure separator 11 at -30 ° F [-34 ° C] and 1278 psia [8,812 kPa (a)] where the vapor (flow 32) is separated from the condensed liquid (flow 33). The steam (flow 32) of the high pressure separator 11 enters the expansion work machine 15 in which the mechanical energy of this portion of the high pressure supply is extracted. The machine 15 expands the vapor substantially isentropically from a pressure of about 1278 psia [8]., 812 kPa (a)] at a pressure of approximately 635 psia [4,378 kPa (a)], with the expansion work cooling the expanded flow 32a to a temperature of approximately -83 ° F [~ 64 ° C]. The expanded and partially condensed flow 32a enters the intermediate pressure separator 18 where the vapor (flow 42) is separated from the condensed liquid (flow 39). The liquid from the intermediate pressure separator (flow 39) is instantaneously expanded slightly above the operating pressure of the depropanizer 19 by the expansion valve 17, cooling the flow 39 to -108 ° F [-78 ° C] (flow 39a ) before it enters the heat exchanger 13 and is heated since it provides cooling to the waste gas flow 49 and the coolant flow 71a, and consequently to the heat exchanger 10 to provide cooling to the incoming feed gas as described at first. The flow 39c, now at -15 ° F [-26 ° C], then enters the depropanizer 19 at a feed point of the middle part of the upper column. The condensed liquid, the flow 33, of the high pressure separator 11 is instantaneously expanded slightly above the operating pressure of the depropanizer 19 by the expansion valve 12, cooling the flow 33 to -93 ° F [-70 ° C] (flow 33a) before it enters the heat exchanger 13 and is heated as it provides cooling to the waste gas flow 49 and the coolant flow 71a, and consequently the heat exchanger 10 to provide cooling to the feed gas incoming as described at the beginning. The flow 33c, now at 50 ° F [10 ° C], then enters the depropanizer 19 at a feed point of the middle part of the lower column. In the depropanizer, the flows 39c and 33c are separated from their methane, components of C2 and components of C3. The depropanizer in tower 19, which operates at approximately 385 psia [2,654 kPa (a)], is a conventional distillation column containing a plurality of vertically separated trays, or one or more packed beds, or a combination of trays and packages . The depropanizer tower may consist of two sections: an upper separator section 19a where any vapor contained in the upper feed is separated from its corresponding liquid portion, and where the steam rising from the lower distillation or depropanisation section 19b is combined with the steam portion (if any) of the upper feed to form a distillation flow 37 which leaves the top of the tower; and a lower, depropanization section 19b containing the trays and / or packages to provide the necessary contact between the liquids falling down and the vapors rising upwards. Depropanising section 19b also includes one or more boilers (such as boiler 20), which heat and evaporate a portion of liquid at the bottom of the column to provide vapors of separations which flow up the column to separate the product liquid, flow 41, methane, C2 components and C3 components. A typical specification for the lower liquid product is that it has a propane to butane ratio of 0.020: 1 on a volume basis. The liquid product flow 41 exits the deethanizer bottom at 286 ° F [141 ° C]. The distillation stream from the top 37 leaves the depropanizer 19 at 36 ° F [2 ° C] and is cooled and partially condensed by commercial grade propane refrigerant in the reflux condenser 21. The partially condensed flow 37a enters the drum reflux 22 to 2 ° F [-17 ° C] where the condensed liquid (flow 44) is separated from the non-condensed vapor (flow 43). The condensed liquid (flow 44) is pumped by the pump 23 to an upper feed point on the depropanizer 19 as reflux flow 44a. The non-condensed vapor (flow 43) of the reflow drum 22 is heated to 94 ° F [34 ° C] in the heat exchanger 24, and a portion (flow 48) is then removed to serve as fuel gauze for the plant. The remainder of the heated vapor (flow 38) is compressed by the compressor 16. After cooling to 100 ° F [38 ° C] in the discharge chiller 25, the 38b flow is further cooled to 15 ° F t-9 ° C] in the heat exchanger 24 by a cross-exchange with the cold vapor, the flow 43. The flow 38c is then combined with the steam from the intermediate pressure separator (flow 42) to form the cold waste gas flow 49. The flow 49 enters heat exchanger 13 and is cooled to -38 ° F [-39 ° C] to -102 ° F [-74 ° C] by the separator liquids (flows 39a and 33a) as described at the beginning and by the coolant flow 71e. The partially condensed stream 49a then enters the heat exchanger 60 and is further cooled by the coolant flow 71d to -254 ° F [-159 ° C] to condense and subcool this, after which it enters a working machine of expansion 61 in which the mechanical energy of the flow is extracted. The machine 61 expands the liquid flow 49b substantially isentropically from a pressure of about 621 psia [4,282 kPa (a)] to the storage pressure of LNG (15.5 psia [107 kPa (a)]), slightly above the atmospheric pressure. The expansion work cools the expanded flow 49c to a temperature of approximately -255 ° F [-159 ° C], after which it is directed to the LNG storage tank 62 which contains the LNG product (flow 50) . Similar to the processes of Figure 1, Figure 3 and Figure 4, most of the cooling of the flow 49 and all of the cooling of the flow 49a is provided by a closed-cycle cooling circuit. The composition of the flow used as the working fluid in the cycle for the process of Figure 5, in percent in approximate mole, is 8.9% nitrogen, 34.3% methane, 41.3% ethane, and 11.0% propane with the rest consisting of heavier hydrocarbons. The flow of coolant 71 leaves the discharge cooler 69 at 100 ° F [38 ° C] and 607 psia [4.185 kPa (a)]. This enters the heat exchanger 10 and is cooled to -30 ° F [-34 ° C] and is partially condensed by the partially heated expanded coolant flow 71f and by another coolant flow. For the simulation of Figure 5, it has been assumed that these other refrigerant streams are commercial quality propane refrigerant at 3 different temperature and pressure levels. The partially condensed refrigerant flow 71a then enters the heat exchanger 13 to be further cooled to -102 ° F [-74 ° C] by the partially heated expanded coolant flow 71e, condensing the refrigerant further (flow 71b). The refrigerant is completely condensed and then subcooled to -254 ° F [-159 ° C] in the heat exchanger 60 by the expanded refrigerant flow 71d. The subcooled liquid flow 71c enters an expansion work machine 63 in which the mechanical energy of the flow is extracted so that it is substantially isentropically expanded from a pressure of about 586 psia [4.040 kPa (a)] to approximately 34 psia [234 kPa (a)]. During expansion a portion of the flow evaporates, resulting in cooling of the total flow to -264 ° F [-164 ° C] (flow 71d). The expanded flow 71d then again enters the heat exchangers 60, 13 and 10 where it provides cooling to the flow 49a, the flow 49, and the refrigerant (flows 71, 71a and 71b) when this is evaporated and superheated. The superheated refrigerant vapor (flow 71g) leaves the heat exchanger 10 at 93 ° F [34 ° C] and is compressed in three stages at 617 psia [4,254 kPa (a)]. Each of the three compression stages (refigerative compressors 64, 66 and 68) is driven by a supplementary energy source and is followed by a cooler (discharge chillers 65, 67 and 69) to remove the compression heat. The compressed flow 71 of the discharge cooler 69 returns to the heat exchanger 10 to complete the cycle. A summary of the flow rates of the flow or current and energy consumption for the process illustrated in Figure 5 is presented in the following table: Table IV (Figure 5) Summary of Flow Flow - Lb.Moles / Hr [kg moles / Hr] Flu or Methane Ethane Propane Butane + Total 31 40, 977 3,861 2,408 1,404 48, 656 32 32,360 2,675 1, 469 701 37,209 33 8, 617 1, 186 939 703 11,447 38 13,133 2, 513 1,941 22 17, 610 39 6,194 1, 648 1,272 674 9, 788 41 0 0 22 1,352 1,375 42 26, 166 1, 027 197 27 27, 421 43 14, 811 2, 834 2,189 25 19,860 48 1, 678 321 248 3 2,250 50 39,299 3,540 2, 138 49 45, 031 Recoveries in Condensates * Propane 95.04% Butane + 99.57% Production Speed 88,390 Lb / Hr [88,390 kg / Hr] LNG Product Production Speed 834.183 Lb / Hr [834.183 kg / Hr] Purity * 87.27% Lower Heating Value 1033.8 BTU / SCF [38.52 MJ / m3] Power Coolant Compression 84,974 HP [139,696 kW] Propane Compression 39,439 HP [64,837 kW] Total Compression 124,413 HP [204,533 kW] Heat Utilizer Demetanizer Boiler 52,913 MBTU / Hr [34,182 kW] * (Based on non-rounded flow rates) Assuming a factor on the flow of 340 days per year for the LNG production plant, the specific energy consumption for the mode of Figure 5 of the present invention is 0.145 HP- Hr / Lb [0.238 kW-Hr / kg]. Compared to the processes of the prior art, the improvement in efficiency is 16-26% for the modality of Figure 5. Compared to the modalities of Figure 1 and Figure 3, the modality of Figure 5 of the present invention requires from 5% to 10% less energy per unit of liquid produced. Compared with the embodiment of Figure 4, the embodiment of Figure 5 of the present invention requires essentially the same energy per unit of liquid produced. Thus, for a given amount of available compression power, the embodiment of Figure 5 could liquefy approximately 5% more natural gas than the embodiment of Figure 1 about 10% more natural gas than the embodiment of Figure 3 or approximately the same amount of natural gas as the modality of Figure 4, by virtue of recovering only the C4 hydrocarbons and heavier as a condensed co-product. The choice between the embodiment of Figure 5 against any of the embodiments of Figure 1, Figure 3 or Figure 4 of the present invention for a particular application will generally be dictated by the monetary value of ethane and propane as part of a product of LGN or GPL against its corresponding value in the LNG product, or by the specification of the value of the heating index for the LNG product (since the LNG heating rate produced by a modality of Figure 1, Figure 3 and Figure 4 is less than that produced by that of the modality of Figure 4). Other Modes One skilled in the art will recognize that the present invention can be adapted for use with all types of LNG liquefaction plants to allow co-production of an NGL flow, a GPL flow, or a condensed flow, as best suits to the needs in the location of a given plant. In addition, it will be recognized that a variety of process configurations can be employed to recover the flow of liquid coproduct. For example, the embodiments of Figures 1 and 3 can be adapted to recover a GPL flow or a condensate flow as the liquid co-product stream instead of an NGL flow as described in the examples 1 and 2 above. The modality of Figure 4 can be -adapted to recover an NGL flow containing a significant fraction of the C2 components present in the feed gas, or recover a condensate flow containing only the C4 and heavier components present. in the feed gas, instead of producing a GPL coproduct as described at the beginning for Example 3. The embodiment of Figure 5 can be adapted to recover an NGL flow containing a significant fraction of the C2 components in the feed gas, or recover a GPL flow containing a significant fraction of the C3 components present in the feed gas, instead of producing a condensed coproduct as described at the beginning for example 4. Figures 1, 3, 4 and 5 they represent the preferred embodiments of the present invention for the indicated process conditions. Figures 6 through 21 describe alternative embodiments of the present invention that may be considered for a particular application. As shown in Figures 6 and 7, all or a portion of condensed liquid (flow 33) of the separator 11 can be supplied to the fractionating tower 19 in a feeding position of the middle part of the separated lower column instead of combined with the steam portion of the separator (flow 34) flowing into the heat exchanger 13. Figure 8 describes an alternative embodiment of the present invention that requires less equipment than the embodiments of Figure 1 and Figure 6, although its consumption of specific energy is somewhat higher. Similarly, Figure 9 describes an alternative embodiment of the present invention that requires less equipment of the embodiments of Figure 3 and Figure 7, again at the expense of a higher specific power consumption. Figures 10 to 14 describe alternative embodiments of the present invention that may require less equipment than the embodiment of Figure 4, although their specific energy consumption may be greater. (Note that as shown in Figures 10 through 14, distillation columns or systems such as deethanizer 19 include preheated absorbent tower designs and overheated, reflowed tower designs). Figures 15 and 16 describe alternative embodiments of the present invention that combine the functions of the separator / absorbent tower 18 and desetanizer 19 of the embodiments of Figures 4 and 10 to 14 in a single fractionation column 19. Depending on the quality of the heavier hydrocarbons in the feed gas and the feed gas prison, the cooled feed flow 31a leaving the heat exchanger 10 may not contain any liquid (because it is above its dew point) , or because it is located above its cricondebara), so that the separator 11 shown in Figures 1 and 3 to 16 is not required, and the cooled feed flow can flow directly to an appropriate expansion device, such as the expansion work machine 15. The gas flow arrangement remaining after the recovery of the liquid co-product flow (flow 37 in the Figures 1, 3, 6 to 11, 13 and 14, flow 47 in Figures 4, 12, 15 and 16, and flow 43 in Figure 5) before it is supplied to heat exchanger 60 for condensation and subcooling can be done in several ways. In the process of Figures 1 and 3 through 16, the flow is heated, compressed at a higher pressure using the energy derived from one or more expansion work machines, partially cooled in a discharge chiller, then further cooled in the cross exchange with the original flow. As shown in Figure 17, some applications may favor compression of the flow at higher pressure, using the supplementary compressor 59 driven by an external power source, for example. As shown by the dotted equipment (heat exchanger 24 and discharge cooler 25) in Figures 1 and 3 through 16, some circumstances may favor the reduction of capital costs of the installation by reducing or eliminating the pre-cooling of the compressed flow before that it enters the heat exchanger 60 (at the expense of the increase of the cooling load on the heat exchanger 60 and the increase in the energy consumption of the cooling compressors 64, 66 and 68). In those cases, the flow 49a leaving the compressor can flow directly to the heat exchanger 24 as shown in Figure 18, or flowing directly to the heat exchanger 60 as shown in Figure 19. If expansion work machines are not used for the expansion of any portions of the high pressure feed gas, a compressor operated by a power source may be used. external energy, such as the compressor 59 shown in Figure 20, instead of the compressor 16. Other circumstances may not justify any compression of the flow at all, so that the flow flows directly to the heat exchanger 60 as shown in the Figure 21 and by the dotted equipment (heat exchanger 24, compressor 16 and discharge cooler 25) in Figures 1 and 3 to 16. If the heat exchanger 24 is not included to heat the flow before the fuel gas for the plant (flow 48) is removed, a supplementary heater 58 may be necessary to heat the fuel gas before it is consumed, using a useful flow or other process flow to supply the necessary heat, as shown in. Figures 19 to 21. Choices like these should be evaluated, generally, for each application since factors such as gas composition, plant size, desired co-product flow recovery level, and equipment available be all considered. According to the present invention, the cooling of the inlet gas flow and the feed flow to the LNG production section can be accomplished in many ways. In the process of Figures 1, 3 and 6 through 9, the inflow of inlet gas 31 is cooled and condensed by external coolant flows and the liquids of the tower of the fractionation tower 19. In Figures 4, 5 and 10 to 14 separator liquids are evaporated instantaneously for this purpose together with external refrigerant flows. In Figures 15 and 16 the tower liquids and evaporator liquids are instantly evaporated for this purpose along with the external coolant flows. And in Figures 17 through 21, only external coolant flows are used to cool the inlet gas flow 31. However, if cold process flows could also be used to supply some of the cooling to the high pressure refrigerant (flow 71a) ) as shown in Figures 4, 5, 10 and 11. In addition, any flow can be used at a cooler temperature than the flow that is being used. For example, a side steam extraction of the separating / absorbing tower 18 or fractionating tower 19 could be removed and used for cooling. The use and distribution of liquids and / or vapors from the tower for heat exchange processes, and the particular arrangement of heat exchangers for the cooling of the inlet gas and the feed gas, must be evaluated for each particular application, as well as the choice of process flows for specific heat exchange services. The selection of a cooling source will depend on a number of factors including, but not limited to, the composition and conditions of the feed gas, the size of the plant, the size of the heat exchanger, the temperature of the potential cooling source , etc. One skilled in the art will also recognize that any combination of the cooling sources or previous cooling methods can be employed in combination to achieve the desired feed flow temperatures. In addition, the additional external cooling that is supplied to the inlet gas flow and the feed flow to the LNG production section can also be achieved in many different ways. In Figures 1 and 3 through 21, the boiling of the single-component refrigerant for high-level external refrigeration has been assumed and the evaporation of the multi-component refrigerant for low level external refrigeration has been assumed, with the single-component refrigerant used to precool the multi-component refrigerant flow. Alternatively, high-level cooling and low-level cooling could be achieved using one-component refrigerants with successively lower boiling temperatures (i.e., "cascade cooling") or a single-component refrigerant. successively lower evaporation pressures. As another alternative, high level cooling and low level cooling could be effected using multiple component coolant flows with their respective compositions adjusted to provide the necessary cooling temperatures. The selection of the method for providing external cooling will depend on a number of factors including, but not limited to, the composition and conditions of the feed gas, the size of the plant, the size of the compressor actuator, the size of the heat exchanger, the absorbed temperature of the ambient heat, etc. One skilled in the art will also recognize that any combination of the methods for providing the external cooling described above, in combination, can be employed to achieve the desired feed flow temperatures.

The subcooling of the flow of the condensed liquid leaving the heat exchanger 60 (flow 49 in Figures 1, 6 and 8, flow 49d in Figures 3, 4, 7 and 9 to 16, flow 49b in Figures 5, 19 and 20, flow 49e in Figure 17, flow 49c in Figure 18, and flow 49a in Figure 21) reduces or eliminates the amount of instantaneous vapor that can be generated during the expansion of the flow to the operating pressure of the storage tank LNG 52. This generally reduces the specific energy consumption to produce the LNG by eliminating the need for instant gas compression. However, some circumstances may favor the reduction of the capital costs of the installation by reducing the size of the heat exchanger 60 and using instantaneous gas and other means for disposing of any instantaneous gas that may be generated. Although the expansion of an individual flow into particular expansion devices is described, alternative means of expansion may be employed where appropriate. For example, the conditions can guarantee the substantially condensed feed flow expansion work (flow 35a in Figures 1, 3, 6 and 7) or the intermediate pressure reflow flow (flow 39 of Figures 1, 6 and 8). ). In addition, instantaneous isothermal expansion can be used instead of expansion work for subcooled liquid flow leaving the heat exchanger 60 (flow 49 in Figures 1, 6 and 8, flow 49d in Figures 3, 4, 7). and 9 through 16, flow 49b in Figures 5, 19 and 20, flow 49e in Figure 17, flow 49c in Figure 18, flow 49a in Figure 21), but will require more subcooling in heat exchanger 60 to avoid the formation of instantaneous steam in the expansion, or also compression of the additional instantaneous steam and other means to dispose of the resulting instantaneous steam. Similarly, instantaneous isothermal expansion can be employed instead of expansion work for the subcooled, high pressure refrigerant flow leaving the heat exchanger 60 (flow 71c in Figures 1 and 3 to 21), with the increase resulting in the consumption of energy for the compression of the refrigerant. Although those which are believed to be the preferred embodiments of the invention have been described, those skilled in the art will recognize that further modifications may be made thereto, for example to adapt the invention to various conditions, types of feeding, other requirements without departing of the spirit of the present invention according to what is defined by the following claims. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention. 84 more volatile steam distillation and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components; (7) the more volatile steam distillation flow is cooled sufficiently to condense at least a part of it, thereby forming a third liquid flow; (8) at least a portion of the expanded steam flow is brought into intimate contact with at least a portion of the third liquid flow in the contact device; and (9) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 17. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) condensed reflux is expanded at lower pressure to form the flow of liquefied natural gas; the improvement characterized in that (1) the flow of natural gas is treated in one or more cooling steps; (2) the flow of cooled natural gas is expanded to an intermediate pressure and subsequently directed to a methane and lighter components and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components; (10) first heat exchange means connected to the distillation column to receive the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion of this and thus form the condensed flow; Y (11) control means adapted to regulate the quantities and temperatures of the feed streams to the distillation column to maintain the temperature of the upper part of the distillation column at a temperature at which the greater portion of the hydrocarbon components is more heavy is recovered in the relatively less volatile fraction. 46. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means connected cooperatively to receive the natural gas flow and cooling it under pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means connected to the first heat exchange means for receiving the flow 123 (b) first expansion means connected to the first heat exchange means for receiving the condensed flow and expanding this at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool this under sufficient pressure to partially condense this; (2) separation means connected to the second heat exchange means for receiving the flow of partially condensed natural gas and separating it into a vapor flow and a first liquid flow; (3) first dividing means connected to the separation means for receiving the steam flow and dividing this into at least a first gas flow and a second gas flow; (4) combination means connected to the first dividing means and to the separation means for receiving the first gas flow and at least a portion of the first liquid flow and combining them in a combined flow; (5) third heat exchange means connected to the combining means to receive the combined flow and to cool it sufficiently to condense this substantially; 170 (14) control means adapted to regulate the quantities and temperatures of the feed streams to the distillation column to maintain the temperature of the upper part of the distillation column at a temperature at which the major portion of the hydrocarbon components more heavy is recovered in the relatively less volatile fraction. 65. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more heat exchange means connected cooperatively to receive the flow of natural gas and cooling this under pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means connected to the first heat exchange means for receiving the condensed flow and expanding this at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool this under pressure; (2) second expansion means connected to the second heat exchange means to receive the flow of cooled natural gas and expand this at a pressure

Claims

• 62 CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that (1) the flow of natural gas is treated in one or more cooling steps; (2) the flow of cooled natural gas is expanded to an intermediate pressure; (3) The flow of expanded chilled natural gas is directed to a distillation column, where the flow is separated into a volatile waste gas fraction containing a larger portion of methane and lighter components and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components; (4) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof; 63 (5) the condensed portion is divided into at least two portions to thereby form the condensed flow and a liquid flow; and (6) the liquid flow is directed towards the distillation column as a feed higher than this one. 2. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that (1) the flow of natural gas is treated in one or more cooling steps to partially condense it; (2) the flow of partially condensed natural gas is separated to thereby provide at least a vapor flow and a first liquid flow; (3) the steam flow is expanded to an intermediate pressure; (4) the first liquid flow is expanded to the intermediate pressure; (5) at least the expanded steam flow and the first expanded liquid flow are directed to a column 64 distillation, where the flows are separated into a fraction of volatile waste gas - which contains a larger portion of methane and the lighter components and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components; (6) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof; (7) the condensed portion is divided into at least two portions to thereby form the condensed flow and a second liquid flow; and (8) the second liquid flow is directed towards the distillation column as a feed higher than this one. 3. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that (1) the flow of natural gas is treated in one or more cooling steps; (2) The flow of cooled natural gas is divided into 65 at least a first gas flow and a second gas flow; (3) the first gaseous flow is cooled to substantially condense all of this and subsequently expand it to an intermediate pressure; (4) the second gas flow is expanded to the intermediate pressure; (5) the first condensed, substantially expanded gas flow and the second expanded gas flow are directed to a distillation column where the flows are separated into a fraction of volatile waste gas containing a larger portion of methane and the lighter components and a relatively less volatile fraction that contains a larger portion of the heavier hydrocarbon components; and (6) the volatile waste gas fraction is cooled under pressure to condense at least a portion of it - and thereby form the condensed flow. 4. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; 66 the improvement, characterized by (1) the flow of natural gas is treated in one or more cooling steps to partially condense it; (2) the flow of partially condensed natural gas is separated to thereby provide a vapor flow and a liquid flow; (3) the vapor flow is divided into at least a first gas flow and a second gas flow; (4) the first gaseous flow is cooled to substantially condense all of it and is subsequently expanded to an intermediate pressure; (5) the second gas flow is expanded to the intermediate pressure; (6) the liquid flow is expanded to the intermediate pressure; (7) the first condensed gaseous flow, substantially expanded, the second expanded gaseous flow and the expanded liquid flow are directed to a distillation column where the flows are separated into a volatile waste gas fraction containing a larger portion of methane and lighter components and a relatively less volatile fraction containing a larger portion of the heavier idrocarburic components; and (8) the fraction of volatile waste gas is cooled under pressure to condense at least a portion of it and thus form the condensed flow. 5. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that (1) the flow of natural gas is treated in one or more cooling steps to partially condense it; (2) the flow of partially condensed natural gas is separated to thereby provide at least one vapor flow and one liquid flow, - (3) the vapor flow is divided into at least one first gas stream and one. second gas flow; (4) the first gas flow is combined with at least a portion of the liquid flow, thereby forming a combined flow; (5) the combined flow is cooled to substantially condense all of it and then be expanded to an intermediate pressure; (6) the second gas flow is expanded to the intermediate pressure; 68 (7) any remaining portion of the liquid flow is expanded to the intermediate pressure; (8) the condensed, substantially expanded, condensed flow, the second expanded gas flow and the remaining portion of the liquid flow are directed to a distillation column where the flows are separated into a fraction of volatile waste gas containing a larger portion of methane and the lighter components and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components; and (9) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 6. In a process - to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion of it and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that (1) the flow of natural gas is treated in one or more cooling steps; (2) The flow of cooled natural gas is divided to 69 minus a first gaseous flow and a second gaseous flow; (3) the first gaseous flow is cooled to substantially condense all of it and is subsequently expanded to an intermediate pressure; (4) the second gas flow is expanded to the intermediate pressure; (5) the first condensed, substantially expanded gas flow and the second expanded gas flow are directed to a distillation column where the flows are separated into a volatile waste gas fraction containing a larger portion of methane and the lighter components and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components; (6) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof; (7) the condensed portion is divided into at least two portions to thereby form the condensed flow and a liquid flow; and (8) the liquid flow is directed towards the distillation column as a feed higher than this one. 7. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled below 70 pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that (1) the flow of natural gas is treated in one or more cooling steps to partially condense it; (2) the flow of partially condensed natural gas is separated to thereby provide a vapor flow and a first liquid flow; (3) the vapor flow is divided into at least a first gas flow and a second gas flow; (4) the first gaseous flow is cooled to substantially condense all of this and subsequently expand it to an intermediate pressure; (5) the second gas flow is expanded to the intermediate pressure; (6) the first liquid flow is expanded to the intermediate pressure; (7) The first gaseous, condensed, substantially expanded gas flow, the second expanded gas flow and the first expanded liquid flow are directed to a distillation column where the flows are separated into a fraction of volatile waste gas containing a larger portion of the gas. methane and lighter components and a fraction 71 relatively less volatile containing a larger portion of the heavier hydrocarbon components; (8) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof; (9) the condensed portion is divided into at least two portions to thereby form the condensed flow and the second liquid flow; and (10) the second liquid flow is directed to the distillation column as a feed higher than this. 8. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that (1) the flow of natural gas is treated in one or more cooling steps to partially condense it; (2) the flow of partially condensed natural gas is separated to thereby provide a vapor flow and a first liquid flow; (3) the vapor flow is divided into at least a first gas flow and a second gas flow; 72 (4) the first gas flow is combined with at least a portion of the first liquid flow, thereby forming a combined flow; (5) the combined flow is cooled to substantially condense all of this and subsequently expand it to an intermediate pressure; (6) the second gas flow is expanded to the intermediate pressure; (7) any remaining portion of the first liquid flow is expanded to the intermediate pressure; (8) the combined, condensed, substantially expanded flow, the second expanded gas flow and the remaining portion of the first liquid flow are directed to a distillation column where the flows are separated into a volatile waste gas fraction containing a larger portion of methane and lighter components and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components; (9) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof; (10) the condensed portion is divided into at least two portions to thereby form the condensed flow and the second liquid flow; and (11) the second liquid flow is directed to the distillation column as a feed greater than 73 this. 9. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that (1) the flow of natural gas is treated in one or more cooling steps; (2) the flow of cooled natural gas is expanded to an intermediate pressure; (3) the flow of cooled, expanded natural gas is separated to thereby provide a vapor flow and a liquid flow; (4) the liquid flow is expanded to a lower intermediate pressure; (5) the flow of expanded liquid is directed to a distillation column where the flow is separated into a more volatile steam distillation stream and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components; (6) The most volatile steam distillation flow is 74 combined with the vapor flow to form a volatile waste gas fraction containing a larger portion of methane and lighter components; and (7) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 10. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that (1) the flow of natural gas is treated in one or more cooling steps to substantially condense it; (2) the flow of partially condensed natural gas is separated to thereby provide a first flow of steam and a first flow of liquid; "(3) the first steam flow is expanded to an intermediate pressure; (4) the first expanded steam flow is separated to thereby provide a second steam flow and a second liquid flow; 75 (5) the second liquid flow is expanded to a lower intermediate pressure; (6) the first liquid flow is expanded at a lower intermediate pressure; (7) The second expanded liquid flow and the first expanded liquid flow are directed to a distillation column, where the flows are separated into a more volatile steam distillation flow and a relatively less volatile fraction containing a larger portion of the liquid. the heavier hydrocarbon components; (8) the more volatile steam distillation stream is combined with the second vapor stream to form a volatile waste gas fraction containing a larger portion of methane and lighter components; and (9) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 11. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; 76 the improvement, characterized in that (1) the flow of natural gas is treated in one or more cooling steps; (2) The flow of cooled natural gas is expanded to an intermediate pressure and subsequently directed to a contact device, thereby forming a volatile waste gas fraction containing a larger portion of methane and lighter components and a first flow of liquid; (3) the first liquid flow is directed to a distillation column where the flow is separated into a more volatile steam distillation stream and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components; (4) the more volatile steam distillation flow is cooled sufficiently to condense at least part of it, thereby forming a second liquid flow; (5) at least a portion of the flow of cooled, expanded natural gas is brought into intimate contact with at least a portion of the second liquid flow in the contact device; and (6) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 12. In a process to liquefy a gas flow 77 natural containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion of it and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that (1) the flow of natural gas is treated in one or more cooling steps to partially condense this; (2) the flow of partially condensed natural gas is separated to thereby provide a vapor flow and a first liquid flow; (3) the vapor flow is expanded to an intermediate pressure and subsequently directed to a contact device, thereby forming a volatile waste gas fraction containing a larger portion of methane and lighter components and a second liquid flow; (4) the first liquid flow is expanded to the intermediate pressure; (5) The second liquid flow and the first expanded liquid flow are directed to a distillation column, where the flows are separated into a more volatile steam distillation flow and a relatively less volatile fraction containing a larger portion of the 78 heavier hydrocarbon components; (6) the more volatile steam distillation flow is cooled sufficiently to condense at least a part of it, thereby forming a third liquid flow; (7) at least a portion of the expanded steam flow is brought into intimate contact with at least part of a third liquid flow in the contact device; and (8) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 13. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that (1) the flow of natural gas is treated in one or more cooling steps; (2) the flow of cooled natural gas is expanded to an intermediate pressure and subsequently directed to a contact device, thereby forming a first vapor flow and a first liquid flow; 79 (3) the first liquid flow is directed to a distillation column where the flow is separated into a more volatile steam distillation stream and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components; (4) the more volatile distillation steam flow is sufficiently cooled to condense at least part of it, to thereby form a second vapor flow and a second liquid flow; (5) a portion of the second liquid flow is directed to a distillation column as a feed greater than this; (6) at least a portion of the flow of cooled, expanded natural gas is brought into intimate contact with at least a portion of the remaining portion of the second liquid flow in the contact device; (7) the first steam flow is combined with the second steam flow to form a volatile waste gas fraction containing a larger portion of methane and lighter components; and (8) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 14. In a process to liquefy a flow of natural gas containing methane and hydrocarbon components plus 80 heavy where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement characterized in that (1) the flow of natural gas is treated in one or more cooling steps to partially condense this; (2) the flow of partially condensed natural gas is separated to thereby provide a first flow of steam and a first flow of liquid; (3) the first steam flow is expanded to an intermediate pressure and by. thus directed to a contact device, thereby forming a second vapor flow and a second liquid flow; (4) the first liquid flow is expanded to the intermediate pressure; (5) the second liquid flow and the first expanded liquid flow are directed to a distillation column where the flows are separated into a more volatile steam distillation flow and a relatively less volatile fraction containing a larger portion of idrocarburic components heavier; (6) the most volatile steam distillation flow 81 it is cooled sufficiently to condense at least part of it, thereby forming a third vapor flow and a third liquid flow; (7) a portion of the third liquid flow is directed towards the distillation column as a feed higher than this; (8) At least a portion of the first expanded steam flow is brought into intimate contact with at least a portion of the remaining portion of the third liquid flow in the contact device; (9) the second flow of. steam is combined with the third vapor stream to form a volatile waste gas fraction containing a larger portion of methane and lighter components; and (10) the volatile waste gas fraction is filtered under pressure to condense at least a portion thereof and thereby form the condensed flow. 15. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) condensed reflux is expanded at lower pressure to form the flow of liquefied natural gas; 82 the improvement characterized by (1) the natural gas flow is treated in one or more cooling steps; (2) The flow of cooled natural gas is expanded to an intermediate pressure and therefore directed to a contact device, thereby forming a volatile waste gas fraction containing a larger portion of methane and lighter components and a first liquid flow; (3) the first liquid flow is heated and then directed to a distillation column, where the flow is separated into a more volatile steam distillation flow and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components; (4) the more volatile steam distillation flow is cooled sufficiently to condense at least part of it, thereby forming a second liquid flow, - (5) at least a portion of the flow of cooled, expanded natural gas, - it is brought into intimate contact with at least a part of the second liquid flow in the contact device; and (6) the. The volatile waste gas fraction is cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 83 16. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded under more pressure to form the flow of liquefied natural gas; the improvement characterized in that (1) the flow of natural gas is treated in one or more cooling steps to partially condense this; (2) the flow of partially condensed natural gas is separated to thereby provide a vapor flow and a first liquid flow; (3) the steam flow is expanded to an intermediate pressure and subsequently directed to a contact device, thereby forming a volatile waste gas fraction containing a larger portion of methane and lighter components and a second liquid flow; (4) the second liquid flow is heated; (5) the first liquid flow is expanded at intermediate pressure; (6) the second flow of heated liquid and the first flow of expanded liquid are directed to a distillation column, where the flows are separated in a flow of 85 contact device, thereby forming a first flow of steam and a first flow of liquid; (3) the first liquid flow is heated and then directed to a distillation column, where the flow is separated into a more volatile steam distillation stream and a relatively less volatile fraction containing a larger portion of heavier hydrocarbon components; (4) the more volatile steam distillation flow is sufficiently cooled to condense at least part of it, thereby forming a second vapor flow and a second liquid flow; (5) a portion of the second liquid flow is directed towards the distillation column as a feed higher than this; (6) at least a portion of the flow of cooled, expanded natural gas is brought into intimate contact with at least a portion of the remaining portion of the second liquid flow in the contact device; (7) the first steam flow is combined with the second steam flow to form a volatile waste gas fraction containing a larger portion of methane and lighter components; and (8) the volatile waste gas fraction is cooled under pressure to condense at least a portion of 86 it and thus form the condensed flow. 18. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement characterized in that (1) the flow of natural gas is treated in one or more cooling steps to partially condense this; (2) the flow of partially condensed natural gas is separated to thereby provide a first flow of steam and a first flow of liquid; (3) the first steam flow is expanded to an intermediate pressure and subsequently directed to a contact device, thereby forming a second steam flow and a second liquid flow; (4) the second liquid flow is heated; (5) the first liquid flow is expanded to the intermediate pressure; (6) The second flow of heated liquid and the first expanded liquid flow are directed to a distillation column where the flows are separated into a liquid. more volatile steam distillation flow and a relatively less volatile portion containing a larger portion of the heavier hydrocarbon components; (7) the more volatile steam distillation flow is sufficiently cooled to condense at least part of it, thereby forming a third vapor flow and a third liquid flow; (8) a portion of the third liquid flow is directed to the distillation column as a feed higher than this; (9) at least a portion of the first expanded steam flow is brought into intimate contact with at least a portion of the remaining portion of the third liquid flow in the contact device; (10) the second steam flow is combined with the third steam flow to form a volatile waste gas fraction containing a larger portion of methane and lighter components; and (11) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 19. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled below pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement characterized in that (1) the flow of natural gas is treated in one or more cooling steps; (2) The flow of cooled natural gas is expanded to an intermediate pressure and therefore directed to a supply position of the middle column on the distillation column where the flow is separated in a more volatile steam distillation flow and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components; (3) A steam distillation flow is withdrawn from a region of the distillation column below the flow of cooled natural gas, expanded and cooled sufficiently to condense at least part of it, thereby forming a vapor flow and a flow of liquid; (4) at least a portion of the cooled, expanded natural gas stream is brought into intimate contact with at least a portion of the liquid flow in the distillation column; (5) the vapor flow is combined with the more volatile steam distillation stream to form a volatile waste gas fraction containing a larger portion of methane 89 and lighter components; and (6) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 20. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement characterized in that (1) the flow of natural gas is treated in one or more cooling steps to partially condense this; (2) the flow of partially condensed natural gas is separated to thereby provide a first flow of vapors and a first flow of liquid; (3) the first steam flow and the first liquid flow are expanded to an intermediate pressure; (4) The first expanded steam flow and the first expanded liquid flow are directed to half-column feed positions on a distillation column where the flows are separated into a more volatile steam distillation flow and a relatively low fraction. less volatile containing a larger portion of heavier hydrocarbon components; (5) a steam distillation flow is withdrawn from a region of the distillation column below the first expanded steam flow and cooled sufficiently to condense at least part of it, thereby forming a second steam flow and a second flow of liquid; (6) at least a portion of the first expanded steam flow is brought into intimate contact with at least a part of the second liquid flow in the distillation column; (7) the second vapor flow is combined with the more volatile steam distillation stream to form a volatile waste gas fraction containing a larger portion of methane and lighter components; and (8) the more volatile waste gas fraction is cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 21. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; 91 the improvement characterized in that (1) the flow of natural gas is treated in one or more cooling steps; (2) The flow of cooled natural gas is expanded to an intermediate pressure and then directed to a supply position of the middle column on a distillation column where the flow is separated in a more volatile steam distillation flow and a relatively low fraction. less volatile containing a greater portion of the heavier hydrocarbon components; (3) a steam distillation flow is withdrawn from a region of the distillation column under the flow of cooled natural gas, expanded and cooled sufficiently to condense at least a part of it, thus forming a vapor flow and a liquid flow; (4) a portion of the liquid flow is supplied to the distillation column as another feed to it, at a feeding location substantially in the same region where the steam distillation flow is withdrawn; (5) at least a portion of the flow of expanded, cooled natural gas is brought into intimate contact with at least a portion of the remaining portion of the liquid flow in the distillation column; (6) the steam flow is combined with the flow of 92 more volatile steam distillation to form a volatile waste gas fraction containing a larger portion of methane and lighter components; and (7) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 22. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement characterized in that (1) the flow of natural gas is treated in one or more cooling steps to partially condense this; (2) the flow of partially condensed natural gas is separated to thereby provide a first flow of steam and a first flow of liquid; (3) the first steam flow and the first liquid flow are expanded to an intermediate pressure; (4) the first expanded steam flow and the first expanded liquid flow are directed to the middle column feed positions on a column of 93 distillation where the flows are separated into a more volatile steam distillation stream and a relatively less volatile fraction containing a larger portion of heavier hydrocarbon components; (5) A steam distillation flow is withdrawn from a region of the distillation column below the first expanded steam flow and sufficiently cooled to condense at least part of it, thereby forming a second steam flow and a second flow of liquid; (6) a portion of the second liquid flow is supplied to the distillation column as another feed to it, at a feeding location substantially in the same region where the steam distillation flow is withdrawn; (7) at least a portion of the first expanded steam flow is brought into intimate contact with at least part of the remaining portion of the second liquid flow in the distillation column; (8) the second vapor flow is combined with the more volatile steam distillation stream to form a volatile waste gas fraction containing a larger portion of methane and lighter components; and (9) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 94 23. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion of it and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement characterized in that (1) the flow of natural gas is treated in one or more cooling steps; (2) The flow of cooled natural gas is expanded to an intermediate pressure and then directed to a supply position of the middle column on a distillation column where the flow is separated in a more volatile steam distillation flow and a relatively low fraction. less volatile containing a larger portion of heavier hydrocarbon components; (3) a vapor distillation flow withdrawn from a region of the distillation column below the flow of cooled natural gas expanded and cooled sufficiently to condense at least a portion of it thereby forming a vapor flow and a flow of liquid; (4) At least a portion of the flow of cooled, expanded natural gas is brought into intimate contact with at least 95 a part of the liquid flow in the distillation column; (5) A liquid distillation flow is removed from the distillation column at a location above the region where the steam distillation flow is removed, after which the liquid distillation flow is heated and subsequently directed again to the distillation column with another feed to it, at a place below the region where the steam distillation flow is withdrawn; (6) the vapor flow is combined with the more volatile steam distillation stream to form a volatile waste gas fraction containing a larger portion of methane and lighter components; and (7) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 24. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement characterized because 96 (1) the flow of natural gas is treated in one or more cooling steps to partially condense this; (2) the flow of partially condensed natural gas is separated to thereby provide a first flow of vapors and a first flow of liquid; (3) the first steam flow and the first liquid flow are expanded to an intermediate pressure; (4) the first expanded steam flow and the first expanded liquid flow are directed to middle column feed positions on a distillation column where the flows are separated into a more volatile steam distillation stream and a relatively less fraction volatile that contains a larger portion of the heavier hydrocarbon components; (5) A steam distillation flow is withdrawn from a region of the distillation column below the first expanded steam flow and cooled sufficiently to condense at least part of it, thereby forming a second steam flow and a second liquid flow; (6) at least a portion of the first expanded steam flow is brought into intimate contact with at least part of the second liquid flow in the distillation column; (7) A liquid distillation flow is removed from the distillation column at a location above the region, where the steam distillation flow is withdrawn, whereby the liquid distillation flow is heated and subsequently redirected to the distillation column with another feed to it at a location below the region where the steam distillation flow is withdrawn; (8) the second vapor flow is combined with the more volatile steam distillation stream to form a volatile waste gas fraction containing a larger portion of the methane and lighter components; and (9) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof to thereby form the condensed flow. 25. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement characterized in that (1) the flow of natural gas is treated in one or more cooling steps; (2) the flow of cooled natural gas is expanded to a pressure and then directed to a supply position of the middle column on a column of 98 distillation where the flow is separated from a more volatile steam distillation stream and a relatively less volatile fraction containing a larger portion of heavier hydrocarbon components; (3) a steam distillation flow is withdrawn from a region of the distillation column below the flow of cooled natural gas, expanded and cooled sufficiently to condense at least part of this thereby forming a vapor flow and a flow of liquid; (4) a portion of the liquid flow is supplied to the distillation column as feed to it, the feeding place having substantially in the same region where the steam distillation flow is removed; (5) at least a portion of the flow of expanded, cooled natural gas is brought into intimate contact with at least part of the remaining portion of the liquid flow and the distillation column; (6) A distillation flow of the liquid is removed from the distillation column at a location above the region where the steam distillation flow is removed, after which the distillation flow of liquid is heated and subsequently redirected to the distillation column as another feed to it at a place below the region where the distillation flow is withdrawn steam; (7) the steam flow is combined with the more volatile steam distillation stream to form a volatile waste gas fraction containing a larger portion of methane and lighter components; and (8) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 26. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) condensed reflux is expanded at lower pressure to form the flow of liquefied natural gas; the improvement characterized in that (1) the flow of natural gas is treated in one or more cooling steps to partially condense this; (2) the flow of partially condensed natural gas is separated to thereby provide a first flow of steam and a first flow of liquid; (3) the first steam flow and the first liquid flow are expanded to an intermediate pressure; (4) the first expanded steam flow and the first 100 expanded liquid flow are directed to middle column feed positions on a distillation column where the flows are separated into a more volatile steam distillation stream and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components; (5) A steam distillation flow is withdrawn from the distillation column region under the first expanded steam flow and cooled sufficiently to condense at least part of it, thus forming a second steam flow and a second liquid flow; (6) a portion of the second liquid flow is supplied to the distillation column with another feed to it, at a feed location substantially in the same region where the steam distillation flow is removed; (7) at least a portion of the first expanded steam flow is brought into intimate contact with at least part of the remaining portion of the second liquid flow in the distillation column; (8) A liquid distillation flow is removed from the distillation column at a location above the region where the steam distillation flow is removed, after which the liquid distillation flow is heated and subsequently redirected to the column of 101 distillation as another feed to it at a place below the region where the steam distillation flow is removed; (9) the second vapor flow is combined with the more volatile steam distillation stream to form a volatile waste gas fraction containing a larger portion of methane and lighter components; and (10) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 27. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion thereof and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that it consists essentially of the processing steps where (1) the flow of natural gas is treated in one or more cooling steps; (2) the flow of cooled natural gas is expanded to an intermediate portion; (3) The flow of expanded chilled natural gas is 102 directed to a distillation column where the flow is separated into a volatile waste gas fraction containing a larger portion of methane and lighter components and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components; and (4) the volatile natural gas fraction is cooled under pressure to condense at least a portion thereof and thereby form a condensed flow. 28. In a process to liquefy a flow of natural gas containing methane and heavier hydrocarbon components where (a) the flow of natural gas is cooled under pressure to condense at least a portion of it and form a condensed flow; and (b) the condensed flow is expanded at lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that it consists essentially of the processing steps where (1) the flow of natural gas is treated in one or more cooling steps to partially condense it; (2) the flow of partially condensed natural gas is separated to thereby provide at least a vapor flow and a liquid flow; (3) the steam flow is expanded to an intermediate pressure; 103 (4) the liquid flow is expanded to the intermediate pressure; (5) at least the expanded steam flow and the expanded liquid flow are directed to a distillation column where the flows are separated into a volatile waste gas fraction containing a larger portion of methane and lighter components and a relatively small fraction. less volatile containing a greater portion of the heavier hydrocarbon components; and (6) the volatile waste gas fraction is cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 29. The improvement in accordance with claim 3, 4, 5, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 or 28 , characterized in that the volatile waste gas fraction is compressed and subsequently cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 30. The improvement according to claim 1 or 6, characterized in that (1) the volatile waste gas fraction is compressed and subsequently cooled under pressure to condense at least a portion thereof; and (2) the condensed portion is divided into at least two portions to thereby form the condensed stream and the flow of liquid. 31. The improvement in accordance with the claim 2, 7 or 8, characterized in that; (1) the volatile waste gas fraction is compressed and subsequently cooled under pressure to condense at least a portion thereof; (2) the condensed portion is divided into at least two portions to thereby form the condensed flow and the second liquid flow. 32. The improvement in accordance with the claim 9, characterized in that the more volatile steam distillation flow is compressed and then combined with the steam flow to form the volatile waste gas fraction containing a larger portion of methane and lighter components. 33. The improvement in accordance with the claim 10, characterized in that the more volatile steam distillation flow is compressed and subsequently combined with the second vapor flow to form the volatile waste gas fraction containing a larger portion of the methane and lighter components. 34. The improvement in accordance with the claim 3, 4, 5, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 or 28, characterized in that the fraction of volatile waste gas it is heated, compressed and subsequently 105 cooled under pressure to condense at least a portion thereof and thereby form the condensed flow. 35. The improvement according to claim 1 or 6, characterized in that: (1) the volatile residual gas fraction is heated, compressed, and then cooled under pressure to condense at least a portion thereof; and (2) the condensed portion is divided into at least two portions to thereby form the condensed flow and the liquid flow. 36. The improvement according to claim 2, 7 or 8, characterized in that (1) the volatile waste gas fraction is heated, compressed, and subsequently cooled under pressure to condense at least a portion thereof; and (2) the condensed portion is divided into at least two portions to thereby form the condensed flow and the second liquid flow. 37. The improvement according to claim 9, characterized in that the more volatile steam distillation flow is heated, compressed, cooled, and subsequently combined with the steam flow to form the volatile waste gas fraction containing a larger portion of methane and lighter components. 38. The improvement in accordance with claim 106 10, characterized by the more volatile steam distillation flow being heated, compressed, cooled and subsequently combined with the second vapor flow to form the volatile waste gas fraction containing a larger portion of methane and lighter components. 39. The improvement in accordance with claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26 , 27, 28, 32, 33, 37 or 38, characterized by the volatile residual gas fraction containing a larger portion of methane, lighter components and components of C2. 40. The improvement according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 32, 33, 37 or 38, characterized by the volatile waste gas fraction containing a larger portion of methane, lighter components, C2 components and C3 components. 41. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means connected cooperatively to receive the natural gas flow and cooling it under pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion media, connected to the 107 first heat exchange means for receiving the condensed flow and expanding it at lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means connected cooperatively to receive the flow of natural gas and to cool it under pressure; (2) second expansion means connected to the second heat exchange means for receiving the flow of cooled natural gas and expanding it to an intermediate pressure; (3) a distillation column connected to receive the flow of cooled, expanded natural gas with the distillation column adapted to separate the flow into a volatile waste gas fraction containing a larger portion of methane and lighter components and a relatively small fraction less volatile containing a larger portion of heavier hydrocarbon components; (4) first heat exchange means connected to the distillation column to receive the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion of this; (5) Dividers connected to the first 108 heat exchange to receive the condensed portion and divide it into at least two portions, thus forming the condensed flow and a liquid flow, the dividing means are further connected to the distillation column to direct the flow of liquid towards the column of distillation as a food superior to this one; and (6) control means adapted to regulate the quantities and temperatures of the feed streams to the distillation column to maintain the temperature in the upper part of the distillation column at a temperature such that the major portion of the hydrocarbon components more heavy is recovered in the relatively less volatile fraction. 42. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means cooperatively connected to receive the flow of natural gas and cooling it under pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means, connected to the first heat exchange means for receiving the condensed flow and expanding it at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized because the apparatus includes 109 (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool it under sufficient pressure to partially condense it; (2) separation means connected to the second heat exchange means for receiving the flow of partially condensed natural gas and separating it in a vapor flow and a liquid flow; (3) second expansion means connected to the separation means to receive the steam flow and expand it to an intermediate pressure; (4) third expansion means connected to the separation means to receive the first liquid flow and expand it at intermediate pressure; (5) a distillation column connected to receive the expanded steam flow and the first expanded liquid flow, the distillation column adapted to separate the flows into a volatile waste gas fraction containing a larger portion of methane and lighter components and a relatively less volatile fraction containing a larger portion of heavier hydrocarbon components; (6) first heat exchange means connected to the distillation column to receive the volatile waste gas fraction, with the first means of 110 heat exchange adapted to cool the volatile waste gas fraction under pressure to condense at least a portion thereof; (7) dividing means connected to the first heat exchange means for receiving the condensed portion and dividing it into at least two portions, thereby forming the condensed flow and a second liquid flow, the dividing means being further connected to the distillation column for directing the second liquid flow to the distillation column as a feed higher than this; and (8) control means adapted to regulate the quantities and temperatures of the streams fed into the distillation column to maintain the temperature in the upper part of the distillation column at a temperature at which the major portion of the hydrocarbon components is higher. are recovered in the relatively less volatile fraction. 43. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means connected in a cooperative manner to receive the flow of natural gas and cooling it under pressure to condense at least a portion thereof and form a condensed flow; and 111 (b) first expansion means, connected to the first heat exchange means for receiving the condensed flow and expanding it at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means connected cooperatively to receive the flow of natural gas and to cool it under pressure; (2) dividing means connected to the second heat exchange means for receiving the flow of cooled natural gas and dividing it into at least a first gas stream and a second gaseous stream; (3) third heat exchange means connected to the dividing means for receiving the first gaseous flow and for cooling it sufficiently to substantially condense it; (4) second expansion means connected to the third heat exchange means for receiving its first substantially condensed gaseous flow and expanding it to an intermediate pressure; (5) third expansion means connected to the dividing means for receiving the second gaseous flow and expanding it at intermediate pressure; (6) a distillation column connected to receive the first substantially condensed gaseous flow 112 expanded and the second expanded gas flow, with a distillation column adapted to separate the flows into a volatile waste gas fraction containing a larger portion of methane and lighter components and a relatively less volatile fraction containing a larger portion of hydrocarbon components heavier; (7) the first heat exchange means connected to the distillation column to receive the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion of this and thus form the condensed flow; Y (8) control means adapted to regulate the quantities and temperatures of the feed streams to the distillation column to maintain the temperature in the upper part of the distillation column at a temperature at which the major portion of the hydrocarbon components more heavy is recovered in the relatively less volatile fraction. Four . In an apparatus for the liquefaction of a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means cooperatively connected to receive the flow of natural gas and to cool this one under pressure to condense to 113 minus a portion thereof and form a condensed flow; and (b) first expansion means, connected to the first heat exchange means for receiving the condensed flow and expanding it at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool it under sufficient pressure to partially condense it; (2) separation means connected to the second heat exchange means for receiving the flow of partially condensed natural gas and separating it in a vapor flow and a liquid flow; (3) dividing means connected to the separation means for receiving the steam flow and dividing it into at least a first gas flow and a second gas flow; (4) third heat exchange means connected to the dividing means for receiving the first gaseous flow and for cooling it sufficiently to substantially condense it; (5) second expansion means connected to the third heat exchange means for receiving the first substantially condensed gaseous flow and expanding it to an intermediate portion; 114 (6) third expansion means connected to the dividing means to receive the second gaseous flow and expand it to intermediate pressure; (7) fourth expansion means connected to the separation means to receive the liquid flow and expand it at intermediate pressure; (8) a distillation column connected to receive the first substantially condensed, expanded gaseous stream, the second expanded gaseous stream, and the expanded liquid stream, with the distillation column adapted to separate the streams into a volatile waste gas fraction that it contains a larger portion of methane and lighter components and a relatively less volatile fraction that contains a larger portion of heavier hydrocarbon components; (9) first heat exchange means connected to the distillation column to receive the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion of this and thus form the condensed flow; and (10) control means adapted to regulate the quantities and temperatures of the feed streams to the distillation column to maintain the temperature at the top of the distillation column at a temperature to which the larger portion of the heavier hydrocarbon components is recovered in the relatively less volatile fraction. 45. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means cooperatively connected to receive the flow of natural gas and cooling it under pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means, connected to the first heat exchange means for receiving the condensed flow and expanding it at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means connected cooperatively to receive the flow of natural gas and to cool it under sufficient pressure to partially condense it; (2) separation means connected to the second heat exchange means for receiving the flow of partially condensed natural gas and separating it in a vapor flow and a liquid flow, - (3) dividing means connected to the separation means to receive the steam flow and divide it into 116 at least a first gas flow and a second gas flow; (4) combination means connected to the dividing means and separating means for receiving the first gas flow and at least a portion of the liquid flow and combining them in a combined flow; (5) third heat exchange means connected to the combining means to receive the combined flow and to cool it sufficiently to substantially condense it; (6) second expansion means connected to the third heat exchange means for receiving the substantially condensed combined flow and expanding it at an intermediate pressure; (7) third expansion means connected to the dividing means for receiving the second gaseous flow and expanding it at intermediate pressure; (8) fourth expansion means connected to the separation means to receive any remaining portion of the liquid flow and expand it to the intermediate pressure; (9) a distillation column connected to receive the combined, substantially condensed, expanded flow, the second expanded gaseous flow, and the remaining expanded portion of the liquid flow, with the distillation column adapted to separate the flows in a gas fraction volatile residual containing a portion greater than 118 condensed and expand it at lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool this under pressure; (2) first dividing means connected to the second heat exchange means for receiving the flow of cooled natural gas and dividing this into at least a first gas flow and a second gas flow; (3) third heat exchange means connected to the first dividing means for receiving the first gaseous flow and for cooling it sufficiently to substantially condense this; (4) second expansion means connected to the third heat exchange means for receiving the first substantially condensed gaseous flow and expanding this at an intermediate pressure; (5) third expansion means connected to the first dividing means for receiving the second gaseous flow and expanding this at intermediate pressure; (S) a distillation column connected to receive the first substantially condensed, expanded gaseous flow and the second expanded gaseous flow, with the distillation column adapted to separate the flows in a fraction of volatile waste gas that contains a larger portion of methane and lighter components and a relatively less volatile fraction that contains a larger portion of heavier hydrocarbon components; (7) the first heat exchange means connected to the distillation column to receive the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion this; (8) second dividing means connected to the first heat exchange means for receiving the condensed portion and dividing it into at least two portions, thereby forming the condensed flow and a liquid flow, the second dividing means being further connected. to the distillation column to direct the flow of liquid to the distillation column as a feed higher than this; and (9) control means adapted to regulate the quantities and temperatures of the streams fed to the distillation column to maintain the temperature in the upper part of the distillation column at a temperature at which the greater portion of the hydrocarbon components is higher. heavy is recovered in the relatively less volatile fraction. 120 47. In an apparatus for the liquefaction of a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means cooperatively connected to receive the flow of natural gas and to cool this under pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means connected to the first heat exchange means for receiving the condensed flow and expanding this at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool this under sufficient pressure to partially condense this; (2) separation means connected to the second heat exchange means for receiving the flow of partially condensed natural gas and separating it into a vapor flow and a first liquid flow; (3) first dividing means connected to the separation means for receiving the steam flow and dividing this into at least a first gas flow and a second gas flow; (4) third heat exchange means 121 connected to the first dividing means for receiving the first gaseous flow to cool it sufficiently to condense this substantially; (5) second expansion means connected to the third heat exchange means for receiving the first substantially condensed gaseous flow and expanding it to an intermediate pressure; (6) third expansion means connected to the first dividing means for receiving the second gaseous flow and expanding this at intermediate pressure; (7) fourth expansion means connected to the separation means for receiving the first flow of liquid and expanding this at intermediate pressure; (8) a distillation column connected to receive the first substantially condensed, expanded gaseous stream, the second expanded gaseous stream and the first expanded liquid stream, with the distillation column adapted to separate the fluxes in a volatile waste gas fraction containing a larger portion of methane and lighter components and a relatively less volatile fraction containing a larger portion of heavier hydrocarbon components; (9) the first heat exchange means connected to the distillation column to receive the volatile waste gas fraction, with the first 122 heat exchange adapted to cool the volatile waste gas fraction under pressure to condense at least a portion thereof; (10) second dividing means connected to the first heat exchange means for receiving the condensed portion and dividing it into at least two portions, thereby forming the condensed flow and a second liquid flow, the second dividing means being further connected to the distillation column to direct the second liquid flow to the distillation column as a feed higher than this; and (11) control means adapted to regulate the quantities and temperatures of the feed streams to the distillation column to maintain the temperature at the top of the distillation column at a temperature at which the major portion of the hydrocarbon components heavier is recovered - in the relatively less volatile fraction. 48. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means cooperatively connected to receive the flow of natural gas and cooling this low pressure to condense at least a portion thereof and form a condensed flow; and 124 (6) second expansion means connected to the third heat exchange means to receive the substantially condensed combined flow and expand this at an intermediate pressure; (7) third expansion means connected to the first dividing means for receiving the second gaseous flow and expanding this at intermediate pressure; (8) fourth expansion means connected to the separation means to receive any remaining portion of the first liquid flow and expand it at intermediate pressure; (9) a distillation column connected to receive the substantially condensed, expanded combined flow, the second expanded gas flow and the expanded remaining portion of the first liquid flow, with the distillation column adapted to separate the flows in a residual gas fraction volatile that contains a larger portion of methane and lighter components and a relatively less volatile fraction that contains a larger portion of heavier hydrocarbon components; (10) the first heat exchange means connected to the distillation column to receive the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least one 125 portion of this; (11) second dividing means connected to the first heat exchange means for receiving the condensed portion and dividing it into at least two portions, thereby forming the condensed flow and a second liquid flow, the second dividing means being further connected to the distillation column for directing the second liquid flow to the distillation column as a feed higher than this; and (12) control means adapted to regulate the quantities and temperatures of the feed streams to the distillation column to maintain the temperature at the top of the distillation column at a temperature at which the major portion of the hydrocarbon components heavier is recovered in the relatively less volatile fraction. 49. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means connected cooperatively to receive the flow of natural gas and cooling this low pressure to condense at least a portion thereof and form a condensate; and (b) first expansion means connected to the first heat exchange means for receiving the flow 126 condensed and expand this at lower pressure to form the flow of liquefied natural gas; the improvement, characterized by the device includes (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool this under pressure; (2) second expansion means connected to the second heat exchange means for receiving the flow of a cooled natural gas and expanding it to an intermediate pressure; (3) separation means connected to the second expansion means for receiving the cooled, expanded natural flow and separating it into a vapor flow and a liquid flow; (4) third expansion means connected to the separation means to receive the liquid flow and expand this at lower intermediate pressure; (5) a distillation column connected to receive the expanded liquid flow, with the distillation column adapted to separate the flow into one or more volatile vapor distillation streams and a relatively less volatile fraction containing a larger portion of the components heavier hydrocarbons; (6) combination means connected to the separation means and the distillation column to receive the 127 steam flow and the more volatile steam distillation stream and combine them to form a volatile waste gas fraction containing a larger portion of methane and lighter components (7) first heat exchange media connected to the combining means to receive the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion thereof and thereby form the condensed flow; Y (8) control means adapted to regulate the quantities and temperatures of the feed streams to the distillation column to maintain the temperature in the upper part of the distillation column at a temperature at which the major portion of the hydrocarbon components more heavy is recovered in the relatively less volatile fraction. 50. In an apparatus for the liquefaction of a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means connected cooperatively to receive the flow of natural gas and cooling this low pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion media connected to the 128 first heat exchange means to receive the condensed flow and expand this - at lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool this under sufficient pressure to partially condense this; (2) first separation means connected to the second heat exchange means for receiving the flow of partially condensed natural gas and separating it into a first steam flow and a first liquid flow; (3) second expansion means connected to the first separation means for receiving the first steam flow and expanding it at an intermediate pressure; (4) second separation means connected to the second expansion means for receiving the first expanded vapor flow and separating it into a second vapor flow and a second liquid flow; (5) third expansion means connected to the second separation means for receiving the second liquid flow and expanding it to a lower intermediate pressure; (6) fourth expansion means connected to the first separation means for receiving the first liquid flow and expanding this to a lower intermediate pressure; 129 (7) a distillation column connected to receive the second expanded liquid flow and the first expanded liquid flow, with the distillation column adapted to separate the flows into a more volatile steam distillation stream and a relatively less volatile fraction than contains a larger portion of heavier hydrocarbon components; (8) combining means connected to the second separation means and the distillation column to receive the second vapor flow and the more volatile steam distillation flow and combine them to form a volatile waste gas fraction containing a larger portion of methane and lighter components; (9) the first heat exchange means connected to the combining means for receiving the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion of this and thus form the condensed flow; and (10) control means adapted to regulate the quantities and temperatures of the feed streams to the distillation column to maintain the temperature at the top of the distillation column at a temperature at which the major portion of the hydrocarbon components heavier is recovered in the relatively less 130 fraction volatile 51. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means cooperatively connected to receive the flow of natural gas and cooling this low pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means connected to the first heat exchange means for receiving the condensed flow and expanding this at a lower pressure to form the liquefied natural gas flow; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool this under pressure; (2) second expansion means connected to the second heat exchange means for receiving the flow of cooled natural gas and expanding it to an intermediate pressure; (3) contact and separation means connected to receive the flow of expanded cooled natural gas, with the contact and separation means containing at least one contact device for mixing the liquid and the vapor, and including separation means for separating the vapor and the 131 liquid after having been mixed to form a volatile waste gas fraction containing a larger portion of methane and lighter components and a first liquid flow; (4) a distillation column connected to receive the first liquid flow, with the first distillation column adapted to separate the flow in a more volatile distillation stream and a relatively less volatile fraction containing a larger portion of heavier hydrocarbon components; (5) third heat exchange means connected to the distillation column to receive the most volatile steam distillation flow and to cool it sufficiently to condense at least part of it, thereby forming a second liquid flow; (6) the contact and separation means are further connected to the third heat exchange means for receiving the second liquid flow, so that at least a portion of the flow of cooled, expanded natural gas is brought into intimate contact with at least part of the second liquid flow in the contact device; (7) the first heat exchange means connected to the contact and separation means to receive the volatile waste gas fraction, with the first heat exchange means adapted to cool the fraction of 132 volatile waste gas under pressure to condense at least a portion thereof and thereby form the condensed flow; Y (8) control means adapted to regulate the quantities and temperatures of the feed streams to the contact and separation means and the distillation column to maintain the temperatures at the top of the contact and separation media and the distillation column at temperatures at which the larger portion of the heavier hydrocarbon components is recovered in the relatively less volatile fraction. 52. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means cooperatively connected to receive the flow of natural gas and cooling this low pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means connected to the first heat exchange means for receiving the condensed flow and expanding this at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means connected in a cooperative manner to receive the natural gas flow and to cool this low-pressure sufficient for 133 partially condense this; (2) separation means connected to the second heat exchange means for receiving the flow of partially condensed natural gas and separating it into a vapor flow and a first liquid flow; (3) second expansion means connected to the separation means to receive the steam flow and expand it at an intermediate pressure; (4) contact and separation means connected to receive the expanded steam flow, with the contact and separation means containing at least one contact device for mixing the liquid and vapor, including separation means to separate the vapor and the liquid afterwards mixed to form a volatile waste gas fraction containing a larger portion of methane and lighter components and a second liquid flow; (5) third expansion means connected to the separation means to receive the first flow of liquid and expand it at intermediate pressure; (6) a distillation column connected to receive the second liquid flow and the first expanded liquid flow, with the distillation column adapted to separate the streams in a more volatile steam distillation stream and a relatively less volatile fraction containing a larger portion of hydrocarbon components plus 134 heavy (7) third heat exchange means connected to the distillation column to receive the most volatile steam distillation flow and to cool it sufficiently to condense at least part of it, thereby forming a third liquid flow; (8) contact and separation means further connected to the third heat exchange means for receiving the third liquid flow, so that at least a portion of the expanded vapor flow is brought into intimate contact with at least part of the third flow of liquid in the contact device; (9) first heat exchange means connected to the contact and separation means for receiving the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion thereof and thus form the condensed flow; Y (10) control means adapted to regulate the quantities and temperatures of the feed streams to the contact and separation means and the distillation column to maintain the temperatures of the upper part of the contact and separation media and the distillation column at a temperature at which the largest portion of the heavier hydrocarbon components is recovered at 135 ° C. relatively less volatile fraction. 53. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means cooperatively connected to receive the flow of natural gas and cooling this under pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means connected to the first heat exchange means for receiving the condensed flow and expanding this at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool this under pressure; (2) second expansion means connected to the second heat exchange means for receiving the flow of cooled natural gas and expanding it to an intermediate pressure; (3) contact and separation means connected to receive the flow of expanded cooled natural gas, with the contact and separation means containing at least one contact device for mixing the liquid and vapor, including separation means for separating the steam and the ± 36 liquid after mixing to form a first flow of steam and a first flow of liquid; (4) a distillation column connected to receive the first liquid flow, with a distillation column adapted to separate the flow in a more volatile steam distillation stream and a relatively less volatile fraction containing a larger portion of hydrocarbon components more heavy (5) third heat exchange means connected to the distillation column to receive the most volatile steam distillation flow and to cool this sufficiently to at least partially condense this; (6) separation means connected to the third heat exchange means for receiving the most volatile, cooled steam distillation flow, and separating this in a second steam flow and a second liquid flow; (7) dividing means connected to the separation means for receiving the second flow of liquid and for dividing this in at least a first portion and a second portion, the dividing means being further connected to the distillation column for supplying the first portion of the liquid. second flow of liquid to the distillation column as a feed exceeding stacking) contact and separation means which are further connected to the dividing means for receiving the second portion of the second liquid flow, so that at least a portion of the expanded, cooled natural gas flow is brought into intimate contact with at least part of the second portion of the second liquid flow in the contact device; (9) combination means connected to the contacting and separating means and separation means for receiving the first the first steam flow and the second steam flow and combining them to form a volatile waste gas fraction containing a larger portion of methane and lighter components; (10) first heat exchange means connected to the combining means for receiving the volatile residual gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion of this and thus form the condensed flow; and (11) control means adapted to regulate the quantities and temperatures of the feed streams to the contact and separation means and the distillation column to maintain the temperatures of the upper part of the contact and separation means and the column of distillation at a temperature at which the larger portion of the heavier hydrocarbon components is recovered in the relatively less volatile fraction. 138 54. In an apparatus for the liquefaction of a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means cooperatively connected to receive the flow of natural gas and to cool this under pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means connected to the first heat exchange means for receiving the condensed flow and expanding this at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool this under sufficient pressure to partially condense this; (2) first separation means connected to the second heat exchange means for receiving the flow of partially condensed natural gas and separating it into a first steam flow and a first liquid flow; (3) second expansion means connected to the first separation means for receiving the first steam flow and expanding it at an intermediate pressure; (4) contact and separation means connected to receive the first expanded steam flow, with the contact and separation means containing at least one contact device for mixing the liquid and the vapor, and including separating means for separating the vapor and the liquid after mixing them to form a second vapor flow and a second liquid flow; (5) third expansion means, connected to the separation means for receiving the first liquid flow and expanding this at intermediate pressure; (6) a distillation column connected to receive the second liquid flow and the first expanded liquid flow, with the distillation column adapted to separate the streams in a more volatile steam distillation stream and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components; (7) third heat exchange means connected to the distillation column to receive the most volatile steam distillation flow and to cool this sufficiently to condense at least part of this; (8) second separation means connected to the third heat exchange means for receiving the more volatile, cooled, steam distillation flow and separating it into a third steam flow and a third liquid flow; (9) dividing means connected to the second separation means for receiving the third liquid flow 140 and to divide this into at least a first portion and a second portion, the dividing means are further connected to the first distillation column to supply the first portion of the third liquid flow to the distillation column as a feed greater thereto; (10) the contact and separation means are further connected to the dividing means for receiving the second portion of the third liquid flow, so that at least a portion of the first expanded vapor flow is brought into intimate contact with at least part of the second portion of the third liquid flow in the contact device; (11) combination means connected to the contact and separation means and separation means for receiving the second steam flow and the third steam flow and combining them to form a volatile waste gas fraction containing a larger portion of methane and lighter components; (12) first heat exchange means connected to the combining means for receiving the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion of this and thus form the condensed flow; and (13) control means adapted to regulate the quantities and temperatures of the feed streams to the contact and separation media and the distillation column to maintain the temperatures of the upper part of the contact and separation media and the distillation column at a temperature at which the largest portion of The heavier hydrocarbon components are recovered in the relatively less volatile fraction. 55. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means connected cooperatively to receive the natural gas flow and cooling this low pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means connected to the first heat exchange means for receiving the condensed flow and expanding this at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool this under pressure; (2) second expansion means connected to the second heat exchange means for receiving the flow of cooled natural gas and expanding this at a pressure 142 intermediate; (3) contact and separation means connected to receive the flow of cooled, expanded natural gas, with the contact and separation means containing at least one contact device for mixing the liquid and the vapor, and including separation means for separating vapor and liquid after mixing them to form a volatile waste gas fraction containing a larger portion of methane and lighter components and a first liquid flow; (4) third heat exchange means connected to the contact and separation means to receive the first flow of liquid and heat it; (5) a distillation column connected to receive the first hot liquid flow, with the distillation column adapted to separate the flow in a more volatile steam distillation stream and a relatively less volatile fraction containing a larger portion of the components heavier hydrocarbons; (6) fourth heat exchange means connected to the distillation column to receive the most volatile steam distillation flow and to cool it sufficiently to condense at least part of it, thereby forming a second liquid flow; (7) contact and separation means that are further connected to fourth heat exchange means 143 to receive the second liquid flow, so that at least a portion of the flow of cooled, expanded natural gas is brought into intimate contact with at least part of the second liquid flow in the contact device; (8) the first heat exchange means connected to the contact and separation means for receiving the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion thereof and thus form the condensed flow; and (9) control means adapted to regulate the quantities and temperatures of the feed streams to the contact and separation means and the distillation column to maintain the temperatures of the upper part of the contact and separation means and the column of distillation at a temperature at which the larger portion of the heavier hydrocarbon components is recovered in the relatively less volatile fraction. 56. In an apparatus for the liquefaction of a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means connected cooperatively to receive the flow of natural gas and cooling this low pressure to condense at least a portion thereof and form a condensed flow; and 144 (b) first expansion means connected to the first heat exchange means for receiving the condensed flow and expanding this at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool this under pressure sufficiently to partially condense this; (2) separation means connected to the second heat exchange means for receiving the flow of partially condensed natural gas and separating it into a first steam flow and a first liquid flow; (3) second expansion means connected to the separation means for receiving the first steam flow and expanding it at an intermediate pressure; (4) contact and separation means connected to receive the first expanded vapor flow, with the contact and separation means containing at least one contact device for mixing the liquid and the vapor, and including separation means for separating the vapor and the liquid after mixing to form a fraction of the volatile waste gas containing a higher pressure of methane and lighter components and a second flow of liquid; (5) third heat exchange means, 145 connected to the contact and separation means to receive the second flow of liquid and heat it; (6) third expansion means connected to the separation means for receiving the first flow of liquid and expanding this at intermediate pressure; (7) a distillation column connected to receive the second flow of hot liquid and the first flow of expanded liquid, with the distillation column adapted to separate the flows into a more volatile steam distillation stream and a relatively less volatile fraction than contains a larger portion of the heavier hydrocarbon components; (8) fourth heat exchange means connected to the distillation column to receive the most volatile steam distillation flow and to cool it sufficiently to condense at least part of it, thereby forming a third liquid flow; (9) contact and separation means that are further connected to fourth heat exchange means for receiving the third liquid flow, so that at least a portion of the first expanded steam flow is brought into intimate contact with at least part of the third flow of liquid in the contact device; (10) first heat exchange means connected to the contact and separation means to receive 146 the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion thereof and thereby form the condensed flow; and (11) control means adapted to regulate the quantities and temperatures of the feed streams to the contacting and separating means and the distillation column to maintain the temperatures of the upper part of the contact and separation means and the column of distillation at a temperature at which the larger portion of the heavier hydrocarbon components is recovered in the relatively less volatile fraction. 57. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means cooperatively connected to receive the flow of natural gas and cooling this low pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means connected to the first heat exchange means for receiving the condensed flow and expanding this at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second means of exchange of 147 heat connected cooperatively to receive the flow of natural gas and cool this under pressure; (2) second expansion means connected to the second heat exchange means for receiving the flow of cooled natural gas and expanding it to an intermediate pressure; (3) contact and separation means connected to receive the flow of cooled, expanded natural gas, with the contact and separation means contained in at least one contact device for mixing the liquid and the vapor and including separation means for separating the vapor and the liquid after being mixed to form a first flow of steam and a first flow of liquid; (4) third heat exchange means connected with the contact and separation means to receive the first liquid flow and heat it; (5) a distillation column connected to receive the first hot liquid flow, with the distillation column adapted to separate the flow in a more volatile steam distillation stream and a relatively less volatile fraction containing a larger portion of the components heavier hydrocarbons; (6) fourth heat exchange means connected to the distillation column to 'receive the most volatile steam distillation flow and cool this enough to condense at least part of it; (7) separation means connected to the fourth heat exchange means for receiving the most volatile, cooled, steam distillation flow and separating this in a second steam flow and a second liquid flow; (8) dividing means connected to the separation means for receiving the second flow of liquid and for dividing it into at least a first portion and a second portion, the dividing means being further connected to the distillation column to supply the first portion of the liquid. second flow of liquid to the distillation column as a feed higher than this; (9) contact and separation means which are further connected to the dividing means for receiving the second portion of the second liquid flow, so that at least a portion of the flow of expanded, cooled natural gas is brought into intimate contact with the less part of the second portion of the second liquid flow in the contact device; (10) combination means connected to the contact and separation means for receiving the first steam flow and the second steam flow and combining them to form a volatile waste gas fraction containing a larger portion of methane and lighter components; (11) first heat exchange media 149 connected to the combining means for receiving the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion thereof and thereby form the condensed flow and (12) control means adapted to regulate the quantities and temperatures of the feed streams to the contact and separation means and the distillation column to maintain the temperatures of the top of the contact and separation media and the column of distillation at a temperature at which the larger portion of the heavier hydrocarbon components is recovered in the relatively less volatile fraction. 58. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means cooperatively connected to receive the flow of natural gas and cooling it under pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means, connected to the first heat exchange means for receiving the condensed flow and expanding it at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized because the device includes 150 (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool it under pressure sufficiently to partially condense it; (2) first separation means connected to the second heat exchange means for receiving the flow of partially condensed natural gas and separating it in a first flow of steam and a first flow of liquid; (3) second expansion means connected to the first separation means for receiving the first steam flow and expanding it to an intermediate pressure; (4) contact and separation means connected to receive the first expanded steam flow, with the contact and separation means containing at least one contact device for mixing liquid and vapor and include separation means for separating the vapor and the liquid afterwards of mixing them to form a second steam flow and a second liquid flow, - (5) third heat exchange means connected to the contact and separation means to receive the second flow of liquid and heat it; (6) third portion means connected to the separation means for receiving the first liquid flow and expanding it at intermediate pressure; (7) a connected distillation column for 151 receive the second flow of hot liquid and the first flow of expandable liquid, with the distribution column adapted to separate the flows in a more volatile steam distillation flow and a relatively less volatile fraction containing a larger portion of the hydrocarbon components heavy (8) fourth heat exchange means connected to the distillation column to receive the most volatile steam distillation flow and to cool it sufficiently to condense at least part of it; (9) second separation means connected to the fourth heat exchange means for receiving the most volatile steam distillation flow cooled and separating it into a third steam flow and a third liquid flow; (10) dividing means connected to the second separation means to receive the third liquid flow and to divide it into at least one first portion and a second portion, the dividing means being further connected in the distillation column to supply the first portion of the third liquid flow to the distillation column as a feed greater than this; (11) the contact and separation means are further connected to the dividing means for receiving the second portion of the third liquid flow, so that at least a portion of the first expanded vapor flow is 152 placed in intimate contact with at least part of the second portion of the third liquid flow in the contact device; (12) contact means connected to the contact and separation means and the second separation means for receiving the second steam flow and the third steam flow and combining them to form a volatile waste gas fraction containing a larger portion of methane and lighter components; (13) first heat exchange means connected to the combining means for receiving the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas portion under pressure to condense at least a portion of and thus form the condensed flow; (14) control means adapted to regulate the quantities and temperatures of the feed streams to the contact and separation means and the distillation column to maintain the temperatures at the top of the contact and separation means in the distillation column at temperatures at which the larger portion of the heavier hydrocarbon components is recovered in the relatively less volatile fraction. 59. In a device for the liquefaction of a natural gas stream containing methane and components heavier hydrocarbons, there being in the apparatus (a) one or more first heat exchange means cooperatively connected to receive the flow of natural gas and to cool it under pressure to condense at least a portion thereof and form a condensed flow and (b) first expansion means, connected to the first heat exchange means for receiving the condensed flow and expanding it at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means connected cooperatively to receive the flow of natural gas and to cool it under pressure; (2) second expansion means connected to the second heat exchange means for receiving the flow of cooled natural gas and expanding it to an intermediate pressure; (3) a distillation column connected to receive the flow of cooled natural gas, with the distillation column adapted to separate the flow into a more volatile steam distillation stream and a relatively less volatile fraction containing a larger portion of the components heavier hydrocarbons, - (4) means for removing steam connected to the distillation column to receive a distillation flow 154 of steam from a region of the distillation column below the flow of cooled, expanded natural gas; (5) third heat exchange means connected to the means for removing steam to receive the steam distillation flow and cooling it sufficiently to condense at least part of it; (6) separation means connected to the third heat exchange means for receiving the distillation flow of cooled vapor and separating it in a vapor flow and a liquid flow; (7) The distillation column is further connected to the separation means for receiving the flow of the liquid, so that at least a portion of the flow of cooled, expanded natural gas is brought into intimate contact with at least part of the flow of the liquid. liquid in the distillation column; (8) combination means connected to the distillation column and separation means to receive the most volatile steam distillation flow and vapor flow and combine them to form a volatile waste gas fraction containing a larger portion. of methane and lighter components; (9) the first heat exchange means connected to the combining means for receiving the volatile residual gas fraction, with the first means of heat adapted to cool the volatile waste gas fraction under pressure to condense at least a portion thereof and thereby form the condensed flow; and (10) control means adapted to regulate the quantities and temperatures of the feed streams to the distillation column to maintain the temperature at the top of the distillation column at a temperature at which the major portion of the hydrocarbon components heavier is recovered in the relatively less volatile fraction. 60. In an apparatus for the liquefaction of a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means cooperatively connected to receive the flow of natural gas and cooling it under pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means, adapted to the first heat exchange means to receive the condensed flow and expand it at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool it under sufficient pressure to partially condense this one; (2) first separation means connected to the second heat exchange means for receiving the flow of partially condensed natural gas and separating it in a first flow of steam and a first flow of liquid; (3) second expansion means connected to the first separation means for receiving the first steam flow and expanding it to an intermediate pressure; (4) third expansion means connected to the first separation means for receiving the first liquid flow and expanding it to the intermediate pressure; (5) a distillation column connected to receive the first expanded vapor flow and the first expanded liquid flow, with the distillation column adapted to separate the flows in a more volatile steam distillation flow and a relatively less volatile fraction than contains a larger portion of the heavier hydrocarbon components; (6) means for removing the vapor connected to the distillation column to receive a steam distillation flow from a region of the distillation column below the first expanded steam flow; (7) third heat exchange means connected to the means for removing steam to receive the steam distillation flow and to cool it sufficiently to condense at least part of it; (8) second separation means connected to the third heat exchange means for receiving the cooled steam distillation flow and separating it in a second steam flow and a second liquid flow; (9) The distillation column is further connected to the second separation means for receiving the second liquid flow, so that at least a portion of the first expanded vapor flow is brought into intimate contact with at least part of the second flow of liquid. liquid in the distillation column; (10) combining means connected to the distillation column and the second separation means to receive the most volatile steam distillation flow and the second vapor flow and combine them to form a volatile waste gas fraction containing a larger portion of the Ethane and lighter components; (11) first heat exchange means connected to the combining means for receiving the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile residual gas fraction under pressure to condense at least a portion of and thus form the condensed flow; and (12) control means adapted to regulate the quantities and temperatures of the feed streams to the 158 distillation column to maintain the temperature at the top of the distillation column at a temperature at which the larger portion of the heavier hydrocarbon components is recovered in the relatively less volatile fraction. 61. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means cooperatively connected to receive the flow of natural gas and cooling it under pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means, connected to the first heat exchange means for receiving the condensed flow and expanding it at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means connected cooperatively to receive the flow of natural gas and to cool it under pressure; (2) second expansion means connected to the second heat exchange means for receiving the flow of cooled natural gas and expanding it to an intermediate pressure; (3) a connected distillation column for 159 receiving the flow of cooled natural gas, with the distillation column adapted to separate the flow in a non-volatile steam distillation stream and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components; (4) means for removing steam connected to the distillation column to receive a steam distillation flow from a region of the distillation column below the flow of cooled, expanded natural gas; (5) third heat exchange means connected to the means for removing steam to receive the steam distillation flow and cooling it sufficiently to condense at least part of it; (6) separation means connected to the third heat exchange means for receiving the distillation flow of cooled vapor and separating it in a vapor flow and a liquid flow; (7) dividing means connected to the separation means for receiving the liquid flow and dividing it into at least a first portion and a second portion, the dividing means are further connected to the distillation column to supply the first portion of the flow of liquid. liquid to the distillation column at a substantially same feeding location, region where the steam distillation flow is withdrawn; 160 (8) The distillation column is further connected to the dividing means for receiving the second portion of the liquid flow, so that at least a portion of the flow of expanded cooled natural gas is brought into intimate contact with at least a portion of the second portion of the liquid flow in the distillation column; (9) combination means connected to the distillation column and separation means to receive the most volatile steam distillation flow and vapor flow and combine them to form a volatile waste gas fraction containing a larger portion of methane and lighter components; (10) first heat exchange means connected to the combining means for receiving the volatile residual gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion of this and thus form the condensed flow; and (11) control means adapted to regulate the quantities and temperatures of the feed streams to the distillation column to maintain the temperature at the top of the distillation column at a temperature at which the major portion of the hydrocarbon components heavier is recovered in the relatively less 161 fraction volatile 62. In an apparatus for the liquefaction of a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more first heat exchange means connected cooperatively to receive the flow of natural gas and cooling it under pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means, connected to the first heat exchange means for receiving the condensed flow and expanding it at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means connected cooperatively to receive the flow of natural gas and to cool it under sufficient pressure to partially condense it; (2) first separation means connected to the second heat exchange means for receiving the flow of partially condensed natural gas and separating it into a first steam flow and a first liquid flow; (3) second expansion means connected to the first separation means for receiving the first steam flow and expanding it to an intermediate pressure; (4) third expansion media connected to the 162 first separation means for receiving the first liquid flow and expanding it to the intermediate pressure; (5) a distillation column connected to receive the first expanded vapor flow and the first expanded liquid flow, with the distillation column adapted to separate the flows into a more volatile steam distillation stream and a relatively less volatile fraction than contains a larger portion of the heavier hydrocarbon components; (6) means for removing the vapor connected to the distillation column to receive a steam distillation flow from a region of the distillation column below the first expanded steam flow; (7) third heat exchange means connected to the means for removing steam to receive the steam distillation flow and cooling it sufficiently to condense at least part of it; (8) second separation means connected to the third heat exchange means for receiving the cooled steam distillation flow and separating it in a second steam flow and a second liquid flow; (9) dividing means connected to the second separation means to receive the second liquid flow and to divide it into at least a first portion and a second portion, the dividing means are further connected to the distillation column for supplying the first portion of the second liquid flow to the distillation column at a feeding location in substantially the same region where the distillation flow is withdrawn; (10) The distillation column is further connected to the dividing means for receiving the second portion of the second liquid flow, so that at least a portion of the first expanded vapor flow is brought into intimate contact with at least a portion of the second portion of the liquid flow in the distillation column; (11) combination means connected to the distillation column and separation means to receive the most volatile steam distillation flow and the second vapor flow and combine them to form a volatile waste gas fraction containing a larger portion of methane and lighter components (12) first heat exchange means connected to the combining means for receiving the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense the minus a portion thereof and thereby form the condensed flow; and (13) control means adapted to regulate the quantities and temperatures of the feed streams to the distillation column to maintain the temperature at the top 164 from the distillation column at a temperature at which the larger portion of the heavier hydrocarbon components is recovered in the relatively less volatile fraction. 63. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more heat exchange means connected cooperatively to receive the flow of natural gas and cooling this under pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means connected to the first heat exchange means for receiving the condensed flow and expanding this at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool this under pressure; (2) second expansion means connected to the second heat exchange means for receiving the flow of cooled natural gas and expanding it to an intermediate pressure; (3) a distillation column connected to receive the flow of cooled natural gas, with the distillation column adapted to separate the flow in a flow of 165 more volatile steam distillation and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components, - (4) means for removing steam connected to the distillation column to receive a steam distillation stream from a region of the distillation column below the flow of cooled, expanded natural gas; (5) third heat exchange means connected to the means for removing steam to receive the steam distillation flow and cooling it sufficiently to condense at least part of it; (6) separation means connected to the third heat exchange means to receive the cooled steam distillation flow and separate this in a. vapor flow and a liquid flow; (7) The distillation column is further connected to the separation means for receiving the liquid flow, so that at least a portion of the flow of expanded cooled natural gas is brought into intimate contact with at least part of the liquid flow in the distillation column; (8) means for removing liquid connected to the distillation column to receive a distillation flow of liquid from a region of the distillation column above the means for removing steam; 166 (9) fourth heat exchange means connected with the means for removing liquid to receive the liquid distillation flow and heat it, the fourth heat exchange means are further connected to the distillation column to supply the liquid distillation flow heated in the distillation column in a place below the means for removing steam; (10) combining means connected to the distillation column and separation means to receive the most volatile steam distillation flow and vapor flow and combine them to form a volatile waste gas fraction containing a larger portion of methane and lighter components; (11) first heat exchange means connected to the combining means for receiving the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion of this and thus form the condensed flow; and (12) control means adapted to regulate the quantities and temperatures of the feed streams to the distillation column to maintain the temperature of the top of the distillation column at a temperature at which the major portion of the hydrocarbon components heavier is recovered in the relatively less 167 fraction volatile 64. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more heat exchange means connected cooperatively to receive the flow of natural gas and cool this under pressure to condense at least a portion of it and form a condensed flow; and (b) first expansion means connected to the first heat exchange means for receiving the condensed flow and expanding this at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool this under pressure sufficiently to partially condense this; (2) first separation means connected to the second heat exchange means for receiving the flow of partially condensed natural gas and separating it in a first flow of steam and a first flow of liquid; (3) second expansion means connected to the first separation means for receiving the first steam flow and expanding it at an intermediate pressure; (4) third expansion media connected to the 168 we will take separation means to receive the first flow of liquid and expand this - to the intermediate pressure; (5) a distillation column connected to receive the first expanded vapor flow and the first expanded liquid flow, with the distillation column adapted to separate the flows in a more volatile steam distillation flow and a relatively less volatile fraction than contains a larger portion of the heavier hydrocarbon components, - (6) means for removing steam connected to the distillation column to receive a steam distillation flow from a region of the distillation column below the first expanded steam flow; (7) third heat exchange means connected to the means for removing steam to receive the steam distillation flow and cooling it sufficiently to condense at least part of it; (8) second separation means connected to the third heat exchange means for receiving the cooled steam distillation flow and separating it in a second steam flow and a second liquid flow; (9) The distillation column is further adapted to be connected to the second separation means for receiving the second liquid flow, so that at least a portion of the first expanded vapor flow is set to 169 intimate contact with at least part of the second liquid flow in the distillation column; (10) means for removing liquid connected to the distillation column to receive a distillation flow of liquid from a region of the distillation column above the means for removing steam; (11) fourth heat exchange means connected to the means for removing liquid to receive the distillation flow of heated liquid, the fourth heat exchange means are further connected to the distillation column to supply the hot liquid distillation flow to the distillation column in a place in lieu or of the means for removing steam; (12) combination means connected to the distillation column and the second separation means to receive the most volatile steam distillation flow and the second vapor flow and combine them to form a volatile waste gas fraction containing a larger portion of methane and lighter components; (13) first heat exchange means connected to the combining means for receiving the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion of this and thus form the condensed flow; and intermediate; (3) a distillation column connected to receive the flow of cooled natural gas, with the distillation column adapted to separate the flow into a more volatile steam distillation stream and a relatively less volatile fraction containing a larger portion of the components heavier hydrocarbons; (4) means for removing steam connected to the distillation column to receive a distillation flow from a region of the steam distillation column below the flow of cooled, expanded natural gas; (5) third heat exchange means connected to the means for removing steam to receive the steam distillation flow and cooling it sufficiently to condense at least part of this; (6) separation means connected to the third heat exchange means for receiving the cooled steam distillation flow and separating it into a vapor flow and a liquid flow; (7) dividing means connected to the separation means for receiving the liquid flow and dividing it into at least a first portion and a second portion, the dividing means are further connected to the distribution column to add the first portion of the flow of liquid to the distillation column at a feeding place substantially in the same region where the steam distillation flow is removed; (8) The distillation column is further connected to the dividing means for receiving the second portion of the liquid flow, so that at least a portion of the expanded, cooled natural gas flow is brought into intimate contact with at least part of the the second portion of the liquid flow in the distillation column; (9) means for removing liquid connected to the distillation column to receive a liquid distillation flow from a region of the distillation column above the means for removing steam; (10) fourth heat exchange means connected with the means for withdrawing liquid to receive the liquid distillation flow and heating it, the fourth heat exchange means are further connected to the distillation column to supply the distillation flow of heated liquid in the distillation column at a place below of the means for removing steam; (11) combining means connected to the distillation column, the separation means for receiving the most volatile steam distillation flow and the vapor flow and combining them to form a volatile waste gas fraction containing a larger portion of methane and lighter components; (12) first heat exchange means connected to the combining means for receiving the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion of this and thus form the condensed flow; Y (13) control means adapted to regulate the quantities and temperatures of the feed streams to the distillation column to maintain the temperature of the top of the distillation column at a temperature at which the major portion of the hydrocarbon components heavier is recovered in the relatively less volatile fraction. 66. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more heat exchange means connected cooperatively to receive the flow of natural gas and cooling this under pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means connected to the first heat exchange means for receiving the condensed flow and expanding this at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus includes (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool this low pressure sufficiently to partially condense this; (2) first separation means connected to the second heat exchange means for receiving the flow of partially condensed natural gas and separating it into a first steam flow and a first liquid flow; (3) second expansion means connected to the first separation means for receiving the first steam flow and expanding it at an intermediate pressure; (4) third expansion means connected to the separation means to receive the first liquid flow and expand this to the intermediate pressure; (5) a distillation column connected to receive the first expanded vapor flow and the first expanded liquid flow, with the distillation column adapted to separate the flows in a more volatile steam distillation flow and a relatively less volatile fraction than contains a larger portion of the heavier hydrocarbon components; (6) means for removing steam connected to the distillation column to receive a steam distillation flow from a region of the distillation column below the first expanded vapor or flux; (7) third heat exchange means connected to the means for removing steam to receive the steam distillation flow and cooling it sufficiently to condense at least part of it; (8) second separation means connected to the third heat exchange means for receiving the cooled steam distillation flow and separating it in a second steam flow and a second liquid flow; (9) dividing means connected to the second separation means for receiving the second liquid flow, and for dividing this into at least a portion and a second portion, the dividing means are further connected to the distillation column to supply the first portion of the second liquid flow in the distillation column at a feeding location substantially in the same region where the steam distillation flow is removed; (10) The distillation column is further connected to the dividing means for receiving the second portion of the second liquid flow so that at least a portion of the first expanded vapor flow is brought into intimate contact with at least part of the second portion. of the second liquid flow in the distillation column; (11) means for removing liquid connected to the distillation column to receive a distillation flow of liquid from a region of the distillation column above the means for removing steam; (12) fourth heat exchange means connected to the means for removing liquid to receive the distillation flow of heated liquid, the fourth heat exchange means are further connected to the distillation column to supply the hot liquid distillation flow to the distillation column in a place below the means for removing steam; (13) combination means connected to the distillation column and the second separation means to receive the most volatile steam distillation flow and the second vapor flow and combine them to form a volatile waste gas fraction containing a larger portion of methane and lighter components; (14) first heat exchange means connected to the combining means for receiving the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion of this and thus form the condensed flow; and (15) control means adapted to regulate the quantities and temperatures of the feed streams to the distillation column to maintain the temperature of the top of the distillation column at a temperature at which the major portion of the hydrocarbon components heavier is recovered in the relatively less volatile fraction. 67. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more heat exchange means connected cooperatively to receive the flow of natural gas and cooling this under pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means connected to the first heat exchange means for receiving the condensed flow and expanding this at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus consists essentially of (1) one or more · second heat exchange means cooperatively connected to receive the flow of natural gas and to cool this under pressure; (2) second expansion means connected to the second heat exchange means for receiving the flow of cooled natural gas and expanding it to an intermediate pressure; (3) the distillation connected to receive the flow of cooled, expanded natural gas, with the distillation column adapted to separate the flow into a fraction of volatile waste gas containing a larger portion of methane and lighter components and a relatively less fraction volatile that contains a larger fraction of the heavier hydrocarbon components; (4) the first heat exchange means connected to the distillation column to receive the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction under pressure to condense at least a portion of this and thus form the condensed flow; Y (5) control means adapted to regulate the quantity and temperature of the feed streams to the distillation column to maintain the temperature of the upper part of the distillation column at a temperature at which the major portion of the hydrocarbon components more heavy is recovered in the relatively less volatile fraction. 68. In an apparatus for liquefying a flow of natural gas containing methane and heavier hydrocarbon components, there being in the apparatus (a) one or more heat exchange means connected cooperatively to receive the flow of natural gas and cooling this under pressure to condense at least a portion thereof and form a condensed flow; and (b) first expansion means connected to the first heat exchange means for receiving the condensed flow and expanding this at a lower pressure to form the flow of liquefied natural gas; the improvement, characterized in that the apparatus consists essentially of (1) one or more second heat exchange means cooperatively connected to receive the flow of natural gas and to cool this under pressure sufficiently to partially condense this; (2) separation means connected to the second heat exchange means for receiving the flow of partially condensed natural gas and separating it into a first steam flow and a first liquid flow; (3) second expansion means connected to the separation means for receiving the first steam flow and expanding it at an intermediate pressure; (4) third expansion means connected to the separation means to receive the liquid flow and expand it to the intermediate pressure; (5) a distillation column connected to receive the flow of expanded steam and expanded liquid flow, with the distillation column adapted to separate the flows, into a fraction of volatile waste gas with a larger portion of methane and lighter components and a relatively less volatile fraction containing a larger portion of the heavier hydrocarbon components; (6) the first heat exchange means connected to the distillation column to receive the volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile residual gas portion for low pressure to condense at least one fraction thereof and thus form the condensed flow; and (7) control means adapted to regulate the quantities and temperatures of the feed streams to the distillation column to maintain the temperature at the top of the distillation column at a temperature at which the major portion of the hydrocarbon components heavier is recovered in the relatively less volatile fraction. 69. The improvement according to claims 43, 44, 45, 67 or 68, characterized in that the apparatus includes (1) compression means connected to the distillation column to receive the volatile waste gas portion and compress it; and (2) first heat exchange means connected to the compression means for receiving the compressed volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction compressed under pressure to condense at least a portion of this and thus form the condensed flow. 70. An improvement according to claim 41, characterized in that the apparatus includes: (1) compression means connected to the distillation column to receive the volatile waste gas fraction and compress it; (2) first heat exchange means connected to the compression means for receiving the compressed volatile waste gas fraction, with the first heat exchange means adapted to cool the fraction of volatile waste gas compressed under pressure to condense at least one portion of this; and (3) first dividing means connected to the first heat exchange means for receiving the condensed portion and dividing this, in at least two portions, thus forming the condensed flow and the liquid flow, the dividing means are further connected to the distillation column to direct the flow of liquid to the distillation column as a feed greater than this. 71. The improvement according to claim 42, characterized in that the apparatus includes: (1) compression means connected to the distillation column to receive the volatile waste gas fraction and compress it; (2) first heat exchange means connected to the compression means for receiving the compressed volatile waste gas fraction, with the first heat exchange means adapted to cool the fraction of volatile waste gas compressed under pressure to condense at least one portion of this; and (3) dividing means connected to the first heat exchange means for receiving the condensed portion and dividing it into at least two portions, thereby forming the condensed flow and the second liquid flow, the dividing means are further connected to the distillation column to direct the second flow of liquid to the distillation column as a feed higher than this. 72. The improvement according to claim 46, characterized in that the apparatus includes: (1) compression means connected to the distillation column to receive the fraction of volatile waste gas and compress it; (2) first heat exchange means connected to the compression means for receiving the compressed volatile waste gas fraction, with the first heat exchange means adapted to cool the fraction of volatile waste gas compressed under pressure to condense at least one portion of this; and (3) second dividing means connected to the first heat exchange means for receiving the condensed portion and dividing it into at least two portions, thereby forming the condensed flow and the second liquid flow, the dividing means are further connected. to the distillation column to direct the second liquid flow to the distillation column as a feed higher than this. 73. The improvement according to claim 47 or 48, characterized in that the apparatus includes: (1) compression means connected to the distillation column to receive the volatile waste gas fraction and compress it; (2) first heat exchange means connected to the compression means for receiving the compressed volatile waste gas fraction, with the first heat exchange means adapted to cool the fraction of volatile waste gas compressed under pressure to condense at least one portion of this; and (3) second dividing means connected to the first heat exchange means for receiving the condensed portion and dividing it into at least two portions, thereby forming the condensed flow and the second liquid flow, the second dividing means being connected in addition to the distillation column to direct the second flow of liquid to the distillation column as a feed higher than this. 7 The improvement in accordance with the claim 49, characterized in that the apparatus includes: (1) compression means connected to the distillation column to receive the most volatile steam distillation flow and compress this; and (2) combination means connected to the separating means and the compression means to receive the more volatile compressed vapor distillation steam flow and flow and combine them to form the volatile waste gas fraction containing a larger portion of methane. and lighter components. 75. The improvement in accordance with the claim 50, characterized in that the apparatus includes-. (1) compression means connected to the distillation column to receive the most volatile steam distillation flow and compress this; and (2) combination means connected to the second separation means and the compression means for receiving the second vapor flow and the more volatile vapor distillation flow compressed and combining them to form a volatile waste gas fraction containing a Larger portion of methane and lighter components. 76. The improvement according to claim 51, 52, 55 or 56, characterized in that the apparatus includes: (1) compression means connected to the contact and separation means for receiving the volatile waste gas fraction and compressing it; and (2) first heat exchange means connected to the compression means for receiving the compressed volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction compressed under pressure to condense at least a portion of this and thus form the condensed flow. 77. The improvement according to claim 53, 54, 57, 58, 59, 60, 61, 62, 63, 64, 65, or 66, characterized in that the apparatus includes: (1) compression means connected to the means of combination to receive the volatile waste gas fraction and compress it; and (2) first heat exchange means connected to the compression means for receiving the compressed volatile waste gas fraction, with the first heat exchange means adapted to cool the volatile waste gas fraction compressed under pressure to condense at least a portion of this and thus form the condensed flow. 78. The improvement according to claim 43, 44, 45, 67 or 68, characterized in that the apparatus includes: (1) heating means connected to the distillation column to receive the volatile residual gas fraction and heat it; (2) compression means connected to the heating means for receiving the hot volatile waste gas fraction and compressing it; and (3) first heat exchange means connected to the compression means for receiving the fraction of hot, compressed volatile waste gas, with the first heat exchange means adapted to cool the fraction of hot, compressed volatile waste gas, under pressure, to condense at least a portion thereof and thereby form condensed flow. 79. The improvement according to claim 41, characterized in that the apparatus includes: (1) heating means connected to the distillation column to receive the volatile waste gas fraction and heat it; (2) compression means connected to the heating means for receiving the hot volatile waste gas fraction and compressing it; (3) first heat exchange means connected to the compression means for receiving the fraction of hot, compressed volatile waste gas, with the first heat exchange means adapted to cool the hot, compressed volatile waste gas fraction, under pressure, to condense at least a portion thereof; and (4) dividing means connected to the first heat exchange means for receiving the condensed portion and diluting it in at least two portions, thereby forming the condensed flow and the liquid flow, the dividing means are further connected to the distillation column to direct the flow of liquid to the distillation column as a feed higher than this. 80. The improvement according to claim 42, characterized in that the apparatus includes: (1) heating means connected to the distillation column to receive the fraction of volatile waste gas and heat this; (2) compression means connected to the heating means for receiving the hot volatile waste gas fraction and compressing it; (3) first heat exchange means connected to the compression means for receiving the fraction of hot, compressed volatile waste gas, with the first heat exchange means adapted to cool the fraction of hot volatile waste gas, compressed, under pressure , to condense at least a portion thereof; and (4) dividing means connected to the first heat exchange means for receiving the condensed portion and dividing it into at least two portions, thereby forming the condensed flow and the second liquid flow, the dividing means are further connected to the distillation column to direct the second flow of liquid to the distillation column as a feed higher than this. 81. The improvement according to claim 46, characterized in that the apparatus includes: (1) heating means connected to the distillation column to receive the volatile residual gas fraction and heat it; (2) compression means connected to the heating means for receiving the hot volatile waste gas fraction and compressing it; (3) first heat exchange means connected to the compression means for receiving the portion of hot, compressed volatile waste gas, with the first heat exchange means adapted to cool the hot volatile waste gas fraction, compressed, under pressure , to condense at least a portion thereof; and (4) second dividing means connected to the first heat exchange means for receiving the condensed portion and dividing it into at least two portions, thereby forming the condensed flow and the liquid flow, the second dividing means being connected in addition to the distillation column to direct the flow of liquid to the distillation column as a feed higher than this. 82. The improvement in accordance with the claim 47 or 48, characterized in that the apparatus includes: (1) heating means connected to the distillation column to receive the volatile residual gas fraction and heat it; (2) compression means connected to the heating means for receiving the hot volatile waste gas fraction and compressing it; (3) first heat exchange means connected to the compression means for receiving the fraction of hot, compressed volatile waste gas, with the first heat exchange means adapted to cool the fraction of hot volatile waste gas, compressed, under pressure , to condense at least a portion thereof; and (4) second dividing means connected to the first heat exchange means for receiving the condensed portion and dividing it into at least two portions, thereby forming the condensed flow and the second liquid flow, the second dividing means being further connected to the distillation column to direct the second liquid flow to the distillation column as a feed higher than this. 83. The improvement according to claim 49, characterized in that the apparatus includes: (1) heating means connected to the distillation column to receive the most volatile steam distillation flow and heat it; (2) compression means connected to the heating means for receiving the hottest volatile steam distillation flow and compressing it; (3) cooling means connected to the compression means to receive the most volatile hot, compressed steam distillation flow, and to cool it; (4) combination means connected to the separation means and the cooling means to receive the vapor flow and the more volatile, compressed, cold vapor distillation flow, and combine them to form a volatile waste gas fraction containing a portion Greater methane and light components. 84. The improvement according to claim 50, characterized in that the apparatus includes: (1) heating means connected to the distillation column to receive the most volatile steam distillation flow and heat it; (2) compression means connected to the heating means to receive the most volatile, hot steam distillation flow and compress this; (3) cooling means connected to the compression means to receive the most volatile hot, compressed steam distillation flow, and to cool it; (4) combination means connected to the second separation means and the cooling means for receiving the second vapor flow and the more volatile, compressed, cold vapor distillation flow, and combining them to form a volatile waste gas fraction containing a larger portion of methane and lighter components. 85. The improvement in accordance with the claim 51, 52, 55 or 56 characterized in that the apparatus includes (1) heating means connected to the contact and separation means to receive the volatile waste gas fraction and heat it; (2) compression means connected to the heating means for receiving the hot volatile waste gas fraction and compressing it; and (3) first heat exchange means connected to the compression means for receiving the fraction of hot, compressed volatile waste gas, with the first heat exchange means adapted to cool the fraction of hot, compressed volatile waste gas, under pressure to condense at least a portion thereof and thereby form the condensed flow. 86. The improvement according to claim 53, 54, 57, 58, 59, 60, 61, 62, 63, 64, 65 or 66 characterized in that the apparatus includes (1) heating means connected to the combination means for receive the volatile residual gas fraction and heat it; (2) compression means connected to the heating means to receive the hot volatile waste gas fraction and compress this; and (3) 'first heat exchange means connected to the compression means for receiving the fraction of hot waste gas, compressed, with the first heat exchange means adapted to cool the fraction of hot volatile waste gas, compressed under pressure to condense at least a portion thereof and thereby form the condensed flow. 87. The improvement according to claim 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61 ,. 62, 63, 64, 65, 66, 67, 68, 70, 71, 72, 74, 75, 79, 80, 81, 83 or 84, characterized in that the volatile waste gas fraction contains a larger portion of methane, more components lightweight, and C2 components. 88. The improvement according to claim 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61 , 62, 63, 64, 65, 66, 67, 68, 70, 71, 72, 74, 75, 79, 80, 81, 83 or 84, characterized in that the fraction of volatile waste gas contains a greater portion of methane, components lighter, C2 components and C3 components. 89. The improvement in accordance with the claim 29, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, and C2 components. 90. The improvement in accordance with the claim 30, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, and C2 components. 91. The improvement in accordance with the claim 31, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, and C2 components. 92. The improvement according to claim 34, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, and C2-93 components. The improvement in accordance with the claim 35, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, and C2 components. 94. The improvement in accordance with the claim 36, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, and C2 components. 95. The improvement in accordance with the claim 29, characterized in that the fraction of volatile waste gas contains a larger portion of methane, light components, components of C2, and components of C3. 96. The improvement in accordance with the claim 30, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, C2 components, and C3 components. 97. The improvement according to claim 311, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, C2 components, and C3 components. 98. The improvement according to claim 34, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, C2 components, and C3 components. 99. The improvement in accordance with the claim 35, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, C2 components, and C3 components. 100. The improvement in accordance with the claim 36, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, C2 components, and C3 components. 101. The improvement in accordance with the claim 69, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, and C2 components. 102. The improvement according to claim 73, characterized in that the fraction of volatile waste gas contains a larger portion of methane, lighter components, and components of C2. 103. The improvement in accordance with the claim 76, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, and C2 components. 104. The improvement in accordance with the claim 77, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, and C2 components. 105. The improvement according to claim 78, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, and C2 components. 106. The improvement in accordance with the claim 82, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, and C2 components. 107. The improvement according to claim 85, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, and C2 components. 108. The improvement according to claim 86, characterized in that the fraction of volatile waste gas contains a larger portion of methane, lighter components, and components of C2. 109. The improvement according to claim 69, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, C2 components, and C3 components. 110. The improvement according to claim 73, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, C2 components, and C3 components. 111. The improvement according to claim 76, characterized in that the fraction of volatile waste gas contains a larger portion of methane, light components, components of C2, and components of C3. 112. The improvement according to claim 77, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, C2 components, and C3 components. 113. The improvement according to claim 78, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, C2 components, and C3 components. 114. The improvement according to claim 82, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, C2 components, and C3 components. 115. The improvement in accordance with the claim 85, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, C2 components, and C3 components. 116. The improvement in accordance with the claim 86, characterized in that the volatile waste gas fraction contains a larger portion of methane, lighter components, C2 components, and C3 components.