Hydrocarbons synthesis from a simulated biosyngas feed over FE/SIO 2 catalysts

Abstract

The Fischer Tropsch reaction, using a simulated gas mixture similar to that obtained from biomass transformation (biosyngas), was studied over Fe/SiO 2 catalysts. The reaction was carried out in a stainless steel fixed bed reactor at 300 °C and 1 MPa. Excess solvent impregnation was used to prepare the catalysts. Nitrogen adsorption at -196 °C, thermal programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) were used as characterization methods. The highest CO conversion was obtained for the catalyst with Fe-loading of 15wt% whereas it decreased at higher Fe loadings. The decrease of the activity is explained in terms of the drop of the active sites due to the formation of large Fe metallic aggregates. The Fe/SiO2 catalysts presented a wide distribution of liquid hydrocarbons (C6 to C18+) and high methane formation. The liquid product distribution was related to the average size of iron particles. The increase of iron particle size favours the formation of hydrocarbons centred in C11-14 chain length. © 2010.