Liquefied Natural Gas and Hydrocarbon Gas Processing

Abstract

A process for the recovery of ethane, ethylene, propane, propylene, and heavier hydrocarbons from a liquefied natural gas (LNG) stream and a hydrocarbon gas stream is disclosed. The LNG feed stream is divided into two portions. The first portion is supplied to a fractionation column at a first upper mid-column feed point. The second portion is directed in heat exchange relation with a first portion of a warmer distillation stream rising from the fractionation stages of the column, whereby the LNG feed stream is partially heated and the distillation stream is totally condensed. The condensed distillation stream is divided into a “lean” LNG stream and a reflux stream, whereupon the reflux stream is supplied to the column at a top column feed position. The second portion of the LNG feed stream is heated further to partially or totally vaporize it and thereafter supplied to the column at a first lower mid-column feed position. The gas stream is divided into two portions. The second portion is expanded to the operating pressure of the column, then both portions are directed in heat exchange relation with the lean LNG stream and the second portion of the warmer distillation stream, whereby both portions of the gas stream are cooled, the lean LNG stream is vaporized, and the second portion of the distillation stream is heated. The first portion of the gas stream, which has been cooled to substantial condensation, is supplied to the column at a second upper mid-column feed point, and the second portion is supplied to the column at a second lower mid-column feed point. The quantities and temperatures of the feeds to the column are effective to maintain the column overhead temperature at a temperature whereby the major portion of the desired components is recovered in the bottom liquid product from the column.

1 . A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components and a gas stream containing methane and heavier hydrocarbon components into a volatile residue gas fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components wherein
 (a) said liquefied natural gas is divided into at least a first liquid stream and a second liquid stream;   (b) said first liquid stream is expanded to lower pressure and is thereafter supplied to a distillation column at a first upper mid-column feed position;   (c) said second liquid stream is heated sufficiently to vaporize it, thereby forming a vapor stream;   (d) said vapor stream is expanded to said lower pressure and is supplied to said distillation column at a first lower mid-column feed position;   (e) said gas stream is divided into at least a first gaseous stream and a second gaseous stream;   (f) said first gaseous stream is cooled to condense substantially all of it and is thereafter expanded to said lower pressure whereby it is further cooled;   (g) said expanded substantially condensed first gaseous stream is thereafter supplied to said distillation column at a second upper mid-column feed position;   (h) said second gaseous stream is expanded to said lower pressure, is cooled, and is thereafter supplied to said distillation column at a second lower mid-column feed position;   (i) an overhead distillation stream is withdrawn from an upper region of said distillation column and divided into at least a first portion and a second portion, whereupon said first portion is compressed to higher pressure;   (j) said compressed first portion is cooled sufficiently to at least partially condense it and form thereby a condensed stream, with said cooling supplying at least a portion of said heating of said second liquid stream;   (k) said condensed stream is divided into at least a volatile liquid stream and a reflux stream;   (l) said reflux stream is further cooled, with said cooling supplying at least a portion of said heating of said second liquid stream;   (m) said further cooled reflux stream is supplied to said distillation column at a top column feed position;   (n) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream and said expanded second gaseous stream;   (o) said second portion is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream and said expanded second gaseous stream;   (p) said vaporized volatile liquid stream and said heated second portion are combined to form said volatile residue gas fraction containing a major portion of said methane; and   (q) the quantity and temperature of said reflux stream and the temperatures of said feeds to said distillation column are effective to maintain the overhead temperature of said distillation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction by fractionation in said distillation column.   
   
   
       2 . A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components and a gas stream containing methane and heavier hydrocarbon components into a volatile residue gas fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components wherein
 (a) said liquefied natural gas is divided into at least a first liquid stream and a second liquid stream;   (b) said first liquid stream is expanded to lower pressure and is thereafter supplied to a distillation column at a first upper mid-column feed position;   (c) said second liquid stream is heated sufficiently to vaporize it, thereby forming a first vapor stream;   (d) said first vapor stream is expanded to said lower pressure and thereafter supplied to said distillation column at a first lower mid-column feed position;   (e) said gas stream is divided into at least a first gaseous stream and a second gaseous stream;   (f) said first gaseous stream is cooled to condense substantially all of it and is thereafter expanded to said lower pressure whereby it is further cooled;   (g) said expanded substantially condensed first gaseous stream is thereafter supplied to said distillation column at a second upper mid-column feed position;   (h) said second gaseous stream is expanded to said lower pressure and is thereafter cooled sufficiently to partially condense it;   (i) said partially condensed expanded second gaseous stream is separated thereby to provide a second vapor stream and a third liquid stream;   (j) said second vapor stream is further cooled and thereafter supplied to said distillation column at a second lower mid-column feed position;   (k) said third liquid stream is supplied to said distillation column at a third lower mid-column feed position;   (l) an overhead distillation stream is withdrawn from an upper region of said distillation column and divided into at least a first portion and a second portion, whereupon said first portion is compressed to higher pressure;   (m) said compressed first portion is cooled sufficiently to at least partially condense it and form thereby a condensed stream, with said cooling supplying at least a portion of said heating of said second liquid stream;   (n) said condensed stream is divided into at least a volatile liquid stream and a reflux stream;   (o) said reflux stream is further cooled, with said cooling supplying at least a portion of said heating of said second liquid stream;   (p) said further cooled reflux stream is supplied to said distillation column at a top column feed position;   (q) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said expanded second gaseous stream, and said second vapor stream;   (r) said second portion is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said expanded second gaseous stream, and said second vapor stream;   (s) said vaporized volatile liquid stream and said heated second portion are combined to form said volatile residue gas fraction containing a major portion of said methane; and   (t) the quantity and temperature of said reflux stream and the temperatures of said feeds to said distillation column are effective to maintain the overhead temperature of said distillation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction by fractionation in said distillation column.   
   
   
       3 . A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components and a gas stream containing methane and heavier hydrocarbon components into a volatile residue gas fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components wherein
 (a) said liquefied natural gas is divided into at least a first liquid stream and a second liquid stream;   (b) said first liquid stream is expanded to lower pressure and is thereafter supplied to a distillation column at a first upper mid-column feed position;   (c) said second liquid stream is heated sufficiently to partially vaporize it;   (d) said partially vaporized second liquid stream is separated thereby to provide a vapor stream and a third liquid stream;   (e) said vapor stream is expanded to said lower pressure and is supplied to said distillation column at a first lower mid-column feed position;   (f) said gas stream is divided into at least a first gaseous stream and a second gaseous stream;   (g) said first gaseous stream is cooled to condense substantially all of it and is thereafter expanded to said lower pressure whereby it is further cooled;   (h) said expanded substantially condensed first gaseous stream is thereafter supplied to said distillation column at a second upper mid-column feed position;   (i) said second gaseous stream is expanded to said lower pressure, is cooled, and is thereafter supplied to said distillation column at a second lower mid-column feed position;   (j) said third liquid stream is expanded to said lower pressure and thereafter supplied to said distillation column at a third lower mid-column feed position;   (k) an overhead distillation stream is withdrawn from an upper region of said distillation column and divided into at least a first portion and a second portion, whereupon said first portion is compressed to higher pressure;   (l) said compressed first portion is cooled sufficiently to at least partially condense it and form thereby a condensed stream, with said cooling supplying at least a portion of said heating of said second liquid stream;   (m) said condensed stream is divided into at least a volatile liquid stream and a reflux stream;   (n) said reflux stream is further cooled, with said cooling supplying at least a portion of said heating of said second liquid stream;   (o) said further cooled reflux stream is supplied to said distillation column at a top column feed position;   (p) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream and said expanded second gaseous stream;   (q) said second portion is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream and said expanded second gaseous stream;   (r) said vaporized volatile liquid stream and said heated second portion are combined to form said volatile residue gas fraction containing a major portion of said methane; and   (s) the quantity and temperature of said reflux stream and the temperatures of said feeds to said distillation column are effective to maintain the overhead temperature of said distillation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction by fractionation in said distillation column.   
   
   
       4 . A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components and a gas stream containing methane and heavier hydrocarbon components into a volatile residue gas fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components wherein
 (a) said liquefied natural gas is divided into at least a first liquid stream and a second liquid stream;   (b) said first liquid stream is expanded to lower pressure and is thereafter supplied to a distillation column at a first upper mid-column feed position;   (c) said second liquid stream is heated sufficiently to partially vaporize it;   (d) said partially vaporized second liquid stream is separated thereby to provide a first vapor stream and a third liquid stream;   (e) said first vapor stream is expanded to said lower pressure and thereafter supplied to said distillation column at a first lower mid-column feed position;   (f) said gas stream is divided into at least a first gaseous stream and a second gaseous stream;   (g) said first gaseous stream is cooled to condense substantially all of it and is thereafter expanded to said lower pressure whereby it is further cooled;   (h) said expanded substantially condensed first gaseous stream is thereafter supplied to said distillation column at a second upper mid-column feed position;   (i) said second gaseous stream is expanded to said lower pressure;   (j) said expanded second gaseous stream is cooled sufficiently to partially condense it;   (k) said partially condensed expanded second gaseous stream is separated thereby to provide a second vapor stream and a fourth liquid stream;   (l) said second vapor stream is further cooled and thereafter supplied to said distillation column at a second lower mid-column feed position;   (m) said third liquid stream is expanded to said lower pressure and thereafter supplied to said distillation column at a third lower mid-column feed position;   (n) said fourth liquid stream is supplied to said distillation column at a fourth lower mid-column feed position;   (o) an overhead distillation stream is withdrawn from an upper region of said distillation column and divided into at least a first portion and a second portion, whereupon said first portion is compressed to higher pressure;   (p) said compressed first portion is cooled sufficiently to at least partially condense it and form thereby a condensed stream, with said cooling supplying at least a portion of said heating of said second liquid stream;   (q) said condensed stream is divided into at least a volatile liquid stream and a reflux stream;   (r) said reflux stream is further cooled, with said cooling supplying at least a portion of said heating of said second liquid stream;   (s) said further cooled reflux stream is supplied to said distillation column at a top column feed position;   (t) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said expanded second gaseous stream, and said second vapor stream;   (u) said second portion is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said expanded second gaseous stream, and said second vapor stream;   (v) said vaporized volatile liquid stream and said heated second portion are combined to form said volatile residue gas fraction containing a major portion of said methane; and   (w) the quantity and temperature of said reflux stream and the temperatures of said feeds to said distillation column are effective to maintain the overhead temperature of said distillation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction by fractionation in said distillation column.   
   
   
       5 . The process according to  claim 1  or  3  wherein
 (a) said second portion is compressed to higher pressure;   (b) said compressed second portion is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream and said expanded second gaseous stream; and   (c) said vaporized volatile liquid stream and said heated compressed second portion are combined to form said volatile residue gas fraction.   
   
   
       6 . The process according to  claim 2  or  4  wherein
 (a) said second portion is compressed to higher pressure;   (b) said compressed second portion is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said expanded second gaseous stream, and said second vapor stream; and   (c) said vaporized volatile liquid stream and said heated compressed second portion are combined to form said volatile residue gas fraction.   
   
   
       7 . The process according to  claim 1  or  3  wherein
 (a) said second gaseous stream is cooled prior to said expansion;   (b) said second portion is compressed to higher pressure;   (c) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said second gaseous stream, and said expanded second gaseous stream;   (d) said compressed second portion is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said second gaseous stream, and said expanded second gaseous stream; and   (e) said vaporized volatile liquid stream and said heated compressed second portion are combined to form said volatile residue gas fraction.   
   
   
       8 . The process according to  claim 2  wherein
 (a) said second gaseous stream is cooled sufficiently to partially condense it;   (b) said partially condensed second gaseous stream is separated thereby to provide said second vapor stream and said third liquid stream;   (c) said second vapor stream is expanded to said lower pressure, is cooled, and is thereafter supplied to said distillation column at said second lower mid-column feed position;   (d) said third liquid stream is expanded to said lower pressure and thereafter supplied to said distillation column at said third lower mid-column feed position;   (e) said second portion is compressed to higher pressure;   (f) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said second gaseous stream, and said expanded second vapor stream;   (g) said compressed second portion is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said second gaseous stream, and said expanded second vapor stream; and   (h) said vaporized volatile liquid stream and said heated compressed second portion are combined to form said volatile residue gas fraction.   
   
   
       9 . The process according to  claim 4  wherein
 (a) said second gaseous stream is cooled sufficiently to partially condense it;   (b) said partially condensed second gaseous stream is separated thereby to provide said second vapor stream and said fourth liquid stream;   (c) said second vapor stream is expanded to said lower pressure, is cooled, and is thereafter supplied to said distillation column at said second lower mid-column feed position;   (d) said fourth liquid stream is expanded to said lower pressure and thereafter supplied to said distillation column at said fourth lower mid-column feed position;   (e) said second portion is compressed to higher pressure;   (f) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said second gaseous stream, and said expanded second vapor stream;   (g) said compressed second portion is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said second gaseous stream, and said expanded second vapor stream; and   (h) said vaporized volatile liquid stream and said heated compressed second portion are combined to form said volatile residue gas fraction.   
   
   
       10 . The process according to  claim 8  wherein
 (a) said gas stream is cooled sufficiently to partially condense it;   (b) said partially condensed gas stream is separated thereby to provide said second vapor stream and said third liquid stream;   (c) said second vapor stream is divided into at least said first gaseous stream and said second gaseous stream;   (d) said second gaseous stream is expanded to said lower pressure, is cooled, and is thereafter supplied to said distillation column at said second lower mid-column feed position;   (e) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said gas stream, said first gaseous stream, and said expanded second gaseous stream; and   (f) said compressed second portion is heated, with said heating supplying at least a portion of said cooling of one or more of said gas stream, said first gaseous stream, and said expanded second gaseous stream.   
   
   
       11 . The process according to  claim 9  wherein
 (a) said gas stream is cooled sufficiently to partially condense it;   (b) said partially condensed gas stream is separated thereby to provide said second vapor stream and said fourth liquid stream;   (c) said second vapor stream is divided into at least said first gaseous stream and said second gaseous stream;   (d) said second gaseous stream is expanded to said lower pressure, is cooled, and is thereafter supplied to said distillation column at said second lower mid-column feed position;   (e) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said gas stream, said first gaseous stream, and said expanded second gaseous stream; and   (f) said compressed second portion is heated, with said heating supplying at least a portion of said cooling of one or more of said gas stream, said first gaseous stream, and said expanded second gaseous stream.   
   
   
       12 . A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components and a gas stream containing methane and heavier hydrocarbon components into a volatile residue gas fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components wherein
 (a) said liquefied natural gas is divided into at least a first liquid stream and a second liquid stream;   (b) said first liquid stream is expanded to a first lower pressure and is thereafter supplied to a first distillation column at an upper mid-column feed position;   (c) said second liquid stream is heated sufficiently to vaporize it, thereby forming a vapor stream;   (d) said vapor stream is expanded to said first lower pressure and is supplied to said first distillation column at a lower mid-column feed position;   (e) a first overhead distillation stream is withdrawn from an upper region of said first distillation column and compressed to higher pressure;   (f) said compressed first overhead distillation stream is cooled sufficiently to at least partially condense it and form thereby a condensed stream, with said cooling supplying at least a portion of said heating of said second liquid stream;   (g) said condensed stream is divided into at least a volatile liquid stream and a reflux liquid stream;   (h) said reflux liquid stream is further cooled, with said cooling supplying at least a portion of said heating of said second liquid stream;   (i) said further cooled reflux liquid stream is divided into at least a first reflux stream and a second reflux stream;   (j) said first reflux stream is supplied to said first distillation column at a top column feed position;   (k) said gas stream is divided into at least a first gaseous stream and a second gaseous stream;   (l) said first gaseous stream is cooled to condense substantially all of it and is thereafter expanded to a second lower pressure whereby it is further cooled;   (m) said expanded substantially condensed first gaseous stream is thereafter supplied to a second distillation column at an upper mid-column feed position;   (n) said second gaseous stream is expanded to said second lower pressure, is cooled, and is thereafter supplied to said second distillation column at a lower mid-column feed position;   (o) said second reflux stream is supplied to said second distillation column at a top column feed position;   (p) a second overhead distillation stream is withdrawn from an upper region of said second distillation column;   (q) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream and said expanded second gaseous stream;   (r) said second overhead distillation stream is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream and said expanded second gaseous stream;   (s) said vaporized volatile liquid stream and said heated second overhead distillation stream are combined to form said volatile residue gas fraction containing a major portion of said methane;   (t) a first bottom liquid from said first distillation column and a second bottom liquid from said second distillation column are combined to form said relatively less volatile liquid fraction; and   (u) the quantities and temperatures of said first and second reflux streams and the temperatures of said feeds to said first and second distillation columns are effective to maintain the overhead temperatures of said first and second distillation columns at temperatures whereby the major portion of said heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction by fractionation in said first and second distillation columns.   
   
   
       13 . A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components and a gas stream containing methane and heavier hydrocarbon components into a volatile residue gas fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components wherein
 (a) said liquefied natural gas is divided into at least a first liquid stream and a second liquid stream;   (b) said first liquid stream is expanded to a first lower pressure and is thereafter supplied to a first distillation column at an upper mid-column feed position;   (c) said second liquid stream is heated sufficiently to vaporize it, thereby forming a first vapor stream;   (d) said first vapor stream is expanded to said first lower pressure and thereafter supplied to said first distillation column at a lower mid-column feed position;   (e) a first overhead distillation stream is withdrawn from an upper region of said first distillation column and compressed to higher pressure;   (f) said compressed first overhead distillation stream is cooled sufficiently to at least partially condense it and form thereby a condensed stream, with said cooling supplying at least a portion of said heating of said second liquid stream;   (g) said condensed stream is divided into at least a volatile liquid stream and a reflux liquid stream;   (h) said reflux liquid stream is further cooled, with said cooling supplying at least a portion of said heating of said second liquid stream;   (i) said further cooled reflux liquid stream is divided into at least a first reflux stream and a second reflux stream;   (j) said first reflux stream is supplied to said first distillation column at a top column feed position;   (k) said gas stream is divided into at least a first gaseous stream and a second gaseous stream;   (l) said first gaseous stream is cooled to condense substantially all of it and is thereafter expanded to a second lower pressure whereby it is further cooled;   (m) said expanded substantially condensed first gaseous stream is thereafter supplied to a second distillation column at an upper mid-column feed position;   (n) said second gaseous stream is expanded to said second lower pressure and is thereafter cooled sufficiently to partially condense it;   (o) said partially condensed expanded second gaseous stream is separated thereby to provide a second vapor stream and a third liquid stream;   (p) said second vapor stream is further cooled and thereafter supplied to said second distillation column at a first lower mid-column feed position;   (q) said third liquid stream is supplied to said second distillation column at a second lower mid-column feed position;   (r) said second reflux stream is supplied to said second distillation column at a top column feed position;   (s) a second overhead distillation stream is withdrawn from an upper region of said second distillation column;   (t) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said expanded second gaseous stream, and said second vapor stream;   (u) said second overhead distillation stream is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said expanded second gaseous stream, and said second vapor stream;   (v) said vaporized volatile liquid stream and said heated second overhead distillation stream are combined to form said volatile residue gas fraction containing a major portion of said methane;   (w) a first bottom liquid from said first distillation column and a second bottom liquid from said second distillation column are combined to form said relatively less volatile liquid fraction; and   (x) the quantities and temperatures of said first and second reflux streams and the temperatures of said feeds to said first and second distillation columns are effective to maintain the overhead temperatures of said first and second distillation columns at temperatures whereby the major portion of said heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction by fractionation in said first and second distillation columns.   
   
   
       14 . A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components and a gas stream containing methane and heavier hydrocarbon components into a volatile residue gas fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components wherein
 (a) said liquefied natural gas is divided into at least a first liquid stream and a second liquid stream;   (b) said first liquid stream is expanded to a first lower pressure and is thereafter supplied to a first distillation column at an upper mid-column feed position;   (c) said second liquid stream is heated sufficiently to partially vaporize it;   (d) said partially vaporized second liquid stream is separated thereby to provide a vapor stream and a third liquid stream;   (e) said vapor stream is expanded to said first lower pressure and is supplied to said first distillation column at a first lower mid-column feed position;   (f) said third liquid stream is expanded to said first lower pressure and thereafter supplied to said first distillation column at a second lower mid-column feed position;   (g) a first overhead distillation stream is withdrawn from an upper region of said first distillation column and compressed to higher pressure;   (h) said compressed first overhead distillation stream is cooled sufficiently to at least partially condense it and form thereby a condensed stream, with said cooling supplying at least a portion of said heating of said second liquid stream;   (i) said condensed stream is divided into at least a volatile liquid stream and a reflux liquid stream;   (j) said reflux liquid stream is further cooled, with said cooling supplying at least a portion of said heating of said second liquid stream;   (k) said further cooled reflux liquid stream is divided into at least a first reflux stream and a second reflux stream;   (l) said first reflux stream is supplied to said first distillation column at a top column feed position;   (m) said gas stream is divided into at least a first gaseous stream and a second gaseous stream;   (n) said first gaseous stream is cooled to condense substantially all of it and is thereafter expanded to a second lower pressure whereby it is further cooled;   (o) said expanded substantially condensed first gaseous stream is thereafter supplied to a second distillation column at an upper mid-column feed position;   (p) said second gaseous stream is expanded to said second lower pressure, is cooled, and is thereafter supplied to said second distillation column at a lower mid-column feed position;   (q) said second reflux stream is supplied to said second distillation column at a top column feed position;   (r) a second overhead distillation stream is withdrawn from an upper region of said second distillation column;   (s) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream and said expanded second gaseous stream;   (t) said second overhead distillation stream is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream and said expanded second gaseous stream;   (u) said vaporized volatile liquid stream and said heated second overhead distillation stream are combined to form said volatile residue gas fraction containing a major portion of said methane;   (v) a first bottom liquid from said first distillation column and a second bottom liquid from said second distillation column are combined to form said relatively less volatile liquid fraction; and   (w) the quantities and temperatures of said first and second reflux streams and the temperatures of said feeds to said first and second distillation columns are effective to maintain the overhead temperatures of said first and second distillation columns at temperatures whereby the major portion of said heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction by fractionation in said first and second distillation columns.   
   
   
       15 . A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components and a gas stream containing methane and heavier hydrocarbon components into a volatile residue gas fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components wherein
 (a) said liquefied natural gas is divided into at least a first liquid stream and a second liquid stream;   (b) said first liquid stream is expanded to a first lower pressure and is thereafter supplied to a first distillation column at an upper mid-column feed position;   (c) said second liquid stream is heated sufficiently to partially vaporize it;   (d) said partially vaporized second liquid stream is separated thereby to provide a first vapor stream and a third liquid stream;   (e) said first vapor stream is expanded to said first lower pressure and thereafter supplied to said first distillation column at a first lower mid-column feed position;   (f) said third liquid stream is expanded to said first lower pressure and thereafter supplied to said first distillation column at a second lower mid-column feed position;   (g) a first overhead distillation stream is withdrawn from an upper region of said first distillation column and compressed to higher pressure;   (h) said compressed first overhead distillation stream is cooled sufficiently to at least partially condense it and form thereby a condensed stream, with said cooling supplying at least a portion of said heating of said second liquid stream;   (i) said condensed stream is divided into at least a volatile liquid stream and a reflux liquid stream;   (j) said reflux liquid stream is further cooled, with said cooling supplying at least a portion of said heating of said second liquid stream;   (k) said further cooled reflux liquid stream is divided into at least a first reflux stream and a second reflux stream;   (l) said first reflux stream is supplied to said first distillation column at a top column feed position;   (m) said gas stream is divided into at least a first gaseous stream and a second gaseous stream;   (n) said first gaseous stream is cooled to condense substantially all of it and is thereafter expanded to a second lower pressure whereby it is further cooled;   (o) said expanded substantially condensed first gaseous stream is thereafter supplied to a second distillation column at an upper mid-column feed position;   (p) said second gaseous stream is expanded to said second lower pressure and is thereafter cooled sufficiently to partially condense it;   (q) said partially condensed expanded second gaseous stream is separated thereby to provide a second vapor stream and a fourth liquid stream;   (r) said second vapor stream is further cooled and thereafter supplied to said second distillation column at a first lower mid-column feed position;   (s) said fourth liquid stream is supplied to said second distillation column at a second lower mid-column feed position;   (t) said second reflux stream is supplied to said second distillation column at a top column feed position;   (u) a second overhead distillation stream is withdrawn from an upper region of said second distillation column;   (v) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said expanded second gaseous stream, and said second vapor stream;   (w) said second overhead distillation stream is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said expanded second gaseous stream, and said second vapor stream;   (x) said vaporized volatile liquid stream and said heated second overhead distillation stream are combined to form said volatile residue gas fraction containing a major portion of said methane;   (y) a first bottom liquid from said first distillation column and a second bottom liquid from said second distillation column are combined to form said relatively less volatile liquid fraction; and   (z) the quantities and temperatures of said first and second reflux streams and the temperatures of said feeds to said first and second distillation columns are effective to maintain the overhead temperatures of said first and second distillation columns at temperatures whereby the major portion of said heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction by fractionation in said first and second distillation columns.   
   
   
       16 . The process according to  claim 12  or  14  wherein
 (a) said second overhead distillation stream is compressed to higher pressure;   (b) said compressed second overhead distillation stream is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream and said expanded second gaseous stream; and   (c) said vaporized volatile liquid stream and said heated compressed second overhead distillation stream are combined to form said volatile residue gas fraction.   
   
   
       17 . The process according to  claim 13  or  15  wherein
 (a) said second overhead distillation stream is compressed to higher pressure;   (b) said compressed second overhead distillation stream is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said expanded second gaseous stream, and said second vapor stream; and   (c) said vaporized volatile liquid stream and said heated compressed second overhead distillation stream are combined to form said volatile residue gas fraction.   
   
   
       18 . The process according to  claim 12  or  14  wherein
 (a) said second gaseous stream is cooled prior to said expansion;   (b) said second overhead distillation stream is compressed to higher pressure;   (c) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said second gaseous stream, and said expanded second gaseous stream;   (d) said compressed second overhead distillation stream is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said second gaseous stream, and said expanded second gaseous stream; and   (e) said vaporized volatile liquid stream and said heated compressed second overhead distillation stream are combined to form said volatile residue gas fraction.   
   
   
       19 . The process according to  claim 13  wherein
 (a) said second gaseous stream is cooled sufficiently to partially condense it;   (b) said partially condensed second gaseous stream is separated thereby to provide said second vapor stream and said third liquid stream;   (c) said second vapor stream is expanded to said second lower pressure, is cooled, and is thereafter supplied to said second distillation column at said first lower mid-column feed position;   (d) said third liquid stream is expanded to said second lower pressure and thereafter supplied to said second distillation column at said second lower mid-column feed position;   (e) said second overhead distillation stream is compressed to higher pressure;   (f) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said second gaseous stream, and said expanded second vapor stream;   (g) said compressed second overhead distillation stream is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said second gaseous stream, and said expanded second vapor stream; and   (h) said vaporized volatile liquid stream and said heated compressed second overhead distillation stream are combined to form said volatile residue gas fraction.   
   
   
       20 . The process according to  claim 15  wherein
 (a) said second gaseous stream is cooled sufficiently to partially condense it;   (b) said partially condensed second gaseous stream is separated thereby to provide said second vapor stream and said fourth liquid stream;   (c) said second vapor stream is expanded to said second lower pressure, is cooled, and is thereafter supplied to said second distillation column at said first lower mid-column feed position;   (d) said fourth liquid stream is expanded to said second lower pressure and thereafter supplied to said second distillation column at said second lower mid-column feed position;   (e) said second overhead distillation stream is compressed to higher pressure;   (f) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said second gaseous stream, and said expanded second vapor stream;   (g) said compressed second overhead distillation stream is heated, with said heating supplying at least a portion of said cooling of one or more of said first gaseous stream, said second gaseous stream, and said expanded second vapor stream; and   (h) said vaporized volatile liquid stream and said heated compressed second overhead distillation stream are combined to form said volatile residue gas fraction.   
   
   
       21 . The process according to  claim 19  wherein
 (a) said gas stream is cooled sufficiently to partially condense it;   (b) said partially condensed gas stream is separated thereby to provide said second vapor stream and said third liquid stream;   (c) said second vapor stream is divided into at least said first gaseous stream and said second gaseous stream;   (d) said second gaseous stream is expanded to said second lower pressure, is cooled, and is thereafter supplied to said second distillation column at said first lower mid-column feed position;   (e) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said gas stream, said first gaseous stream, and said expanded second gaseous stream; and   (f) said compressed second overhead distillation stream is heated, with said heating supplying at least a portion of said cooling of one or more of said gas stream, said first gaseous stream, and said expanded second gaseous stream.   
   
   
       22 . The process according to  claim 20  wherein
 (a) said gas stream is cooled sufficiently to partially condense it;   (b) said partially condensed gas stream is separated thereby to provide said second vapor stream and said fourth liquid stream;   (c) said second vapor stream is divided into at least said first gaseous stream and said second gaseous stream;   (d) said second gaseous stream is expanded to said second lower pressure, is cooled, and is thereafter supplied to said second distillation column at said first lower mid-column feed position;   (e) said volatile liquid stream is heated sufficiently to vaporize it, with said heating supplying at least a portion of said cooling of one or more of said gas stream, said first gaseous stream, and said expanded second gaseous stream; and   (f) said compressed second overhead distillation stream is heated, with said heating supplying at least a portion of said cooling of one or more of said gas stream, said first gaseous stream, and said expanded second gaseous stream.   
   
   
       23 . The process according to  claim 1 ,  2 ,  3 ,  4 ,  8 ,  9 ,  10 , or  11  wherein
 (a) said liquefied natural gas is heated and thereafter divided into at least said first liquid stream and said second liquid stream; and   (b) said cooling of said compressed first portion and said reflux stream supply at least a portion of said heating of said liquefied natural gas.   
   
   
       24 . The process according to  claim 5  wherein
 (a) said liquefied natural gas is heated and thereafter divided into at least said first liquid stream and said second liquid stream; and   (b) said cooling of said compressed first portion and said reflux stream supply at least a portion of said heating of said liquefied natural gas.   
   
   
       25 . The process according to  claim 6  wherein
 (a) said liquefied natural gas is heated and thereafter divided into at least said first liquid stream and said second liquid stream; and   (b) said cooling of said compressed first portion and said reflux stream supply at least a portion of said heating of said liquefied natural gas.   
   
   
       26 . The process according to  claim 7  wherein
 (a) said liquefied natural gas is heated and thereafter divided into at least said first liquid stream and said second liquid stream; and   (b) said cooling of said compressed first portion and said reflux stream supply at least a portion of said heating of said liquefied natural gas.   
   
   
       27 . The process according to  claim 12 ,  13 ,  14 ,  15 ,  19 ,  20 ,  21 , or  22  wherein
 (a) said liquefied natural gas is heated and thereafter divided into at least said first liquid stream and said second liquid stream; and   (b) said cooling of said compressed first overhead distillation stream and said reflux liquid stream supply at least a portion of said heating of said liquefied natural gas.   
   
   
       28 . The process according to  claim 16  wherein
 (a) said liquefied natural gas is heated and thereafter divided into at least said first liquid stream and said second liquid stream; and   (b) said cooling of said compressed first overhead distillation stream and said reflux liquid stream supply at least a portion of said heating of said liquefied natural gas.   
   
   
       29 . The process according to  claim 17  wherein
 (a) said liquefied natural gas is heated and thereafter divided into at least said first liquid stream and said second liquid stream; and   (b) said cooling of said compressed first overhead distillation stream and said reflux liquid stream supply at least a portion of said heating of said liquefied natural gas.   
   
   
       30 . The process according to  claim 18  wherein
 (a) said liquefied natural gas is heated and thereafter divided into at least said first liquid stream and said second liquid stream; and   (b) said cooling of said compressed first overhead distillation stream and said reflux liquid stream supply at least a portion of said heating of said liquefied natural gas.   
   
   
       31 . The process according to  claim 1 ,  2 ,  3 ,  4 ,  8 ,  9 ,  10 ,  11 ,  12 ,  13 ,  14 ,  15 ,  19 ,  20 ,  21 , or  22  wherein said volatile residue gas fraction contains a major portion of said methane and C 2  components. 
   
   
       32 . The process according to  claim 5  wherein said volatile residue gas fraction contains a major portion of said methane and C 2  components. 
   
   
       33 . The process according to  claim 6  wherein said volatile residue gas fraction contains a major portion of said methane and C 2  components. 
   
   
       34 . The process according to  claim 7  wherein said volatile residue gas fraction contains a major portion of said methane and C 2  components. 
   
   
       35 . The process according to  claim 16  wherein said volatile residue gas fraction contains a major portion of said methane and C 2  components 
   
   
       36 . The process according to  claim 17  wherein said volatile residue gas fraction contains a major portion of said methane and C 2  components. 
   
   
       37 . The process according to  claim 18  wherein said volatile residue gas fraction contains a major portion of said methane and C 2  components. 
   
   
       38 . The process according to  claim 23  wherein said volatile residue gas fraction contains a major portion of said methane and C 2  components. 
   
   
       39 . The process according to  claim 24  wherein said volatile residue gas fraction contains a major portion of said methane and C 2  components. 
   
   
       40 . The process according to  claim 25  wherein said volatile residue gas fraction contains a major portion of said methane and C 2  components. 
   
   
       41 . The process according to  claim 26  wherein said volatile residue gas fraction contains a major portion of said methane and C 2  components. 
   
   
       42 . The process according to  claim 27  wherein said volatile residue gas fraction contains a major portion of said methane and C 2  components. 
   
   
       43 . The process according to  claim 28  wherein said volatile residue gas fraction contains a major portion of said methane and C 2  components. 
   
   
       44 . The process according to  claim 29  wherein said volatile residue gas fraction contains a major portion of said methane and C 2  components. 
   
   
       45 . The process according to  claim 30  wherein said volatile residue gas fraction contains a major portion of said methane and C 2  components.