POISONING OF IRON CATALYST BY COS IN SYNGAS FOR FISCHER-TROPSCH SYNTHESIS

As a part of converting coal to liquid fuels, the poisoning of commerc ial Fe-Cu-K catalyst in Fischer-Tropsch (FT) synthesis by carbonyl sul fide in synthesis gas was tested. Reduced coprecipitated Fe-Cu-K catal yst was investigated with synthesis gas containing 73.2, 184, 232.4, a nd 350.8 mg of sulfur as COS per cubic meter at 524 K under 2.31 MPa, with an hourly space velocity of 1854. The catalyst activity decreased rapidly in the first few hours of poisoning process, and finally decr eased linearly with amount of sulfur fed to the catalyst until the rel ative activity was 0.01 to 0.05. The deactivation rates were different with the content of sulfur in synthesis gas. The selectivity to metha ne and gaseous C-2-C-4 hydrocarbons increased when the catalyst was po isoned by COS. The weight content of C-5(+) in product decreased signi ficantly with increasing sulfur fed to catalyst. The water-gas shift r eaction in FT synthesis was also discussed in this work.