Process and plant for production of carbon monoxide and hydrogen

摘要

A process and plant for the combined production of carbon monoxide and an ammonia synthesis from a feed gas mixture containing essentially hydrogen, carbon monoxide and other constituents including methane. The process comprises subjecting the feed gas mixture at high pressure to partial condensation through a heat exchanger followed by separation to produce an impure hydrogen flow and a condensed fraction rich in carbon monoxide. The carbon monoxide is cryogenically purified from the condensed fraction by separation and removal of dissolved hydrogen. The hydrogen is sent to a washing column, and is then cryogenically purified by washing with nitrogen in the washing column while drawing off a liquid fraction rich in carbon monoxide at the base of the washing column. An ammonia synthesis mixture is produced by adding a nitrogen supplement taken from a high-pressure nitrogen stream, and from the hydrogen flow produced at the head of the washing column.