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.
