GB1057302A - Improvements in or relating to methods for carrying out exothermic catalytic high pressure gas synthesis - Google Patents

Abstract

In an exothermic catalytic high pressure gas synthesis of ammonia, a stream of reaction gas is passed through a first catalyst bed section in gas synthesis contact with the catalyst, through a second catalyst bed section out of gas synthesis contact with the bed and in indirect heat exchange with a liquid coolant, back through the second catalyst bed section still out of gas synthesis contact with the catalyst, and finally through the second catalyst bed section in gas synthesis contact with the catalyst. In Fig. 1, <PICT:1057302/C1/1> synthesis gases leaving the upper catalyst layer 2 flow through the annular space between pipe 4 and gas-liquid heat exchanger tubes 6, upwardly through tubes 8 which pass through the lower catalyst layer 5, downwardly through catalyst layer 5, and out at 11. In the embodiment of Fig. 2 (not shown), the tubes 8 pass into the upper catalyst layer and are then encased in tubes 13 closed at their upper ends, so that the gases are redirected to flow downwardly through the annular spaces between tubes 8 and 13 and enter the lower catalyst bed. The gases leaving at 11 may be passed into a third catalyst layer 12 in heat-exchange with the initial gas mixture. Alternatively, the third catalyst layer may be omitted.