Bifunctional cobalt catalyst for the synthesis of waxy diesel fuel by the Fischer–Tropsch method – from development to introduction. Part 2. Optimization of the catalyst component composition

Abstract

The effect exerted by the content of metallic (Co-Al2O3/SiO2 catalyst) and acidic (ZSM-5 zeolite in the H-form) components on the properties of bifunctional catalyst for the integrated synthesis of waxy diesel fuel by the Fischer–Tropsch method was studied. Catalysts represented by a composite mixture with a boehmite binder were characterized by XRD, BET and TPR methods. The testing was performed in a flow reactor with a fixed catalyst bed at a pressure of 2.0 MPa, temperature 240 °С and gas hourly space velocity 1000 h–1. Activity and selectivity of the catalysts as well as the fractional and hydrocarbon composition of the products were investigated in dependence on the ratio of components. It was found that productivity of the synthesis for С5+ hydrocarbons and selectivity for the С11–С18 diesel fraction products with a high content of isomeric products correlated with the ratio of metallic and acidic components in the catalysts. The composition of the catalyst recommended for the diesel fuel production has the 1.17 ratio of metallic and acidic components.