Hydrocarbon Gas Processing

• US 20110067443A1
• Filed: 08/26/2010
• Published: 03/24/2011
• Est. Priority Date: 09/21/2009
• Status: Abandoned Application

• 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.
• Application Number:
  US12/869,139
• Publication Number:
  US 20110067443A1
• 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 2200/30 using a side column in a single pressure column system
• CPC Class Codes: F25J 2200/74 Refluxing the column with at least a part of the partially condensed overhead gas
• 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 2200/90 Details relating to column internals, e.g. structured packing, gas or liquid distribution
• CPC Class Codes: F25J 2200/92 Details relating to the feed point
• CPC Class Codes: F25J 2200/94 Details relating to the withdrawal point
• CPC Class Codes: F25J 2205/04 in the feed line, i.e. upstream of the fractionation step
• CPC Class Codes: F25J 2210/06 Splitting of the feed stream, e.g. for treating or cooling in different ways
• CPC Class Codes: F25J 2210/60 Natural gas or synthetic natural gas [SNG]
• CPC Class Codes: F25J 2215/60 Methane
• 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 2240/40 Expansion without extracting work, i.e. isenthalpic throttling, e.g. JT valve, regulating valve or venturi, or isentropic nozzle, e.g. Laval
• CPC Class Codes: F25J 2270/02 Internal refrigeration with liquid vaporising loop
• CPC Class Codes: F25J 2270/12 External refrigeration with liquid vaporising loop
• CPC Class Codes: F25J 2290/12 Particular process parameters like pressure, temperature, ratios
• 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 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 and an apparatus are disclosed for the recovery of ethane, ethylene, propane, propylene, and heavier hydrocarbon components from a hydrocarbon gas stream. The stream is cooled and divided into first and second streams. The first stream is further cooled to condense substantially all of it and is thereafter expanded to the fractionation tower pressure and supplied to the fractionation tower at an upper mid-column feed position. The second stream is expanded to the tower pressure and supplied to the column at a mid-column feed position. A distillation vapor stream is withdrawn from the column above the feed point of the first stream, combined with a portion of the tower overhead vapor stream, compressed to higher pressure, and directed into heat exchange relation with the remaining tower overhead vapor stream to cool the compressed combined vapor stream and condense at least a part of it, forming a condensed stream. At least a portion of the condensed stream is expanded to the tower pressure and directed to the fractionation tower as its top feed. 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 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 following cooling, said cooled stream is divided into first and second streams; and

(1) said first stream is cooled to condense substantially all of it and is thereafter expanded to said lower pressure whereby it is further cooled;

(2) said expanded cooled first stream is thereafter supplied to said distillation column at an upper mid-column feed position;

(3) said second stream is expanded to said lower pressure and is supplied to said distillation column at a mid-column feed position below said upper mid-column feed position;

(4) an overhead vapor stream is withdrawn from an upper region of said distillation column and divided into at least a first portion and a second portion;

(5) a distillation vapor stream is withdrawn from a region of said distillation column above said upper mid-column feed position and is combined with said first portion to form a combined vapor stream;

(6) said combined vapor stream is compressed to higher pressure;

(7) said compressed combined vapor stream is directed into heat exchange relation with said second portion, whereby said second portion is heated and said compressed combined vapor stream is cooled sufficiently to condense at least a part of it and thereby form a condensed stream, and thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(8) at least a portion of said condensed stream is expanded to said lower pressure and is thereafter supplied to said distillation column at a top feed position; and

(9) 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.

11. The improvement according to claim 1, 2, 3, 4, or 5 wherein said distillation vapor stream is withdrawn from a region of said distillation column below said upper mid-column feed position and above said mid-column feed position.

12. The improvement according to claim 1, 2, 3, 4, or 5 wherein said distillation vapor stream is withdrawn from a region of said distillation column below said mid-column feed position.

2. 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 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 prior to cooling, said gas stream is divided into first and second streams; and

(1) said first stream is cooled to condense substantially all of it and is thereafter expanded to said lower pressure whereby it is further cooled;

(2) said expanded cooled first stream is thereafter supplied to said distillation column at an upper mid-column feed position;

(3) said second stream is cooled and thereafter expanded to said lower pressure and supplied to said distillation column at a mid-column feed position below said upper mid-column feed position;

(4) an overhead vapor stream is withdrawn from an upper region of said distillation column and divided into at least a first portion and a second portion;

(5) a distillation vapor stream is withdrawn from a region of said distillation column above said upper mid-column feed position and is combined with said first portion to form a combined vapor stream;

(6) said combined vapor stream is compressed to higher pressure;

(7) said compressed combined vapor stream is directed into heat exchange relation with said second portion, whereby said second portion is heated and said compressed combined vapor stream is cooled sufficiently to condense at least a part of it and thereby form a condensed stream, and thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(8) at least a portion of said condensed stream is expanded to said lower pressure and is thereafter supplied to said distillation column at a top feed position; and

(9) 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.

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 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 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 thereafter divided into first and second streams;

(3) said first stream is cooled to condense substantially all of it and is thereafter expanded to said lower pressure whereby it is further cooled;

(4) said expanded cooled first stream is thereafter supplied to said distillation column at an upper mid-column feed position;

(5) said second stream is expanded to said lower pressure and is supplied to said distillation column at a mid-column feed position below said upper mid-column feed position;

(6) at least a portion of said at least one liquid stream is expanded to said lower pressure and is supplied to said distillation column at a lower mid-column feed position below said mid-column feed position;

(7) an overhead vapor stream is withdrawn from an upper region of said distillation column and divided into at least a first portion and a second portion;

(8) a distillation vapor stream is withdrawn from a region of said distillation column above said upper mid-column feed position and is combined with said first portion to form a combined vapor stream;

(9) said combined vapor stream is compressed to higher pressure;

(10) said compressed combined vapor stream is directed into heat exchange relation with said second portion, whereby said second portion is heated and said compressed combined vapor stream is cooled sufficiently to condense at least a part of it and thereby form a condensed stream, and thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(11) at least a portion of said condensed stream is expanded to said lower pressure and is thereafter supplied to said distillation column at a top feed position; and

(12) 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. 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 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 prior to cooling, said gas stream is divided into first and second streams; and

(1) said first stream is cooled to condense substantially all of it and is thereafter expanded to said lower pressure whereby it is further cooled;

(2) said expanded cooled first stream is thereafter supplied to said distillation column at an upper mid-column feed position;

(3) said second stream is cooled under pressure sufficiently to partially condense it;

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

(5) said vapor stream is expanded to said lower pressure and is supplied to said distillation column at a mid-column feed position below said upper mid-column feed position;

(6) at least a portion of said at least one liquid stream is expanded to said lower pressure and is supplied to said distillation column at a lower mid-column feed position below said mid-column feed position;

(7) an overhead vapor stream is withdrawn from an upper region of said distillation column and divided into at least a first portion and a second portion;

(8) a distillation vapor stream is withdrawn from a region of said distillation column above said upper mid-column feed position and is combined with said first portion to form a combined vapor stream;

(9) said combined vapor stream is compressed to higher pressure;

(10) said compressed combined vapor stream is directed into heat exchange relation with said second portion, whereby said second portion is heated and said compressed combined vapor stream is cooled sufficiently to condense at least a part of it and thereby form a condensed stream, and thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(11) at least a portion of said condensed stream is expanded to said lower pressure and is thereafter supplied to said distillation column at a top feed position; and

(12) 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.

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 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 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 thereafter divided into first and second streams;

(3) said first stream is combined with at least a portion of said at least one liquid stream to form a combined stream, whereupon said combined stream is cooled to condense substantially all of it and is thereafter expanded to said lower pressure whereby it is further cooled;

(4) said expanded cooled combined stream is thereafter supplied to said distillation column at an upper mid-column feed position;

(5) said second stream is expanded to said lower pressure and is supplied to said distillation column at a mid-column feed position below said upper mid-column feed position;

(6) any remaining portion of said at least one liquid stream is expanded to said lower pressure and is supplied to said distillation column at a lower mid-column feed position below said mid-column feed position;

(7) an overhead vapor stream is withdrawn from an upper region of said distillation column and divided into at least a first portion and a second portion;

(8) a distillation vapor stream is withdrawn from a region of said distillation column above said upper mid-column feed position and is combined with said first portion to form a combined vapor stream;

(9) said combined vapor stream is compressed to higher pressure;

(10) said compressed combined vapor stream is directed into heat exchange relation with said second portion, whereby said second portion is heated and said compressed combined vapor stream is cooled sufficiently to condense at least a part of it and thereby form a condensed stream, and thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(11) at least a portion of said condensed stream is expanded to said lower pressure and is thereafter supplied to said distillation column at a top feed position; and

(12) 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. 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 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 following cooling, said cooled stream is divided into first and second streams; and

(1) said first stream is cooled to condense substantially all of it and is thereafter expanded to said lower pressure whereby it is further cooled;

(2) said expanded cooled first stream is thereafter supplied at a mid-column feed position to a contacting and separating device that produces a first overhead vapor stream and a bottom liquid stream, whereupon said bottom liquid stream is supplied to said distillation column;

(3) said second stream is expanded to said lower pressure and is supplied to said contacting and separating device at a first lower column feed position below said mid-column feed position;

(4) a second overhead vapor stream is withdrawn from an upper region of said distillation column and is supplied to said contacting and separating device at a second lower column feed position below said mid-column feed position;

(5) said first overhead vapor stream is divided into at least a first portion and a second portion;

(6) a distillation vapor stream is withdrawn from a region of said contacting and separating device above said mid-column feed position and is combined with said first portion to form a combined vapor stream;

(7) said combined vapor stream is compressed to higher pressure;

(8) said compressed combined vapor stream is directed into heat exchange relation with said second portion, whereby said second portion is heated and said compressed combined vapor stream is cooled sufficiently to condense at least a part of it and thereby form a condensed stream, and thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(9) at least a portion of said condensed stream is expanded to said lower pressure and is thereafter supplied to said contacting and separating device at a top 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.

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 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 prior to cooling, said gas stream is divided into first and second streams; and

(1) said first stream is cooled to condense substantially all of it and is thereafter expanded to said lower pressure whereby it is further cooled;

(2) said expanded cooled first stream is thereafter supplied at a mid-column feed position to a contacting and separating device that produces a first overhead vapor stream and a bottom liquid stream, whereupon said bottom liquid stream is supplied to said distillation column;

(3) said second stream is cooled and thereafter expanded to said lower pressure and supplied to said contacting and separating device at a first lower column feed position below said mid-column feed position;

(4) a second overhead vapor stream is withdrawn from an upper region of said distillation column and is supplied to said contacting and separating device at a second lower column feed position below said mid-column feed position;

(5) said first overhead vapor stream is divided into at least a first portion and a second portion;

(6) a distillation vapor stream is withdrawn from a region of said contacting and separating device above said mid-column feed position and is combined with said first portion to form a combined vapor stream;

(7) said combined vapor stream is compressed to higher pressure;

(8) said compressed combined vapor stream is directed into heat exchange relation with said second portion, whereby said second portion is heated and said compressed combined vapor stream is cooled sufficiently to condense at least a part of it and thereby form a condensed stream, and thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(9) at least a portion of said condensed stream is expanded to said lower pressure and is thereafter supplied to said contacting and separating device at a top 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.

8. 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 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 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 thereafter divided into first and second streams;

(3) said first stream is cooled to condense substantially all of it and is thereafter expanded to said lower pressure whereby it is further cooled;

(4) said expanded cooled first stream is thereafter supplied at a mid-column feed position to a contacting and separating device that produces a first overhead vapor stream and a bottom liquid stream, whereupon said bottom liquid stream is supplied to said distillation column;

(5) said second stream is expanded to said lower pressure and is supplied to said contacting and separating device at a first lower column feed position below said mid-column feed position;

(6) at least a portion of said at least one liquid stream is expanded to said lower pressure and is supplied to said distillation column at a mid-column feed position;

(7) a second overhead vapor stream is withdrawn from an upper region of said distillation column and is supplied to said contacting and separating device at a second lower column feed position below said mid-column feed position;

(8) said first overhead vapor stream is divided into at least a first portion and a second portion;

(9) a distillation vapor stream is withdrawn from a region of said contacting and separating device above said mid-column feed position and is combined with said first portion to form a combined vapor stream;

(10) said combined vapor stream is compressed to higher pressure;

(11) said compressed combined vapor stream is directed into heat exchange relation with said second portion, whereby said second portion is heated and said compressed combined vapor stream is cooled sufficiently to condense at least a part of it and thereby form a condensed stream, and thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(12) at least a portion of said condensed stream is expanded to said lower pressure and is thereafter supplied to said contacting and separating device at a top feed position; and

(13) 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.

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 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 prior to cooling, said gas stream is divided into first and second streams; and

(1) said first stream is cooled to condense substantially all of it and is thereafter expanded to said lower pressure whereby it is further cooled;

(2) said expanded cooled first stream is thereafter supplied at a mid-column 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;

(3) said second stream is cooled under pressure sufficiently to partially condense it;

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

(5) said vapor stream is expanded to said lower pressure and is supplied to said contacting and separating device at a first lower column feed position below said mid-column feed position;

(6) at least a portion of said at least one liquid stream is expanded to said lower pressure and is supplied to said distillation column at a mid-column feed position;

(7) a second overhead vapor stream is withdrawn from an upper region of said distillation column and is supplied to said contacting and separating device at a second lower column feed position below said mid-column feed position;

(8) said first overhead vapor stream is divided into at least a first portion and a second portion;

(9) a distillation vapor stream is withdrawn from a region of said contacting and separating device above said mid-column feed position and is combined with said first portion to form a combined vapor stream;

(10) said combined vapor stream is compressed to higher pressure;

(11) said compressed combined vapor stream is directed into heat exchange relation with said second portion, whereby said second portion is heated and said compressed combined vapor stream is cooled sufficiently to condense at least a part of it and thereby form a condensed stream, and thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(12) at least a portion of said condensed stream is expanded to said lower pressure and is thereafter supplied to said contacting and separating device at a top feed position; and

(13) 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. 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 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 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 thereafter divided into first and second streams;

(3) said first stream is combined with at least a portion of said at least one liquid stream to form a combined stream, whereupon said combined stream is cooled to condense substantially all of it and is thereafter expanded to said lower pressure whereby it is further cooled;

(4) said expanded cooled combined stream is thereafter supplied at a mid-column feed position to a contacting and separating device that produces a first overhead vapor stream and a bottom liquid stream, whereupon said bottom liquid stream is supplied to said distillation column;

(5) said second stream is expanded to said lower pressure and is supplied to said contacting and separating device at a first lower column feed position below said mid-column feed position;

(6) any remaining portion of said at least one liquid stream is expanded to said lower pressure and is supplied to said distillation column at a mid-column feed position;

(7) a second overhead vapor stream is withdrawn from an upper region of said distillation column and is supplied to said contacting and separating device at a second lower column feed position below said mid-column feed position;

(8) said first overhead vapor stream is divided into at least a first portion and a second portion;

(9) a distillation vapor stream is withdrawn from a region of said contacting and separating device above said mid-column feed position and is combined with said first portion to form a combined vapor stream;

(10) said combined vapor stream is compressed to higher pressure;

(11) said compressed combined vapor stream is directed into heat exchange relation with said second portion, whereby said second portion is heated and said compressed combined vapor stream is cooled sufficiently to condense at least a part of it and thereby form a condensed stream, and thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(12) at least a portion of said condensed stream is expanded to said lower pressure and is thereafter supplied to said contacting and separating device at a top feed position; and

(13) 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.

13. The improvement according to claim 6, 7, 8, 9, or 10 wherein said distillation vapor stream is withdrawn from a region of said contacting and separating device below said mid-column feed position and above said first and second lower column feed positions.

14. The improvement according to claim 6, 7, 8, 9, or 10 wherein said second overhead vapor stream is divided into said distillation vapor stream and a second distillation vapor stream, whereupon said second distillation vapor stream is supplied to said contacting and separating device at said second lower column feed position.

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 stream 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 stream, said distillation column being adapted to separate said further cooled stream into an overhead vapor stream and said relatively less volatile fraction;

the improvement wherein said apparatus includes

(1) first dividing means connected to said first cooling means to receive said cooled stream and divide it into first and second streams;

(2) second cooling means connected to said first dividing means to receive said first stream and cool it sufficiently to substantially condense it;

(3) second expansion means connected to said second cooling means to receive said substantially condensed first stream and expand it to said lower pressure, said second expansion means being further connected to said distillation column to supply said expanded cooled first stream to said distillation column at an upper mid-column feed position;

(4) said first expansion means being connected to said first dividing means to receive said second stream and expand it to said lower pressure, said first expansion means being further connected to said distillation column to supply said expanded second stream to said distillation column at a mid-column feed position below said upper mid-column feed position;

(5) second dividing means connected to said distillation column to receive said overhead vapor stream separated therein and divide it into at least a first portion and a second portion;

(6) heat exchange means connected to said second dividing means to receive at least a portion of said second portion and heat it, thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(7) vapor withdrawing means connected to said distillation column to receive a distillation vapor stream from a region of said distillation column above said upper mid-column feed position;

(8) combining means connected to said second dividing means and said vapor withdrawing means to receive said first portion and said distillation vapor stream and form a combined vapor stream;

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

(10) said heat exchange means being further connected to said compressing means to receive said compressed combined vapor stream and cool it sufficiently to condense at least a part of it, thereby forming a condensed stream while supplying at least a portion of the heating of step (6);

(11) third expansion means connected to said heat exchange means to receive said condensed stream and expand it to said lower pressure, said third expansion means being further connected to said distillation column to supply at least a portion of said expanded condensed stream to said distillation column at a top feed position; and

(12) 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.

25. The improvement according to claim 15, 16, 17, 18, or 19 wherein said vapor withdrawing means is connected to said distillation column to receive said distillation vapor stream from a region of said distillation column below said upper mid-column feed position and above said mid-column feed position.

26. The improvement according to claim 15, 16, 17, 18, or 19 wherein said vapor withdrawing means is connected to said distillation column to receive said distillation vapor stream from a region of said distillation column below said mid-column feed position.

16. 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 stream 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 stream, said distillation column being adapted to separate said further cooled stream into an overhead vapor stream and said relatively less volatile fraction;

the improvement wherein said apparatus includes

(1) first dividing means prior to said first cooling means to divide said gas stream into first and second streams;

(2) second cooling means connected to said first dividing means to receive said first stream and cool it sufficiently to substantially condense it;

(3) second expansion means connected to said second cooling means to receive said substantially condensed first stream and expand it to said lower pressure, said second expansion means being further connected to said distillation column to supply said expanded cooled first stream to said distillation column at an upper mid-column feed position;

(4) said first cooling means being connected to said first dividing means to receive said second stream and cool it;

(5) said first expansion means being connected to said first cooling means to receive said cooled second stream and expand it to said lower pressure, said first expansion means being further connected to said distillation column to supply said expanded cooled second stream to said distillation column at a mid-column feed position below said upper mid-column feed position;

(6) second dividing means connected to said distillation column to receive said overhead vapor stream separated therein and divide it into at least a first portion and a second portion;

(7) heat exchange means connected to said second dividing means to receive at least a portion of said second portion and heat it, thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(8) vapor withdrawing means connected to said distillation column to receive a distillation vapor stream from a region of said distillation column above said upper mid-column feed position;

(9) combining means connected to said second dividing means and said vapor withdrawing means to receive said first portion and said distillation vapor stream and form a combined vapor stream;

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

(11) said heat exchange means being further connected to said compressing means to receive said compressed combined vapor stream and cool it sufficiently to condense at least a part of it, thereby forming a condensed stream while supplying at least a portion of the heating of step (7);

(12) third expansion means connected to said heat exchange means to receive said condensed stream and expand it to said lower pressure, said third expansion means being further connected to said distillation column to supply at least a portion of said expanded condensed stream to said distillation column at a top feed position; and

(13) 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.

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 stream 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 stream, said distillation column being adapted to separate said further cooled stream into an overhead vapor stream and said relatively less volatile fraction;

the improvement 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) first dividing means connected to said separating means to receive said vapor stream and divide it into first and second streams;

(4) second cooling means connected to said first dividing means to receive said first stream and cool it sufficiently to substantially condense it;

(5) second expansion means connected to said second cooling means to receive said substantially condensed first stream and expand it to said lower pressure, said second expansion means being further connected to said distillation column to supply said expanded cooled first stream to said distillation column at an upper mid-column feed position;

(6) said first expansion means being connected to said first dividing means to receive said second stream and expand it to said lower pressure, said first expansion means being further connected to said distillation column to supply said expanded second stream to said distillation column at a mid-column feed position below said upper mid-column feed position;

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

(8) second dividing means connected to said distillation column to receive said overhead vapor stream separated therein and divide it into at least a first portion and a second portion;

(9) heat exchange means connected to said second dividing means to receive at least a portion of said second portion and heat it, thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(10) vapor withdrawing means connected to said distillation column to receive a distillation vapor stream from a region of said distillation column above said upper mid-column feed position;

(11) combining means connected to said second dividing means and said vapor withdrawing means to receive said first portion and said distillation vapor stream and form a combined vapor stream;

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

(13) said heat exchange means being further connected to said compressing means to receive said compressed combined vapor stream and cool it sufficiently to condense at least a part of it, thereby forming a condensed stream while supplying at least a portion of the heating of step (9);

(14) fourth expansion means connected to said heat exchange means to receive said condensed stream and expand it to said lower pressure, said fourth expansion means being further connected to said distillation column to supply at least a portion of said expanded condensed stream to said distillation column at a top feed position; and

(15) 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. 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 stream 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 stream, said distillation column being adapted to separate said further cooled stream into an overhead vapor stream and said relatively less volatile fraction;

the improvement wherein said apparatus includes

(1) first dividing means prior to said first cooling means to divide said gas stream into first and second streams;

(2) second cooling means connected to said first dividing means to receive said first stream and cool it sufficiently to substantially condense it;

(3) second expansion means connected to said second cooling means to receive said substantially condensed first stream and expand it to said lower pressure, said second expansion means being further connected to said distillation column to supply said expanded cooled first stream to said distillation column at an upper mid-column feed position;

(4) said first cooling means being connected to said first dividing means to receive said second stream, said first cooling means being adapted to cool said second stream under pressure sufficiently to partially condense it;

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

(6) said first expansion means being 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 a mid-column feed position below said upper mid-column feed position;

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

(8) second dividing means connected to said distillation column to receive said overhead vapor stream separated therein and divide it into at least a first portion and a second portion;

(9) heat exchange means connected to said second dividing means to receive at least a portion of said second portion and heat it, thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(10) vapor withdrawing means connected to said distillation column to receive a distillation vapor stream from a region of said distillation column above said upper mid-column feed position;

(11) combining means connected to said second dividing means and said vapor withdrawing means to receive said first portion and said distillation vapor stream and form a combined vapor stream;

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

(13) said heat exchange means being further connected to said compressing means to receive said compressed combined vapor stream and cool it sufficiently to condense at least a part of it, thereby forming a condensed stream while supplying at least a portion of the heating of step (9);

(14) fourth expansion means connected to said heat exchange means to receive said condensed stream and expand it to said lower pressure, said fourth expansion means being further connected to said distillation column to supply at least a portion of said expanded condensed stream to said distillation column at a top feed position; and

(15) 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.

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 stream 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 stream, said distillation column being adapted to separate said further cooled stream into an overhead vapor stream and said relatively less volatile fraction;

the improvement 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) first dividing means connected to said separating means to receive said vapor stream and divide it into first and second streams;

(4) first combining means connected to said first dividing means and said separating means to receive said first stream and at least a portion of said at least one liquid stream and form a combined stream;

(5) second cooling means connected to said first combining means to receive said combined stream and cool it sufficiently to substantially condense it;

(6) second expansion means connected to said second cooling means to receive said substantially condensed combined stream and expand it to said lower pressure, said second expansion means being further connected to said distillation column to supply said expanded cooled combined stream to said distillation column at an upper mid-column feed position;

(7) said first expansion means being connected to said first dividing means to receive said second stream and expand it to said lower pressure, said first expansion means being further connected to said distillation column to supply said expanded second stream to said distillation column at a mid-column feed position below said upper mid-column feed position;

(8) third expansion means being connected to said separating means to receive any remaining portion 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 lower mid-column feed position below said mid-column feed position;

(9) second dividing means connected to said distillation column to receive said overhead vapor stream separated therein and divide it into at least a first portion and a second portion;

(10) heat exchange means connected to said second dividing means to receive at least a portion of said second portion and heat it, thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(11) vapor withdrawing means connected to said distillation column to receive a distillation vapor stream from a region of said distillation column above said upper mid-column feed position;

(12) second combining means connected to said second dividing means and said vapor withdrawing means to receive said first portion and said distillation vapor stream and form a combined vapor stream;

(13) compressing means connected to said second combining means to receive said combined vapor stream and compress it to higher pressure;

(14) said heat exchange means being further connected to said compressing means to receive said compressed combined vapor stream and cool it sufficiently to condense at least a part of it, thereby forming a condensed stream while supplying at least a portion of the heating of step (10);

(15) fourth expansion means connected to said heat exchange means to receive said condensed stream and expand it to said lower pressure, said fourth expansion means being further connected to said distillation column to supply at least a portion of said expanded condensed stream to said distillation column at a top feed position; and

(16) 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.

20. 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 stream 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 stream, said distillation column being adapted to separate said further cooled stream into a first overhead vapor stream and said relatively less volatile fraction;

the improvement wherein said apparatus includes

(1) first dividing means connected to said first cooling means to receive said cooled stream and divide it into first and second streams;

(2) second cooling means connected to said first dividing means to receive said first stream and cool it sufficiently to substantially condense it;

(3) second expansion means connected to said second cooling means to receive said substantially condensed first stream and expand it to said lower pressure, said second expansion means being further connected to a contacting and separating means to supply said expanded cooled first stream to said contacting and separating means at a mid-column feed position, said contacting and separating means being adapted to produce a second overhead vapor stream and a bottom liquid stream;

(4) said first expansion means being connected to said first dividing means to receive said second 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 second stream to said contacting and separating means at a first lower column feed position below said mid-column feed position;

(5) said distillation column being connected to said contacting and separating means to receive at least a portion of said bottom liquid stream;

(6) said contacting and separating means being further connected to said distillation column to receive at least a portion of said first overhead vapor stream at a second lower column feed position below said mid-column feed position;

(7) second dividing means connected to said contacting and separating means to receive said second overhead vapor stream separated therein and divide it into at least a first portion and a second portion;

(8) heat exchange means connected to said second dividing means to receive at least a portion of said second portion and heat it, thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(9) vapor withdrawing means connected to said contacting and separating means to receive a distillation vapor stream from a region of said contacting and separating device above said mid-column feed position;

(10) combining means connected to said second dividing means and said vapor withdrawing means to receive said first portion and said distillation vapor stream and form a combined vapor stream;

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

(12) said heat exchange means being further connected to said compressing means to receive said compressed combined vapor stream and cool it sufficiently to condense at least a part of it, thereby forming a condensed stream while supplying at least a portion of the heating of step (8);

(13) third expansion means connected to said heat exchange means to receive said condensed stream and expand it to said lower pressure, said third expansion means being further connected to said contacting and separating means to supply at least a portion of said expanded condensed stream to said contacting and separating means at a top feed position; and

(14) 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.

27. The improvement according to claim 20, 21, 22, 23, or 24 wherein said vapor withdrawing means is connected to said contacting and separating means to receive said distillation vapor stream from a region of said contacting and separating means below said mid-column feed position and above said first and second lower column feed positions.

28. The improvement according to claim 20, 21, 22, or 23 wherein

(1) a third dividing means is connected to said distillation column to receive said first overhead vapor stream and divide it into said distillation vapor stream and a second distillation vapor stream;

(2) said contacting and separating device is adapted to be connected to said third dividing means to receive said second distillation vapor stream at said second lower column feed position; and

(3) said combining means is adapted to be connected to said third dividing means to receive said distillation vapor stream.

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 stream 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 stream, said distillation column being adapted to separate said further cooled stream into a first overhead vapor stream and said relatively less volatile fraction;

the improvement wherein said apparatus includes

(1) first dividing means prior to said first cooling means to divide said gas stream into first and second streams;

(2) second cooling means connected to said first dividing means to receive said first stream and cool it sufficiently to substantially condense it;

(3) second expansion means connected to said second cooling means to receive said substantially condensed first stream and expand it to said lower pressure, said second expansion means being further connected to a contacting and separating means to supply said expanded cooled first stream to said contacting and separating means at a mid-column feed position, said contacting and separating means being adapted to produce a second overhead vapor stream and a bottom liquid stream;

(4) said first cooling means being connected to said first dividing means to receive said second stream and cool it;

(5) said first expansion means being connected to said first cooling means to receive said cooled second 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 cooled second stream to said contacting and separating means at a first lower column feed position below said mid-column feed position;

(6) said distillation column being connected to said contacting and separating means to receive at least a portion of said bottom liquid stream;

(7) said contacting and separating means being further connected to said distillation column to receive at least a portion of said first overhead vapor stream at a second lower column feed position below said mid-column feed position;

(8) second dividing means connected to said contacting and separating means to receive said second overhead vapor stream separated therein and divide it into at least a first portion and a second portion;

(9) heat exchange means connected to said second dividing means to receive at least a portion of said second portion and heat it, thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(10) vapor withdrawing means connected to said contacting and separating means to receive a distillation vapor stream from a region of said contacting and separating device above said mid-column feed position;

(11) combining means connected to said second dividing means and said vapor withdrawing means to receive said first portion and said distillation vapor stream and form a combined vapor stream;

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

(13) said heat exchange means being further connected to said compressing means to receive said compressed combined vapor stream and cool it sufficiently to condense at least a part of it, thereby forming a condensed stream while supplying at least a portion of the heating of step (9);

(14) third expansion means connected to said heat exchange means to receive said condensed stream and expand it to said lower pressure, said third expansion means being further connected to said contacting and separating means to supply at least a portion of said expanded condensed stream to said contacting and separating means at a top 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.

22. 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 stream 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 stream, said distillation column being adapted to separate said further cooled stream into a first overhead vapor stream and said relatively less volatile fraction;

the improvement 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) first dividing means connected to said separating means to receive said vapor stream and divide it into first and second streams;

(4) second cooling means connected to said first dividing means to receive said first stream and cool it sufficiently to substantially condense it;

(5) second expansion means connected to said second cooling means to receive said substantially condensed first stream and expand it to said lower pressure, said second expansion means being further connected to a contacting and separating means to supply said expanded cooled first stream to said contacting and separating means at a mid-column feed position, said contacting and separating means being adapted to produce a second overhead vapor stream and a bottom liquid stream;

(6) said first expansion means being connected to said first dividing means to receive said second 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 second stream to said contacting and separating means at a first lower column feed position below said mid-column feed position;

(7) third expansion means connected to said separating means to receive at least a portion of said at least one liquid stream and expand it to said lower pressure, 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;

(8) said distillation column being connected to said contacting and separating means to receive at least a portion of said bottom liquid stream;

(9) said contacting and separating means being further connected to said distillation column to receive at least a portion of said first overhead vapor stream at a second lower column feed position below said mid-column feed position;

(10) second dividing means connected to said contacting and separating means to receive said second overhead vapor stream separated therein and divide it into at least a first portion and a second portion;

(11) heat exchange means connected to said second dividing means to receive at least a portion of said second portion and heat it, thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(12) vapor withdrawing means connected to said contacting and separating means to receive a distillation vapor stream from a region of said contacting and separating device above said mid-column feed position;

(13) combining means connected to said second dividing means and said vapor withdrawing means to receive said first portion and said distillation vapor stream and form a combined vapor stream;

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

(15) said heat exchange means being further connected to said compressing means to receive said compressed combined vapor stream and cool it sufficiently to condense at least a part of it, thereby forming a condensed stream while supplying at least a portion of the heating of step (11);

(16) fourth expansion means connected to said heat exchange means to receive said condensed stream and expand it to said lower pressure, said fourth expansion means being further connected to said contacting and separating means to supply at least a portion of said expanded condensed stream to said contacting and separating means at a top feed position; and

(17) 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.

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 stream 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 stream, said distillation column being adapted to separate said further cooled stream into a first overhead vapor stream and said relatively less volatile fraction;

the improvement wherein said apparatus includes

(1) first dividing means prior to said first cooling means to divide said gas stream into first and second streams;

(2) second cooling means connected to said first dividing means to receive said first stream and cool it sufficiently to substantially condense it;

(3) second expansion means connected to said second cooling means to receive said substantially condensed first stream and expand it to said lower pressure, said second expansion means being further connected to a contacting and separating means to supply said expanded cooled first stream to said contacting and separating means at a mid-column feed position, said contacting and separating means being adapted to produce a second overhead vapor stream and a bottom liquid stream;

(4) said first cooling means being connected to said first dividing means to receive said second stream, said first cooling means being adapted to cool said second stream under pressure sufficiently to partially condense it;

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

(6) said first expansion means being 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 contacting and separating means to supply said expanded vapor stream to said contacting and separating means at a first lower column feed position below said mid-column feed position;

(7) third expansion means connected to said separating means to receive at least a portion of said at least one liquid stream and expand it to said lower pressure, 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;

(8) said distillation column being connected to said contacting and separating means to receive at least a portion of said bottom liquid stream;

(9) said contacting and separating means being further connected to said distillation column to receive at least a portion of said first overhead vapor stream at a second lower column feed position below said mid-column feed position;

(10) second dividing means connected to said contacting and separating means to receive said second overhead vapor stream separated therein and divide it into at least a first portion and a second portion;

(11) heat exchange means connected to said second dividing means to receive at least a portion of said second portion and heat it, thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(12) vapor withdrawing means connected to said contacting and separating means to receive a distillation vapor stream from a region of said contacting and separating device above said mid-column feed position;

(13) combining means connected to said second dividing means and said vapor withdrawing means to receive said first portion and said distillation vapor stream and form a combined vapor stream;

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

(15) said heat exchange means being further connected to said compressing means to receive said compressed combined vapor stream and cool it sufficiently to condense at least a part of it, thereby forming a condensed stream while supplying at least a portion of the heating of step (11);

(16) fourth expansion means connected to said heat exchange means to receive said condensed stream and expand it to said lower pressure, said fourth expansion means being further connected to said contacting and separating means to supply at least a portion of said expanded condensed stream to said contacting and separating means at a top feed position; and

(17) 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. 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 stream 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 stream, said distillation column being adapted to separate said further cooled stream into a first overhead vapor stream and said relatively less volatile fraction;

the improvement 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) first dividing means connected to said separating means to receive said vapor stream and divide it into first and second streams;

(4) first combining means connected to said first dividing means and said separating means to receive said first stream and at least a portion of said at least one liquid stream and form a combined stream;

(5) second cooling means connected to said first combining means to receive said combined stream and cool it sufficiently to substantially condense it;

(6) second expansion means connected to said second cooling means to receive said substantially condensed combined stream and expand it to said lower pressure, said second expansion means being further connected to a contacting and separating means to supply said expanded cooled combined stream to said contacting and separating means at a mid-column feed position, said contacting and separating means being adapted to produce a second overhead vapor stream and a bottom liquid stream;

(7) said first expansion means being connected to said first dividing means to receive said second 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 second stream to said contacting and separating means at a first lower column feed position below said mid-column feed position;

(8) third expansion means connected to said separating means to receive any remaining portion 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;

(9) said distillation column being connected to said contacting and separating means to receive at least a portion of said bottom liquid stream;

(10) said contacting and separating means being further connected to said distillation column to receive at least a portion of said first overhead vapor stream at a second lower column feed position below said mid-column feed position;

(11) second dividing means connected to said contacting and separating means to receive said second overhead vapor stream separated therein and divide it into at least a first portion and a second portion;

(12) heat exchange means connected to said second dividing means to receive at least a portion of said second portion and heat it, thereafter discharging at least a portion of said heated second portion as said volatile residue gas fraction;

(13) vapor withdrawing means connected to said contacting and separating means to receive a distillation vapor stream from a region of said contacting and separating device above said mid-column feed position;

(14) second combining means connected to said second dividing means and said vapor withdrawing means to receive said first portion and said distillation vapor stream and form a combined vapor stream;

(15) compressing means connected to said second combining means to receive said combined vapor stream and compress it to higher pressure;

(16) said heat exchange means being further connected to said compressing means to receive said compressed combined vapor stream and cool it sufficiently to condense at least a part of it, thereby forming a condensed stream while supplying at least a portion of the heating of step (12);

(17) fourth expansion means connected to said heat exchange means to receive said condensed stream and expand it to said lower pressure, said fourth expansion means being further connected to said contacting and separating means to supply at least a portion of said expanded condensed stream to said contacting and separating means at a top feed position; and

(18) 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.

29. The improvement according to claim 24 wherein

(1) a third dividing means is connected to said distillation column to receive said first overhead vapor stream and divide it into said distillation vapor stream and a second distillation vapor stream;

(2) said contacting and separating device is adapted to be connected to said third dividing means to receive said second distillation vapor stream at said second lower column feed position; and

(3) said second combining means is adapted to be connected to said third dividing means to receive said distillation vapor stream.