Abstract: A method for synthesis of ammonia includes compressing a synthesis gas containing hydrogen and nitrogen in a multi-stage (50, 56 and 57) centrifugal compressor. The synthesis gas is compressed to a pressure of from about 800 to 900 psia in the first stage (50) of the compressor, and withdrawn therefrom and subjected to cooling and dehydration by contact with liquid ammonia in a dehydrator (54). The cooled, dehydrated synthesis gas is then returned to the compressor and introduced into the second stage (56) thereof. Because of this interstage cooling and dehydration, compressor speed may be reduced and significant savings in power consumption are attained because of the favorable effect of the dehydrator (54) on the last two stages (56, 57) of the compressor. Additional power saving is realized because refrigeration requirements for the synthesis loop are reduced.

Abstract: A method for synthesis of ammonia includes compressing a synthesis gas containing hydrogen and nitrogen in a multi-stage (50, 56 and 57) centrifugal compressor. The synthesis gas is compressed to a pressure of from about 800 to 900 psia in the first stage (50) of the compressor, and withdrawn therefrom and subjected to cooling and dehydration by contact with liquid ammonia in a dehydrator (54). The cooled, dehydrated synthesis gas is then returned to the compressor and introduced into the second stage (56) thereof. Because of this interstage cooling and dehydration, compressor speed may be reduced and significant savings in power consumption are attained because of the favorable effect of the dehydrator (54) on the last two stages (56, 57) of the compressor. Additional power saving is realized because refrigeration requirements for the synthesis loop are reduced.