Indexed on: 30 Jun '18Published on: 20 Jun '18Published in: Industrial & Engineering Chemistry
Conversion of CO2 by hydrogenation into higher hydrocarbons has attracted much attention due to the continuous increasing concentration of CO2 in the atmosphere. Fe5C2 was used as the active site and mixed with K-modified supports for CO2 hydrogenation to synthesize value-added hydrocarbons. A series of supports were tested, and the alkaline Al2O3 was the best choice for light olefins and C5+ hydrocarbons. The transformation of product selectivity at time on stream demonstrated that potassium migrated into Fe5C2 during reaction. The selectivity of C2+ is 69.2% containing 35.8% C2–C4= and 29.1% C5+ value-added hydrocarbons with the 31.5% CO2 conversion (H2/CO2 = 3). When the ratio of H2 and CO2 was switched to 4, CO2 conversion improved to 40.9%, and the C2+ selectivity to 73.5%, containing 37.3% C2–C4= and 31.1% C5+ value-added hydrocarbons. The mixture catalysts can be directly used without any reduction before reaction, reducing the consumption H2 and simplifying the operation.