KR20040018265A - Natural gas liquefaction - Google Patents

Abstract

A combined natural gas 50 liquefaction process is disclosed to produce a liquid stream containing heavy hydrocarbons that is superior to methane 41. In this process, the liquefied natural gas stream 31 is partially cooled, expanded to intermediate pressures 14 and 15 and supplied to the distillation column 19. The bottom product 41 from this distillation column optionally contains a large number of any hydrocarbons heavier than methane, which can reduce the purity of the liquefied natural gas 50. Residual gas stream 37 from distillation column 19 is expanded to a high medium pressure (16), cooled under pressure (60) to condense the stream, and then expanded to low pressure (61) to liquefy the natural gas stream. Form.

Description

NATURAL GAS LIQUEFACTION

Natural gas is generally recovered from gas wells that have been drilled into the underground reservoir. Natural gas is usually dominated by methane, ie methane contains at least 50 mole percent (mol%) of natural gas. Depending on the particular underground reservoir, natural gas also contains relatively small amounts of heavier hydrocarbons such as ethane, propane, butane, pentane and the like, as well as water, hydrogen, nitrogen, carbon dioxide and other gases.

Most natural gas is treated in gaseous form. The most common means for transporting natural gas from gas wellheads to gas processing plants to natural gas consumers is the high pressure gas delivery pipeline. However, under various circumstances it is known to liquefy natural gas for transportation or use. For example, at a distance, there is often no pipeline infrastructure that allows for convenient transportation to the natural gas trading market. In this case, very low cost LNG related to gaseous natural gas can be used to distribute LNG using offshore shipping and transport trucks, thereby significantly reducing transportation costs.

Another situation where liquefaction of natural gas is desirable is when natural gas is used as a vehicle fuel. In large metropolitan areas, a large number of buses, taxis, trucks, etc., can be powered by LNG if a practical source of LNG is available. Vehicles that use LNG as fuel generate significantly less air pollution due to the clean combustion characteristics of natural gas compared to similar vehicles powered by gasoline and diesel engines that burn high molecular weight hydrocarbons. If LNG is of high purity (i.e. methane purity of 95 mol% or more), the carbon and hydrogen to methane is lower than all other hydrocarbon fuels, resulting in very low carbon dioxide (greenhouse gas) emissions.

The present invention relates to a process for treating natural gas or other methane rich gas streams to produce liquefied natural gas (LNG) having a liquid stream containing high purity methane and heavy hydrocarbons predominant over methane.

1 is a flow chart of a natural gas liquefaction plant adapted to co-produce NGLs in accordance with the present invention.

2 is a pressure-enthalpy state diagram of methane used to illustrate the advantages of the present invention with respect to prior art treatments.

3 is a flow chart of an optional natural gas liquefaction plant adapted to co-produce NGLs in accordance with the present invention.

4 is a flow chart of an optional natural gas liquefaction plant adapted to co-produce LPG in accordance with the present invention.

5 is a flow chart of an optional natural gas liquefaction plant adapted to co-produce condensate in accordance with the present invention.

6 is a flow chart of an optional natural gas liquefaction plant adapted to co-produce a liquid stream in accordance with the present invention.

7 is a flow chart of an optional natural gas liquefaction plant adapted to co-produce a liquid stream in accordance with the present invention.

8 is a flow chart of an optional natural gas liquefaction plant adapted to co-produce a liquid stream in accordance with the present invention.

9 is a flow chart of an optional natural gas liquefaction plant adapted to co-produce a liquid stream in accordance with the present invention.

10 is a flow diagram of an optional natural gas liquefaction plant adapted to co-produce a liquid stream in accordance with the present invention.

11 is a flow chart of an optional natural gas liquefaction plant adapted to co-produce a liquid stream in accordance with the present invention.

12 is a flow chart of an optional natural gas liquefaction plant adapted to co-produce a liquid stream in accordance with the present invention.

13 is a flow chart of an optional natural gas liquefaction plant adapted to co-produce a liquid stream in accordance with the present invention.

14 is a flow chart of an optional natural gas liquefaction plant adapted to co-produce a liquid stream in accordance with the present invention.

15 is a flow diagram of an optional natural gas liquefaction plant adapted to co-produce a liquid stream in accordance with the present invention.

16 is a flow chart of an optional natural gas liquefaction plant adapted to co-produce a liquid stream in accordance with the present invention.

17 is a flow chart of an optional natural gas liquefaction plant adapted to co-produce a liquid stream in accordance with the present invention.

18 is a flow chart of an optional natural gas liquefaction plant adapted to co-produce a liquid stream in accordance with the present invention.

19 is a flow chart of an optional natural gas liquefaction plant adapted to co-produce a liquid stream in accordance with the present invention.

20 is a flow diagram of an optional natural gas liquefaction plant adapted to co-produce a liquid stream in accordance with the present invention.

21 is a flow diagram of an optional natural gas liquefaction plant adapted to co-produce a liquid stream in accordance with the present invention.

FIELD OF THE INVENTION The present invention relates generally to the liquefaction of natural gas, while liquefied petroleum gas (LPG) or butane consisting of natural gas liquids (NGL) consisting of ethane, propane, butane and heavy hydrocarbon components, propane, butane and heavy hydrocarbon components. It relates to the production of co-products of liquid streams consisting primarily of hydrocarbons heavier than methane, such as condensate and heavy hydrocarbon components. The production of by-product liquid streams has two important advantages: The LNG produced has high purity methane, and the by-product liquid is a useful product that can be used for many other uses. The natural gas stream treated according to the invention is approximately mole percent, with 84.2% methane, 7.9% ethane and other C ₂ components, 4.9% propane and other C ₃ components, 1.0% iso-, with the remainder consisting of nitrogen and carbon dioxide. Butane (iso-butane), 1.1% normal-butane, 0.8% pentane ⁺ are generally analyzed. Sulfur containing gas is also sometimes present.

Various methods for liquefying natural gas are known. For example, Finn, Adrian J., Grant L., for the investigation of many of these treatments. Grant L. Johnson, and Terry R. "Marine" in the Gas Processors Association's 79th Annual Meeting, 429-450 (March 13-March 15, 2000, Atlanta, Georgia, USA), published by Terry R. Tomlinson et al. And LNG Technology for Mid-Scale Plants "and the 80th Annual Meeting of the Association of Gas Processors announced by Kikawa Oshitsugi, Masaaki Ohishi and Noriyoshi Nozawa (from March 12, 2001 to March 14, See “Optimizing the Power System of a Base-Road LNG Plant” in San Antonio, Texas, USA. US Patent No. 4,445,917; No. 4,525,185; 4,545,795; 4,755,200; 4,755,200; 5,291,736; 5,291,736; 5,363,655; 5,363,655; 5,365,740; 5,365,740; 5,600,969; 5,600,969; 5,615,561; 5,615,561; 5,651,269; 5,651,269; 5,755,114; 5,755,114; 5,893,274; 5,893,274; No. 6,014,869; 6,062,041; 6,062,041; No. 6,119,479; 6,125,653; 6,125,653; 6,250,105 B1; 6,269,655 B1; 6,272,882 B1; 6,308,531 B1; 6,324,867 B1; And 6,347,532 B1 also describe related methods. These methods generally involve purifying, cooling, condensing and expanding natural gas (by removing water and problematic compounds such as carbon dioxide and sulfur compounds). Cooling and condensation of natural gas can be accomplished in many different ways. "Cascade refrigeration" employs heat exchange of natural gas by a plurality of refrigerants having successive low boiling points such as propane, ethane, and methane. Optionally, this heat exchange can be accomplished by evaporating a single refrigerant to a plurality of different pressure levels.

“Multi-component refrigeration” employs heat exchange of natural gas by one or more refrigerant fluids composed of multiple refrigerant components instead of multiple single component refrigerants. The expansion of the natural gas can be made isenthalpically (eg using Joule-Thompson expansion) and isentropically (eg using a work-expansion turbine).

Regardless of the method used to liquefy the natural gas stream, it commonly requires the removal of significant fractions of hydrocarbons heavier than methane before the methane-rich stream is liquefied. There are several reasons for this hydrocarbon removal step, which include the need to control the calorific value of the LNG stream and the values these heavy hydrocarbon components themselves have. Unfortunately, little attention has been paid to the efficiency of the hydrocarbon removal step so far.

According to the present invention, it can be seen that the careful integration of the hydrocarbon removal step into the LNG liquefaction process can produce both LNG and separated heavy hydrocarbon liquid products using much less energy than prior art treatments. Although the present invention can be applied under low pressure, it is particularly advantageous when the gas supply is treated in the range of 2,758 to 10,342 kPa (a) [400 to 1500 psia] or more.

In the following description of the figures, the table provides an overview of the flow rates calculated during typical processing conditions. In the table below, the values for flow rate (moles / hour) are shown for the convenience to be closest to the integer. The total stream flow rate shown in the table includes all of the non-hydrocarbon components and therefore is generally greater than the sum of the stream flow rates of the hydrocarbon components. The temperature indicated is a temperature value that is approximately an integer. The process design calculations performed to compare the processes shown in the figures are based on the assumption that there is no heat leakage from (or from) the process. Commercially available insulation materials make this assumption very reasonable and are generally made by skilled workers.

For convenience, the processing parameters are recorded in both traditional British and international units (SI). The molar flow rates given in the table may be interpreted as pound moles per hour or kilogram moles per hour. The energy consumptions reported in horsepower (HP) and / or thousands of British thermodynamic units (MBTU / Hr) per hour correspond to the molar flow rates stated in pound moles per hour. The energy consumption, reported in kilowatts (kW), corresponds to the molar flow rate stated in kilogram moles per hour. The production rate reported in pounds per hour (Lb / Hr) corresponds to the molar flow rate stated in pounds per hour. The production rate reported in kilograms per hour (kg / Hr) corresponds to the molar flow rate stated in kilograms per hour.

First embodiment

With reference to FIG. 1, an example of a treatment according to the invention is described where the production of NGL by-products containing mostly ethane and heavy hydrocarbons in a natural gas feed stream is desired. In this simulation of the invention, the inlet gas enters the plant as stream 31 at 32 ° C. [90 ° F.] and 8860 kPa (a) [1285 psia]. If the product stream contains carbon dioxide and / or sulfur compound concentrations that can interfere with meeting specifications, these compounds are removed by appropriate pretreatment of the feed gas (not shown). In addition, the feed stream is usually dehydrated to prevent hydrate (ice) formation under cryogenic conditions. Solid desiccants are usually used for this purpose.

Feed stream 31 is cooled in heat exchanger 10 by heat exchange with a refrigerant stream and a deboiler side reboiler liquid (stream 40) to -55 ° C [-68 ° F]. Note that the heat exchanger 10 is typically represented by one of a number of individual heat exchangers or a single multi-channel heat exchanger or a combination thereof (the determination of whether to use more than one heat exchanger for the indicated cooling service is as follows. But not limited to, depending on a number of factors including inlet gas flow rate, heat exchanger size, stream temperature, etc.). The cooled stream 31a is subjected to −34 ° C. [−30 ° F.] and 8,812 kPa (a) [1278psia] in a separation device 11 where steam (stream 32) is separated from condensed liquid (stream 33). Enter.

From the separation device 11 the steam (stream 32) is split into two streams 34, 36. Stream 34 containing about 20% of the total vapor is combined with stream 33, the condensed liquid, to form stream 35. The combined stream 35 passes through the heat exchanger 13 in a heat exchange relationship with the refrigerant stream 71e, whereby the stream 35a cools and condenses. The stream 35a, typically condensed to -85 [deg.] C. [-120 [deg.] F., is then operated at an operating pressure of the fractionation tower 19 (approximately 3206 kPa (a) [465 psia]) through a suitable expansion device such as an expansion valve 14. Into the flash. A portion of the expanded stream is vaporized so that the entire stream is cooled. In the process shown in FIG. 1, the expanded stream 35b leaving the expansion valve 14 reaches a temperature of −86 ° C. [−122 ° F.], and the demethanation unit 19b of the fractionation tower 19 It is supplied to the midpoint supply position.

The remaining 80% of the steam from the separation device 11 (stream 36) enters the work expansion device 15 where mechanical energy is extracted from this portion of the high pressure feed. Apparatus 15 expands the vapor from a pressure of about 8812 kPa (a) [1278 psia] to isotropically tower operating pressure, with the workpiece expansion at approximately −75 ° C. [−103 ° F.], expanding stream 36a. ) To cool. Commercially available expansion devices can recover from about 80% to 85% of theoretically usable work with ideal isentropic expansion. The recovered work is often used to drive a centrifugal compressor 16 that can be used, for example, to recompress tower overhead gas (stream 38). The expanded and partially condensed stream 36a is sent as feed to the lower middle column feed point of the distillation column 19.

The demethanation device of the fractionation tower 19 is a distillation column of the prior art comprising a plurality of vertically spaced trays, one or more packed beds, or a combination of trays and packings. Although common in natural gas processing plants, a fractionation tower consists of two parts. The upper portion 19a is divided into the vapor and liquid portions, respectively, and the vapor from the lower distillation or demethanation 19b is combined with the vapor portion (if any) of the upper feed, so that the top of the tower is -93 ° C. Separator to form a cooling demethanizer overhead vapor (stream 37) exiting to [-135 [deg.] F.]. Lower demethanation 19b includes a tray and / or packing and provides the necessary contact between the liquid falling down and the vapor rising upwards. The demethanation unit also includes one or more reboilers (such as reboiler 20), which heats and vaporizes a portion of the liquid flowing under the column to provide stripping vapor that flows over the column. The liquid product stream 41 exits the bottom of the tower to 46 ° C. [115 ° F.] based on a typical specification of 0.020: 1 on a molar basis of the bottom product.

The demethanizer overhead steam (stream 37) is warmed in the heat exchanger 24 to 32 ° C. [90 ° F.], and a portion of the heated demethanizer overhead steam is taken out of the plant to produce fuel gas (stream (The amount of fuel gas to be taken out in this embodiment is mainly determined by the fuel required for the engine and / or turbine driving the gas compressor of the plant, such as refrigerant compressors 64, 66, 68, etc.). .). The remainder of the warmed demethanizer overhead steam (stream 38) is compressed by a compressor 16 driven by expansion devices 15, 61, 63. After cooling to 38 [deg.] C. [100 [deg.] F.] in the exhaust cooling unit 25, stream 38b cross-exchanges stream 37, which is a cooling de-methanizer overhead vapor, at -86 [deg.] C. in heat exchanger 24; -123 [deg.] F.

Stream 38c then enters heat exchanger 60 and is further cooled by refrigerant stream 71d. After cooling to medium temperature, stream 38c is split into two portions. The first portion, stream 49, is further cooled to -160 [deg.] C. [-257 [deg.] F.) to condense and supercool the stream in heat exchanger 60, and then to the work expansion device 61 where mechanical energy is extracted from the stream. Enter. Apparatus 61 expands liquid stream 49 isotropically from a pressure of about 3,878 kPa (a) [562 psia] to an LNG storage pressure (107 kPa (a) [15.5 psia]) slightly above atmospheric pressure. The work expansion will cool the expanded stream 49a to a temperature of approximately -161 ° C. [-258 ° F.], which is then sent to the LNG storage tank 62 containing the LNG product (stream 50).

The other part of stream 38c, stream 39, is taken out of heat exchanger 60 to -107 [deg.] C. [-160 [deg.] F.), and through the appropriate expansion device such as expansion valve 17, Flashes up to working pressure In the process shown in FIG. 1, since there is no vaporization in the expanded stream 39a, the temperature of the stream is only slightly dropped, leaving the expansion valve 17 to a temperature of −107 ° C. [−161 ° F.]. The expanded stream 39a is then fed to the separator device 19a in the upper region of the fractionation tower 19. The liquid separated here becomes the top feed of the demethanation unit 19b.

Total cooling to streams 35 and 38c is provided by a closed cycle refrigeration loop. The working fluid for this cycle is a mixture of hydrocarbons and nitrogen, the composition of which is adjusted as necessary to provide the required refrigerant temperature while condensing at moderate pressure using commercially available coolants. In this case, since it is assumed that it has been condensed by cooling water, a refrigerant mixture composed of nitrogen, methane, ethane, propane, and heavy hydrocarbons is used in the simulation of the treatment of FIG. 1. The stream has a composition of 7.5% nitrogen, 41.0% methane, 41.5% ethane, and 10.0% propane in approximately mole percent with the remainder consisting of heavy hydrocarbons.

The refrigerant stream 71 leaves the exhaust cooling device 69 at 38 ° C. [100 ° F.] and 4,185 kPa (a) [607 psia]. The stream enters heat exchanger 10 and is cooled to −35 ° C. [−31 ° F.] and partially condensed by the partially warmed expanded refrigerant stream 71f and other refrigerant streams. In the simulation of FIG. 1, these different refrigerant streams are assumed to be propane refrigerants sold at three different temperature and pressure levels. The partially condensed refrigerant stream 71a then enters the heat exchanger 13 and is further cooled to -81 ° C [-114 ° F] by the partially warmed expanded refrigerant stream 71e and the refrigerant to be partially subcooled. (Stream 71b) is condensed. The refrigerant is further subcooled to -160 ° C [-257 ° F] in the heat exchanger 60 by the expanded refrigerant stream 71d. The supercooled liquid stream 71c enters the work expansion device 63 and the device is mechanically moved from the stream such that it is isentropically expanded from a pressure of about 4,040 kPa (a) [586 psia] to a pressure of about 234 kPa (a) [34 psia]. Extract energy. A portion of the expanded stream is vaporized to cool the entire stream (stream 71d) to -164 ° C [-263 ° F]. The expanded stream 71d then reenters the heat exchangers 60, 13 and 10 and cools the vaporized and superheated streams 38c and 35 and the refrigerant (streams 71, 71a and 71b).

The superheated refrigerant vapor (stream 71 g) leaves the heat exchanger 10 at 34 ° C. [93 ° F.] and is compressed in three steps to 4,254 kPa (a) [617 psia]. Each of the three compression stages (refrigerant compressors 64, 66, 68) is driven by an additional power source and follows a cooling device (exhaust cooling devices 65, 67, 69) to remove the heat of compression. Compressed stream 71 from exhaust cooling apparatus 69 returns to heat exchanger 10 to complete the cycle.

An overview of the stream flow rate and energy consumption of the process shown in FIG. 1 is described in the table below.

Table 1

(Figure 1)

Stream Flow Rate Overview- Kg moles / Hr [Lb.Moles / Hr]

Stream methane ethane Propane Bhutan + all 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

Recovery of NGL *

Ethane 95.06%

Propane100.00%

Butane + 100.00%

Production rate 308,147 Lb / Hr [308,147 kg / Hr]

LNG products

Production rate610,813 Lb / Hr [610,813 kg / Hr]

Purity * 99.52%

Low calorific value 912.3 BTU / SCF [33.99 MJ / ㎥]

power

Refrigerant Compression 103,957 HP [170,904 kW]

Propane Compression 33,815 HP [55,591 kW]

Total Compression 137,772 HP [226,495 kW]

Heat of auxiliary equipment

Demethanizer Reboiler 29,364 MBTU / Hr [18,969 kW]

* (Based on flow, not integer)

The efficiency of LNG production processing is usually compared using the required “specific power consumption”, which is the ratio of the total cooling compression power to the total liquid production rate. Published non-powered information of the prior art for producing LNG ranges from 0.276 kW-Hr / kg [0.168 HP-Hr / Lb] to 0.300 kW-Hr / kg [0.182 HP-Hr / Lb]. It is believed that this was based on 340 days of operation at the LNG production plant. On the same basis, the non-power consumption of the embodiment of FIG. 1 of the present invention is 0.265 kW-Hr / kg [0.161 HP-Hr / Lb], which gives an efficiency improvement of 4% to 13% over the prior art treatment. do. In addition, the non-power consumption of prior art processing is not only NGL (C ₂ and heavy hydrocarbon) liquid streams, but LPG (C ₃ and heavy hydrocarbons) or relatively low recovery levels of condensate (C) as shown in this example of the invention. ₄ and heavier hydrocarbons) is based on co-producing only the liquid stream. Prior art processes require significantly more cooling power to co-produce NGL streams instead of LPG streams or condensate streams.

There are two main factors that account for the improved efficiency of the present invention. The first factor can be seen by examining the thermodynamics of the liquefaction process when applied to a high pressure gas stream as contemplated in this embodiment. Since the main component of this stream is methane, the thermodynamic properties of methane can be used to compare the cycle used in the present invention with the liquefaction cycle employed in the prior art treatment. 2 includes a pressure-enthalpy state diagram of methane. In most liquefaction cycles of the prior art, all cooling of the gas stream is achieved where the stream is at high pressure (paths A-B), after which the stream is expanded (path B-C) to the pressure of the LNG storage vessel (slightly above atmospheric pressure) . This expansion step can employ a work expansion device, which can typically recover about 75% to 80% of the theoretically available work with ideal isentropic expansion. For simplicity, the overall isentropic expansion is shown in Figure 2 by paths B-C. Even so, since the constant entropy line is nearly perpendicular in the liquid region of the state diagram, the enthalpy reduction provided by this work expansion is very small.

In contrast, the liquefaction cycle of the present invention will be described. After partial cooling to high pressure (paths A-A '), the gas stream is workpiece expanded to medium pressure (paths A'-A ") (again, for the sake of simplicity the total isentropic expansion). The remainder of the cooling is at medium pressure (paths A ″ -B ′), and then the stream expands to the pressure of the LNG storage vessel (paths B′-C). Since a constant entropy slope is not steep in the vapor region of the state diagram, a significantly greater enthalpy reduction is provided by the first work expansion step (path A′-A ″) of the present invention. Therefore, the total amount of cooling required for the present invention (sum of paths A-A 'and paths A-B') is less than the amount of cooling (paths A-B) required for the prior art processing, and liquefied the gas stream. The amount of cooling (and thus cooling compression) required to do so is reduced.

A second factor describing the improved efficiency of the present invention is the excellent performance of the hydrocarbon distillation system at mastic copper pressure. Most of the hydrocarbon removal steps in the prior art processes are carried out at high pressures and use scrub columns which typically employ a cooling hydrocarbon liquid as the absorbent stream to remove heavy hydrocarbons from the inlet gas stream. Operating the scrub column at high pressure is not very efficient and as a result a significant fraction of methane and ethane is co-absorbed from the gas stream, which must be continuously stripped from the sorbent liquid and cooled to be part of the LNG product. In the present invention, the hydrocarbon removal step is led to a medium pressure in which the vapor-liquid equilibrium is more advantageous, with the result that the desired heavy hydrocarbons of the by-product liquid stream are recovered very efficiently.

Second embodiment

If the specification for the LNG product allows more ethane contained in the feed gas recovered from the LNG product, a simpler embodiment may be employed in the present invention. 3 illustrates this alternative embodiment. The inlet gas composition and conditions considered in the processing shown in FIG. 3 are the same as in FIG. 1. Thus, the process of FIG. 3 can be compared with the embodiment shown in FIG.

In the simulation of the FIG. 3 process, the inlet gas cooling, separation, and expansion design for the NGL recovery is essentially the same as that used in FIG. 1. The inlet gas enters the plant as stream 31 at 32 ° C. [90 ° F.] and 8860 kPa (a) [1285 psia], and is refracted by the refrigerant stream and the deboiler side reboiler liquid (stream 40). It is cooled in the heat exchanger 10 by heat exchange at [° C] [-35 ° F]. The cooled stream 31a is subjected to −34 ° C. [−30 ° F.] and 8,812 kPa (a) [1278psia] in a separation device 11 where steam (stream 32) is separated from condensed liquid (stream 33). Enter.

From the separation device 11 the steam (stream 32) is split into two streams 34, 36. Stream 34 containing about 20% of the total vapor is combined with stream 33, the condensed liquid, to form stream 35. The combined stream 35 is cooled by passing through a heat exchanger 13 of heat exchange associated with the refrigerant stream 71e to condense the stream 35a to a large extent. The stream 35a, typically condensed to -85 [deg.] C. [-120 [deg.] F., is then operated at an operating pressure of the fractionation tower 19 (approximately 3206 kPa (a) [465 psia]) through a suitable expansion device such as an expansion valve 14. Into the flash. A portion of the expanded stream is vaporized so that the entire stream is cooled. In the process shown in FIG. 3, the expanded stream 35b leaving the expansion valve 14 reaches a temperature of −86 ° C. [−122 ° F.] and is connected to the separation device in the upper region of the fractionation tower 19. Supplied. The separated liquid here becomes the top feed of the demethanation unit in the lower region of the fractionation tower 19.

The remaining 80% of the steam from the separation device 11 (stream 36) enters the work expansion device 15 where mechanical energy is extracted from this portion of the high pressure feed. Apparatus 15 expands the vapor from a pressure of about 8812 kPa (a) [1278 psia] to isotropically tower operating pressure, with the workpiece expansion at approximately −75 ° C. [−103 ° F.], expanding stream 36a. ) To cool. The expanded and partially condensed stream 36a is sent as feed to the middle column feed point of the distillation column 19.

The cold demethanizer overhead steam (stream 37) exits the top of the fractionation tower 19 at -86 ° C [-123 ° F]. The liquid product stream 41 exits the bottom of the tower to 48 ° C. [118 ° F.] based on a typical specification of 0.020: 1 on a molar basis for the bottom product.

The demethanizer overhead steam (stream 37) is warmed in heat exchanger 24 to 32 ° C. [90 ° F.], which portion (stream 48) is then taken out to act as fuel gas for the plant. The remainder of the warmed demethanizer overhead vapor (stream 49) is compressed by compressor 16. After cooling to 38 [deg.] C. [100 [deg.] F.] in the exhaust cooling unit 25, stream 49b is exchanged at -80 [deg.] C. in heat exchanger 24 by cross-changing stream 37, which is a cooling demethanizer overhead vapor. -112 [deg.] F.

Stream 49c is then further cooled to -160 ° C [-257 ° F] by refrigerant stream 71d to enter heat exchanger 60 to condense and supercool the stream, after which mechanical energy is extracted from the stream. Enter the expansion device 61. The device 61 expands the liquid stream 49d isotropically from a pressure of about 4,021 kPa (a) [583psia] to an LNG storage pressure 107 kPa (a) [15.5 psia] slightly above atmospheric pressure. The work expansion will cool the expanded stream 49e to a temperature of approximately -161 ° C. [-258 ° F.], which is then sent to the LNG storage tank 62 containing the LNG product (stream 50).

Similar to the process of FIG. 1, total cooling for streams 35 and 49c is provided by a closed cycle cooling loop. The stream used as the working fluid of the cycle of FIG. 3 has a composition of 7.5% nitrogen, 40.0% methane, 42.5% ethane, and 10.0% propane, in approximately mole percent, with the remainder consisting of heavy hydrocarbons. The refrigerant stream 71 leaves the exhaust cooling device 69 at 38 ° C. [100 ° F.] and 4,185 kPa (a) [607 psia]. The stream enters heat exchanger 10 and is cooled to −35 ° C. [−31 ° F.] and partially condensed by the partially warmed expanded refrigerant stream 71f and other refrigerant streams. In the simulation of FIG. 3, these different refrigerant streams are assumed to be propane refrigerants sold at three different temperature and pressure levels. The partially condensed refrigerant stream 71a then enters the heat exchanger 13 and is further cooled to -85 ° C [-121 ° F] by the partially warmed expanded refrigerant stream 71e and the refrigerant (stream 71 Condenses)) and partially cools. The refrigerant is further subcooled to -160 ° C [-257 ° F] in the heat exchanger 60 by the expanded refrigerant stream 71d. The supercooled liquid stream 71c enters the work expansion device 63 and the device is mechanically moved from the stream such that it is isentropically expanded from a pressure of about 4,040 kPa (a) [586 psia] to a pressure of about 234 kPa (a) [34 psia]. Extract energy. A portion of the expanded stream is vaporized to cool the entire stream (stream 71d) to -164 ° C [-263 ° F]. The expanded stream 71d then reenters the heat exchangers 60, 13 and 10 and cools the vaporized and superheated streams 49c and 35 and the refrigerant (streams 71, 71a and 71b).

The superheated refrigerant vapor (stream 71g) leaves the heat exchanger 10 at 34 ° C. [93 ° F.] and is compressed in three steps to 4,254 kPa (a) [617 psia]. Each of the three compression stages (refrigerant compressors 64, 66, 68) is driven by an additional power source and follows a cooling device (exhaust cooling devices 65, 67, 69) for the removal of compressed heat. Compressed stream 71 from exhaust cooling apparatus 69 returns to heat exchanger 10 to complete the cycle.

An overview of the stream flow rate and energy consumption of the process shown in FIG. 3 is described in the table below.

TABLE 2

(Figure 3)

Stream Flow Rate Overview- Kg moles / Hr [Lb.Moles / Hr]

Stream methane ethane Propane Bhutan + all 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 37,941 445 58 7 38,456

Recovery of NGL *

Ethane 87.57%

Propane 97.41%

Butane + 99.47%

Production rate 296,175 Lb / Hr [296,175 kg / Hr]

LNG products

Production 625,152 Lb / Hr [625,152 kg / Hr]

Purity * 98.66%

Low calorific value 919.7 BTU / SCF [34.27 MJ / ㎥]

power

Refrigerant Compression 96,560 HP [158,743 kW]

Propane Compression 34,724 HP [57,086 kW]

Total Compression 131,284 HP [215,829 kW]

Heat of auxiliary equipment

Demethanizer Reboiler22,177 MBTU / Hr [14,326 kW]

* (Based on flow, not integer)

Assuming that the LNG production plant has been operating for 340 days per year, the specific power consumption of the embodiment of FIG. 3 of the present invention is 0.251 kW-Hr / kg [0.153 HP-Hr / Lb]. Compared to prior art processing, the embodiment of FIG. 3 gives an efficiency improvement of 10% to 20%. As mentioned earlier in the embodiment of FIG. 1, this efficiency improvement is possible in the present invention even though NGL by-products are produced rather than LPG or condensate by-products produced by prior art processing.

Compared to the embodiment of FIG. 1, the embodiment of FIG. 3 of the present invention requires about 5% less power per unit of liquid produced. Thus, at the given usable amount of compressive power, the embodiment of FIG. 3 can liquefy about 5% more natural gas than the embodiment of FIG. 1 by less recovery of C ₂ and heavy hydrocarbons of the NGL by-product. The choice for a particular application between the embodiments of FIGS. 1 and 3 of the present invention is based on the monetary value of the heavy hydrocarbons of the NGL product or the calorific value for the LNG product (the implementation of FIG. 1) for the corresponding value of the LNG product. Generally because the calorific value of the LNG produced by the example is lower than the calorific value produced by the embodiment of FIG. 3).

Third embodiment

If the specification for the LNG product allows more ethane contained in the feed gas recovered from the LNG product, or if there is no market for ethane-containing liquid by-products, an alternative embodiment of the present invention as shown in Figure 4 is an LPG by-product. It may be employed to produce a stream. Influent gas compositions and conditions considered in the processing shown in FIG. 4 are the same as in FIGS. 1 and 3. Thus, the process of FIG. 4 can be compared with the embodiment shown in FIGS. 1 and 3.

In the simulation of the process of FIG. 4, the inlet gas enters the plant as stream 31 at 32 ° C. [90 ° F.] and 8860 kPa (a) [1285 psia], which is caused by the refrigerant stream and flashed separator liquid 33a. By heat exchange, it is cooled in the heat exchanger 10 to -43 degreeC [-46 degreeF]. The cooled stream 31a is subjected to -18 ° C [-1 ° F] and 8,812 kPa (a) [1278psia] in a separation device 11 where steam (stream 32) is separated from condensed liquid (stream 33). Enter.

Steam (stream 32) from separation device 11 enters work expansion device 15 which extracts mechanical energy from this portion of the high pressure feed. The device 15 expands the vapor substantially isentropically from a pressure of about 8,812 kPa (a) [1278 psia] to a pressure of about 3,034 kPa (a) [440 psia] (the operating pressure of the separator / absorber tower 18). The work expansion causes cooling of the expanded stream 32a to a temperature of approximately −63 ° C. [−81 ° F.]. Expanded and partially condensed stream 32a is fed to absorber 18b in the lower region of separator / absorber tower 18. The liquid portion of the expanded stream mixes with the liquid falling down from the absorbent portion, and the combined liquid stream 40 exits the bottom of the separator / absorber tower 18 at -66 ° C [-86 ° F]. The vapor portion of the expanded stream rises upwards through the absorbing portion and contacts the cooling liquid falling downwards to condense and absorb the C ₃ and heavy components.

Separator / absorber tower 18 is a distillation column of the prior art comprising a plurality of vertically spaced trays, one or more packed beds, or a combination of trays and packings. Although common in natural gas processing plants, the separator / absorber tower consists of two parts. The upper portion 18a is a tower in which any vapor contained in the top feed is separated from its corresponding liquid portion, and vapors rising from the lower distillation or absorber 18b combine with the steam portion (if any) of the top feed. Separator to form a cold distillation stream 37 exiting the top. The lower absorber 18b includes a tray and / or packing and provides the necessary contact between the liquid falling downward and the vapor rising upward to condense and absorb the C ₃ and heavy components.

The combined liquid stream 40 from the bottom of the separator / absorber tower 18 is sent to the heat exchanger 13 by a pump 26 and the stream 40a is deethanized unit overhead (stream 42 Heating) by providing cooling of the refrigerant (stream 71a)). The combined liquid stream is heated to -31 [deg.] C. [-24 [deg.] F. and partially vaporizes stream 40b before the stream is fed as a middle column feed of deethanization apparatus 19. Separator liquid (stream 33) is passed to expansion valve 12 which cools stream 33 to -43 ° C. [-46 ° F.] (stream 33a) before the stream cools the inlet feed gas described above. By flash expansion slightly above the operating pressure of the deethanization apparatus 19. Stream 33b is currently at 29 ° C. [85 ° F.] and then enters the lower middle column feed point of the deethanization unit 19. In the deethanization apparatus, streams 40b and 33b are stripped of the methane and C ₂ components of the stream. The deethanation apparatus of tower 19 operating at about 3123 kPa (a) [453 psia] also includes prior art distillation comprising a plurality of vertically spaced trays, one or more packed beds, or a combination of trays and packings. It is a pillar. The deethanizer tower has two parts: any vapor contained in the top feed is separated from its corresponding liquid portion, and the vapors raised from the bottom distillation or deethanization 19b are vapors of the top feed (if Top separation device portion 19a, in combination with (if present), to form a distillation stream 42 exiting the top of the tower; It comprises a tray and / or packing and consists of a lower deethanization 19b which provides the requisite contact between the liquid falling downward and the vapor rising upward. Deethanization 19b also includes one or more reboilers (reboilers 20), which heat and vaporize a portion of the bottom liquid of the column to vaporize stream 41, which is a liquid product of methane and C ₂ components. Provide stripping vapor flowing over the column to remove. Typical specifications for bottom liquid products have a ratio of ethane and propane on a molar basis of 0.020: 1. The liquid product stream 41 exits the bottom of the deethanization apparatus at 101 ° C. [214 ° F.].

The operating pressure of the deethanizer 19 is maintained slightly above the operating pressure of the separator / absorber tower 18. This causes deethanizer overhead steam (stream 42) to flow to the top of separator / absorber tower 18 in a pressure stream through heat exchanger 13. In the heat exchanger 13, the deethanization unit overhead vapor of -28 ° C [-19 ° F] is combined with the liquid stream (stream 40a) combined from the bottom of the separator / absorber tower 18 to -67 ° C. Cool to [−89 ° F.] (stream 42a) and heat exchange with flashed refrigerant stream 71e which partially condenses. The partially condensed stream enters a reflux drum 22, which separates the condensed liquid (stream 44) from uncondensed vapor (stream 43). Stream 43 combines with a distillation vapor stream (stream 37) leaving the upper region of separator / absorber tower 18 to form a cooling residual gas stream 47. The condensed liquid (stream 44) is pumped to high pressure by pump 23, after which stream 44a is divided into two parts. A portion of stream 45 is directed to the upper separator section of separator / absorber tower 18 and acts as a cooling liquid in contact with the vapor rising upward through the absorber. The other portion is fed to the deethanization unit 19 as a countercurrent stream 46 flowing at -67 ° C [-89 ° F] to the top feed point of the deethanization unit 19.

The cooling residual gas (stream 47) is warmed from −70 ° C. [−94 ° F.] to 34 ° C. [94 ° F.] in the heat exchanger 24, and the portion (stream 48) is then taken out and the fuel gas for the plant. Act as. The remainder of the warmed residual gas (stream 49) is compressed by the compression device 16. After cooling to 38 [deg.] C. [100 [deg.] F.] in the exhaust cooling apparatus 25, stream 49b is subjected to -61 [deg.] F. [-78 [deg.] F.] in the heat exchanger 24 by cross-exchange of stream 47 which is cooling residual gas. Is further cooled.

Stream 49c then enters heat exchanger 60 and is further cooled to -160 ° C [-255 ° F] by refrigerant stream 71d to condense and supercool the stream, after which mechanical energy is extracted from the stream. The work inflation device 61 enters. Apparatus 61 expands the liquid stream 49d substantially isotropically from a pressure of about 4,465 kPa (a) [648 psia] to an LNG storage pressure 107 kPa (a) [15.5 psia] slightly above atmospheric pressure. The work expansion will cool the expanded stream 49e to a temperature of approximately -160 ° C [-256 ° F], which is then sent to the LNG storage tank 62 containing the LNG product (stream 50).

Similar to the processing of FIGS. 1 and 3, multiple cooling for stream 42 and total cooling for stream 49c are provided by a closed cycle cooling loop. The stream used as working fluid for the cycle of the FIG. 4 process has a composition of 8.7% nitrogen, 30.0% methane, 45.8% ethane, and 11.0% propane, in approximately mole percent with the remainder consisting of heavy hydrocarbons. The refrigerant stream 71 leaves the exhaust cooling device 69 at 38 ° C. [100 ° F.] and 4,185 kPa (a) [607 psia]. The stream enters heat exchanger 10 and is cooled to -27 ° C [-17 ° F] and partially condensed by the partially warmed expanded refrigerant stream 71f and other refrigerant streams. In the simulation of FIG. 4, these different refrigerant streams are assumed to be propane refrigerants sold at three different temperature and pressure levels. The partially condensed refrigerant stream 71a then enters the heat exchanger 13 and is further cooled to -67 ° C [-89 ° F] by the partially warmed expanded refrigerant stream 71e and the refrigerant (stream 71b). More condensation). The refrigerant is condensed entirely and then supercooled to -160 ° C [-255 ° F] in the heat exchanger 60 by the expanded refrigerant stream 71d. The supercooled liquid stream 71c enters the work expansion device 63, which is in such an entropy expansion that it is generally isentropically expanded from a pressure of about 4,040 kPa (a) [586 psia] to a pressure of about 234 kPa (a) [34 psia]. Mechanical energy is extracted from the A portion of the expanded stream is vaporized to cool the entire stream (stream 71d) to -164 ° C [-264 ° F]. Expanded stream 71d then re-enters stream 49c, 42 and heat exchangers 60, 13, 10 that cool the vaporized superheated refrigerant (streams 71, 71a, 71b).

The superheated refrigerant vapor (stream 71g) leaves the heat exchanger 10 at 32 ° C. [90 ° F.] and is compressed in three stages to 4,254 kPa (a) [617 psia]. Each of the three compression stages (refrigerant compressors 64, 66, 68) is driven by an additional power source and follows a cooling device (exhaust cooling devices 65, 67, 69) for the removal of compressed heat. Compressed stream 71 from exhaust cooling apparatus 69 returns to heat exchanger 10 to complete the cycle.

An overview of the stream flow rate and energy consumption of the process shown in FIG. 4 is described in the table below.

TABLE 3

(Figure 4)

Stream Flow Rate Overview- Kg moles / Hr [Lb.Moles / Hr]

Stream methane ethane Propane Bhutan + all 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 One 0 2,684 50 38,524 3,585 21 0 42,135

Recovery of LPG *

Propane 99.08%

Butane + 100.00%

Production 197,051 Lb / Hr [197,051 kg / Hr]

LNG products

Production rate726,918 Lb / Hr [726,918 kg / Hr]

Purity * 91.43%

Low calorific value 969.9 BTU / SCF [36.14 MJ / ㎥]

power

Refrigerant Compression 95,424 HP [156,876 kW]

Propane Compression 28,060 HP [46,130 kW]

Total Compression123,484 HP [203,006 kW]

Heat of auxiliary equipment

Demethanizer Reboiler 55,070 MBTU / Hr [35,575 kW]

* (Based on flow, not integer)

Assuming that the LNG production plant has been operating for 340 days per year, the non-power consumption of the embodiment of FIG. 4 of the present invention is 0.236 kW-Hr / kg [0.143 HP-Hr / Lb]. Compared to prior art processing, the embodiment of FIG. 4 confers an efficiency improvement of 17% to 27%.

Compared to the embodiment of FIGS. 1 and 3, the embodiment of FIG. 4 of the present invention requires about 6% to 11% less power per unit of liquid produced. Thus, at a given usable amount of compressive power, the embodiment of FIG. 4 is about 6% more natural gas or the embodiment of FIG. 3 than the embodiment of FIG. 1 by recovering only C ₃ and heavy hydrocarbons of LPG by-products. About 11% more natural gas can be liquefied. The choice for a particular application between the embodiment of FIG. 4 and one of the embodiments of FIG. 1 or 3 of the present invention is based on the monetary value of the ethylene or the monetary value of the LNG product to the corresponding value of the LNG product. Generally required by one of the specifications (since the calorific value of the LNG produced by the embodiment of FIGS. 1 and 3 is lower than the calorific value produced by the embodiment of FIG. 4).

Fourth embodiment

If the specification for the LNG product permits more ethane and propane contained in the feed gas recovered from the LNG product, or if there is no market for liquid by-products containing ethane and propane, optional implementation of the invention as shown in FIG. An example may be employed to produce the condensate byproduct stream. Influent gas compositions and conditions considered in the processing shown in FIG. 5 are the same as those in FIGS. 1, 3 and 4. Thus, the process of Fig. 5 can be compared with the embodiment shown in Figs. 1, 3 and 4.

In the simulation of the FIG. 5 process, the inlet gas enters the plant as stream 31 at 32 ° C. [90 ° F.] and 8,860 kPa (a) [1285 psia], flashed to a refrigerant stream, −38 ° C. [−37 ° F.]. It is cooled in the heat exchanger 10 by heat exchange with a high pressure separator liquid (stream 33b) and an intermediate pressure separator liquid (stream 39b) flashed to -38 ° C [-37 ° F]. The cooled stream 31a is supplied at −34 ° C. [−30 ° F.] and 8,812 kPa (a) [1278psia] in a high pressure separation unit 11 where steam (stream 32) is separated from condensed liquid (stream 33). Enter

Steam (stream 32) from separation device 11 enters work expansion device 15 which extracts mechanical energy from this portion of the high pressure feed. The device 15 expands the vapor isotropically, from a pressure of about 8,812 kPa (a) [1278 psia] to a pressure of about 4,378 kPa (a) [635 psia], with the work expansion being approximately -64 ° C. [-83 ° F.]. At this temperature, the expanded stream 32a is cooled. The expanded and partially condensed stream 32a enters the intermediate pressure separation device 18, and vapor (stream 42) is separated from the condensation liquid (stream 39). The intermediate pressure separator device (stream 39) cools stream 39 to −78 ° C. [−108 ° F.] before entering heat exchanger 13 (stream 39a) and residual gas stream 49 and The expansion valve 17 provided to the heat exchanger 10 to cool the refrigerant stream 71a to cool the inlet feed gas described above is flash expanded and heated slightly above the operating pressure of the depropanification apparatus 19. Stream 39c is currently -26 [deg.] C. [-15 [deg.] F.] and then enters the upper middle column feed point of the depropane plate 19.

Stream 33, which is a liquid condensed from the high pressure separation device 11, cools stream 33 to -70 ° C [-93 ° F] (33a) before entering heat exchanger 13 and residual gas stream 49 ) And an expansion valve provided to the heat exchanger 10 to cool the refrigerant stream 71a to cool the inlet feed gas described above, which is slightly expanded above the operating pressure of the depropanification apparatus 19 and heated. Stream 33c is now 10 ° C. [50 ° F.] and then enters the lower middle column feed point of the depropanification apparatus 19. In a depropane apparatus, streams 39c and 33c remove its methane, C ₂ and C ₃ components. The depropanification apparatus of tower 19 operating at about 2,654 kPa (a) [385 psia] is a distillation column of the prior art comprising a plurality of vertically spaced trays, one or more packed beds, or a combination of trays and packings. to be. The depropanizer tower is equipped with two parts: any vapor contained in the top feed is separated from its corresponding liquid portion, and the vapors raised from the bottom distillation or depropanate 19b, if any, Top separation device portion 19a in combination with the to form a distillation stream 37 exiting the top of the tower; It comprises a tray and / or packing and consists of a lower depropane plate 19b which provides the requisite contact between the liquid falling down and the vapor rising upwards. The depropane plate 19b also comprises one or more reboilers (reboilers 20), which heat and vaporize a portion of the bottom liquid of the column to produce a stream of liquid product of methane, C ₂ and C ₃ components ( Provide stripping steam flowing over the column to remove 41). Typical specifications for bottom liquid products have a ratio of propane to butane on a molar basis of 0.020: 1. The liquid product stream 41 exits the bottom of the deethanization apparatus at 141 ° C. [286 ° F.].

The overhead distillation stream 37 leaves the depropane platen unit 19 at 2 ° C. [36 ° F.] and is cooled and partially condensed by the commercial propane refrigerant of the countercurrent condenser 21. Partially condensed stream 37a enters countercurrent drum 22 at −17 ° C. [2 ° F.], which separates condensed liquid (stream 44) from uncondensed vapor (stream 43). The condensed liquid (stream 44) is pumped by pump 23 to the top feed point of the depropane platen apparatus 19 as countercurrent stream 44a.

Uncondensed steam (stream 43) from countercurrent drum 22 is warmed to 34 ° C. [94 ° F.] in heat exchanger 24, and one portion (stream 48) is then taken out as fuel gas for the plant. Works. The remainder of the warmed vapor (stream 38) is compressed by the compression device 16. After cooling to 38 ° C. [100 ° F.] in the exhaust cooling unit 25, stream 38b is further cooled to −9 ° C. [15 ° F.] in heat exchanger 24 by cross-exchange of stream 43 which is cooling steam. Is cooled.

Stream 38c is then combined with intermediate pressure separator vapor (stream 42) to form a cooling residual gas stream 49. Stream 49 then enters heat exchanger 13 and from -39 [deg.] C. [-38 [deg.] F.] to -74 [deg.] C. by means of separator liquid (streams 39a, 33a) and refrigerant stream 71d as described above. Further cooled to [-102 ° F]. Partially condensed stream 49a then enters heat exchanger 60 and is further cooled to -159 [deg.] C. [-254 [deg.] F.] to condense by refrigerant stream 71d to overcool. Enter the work expansion device 61 extracted from the. Apparatus 61 expands liquid stream 49b isotropically from a pressure of about 4282 kPa (a) [621 psia] to an LNG storage pressure (107 kPa (a) [15.5 psia]) slightly above atmospheric pressure. The work expansion will cool the expanded stream 49c to a temperature of approximately -159 ° C. [-255 ° F.], which is then sent to an LNG storage tank 62 containing the LNG product (stream 50).

Similar to the processing of FIGS. 1, 3, and 4, multiple cooling for stream 49 and total cooling for stream 49a are provided by a closed cycle cooling loop. The stream used as working fluid for the cycle of the FIG. 5 process has a composition of 8.9% nitrogen, 34.3% methane, 41.3% ethane, and 11.0% propane, in approximately mole percent with the remainder consisting of heavy hydrocarbons. The refrigerant stream 71 leaves the exhaust cooling device 69 at 38 ° C. [100 ° F.] and 4,185 kPa (a) [607 psia]. The stream enters heat exchanger 10 and is cooled to −34 ° C. [−30 ° F.] and partially condensed by the partially warmed expanded refrigerant stream 71f and other refrigerant streams. In the simulation of FIG. 5, these different refrigerant streams are assumed to be propane refrigerants sold at three different temperature and pressure levels. The partially condensed refrigerant stream 71a then enters the heat exchanger 13 and is further cooled to -74 ° C [-102 ° F] by the partially warmed expanded refrigerant stream 71e and the refrigerant (stream 71b). More condensation). The refrigerant is condensed entirely and then subcooled to -159 ° C [-254 ° F] in the heat exchanger 60 by the expanded refrigerant stream 71d. The supercooled liquid stream 71c enters the work expansion device 63, which is expanded from the stream to isentropically expanded from a pressure of about 4,040 kPa (a) [586 psia] to a pressure of about 234 kPa (a) [34 psia]. Extract mechanical energy. A portion of the expanded stream is vaporized to cool the entire stream (stream 71d) to -164 ° C [-264 ° F]. Expanded stream 71d then re-enters heat exchanger 60, 13, 10 to cool streams 49a and 49 and the vaporized superheated refrigerant (streams 71, 71a and 71b).

The superheated refrigerant vapor (stream 71g) leaves the heat exchanger 10 at 34 ° C. [93 ° F.] and is compressed in three stages to 4,254 kPa (a) [617 psia]. Each of the three compression stages (refrigerant compressors 64, 66, 68) is driven by an additional power source and follows a cooling device (exhaust cooling devices 65, 67, 69) for the removal of compressed heat. Compressed stream 71 from exhaust cooling apparatus 69 returns to heat exchanger 10 to complete the cycle.

An overview of the stream flow rate and energy consumption of the process shown in FIG. 5 is described in the table below.

Table 4

(Figure 5)

Stream Flow Rate Overview- Kg moles / Hr [Lb.Moles / Hr]

Stream methane ethane Propane Bhutan + all 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

Recovery of Condensate *

Butane 95.04%

Pentane + 99.57%

Production rate 88,390 Lb / Hr [88,390 kg / Hr]

LNG products

Production rate834,183 Lb / Hr [834,183 kg / Hr]

Purity * 87.27%

Low calorific value 1033.8 BTU / SCF [38.52 MJ / ㎥]

power

Refrigerant Compression 84,974 HP [139,696 kW]

Propane Compression 39,439 HP [64,837 kW]

Total Compression 124,413 HP [204,533 kW]

Heat of auxiliary equipment

Demethanizer Reboiler52,913 MBTU / Hr [34,182 kW]

* (Based on flow, not integer)

Assuming that the LNG production plant started operation for 340 days a year, the non-power consumption of the embodiment of FIG. 5 of the present invention is 0.238 kW-Hr / kg [0.145 HP-Hr / Lb]. Compared to the prior art processing, the embodiment of FIG. 5 gives an efficiency improvement of 16% to 26%.

In contrast to the embodiment of FIGS. 1 and 3, the embodiment of FIG. 5 of the present invention requires about 5% to 10% less power per unit of liquid produced. Compared to the embodiment of FIG. 4, the embodiment of FIG. 5 of the present invention requires essentially the same power as the power per unit of liquid produced. Thus, at a given usable amount of compressive power, the embodiment of FIG. 5 is about 10% more natural gas or the embodiment of FIG. 4 than the embodiment of FIG. 3 by recovering only C ₄ and heavy hydrocarbons of the condensate by-product. The same amount of natural gas can be liquefied. The choice for a particular application between the embodiment of FIG. 5 and one of the embodiments of FIG. 1, FIG. 3 or FIG. 4 of the present invention is based on the monetary value of ethane and propane of NGL or LPG products over the corresponding value of LNG products. Or as generally required by one of the specifications of the calorific value for the LNG product (since the calorific value of the LNG produced by the embodiment of FIGS. 1, 3 and 4 is lower than the calorific value produced by the embodiment of FIG. 5). do.

Another embodiment

It will be appreciated by those skilled in the art that the present invention can be used in any type of LNG liquefaction plant to co-produce NGL streams, LPG streams, or condensate streams to suit the needs of a given plant location. It can also be appreciated that various treatment configurations can be employed to recover the liquid byproduct stream. For example, the embodiments of FIGS. 1 and 3 may allow recovery of LPG streams or condensate streams as liquid by-product streams rather than NGL streams as described above in the first and second embodiments. The embodiment of FIG. 4 recovers an NGL stream containing a significant fraction of the C ₂ components present in the feed gas rather than producing LPG by-products as described above in the third embodiment, or C ₄ present in the feed gas. It is possible to recover the condensate stream containing only components and heavy components. The embodiment of FIG. 5 recovers an NGL stream containing a significant fraction of the C ₂ components present in the feed gas rather than producing condensate by-products as described above in the fourth embodiment, or the C ₃ components present in the feed gas. It is possible to recover an LPG stream containing a significant fraction of.

1, 3, 4 and 5 show preferred embodiments of the invention for the indicated processing conditions. 6-21 illustrate alternative embodiments of the invention that may be considered for a particular application. As shown in FIGS. 6 and 7, all or part of the liquid condensed from the separator 11 (stream 33) is part of the separator vapor (stream 34) entering the heat exchanger 13. Rather than compounding with, it may be fed to a fractionation tower 19 at a separate lower intermediate column feed location. FIG. 8 illustrates an alternative embodiment of the present invention that requires less equipment than the embodiment of FIGS. 1 and 6, although its non-power consumption is rather high. Similarly, FIG. 9 shows an alternative embodiment of the present invention that requires less equipment than the embodiment of FIGS. 3 and 7 with high non-power consumption costs. 10-14 illustrate alternative embodiments of the present invention that require less equipment than the embodiment of FIG. 4, although their non-power consumption may be high (de-ethanization, as shown in FIGS. 10-14). Note that a distillation column or system such as device 19 includes both a reboiler absorber tower design and a backflow, reboiled tower design.). 15 and 16 show that a single fractionation column 19 also functions as the separator / absorber tower 18 and deethanization device 19 of the embodiment of FIGS. 4, 10-14. Depending on the amount of heavy hydrocarbons in the feed gas and feed gas pressure, the cooled feed stream 31a leaving the heat exchanger 10 may not contain any liquid (the stream is above the dew point, or Or because of exceeding the maximum critical pressure (cricondenbar)), the separation device 11 shown in FIGS. 1, 3 to 16 is not required, and the cooled feed stream is subjected to a suitable expansion such as the work expansion device 15. Can flow directly to the device.

The gas stream remaining after recovery of the liquid by-product stream (stream 37 of FIGS. 1, 3, 6-11, 13 and 14, before being fed to the heat exchanger 60 for condensation and subcooling), The arrangement of the streams 47 of FIGS. 4, 12, 15 and 16 and the stream 43 of FIG. 5 may be made in various ways. 1, 3 to 16, the stream is compressed to high pressure using energy from one or more work expansion devices, partially cooled in an exhaust cooling device, and then further by cross-exchange by the original stream. Is cooled. As shown in FIG. 17, it may be advantageous for many applications to compress the stream at high pressure, for example using an additional compression device 59 driven by an external power source. As shown by the equipment indicated by dashed lines in FIGS. 1, 3 to 16 (heat exchanger 24 and exhaust cooling apparatus 25), in many situations compression before entering heat exchanger 60. It may be advantageous to reduce the capital cost of the installation (increasing the cooling load of the heat exchanger 60 and increasing the power consumption of the refrigerant compressors 64, 66, 68) by reducing or eliminating the precooling of the circulated stream. have. In this case, the stream 49a leaving the compression device may also flow directly to the heat exchanger 24 as shown in 18 or directly to the heat exchanger 60 as shown in FIG. 19. If the work expansion device is not used to inflate any portion of the high pressure feed gas, a compression device driven by an external power source such as the compression device 59 shown in FIG. 20 may be used instead of the compression device 16. . In other situations no compression of the stream can be justified, so that the stream has a heat exchanger 60 as shown in FIG. 21 and equipment indicated by dashed lines in FIGS. 1, 3 to 16 (heat exchanger 24, compression). Directly by the apparatus 16 and the exhaust cooling apparatus 25. If heating the stream before the plant fuel gas (stream 48) is taken out is not included in the heat exchanger 24, an additional heater 58 may be used as shown in FIGS. 19-21 before the fuel gas is consumed. Similarly, it may be required to heat the fuel gas using an auxiliary plant stream or other process stream to provide the necessary heat. The selection conditions that must generally be evaluated for each application must all take into account factors such as gas consumption, plant size, desired by-product stream recovery levels and available equipment.

According to the invention, the cooling of the inlet gas stream and the feed stream in the LNG production unit may be accomplished in various ways. In the processing of FIGS. 1, 3, 6-9 the inlet gas stream 31 is cooled and condensed by an external refrigerant stream and tower liquid from the fractionation tower 19. 4, 5, 10-14, flashed separator device liquid is used for this purpose along with the external refrigerant stream. 15 and 16, tower liquid and flashed separator device liquid are used for this purpose along with the external refrigerant stream. In FIGS. 17-21 only external refrigerant streams are used to cool the inlet gas stream 31. However, a cooling treatment stream can also be used to supply some cooling to the high pressure refrigerant (stream 71a) as shown in FIGS. 4, 5, 10 and 11. In addition, any stream having a lower temperature than the stream to be cooled may be used. For example, a side draw of steam may be withdrawn from the separator / absorber tower 18 or fractionation tower 19 and used for cooling. The specific arrangement of heat exchangers for the use and distribution of tower liquids and / or vapors for heat exchange treatment, for cooling the inlet and feed gases, as well as the selection of the treatment stream for a particular heat exchange facility, must be evaluated for each particular application. The choice of cooling source depends on a number of factors including, but not limited to, feed gas composition and condition, plant size, heat exchanger size, and potential cooling source temperature. It will be appreciated by those skilled in the art that any combination of cooling sources or cooling methods may be employed in combination to obtain the desired feed stream temperature.

In addition, additional external cooling to the inlet gas stream and the feed stream to the LNG production unit may be achieved in a variety of different ways. 1, 3 to 21, since the single composition refrigerant is used for the preliminary cooling of the multiple composition refrigerant stream, the boiling of the single composition refrigerant is assumed to be a high level of external cooling, and the vapor of the multi composition refrigerant Vaporizing is assumed to be a low level of external cooling. Optionally, both high and low levels of cooling can be achieved using a single composition refrigerant (ie cascade cooling) by successive low boiling points, or by using a single composition refrigerant up to a continuous low evaporation pressure. have. As another alternative, both high level cooling and low level cooling can be achieved using a multi-component refrigerant stream with each composition adjusted to provide the required cooling temperature. The choice of method of providing external cooling is not limited to the following, including a number of factors including feed gas composition, plant size, drive unit size of the compression device, heat exchanger size, enclosed heat sink temperature, and the like. Follow. It will be appreciated by those skilled in the art that any combination of the methods for providing external cooling described above may be employed in combination to obtain the desired feed stream temperature.

Condensed liquid stream leaving heat exchanger 60 (stream 49 of FIGS. 1, 6, and 8, stream 49d of FIGS. 3, 4, 7, 9-16, and 5, FIG. Subcooling of the stream 49b of FIGS. 19 and 20, the stream 49e of FIG. 17, the stream 49c of FIG. 18, and the stream 49a of FIG. 21) causes the stream to expand to the working pressure of the LNG storage tank 62. Reduce or eliminate the amount of flash steam that may be generated. This generally eliminates the need for flash gas compression, thereby reducing the non-power consumption for producing LNG. However, in many situations it may be advantageous to reduce the capital cost of the installation by reducing the size of the heat exchanger 60 and placing any flash that may be generated using flash gas compression or other means.

While individual stream expansions are shown in special expansion devices, optional expansion means may be employed where appropriate. For example, a work expanding or intermediate pressure backflow stream (stream 39 of FIGS. 1, 6, and 8) of a generally condensed feed stream (stream 35a of FIGS. 1, 3, 6, and 7) may be used. Requirements can also be guaranteed. The supercooled liquid stream (stream 49 of FIGS. 1, 6 and 8, streams of FIGS. 3, 4, 7, 9 and 16) in which isoenthalpy flash expansion leaves heat exchanger 60. 49d), stream 49b in FIGS. 5, 19 and 20, stream 49e in FIG. 17, stream 49c in FIG. 18, stream 49a in FIG. In order to avoid flash steam formation of expansion, one would need to either subcool more in the heat exchanger 60 or add flash steam compression or add other means for the placement of the resulting flash steam. Similarly, isoenthalpy flash expansion may be used in place of work cooling for the supercooled high pressure refrigerant stream (stream 71c of FIGS. 1, 3-21) leaving heat exchanger 60, resulting in compression of the refrigerant. Power consumption increases.

While what has been described as what is considered to be a preferred embodiment of the present invention, there are other modifications and variations that apply various conditions, forms of supply, or other requirements of the invention, without departing, for example, from the spirit of the invention as defined by the following claims. Other variations are possible to be appreciated by the skilled artisan.

According to the present invention, the hydrocarbon removal step into the LNG liquefaction process can be incorporated to produce both LNG and separated heavy hydrocarbon liquid products using much less energy than prior art processes.

Claims (116)

(a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes; (2) the cooled natural gas stream is expanded to medium pressure; (3) The expanded cooled natural gas stream is directed into a distillation column, which stream is relatively volatile containing most of the heavy hydrocarbon component and the volatile residual gas fraction containing mostly the methane and light components. Separated into smaller classes; (4) said volatile residual gas fraction is cooled under pressure to condense at least a portion of the gas fraction; (5) said condensation portion is divided into at least two portions to form said condensation stream and a liquid stream; (6) The liquid stream is liquefied, characterized in that it is sent as a top feed to the distillation column. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes to partially condense; (2) said partially condensed natural gas stream is separated to provide at least a vapor stream and a first liquid stream; (3) the vapor stream is expanded to medium pressure; (4) said first liquid stream is expanded to said intermediate pressure; (5) At least the expanded vapor stream and the expanded first liquid stream are sent into a distillation column, the stream being relatively volatile containing most of the heavy hydrocarbon component and the volatile residual gas fraction containing mostly the methane and light components. Separated into smaller classes; (6) said volatile residual gas fraction is cooled under pressure to at least partially condense; (7) said condensation portion is divided into at least two portions to form said condensation stream and a second liquid stream; (8) The second liquid stream is sent to the distillation column as a top feed. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes; (2) said cooled natural gas stream is divided into at least a first gas stream and a second gas stream; (3) said first gas stream is cooled to condense substantially all of it and is thereafter expanded to intermediate pressure; (4) said second gas stream is expanded to said intermediate pressure; (5) The expanded and generally condensed first gas stream and the expanded second expanded gas stream are sent into a distillation column, where the streams contain most of the volatile residual gas fraction and most of the heavy hydrocarbon components that contain most of the methane and light components. Separated into relatively less volatile fractions containing; And (6) said volatile residual gas fraction is cooled under pressure to condense at least a portion of the gas fraction to form said condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes to partially condense; (2) said partially condensed natural gas stream is separated to provide a vapor stream and a first liquid stream; (3) said vapor stream is divided into at least a first gas stream and a second gas stream; (4) said first gas stream is cooled to condense substantially all of it, and thereafter expands to intermediate pressure; (5) said second gas stream is expanded to said intermediate pressure; (6) said liquid stream is expanded to said intermediate pressure; (7) said expanded and generally condensed first gas stream, said expanded second gas stream, and said expanded liquid stream are directed into a distillation column, said streams containing volatile residual gas fractions containing mostly the methane and light components. And a relatively less volatile fraction containing most of the heavy hydrocarbon component; And (8) said volatile residual gas fraction is cooled to condense at least a portion of the gas fraction under pressure to form said condensed stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes to partially condense; (2) said partially condensed natural gas stream is separated to provide at least a vapor stream and a liquid stream; (3) said vapor stream is divided into at least a first gas stream and a second gas stream; (4) said first gas stream combines with at least a portion of said liquid stream to form a combined stream; (5) said combined stream is cooled to condense substantially all of it and thereafter expanded to medium pressure; (6) said second gas stream is expanded to said intermediate pressure; (7) the remaining residual portion of the liquid stream is expanded to the intermediate pressure; (8) said expanded and generally condensed combined stream, said expanded second gas stream, and said residual portion of said liquid stream are sent into a distillation column, said streams containing volatile residual gas containing mostly the methane and light components. Separated into fractions and relatively less volatile fractions containing most of the heavy hydrocarbon component; And (9) said volatile residual gas fraction is cooled to condense at least a portion of the gas fraction under pressure to form said condensed stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes; (2) said cooled natural gas stream is divided into at least a first gas stream and a second gas stream; (3) said first gas stream is cooled to condense substantially all of it and is thereafter expanded to intermediate pressure; (4) said second gas stream is expanded to said intermediate pressure; (5) said expanded and generally condensed first gas stream and said expanded second gas stream are directed into a distillation column, said streams containing most of the volatile residual gas fraction and most of the heavy hydrocarbon components, containing most of the methane and light components. Are separated into relatively less volatile classifications; (6) said volatile residual gas fraction is cooled under pressure to at least partially condense; (7) said condensation portion is divided into at least two portions to form said condensation stream and a liquid stream; (8) The liquid stream is liquefied, characterized in that it is sent as a top feed to the distillation column. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes to partially condense; (2) said partially condensed natural gas stream is separated to provide at least a vapor stream and a first liquid stream; (3) said vapor stream is divided into at least a first gas stream and a second gas stream; (4) said first gas stream is cooled to condense substantially all of it, and thereafter expands to intermediate pressure; (5) said second gas stream is expanded to said intermediate pressure; (6) said liquid stream is expanded to said intermediate pressure; (7) said expanded and generally condensed first gas stream, said expanded second gas stream, and said expanded first liquid stream are directed into a distillation column, said streams containing volatile residues containing mostly the methane and light components. Separated into gaseous fractions and relatively less volatile fractions containing most of the heavy hydrocarbon component; (8) said volatile residual gas fraction is cooled to condense at least a portion of the gas fraction under pressure; (9) said condensed portion is divided into at least two portions to form said condensed stream and a second liquid stream; (10) The second liquid stream is directed to the distillation column as a top feed. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes to partially condense; (2) said partially condensed natural gas stream is separated to provide at least a vapor stream and a first liquid stream; (3) said vapor stream is divided into at least a first gas stream and a second gas stream; (4) said first gas stream combines with at least a portion of said first liquid stream to form a combined stream; (5) said combined stream is cooled to condense substantially all of it and thereafter expanded to medium pressure; (6) said second gas stream is expanded to said intermediate pressure; (7) the remaining residual portion of the liquid stream is expanded to the intermediate pressure; (8) said expanded and generally condensed combined stream, said expanded second gas stream, and said residual portion of said first liquid stream are directed into a distillation column, said streams being volatile containing mostly of methane and light components Separation into residual gas fraction and relatively less volatile fraction containing most of the heavy hydrocarbon component; (9) said volatile residual gas fraction is cooled to condense at least a portion under pressure; (10) said condensed portion is divided into at least two portions to form said condensed stream and a second liquid stream; (11) The second liquid stream is directed to the distillation column as a top feed. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes; (2) the cooled natural gas stream is expanded to medium pressure; (3) said expanded cooled natural gas stream is separated to provide a vapor stream and a liquid stream; (4) the liquid stream is expanded to low medium pressure; (5) said expanded liquid stream is directed into a distillation column, said stream being separated into a relatively volatile fraction containing mostly volatile vapor distillation stream and said heavy hydrocarbon component; (6) the highly volatile vapor distillation stream combines with the vapor stream to form a volatile residual gas fraction containing mostly the methane and light components; (7) The volatile residual gas fraction is cooled under pressure to form the condensate stream by condensing at least a portion of the gas fraction. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes to partially condense; (2) said partially condensed natural gas stream is separated to provide at least a first vapor stream and a first liquid stream; (3) said first vapor stream is expanded to medium pressure; (4) said expanded first vapor stream is separated to provide a second vapor stream and a second liquid stream; (5) said second liquid stream is expanded to low intermediate pressure; (6) said first liquid stream is expanded to said low intermediate pressure; (7) said expanded second liquid stream and said expanded first liquid stream are sent into a distillation column, wherein said streams are separated into a relatively less volatile fraction containing mostly volatile vapor distillation streams and said heavy hydrocarbon components. To be; (8) the highly volatile vapor distillation stream combines with the second vapor stream to form a volatile residual gas fraction containing mostly the methane and light components; And (9) said volatile residual gas fraction is cooled under pressure to condense at least a portion to form said condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes; (2) said natural gas stream is expanded to medium pressure and then sent to a contacting device to form a volatile residual gas fraction and a first liquid stream containing mostly the methane and light components; (3) a first liquid stream is sent to the distillation column, where the stream is separated into a relatively volatile fraction containing mostly volatile vapor distillation stream and the heavy hydrocarbon component; (4) said volatile vapor distillation stream is sufficiently cooled to condense at least a portion to form a second liquid stream; (5) at least a portion of the expanded cooled natural gas stream is in direct contact with at least a portion of the second liquid stream in the contact device; (6) The volatile residual gas fraction is cooled under pressure to condense at least a portion to form the condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes to partially condense; (2) said partially condensed natural gas stream is separated to provide a vapor stream and a first liquid stream; (3) the vapor stream is expanded to medium pressure and then sent to a contacting device to form a volatile residual gas fraction and a second liquid stream containing mostly the methane and light components; (4) said first liquid stream is expanded to said intermediate pressure; (5) said second liquid stream and said expanded first liquid stream are directed to a distillation column, said streams being separated into a relatively volatile fraction containing mostly volatile vapor distillation stream and said heavy hydrocarbon component; (6) said volatile vapor distillation stream is sufficiently cooled to condense at least a portion to form a third liquid stream; (7) at least a portion of the expanded cooled natural gas stream is in direct contact with at least a portion of the third liquid stream in the contact device; (8) The volatile residual gas fraction is cooled under pressure to condense at least a portion to form the condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes; (2) said cooled natural gas stream is expanded to an intermediate pressure and then sent to a contacting device to form a first vapor stream and a first liquid stream; (3) said first liquid stream is sent to a distillation column, said stream being separated into a highly volatile vapor distillation stream and a relatively less volatile fraction containing most of said heavy hydrocarbon component; (4) said highly volatile vapor distillation stream is sufficiently cooled to condense at least a portion to form a second vapor stream and a second liquid stream; (5) a portion of the second liquid stream is sent to the distillation column as a top feed; (6) at least a portion of the expanded cooled natural gas stream is in direct contact with at least a portion of the remaining portion of the second liquid stream in the contact device; (7) said first vapor stream is combined with said second vapor to form a volatile residual gas fraction containing mostly the methane and light components; (8) The volatile residual gas fraction is cooled under pressure to condense at least a portion to form the condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes to partially condense; (2) said partially condensed natural gas stream is separated to provide a first vapor stream and a first liquid stream; (3) said first vapor stream is expanded to an intermediate pressure and then sent to a contactor to form a second vapor stream and a second liquid stream; (4) said first liquid stream is expanded to said intermediate pressure; (5) said second liquid stream and said expanded first liquid stream are directed to a distillation column, said streams being separated into a relatively volatile fraction containing mostly volatile vapor distillation stream and said heavy hydrocarbon component; (6) said highly volatile vapor distillation stream is sufficiently cooled to condense at least a portion to form a third vapor stream and a third liquid stream; (7) a portion of the third liquid stream is sent to the distillation column as a top feed; (8) at least a portion of the expanded first vapor stream is in direct contact with at least a portion of the remaining portion of the third liquid stream in the contact device; (9) the second vapor stream is combined with the third vapor to form a volatile residual gas fraction containing mostly the methane and light components; (10) The volatile residual gas fraction is cooled under pressure to condense at least a portion to form the condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes; (2) the cooled natural gas stream is expanded to medium pressure and then sent to a contacting device to form a volatile residual gas fraction and a first liquid stream containing mostly the methane and light components; (3) said first liquid stream is heated and then sent to a distillation column, said stream being separated into a relatively volatile fraction containing mostly volatile vapor distillation stream and said heavy hydrocarbon component; (4) said highly volatile vapor distillation stream is sufficiently cooled to condense at least a portion to form a second liquid stream; (5) at least a portion of the expanded cooled natural gas stream is in direct contact with at least a portion of the second liquid stream in the contact device; (6) The volatile residual gas fraction is cooled under pressure to condense at least a portion to form the condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes to partially condense; (2) said partially condensed natural gas stream is separated to provide a vapor stream and a first liquid stream; (3) the vapor stream is expanded to medium pressure and then sent to a contacting device to form a volatile residual gas fraction and a second liquid stream containing mostly the methane and light components; (4) said second liquid stream is heated; (5) said first liquid stream is expanded to said intermediate pressure; (6) said heated second liquid stream and said expanded first liquid stream are directed to a distillation column, said streams being separated into a relatively volatile fraction containing mostly volatile vapor distillation streams and said heavy hydrocarbon components. Will; (7) said highly volatile vapor distillation stream is sufficiently cooled to condense at least a portion to form a third liquid stream; (8) at least a portion of the expanded vapor stream is in direct contact with at least a portion of the third liquid stream in the contact device; And (9) said volatile residual gas fraction is cooled under pressure to condense at least a portion to form said condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes; (2) said cooled natural gas stream is expanded to an intermediate pressure and then sent to a contactor to form a first vapor stream and a first liquid stream; (3) said first liquid stream is heated and then sent to a distillation column, said stream being separated into a relatively volatile fraction containing mostly volatile vapor distillation stream and said heavy hydrocarbon component; (4) said highly volatile vapor distillation stream is sufficiently cooled to condense at least a portion to form a second vapor stream and a second liquid stream; (5) a portion of the second liquid stream is sent to the distillation column as a top feed; (6) at least a portion of the expanded cooled natural gas stream is in direct contact with at least a portion of the remaining portion of the second liquid stream in the contacting device; (7) said first vapor stream is combined with said second vapor to form a volatile residual gas fraction containing mostly the methane and light components; (8) The volatile residual gas fraction is cooled under pressure to condense at least a portion to form the condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes to partially condense; (2) said partially condensed natural gas stream is separated to provide a first vapor stream and a first liquid stream; (3) said first vapor stream is expanded to intermediate pressure and then sent to a contact device thereby forming a second vapor stream and a second liquid stream; (4) said second liquid stream is heated; (5) said first liquid stream is expanded to said intermediate pressure; (6) said heated second liquid stream and said expanded first liquid stream are directed to a distillation column, said streams being separated into a relatively volatile fraction containing mostly volatile vapor distillation streams and said heavy hydrocarbon components. Will; (7) said highly volatile vapor distillation stream is sufficiently cooled to condense at least a portion to form a third vapor stream and a third liquid stream; (8) a portion of the second liquid stream is sent to the distillation column as a top feed; (9) at least a portion of the expanded first vapor stream is in direct contact with at least a portion of the remaining portion of the third liquid stream in the contact device; (10) the second vapor stream is combined with the third vapor stream and forms a volatile residual gas fraction containing mostly the methane and light components; (11) The volatile residual gas fraction is cooled under pressure to condense at least a portion to form the condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes; (2) The cooled natural gas stream is expanded to medium pressure and then sent to the mid-column feed position of the distillation column, the stream containing most of the highly volatile vapor distillation stream and the heavy hydrocarbon component. Are separated into relatively less volatile classifications; (3) a vapor distillation stream is withdrawn from the area of the distillation column below the expanded cooled natural gas stream, sufficiently cooled to condense at least a portion to form a vapor stream and a liquid stream; (4) at least a portion of the expanded cooled natural gas stream is in direct contact with at least a portion of the liquid stream in the distillation column; (5) the vapor stream is combined with the highly volatile vapor distillation stream and forms a volatile residual gas fraction containing mostly the methane and light components; (6) The volatile residual gas fraction is cooled under pressure to condense at least a portion to form the condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes to partially condense; (2) said partially condensed natural gas stream is separated to provide a first vapor stream and a first liquid stream; (3) said first vapor stream and said first liquid stream are expanded to medium pressure; (4) said expanded first vapor stream and said expanded first liquid stream are directed to a middle column feed location of the distillation column, said streams being relatively volatile containing most of the highly volatile vapor distillation stream and the heavy hydrocarbon component. Are separated into smaller classes; (5) a vapor distillation stream is withdrawn from the area of the distillation column below the expanded first vapor stream and is cooled sufficiently to condense at least a portion to form a second vapor stream and a second liquid stream; (6) at least a portion of the expanded first vapor stream is in direct contact with at least a portion of the second liquid stream of the distillation column; (7) said second vapor stream is combined with said highly volatile vapor distillation stream and forms a volatile residual gas fraction that contains most of said methane and light components; (8) The volatile residual gas fraction is cooled under pressure to condense at least a portion to form the condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes; (2) The cooled natural gas stream is expanded to medium pressure and then sent to the middle column feed point of the distillation column, the stream being a relatively less volatile fraction containing mostly volatile vapor distillation streams and the heavy hydrocarbon components. To be separated; (3) a vapor distillation stream is withdrawn from the area of the distillation column below the expanded cooled natural gas stream, sufficiently cooled to condense at least a portion to form a vapor stream and a liquid stream; (4) a portion of the liquid stream is fed to the distillation column as another feed in a feed zone that is generally in the same zone, and the distillation stream is withdrawn; (5) at least a portion of the expanded cooled natural gas stream is in direct contact with at least a portion of the remaining portion of the liquid stream in the distillation column; (6) the vapor stream forms a volatile residual gas fraction containing mostly the methane and light components; (7) The volatile residual gas fraction is cooled under pressure to condense at least a portion to form the condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes to partially condense; (2) said partially condensed natural gas stream is separated to provide a first vapor stream and a first liquid stream; (3) said first vapor stream and said first liquid stream are expanded to medium pressure; (4) said expanded first vapor stream and said expanded first liquid stream are directed to a middle column feed location of the distillation column, said streams being relatively volatile containing most of the highly volatile vapor distillation stream and the heavy hydrocarbon component. Are separated into smaller classes; (5) a vapor distillation stream is withdrawn from the area of the distillation column below the expanded first vapor stream and is cooled sufficiently to condense at least a portion to form a second vapor stream and a second liquid stream; (6) a portion of the second liquid stream is fed to the distillation column as another feed in a feed zone that is generally in the same zone, and the distillation stream is withdrawn; (7) at least a portion of the expanded first vapor stream is in direct contact with at least a portion of the second liquid stream of the distillation column; (8) said second vapor stream is combined with said highly volatile vapor distillation stream and forms a volatile residual gas fraction that contains most of said methane and light components; And (9) said volatile residual gas fraction is cooled under pressure to condense at least a portion to form said condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes; (2) The cooled natural gas stream is expanded to medium pressure and then sent to the middle column feed point of the distillation column, where the stream is a relatively volatile fraction containing mostly volatile vapor distillation streams and the heavy hydrocarbon components. Separated into; (3) a vapor distillation stream is withdrawn from the area of the distillation column below the expanded cooled natural gas stream, sufficiently cooled to condense at least a portion to form a vapor stream and a liquid stream; (4) at least a portion of the expanded natural gas stream is in direct contact with at least a portion of the liquid stream in the distillation column; (5) the liquid distillation stream is withdrawn from the distillation column at a position above the region where the vapor distillation stream is drawn out, and the liquid distillation is heated and then at a position in the region below the region where the vapor distillation stream is drawn out. As it is fed back to the distillation column; (6) said vapor stream is combined with said highly volatile distillation stream and forms a volatile residual gas fraction containing mostly said methane and light components; (7) The volatile residual gas fraction is cooled under pressure to condense at least a portion to form the condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes to partially condense; (2) said partially condensed natural gas stream is separated to provide a first vapor stream and a first liquid stream; (3) said first vapor stream and said first liquid stream are expanded to medium pressure; (4) said expanded first vapor stream and said expanded first liquid stream are directed to a middle column feed location of the distillation column, said streams being relatively volatile containing most of the highly volatile vapor distillation stream and the heavy hydrocarbon component. Are separated into smaller classes; (5) a vapor distillation stream is withdrawn from the area of the distillation column below the expanded first vapor stream and is cooled sufficiently to condense at least a portion to form a second vapor stream and a second liquid stream; (6) at least a portion of the expanded first vapor stream is in direct contact with at least a portion of the second liquid stream of the distillation column; (7) A liquid distillation stream is withdrawn from the distillation column at a position above the region where the vapor distillation stream is drawn out, and the liquid distillation stream is heated and then at a position in the region below the region where the vapor distillation stream is drawn out. As it is fed back to the distillation column; (8) said second vapor stream combines with said highly volatile distillation stream and forms a volatile residual gas fraction that contains most of said methane and light components; And (9) said volatile residual gas fraction is cooled under pressure to condense at least a portion to form said condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes; (2) The cooled natural gas stream is expanded to medium pressure and then sent to the middle column feed point of the distillation column, where the stream is a relatively volatile fraction containing mostly volatile vapor distillation streams and the heavy hydrocarbon components. Separated into; (3) a vapor distillation stream is withdrawn from the area of the distillation column below the expanded cooled natural gas stream, sufficiently cooled to condense at least a portion to form a vapor stream and a liquid stream; (4) a portion of the liquid stream is fed to the distillation column as another feed in a feed zone that is generally in the same zone, and the distillation stream is withdrawn; (5) at least a portion of the expanded cooled flue gas stream is in direct contact with at least a portion of the remaining portion of the liquid stream in the distillation column; (6) A liquid distillation stream is withdrawn from the distillation column at a position above the region where the vapor distillation stream is drawn out, and the liquid distillation stream is heated and then at a position in the region below the region where the vapor distillation stream is drawn out. As it is fed back to the distillation column; (7) said vapor stream combines with said highly volatile distillation stream and forms a volatile residual gas fraction that contains most of said methane and light components; (8) The volatile residual gas fraction is cooled under pressure to condense at least a portion to form the condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes to partially condense; (2) said partially condensed natural gas stream is separated to provide a first vapor stream and a first liquid stream; (3) said first vapor stream and said first liquid stream are expanded to medium pressure; (4) said expanded first vapor stream and said expanded first liquid stream are directed to a middle column feed location of the distillation column, said streams being relatively volatile containing most of the highly volatile vapor distillation stream and the heavy hydrocarbon component. Are separated into smaller classes; (5) a vapor distillation stream is withdrawn from the area of the distillation column below the expanded first vapor stream and is cooled sufficiently to condense at least a portion to form a second vapor stream and a second liquid stream; (6) in a feed zone in which a portion of the second liquid stream is generally in the same zone, as another feed to the distillation column, the distillation stream is taken out; (7) at least a portion of the expanded first vapor stream is in direct contact with at least a portion of the remaining portion of the second liquid stream of the distillation column; (8) A liquid distillation stream is withdrawn from the distillation column at a position above the region where the vapor distillation stream is drawn out, and the liquid distillation stream is heated and then at a position in the region below the region where the vapor distillation stream is drawn out. As it is fed back to the distillation column; (9) said second vapor stream combines with said highly volatile distillation stream and forms a volatile residual gas fraction that contains most of said methane and light components; (10) The volatile residual gas fraction is cooled under pressure to condense at least a portion to form the condensate stream. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes; (2) said cooled natural gas stream is expanded to medium pressure; (3) said expanded cooled natural gas stream is sent to a distillation column, said stream being separated into a volatile residual gas fraction containing the methane and light components and a relatively less volatile fraction containing most of the heavy hydrocarbon components. ; And (4) said volatile residual gas fraction is essentially cooled to form a condensate stream by cooling under pressure to condense at least a portion thereof. (a) the natural gas stream is cooled under pressure to condense at least a portion of the gas to form a condensed stream; (b) a process for liquefying a natural gas stream containing methane and heavy hydrocarbon components, wherein the condensed stream is expanded to low pressure to form a liquefied natural gas stream, (1) said natural gas stream is treated in one or more cooling processes to partially condense; (2) said partially condensed natural gas stream is separated to provide at least a vapor stream and a liquid stream; (3) said vapor stream is expanded to medium pressure; (4) said liquid stream is expanded to said intermediate pressure; (5) at least said expanded vapor stream and said expanded liquid stream are sent to a distillation column, said stream having a relatively low volatility fraction containing most of the methane and light components and a relatively low volatility containing most of the heavy hydrocarbon components. Separated into classifications; (6) said volatile residual gas fraction being essentially cooled to condense at least a portion to form said condensate stream, thereby liquefying a natural gas stream. Claims 3, 4, 5, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 The method according to any one of claims, 21, 22, 23, 24, 25, 26, 27, and 28, The volatile residual gas fraction is compressed and then cooled under pressure to condense at least a portion to form the condensate stream. The method according to any one of claims 1 to 6, (1) the volatile residual gas fraction is compressed and then cooled under pressure to condense at least a portion; (2) The condensed portion is divided into at least two portions to form the condensate stream and the liquid stream. The method according to any one of claims 2, 7, and 8, (1) the volatile residual gas fraction is compressed and then cooled under pressure to condense at least a portion; (2) The condensed portion is divided into at least two portions to form the condensate stream and the second liquid stream. The method of claim 9, And wherein said highly volatile vapor distillation stream is compressed and thereafter combined with said vapor stream to form said volatile residual gas fraction that contains most of said methane and light constituents. The method of claim 10, And wherein said highly volatile vapor distillation stream is compressed and thereafter combined with said second vapor stream to form said volatile residual gas fraction which contains most of said methane and light constituents. Claims 3, 4, 5, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 The method according to any one of claims, 21, 22, 23, 24, 25, 26, 27, and 28, The volatile residual gas fraction is heated, compressed and then cooled under pressure to condense at least a portion to form the condensate stream. The method according to any one of claims 1 to 6, (1) the volatile residual gas fraction is heated, compressed and then cooled under pressure to condense at least a portion; (2) The condensed portion is divided into at least two portions to form the condensate stream and the liquid stream. The method according to any one of claims 2, 7, and 8, (1) the volatile residual gas fraction is heated, compressed and then cooled under pressure to condense at least a portion; (2) The condensed portion is divided into at least two portions to form the condensate stream and the second liquid stream. The method of claim 9, The highly volatile vapor distillation stream is heated, compressed and cooled and then combined with the vapor stream to form the volatile residual gas fraction containing mostly the methane and light components. . The method of claim 10, The highly volatile vapor distillation stream is heated, compressed and cooled and then combined with the second vapor stream to form the volatile residual gas fraction containing mostly the methane and light components of the natural gas stream. Liquefaction method. Claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 Claims 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, The method according to any one of claims 26, 27, 28, 32, 33, 37, 38, Wherein the volatile residual gas fraction contains mostly the methane, light and C ₂ components. Claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 Claims 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, The method according to any one of claims 26, 27, 28, 32, 33, 37, 38, Wherein the volatile residual gas fraction contains mostly the methane, light component, C ₂ component and C ₃ component. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) at least one second heat exchange means connected to receive said natural gas stream and cooperate to cool said gas stream under pressure; (2) second expansion means connected to said second heat exchange means to receive said cooled natural gas stream and expand the gas stream under medium pressure; (3) a distillation column connected to receive the expanded cooled natural gas stream, the distillation column being a volatile residual gas fraction containing mostly the methane and light components and a relatively less volatile fraction containing most of the heavy hydrocarbon components. To be separated; (4) said first heat exchange means connected to said distillation column to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure such that at least a portion of said gas fraction is condensed; (5) dividing means connected to said first heat exchange means to receive said condensation portion and divide said condensation portion into at least two portions to form said condensation stream and a liquid stream, said dividing means distilling said liquid stream to said distillation Further connected to the distillation column to send as the top feed of the column; (6) control means for adjusting the temperature and amount of the feed stream in the distillation column to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the relatively less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) at least one second heat exchange means connected to receive said natural gas stream and cooperate to condensate the gas stream partially by cooling said gas stream sufficiently under pressure; (2) separating means connected to said second heat exchange means to receive said partially condensed natural gas stream and to separate said gas stream into a vapor stream and a first liquid stream; (3) second expansion means connected to said separation means to receive said vapor stream and expand the gas stream under medium pressure; (4) third expansion means connected to said separation means to receive said first liquid stream and expand said gas stream under said intermediate pressure; (5) a distillation column connected to receive said expanded vapor stream and said expanded first liquid stream, said distillation column being relatively volatile containing most of the heavy hydrocarbon component and the volatile residual gas fraction containing mostly the methane and light components; Less fractionation allowed the stream to separate; (6) said first heat exchange means connected to said distillation column to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure such that at least a portion of said gas fraction is condensed; (7) dividing means connected to said first heat exchange means to receive said condensation portion and divide said condensation portion into at least two portions to form said condensation stream and said second liquid stream, said dividing means being said second liquid Further connected to the distillation column to direct the stream as a top feed of the distillation column; (8) control means for adjusting the temperature and amount of the feed stream in the distillation column to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the relatively less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) at least one second heat exchange means connected to receive said natural gas stream and cooperate to cool said gas stream under pressure; (2) dividing means connected to said second heat exchange means to receive said cooled natural gas stream and divide said gas stream into at least a first gas stream and a second gas stream; (3) third heat exchange means connected to said dividing means to receive said first gas stream and cool the gas stream sufficiently to generally condense the gas stream; (4) second expansion means connected to said third heat exchange means to receive said generally condensed first gas stream and expand the gas stream at an intermediate pressure; (5) third expansion means connected to said dividing means to receive said second gas stream and expand said gas stream at said intermediate pressure; (6) a distillation column connected to receive said expanded generally condensed first gas stream and said expanded second gas stream, said distillation column containing most of the volatile residual gas fraction and most of the heavy hydrocarbon component, containing most of the methane and light components; To separate the stream into relatively less volatile fractions; (7) said first heat exchange means connected to said distillation column to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of the gas fraction so that said condensate stream is To form; (8) control means for adjusting the temperature and amount of the feed stream in the distillation column to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the relatively less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) one or more second heat exchange means connected to receive said natural gas stream and cooperate to cooperate to partially cool the gas stream by sufficiently cooling the gas stream under pressure; (2) separating means connected to said second heat exchange means to receive said partially condensed natural gas stream and to separate said gas stream into at least a vapor stream and a liquid stream; (3) dividing means connected to said separating means to receive said vapor stream and divide said vapor stream into at least a first gas stream and a second gas stream; (4) third heat exchange means connected to said dividing means to receive said first gas stream and cool the gas stream sufficiently to generally condense the gas stream; (5) second expansion means connected to said third heat exchange means to receive said generally condensed first gas stream and expand the gas stream at an intermediate pressure; (6) third expansion means connected to said dividing means to receive said second gas stream and expand said gas stream at said intermediate pressure; (7) fourth expansion means connected to said separating means to receive said liquid stream and expand said liquid stream at said intermediate pressure; (8) a distillation column connected to receive said expanded generally condensed first gas stream, said expanded second gas stream and said expanded liquid stream, said distillation column comprising a volatile residual gas fraction containing mostly the methane and light components; and Allowing the stream to be separated into a relatively less volatile fraction containing most of the heavy hydrocarbon component; (9) the first heat exchange means connected to the distillation column to receive the volatile residual gas fraction, the first heat exchange means cooling the volatile residual gas fraction under pressure to condense at least a portion of the gas fraction so that the condensate stream is To form; (10) control means for adjusting the temperature and amount of the feed stream in the distillation column to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the relatively less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) one or more second heat exchange means connected to receive said natural gas stream and cooperate to cooperate to partially cool the gas stream by sufficiently cooling the gas stream under pressure; (2) separating means connected to said second heat exchange means to receive said partially condensed natural gas stream and to separate said gas stream into a vapor stream and a liquid stream; (3) dividing means connected to said separating means to receive said vapor stream and divide said vapor stream into at least a first gas stream and a second gas stream; (4) combining means connected to said dividing means and connected to said separating means to receive at least a portion of said first gas stream and said liquid stream and to combine them into a combined stream; (5) third heat exchange means connected to said combining means to receive said combined stream and to sufficiently cool the combined stream to generally condense the combined stream; (6) second expansion means connected to said third heat exchange means to receive said generally condensed combined stream and expand said combined stream at medium pressure; (7) third expansion means connected to said dividing means to receive said second gas stream and expand said gas stream at said intermediate pressure; (8) fourth expansion means connected to said separating means to receive at least a residual portion of said liquid stream and expand said residual portion at said intermediate pressure; (9) a distillation column connected to receive the expanded generally condensed combined stream, the expanded second gas stream, and the expanded residual portion of the liquid stream, wherein the distillation column contains a volatile residue containing mostly the methane and light components. To separate the stream into a gas fraction and a relatively less volatile fraction containing most of the heavy hydrocarbon component; (10) said first heat exchange means connected to said distillation column to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of said gas fraction so that said condensate stream is To form; (11) control means for controlling the temperature and amount of the feed stream in the distillation column to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the relatively less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) at least one second heat exchange means connected to the natural gas stream and cooperating to cool the gas stream under pressure; (2) dividing means connected to said heat exchange means to receive said cooled natural gas stream and divide said gas stream into at least a first gas stream and a second gas stream; (3) third heat exchange means connected to said first dividing means to receive said first gas stream and cool the gas stream sufficiently to generally condense the gas stream; (4) second expansion means connected to said third heat exchange means to receive said generally condensed first gas stream and expand the gas stream at an intermediate pressure; (5) third expansion means connected to said dividing means to receive said second gas stream and expand said gas stream at said intermediate pressure; (6) a distillation column connected to receive said expanded generally condensed first gas stream and said expanded second gas stream, said distillation column comprising a majority of the volatile residual gas fraction containing most of the methane and light components and the heavy hydrocarbon component. Separating the stream into a relatively less volatile fraction containing; (7) said first heat exchange means connected to said distillation column to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of the gas fraction so that said condensate stream is To form; (8) second dividing means connected to said first heat exchange means to receive said condensation portion and divide said condensation portion into at least two portions to form said condensation stream and a liquid stream, said second dividing means for separating said liquid stream; Further connected to the distillation column to send as the top feed of the distillation column; (9) control means for adjusting the temperature and amount of the feed stream in the distillation column to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the relatively less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) one or more second heat exchange means connected to receive said natural gas stream and cooperate to cooperate to partially cool the gas stream by sufficiently cooling the gas stream under pressure; (2) separating means connected to said second heat exchange means to receive said partially condensed natural gas stream and to separate said gas stream into a vapor stream and a liquid stream; (3) first dividing means connected to said separating means to receive said vapor stream and divide said vapor stream into at least a first gas stream and a second gas stream; (4) third heat exchange means connected to said first dividing means to receive said generally condensed first gas stream and cool the gas stream sufficiently to generally condense the gas stream; (5) second expansion means connected to said third heat exchange means to receive said generally condensed first gas stream and expand the gas stream at an intermediate pressure; (6) third expansion means connected to said first dividing means to receive said second gas stream and expand said gas stream at said intermediate pressure; (7) fourth expansion means connected to said separation means to receive said first liquid stream and expand said liquid stream at said intermediate pressure; (8) a distillation column connected to receive said expanded generally condensed first gas stream, said expanded second gas stream, and said expanded first liquid stream, said distillation column having a volatile residue containing most of said methane and light components; To separate the stream into a gas fraction and a relatively less volatile fraction containing most of the heavy hydrocarbon component; (9) the first heat exchange means connected to the distillation column to receive the volatile residual gas fraction, the first heat exchange means cooling the volatile residual gas fraction under pressure to condense at least a portion of the gas fraction so that the condensate stream is To form; (10) second dividing means connected to said first heat exchange means to receive said condensation portion and divide said condensation portion into at least two portions to form said condensation stream and a second liquid stream, said second dividing means being said first; Two liquid streams are further connected to said distillation column to direct it as a top feed of said distillation column; (11) control means for controlling the temperature and amount of the feed stream in the distillation column to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the relatively less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) one or more second heat exchange means connected to receive said natural gas stream and cool the gas stream under pressure to condense at least a portion of the gas stream to form a condensate stream; (2) separating means connected to said second heat exchange means to receive said partially condensed natural gas stream and to separate said gas stream into a vapor stream and a first liquid stream; (3) first dividing means connected to said separating means to receive said vapor stream and divide said vapor stream into at least a first gas stream and a second gas stream; (4) combining means connected to said first dividing means and connected to said separating means to receive said first gas stream and at least a portion of said first liquid stream and to combine them into a combined stream; (5) third heat exchange means connected to said combining means to receive said combined stream and to sufficiently cool the combined stream to generally condense the combined stream; (6) second expansion means connected to said third heat exchange means to receive said generally condensed combined stream and expand said combined stream at medium pressure; (7) third expansion means connected to said first dividing means to receive said second gas stream and expand said gas stream at said intermediate pressure; (8) fourth expansion means connected to said separating means to receive at least a residual portion of said first liquid stream and expand said residual portion at said intermediate pressure; (9) a distillation column connected to receive the expanded generally condensed combined stream, the expanded second gas stream, and the remaining portion of the expanded first liquid stream, the distillation column containing most of the methane and light components Separating the stream into a volatile residual gas fraction and a relatively less volatile fraction containing most of the heavy hydrocarbon component; (10) said first heat exchange means connected to said distillation column to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure such that at least a portion of said gas fraction is condensed; (11) second dividing means connected to said first heat exchange means to receive said condensation portion and divide said condensation portion into at least two portions, thereby forming said condensation stream and said second liquid stream, said second dividing means being said first; Two liquid streams are further connected to said distillation column to direct it as a top feed of said distillation column; (12) control means for adjusting the temperature and amount of the feed stream in the distillation column to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the relatively less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) at least one second heat exchange means connected to receive said natural gas stream and cooperate to cool said gas stream under pressure; (2) second expansion means connected to said second heat exchange means to receive said cooled gas stream and expand the gas stream to medium pressure; (3) separating means connected to said second expansion means to receive said expanded cooled natural gas stream and to separate the gas stream into at least a vapor stream and a liquid stream; (4) third expansion means connected to said separation means to receive said liquid stream and expand said liquid stream at said intermediate pressure; (5) a distillation column connected to receive the expanded liquid stream, the distillation column being such that the stream is separated into a volatile residual gas fraction containing mostly the methane and light components and a relatively less volatile fraction containing most of the heavy hydrocarbon components. One; (6) compounding means connected to said separating means and connected to said distillation column to receive said vapor stream and said volatile vapor distillation stream and to combine them to form a volatile residual gas fraction containing mostly methane and light components; (7) said first heat exchange means connected to said compounding means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of said gas fraction so that said condensate stream is To form; (8) control means for adjusting the temperature and amount of the feed stream in the distillation column to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the relatively less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) one or more second heat exchange means connected to receive said natural gas stream and cooperate to cool said gas stream under pressure to partially condense the gas stream; (2) first separating means connected to said second heat exchange means to receive said partially condensed natural gas stream and to separate said gas stream into a first vapor stream and a first liquid stream; (3) second expansion means connected to said first separating means to receive said first vapor stream and expand the vapor stream to medium pressure; (4) second separating means for receiving said expanded first vapor stream and separating said vapor stream into a second vapor stream and a second liquid stream and connected to said second expansion means; (5) third expansion means connected to said second separating means to receive said second liquid stream and expand said liquid stream to a lower intermediate pressure; (6) fourth expansion means connected to said first separating means to receive said first liquid stream and expand said liquid stream to said lower intermediate pressure; (7) a distillation column connected to receive said expanded second liquid stream and said expanded first liquid stream, said distillation column being classified into a relatively less volatile fraction containing mostly volatile vapor distillation streams and said heavy hydrocarbon components; Causing the stream to separate; (8) a compound connected to said second separating means and said distillation column to receive said second vapor stream and said highly volatile vapor distillation stream and combine them to form a volatile residual gas fraction containing mostly methane and light components; Way; (9) said first heat exchange means connected to said compounding means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of the gas fraction so that said condensate stream is To form; (10) control means for adjusting the temperature and amount of the feed stream in the distillation column to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the relatively less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) at least one second heat exchange means connected to receive said natural gas stream and cooperate to cool said gas stream under pressure; (2) second expansion means connected to said second heat exchange means to receive said cooled natural gas stream and expand the gas stream to medium pressure; (3) said contacting and separating means connected to receive said expanded cooled natural gas stream, said contacting and separating means comprising at least one contacting device for mixing liquid and steam, said mixture being capable of separating the vapor and liquid after mixing And separation means for forming a first liquid stream and a volatile residual gas fraction containing mostly light components; (4) a distillation column connected to receive the first liquid stream, the distillation column causing the stream to be separated into a relatively less volatile fraction containing mostly the volatile vapor distillation stream and the heavy hydrocarbon component; (5) third heat exchange means connected to said distillation column to receive said highly volatile vapor distillation stream and cool said distillation stream sufficiently to condense at least a portion of said distillation stream to form a second liquid stream; (6) said contacting and separating means are further connected to said third heat exchange means to receive said second liquid stream such that said expanded cooled natural gas stream is in direct contact with at least a portion of said second liquid stream of said contactor; (7) said first heat exchange means connected to said contacting and separating means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of the gas fraction so as to condense Causing a stream to form; (8) said feed to said contacting and separating means and said distillation column to maintain an overhead temperature of said contacting and separating means and said distillation column at a temperature at which a majority of said heavy hydrocarbon components are recovered in said less volatile fraction. And control means for adjusting the temperature and amount of the stream. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) one or more second heat exchange means connected to receive said natural gas stream and cooperate to cooperate to partially cool the gas stream by sufficiently cooling the gas stream under pressure; (2) separating means connected to said second heat exchange means to receive said partially condensed natural gas stream and to separate said gas stream into a vapor stream and a first liquid stream; (3) second expansion means connected to said separation means to receive said vapor stream and expand said vapor stream to medium pressure; (4) contacting and separating means connected to receive said expanded vapor stream, said contacting and separating means comprising at least one contacting device for mixing liquid and steam, wherein after mixing the vapor and liquid separate the methane and light Volatile residual gas fractions containing mostly constituents and separation means for forming a second liquid stream; (5) third expansion means connected to said separation means to receive said first liquid stream and expand said liquid stream to said intermediate pressure; (6) a distillation column connected to receive said second liquid stream and said expanded first liquid stream, said distillation column being a relatively less volatile fraction containing mostly volatile vapor distillation streams and said heavy hydrocarbon components. To be separated; (7) third heat exchange means connected to said distillation column to receive said highly volatile vapor distillation stream and cool said distillation stream sufficiently to condense at least a portion of said distillation stream to form a third liquid stream; (8) said contacting and separating means are further connected to said third heat exchange means to receive said third liquid stream such that said expanded vapor stream is in direct contact with at least a portion of said third liquid stream of said contactor; (9) said first heat exchange means connected to said contacting and separating means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of the gas fraction so as to condense Causing a stream to form; (10) said feed to said contacting and separating means and said distillation column to maintain an overhead temperature of said contacting and separating means and said distillation column at a temperature at which a majority of said heavy hydrocarbon components are recovered in said less volatile fraction. And control means for adjusting the temperature and amount of the stream. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) at least one second heat exchange means connected to receive said natural gas stream and cooperate to cool said gas stream under pressure; (2) second expansion means connected to said second heat exchange means to receive said cooled natural gas stream and expand the gas stream to medium pressure; (3) said contacting and separating means connected to receive said expanded cooled natural gas stream, said contacting and separating means comprising at least one contacting device for mixing liquid and vapor, said mixture being capable of separating first vapor and liquid after mixing Separating means for forming a vapor stream and a first liquid stream; (4) a distillation column connected to receive the first liquid stream, the distillation column causing the stream to be separated into a relatively less volatile fraction containing mostly the volatile vapor distillation stream and the heavy hydrocarbon component; (5) third heat exchange means connected to said distillation column to receive said highly volatile vapor distillation stream and to cool said distillation stream sufficiently to condense at least a portion of the distillation stream; (6) separating means connected to said third heat exchange means to receive said cooled highly volatile vapor distillation stream and to separate said distillation stream into a second vapor stream and a second liquid stream; (7) dividing means connected to said separating means to receive said second liquid stream and divide said liquid stream into at least a first portion and a second portion, said dividing means distilling said first portion of said second liquid stream Further connected to the distillation column to send as the top feed of the column; (8) said means for contacting and separating means said support of said second liquid stream such that at least a portion of said expanded cooled natural gas stream is in direct contact with at least a portion of said second portion of said second liquid stream of said contactor. Further connected to said dividing means to receive a portion; (9) compounding means connected to said contacting and separating means and said separating means to receive said first vapor stream and said second vapor stream and combine them to form a volatile residual gas fraction containing mostly the methane and light components; (10) said first heat exchange means connected to said compounding means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of said gas fraction so that said condensate stream is To form; (11) said feed to said contacting and separating means and said distillation column to maintain an overhead temperature of said contacting and separating means and said distillation column at a temperature at which a majority of said heavy hydrocarbon components are recovered in said less volatile fraction. And control means for adjusting the temperature and amount of the stream. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) one or more second heat exchange means connected to receive said natural gas stream and cooperate to cooperate to partially cool the gas stream by sufficiently cooling the gas stream under pressure; (2) first separating means connected to said second heat exchange means to receive said partially condensed natural gas stream and to separate said gas stream into a first vapor stream and a first liquid stream; (3) second expansion means connected to said first separating means to receive said first vapor stream and expand the vapor stream to medium pressure; (4) contacting and separating means connected to receive said expanded first vapor stream, said contacting and separating means comprising at least one contacting device for mixing liquid and vapor, wherein after mixing, the vapor and liquid are separated to form a second Separating means for forming a vapor stream and a second liquid stream; (5) third expansion means connected to said separation means to receive said first liquid stream and expand said liquid stream to said intermediate pressure; (6) a distillation column connected to receive said second liquid stream and said expanded first liquid stream, said distillation column being a relatively less volatile fraction containing mostly volatile vapor distillation streams and said heavy hydrocarbon components. To be separated; (7) third heat exchange means connected to said distillation column to receive said highly volatile vapor distillation stream and to cool said distillation stream sufficiently to condense at least a portion of the distillation stream; (8) second separation means connected to said third heat exchange means to receive said cooled highly volatile vapor distillation stream and to separate said distillation stream into a third vapor stream and a third liquid stream; (9) dividing means connected to said second separating means to receive said third liquid stream and divide said liquid stream into at least a first portion and a second portion, said dividing means separating said first portion of said third liquid stream; Further connected to the distillation column to send as a top feed of the distillation column; (10) said means for contacting and separating means for said second of said third liquid stream such that at least a portion of said expanded first vapor stream is in direct contact with at least a portion of said second portion of said third liquid stream of said contactor; Further connected to said dividing means to receive a portion; (11) compounding means connected to said contacting and separating means and to said separating means to receive said second vapor stream and said third vapor stream and combine them to form a volatile residual gas fraction containing mostly the methane and light components; (12) said first heat exchange means connected to said compounding means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of the gas fraction so that said condensate stream is To form; (13) said feed to said contacting and separating means and said distillation column to maintain the overhead temperature of said contacting and separating means and said distillation column at a temperature at which a majority of said heavy hydrocarbon components are recovered in said less volatile fraction. And control means for adjusting the temperature and amount of the stream. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) at least one second heat exchange means connected to receive said natural gas stream and cooperate to cool said gas stream under pressure; (2) second expansion means connected to said second heat exchange means to receive said cooled natural gas stream and expand the gas stream to medium pressure; (3) said contacting and separating means connected to receive said expanded cooled natural gas stream, said contacting and separating means comprising at least one contacting device for mixing liquid and steam, said mixture being capable of separating the vapor and liquid after mixing And separation means for forming a first liquid stream and a volatile residual gas fraction containing mostly light components; (4) third heat exchange means connected to said contacting and separating means to receive said first liquid stream and heat the liquid stream; (5) a distillation column connected to receive the heated first liquid stream, the distillation column causing the stream to be separated into a relatively less volatile fraction containing mostly the volatile vapor distillation stream and the heavy hydrocarbon component; (6) fourth heat exchange means connected to said distillation column to receive said highly volatile vapor distillation stream and cool said distillation stream sufficiently to condense at least a portion of said distillation stream to form a second liquid stream; (7) said contacting and separating means being adapted to receive said second heat exchange means such that at least a portion of said expanded cooled natural gas stream is in direct contact with at least a portion of said second liquid stream of said contactor. More connected; (8) said first heat exchange means connected to said contacting and separating means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of the gas fraction so as to condense Causing a stream to form; (9) said feed to said contacting and separating means and said distillation column to maintain the overhead temperature of said contacting and separating means and said distillation column at a temperature at which a majority of said heavy hydrocarbon components are recovered in said less volatile fraction. And control means for adjusting the temperature and amount of the stream. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) one or more second heat exchange means connected to receive said natural gas stream and cooperate to cooperate to partially cool the gas stream by sufficiently cooling the gas stream under pressure; (2) separating means connected to said second heat exchange means to receive said partially condensed natural gas stream and to separate said gas stream into a first vapor stream and a first liquid stream; (3) second expansion means connected to said separation means to receive said first vapor stream and expand the vapor stream to medium pressure; (4) contacting and separating means connected to receive said expanded first vapor stream, said contacting and separating means comprising at least one contacting device for mixing liquid and vapor, said mixture being capable of separating the vapor and liquid after mixing And separation means for forming a first liquid stream and a volatile residual gas fraction containing mostly light components; (5) third heat exchange means connected to said contacting and separating means to receive said second liquid stream and heat the liquid stream; (6) third expansion means connected to said separation means to receive said first liquid stream and expand said liquid stream to said intermediate pressure; (7) a distillation column connected to receive the heated second liquid stream and the expanded first liquid stream, the distillation column being classified into a relatively less volatile fraction containing mostly a volatile vapor distillation stream and the heavy hydrocarbon component; Causing the stream to separate; (8) fourth heat exchange means connected to said distillation column to receive said highly volatile vapor distillation stream and cool said distillation stream sufficiently to condense at least a portion of said distillation stream to form a third liquid stream; (9) said contacting and separating means being adapted for receiving said third heat stream such that at least a portion of said expanded first vapor stream is in direct contact with at least a portion of said third liquid stream of said contactor. More connected; (10) said first heat exchange means connected to said contacting and separating means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of said gas fraction so as to condense said condensation; Causing a stream to form; (11) said feed to said contacting and separating means and said distillation column to maintain an overhead temperature of said contacting and separating means and said distillation column at a temperature at which a majority of said heavy hydrocarbon components are recovered in said less volatile fraction. And control means for adjusting the temperature and amount of the stream. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) at least one second heat exchange means connected to receive said natural gas stream and cooperate to cool said gas stream under pressure; (2) second expansion means connected to said second heat exchange means to receive said cooled natural gas stream and expand a vapor stream to medium pressure; (3) said contacting and separating means connected to receive said expanded cooled natural gas stream, said contacting and separating means comprising at least one contacting device for mixing liquid and vapor, said mixture being capable of separating first vapor and liquid after mixing Separating means for forming a vapor stream and a first liquid stream; (4) third heat exchange means connected to said contacting and separating means to receive said first liquid stream and heat the liquid stream; (5) a distillation column connected to receive the heated first liquid stream, the distillation column causing the stream to be separated into a relatively less volatile fraction containing mostly the volatile vapor distillation stream and the heavy hydrocarbon component; (6) fourth heat exchange means connected to said distillation column to receive said highly volatile vapor distillation stream and to cool said distillation stream sufficiently to condense at least a portion of the distillation stream; (7) separating means connected to said fourth heat exchange means to receive said cooled volatile strong vapor distillation stream and to separate said distillation stream into a second vapor stream and a second liquid stream; (8) dividing means connected to said dividing means to receive said second liquid stream and divide said liquid stream into at least a first portion and a second portion, said dividing means further comprising said first portion of said second water liquid stream Further connected to the distillation column to send as the top feed of the distillation column; (9) said contacting and separating means for said second of said second liquid stream such that at least a portion of said expanded cooled natural gas stream is in direct contact with at least a portion of said second portion of said second liquid stream of said contactor. Further connected to said dividing means to receive a portion; (10) compounding means connected to said contacting and separating means and said separating means to receive said first vapor stream and said second vapor stream and combine them to form a volatile residual gas fraction containing mostly the methane and light components; (11) said first heat exchange means connected to said compounding means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of the gas fraction so that said condensate stream is To form; (12) said feed to said contacting and separating means and said distillation column to maintain an overhead temperature of said contacting and separating means and said distillation column at a temperature at which a majority of said heavy hydrocarbon components are recovered in said less volatile fraction. And control means for adjusting the temperature and amount of the stream. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) one or more second heat exchange means connected to receive said natural gas stream and cooperate to cooperate to partially cool the gas stream by sufficiently cooling the gas stream under pressure; (2) first separating means connected to said second heat exchange means to receive said partially condensed natural gas stream and to separate said gas stream into a first vapor stream and a first liquid stream; (3) second expansion means connected to said first separating means to receive said first vapor stream and expand the vapor stream to medium pressure; (4) contacting and separating means connected to receive said expanded first vapor stream, said contacting and separating means comprising at least one contacting device for mixing liquid and vapor, wherein after mixing, the vapor and liquid are separated to form a second Separating means for forming a vapor stream and a second liquid stream; (5) third heat exchange means connected to said contacting and separating means to receive said second liquid stream and heat the liquid stream; (6) third expansion means connected to said separation means to receive said first liquid stream and expand said liquid stream to said intermediate pressure; (7) a distillation column connected to receive the heated second liquid stream and the expanded first liquid stream, the distillation column being classified into a relatively less volatile fraction containing mostly a volatile vapor distillation stream and the heavy hydrocarbon component; Causing the stream to separate; (8) fourth heat exchange means connected to said distillation column to receive said highly volatile vapor distillation stream and to sufficiently cool the distillation stream to condense at least a portion of the distillation stream; (9) second separation means connected to said fourth heat exchange means to receive said cooled highly volatile vapor distillation stream and to separate said distillation stream into a third vapor stream and a third liquid stream; (10) dividing means connected to said second separating means to receive said third liquid stream and divide said liquid stream into at least a first portion and a second portion, said dividing means separating said first portion of said third liquid stream; Further connected to the distillation column to send as a top feed of the distillation column; (11) said means for contacting and separating means said second of said third liquid stream such that at least a portion of said expanded first vapor stream is in direct contact with at least a portion of said second portion of said third liquid stream of said contactor. Further connected to said dividing means to receive a portion; (12) compounding means connected to said contacting and separating means and said separating means to receive said second vapor stream and said third vapor stream and combine them to form a volatile residual gas fraction containing mostly methane and light components; (13) said first heat exchange means connected to said compounding means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of said gas fraction so that said condensate stream is To form; (14) said feed to said contacting and separating means and said distillation column to maintain an overhead temperature of said contacting and separating means and said distillation column at a temperature at which a majority of said heavy hydrocarbon components are recovered in said less volatile fraction. And control means for adjusting the temperature and amount of the stream. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) at least one second heat exchange means connected to receive said natural gas stream and cooperate to cool said gas stream under pressure; (2) second expansion means connected to said second heat exchange means to receive said cooled natural gas stream and expand a vapor stream to medium pressure; (3) a distillation column connected to receive the expanded cooled natural gas stream, the distillation column causing the stream to be separated into a relatively less volatile fraction containing mostly volatile vapor distillation streams and the heavy hydrocarbon components; (4) vapor extraction means connected to said distillation column to receive a vapor distillation stream from the region of said distillation column below said expanded cooled natural gas stream; (5) third heat exchange means connected to said vapor extraction means to receive said vapor distillation stream and to sufficiently cool the distillation stream to condense at least a portion of the distillation stream; (6) separating means connected to said third heat exchange means to receive said cooled vapor distillation stream and to separate said distillation stream into a vapor stream and a liquid stream; (7) said distillation column further connected to said separating means to receive said liquid stream such that at least a portion of said expanded cooled natural gas stream is in direct contact with at least a portion of said liquid stream of said contactor; (8) compounding means connected to said distillation column and said separating means to receive said highly volatile vapor distillation stream and said vapor stream and combine them to form a volatile residual gas fraction containing mostly the methane and light components; (9) said first heat exchange means connected to said compounding means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of the gas fraction so that said condensate stream To form; (10) control means for adjusting the temperature and amount of the feed stream in the distillation column to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the relatively less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) one or more second heat exchange means connected to receive said natural gas stream and cooperate to cooperate to partially cool the gas stream by sufficiently cooling the gas stream under pressure; (2) first separation means adapted to receive said partially condensed natural gas stream and to separate the gas stream into a first vapor stream and a first liquid stream; (3) second expansion means connected to said first separating means to receive said first vapor stream and expand the vapor stream to medium pressure; (4) third expansion means connected to said first separating means to receive said first liquid stream and expand said liquid stream to medium pressure; (5) a distillation column connected to receive the expanded first vapor stream and the expanded first liquid stream, the distillation column being classified into a relatively less volatile fraction containing mostly the volatile vapor distillation stream and the heavy hydrocarbon component; Causing the stream to separate; (6) vapor withdrawing means connected to said distillation column to receive a vapor distillation stream from the region of said distillation column below said expanded first vapor stream; (7) third heat exchange means connected to said vapor extraction means to receive said vapor distillation stream and to sufficiently cool the distillation stream to condense at least a portion of the distillation stream; (8) second separation means connected to said third heat exchange means to receive said cooled vapor distillation stream and to separate said distillation stream into a second vapor stream and a second liquid stream; (9) said distillation column further connected to said second separating means to receive said second liquid stream such that at least a portion of said expanded first vapor distillation stream is in direct contact with at least a portion of said second liquid stream of said distillation column; ; (10) compounding means connected to said distillation column and said second separating means to receive said highly volatile vapor distillation stream and said second vapor stream and combine them to form a volatile residual gas fraction containing mostly the methane and light components; ; (11) said first heat exchange means connected to said compounding means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of the gas fraction so that said condensate stream is To form; (12) control means for adjusting the temperature and amount of the feed stream to the distillation column to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) at least one second heat exchange means connected to receive said natural gas stream and cooperate to cool said gas stream under pressure; (2) second expansion means connected to said second heat exchange means to receive said cooled natural gas stream and expand the gas stream to medium pressure; (3) a distillation column connected to receive the expanded cooled natural gas stream, the distillation column causing the stream to be separated into a relatively less volatile fraction containing mostly volatile vapor distillation streams and the heavy hydrocarbon components; (4) vapor extraction means connected to said distillation column to receive a vapor distillation stream from the region of said distillation column below said expanded cooled natural gas stream; (5) third heat exchange means connected to said vapor extraction means to receive said vapor distillation stream and to sufficiently cool the distillation stream to condense at least a portion of the distillation stream; (6) separating means connected to said third heat exchange means to receive said cooled vapor distillation stream and to separate said distillation stream into a vapor stream and a liquid stream; (7) dividing means connected to said dividing means to receive said liquid stream and divide said liquid stream into at least a first portion and a second portion, said dividing means being at a feed position in a region substantially the same as the vapor distillation stream is extracted from Further connected to the distillation column to supply the first portion of the liquid stream as a feed to the distillation column; (8) said dividing means further connected to receive said second portion of said liquid stream such that at least a portion of said expanded cooled natural gas stream is in direct contact with at least a portion of said second portion of said liquid stream in said distillation column; The distillation column; (9) compounding means connected to said distillation column and said separating means to receive said highly volatile vapor distillation stream and said vapor stream and combine them to form a volatile residual gas fraction containing mostly methane and light components; (10) said first heat exchange means connected to said compounding means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of said gas fraction so that said condensate stream is To form; (11) control means for causing the distillation column to adjust the temperature and amount of the feed stream to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the relatively less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) one or more second heat exchange means connected to receive said natural gas stream and cooperate to cooperate to partially cool the gas stream by sufficiently cooling the gas stream under pressure; (2) first separation means adapted to receive said partially condensed natural gas stream and to separate the gas stream into a first vapor stream and a first liquid stream; (3) second expansion means connected to said first separating means to receive said first vapor stream and expand the vapor stream to medium pressure; (4) third expansion means connected to said first separating means to receive said first liquid stream and expand said liquid stream to medium pressure; (5) a distillation column connected to receive the expanded first vapor stream and the expanded first liquid stream, the distillation column being classified into a relatively less volatile fraction containing mostly the volatile vapor distillation stream and the heavy hydrocarbon component; Causing the stream to separate; (6) vapor extraction means connected to said distillation column to receive a vapor distillation stream from the region of said distillation column below said expanded first vapor stream; (7) third heat exchange means connected to said vapor extraction means to receive said vapor distillation stream and to sufficiently cool the distillation stream to condense at least a portion of the distillation stream; (8) second separation means connected to said third heat exchange means to receive said cooled vapor distillation stream and to separate said distillation stream into a second vapor stream and a second liquid stream; (9) dividing means connected to said second separating means to receive said second liquid stream and divide said liquid stream into at least a first portion and a second portion, said dividing means being in a region substantially the same as that in which said vapor distillation stream is extracted; Further connected to the distillation column to supply the first portion of the liquid stream to the distillation column as a feed to a feed position; (10) receiving the second portion of the second liquid stream such that at least a portion of the expanded first vapor distillation stream is in direct contact with at least a portion of the second portion of the second liquid stream of the distillation column; The distillation column further connected to the dividing means; (11) compounding means connected to said distillation column and said separating means to receive said highly volatile vapor distillation stream and said second vapor stream and combine them to form a volatile residual gas fraction containing mostly methane and light components; (12) said first heat exchange means connected to said compounding means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of the gas fraction so that said condensate stream is To form; (13) control means for causing the distillation column to adjust the temperature and amount of the feed stream to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) at least one second heat exchange means connected to receive said natural gas stream and cooperate to cool said gas stream under pressure; (2) second expansion means connected to said second heat exchange means to receive said cooled natural gas stream and expand the gas stream to medium pressure; (3) a distillation column connected to receive the expanded cooled natural gas stream, the distillation column causing the stream to be separated into a relatively less volatile fraction containing mostly volatile vapor distillation streams and the heavy hydrocarbon components; (4) vapor extraction means connected to said distillation column to receive a vapor distillation stream from the region of said distillation column below said expanded cooled natural gas stream; (5) third heat exchange means connected to said vapor extraction means to receive said vapor distillation stream and to sufficiently cool the distillation stream to condense at least a portion of the distillation stream; (6) separating means connected to said third heat exchange means to receive said cooled vapor distillation stream and to separate said distillation stream into a vapor stream and a liquid stream; (7) said dividing column is further connected to said dividing means to receive said liquid stream such that at least a portion of said expanded cooled natural gas stream is in direct contact with at least a portion of said liquid stream in said distillation column; (8) liquid extraction means connected to said distillation column to receive a liquid distillation stream from said area of said distillation column above said area of said distillation column of said middle stage extraction means; (9) fourth heat exchange means connected to said liquid extraction means to receive said liquid distillation stream and heat said distillation stream, said fourth heat exchange means being in said position below said distillation column of said vapor extraction means; Is further connected to the distillation column to feed the distillation stream; (10) compounding means connected to said distillation column and said separating means to receive said highly volatile vapor distillation stream and said vapor stream and combine them to form a volatile residual gas fraction containing mostly the methane and light components; (11) said first heat exchange means connected to said compounding means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of the gas fraction so that said condensate stream is To form; (12) control means for adjusting the temperature and amount of the feed stream to the distillation column to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) one or more second heat exchange means connected to receive said natural gas stream and cooperate to cooperate to partially cool the gas stream by sufficiently cooling the gas stream under pressure; (2) first separation means adapted to receive said partially condensed natural gas stream and to separate the gas stream into a first vapor stream and a first liquid stream; (3) second expansion means connected to said first separating means to receive said first vapor stream and expand the vapor stream to medium pressure; (4) third expansion means connected to said first separating means to receive said first liquid stream and expand said liquid stream to medium pressure; (5) a distillation column connected to receive the expanded first vapor stream and the expanded first liquid stream, the distillation column being classified into a relatively less volatile fraction containing mostly the volatile vapor distillation stream and the heavy hydrocarbon component; Causing the stream to separate; (6) vapor extraction means connected to said distillation column to receive a vapor distillation stream from the region of said distillation column below said expanded first vapor stream; (7) third heat exchange means connected to said vapor extraction means to receive said vapor distillation stream and to sufficiently cool the distillation stream to condense at least a portion of the distillation stream; (8) second separation means connected to said third heat exchange means to receive said cooled vapor distillation stream and to separate said distillation stream into a second vapor stream and a second liquid stream; (9) said distillation column further connected to said second separating means to receive said second liquid stream such that at least a portion of said expanded first vapor distillation stream is in direct contact with at least a portion of said second liquid stream of said distillation column ; (10) liquid extraction means connected to said distillation column to receive a liquid distillation stream from the area of said distillation column above said area of said distillation column of said vapor extraction means; (11) fourth heat exchange means connected to said liquid extraction means to receive said liquid distillation stream and heat said distillation stream, said fourth heat exchange means being in said position below said distillation column of said vapor extraction means; Is further connected to the distillation column to supply as feed to the distillation stream; (12) compounding means connected to said distillation column and said separating means to receive said highly volatile vapor distillation stream and said vapor stream and combine them to form a volatile residual gas fraction containing mostly the methane and light components; (13) said first heat exchange means connected to said compounding means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of said gas fraction so that said condensate stream is To form; (14) control means for controlling the temperature and amount of the feed stream in the distillation column to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the relatively less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) at least one second heat exchange means connected to receive said natural gas stream and cooperate to cool said gas stream under pressure; (2) second expansion means connected to said second heat exchange means to receive said cooled natural gas stream and expand the gas stream to medium pressure; (3) a distillation column connected to receive the expanded cooled natural gas stream, the distillation column causing the stream to be separated into a relatively less volatile fraction containing mostly volatile vapor distillation streams and the heavy hydrocarbon components; (4) vapor extraction means connected to said distillation column to receive a vapor distillation stream from the region of said distillation column below said expanded cooled natural gas stream; (5) third heat exchange means connected to said vapor extraction means to receive said vapor distillation stream and to sufficiently cool the distillation stream to condense at least a portion of the distillation stream; (6) separating means connected to said third heat exchange means to receive said cooled vapor distillation stream and to separate said distillation stream into a vapor stream and a liquid stream; (7) dividing means connected to said dividing means to receive said liquid stream and divide said liquid stream into at least a first portion and a second portion, said dividing means being at a feed position in a region substantially the same as the vapor distillation stream is extracted from Further connected to the distillation column to supply the first portion of the liquid stream as a feed to the distillation column; (8) said distillation column having said dividing portion so as to receive said second portion of said liquid stream such that at least a portion of said expanded cooled natural gas stream is in direct contact with at least a portion of said second portion of said liquid stream in said distillation column; Means are further connected; (9) liquid extraction means connected to said distillation column to receive a liquid distillation stream from said area of said distillation column above said area of said distillation column of said vapor extraction means; (10) fourth heat exchange means connected to said liquid extraction means to receive said liquid distillation stream and heat said distillation stream, said fourth heat exchange means being in said position below said distillation column of said vapor extraction means Is further connected to the distillation column to supply as feed to the distillation column; (11) compounding means connected to said distillation column and said separating means to receive said highly volatile vapor distillation stream and said vapor stream and combine them to form a volatile residual gas fraction containing mostly methane and light components; (12) said first heat exchange means connected to said compounding means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of the gas fraction so that said condensate stream is To form; (13) control means for causing the distillation column to adjust the temperature and amount of the feed stream to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) one or more second heat exchange means connected to receive said natural gas stream and cooperate to cooperate to partially cool the gas stream by sufficiently cooling the gas stream under pressure; (2) first separation means adapted to receive said partially condensed natural gas stream and to separate the gas stream into a first vapor stream and a first liquid stream; (3) second expansion means connected to said first separating means to receive said first vapor stream and expand the vapor stream to medium pressure; (4) third expansion means connected to said first separating means to receive said first liquid stream and expand said liquid stream to medium pressure; (5) a distillation column connected to receive the expanded first vapor stream and the expanded first liquid stream, the distillation column being classified into a relatively less volatile fraction containing mostly the volatile vapor distillation stream and the heavy hydrocarbon component; Causing the stream to separate; (6) vapor extraction means connected to said distillation column to receive a vapor distillation stream from the region of said distillation column below said expanded first vapor stream; (7) third heat exchange means connected to said vapor extraction means to receive said vapor distillation stream and to sufficiently cool the distillation stream to condense at least a portion of the distillation stream; (8) second separation means connected to said third heat exchange means to receive said cooled vapor distillation stream and to separate said distillation stream into a second vapor stream and a second liquid stream; (9) dividing means connected to said second separating means to receive said second liquid stream and divide said liquid stream into at least a first portion and a second portion, said dividing means being in the same region as said vapor distillation stream is extracted Is further connected to the distillation column to supply the first portion of the second liquid stream as a feed to the distillation column at a supply position of; (10) said dividing to receive said second portion of said second liquid stream such that at least a portion of said expanded first vapor stream is in direct contact with at least a portion of said second portion of said second liquid stream of said distillation column The distillation column further connected by means; (11) liquid extraction means connected to the distillation column to receive a liquid distillation stream from the area of the distillation column above the area of the distillation column of the vapor extraction means; (12) fourth heat exchange means connected to said liquid extraction means to receive said liquid distillation stream and heat said distillation stream, said fourth heat exchange means being located at said position below said distillation column of said vapor extraction means; Is further connected to the distillation column to supply as feed to the distillation column; (13) compounding means connected to said distillation column and said separating means to receive said highly volatile vapor distillation stream and said vapor stream and combine to form a volatile residual gas fraction containing mostly methane and light components; (14) said first heat exchange means connected to said compounding means to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of said gas fraction so that said condensate stream is To form; (15) control means for controlling the temperature and amount of the feed stream in the distillation column to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon component is recovered in the less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) at least one second heat exchange means connected to receive said natural gas stream and cooperate to cool said gas stream under pressure; (2) second expansion means connected to said second heat exchange means to receive said cooled natural gas stream and expand the gas stream to medium pressure; (3) a distillation column connected to receive the expanded cooled natural gas stream, the distillation column being divided into a volatile residual gas fraction containing mostly the methane and light components and a relatively less volatile fraction containing most of the heavy hydrocarbon components. To be separated; (4) said first heat exchange means connected to said distillation column to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of the gas fraction so that said condensate stream is To form; (5) control means for causing the distillation column to adjust the temperature and amount of the feed stream such that the overhead temperature of the distillation column is maintained at a temperature where most of the heavy hydrocarbon component is recovered in the relatively less volatile fraction. Apparatus for liquefying natural gas streams. A liquefaction apparatus of a natural gas stream containing methane and heavy hydrocarbon components, The apparatus comprises: (a) one or more first heat exchange means connected to receive the natural gas stream and cooperate to condense at least a portion of the gas under pressure to form a condensed stream; And (b) first expansion means connected to said first heat exchange means to receive said condensed stream and expand the stream at low pressure to form said liquefied natural gas stream, The device, (1) one or more second heat exchange means connected to receive said natural gas stream and cooperate to cooperate to partially cool the gas stream by sufficiently cooling the gas stream under pressure; (2) separating means adapted to receive said partially condensed natural gas stream and to separate the gas stream into a vapor stream and a liquid stream; (3) second expansion means connected to said separation means to receive said vapor stream and expand said vapor stream to medium pressure; (4) third expansion means connected to the separation means to receive the liquid stream and expand the liquid stream to medium pressure; (5) a distillation column connected to receive the expanded vapor stream and the expanded liquid stream, the distillation column being a volatile residual gas fraction containing mostly the methane and light components and a relatively less volatile fraction containing most of the heavy hydrocarbon components. Allowing the stream to separate; (6) said first heat exchange means connected to said distillation column to receive said volatile residual gas fraction, said first heat exchange means cooling said volatile residual gas fraction under pressure to condense at least a portion of the gas fraction so that said condensate stream To form; (7) control means for causing the distillation column to adjust the temperature and amount of the feed stream to maintain the overhead temperature of the distillation column at a temperature where most of the heavy hydrocarbon components are recovered in the less volatile fraction. Apparatus for liquefying natural gas streams. The method according to any one of claims 43, 44, 45, 67, 68, The device, (1) compression means connected to said distillation column to receive said volatile residual gas fraction to compress the gas fraction; (2) said compression means being adapted to receive said compressed volatile residual gas fraction, wherein said compressed volatile residual gas fraction is cooled under pressure to condense at least a portion of said gas fraction to form said condensate stream; And a first heat exchange means. The method of claim 41, wherein The device, (1) compression means connected to said distillation column to receive said volatile residual gas fraction to compress the gas fraction; (2) said first heat exchange means connected to said compression means to receive said compressed volatile residual gas fraction, said first heat exchange means cooling said compressed volatile residual gas fraction under pressure to condense at least a portion of said gas fraction; Allowing the condensate stream to form; (3) being connected to said first heat exchange means to receive said condensation portion and divide said condensation portion into at least two portions to form said condensation stream and said liquid stream, said liquid stream as a top feed of said distillation column. And said dividing means further connected to said distillation column to be sent. The method of claim 42, wherein The device, (1) compression means connected to said distillation column to receive said volatile residual gas fraction to compress the gas fraction; (2) said first heat exchange means connected to said compression means to receive said compressed volatile residual gas fraction, said first heat exchange means cooling said compressed volatile residual gas fraction under pressure to condense at least a portion of said gas fraction; Allowing the condensate stream to form; (3) being connected to said first heat exchange means to receive said condensation portion and divide said condensation portion into at least two portions to form said condensation stream and said second liquid stream, wherein said second liquid stream is connected to said distillation column. And said dividing means further connected to said distillation column to send as a top feed. 47. The method of claim 46 wherein The device, (1) compression means connected to said distillation column to receive said volatile residual gas fraction to compress the gas fraction; (2) said first heat exchange means connected to said compression means to receive said compressed volatile residual gas fraction, said first heat exchange means cooling said compressed volatile residual gas fraction under pressure to condense at least a portion of said gas fraction; Allowing the condensate stream to form; (3) being connected to said first heat exchange means to receive said condensation portion and divide said condensation portion into at least two portions to form said condensation stream and said liquid stream, said liquid stream as a top feed of said distillation column. And said second dividing means further connected to said distillation column to be sent. 49. The method of claim 47 or 48, The device, (1) compression means connected to said distillation column to receive said volatile residual gas fraction to compress the gas fraction; (2) said first heat exchange means connected to said compression means to receive said compressed volatile residual gas fraction, said first heat exchange means cooling said compressed volatile residual gas fraction under pressure to condense at least a portion of said gas fraction; Allowing the condensate stream to form; (3) being connected to said first heat exchange means to receive said condensation portion and divide said condensation portion into at least two portions to form said condensation stream and said second liquid stream, wherein said second liquid stream is connected to said distillation column. And said second dividing means further connected to said distillation column to send as a top feed. The method of claim 49, The device, (1) compression means connected to said distillation column to receive said highly volatile vapor distillation stream and to compress the distillation stream; (2) said combining means connected to said separating means and said compressing means to receive said vapor stream and said compressed highly volatile distillation stream and combine them to form said volatile residual gas fraction containing mostly methane and light components; And liquefied natural gas stream. 51. The method of claim 50, The device, (1) compression means connected to said distillation column to receive said highly volatile vapor distillation stream and to compress the distillation stream; (2) connected to said second separating means and said compressing means to receive said second vapor stream and said compressed highly volatile distillation stream and combine to form said volatile residual gas fraction containing mostly methane and light components; And said compounding means. The method according to any one of claims 51, 52, 55, 56, The device, (1) compression means connected to said distillation column to receive said highly volatile vapor distillation stream and to compress the distillation stream; (2) being connected to said compression means to receive said compressed volatile residual gas fraction, wherein said compressed volatile residual gas fraction is cooled under pressure such that said condensate stream is formed by condensing at least a portion of the gas fraction; And a first heat exchange means. Any one of claims 53, 54, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66 According to claim, The device, (1) compression means connected to said distillation column to receive said highly volatile vapor distillation stream and to compress the distillation stream; (2) being connected to said compression means to receive said compressed volatile residual gas fraction, wherein said compressed volatile residual gas fraction is cooled under pressure such that said condensate stream is formed by condensing at least a portion of the gas fraction; And a first heat exchange means. The method according to any one of claims 43, 44, 45, 67, 68, The device, (1) heating means connected to said distillation column to receive said highly volatile vapor distillation stream and to heat the distillation stream; (2) compression means connected to said heating means to receive said heated highly volatile vapor distillation stream and to compress the distillation stream; (3) being connected to the compression means to receive the compressed heated volatile residual gas fraction, wherein the compressed heated volatile residual gas fraction is cooled under pressure to condense at least a portion of the gas fraction so that the condensate stream is formed. And said first heat exchange means. The method of claim 41, wherein The device, (1) heating means connected to said distillation column to receive said highly volatile vapor distillation stream and to heat the distillation stream; (2) compression means connected to said heating means to receive said heated highly volatile vapor distillation stream and to compress the distillation stream; (3) said first heat exchange means connected to said compression means to receive said compressed heated volatile residual gas fraction, said heat exchange means cooling said compressed heated volatile residual gas fraction under pressure to recover at least a portion of the gas fraction. Condensation; (4) being connected to said first heat exchange means to receive said condensation portion and divide said condensation portion into at least two portions to form said condensation stream and said liquid stream, said liquid stream as the top feed of said distillation column. And said dividing means further connected to said distillation column to be sent. The method of claim 42, wherein The device, (1) heating means connected to said distillation column to receive said highly volatile vapor distillation stream and to heat the distillation stream; (2) compression means connected to said heating means to receive said heated highly volatile vapor distillation stream and to compress the distillation stream; (3) said first heat exchange means connected to said compression means to receive said compressed heated volatile residual gas fraction, said heat exchange means cooling said compressed heated volatile residual gas fraction under pressure to recover at least a portion of the gas fraction. Condensation; (4) being connected to said first heat exchange means to receive said condensation portion and divide said condensation portion into at least two portions to form said condensation stream and said second liquid stream, wherein said second liquid stream is connected to said distillation column. And said dividing means further connected to said distillation column to send as a top feed. 47. The method of claim 46 wherein The device, (1) heating means connected to said distillation column to receive said highly volatile vapor distillation stream and to heat the distillation stream; (2) compression means connected to said heating means to receive said heated highly volatile vapor distillation stream and to compress the distillation stream; (3) said first heat exchange means connected to said compression means to receive said compressed heated volatile residual gas fraction, said heat exchange means cooling said compressed heated volatile residual gas fraction under pressure to recover at least a portion of the gas fraction. Condensation; (4) being connected to said first heat exchange means to receive said condensation portion and divide said condensation portion into at least two portions to form said condensation stream and said liquid stream, said liquid stream as the top feed of said distillation column. And said second dividing means further connected to said distillation column to be sent. 49. The method of claim 47 or 48, The device, (1) heating means connected to said distillation column to receive said highly volatile vapor distillation stream and to heat the distillation stream; (2) compression means connected to said heating means to receive said heated highly volatile vapor distillation stream and to compress the distillation stream; (3) said first heat exchange means connected to said compression means to receive said compressed heated volatile residual gas fraction, said heat exchange means cooling said compressed heated volatile residual gas fraction under pressure to recover at least a portion of the gas fraction. Condensation; (4) being connected to said first heat exchange means to receive said condensation portion and divide said condensation portion into at least two portions to form said condensation stream and said liquid stream, said liquid stream as the top feed of said distillation column. And said second dividing means further connected to said distillation column to be sent. The method of claim 49, The device, (1) heating means connected to said distillation column to receive said highly volatile vapor distillation stream and to heat the distillation stream; (2) compression means connected to said heating means to receive said heated highly volatile vapor distillation stream and to compress the distillation stream; (3) cooling means connected to said compression means to receive said compressed heated volatile vapor distillation stream and cool said distillation stream; (4) said combining means connected to said separating means and said cooling means to receive said vapor stream and said cooled compressed highly volatile distillation stream and combine to form a volatile residual gas fraction containing mostly the methane and light components; And liquefied natural gas stream. 51. The method of claim 50, The device, (1) heating means connected to said distillation column to receive said highly volatile vapor distillation stream and to heat the distillation stream; (2) compression means connected to said heating means to receive said heated highly volatile vapor distillation stream and to compress the distillation stream; (3) cooling means connected to said compression means to receive said compressed heated volatile vapor distillation stream and cool said distillation stream; (4) connected to said second separating means and said cooling means to receive said second vapor stream and said cooled compressed volatile distillation stream and combine them to form a volatile residual gas fraction containing mostly the methane and light components; And said compounding means. The method according to any one of claims 51, 52, 55, 56, (1) heating means connected to said contacting and separating means to receive said volatile residual gas fraction and to heat the gas fraction; (2) compression means connected to said heating means to receive said heated volatile residual gas fraction and to compress the gas fraction; (3) connected to the compression means to receive the compressed heated volatile residual gas fraction, wherein the compressed heated volatile residual gas fraction is cooled under pressure to condense at least a portion of the gas fraction so that the condensate stream is formed. And said first heat exchange means being liquefied. Any one of claims 53, 54, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66 According to claim, (1) heating means connected to the compression means to receive the volatile residual gas fraction and to heat the gas fraction; (2) compression means connected to said heating means to receive said heated volatile residual gas fraction and to compress the gas fraction; (3) connected to the compression means to receive the compressed heated volatile residual gas fraction, wherein the compressed heated volatile residual gas fraction is cooled under pressure to condense at least a portion of the gas fraction so that the condensate stream is formed. And said first heat exchange means being liquefied. Claims 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53 Claims 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 70, 71, 72, 74, 75, 79, 80, 81, 83, 84 The method of claim 1, wherein And the volatile residual gas fraction contains mostly the methane, light and C ₂ components. Claims 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53 Claims 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, Claims 66, 67, 68, 70, 71, 72, 74, 75, 79, 80, 81, 83, 84 The method of claim 1, wherein The volatile residual gas fractionation comprises most of the methane, light component, C ₂ component and C ₃ component. The method of claim 29, And the volatile residual gas fraction contains mostly the methane, light and C ₂ components. The method of claim 30, And the volatile residual gas fraction contains mostly the methane, light and C ₂ components. The method of claim 31, wherein And the volatile residual gas fraction contains mostly the methane, light and C ₂ components. The method of claim 34, wherein And the volatile residual gas fraction contains mostly the methane, light and C ₂ components. 36. The method of claim 35 wherein And the volatile residual gas fraction contains mostly the methane, light and C ₂ components. The method of claim 36, And the volatile residual gas fraction contains mostly the methane, light and C ₂ components. The method of claim 29, The volatile residual gas fractionation comprises most of the methane, light component, C ₂ component and C ₃ component. The method of claim 30, The volatile residual gas fractionation comprises most of the methane, light component, C ₂ component and C ₃ component. The method of claim 31, wherein The volatile residual gas fractionation comprises most of the methane, light component, C ₂ component and C ₃ component. The method of claim 34, wherein The volatile residual gas fractionation comprises most of the methane, light component, C ₂ component and C ₃ component. 36. The method of claim 35 wherein The volatile residual gas fractionation comprises most of the methane, light component, C ₂ component and C ₃ component. The method of claim 36, The volatile residual gas fractionation comprises most of the methane, light component, C ₂ component and C ₃ component. The method of claim 69, wherein And the volatile residual gas fraction contains mostly the methane, light and C ₂ components. The method of claim 73, And the volatile residual gas fraction contains mostly the methane, light and C ₂ components. 77. The method of claim 76, And the volatile residual gas fraction contains mostly the methane, light and C ₂ components. 78. The method of claim 77 wherein And the volatile residual gas fraction contains mostly the methane, light and C ₂ components. The method of claim 78, And the volatile residual gas fraction contains mostly the methane, light and C ₂ components. 83. The method of claim 82, And the volatile residual gas fraction contains mostly the methane, light and C ₂ components. 86. The method of claim 85, And the volatile residual gas fraction contains mostly the methane, light and C ₂ components. 87. The method of claim 86, And the volatile residual gas fraction contains mostly the methane, light and C ₂ components. The method of claim 69, wherein The volatile residual gas fractionation comprises most of the methane, light component, C ₂ component and C ₃ component. The method of claim 73, The volatile residual gas fractionation comprises most of the methane, light component, C ₂ component and C ₃ component. 77. The method of claim 76, The volatile residual gas fractionation comprises most of the methane, light component, C ₂ component and C ₃ component. 78. The method of claim 77 wherein The volatile residual gas fractionation comprises most of the methane, light component, C ₂ component and C ₃ component. The method of claim 78, The volatile residual gas fractionation comprises most of the methane, light component, C ₂ component and C ₃ component. 83. The method of claim 82, The volatile residual gas fractionation comprises most of the methane, light component, C ₂ component and C ₃ component. 86. The method of claim 85, The volatile residual gas fractionation comprises most of the methane, light component, C ₂ component and C ₃ component. 87. The method of claim 86, The volatile residual gas fractionation comprises most of the methane, light component, C ₂ component and C ₃ component.