JP5552159B2 - Treatment of hydrocarbon gas - Google Patents

Description

  The present invention relates to a process and apparatus for the separation of gases containing hydrocarbons. Applicants claim the benefit of 61/186361, filed June 11, 2009, a prior provisional US patent application, under 35 USC 119 (e). Applicants also claim benefit as a continuation-in-part of 12/69616, filed on January 19, 2010, a prior US patent application, based on United States Code 35, 120. The Designated Agent SME Product LP and Autoloff Engineers Limited were in a joint research contract in effect before the invention of this application was made.

  Ethylene, ethane, propylene, propane and / or heavier hydrocarbons, for example, from natural gas, refinery gas, and other hydrocarbon materials such as coal, crude oil, naphtha, oil shale, tar sand, and lignite It can be recovered from various gases such as the resulting synthesis gas stream. Usually, the main components of natural gas are methane and ethane, that is, methane and ethane together constitute at least 50 mole percent of the total gas. This gas also contains relatively small amounts of heavier hydrocarbons such as propane, butane, pentane, as well as hydrogen, nitrogen, carbon dioxide, and other gases.

The present invention generally relates to the recovery of ethylene, ethane, propylene, propane and heavier hydrocarbons from such gas streams. A typical analysis of a gas stream processed in accordance with the present invention is, in an approximate mole percent, 90.3 percent methane, 4.0 percent ethane and other C ₂ components, 1.7 percent propane and others. C ₃ component, 0.3 percent isobutane, 0.5 percent normal butane, and 0.8 percent pentane, plus the remainder will be composed of nitrogen and carbon dioxide. Gases containing sulfur may also be present.

  Historically, the price of ethane, ethylene, propane, propylene, and heavier components as liquid products, since the price of natural gas and its natural gas liquid (NGL) components both fluctuate periodically May fluctuate. This creates a need for processes that can provide more efficient recovery of these products, and processes that can provide efficient recovery with less capital investment. Available processes for separating these materials include processes based on gas cooling and refrigeration, oil absorption, and cooled oil absorption. In addition, low temperature processes are becoming popular because they can generate power and at the same time utilize economical equipment that removes heat from the expanded and processed gas. Depending on the pressure of the gas source, the richness of the gas (content of ethane, ethylene, and heavier hydrocarbons) and the desired end product, any of these processes or combinations thereof may be used.

Currently, the cold expansion process is generally preferred for the recovery of natural gas liquids, which is the simplest and easiest to start, operational flexibility, good efficiency, safety and good reliability. This is to provide sex. U.S. Pat.Nos. 3,292,380, 4,061,481, 4,140,504, 4,157,904, 4,171,964, 4,185,978, 4,251,249, 4,278,457, 4,45,824, 4,461,039 No. 4,687,499, No. 4,689,063, No. 4,690,702, No. 4,854,955, No. 4,869,740, No. 4,889,545, No. 5,275,055, No. 5,555,754, No. 5,565,554, No. 5,568,737. No. 5717712, No. 5799507, No. 5881569, No. 589
No. 0378, No. 5,983,664, No. 6,182,469, No. 6,578,379, No. 6,721,880, No. 6,915,662, No. 7,191,617, No. 7,219,513, U.S. Reissued Patent No. 33408, and Pending U.S. Patent Application Nos. 11 / 430,212, 11/839633, 11/971491, and 12/206230 describe a related process (however, the description of the present invention is May be based on different processing conditions than those described in the cited US patents).

In a typical cold expansion recovery process, the pressurized feed gas stream is cooled by heat exchange with other streams of the process and / or by an external cooling source such as a propane compression cooling system. Gas is cooled, in one or more separators, condensed liquid as a high-pressure liquid containing several desirable C _{2 +} components may be recovered. Depending on the richness of the gas and the amount of liquid formed, the high pressure liquid may be expanded to a lower pressure and fractionated. Evaporation that occurs while the liquid expands results in further cooling of the stream. Under some conditions, it is desirable to pre-cool the high pressure liquid prior to expansion in order to further reduce the temperature caused by expansion. The expanded stream containing the liquid and vapor mixture is fractionated in a distillation (demethanizer or deethanizer) column. Distilling the expansion cooled stream (each stream) in the column, preferably C ₂ components as the bottom liquid product from the hydrocarbon components of the C ₃ components and heavier, residual methane, nitrogen and other volatile or separating gases as overhead vapor, or separating bottoms methane from hydrocarbon components desired C ₃ components and heavier as a liquid product, C ₂ components, nitrogen and other volatile gases as overhead vapor.

  If the feed gas is not fully condensed (typically not fully condensed), the vapor remaining from the partial condensation can be split into two streams. One part of the vapor passes through a work expansion device or engine, or an expansion valve, to a lower pressure where further liquid is condensed as a result of further cooling of the stream. The pressure after expansion is essentially the same as the pressure at which the distillation column is operating. The combined vapor and liquid phase produced by the expansion are fed as feed to the column.

  The remainder of the steam is cooled and substantially condensed by heat exchange with other process streams such as cold fractionator overhead. Some or all of the high pressure liquid may merge with this vapor portion prior to cooling. Subsequently, the resulting cooled stream is expanded through a suitable expansion device, such as an expansion valve, to the pressure at which the demethanizer is operated. The entire stream is cooled by evaporating some of the liquid during expansion. Subsequently, the flash expanded stream is fed to the demethanizer as a feed to the top. Typically, the vapor portion of the flash expanded stream and the demethanizer overhead vapor are combined as residual methane product gas in the upper separator section of the fractionation tower. Alternatively, a cooled and expanded stream may be fed to the separator to provide vapor and liquid streams. This vapor merges with the tower overhead and the liquid is fed to the column as a feed to the top of the column.

In an ideal operation of such a separation process, the residual gas resulting from the process contains substantially all of the methane in the feed gas, is essentially free of heavier hydrocarbon components, and is desorbed. The bottom fraction exiting the methane unit contains substantially all of the heavier hydrocarbon components and is essentially free of methane or higher volatile components. In practice, however, this ideal situation cannot be obtained because the conventional demethanizer is operated primarily as a stripping column. Thus, the methane product of the process typically includes the vapor exiting the fractionation stage at the top of the column along with the vapor that has not been treated in any rectification step. Top of the liquid feed, C ₂ components of substantial amounts, C ₃ components, containing the hydrocarbon component of C 4 ₊ components and heavier, the amount of C ₂ components balances corresponding thereto in the vapor, C ₃ components As the C ₄ component and heavier hydrocarbon components exit the fractionation stage at the top of the demethanizer, significant loss of C ₂ , C ₃ and C ₄ + components occurs. The vapors rising, C ₂ components, if C ₃ components, C ₄ components and more hydrocarbon components heavier can be contacted with a significant amount of liquid (reflux) such as can be absorbed from the steam, these It is possible to significantly reduce the loss of desirable components.

  In recent years, the preferred process for hydrocarbon separation has provided additional rectification of the rising vapor using the upper absorption section. The reflux stream source for the upper rectification section is typically a stream recycled from the residual gas supplied under pressure. Typically, the recycled residual gas stream is cooled and substantially condensed by heat exchange with other process streams (eg, cold fractionator overhead). Subsequently, the resulting substantially condensed stream is expanded via a suitable expansion device, such as an expansion valve, to a pressure that operates the demethanizer. Usually, the entire stream is cooled by evaporating some of the liquid during expansion. Subsequently, the flash expanded stream is fed to the demethanizer as a feed to the top. Typically, in the upper separator section of the fractionation tower, the vapor portion of the expanded stream and the demethanizer overhead vapor are combined as residual methane product gas. Alternatively, a cooled and expanded stream may be fed to the separator to provide a vapor and liquid stream so that the vapor can then join the tower overhead and the liquid feed to the top of the column. As supplied to the column. Exemplary process schemes of this type include U.S. Pat. Nos. 4,889,545, 5,568,737, and 5,881,569, co-pending U.S. Patent Application Nos. 11 / 430,212 and 11/971491, and Mowrey, E .; Ross's “Efficient, High Recovery of Liquids from Natural Gas Optimized, 1st, 3rd, High2) .

U.S. Pat. No. 3,292,380 US Patent No. 4061481 U.S. Pat. No. 4,140,504 U.S. Pat.No. 4,157,904 U.S. Pat. No. 4,171,964 U.S. Pat. No. 4,185,978 U.S. Pat. No. 4,251,249 U.S. Pat. No. 4,278,457 U.S. Pat. No. 4,519,824 US Pat. No. 4,617,039 U.S. Pat. No. 4,687,499 U.S. Pat. No. 4,689,063 U.S. Pat. No. 4,690,702 U.S. Pat. No. 4,854,955 U.S. Pat. No. 4,869,740 U.S. Pat. No. 4,889,545 US Pat. No. 5,275,005 US Pat. No. 5,555,748 US Pat. No. 5,565,554 US Pat. No. 5,568,737 US Pat. No. 5,771,712 US Pat. No. 5,799,507 U.S. Pat. No. 5,881,569 US Pat. No. 5,890,378 US Pat. No. 5,983,664 US Pat. No. 6,182,469 US Pat. No. 6,578,379 U.S. Pat. No. 6,712,880 US Pat. No. 6,915,662 US Pat. No. 7,191,617 U.S. Pat. No. 7,219,513 US Reissue Patent No. 33408 US patent application Ser. No. 11 / 430,212 U.S. Patent Application No. 11/839633 US patent application Ser. No. 11 / 971,491 US Patent Application No. 12/206230

Mowrey, E .; Ross's “Efficient, High Recovery of Liquids from Natural Gas Optimized, 1st, 3rd, 1st, 3rd, 3rd, 1st, 3rd, 3rd, 1st, 1st, 3rd, 1st, 3rd, 1st, 1st, 3rd, 1st, 3rd, 3rd

  The present invention uses a new means of performing the various processes described above more efficiently and using fewer equipment components. This is accomplished by integrating conventional individual equipment into a common housing, thereby reducing the plot space required in the processing plant and reducing capital costs at the facility. Surprisingly, Applicants have also noted that smaller configurations also significantly reduce the power consumption required to achieve a given recovery level, thereby increasing process efficiency and reducing facility operating costs. I found out. In addition, the smaller configuration eliminates many of the pipes used to interconnect individual equipment within a traditional factory design, reducing capital costs and removing the associated flange tube connections. Since pipe flanges can be a source of leakage of hydrocarbons (volatile organic compounds, VOCs that contribute to greenhouse gases and also serve as precursors for the formation of the ozone layer in the atmosphere), removing these flanges Reduce atmospheric emissions that can be harmful to the environment.

In accordance with the present invention, it has been found that greater than 95 percent C ₂ recovery is obtained. Similarly, in examples where C ₂ component recovery is not desired, greater than 95 percent C ₃ recovery may be maintained. The present invention further provides C ₂ component (or C ₃ component) and heavier component and methane (or C ₂ component) with lower energy consumption compared to the prior art while maintaining the same recovery level. ) And lighter components can be substantially separated by 100 percent. Although the present invention is applicable at lower pressures and higher temperatures, the process feed gas is 400-1500 psia (2758-10342 kPa (2) under conditions where NGL recovery column overhead temperatures of −50 ° F. (−46 ° C.) or less are required. a)) The above is particularly advantageous.

  For a better understanding of the present invention, reference is made to the following examples and figures. Reference is made to the following drawings.

1 is a flow diagram of a prior art natural gas processing plant according to US Pat. No. 5,568,737. 1 is a flow diagram of a natural gas processing plant according to the present invention. FIG. 4 is a flow diagram illustrating selective means for applying the present invention to a natural gas stream. FIG. 4 is a flow diagram illustrating selective means for applying the present invention to a natural gas stream. FIG. 4 is a flow diagram illustrating selective means for applying the present invention to a natural gas stream. FIG. 4 is a flow diagram illustrating selective means for applying the present invention to a natural gas stream. FIG. 4 is a flow diagram illustrating selective means for applying the present invention to a natural gas stream. FIG. 4 is a flow diagram illustrating selective means for applying the present invention to a natural gas stream. FIG. 4 is a flow diagram illustrating selective means for applying the present invention to a natural gas stream.

  In the following description of the above figure, a table summarizing the calculated flow rates for representative process conditions is provided. In the table shown in the present specification, the value relating to the flow rate (mole / hour) is rounded off to the first decimal place for convenience. The total stream speed shown in the table includes all of the non-hydrocarbon components and is therefore generally greater than the sum of the stream flow rates for the hydrocarbon components. The temperatures shown are approximate values rounded to the nearest number. Also, the process design calculations made to compare the processes shown in the figure are based on the assumption that there is no heat leakage from (or out of) the process to (or from) the environment. Should be noted. The quality of commercially available insulation makes this assumption quite reasonable and can typically be made by one skilled in the art.

  For convenience, process parameters are reported in both conventional British units and International Unit System (SI) units. The molar flow rates shown in the table may be interpreted in either pound moles / hour or kilogram moles / hour. The energy consumption reported as horsepower (HP) and / or 1000 British thermal units / hour (MBTU / Hr) corresponds to the molar flow rate stated in pound moles / hour. The energy consumption reported as kilowatts (kW) corresponds to the molar flow rate described in kilogram mol / hour.

DESCRIPTION OF THE PRIOR ART FIG. 1 is a process flow diagram showing the design of a processing plant for recovering C ₂ + components from natural gas using the prior art according to US Pat. No. 5,568,737. In the simulation of this process, the inlet gas enters the plant as stream 31 at 110 ° F. (43 ° C.) and 915 psia (6307 kPa (a)). If the inlet gas contains a concentration of sulfur compounds that would prevent the product stream from meeting specifications, the sulfur compounds are removed by appropriate pretreatment of the feed gas (not shown). In addition, the feed stream is usually dehydrated to prevent the formation of hydrates (ice) under low temperature conditions. For this purpose, typically a solid desiccant is used.

The feed stream 31 is separated into two parts, streams 32 and 33. Stream 32 is cooled to −26 ° F. (−32 ° C.) by heat exchanging with chilled distilled steam stream 41 a in heat exchanger 10, while stream 33 is 41 in heat exchanger 11. -32 ° F. (-35 ° C.) by heat exchange with the demethanizer reboiler liquid (stream 43) at −F (5 ° C.) and the side reboiler liquid (stream 42) at −49 ° F. ). Streams 32a and 33a rejoin to form stream 31a, which enters separator 12 at -28 ° F (-33 ° C) and 893 psia (6155 kPa (a)) where it condenses with steam (stream 34) Liquid (stream 35) is separated.

  Vapor (stream 34) from separator 12 is separated into two streams 36 and 39. Stream 36, which contains about 27 percent of the total steam, merges with the separation liquid (stream 35), and merged stream 38 passes through heat exchanger 13 and has a heat exchange relationship with cooled distilled vapor stream 41. Cooled and substantially condensed. Subsequently, the resulting substantially condensed stream 38 at −139 ° F. (−95 ° C.) is passed through the expansion valve 14 to the operating pressure of the fractionator 18 (approximately 396 psia (2730 kPa (a))). Flash inflates. The entire stream is cooled by vaporizing a portion of the stream during expansion. In the process illustrated in FIG. 1, the expanded stream 38b exiting expansion valve 14 reaches a temperature of −140 ° F. (−95 ° C.) and is fed to fractionation column 18 at the first intermediate column feed point. Is done.

  The remaining 73 percent of steam from the separator 12 (stream 39) enters the work expansion device 15 where mechanical energy is extracted from this portion of the high pressure feed. The apparatus 15 expands this vapor substantially isentropically to the tower operating pressure, and its work expansion cools the expanded stream 39a to a temperature of about -95 ° F (-71 ° C). A typical commercial expansion device can recover on the order of 80 to 85 percent of the theoretically available work with ideal isentropic expansion. The recovered work is often used, for example, to drive a centrifugal compressor (eg, item 16) that can be used to recompress the heated distillation vapor stream (stream 41b). Subsequently, the partially condensed and expanded stream 39a is fed as feed to the fractionation tower 18 at the feed point of the second intermediate column.

  The recompressed and cooled distillation vapor stream 41e is separated into two streams. One part is stream 46, a volatile residual gas product. The other part is the recycle stream 45, which flows to the heat exchanger 10 where it is cooled to -26 ° F (-32 ° C) by heat exchange with the cooled distillation steam stream 41a. Subsequently, the cooled recycle stream 45a flows to the heat exchanger 13, where it is cooled to -139 ° F (-95 ° C) by heat exchange with the cooled distillation steam stream 41 and substantially condensed. Subsequently, the substantially condensed stream 45b is expanded through a suitable expansion device, such as expansion valve 22, to a pressure that operates the demethanizer so that the entire stream is −147 ° F. (−99 ° C. ). Subsequently, the expanded stream 45c is supplied to the fractionation tower 18 as a feed to the top of the column. The vapor portion of stream 45c (if present) merges with the vapor exiting the column top fractionation stage to form a distillation vapor stream 41 exiting the upper region of the column.

The demethanizer in column 18 is a conventional distillation column containing a plurality of vertically spaced trays, one or more packed beds, or a combination of trays and packing materials. As is often the case with natural gas processing plants, the fractionation tower may consist of two sections. The upper section 18a is a separator, where the partially vaporized top feed is separated into a vapor portion and a liquid portion, respectively, where further the vapor rising from the lower distillation or demethanization section 18b is the vapor portion of the top feed. To form a cold demethanizer overhead vapor (stream 41), which is −144 ° F.
Exit from the top of the tower at (-98 ° C). The lower demethanizer section 18b contains a plurality of trays and / or fillers, thereby providing the necessary contact between the descending liquid and the ascending vapor. The demethanizer section 18b also includes a reboiler (eg, the reboiler and side reboiler described above), which can heat and evaporate a portion of the liquid flowing down the column to provide stripping vapor. The stripping vapor flows up the column and strips the liquid product of methane and lighter components, ie, stream 44.

  The liquid product stream 44 exits the bottom of the column at 64 ° F. (18 ° C.) based on a typical specification with a methane: ethane ratio of 0.010: 1 on a mass basis at the bottom product. The demethanizer overhead vapor stream 41 passes countercurrently to the incoming feed gas and recycle stream, is heated to −40 ° F. (−40 ° C.) in the heat exchanger 13 (stream 41a), and Heat to 104 ° F. (40 ° C.) in heat exchanger 10 (stream 41b). Subsequently, the distillation vapor stream is compressed again in two stages. The first stage is a compressor 16 driven by an expansion device 15. The second stage is a compressor 20 driven by an auxiliary power source, which compresses the residual gas (stream 41d) to the sales line pressure. After cooling to 110 ° F. (43 ° C.) in discharge cooler 21, stream 41e is split into residual gas product (stream 46) and recycle stream 45 as described above. Residual gas stream 46 is sent to the sales gas pipeline at 915 psia (6307 kPa (a)) sufficient to meet the line requirements (usually on the order of inlet pressure).

The following table provides a summary of stream flow rate and energy consumption for the process described in FIG.

DESCRIPTION OF THE INVENTION FIG. 2 illustrates a flow diagram of a process according to the invention. The feed gas composition and conditions considered in the process shown in FIG. 2 are the same as those shown in FIG. Therefore, to illustrate the advantages of the present invention, the process of FIG. 2 can be compared to the process of FIG.

  In the simulation of the process of FIG. 2, the inlet gas enters the plant as stream 31 and is separated into two partial streams 32 and 33. The first part, stream 32, enters the heat exchange means in the upper region of feed cooling section 118a within processing assembly 118. This heat exchange means consists of fin and tube heat exchangers, plate heat exchangers, brass aluminum heat exchangers or other types of heat transfer devices including multi-pass and / or multi-service heat exchangers. May be. The heat exchanging means is a stream 32 flowing through one path of the heat exchanging means and a distilled steam stream rising from the separator section 118b inside the processing assembly 118 and heated by the heat exchanging means in the lower region of the feed cooling section 118a. Configured to provide heat exchange between the two. Stream 32 is cooled while heating the distillate vapor stream, and a −25 ° F. (−32 ° C.) stream 32a exits the heat exchange means.

The second part, stream 33, is demethanized section 11 inside processing assembly 118.
Enter the heat and mass transfer means in 8e. This heat and mass transfer means may be from fin and tube heat exchangers, plate heat exchangers, brass aluminum heat exchangers, or other types of heat transfer devices including multi-pass and / or multi-service heat exchangers. It may be configured. The heat and mass transfer means provides heat exchange between the stream 33 flowing through one path of the heat and mass transfer means and the distilled liquid stream flowing down from the absorption section 118d inside the processing assembly 118. Configured as follows. This causes stream 33 to cool while heating the distilled liquid stream, and stream 33a is cooled to -47 ° F (-44 ° C) before exiting the heat and mass transfer means. As the distillation liquid stream is heated, a portion of it vaporizes to form an ascending stripping vapor and the remaining liquid continues to flow down through the heat and mass transfer means. The heat and mass transfer means provide continuous contact between the stripping vapor and the distilled liquid stream, thereby also acting to provide mass transfer between the vapor and liquid phase, methane and lighter components The liquid product stream 44 is stripped.

  Stream 32a and stream 33a rejoin to form stream 31a, and stream 31a enters separator section 118f within processing assembly 118 at -32 ° F (-36 ° C) and 900 psia (6203 kPa (a)). And the vapor (stream 34) is separated from the condensed liquid (stream 35). Separator section 118f has an inner top or other means that separates from demethanization section 118e, which allows the two sections within processing assembly 118 to operate at different pressures.

  Vapor (stream 34) from separator section 118f is separated into two streams 36 and 39. Stream 36, which comprises about 27 percent of the total vapor, merges with the separated liquid (part 37 of stream 35), and merged stream 38 is the heat in the lower region of feed cooling section 118a within processing assembly 118. Enter the exchange. This heat exchange means is likewise from fin and tube type heat exchangers, plate type heat exchangers, brass aluminum type heat exchangers, or other types of heat transfer devices including multi-pass and / or multi-service heat exchangers. It may be configured. The heat exchange means is configured to provide heat exchange between the stream 38 flowing through one path of the heat exchange means and the distilled liquid stream rising from the separator section 118b. Here, stream 38 is cooled and substantially condensed while heating the distillation vapor stream.

  The resulting substantially condensed stream 38a is then passed through the expansion valve 14 at -138 ° F. (−95 ° C.) through the rectification section 118c (absorption means) and absorption section 118d within the processing assembly 118. Flash expands to the operating pressure (about 400 psia (2758 kPa (a))) of (another absorbing means). The entire stream is cooled by vaporizing a portion of the stream during expansion. In the process illustrated in FIG. 2, the expanded stream 38b exiting the expansion valve 14 reaches a temperature of −139 ° F. (−95 ° C.), and the rectification section 118c and absorption section 118d of the processing assembly 118 are separated. Supplied in between. The liquid in the stream 38b merges with the liquid descending from the rectification section 118c and moves to the absorption section 118d. On the other hand, any steam that has joined the steam rising from the absorption section 118d moves to the rectification section 118c.

The remaining 73 percent (stream 39) of steam from separator section 118f enters work expansion device 15 where mechanical energy is extracted from this portion of the high pressure feed. The apparatus 15 expands this vapor substantially isentropically to the operating pressure of the absorption section 118d, and its work expansion cools the expanded stream 39a to a temperature of about −99 ° F. (−73 ° C.). Subsequently, the partially condensed and expanded stream 39a is fed as a feed to the lower region of the absorbent section 118d within the processing assembly 118.

  The recompressed and cooled distillation vapor stream 41c is separated into two streams. One part is stream 46, a volatile residual gas product. The other part is the recirculation stream 45 and enters the heat exchange means in the feed cooling section 118a inside the processing assembly 118. This heat exchange means also consists of fin and tube type heat exchangers, plate type heat exchangers, brass aluminum type heat exchangers, or other types of heat transfer devices including multi-pass and / or multi-service heat exchangers May be. The heat exchange means is configured to provide heat exchange between the stream 45 flowing through one path of the heat exchange means and the distillation vapor stream rising from the separator section 118b. Thereby, the stream 45 is cooled and substantially condensed while heating the distillation vapor stream.

  The substantially condensed recycle stream 45a exits the heat exchange means in the feed cooling section 118a at -138 ° F (-95 ° C) and passes through the expansion valve 22 to the rectification section 118c inside the processing assembly 118. The flash expands to the operating pressure. The entire stream is cooled by vaporizing a portion of the stream during expansion. In the process illustrated in FIG. 2, the expanded stream 45b exiting the expansion valve 22 reaches a temperature of −146 ° F. (−99 ° C.) and is fed to the separator section 118b inside the processing assembly 118. The separated liquid then moves to the rectification section 118c, while the residual steam joins with the vapor rising from the rectification section 118c to form a distillation vapor stream that is heated in the cooling section 118a.

The rectification section 118c and the absorption section 118d each include absorption means consisting of a plurality of vertically spaced trays, one or more packed beds, or a combination of trays and packing materials. The trays and / or fillers in the rectification section 118c and the absorption section 118d provide the necessary contact between the rising vapor and the falling cooled liquid. The liquid portion of the expanded stream 39a mixes with the liquid descending from the absorption section 118d, and the merged liquid continues to proceed to the lower demethanizer section 118e. The stripping vapor that has risen from the demethanizer section 118e joins the vapor portion of the expanded stream 39a, rises through the absorption section 118d, and contacts the cooled liquid that has descended. Then, C ₂ components in these vapors to condense and absorb most of the components of the C ₃ components, and heavier. The vapor rising from the absorption section 118d merges with a portion of the vapor portion of the expanded stream 38b, rises through the rectification section 118c, and the cooled liquid portion of the expanded stream 45b descending. Contact. Then, most of the C ₂ component, C ₃ component, and heavier components remaining in these vapors are condensed and absorbed. The liquid portion of the expanded stream 38b mixes with the liquid descending from the rectification section 118c, and the merged liquid continues to travel to the lower absorption section 118d.

Distillation liquid flowing down from the heat and mass transfer means in the demethanization section 118e inside the processing assembly 118 is stripped of methane and lighter components. The resulting liquid product (stream 44) exits the lower region of the demethanization section 118e and exits the processing assembly 118 at 65 ° F. (18 ° C.). The distillation vapor stream rising from the separator section 118b is warmed in a feed cooling section 118a that provides cooling to the previously described streams 32, 38, and 45. The resulting distilled vapor stream 41 exits the processing assembly 118 at 105 ° F. (40 ° C.). Subsequently, the distillation vapor stream is compressed again in two stages. The first stage is the compressor 16 driven by the expansion device 15, and the second stage is the compressor 20 driven by the auxiliary power source. Stream 41b is cooled to 110 ° F. (43 ° C.) in discharge cooler 21 and stream 41c
, The recycle stream 45 is withdrawn as described above to form a residual gas stream 46 that is sent to the sales gas pipeline at 915 psia (6307 kPa (a)).

The following table provides a summary of stream flow rate and energy consumption for the process described in FIG.

  A comparison between Table 1 and Table 2 shows that the present invention maintains substantially the same recovery rate as the prior art. Also, further comparison between Table 1 and Table 2 shows that product yield was achieved using significantly less power than the prior art. In terms of recovery efficiency (defined by the amount of ethane recovered per power unit), the present invention shows an improvement of over 6 percent over the prior art of the process of FIG.

The improvement in recovery efficiency provided by the present invention over the prior art of the process of FIG. 1 is mainly due to two factors. For one, the small configuration of heat exchange means in the feed cooling section 118a within the processing assembly 118 and heat and mass transfer means in the demethanization section 118e is due to the interconnecting pipes used in conventional processing plants. Removing pressure drop. As a result, compared to the prior art, a portion of the feed gas flowing to the expansion device 15 has a higher pressure in the present invention, and the expansion device 15 of the present invention has a higher outlet pressure, so It is possible to generate as much power as that generated at a low outlet pressure. Therefore, the rectification section 118c and absorption section 118d within the processing assembly 118 of the present invention can operate at higher pressures than the prior art fractionation column 18 while maintaining the same recovery levels as in the prior art. This high operating pressure, and the reduced pressure drop for the distilled steam stream due to the removal of the interconnect pipes, causes the distilled steam stream entering the compressor 20 to be significantly higher in pressure. This reduces the power required to return the residual gas required by the present invention to the pipeline pressure.

  Another advantage is the heat and material in the demethanizer section 118e for simultaneously heating the distilled liquid exiting the absorption section 118d while allowing the resulting vapor to contact the liquid and strip its volatile components. The use of moving means is more efficient than the use of a conventional distillation column with an external reboiler. Volatile components are continuously stripped from the liquid, reducing the concentration of volatile components in the stripping vapor more quickly. This improves the stripping efficiency in the present invention.

  In addition to improving processing efficiency, the present invention provides two additional advantages over the prior art. One advantage is that the processing assembly 118 of the present invention, which is a compact configuration, has five individual pieces of equipment in the prior art (heat exchangers 10, 11, and 13, shown in FIG. 1, separator 12, and fractional distillation). The tower 18) can be replaced by a single piece of equipment (processing assembly 118 shown in FIG. 2). This reduces the required plot space, eliminates interconnect pipes, and reduces the capital cost of processing plants utilizing the present invention over the prior art. Another advantage is that the removal of interconnect pipes reduces the number of potential sources of leakage in the plant because the processing plant utilizing the present invention requires very few flange joints compared to the prior art. Can be reduced. Hydrocarbons are volatile organic compounds (VOCs), some of which are classified as greenhouse gases and some can be precursors of atmospheric ozone formation. This means that the present invention can reduce atmospheric emissions that can be harmful to the environment.

Other Embodiments In certain circumstances, it is preferable to supply the liquid stream 35 directly to the lower region of the absorbent section 118d by the stream 40, as shown in FIGS. 2, 4, 6, and 8. In such a case, a suitable expansion device (eg, expansion valve 17) is used to expand the liquid to the operating pressure of the absorption section 118d, and the resulting expanded liquid stream 40a is in the lower region of the absorption section 118d. Supplied as a feed (indicated by a broken line). In certain circumstances, a portion of the liquid stream 35 (stream 37) and the vapor in the stream 36 (FIGS. 2 and 6) or the cooled second portion 33a (FIGS. 4 and 8) are merged. To form a merged stream 38 and send the remaining portion of the liquid stream 35 to the lower region of the absorbent section 118d by stream 40 / 40a. In certain circumstances, the expanded liquid stream 40a is merged with the expanded stream 39a (FIGS. 2 and 6) or the expanded stream 34a (FIGS. 4 and 8), followed by the merged stream. Is preferably supplied as a single feed to the lower region of the absorbent section 118d.

If the feed gas is more abundant, the amount of liquid separated in stream 35 is between expanded liquid 39a and expanded liquid stream 40a, as shown in FIGS. 5 and 9 may be sufficient to favor the placement of additional mass transfer zones in the demethanization section 118e between the expanded stream 34a and the expanded liquid stream 40a. In such a case, the heat and mass transfer means within the demethanizer section 118e can be configured at the top and bottom, and the expanded liquid stream 40a can be inserted between the two parts. As shown by the dashed line, in certain circumstances, a portion of the liquid stream 35 (stream 37) and the vapor in the stream 36 (FIGS. 3 and 7) or the cooled second portion 33a (FIGS. 5 and 9) to form a merged stream 38, while the remaining portion of the liquid stream 35 (stream 40) expands to a lower pressure, with the top of the heat and mass transfer means inside the demethanizer section 118e. It is preferable to supply as a stream 40a between the lower part.

  In certain circumstances, it is preferred that the cooled first and second portions (streams 32a and 33a) do not merge, as shown in FIGS. 4, 5, 8, and 9. In such a case, only the cooled first portion 32a moves to the separator section 118f (FIGS. 4 and 5) inside the processing assembly 118, or to the separator 12 (FIGS. 8 and 9), where Vapor (stream 34) is separated from the condensed liquid (stream 35). The vapor stream 34 enters the work expansion device 15 where it expands substantially isentropically to the operating pressure of the absorption section 118d, and shortly thereafter, the expanded stream 34a is absorbed by the absorption section 118d within the processing assembly 118. Is supplied as a feed to the lower region of The cooled second portion 33a merges with the separated liquid (part stream 37 of stream 35) and the merged stream 38 exchanges heat in the lower region of the feed cooling section 118a within the processing assembly 118. Moves to the means and is cooled and substantially condensed. As soon as the substantially condensed stream 38a is flash expanded via the expansion valve 14 to the operating pressure of the rectification section 118c and the absorption section 118d, the expanded stream 38b is rectified in the rectification section 118c in the processing assembly 118. And the absorption section 118d. In certain circumstances, only a portion of the liquid stream 35 (stream 37) joins the cooled second portion 33a, and the remaining portion (stream 40) passes through the expansion valve 17 to the absorption section. It is preferable to supply the lower region of 118d. In other environments, it is preferable to route all of the liquid stream 35 through the expansion valve 17 to the lower region of the absorption section 118d.

  In certain circumstances, it may be advantageous to use an external separator device rather than including a separator section 118f in the processing assembly 118 to separate the cooled feedstream 31a or the cooled first portion 32a. Become. As shown in FIGS. 6 and 7, a separator 12 may be used to separate the cooled feed stream 31 a into a vapor stream 34 and a liquid stream 35. Similarly, as shown in FIGS. 8 and 9, a separator 12 may be used to separate the cooled first portion 32 a into a vapor stream 34 and a liquid stream 35.

  Depending on the amount of heavier hydrocarbons in the feed gas and the feed gas pressure, the cooled feed stream 31a entering the separator section 118f shown in FIGS. 2 and 3 or the separator 12 shown in FIGS. (Or the cooled first portion 32a entering the separator section 118f shown in FIGS. 4 and 5 or the separator 12 shown in FIGS. 8 and 9) may not contain any liquid (because it has its dew point). Because it exceeds or exceeds its CLICON Denver). In such a case, there is no liquid in streams 35 and 37 (shown in broken lines), vapor stream 36 exiting separator section 118f (FIGS. 2 and 3), vapor stream 36 exiting separator 12 (FIG. 2). 6 and 7), or only the cooled second portion 33a (FIGS. 4, 5, 8, and 9) flows into stream 38, and a rectifying section 118c and an absorbing section 118d in the processing assembly 118 Into an expanded, substantially condensed stream 38b fed in between. In such an environment, the separator section 118f (FIGS. 2-5) in the processing assembly 118 or the separator 12 (FIGS. 6-9) is not required.

  Feed gas conditions, plant size, available equipment, or other factors may indicate that removal of work expansion device 15 or replacement with an alternative expansion device (such as an expansion valve) is feasible. While individual stream inflation has been indicated by a particular inflation device, other inflation means may be used if desired. For example, some conditions require work expansion of a portion of the substantially condensed feed stream (stream 38a) or a substantially condensed recycle stream (stream 45a).

In accordance with the present invention, an external cooling device that supplements the cooling that is applicable to the inlet gas from the distilled vapor and the liquid stream may be utilized, especially when the inlet gas is rich. In such a case, the heat and mass transfer means (or the cooled feed stream 31a or the cooled first portion 32a does not contain any liquid in the separator section 118f shown by the broken lines in FIGS. May include a gas collecting means), or the separator 12 indicated by a broken line in FIGS. 6 to 9 may include a heat and mass transfer means. This heat and mass transfer means may be from fin and tube heat exchangers, plate heat exchangers, brass aluminum heat exchangers, or other types of heat transfer devices including multi-pass and / or multi-service heat exchangers. It may be configured. The heat and mass transfer means may include a cooling stream (eg, propane) that flows through one path of the heat and mass transfer means and a rising stream 31a (FIGS. 2, 3, 6, and 7), or a stream 32a (FIGS. 4, 5, 8, and 9) configured to provide heat exchange with the vapor portion so that the cooling stream is a portion of the liquid removed in stream 35 The descending vapor and the condensed additional liquid are further cooled. Alternatively, stream 31a enters separator section 118f (FIGS. 2 and 3) or separator 12 (FIGS. 6 and 7) or stream 32a enters separator section 118f (FIGS. 4 and 5) or separator 12 (FIGS. 8 and 8). Prior to entering FIG. 9), one or more conventional gas cooling devices may be used with the cooling stream to cool the stream 32a, the stream 33a and / or the stream 31a.

Depending on the feed gas temperature and abundance and the amount of C ₂ component recovered in the liquid product stream 44, the liquid exiting the demethanizer section 118 is available from stream 33 to meet product specifications. Heating may be insufficient. In such a case, the heat and mass transfer means inside the demethanizer section 118e may include a device that supplements the heating in addition to the heating medium indicated by the broken lines in FIGS. Alternatively, additional heat and mass transfer means may be included in the lower region of the demethanization section 118e to supplement the heating. Alternatively, the stream 33 may be heated with a heating medium before being supplied to the heat and mass transfer means within the demethanizer section 118e.

  Integrating these heat exchange means within a single multi-pass and / or multi-service heat transfer device, depending on the type of heat transfer device selected in the heat exchange means in the upper and lower regions of the feed cooling section 118a Is also possible. In such cases, the multi-pass and / or multi-service heat transfer device distributes, separates, and collects stream 32, stream 38, stream 45, and distilled vapor stream to achieve the desired cooling and heating. Appropriate means may be included.

  In certain circumstances, it is preferred that additional mass transfer means be provided in the upper region of the demethanization section 118e. In such a case, the expanded stream 39a (FIGS. 2, 3, 6, and 7) or the expanded stream 34a (FIGS. 4, 5, 8, and 9) is absorbed by the absorbent section 118d. The mass transfer means may be disposed below the position where it enters the lower region of the gas and above the position where the cooled second portion 33a exits the heat and mass transfer means inside the demethanizer section 118e.

In the embodiments shown in FIGS. 2, 3, 6 and 7 of the present invention, a less preferred choice is to place a separator device in the cooled first part 3 2 a, the cooled second part 3 3 a placing a separator unit, the forming a vapor stream 34 joins the vapor stream separated therein, and a liquid stream 35 joins the separated liquid stream therein Is to form. Another less preferred option of the present invention is to cool the stream 37 in individual heat exchange means within the feed cooling section 118a (stream 37 and stream 36 or stream 33a merge to form a merged stream 38. Rather, it is to expand the cooled stream in individual expansion devices and feed the expanded stream to an intermediate region of the absorbent section 118d.

  The relative amount of feed present in each branch from the split steam feed changes depending on several factors including gas pressure, feed gas composition, the amount of heat that can be economically removed from the feed, and the amount of horsepower available It is understood that it is possible. Increasing the feed above the absorption section 118d increases recovery but also reduces the power recovered from the expander. This increases the required recompression horsepower. Increasing the feed below the absorption section 118d reduces horsepower consumption but also reduces product recovery.

The present invention provides for the recovery of C ₂ component, C ₃ component, and heavier hydrocarbon component, or C ₃ component and heavier hydrocarbon component per utility consumption required to operate the process. Provide improvements. Improvements in utility consumption required to operate this process can include reducing the power required for compression or recompression, reducing the power required for external cooling, reducing the energy requirements to supplement heating, or Can be realized in combination.

  Having described what are considered to be the preferred embodiments of the invention, those skilled in the art will recognize the invention under various conditions without departing from the spirit of the invention, for example, as defined by the following claims. It will be appreciated that other and further modifications are possible to adapt to the type of feed or other requirements.

Claims (25)

Methane, _{C 2} components, _{C 3} components, and more gas stream containing hydrocarbon components heavier (31), a volatile residue gas fraction (46), most of the _{C 2} Ingredient, wherein C ₃ most of the components, and most or containing or most of the C ₃ ingredient, hydrocarbon components heavier than the, and the relative containing most of the hydrocarbon components heavier than the For separating it into a fraction (44) that is low in volatility,
(1) separating the gas stream (31) into a first part (32) and a second part (33) ;
(2) cooling (118a) the first portion (32) ;
(3) cooling (118e) the second part (33) ;
(4) joining the cooled first portion (32a) and the cooled second portion (33a) to form cooled gas streams (31a, 34) ;
(5) separating the cooled gas stream (31a, 34) into a first stream (36) and a second stream (39) ;
(6) Cool the first stream (36, 38) (118e) , condense substantially all of it (38a) , then expand to a lower pressure (14) and further cool (38b) And
(7) The expanded and cooled first stream (38b) is fed into a feed cooling section (118a), a separator section (118b), a rectification section (118c), an absorption section (118d) and a demethanization section (118e). Is supplied as a feed between the first absorption means (118c) and the second absorption means (118d) accommodated in the processing assembly (118) that accommodates the first absorption means (118c). and it is disposed above the second absorbing means (118d),
(8) expanding the second stream (39) to the lower pressure (15) and feeding it to the second absorption means (118d) as a bottom feed (39a) ;
(9) collecting and heating (118a) a distillate vapor stream from the upper region of the first absorption means (118c) , followed by heating the distillate vapor stream (41) from the processing assembly (118 ) ; Discharging,
(10) compressing the heated distilled steam stream (41) to higher pressures (41a, 41b, 41c) (16, 20) followed by the volatile residual gas fraction (46) and compression recirculation Separating into a stream (45) ;
(11) cooling (118a) the compressed recycle stream (45 ) and condensing substantially all (45a) thereof;
(12) The substantially condensed compressed recycle stream (45a) is expanded to the lower pressure (22) and fed to the first absorption means (118c) as a feed (45b) to the top. And
(13) The heating of the distillation vapor stream is accomplished by one or more heat exchange means (118a) housed in the processing assembly (118) , thereby providing steps (2), (6), and Providing at least a portion of the cooling in (11);
(14) collecting a distilled liquid stream from the lower region of the second absorption means (118d) and heating it by heat and mass transfer means (118e) contained in the processing assembly (118) , thereby Simultaneously stripping higher volatile components exiting the distillation liquid stream (41) , followed by the heating and stripped distillation liquid stream as the relatively less volatile fraction (44). Providing at least a portion of the cooling in step (3) while discharging from the processing assembly (118) ;
(15) The amount and temperature of the feed stream (45b, 38b, 39a) relative to the first and second absorption means (118c, 118d) is determined by the components in the relatively volatile fraction (44). and the majority of it is effective to maintain the temperature of the upper region of the first absorption means to a temperature such as is recovered (118c),
Including a method. (A) joins a second portion which is cooled in a first portion (32a) and the step that has been cooled in the step (4) (4) (33a ), partially condensed gas stream ( 31a)
(B) providing the vapor stream (34) and at least one liquid stream (35) by feeding the partially condensed gas stream (31a) to a separation means (12 or 118f) and separating there; And
(C) separating the said vapor stream (34) a first stream (36) and a second stream (39),
(D) at least a portion (40 ) of the at least one liquid stream (35) is expanded to the lower pressure (17) and fed to the absorption means (118d) as an additional bottom feed (40a) ;
The method of claim 1. (A) the step of (c) a first stream (36) of, and is combined with at least part of the (37) of at least one liquid stream of step (b) (35), merged stream (38) Form
(B) cooling the combined stream (38) , condensing substantially all of it (38a) , and subsequently expanding to a lower pressure (14) further cooling (38b) ;
(C) Stream cooling said inflating (38b), supplied as a feed during the said housed in a processing assembly (118) first and second absorbing means (118c, 118d),
(D) all remaining portion (40), the more inflated at low pressure until (17), the second absorbing means as an additional bottom feed of at least one liquid stream of step (b) (35) (118d) ,
The method of claim 2. (A) cooling (118a) the first part (32) of said step (2 ) and expanding it to a lower pressure (34a) (15) ;
(B) cooling the second portion (33) of the step (3), its substantial all to condense (38a), then the more inflated to a low pressure (14), thereby further cooling (38b)
(C) supplying the expanded and cooled second portion (38b) as a feed between the first and second absorbing means (118c, 118d) ;
(D) supplying the expanded and cooled first portion (34a) as a bottom feed to the second absorption means (118d) ;
The method of claim 1. (A) the first part (32) of step (2) is sufficiently cooled (118a) and partially condensed (32a) ;
(B) The partially condensed first part (32a) is fed to a separating means (12 or 118f) and separated therein to obtain a vapor stream (34) and at least one liquid stream (35 )
(C) expanding the vapor stream (34) to the lower pressure (15) and supplying it as the first bottom feed (34a) to the second absorption means (118d) ;
(D) at least a portion (40 ) of the at least one liquid stream (35) is expanded to a lower pressure (17) and an additional bottom feed (40a) to the second absorption means (118d ) As supply,
The method of claim 4. (A) the second part (33) is cooled (118e) and then merged with at least a part (37) of at least one liquid stream (35) of the step (b ) and merged stream (38 ) to form,
(B) cooling the stream (38) that the merging (118a), the substantial all to condense (38a), then more is inflated to a low pressure (14), thereby to further cool (38b),
(C) supplying the expanded and cooled combined stream (38b) as a feed between the first and second absorbing means (118c, 118d) ;
; (D) step all portions (40) of the remaining (b) at least one liquid stream (35) is expanded to a low pressure than the (17), the additional the relative second absorption means (118d) Feed as bottom feed (40a) ,
The method of claim 5. (1) disposing the heat and mass transfer means (118e) in upper and lower regions;
(2) wherein at least a portion of said expanded at least one liquid stream step (d) the (40a), supplied to the processing assembly (118), said upper portion of said heat and mass transfer means (118e) region and entering is Ru between the lower region, the method according to claim 2 or 5. ( 1) disposing the heat and mass transfer means (118e) in upper and lower regions;
( 2) supplying at least a portion (40a) of the expanded at least one liquid stream of step (d) to the processing assembly (118) and the upper portion of the heat and mass transfer means (118e); The method according to claim 3 or 6, wherein the method is placed between a region and the lower region. The method of claim 2, 3, 5, 6, 7 or 8 , wherein the separating means (118f) is housed within the processing assembly (118) . (1) A gas collecting means (118f) is accommodated in the processing assembly (118) ,
(2) external additional heat and mass transfer means comprising one or more paths for the cooling medium, ARE INCLUDED within said gas collection means (118f),
(3) Supply the cooled gas stream (31a) of step (4) to the gas collection means (118f) and lead to the additional heat and mass transfer means further cooled by the external cooling medium. ,
(4) The method according to claim 1, wherein the further cooled gas stream (34) is separated into the first stream (36) and the second stream (39) . (1) A gas collecting means (118f) is accommodated in the processing assembly (118) ,
(2) an external additional heat and mass transfer means comprises one or more paths for the cooling medium, ARE INCLUDED inside the gas collecting means (118f),
(3) The additional heat and mass transfer means for supplying the cooled first portion (32a) of step (a) to the gas collection means (118f) and further cooling by the external cooling medium. Lead to
(4) The further cooled first part (34) is expanded to a lower pressure (15) and subsequently fed to the second absorption means (118d) as the bottom feed (34a) . The method of claim 4. (1) including additional heat and mass transfer means including one or more paths for an external cooling medium within said separation means (12 or 118f) ;
(2) directing the vapor stream of step (b) to the additional heat and mass transfer means cooled by the external cooling medium to form additional condensate;
(3) The condensate according to claim 2, 3, 5, 6, 7, 8 , or 9 , wherein the condensate is part (35) of at least one liquid stream separated there in step (b) . Method. The heat and mass transfer means (118e) is external heating that supplements the heating provided by the second portion (33) for stripping the higher volatile components exiting the distillation liquid stream. 13. A method according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, comprising one or more paths leading to the medium. A gas stream containing methane, a C ₂ component, a C ₃ component and a heavier hydrocarbon component, a volatile residual gas fraction, a majority of the C ₂ component, a majority of the C ₃ component, and or containing most of the hydrocarbon components heavier than the, or the C ₃ most of the components, and a relatively less volatile fraction containing a major portion of the hydrocarbon components heavier than the A device for separating
(1) first separation means for separating the gas stream (31) into a first part (32) and a second part (33) ;
(2) heat exchange means ( 32a) connected to the first separation means and contained in the processing assembly (118 ) for receiving the first part (32) and cooling it (32a) 118a)
(3) heat and material connected to the first separation means and contained in the processing assembly (118 ) for receiving and cooling the second part (33) (33a) Moving means (118e) ;
(4) Connected to the heat exchange means (118a) and the heat and mass transfer means (118e) , the cooled first part (32a) and the cooled second part (33a) Means for receiving and forming a cooled gas stream (31a, 34) ;
(5) second separation means connected to the merging means for receiving the cooled gas stream (31a, 34) and separating it into first and second streams (36, 39) ;
(6) the heat exchange means further connected to the second separation means and receiving the first stream (36, 38) and sufficiently cooling it to substantially condense (38a) ; ,
(7) connected to the heat exchange means (118a) and accepts the substantially condensed first stream (38a) and expands it to a lower pressure (38b) first expansion means (14) ) And
(8) a first stream (38b) connected to the first expansion means (14) and contained in the processing assembly (118) , as the feed between them, the expanded and cooled first stream (38b); First and second absorption means (118c, 118d) for receiving the absorption means, wherein the first absorption means (118c) is disposed above the second absorption means (118d) ;
(9) Second expansion means (15) connected to said second separation means and receiving said second stream (39) and expanding it to said lower pressure (39a) comprising a bottom portion Second expansion means (15) further connected to the second absorption means (118d) to supply the expanded second stream (39c) thereto as a feed;
(10) steam connected to the first absorption means (118c) and contained in the processing assembly (118) for receiving a distilled steam stream from an upper region of the first absorption means (118c) ; Collection means;
(11) further connected to the steam collecting means (118b) , receiving the distilled steam stream, heating it, and supplying at least a portion (118a) of cooling in steps (2) and (6); Subsequently, said heat exchange means for discharging said heated distillation steam stream (41) from said processing assembly (118) ;
(12) receiving said heated distillation vapor stream (41), it and the more compressed to a high pressure (41a, 41b) compression means for the connection with the processing assembly (118) for (16, 20),
(13) Cooling means (21) connected to the compression means (20) for receiving and cooling the compressed distilled steam stream (41b) ;
(14) connected to the cooling means (21) for receiving the cooled compressed distillation vapor stream (41c) and separating it into the volatile residual gas fraction (46) and the compressed recycle stream (45). A third separating means,
(15) Accept the compressed recycle stream (45) and cool it sufficiently to substantially condense (45a) , thereby providing at least a portion of the heating (118a) in step (11) The heat exchange means (118a) further connected to the third separation means;
(16) Third expansion means ( 45b) connected to the heat exchange means (118a) and receiving the substantially condensed compressed recycle stream (45a) and expanding it to the lower pressure (45b) . 32) third expansion means (22) further connected to the first absorption means (118c) and supplying the expanded recirculation stream (45b) thereto as a feed to the top When,
(17) Liquid connected to the second absorbent means (118d) and contained in the processing assembly (118) for receiving a distilled liquid stream from a lower region of the second absorbent means (118d) Collection means;
(18) further connected to the liquid collecting means for receiving and heating the distilled liquid stream, simultaneously stripping higher volatile components exiting the distilled liquid stream, followed by the heating The heat supplying at least a portion of the cooling in step (3) while discharging the stripped distilled liquid stream from the processing assembly (118) as the relatively volatile fraction (44) ; Mass transfer means (118e) ;
(19) Adjusting the amount and temperature of the feed stream (45b, 38b, 39a) to the first and second absorption means (118c, 118d) , and adjusting the relatively low-volatility fraction (44 And control means for maintaining the temperature of the upper region of the first absorption means (118c) at such a temperature that most of the components therein are recovered. (A) said coupling means being connected to said heat exchange means (118a) and said heat and mass transfer means (118e), from the said (2) cooled first portion (32a) and the (3) Receiving said cooled second part (33a ) and forming a partially condensed gas stream (31a) ;
(B) Separation means (12 or 118f) is connected to the coupling means and accepts the partially condensed gas stream (31a) into the vapor stream (34) and at least one liquid stream (35) . Separate and
(C) the second separation means is connected to the separation means (12 or 118f), accepts the vapor stream (34 ) and separates it into first and second streams (36, 39) ;
(D) a fourth expansion means (17) is connected to the separation means (12 or 118f), accepts at least a part (40) of the at least one liquid stream (35) and expands to a lower pressure; The fourth expansion means (17) is connected to the second absorption means (118d ) and supplies the expansion liquid stream (40a) as a second bottom feed,
The apparatus according to claim 14 . (A) a further combining means is connected to the second separating means and the separating means (12 or 188f), the first stream (36) from (c ) and at least one from (b) Accepts at least a portion (37 ) of the liquid stream (35 ) to form a connected stream (38) ;
(B) said heat exchange means (118a) is further connected to the further coupling means, the receiving coupling stream (38), sufficiently cool it to substantially condense (38a),
(C) said first expansion means (14) is connected to said heat exchange means (118a), said receiving substantially condensed coupled stream (38a), is expanded lower pressure (38b),
(D) The first and second absorption means (118c and 118d) are connected to the first expansion means (14) and feed between the first and second absorption means (118c, 118d). the receiving expansion to cool the merged stream (38b) as,
(E) The fourth expansion means (17) is connected to the separation means (12 or 118f ) and accepts all remaining portions (40) of at least one liquid stream (35) from (b). the more inflated to a low pressure (40a), said fourth expansion means (17) is further connected to the second absorbing means (118d), wherein-expanded liquid stream as an additional bottom feed (40a) Supply,
The apparatus according to claim 15 . (A) said heat exchange means (118a) is connected to the heating and mass transfer means (118e), the receiving the cooled second portion of the (3) (33a, 38) , and further sufficiently cooled Te, substantially condensed (38a),
(B) said first expansion means (14) is connected to said heat exchange means (118a), said substantially condensed second portion receiving the (38a), is expanded lower pressure (38b),
(C) The first and second absorption means (118c, 118d) are connected to the first expansion means (14) and feed between the first and second absorption means (118c, 118d). Receiving the expanded and cooled second part (38b) as
; (D) second expansion means (15) is connected to said heat exchange means (118a), said receiving (2) cooled first portion from (32a), is expanded the more the low pressure ( 34a) the second expansion means (15) is connected to the second absorption means and supplies the expanded and cooled first part (34a) as a bottom feed;
The apparatus according to claim 14 . (A) The heat exchanging means (118a) is connected to the first dividing means, accepts the first part (32) from (2) , cools sufficiently and condenses it partially ( 32a)
(B) Separation means (12 or 118f) is connected to the heat exchange means (118a), receives the partially condensed first part (32a), and comprises a vapor stream (34) and at least one liquid stream ( 35) ,
(C) The second expansion means (15) is connected to the separation means (12 or 118f), receives the steam stream (34) and expands it to the lower pressure (34a) , and the second expansion means (15) is further connected to a second absorption means (118d ) and supplies the expanded steam stream (34a) as a first bottom feed;
(D) A fourth expansion means (17) is connected to the separation means (12 or 118f ) and receives at least a part (40) of the at least one liquid stream (35) and expands it to the lower pressure ( 40a) the fourth expansion means (17) is further connected to the second absorption means and supplies the expanded liquid stream (40a) as an additional bottom feed;
The apparatus of claim 17 . (A) a further merging means is connected to said heat and mass transport means (118e) and said separation means (12 or 118f), and at least one from said cooled second part (33a) and said (b) Receiving at least a portion (37) of one liquid stream (35 ) and forming a confluence stream (38) ;
(B) the heat exchange means (118a) is connected to the further merging means, accepts the merging stream (38) , cools and substantially condenses (38a) ;
(C) said first expansion means (14) is connected to said heat exchange means (118a), said substantially accept condensed merged stream (38a), is expanded lower pressure (38b),
; (D) first and second absorbing means (118c, 118d) is connected to said first expansion means (14), said first and second absorbing means (118c, 118d) feed to between Accepting said expanded and cooled combined stream (38b) as
(E) The fourth expansion means (17) is connected to the separation means (12 or 118f ) and accepts all remaining portions (40) of at least one liquid stream (35) from (b). , low pressure until inflating it from the (40a), said fourth expansion means (17) is further connected to the second absorbing means (118d), the additional bottom Zhang liquid stream (40a described above Rise as a feed )
The apparatus according to claim 18 . (1) the heat and mass transfer means (118e) is disposed in the upper and lower regions;
(2) The processing assembly (118) is connected to the fourth expansion means (17) and receives the expanded liquid stream (40a) from (d) , which is received by the heat and mass transfer means. 20. Apparatus according to claim 15 , 16 , 18 or 19 leading between the upper region and the lower region of (118e) . 21. Apparatus according to claim 15 , 16, 18 , 19 or 20 , wherein said separating means (118f) is housed in said processing assembly (118) . (1) A gas collecting means (118f) is accommodated in the processing assembly (118) ,
(2) Additional heat and mass transfer means including one or more paths for an external cooling medium are included within the gas collection means (118f) ;
(3) The gas collecting means (118f) is connected to the merging means and accepts the cooled gas stream (31a) from (4) , which is further cooled by the external cooling medium. Leading to additional heat and mass transfer means,
(4) the second separating means is adapted to connect to the gas collecting means (118f ) and accepts the further cooled gas stream (34) , which is connected to the first stream (36) and the first stream (36) ; 15. A device according to claim 14 , which separates into two streams (39) . (1) A gas collecting means (118f) is accommodated in the processing assembly (118) ,
(2) Additional heat and mass transfer means including one or more paths for an external cooling medium are included within the gas collection means (118f) ;
(3) The gas collecting means (118f) is connected to the heat exchanging means (118a) and receives the cooled first portion (32a) from (2) , which is received as the external cooling medium. Leading to the additional heat and mass transfer means further cooled by
(4) The second expansion means (15) is adapted to connect to the gas collection means (118f) , accepts the further cooled first part and expands it to the lower pressure (34a). ) , The second expansion means (15) is further connected to the second absorption means (118d) , and the expanded and further cooled first portion (34a) is used as the bottom feed there. The apparatus of claim 17 , wherein the apparatus is supplied. (1) Additional heat and mass transfer means including one or more paths for an external cooling medium are included within the separation means (12 or 118f) ;
(2) directing the vapor stream to the additional heat and mass transfer means cooled by the external cooling medium to form additional condensate;
(3) making said condensate part of at least one liquid stream (35) from said (b) separated there;
Device according to claim 15 , 16 , 18 , 19 , 20 or 21 . Said heat and mass transfer means (118e), for the stripping of more volatile components from said exiting from the distillation liquid stream, an external heating medium supplement the heating provided by the second portion (33) 25. Apparatus according to claim 14, 15, 16, 17, 18 , 19, 20 , 21, 22, 23 or 24 , comprising one or more paths for use.

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