Liquefied natural gas processing

• US 20060000234A1
• Filed: 06/03/2005
• Published: 01/05/2006
• Est. Priority Date: 07/01/2004
• Status: Active Grant

• Current Assignee: Ortloff Enigneers, Ltd.
• Original Assignee: Ortloff Enigneers, Ltd.
• Inventors: Hudson, Hank M., Cuellar, Kyle T., Wilkinson, John D.
• Granted Patent: US 7,216,507 B2
• Time in Patent Office: Days
• US Class Current: 62/620
• CPC Class Codes: F25J 2200/02 in a single pressure main column system
• CPC Class Codes: F25J 2200/04 in a dual pressure main column system
• CPC Class Codes: F25J 2200/70 Refluxing the column with a condensed part of the feed stream, i.e. fractionator top is stripped or self-rectified
• CPC Class Codes: F25J 2200/72 Refluxing the column with at least a part of the totally condensed overhead gas
• CPC Class Codes: F25J 2200/76 Refluxing the column with condensed overhead gas being cycled in a quasi-closed loop refrigeration cycle
• CPC Class Codes: F25J 2205/04 in the feed line, i.e. upstream of the fractionation step
• CPC Class Codes: F25J 2210/06 Splitting of the feed stream, e.g. for treating or cooling in different ways
• CPC Class Codes: F25J 2230/08 Cold compressor, i.e. suction of the gas at cryogenic temperature and generally without afterstage-cooler
• CPC Class Codes: F25J 2230/60 the fluid being hydrocarbons or a mixture of hydrocarbons
• CPC Class Codes: F25J 2235/60 the fluid being (a mixture of) hydrocarbons
• CPC Class Codes: F25J 2240/02 Expansion of a process fluid in a work-extracting turbine (i.e. isentropic expansion), e.g. of the feed stream
• CPC Class Codes: F25J 2245/02 Recycle of a stream in general, e.g. a by-pass stream
• CPC Class Codes: F25J 3/0214 Liquefied natural gas
• CPC Class Codes: F25J 3/0233 separation of CnHm with 1 carbon atom or more
• CPC Class Codes: F25J 3/0238 separation of CnHm with 2 carbon atoms or more
• CPC Class Codes: F25J 3/0242 separation of CnHm with 3 carbon atoms or more

Abstract

A process and apparatus for the recovery of ethane, ethylene, propane, propylene, and heavier hydrocarbons from a liquefied natural gas (LNG) stream is disclosed. The LNG feed stream is divided into two portions. The first portion is supplied to a fractionation column at an upper mid-column feed point. The second portion is directed in heat exchange relation with a warmer distillation stream rising from the fractionation stages of the column, whereby this portion of the LNG feed stream is partially heated and the distillation stream is totally condensed. The condensed distillation stream is divided into a “lean” LNG product stream and a reflux stream, whereupon the reflux stream is supplied to the column at a top column feed position. The partially heated portion of the LNG feed stream is heated further to partially or totally vaporize it and thereafter supplied to the column at a lower mid-column feed position. 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.

Claims

1. A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid 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 stream and a second stream;

(b) said first stream is expanded to lower pressure and is thereafter supplied to a fractionation column at an upper mid-column feed position;

(c) said second stream is heated sufficiently to partially vaporize it, thereby forming a vapor stream and a liquid stream;

(d) said vapor stream is expanded to said lower pressure and is supplied to said fractionation column at a first lower mid-column feed position;

(e) said liquid stream is expanded to said lower pressure and is supplied to said fractionation column at a second lower mid-column feed position;

(f) a vapor distillation stream is withdrawn from an upper region of said fractionation column and compressed;

(g) said compressed vapor 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 stream;

(h) said condensed stream is divided into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream;

(i) said reflux stream is supplied to said fractionation column at a top column feed position; and

(j) the quantity and temperature of said reflux stream and the temperatures of said feeds to said fractionation column are effective to maintain the overhead temperature of said fractionation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

17. The process according to claim 1 or 3 wherein said reflux stream is further cooled and is thereafter supplied to said fractionation column at said top column feed position, with said cooling supplying at least a portion of said heating of said second stream.

23. The process according to claim 1, 2, 3, or 4 wherein

(a) said reflux stream is further cooled and is thereafter supplied to said fractionation column at said top column feed position;

(b) said first stream is expanded to said lower pressure and is thereafter heated, with said heating supplying at least a portion of said further cooling of said reflux stream; and

(c) said heated expanded first stream is supplied to said fractionation column at said upper mid-column feed position.

53. The process according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 19, 21, or 22 wherein a major portion of said methane and C₂ components is recovered in said volatile liquid fraction and a major portion of C₃ components and heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction.

54. The process according to claim 17 wherein a major portion of said methane and C₂ components is recovered in said volatile liquid fraction and a major portion of C₃ components and heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction.

57. The process according to claim 23 wherein a major portion of said methane and C₂ components is recovered in said volatile liquid fraction and a major portion of C₃ components and heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction.

2. A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid 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 heated and is thereafter divided into at least a first stream and a second stream;

(b) said first stream is expanded to lower pressure and is thereafter supplied to a fractionation column at an upper mid-column feed position;

(c) said second stream is heated sufficiently to partially vaporize it, thereby forming a vapor stream and a liquid stream;

(d) said vapor stream is expanded to said lower pressure and is supplied to said fractionation column at a first lower mid-column feed position;

(e) said liquid stream is expanded to said lower pressure and is supplied to said fractionation column at a second lower mid-column feed position;

(f) a vapor distillation stream is withdrawn from an upper region of said fractionation column and compressed;

(g) said compressed vapor 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 liquefied natural gas;

(h) said condensed stream is divided into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream;

(i) said reflux stream is supplied to said fractionation column at a top column feed position; and

(j) the quantity and temperature of said reflux stream and the temperatures of said feeds to said fractionation column are effective to maintain the overhead temperature of said fractionation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

18. The process according to claim 2, 4, 5, 6, 7, or 8 wherein said reflux stream is further cooled and is thereafter supplied to said fractionation column at said top column feed position, with said cooling supplying at least a portion of said heating of said liquefied natural gas.

55. The process according to claim 18 wherein a major portion of said methane and C₂ components is recovered in said volatile liquid fraction and a major portion of C₃ components and heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction.

3. A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid 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 stream and a second stream;

(b) said first stream is expanded to lower pressure and is thereafter supplied to a fractionation column at an upper mid-column feed position;

(c) said second 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 fractionation column at a lower mid-column feed position;

(e) a vapor distillation stream is withdrawn from an upper region of said fractionation column and compressed;

(f) said compressed vapor 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 stream;

(g) said condensed stream is divided into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream;

(h) said reflux stream is supplied to said fractionation column at a top column feed position; and

(i) the quantity and temperature of said reflux stream and the temperatures of said feeds to said fractionation column are effective to maintain the overhead temperature of said fractionation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

4. A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid 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 heated and is thereafter divided into at least a first stream and a second stream;

(b) said first stream is expanded to lower pressure and is thereafter supplied to a fractionation column at an upper mid-column feed position;

(c) said second 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 fractionation column at a lower mid-column feed position;

(e) a vapor distillation stream is withdrawn from an upper region of said fractionation column and compressed;

(f) said compressed vapor 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 liquefied natural gas;

(g) said condensed stream is divided into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream;

(h) said reflux stream is supplied to said fractionation column at a top column feed position; and

(i) the quantity and temperature of said reflux stream and the temperatures of said feeds to said fractionation column are effective to maintain the overhead temperature of said fractionation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

5. A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid 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 heated sufficiently to partially vaporize it, thereby forming a vapor stream and a liquid stream;

(b) said vapor stream is divided into at least a first stream and a second stream;

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

(d) said expanded cooled first stream is supplied to a fractionation column at an upper mid-column feed position;

(e) said second stream is expanded to said lower pressure and is supplied to said fractionation column at a first lower mid-column feed position;

(f) said liquid stream is expanded to said lower pressure and is supplied to said fractionation column at a second lower mid-column feed position;

(g) a vapor distillation stream is withdrawn from an upper region of said fractionation column and heated, with said heating supplying at least a portion of said cooling of said first stream;

(h) said heated vapor distillation stream is compressed;

(i) said compressed heated vapor 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 liquefied natural gas;

(j) said condensed stream is divided into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream;

(k) said reflux stream is supplied to said fractionation column at a top column feed position; and

(l) the quantity and temperature of said reflux stream and the temperatures of said feeds to said fractionation column are effective to maintain the overhead temperature of said fractionation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

6. A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid 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 heated sufficiently to vaporize it, thereby forming a vapor stream;

(b) said vapor stream is divided into at least a first stream and a second stream;

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

(d) said expanded cooled first stream is supplied to a fractionation column at an upper mid-column feed position;

(e) said second stream is expanded to said lower pressure and is supplied to said fractionation column at a lower mid-column feed position;

(f) a vapor distillation stream is withdrawn from an upper region of said fractionation column and heated, with said heating supplying at least a portion of said cooling of said first stream;

(g) said heated vapor distillation stream is compressed;

(h) said compressed heated vapor 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 liquefied natural gas;

(i) said condensed stream is divided into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream;

(j) said reflux stream is supplied to said fractionation column at a top column feed position; and

(k) the quantity and temperature of said reflux stream and the temperatures of said feeds to said fractionation column are effective to maintain the overhead temperature of said fractionation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

7. A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid 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 heated sufficiently to partially vaporize it, thereby forming a vapor stream and a liquid stream;

(b) said vapor stream is expanded to lower pressure and is thereafter supplied to a fractionation column at a first mid-column feed position;

(c) said liquid stream is expanded to said lower pressure and is supplied to said fractionation column at a second mid-column feed position;

(d) a vapor distillation stream is withdrawn from an upper region of said fractionation column and compressed;

(e) said compressed vapor 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 liquefied natural gas;

(f) said condensed stream is divided into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream;

(g) said reflux stream is supplied to said fractionation column at a top column feed position; and

(h) the quantity and temperature of said reflux stream and the temperatures of said feeds to said fractionation column are effective to maintain the overhead temperature of said fractionation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

8. A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid 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 heated sufficiently to vaporize it, thereby forming a vapor stream;

(b) said vapor stream is expanded to lower pressure and is thereafter supplied to a fractionation column at a mid-column feed position;

(c) a vapor distillation stream is withdrawn from an upper region of said fractionation column and compressed;

(d) said compressed vapor 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 liquefied natural gas;

(e) said condensed stream is divided into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream;

(f) said reflux stream is supplied to said fractionation column at a top column feed position; and

(g) the quantity and temperature of said reflux stream and the temperature of said feed to said fractionation column are effective to maintain the overhead temperature of said fractionation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

9. A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid 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 stream and a second stream;

(b) said first stream is expanded to lower pressure and is thereafter supplied at a first mid-column feed position to an absorber column that produces an overhead vapor stream and a bottom liquid stream;

(c) said second stream is heated sufficiently to at least partially vaporize it;

(d) said heated second stream is expanded to said lower pressure and is supplied to said absorber column at a lower feed position;

(e) said bottom liquid stream is supplied to a fractionation stripper column at a top column feed position;

(f) a vapor distillation stream is withdrawn from an upper region of said fractionation stripper column and cooled to condense substantially all of it, with said cooling supplying at least a portion of said heating of said second stream;

(g) said substantially condensed stream is pumped and is thereafter supplied to said absorber column at a second mid-column feed position;

(h) said overhead vapor 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 stream;

(i) said condensed stream is pumped and is thereafter divided into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream;

(j) said reflux stream is supplied to said absorber column at a top column feed position; and

(k) the quantity and temperature of said reflux stream and the temperatures of said feeds to said absorber column and said fractionation stripper column are effective to maintain the overhead temperatures of said absorber column and said fractionation stripper column at temperatures whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

19. The process according to claim 9 wherein said reflux stream is further cooled and is thereafter supplied to said absorber column at said top column feed position, with said cooling supplying at least a portion of said heating of said second stream.

10. A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid 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 heated and is thereafter divided into at least a first stream and a second stream;

(b) said first stream is expanded to lower pressure and is thereafter supplied at a first mid-column feed position to an absorber column that produces an overhead vapor stream and a bottom liquid stream;

(c) said second stream is heated sufficiently to at least partially vaporize it;

(d) said heated second stream is expanded to said lower pressure and is supplied to said absorber column at a lower feed position;

(e) said bottom liquid stream is supplied to a fractionation stripper column at a top column feed position;

(f) a vapor distillation stream is withdrawn from an upper region of said fractionation stripper column and cooled to condense substantially all of it, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(g) said substantially condensed stream is pumped and is thereafter supplied to said absorber column at a second mid-column feed position;

(h) said overhead vapor 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 liquefied natural gas;

(i) said condensed stream is pumped and is thereafter divided into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream;

(j) said reflux stream is supplied to said absorber column at a top column feed position; and

(k) the quantity and temperature of said reflux stream and the temperatures of said feeds to said absorber column and said fractionation stripper column are effective to maintain the overhead temperatures of said absorber column and said fractionation stripper column at temperatures whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

20. The process according to claim 10, 11, 12, 13, 14, 15, or 16 wherein said reflux stream is further cooled and is thereafter supplied to said absorber column at said top column feed position, with said cooling supplying at least a portion of said heating of said liquefied natural gas.

24. The process according to claim 9 or 10 wherein

(a) said reflux stream is further cooled and is thereafter supplied to said absorber column at said top column feed position;

(b) said first stream is expanded to said lower pressure and is thereafter heated, with said heating supplying at least a portion of said further cooling of said reflux stream; and

(c) said heated expanded first stream is supplied to said absorber column at said first mid-column feed position.

25. The process according to claim 9 or 10 wherein

(a) said reflux stream is further cooled and is thereafter supplied to said absorber column at said top column feed position;

(b) said substantially condensed stream is pumped and is thereafter heated, with said heating supplying at least a portion of said further cooling of said reflux stream; and

(c) said heated pumped substantially condensed stream is supplied to said absorber column at said second mid-column feed position.

56. The process according to claim 20 wherein a major portion of said methane and C₂ components is recovered in said volatile liquid fraction and a major portion of C₃ components and heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction.

58. The process according to claim 24 wherein a major portion of said methane and C₂ components is recovered in said volatile liquid fraction and a major portion of C₃ components and heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction.

59. The process according to claim 25 wherein a major portion of said methane and C₂ components is recovered in said volatile liquid fraction and a major portion of C₃ components and heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction.

11. A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid 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 heated sufficiently to at least partially vaporize it;

(b) said heated liquefied natural gas is expanded to lower pressure and is thereafter supplied at a lower feed position to an absorber column that produces an overhead vapor stream and a bottom liquid stream;

(c) said bottom liquid stream is supplied to a fractionation stripper column at a top column feed position;

(d) a vapor distillation stream is withdrawn from an upper region of said fractionation stripper column and compressed;

(e) said compressed vapor distillation stream is cooled sufficiently to at least partially condense it, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(f) said cooled compressed stream is supplied to said absorber column at a mid-column feed position;

(g) said overhead vapor 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 liquefied natural gas;

(h) said condensed stream is pumped and is thereafter divided into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream;

(i) said reflux stream is supplied to said absorber column at a top column feed position; and

(j) the quantity and temperature of said reflux stream and the temperatures of said feeds to said absorber column and said fractionation stripper column are effective to maintain the overhead temperatures of said absorber column and said fractionation stripper column at temperatures whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

12. A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid 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 heated sufficiently to at least partially vaporize it;

(b) said heated liquefied natural gas is expanded to lower pressure and is thereafter supplied at a lower feed position to an absorber column that produces an overhead vapor stream and a bottom liquid stream;

(c) said bottom liquid stream is supplied to a fractionation stripper column at a top column feed position;

(d) a vapor distillation stream is withdrawn from an upper region of said fractionation stripper column and cooled to condense substantially all of it, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(e) said substantially condensed stream is pumped and is thereafter supplied to said absorber column at a mid-column feed position;

(f) said overhead vapor 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 liquefied natural gas;

(g) said condensed stream is pumped and is thereafter divided into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream;

(h) said reflux stream is supplied to said absorber column at a top column feed position; and

(i) the quantity and temperature of said reflux stream and the temperatures of said feeds to said absorber column and said fractionation stripper column are effective to maintain the overhead temperatures of said absorber column and said fractionation stripper column at temperatures whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

21. The process according to claim 12 wherein said pumped substantially condensed stream is heated and is thereafter supplied to said absorber column at said mid-column feed position, with said heating supplying at least a portion of said cooling of said vapor distillation stream or said overhead vapor stream.

22. The process according to claim 21 wherein said reflux stream is further cooled and is thereafter supplied to said absorber column at said top column feed position, with said cooling supplying at least a portion of said heating of said liquefied natural gas.

13. A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid 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 heated sufficiently to partially vaporize it, thereby forming a vapor stream and a liquid stream;

(b) said vapor stream is expanded to lower pressure and is thereafter supplied at a first lower feed position to an absorber column that produces an overhead vapor stream and a bottom liquid stream;

(c) said liquid stream is expanded to said lower pressure and is supplied to said absorber column at a second lower feed position;

(d) said bottom liquid stream is supplied to a fractionation stripper column at a top column feed position;

(e) a vapor distillation stream is withdrawn from an upper region of said fractionation stripper column and compressed;

(f) said compressed vapor distillation stream is cooled sufficiently to at least partially condense it, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(g) said cooled compressed stream is supplied to said absorber column at a mid-column feed position;

(h) said overhead vapor stream is compressed;

(i) said compressed overhead vapor 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 liquefied natural gas;

(j) said condensed stream is divided into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream;

(k) said reflux stream is supplied to said absorber column at a top column feed position; and

(l) the quantity and temperature of said reflux stream and the temperatures of said feeds to said absorber column and said fractionation stripper column are effective to maintain the overhead temperatures of said absorber column and said fractionation stripper column at temperatures whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

14. A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid 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 heated sufficiently to at least partially vaporize it;

(b) said heated liquefied natural gas is expanded to lower pressure and is thereafter supplied at a lower feed position to an absorber column that produces an overhead vapor stream and a bottom liquid stream;

(c) said bottom liquid stream is supplied to a fractionation stripper column at a top column feed position;

(d) a vapor distillation stream is withdrawn from an upper region of said fractionation stripper column and compressed;

(e) said compressed vapor distillation stream is cooled sufficiently to at least partially condense it, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(f) said cooled compressed stream is supplied to said absorber column at a mid-column feed position;

(g) said overhead vapor stream is compressed;

(h) said compressed overhead vapor 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 liquefied natural gas;

(i) said condensed stream is divided into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream;

(j) said reflux stream is supplied to said absorber column at a top column feed position; and

(k) the quantity and temperature of said reflux stream and the temperatures of said feeds to said absorber column and said fractionation stripper column are effective to maintain the overhead temperatures of said absorber column and said fractionation stripper column at temperatures whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

15. A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid 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 heated sufficiently to partially vaporize it, thereby forming a vapor stream and a liquid stream;

(b) said vapor stream is expanded to lower pressure and is thereafter supplied at a first lower feed position to an absorber column that produces an overhead vapor stream and a bottom liquid stream;

(c) said liquid stream is expanded to said lower pressure and is supplied to said absorber column at a second lower feed position;

(d) said bottom liquid stream is pumped and is thereafter supplied to a fractionation stripper column at a top column feed position;

(e) a vapor distillation stream is withdrawn from an upper region of said fractionation stripper column and cooled sufficiently to at least partially condense it, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(f) said cooled distillation stream is supplied to said absorber column at a mid-column feed position;

(g) said overhead vapor stream is compressed;

(h) said compressed overhead vapor 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 liquefied natural gas;

(i) said condensed stream is divided into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream;

(j) said reflux stream is supplied to said absorber column at a top column feed position; and

(k) the quantity and temperature of said reflux stream and the temperatures of said feeds to said absorber column and said fractionation stripper column are effective to maintain the overhead temperatures of said absorber column and said fractionation stripper column at temperatures whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

16. A process for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid 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 heated sufficiently to at least partially vaporize it;

(b) said heated liquefied natural gas is expanded to lower pressure and is thereafter supplied at a lower feed position to an absorber column that produces an overhead vapor stream and a bottom liquid stream;

(c) said bottom liquid stream is pumped and is thereafter supplied to a fractionation stripper column at a top column feed position;

(d) a vapor distillation stream is withdrawn from an upper region of said fractionation stripper column and cooled sufficiently to at least partially condense it, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(e) said cooled distillation stream is supplied to said absorber column at a mid-column feed position;

(f) said overhead vapor stream is compressed;

(g) said compressed overhead vapor 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 liquefied natural gas;

(h) said condensed stream is divided into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream;

(i) said reflux stream is supplied to said absorber column at a top column feed position; and

(j) the quantity and temperature of said reflux stream and the temperatures of said feeds to said absorber column and said fractionation stripper column are effective to maintain the overhead temperatures of said absorber column and said fractionation stripper column at temperatures whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

26. An apparatus for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components comprising

(a) first dividing means connected to receive said liquefied natural gas and divide it into at least a first stream and a second stream;

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

(c) heat exchange means connected to said first dividing means to receive said second stream and heat it sufficiently to partially vaporize it;

(d) separation means connected to said heat exchange means to receive said heated partially vaporized second stream and separate it into a vapor stream and a liquid stream;

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

(f) third expansion means connected to said separation means to receive said liquid stream and expand it to said lower pressure, said third expansion means being further connected to said fractionation column to supply said expanded liquid stream at a second lower mid-column feed position;

(g) withdrawing means connected to an upper region of said fractionation column to withdraw a vapor distillation stream;

(h) compressing means connected to said withdrawing means to receive said vapor distillation stream and compress it;

(i) said heat exchange means further connected to said compressing means to receive said compressed vapor distillation stream and cool it sufficiently to at least partially condense it and form thereby a condensed steam, with said cooling supplying at least a portion of said heating of said second stream;

(j) second dividing means connected to said heat exchange means to receive said condensed stream and divide it into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream, said second dividing means being further connected to said fractionation column to supply said reflux stream to said fractionation column at a top column feed position; and

(k) control means adapted to regulate the quantity and temperature of said reflux stream and the temperatures of said feed streams to said fractionation column to maintain the overhead temperature of said fractionation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

42. The apparatus according to claim 26 or 28 wherein said heat exchange means is further connected to said second dividing means to receive said reflux stream and further cool it, said heat exchange means being further connected to said fractionation column to supply said further cooled reflux stream at said top column feed position, with said cooling supplying at least a portion of said heating of said second stream.

50. The apparatus according to claim 26, 27, 28, or 29 wherein

(a) a second heat exchange means is connected to said second dividing means to receive said reflux stream and further cool it, said second heat exchange means being further connected to said fractionation column to supply said further cooled reflux stream at said top column feed position;

and

(b) said second heat exchange means is further connected to said first expansion means to receive said expanded first stream and heat it, said second heat exchange means being further connected to said fractionation column to supply said heated expanded first stream at said upper mid-column feed position, with said heating supplying at least a portion of said further cooling of said reflux stream.

60. The apparatus according to claim 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 45, 46, 48, or 49 wherein a major portion of said methane and C₂ components is recovered in said volatile liquid fraction and a major portion of C₃ components and heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction.

61. The apparatus according to claim 42 wherein a major portion of said methane and C₂ components is recovered in said volatile liquid fraction and a major portion of C₃ components and heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction.

65. The apparatus according to claim 50 wherein a major portion of said methane and C₂ components is recovered in said volatile liquid fraction and a major portion of C₃ components and heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction.

27. An apparatus for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components comprising

(a) heat exchange means connected to receive said liquefied natural gas and heat it;

(b) first dividing means connected to said heat exchange means receive said heated liquefied natural gas and divide it into at least a first stream and a second stream;

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

(d) heating means connected to said first dividing means to receive said second stream and heat it sufficiently to partially vaporize it;

(e) separation means connected to said heating means to receive said heated partially vaporized second stream and separate it into a vapor stream and a liquid stream;

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

(g) third expansion means connected to said separation means to receive said liquid stream and expand it to said lower pressure, said third expansion means being further connected to said fractionation column to supply said expanded liquid stream at a second lower mid-column feed position;

(h) withdrawing means connected to an upper region of said fractionation column to withdraw a vapor distillation stream;

(i) compressing means connected to said withdrawing means to receive said vapor distillation stream and compress it;

(j) said heat exchange means further connected to said compressing means to receive said compressed vapor distillation stream and cool it sufficiently to at least partially condense it and form thereby a condensed steam, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(k) second dividing means connected to said heat exchange means to receive said condensed stream and divide it into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream, said second dividing means being further connected to said fractionation column to supply said reflux stream to said fractionation column at a top column feed position; and

(l) control means adapted to regulate the quantity and temperature of said reflux stream and the temperatures of said feed streams to said fractionation column to maintain the overhead temperature of said fractionation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

43. The apparatus according to claim 27, 29, 30, or 31 wherein said heat exchange means is further connected to said second dividing means to receive said reflux stream and further cool it, said heat exchange means being further connected to said fractionation column to supply said further cooled reflux stream at said top column feed position, with said cooling supplying at least a portion of said heating of said liquefied natural gas.

62. The apparatus according to claim 43 wherein a major portion of said methane and C₂ components is recovered in said volatile liquid fraction and a major portion of C₃ components and heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction.

28. An apparatus for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components comprising

(a) first dividing means connected to receive said liquefied natural gas and divide it into at least a first stream and a second stream;

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

(c) heat exchange means connected to said first dividing means to receive said second stream and heat it sufficiently to vaporize it, thereby forming a vapor stream;

(d) second expansion means connected to said heat exchange means to receive said vapor stream and expand it to said lower pressure, said second expansion means being further connected to said fractionation column to supply said expanded vapor stream at a lower mid-column feed position;

(e) withdrawing means connected to an upper region of said fractionation column to withdraw a vapor distillation stream;

(f) compressing means connected to said withdrawing means to receive said vapor distillation stream and compress it;

(g) said heat exchange means further connected to said compressing means to receive said compressed vapor distillation stream and cool it sufficiently to at least partially condense it and form thereby a condensed steam, with said cooling supplying at least a portion of said heating of said second stream;

(h) second dividing means connected to said heat exchange means to receive said condensed stream and divide it into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream, said second dividing means being further connected to said fractionation column to supply said reflux stream to said fractionation column at a top column feed position; and

(i) control means adapted to regulate the quantity and temperature of said reflux stream and the temperatures of said feed streams to said fractionation column to maintain the overhead temperature of said fractionation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

29. An apparatus for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components comprising

(a) heat exchange means connected to receive said liquefied natural gas and heat it;

(b) first dividing means connected to said heat exchange means receive said heated liquefied natural gas and divide it into at least a first stream and a second stream;

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

(d) heating means connected to said first dividing means to receive said second stream and heat it sufficiently to vaporize it, thereby forming a vapor stream;

(e) second expansion means connected to said heating means to receive said vapor stream and expand it to said lower pressure, said second expansion means being further connected to said fractionation column to supply said expanded vapor stream at a lower mid-column feed position;

(f) withdrawing means connected to an upper region of said fractionation column to withdraw a vapor distillation stream;

(g) compressing means connected to said withdrawing means to receive said vapor distillation stream and compress it;

(h) said heat exchange means further connected to said compressing means to receive said compressed vapor distillation stream and cool it sufficiently to at least partially condense it and form thereby a condensed steam, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(i) second dividing means connected to said heat exchange means to receive said condensed stream and divide it into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream, said second dividing means being further connected to said fractionation column to supply said reflux stream to said fractionation column at a top column feed position; and

(j) control means adapted to regulate the quantity and temperature of said reflux stream and the temperatures of said feed streams to said fractionation column to maintain the overhead temperature of said fractionation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

30. An apparatus for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components comprising

(a) first heat exchange means connected to receive said liquefied natural gas and heat it sufficiently to partially vaporize it;

(b) separation means connected to said first heat exchange means to receive said heated partially vaporized stream and separate it into a vapor stream and a liquid stream;

(c) first dividing means connected to said separation means receive said vapor stream and divide it into at least a first stream and a second stream;

(d) second heat exchange means connected to said first dividing means to receive said first stream and to cool it sufficiently to substantially condense it;

(e) first expansion means connected to said second heat exchange means to receive said substantially condensed first stream and expand it to lower pressure, said first expansion means being further connected to a fractionation column to supply said expanded first stream at an upper mid-column feed position;

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

(g) third expansion means connected to said separation means to receive said liquid stream and expand it to said lower pressure, said third expansion means being further connected to said fractionation column to supply said expanded liquid stream at a second lower mid-column feed position;

(h) withdrawing means connected to an upper region of said fractionation column to withdraw a vapor distillation stream;

(i) said second heat exchange means further connected to said withdrawing means to receive said vapor distillation stream and heat it, with said heating supplying at least a portion of said cooling of said first stream;

(j) compressing means connected to said second heat exchange means to receive said heated vapor distillation stream and compress it;

(k) said first heat exchange means further connected to said compressing means to receive said compressed heated vapor distillation stream and cool it sufficiently to at least partially condense it and form thereby a condensed steam, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(l) second dividing means connected to said first heat exchange means to receive said condensed stream and divide it into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream, said second dividing means being further connected to said fractionation column to supply said reflux stream to said fractionation column at a top column feed position; and

(m) control means adapted to regulate the quantity and temperature of said reflux stream and the temperatures of said feed streams to said fractionation column to maintain the overhead temperature of said fractionation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

31. An apparatus for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components comprising

(a) first heat exchange means connected to receive said liquefied natural gas and heat it sufficiently to vaporize it, thereby forming a vapor stream;

(b) first dividing means connected to said first heat exchange means to receive said vapor stream and divide it into at least a first stream and a second stream;

(c) second heat exchange means connected to said first dividing means to receive said first stream and to cool it sufficiently to substantially condense it;

(d) first expansion means connected to said second heat exchange means to receive said substantially condensed first stream and expand it to lower pressure, said first expansion means being further connected to a fractionation column to supply said expanded first stream at an upper mid-column feed position;

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

(f) withdrawing means connected to an upper region of said fractionation column to withdraw a vapor distillation stream;

(g) said second heat exchange means further connected to said withdrawing means to receive said vapor distillation stream and heat it, with said heating supplying at least a portion of said cooling of said first stream;

(h) compressing means connected to said second heat exchange means to receive said heated vapor distillation stream and compress it;

(i) said first heat exchange means further connected to said compressing means to receive said compressed heated vapor distillation stream and cool it sufficiently to at least partially condense it and form thereby a condensed steam, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(j) second dividing means connected to said first heat exchange means to receive said condensed stream and divide it into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream, said second dividing means being further connected to said fractionation column to supply said reflux stream to said fractionation column at a top column feed position; and

(k) control means adapted to regulate the quantity and temperature of said reflux stream and the temperatures of said feed streams to said fractionation column to maintain the overhead temperature of said fractionation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

32. An apparatus for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components comprising

(a) heat exchange means connected to receive said liquefied natural gas and heat it sufficiently to partially vaporize it;

(b) separation means connected to said heat exchange means to receive said heated partially vaporized stream and separate it into a vapor stream and a liquid stream;

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

(d) second expansion means connected to said separation means to receive said liquid stream and expand it to said lower pressure, said second expansion means being further connected to said fractionation column to supply said expanded liquid stream at a second mid-column feed position;

(e) withdrawing means connected to an upper region of said fractionation column to withdraw a vapor distillation stream;

(f) compressing means connected to said withdrawing means to receive said vapor distillation stream and compress it;

(g) said heat exchange means further connected to said compressing means to receive said compressed vapor distillation stream and cool it sufficiently to at least partially condense it and form thereby a condensed steam, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(h) dividing means connected to said heat exchange means to receive said condensed stream and divide it into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream, said dividing means being further connected to said fractionation column to supply said reflux stream to said fractionation column at a top column feed position; and

(i) control means adapted to regulate the quantity and temperature of said reflux stream and the temperatures of said feed streams to said fractionation column to maintain the overhead temperature of said fractionation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

44. The apparatus according to claim 32 or 33 wherein said heat exchange means is further connected to said dividing means to receive said reflux stream and further cool it, said heat exchange means being further connected to said fractionation column to supply said further cooled reflux stream at said top column feed position, with said cooling supplying at least a portion of said heating of said liquefied natural gas.

63. The apparatus according to claim 44 wherein a major portion of said methane and C₂ components is recovered in said volatile liquid fraction and a major portion of C₃ components and heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction.

33. An apparatus for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components comprising

(a) heat exchange means connected to receive said liquefied natural gas and heat it sufficiently to vaporize it, thereby forming a vapor stream;

(b) expansion means connected to said heat exchange means to receive said vapor stream and expand it to lower pressure, said expansion means being further connected to a fractionation column to supply said expanded vapor stream at a mid-column feed position;

(c) withdrawing means connected to an upper region of said fractionation column to withdraw a vapor distillation stream;

(d) compressing means connected to said withdrawing means to receive said vapor distillation stream and compress it;

(e) said heat exchange means further connected to said compressing means to receive said compressed vapor distillation stream and cool it sufficiently to at least partially condense it and form thereby a condensed steam, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(f) dividing means connected to said heat exchange means to receive said condensed stream and divide it into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream, said dividing means being further connected to said fractionation column to supply said reflux stream to said fractionation column at a top column feed position; and

(g) control means adapted to regulate the quantity and temperature of said reflux stream and the temperature of said feed stream to said fractionation column to maintain the overhead temperature of said fractionation column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

34. An apparatus for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components comprising

(a) first dividing means connected to receive said liquefied natural gas and divide it into at least a first stream and a second stream;

(b) first expansion means connected to said first dividing means to receive said first stream and expand it to lower pressure, said first expansion means being further connected to supply said expanded first stream at a first mid-column feed position on an absorber column that produces an overhead vapor stream and a bottom liquid stream;

(c) heat exchange means connected to said first dividing means to receive said second stream and heat it sufficiently to at least partially vaporize it;

(d) second expansion means connected to said heat exchange means to receive said heated second stream and expand it to said lower pressure, said second expansion means being further connected to said absorber column to supply said expanded heated second stream at a lower feed position;

(e) a fractionation stripper column connected to said absorber column to receive said bottom liquid stream at a top column feed position;

(f) first withdrawing means connected to an upper region of said fractionation stripper column to withdraw a vapor distillation stream;

(g) said heat exchange means further connected to said first withdrawing means to receive said vapor distillation stream and cool it to condense substantially all of it, with said cooling supplying at least a portion of said heating of said second stream;

(h) first pumping means connected to said heat exchange means to receive said substantially condensed stream and pump it, said first pumping means being further connected to said absorber column to supply said pumped substantially condensed stream at a second mid-column feed position;

(i) second withdrawing means connected to an upper region of said absorber column to withdraw said overhead vapor stream;

(j) said heat exchange means further connected to said second withdrawing means to receive said overhead vapor stream and cool it sufficiently to at least partially condense it and form thereby a condensed steam, with said cooling supplying at least a portion of said heating of said second stream;

(k) second pumping means connected to said heat exchange means to receive said condensed stream and pump it;

(l) second dividing means connected to said second pumping means to receive said pumped condensed stream and divide it into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream, said second dividing means being further connected to said absorber column to supply said reflux stream to said absorber column at a top column feed position; and

(m) control means adapted to regulate the quantity and temperature of said reflux stream and the temperatures of said feed streams to said absorber column and said fractionation stripper column to maintain the overhead temperatures of said absorber column and said fractionation stripper column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

45. The apparatus according to claim 34 wherein said heat exchange means is further connected to said second dividing means to receive said reflux stream and further cool it, said heat exchange means being further connected to said absorber column to supply said further cooled reflux stream at said top column feed position, with said cooling supplying at least a portion of said heating of said second stream.

51. The apparatus according to claim 34 or 35 wherein

(a) a second heat exchange means is connected to said second dividing means to receive said reflux stream and further cool it, said second heat exchange means being further connected to said absorber column to supply said further cooled reflux stream at said top column feed position;

and

(b) said second heat exchange means is further connected to said first expansion means to receive said expanded first stream and heat it, said second heat exchange means being further connected to said absorber column to supply said heated expanded first stream at said first mid-column feed position, with said heating supplying at least a portion of said further cooling of said reflux stream.

52. The apparatus according to claim 34 or 35 wherein

(a) a second heat exchange means is connected to said second dividing means to receive said reflux stream and further cool it, said second heat exchange means being further connected to said absorber column to supply said further cooled reflux stream at said top column feed position;

and

(b) said second heat exchange means is further connected to said first pumping means to receive said pumped substantially condensed stream and heat it, said second heat exchange means being further connected to said absorber column to supply said heated pumped substantially condensed stream at said second mid-column feed position, with said heating supplying at least a portion of said further cooling of said reflux stream.

66. The apparatus according to claim 51 wherein a major portion of said methane and C₂ components is recovered in said volatile liquid fraction and a major portion of C₃ components and heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction.

67. The apparatus according to claim 52 wherein a major portion of said methane and C₂ components is recovered in said volatile liquid fraction and a major portion of C₃ components and heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction.

35. An apparatus for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components comprising

(a) heat exchange means connected to receive said liquefied natural gas and heat it;

(b) first dividing means connected to said heat exchange means receive said heated liquefied natural gas and divide it into at least a first stream and a second stream;

(c) first expansion means connected to said first dividing means to receive said first stream and expand it to lower pressure, said first expansion means being further connected to supply said expanded first stream at a first mid-column feed position on an absorber column that produces an overhead vapor stream and a bottom liquid stream;

(d) heating means connected to said first dividing means to receive said second stream and heat it sufficiently to at least partially vaporize it;

(e) second expansion means connected to said heating means to receive said heated second stream and expand it to said lower pressure, said second expansion means being further connected to said absorber column to supply said expanded heated second stream at a lower feed position;

(f) a fractionation stripper column connected to said absorber column to receive said bottom liquid stream at a top column feed position;

(g) first withdrawing means connected to an upper region of said fractionation stripper column to withdraw a vapor distillation stream;

(h) said heat exchange means further connected to said first withdrawing means to receive said vapor distillation stream and cool it to condense substantially all of it, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(i) first pumping means connected to said heat exchange means to receive said substantially condensed stream and pump it, said first pumping means being further connected to said absorber column to supply said pumped substantially condensed stream at a second mid-column feed position;

(j) second withdrawing means connected to an upper region of said absorber column to withdraw said overhead vapor stream;

(k) said heat exchange means further connected to said second withdrawing means to receive said overhead vapor stream and cool it sufficiently to at least partially condense it and form thereby a condensed steam, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(l) second pumping means connected to said heat exchange means to receive said condensed stream and pump it;

(m) second dividing means connected to said second pumping means to receive said pumped condensed stream and divide it into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream, said second dividing means being further connected to said absorber column to supply said reflux stream to said absorber column at a top column feed position; and

(n) control means adapted to regulate the quantity and temperature of said reflux stream and the temperatures of said feed streams to said absorber column and said fractionation stripper column to maintain the overhead temperatures of said absorber column and said fractionation stripper column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

46. The apparatus according to claim 35 wherein said heat exchange means is further connected to said second dividing means to receive said reflux stream and further cool it, said heat exchange means being further connected to said absorber column to supply said further cooled reflux stream at said top column feed position, with said cooling supplying at least a portion of said heating of said liquefied natural gas.

36. An apparatus for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components comprising

(a) heat exchange means connected to receive said liquefied natural gas and heat it sufficiently to at least partially vaporize it;

(b) expansion means connected to said heat exchange means to receive said heated liquefied natural gas and expand it to lower pressure, said expansion means being further connected to supply said expanded heated liquefied natural gas at a lower feed position on an absorber column that produces an overhead vapor stream and a bottom liquid stream;

(c) a fractionation stripper column connected to said absorber column to receive said bottom liquid stream at a top column feed position;

(d) first withdrawing means connected to an upper region of said fractionation stripper column to withdraw a vapor distillation stream;

(e) compressing means connect to said first withdrawing means to receive said vapor distillation stream and compress it;

(f) said heat exchange means further connected to said compressing means to receive said compressed vapor distillation stream and cool it sufficiently to at least partially condense it, with said cooling supplying at least a portion of said heating of said liquefied natural gas, said heat exchange means being further connected to said absorber column to supply said cooled compressed stream at a mid-column feed position;

(g) second withdrawing means connected to an upper region of said absorber column to withdraw said overhead vapor stream;

(h) said heat exchange means further connected to said second withdrawing means to receive said overhead vapor stream and cool it sufficiently to at least partially condense it and form thereby a condensed steam, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(i) pumping means connected to said heat exchange means to receive said condensed stream and pump it;

(j) second dividing means connected to said pumping means to receive said pumped condensed stream and divide it into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream, said second dividing means being further connected to said absorber column to supply said reflux stream to said absorber column at a top column feed position; and

(k) control means adapted to regulate the quantity and temperature of said reflux stream and the temperatures of said feed streams to said absorber column and said fractionation stripper column to maintain the overhead temperatures of said absorber column and said fractionation stripper column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

47. The apparatus according to claim 36, 37, 38, 39, 40, or 41 wherein said heat exchange means is further connected to said dividing means to receive said reflux stream and further cool it, said heat exchange means being further connected to said absorber column to supply said further cooled reflux stream at said top column feed position, with said cooling supplying at least a portion of said heating of said liquefied natural gas.

64. The apparatus according to claim 47 wherein a major portion of said methane and C₂ components is recovered in said volatile liquid fraction and a major portion of C₃ components and heavier hydrocarbon components is recovered in said relatively less volatile liquid fraction.

37. An apparatus for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components comprising

(a) heat exchange means connected to receive said liquefied natural gas and heat it sufficiently to at least partially vaporize it;

(b) expansion means connected to said heat exchange means to receive said heated liquefied natural gas and expand it to lower pressure, said expansion means being further connected to supply said expanded heated liquefied natural gas at a lower feed position on an absorber column that produces an overhead vapor stream and a bottom liquid stream;

(c) a fractionation stripper column connected to said absorber column to receive said bottom liquid stream at a top column feed position;

(d) first withdrawing means connected to an upper region of said fractionation stripper column to withdraw a vapor distillation stream;

(e) said heat exchange means further connected to said first withdrawing means to receive said vapor distillation stream and cool it to condense substantially all of it, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(f) first pumping means connected to said heat exchange means to receive said substantially condensed stream and pump it, said first pumping means being further connected to said absorber column to supply said pumped substantially condensed stream at a mid-column feed position;

(g) second withdrawing means connected to an upper region of said absorber column to withdraw said overhead vapor stream;

(h) said heat exchange means further connected to said second withdrawing means to receive said overhead vapor stream and cool it sufficiently to at least partially condense it and form thereby a condensed steam, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(i) second pumping means connected to said heat exchange means to receive said condensed stream and pump it;

(j) dividing means connected to said second pumping means to receive said pumped condensed stream and divide it into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream, said dividing means being further connected to said absorber column to supply said reflux stream to said absorber column at a top column feed position; and

(k) control means adapted to regulate the quantity and temperature of said reflux stream and the temperatures of said feed streams to said absorber column and said fractionation stripper column to maintain the overhead temperatures of said absorber column and said fractionation stripper column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

48. The apparatus according to claim 37 wherein said heat exchange means is further connected to said first pumping means to receive said pumped substantially condensed stream and heat it, said heat exchange means being further connected to said absorber column to supply said heated pumped stream at said mid-column feed position, with said heating supplying at least a portion of said cooling of said vapor distillation stream or said overhead vapor stream.

49. The apparatus according to claim 48 wherein said heat exchange means is further connected to said dividing means to receive said reflux stream and further cool it, said heat exchange means being further connected to said absorber column to supply said further cooled reflux stream at said top column feed position, with said cooling supplying at least a portion of said heating of said liquefied natural gas.

38. An apparatus for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components comprising

(a) heat exchange means connected to receive said liquefied natural gas and heat it sufficiently to partially vaporize it;

(b) separation means connected to said heat exchange means to receive said heated partially vaporized stream and separate it into a vapor stream and a liquid stream;

(c) first expansion means connected to said separation means to receive said vapor stream and expand it to lower pressure, said first expansion means being further connected to supply said expanded vapor stream at a first lower feed position on an absorber column that produces an overhead vapor stream and a bottom liquid stream;

(d) second expansion means connected to said separation means to receive said liquid stream and expand it to said lower pressure, said second expansion means being further connected to said absorber column to supply said expanded liquid stream at a second lower feed position;

(e) a fractionation stripper column connected to said absorber column to receive said bottom liquid stream at a top column feed position;

(f) first withdrawing means connected to an upper region of said fractionation stripper column to withdraw a vapor distillation stream;

(g) first compressing means connect to said first withdrawing means to receive said vapor distillation stream and compress it;

(h) said heat exchange means further connected to said first compressing means to receive said compressed vapor distillation stream and cool it sufficiently to at least partially condense it, with said cooling supplying at least a portion of said heating of said liquefied natural gas, said heat exchange means being further connected to said absorber column to supply said cooled compressed stream at a mid-column feed position;

(i) second withdrawing means connected to an upper region of said absorber column to withdraw said overhead vapor stream;

(j) second compressing means connect to said second withdrawing means to receive said overhead vapor stream and compress it;

(k) said heat exchange means further connected to said second compressing means to receive said compressed overhead vapor stream and cool it sufficiently to at least partially condense it and form thereby a condensed steam, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(l) dividing means connected to said heat exchange means to receive said condensed stream and divide it into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream, said dividing means being further connected to said absorber column to supply said reflux stream to said absorber column at a top column feed position; and

(m) control means adapted to regulate the quantity and temperature of said reflux stream and the temperatures of said feed streams to said absorber column and said fractionation stripper column to maintain the overhead temperatures of said absorber column and said fractionation stripper column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

39. An apparatus for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components comprising

(a) heat exchange means connected to receive said liquefied natural gas and heat it sufficiently to at least partially vaporize it;

(b) expansion means connected to said heat exchange means to receive said heated liquefied natural gas and expand it to lower pressure, said expansion means being further connected to supply said expanded heated liquefied natural gas at a lower feed position on an absorber column that produces an overhead vapor stream and a bottom liquid stream;

(c) a fractionation stripper column connected to said absorber column to receive said bottom liquid stream at a top column feed position;

(d) first withdrawing means connected to an upper region of said fractionation stripper column to withdraw a vapor distillation stream;

(e) first compressing means connect to said first withdrawing means to receive said vapor distillation stream and compress it;

(f) said heat exchange means further connected to said first compressing means to receive said compressed vapor distillation stream and cool it sufficiently to at least partially condense it, with said cooling supplying at least a portion of said heating of said liquefied natural gas, said heat exchange means being further connected to said absorber column to supply said cooled compressed stream at a mid-column feed position;

(g) second withdrawing means connected to an upper region of said absorber column to withdraw said overhead vapor stream;

(h) second compressing means connect to said second withdrawing means to receive said overhead vapor stream and compress it;

(i) said heat exchange means further connected to said second compressing means to receive said compressed overhead vapor stream and cool it sufficiently to at least partially condense it and form thereby a condensed steam, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(j) dividing means connected to said heat exchange means to receive said condensed stream and divide it into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream, said dividing means being further connected to said absorber column to supply said reflux stream to said absorber column at a top column feed position; and

(k) control means adapted to regulate the quantity and temperature of said reflux stream and the temperatures of said feed streams to said absorber column and said fractionation stripper column to maintain the overhead temperatures of said absorber column and said fractionation stripper column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

40. An apparatus for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components comprising

(a) heat exchange means connected to receive said liquefied natural gas and heat it sufficiently to partially vaporize it;

(b) separation means connected to said heat exchange means to receive said heated partially vaporized stream and separate it into a vapor stream and a liquid stream;

(c) first expansion means connected to said separation means to receive said vapor stream and expand it to lower pressure, said first expansion means being further connected to supply said expanded vapor stream at a first lower feed position on an absorber column that produces an overhead vapor stream and a bottom liquid stream;

(d) second expansion means connected to said separation means to receive said liquid stream and expand it to said lower pressure, said second expansion means being further connected to said absorber column to supply said expanded liquid stream at a second lower feed position;

(e) pumping means connected to said absorber column to receive said bottom liquid stream and pump it;

(f) a fractionation stripper column connected to said pumping means to receive said pumped bottom liquid stream at a top column feed position;

(g) first withdrawing means connected to an upper region of said fractionation stripper column to withdraw a vapor distillation stream;

(h) said heat exchange means further connected to said first withdrawing means to receive said vapor distillation stream and cool it sufficiently to at least partially condense it, with said cooling supplying at least a portion of said heating of said liquefied natural gas, said heat exchange means being further connected to said absorber column to supply said cooled distillation stream at a mid-column feed position;

(i) second withdrawing means connected to an upper region of said absorber column to withdraw said overhead vapor stream;

(j) compressing means connect to said second withdrawing means to receive said overhead vapor stream and compress it;

(k) said heat exchange means further connected to said compressing means to receive said compressed overhead vapor stream and cool it sufficiently to at least partially condense it and form thereby a condensed steam, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(l) dividing means connected to said heat exchange means to receive said condensed stream and divide it into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream, said dividing means being further connected to said absorber column to supply said reflux stream to said absorber column at a top column feed position; and

(m) control means adapted to regulate the quantity and temperature of said reflux stream and the temperatures of said feed streams to said absorber column and said fractionation stripper column to maintain the overhead temperatures of said absorber column and said fractionation stripper column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

41. An apparatus for the separation of liquefied natural gas containing methane and heavier hydrocarbon components into a volatile liquid fraction containing a major portion of said methane and a relatively less volatile liquid fraction containing a major portion of said heavier hydrocarbon components comprising

(a) heat exchange means connected to receive said liquefied natural gas and heat it sufficiently to at least partially vaporize it;

(b) expansion means connected to said heat exchange means to receive said heated liquefied natural gas and expand it to lower pressure, said expansion means being further connected to supply said expanded heated liquefied natural gas at a lower feed position on an absorber column that produces an overhead vapor stream and a bottom liquid stream;

(c) pumping means connected to said absorber column to receive said bottom liquid stream and pump it;

(d) a fractionation stripper column connected to said pumping means to receive said pumped bottom liquid stream at a top column feed position;

(e) first withdrawing means connected to an upper region of said fractionation stripper column to withdraw a vapor distillation stream;

(f) said heat exchange means further connected to said first withdrawing means to receive said vapor distillation stream and cool it sufficiently to at least partially condense it, with said cooling supplying at least a portion of said heating of said liquefied natural gas, said heat exchange means being further connected to said absorber column to supply said cooled distillation stream at a mid-column feed position;

(g) second withdrawing means connected to an upper region of said absorber column to withdraw said overhead vapor stream;

(h) compressing means connect to said second withdrawing means to receive said overhead vapor stream and compress it;

(i) said heat exchange means further connected to said compressing means to receive said compressed overhead vapor stream and cool it sufficiently to at least partially condense it and form thereby a condensed steam, with said cooling supplying at least a portion of said heating of said liquefied natural gas;

(j) dividing means connected to said heat exchange means to receive said condensed stream and divide it into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream, said dividing means being further connected to said absorber column to supply said reflux stream to said absorber column at a top column feed position; and

(k) control means adapted to regulate the quantity and temperature of said reflux stream and the temperatures of said feed streams to said absorber column and said fractionation stripper column to maintain the overhead temperatures of said absorber column and said fractionation stripper column at a temperature whereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.