Interaction between Weibull parameters and mechanical strength reliability of industrial-scale water gas shift catalysts

Abstract

A fundamental step in the production of an industrial catalyst is its crushing strength assessment. Limited literature exists in which the strength reliability of supported catalysts is investigated from production to their application in a reactor. In this work, cylindrical supports were prepared by pelletizing high porosity γ-alumina powder, and Cu–Zn/γ-Al2O3 catalysts were prepared by impregnation of the pelletized γ-alumina supports with an aqueous solution of copper and zinc nitrates. The support-forming variables, such as binder concentration, compaction pressure, calcination temperature, and drying procedure were investigated. The Weibull method was used to analyze the crushing strength data of the supports, and the fresh and used catalysts before and after the low-temperature water gas shift reaction. Support formation at a 50wt% binder concentration, 1148MPa compaction pressure, 500°C calcination temperature, and rapid drying (100°C, 8h) led to the maximum support mechanical reliability. The most reliable catalyst with respect to simultaneous appropriate catalytic performance and mechanical strength was prepared from a support with the lowest mean crushing strength (26.25MPa). This work illustrates the importance of the Weibull modulus as a useful mechanical reliability index in manufacturing a supported solid catalyst.