Synthesis of Aromatic-Rich Gasoline-Range Hydrocarbons from Biomass-Derived Syngas over a Pd-Promoted Fe/HZSM-5 Catalyst

The production of aromatic-rich gasoline-range hydrocarbons from wood biomass-derived syngas (biosyngas) was studied by the Fischer-Tropsch synthesis (FTS) over a Pd-promoted Fe/HZSM-5 catalyst. The Pd promoter enhances the catalytic performance of the Fe/HZSM-5 catalyst and promotes the formation of aromatic hydrocarbons. The reaction conditions, i.e., temperature, pressure, and gas hourly space velocity (GHSV), significantly affected the aromatic hydrocarbon selectivity. The higher reaction temperature leads to the higher selectivity toward aromatics in liquid hydrocarbon products. An increase in the reaction pressure also favors the formation of aromatics, but its effect is not as significant as that of the reaction temperature. GHSV has a negative effect on the formation of aromatics because of the short-time contact of the reactant gas with the catalyst. The aromatic hydrocarbon selectivity ranges from 29 to 45%, which is dependent upon the reaction conditions. Aromatic hydrocarbons are mainly composed of xylenes and trimethyl, tetramethyl, and 1,2-dimethyl-3-ethyl benzenes. This study indicates that the Pd-promoted Fe/HZSM-5 catalyst can efficiently convert the biosyngas to aromatic-rich gasoline-range hydrocarbons.