Improving the attrition resistance of slurry phase heterogeneous catalysts

Slurry phase heterogeneous catalysts for processes such as Fischer-Tropsch (F-T) synthesis must exhibit a high degree of attrition resistance. The pre cipitated Fe-Cu catalyst used for F-T synthesis is quite weak in its as-pre pared state. Spray-drying yields spherical particles which show some improv ement in attrition resistance. However, the formation of fines (< 5 mu m) i n this powder shows that it is not suitable as a slurry phase catalyst. In this paper, we report on the use of a silica binder to improve the strength of spray-dried agglomerates. The attrition resistance was measured using u ltrasonic fragmentation followed by sedigraph particle size analysis. The a ttrition strength of the iron oxide catalyst agglomerates was compared to t hat of a commercial alumina powder, which was used as a reference material. The role of calcination (before or after spray-drying) and the method of s ilica binder addition (before or after spray-drying) was investigated. (C) 2000 Elsevier Science S.A. All rights reserved.