UTILIZING PURGE GAS FROM AMMONIA SYNTHESIS

摘要

The invention provides an improved ammonium synthesis process. A synthesis gas is separated with a membrane into a hydrogen-rich gas and a hydrogen-depleted gas. The hydrogen rich gas is shifted with steam to convert carbon monoxide to carbon dioxide and hydrogen. Carbon dioxide is removed from the shifted gas, and remaining carbon oxides are methanized. This gas is admixed with nitrogen and with recycled ammonia synthesis feedstock gas. This ammonia synthesis feedstock gas is then cycled in an ammonia synthesis reactor. A purge gas stream is withdrawn from the ammonia synthesis feedstock gas and is admixed with the hydrogen-depleted gas. The hydrogen-depleted gas and the purge gas are combusted, usually in a combustion turbine, to generate heat or power. Lower purity hydrogen can therefore be used in the synthesis of the ammonia.