Selective CO Hydrogenation Over Bimetallic Co-Fe Catalysts for the Production of Light Paraffin Hydrocarbons (C₂–C₄): Effect of Space Velocity, Reaction Pressure and Temperature

Abstract

Synthetic natural gas (SNG) using syngas from coal and biomass has attracted much attention as a potential substitute for fossil fuels because of environmental advantages. However, heating value of SNG is below the standard heating value for power generation (especially in South Korea and Japan). In this study, bimetallic Co-Fe catalyst was developed for the production of light paraffin hydrocarbons (C2−C4 as well as CH4) for usage as mixing gases to improve the heating value of SNG. The catalytic performance was monitored by varying space velocity, reaction pressure and temperature. The CO conversion increases with decrease in space velocities, and with an increase in reaction pressure and temperature. CH4 yield increases and C2+ yield decreases with increasing reaction temperature at all reaction pressure and space velocities. In addition, improved CH4 yield at higher reaction pressure (20 bar) implies that higher reaction pressure is a favorable condition for secondary CO2 methanation reaction. The bimetallic Co-Fe catalyst showed the best results with 99.7% CO conversion, 36.1% C2−C4 yield and 0.90 paraffin ratio at H2/CO of 3.0, space velocity of 4000 mL/g/h, reaction pressure of 20 bar, and temperature of 350 °C.

Keywords

• Synthetic natural gas (SNG)
• Cobalt
• Iron
• Fischer-Tropsch synthesis
• C₂–C₄ hydrocarbons
• paraffin ratio