KR20120027488A - Hydrocarbon gas processing - Google Patents

Abstract

A method and apparatus for recovering heavy hydrocarbon components from a hydrocarbon gas stream in a compact processing assembly is disclosed. The gas stream is cooled, condensed, expanded to a lower pressure, and fed as feed to absorbing means in the processing assembly. The distillation liquid stream is collected from the absorbing means and directed to the heat and mass transfer means within the processing assembly to strip its volatile components while cooling the gas stream. The distillation stream is collected from the heat and mass transfer means and cooled sufficiently to at least partially condense it and form a condensed stream with the residual vapor stream. The amount and temperature of the feed is maintained at the temperature at which most of the desired components are recovered in the stripped distillation liquid stream.

Description

Hydrocarbon gas treatment method {HYDROCARBON GAS PROCESSING}

The present invention relates to a gas separation method and apparatus comprising a hydrocarbon. Applicants filed in accordance with Title U.S. Proclaim provisional application number 61 / 186,361. Applicant is required to file a U.S. U.S. Patent Application Serial No. 12 / 772,472, filed March 31, 2010, and in part- continuous application. US patent application filed as part-continuous application of patent application No. 12 / 750,862 and US application patent filed March 19, 2010 as part-continuous application of US patent application No. 12 / 717,394 Priority is claimed as part-continuous application of No. 12 / 689,616 and as part of part-continuous application of US Patent Application No. 12 / 372,604, filed February 17, 2009. Assignee S.M.E. Products LP and Ortloff Engineers, Ltd. were parties to a joint research agreement that was valid before the invention of the present application.

Ethylene, ethane, propylene, propane, and / or heavier hydrocarbons include natural gas, refinery gas, and coal, crude oil, naphtha, oil shale, tar sands, and lignite. Can be recovered from various gases, such as synthesis gas streams obtained from other hydrocarbon materials. Natural gas usually has mainly methane and ethane as its main part, ie methane and ethane together constitute at least (50) mole percent of the gas. Natural gas also contains relatively minor amounts of heavy hydrocarbons such as propane, butane, pentane and the like, as well as hydrogen, nitrogen, carbon dioxide and other gases and the like.

The present invention relates generally to the recovery of ethylene, ethane, propylene, propane, and heavy hydrocarbons from such gas streams. Typical analyzes of the gas streams to be treated according to the invention are in approximate mole percent, 90.3% methane, 4.0% ethane and other C ₂ components, 1.7% propane and other C ₃ components, 0.3% isobutane, 0.5 % Normal butane, and 0.8% pentane plus, and the balance is nitrogen and carbon dioxide. There is also often a gas containing sulfur.

Historically, periodic price fluctuations of natural gas and its liquefied natural gas (NGL) components have often degraded the value-added ethane, ethylene, propane, propylene, and heavy hydrocarbon components as liquid products. This has led to the need for a process that can recover these products more efficiently, a method that provides efficient recovery with less capital investment, and a process that can be easily adapted or adjusted to alter the recovery of specific components over a wide range. Imported Processes available for the separation of these materials include processes based on cooling and refrigeration of gases, absorption of oil and absorption of cooling oil. In addition, cryogenic processes are becoming commonplace because high-efficiency devices are available that expand the gas being processed while producing power and at the same time recover heat from it. Depending on the pressure of the gas source, the richness of the gas (ethane, ethylene, and heavy hydrocarbon content) and the desired end product, each or a combination of these processes can be used.

Cryogenic expansion processes are currently generally preferred for liquefied natural gas recovery because they provide maximum simplicity with easy start, work flexibility, good efficiency, stability and good reliability. U.S. Patent number 3,292,380; 4,061,481; 4,061,481; 4,140,504; 4,140,504; 4,157,904; 4,157,904; No. 4,171,964; No. 4,185,978; No. 4,251,249; 4,278,457; No. 4,519,824; 4,617,039; 4,687,499; No. 4,689,063; 4,690,702; 4,690,702; No. 4,854,955; No. 4,869,740; No. 4,889,545; 5,275,005; 5,275,005; 5,555,748; 5,555,748; 5,566,554; 5,566,554; 5,568,737; 5,568,737; No. 5,771,712; 5,799,507; 5,799,507; 5,881,569; 5,881,569; 5,890,378; 5,890,378; 5,983,664; 5,983,664; No. 6,182,469; No. 6,578,379; 6,712,880; 6,915,662; 6,915,662; No. 7,191,617; No. 7,219,513; Reannounced U.S. Patent number 33,408; And co-pending application 11 / 430,412; 11 / 839,693; 11 / 971,491; And 12 / 206,230 describe related processes (in some cases the description of the invention is based on different process conditions than those described in the referenced US patent).

In a typical cryogenic expansion recovery process, the gas stream supplied under pressure is cooled by heat exchange with an external cooling source, such as another stream of the process and / or a propane compression-cooling system. If the gas is cooled, and can be collected in one or more separators (separator) as a high pressure liquid to the liquid condenses part containing the desired C ₂ + components. Depending on the richness of the gas and the amount of liquid formed, the high pressure liquid may expand to low pressure and fractionate distillate. Evaporation in the expansion phase of the liquid results in additional cooling of the stream. Under certain conditions, it may be desirable to pre-cool the high pressure liquid prior to expansion to further lower the temperature due to expansion. The expanded stream, consisting of a liquid and vapor mixture, is fractionated in a distillation (demethanizer or deethanizer) column. In this column, the expansion cooled stream (s) is distilled off to allow methane, nitrogen and other residues remaining as overhead vapors from the desired C ₂ component, C ₃ component and heavy hydrocarbon component as the bottom liquid product. Volatile gases are separated or methane, C ₂ components, nitrogen and other volatile gases remaining as overhead vapors are separated from the desired C ₃ and heavy hydrocarbon components as the bottom liquid product.

If the feed gas is not completely condensed (usually not), the partial vapor can separate the remaining steam into two streams. A portion of the vapor can be conveyed to the low pressure side where additional liquid is condensed by further cooling of the stream via a work expansion machine or engine, or expansion valve. The pressure after expansion is essentially the same as the pressure at which the distillation column is operated. The combined vapor-liquid phases obtained from the expansion are provided as feed to the column.

The remainder of the vapor is substantially cooled and condensed by heat exchange with other process streams, for example cold fractionation towers. Some or all of the high pressure-liquid may combine with this steam portion before cooling. The resulting cooled stream is then expanded through a suitable expansion device, such as an expansion valve, to the pressure at which the demethane absorber is operated. During expansion, the liquid portion evaporates, resulting in cooling of the entire stream. The flash expanded stream is then fed as a top feed to the demethane absorber. In general, the vapor portion of the flash expanded stream and the demethane absorber overhead vapor are mixed in the upper separation section of the fractionation tower as residual methane product gas. Alternatively, the cooled, expanded stream is fed to the separator to provide vapor and liquid streams. The vapor is mixed with the top and the liquid is fed to the column as a top column feed.

In the ideal operation of such a separation process, the residual gas leaving the process contains substantially all of the methane in the feed gas, essentially no heavy hydrocarbon components, and the bottom fraction leaving the demethane absorber is essentially methane or volatile. It contains no components at all and contains substantially all of the heavy hydrocarbon components. In practice, however, this ideal situation is not achieved because conventional demethane absorbers are mostly operated with stripping columns. Thus, the methane product of the process generally contains steam leaving the upper zone fractional distillation stage of the column, along with the steam not undergoing any rectification stage. The overhead liquid feed may contain these components and C ₃ Of significant C ₃ and C ₄ + components because they contain significant amounts of heavy hydrocarbon components derived from the corresponding equilibrium amounts of components and C ₄ + components and of the heavy hydrocarbon components in the steam leaving the upper fractional distillation stage of the demethane absorber. Loss occurs. The loss of these preferred components is significantly reduced by bringing the rising vapors into contact with a significant amount of liquid (reflux) capable of absorbing the C ₃ component, C ₄ component and heavy hydrocarbons from the steam.

Recently, preferred hydrocarbon separation processes use the upper region absorber section to provide additional rectification of the rising vapor. One process for generating the reflux stream for the upper rectifying section is to use lateral extraction of the vapor rising from the bottom of the fractionation tower. Due to the relatively high concentration of C ₂ components in the bottoms steam of the fractionation tower, a significant amount of liquid can be obtained by using only the cooling available for cold steam, sometimes leaving the upper rectification section, without raising its pressure in this side extraction stream. Can be condensed. These condensed liquids, mainly liquid methane and ethane, are used to absorb the C ₃ component, C ₄ component and bihydrocarbon component from the rising vapor through the upper rectifying section, thus containing these beneficial substances contained in the bottom liquid product from the demethane absorber. The components can be collected. US Pat. No. 7,191,617 is an example of this kind of process.

The present invention utilizes novel means for performing the various steps described above more effectively and with fewer devices. This is achieved by combining what has been individual devices up to now into a common housing, thereby reducing the space required for the treatment plant and reducing the capital cost of the facility. Surprisingly, Applicants have found that a more compact deployment also significantly reduces the power consumption required to achieve a constant recovery level, thereby increasing process efficiency and reducing plant operating costs. In addition, the more compact layout eliminates much of the piping used to connect individual equipment to each other in conventional plant designs, further reducing investment costs and also eliminating associated flanged piping connections. Because pipe flanges are a potential leak source (of hydrocarbons, which are volatile organic compounds (VOCs) that cause greenhouse gases and may also be precursors to atmospheric ozone formation), removal of these flanges can destroy the atmosphere. Reduces the potential for emissions.

According to the present invention, it has been found that more than 99% of C ₃ and C ₄ + recovery is possible without loss in C ₂ component recovery without the need for compression of the reflux stream to the demethane absorber. The present invention provides the additional advantage of maintaining at least 99% recovery of the C ₃ and C ₄ + components while adjusting the recovery of the C ₂ component from a high value to a low value. Furthermore, the present invention is essentially 100% of methane (or C ₂ component) and light components from C ₂ (or C ₃ ) and heavy components while maintaining the same recovery level with reduced energy requirements compared to the prior art. Enable separation. Although the present invention is applicable at lower pressures and higher temperatures, the process feed gas may be treated at 400 to 1500 psia [2,758 to 10,342] under conditions that require an NGL recovery column top temperature of -50 ° F. [-46 ° C.] or less. kPa (a)] is particularly advantageous when in the range.

To better understand the present invention, reference is made to the following examples and figures.

1 is a flow chart of a natural gas treatment plant of the prior art according to US Pat. No. 7,191,617;
2 is a flow chart of a natural gas processing plant according to the present invention.
3 to 9 are flow charts illustrating alternative means of the invention applied to a natural gas stream.

In the following description of the figure, tables are provided summarizing the calculated flow rates for representative process conditions. In the tables presented here, the values for flow rates (moles per hour) have been rounded to the nearest integer for convenience. The total flow rate shown in the table includes all non-hydrocarbon components and is therefore generally greater than the sum of the stream flow rates of the hydrocarbon components. The temperature shown is an approximation rounded up to the nearest integer. It should also be noted that the process design calculations performed for the purpose of comparing the processes shown in the figures are based on the assumption that there is no heat leakage from the surroundings to the process or from the process to the surroundings. The quality of commercially available insulators makes this a very reasonable assumption and also what is generally made by those skilled in the art.

For convenience, process parameters are listed in both traditional British and International Standard (SI) units. The molar flow rates given in the table can be interpreted as pound moles per hour or kg moles per hour. The energy consumption reported in horsepower (HP) and / or thousands of British thermal units (MBTU / Hr) per hour corresponds to the molar flow rate stated in pound moles per hour. The energy consumption, reported in kilowatts (kW), corresponds to the molar flow rate described above in kg moles per hour.

Description of the prior art

1 is a process flow diagram illustrating a design of a process plant for recovery of C ₂ + components from natural gas using prior art according to US Patent No. 7,191,617. In the simulation of this process, the inlet gas enters the plant as stream 31 at a temperature of 110 ° F. [43 ° C.] and a pressure of 915 psia [6,307 kPa (a)]. If the incoming gas contains a concentration of sulfur compounds that inhibit the product stream from being in compliance, these sulfur compounds are removed by appropriate pretreatment of the feed gas (not shown). In addition, the feed stream is typically dehydrated to prevent the formation of hydrates (ice) under cryogenic conditions. Solid desiccants have generally been used for this purpose.

Feed stream 31 is divided into two parts, stream 32 and stream 33. Stream 32 is cooled to -32 ° F [-36 ° C] in heat exchanger 10 by heat exchange with a cooled residual gas stream 50a and stream 33 at a temperature of 50 ° F [10 ° C]. -18 in the heat exchanger 11 by heat exchange with a demethane absorber reboiler liquid (stream 43) and a side reboiler liquid (stream 42) at a temperature of -36 ° F [-38 ° C]. Cool to ℉ [-28 ° C]. Stream 32a and stream 33a are recombined to form stream 31a, which is subjected to separator 12 under a temperature of -28 ° F. [-33 ° C.] and a pressure of 893 psia [6,155 kPa (a)]. And vapor (stream 34) is separated from the condensed liquid (stream 35). The separator liquid (stream 35) is expanded by the expansion valve 17 to the working pressure of the fractionation tower 18 (approximately 401 psia [2,765 kPa (a)]) and the fractionation tower 18 at the lower intermediate column feed point. Stream 35a is cooled to −52 ° F. [−46 ° C.] prior to feeding.

The vapor from the separator 12 (stream 34) is divided into two streams, stream 38 and stream 39. Stream 38 containing about 32% of the total vapor is passed through a heat exchanger 13 in heat exchange relationship with the cooled residual gas stream 50 where it is cooled to substantially condense. Substantially condensed stream 38a produced at a temperature of −130 ° F. [−90 ° C.] is then flash expanded through expansion valve 14 to expand to the working pressure of fractional distillation tower 18. During expansion, a portion of the stream is evaporated to allow cooling of the entire stream. In the process shown in FIG. 1, expanded stream 38b leaving expansion valve 14 reaches a temperature of -140 ° F. [-96 ° C.] and is fed to fractionation tower 18 at the upper mid-column feed point. .

The remaining 68% of the steam from the separator 12 (stream 39) enters one inflator 15 where mechanical energy is extracted from this portion of the high pressure feed. This expander 15 expands the vapor substantially in an entropy manner to the fractionation tower operating pressure, and this one expansion cools the expanded stream 39a to a temperature of approximately -94 ° F. [-70 ° C.]. Typical inflators on the market can recover nearly 80-85% of theoretically available work in an ideal isenprop mode expansion. The recovered work is often used, for example, to drive a heated residual gas stream (a centrifugal compressor (eg, item 16) that can be used to recompress stream 50b). 39a) is then fed as feed to fractionation tower 18 at the lower mid-column feed point.

The demethane absorber in the fractionation tower 18 is a conventional distillation column having a plurality of vertically spaced trays, one or more packed beds or a combination of some trays and packed beds. As is often the case in natural gas treatment plants, the demethane absorber fractionation tower falls in two sections: the vapor portion of the ascending streams 38b, 39a and falling downwards, giving the C ₂ component, C ₃ component and An upper absorption (commutation) section 18a comprising said trays and / or a packed bed providing the necessary contact between the cooling liquid to condense and absorb heavier components; And a bottom stripping (talmethane) section 18b comprising the trays and / or packed bed providing the necessary contact between the liquid falling down and the vapor rising up. The demethane section 18b is also used to heat and evaporate a portion of the liquid flowing down the column to provide stripping vapor flowing over the column to strip the liquid product of the methane and lighter components (stream 44). Boilers (reboilers and side reboilers already described) are also included. The liquid product stream 44 exits the bottom of the fractionation tower at a temperature of 74 ° F. [23 ° C.], based on the methane to ethane ratio of 0.010: 1, based on conventional specifications, based on the mass of the bottom product.

A portion of the distillation vapor (stream 45) is recovered from the top of the stripping section 18b. This stream is then cooled from -109 ° F [-78 ° C] to -134 ° F [-92 ° C] and exits the top of the demethane absorber 18 at a temperature of -139 ° F [-95 ° C]. Partially condensed in the heat exchanger 20 by heat exchange with the exiting cooled demethane absorber overhead stream 41 (stream 45a). The cooled demethane absorber overhead stream is slightly warmed to a temperature of -134 ° F. [-92 ° C.] while cooling and condensing at least a portion of stream 45 (stream 41a).

The operating pressure 398 psia [2,748 kPa (a)] in the reflux separator 21 is kept slightly lower than the operating pressure of the demethane absorber 18. This provides the driving force for the distillation vapor stream 45 to flow through the heat exchanger 20 to the reflux separator 21, where the condensed liquid (stream 47) is subjected to uncondensed vapor (stream 46). )). Stream 46 is then combined with the warmed methane absorber overhead stream 41a from heat exchanger 20 to form a cooled residual gas stream 50 at a temperature of -134 ° F. [-92 ° C.].

Liquid stream 47 from reflux separator 21 is extruded by pump 22 to a pressure slightly above the operating pressure of demethane absorber 18, and stream 47a is then cooled top column feed (reflux) ) Is supplied to the demethane absorber 18. This cooled liquid reflux absorbs and condenses the C ₃ and heavier components that rise in the upper rectifier of the absorption section 18a of the methane absorber 18.

The distillation vapor stream (stream 41) forming the fractionation tower column top (stream 41) is warmed in the heat exchanger 20 while providing cooling to the distillation stream 45 as previously described and then combined with the stream 46 Form a cooled residual gas stream 50. Residual gas is heated in heat exchanger 13 (where -46 ° F. [-44 ° C.] (stream 50a)) and in heat exchanger 10 (while providing cooling as previously described) at 102 ° F. 39 ° C.] (heated up to stream 50b) to the counter flow with the inlet feed gas. The residual gas is then recompressed in two stages. The first stage is the compressor 16 driven by the expander 15. The second stage is a compressor 23 driven by a supplemental power source that compresses residual gas (stream 50d) up to sales line pressure. After cooling to 110 [deg.] F. [43 [deg.] C.] in the exhaust cooler 24, the residual gas stream 50e is 915 psia [6,307 kPa (a)] (typically roughly comparable to the inlet pressure) to meet the line requirements. The pressure of the gas flows into the piping for sale.

A summary of stream flow rates and energy consumption for the process illustrated in FIG. 1 is set forth in the following table:

Description of the invention

2 illustrates a flowchart of a process according to the invention. The feed gas compositions and conditions considered in the process shown in FIG. 2 are the same as those of FIG. 1. Thus, the process of FIG. 2 can be compared with the process of FIG. 1 to illustrate the advantages of the present invention.

In the process simulation of FIG. 2, the inlet gas enters the plant as stream 31 and is divided into two parts, stream 32 and stream 33. The first portion, stream 32, enters heat exchange means at the top of the feed cooling section 118a in the processing assembly 118. Such heat exchange means consist of fin tube type heat exchangers, plate heat exchangers, parallel flow aluminum heat exchangers, or other types of heat transfer devices including multipass and / or multiservice heat exchangers. Can be. The heat exchange means is retained from the condensation section 118b in the stream 32 flowing through one passage of the heat exchange means and in the processing assembly 118 that was heated in the heat exchange means below the feed cooling section 118a. And to provide heat exchange between the gas streams. Stream 32 is cooled while further heating the residual gas stream together with stream 32a leaving the heat exchange means at a temperature of −30 ° F. [−35 ° C.].

The second portion, stream 33, enters the heat and mass transfer means in the stripping section 118e in the processing assembly 118. The heat and material transfer means may also consist of fin tube type heat exchangers, plate heat exchangers, parallel flow aluminum heat exchangers, or other types of heat transfer devices including multiple passages and / or multiple service heat exchangers. The heat and mass transfer means is configured to provide heat exchange between the stream 33 flowing through one passage of the heat and mass transfer means and the distillation liquid stream flowing down from the absorption section 118d in the treatment assembly 118, Thus, the stream 33 is configured to heat the distillation liquid stream before the stream 33 leaves the heat and mass transfer means and to cool the stream 33 while cooling the stream 33a to a temperature of -42 ° F. [-41 ° C.]. do. As the distillation liquid stream is heated, a portion of it is evaporated to form a stripping vapor that rises upward as the residual liquid continues to flow down through the heat and mass transfer means. The heat and mass transfer means serve to provide continuous contact between the stripping vapor and the distillation liquid stream to strip mass the liquid product stream 44 of methane and lighter components while providing mass transfer between the vapor and liquid phases.

Streams 32a and 33a recombine to form stream 31a, which is treated at a temperature of −34 ° F. [−37 ° C.] and a pressure of 900 psia [6,203 kPa (a)]. ) Into separation section 118f whereby steam (stream 34) is separated from condensed liquid (stream 35). Separator section 118f has an internal head or other means to separate separator section 118f from stripping section 118e so that the two sections within processing assembly 118 can operate at different pressures.

The vapor (stream 34) and the liquid (stream 35) having two streams, i.e., stream 36 and stream 39, and stream 37 and stream each from the separator section (118f) ( Divided into 40). Stream 36 containing about 31% of the total vapor is combined with stream 37 containing about 50% of the total liquid and the combined stream 38 is fed to the cooling section 118a in the processing assembly 118. Enter the heat exchange means at the bottom of the The heat exchange means may likewise consist of other types of heat transfer devices, including finned tube heat exchangers, plate heat exchangers, parallel flow aluminum heat exchangers, or multiple passages and / or multiple service heat exchangers. The heat exchange means provides heat exchange between the stream 38 flowing through one passage of the heat exchange means and the residual gas stream in the condensation section 118b, so that the stream 38 substantially reduces the heating of the residual gas stream. Configured to cool and condense.

Substantially condensed stream 38a produced at a temperature of −128 ° F. [−89 ° C.] is followed by rectification section 118c (absorption means) and absorption section 118d (another absorption means) within treatment assembly 118. Flash expansion through expansion valve 14 to an operating pressure of approximately 402 psia [2,772 kPa (a)]. A portion of the stream may evaporate during expansion to allow cooling of the entire stream. In the process shown in FIG. 2, the expanded stream 38b leaving expansion valve 14 reaches a temperature of −139 ° F. [−95 ° C.] and is located between rectifying section 118c and absorption section 118d. Supplied to the processing assembly 118.

The remaining 69% of the steam from separator section 118f (stream 39) enters one inflator 15 where mechanical energy is extracted from a portion of this high pressure feed. The expander 15 expands the vapor in an isentropic manner up to the working pressure of the absorption section 118d, which one expansion cools the expanded stream 39a to a temperature of approximately -100 ° F. [-73 ° C.]. . The partially condensed expanded stream 39a is then supplied as a feed to the bottom of the absorption section 118d in the processing assembly 118 and is in contact with the liquid supplied to the top of the absorption section 118d. The remaining 50% of the liquid from the separator section 118f (stream 40) is expanded by the expansion valve 17 to the working pressure of the stripping section 118e in the processing assembly 118 and the stream 40a Cool down to a temperature of -60 ° F [-51 ° C]. The heat and mass transfer means in the stripping section 118e are configured at the top and bottom so that the expanded liquid stream 40a can enter the stripping section 118e between the top and the bottom.

A portion of the distillation vapor (first distillation vapor stream 45) is recovered from the top of the stripping section 118e at a temperature of -95 ° F. [-71 ° C.] and the condensation section 118b in the treatment assembly 118. To heat exchange means. The heat exchange means may likewise consist of other types of heat transfer devices, including finned tube heat exchangers, plate heat exchangers, parallel flow aluminum heat exchangers, or multiple passages and / or multiple service heat exchangers. The heat exchange means is provided with heat exchange between the first distillation vapor stream 45 flowing through one passage of the heat exchange means and the second distillation vapor stream resulting from the rectifying section 118e in the treatment assembly 118, The second distillation vapor stream is configured to heat while cooling the first distillation vapor stream 45. Stream 45 is cooled to a temperature of -134 ° F. [-92 ° C.], at least partially condensed, and then exits the heat exchange means and separates into its vapor and liquid phases, respectively. The vapor phase, if present, combines with a heated second distillation vapor stream exiting the heat exchange means to form a residual gas stream that provides cooling in feed cooling section 118a as previously described. The liquid phase (stream 48) is treated by gravity flow to process assembly 118. It is supplied as a cooled top column feed (reflux) to the top of the rectifying section 118c in the chamber.

The rectifying section 118c and the absorbing section 118d comprise absorbing means consisting of a plurality of trays vertically spaced, at least one packed bed, or any combination of trays and packed bed. The trays and / or packed bed in the rectifying section 118c and the absorbing section 118d provide the necessary contact between the vapor rising up and the cooling liquid falling down. The liquid portion of the expanded stream 39a mixes with the liquid falling down from the absorbing section 118d, and the mixed liquid continues to the bottom stripping section 118e. Stripping vapors arising from the stripping section 118e mix with the vapor portion of the expanded stream 39a and ascend up through the absorption section 118d and come into contact with the cooling liquid falling down, thereby removing C ₂ from these vapors. Condenses and absorbs most of the components, C ₃ components, and heavier components. Vapor from the absorption section 118d combines with the vapor portion of the expanded stream 38b and rises up through the rectifying section 118c and is in contact with the falling cooling liquid (stream 48), Most of the C ₃ and heavier components remaining in these vapors condense and absorb. The liquid portion of the expanded stream 38b mixes with the liquid falling down from the rectifying section 118c and this mixed liquid continues to the lower absorption section 118d.

Methane and lighter components were stripped in the distillation liquid flowing down from the heat and mass transfer means in the processing assembly 118 internal stripping section 118e. The resulting liquid product (stream 44) exits the bottom of stripping section 118e and leaves treatment assembly 118 at a temperature of 74 ° F. [23 ° C.]. The second distillation vapor stream from rectification section 118c is warmed in condensation section 118b and provides cooling to stream 45, as previously described. The warmed second distillation vapor stream combines with steam separated from the cooled first distillation vapor stream 45, as previously described. The resulting residual gas stream is heated in feed cooling section 118a and provides cooling to streams 32 and 38, as previously described, so that residual gas stream 50 is then 104 [deg.] F. [40 [deg.] C.] Leaves the processing assembly 118 at a temperature of. The residual gas stream is recompressed in two stages, consisting of a compressor 16 driven by the expander 15 and a compressor 23 driven by a supplemental power source. After cooling to 110 [deg.] F. [43 [deg.] C.] in the exhaust cooler 24, the residual gas stream 50c is reduced to 915 psia [6,307 kPa (a)] (typically roughly equal to the inlet pressure) sufficient to meet the line requirements. Under pressure flows into the gas piping for sale.

A summary of stream flow rates and energy consumption for the process illustrated in FIG. 2 is set forth in the following table:

Compared to the prior art, the present invention maintains essentially the same ethane recovery (85.03% vs. 85.00% -prior art) in comparison of Tables I and II, propane recovery slightly improved from 99.11% to 99.16%, and essentially It shows the same butane + recovery (99.98% vs. 99.99% -prior art). However, further comparisons of Tables I and II show that the product yields were obtained using significantly less power than the prior art. In terms of recovery efficiency (defined as the amount of ethane recovered per unit power), the present invention represents an improvement of at least 5% over the prior art of the FIG. 1 process.

The improvement in recovery efficiency provided by the present invention over the prior art recovery efficiency of the FIG. 1 process is mainly due to two factors. First, processing assembly 118 The compact arrangement of the heat exchange means in the supply cooling section 118a and the condensation section 118b and the heat and mass transfer means in the stripping section 118e is the pressure imposed by the interconnected piping found in conventional processing plants. Relieve the descent. The result is that the residual gas flowing into the compressor 16 is at a higher pressure in the present invention and the residual gas entering the compressor 23 is at a significantly higher pressure as compared to the prior art, whereby the present invention allows the residual gas to be piped. Reduce the power needed to return to pressure.

Second, use of heat and mass transfer means in stripping section 118e to simultaneously heat the distillation liquid leaving absorbing section 118d, making the vapor produced in contact with the distillation liquid and stripping its volatile components. It is more efficient than using a conventional distillation column with an external reboiler. The volatile components continue to be stripped from the liquid, lowering the concentration of the volatile components contained in the stripping vapor more quickly, thereby improving the stripping efficiency of the present invention.

The present invention also provides two other advantages over the prior art, in addition to improving process efficiency. First, the compact arrangement of the treatment assembly 118 of the present invention comprises eight separate equipment items of the prior art (heat exchanger 10, 11, 13 and 20, separator 12, Reflux separator 21, reflux pump 22, and fractionation tower 18 are replaced with a single piece of equipment (treatment assembly 118 in FIG. 2). This reduces ground space requirements, eliminates interconnecting piping, eliminates the power consumed by the reflux pump, and reduces the operating and capital costs of the treatment plant used in the present invention as compared to the prior art. Secondly, the elimination of interconnecting piping means that the treatment plant using the present invention has much fewer flanged connections than in the prior art, thus reducing the number of potential leak sources in the plant. Hydrocarbons are volatile organic compounds (VOCs), some of which are classified as greenhouse gases, and some may be precursors to atmospheric ozone formation, and the present invention has the potential for air emissions that can damage the environment. It means to reduce.

Etc Examples

As described above for the embodiment of the present invention shown in FIG. 2, the first distillation vapor stream 45 is partially condensed, and the resulting condensate is directed to the rectifying section 118c of the treatment assembly 118. It was used to absorb effective C ₃ and heavier components from the vapor rising through. However, the present invention is not limited to this embodiment. For example, only a portion of these vapors may be treated in this manner, or in other design considerations, a portion of the steam or condensate may have to bypass the rectifying section 118c and / or the absorbing section 118d of the treatment assembly 118. In this case it may be beneficial to use only a portion of the condensate as an absorbent. In some situations, it may be advantageous to condense all rather than partially condense the first distillation vapor stream 45 in the condensation section 118b. In other situations, full vapor side extraction from stripping section 118e may be advantageous than partial vapor side extraction of first distillation vapor stream 45. It should also be appreciated that depending on the composition of the feed gas stream, it may be beneficial to use external cooling to provide partial cooling of the first distillation vapor stream 45 in the condensation section 118b.

If the feed gas is less dense, the amount of liquid separated in the stream 35 is stripped between the expanded stream 39a and the expanded liquid stream 40a shown in FIGS. 2, 4, 6 and 8. The additional mass transfer region of section 118e may be small enough to not be reasonable. In this case, the heat and mass transfer means in the stripping section 118e may consist of a single section, and the expanded liquid stream 40a is introduced over the mass transfer means as shown in FIGS. 3, 5, 7 and 9. In some situations it may be advantageous for the expanded liquid stream 40a and expanded stream 39a to be combined such that the combined stream to the bottom of the absorption section 118d is supplied as a single feed. In some situations it may be advantageous to feed both the liquid stream 35 directly through the stream 40 to the stripping section 118e or to combine both the stream 36 and the liquid stream 35 via the stream 37. have. In the former case, there is no flow in stream 37 (indicated by dashed lines in FIGS. 2-9), and in separator section 118f (FIGS. 2-5)) or in separators 12 (FIGS. 6-9) and 13. In stream 36 only steam flows towards stream 38. In the latter case, an expansion device (such as expansion valve 17) for the stream 40 is not necessary (indicated by broken lines in FIGS. 3, 5, 7 and 9).

In some situations, it may be advantageous to use an external separator vessel to separate the cooled feed stream 31a rather than including the separator section 118f in the processing assembly 118. As shown in FIGS. 6-9, separator 12 may be used to separate the cooled feed stream 31a into a vapor stream 34 and a liquid stream 35.

In some situations, the lower portion of the feed cooling section 118a using a second portion (stream 33a in FIGS. 2-9) cooled in place of the first portion of stream 34 (stream 36). It may be advantageous to create a stream 38 which flows to the heat exchange means at. In this case, only the cooled first portion (stream 32a) is fed to separator section 118f (FIGS. 2-5) or separator 12 (FIGS. 6-9) and the resulting vapor stream 34 All are fed to one inflator 15.

Depending on the amount of bicarbonate in the feed gas and the feed gas pressure, the cooled feed stream 31a entering the separator section 118f in FIGS. 3 and 5, or the separator 12 in FIGS. 7 and 9 does not contain any liquid. (Because it is above its dew point or above its critical condensation pressure). In this case, there is no liquid in the streams 35, 37 (indicated by dashed lines), only the vapor contained in the stream 36 from the separator section 118f (FIGS. 3 and 5) or the stream from the separator 12 ( Vapor contained in FIG. 36 (FIGS. 7 and 9) flows into stream 38 and the expanded and substantially condensed stream (s) supplied to treatment assembly 118 between rectifying section 118c and absorbing section 118d. 38b). In such a situation, separator section 118f (FIGS. 3 and 5) or separator 12 (FIGS. 7 and 9) in processing assembly 118 may not be required.

Feed gas conditions, plant size, available equipment, or other factors may indicate that removal of one inflator 15, or replacement with an alternative expansion device (eg, expansion valve), is justified. Although individual stream expansion is shown in certain expansion devices, alternative expansion means can be used where appropriate. For example, depending on the conditions, one expansion of the substantially condensed portion of the feed stream (stream 38a) may be ensured.

According to the invention, external cooling can be used to supplement the inlet gas from the distillation vapor and the liquid stream, in particular in the case of abundant inlet gas. In such a case, the heat and mass transfer means may be included in the separator section 118f as shown by dashed lines in FIGS. 2-5 (or capture means if no liquid is included in the cooled feed stream 31a), or FIG. As shown by dashed lines at 6-9, heat and mass transfer means may be included in separator 12. The heat and material transfer means may consist of fin tube type heat exchangers, plate heat exchangers, parallel flow aluminum heat exchangers, or other types of heat transfer devices including multiple passages and / or multiple service heat exchangers. The heat and mass transfer means is arranged between a cooling stream (e.g., propane) flowing through one passage of the heat and mass transfer means and the steam portion of the stream 31a flowing upwards so that the coolant further cools the steam and further condenses additional liquid. Heat exchange is provided, and the additional liquid falls down to become part of the liquid removed from the stream 35. Alternatively, prior to stream 31a entering separator section 118f (FIGS. 2-5) or separator 12 (FIGS. 6-9), a stream 32a, using a conventional gas cooler with coolant, Stream 33a and / or stream 31a may be cooled.

Depending on the temperature and enrichment of the feed gas and the amount of C ₂ component to be recovered in the liquid product stream 44, the heating available from stream 33 to ensure that the liquid leaving stripping section 118e meets product specifications. It may not be enough. In such a case, the heat and mass transfer means in stripping section 118e may comprise a feed that provides supplemental heating to the heating medium, as shown by the dashed lines in FIGS. 2-9. Alternatively, another heat and mass transfer means may be included at the bottom of the stripping section 118e to provide supplemental heating, or the stream 33 may be heated before being fed to the heat and mass transfer means in the stripping section 118e. Can be heated to the medium.

Depending on the type of heat transfer device selected as the heat exchange means in the top and bottom of the feed cooling section 118a and / or in the condensation section 118b, these heat exchange means may be divided into a single multiple passage and / or multiple service heat transfer device. It is also possible to combine in. In such a case, the multiple passages and / or multiple service heat transfer devices may comprise steam separated from the stream 32, the stream 38, the stream 45, the cooled stream 45 and the second to obtain the desired cooling and heating. Suitable means for distributing, separating and collecting the distillation vapor stream.

In some situations it may be advantageous to provide additional mass transfer on top of the stripping section 118e. In this case, the mass transfer means will be located at the bottom where the expanded stream 39a enters the bottom of the absorption section 118d and at the top where the cooled second portion 33a leaves the heat and mass transfer means in the stripping section 118e. Can be.

Somewhat less preferred choices in the embodiments of FIGS. 2-5 of the present invention provide a separator vessel for the cooled first portion 32a and a separator vessel for the cooled second portion 33a, wherein the separated steam The streams are combined to form a vapor stream 34, and the separated liquid streams are combined here to form a liquid stream 35. Another somewhat less preferred option of the invention is feed cooling section 118a (rather than combining stream 37 and stream 36 to form a combined stream 38). Cooling stream 37 in a separate heat exchange means, expanding the cooled stream in a separate expansion device, and feeding the expanded stream to the middle portion of absorbing section 118d.

In some situations, it may be beneficial to provide reflux for the top of the stripping section 118e where lower recovery levels of the C ₂ component are particularly desirable. In such a case, the liquid phase of the cooled stream 45 leaving the heat exchange means in the condensation section 118b may be divided into two parts, stream 48 and stream 49. Stream 48 is fed to rectification section 118c as the top feed, while stream 49 is fed to the top of stripping section 118e to recover the first distillation vapor stream 45, prior to the treatment assembly. This section of 118 may partially rectify the distillation vapor. In some cases, the flow by gravity of streams 48 and 49 will be suitable (FIGS. 2, 3, 6, and 7), while in other cases, liquid phase (using reflux pump 22) may be used. Extrusion of stream 47) may be preferred (FIGS. 4, 5, 8, and 9). The relative amount of liquid phase split into streams 48 and 49 depends on several factors, including gas pressure, feed gas composition, desired C ₂ component recovery level, and amount of horsepower available. Optimal partitioning is generally unpredictable without evaluating the specific circumstances for the particular use of the present invention. In some situations, all of the liquid phase is fed to the rectifying section 118c in stream 48 as the top feed, and stripping section 118e in stream 49, as shown by dashed lines to stream 49. It may be advantageous to supply nothing at the top of the.

The relative amount of feed found in each branch of the split steam feed depends on several factors, including gas pressure, feed gas composition, the amount of heat economically extracted from the feed, and the amount of horsepower available. Get to know. Absorption Section (118d) More feeds above can increase recovery, but reduce the power recovered from the inflator, thereby increasing the recompression horsepower demand. Increasing the feed below the absorption section 118d reduces horsepower consumption but can also reduce product recovery.

The present invention provides an improved recovery of the C ₂ component, C ₃ component and heavy hydrocarbon component, or provides an improved recovery of the C ₃ component and heavy hydrocarbon component per utility consumption required to operate the process. Improvements in utility consumption required to operate the process include reduced power requirements for compression or recompression, reduced power requirements for external refrigeration, reduced energy requirements for supplemental heating, and reduced energy requirements for fractionation tower reboiling. In the form or combinations thereof.

While what has been described as preferred embodiments of the invention has been described, those skilled in the art can adapt the invention to various conditions, types of supplies and other requirements without departing from the spirit of the invention as defined in the following claims. Be aware that you can make other changes and modifications.

Claims (34)

A gas stream comprising methane, C ₂ components, C ₃ components, and heavier hydrocarbon components comprises a volatile residual gas fraction and most of the C ₂ components, C ₃ components, and heavy hydrocarbon components. In the method for separating into a relatively less volatile oil comprising or comprising the C ₃ components and heavy hydrocarbon components,
(1) said gas stream is divided into a first portion and a second portion;
(2) said first portion is cooled;
(3) said second portion is cooled;
(4) said cooled first portion is combined with said cooled second portion to form a cooled gas stream;
(5) said cooled gas stream is divided into first and second streams;
(6) said first stream is cooled to substantially condense both of the first stream, and then expands to a lower pressure whereby the first stream is cooled further;
(7) said expanded cooled first stream is supplied as a feed between a first absorbing means and a second absorbing means embedded in a processing assembly, said first absorbing means being located above said second absorbing means;
(8) said second stream is expanded to said lower pressure and is supplied as a bottom feed to said second absorbing means;
(9) The distillation liquid stream is collected from the lower region portion of the second absorbing means and heated in heat and mass transfer means embedded in the processing assembly, thereby supplying at least a portion of the cooling of step (3) and simultaneously Stripping more volatile components from the distillation liquid stream, and then the heated and stripped distillation liquid stream from the processing assembly is withdrawn into the relatively less volatile fraction;
(10) a first distillation vapor stream is collected from said upper region portion of said heat and mass transfer means and cooled enough to condense at least a portion thereof, thereby cooling the condensed stream and said first distillation vapor stream. Forming a residual vapor stream comprising any remaining uncondensed vapor;
(11) at least a portion of the condensed stream is fed to the first absorbing means as a top feed;
(12) a second distillation vapor stream is collected from the upper region portion of the first absorbing means and heated;
(13) said heated second distillation vapor stream is combined with any of said residual vapor stream to form a combined vapor stream;
(14) the combined vapor stream is heated, and then the heated combined vapor stream is withdrawn from the processing assembly as the volatile residual gas fraction;
(15) said heating of said second distillation vapor stream and said combined vapor stream takes place in one or more heat exchange means embedded in said processing assembly, thereby providing steps (2), (6), and (10) Supply at least a portion of the cooling of the battery; And
(16) the amount and temperature of the feed streams directed to the first and second absorbing means is equal to the temperature of the upper region portion of the first absorbing means at a temperature at which the majority of the components in the relatively less volatile fraction are recovered. Effective way to maintain. A gas stream comprising methane, C ₂ components, C ₃ components, and heavy hydrocarbon components comprises a volatile residual gas fraction and a majority of the C ₂ components, C ₃ components, and heavy hydrocarbon components or In the method for separating into a relatively less volatile oil containing the C ₃ components and heavy hydrocarbon components,
(1) said gas stream is divided into a first portion and a second portion;
(2) said first portion is cooled;
(3) said second portion is cooled;
(4) said cooled first portion is combined with said cooled second portion to form a partially condensed gas stream;
(5) said partially condensed gas stream is fed to a separation means, where it is separated to provide a vapor stream and at least one liquid stream;
(6) said vapor stream is divided into a first stream and a second stream;
(7) said first stream is cooled to substantially condense both of the first stream and then expands to a lower pressure whereby the first stream is cooled further;
(8) said expanded cooled first stream is supplied as a feed between a first absorbing means and a second absorbing means embedded in a processing assembly, said first absorbing means being located above said second absorbing means;
(9) said second stream is expanded to said lower pressure and is supplied as a bottom feed to said second absorbing means;
(10) A distillation liquid stream is collected from said lower region portion of said second absorbing means and heated in heat and mass transfer means embedded in said processing assembly, thereby providing at least a portion of the cooling of step (3) and At the same time stripping more volatile components from the distillation liquid stream and then from the processing assembly the heated, stripped distillation liquid stream is discharged as a relatively less volatile fraction;
(11) at least a portion of said at least one liquid stream is expanded to said lower pressure and is supplied as a feed to a processing assembly below said second absorbing means and above said heat and mass transfer means;
(12) a first distillation vapor stream is collected from the upper region portion of the heat and mass transfer means and cooled to condense at least a portion thereof, thereby cooling the condensed stream and the first distillation vapor stream. Forming a residual vapor stream comprising any remaining uncondensed vapor;
(13) at least a portion of the condensed stream is fed to the first absorbing means as a top feed;
(14) a second distillation vapor stream is collected from the upper region portion of the first absorbing means and heated;
(15) said heated second distillation vapor stream is combined with any of said residual vapor stream to form a combined vapor stream;
(16) the combined vapor stream is heated and then the heated combined vapor stream is withdrawn from the processing assembly as the volatile residual gas fraction;
(17) The heating of the second distillation vapor stream and the combined vapor stream takes place in one or more heat exchange means built into the treatment assembly, whereby the steps (2), (7), and (12) Supply at least a portion of the cooling; And
(18) The amount and temperature of the feed streams directed to the first and second absorbing means is equal to the temperature of the upper region portion of the first absorbing means at the temperature at which the majority of the components in the relatively less volatile fraction are recovered. Effective way to maintain. A gas stream comprising methane, C ₂ components, C ₃ components, and heavy hydrocarbon components comprises a volatile residual gas fraction and a majority of the C ₂ components, C ₃ components, and heavy hydrocarbon components or In the method of separating as a relatively less volatile oil comprising the C ₃ components and the heavy hydrocarbon components,
(1) said gas stream is divided into a first portion and a second portion;
(2) said first portion is cooled;
(3) said second portion is cooled;
(4) said cooled first portion is combined with said cooled second portion to form a partially condensed gas stream;
(5) said partially condensed gas stream is fed to a separation means, where it is separated to provide a vapor stream and at least one liquid stream;
(6) said vapor stream is divided into a first stream and a second stream;
(7) said first stream is combined with at least a portion of said at least one liquid stream to form a combined stream;
(8) the combined stream is cooled to substantially condense both of the combined streams and then expand to a lower pressure whereby the combined streams are cooled further;
(9) said expanded cooled combined stream is supplied as a feed between a first absorbing means and a second absorbing means embedded in a processing assembly, said first absorbing means being located above said second absorbing means;
(10) said second stream is expanded to said lower pressure and is supplied as a bottom feed to said second absorbing means;
(11) A distillation liquid stream is collected from said lower region portion of said second absorbing means and heated in heat and mass transfer means embedded in said processing assembly, thereby providing at least a portion of the cooling of step (3) and At the same time stripping more volatile components from the distillation liquid stream, and then from the processing assembly the heated, stripped distillation liquid stream is withdrawn as the relatively less volatile fraction;
(12) any remaining portion of said at least one liquid stream is expanded to said lower pressure and is supplied as a feed to said processing assembly below said second absorbing means and above said heat and mass transfer means;
(13) a first distillation vapor stream is collected from said upper region portion of said heat and mass transfer means and cooled enough to condense at least a portion thereof, thereby cooling the condensed stream and said first distillation vapor stream. Forming a residual vapor stream comprising any remaining uncondensed vapor;
(14) at least a portion of the condensed stream is fed to the first absorbing means as a top feed;
(15) a second distillation vapor stream is collected from the upper region portion of the first absorbing means and heated;
(16) said heated second distillation vapor stream is combined with any of said residual vapor stream to form a combined vapor stream;
(17) the combined vapor stream is heated, and then the heated combined vapor stream is withdrawn from the processing assembly as the volatile residual gas fraction;
(18) Heating of the second distillation vapor stream and the combined vapor stream takes place in one or more heat exchange means built into the treatment assembly, thereby cooling the steps (2), (8) and (13). Supply at least a portion of the; And
(19) The amount and temperature of the feed stream directed to the first and second absorbing means is such that the temperature of the upper region portion of the first absorbing means is at a temperature at which the majority of the components in the relatively less volatile fraction are recovered. Effective way to maintain. The method of claim 2, wherein the separating means is embedded in the processing assembly. The method of claim 3 wherein said separating means is embedded in said processing assembly. The method according to claim 2,
(1) said heat and mass transfer means is disposed in an upper region and a lower region portion; And
(2) said expanded at least a portion of said at least one liquid stream is supplied to said processing assembly for entry between said upper and lower region portions of said heat and mass transfer means. The method according to claim 3,
(1) said heat and mass transfer means is disposed in an upper region and a lower region portion; And
(2) any remaining portion of the at least one liquid stream that is expanded is supplied to the processing assembly for entry between the upper region portion and the lower region portion of the heat and mass transfer means. The method of claim 4,
(1) said heat and mass transfer means is disposed in an upper region and a lower region portion; And
(2) said expanded at least part of said at least one liquid stream is supplied to said processing assembly for entry between said upper and lower region portions of said heat and mass transfer means. The method according to claim 5,
(1) said heat and mass transfer means is disposed in an upper region and a lower region portion; And
(2) said expanded any remaining portion of said at least one liquid stream is supplied to said processing assembly for entry between said upper and lower region portions of said heat and mass transfer means. The method according to claim 1,
(1) a collecting means is embedded in said processing assembly;
(2) an additional heat and mass transfer means is included in said collecting means, said additional heat and mass transfer means including one or more passages for an external refrigerant;
(3) said cooled gas stream is supplied to said collecting means and further cooled by said external refrigerant towards said additional heat and mass transfer means; And
(4) the further cooled gas stream is divided into the first and second streams. The method according to any one of claims 2, 3, 4, 5, 6, 7, 8 or 9,
(1) an additional heat and mass transfer means is included in said separating means, said additional heat and mass transfer means comprising one or more passages for an external refrigerant;
(2) said vapor stream is cooled by said external refrigerant towards said additional heat and mass transfer means to form additional condensate; And
(3) said further condensate becomes part of said at least one liquid stream separated therein. The method according to any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10,
(1) said condensed stream is split into at least a first and a second reflux stream;
(2) said first reflux stream is supplied to said first absorbing means as said top feed; And
(3) said second reflux stream is fed as feed to said processing assembly under said second absorbing means and above said heat and mass transfer means. The method of claim 11,
(1) said condensed stream is split into at least a first and a second reflux stream;
(2) said first reflux stream is supplied to said first absorbing means as said top feed; And
(3) said second reflux stream is fed as feed to said processing assembly under said second absorbing means and above said heat and mass transfer means. The method according to any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10,
Wherein said heat and mass transfer means comprises at least one passage for an external heating medium for heat replenishment supplied by said second portion for stripping said more volatile components from said distillation liquid stream. The method of claim 11, wherein the heat and mass transfer means comprises one or more passages for an external heating medium for heat replenishment supplied by the second portion to strip the more volatile components from the distillation liquid stream. The method of claim 12, wherein the heat and mass transfer means comprises one or more passages for an external heating medium for heat replenishment supplied by the second portion for stripping the more volatile components from the distillation liquid stream. The method of claim 13, wherein the heat and mass transfer means comprises one or more passageways for an external heating medium for heat replenishment supplied by the second portion for stripping the more volatile components from the distillation liquid stream. A gas stream comprising methane, C ₂ components, C ₃ components, and heavy hydrocarbon components comprises a volatile residual gas fraction and a majority of the C ₂ components, C ₃ components, and heavy hydrocarbon components or A device for separating as a relatively less volatile fraction comprising the C ₃ components and the heavy hydrocarbon components,
(1) first dividing means for dividing the gas stream into first and second portions;
(2) heat exchange means embedded in a processing assembly and connected to said first dividing means to receive said first portion and cool it;
(3) heat and material transfer means embedded in said processing assembly and connected to said first dividing means to receive said second portion and cool it;
(4) first combining means connected to said heat exchange means and said heat and mass transfer means to receive said cooled first portion and said cooled second portion to form a cooled gas stream;
(5) second dividing means connected to said first combining means to receive said cooled gas stream and divide it into first and second streams;
(6) said heat exchange means being further connected to said second dividing means to receive said first stream and cool it sufficiently to substantially condense;
(7) first expansion means connected to said heat exchange means to receive said substantially condensed first stream and expand it to lower pressure;
(8) said expanded cooled first stream embedded in said processing assembly and connected to said first expansion means, said first absorbing means being supplied as a feed between said first absorbing means and said second absorbing means. Wherein the first absorbing means comprises: first and second absorbing means positioned above the second absorbing means;
(9) second expansion means connected to said second dividing means to receive said second stream and expand it to said lower pressure, said second expansion means being further connected to said second absorbing means and therewith said expanded second Second expansion means for feeding the stream as a bottom feed;
(10) liquid collecting means embedded in said processing assembly and connected to said second absorbing means to receive a distillation liquid stream from said lower region portion of said second absorbing means;
(11) said heat and mass transfer means being further connected to said liquid collecting means to receive said distillate liquid stream and to heat it, thereby supplying at least a portion of the cooling of step (3) and at the same time said distillation liquid Stripping more volatile components from the stream, and then the heated, stripped distillation liquid stream from the processing assembly is withdrawn as the relatively less volatile fraction;
(12) first vapor collection means embedded in said processing assembly and connected to said heat transfer material means for receiving a first distillation vapor stream from said upper region portion of said heat transfer material means;
(13) said heat exchange means being further connected to said first vapor collection means to cool it enough to receive said first distillation vapor stream and to condense at least a portion thereof; Thereby forming a residual vapor stream comprising the condensed stream and any uncondensed vapor remaining after the first distillation vapor stream has cooled;
(14) said first absorbing means being further connected to said heat exchange means to receive at least a portion of said condensed stream as a top feed thereto;
(15) second vapor collecting means embedded in said processing assembly and connected to said first absorbing means to receive a second distillation vapor stream from said upper region portion of said first absorbing means;
(16) said heat exchange means being further connected to said second vapor collecting means to receive said second distillation vapor stream and heat it, thereby supplying at least a portion of the cooling of step (13);
(17) second combining means connected to said heat exchange means to receive said heated second distillation vapor stream and any said residual vapor stream to form a combined vapor stream;
(18) said heat exchange means being further connected to said second combining means to receive and heat said combined vapor stream, thereby supplying at least a portion of the cooling of steps (2) and (6); Then draining the heated combined vapor stream from the processing assembly as the volatile residual gas fraction; And
(19) of said feed stream directed to said first and second absorbing means to maintain a temperature of said upper region portion of said first absorbing means at a temperature at which a majority of said components in said relatively less volatile fraction are recovered. A device comprising control means adapted to control the amount and temperature. A gas stream comprising methane, C ₂ components, C ₃ components, and heavy hydrocarbon components comprises a volatile residual gas fraction and the majority of the C ₂ components, C ₃ components, and heavy hydrocarbon components or the C the _three components of the apparatus and of the relative separation as the less volatile fraction containing a hydrocarbon component,
(1) first dividing means for dividing the gas stream into first and second portions;
(2) heat exchange means embedded in a processing assembly and connected to said first dividing means to receive said first portion and cool it;
(3) heat and material transfer means embedded in said processing assembly and connected to said first dividing means to receive said second portion and cool it;
(4) first combining means connected to said heat exchange means and said heat and mass transfer means to receive said cooled first portion and said cooled second portion to form a partially condensed gas stream;
(5) separating means connected to said first combining means to receive said partially condensed gas stream and separate it into a vapor stream and at least one liquid stream;
(6) second dividing means connected to said separating means to receive said vapor stream and divide it into first and second streams;
(7) said heat exchange means being further connected to said second dividing means to receive said first stream and cool it sufficiently to substantially condense;
(8) first expansion means connected to said heat exchange means to receive said substantially condensed first stream and expand it to lower pressure;
(9) first and second absorbing means embedded in said processing assembly and connected to said first expanding means, said expanded cooled first stream being supplied as a feed between said first absorbing means and said second absorbing means; And the first absorbing means includes: first and second absorbing means positioned above the second absorbing means;
(10) second expansion means connected to said second dividing means to receive said second stream and expand it to said lower pressure, said second expansion means being further connected to said second absorbing means and therewith said expanded second Second expansion means for feeding the stream as a bottom feed;
(11) liquid collecting means embedded in said processing assembly and connected to said second absorbing means to receive a distillation liquid stream from a lower region portion of said second absorbing means;
(12) said heat and mass transfer means being further connected to said liquid collecting means to receive said distillate liquid stream and to heat it, thereby supplying at least a portion of the cooling of step (3), and at the same time said distillation liquid Stripping more volatile components from the stream, and then the heated, stripped distillation liquid stream from the processing assembly exits as a relatively less volatile fraction;
(13) third expansion means connected to said separating means to receive at least a portion of said at least one liquid stream and expand it to said lower pressure, further connected to said processing assembly to expand said expanded liquid stream Third expansion means for supplying as a feed below said second absorbing means and above said heat and mass transfer means;
(14) first vapor collecting means embedded in said processing assembly and connected to said heat and mass transfer means to receive a first distillation vapor stream from said upper region portion of said heat and mass transfer means;
(15) said heat exchange means being further connected to said first vapor collection means to cool it sufficient to receive said first distillation vapor stream and to condense at least a portion thereof, thereby condensing the stream with said first Forming a residual vapor stream comprising any uncondensed vapor remaining after the distillation vapor stream has cooled;
(16) said first absorbing means being further connected to said heat exchange means to receive at least a portion of said condensed stream as a top feed thereto;
(17) second vapor collecting means embedded in said processing assembly and connected to said first absorbing means to receive a second distillation vapor stream from said upper region portion of said first absorbing means;
(18) said heat exchange means being further connected to said second vapor collecting means to receive and heat said second distillation vapor stream, thereby supplying at least a portion of the cooling of step (15);
(19) second combining means connected to said heat exchange means to receive said heated second distillation vapor stream and any said residual vapor stream to form a combined vapor stream;
(20) said heat exchange means being further connected to said second combining means to receive and heat said combined vapor stream, thereby supplying at least a portion of the cooling of steps (2) and (7); Then draining the heated combined vapor stream from the processing assembly as the volatile residual gas fraction; And
(21) the amount of feed stream directed to the first and second absorbing means to maintain the temperature of the upper region portion of the first absorbing means at a temperature at which the majority of the components in the relatively less volatile fraction are recovered; A device comprising regulating means adapted to regulate the temperature. A gas stream comprising methane, C ₂ components, C ₃ components, and heavy hydrocarbon components comprises a volatile residual gas fraction and the majority of the C ₂ components, C ₃ components, and heavy hydrocarbon components or the C the _three components of the apparatus and of the relative separation as the less volatile fraction containing a hydrocarbon component,
(1) first dividing means for dividing the gas stream into first and second portions;
(2) heat exchange means embedded in a processing assembly and connected to said first dividing means to receive said first portion and cool it;
(3) heat and material transfer means embedded in said processing assembly and connected to said first dividing means to receive said second portion and cool it;
(4) first combining means connected to said heat exchange means and said heat and mass transfer means to receive said cooled first portion and said cooled second portion to form a partially condensed gas stream;
(5) first separating means connected to said first combining means to receive said partially condensed gas stream and separate it into a vapor stream and at least one liquid stream;
(6) second dividing means connected to said separating means to receive said vapor stream and divide it into first and second streams;
(7) second combining means connected to said second dividing means and separating means to receive at least a portion of said first stream and said at least one liquid stream and form a combined stream;
(8) said heat exchange means being further connected to said second combining means to receive said combined stream and cool it sufficiently to substantially condense;
(9) first expansion means connected to said heat exchange means to receive said substantially condensed combined stream and expand it to lower pressure;
(10) said expanded cooled combined stream embedded in said processing assembly and connected to said first expansion means, said first and second absorbing means being supplied as a feed between said first absorbing means and said second absorbing means. Wherein the first absorbing means comprises: first and second absorbing means positioned above the second absorbing means;
(11) second expansion means connected to said second dividing means to receive said second stream and expand it to said lower pressure, said second expansion means being further connected to said second absorbing means and therewith said expanded second Second expansion means for feeding the stream as a bottom feed;
(12) liquid collecting means embedded in said processing assembly and connected to said second absorbing means to receive a distillation liquid stream from said lower region portion of said second absorbing means;
(13) said heat and mass transfer means being further connected to said liquid collecting means to receive said distillate liquid stream and to heat it, thereby supplying at least a portion of the cooling of step (3), and at the same time said distillation liquid Stripping more volatile components from the stream, and then the heated, stripped distillation liquid stream from the processing assembly is withdrawn as the relatively less volatile fraction;
(14) third expansion means connected to said separation means to receive any remaining portion of said at least one liquid stream and expand it to said lower pressure, wherein said expansion means is further connected to said processing assembly to Third expansion means for supplying a liquid stream as a feed below said second absorbing means and above said heat and mass transfer means;
(15) first vapor collecting means embedded in said processing assembly and connected to said heat and mass transfer means to receive a first distillation vapor stream from said upper region portion of said heat and mass transfer means;
(16) said heat exchange means being further connected to said first vapor collection means to cool it sufficient to receive said first distillation vapor stream and to condense at least a portion thereof, thereby condensing the stream and said first Forming a residual vapor stream comprising any uncondensed vapor remaining after the distillation vapor stream has cooled;
(17) said first absorbing means being further connected to said heat exchange means to receive at least a portion of said condensed stream as a top feed thereto;
(18) second vapor collecting means embedded in said processing assembly and connected to said first absorbing means to receive a second distillation vapor stream from said upper region portion of said first absorbing means;
(19) said heat exchange means being further connected to said second vapor collecting means to receive said second distillation vapor stream and heat it, thereby supplying at least a portion of the cooling of step (16);
(20) third combining means connected to said heat exchange means to receive said heated second distillation vapor stream and any said residual vapor stream to form a combined vapor stream;
(21) said heat exchange means being further connected to said third coupling means to receive said combined vapor stream and heat it, thereby supplying at least a portion of the cooling of steps (2) and (8); Then draining the heated combined vapor stream from the processing assembly as the volatile residual gas fraction; And
(22) of said feed streams directed to said first and second absorbing means to maintain a temperature of said upper region portion of said first absorbing means at a temperature at which a majority of said components in said relatively less volatile fraction are recovered. A device comprising control means adapted to control the amount and temperature. 20. The apparatus of claim 19, wherein said separating means is embedded within said processing assembly. 21. The apparatus of claim 20, wherein said separating means is embedded in said processing assembly. The method of claim 19,
(1) said heat and mass transfer means is disposed in an upper region and a lower region portion; And
(2) said processing assembly is connected to said third expansion means to receive said expanded liquid stream and direct it between said upper and lower region portions of said heat and mass transfer means. The method of claim 20,
(1) said heat and mass transfer means is disposed in an upper region and a lower region portion; And
(2) said processing assembly is connected to said third expansion means to receive said expanded liquid stream and direct it between said upper and lower region portions of said heat and mass transfer means. The method according to claim 21,
(1) said heat and mass transfer means is disposed in an upper region and a lower region portion; And
(2) said processing assembly is connected to said third expansion means to receive said expanded liquid stream and direct it between said upper and lower region portions of said heat and mass transfer means. The method according to claim 22,
(1) said heat and mass transfer means is disposed in an upper region and a lower region portion; And
(2) said processing assembly is connected to said third expansion means to receive said expanded liquid stream and direct it between said upper and lower region portions of said heat and mass transfer means. The method according to claim 18,
(1) a collecting means is embedded in said processing assembly;
(2) additional heat and mass transfer means are included in the collecting means, wherein the additional heat and mass transfer means includes one or more passages for external refrigerant;
(3) said collecting means is connected to said first combining means to receive said cooled gas stream and send it to said additional heat and mass transfer means for further cooling by said external refrigerant; And
(4) said second dividing means adapted to be connected to said collecting means to receive said cooler gas stream and divide it into said first and second streams. The method according to claim 19, 20, 21, 22, 23, 24, 25, or 26,
(1) an additional heat and mass transfer means is included in said separating means, said additional heat and mass transfer means including one or more passages for an external refrigerant;
(2) said vapor stream is cooled by said external refrigerant towards said additional heat and mass transfer means to form additional condensate; And
(3) said further condensate being part of said at least one liquid stream separated therein. The method according to any one of claims 18, 19, 20, 21, 22, 23, 24, 25, 26 or 27,
(1) a third dividing means is connected to said heat exchange means to receive said condensed stream and divides it into at least first and second reflux streams;
(2) said first absorbing means is adapted to be connected to said third dividing means to receive said first reflux stream as said top feed; And
(3) said heat and mass transfer means adapted to be connected to said third dividing means to receive said second reflux stream as a top feed thereto. 29. The method of claim 28,
(1) a third dividing means is connected to said heat exchange means to receive said condensed stream and divides it into at least first and second reflux streams;
(2) said first absorbing means is adapted to be connected to said third dividing means to receive said first reflux stream as said top feed; And
(3) said heat and mass transfer means adapted to be connected to said third dividing means to receive said second reflux stream as a top feed thereto. 28. The method of claim 18, 19, 20, 21, 22, 23, 24, 25, 26 or 27, wherein the heat and mass transfer means is adapted to strip the more volatile components from the distillation liquid stream. And at least one passageway for an external heating medium for supplementing heat supplied by the portion. 29. The apparatus of claim 28, wherein the heat and mass transfer means comprises one or more passages for an external heating medium for heat replenishment supplied by the second portion for stripping the more volatile components from the distillation liquid stream. 30. The apparatus of claim 29, wherein the heat and mass transfer means comprises one or more passages for an external heating medium for heat replenishment supplied by the second portion for stripping the more volatile components from the distillation liquid stream. 31. The apparatus of claim 30, wherein the heat and mass transfer means comprises at least one passage for an external heating medium for heat replenishment supplied by the second portion to strip the more volatile components from the distillation liquid stream.

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