Development of Bimodal Catalysts for Jet-fuel Synthesis via Fischer-Tropsch Synthesis

Abstract

Jet fuel synthesis from biomass syngas via Fischer-Tropsch synthesis was firstly conducted using Co/ZrO₂-SiO₂ bimodal catalyst in a slurry-phase reaction process. To break the limitation of classic ASF distribution law, a part of olefin was added into the reaction with the syngas to enhance the selectivity of C₈-C₁₆ selectivity, suppressing the formation rate of lighter hydrocarbons. The employed bimodal catalyst exhibited higher activity and higher selectivity than the uni-modal catalyst. It was clarified that the mesopores of the bimodal catalyst accelerated the mass transfer efficiency because the reactants and products here were heavier than those in conventional slurry-phase Fischer-Tropsch synthesis. Simultaneously, micropores of the bimodal catalyst realized the high dispersion of the supported cobalt particles, tuning the balance between dispersion and reduction degree of the supported cobalt. ZrO₂ acted as not only building blocks for the micropores of the bimodal spatial structure, but also as a promoter for Co/SiO₂ Fischer-Tropsch synthesis catalyst chemically. The comprehensive effect derived from bimodal spatial effect and ZrO₂ promoter effect realized the high activity of the Co/ZrO₂-SiO₂ bimodal catalyst. With the aid of the added 1-decene, new C-C bond formation was initiated and more carbene was connected to 1-decene, resulting in the boosted C₈-C₁₆ selectivity.