Hydrocarbon gas processing

• US 20060283207A1
• Filed: 05/09/2006
• Published: 12/21/2006
• Est. Priority Date: 06/20/2005
• Status: Active Grant

• Current Assignee: UOP Llc (Honeywell International Inc.)
• Original Assignee: Ortloff Enigneers, Ltd.
• Inventors: Hudson, Hank M., Lynch, Joe T., Cuellar, Kyle T., Martinez, Tony L., Wilkinson, John D., Pitman, Richard N.
• Granted Patent: US 9,080,810 B2
• Time in Patent Office: Days
• US Class Current: 62/620
• CPC Class Codes: F25J 2200/02 in a single pressure main column system
• CPC Class Codes: F25J 2200/04 in a dual pressure main column system
• CPC Class Codes: F25J 2200/30 using a side column in a single pressure column system
• CPC Class Codes: F25J 2200/70 Refluxing the column with a condensed part of the feed stream, i.e. fractionator top is stripped or self-rectified
• CPC Class Codes: F25J 2200/76 Refluxing the column with condensed overhead gas being cycled in a quasi-closed loop refrigeration cycle
• CPC Class Codes: F25J 2200/78 Refluxing the column with a liquid stream originating from an upstream or downstream fractionator column
• CPC Class Codes: F25J 2205/02 using simple phase separation in a vessel or drum
• CPC Class Codes: F25J 2205/04 in the feed line, i.e. upstream of the fractionation step
• CPC Class Codes: F25J 2220/66 Separating acid gases, e.g. CO2, SO2, H2S or RSH
• CPC Class Codes: F25J 2230/08 Cold compressor, i.e. suction of the gas at cryogenic temperature and generally without afterstage-cooler
• CPC Class Codes: F25J 2235/60 the fluid being (a mixture of) hydrocarbons
• CPC Class Codes: F25J 2240/02 Expansion of a process fluid in a work-extracting turbine (i.e. isentropic expansion), e.g. of the feed stream
• CPC Class Codes: F25J 2280/02 Control in general, load changes, different modes ("runs"), measurements
• CPC Class Codes: F25J 2290/40 Vertical layout or arrangement of cold equipments within in the cold box, e.g. columns, condensers, heat exchangers etc.
• CPC Class Codes: F25J 2290/80 Retrofitting, revamping or debottlenecking of existing plant
• CPC Class Codes: F25J 3/0209 Natural gas or substitute natural gas
• CPC Class Codes: F25J 3/0233 separation of CnHm with 1 carbon atom or more
• CPC Class Codes: F25J 3/0238 separation of CnHm with 2 carbon atoms or more

Abstract

A process for the recovery of ethane, ethylene, propane, propylene, and heavier hydrocarbon components from a hydrocarbon gas stream is disclosed. The stream is cooled and is thereafter expanded to the fractionation tower pressure and supplied to the fractionation tower at a lower mid-column feed position. A distillation stream is withdrawn from the column below the feed point of the stream and is then directed into heat exchange relation with the tower overhead vapor stream to cool the distillation stream and condense at least a part of it, forming a condensed stream. At least a portion of the condensed stream is directed to the fractionation tower at an upper mid-column feed position. A recycle stream is withdrawn from the tower overhead after it has been warmed and compressed. The compressed recycle stream is cooled sufficiently to substantially condense it, and is then expanded to the pressure of the fractionation tower and supplied to the tower at a top column feed position. The quantities and temperatures of the feeds to the fractionation tower are effective to maintain the overhead temperature of the fractionation tower at a temperature whereby the major portion of the desired components is recovered.

Claims

1. In a process for the separation of a gas stream containing methane, C₂ components, C₃ components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C₂ components, C₃ components, and heavier hydrocarbon components or said C₃ components and heavier hydrocarbon components, in which process

(a) said gas stream is cooled under pressure to provide a cooled stream;

(b) said cooled stream is expanded to a lower pressure whereby it is further cooled; and

(c) said further cooled expanded stream is directed into a distillation column and fractionated at said lower pressure whereby the components of said relatively less volatile fraction are recovered;

the improvement wherein said further cooled expanded stream is directed to a first mid-column feed position on said distillation column; and

(1) a vapor distillation stream is withdrawn from a region of said distillation column below said first mid-column feed position and is cooled sufficiently to condense at least a part of it, thereby forming a condensed stream and a residual vapor stream containing any uncondensed vapor remaining after said vapor distillation stream is cooled;

(2) at least a portion of said condensed stream is supplied to said distillation column at a second mid-column feed position above said first mid-column feed position;

(3) an overhead vapor stream is withdrawn from an upper region of said distillation column and is directed into heat exchange relation with at least said vapor distillation stream and heated, thereby to supply at least a portion of the cooling of step (1);

(4) said heated overhead vapor stream is combined with any said residual vapor stream to form a heated combined vapor stream;

(5) said heated combined vapor stream is compressed to higher pressure and thereafter divided into said volatile residue gas fraction and a compressed recycle stream;

(6) said compressed recycle stream is cooled sufficiently to substantially condense it;

(7) said substantially condensed compressed recycle stream is expanded to said lower pressure and supplied to said distillation column at a top feed position; and

(8) the quantities and temperatures of said feed streams to said distillation column are effective to maintain the overhead temperature of said distillation column at a temperature whereby the major portions of the components in said relatively less volatile fraction are recovered.

2. The improvement according to claim 1 wherein said gas stream is cooled sufficiently to partially condense it;

and

(1) said partially condensed gas stream is separated thereby to provide a vapor stream and at least one liquid stream;

(2) said vapor stream is expanded to said lower pressure whereby it is further cooled, and thereafter supplied to said distillation column at said first mid-column feed position; and

(3) from 0% to 100% of said at least one liquid stream is expanded to said lower pressure and supplied to said distillation column at a third mid-column feed position;

(4) from 100% to 0% of said at least one liquid stream is expanded to said lower pressure and combined with said vapor distillation stream to form a combined stream;

(5) said combined stream is cooled sufficiently to condense at least a part of it, thereby forming said condensed stream and said residual vapor stream containing any uncondensed vapor remaining after said combined stream is cooled; and

(6) said overhead vapor stream is directed into heat exchange relation with at least said combined stream and heated, thereby to supply at least a portion of the cooling of step (5).

3. In a process for the separation of a gas stream containing methane, C₂ components, C₃ components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C₂ components, C₃ components, and heavier hydrocarbon components or said C₃ components and heavier hydrocarbon components, in which process

(a) said gas stream is cooled under pressure to provide a cooled stream;

(b) said cooled stream is expanded to a lower pressure whereby it is further cooled; and

(c) said further cooled expanded stream is directed into a distillation column and fractionated at said lower pressure whereby the components of said relatively less volatile fraction are recovered;

the improvement wherein said further cooled expanded stream is directed to a first mid-column feed position on said distillation column; and

(1) a vapor distillation stream is withdrawn from a region of said distillation column below said first mid-column feed position and compressed to an intermediate pressure;

(2) said compressed vapor distillation stream is cooled sufficiently to condense at least a part of it, thereby forming a condensed stream;

(3) at least a portion of said condensed stream is supplied to said distillation column at a second mid-column feed position above said first mid-column feed position;

(4) an overhead vapor stream is withdrawn from an upper region of said distillation column and is directed into heat exchange relation with at least said compressed vapor distillation stream and heated, thereby to supply at least a portion of the cooling of step (2);

(5) said heated overhead vapor stream is compressed to higher pressure and thereafter divided into said volatile residue gas fraction and a compressed recycle stream;

(6) said compressed recycle stream is cooled sufficiently to substantially condense it;

(7) said substantially condensed compressed recycle stream is expanded to said lower pressure and supplied to said distillation column at a top feed position; and

(8) the quantities and temperatures of said feed streams to said distillation column are effective to maintain the overhead temperature of said distillation column at a temperature whereby the major portions of the components in said relatively less volatile fraction are recovered.

4. The improvement according to claim 3 wherein said gas stream is cooled sufficiently to partially condense it;

and

(1) said partially condensed gas stream is separated thereby to provide a vapor stream and at least one liquid stream;

(2) said vapor stream is expanded to said lower pressure whereby it is further cooled, and thereafter supplied to said distillation column at said first mid-column feed position;

(3) from 0% to 100% of said at least one liquid stream is expanded to said lower pressure and supplied to said distillation column at a third mid-column feed position;

(4) from 100% to 0% of said at least one liquid stream is expanded to said intermediate pressure and combined with said compressed vapor distillation stream to form a combined stream;

(5) said combined stream is cooled sufficiently to condense at least a part of it, thereby forming said condensed stream; and

(6) said overhead vapor stream is directed into heat exchange relation with at least said combined stream and heated, thereby to supply at least a portion of the cooling of step (5).

5. In a process for the separation of a gas stream containing methane, C₂ components, C₃ components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C₂ components, C₃ components, and heavier hydrocarbon components or said C₃ components and heavier hydrocarbon components, in which process

(a) said gas stream is cooled under pressure to provide a cooled stream;

(b) said cooled stream is expanded to a lower pressure whereby it is further cooled; and

(c) said further cooled expanded stream is directed into a distillation column and fractionated at said lower pressure whereby the components of said relatively less volatile fraction are recovered;

the improvement wherein said further cooled expanded stream is directed to a first mid-column feed position on said distillation column; and

(1) a vapor distillation stream is withdrawn from a region of said distillation column below said first mid-column feed position and is cooled sufficiently to condense at least a part of it, thereby forming a condensed stream and a residual vapor stream containing any uncondensed vapor remaining after said vapor distillation stream is cooled;

(2) at least a portion of said condensed stream is supplied to said distillation column at a second mid-column feed position above said first mid-column feed position;

(3) an overhead vapor stream is withdrawn from an upper region of said distillation column and combined with any said residual vapor stream to form a combined vapor stream;

(4) said combined vapor stream is directed into heat exchange relation with at least said vapor distillation stream and heated, thereby to supply at least a portion of the cooling of step (1);

(5) said heated combined vapor stream is compressed to higher pressure and thereafter divided into said volatile residue gas fraction and a compressed recycle stream;

(6) said compressed recycle stream is cooled sufficiently to substantially condense it;

(7) said substantially condensed compressed recycle stream is expanded to said lower pressure and supplied to said distillation column at a top feed position; and

(8) the quantities and temperatures of said feed streams to said distillation column are effective to maintain the overhead temperature of said distillation column at a temperature whereby the major portions of the components in said relatively less volatile fraction are recovered.

6. The improvement according to claim 5 wherein said gas stream is cooled sufficiently to partially condense it;

and

(1) said partially condensed gas stream is separated thereby to provide a vapor stream and at least one liquid stream;

(2) said vapor stream is expanded to said lower pressure whereby it is further cooled, and thereafter supplied to said distillation column at said first mid-column feed position;

(3) from 0% to 100% of said at least one liquid stream is expanded to said lower pressure and supplied to said distillation column at a third mid-column feed position;

(4) from 100% to 0% of said at least one liquid stream is expanded to said lower pressure and combined with said vapor distillation stream to form a combined stream;

(5) said combined stream is cooled sufficiently to condense at least a part of it, thereby forming said condensed stream and said residual vapor stream containing any uncondensed vapor remaining after said combined stream is cooled; and

(6) said combined vapor stream is directed into heat exchange relation with at least said combined stream and heated, thereby to supply at least a portion of the cooling of step (5).

7. In a process for the separation of a gas stream containing methane, C₂ components, C₃ components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C₂ components, C₃ components, and heavier hydrocarbon components or said C₃ components and heavier hydrocarbon components, in which process

(a) said gas stream is cooled under pressure to provide a cooled stream;

(b) said cooled stream is expanded to a lower pressure whereby it is further cooled; and

(c) said further cooled expanded stream is directed into a distillation column and fractionated at said lower pressure whereby the components of said relatively less volatile fraction are recovered;

the improvement wherein

(1) said further cooled expanded stream is supplied at a first lower feed position to a contacting and separating device that produces an overhead vapor stream and a bottom liquid stream, whereupon said bottom liquid stream is supplied to said distillation column;

(2) a vapor distillation stream is withdrawn from an upper region of said distillation column to form at least a first distillation stream;

(3) said first distillation stream is cooled sufficiently to condense at least a part of it, thereby forming a condensed stream and a residual vapor stream containing any uncondensed vapor remaining after said first distillation stream is cooled;

(4) at least a portion of said condensed stream is supplied to said contacting and separating device at a mid-column feed position;

(5) said overhead vapor stream is directed into heat exchange relation with at least said first distillation stream and heated, thereby to supply at least a portion of the cooling of step (3);

(6) said heated overhead vapor stream is combined with any said residual vapor stream to form a heated combined vapor stream;

(7) said heated combined vapor stream is compressed to higher pressure and thereafter divided into said volatile residue gas fraction and a compressed recycle stream;

(8) said compressed recycle stream is cooled sufficiently to substantially condense it;

(9) said substantially condensed compressed recycle stream is expanded to said lower pressure and supplied to said contacting and separating device at a top feed position;

(10) any remaining portion of said vapor distillation stream is directed to said contacting and separating device at a second lower feed position; and

(11) the quantities and temperatures of said feed streams to said contacting and separating device are effective to maintain the overhead temperature of said contacting and separating device at a temperature whereby the major portions of the components in said relatively less volatile fraction are recovered.

8. The improvement according to claim 7 wherein said gas stream is cooled sufficiently to partially condense it;

and

(1) said partially condensed gas stream is separated thereby to provide a vapor stream and at least one liquid stream;

(2) said vapor stream is expanded to said lower pressure whereby it is further cooled, and thereafter supplied to said contacting and separating device at said first lower column feed position;

(3) from 0% to 100% of said at least one liquid stream is expanded to said lower pressure and supplied to said distillation column at a mid-column feed position;

(4) from 100% to 0% of said at least one liquid stream is expanded to said lower pressure and combined with said first distillation stream to form a combined stream;

(5) said combined stream is cooled sufficiently to condense at least a part of it, thereby forming said condensed stream and said residual vapor stream containing any uncondensed vapor remaining after said combined stream is cooled; and

(6) said overhead vapor stream is directed into heat exchange relation with at least said combined stream and heated, thereby to supply at least a portion of the cooling of step (5).

9. In a process for the separation of a gas stream containing methane, C₂ components, C₃ components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C₂ components, C₃ components, and heavier hydrocarbon components or said C₃ components and heavier hydrocarbon components, in which process

(a) said gas stream is cooled under pressure to provide a cooled stream;

(b) said cooled stream is expanded to a lower pressure whereby it is further cooled; and

(c) said further cooled expanded stream is directed into a distillation column and fractionated at said lower pressure whereby the components of said relatively less volatile fraction are recovered;

the improvement wherein said cooled stream is expanded to an intermediate pressure whereby it is further cooled; and

(1) said further cooled expanded stream is supplied at a first lower feed position to a contacting and separating device that produces an overhead vapor stream and a bottom liquid stream, whereupon said bottom liquid stream is expanded to said lower pressure and thereafter supplied to said distillation column;

(2) a vapor distillation stream is withdrawn from an upper region of said distillation column to form at least a first distillation stream;

(3) said first distillation stream is cooled sufficiently to condense at least a part of it, thereby forming a condensed stream and a residual vapor stream containing any uncondensed vapor remaining after said first distillation stream is cooled;

(4) at least a portion of said condensed stream is supplied to said contacting and separating device at a mid-column feed position;

(5) said overhead vapor stream is directed into heat exchange relation with at least said first distillation stream and heated, thereby to supply at least a portion of the cooling of step (3);

(6) said heated overhead vapor stream is combined with any said residual vapor stream to form a heated combined vapor stream;

(7) said heated combined vapor stream is compressed to higher pressure and thereafter divided into said volatile residue gas fraction and a compressed recycle stream;

(8) said compressed recycle stream is cooled sufficiently to substantially condense it;

(9) said substantially condensed compressed recycle stream is expanded to said intermediate pressure and supplied to said contacting and separating device at a top feed position;

(10) any remaining portion of said vapor distillation stream is compressed to said intermediate pressure and thereafter directed to said contacting and separating device at a second lower feed position; and

(11) the quantities and temperatures of said feed streams to said contacting and separating device are effective to maintain the overhead temperature of said contacting and separating device at a temperature whereby the major portions of the components in said relatively less volatile fraction are recovered.

10. The improvement according to claim 9 wherein said gas stream is cooled sufficiently to partially condense it;

and

(1) said partially condensed gas stream is separated thereby to provide a vapor stream and at least one liquid stream;

(2) said vapor stream is expanded to said intermediate pressure whereby it is further cooled, and thereafter supplied to said contacting and separating device at said first lower column feed position;

(3) from 0% to 100% of said at least one liquid stream is expanded to said lower pressure and supplied to said distillation column at a mid-column feed position;

(4) from 100% to 0% of said at least one liquid stream is expanded to said lower pressure and combined with said first distillation stream to form a combined stream;

(5) said combined stream is cooled sufficiently to condense at least a part of it, thereby forming said condensed stream and said residual vapor stream containing any uncondensed vapor remaining after said combined stream is cooled; and

(6) said overhead vapor stream is directed into heat exchange relation with at least said combined stream and heated, thereby to supply at least a portion of the cooling of step (5).

11. In a process for the separation of a gas stream containing methane, C₂ components, C₃ components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C₂ components, C₃ components, and heavier hydrocarbon components or said C₃ components and heavier hydrocarbon components, in which process

(a) said gas stream is cooled under pressure to provide a cooled stream;

(b) said cooled stream is expanded to a lower pressure whereby it is further cooled; and

(c) said further cooled expanded stream is directed into a distillation column and fractionated at said lower pressure whereby the components of said relatively less volatile fraction are recovered;

the improvement wherein said cooled stream is expanded to an intermediate pressure whereby it is further cooled; and

(1) said further cooled expanded stream is supplied at a first lower feed position to a contacting and separating device that produces an overhead vapor stream and a bottom liquid stream, whereupon said bottom liquid stream is expanded to said lower pressure and thereafter supplied to said distillation column;

(2) a vapor distillation stream is withdrawn from an upper region of said distillation column, compressed to said intermediate pressure, and divided to form a first compressed distillation stream and a second compressed distillation stream;

(3) said first compressed distillation stream is cooled sufficiently to condense at least a part of it, thereby forming a condensed stream;

(4) at least a portion of said condensed stream is supplied to said contacting and separating device at a mid-column feed position;

(5) said overhead vapor stream is directed into heat exchange relation with at least said first compressed distillation stream and heated, thereby to supply at least a portion of the cooling of step (3);

(6) said heated overhead vapor stream is compressed to higher pressure and thereafter divided into said volatile residue gas fraction and a compressed recycle stream;

(7) said compressed recycle stream is cooled sufficiently to substantially condense it;

(8) said substantially condensed compressed recycle stream is expanded to said intermediate pressure and supplied to said contacting and separating device at a top feed position;

(9) said second compressed vapor distillation stream is directed to said contacting and separating device at a second lower feed position; and

(10) the quantities and temperatures of said feed streams to said contacting and separating device are effective to maintain the overhead temperature of said contacting and separating device at a temperature whereby the major portions of the components in said relatively less volatile fraction are recovered.

12. The improvement according to claim 11 wherein said gas stream is cooled sufficiently to partially condense it;

and

(1) said partially condensed gas stream is separated thereby to provide a vapor stream and at least one liquid stream;

(2) said vapor stream is expanded to said intermediate pressure whereby it is further cooled, and thereafter supplied to said contacting and separating device at said first lower column feed position;

(3) from 0% to 100% of said at least one liquid stream is expanded to said lower pressure and supplied to said distillation column at a mid-column feed position;

(4) from 100% to 0% of said at least one liquid stream is expanded to said intermediate pressure and combined with said first compressed distillation stream to form a combined stream;

(5) said combined stream is cooled sufficiently to condense at least a part of it, thereby forming said condensed stream; and

(6) said overhead vapor stream is directed into heat exchange relation with at least said combined stream and heated, thereby to supply at least a portion of the cooling of step (5).

13. In an apparatus for the separation of a gas stream containing methane, C₂ components, C₃ components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C₂ components, C₃ components, and heavier hydrocarbon components or said C₃ components and heavier hydrocarbon components, in said apparatus there being

(a) a first cooling means to cool said gas under pressure connected to provide a cooled stream under pressure;

(b) a first expansion means connected to receive at least a portion of said cooled stream under pressure and expand it to a lower pressure, whereby said stream is further cooled; and

(c) a distillation column connected to receive said further cooled expanded stream, said distillation column being adapted to separate said further cooled expanded stream into an overhead vapor stream and said relatively less volatile fraction;

the improvement wherein said apparatus includes

(1) said distillation column connected to said first expansion means to receive said further cooled expanded stream at a first mid-column feed position on said distillation column;

(2) vapor withdrawing means connected to said distillation column to receive a vapor distillation stream from a region of said distillation column below said first mid-column feed position;

(3) heat exchange means connected to said vapor withdrawing means to receive said vapor distillation stream and cool it sufficiently to condense at least a part of it;

(4) first separating means connected to said heat exchange means to receive said at least partially condensed distillation stream and separate it, thereby forming a condensed stream and a residual vapor stream containing any uncondensed vapor remaining after said vapor distillation stream is cooled, said first separating means being further connected to said distillation column to supply at least a portion of said condensed stream to said distillation column at a second mid-column feed position above said first mid-column feed position;

(5) said distillation column being further connected to said heat exchange means to direct at least a portion of said overhead vapor stream separated therein into heat exchange relation with at least said vapor distillation stream and heat said overhead vapor stream, thereby to supply at least a portion of the cooling of element (3);

(6) first combining means connected to combine said heated overhead vapor stream and any said residual vapor stream into a heated combined vapor stream;

(7) compressing means connected to said first combining means to receive said heated combined vapor stream and compress it to higher pressure;

(8) dividing means connected to said compressing means to receive said compressed heated combined vapor stream and divide it into said volatile residue gas fraction and a compressed recycle stream;

(9) second cooling means connected to said dividing means to receive said compressed recycle stream and cool it sufficiently to substantially condense it;

(10) second expansion means connected to said second cooling means to receive said substantially condensed compressed recycle stream and expand it to said lower pressure, said second expansion means being further connected to said distillation column to supply said expanded condensed recycle stream to said distillation column at a top feed position; and

(11) control means adapted to regulate the quantities and temperatures of said feed streams to said distillation column to maintain the overhead temperature of said distillation column at a temperature whereby the major portions of the components in said relatively less volatile fraction are recovered.

14. The improvement according to claim 13 wherein said apparatus includes

(1) said first cooling means being adapted to cool said gas stream under pressure sufficiently to partially condense it;

(2) second separating means connected to said first cooling means to receive said partially condensed gas stream and separate it into a vapor stream and at least one liquid stream;

(3) said first expansion means connected to said second separating means to receive said vapor stream and expand it to said lower pressure, said first expansion means being further connected to said distillation column to supply said expanded vapor stream to said distillation column at said first mid-column feed position;

(4) third expansion means connected to said second separating means to receive from 0% to 100% of said at least one liquid stream and expand it to said lower pressure, said third expansion means being further connected to said distillation column to supply said expanded liquid stream to said distillation column at a third mid-column feed position;

(5) fourth expansion means connected to said second separating means to receive from 100% to 0% of said at least one liquid stream and expand it to said lower pressure;

(6) second combining means connected to said fourth expansion means to receive said expanded portion, said second combining means being further connected to said vapor withdrawing means to receive said vapor distillation stream and thereby combine said streams to form a combined stream;

(7) said heat exchange means connected to said second combining means to receive said combined stream and cool it sufficiently to condense at least a part of it, said heat exchange means being further connected to supply said at least partially condensed combined stream to said first separating means; and

(8) said heat exchange means being further connected to said distillation column to direct at least a portion of said overhead vapor stream separated therein into heat exchange relation with at least said combined stream and heat said overhead vapor stream, thereby to supply at least a portion of the cooling of element (7).

15. In an apparatus for the separation of a gas stream containing methane, C₂ components, C₃ components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C₂ components, C₃ components, and heavier hydrocarbon components or said C₃ components and heavier hydrocarbon components, in said apparatus there being

(a) a first cooling means to cool said gas under pressure connected to provide a cooled stream under pressure;

(b) a first expansion means connected to receive at least a portion of said cooled stream under pressure and expand it to a lower pressure, whereby said stream is further cooled; and

(c) a distillation column connected to receive said further cooled expanded stream, said distillation column being adapted to separate said further cooled expanded stream into an overhead vapor stream and said relatively less volatile fraction;

the improvement wherein said apparatus includes

(1) said distillation column connected to said first expansion means to receive said further cooled expanded stream at a first mid-column feed position on said distillation column;

(2) vapor withdrawing means connected to said distillation column to receive a vapor distillation stream from a region of said distillation column below said first mid-column feed position;

(3) first compressing means connected to said vapor withdrawing means to receive said vapor distillation stream and compress it to intermediate pressure;

(4) heat exchange means connected to said first compressing means to receive said compressed vapor distillation stream and cool it sufficiently to condense at least a part of it, thereby forming a condensed stream, said heat exchange means being further connected to said distillation column to supply at least a portion of said condensed stream to said distillation column at a second mid-column feed position above said first mid-column feed position;

(5) said distillation column being further connected to said heat exchange means to direct at least a portion of said overhead vapor stream separated therein into heat exchange relation with at least said compressed vapor distillation stream and heat said overhead vapor stream, thereby to supply at least a portion of the cooling of element (4);

(6) second compressing means connected to said heat exchange means to receive said heated overhead vapor stream and compress it to higher pressure;

(7) dividing means connected to said second compressing means to receive said compressed heated overhead vapor stream and divide it into said volatile residue gas fraction and a compressed recycle stream;

(8) second cooling means connected to said dividing means to receive said compressed recycle stream and cool it sufficiently to substantially condense it;

(9) second expansion means connected to said second cooling means to receive said substantially condensed compressed recycle stream and expand it to said lower pressure, said second expansion means being further connected to said distillation column to supply said expanded condensed recycle stream to said distillation column at a top feed position; and

(10) control means adapted to regulate the quantities and temperatures of said feed streams to said distillation column to maintain the overhead temperature of said distillation column at a temperature whereby the major portions of the components in said relatively less volatile fraction are recovered.

16. The improvement according to claim 15 wherein said apparatus includes

(1) said first cooling means being adapted to cool said gas stream under pressure sufficiently to partially condense it;

(2) separating means connected to said first cooling means to receive said partially condensed gas stream and separate it into a vapor stream and at least one liquid stream;

(3) said first expansion means connected to said separating means to receive said vapor stream and expand it to said lower pressure, said first expansion means being further connected to said distillation column to supply said expanded vapor stream to said distillation column at said first mid-column feed position;

(4) third expansion means connected to said separating means to receive from 0% to 100% of said at least one liquid stream and expand it to said lower pressure, said third expansion means being further connected to said distillation column to supply said expanded liquid stream to said distillation column at a third mid-column feed position;

(5) fourth expansion means connected to said separating means to receive from 100% to 0% of said at least one liquid stream and expand it to said intermediate pressure;

(6) combining means connected to said fourth expansion means to receive said expanded portion, said combining means being further connected to said first compressing means to receive said compressed vapor distillation stream and thereby combine said streams to form a combined stream;

(7) said heat exchange means connected to said combining means to receive said combined stream and cool it sufficiently to condense at least a part of it, thereby forming a condensed stream, said heat exchange means being further connected to said distillation column to supply at least a portion of said condensed stream to said distillation column at said second mid-column feed position above said first mid-column feed position; and

(8) said heat exchange means being further connected to said distillation column to direct at least a portion of said overhead vapor stream separated therein into heat exchange relation with at least said combined stream and heat said overhead vapor stream, thereby to supply at least a portion of the cooling of element (7).

17. In an apparatus for the separation of a gas stream containing methane, C₂ components, C₃ components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C₂ components, C₃ components, and heavier hydrocarbon components or said C₃ components and heavier hydrocarbon components, in said apparatus there being

(a) a first cooling means to cool said gas under pressure connected to provide a cooled stream under pressure;

(b) a first expansion means connected to receive at least a portion of said cooled stream under pressure and expand it to a lower pressure, whereby said stream is further cooled; and

(c) a distillation column connected to receive said further cooled expanded stream, said distillation column being adapted to separate said further cooled expanded stream into an overhead vapor stream and said relatively less volatile fraction;

the improvement wherein said apparatus includes

(1) said distillation column connected to said first expansion means to receive said further cooled expanded stream at a first mid-column feed position on said distillation column;

(2) vapor withdrawing means connected to said distillation column to receive a vapor distillation stream from a region of said distillation column below said first mid-column feed position;

(3) heat exchange means connected to said vapor withdrawing means to receive said vapor distillation stream and cool it sufficiently to condense at least a part of it;

(4) first separating means connected to said heat exchange means to receive said at least partially condensed distillation stream and separate it, thereby forming a condensed stream and a residual vapor stream containing any uncondensed vapor remaining after said vapor distillation stream is cooled, said first separating means being further connected to said distillation column to supply at least a portion of said condensed stream to said distillation column at a second mid-column feed position above said first mid-column feed position;

(5) first combining means connected to combine said overhead vapor stream and any said residual vapor stream into a combined vapor stream;

(6) said first combining means being further connected to said heat exchange means to direct at least a portion of said combined vapor stream into heat exchange relation with at least said vapor distillation stream and heat said combined vapor stream, thereby to supply at least a portion of the cooling of element (3);

(7) compressing means connected to said heat exchange means to receive said heated combined vapor stream and compress it to higher pressure;

(8) dividing means connected to said compressing means to receive said compressed heated combined vapor stream and divide it into said volatile residue gas fraction and a compressed recycle stream;

(9) second cooling means connected to said dividing means to receive said compressed recycle stream and cool it sufficiently to substantially condense it;

(10) second expansion means connected to said second cooling means to receive said substantially condensed compressed recycle stream and expand it to said lower pressure, said second expansion means being further connected to said distillation column to supply said expanded condensed recycle stream to said distillation column at a top feed position; and

(11) control means adapted to regulate the quantities and temperatures of said feed streams to said distillation column to maintain the overhead temperature of said distillation column at a temperature whereby the major portions of the components in said relatively less volatile fraction are recovered.

18. The improvement according to claim 17 wherein said apparatus includes

(1) said first cooling means being adapted to cool said gas stream under pressure sufficiently to partially condense it;

(2) second separating means connected to said first cooling means to receive said partially condensed gas stream and separate it into a vapor stream and at least one liquid stream;

(3) said first expansion means connected to said second separating means to receive said vapor stream and expand it to said lower pressure, said first expansion means being further connected to said distillation column to supply said expanded vapor stream to said distillation column at said first mid-column feed position;

(4) third expansion means connected to said second separating means to receive from 0% to 100% of said at least one liquid stream and expand it to said lower pressure, said third expansion means being further connected to said distillation column to supply said expanded liquid stream to said distillation column at a third mid-column feed position;

(5) fourth expansion means connected to said second separating means to receive from 100% to 0% of said at least one liquid stream and expand it to said lower pressure;

(6) second combining means connected to said fourth expansion means to receive said expanded portion, said second combining means being further connected to said vapor withdrawing means to receive said vapor distillation stream and thereby combine said streams to form a combined stream;

(7) said heat exchange means connected to said second combining means to receive said combined stream and cool it sufficiently to condense at least a part of it, said heat exchange means being further connected to supply said at least partially condensed combined stream to said first separating means; and

(8) said heat exchange means being further connected to said distillation column to direct at least a portion of said overhead vapor stream separated therein into heat exchange relation with at least said combined stream and heat said overhead vapor stream, thereby to supply at least a portion of the cooling of element (7).

19. In an apparatus for the separation of a gas stream containing methane, C₂ components, C₃ components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C₂ components, C₃ components, and heavier hydrocarbon components or said C₃ components and heavier hydrocarbon components, in said apparatus there being

(a) a first cooling means to cool said gas under pressure connected to provide a cooled stream under pressure;

(b) a first expansion means connected to receive at least a portion of said cooled stream under pressure and expand it to a lower pressure, whereby said stream is further cooled; and

(c) a distillation column connected to receive said further cooled expanded stream, said distillation column being adapted to separate said further cooled expanded stream into an overhead vapor stream and said relatively less volatile fraction;

the improvement wherein said apparatus includes

(1) contacting and separating means connected to said first expansion means to receive said further cooled expanded stream at a first lower column feed position on said contacting and separating means, said contacting and separating means being adapted to produce an overhead vapor stream and a bottom liquid stream;

(2) said contacting and separating means further connected to said distillation column to supply said bottom liquid stream to said distillation column;

(3) vapor withdrawing means connected to said distillation column to receive a vapor distillation stream from an upper region of said distillation column to form at least a first distillation stream;

(4) heat exchange means connected to said vapor withdrawing means to receive said first distillation stream and cool it sufficiently to condense at least a part of it;

(5) first separating means connected to said heat exchange means to receive said at least partially condensed first distillation stream and separate it, thereby forming a condensed stream and a residual vapor stream containing any uncondensed vapor remaining after said vapor distillation stream is cooled, said first separating means being further connected to said contacting and separating means to supply at least a portion of said condensed stream to said contacting and separating means at a mid-column feed position;

(6) said contacting and separating means being further connected to said heat exchange means to direct at least a portion of said overhead vapor stream separated therein into heat exchange relation with at least said first distillation stream and heat said overhead vapor stream, thereby to supply at least a portion of the cooling of element (4);

(7) first combining means connected to combine said heated overhead vapor stream and any said residual vapor stream into a heated combined vapor stream;

(8) compressing means connected to said first combining means to receive said heated combined vapor stream and compress it to higher pressure;

(9) dividing means connected to said compressing means to receive said compressed heated combined vapor stream and divide it into said volatile residue gas fraction and a compressed recycle stream;

(10) second cooling means connected to said dividing means to receive said compressed recycle stream and cool it sufficiently to substantially condense it;

(11) second expansion means connected to said second cooling means to receive said substantially condensed compressed recycle stream and expand it to said lower pressure, said second expansion means being further connected to said contacting and separating means to supply said expanded condensed recycle stream to said contacting and separating means at a top feed position;

(12) said contacting and separating means being further connected to said vapor withdrawing means to receive any remaining portion of said vapor distillation stream at a second lower column feed position; and

(13) control means adapted to regulate the quantities and temperatures of said feed streams to said contacting and separating means to maintain the overhead temperature of said contacting and separating means at a temperature whereby the major portions of the components in said relatively less volatile fraction are recovered.

20. The improvement according to claim 19 wherein said apparatus includes

(1) said first cooling means being adapted to cool said gas stream under pressure sufficiently to partially condense it;

(2) second separating means connected to said first cooling means to receive said partially condensed gas stream and separate it into a vapor stream and at least one liquid stream;

(3) said first expansion means connected to said second separating means to receive said vapor stream and expand it to said lower pressure, said first expansion means being further connected to said contacting and separating means to supply said expanded vapor stream to said contacting and separating means at said first lower column feed position;

(4) third expansion means connected to said second separating means to receive from 0% to 100% of said at least one liquid stream and expand it to said lower pressure, said third expansion means being further connected to said distillation column to supply said expanded liquid stream to said distillation column at a mid-column feed position;

(5) fourth expansion means connected to said second separating means to receive from 100% to 0% of said at least one liquid stream and expand it to said lower pressure;

(6) second combining means connected to said fourth expansion means to receive said expanded portion, said second combining means being further connected to said vapor withdrawing means to receive said first distillation stream and thereby combine said streams to form a combined stream;

(7) said heat exchange means connected to said second combining means to receive said combined stream and cool it sufficiently to condense at least a part of it, said heat exchange means being further connected to supply said at least partially condensed combined stream to said first separating means; and

(8) said heat exchange means being further connected to said contacting and separating means to direct at least a portion of said overhead vapor stream separated therein into heat exchange relation with at least said combined stream and heat said overhead vapor stream, thereby to supply at least a portion of the cooling of element (7).

21. In an apparatus for the separation of a gas stream containing methane, C₂ components, C₃ components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C₂ components, C₃ components, and heavier hydrocarbon components or said C₃ components and heavier hydrocarbon components, in said apparatus there being

(a) a first cooling means to cool said gas under pressure connected to provide a cooled stream under pressure;

(b) a first expansion means connected to receive at least a portion of said cooled stream under pressure and expand it to a lower pressure, whereby said stream is further cooled; and

(c) a distillation column connected to receive said further cooled expanded stream, said distillation column being adapted to separate said further cooled expanded stream into an overhead vapor stream and said relatively less volatile fraction;

the improvement wherein said apparatus includes

(1) said first expansion means being adapted to expand said at least a portion of said cooled stream to an intermediate pressure whereby said stream is further cooled;

(2) contacting and separating means connected to said first expansion means to receive said further cooled expanded stream at a first lower column feed position on said contacting and separating means, said contacting and separating means being adapted to produce an overhead vapor stream and a bottom liquid stream;

(3) second expansion means connected to said contacting and separating means to receive said bottom liquid stream and expand it to said lower pressure;

(4) said second expansion means further connected to said distillation column to supply said expanded bottom liquid stream to said distillation column;

(5) vapor withdrawing means connected to said distillation column to receive a vapor distillation stream from an upper region of said distillation column to form at least a first distillation stream;

(6) heat exchange means connected to said vapor withdrawing means to receive said first distillation stream and cool it sufficiently to condense at least a part of it;

(7) first separating means connected to said heat exchange means to receive said at least partially condensed first distillation stream and separate it, thereby forming a condensed stream and a residual vapor stream containing any uncondensed vapor remaining after said first distillation stream is cooled, said first separating means being further connected to said contacting and separating means to supply at least a portion of said condensed stream to said contacting and separating means at a mid-column feed position;

(8) said contacting and separating means being further connected to said heat exchange means to direct at least a portion of said overhead vapor stream separated therein into heat exchange relation with at least said first distillation stream and heat said overhead vapor stream, thereby to supply at least a portion of the cooling of element (6);

(9) first combining means connected to combine said heated overhead vapor stream and any said residual vapor stream into a heated combined vapor stream;

(10) first compressing means connected to said first combining means to receive said heated combined vapor stream and compress it to higher pressure;

(11) dividing means connected to said first compressing means to receive said compressed heated combined vapor stream and divide it into said volatile residue gas fraction and a compressed recycle stream;

(12) second cooling means connected to said dividing means to receive said compressed recycle stream and cool it sufficiently to substantially condense it;

(13) third expansion means connected to said second cooling means to receive said substantially condensed compressed recycle stream and expand it to said intermediate pressure, said third expansion means being further connected to said contacting and separating means to supply said expanded condensed recycle stream to said contacting and separating means at a top feed position;

(14) second compressing means connected to said vapor withdrawing means to receive any remaining portion of said vapor distillation stream and compress it to said intermediate pressure;

(15) said contacting and separating means being further connected to said second compressing means to receive said compressed any remaining portion of said vapor distillation stream at a second lower column feed position; and

(16) control means adapted to regulate the quantities and temperatures of said feed streams to said contacting and separating means to maintain the overhead temperature of said contacting and separating means at a temperature whereby the major portions of the components in said relatively less volatile fraction are recovered.

22. The improvement according to claim 21 wherein said apparatus includes

(1) said first cooling means being adapted to cool said gas stream under pressure sufficiently to partially condense it;

(2) second separating means connected to said first cooling means to receive said partially condensed gas stream and separate it into a vapor stream and at least one liquid stream;

(3) said first expansion means connected to said second separating means to receive said vapor stream and expand it to said intermediate pressure, said first expansion means being further connected to said contacting and separating means to supply said expanded vapor stream to said contacting and separating means at said first lower column feed position;

(4) fourth expansion means connected to said second separating means to receive from 0% to 100% of said at least one liquid stream and expand it to said lower pressure, said fourth expansion means being further connected to said distillation column to supply said expanded liquid stream to said distillation column at a mid-column feed position;

(5) fifth expansion means connected to said second separating means to receive from 100% to 0% of said at least one liquid stream and expand it to said lower pressure;

(6) second combining means connected to said fifth expansion means to receive said expanded portion, said second combining means being further connected to said vapor withdrawing means to receive said first distillation stream and thereby combine said streams to form a combined stream;

(7) said heat exchange means connected to said second combining means to receive said combined stream and cool it sufficiently to condense at least a part of it, said heat exchange means being further connected to supply said at least partially condensed combined stream to said first separating means; and

(8) said heat exchange means being further connected to said contacting and separating means to direct at least a portion of said overhead vapor stream separated therein into heat exchange relation with at least said combined stream and heat said overhead vapor stream, thereby to supply at least a portion of the cooling of element (7).

23. In an apparatus for the separation of a gas stream containing methane, C₂ components, C₃ components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C₂ components, C₃ components, and heavier hydrocarbon components or said C₃ components and heavier hydrocarbon components, in said apparatus there being

(a) a first cooling means to cool said gas under pressure connected to provide a cooled stream under pressure;

(b) a first expansion means connected to receive at least a portion of said cooled stream under pressure and expand it to a lower pressure, whereby said stream is further cooled; and

(c) a distillation column connected to receive said further cooled expanded stream, said distillation column being adapted to separate said further cooled expanded stream into an overhead vapor stream and said relatively less volatile fraction;

the improvement wherein said apparatus includes

(1) said first expansion means being adapted to expand said at least a portion of said cooled stream to an intermediate pressure whereby said stream is further cooled;

(2) contacting and separating means connected to said first expansion means to receive said further cooled expanded stream at a first lower column feed position on said contacting and separating means, said contacting and separating means being adapted to produce an overhead vapor stream and a bottom liquid stream;

(3) second expansion means connected to said contacting and separating means to receive said bottom liquid stream and expand it to said lower pressure;

(4) said second expansion means further connected to said distillation column to supply said expanded bottom liquid stream to said distillation column;

(5) vapor withdrawing means connected to said distillation column to receive a vapor distillation stream from an upper region of said distillation column;

(6) first compressing means connected to said vapor withdrawing means to receive said vapor distillation stream and compress it to said intermediate pressure, thereby forming a compressed distillation stream;

(7) first dividing means connected to said first compressing means to receive said compressed distillation stream and divide it into a first compressed distillation stream and a second compressed distillation stream;

(8) heat exchange means connected to said first dividing means to receive said first compressed distillation stream and cool it sufficiently to condense at least a part of it, thereby forming a condensed stream, said heat exchange means being further connected to said contacting and separating means to supply at least a portion of said condensed stream to said contacting and separating means at a mid-column feed position;

(9) said contacting and separating means being further connected to said heat exchange means to direct at least a portion of said overhead vapor stream separated therein into heat exchange relation with at least said first compressed distillation stream and heat said overhead vapor stream, thereby to supply at least a portion of the cooling of element (8);

(10) second compressing means connected to said heat exchange means to receive said heated overhead vapor stream and compress it to higher pressure;

(11) second dividing means connected to said second compressing means to receive said compressed heated overhead vapor stream and divide it into said volatile residue gas fraction and a compressed recycle stream;

(12) second cooling means connected to said dividing means to receive said compressed recycle stream and cool it sufficiently to substantially condense it;

(13) third expansion means connected to said second cooling means to receive said substantially condensed compressed recycle stream and expand it to said intermediate pressure, said third expansion means being further connected to said contacting and separating means to supply said expanded condensed recycle stream to said contacting and separating means at a top feed position;

(14) said contacting and separating means being further connected to said first dividing means to receive said second compressed vapor distillation stream at a second lower column feed position; and

(15) control means adapted to regulate the quantities and temperatures of said feed streams to said contacting and separating means to maintain the overhead temperature of said contacting and separating means at a temperature whereby the major portions of the components in said relatively less volatile fraction are recovered.

24. The improvement according to claim 23 wherein said apparatus includes

(1) said first cooling means being adapted to cool said gas stream under pressure sufficiently to partially condense it;

(2) separating means connected to said first cooling means to receive said partially condensed gas stream and separate it into a vapor stream and at least one liquid stream;

(3) said first expansion means connected to said separating means to receive said vapor stream and expand it to said intermediate pressure, said first expansion means being further connected to said contacting and separating means to supply said expanded vapor stream to said contacting and separating means at said first lower column feed position;

(4) fourth expansion means connected to said separating means to receive from 0% to 100% of said at least one liquid stream and expand it to said lower pressure, said fourth expansion means being further connected to said distillation column to supply said expanded liquid stream to said distillation column at a mid-column feed position;

(5) fifth expansion means connected to said separating means to receive from 100% to 0% of said at least one liquid stream and expand it to said intermediate pressure;

(6) combining means connected to said fifth expansion means to receive said expanded portion, said combining means being further connected to said first compressing means to receive said first compressed distillation stream and thereby combine said streams to form a combined stream;

(7) said heat exchange means connected to said combining means to receive said combined stream and cool it sufficiently to condense at least a part of it, thereby forming a condensed stream, said heat exchange means being further connected to said contacting and separating means to supply at least a portion of said condensed stream to said contacting and separating means at said mid-column feed position; and

(8) said heat exchange means being further connected to said contacting and separating means to direct at least a portion of said overhead vapor stream separated therein into heat exchange relation with at least said combined stream and heat said overhead vapor stream, thereby to supply at least a portion of the cooling of element (7).