Abstract 1,069,331. Cold separation of gas mixtures. CONCH INTERNATIONAL METHANE Ltd. Feb. 19, 1965, No. 7300/65. Heading F4P. Separation of compressed natural gaseous methane containing 15% nitrogen into substantially pure product liquid methane withdrawn through a line (12), product gaseous methane containing about 15% nitrogen withdrawn through a line (16), and gaseous nitrogen containing about 35% methane withdrawn through a line (20) for use as fuel gas is effected by cooling compressed feed gas in an exchanger (J), expanding in a turbine (E), flashing into a vessel (R), withdrawing flash vapour through a line (7), condensing it in an ethylene vaporizer (K) and passing to a separating column (Q), withdrawing condensate from vessel (R) mixing it at (10) with bottom liquid from column (Q) cooling in vaporizer (K) and flashing in series arranged vessels (V, T, S) connected to said product lines (12, 16); the fuel gas line (20) being connected to the overhead line (18) of column (Q). Liquid ethylene is supplied to vaporizer (K) from a flash vessel (X) which in turn is supplied by compressors (D, F) discharging through a line (22), a heat exchanger (L) cooled by separated gaseous products and by vapour from (K and X) which vapours are returned through a line (26) to the inlet of compressor (D). The reflux condenser (N) of column (Q) is cooled by liquid methane withdrawn from a flash vessel (Y) supplied by a compressor (B) through a line (28), heat exchanger (L), vaporizer (K) and a heat exchanger (M) and the flash vapour is returned through lines (31, 32) to the compressor inlet.
PROCESS FOR OBTAINING A LIQUEFIED PRODUCT AN A GASEOUS PRODUCTS FROM A GASEOUS FEED MIXTURE FROM WHICH HAVE BEEN REMOVED THE IMPURITIES OF WATER AND ACID TO PROVIDE AN IMPURITY FREE FEED STREAM ESSENTIALLY OF A COMBUSTIBLE HIGHER BOILING POINT COMPONENT AND A LOWER BOILING POINT COMPONENT, SAID LIQUIEFIED PRODUCT COMPRISING SUBSTANTIALLY ONLY HIGHER BOILING COMPONENT, SAID GASEOUS PRODUCT HAVING A SPECIFIED PROPORTION OF THE LOWER BOILING COMPONENT; SAID PROCESS COMPRISING THE STEPS OF (A) COLLING THE IMPURITY FREE FEED STREAM AT HIGH PRESSURE TO SUB-AMBIENT TEMPERATURE, (B) EXPANDING THE COOLED FEED STREAM IN AN EXPANSION MACHINE, (C) FLASHING EXPANDED GAS FROM STEP (B) INTO A FEED STREAM FLASH VESSEL, (D) CONDENSING THE FLASH VAPORS FROM THE FEED STREAM FLASH VESSEL BY INDIRECT HEAT EXCHANGE WITH A BOILING REFRIGERANT, (E) FEEDING SAID CONDENSED VAPORS TO A DISTILLATION COLUMN TO PRODUCE A TOP GAS AND A BOTTOM PRODUCT,
Claim 2
Dependent Claim
147 words
PROCESS FOR OBTAINING A LIQUEFIED PRODUCT AN A GASEOUS PRODUCTS FROM A GASEOUS FEED MIXTURE FROM WHICH HAVE BEEN REMOVED THE IMPURITIES OF WATER AND ACID TO PROVIDE AN IMPURITY FREE FEED STREAM ESSENTIALLY OF A COMBUSTIBLE HIGHER BOILING POINT COMPONENT AND A LOWER BOILING POINT COMPONENT, SAID LIQUIEFIED PRODUCT COMPRISING SUBSTANTIALLY ONLY HIGHER BOILING COMPONENT, SAID GASEOUS PRODUCT HAVING A SPECIFIED PROPORTION OF THE LOWER BOILING COMPONENT; SAID PROCESS COMPRISING THE STEPS OF (A) COLLING THE IMPURITY FREE FEED STREAM AT HIGH PRESSURE TO SUB-AMBIENT TEMPERATURE, (B) EXPANDING THE COOLED FEED STREAM IN AN EXPANSION MACHINE, (C) FLASHING EXPANDED GAS FROM STEP (B) INTO A FEED STREAM FLASH VESSEL, (D) CONDENSING THE FLASH VAPORS FROM THE FEED STREAM FLASH VESSEL BY INDIRECT HEAT EXCHANGE WITH A BOILING REFRIGERANT, (E) FEEDING SAID CONDENSED VAPORS TO A DISTILLATION COLUMN TO PRODUCE A TOP GAS AND A BOTTOM PRODUCT,