Process for purifying gases and synthesis of ammonia therefrom

Claim 1

IN A PROCESS FOR FRACTIONATING A GASEOUS MIXTURE CONTAINING A NORMALLY GASEOUS ACIDIC IMPURITY INCLUDING THE STEPS OF REMOVING THE ACIDIC IMPURITY FROM THE GASEOUS MIXTURE AND SEPARATING THE GASEOUS MIXTURE INTO AT LEAST TWO FRACTIONS BY A FRACTIONATING PROCESS WHICH CANNOT TOLERATE THE ACIDIC IMPURITY, THE IMPROVEMENT IN REMOVING THE ACIDIC IMPURITY FROM THE GASEOUS MIXTURE COMPRISING THE STEPS OF PASSING THE GASEOUS MIXTURE INTO A FIRST ABSORPTION ZONE, ABSORBING THE ACIDIC IMPURITY BY CONTACTING THE GASEOUS MIXTURE WITH A FRESH AQUEOUS AMMONIA SOLUTION IN THE FIRST ABSORPTION ZONE, THE GASEOUS MIXTURE BEING CONTACTED WITH A VOLUME OF FRESH AMMONIA SOLUTION IN EXCESS OF THE THEORETICAL MINIMUM REQUIRED TO ABSORB THE ACIDIC IMPURITY, REMOVING SPENT AQUEOUS AMMONIA SOLUTION TOGETHER WITH THE ABSORBED ACIDIC IMPURITY FROM THE FIRST ABSORPTION ZONE, REMOVING A NORMALLY GASEOUS ACIDIC IMPURITY FROM WATER CONTAINING THE SAME AND REDUCING THE TEMPERATURE OF THE WATER BY STRIPPING THE WATER WITH A DRY GASEOUS STRIPPING AGENT FREE OF THE NORMALLY GASEOUS ACIDIC IMPURITY, THE DRY GASEOUS STRIPPING AGENT CONSISTING ESSENTIALLY OF AT LEAST ONE FRACTION SEPARATED FROM THE GASEOUS MIXTURE IN THE FRACTIONATING PROCESS, THE QUANTITY OF DRY GASEOUS STRIPPING AGENT USED IN STRIPPING THE WATER BEING GREATER THAN THE THEORETICAL MINIMUM REQUIRED TO REMOVE THE ACIDIC IMPURITY, CONTENT AND SUCH AS TO MATERIALLY REDUCE THE TEMPERATURE, PASSING GASEOUS EFFLUENT SUBSTANTIALLY FREE OF ACIDIC IMPURITY AND CONTAINING ENTRAINED AMMONIA FROM THE FIRST ABSORPTION ZONE INTO A SECOND ABSORPTION ZONE, ABSORBING THE AMMONIA BY CONTACTING THE GASEOUS EFFLUENT IN THE SECOND ABSORPTION ZONE WITH THE WATER STRIPPED GREE OF THE ACIDIC IMPURITY, THE GASEOUS EFFLUENT BEING CONTACTED WITH AN EXCESS OF WATER OVER THE THEORETICAL MINIMUM REQUIRED TO ABSORB THE AMMONIA CONTENT, REMOVING WATER TOGETHER WITH ABSORBED AMMONIA FROM THE SECOND ABSORPTION ZONE, AND WITHDRAWING A GASEOUS EFFLUENT SUBSTANTIALLY FREE OF THE ACIDIC IMPURITY AND AMMONIA FROM THE SECOND ABSORPTION ZONE.