Efficient Fischer-Tropsch to light olefins over iron-based catalyst with low methane selectivity and high olefin/paraffin ratio

Biomass, biogas, and other carbon-based matters can be processed to generate syngas, which may be catalytically converted to useful hydrocarbons through Fischer-Tropsch reactions. A series of Fe/K catalysts were synthesized using high temperature treated supports with different ratios of zinc aluminate spinel to alumina and were examined by XRD, ICP, FESEM, CO2-TPD, nitrogen physisorption, and syngas conversion tests. At a total pressure of 2 MPa (≈ 20 bar) and a CO conversion of 38.3%, the C2, C3 and C4 olefin/paraffin ratios of catalyst 15%Fe/2%K2O/83%(ZnAl2O4·1Al2O3) exhibit impressive values of 9.8, 17.7 and 13.0, respectively. Meanwhile, its C2=-C4= HC selectivity reaches a considerable value of 52.1%, where its C2, C3 and C4 olefin fractions attain ultra-high values of 90.7%, 94.7%, and 92.9%, respectively. Its methane HC selectivity is also successfully restrained to be lower than 9% even at the highest CO conversion.