Attrition properties of precipitated iron Fischer-Tropsch catalysts

摘要

While precipitated iron catalysts provide optimal activity and selectivity for Fischer-Tropsch(F-T)Synthesis with coal-derived synthesis gas their attrition resistance under reaction conditions has been questioned.It is well known that iron oxides undergo phase transformations during activation and reaction,leading to changes in volume,which are a primary cause of catalyst break up('chemical attrition').In this paper we report on attrition properties of precipitated Fe catalysts under both inert and reactive conditions in a stirred tank slurry reactor(STSR).Our results show that after 364 h of testing in the STSR,the particle size reduction due to fracture and erosion was moderate.The observed increase in fraction of particles smaller than 10 mum was small(7.8%).Catalytic performance was excellent,yielding low methane and high C5~+selectivities of 2.6 and 82.5%,respectively,at 78.5% single pass conversion.We conclude therefore that iron catalysts used in this study have adequate attrition resistance and desirable F-T activity and selectivity for use in conversion of coal-derived syngas to liquid fuels in the slurry bubble column reactor.