Attrition studies with precipitated iron Fischer–Tropsch catalysts under reaction conditions

Abstract

Iron Fischer–Tropsch (F–T) catalyst particles break-up during reaction in slurry phase reactors by physical attrition, and due to chemical stresses caused by phase transformations. Although “chemical” attrition is known to be important with iron (Fe) F–T catalysts, there have been no studies of attrition properties of precipitated Fe catalysts under reaction conditions. Here we report on attrition properties of three precipitated Fe catalysts (100 Fe/3–5 Cu/4–6 K/16–25 SiO2) during F–T synthesis in a stirred tank slurry reactor (STSR). Our results show that after 295–497 h of F–T synthesis with these three catalysts in the STSR, the particle size reduction by fracture was moderate, whereas erosion (generation of particles smaller than 10 μm) was small (2.3–2.7). The attrition strength of these catalysts is adequate for use in Slurry bubble column reactors (SBCRs) for F–T synthesis.