| 摘要 |
1,011,453. Gas liquefaction process. CONCH INTERNATIONAL METHANE Ltd. July 10, 1964 [Jan. 23, 1964], No. 3017/64. Heading F4P. A process for the production of natural gas at a pressure below well head pressure and for the production of liquefied gas at a still lower pressure comprises isentropically expanding at a turbine 44 a first portion 8 of well head gas, passing the so cooled gas in indirect heat exchange at 17 with a second portion 9 of well head gas and feeding it into a distribution line 18, further cooling the said second portion of well head gas at 23, isentropically expanding it at a turbine 25, further cooling the cold expanded gas at 27 and isenthalpically expanding it at a valve 29 to produce flash gas and liquefied gas in a vessel 30 from which product liquefied gas is withdrawn by a pump 31 for storage in a vessel 33 whilst flash gas is withdrawn from vessel 30, used to cool exchangers 23, 27 after which it is compressed at 37 and passed to the distribution line 18. The first portion of well head gas is freed of methane hydrate in a separator 11 and the second portion is dried by passage through alternating molecular sieves 19, 19a which are regenerated by bleeding substantially pure methane from the compressor 37, heating at 40 and delivering it through a line 42 for use as fuel gas. The carbon dioxide content of the well head gas collects as a slurry in flash vessel 30 and is removed from the liquefied product by a centrifugal separator 32. In a modification, gas leaving turbine 25 is freed of nitrogen by absorption. |
