Abstract 1,056,013. Liquefaction of methane. CONCH INTERNATIONAL METHANE Ltd. May 7, 1965 [July 15, 1964], No. 19329/65. Heading F4P. Compressed natural methane is passed from a feed line 1 through heat exchangers 2, 3 cooled by an external evaporating refrigerant, e.g. propane circulated by compressors 8, 18, and the so-cooled compressed feed gas is further cooled and condensed by heat exchange at 22, 23, 24 with a wholly gaseous refrigerant which has been compressed at 37, 38, 39, 41 cooled by heat exchange at 13, 21 with a portion of the evaporating propane and expanded at turbines 47, 48. As described the wholly gaseous refrigerant comprising methane withdrawn from a product storage vessel 31 at ambient pressure through a line 34 leading to the inlet of compressor 37 where it is joined by methane gas withdrawn from a flash vessel 28 through a line 30 and by expanded methane from tubine 48 after traversing exchangers 22, 23, 24.
METHOD OF LIQUEFYING A GAS COMPRISING (A) SUPPLYING THE GAS IN A MAIN FEED STREAM AT HIGH PRESSURE EXCEDING 300 P.S.I.A. AND SUBSTANTIALLY AMBIENT TEMPERATURE, (B) PROVIDING A SEPARATE LIQUID PROPANE EVAPORATING REFRIGERANT IN A VAPOR COMPRESSION CYCLE, (C) DIVIDING THE LIQUID REFREGERANT IN PARALLEL PATHS, (D) COOLING THE FEED GAS BY HEAT EXCHANGE WITH A THROTTLED SEPARATE EVAPORATING REFRIGERANT FROM ONE OF THE PATHS WHILE MAINTAINING THE FEED GAS AT ITS HIGH PRESSURE, (E) FURTHER COOLING AND CONDENSING THE FEED GAS AT SAID HIGH PRESSURE BY HEAT EXCHANGE WITH A SECOND REFRIGERANT IN A RECIRCULATING GAS EXPANSION CYCLE WHEREIN SAID SECOND REFRIGERANT IS COMPRESSED AS A GAS, COOLED TO SUBSTANTIALLY AMBIENT TEMPERATURE AS A GAS, EXPANDED TO A LOW TEMPERATUER AS A GAS, AND HEAT EXCHANGED WITH THE FEED GAS, (F) PRE-COOLING SAID SECOND REFRIGERANT AFTER ITS COMPRESSION AND PRIOR TO ITS EXPANSION BY HEAT EX-
Claim 2
Dependent Claim
147 words
METHOD OF LIQUEFYING A GAS COMPRISING (A) SUPPLYING THE GAS IN A MAIN FEED STREAM AT HIGH PRESSURE EXCEDING 300 P.S.I.A. AND SUBSTANTIALLY AMBIENT TEMPERATURE, (B) PROVIDING A SEPARATE LIQUID PROPANE EVAPORATING REFRIGERANT IN A VAPOR COMPRESSION CYCLE, (C) DIVIDING THE LIQUID REFREGERANT IN PARALLEL PATHS, (D) COOLING THE FEED GAS BY HEAT EXCHANGE WITH A THROTTLED SEPARATE EVAPORATING REFRIGERANT FROM ONE OF THE PATHS WHILE MAINTAINING THE FEED GAS AT ITS HIGH PRESSURE, (E) FURTHER COOLING AND CONDENSING THE FEED GAS AT SAID HIGH PRESSURE BY HEAT EXCHANGE WITH A SECOND REFRIGERANT IN A RECIRCULATING GAS EXPANSION CYCLE WHEREIN SAID SECOND REFRIGERANT IS COMPRESSED AS A GAS, COOLED TO SUBSTANTIALLY AMBIENT TEMPERATURE AS A GAS, EXPANDED TO A LOW TEMPERATUER AS A GAS, AND HEAT EXCHANGED WITH THE FEED GAS, (F) PRE-COOLING SAID SECOND REFRIGERANT AFTER ITS COMPRESSION AND PRIOR TO ITS EXPANSION BY HEAT EX-