Gas absorption

Claim 1

AN AUTO-REFRIGERATED ABSORPTION PROCESS FOR THE REMOVAL AT SUPER-ATMOSPHERIC PRESSURES OF HYDRATE FORMING ACIDIC GASES CONSISTING PREDOMINANTLY OF CARBON DIOXIDE FROM A CARBON DIOXIDE CONTAINING FEED OF MIXED GASES INCLUDING A DESIRED PRODUCT GAS WHICH COMPRISES: (A) CHILLING THE FEED OF MIXED GASES B INDIRECT HEAT EXCHANGE WITH THE SUBSEQUENTLY SEPARATED ACIDIC-GASFREE PRODUCT GAS AND AT LEAST A PORTION OF THE SUBSEQUENTLY SEPARATED ACIDIC GASES; (B) PASSING SAID CHILLED FEED OF MIXED GASES THROUGH AN ABSORPTION ZONE IN COUNTERCURRENT CONTACT WITH AQUEOUS ACETONE CONTAINING 2 TO 10 WEIGHT PERCENT WATER AT TEMPERATURES OF -20*F. TO 50*F. AND SUPER-ATMOSPHERIC PRESSURE WHEREBY THE MAJOR PORTION OF THE ACIDIC GASES IS ABSORBED IN THE AQUEOUS ACETONE TO GIVE A PRODUCT GAS LOW IN ACIDIC GASES; (C) SEPARATING THE AQUEOUS ACETONE RICH IN ACIDIC GASES FROM THE PRODUCT GAS; (D) REMOVING AND EXPANDING SAID AQUEOUS RICH IN ACIDIC GASES AT SUBSTANTIALLY THE TEMPERATURE IT LEAVES THE ABSORPTION ZONE TO A LOW PRESSURE STRIPPING ZONE; (E) STRIPPING SAID ACIDIC GASES FROM SAID AQUEOUS ACETONE IN THE STIPPING ZONE BY CONTACTING SAME AND VAPORIZING SOME ACETONE WITH A STRIPPING GAS ESSENTIALLY FREE OF ACIDIC GASES TO PRODUCE AQUEOUS ACETONE ESSENTIALLY OF ACIDIC GASES THERBY PROVIDING AUTO-REFRIGERATION BY THE STRIPPING OF THE ACIDIC GASES AND BY VAPORIZATION OF PART OF THE ACETONE; (F) PUMPING THE AQUEOUS ACETONE FROM THE STRIPPING ZONE TO ESSENTIALLY THE PRESSURE OF THE ABSORPTION ZONE AND PASSING SAID AQUEOUS ACETONE AT ESSENTIALLY THE SAME TEMPERATURE AS IT LEAVES THE STRIPPING ZONE TO THE ABSORPTION ZONE; (G) SAID INDIRECT HEAT-EXCHANGE OF STEP (A) HEATING THE SEPARATED ACIDIC-GAS-FREE PRODUCT GAS FROM THE ABSORPTION ZONE AND AT LEAST THE PORTION OF STRIPPED ACIDIC GAS FROM THE STRIPPING ZONE TO ESSENTIALLY AMBIENT TEMPERATURE BY INDIRECT HEAT EXCHANGE WITH THE FEED OF MIXED GASES; (H) RECOVERING ACETONE VAPORS IN THE PRODUCT GAS COMING FROM SAID INDIRECT HEAT EXCHANGE BY SCRUBBING SAID ACID-GAS-FREE PRODUCT GAS WITH WATER TO FORM A WATER ACETONE SOLUTION; (I) RECOVERING ACETONE VAPORS IN THE STRIPPED ACIDIC GASES BY SCRUBBING SAID STRIPPED ACIDIC GASES WITH WATER TO FORM A WATER ACETONE SOLUTION; (J) FRACTIONATING THE WATER-ACETONE SOLUTIONS FROM STEPS (H) AND (I) TO PRODUCE A CONCENTRATED AQUEOUS ACETONE AND WATER; (K) RETURNING THE WATER TO THE WATER SCRUBBING STEPS (H) AND (I) AND RETURNING THE CONCENTRATED AQUEOUS ACETONE TO THE STRIPPING ZONE.