Attrition resistance and catalytic performance of spray-dried iron Fischer-Tropsch catalysts in a stirred-tank slurry reactor

Attrition properties of two spray-dried iron Fischer-Tropsch (F-T) catalysts with compositions 100:5:4.2:11 Fe/Cu/K/(P)SiO2 (catalyst P; P = precipitated) and 100:5:4.2:1.1 Fe/Cu/K/(B)SiO2 (catalyst B; B = binder) were studied under reactive conditions in a stirred-tank slurry reactor (STSR) by determining particle size distribution and morphology before and after reaction tests. Catalyst P experienced a large reduction in Sauter mean diameter (87%) after 380 h of testing in the STSR, which is attributed to its morphology (large number of irregularly shaped particles). Low attrition strength of this catalyst was also evident from considerable generation of fine particles (<10 mum) during the STSR test (62.5% increase in fraction of fines). Catalyst B, consisting of largely spherical particles, experienced a smaller reduction in Sauter mean diameter (39.9%) and generation of fine particles was much smaller (3.7%). These two catalysts had excellent selectivity characteristics (low methane and high C-5(+) yields), but their productivity and stability (deactivation rate) need to be improved.