Hydrocarbon Gas Processing
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 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, heated, and supplied to the fractionation tower at an upper mid-column feed position. The second stream is expanded to the tower pressure and is then 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 A distillation vapor stream is withdrawn from the column above the feed point of the second stream and is then directed into heat exchange relation with the expanded cooled first stream and the tower overhead vapor stream to cool the distillation vapor 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 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.
1 . In a process for the separation of a gas stream containing methane, C 2 components, C 3 components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C 2 components, C 3 components, and heavier hydrocarbon components or said C 3 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 heated and 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 heated, thereafter discharging at least a portion of said heated overhead vapor stream as said volatile residue gas fraction;
(5) a 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 and is directed into heat exchange relation with said expanded cooled first stream and said overhead vapor stream, whereby said distillation vapor stream is cooled sufficiently to condense at least a part of it and thereby form a residual vapor stream and a condensed stream, thereby supplying at least a portion of the heating of steps (2) and (4);
(6) at least a portion of said condensed stream is supplied to said distillation column at a top feed position; and
(7) 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 . In a process for the separation of a gas stream containing methane, C 2 components, C 3 components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C 2 components, C 3 components, and heavier hydrocarbon components or said C 3 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 heated and 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 heated, thereafter discharging at least a portion of said heated overhead vapor stream as said volatile residue gas fraction;
(8) a 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 and is directed into heat exchange relation with said expanded cooled first stream and said overhead vapor stream, whereby said distillation vapor stream is cooled sufficiently to condense at least a part of it and thereby form a residual vapor stream and a condensed stream, thereby supplying at least a portion of the heating of steps (4) and (7);
(9) at least a portion of said condensed stream is supplied to said distillation column at a top feed position; and
(10) 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, C 2 components, C 3 components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C 2 components, C 3 components, and heavier hydrocarbon components or said C 3 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 heated and 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 heated, thereafter discharging at least a portion of said heated overhead vapor stream as said volatile residue gas fraction;
(8) a 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 and is directed into heat exchange relation with said expanded cooled combined stream and said overhead vapor stream, whereby said distillation vapor stream is cooled sufficiently to condense at least a part of it and thereby form a residual vapor stream and a condensed stream, thereby supplying at least a portion of the heating of steps (4) and (7);
(9) at least a portion of said condensed stream is supplied to said distillation column at a top feed position; and
(10) 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, C 2 components, C 3 components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C 2 components, C 3 components, and heavier hydrocarbon components or said C 3 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 heated and 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 heated, thereafter discharging at least a portion of said heated first overhead vapor stream as said volatile residue gas fraction;
(6) a 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 and is directed into heat exchange relation with said expanded cooled first stream and said first overhead vapor stream, whereby said distillation vapor stream is cooled sufficiently to condense at least a part of it and thereby form a residual vapor stream and a condensed stream, thereby supplying at least a portion of the heating of steps (2) and (5);
(7) at least a portion of said condensed stream is supplied to said contacting and separating device at a top feed position; and
(8) 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.
5 . In a process for the separation of a gas stream containing methane, C 2 components, C 3 components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C 2 components, C 3 components, and heavier hydrocarbon components or said C 3 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 heated and 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 heated, thereafter discharging at least a portion of said heated first overhead vapor stream as said volatile residue gas fraction;
(9) a 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 and is directed into heat exchange relation with said expanded cooled first stream and said first overhead vapor stream, whereby said distillation vapor stream is cooled sufficiently to condense at least a part of it and thereby form a residual vapor stream and a condensed stream, thereby supplying at least a portion of the heating of steps (4) and (8);
(10) at least a portion of said condensed stream is supplied to said contacting and separating device at a top 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.
6 . In a process for the separation of a gas stream containing methane, C 2 components, C 3 components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C 2 components, C 3 components, and heavier hydrocarbon components or said C 3 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 heated and 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 heated, thereafter discharging at least a portion of said heated first overhead vapor stream as said volatile residue gas fraction;
(9) a 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 and is directed into heat exchange relation with said expanded cooled combined stream and said first overhead vapor stream, whereby said distillation vapor stream is cooled sufficiently to condense at least a part of it and thereby form a residual vapor stream and a condensed stream, thereby supplying at least a portion of the heating of steps (4) and (8);
(10) at least a portion of said condensed stream is supplied to said contacting and separating device at a top 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.
7 . The improvement according to claim 1 wherein
(1) said overhead vapor stream is combined with said residual vapor stream to form a combined vapor stream; and
(2) said combined vapor stream is directed into heat exchange relation with said distillation vapor stream and heated, thereby to supply at least a portion of said cooling of said distillation vapor stream, and thereafter discharging at least a portion of said heated combined vapor stream as said volatile residue gas fraction.
8 . The improvement according to claim 2 wherein
(1) said overhead vapor stream is combined with said residual vapor stream to form a combined vapor stream; and
(2) said combined vapor stream is directed into heat exchange relation with said distillation vapor stream and heated, thereby to supply at least a portion of said cooling of said distillation vapor stream, and thereafter discharging at least a portion of said heated combined vapor stream as said volatile residue gas fraction.
9 . The improvement according to claim 3 wherein
(1) said overhead vapor stream is combined with said residual vapor stream to form a combined vapor stream; and
(2) said combined vapor stream is directed into heat exchange relation with said distillation vapor stream and heated, thereby to supply at least a portion of said cooling of said distillation vapor stream, and thereafter discharging at least a portion of said heated combined vapor stream as said volatile residue gas fraction.
10 . The improvement according to claim 4 wherein
(1) said first overhead vapor stream is combined with said residual vapor stream to form a combined vapor stream; and
(2) said combined vapor stream is directed into heat exchange relation with said distillation vapor stream and heated, thereby to supply at least a portion of said cooling of said distillation vapor stream, and thereafter discharging at least a portion of said heated combined vapor stream as said volatile residue gas fraction.
11 . The improvement according to claim 5 wherein
(1) said first overhead vapor stream is combined with said residual vapor stream to form a combined vapor stream; and
(2) said combined vapor stream is directed into heat exchange relation with said distillation vapor stream and heated, thereby to supply at least a portion of said cooling of said distillation vapor stream, and thereafter discharging at least a portion of said heated combined vapor stream as said volatile residue gas fraction.
12 . The improvement according to claim 6 wherein
(1) said first overhead vapor stream is combined with said residual vapor stream to form a combined vapor stream; and
(2) said combined vapor stream is directed into heat exchange relation with said distillation vapor stream and heated, thereby to supply at least a portion of said cooling of said distillation vapor stream, and thereafter discharging at least a portion of said heated combined vapor stream as said volatile residue gas fraction.
13 . The improvement according to claim 1 , 2 , 3 , 7 , 8 , or 9 wherein said distillation vapor stream is withdrawn from a region of said distillation column below said mid-column feed position.
14 . The improvement according to claim 1 , 2 , 3 , 7 , 8 , or 9 wherein
(1) a first distillation vapor stream is withdrawn from said region of said distillation column below said upper mid-column feed position and above said mid-column feed position;
(2) a second distillation vapor stream is withdrawn from a region of said distillation column below said mid-column feed position; and
(3) said first distillation vapor stream is combined with said second distillation vapor stream to form said distillation vapor stream.
15 . The improvement according to claim 4 , 5 , 6 , 10 , 11 , or 12 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.
16 . The improvement according to claim 4 , 5 , 6 , 10 , 11 , or 12 wherein
(1) a first distillation vapor stream is withdrawn from said region of said contacting and separating device below said mid-column feed position and above said first and second lower column feed positions;
(2) said second overhead vapor stream is divided into a second distillation vapor stream and a third distillation vapor stream, whereupon said second distillation vapor stream is supplied to said contacting and separating device at said second lower column feed position;
(3) said first distillation vapor stream is combined with said third distillation vapor stream to form said distillation vapor stream.
17 . The improvement according to claim 1 , 2 , 3 , 7 , 8 , or 9 wherein
(1) said condensed stream is divided into at least a first portion and a second portion;
(2) said first portion is supplied to said distillation column at said top feed position; and
(3) said second portion is supplied to said distillation column at a second mid-column feed position below said mid-column feed position.
18 . The improvement according to claim 13 wherein
(1) said condensed stream is divided into at least a first portion and a second portion;
(2) said first portion is supplied to said distillation column at said top feed position; and
(3) said second portion is supplied to said distillation column at a second mid-column feed position below said mid-column feed position.
19 . The improvement according to claim 14 wherein
(1) said condensed stream is divided into at least a first portion and a second portion;
(2) said first portion is supplied to said distillation column at said top feed position; and
(3) said second portion is supplied to said distillation column at a second mid-column feed position below said mid-column feed position.
20 . The improvement according to claim 4 , 5 , 6 , 10 , 11 , or 12 wherein
(1) said condensed stream is divided into at least a first portion and a second portion;
(2) said first portion is supplied to said contacting and separating device at said top feed position; and
(3) said second portion is supplied to said distillation column at a top feed position.
21 . The improvement according to claim 15 wherein
(1) said condensed stream is divided into at least a first portion and a second portion;
(2) said first portion is supplied to said contacting and separating device at said top feed position; and
(3) said second portion is supplied to said distillation column at a top feed position.
22 . The improvement according to claim 16 wherein
(1) said condensed stream is divided into at least a first portion and a second portion;
(2) said first portion is supplied to said contacting and separating device at said top feed position; and
(3) said second portion is supplied to said distillation column at a top feed position.
23 . In an apparatus for the separation of a gas stream containing methane, C 2 components, C 3 components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C 2 components, C 3 components, and heavier hydrocarbon components or said C 3 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) 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 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;
(4) heat exchange means connected to said second expansion means to receive said expanded cooled first stream and heat it, said heat exchange means being further connected to said distillation column to supply said heated expanded first stream to said distillation column at an upper mid-column feed position;
(5) said first expansion means being connected to said 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;
(6) said heat exchange means being further connected to said distillation column to receive at least a portion of said overhead vapor stream separated therein and heat it, thereafter discharging at least a portion of said heated overhead vapor stream 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 below said upper mid-column feed position and above said mid-column feed position;
(8) said heat exchange means being further connected to said vapor withdrawing means to receive said distillation vapor stream and cool it sufficiently to condense at least a part of it, thereby supplying at least a portion of the heating of steps (4) and (6);
(9) separating means connected to said heat exchange means to receive said partially condensed distillation vapor stream and separate it, thereby forming a residual vapor stream and a condensed stream, said 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 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.
24 . In an apparatus for the separation of a gas stream containing methane, C 2 components, C 3 components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C 2 components, C 3 components, and heavier hydrocarbon components or said C 3 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) first 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) dividing means connected to said first separating means to receive said vapor stream and divide it into first and second streams;
(4) second cooling means connected to said 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;
(6) heat exchange means connected to said second expansion means to receive said expanded cooled first stream and heat it, said heat exchange means being further connected to said distillation column to supply said heated expanded first stream to said distillation column at an upper mid-column feed position;
(7) said first expansion means being connected to said 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 connected to said first 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;
(9) said heat exchange means being further connected to said distillation column to receive at least a portion of said overhead vapor stream separated therein and heat it, thereafter discharging at least a portion of said heated overhead vapor stream 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 below said upper mid-column feed position and above said mid-column feed position;
(11) said heat exchange means being further connected to said vapor withdrawing means to receive said distillation vapor stream and cool it sufficiently to condense at least a part of it, thereby supplying at least a portion of the heating of steps (6) and (9);
(12) second separating means connected to said heat exchange means to receive said partially condensed distillation vapor stream and separate it, thereby forming a residual vapor stream and a condensed stream, said second 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 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.
25 . In an apparatus for the separation of a gas stream containing methane, C 2 components, C 3 components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C 2 components, C 3 components, and heavier hydrocarbon components or said C 3 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) first 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) dividing means connected to said first separating means to receive said vapor stream and divide it into first and second streams;
(4) combining means connected to said dividing means and said first 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 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;
(7) heat exchange means connected to said second expansion means to receive said expanded cooled combined stream and heat it, said heat exchange means being further connected to said distillation column to supply said heated expanded combined stream to said distillation column at an upper mid-column feed position;
(8) said first expansion means being connected to said 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;
(9) third expansion means being connected to said first 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;
(10) said heat exchange means being further connected to said distillation column to receive at least a portion of said overhead vapor stream separated therein and heat it, thereafter discharging at least a portion of said heated overhead vapor stream 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 below said upper mid-column feed position and above said mid-column feed position;
(12) said heat exchange means being further connected to said vapor withdrawing means to receive said distillation vapor stream and cool it sufficiently to condense at least a part of it, thereby supplying at least a portion of the heating of steps (7) and (10);
(13) second separating means connected to said heat exchange means to receive said partially condensed distillation vapor stream and separate it, thereby forming a residual vapor stream and a condensed stream, said second 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 top feed position; and
(14) 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.
26 . In an apparatus for the separation of a gas stream containing methane, C 2 components, C 3 components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C 2 components, C 3 components, and heavier hydrocarbon components or said C 3 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) 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 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;
(4) heat exchange means connected to said second expansion means to receive said expanded cooled first stream and heat it, said heat exchange means being further connected to a contacting and separating means to supply said heated expanded 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;
(5) said first expansion means being connected to said 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;
(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) said heat exchange means being further connected to said contacting and separating means to receive at least a portion of said second overhead vapor stream separated therein and heat it, thereafter discharging at least a portion of said heated second overhead vapor stream 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 below said mid-column feed position and above said first and second lower column feed positions;
(10) said heat exchange means being further connected to said vapor withdrawing means to receive said distillation vapor stream and cool it sufficiently to condense at least a part of it, thereby supplying at least a portion of the heating of steps (4) and (8);
(11) separating means connected to said heat exchange means to receive said partially condensed distillation vapor stream and separate it, thereby forming a residual vapor stream and a condensed stream, said 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 top feed position; and
(12) 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 . In an apparatus for the separation of a gas stream containing methane, C 2 components, C 3 components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C 2 components, C 3 components, and heavier hydrocarbon components or said C 3 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) first 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) dividing means connected to said first separating means to receive said vapor stream and divide it into first and second streams;
(4) second cooling means connected to said 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;
(6) heat exchange means connected to said second expansion means to receive said expanded cooled first stream and heat it, said heat exchange means being further connected to a contacting and separating means to supply said heated expanded 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;
(7) said first expansion means being connected to said 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 first 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;
(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) said heat exchange means being further connected to said contacting and separating means to receive at least a portion of said second overhead vapor stream separated therein and heat it, thereafter discharging at least a portion of said heated second overhead vapor stream 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 below said mid-column feed position and above said first and second lower column feed positions;
(13) said heat exchange means being further connected to said vapor withdrawing means to receive said distillation vapor stream and cool it sufficiently to condense at least a part of it, thereby supplying at least a portion of the heating of steps (6) and (11);
(14) second separating means connected to said heat exchange means to receive said partially condensed distillation vapor stream and separate it, thereby forming a residual vapor stream and a condensed stream, said second 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 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.
28 . In an apparatus for the separation of a gas stream containing methane, C 2 components, C 3 components, and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing a major portion of said C 2 components, C 3 components, and heavier hydrocarbon components or said C 3 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) first 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) dividing means connected to said first separating means to receive said vapor stream and divide it into first and second streams;
(4) combining means connected to said dividing means and said first 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 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;
(7) heat exchange means connected to said second expansion means to receive said expanded cooled combined stream and heat it, said heat exchange means being further connected to a contacting and separating means to supply said heated expanded 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;
(8) said first expansion means being connected to said 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;
(9) third expansion means connected to said first 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;
(10) said distillation column being connected to said contacting and separating means to receive at least a portion of said bottom liquid stream;
(11) 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;
(12) said heat exchange means being further connected to said contacting and separating means to receive at least a portion of said second overhead vapor stream separated therein and heat it, thereafter discharging at least a portion of said heated second overhead vapor stream 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 below said mid-column feed position and above said first and second lower column feed positions;
(14) said heat exchange means being further connected to said vapor withdrawing means to receive said distillation vapor stream and cool it sufficiently to condense at least a part of it, thereby supplying at least a portion of the heating of steps (7) and (12);
(15) second separating means connected to said heat exchange means to receive said partially condensed distillation vapor stream and separate it, thereby forming a residual vapor stream and a condensed stream, said second 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 top 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.
29 . The improvement according to claim 23 wherein
(1) a combining means is connected to said distillation column and said separating means to receive said overhead vapor stream and said residual vapor stream and form a combined vapor stream; and
(2) said heat exchange means is adapted to receive said combined vapor stream from said combining means and direct it into heat exchange relation with said distillation vapor stream, thereby heating said combined vapor stream and supplying at least a portion of said cooling of said distillation vapor stream, and thereafter discharging at least a portion of said heated combined vapor stream as said volatile residue gas fraction.
30 . The improvement according to claim 24 wherein
(1) a combining means is connected to said distillation column and said second separating means to receive said overhead vapor stream and said residual vapor stream and form a combined vapor stream; and
(2) said heat exchange means is adapted to receive said combined vapor stream from said combining means and direct it into heat exchange relation with said distillation vapor stream, thereby heating said combined vapor stream and supplying at least a portion of said cooling of said distillation vapor stream, and thereafter discharging at least a portion of said heated combined vapor stream as said volatile residue gas fraction.
31 . The improvement according to claim 25 wherein
(1) a second combining means is connected to said distillation column and said second separating means to receive said overhead vapor stream and said residual vapor stream and form a combined vapor stream; and
(2) said heat exchange means is adapted to receive said combined vapor stream from said second combining means and direct it into heat exchange relation with said distillation vapor stream, thereby heating said combined vapor stream and supplying at least a portion of said cooling of said distillation vapor stream, and thereafter discharging at least a portion of said heated combined vapor stream as said volatile residue gas fraction.
32 . The improvement according to claim 26 wherein
(1) a combining means is connected to said contacting and separating means and said separating means to receive said second overhead vapor stream and said residual vapor stream and form a combined vapor stream; and
(2) said heat exchange means is adapted to receive said combined vapor stream from said combining means and direct it into heat exchange relation with said distillation vapor stream, thereby heating said combined vapor stream and supplying at least a portion of said cooling of said distillation vapor stream, and thereafter discharging at least a portion of said heated combined vapor stream as said volatile residue gas fraction.
33 . The improvement according to claim 27 wherein
(1) a combining means is connected to said contacting and separating means and said second separating means to receive said second overhead vapor stream and said residual vapor stream and form a combined vapor stream; and
(2) said heat exchange means is adapted to receive said combined vapor stream from said combining means and direct it into heat exchange relation with said distillation vapor stream, thereby heating said combined vapor stream and supplying at least a portion of said cooling of said distillation vapor stream, and thereafter discharging at least a portion of said heated combined vapor stream as said volatile residue gas fraction.
34 . The improvement according to claim 28 wherein
(1) a second combining means is connected to said contacting and separating means and said second separating means to receive said second overhead vapor stream and said residual vapor stream and form a combined vapor stream; and
(2) said heat exchange means is adapted to receive said combined vapor stream from said second combining means and direct it into heat exchange relation with said distillation vapor stream, thereby heating said combined vapor stream and supplying at least a portion of said cooling of said distillation vapor stream, and thereafter discharging at least a portion of said heated combined vapor stream as said volatile residue gas fraction.
35 . The improvement according to claim 23 or 29 wherein said vapor withdrawing means is adapted to be connected to said distillation column to receive said distillation vapor stream from a region of said distillation column below said mid-column feed position.
36 . The improvement according to claim 24 , 25 , 30 , or 31 wherein said vapor withdrawing means is adapted to be connected to said distillation column to receive said distillation vapor stream from a region of said distillation column below said mid-column feed position.
37 . The improvement according to claim 23 wherein
(1) said vapor withdrawing means is adapted to be connected to said distillation column to receive a first distillation vapor stream from said region of said distillation column below said upper mid-column feed position and above said mid-column feed position;
(2) a second vapor withdrawing means is connected to said distillation column to receive a second distillation vapor stream from a region of said distillation column below said mid-column feed position;
(3) a combining means is connected to said vapor withdrawing means and said second vapor withdrawing means to receive said first distillation vapor stream and said second distillation vapor stream and form said distillation vapor stream; and
(4) said heat exchange means is adapted to be connected to said combining means to receive said distillation vapor stream.
38 . The improvement according to claim 24 wherein
(1) said vapor withdrawing means is adapted to be connected to said distillation column to receive a first distillation vapor stream from said region of said distillation column below said upper mid-column feed position and above said mid-column feed position;
(2) a second vapor withdrawing means is connected to said distillation column to receive a second distillation vapor stream from a region of said distillation column below said mid-column feed position;
(3) a combining means is connected to said vapor withdrawing means and said second vapor withdrawing means to receive said first distillation vapor stream and said second distillation vapor stream and form said distillation vapor stream; and
(4) said heat exchange means is adapted to be connected to said combining means to receive said distillation vapor stream.
39 . The improvement according to claim 25 or 30 wherein
(1) said vapor withdrawing means is adapted to be connected to said distillation column to receive a first distillation vapor stream from said region of said distillation column below said upper mid-column feed position and above said mid-column feed position;
(2) a second vapor withdrawing means is connected to said distillation column to receive a second distillation vapor stream from a region of said distillation column below said mid-column feed position;
(3) a second combining means is connected to said vapor withdrawing means and said second vapor withdrawing means to receive said first distillation vapor stream and said second distillation vapor stream and form said distillation vapor stream; and
(4) said heat exchange means is adapted to be connected to said second combining means to receive said distillation vapor stream.
40 . The improvement according to claim 29 wherein
(1) said vapor withdrawing means is adapted to be connected to said distillation column to receive a first distillation vapor stream from said region of said distillation column below said upper mid-column feed position and above said mid-column feed position;
(2) a second vapor withdrawing means is connected to said distillation column to receive a second distillation vapor stream from a region of said distillation column below said mid-column feed position;
(3) a second combining means is connected to said vapor withdrawing means and said second vapor withdrawing means to receive said first distillation vapor stream and said second distillation vapor stream and form said distillation vapor stream; and
(4) said heat exchange means is adapted to be connected to said second combining means to receive said distillation vapor stream.
41 . The improvement according to claim 31 wherein
(1) said vapor withdrawing means is adapted to be connected to said distillation column to receive a first distillation vapor stream from said region of said distillation column below said upper mid-column feed position and above said mid-column feed position;
(2) a second vapor withdrawing means is connected to said distillation column to receive a second distillation vapor stream from a region of said distillation column below said mid-column feed position;
(3) a third combining means is connected to said vapor withdrawing means and said second vapor withdrawing means to receive said first distillation vapor stream and said second distillation vapor stream and form said distillation vapor stream; and
(4) said heat exchange means is adapted to be connected to said third combining means to receive said distillation vapor stream.
42 . The improvement according to claim 26 or 32 wherein
(1) a second 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 means is adapted to be connected to said second dividing means to receive said second distillation vapor stream at said second lower column feed position; and
(3) said heat exchange means is adapted to be connected to said second dividing means to receive said distillation vapor stream.
43 . The improvement according to claim 27 , 28 , 33 , or 34 wherein
(1) a second 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 means is adapted to be connected to said second dividing means to receive said second distillation vapor stream at said second lower column feed position; and
(3) said heat exchange means is adapted to be connected to said second dividing means to receive said distillation vapor stream.
44 . The improvement according to claim 26 wherein
(1) said vapor withdrawing means is adapted to be connected to said contacting and separating means to receive a first distillation vapor stream from said region of said contacting and separating means below said mid-column feed position and above said first and second lower column feed positions;
(2) a second dividing means is connected to said distillation column to receive said first overhead vapor stream and divide it into a second distillation vapor stream and a third distillation vapor stream;
(3) said contacting and separating means is adapted to be connected to said second dividing means to receive said second distillation vapor stream at said second lower column feed position;
(4) a combining means is connected to said vapor withdrawing means and said second dividing means to receive said first distillation vapor stream and said third distillation vapor stream and form said distillation vapor stream; and
(5) said heat exchange means is adapted to be connected to said combining means to receive said distillation vapor stream.
45 . The improvement according to claim 27 wherein
(1) said vapor withdrawing means is adapted to be connected to said contacting and separating means to receive a first distillation vapor stream from said region of said contacting and separating means below said mid-column feed position and above said first and second lower column feed positions;
(2) a second dividing means is connected to said distillation column to receive said first overhead vapor stream and divide it into a second distillation vapor stream and a third distillation vapor stream;
(3) said contacting and separating means is adapted to be connected to said second dividing means to receive said second distillation vapor stream at said second lower column feed position;
(4) a combining means is connected to said vapor withdrawing means and said second dividing means to receive said first distillation vapor stream and said third distillation vapor stream and form said distillation vapor stream; and
(5) said heat exchange means is adapted to be connected to said combining means to receive said distillation vapor stream.
46 . The improvement according to claim 28 or 33 wherein
(1) said vapor withdrawing means is adapted to be connected to said contacting and separating means to receive a first distillation vapor stream from said region of said contacting and separating means below said mid-column feed position and above said first and second lower column feed positions;
(2) a second dividing means is connected to said distillation column to receive said first overhead vapor stream and divide it into a second distillation vapor stream and a third distillation vapor stream;
(3) said contacting and separating means is adapted to be connected to said second dividing means to receive said second distillation vapor stream at said second lower column feed position;
(4) a second combining means is connected to said vapor withdrawing means and said second dividing means to receive said first distillation vapor stream and said third distillation vapor stream and form said distillation vapor stream; and
(5) said heat exchange means is adapted to be connected to said second combining means to receive said distillation vapor stream.
47 . The improvement according to claim 32 wherein
(1) said vapor withdrawing means is adapted to be connected to said contacting and separating means to receive a first distillation vapor stream from said region of said contacting and separating means below said mid-column feed position and above said first and second lower column feed positions;
(2) a second dividing means is connected to said distillation column to receive said first overhead vapor stream and divide it into a second distillation vapor stream and a third distillation vapor stream;
(3) said contacting and separating means is adapted to be connected to said second dividing means to receive said second distillation vapor stream at said second lower column feed position;
(4) a second combining means is connected to said vapor withdrawing means and said second dividing means to receive said first distillation vapor stream and said third distillation vapor stream and form said distillation vapor stream; and
(5) said heat exchange means is adapted to be connected to said second combining means to receive said distillation vapor stream.
48 . The improvement according to claim 34 wherein
(1) said vapor withdrawing means is adapted to be connected to said contacting and separating means to receive a first distillation vapor stream from said region of said contacting and separating means below said mid-column feed position and above said first and second lower column feed positions;
(2) a second dividing means is connected to said distillation column to receive said first overhead vapor stream and divide it into a second distillation vapor stream and a third distillation vapor stream;
(3) said contacting and separating means is adapted to be connected to said second dividing means to receive said second distillation vapor stream at said second lower column feed position;
(4) a third combining means is connected to said vapor withdrawing means and said second dividing means to receive said first distillation vapor stream and said third distillation vapor stream and form said distillation vapor stream; and
(5) said heat exchange means is adapted to be connected to said third combining means to receive said distillation vapor stream.
49 . The improvement according to claim 23 , 29 , 37 , or 40 wherein
(1) a second dividing means is connected to said separating means to receive said condensed stream and divide it into at least a first portion and a second portion;
(2) said distillation column is adapted to be connected to said second dividing means to receive said first portion at said top feed position; and
(3) said distillation column is further adapted to be connected to said second dividing means to receive said second portion at a second mid-column feed position below said mid-column feed position.
50 . The improvement according to claim 24 , 25 , 30 , 31 , 38 , or 41 wherein
(1) a second dividing means is connected to said second separating means to receive said condensed stream and divide it into at least a first portion and a second portion;
(2) said distillation column is adapted to be connected to said second dividing means to receive said first portion at said top feed position; and
(3) said distillation column is further adapted to be connected to said second dividing means to receive said second portion at a second mid-column feed position below said mid-column feed position.
51 . The improvement according to claim 35 wherein
(1) a second dividing means is connected to said separating means to receive said condensed stream and divide it into at least a first portion and a second portion;
(2) said distillation column is adapted to be connected to said second dividing means to receive said first portion at said top feed position; and
(3) said distillation column is further adapted to be connected to said second dividing means to receive said second portion at a second mid-column feed position below said mid-column feed position.
52 . The improvement according to claim 36 wherein
(1) a second dividing means is connected to said second separating means to receive said condensed stream and divide it into at least a first portion and a second portion;
(2) said distillation column is adapted to be connected to said second dividing means to receive said first portion at said top feed position; and
(3) said distillation column is further adapted to be connected to said second dividing means to receive said second portion at a second mid-column feed position below said mid-column feed position.
53 . The improvement according to claim 39 wherein
(1) a second dividing means is connected to said second separating means to receive said condensed stream and divide it into at least a first portion and a second portion;
(2) said distillation column is adapted to be connected to said second dividing means to receive said first portion at said top feed position; and
(3) said distillation column is further adapted to be connected to said second dividing means to receive said second portion at a second mid-column feed position below said mid-column feed position.
54 . The improvement according to claim 26 or 32 wherein
(1) a second dividing means is connected to said separating means to receive said condensed stream and divide it into at least a first portion and a second portion;
(2) said contacting and separating means is adapted to be connected to said second dividing means to receive said first portion at said top feed position; and
(3) said distillation column is adapted to be connected to said second dividing means to receive said second portion at a top feed position.
55 . The improvement according to claim 27 , 28 , 33 , or 34 wherein
(1) a second dividing means is connected to said second separating means to receive said condensed stream and divide it into at least a first portion and a second portion;
(2) said contacting and separating means is adapted to be connected to said second dividing means to receive said first portion at said top feed position; and
(3) said distillation column is adapted to be connected to said second dividing means to receive said second portion at a top feed position.
56 . The improvement according to claim 42 wherein
(1) a third dividing means is connected to said separating means to receive said condensed stream and divide it into at least a first portion and a second portion;
(2) said contacting and separating means is adapted to be connected to said third dividing means to receive said first portion at said top feed position; and
(3) said distillation column is adapted to be connected to said third dividing means to receive said second portion at a top feed position.
57 . The improvement according to claim 43 wherein
(1) a third dividing means is connected to said second separating means to receive said condensed stream and divide it into at least a first portion and a second portion;
(2) said contacting and separating means is adapted to be connected to said third dividing means to receive said first portion at said top feed position; and
(3) said distillation column is adapted to be connected to said third dividing means to receive said second portion at a top feed position.
58 . The improvement according to claim 44 or 47 wherein
(1) a third dividing means is connected to said separating means to receive said condensed stream and divide it into at least a first portion and a second portion;
(2) said contacting and separating means is adapted to be connected to said third dividing means to receive said first portion at said top feed position; and
(3) said distillation column is adapted to be connected to said third dividing means to receive said second portion at a top feed position.
59 . The improvement according to claim 45 or 48 wherein
(1) a third dividing means is connected to said second separating means to receive said condensed stream and divide it into at least a first portion and a second portion;
(2) said contacting and separating means is adapted to be connected to said third dividing means to receive said first portion at said top feed position; and
(3) said distillation column is adapted to be connected to said third dividing means to receive said second portion at a top feed position.
60 . The improvement according to claim 46 wherein
(1) a third dividing means is connected to said second separating means to receive said condensed stream and divide it into at least a first portion and a second portion;
(2) said contacting and separating means is adapted to be connected to said third dividing means to receive said first portion at said top feed position; and
(3) said distillation column is adapted to be connected to said third dividing means to receive said second portion at a top feed position.