Anhydrous ammonia scrubbing of ammonia synthesis gas

Claim 1

A METHOD FOR THE PURIFICATION AND COMPRESSION OF AMMONIA SYNTHESIS GAS WHICH COMPRISES SCRUBBING SYNTHESIS GAS WITH SUBSTANTIALLY ANDYDROUS LIQUID AMMONIA AT A PRESSURE IN THE RANGE OF 2 KG./SQ. CM. TO 100 KG./SQ. CM., SAID SYNTHESIS GAS INITIALLY CONSISTING PRINCIPALLY OF A NITROGEN-HYDROGEN MIXTURE AND CONTAINING MINOR RESIDUAL AMOUNTS OF IMPURITIES INCLUDING CARBON DIOXIDE AND WATER VAPOR, WHEREBY SAID SYNTHESIS GAS IS COOLED TO A TEMPERATURE IN THE RANGE OF -10*C. TO -50*C. AND SUBSTANTIALLY SATURATED WITH AMMONIA VAPOR, AND A MAJOR PORTION OF SAID IMPURITIES INCLUDING SUBSTANTIALLY ALL OF SAID WATER VAPOR IS DISSOLVED IN SAID ANHYDROUS LIQUID AMMONIA, COMPRESSING THE COOLED SYNTHESIS GAS, COOLING THE RESULTING COMPRESSED SYNTHESIS GAS TO A TEMPERATURE BELOW 0*C., WHEREBY A PORTION OF SAID AMMONIA VAPOR IS CONDENSED TO ANHYDROUS LIQUID AMMONIA CONTAINING DISSOLVED IMPURITIES DERIVED FROM SAID SYNTHESIS GAS, SEPARATING SAID CONDENSED ANHYDROUS LIQUID AMMONIA FROM THE RESULTING SUBSTANTIALLY IMPURITY-FREE SYNTHESIS GAS, AND PASSING SAID SUBSTANTIALLY IMPURITY-FREE SYNTHESIS GAS TO AMMONIA SYNTHESIS.

Claim 2

A METHOD FOR THE PURIFICATION AND COMPRESSION OF AMMONIA SYNTHESIS GAS WHICH COMPRISES SCRUBBING SYNTHESIS GAS WITH SUBSTANTIALLY ANDYDROUS LIQUID AMMONIA AT A PRESSURE IN THE RANGE OF 2 KG./SQ. CM. TO 100 KG./SQ. CM., SAID SYNTHESIS GAS INITIALLY CONSISTING PRINCIPALLY OF A NITROGEN-HYDROGEN MIXTURE AND CONTAINING MINOR RESIDUAL AMOUNTS OF IMPURITIES INCLUDING CARBON DIOXIDE AND WATER VAPOR, WHEREBY SAID SYNTHESIS GAS IS COOLED TO A TEMPERATURE IN THE RANGE OF -10*C. TO -50*C. AND SUBSTANTIALLY SATURATED WITH AMMONIA VAPOR, AND A MAJOR PORTION OF SAID IMPURITIES INCLUDING SUBSTANTIALLY ALL OF SAID WATER VAPOR IS DISSOLVED IN SAID ANHYDROUS LIQUID AMMONIA, COMPRESSING THE COOLED SYNTHESIS GAS, COOLING THE RESULTING COMPRESSED SYNTHESIS GAS TO A TEMPERATURE BELOW 0*C., WHEREBY A PORTION OF SAID AMMONIA VAPOR IS CONDENSED TO ANHYDROUS LIQUID AMMONIA CONTAINING DISSOLVED IMPURITIES DERIVED FROM SAID SYNTHESIS GAS, SEPARATING SAID CONDENSED ANHYDROUS LIQUID AMMONIA FROM THE RESULTING SUBSTANTIALLY IMPURITY-FREE SYNTHESIS GAS, AND PASSING SAID SUBSTANTIALLY IMPURITY-FREE SYNTHESIS GAS TO AMMONIA SYNTHESIS.