Catalyst development for selective conversion of syngas to mainly aromatic hydrocarbons

The paper describes the following catalytic systems tested in the Fischer-Tropsch reaction and characterized by XPS, TEM, and CO chemisorption: (i) Fe/Mn oxides impregnated with Co, Cu, Pd, Rh and K, respectively, (ii) Co/Mn oxide catalysts with different compositions to maximize the formation of olefinic products. The impregnation of Fe/Mn oxides with Cu and a Co/Mn ratio of 1:4 led to the most promising catalysts. (iii) Rh/SiO2 catalysts doped with rare earth compounds and ThO2 to maximize the formation of oxygenates (iv) Mixtures of the catalysts (i), (ii), or (iii) with pentasil zeolites to form aromatic hydrocarbons. Two modes of operation were tested, namely a single-bed reactor with a mechanical mixture of the components, and a dual-bed operation with the FT component and the zeolite, respectively, in separate reactors. The optimal zeolite for the formation of the aromatics from propene was determined. A knowledge-based expert system for catalyst selection was developed.