BRPI1105257B1 - process and apparatus for separating a gaseous stream containing methane, c2 components, c3 components, and heavier hydrocarbon components into a gas fraction of volatile residue and a relatively less volatile fraction that contains a large part of components c2, components c3, and heavier hydrocarbon components or c3 components and heavier hydrocarbon components - Google Patents

Abstract

HYDROCARBON GAS PROCESSING. The invention relates to a process and apparatus for a compact processing assembly for recovering C2 components (or C3 components) and heavier hydrocarbon components from a hydrocarbon gas stream. The gas stream is cooled and divided into first and second streams. The first stream is additionally cooled to condense it considerably completely, expanded to decrease the pressure and supplied as a top feed for an absorbent medium. The second stream is also expanded to decrease pressure and fed to the bottom of the absorbent medium. A stream of distillation vapor from the absorbent medium is heated by cooling the gas stream and the first stream. A stream of liquid distillation from the absorbent medium is fed to a mass and heat transfer medium to heat it and cool its volatile components during the cooling of the gas stream. The absorbent medium and the mass and heat transfer medium are housed in the processing assembly.

Description

BACKGROUND OF THE INVENTION

[001] Ethylene, ethane, propylene propylene and / or heavier hydrocarbons can be recovered from a variety of gases, such as natural gas, refinery gas and synthetic gas streams obtained from materials of other hydrocarbons, such as coal , crude oil, naphtha, shale oil, tar sands and lignite. Natural gas normally has a higher proportion of methane and ethane, that is, methane and ethane together make up at least 50 mole percent of the gas. The gas also contains relatively smaller amounts of heavier hydrocarbons, such as propane, butanes, penanes and the like, as well as hydrogen, nitrogen, carbon dioxide and other gases.

[002] The present invention is generally related to the recovery of heavier ethylene, ethane, propylene, propane and hydrocarbons from gas streams. A typical analysis of a gas stream to be processed according to this invention would be, approximately mol%, 90.0% methane, 4.0% ethane and other C2 components, 1.7% propane and others C3 components, 0.3% isobutane, 0.5% normal butane and 0.8% pentanes, with the balance made of nitrogen and carbon dioxide. Sulfur-containing gases are also present at times.

[003] Cyclical fluctuations historically in natural gas prices and their natural resources of liquefied gas (NGL) constituents have sometimes reduced the incremental value of ethane, ethylene, propane, propylene and heavier components, such as liquid products. This has resulted in a demand for processes that can provide a more efficient recovery of these products and for processes that can provide efficient recoveries with less capital investment. Processes available for separating these materials include those based on gas cooling and cooling, oil absorption and refrigerated oil absorption. In addition, cryogenic processes have become popular due to the availability of economical equipment that produces energy while expanding and extracting heat from the gas being processed. Depending on the pressure of the gas source, the richness (ethane, ethylene and heavier hydrocarbon content) of the gas and the desired end products, each of these processes, or a combination of them, can be employed.

[004] The cryogenic expansion process is now generally preferred for recovery of natural gas liquids, as it provides maximum simplicity and ease of startup, operational flexibility, good efficiency, safety and good reliability. U.S. Patent Nos. 3,292,380; 4,061,481; 4,140,504; 4,157,904; 4,171,964; 4,185,978; 4,251,249; 4,278,457; 4,519,824; 4,617,039; 4,687,499; 4,689,063; 4,690,702; 4,854,955; 4,869,740; 4,889,545; 5,275,005; 5,555,748; 5,566,554; 5,568,737; 5,771,712; 5,799,507; 5,881,569; 5,890,378; 5,983,664; 6,182,469; 6,578,379; 6,712,880; 6,915,662; 7,191,617; 7,219,513; reference to U.S. Patent No. 33,408; and copending orders No. 11 / 430,412; 11 / 839,693; 11 / 971,491; 12 / 206,230; 12 / 689,616; 12 / 717,394; 12 / 750,862; 12 / 772,472; 12 / 781,259; 12 / 868,993; 12 / 869,007; 12 / 869,139; and 12 / 979,563 describe relevant processes (although the description of the present invention, in some cases, is based on processing conditions other than those described in the aforementioned U.S. Patents).

[005] In a typical cryogenic expansion recovery process, a feed gas stream under pressure is cooled by heat exchange with other process streams and / or external refrigeration sources, such as a propane compression refrigeration system . As the gas is cooled, the liquids can be condensed and collected in one or more separators as high pressure liquids containing some of the desired C2 + components. Depending on the richness of the gas and the amount of liquids formed, the high pressure liquids can be expanded to a lower and fractionated pressure. The vaporization that occurs during the expansion of the liquids results in the additional cooling of the chain. Under certain conditions, pre-cooling of high pressure liquids before expansion may be desirable in order to further reduce the temperature resulting from the expansion. The expanded stream, which comprises a mixture of liquid and steam, is fractionated in a distillation column (demethanizer or deethanizer). In the column, the chilled expansion stream (s) is (are) distilled to separate residual methane, nitrogen and other volatile gases such as vapor overhead from the desired C2 components, C3 components and heavier hydrocarbons, as a product of the lower liquid, or in separate residual methane, C2 components, nitrogen and other volatile gases as vapor at the top from the desired C3 components, and heavier hydrocarbon components, as a product of the lower liquid.

[006] If the supply gas is not fully condensed (normally it is not), the remaining steam from partial condensation can be divided into two streams. A portion of the steam is passed through an expansion machine or working motor, or an expansion valve, for a lower pressure in which the additional liquids are condensed as a result of further cooling the current. The pressure after expansion is essentially the same as the pressure at which the distillation column is operated. The combined liquid vapor phases resulting from the expansion are provided with power to the column.

[007] The remaining part of the steam is cooled to considerable condensation by heat exchange with other process currents, for example, cold fractionation tower at the top. Some or all of the high pressure liquids can be combined with this part of steam before cooling. The resulting cooling stream is then expanded through an appropriate expansion device, such as an expansion valve, to the pressure at which the demethanizer is operated. During the expansion, some of the liquid will evaporate, resulting in the total current cooling. The expanded current is then supplied with the upper supply to the demethanizer. Typically, the steam portion of the expanded stream and the steam from the demonizer at the top combine in an upper section of the separator in the fractionation tower as the residual methane product gas. Alternatively, the chilled and expanded stream can be supplied to a separator to provide steam and liquid streams. The steam is combined with the tower at the top and the liquid is supplied to the column as an upper column feed.

[008] The present invention uses a new way of performing the various steps described above more efficiently and using fewer pieces of equipment. This is achieved by combining what have hitherto been items of individual equipment in a common housing, thus reducing the land space required for the processing plant and reducing the capital cost of the facilities. Surprisingly, depositors have found that the more compact arrangement also significantly reduces the energy consumption required to achieve a given level of recovery, thereby increasing the efficiency of the process and reducing the operational cost of the installation. In addition, the more compact arrangement also eliminates much of the piping used to interconnect individual equipment items in traditional plant designs, further reducing the cost of capital and also eliminating the associated flanged pipe connections. Since piping flanges are a potential source of hydrocarbon spills (which are volatile organic compounds, VOCs, which contribute to greenhouse gases and can also be precursors of ozone formation in the atmosphere), eliminating these flanges reduces the potential for atmospheric emissions that can harm the environment.

[009] In accordance with the present invention, it has been found that C2 recoveries greater than 88% can be obtained. Likewise, in cases where the recovery of C2 components is not desired, C3 recoveries greater than 93% can be maintained. Furthermore, the present invention makes it essentially 100% possible to separate methane (or C2 components) and lighter components from C2 components (or C3 components) and heavier components at lower power requirements compared to the state technique, maintaining the same level of recovery. The present invention, although applicable at low pressures and higher temperatures, is particularly advantageous when processing feed gases in the range of 400-1500 psia [2,758 to 10,342 kPa (a)] or higher in conditions requiring high temperatures in the NGL recovery column 50 ° F [46 ° C] or cooler.

[010] For a better understanding of the present invention, reference is made to the following examples and drawings. Referring to the drawings:

[011] Figure 1 is a flow diagram of a prior art natural gas processing plant according to U.S. Patent No. 4,157,904;

[012] Figure 2 is a flow diagram of a natural gas processing plant in accordance with the present invention; and

[013] Figures 3 to 17 are flow diagrams illustrating the alternative means of applying the present invention to a natural gas stream.

[014] In the following explanation of the figures above, tables are provided summarizing the flow rates calculated for the conditions of the representative process. In the tables that appear here, the values for flow rates (in moles per hour) have been rounded up to the nearest whole number for convenience. The total flow rates shown in the tables include all hydrocarbon components and therefore are generally not greater than the sum of the flow rates for the hydrocarbon components. The temperatures indicated are approximate values rounded to the nearest degree. It should also be noted that the design process calculations performed in order to compare the processes described in the figures are based on the assumption of no heat leakage from (or to) the environment (or from) the process. The quality of the insulation materials available on the market makes this a very reasonable assumption and is usually made by those skilled in the art.

[015] For convenience, process parameters are reported in both traditional British units and in Système International d'Unités (SI) units. The molar flows given in the tables can be interpreted as moles-pound per hour, or moles-kg per hour. The energy consumptions reported as horsepower (HP) and / or thousands of British thermal units per hour (MBTU / Hr) correspond to the molar flows indicated in moles-pounds per hour. The energy consumptions reported as kilowatts (kW) correspond to the molar flow rates indicated in moles-kg per hour.

DESCRIPTION OF THE STATE OF THE TECHNIQUE

[016] Figure 1 is a process flow diagram showing the design of a processing plant to recover C2 + components from natural gas using the state of the art according to Pat. U.S. No. 4,157,904. In this process simulation, the intake gas enters the plant at 101 ° F [39 ° C] and 915 psia [6,307 kPa (a)] as current 31. If the intake gas contains a concentration of sulfur compounds, which would prevent When product streams meet specifications, sulfur compounds are removed by proper pre-treatment of the feed gas (not shown). In addition, the feed stream is generally dehydrated to prevent the formation of hydrates (ice) in cryogenic conditions. Solid desiccant has typically been used for this purpose.

[017] The supply stream 31 is divided into two parts, stream 32 and 33. Stream 32 is cooled to 31 ° F [35 ° C] in heat exchanger 10 by heat exchange with the cooled residual gas (stream 41a ), while the current 33 is cooled to 37 ° F [38 ° C] in the heat exchanger 11 by heat exchange with liquids from the 43 ° F [6 ° C] demethanizer reheat exchanger (current 43) and liquids of the side reheat exchanger at -47 ° F [-44 ° C] (current 42). Streams 32a and 33a recombine to form stream 31a, which enters the separator 12 to 33 ° F [36 ° C] and 893 psia [6,155 kPa (a)], where the steam (stream 34) is separated from the condensed liquid (current 35).

[018] The steam (stream 34) of the separator 12 is divided into two streams, 36 and 39. Stream 36, containing about 32% of the total steam, is combined with the liquid from the separator (stream 35), and the stream combined 38 passes through the heat exchanger 13 in relation to the heat exchange with the cold residual gas (stream 41), where it is cooled to considerable condensation. The resulting considerably condensed current 38a at 131 ° F [90 ° C] is then expanded in flash through the expansion valve 14 at the operating pressure (approximately 410 psia [2,827 kPa (a)]) of the fractionation tower 18. During expansion, part of the stream is vaporized, resulting in the total stream cooling. In the process illustrated in figure 1, the expanded current 38b leaving the expansion valve 14 reaches a temperature of 137 ° F [94 ° C] and is supplied to the separator section 18a in the upper region of the fractionation tower 18. The liquids separated in it, they become the upper feed for the demobilization section 18b.

[019] The remaining 68% of the separator vapor 12 (chain 39) enters a working expansion machine 15 in which mechanical energy is extracted from this part of the high pressure supply. The machine 15 expands steam considerably isoentropically to the operating pressure of the tower, with the working expansion cooling the expanded current 39a to a temperature of approximately 97 ° F [72 ° C]. Typical commercially available expanders are capable of recovering on the order of 80 to 85% of the theoretically available work in an ideal isentropic expansion. The recovered work is often used to drive a centrifugal compressor (like item 16) that can be used to recompress the residual gas (current 41b), for example. The partially condensed expanded current 39a is subsequently supplied as supply to the fractionation tower 18 at a midpoint of the supply column.

[020] The demethanizer in tower 18 is a conventional distillation column containing a plurality of vertically spaced trays, one or more filling beds, or some combination of trays and packaging. As is usually the case in natural gas processing plants, the fractionation tower can consist of two sections. The upper section 18a is a separator where the upper partially vaporized feed is divided into its respective liquid and vapor parts, and in which the steam rising from the lower distillation or demethanization section 18b is combined with the steam part of the upper feed for form the steam at the top of a cold demethanizer (chain 41) that leaves the top of the tower at - 136 ° F [-93 ° C]. The lower demethanization section 18b contains the trays and / or packaging and provides the necessary contact between the liquids that fall and the vapors that rise. The demethanisation section 18b also includes reheat exchangers (such as the reheat exchanger and side reheat exchanger described above) that heat and vaporize a portion of the liquids that flow down the column to supply the vapors that flow into the column. up the column to remove the liquid product, chain 44, of methane and lighter components.

[021] The liquid product stream 44 exits the bottom of the tor at 65 ° F [19 ° C], based on a typical specification of a 0.010: 1 methane to ethane ratio on a mass basis in the product Final. The residual gas (vapor stream at the top of the demethanizer 41) passes against the feed gas stream entering the heat exchanger 13, where it is heated to 44 ° F [42 ° C] (current 41a) and the heat exchanger 10, where it is heated to 96 ° F [36 ° C] (current 41b). The residual gas is then re-compressed in two stages. The first stage is the compressor 16 driven by the expansion machine 15. The second stage is the compressor 20 driven by a complementary energy source that compresses the residual gas (current 41d) for the line pressure. After cooling to 120 ° F [49 ° C] in the discharge chiller 21, the residual gas product (current 41e) flows into the pipeline at 915 psia [6,307 kPa (a)], enough to meet line requirements (usually in the order of the inlet pressure).

[022] A summary of flow rates and energy consumption for the process illustrated in figure 1 is shown in the following table: Table I

DESCRIPTION OF THE INVENTION

[023] Figure 2 illustrates a flow diagram of a process in accordance with the present invention. The composition of the feed gas and the conditions considered in the process shown in figure 2 are the same as in figure 1. Thus, the process of figure 2 can be compared with that of figure 1 to illustrate the advantages of the present invention.

[024] In the simulation of the process in figure 2, the intake gas enters the plant as stream 31 and is divided into two parts, streams 32 and 33. The first part, stream 32, enters a heat exchange medium at the upper region of the cooling supply section 118a within the processing assembly 118. This heat exchange medium may consist of a tube and burr heat exchanger, a plate-type heat exchanger, a plate heat exchanger welded aluminum, or other type of heat transfer device, including multi-pass and / or multiservice heat exchangers. The heat exchange medium is configured to provide heat exchange between the stream 32 flowing through a passage of the heat exchange medium and a distillation vapor stream arising from the separator section 118b within the processing assembly 118 which has been heated in a heat exchange medium in the lower region of the feed cooling section 118a. Stream 32 is cooled while further heating the distillation vapor stream, with stream 32a leaving the heat exchange medium at -26 ° F [-32 ° C].

[025] The second part, stream 33, enters a heat and mass transfer medium in the demethanization section 118d within the processing assembly 118. This heat and mass transfer medium can also be composed of a heat exchanger tube and burr type, a plate type heat exchanger, a welded aluminum heat exchanger, or other type of heat transfer device, including multipass and / or multiservice heat exchangers. The heat and mass transfer medium is configured to provide heat exchange between the stream 33 flowing through a passage of the heat and mass transfer medium and a stream of the distillation liquid flowing down from the absorption section. 118c within the processing assembly 118, so that the stream 33 is cooled while heating the stream of the distillation liquid, cooling the stream 33a to 38 ° F [39 ° C] before leaving the heat and mass transfer medium. As the stream of the distillation liquid is heated, a portion of it is vaporized to form vapors that rise as the remaining liquid continues to flow downward through the heat and mass transfer medium. The heat and mass transfer medium provides permanent contact between the vapors and the stream of the distillation liquid, so that it also works to provide mass transfer between the vapor and the liquid phases, drawing the stream from the liquid product 44 of methane. and lighter components.

[026] Currents 32a and 33a recombine to form current 31a, which enters the separator section 118e within the processing set 118 at 30 ° F [34 ° C] and 898 psia and [6,189 kPa (a)] , when the steam (stream 34) is then separated from the condensed liquid (stream 35). The separator section 118e has an internal head or other means for dividing it from the demethanization section 118d, so that the two sections within the processing assembly 118 can operate at different pressures.

[027] The steam (stream 34) of the separator section 118e is divided into two streams, 36 and 39. Stream 36, containing about 32% of the total steam, is combined with the separated liquid (stream 35, via current 37) and the combined current 38 enters a heat exchange medium in the lower region of the supply cooling section 118a within the processing assembly 118. This heat exchange medium may also be composed of a heat exchanger tube and burr type, a plate type heat exchanger, a welded aluminum heat exchanger, or other type of heat transfer device, including multipass and / or multiservice heat exchangers. The heat exchange medium is configured to provide heat exchange between the current 38 flowing through a passage of the heat exchange medium and the distillation vapor stream arising from the separator section 118b, so that the current 38 it is cooled down to considerable condensation, while heating the steam distillation stream.

[028] The resulting considerably condensed current 38a at 130 ° F [90 ° C] is then expanded in flash through the expansion valve 14 at the operating pressure (approximately 415 psia [2,861 kPa (a)]) of the absorption section 118c (an absorption medium) inside the processing assembly 118. During expansion, a portion of the stream is vaporized, resulting in the total stream being cooled. In the process illustrated in figure 2, the expanded current 38b leaving the expansion valve 14 reaches a temperature of -136 ° F [94 ° C] and is supplied to the separator section 118b within the processing assembly 118. The separated liquids there they are directed to the absorption section 118c, while the remaining vapors combine with the vapors rising from the absorption section 118c to form the distillation vapor stream which is heated in the cooling section 118a.

[029] The remaining 68% of the steam from the separator section 118e (chain 39) enters a working expansion machine 15 in which mechanical energy is extracted from this part of the high pressure supply. The machine 15 expands the steam considerably isoentropically to the operating pressure of the absorption section 118c, with the working expansion cooling the expanded current 39a to a temperature of approximately 94 ° F [70 ° C]. The partially condensed expanded stream 39a is subsequently supplied as power to the lower region of the absorption section 118c within the processing assembly 118.

[030] The absorption section 118c contains a plurality of vertically spaced banjas, one or more filling beds, or some combination of trays and packages. The trays and / or packaging in the absorption section 118c provide the necessary contact between the rising vapors and the cold liquid that descends. The liquid portion of the expanded stream 39a mixes with liquids that descend from the absorption section 118c and the combined liquid continues to descend in the demethanization section 118d. The vapors arising from the demethanization section 118d combine with the vapor part of the expanded stream 39a and rise through the absorption section 118c, to be contacted with the cold liquid that descends, to condense and absorb the components C2, components C3 and the heavier components of these vapors.

[031] The distillation liquid that flows downward from the heat and mass transfer medium in the demethanization section 118d within the processing assembly 118 has been removed from methane and lighter components. The resulting liquid product (stream 44) leaves the lower region of the demethanization section 118d and leaves the processing set 118 at 67 ° F [20 ° C]. The distillation vapor stream that rises from the separator section 118b is heated in the supply cooling section 118a, as it provides cooling for streams 32 and 38, as previously described, and the resulting residual gas stream 41 leaves the assembly 118 to 96 ° F [36 ° C]. The residual gas is then re-compressed in two stages, the compressor 16 driven by the expansion machine 15 and the compressor 20 driven by a supplementary energy source. After stream 41b is cooled to 120 ° F [49 ° C] in the discharge chiller 21, the residual gas product (stream 41c) flows into the 915 psia [6,307 kPa (a)] pipeline.

[032] A summary of flow rates and energy consumption for the process illustrated in figure 2 is presented in the following table: Table II

[033] A comparison of Tables I and II shows that the present invention essentially supports the same recoveries as the state of the art. However, a further comparison of Tables I and II shows that product yields were obtained using significantly less energy than the state of the art. In terms of recovery efficiency (defined by the amount of ethane recovered per unit of energy), the present invention represents an improvement of about 7% over the state of the art of the process of figure 1.

[034] The improvement in recovery efficiency provided by the present invention in relation to the state of the art of the process of figure 1 is mainly due to two factors. First, the compact arrangement of the heat exchange medium in the supply cooling section 118a and the heat and mass transfer medium in the de-metalization section 118d in the processing assembly 118 eliminates the pressure drop imposed by the interconnecting piping found in conventional processing plants. The result is that the portion of the feed gas flowing into the expansion machine 15 is at a higher pressure for the present invention compared to the state of the art, allowing the expansion machine 15 in the present invention to produce so much energy at a higher pressure. output as the expansion machine 15 in the state of the art can produce at a lower outlet pressure. Thus, the absorption section 118c in the processing assembly 118 of the present invention can operate at a higher pressure than the fractionation column 18 of the prior art, maintaining the same level of recovery. This higher operating pressure, in addition to the reduction in pressure drop for the residual gas due to the elimination of the interconnection piping, results in a significantly higher pressure for the residual gas entering the compressor 20, thus reducing the energy required by the present invention. to restore the residual gas to the pipeline pressure.

[035] Second, use the heat and mass transfer medium in the demethanization section 118d to simultaneously heat the distillation liquid that leaves the absorption section 118c while allowing the resulting vapors to come in contact with the liquid and removing their volatile components is more efficient than using a conventional distillation column with external reheating exchangers. The volatile components are removed from the liquid continuously, reducing the concentration of the volatile components in the vapors more quickly and thus improving the removal efficiency for the present invention.

[036] The present invention offers two other advantages in relation to the state of the art besides the increase in processing efficiency. First, the compact arrangement of the processing set 118 of the present invention replaces five different equipment items in the state of the art (heat exchangers 10, 11 and 13; separator 12; and fractionation tower 18, in FIG 1) with a single item of equipment (processing set 118, in figure 2). This reduces space requirements and eliminates interconnection piping, reducing the capital cost of a processing plant using the present invention in relation to the state of the art. Second, the elimination of the interconnecting pipeline means that a processing plant using the present invention has far fewer flanged connections compared to the state of the art, reducing the number of potential sources of leakage in the plant. Hydrocarbons are volatile organic compounds (VOCs), some of which are classified as greenhouse gases and some of which can be precursors of ozone formation in the atmosphere, which means that the present invention reduces the potential for atmospheric emissions that can harm the environment. Other Modalities

[037] Some circumstances may favor the elimination of the supply cooling section 118a from the processing assembly 118 and the use of a heat exchange medium external to the processing assembly for the supply cooling, such as the heat exchanger 10 shown in figures 10 to 17. This arrangement allows processing set 118 to be smaller, which can reduce the overall cost of the plant and / or shorten the manufacturing schedule in some cases. Note that in all cases the heat exchanger 10 is representative of a series of individual heat exchangers, or a single multipass heat exchanger, or any combination of these. Each heat exchanger can consist of a tube and burr heat exchanger, a plate-type heat exchanger, a welded aluminum heat exchanger, or other type of heat transfer device, including multipass heat exchangers and / or multiservice.

[038] Some circumstances may favor the supply of the liquid stream 35 directly to the lower region of the absorption section 118c through the stream 40, as shown in figures 2, 4, 6, 8, 10, 12, 14 and 16. In these cases, an appropriate expansion device (such as expansion valve 17) is used to expand the liquid to the operating pressure of the absorption section 118c and the resulting expanded liquid stream 40a is supplied as feed to the lower region of the section absorption 118c (as shown by the dashed lines). Some circumstances may favor the combination of part of the liquid stream 35 (stream 37) with the steam in stream 36 (FIGS. 2, 6, 10 and 14) or with the second cooled part 33a (FIGS. 4, 8, 12 and 16) to form the combined stream 38 and route the remainder of the liquid stream 35 to the lower region of the absorption section 118c through streams 40 / 40a. Some circumstances may favor the combination of the expanded liquid stream 40a with the expanded stream 39a (FIGS. 2, 6, 10 and 14) or the expanded stream 34a (FIGS. 4, 8, 12 and 16) and, thereafter, the supply of the combined current with the lower region of the absorption section 118c as a single supply.

[039] If the feed gas is richer, the amount of liquid separated in the stream 35 may be large enough to favor the placement of an additional mass transfer zone in the demethanization section 118d between the expanded stream 39a and the expanded liquid stream 40a, as shown in figures 3, 7, 11 and 15, or between the expanded stream 34a and the expanded liquid stream 40a, as shown in figures 5, 9, 13 and 17. In such cases, the heat and mass transfer medium in the demethanization section 118d can be configured in upper and lower parts, so that the expanded liquid stream 40a can be introduced between the two parts. As shown by the dashed lines, some circumstances may favor the combination of a part of the liquid stream 35 (stream 37) with the steam in stream 36 (FIGS. 3, 7, 11 and 15) or with the second cooled part 33a (FIGS. 5, 9, 13 and 17) to form the combined stream 38, while the remainder of the liquid stream 35 (stream 40) is expanded at the lowest pressure and supplied between the upper and lower parts of the heat transfer medium and mass in the demethanization section 118d as the current 40a.

[040] Some circumstances may favor the non-combination of the first and second chilled parts (chains 32a and 33a), as shown in figures 4, 5, 8, 9, 12, 13, 16 and 17. In these cases, only the first cooled part 32a is directed to the section of separator 118e within processing assembly 118 (FIGS. 4, 5, 12 and 13) or separator 12 (FIGS. 8, 9, 16 and 17) where the steam (current) 34) is separated from the condensed liquid (stream 35). The steam stream 34 enters the working expansion machine 15 and is expanded considerably isoentropically to the operating pressure of the absorption section 118c, whereby the expanded stream 34a is supplied as feed to the lower absorption region 118c within the processing assembly 118. The second cooled part 33a is combined with the separated liquid (stream 35, via stream 37) and the combined stream 38 is directed to the heat exchange medium in the lower region of the supply cooling section 118a within the assembly process 118 and cooled to considerable condensation. The considerably condensed current 38a is expanded in flash through the expansion valve 14 at the operating pressure of the absorption section 118c, whereby the expanded current 38b is supplied to the separator section 118b within the processing assembly 118. Some circumstances may favor the combination of only one part (stream 37) of liquid stream 35 with the second cooled part 33a, with the remaining part (stream 40) supplied to the lower region of absorption section 118c via expansion valve 17. Other circumstances may favor the sending the entire liquid stream 35 to the lower region of the absorption section 118c through the expansion valve 17.

[041] In some circumstances, it may be advantageous to use an external separating container to separate the cooled feed stream 31a or the first cooled part 32a, instead of including the separator section 118e in the processing assembly 118. As shown in figures 6 , 7, 14 and 15, separator 12 can be used to separate the cooled feed stream 31a into vapor stream 34 and liquid stream 35. Likewise, as shown in figures 8, 9, 16 and 17, the separator 12 can be used to separate the first cooled part 32a in a stream of steam stream 34 and a stream of liquid 35.

[042] Depending on the heaviest amount of hydrocarbons in the feed gas and the pressure of the feed gas, the chilled feed current 31a that enters the separator section 118 and figures 2, 3, 10 and 11 or the separator 12 in figures 6, 7, 14 and 15 (or the first cooled part 32a entering the section of separator 118e in figures 4, 5, 12 and 13 or in separator 12 of figures 8, 9, 16 and 17) cannot contain no liquid (because it is above its dew point, or because it is above its critical pressure). In these cases, there is no liquid stream 35 and 37 (as shown by the dashed lines), therefore, only vapor from the section of separator 118e in stream 36 (FIGS. 2, 3, 10 and 11), the vapor from separator 12 in the chain 36 (FIGS. 6, 7, 14 and 15), or the second cooled part 33a (FIGS. 4, 5, 8, 9, 12, 13, 16 and 17) flows to chain 38 to become the expanded chain considerably condensed 38b provided for separator section 118b in processing assembly 118. Under these circumstances, separator section 118e in processing assembly 118 (FIGS. 2 to 5 and 10 to 13) or separator 12 (FIGS. 6 to 9 and 14 to 17) may not be required.

[043] Gas supply conditions, plant size, available equipment, or other factors may indicate that the elimination of the working expansion machine 15, or the replacement with an alternative expansion device (such as an expansion valve) , it's viable. Although the expansion of individual currents is portrayed in particular expansion devices, alternative expansion media can be employed whenever necessary. For example, working conditions may justify expanding the considerably condensed portion of the supply current (current 38a).

[044] According to the present invention, the use of external refrigeration to complement the refrigeration available for the inlet gas from the distillation vapor and liquid streams can be employed, especially in the case of a rich inlet gas. In such cases, a heat and mass transfer medium can be included in the separator section 118e (or a gas collection medium in cases where the cooled feed stream 31a or the first cooled part 32a does not contain liquid), as shown by the dashed lines in figures 2 to 5 and 10 to 13, or a heat and mass transfer medium can be included in the separator 12, as shown by the dashed lines in figures 6 to 9 and 14 to 17. This heat transfer medium and mass can consist of a tube and burr heat exchanger, a plate-type heat exchanger, a welded aluminum heat exchanger, or other type of heat transfer device, including multi-pass heat exchangers and / or multiservice. The heat and mass transfer medium is configured to provide heat exchange between a refrigerant stream (e.g., propane) that flows through a passage of the heat and mass transfer medium and the vapor stream part 31a (FIGS. 2, 3, 6, 7, 10, 11, 14 and 15) or chain 32a (FIGS. 4, 5, 8, 9, 12, 13, 16 and 17) that flows upwards, so that the refrigerant cools steam further condenses the additional liquid, which descends to become the liquid removed in stream 35. Alternatively, conventional gas fillers could be used to cool stream 32a, stream 33a and / or stream 31a with refrigerant before whether chain 31a enters separator section 118e (FIGS. 2, 3, 10 and 11) or separator 12 (FIGS. 6, 7, 14 and 15) or whether chain 32a enters separator section 118e (FIGS. 4, 5, 12 and 13) or in the separator 12 (FIGS. 8, 9, 16 and 17).

[045] Depending on the temperature and richness of the supply gas and the amount of C2 components to be recovered in the liquid product stream 44, there may not be enough heating available from the stream 33 to cause the liquid leaving the 118d demethanization section meets product specifications. In such cases, the heat and mass transfer medium in the demethanization section 118d may include provisions for providing supplementary heating with heating medium, as shown by the dashed lines in figures 2 to 17. Alternatively, another heat and mass transfer medium may be included in the lower region of the demethanization section 118d to provide supplemental heating, or the stream 33 can be heated with heating medium before being supplied to the heat and mass transfer medium in the demethanization section 118d.

[046] Depending on the type of heat transfer devices chosen for heat exchange through the upper and lower regions of the supply cooling section 118a, it may be possible to combine these heat exchange means in a single heat exchanger. multipass and / or multiservice heat transfer. In these cases, the multipass and / or multiservice heat transfer device will include the appropriate means for the distribution, segregation and collection of the stream 32, stream 38 and the steam distillation stream, in order to perform the cooling and desired heating.

[047] Some circumstances may favor the provision of additional mass transfer in the upper region of the demethanization section 118d. In these cases, a mass transfer medium can be located below where the expanded stream 39a (FIGS. 2, 3, 6, 7, 10, 11, 14 and 15) or the expanded stream 34a (FIGS. 4, 5, 8, 9, 12, 13, 16 and 17) enters the lower region of the absorption section 118c and above where the second cooled part 33a leaves the heat and mass transfer medium in the demethanization section 118d.

[048] A less preferred option for the modalities of figures 2, 3, 6, 7, 10, 11, 14 and 15 of the present invention is to provide a separating container for the first cooled part 32a, a separating container for the second cooled part 33a, combining the separate vapor streams in it to form the vapor stream 34, and combining the separate liquid streams in it to form the liquid stream 35. Another less preferred option for the present invention is the cooling stream 37 in a separate heat exchange medium within the supply cooling section 118a in figures 2, 3, 4, 5, 6, 7, 8 and 9 or a separate passage in the heat exchanger 10 in figures 10 , 11, 12, 13, 14, 15, 16 and 17 (instead of combining chain 37 with chain 36 or chain 33a to form combined chain 38), expanding the cooled chain in a separate expansion device, and supplying the expanded current to an intermediate region in the absorption section 118 ç.

[049] It will be recognized that the relative amount of feed found in each split of the split steam feed will depend on several factors, including gas pressure, feed gas composition, amount of heat that can be economically extracted from the feed and amount of available power. More feeding above the absorption section 118c can increase recovery, while decreasing the energy recovered from the expander and thus increasing the recompression power requirements. Increasing the feed below the absorption section 118c reduces energy consumption, but can also reduce product recovery.

[050] The present invention provides a better recovery of C2 components, C3 components and heavier hydrocarbon components or of C3 components and heavier hydrocarbon components by the amount of utility consumption required to operate the process. An improvement in the utility consumption required to operate the process may appear in the form of reduced energy requirements for compression or recompression, reduced energy requirements for external cooling, reduced energy requirements for supplementary heating, or a combination of these.

[051] Although what are believed to be preferred embodiments of the invention have been described, those skilled in the art will recognize that other modifications can be made, for example, to adapt the invention to various conditions, types of food, or other requirements, without departing from the spirit of the present invention, as defined by the following claims.

Claims (26)

1. Process for separating a gas stream (31) containing methane, C2 components, C3 components, and heavier hydrocarbon components into a gas fraction of volatile residue (41d) and a relatively less volatile fraction (44) that contains a a large part of the C2 components, C3 components, and heavier hydrocarbon components or the C3 components and heavier hydrocarbon components, characterized by the fact that (i) the gas stream (31) is divided into first (32) and is - second (33) parts; (ii) the first part (32) is cooled (10); (iii) the second part (33) is cooled (118d); (iv) the first cooled part (32a) is combined with a second cooled part (33a) to form a stream of cooled gas (31a, 34); (v) the stream of cooled gas (31a, 34) is divided into first (36) and second (39) streams; (vi) the first stream (36) is cooled (10) to completely condense considerably (38a) and is subsequently expanded (14) to decrease the pressure by which it is cooled even more (38b); (vii) the first stream of refrigerated gas is provided as an upper feed (38b) for an absorption medium (118c) housed in a processing assembly (118); (viii) the second stream (39) is expanded (15) to decrease the pressure and is provided as a lower feed (39a) for the absorption medium (118c); (ix) a stream of distillation vapor (41) is collected from an upper region of the absorption medium (118c) and heated in one or more heat exchange means (10), thus providing at least part of the steps cooling (2) and (6) and, subsequently, discharging the heated distillation steam stream (41a) as the fraction of volatile waste gas; (x) a stream of distillation liquid is collected from a lower region of the absorbent medium (118c) and heated in a mass and heat transfer medium (118d) housed in the assembly (118), to provide at least one part of the cooling of step (3) while removing the most volatile components from the distillation liquid stream and, subsequently, discharging the heated distillation liquid stream and removing it from the processing assembly (118) as a relatively less volatile fraction (44); and (xi) the quantities and temperatures of the feed streams (38b, 39a) for the absorption medium (118c) are effective in maintaining the temperature of the upper region of the absorption medium (118c) at a temperature where the parts major components of the relatively less volatile fraction (44) are recovered. 2. Process according to claim 1, characterized by the fact that (a) the first cooled part (32a) is combined with the second cooled part (33a) to form a partially condensed gas stream (31a ); (b) the partially condensed gas stream (31a) is provided with a separation medium (12) and is separated therein to provide a vapor stream (34) and at least a liquid stream (35); (c) the steam stream (34) is divided into first (36) and second (39) streams; and (d) at least a part (40) of at least one liquid stream (35) is expanded (17) to decrease the pressure and is provided (40a) as a second lower feed for the absorbent medium (118c). Process according to claim 2, characterized by the fact that (a) the first stream (36) is combined with at least part (37) of at least one stream of liquid (35) to form a combined stream (38); (b) the combined stream (38) is cooled to condense considerably completely (38a) and thereafter it is expanded (14) to decrease the pressure through which it is further cooled (38b); (c) the expanded chilled combined stream (38b) is provided as a feed greater than an absorbent medium (118c); (d) any remaining part (40) of at least one liquid stream (35) is expanded (17) to decrease the pressure and is provided (40a) as a second lower feed for the absorbent medium (118c); and (e) the steam distillation stream (41) is heated in one or more heat exchange means (10), so as to provide at least a part of the cooling of steps (2) and (b). 4. Process according to claim 1, characterized by the fact that (a) the first part (32) is cooled (10) and is subsequently expanded (15) to decrease the pressure; (b) the first expanded cooled portion (34a) is supplied as a feed less than an absorbent medium (118c); (c) the second part (33) is cooled (118d, 10) to be considerably condemned completely (38a) and thereafter is exanded (14) to decrease the pressure through which it is additionally cooled ( 38b); (d) the second expanded cooled portion (38b) is provided as a feed superior to the absorbent medium (118c); (e) a stream of distillation vapor (41) is collected from an upper region of the absorbent medium (118c) and heated in one or more heat exchange means (10), to provide at least a part of the cooling of steps (a) and (c) and, (f) the stream of distillation liquid is collected from a lower region of the absorbent medium (118c) and heated in a mass and heat transfer medium (118d) to provide thus, at least a part of the cooling of step (c). 5. Process according to claim 4, characterized by the fact that (a) the first part (32) is cooled (10) enough to partially condense it (32a); (b) the first partially condensed part (32a) is provided with a separation medium (12) and is separated therein to provide a stream of vapor (34) and at least a stream of liquid (35); (c) the vapor stream (34) is expanded (15) to decrease the pressure and is supplied as a first lower feed (34a) to an absorbent medium (118c); and (d) at least a part (40) of the at least one stream of liquid (35) is expanded to decrease the pressure and is provided as an additional bottom feed (40a) to the absorbent medium (118c). 6. Process according to claim 5, characterized by the fact that (i) the second part (33) is cooled (118d) and is subsequently combined with at least a part (37) of at least one liquid stream ( 35) to form a combined stream (38); (ii) the combined current (38) is cooled (10) to condemn itself considerably completely (38a) and thereafter it is expanded (14) to decrease the pressure through which it is further cooled (38b) ; (iii) the expanded chilled combined stream (38b) is provided as a feed superior to the absorbent medium (118c); (iv) any remaining part (40) of at least one stream of liquid (35) is expanded (17) to decrease the pressure and is provided as an additional bottom feed (40a) for the absorbent medium (118c); and (v) a distillation vapor stream (41) is heated in one or more heat exchange means (10), to thereby provide at least a part of the cooling in steps (a) and (ii). 7. Process, according to claim 2 or 5, characterized by the fact that (a) the mass and heat transfer medium (118d) is organized in upper and lower regions; and (b) at least an expanded portion of at least one liquid stream is supplied (40a) to the processing assembly (118) to insert between the upper and lower regions of the mass and heat transfer medium (118d) . 8. Process, according to claim 3 or 6, characterized by the fact that (a) the mass and heat transfer medium (118d) is organized in upper and lower regions; and (b) any remaining expanded portion of at least one stream of liquid is supplied (40a) to the processing assembly (118) to insert itself between the upper and lower regions of the mass and heat transfer medium (118d). Process according to any one of claims 2, 3, 5, 6, 7 or 8, characterized in that the separation medium (118e) is housed in the processing set (118). 10. Process, according to claim 1, characterized by the fact that (a) a gas collection means (118e) is housed in the processing set (118); (b) an additional mass and heat transfer medium is included within the gas collection medium (118e), the additional mass and heat transfer medium including one or more passages to an external cooling medium; (c) the cooled gas stream (31a) is supplied to the gas collection medium (118e) and directed to the mass and additional heat transfer medium to be further cooled by the external cooling medium; and (d) the additional cooled gas stream (34) is divided into the first (36) and second (39) streams. 11. Process, according to claim 4, characterized by the fact that (a) a gas collection means (118e) is housed in the processing set (118); (b) an additional mass and heat transfer medium is included within the gas collection medium (118e), the additional mass and heat transfer medium including one or more passages to an external cooling medium; (c) the first cooled part (32a) is supplied to the gas collection medium (118e) and directed to the mass and additional heat transfer medium to be further cooled by the external cooling medium; and (d) the first additional chilled part (34) is expanded (15) at the lowest pressure and is subsequently supplied as a lower feed (34a) to the absorbent medium (118c). 12. Process according to any one of claims 2, 3, 5, 6, 7, 8 or 9, characterized by the fact that (a) a mass and additional heat transfer medium is included within the separation (12), the mass and additional heat transfer medium including one or more passages to an external cooling medium; (b) the steam stream is directed to the mass transfer medium and additional heat to be cooled by the external cooling medium to form additional condensate; and (c) the condensate becomes a part of at least one liquid stream (35) separated therein. Process according to any one of claims 1 to 12, characterized in that the mass and heat transfer medium (118d) includes one or more passages to an external heating medium to complement the heating provided by the supply gas (33) for removing the most volatile components from the distillation liquid stream. 14. Apparatus for separating a gas stream (31) containing methane, C2 components, C3 components, and heavier hydrocarbon components into a gas fraction of volatile residue (41d) and a relatively less volatile fraction (44) that contains a a large part of the C2 components, C3 components, and heavier hydrocarbon components or the C3 components and heavier hydrocarbon components, characterized by the fact that it comprises (a) the first means of division to divide the gas stream (31) in first (31) and second (32) parts; (b) the first heat exchange means (10) connected to the first means of division to receive a first part (32) and cool it; (c) mass and heat transfer medium (118d) housed in a processing assembly (118) and connected to the first dividing medium to receive the second part (33) and cool it; (d) combination medium connected to the first heat exchange medium (10) and the mass and heat transfer medium (118d) to receive the first cooled part (32a) and the second cooled part (33a) and form a current cooled gas (31a, 34); (e) the second means of division connected to the means of combination to receive the cooled gas stream (31a, 34) and divide it into first (36) and second (39) streams; (f) second heat exchange medium (10) connected to the second division medium to receive the first current (36) and cool it sufficiently to condense it considerably (38a); (g) the first expansion means (14) connected to the second heat exchange means (10) to receive the first considerably condensed current (38a) and expand it to decrease the pressure (38b); (h) absorbent medium (118c) housed in the processing assembly (118) and connected to the first expansion medium (14) to receive the first expanded chilled stream (38b) as a food superior to it; (i) second expansion medium (15) connected to the second dividing medium to receive the second current (39) and expand it to decrease the pressure (39a), the second expansion medium (15) being further connected to the absorbent medium (118c) to supply the second expanded stream (39a) as a feed below it; (j) vapor collection medium (118b) housed in the processing assembly (118) and connected to the absorbent medium (118c) to receive a stream of distillation vapor from a top region of the absorbent medium; (k) the second heat exchange medium (10) is still connected to the vapor collection medium (118b) to receive the steam distillation stream (41) and heat it, so as to supply at least part cooling of step (6); (l) the first heat exchange medium (10) being additionally connected to the second heat exchange medium (10) to receive the heated distillation vapor stream and further heat it, so as to provide at least a portion cooling of step (2) and, subsequently, discharging the heated distillation vapor stream (41a) as the gas fraction of volatile residue; (m) liquid collection medium housed in the processing assembly (118) and connected to the absorbent medium (118c) to receive a stream of distillation liquid from a lower region of the absorbent medium (118c); (n) the mass and heat transfer medium (118d) being additionally connected to the liquid collection medium to receive the stream of distillation liquid and heat it, thus providing at least a part of the cooling of the step (3 ) while removing the most volatile components from the distillation liquid stream and subsequently discharging the extracted and heated distillation stream from the processing assembly (118) as the relatively less volatile fraction (44); and (o) control medium adapted to regulate the quantities and temperatures of the feed streams (38b, 39a) to the absorbent medium (118c) to maintain the temperature of the upper region of the absorbent medium (118c) at a temperature where the parts major components of the relatively less volatile fraction (44) are recovered. 15. Apparatus according to claim 14, characterized by the fact that (a) the combination means is adapted to receive the first cooled port (32a) and the second cooled port (33a) and form a current partially condensed gas (31a); (b) a separating means (12) is connected to the combining means to receive the partially condensed gas stream (31a) and separate it into a stream of steam (34) and at least a stream of liquid (35); (c) the second dividing medium is connected to the separation medium (12) to receive the vapor stream (34) and divide it into first (36) and second (39) streams; and (d) a third expansion means (17) connected to the separation means (12) to receive at least a part (40) of at least one stream of liquid (35) and expand it to decrease the pressure, the third expansion means (17) being additionally connected to the absorbent means (118c) to provide the expanded liquid stream (40a) as an additional bottom feed for it. 16. Apparatus according to claim 15, characterized by the fact that (a) the additional combining means is connected to the second dividing means and the separating means (12) to receive the first current (36) and at least part of at least one liquid dye (35) and form a combined stream (38); (b) the second heat exchange medium (10) is connected to the additional combination medium to receive the combined current (38) and cool it sufficiently to condense it (38a) considerably; (c) the first expansion means (14) is connected to the second heat exchange means (10) to receive the considerably condensed combined current (38a) and expand it to decrease the pressure (38b); (d) the absorbent medium (118c) is connected to the first expansion medium (14) to receive the expanded chilled combined current (38b) as a feed greater than it; (e) the third expansion means (17) is connected to the separation means (12) to receive any remaining part (40) of at least one stream of liquid (35) and expand it to decrease the pressure (40a), the third expansion means (17) being additionally connected to the absorbent means (118c) to provide the remaining expanded portion of at least one stream of liquid (40a) as an additional bottom feed for it; and (f) the second heat exchange medium (10) being further connected to the vapor collection medium (118b) to receive the distillation steam stream (41) and heat it, so as to provide at least one part of the cooling of step (b). 17. Apparatus according to claim 14, characterized by the fact that (a) the second heat exchange medium (10) is connected to the mass and heat transfer medium (118d) to receive the second cooled part (33a) and cool it further and sufficiently to condense it (38a) considerably; (b) the first expansion means (14) is connected to the second heat exchange means (10) to receive the second considerably condensed part (38a) and expand it to decrease the pressure (38b); (c) the absorbent medium (118c) is connected to the first expansion medium (14) to receive the second expanded cooled portion (38b) as a top feed for it; (d) the second expansion medium (15) is connected to the first heat exchange medium (10) to receive the first cooled part (32a) and expand it to decrease the pressure (34a), the second expansion medium ( 15) being further connected to the absorbent medium (118c) to provide the first expanded chilled part (34a) as a lower feed for it; and (e) the second heat exchange medium (10) being further connected to the vapor collection medium (118) to receive the distillation steam stream (41) and heat it, so as to provide at least one part of the cooling of step (a). 18. Apparatus according to claim 17, characterized by the fact that (a) the first heat exchange medium (10) is adapted to receive the first part (32) and cool it sufficiently to condense it (32a) partially; (b) the separation medium (12) is connected to the first heat exchange medium (10) to receive the first partially condensed part (32a) and separate it in a stream of steam (34) and at least one liquid stream (35); (c) the second expansion medium (15) is connected to the separation medium (12) to receive the steam stream (34) and expand it to decrease the pressure (34a), the second expansion medium (15) being further connected to the absorbent medium (118c) to provide the expanded vapor stream (34a) as a first lower feed for it; and (d) the third expansion means (1) is connected to the separation means (12) to receive at least a part (40) of at least one stream of liquid (35) and expand it to decrease the pressure (40a ), the third expansion means (17) being additionally connected to the absorbent means (118c) to provide at least an expanded portion of at least one liquid stream (40a) as an additional bottom feed for it. 19. Apparatus according to claim 18, characterized by the fact that (a) the combination medium is adapted to be connected to the mass and heat transfer medium (118d) and the separation medium (12) for receiving the second cooled part (33a) and at least a part (37) of at least one stream of liquid (35) and forming a combined stream (38); (b) the second heat exchange medium (10) is connected to the combination medium to receive the combined current (38) and cool it sufficiently to condense it (38a); (c) the first expansion means (14) is connected to the second heat exchange means (10) to receive the considerably condensed combined current (38a) and expand it to decrease the pressure (38b); (d) the absorbent medium (118c) is connected to the first expansion medium (14) to receive the expanded chilled combined current (38b) as a top feed for it; (e) the third expansion means (17) is connected to the separation means (12) to receive any remaining part (40) of at least one stream of liquid (35) and expand it to decrease the pressure (40a), the third expansion means (17) being further connected to the absorbent means (118c) to provide at least a remnant expanded portion of at least one stream of liquid (40a) as an additional bottom feed for it; and (f) the second heat exchange medium (10) being further connected to the vapor collection medium (118b) to receive the distillation steam stream (41) and heat it, so as to provide at least one part of the cooling of step (b). 20. Apparatus according to claim 15 or 18, characterized by the fact that (a) the mass and heat transfer medium (118d) is organized in upper and lower regions; and (b) the processing assembly (118) is connected to the third expansion medium (17) to receive at least part of the at least one expanded liquid stream (40a) and direct it between the upper and lower middle regions mass and heat transfer (118d). 21. Apparatus according to claim 16 or 19, characterized by the fact that (a) the mass and heat transfer medium (118d) is organized in upper and lower regions; and (b) the processing assembly (118) is connected to the third expansion medium (17) to receive any remaining part of the at least one stream of liquid (40a) expanded and direct it between the upper and lower regions of the medium mass and heat transfer (118d). 22. Apparatus according to claim 15, 16, 18, 19, 20 or 21, characterized by the fact that the separation means (118e) is housed in the processing assembly (118). 23. Apparatus according to claim 14, characterized by the fact that (a) a gas collection means (118e) is housed in the processing set (118); (b) an additional mass and heat transfer medium is included within the gas collection medium (118e), the additional mass and heat transfer medium including one or more passages to an external cooling medium; (c) the gas collection medium (118e) is connected to the combination medium to receive the cooled gas stream (31a) and direct it to the mass and additional heat transfer medium to be further cooled by the external cooling medium ; and (d) the second dividing medium is adapted to be connected to the gas collection medium (118e) to receive the additional cooled gas stream (34) and divide it into the first (36) and second (39) currents . 24. Apparatus according to claim 17, characterized by the fact that (a) a gas collection means (118e) is housed in the processing set (118); (b) an additional mass and heat transfer medium is included within the gas collection medium (118e), the additional mass and heat transfer medium including one or more passages to an external cooling medium; (c) the gas collection medium (118e) is connected to the first heat exchange medium (10) to receive the first cooled part (32a) and direct it to the mass and additional heat transfer medium to be cooled additionally by means of external cooling; and (d) the second expansion medium (15) is adapted to be connected to the gas collection medium (118e) to receive the first additional cooled part (34) and expand it to decrease the pressure (34a), the second expansion medium (15) being further connected to the absorbent medium (118c) to provide the first expanded expanded chilled portion (34a) as the bottom feed for it. 25. Apparatus according to any one of claims 15, 16, 18, 19, 20, 21 or 22, characterized in that (a) a mass and additional heat transfer medium is included within the separation medium ( 12), the mass and additional heat transfer medium including one or more passages to an external cooling medium; (b) the steam stream is directed to the mass transfer medium and additional heat to be cooled by the external cooling medium to form additional condensate; and (c) the condensate becomes a part of at least one separate liquid stream therein. 26. Apparatus according to any one of claims 14 to 25, characterized in that the mass and heat transfer medium (118d) includes one or more passages to an external heating medium to complement the heating provided by the second part (33) for removing the most volatile components from the distillation liquid stream.

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