Liquefied natural gas processing

• US 7,631,516 B2
• Filed: 05/16/2007
• Issued: 12/15/2009
• Est. Priority Date: 06/02/2006
• Status: Active Grant

• Current Assignee: UOP Llc (Honeywell International Inc.)
• Original Assignee: Ortloff Enigneers, Ltd.
• Inventors: Hudson, Hank M., Cuellar, Kyle T., Wilkinson, John D.
• Primary Examiner(s): DOERRLER, WILLIAM CHARLES
• Application Number:
  US11/749,268
• Publication Number:
  US 20080000265A1
• Time in Patent Office: 944 Days
• Field of Search: 626/20, 626/30, 626/28
• US Class Current: 62/620
• CPC Class Codes: F25J 2200/02 in a single pressure main column system
• 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 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: H04W 28/10 Flow control between communication endpoints

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 vaporized 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 vaporized portion of the LNG feed stream is separated into vapor and liquid streams which are thereafter supplied to the column at lower mid-column feed positions. 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 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 supplied to said fractionation column at a first lower mid-column feed position;

(e) said liquid stream is pumped to higher pressure and heated and is thereafter 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 cooled sufficiently to at least partially condense it, forming 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.

9. The process according to claim 1 wherein

said vapor stream is compressed to higher pressure, whereupon said compressed vapor stream is thereafter supplied to said fractionation column at said first lower mid-column feed position.

17. The process according to claim 1, 3, 5, 7, 9, 11, 13, or 15 wherein said reflux stream is further cooled and is thereafter supplied to said fractionation column a said top column feed position, with said cooling supplying at least a portion of said heating of said second stream.

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 divided into at least a first stream and a second stream;

(b) said first stream is heated 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 supplied to said fractionation column at a first lower mid-column feed position;

(e) said liquid stream is pumped higher pressure and heated and is thereafter 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 cooled sufficiently to at least partially condense it, forming thereby a condensed stream, with said cooling supplying at least a portion of said heating of said first stream and 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.

10. The process according to claim 2 wherein

said vapor stream is compressed to higher pressure, whereupon said compressed vapor stream is thereafter supplied to said fractionation column at said first lower mid-column feed position.

18. The process according to claim 2, 4, 6, 8, 10, 12, 14, or 16 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 first stream and said second stream.

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 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 divided into at least a first vapor stream and a second vapor stream;

(e) said first vapor stream is supplied to said fractionation column at a first lower mid-column feed position;

(f) said liquid stream is heated and is thereafter 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 combined with said second vapor stream to form a combined vapor stream;

(h) said combined vapor stream is cooled sufficiently to at least partially condense it, forming thereby a condensed stream, with said cooling supplying at least a portion of said heating of said second stream;

(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 fractionating 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.

11. The process according to claim 3 wherein

(a) said vapor stream is compressed to higher pressure, whereupon said compressed vapor stream is thereafter divided into at least said first vapor stream and said second vapor stream;

and

(b) said liquid stream is pumped to higher pressure and heated, whereupon said heated pumped liquid stream is thereafter supplied to said fractionation column at said second lower mid-column feed position.

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 divided into at least a first stream and a second stream;

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

(e) said first vapor stream is supplied to said fractionation column at a first lower mid-column feed position;

(f) said liquid stream is heated and is thereafter 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 combined with said second vapor stream to form a combined vapor stream;

(h) said combined vapor stream is cooled sufficiently to at least partially condense it, forming thereby a condensed stream, with said cooling supplying at least a portion of said heating of said first stream and said second stream;

(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.

12. The process according to claim 4 wherein

(a) said vapor stream is compressed to higher pressure, whereupon said compressed vapor stream is thereafter divided into at least said first vapor stream and said second vapor stream;

and

(b) said liquid stream is pumped to higher pressure and heated, whereupon said heated pumped liquid stream is thereafter supplied to said fraction column at said second lower mid-column feed position.

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 divided into at least a first stream and a second stream;

(b) said first stream is 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) sad liquid stream is heated and is thereafter 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 combined with said vapor stream to form a combined vapor stream;

(f) said combined vapor stream is cooled sufficiently to at least partially condense it, forming 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.

13. The process according to claim 5 wherein

(a) said vapor stream is compressed to higher pressure, whereupon said compressed vapor stream is combined with said vapor distillation stream to form said combined vapor stream;

and

(b) said liquid stream is pumped to higher pressure and heated, whereupon said heated pumped liquid stream is thereafter supplied to said fractionation column at said lower mid-column feed position.

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 divided into at least a first stream and a second stream;

(b) said first stream is heated 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 liquid stream is heated and is thereafter 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 combined with said vapor stream to form a combined vapor stream;

(f) said combined vapor stream is cooled sufficiently to at least partially condense it, forming thereby a condensed stream, with said cooling supplying at least a portion of said heating of said first stream and 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.

14. The process according to claim 6 wherein

(a) said vapor stream is compressed to higher pressure, whereupon said compressed vapor stream is combined with said vapor distillation stream to form said combined vapor stream;

and

(b) said liquid stream is pumped to higher pressure and heated, whereupon said heated pumped liquid stream is thereafter supplied to said fractionation column at said lower mid-column feed position.

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 divided into at least a first stream and a second stream;

(b) said first stream is 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 first vapor stream and a first liquid stream;

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

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

(f) said second liquid stream is expanded to said tower 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 combined with said first vapor stream to form a combined vapor stream;

(h) said combined vapor stream is compressed to higher pressure and is thereafter cooled sufficiently to at least partially condense it, forming thereby a condensed stream, with said cooling supplying at least a portion of said heating of said second stream;

(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.

15. The process according to claim 7 wherein said first liquid stream is pumped to higher pressure and thereafter heated sufficiently to at least partially vaporize it, thereby forming said second vapor stream and said second liquid stream.

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 divided into at least a first stream and a second stream;

(b) said first stream is heated 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 first vapor stream and a first liquid stream;

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

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

(f) said second 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 combined with said first vapor stream to form a combined vapor stream;

(h) said combined vapor stream is compressed to higher pressure and is thereafter cooled sufficiently to at least partially condense it, forming thereby a condensed stream, with said cooling supplying at least a portion of said heating of said first stream and said second stream;

(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.

16. The process according to claim 8 wherein said first liquid stream is pumped to higher pressure and thereafter heated sufficiently to at least partially vaporize it, thereby forming said second vapor stream and said second liquid stream.

19. apparatus for the separation or 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) said first dividing means further connected to a fractionation column to supply said 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) said separation means further connected to said fractionation column to supply said vapor stream at a first lower mid-column feed position;

(f) pumping means connected to said separation means to receive said liquid stream and pump it to higher pressure;

(g) heating means connected to said pumping means to receive said pumped liquid stream and heat it, said heating means being further connected to said fractionation column to supply said heated 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 heat exchange means further connected to said withdrawing means to receive said 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.

27. The apparatus according to claim 19 wherein

a compressing means is connected to said separation means to receive said vapor stream and compress it to higher pressure, said compressing means being further connected to said fractionation column to supply said compressed vapor stream at said first lower mid-column feed position.

35. The apparatus according to claim 19, 23, 25, 27, 31, or 33 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.

20. 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 second stream;

(b) heat exchange means connected to said first dividing means receive said first stream and heat it;

(c) said heat exchange means further connected to a fractionation column to supply said heated first stream at an upper mid-column feed position;

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

(f) said separation means further connected to said fractionation column to supply said vapor stream at a first lower mid-column feed position;

(g) pumping means connected to said separation means to receive said liquid stream and pump it to higher pressure;

(h) heating means connected to said pumping means to receive said liquid stream and heat it, said heating means being further connected to said fractionation column to supply said pumped heated liquid stream at a second lower mid-column feed position;

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

(j) said heat exchange means further connected to said withdrawing means to receive said 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 first stream and said second stream;

(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 hereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

28. The apparatus according to claim 20 wherein

a compressing means is connected to said separation means to receive said vapor stream and compress it to higher pressure, said compressing means being further connected to said fractionation column to supply said compressed vapor stream at said first lower mid-column feed position.

37. The apparatus according to claim 20, 24, 26, 28, 32, or 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 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 first stream and said second stream.

21. 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) said first dividing means further connected to a fractionation column to supply said 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 stream heated partially vaporized second stream and separate it into a vapor stream and a liquid stream;

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

(f) said second dividing means further connected to said fractionation column to supply said first vapor stream at a first lower mid-column feed position;

(g) heating means connected to said separation means to receive said liquid stream and heat it, said heating means being her connected to said fractionation column to supply said heated 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) combining means connected to said withdrawing means and said second dividing means to receive said vapor distillation stream and said second vapor stream and form a combined vapor stream;

(j) said heat exchange means further connected to said combining means to receive said combined 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) third 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 third 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.

29. The apparatus according to claim 21 wherein

(a) a compressing means is connected to said separation means to receive said vapor stream and compress it to higher pressure;

(b) said second dividing means is connected to said compressing means to receive said compressed vapor stream and divide it into at least said first vapor stream and said second vapor stream;

(c) a pumping means is connected to said separation means to receive said liquid stream and pump it to higher pressure; and

(d) said heating means is connected to said pumping means to receive said pumped liquid stream, said heating means being adapted to heat said pumped liquid stream and thereafter supply said heated pumped liquid stream at said second lower mid-column feed position.

36. The apparatus according to claim 21 or 29 wherein said heat exchange means is further connected to said third dividing means to receive said reflux stream and further cool it, said heat exchange means being further connected to said fractionation column to supply 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.

22. 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) heat exchange means connected to said first dividing means receive said first stream and heat it;

(c) said heat exchange means further connected to a fractionation column to supply said heated first stream at an upper mid-column feed position

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

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

(g) said second dividing means further connected to said fractionation column to supply said first vapor stream at a first lower mid-column feed position;

(h) heating means connected to said separation means to receive said liquid stream and heat it, said heating means being further connected to said fractionation column to supply said heated liquid stream at a second lower mid-column feed position;

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

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

(k) said heat exchange means further connected to said combining means to receive said combined 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 first stream and said second stream;

(l) third dividing means connected to said heat exchange means to receive said condensed stream and dividing it into at least said volatile liquid fraction containing a major portion of said methane and a reflux stream, said third dividing means being further connected to said fractionation column to column 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.

30. The apparatus according to claim 22 wherein

(a) a compressing means is connected to said separation means to receive said vapor stream and compress it to higher pressure;

(b) said second dividing means is connected to said compressing means to receive said compressed vapor stream and divide it into at least said first vapor stream and said second vapor stream;

(c) a pumping means is connected to said separation means to receive said liquid stream and pump it to higher pressure; and

(d) said heating means is connected to said pumping means to receive said pumped liquid stream, said heating means being adapted to heat said pumped liquid stream and thereafter supply said heated pumped liquid stream at said second lower mid-column feed position

38. The apparatus according to claim 22 or 30 wherein said heat exchange means is further connected to said third 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 first stream and said second stream.

23. 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) said first dividing means further connected to a fractionation column to supply said 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) heating means connected to said separation means to receive said liquid steam and heat it, said heating means being a further connected to said fractionation column to supply said heated liquid 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) combining means connected to said withdrawing means and said separation means to receive said vapor distillation stream and said vapor stream and form a combined vapor stream;

(h) said heat exchange means further connected to said combining means to receive said combined 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;

(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.

31. The apparatus according to claim 23 wherein

(a) a compressing means is connected to said separation means to receive said vapor stream and compress it to higher pressure, said compressing means being further connected to said combining means to supply said compressed vapor stream to said combining means and combine it with sad vapor distillation stream to form said combined vapor stream;

(b) pumping means is connected to said separation means to receive said liquid stream and pump it to higher pressure; and

(c) said heating means is connected to said pumping means to receive said pumped liquid stream, said heating means being adapted to heat said pumped liquid stream and thereafter supply said heated pumped liquid stream at said lower mid-column feed position.

24. 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 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) heat exchange means connected to said first dividing means receive said first stream and heat it;

(c) said heat exchange means further connected to a fractionation column to supply said heated first stream at an upper mid-column feed position;

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

(f) heating means connected to said separation means to receive said liquid stream and heat it, said heating means being further connected to said fractionation column to supply said heated liquid stream at a lower mid-column feed position;

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

(h) combining means connected to said withdrawing means and said separation means to receive said vapor distillation stream and said vapor stream and form a combined vapor stream;

(i) said heat exchange means further connected to said combining means to receive said combined 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 first stream and 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.

32. The apparatus according to claim 24 wherein

(a) a compressing means is connected to said separation means to receive said vapor stream and compress it to higher pressure, said compressing means being further connected to said combining means to supply said compressed vapor stream to said combining means and combine it with said vapor distillation stream to form said combined vapor stream;

(b) a pumping means is connected to said separation means to receive said liquid stream and pump it to higher pressure; and

(c) said heating means is connected to said pumping means to receive said pumped liquid stream, said heating means being adapted to heat said pumped liquid stream and thereafter supply said heated pumped liquid stream at said lower mid-column feed position.

25. 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) said first dividing means further connected to a fractionation column to supply said 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) first separation means connected to said heat exchange means to receive said heated partially vaporized second stream and separate it into a first vapor stream and a first liquid stream;

(e) heating means connected to said first separation means to receive said first liquid stream and heat it sufficiently to at least partially vaporize it;

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

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

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

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

(j) combining means connected to said withdrawing means and said first separation means to receive said vapor distillation stream and said first vapor stream and form a combined vapor stream;

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

(l) said heat exchange means further connected to said compressing means to receive said compressed combined 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;

(m) 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

(n) 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 hereby the major portion of said heavier hydrocarbon components is recovered by fractionation in said relatively less volatile liquid fraction.

33. The apparatus according to claim 25 wherein

(a) a pumping means is connected to said first separation means to receive said first liquid stream and pump it to higher pressure;

and

(b) said heating means is connected to said pumping means to receive said pumped first liquid stream, said heating means being adapted to heat said pumped first liquid stream sufficiently to at least partially vaporized it, forming thereby said at least partially vaporized heated stream.

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) heat exchange means connected to said first dividing means receive said first stream and heat it;

(c) said heat exchange means further connected to a fractionation column to supply said heated first stream at an upper mid-column feed position;

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

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

(f) heating means connected to said first separation means to receive said first liquid stream and heat it sufficiently to at least partially vaporize it;

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

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

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

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

(k) combining means connected to said withdrawing means and said first separation means to receive said vapor distillation stream and said first vapor stream and form a combined vapor stream;

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

(m) said heat exchange means further connected to said compressing means to receive said compressed combined 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 first stream and said second stream;

(n) 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

(o) 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.

34. The apparatus according to claim 26 wherein

(a) a pumping means is connected to said first separation means to receive said first liquid stream and pump it to higher pressure;

and

(b) said heating means is connected to said pumping means to receive said pumped first liquid stream, said heating means being adapted to heat said pumped first liquid stream sufficiently to at least partially vaporize it, forming thereby said at least partially vaporized heated stream.