Patent ID: 7947117
Filing Date: 2011-05-24
Classification: C01B

Abstract:
1. A membrane process for the purification of hydrogen contained in a synthesis gas from steam reforming a petroleum fraction or natural gas comprising modifying a two stage water gas shift (WGS) process comprising a high temperature stage and a low temperature stage so as to obtain a synthesis gas containing less than 5000 ppm of CO, said modifying comprising eliminating the low temperature stage and passing the synthesis gas mixture from high-temperature WGS stage, containing more than 5,000 ppm of CO, into a system comprising three membrane separation units (U 1 , U 2 , U 3 ), whereby said membrane process comprises the following stages: The synthesis gas mixture to be processed ( A first permeate ( A first retentate ( A second permeate ( A second retentate ( from the third membrane separation unit, there is extracted: A third retentate ( A third permeate (