Patent ID: 6589303
Filing Date: 2003-07-08
Classification: B01D,C01B,Y02C,Y02P,Y10S

Abstract:
A hydrogen-production process, comprising the following steps:(a) providing a gas stream containing at least a C1-C4 hydrocarbon, a C5-C8 hydrocarbon and hydrogen; (b) passing the gas stream across the feed side of a polymeric membrane having a feed side and a permeate side, the membrane being selective in favor of the C1-C4 hydrocarbon and the C5-C8 hydrocarbon over hydrogen, under conditions such that a driving force for transmembrane permeation is provided by a pressure difference between the feed and permeate sides; (c) withdrawing from the permeate side a hydrocarbon stream enriched in the C1-C4 hydrocarbon and the C5-C8 hydrocarbon and depleted in hydrogen compared with the gas stream; (d) withdrawing from the feed side a residue stream enriched in hydrogen compared with the gas stream; (e) feeding the hydrocarbon stream to a steam reformer and there reacting the C1-C4 hydrocarbon and the C5-C8 hydrocarbon with steam to form a synthesis gas product stream; (f) passing the synthesis gas product stream and the residue stream through a pressure swing adsorption system thereby selectively adsorbing hydrocarbons and rejecting hydrogen; (g) withdrawing a purified hydrogen product stream from the pressure swing adsorption system; (h) withdrawing a waste gas stream from the pressure swing adsorption system.