Exploring the Influence of Zeolite Textural Properties on the Production of Sustainable Fuels Through Fischer-Tropsch Process

Abstract

The isolated impact of the textural properties of hierarchical zeolites on the one-step Fischer-Tropsch (FT) reaction selectivity was studied. Hierarchical ZSM-5 zeolites with different pore size distributions (PSD) and similar acid properties were successfully prepared evidenced by PXRD, 27Al MAS NMR, N2 physisorption, TEM, TPD NH3 and FTIV. Physical mixtures comprising the zeolites, Co/Al2O3 and Pt/Al2O3 were used for testing. The Mixtures containing Pt/Al2O3 evidenced a decrease on the olefin content of the final products. The addition of zeolite to the mixture increased the CH4 and C2-4 selectivity and a decrease in CO2 selectivity. The hierarchical zeolites increased the selectivity towards liquid products and isomers while decreasing the consecutive cracking. The highest isomer content was obtained with the physical mixture containing the hierarchical zeolite with higher mesopore average size (60 nm) and narrow PSD, suggesting a correlation between the PSD and the isomer content of the final products.

Keywords: Fischer-Tropsch Reaction, ZSM-5 zeolite, Desilication, Bifunctional Catalyst, Pore Size Distribution