Patent ID: 8741971

Claim:
A method of running a Fischer-Tropsch synthesis, the method comprising the steps of: (a) desulfurizing a raw gas containing carbon oxides from coal gasification and then combining the desulfurized raw gas with an H 2 rich gas obtained downstream to obtain an input gas stream, having an H 2 /CO molar ratio of at least 1.5:1 and feeding the input gas stream to a Fischer-Tropsch synthesizer to produce, by catalytic reactions, hydrocarbons from the input gas; (b) separating out the hydrocarbons as liquid products from the input gas to obtain a CO-containing and CO 2 -containing process gas stream in which the CO content is below 20% and removing the CO-containing and CO 2 -containing process gas stream from the Fischer-Tropsch synthesizer; (c) compressing the CO-containing and CO 2 -containing process gas stream leaving the Fischer-Tropsch synthesizer, feeding the compressed gas to a converter in which the CO in the compressed gas reacts with steam to convert the CO to H 2 and CO 2 in the gas stream and removing said converted gas stream from the converter; (d) carrying out a gas treatment following step (c), to remove the CO 2 and/or constituents other than H 2 from the converted gas stream to obtain an H 2 rich gas stream, and combining the H 2 rich gas stream together with the desulfurized raw gas according to step (a) as the input gas stream fed into the Fischer-Tropsch synthesizer; and (e) diverting a partial stream of the desulfurized raw gas, obtained according to step (a), from the Fischer-Tropsch synthesizer, and prior to step (c), feeding the partial stream of the diverted desulfurized raw gas upstream of the compressor into the recirculated gas stream.