Patent ID: 8877155

Claim:
A method for producing hydrogen from an off-gas originating from a gas to liquid (GTL) process, the method comprising the steps of: providing an off-gas stream originating from a gas to liquid (GTL) process, the off-gas stream comprising hydrogen, nitrogen, argon, carbon monoxide, and hydrocarbons; introducing the off-gas stream to a cryogenic unit having a cryogenic distillation column under separation conditions sufficient to affect separation of light ends and heavy ends, the light ends comprising H2, N2, Ar and CO, the heavy ends comprising hydrocarbons; withdrawing the light ends from the cryogenic distillation column and introducing the light ends in the presence of steam to a first CO shift reactor under conditions operable to produce a first shift stream, wherein the first shift stream comprises an increased amount of H2 and CO2 as compared to the light ends; introducing the first shift stream to a first pressure swing absorber (PSA) to produce a first hydrogen product stream and a first tail gas, the first tail gas comprising CO2; withdrawing the heavy ends from the cryogenic distillation column and introducing the heavy ends in the presence of steam to a steam methane reformer (SMR) under conditions operable to reform the hydrocarbons to produce a reformed stream, wherein the reformed stream comprises an increased amount of H2 and CO as compared to the heavy ends; introducing the reformed stream to a second CO shift reactor under conditions operable to produce a second shift stream, wherein the second shift stream comprises an increased amount of H2 and CO2 as compared to the reformed stream; and introducing the second shift stream to a second pressure swing absorber (PSA) to produce a second hydrogen product stream and a second tail gas, the second tail gas comprising CO2 and unreacted hydrocarbons.