BRPI1106070B1 - process and apparatus for separating a gas stream - Google Patents

Abstract

HYDROCARBON GAS PROCESSING. The invention relates to a process and apparatus for a compact processing assembly to recover propane, propylene, and heavier hydrocarbon components from a stream of hydrocarbon gas. The gas stream is cooled, expanded to a lower pressure, and fed to an absorption medium. A first stream of distillation liquid from the absorption medium is fed to a mass transfer medium. A first stream of steam distillation from the mass transfer medium is cooled to partially condense it, forming a stream of residual steam and a stream of condensate. The condensed current is supplied as the upper supply to the absorption medium. A second stream of distillation vapor from the absorption medium is heated by cooling the first stream of distillation vapor, combined with the residual steam stream, and heated by cooling the gas stream. A second stream of liquid distillation from the mass transfer medium is heated in a mass and heat transfer medium to remove its volatile components.

Description

DESCRIPTIVE REPORT BACKGROUND OF THE INVENTION

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

[002] The present invention is generally related to the recovery of propylene, propane, and heavier hydrocarbons from such gas streams. A typical analysis of a gas stream to be processed according to this invention would be, approximately in mol percent, 88.4% methane, 6.2% ethane and other C2 components, 2.6% propane and others C3 components, 0.3% iso-butane, 0.6% normal butane, and 0.8% more pentanes, with the balance made of nitrogen and carbon dioxide. Sulfur-containing gases are also sometimes present.

[003] Historical fluctuations in the prices of both natural gas and constituents of natural liquid gas (NGL) have sometimes reduced the added value of propane, propylene, and heavier components such as liquid products. This has resulted in a demand for processes that can provide more efficient recoveries for these products and for processes that can provide efficient recoveries with less capital investment. Processes available to separate these materials include those based on gas cooling and cooling, oil absorption, and refrigerated oil absorption. Additionally, cryogenic processes have become popular because of the availability of economical equipment that produces power while simultaneously expanding and extracting heat from the gas being processed. Depending on the pressure of the gas source, the richness (content of ethane, ethylene, and heavier hydrocarbons) of the gas, and the desired end products, each of these processes or a combination of this can be employed.

[004] The cryogenic expansion process is currently generally preferred for the recovery of natural liquid gas because it provides maximum simplicity with ease of startup, flexibility of operation, good efficiency, safety, and good reliability. U.S. patent applications numbers. 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; U.S. patent application reissued No. 33,408; and copending patent applications number 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; 12 / 979,563; and 13 / 048,315 describe relevant processes (although the description of the present invention in some cases is based on different processing conditions than those described in the U.S. patent applications cited above).

[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 cooling sources such as a propane compression cooling system. As the gas is cooled, the liquids can be condensed and collected in one or more separators depending on the high pressure liquids that contain some of the desired C3 + components. Depending on the richness of the gas and the amount of liquids formed, high pressure liquids can be expanded to a lower pressure and fractionated. The vaporization that occurs during the expansion of the liquids results in additional cooling of the stream. Under some conditions, pre-cooling of high pressure liquids prior to expansion may be desirable in order to further decrease the temperature resulting from the expansion. The expanded stream, which comprises a mixture of liquid and steam, is fractionated in a distillation column (deethanizer). In the column, the expansion chilled stream (s) is (are) distilled to separate residual methane, C2 components, nitrogen, and volatile gases as suspended vapor from the desired C3 components and more hydrocarbon components. as a bottom liquid product.

[006] If the supply gas is not fully condensed (typically it is not), the remaining vapor from the partial condensation can be passed through a working expansion machine or motor, or an expansion valve, to a lower pressure at which Additional liquids are condensed as a result of further cooling the current. The expanded stream then enters an absorption section in the column and is contacted with cold liquids to absorb the C3 components and the heavier components of the steam portion of the expanded stream. The liquids from the absorption section are then directed to the desetanizing section of the column.

[007] A distillation vapor stream is removed from the upper region of the desetanizing section and is cooled by the heat exchange ratio with the vapor stream suspended from the absorption section, which condenses at least a portion of the distillation vapor stream. The condensate liquid is separated from the distilled vapor chilled stream to produce a reflux stream of cold liquid that is directed to the upper region of the absorption section, where cold liquids can contact the vapor portion of the expanded stream as described previously. The vapor portion (if any) of the distilled vapor chilled stream and the vapor suspended from the absorption section combine to form the residual methane and gas product of component C2.

[008] The separation takes place in this process (production of a residual gas that leaves the process that contains substantially all of the methane and C2 components in the feed gas with essentially none of the heavier C3 components and hydrocarbon components, and a fraction bottom that leaves the deethanizer that contains substantially all the C3 components and the heaviest hydrocarbon components with essentially no methane, C2 components or more volatile components) consumes energy for the cooled feed gas to boil the de-tanning section again, to reflux the absorption section, and / or to compress the residual gas again.

[009] The present invention employs innovative methods of carrying out the various steps described above more efficiently and using fewer pieces of equipment. This is accomplished by combining what have hitherto been items of individual equipment in a common housing, thereby reducing the land space required for the processing plant and reducing the capital cost of the facility. Surprisingly, depositors have found that a more compact layout also significantly reduces the power consumption required to achieve a given level of recovery, thereby increasing the efficiency of the process and reducing the cost of operating the facility. In addition, a more compact layout 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 associated flanged pipe connections. Since piping flanges are a potential source of leakage for hydrocarbons (which are volatile organic compounds, VOCs, which contribute to greenhouse gases and can also be precursors to the formation of atmospheric ozone), eliminating these flanges is reduced. potential for atmospheric emissions that can damage the environment.

[0010] In accordance with the present invention, it has been found that C3 recoveries in excess of 99.6% can be obtained while essentially providing complete rejection of C2 components to the residual gas stream. In addition, the present invention makes it possible essentially 100% separation of C2 components and lighter components from C3 components and heavier components lower energy requirements when compared to the prior art while maintaining the same level of recovery. The present invention, although applicable at lower pressures and warmer temperatures, is particularly advantageous when processing feed gases in the range of 2.588 to 10.342 kPa (a) [400 to 1500 psia] or greater under conditions requiring suspended column temperatures. NGL recovery from -46 ° C [-50 ° F] or cooler.

[0011] For a better understanding of the present invention, references are made to the following examples and drawings. With reference to the drawings:

[0012] Figure 1 is a flow diagram of a prior art natural gas processing plant according to U.S. Patent Publication No. 5,799,507;

[0013] Figure 2 is a flow diagram of a natural gas processing plant according to the present invention; and

[0014] Figures 3 to 21 are flow diagrams illustrating means of alternative application of the present invention to a current natural gas.

[0015] In the explanation of the figures above, the tables are provided to summarize the flow rates calculated for the representative process conditions. In the tables that appear in this document, values for flow rates (in moles per hour) have been rounded to the nearest whole number for convenience. The total flow rates shown in the tables include all non-hydrocarbon components and are therefore generally greater than the sum of the flow rate currents for the hydrocarbon components. The temperatures indicated are approximate values rounded to the nearest degree. It should also be noted that the process design calculations performed for the purpose of comparing the process depicted in the figures are based on the assumption of no heat leakage from (or to) the surrounding processes (or from them). The quality of commercially available insulating materials makes it a reasonable assumption and one that is typically made by those skilled in the art.

[0016] For convenience, process parameters are reported in traditional British units and units in the International System of Units (SI). The molar flow rates given in the tables can be interpreted as soft pounds per hour or soft kilograms per hour. The energy consumption reported as horsepower (HP) and / or thousands of British Thermal Units per hour (MBTU / h) correspond to the molar flow rates quoted in soft pounds per hour. The energy consumption reported as kilowatts (kW) corresponds to the molar flow rates quoted in soft kilograms per hour.

DESCRIPTION OF THE PREVIOUS TECHNIQUE

[0017] Figure 1 is a process flow diagram showing the design of a processing plant to recover C3 + components from natural gas using the prior art in accordance with U.S. Patent No. 5,799,507. In this process simulation, the input gas enters the plant at 43 ° C (110 ° F) and 6,100 kPa (a) (885 psia) as in stream 31. If the input gas has a concentration of sulfur components that would avoid As long as the product streams meet the specifications, the sulfur components are removed through the appropriate pre-treatment of the feed gas (not shown). In addition, the feed stream is generally dehydrated to prevent hydrate (ice) formation under cryogenic conditions. The desiccant solid has typically been used for this purpose.

[0018] The feed stream 31 is cooled in the heat exchanger 10 through heat exchange with cold gas residue (stream 44), low pressure expanded separator liquids (stream 35a), and distillation fluids at -76 ° C (-105 ° F) (current 43). The cooled stream 31a enters the separator 11 at -36 ° C (-34 ° F) and 6.031 kPa (a) (875 psia) where the steam (stream 34) is separated from the condensed liquid (stream 35). The separating liquid (current 35) is expanded to just above the operating pressure (approximately 2.583 kPa (a) (375 psia)) of the fractionation tower 15 through an expansion valve 12, cooling current 35a at -54 ° C ( -65 ° F). The current 35a enters a heat exchanger 10 to provide cooling to the feed gas as previously described, the heating current 35b at 41 ° C (105 ° F) before being supplied to the fractionation tower 15 at a feed point of lower middle column.

[0019] The steam (current 34) from the separator 11 enters a working expansion machine 13 in which mechanical energy is extracted from this portion of the high supply pressure. The machine 13 expands the vapor substantially isentropically to the operating pressure of the fractionation tower 15, with the expansion of heat cooling the expanded current 34a to a temperature of approximately -74 ° C (-100 ° F). 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 generally used to drive a centrifuge compressor (as item 14) that can be used to re-compress the heated waste gas (current 44a), for example. The partially condensed expanded current 34a is therefore supplied as power to the fractionation tower 15 at an upper middle column feed point.

[0020] The desetanizer in tower 15 is a conventional distillation column that contains a plurality of vertically spaced trays, one or more compacted beds, or some combination of trays and compaction. The desetanizer tower consists of two sections: an upper absorption (grinding) section 15a containing the trays and / or compaction to provide the necessary contact between the steam portion of the expanded stream 34a which is raised upwards and the cold liquid that follows in the downward direction to condense and absorb the C3 components and heavier components; and a lower extraction section 15b that contains these trays and / or compactings to provide the necessary contact between the liquids that go downwards and the vapors that are raised upwards. The de-tanning section 15b also includes at least one boiler (like boiler 16) that heats and vaporizes a portion of the liquids that flow down the column to provide the extraction vapors that flow upwards in the column to extract the liquid product, the current 37, of methane, C2 components, and lighter components. The current 34a enters the desetanizer 15 in a medium column feed position located in the lower region of absorption section 15a of desetanizer 15. The liquid portion of the expanded stream 34a mixes with liquids that proceed in the downward direction from the absorption 15a and the combined liquid continues downwards in the deethanizer extraction section 15b 15. The steam portion of the expanded stream 34a rises upwards through an absorption section 15a and makes contact with the cold liquid that goes in the downward direction to condense and absorb the C3 components and heavier components.

[0021] A portion of the distillation vapor (stream 38) is removed from the upper region of the extraction section 15b. This current is then cooled and partially condensed (current 38a) in the exchanger 17 by the heat exchange with cold de-tanner above the current 36 which exits the top of the de-tanner 15 at -79 ° C (-109 ° F). The above-current cold de-tanner is heated to approximately -66 ° C (-33 ° F) (current 36a) as current 38 cools from -35 ° C (-30 ° F) to about -75 ° C ( -103 ° F) (current 38a).

[0022] The operating pressure in the reflux separator 18 is kept slightly above the working pressure of deethanizer 15. This pressure difference provides the driving force that allows the distillation vapor stream 38 to flow through the heat exchanger 17 and then, in the reflux separator 18 where the condensed liquid (stream 40) is separated from the non-condensed vapor (stream 39). The non-condensing vapor stream 39 combines with the stream above the heated deethanizer 36a from the exchanger 17 to form the cold gas residue stream 44 at - 38 ° C (-37 ° F).

[0023] The liquid stream 40 from the reflux separator 18 is pumped by the pump 19 at a pressure slightly above the operating pressure of the desethanizer 15. The resulting stream 40a is then divided into two portions. The first portion (stream 41) is provided as a cold top column feed (reflux) to the upper region of absorption section 15a of deethanizer 15. This cold liquid causes the absorption cooling effect to occur within the absorption (rectification) 15a of deethanizer 15, in which the saturation of the vapor that rises upwards through the tower by vaporization of liquid methane and ethane contained in the stream 41 provides cooling to the section. Note that, as a result, both the steam leaving the upper region (upper stream 36) and the liquids leaving the lower region (distillation liquid stream 43) of absorption section 15a are cooler than the feed currents ( chains 41 and chain 34a) for absorption section 15a. This absorption cooling effect allows the high tower (current 36) to provide the necessary cooling in the heat exchanger 17 to partially condense the distillation stream vapor (current 38) without operating the extraction section 15b at a significantly higher pressure than than the absorption section 15a. This absorption cooling effect also facilitates the reflux current 41 which condenses and absorbs the C3 components and heavier components in the distillation vapor flowing upward through the absorption section 15a. The second portion (current 42) of pumped current 40a is supplied to the upper region of extraction section 15b of deethanizer 15 where the cold liquid acts as a reflux to absorb and condense the C3 components and heavier components that flow upwards from the bottom, so that the distillation vapor stream 38 contains minimal amounts of these components.

[0024] A stream of distillation liquid 43 from the desetanizer 15 is removed from the lower region of the absorption section 15a and is routed to the heat exchanger 10, where it is heated as it provides the cooling of the incoming feed gas, as previously described . Typically, the flow of this liquid from the desetanizer flows through a thermosyphon circulation, however, a pump can be used. The liquid flow is heated to -20 ° C (-4 ° F) partially, before the vaporization stream 43a is returned as medium column feed to the desetanizer 15, in the middle region of the extraction section 15b.

[0025] In the extraction section 15b of the desetanizer 15, the supply currents are extracted from its components of methane and C2. The resulting liquid product stream 37 leaves the bottom of the tower at 94 ° C (201 ° F) based on a typical 0.048: 1 ethane to propane ratio specification on a molar basis in the upper product. The cold residual gas (stream 44) passes countercurrently to the inlet gas in the heat exchanger 10 where it is heated to 37 ° C (98 ° F) (stream 44a). The residual gas is then re-compressed in two stages. In the first stage is compressor 14 driven by expansion machine 13. In the second stage is compressor 20 driven by a supplementary power source that compresses the residual gas (current 44c) to change line pressure. After cooling to 49 ° C (120 ° F) in the discharge cooler 21, the residual gas stream 44d flows into the exchange gas duct at 6.307 kPa (a) (915 psia), sufficient to meet line requirements (typically in order of inlet pressure).

Retornos*

[0026] A summary of current flow rates and energy consumption for the process illustrated in figure 1 is presented in the following table: Table I: (Figure 1) Summary of current flow -kg mol / hour [Lb.Mol /hour]

Returns *

Description of the Invention

[0027] Figure 2 illustrates a flow chart of a process, according to the present invention. The feed gas composition and conditions considered in the process shown in figure 2 are the same as those in figure 1. Consequently, the process of figure 2 can be compared with that of the process of figure 1 to illustrate the advantages of the present invention.

[0028] In the simulation of the process of figure 2, the incoming gas penetrates the plant as the current 31 and penetrates a heat exchange medium in the supply cooling section 115a in the processing assembly 115. This heat exchange medium may comprise a tube-type fin and heat exchanger, a plate-type heat exchanger, a welded aluminum-type heat exchanger, or other type of heat transfer device, which includes multi-step heat exchanger and / or services multiple. The heat exchange medium is configured to provide heat exchange between the stream 31, which passes through a passage of the heat exchange medium and expanded liquids from the flash separator (stream 35a), and a residual gas stream from the condensation 115b in processing assembly 115. Stream 31 is cooled while heating the expanded liquids of the flash separator and the residual gas stream. A first portion (chain 32) of chain 31 is removed from the heat exchange medium after chain 31 has been partially cooled to -4 ° C (25 ° F), while the second remaining portion (chain 33) is additionally cooled to leave the heat exchange medium at -29 ° C (-20 ° F).

[0029] The separator section 115e has an internal head or other means for dividing it from the deethanization section 115d, so that the two sections in the processing assembly 115 can operate at different pressures. The first portion (stream 32) of stream 31 penetrates the lower region of separator section 115e at 6.031 kPa (a) (875 psia) where any condensed liquid is separated from the vapor before the steam is directed into the mass and heat transfer medium within the 115e separator section. This mass and heat transfer medium may additionally comprise a tube-type fin and heat exchanger, a plate-type heat exchanger, a welded aluminum-type heat exchanger, or other type of heat-transfer device, which includes a heat exchanger multistage heat exchangers and / or multiple services. The mass and heat transfer medium is configured to provide heat exchange between the current steam portion 32, which runs upward through a passage of the mass and heat transfer medium, and the distillation liquid stream 43 to from the absorption section 115c in the processing assembly 115 that goes downwards, so that the steam is cooled while heating the liquid distillation stream. As the steam stream is cooled, a portion of it can be condensed and come down while the remaining steam continues to flow upward through the mass and heat transfer medium. The mass and heat transfer medium provides continuous contact between the condensed liquid and the steam so that it also works to provide mass transfer between the liquid and vapor phases to provide partial steam rectification.

[0030] The second portion (chain 33) of chain 31 penetrates the separator section 115e in the processing assembly 115 above the mass and heat transfer medium. Any condensed liquid is separated from the vapor and mixed with any liquid which is condensed from the current vapor part 32 which flows upward through the mass and heat transfer medium. The stream steam portion 33 combines with the steam leaving the mass and heat transfer medium to form the stream 34, which leaves the separator section 115e at -35 ° C (-31 ° F). The liquid portions (if any) of streams 32 and 33 and any condensed liquid, from the stream portion 32 in the mass and heat transfer medium, combine to form the stream 35, which leaves the separator section 115e at -26 ° C (-15 ° F). It expands slightly above the operating pressure (approximately 2,639 kPa (a) (383 psia)) of de-deaanizing section 115d in processing assembly 115 by expansion valve 12, cooling current 35a at -41 ° C (-42 ° F). The current 35a penetrates the heat exchange medium of the supply cooling section 115a to provide cooling to the supply gas as previously described, the heating current being 35b at 39 ° C (103 ° F) before being supplied to the section deethanization 115b in processing assembly 115 at a lower mid-column feed point.

[0031] The steam (current 34) from the separator section 115e enters a working expansion machine 13 in which mechanical energy is extracted from this portion of the high pressure feed. The machine 13 expands the vapor substantially, isentropically, to the operating pressure (approximately 2.618 kPa (a) (380 psia)) of absorption section 115c, with the working expansion cooling of the expanded current 34a to a temperature approximately -72 ° C (-98 ° F). The partially condensed expanded current 34a has since been supplied as power to the lower region of the absorption section 115c in the processing assembly 115.

[0032] The absorption section 115c contains an absorption medium consisting of a plurality of vertically spaced trays, one or more packed beds or some combination of trays and packaging. The trays and / or packaging in the absorption section 115c provide the necessary contact between the rising vapors in an upward direction and the cold liquid that falls in a downward direction. The expanded stream vapor portion 34a goes upwards through the absorption medium in the absorption section 115c to come in contact with the cold liquid downwards to condense and absorb most of the C3 components and heavier components from these vapors . The liquid portion of expanded stream 34a mixes with liquids downwardly from the absorption medium in the absorption section 115c to form the distillation liquid stream 43, which is removed from the lower region of the absorption section 115c at -74 ° C (-102 ° F). The distillation liquid is heated to -23 ° C (-9 ° F) as it cools the stream vapor portion 32 in separator section 115e, as previously described, with the heated distillation liquid stream 43a after being supplied to the deethanization section 115d in processing assembly 115 at an upper middle column feed point. Typically, the flow of this liquid, from the absorption section 115c, through the mass and heat transfer medium in the separator section 115e to the deethanization section 115d flows through the thermosyphon circulation, however, a pump can be used.

[0033] The absorbent section 115c has an internal head or other means of dividing from the deethanization section 115d, so that the two sections within the processing assembly 115 can operate with the pressure of the deethanization section 115d slightly higher than that absorbent section 115c. This pressure difference provides the driving force that allows a first stream of distillation vapor (stream 38) to be removed from the upper region of the deethanization section 115d and directed to the heat exchange medium in the condensation section 115b within the processing 115. This heat exchange medium may likewise comprise a tube and fin type heat exchanger, a plate type heat exchanger, a brazed aluminum type heat exchanger, or other type of heat exchanger. heat transfer device, which includes multiple pass heat exchangers and / or multiple services. The heat exchange medium is configured to provide heat exchange between the first distillation vapor stream 38 flowing through a passage of the heat exchange medium and a second distillation vapor stream arising from the absorbent section 115c within of the processing assembly 115. The second stream of distillation steam is heated while at least partially condensing the stream 38, which after this leaves the heat exchange medium and is separated into its respective liquid and vapor phases. The vapor phase (if any) combines with the second heated distillation vapor stream exiting the heat exchange medium to form the residual gas stream that provides cooling in the supply cooling section 115a as previously described. The liquid phase is divided into two portions, currents 41 and 42.

[0034] The first portion (stream 41) is supplied as a cooled upper column feed (reflux) to the upper region of the absorbent section 115c within the processing assembly 115 by gravity flow. This cooled liquid causes an absorption cooling effect within the absorption (rectification) section 115a, in which the saturation of the vapors arising upwardly through the tower by vaporization of ethane and liquid methane contained in the current 41 provides cooling to the section. This absorption cooling effect allows the second distillation stream to provide the necessary cooling in the heat exchange medium in the condensation section 115b to partially condense the first distillation stream (stream 38) without operating the de-cornization section. 115d at a significantly higher pressure than the absorbent section 115c. This absorption cooling effect also facilitates the reflux current 41 to condense and absorb the C3 components and heavier components in the distillation vapor that flows upwardly through the absorbent section 115c. The second portion (stream 42) of the liquid phase separated in the condensation section 115b is supplied as a cooled (reflux) upper column feed to the upper region of the deethanization section 115d within the processing assembly 115 by gravity flow, so that the cooled liquid acts as a reflux to absorb and condense the C3 components and heavier components that flow upwards from below so that the distillation vapor stream 38 contains minimal amounts of these components.

[0035] The deethanization section 115d within the processing assembly 115 contains a mass transfer medium consisting of a plurality of vertically spaced trays, one or more packed layers, or some combination of trays and packaging. The trays and / or packaging in the 115d deethanization section provide the necessary contact between the vapors rising upwards and cooled liquid spilled downwards. The deethanization section 115d also includes a mass transfer medium and heat below the mass transfer medium. This mass and heat transfer medium may also comprise a tube and fin type heat exchanger, a plate type heat exchanger, a brazed aluminum type heat exchanger, or other type of heat transfer device. , which includes multiple pass heat exchangers and / or multiple services. The mass and heat transfer medium is configured to provide heat exchange between a heat medium flowing through a passage of the mass and heat transfer medium and a stream of distillation liquid flowing downwardly from the medium. mass transfer in the deethanization section 115d, so that the stream of distillation liquid is heated. As the stream of distillation liquid is heated, a portion of it is vaporized to form extraction vapors that arise downwardly as the remaining liquid continues to flow downwardly through the mass and heat transfer medium. The mass and heat transfer medium provides continuous contact between the extraction vapors and the distillation liquid stream so that it also works to provide mass transfer between the liquid and vapor phases, extracting the liquid product stream 37 from methane , C2 component, and lighter components. The resulting liquid product (stream 37) leaves the lower region of the deethanization section 115d and leaves the processing assembly 115 to 203 ° F (95 ° C).

[0036] The second stream of distillation vapor that arises from the absorbent section 115c is heated in the condensation section 115b, as it provides cooling to the current 38 as previously described. The second heated distillation vapor stream combines with any steam separate from the first cooled distillation vapor stream 38 as previously described. The resulting residual gas stream is heated in the supply cooling section 115a as it provides cooling to stream 31, as previously described, in which the residual gas stream 44 leaves the processing assembly 115 at 40 ° C (104 ° F ). The residual gas stream is then re-compressed in two stages, in compressor 14 driven by expansion machine 13 and compressor 20 driven by an additional power source. After cooling to 49 ° C (120 ° F) in the discharge cooler 21, the residual gas stream 44c flows into the natural gas pipeline at 6.307 kPa (a) (915 psia), sufficient to meet line requirements (in order of inlet pressure).

Recuperações*

Potência

*(Com base em taxas não arredondadas)[0037] A summary of the current flow rates and energy consumption for the process illustrated in figure 2 is set out below in the following table: Table II (Figure 2) Summary of current flow -Kg moles / Hour (Lb. Moles / Hour)

Recoveries *

Wattage

* (Based on non-rounded rates)

[0038] A comparison of Tables I and II shows that the present invention maintains essentially the same recoveries as the prior art. However, a further comparison of Tables I and II shows that the yields of the product were achieved by using less power than in the prior art. In terms of recovery efficiency (defined by the amount of propane recovered per unit of power), the present invention represents more than 5% improvement over the prior art process of figure 1.

[0039] The improvement in efficiency provided by the present invention on which the prior art of the process of figure 1 occurs primarily due to three factors. First, the compact engagement of the heat exchange medium in the supply cooling section 115a and in the condensation section 115b in the processing assembly 115 eliminates the pressure drop imposed by the interconnecting piping found in conventional processing plants. The result is that the residual gas flowing to the compressor 14 has a higher pressure for the present invention compared to the prior art, so that the residual gas entering the compressor 20 is under significantly high pressure, therefore reducing the power required by the present invention to restore residual gas from the pipe pressure.

[0040] Second, use the mass and heat transfer medium in the deethanization section 115d to simultaneously heat the distillation liquid that leaves the mass transfer medium in the deethanization section 115d while allowing the resulting vapors to contact the liquid and extract its volatile components is more efficient than using a conventional distillation column with external coolers. The volatile components are extracted from the liquid continuously, reducing the concentration of volatile components in the extraction vapors more quickly and therefore improving the extraction efficiency for the present invention.

[0041] Third, using the mass and heat transfer medium in the separator section 115 and simultaneously cooling the stream steam portion 32 while condensing the heavier hydrocarbon components of the steam provides partial rectification of the stream 34 before it is subsequently expanded and supplied as feed to the absorbent section 115c. Consequently, less reflux flow (current 41) is required to rectify the expanded current 34a to remove the heavier C3 components and hydrocarbon components from it, as seen by comparing the flow rate of current 41 in Tables I and II.

[0042] The present invention offers two other advantages over the prior art, in addition to the increase in processing efficiency. First, the compact arrangement of the processing assembly 115 of the present invention replaces six separate equipment items in the prior art (heat exchangers 10 and 17, separator 11, reflux separator 18, reflux pump 19 and fractionation tower 15, in the figure 1) for a simple equipment item (processing assembly 115, in figure 2). This reduces the demands on space for action, eliminates the interconnection piping and eliminates the power consumed by the reflux pump, reducing the capital cost and the operating cost of a processing plant using the present invention over the prior art. Second, the elimination of interconnecting piping means that a processing plant using the present invention has far fewer flanged connections compared to the prior art, reducing the number of sources of potential leakage. Hydrocarbons are volatile organic compounds (VOCs), some of which are classified as greenhouse gases and some of which can be precursors to the formation of atmospheric ozone, which means that the present invention reduces the potential for atmospheric emissions that can harm the environment environment.

Other Modalities

[0043] Certain circumstances may favor the elimination of the supply cooling section 115a and the condensing section 115b of the processing assembly 115, and the use of one or more heat exchange means external to the processing assembly for supply cooling and reflux condensation, such as heat exchangers 23 and 17, shown in figures 14 to 21. This arrangement allows the processing assembly 115 to be smaller, which can reduce the total cost of the plant and / or decrease the manufacturing schedule in some cases. Note that in all cases, exchangers 23 and 17 are representative of a multitude of individual heat exchangers or a single multi-pass heat exchanger, or combinations thereof. Each such heat exchanger may be composed of a fin and tube-type heat exchanger, a plate-type heat exchanger, a brazed aluminum-type heat exchanger or other type of heat transfer device, including heat exchangers. multiple passages or multiservice heat exchangers. In some cases, it may be advantageous to combine feed cooling and reflux condensation in a multiservice heat exchanger. With the heat exchanger 17 external to the processing assembly, the reflux separator 18 and the pump 19 will typically be needed to separate the condensed liquid stream 40 and distribute at least a portion of it to the absorption section 115c as a reflux.

[0044] As previously described for the embodiment of the present invention shown in figure 2, the first distillation stream 38 is partially condensed and the resulting condensate used to absorb valuable C3 components and heavier components from the vapors coming out of the expansion machine of work. However, the present invention is not limited to this embodiment. It may be advantageous, for example, to treat only a portion of the steam output from the working expansion machine in this way, or to use only a portion of the condensate as an absorbent, in cases where other design considerations indicate portions of the machine's output expansion or condensate should bypass absorption section 115c of processing assembly 115. Feed gas conditions, plant size, available equipment or other factors may indicate that the elimination of the work expansion machine 13, or replacement with an alternative expansion device (such as an expansion valve), is feasible, or that total (rather than partial) condensation of the first distillation vapor stream 38 in condensation section 115b within processing assembly 115 (figures 2 to 13) or heat exchanger 17 (figures 14 to 21) is possible or preferable. It should also be noted that, depending on the composition of the feed gas stream, it may be advantageous to use external refrigeration to provide partial cooling of the first distillation steam stream 38 in condensation section 115b (figures 2 to 13) or in the heat exchanger. heat 17 (figures 14 to 21).

[0045] In some circumstances, it may be advantageous to use an external separating container to separate the first and second chilled portions 32 and 33 or the chilled feed stream 31a, instead of including the separating section 115e in the processing assembly 115. As shown in figures 8 and 18, a heat and mass transfer medium in the separator 11 can be used to separate the first and second cooled portions 32 and 33 in the vapor stream 34 and liquid stream 35.

[0046] The use and distribution of the liquid stream 35 from the separator section 115e or separator 11 and the distillation liquid stream 43 from the absorption section 115c for the process heat exchange, the particular arrangement of the heat exchangers heat to cool the feed gas (streams 31 and 32) and the first distillation vapor stream 38, and the choice of process streams for specific heat exchange services must be evaluated for each particular application. For example, figures 4 to 6, 10 to 12 and 20 illustrate the use of the distillation liquid stream 43 to supply a portion of the cooling of the first distillation vapor stream 38 in the condensation section 115b (figures 4, 5, 10 and 11), heat exchanger 10 (figures 6 and 12), or heat exchanger 17 (figures 16 and 20). In these cases, a heat and mass transfer medium may not be necessary in the separating section 115e (figures 4 to 6 and 16) and in the separating 11 (figures 10 to 12 and 20). In the embodiments shown in figures 4 and 10, a pump 22 is used to distribute the stream of distillation liquid 43 to the heat exchange medium in the condensation section 115b. In the embodiments shown in figures 5 and 11, the condensation section 115b is located below the absorption section 115c in the processing assembly 115, so that the flow of the distillation liquid stream 43 is through thermosyphon circulation. In the embodiments shown in figures 6 and 12, a heat exchanger 10 external to the processing assembly 115 is employed and the supply cooling section 115a is located below the absorption section 115c in the processing assembly 115, so that the flow of the Distillation liquid stream 43 is through thermosyphon circulation. (The modalities shown in figures 5, 6, 11 and 12 use the reflux pump 19 to supply reflux to locations above the point in the processing assembly 115 where the liquid phase condensed from the current 38 is collected). In the embodiments shown in figures 16 and 20, thermosyphon circulation may be sufficient to allow the stream of distillation liquid 43 to flow through heat exchanger 17, or pump 22 may be required to circulate current 43. Some circumstances may favor the use of the distillation liquid stream 43 to cool the stream 32 in a heat exchanger external to the processing assembly 115, as the heat exchanger 10 illustrated in figures 3, 9, 15 and 19. Still other circumstances may not favor any heat from the distillation liquid stream 43 and instead use the distillation liquid stream 43 as the reflux to the upper region of the deethanization section 115d, as shown in figures 7, 13, 17 and 21. (For the modalities shown in figures 13 and 21, the pump 22 may be necessary because the gravity flow of the chain 43 may not be possible).

[0047] Depending on the amount of heavier hydrocarbons in the feed gas and the feed gas pressure, the first and second cooled portions 32 and 33 that enter separator section 115e, in figures 2 and 14, or separator 11, in figures 8 and 18 (or the cooled feed stream 31a that enters separator section 115e, in figures 3 to 7 and 15 to 17, or in separator 11, in figures 9 to 13 and 19 to 21) may not contain any liquid ( because it is above its dew point, or because it is above its critical pressure). In these cases, there is no liquid in the stream 35 (as shown by the dashed lines). In these circumstances, separator section 115e in processing assembly 115 (figures 2 to 7 and 14 to 17) and separator 11 (figures 8 to 13 and 18 to 21) may not be required.

[0048] According to the present invention, the use of external refrigeration to supplement the cooling available for the first stream of distillation vapor and / or inlet gas from the second stream of distillation vapor and the stream of distillation liquid it can be used, particularly in the case of a rich inlet gas. In such cases where additional inlet gas cooling is desired, a mass and heat transfer medium may be included in the separator section 115e (or a gas collection medium in such cases where the first and second chilled portions 32 and 33 or the cooled feed stream 31a does not contain liquid) as shown by the dashed lines in figures 3 to 7 and 15 to 17, or a mass and heat transfer medium can be included in the separator 11 as shown by the dashed lines in figures 9 up to 13 and 19 to 21. This mass and heat transfer medium can be comprised of a tube and fin type heat exchanger, a plate type heat exchanger, a brazed aluminum type heat exchanger, or other type of heat transfer device, including multi-pass heat exchangers or heat exchangers. The mass and heat transfer medium is configured to provide heat exchange between a refrigerant stream (eg, propane) that flows through a passage of the mass and heat transfer medium and the vapor portion of the stream 31a flowing to upstream, so that the refrigerant still cools the vapor and condenses the additional liquid, which falls downstream to become part of the liquid removed in stream 35. As shown by the dashed lines in figures 2, 8, 14 and 18, the medium Mass and heat transfer in separator section 115e (figures 2 and 14) or separator 11 (figures 8 and 18) may include delivery to provide supplemental cooling with refrigerant. Alternatively, conventional gas cooler (s) could be used to cool stream 32, stream 33, and / or stream 31a with refrigerant before streams 32 and 33 enter separator section 115e (figures 2 and 14) or separator 11 (figures 8 and 18) or chain 31a to enter separator section 115e (figures 3 to 7 and 15 to 17) or separator 11 (figures 9 to 13 and 19 to 21). In cases where additional cooling of the first distillation vapor stream is desired, the heat exchange medium in the condensing section 115b of the processing assembly 115 (figures 2 through 5, 7 through 11, and 13), the heat exchanger 10 (figures 6 and 12), or heat exchanger 17 (figures 14 through 21) can include supplies to provide supplemental cooling with refrigerant as shown by the dashed lines.

[0049] Depending on the type of heat transfer devices selected for the heat exchange medium in the supply cooling section 115a and the condensing section 115b (figures 2 through 5, 7 through 11, and 13), you can it is possible to combine these heat exchange means in a single multiservice and / or multiple pass heat transfer device. In such cases, the multiservice and / or multipass heat transfer device will include an appropriate means for distributing, segregating and collecting stream 31, stream 32, stream 33, the first distillation stream 38, any stream separated from the cooled stream 38, and the second stream of distillation vapor in order to effect the desired heating and cooling.

[0050] It will also be recognized that the amount of condensed liquid that is extracted between currents 41 and 42 in figures 2 to 6, 8 to 12, 14 to 16, and 18 to 20 will depend on several factors, including pressure of gas, composition of feed gas, and the amount of horsepower available. Optimal separation generally cannot be predicted without assessing the particular circumstances for a specific application of the present invention. Some circumstances may favor the feeding of all the condensed liquid up to the upper region of the absorbent section 115c in chain 41 and none until the upper region of deethanization section 115d in chain 42, as shown by the dashed lines for chain 42. In such cases , the heated distillation liquid stream 43a can be supplied up to the upper region of the deethanization section 115d to serve as reflux.

[0051] The present invention provides improved recovery of C3 components and heavier hydrocarbon components by the amount of installation consumption required to operate the process. An improvement in the installation consumption required to operate the process can appear in the form of reduced power requirements for compression or recompression, reduced power requirements for external cooling, reduced energy requirements for tower reopening, or a combination thereof.

[0052] Although what is believed to be the preferred embodiments of the invention has been described, those skilled in the art will recognize that further and additional modifications can be made to this, for example, adapting 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 (27)

1. Process for separating a gas stream (31) containing methane, C2 components, C3 components, and heavier hydrocarbon components to a fraction of volatile residual gas (44d) and a relatively less volatile fraction (37) which contains a larger portion of the C3 components and heavier hydrocarbon components, in which: (2) said gas stream (31) is cooled in a first heat exchange medium (23); (3) said cooled gas stream (31a, 34) is expanded (13) to a lower pressure, whereby it is further cooled (34a); (4) said expanded cooled gas stream (34a) is supplied as a lower feed to an absorbent medium; (5) a first stream of distillation liquid (43) is collected from a lower region of the absorbent medium (115c) and supplied as an upper feed (43a) to a mass transfer medium (115d); (6) a first stream of distillation vapor (38) is collected from an upper region of mass transfer medium (115d) and cooled sufficiently to condense at least part of it in a second heat exchange medium ( 17); (7) said first at least partially condensed distillation steam stream (38a) is supplied to a separation medium (18) and is separated therefrom, thereby forming a condensed stream (40) and a residual steam stream (39) containing any non-condensing vapor that remains after the first stream of distillation vapor is cooled; (8) at least a portion of the condensed stream (40a) is supplied as a top feed to the absorbent medium (115c); (9) a second stream of distillation vapor (36) is collected from an upper region of the absorbent medium (115c) and heated in the second heat exchange medium (17), thereby supplying at least a portion of the cooling step (5); (10) said second heated steam stream (36a) is combined with any residual steam stream (39) to form a combined steam stream (44); (11) said combined steam stream (44) is heated in the first heat exchange medium (23), thereby to supply at least a portion of the cooling in step (1), and consequently discharging the steam stream combined heat (44a) as the fraction of volatile residual gas (44d); (12) a second stream of distillation liquid is collected from a lower region of the mass transfer medium and heated in a mass and heat transfer medium (115d), thereby to simultaneously extract the most volatile components of the second stream of distillation liquid, and consequently discharge the second stream of heated distillation liquid and extracted from the processing assembly as the relatively less volatile fraction (37); and (13) the quantities and temperatures of the feed streams (34a, 40a) for the absorbent media (115c) are effective in maintaining the temperature of said upper region of said absorbent media (115c) at a temperature by which the portions larger components in the relatively less volatile fraction (37) are covered; characterized by the fact that said absorbent means (115c) and said mass transfer means (115d) are housed in a single processing assembly. 2. Process according to claim 1, characterized by the fact that (a) said gas stream (31) in step (1) is cooled sufficiently to partially condense it in a first heat exchange medium (23 ); (b) said partially condensed gas stream (31a) is supplied to a first separation means (11, 115e) and is separated there to provide a stream of steam (34) and at least a stream of liquid (35); (c) said steam stream (34) is expanded (13) to a lower pressure by which it is further cooled (34a); (d) said expanded steam stream (34a) is supplied as a lower feed to an absorbent medium (115c); (e) said at least one stream of liquid (35) is expanded (12) to the lower pressure; (f) said at least one expanded liquid stream (35a) is heated in the first heat exchange medium (23), thereby supplying at least a portion of the cooling in step (a), and subsequently supplying at least an expanded and heated liquid stream (35b) as a feed lower than the mass transfer medium (115d). 3. Process according to claim 1, characterized by the fact that (a) said first liquid distillation stream (43) in step (4) is collected from a lower region of the absorption medium (115c) and heated in a second heat exchange medium (17), with the first heated liquid distillation stream (43b) subsequently supplied as a feed greater than a mass transfer medium housed in the processing assembly (115d); and (b) said first steam distillation stream (38) in step (5) is collected from an upper region of the mass transfer medium (115d) and cooled sufficiently to condense at least a part of it in the second exchange medium heat (17) to thereby supply at least a portion of the heating of step (a). 4. Process according to claim 3, characterized by the fact that (i) said gas stream (31) in step (1) is cooled sufficiently to partially condense this in a first heat exchange medium (23) ; (ii) said partially condensed gas stream (31a) is supplied to a first separation medium (11, 115e) and is separated therein to provide a vapor stream (34) and at least a liquid stream (35); (iii) said gas stream (34) is expanded (13) to a lower pressure through which it is further cooled (34a); (iv) said cooled and expanded gas stream (34a) is supplied as a feed less than an absorption medium housed in a processing assembly (115c); (v) said at least one liquid stream (35) is expanded (12) to the lower pressure; (vi) said at least one expanded liquid stream (35a) is heated in the first heat exchange medium (23) to thereby supply at least a portion of the cooling in step (i), and subsequently supply at least one expanded and heated liquid stream (35b) as a feed lower than the mass transfer medium (115d). 5. Process according to claim 1, characterized by the fact that (a) said gas stream (31) in step (1) is partially cooled in a first heat exchange medium (23); (b) said partially cooled gas stream is divided into first (32) and second (33) portions; (c) said first portion (32) is additionally cooled in a first heat and mass transfer medium housed in an additional separation medium (11,115e), thus to simultaneously condense any less volatile components (35) of said first portion ; (d) said second portion (33) is additionally cooled in the first heat exchange medium (23); (e) said first additionally cooled portion (32) and second additionally cooled portion (33) are combined to form a cooled gas stream (34); (f) said first stream of distillation liquid (43) in step (4) is collected from a lower region of absorption medium (115c) and heated in the first heat and mass transfer medium (11, 115e), to thus supplying at least a portion of the cooling from step (c), with said stream of heated distillation liquid (43a) thus supplied as a feed greater than a mass transfer medium (115d); and (g) the combined steam stream (44) is heated in the first heat exchange medium (23), so as to supply at least a portion of the cooling from steps (a) and (d), and then release steam stream combined (44a) as said fraction of volatile residual gas (44d). 6. Process according to claim 5, characterized by the fact that (a) said second additionally cooled portion (33) in step (d) is directed to said first separation means (11, 115e) so that any condensed liquids as the first portion is additionally cooled and as the second portion is additionally cooled they are combined to form at least one stream of liquid (35), with the remainder of said first portion additionally cooled and the second portion additionally cooled forming a stream of vapor ( 34); (b) said steam stream (34) is expanded (13) to a lower pressure through which it is further cooled (34a); (c) said expanded cooled steam stream (34a) is provided as a lower feed for an absorption medium (115c); (d) said at least one stream of liquid (35) is expanded (12) to lower pressure; and (e) said at least one expanded liquid stream (35a) is heated in the first heat exchange medium (23), so as to supply at least a portion of the cooling in step (1), and then supply at least one heated expanded liquid stream (35b) as a bottom feed for mass transfer medium (115d). 7. Process according to claim 5, characterized by the fact that (i) said first portion (32) in step (6) is additionally cooled in a third heat exchange medium (10); and (ii) the first stream of distillation liquid (43) in step (4) is collected from a lower region of the absorption medium (115c) and heated in the third heat exchange medium (10), to do so providing at least a portion of the refrigeration of step (i), with said first stream of heated distillation liquid (43a) supplied as a feed greater than a mass transfer medium (115d). 8. Process according to claim 7, characterized in that (a) said first again cooled portion (32a) in step (i) and the second again cooled portion (33) are combined to form a partially condensed stream gas (31a); (b) said partially condensed gas stream (31a) is supplied to an additional separation medium (11, 115e) and is separated there to provide a vapor stream (34) and at least a liquid stream (35); (c) said steam stream (34) is expanded (13) to a lower pressure at which it is cooled again (34a); (d) said expanded cooled steam stream (34a) is supplied as a feed lower than the absorption medium (115c); (e) said at least one liquid stream (35) is expanded (12) to the lower pressure (35a); and (f) said at least one expanded liquid stream (35a) is heated in the first heat exchange medium (23), to thereby provide at least a portion of the partial cooling step (1), and subsequently supply at least an expanded heated liquid stream (35b) as a feed lower than the mass transfer medium (115d). Process according to any one of claims 2, 4, 5, 6 or 8, characterized in that the additional separation medium is housed in the processing assembly. Process according to any one of claims 3, 4, 5, 6, 7, 8 or 9, characterized by the fact that (1) said first heated distillation liquid stream (43a) in step (f) it is supplied to the mass transfer medium (115d) in an intermediate feed position; (2) said condensed stream in step (6) is divided into at least first (41) and second (42) reflux currents; (3) said first reflux current (41) is provided as the feed superior to the absorption medium (115c); and (4) said second reflux current (42) is provided as the upper supply to the mass transfer medium (115d). 11. Process according to any one of claims 1, 3, 7 or 10, characterized by the fact that (1) a gas collection means (115e) is housed in the processing assembly (115); (2) an additional mass and heat transfer medium is included within the gas collection medium (115e), the additional mass and heat transfer medium including one or more passages to an external cooling medium; (3) said cooled gas stream (31) in step (1) is supplied to the gas collection medium and directed to the mass and additional heat transfer medium to be further cooled by the external cooling medium; and (4) the additionally cooled gas stream (34) is expanded (13) to the lower pressure and, consequently, supplied (34a) as the supply lower than the absorption medium (115c). Process according to any one of claims 2, 4, 8, 9 or 10, characterized in that (1) a mass and additional heat transfer medium is included within the first separation medium (11, 115e ), the mass and additional heat transfer medium including one or more passages to an external cooling medium; (2) said steam stream (34) in step (b) is directed to the mass and additional heat transfer medium to be cooled by the external cooling medium to form additional condensate; and (3) said condensate becomes a part of at least one liquid stream (35) in step (b) separated therein. 13. Apparatus for separating a gas stream (31) containing methane, C2 components, C3 components and heavier hydrocarbon components into a fraction of volatile residual gas (44d) and a relatively less volatile fraction (37) which contains a major portion of the C3 components and heavier hydrocarbon components, wherein: (1) a first heat exchange medium (23) to cool the gas stream (31); (2) an expansion means (13) connected to the first heat exchange means (23) to receive the cooled gas stream (31a, 34) and expand it to the lower pressure (34a); (3) an absorption means (115c) connected to the expansion means (13) to receive the cooled gas stream (34a) as a feed less than this; (4) a first liquid collection means connected to said absorption means (115c) to receive a first stream of distillation liquid (43) from a lower region of the absorption means; (5) a mass transfer means (115d) connected to the first liquid collection means to receive said first stream of distillation liquid (43) as a feed greater than this; (6) a first vapor collection means connected to the mass transfer medium (115d) to receive a first distillation vapor stream (38) from an upper region of the mass transfer medium (115d); (7) a second heat exchange medium (17) connected to the first vapor collection medium to receive the first stream of distillation vapor (38) and cool it sufficiently to condense at least a part of it (38a); (8) a separation means (18) connected to the second heat exchange means (17) to receive at least the first partially condensed steam stream (38a) and separate it into a condensed stream (40) and a residual steam stream (39) containing any remaining non-condensing steam after the first distillation steam stream (38) is cooled; (9) said absorption means (115c) being further connected to the separation means (18) to receive at least a portion of the condensed current (40a) as a supply greater than this; (10) a second vapor collection medium connected to the absorption medium (115c) to receive a second stream of distillation vapor (36) from an upper region of the absorption medium (115c); (11) the second heat exchange medium (17) being additionally connected to the second steam collection medium to receive the second steam distillation stream (36) and heat it, thereby supplying at least a portion of the cooling step (7); (12) a combination means connected to the second heat exchange means (17) and separation means (18) to receive the second heated distillation stream (36) and any residual stream (39) and form a combined steam stream (44); (13) said first heat exchange means (23) being additionally connected to the combining means to receive the combined steam stream (44) and heat it, thereby supplying at least a portion of the step cooling (1 ) and, consequently, discharging the heated combined steam stream (44a) as the fraction of volatile residual gas (44d); (14) a second liquid collection means connected to the mass transfer medium (115d) to receive a second stream of distillation liquid from a lower region of the mass transfer medium; (15) a mass and heat transfer medium (115d) connected to the second liquid collection medium to receive said second stream of distillation liquid and heat it, thereby simultaneously extracting the most volatile components from the second distillation liquid stream and thus discharging the heated distillation liquid stream and extracted from the processing assembly as the relatively less volatile fraction; and (16) a control means adapted to regulate the quantities and temperatures of said feed streams (34a, 40a) to the absorption medium (115c) to maintain the temperature of the upper region of the absorption medium (115c) at a temperature across from which the main portions of the components in the relatively less volatile fraction (37) are recovered; characterized by the fact that said absorption means (115c), said first liquid collection means, said first vapor collection means, said second steam collection means, said mass transfer means (115d ) being housed within a processing assembly (115). Apparatus according to claim 13, characterized in that (a) said first heat exchange means (23) is adapted to cool the gas stream (31) of the element (1) sufficiently to partially condense the same (31a); (b) an additional separation medium (11, 115e) is connected to the first heat exchange medium (23) to receive the partially condensed gas stream (31a) and separate it into a vapor stream (34) and at minus a stream of liquid (35); (c) said first expansion means (13) is connected to the additional separation means (11, 115e) to receive the vapor stream (34) and expand it to a lower pressure through which it is further cooled (34a ); (d) said absorption means (115c) is connected to the first expansion means (13) to receive the expanded chilled vapor stream (34a) as a feed below that; (e) said additional expansion means (12) is connected to the additional separation means (11, 115e) to receive at least one stream of liquid (35) and expand it to the lower pressure (35a); and (f) said first heat exchange means (23) is additionally connected to the additional expansion means (12) to receive at least one expanded liquid stream (35a) and heat it, thereby providing at least a portion of the cooling step (a), the first heat exchange medium (23) being further connected to mass transfer medium (115d) to provide at least one heated expanded liquid stream (35b) as a feed below that. 15. Apparatus according to claim 13, characterized by the fact that (a) said second heat exchange means (17) is still connected to the first liquid collection means to receive the first stream of distillation liquid ( 43) of the element (4) and heat it, in order to supply at least a portion of the cooling to the first stream of distillation vapor; (b) said mass transfer means (115d) is connected to a second heat exchange means (17) to receive the first stream of heated distillation liquid (43a) as a feed greater than this; and (c) said second heat exchange means (17) is additionally connected to said first steam collection means to receive the first distillation steam stream (38) from the element (6) and cool it enough to condense at least a part of it, thereby providing at least a portion of the heating from step (a). 16. Apparatus according to claim 15, characterized by the fact that (i) said first heat exchange means (23) is adapted to cool the gas stream (31) of the element (1) enough to condense partially the same (31a); (ii) said additional separation means (11, 115e) is connected to the first heat exchange means (23) to receive the partially condensed gas stream (31a) and separate it into a vapor stream (34) and at least one liquid stream (35); (iii) said expansion means (13) is connected to the additional separation means (11, 115e) to receive the vapor stream (34) and expand it to lower pressures according to which it is further cooled (34a) ; (iv) the absorption medium (115c) is connected to the expansion medium (13) to receive the expanded chilled steam stream (34a) as a feed below that; (v) an additional expansion means (12) is connected to the additional separation means (11, 115e) to receive at least one liquid stream (35) and expand it to the lower pressure (35a); and (vi) the first heat exchange medium (23) is additionally connected to the additional expansion medium (12) to receive the at least expanded liquid stream (35a) and heat it, thereby providing at least a portion of the cooling of step (i), the first heat exchange medium (23) being additionally connected to the mass transfer medium (115d) to provide at least one heated expanded liquid stream (35b) as a feed less than this. 17. Apparatus according to claim 13, characterized by the fact that (a) said first heat exchange means (23) is adapted to partially cool the gas stream (31) of the element (1); (b) a dividing means is connected to the first heat exchange means (23) to receive the partially cooled gas stream and to divide it into first (32) and second (33) portions; (c) an additional mass and heat transfer medium is housed in an additional separation medium (11, 115e) and is connected to the dividing medium to receive said first portion (32) and additionally cool it, thereby condensing, simultaneously, any less volatile components (35) from the first portion; (d) said first heat exchange means (23) is additionally connected to the division means to receive the second portion (33) and to cool it further; (e) said additional combining means is connected to the mass and heat transfer medium and the first heat exchange means (23) to receive the first additionally cooled portion (32) and the second additionally cooled portion (33) and forming a cooled gas stream (34); (f) said expansion means (13) is connected to the additional combination means to receive the cooled gas stream (34) and expand it at a lower pressure (34a); (g) said mass and additional heat transfer medium is further connected to said first liquid collection medium to receive the first distillation liquid stream (43) from the element (4) and heat it, thus providing at least a cooling portion of step (c); (h) the mass transfer medium (115d) is connected to said mass transfer medium and additional heat to receive the first stream of heated distillation liquid (43a) as a feed greater than this; and (i) said first heat exchange means (23) is additionally connected to the combining means to receive the combined steam stream (44) and heat it, thus providing at least a portion of the cooling of steps (a) and (d), and therefore discharging the heated combined steam stream (44a) as the fraction of volatile waste gas (44d). 18. Apparatus according to claim 17, characterized by the fact that (a) the additional separation medium (11, 115e) is further connected to the first heat exchange medium (23) to receive the second additionally cooled portion ( 33) of the element (d) so that any condensed liquids as the first portion (32) of the element (c) is further cooled and as the second portion (33) is further cooled are combined to form at least one liquid stream (35), with the remainder of the first additionally cooled portion (32) and the second additionally cooled portion (33) forming a vapor stream (34); (b) said expansion means (13) is connected to the additional separation means (11, 115e) to receive the vapor stream (34) and expand it to a lower pressure (34a) so that it is further cooled ; (c) said absorption means (115c) is connected to the expansion means (13) to receive the expanded and cooled vapor stream (34a) as a lower feed for it; (d) said additional expansion means (12) is connected to said additional separation means (11, 115e) to receive at least one stream of liquid (35) and expand it to the lower pressure (35a); and (e) the first heat exchange medium (23) is further connected to the additional expansion medium (12) to receive at least the expanded liquid stream (35a) and heat it in order to supply, in this way, at least a portion of the cooling from step (1), the first heat exchange medium (23) being additionally connected to said mass transfer medium (115d) to supply at least the expanded and heated liquid stream (35b) as a lower feed for it. 19. Apparatus according to claim 17, characterized by the fact that (i) a third heat exchange means (10) is connected to the dividing means to receive said first portion (32) of the element (b) and further cool it (32a); (ii) said additional combining means is connected to the third heat exchange means (10) and said first heat exchange means (23) to receive the first additionally cooled portion (32a) and the second additionally cooled portion ( 33) of the element (d) and form a cooled gas stream (31a); (iii) said third heat exchange means (10) is additionally connected to the first liquid collection means to receive the first distillation liquid stream (43) from the element (4) and heat it in order to supply , thus, at least a portion of the cooling in step (i); and (iv) said mass transfer means (115d) is connected to the third heat exchange means (10) to receive the first stream of heated distillation liquid (43a) as a top feed for it. 20. Apparatus according to claim 19, characterized in that (a) said additional combining means is adapted to receive said first additionally cooled portion (32a) of element (i) and the second additionally cooled portion ( 33) of the element (d) and form a partially condensed gas stream (31a); (b) said additional separation means (11, 115e) is connected to the additional combination means to receive the partially condensed gas stream (31a) and separate it into a vapor stream (34) and at least a liquid stream (35); (c) said expansion means (13) is connected to the additional separation means (11, 115e) to receive the vapor stream (34) and expand it to a lower pressure (34a), through which it is further cooled; (d) said absorption means (115c) is connected to the expansion means (13) to receive the expanded chilled vapor stream (34a) as a lower feed therein; (e) said additional expansion means (12) is connected to the additional separation means (11, 115e) to receive at least one liquid stream (35) and expand it to the lower pressure (35a); and (f) said first heat exchange means (23) is additionally connected to the additional expansion means (12) to receive at least one expanded liquid stream (35a) and heat it, to thereby supply at least at least a portion of the cooling step (1), the first heat exchange medium (23) being additionally connected to the mass transfer medium (115d) to provide at least one expanded liquid stream (35b) as a bottom fed at the same. 21. Apparatus according to any one of claims 14, 16, 17, 18 or 20, characterized in that the additional separation medium (115e) is housed in the processing assembly (115). 22. Apparatus according to any one of claims 15, 16 or 21, characterized in that (1) said mass transfer means (115d) is adapted to be connected to the second heat exchange means (17) to receive the first stream of heated distillation liquid (43) from element (a) in an intermediate feed position; (2) a dividing means is connected to said separating means (18) to receive the condensed current (40, 40a) and to divide it into at least first (41) and second (42) reflux currents; (3) said absorption means (115c) is adapted to be connected to said dividing means to receive the first reflux current (41), as the feed above it; and (4) said mass transfer means (115d) is adapted to be connected to the dividing means to receive said second reflux current (42) as the feed above it. 23. Apparatus according to any one of claims 19, 20 or 21, characterized in that (1) the mass transfer medium (115d) is adapted to be connected to the third heat exchange medium (10) for receiving the first stream of heated distillation liquid (43) in an intermediate feed position; (2) an additional dividing means is connected to said separating means (18) to receive the condensed current (40, 40a) and to divide it into at least first (41) and second (42) reflux currents; (3) said absorption means (115c) is adapted to be connected to the additional dividing means to receive said first reflux current (41) as the feed above it; and (4) said mass transfer means (115d) is adapted to be connected to the additional dividing means to receive said second reflux current (42) as the feed above it. 24. Apparatus according to any of claims 17, 18 or 21, characterized in that (1) said mass transfer means (115d) is adapted to be connected to the heat exchange and additional mass for receiving the first stream of heated distillation liquid (43a) from element (g) in an intermediate feed position; (2) an additional dividing means is connected to the second separating means (18) to receive the condensed current (40, 40a) and divide it into at least first (41) and second (42) reflux currents; (3) said absorption means (115c) is adapted to be connected to the additional dividing means to receive the first reflux current (41) as the feed above that; and (4) said mass transfer means (115d) is adapted to be connected to the additional dividing means to receive the second reflux current (42) as the feed above that. 25. Apparatus according to any of claims 13, 15, or 22, characterized in that (1) a gas collection means (115e) is housed in the processing assembly (115); (2) an additional mass and heat transfer medium is included within the gas collection medium (115e), the additional mass and heat transfer medium including one or more passages to an external cooling medium; (3) said gas collection means (115e) is connected to the first heat exchange means (23) to receive the cooled gas stream (31a) from the element (1) and direct it to said transfer means of mass and additional heat to be additionally cooled by the external cooling medium; and (4) the expansion medium (13) is adapted to be connected to the gas collection medium (115e) to receive the additional cooled gas stream (34) and expand it to the lower pressure (34a), the medium expansion valve (13) being further connected to the absorption medium (115c) to supply the additionally expanded chilled gas stream (34a) as the supply below that. 26. Apparatus according to either of claims 19 or 23, characterized in that (1) a gas collection means (115e) is housed in the processing assembly (115); (2) an additional mass and heat transfer medium is included within the gas collection medium (115e), the additional mass and heat transfer medium including one or more passages to an external cooling medium; (3) the gas collection medium (115e) is connected to the additional combining medium to receive the cooled gas stream (31a) from the element (ii) and direct it to the mass and additional heat transfer medium to be additionally cooled by the external cooling medium; and (4) the expansion medium (13) is adapted to be connected to the gas collection medium (115e) to receive the additional cooled gas stream (34) and expand it to the lower pressure (34a), the medium expansion (13) being further connected to the absorption medium (115c) to supply the cooled gas stream (34a) further expanded as the supply below that. 27. Apparatus according to any one of claims 14, 16, 20, 21, 23 or 24, characterized in that (1) an additional mass and heat transfer means is included inside the first separation means (11, 115e), the mass and additional heat transfer medium including one or more passages to an external cooling medium; (2) the steam stream is directed to the mass and additional heat transfer medium to be cooled by the external cooling medium to form additional condensate; and (3) the condensate becomes a part of at least one separate liquid stream therein.

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