The present invention provides for a process for producing carbon
monoxide. A feed gas stream of hydrogen, carbon monoxide and carbon
dioxide is directed to a membrane unit which separates the feed gas
stream into two streams. The stream containing carbon monoxide is
directed to second membrane unit for further purification and the steam
containing the carbon dioxide and hydrogen is fed to a reverse shift
reactor to produce more carbon monoxide. The carbon monoxide recovered
from the reverse shift reactor is purified in a third membrane unit and
directed back to the first membrane unit and is further purified and
recovered as additional carbon monoxide product.