Effect of K-promoter Use in Iron-Based Plasma-Catalytic Conversion of CO2 and CH4 into Higher Value Products

In the new field of plasma-catalytic synthesis, iron-based catalysts have been intensively studied but no study was reported on the use of potassium promoter although it is widely used in thermo-catalytic synthesis. In this frame, we study the effect of K-promoter on iron-based plasma-catalytic conversion of CO2 and CH4 into higher value products, through a series of experiments with and without potassium. As expected, K-promoter increases the selectivity of unsaturated hydrocarbons but also that of long-chain oxygenates (C-3 + acids and alcohols), by changing the H-adsorption property of the catalyst. Based on this selectivity tuning way, this paper proposes a first process optimization attempt for maximizing at the same time the production of liquid products and the share of unsaturated hydrocarbons. Coproduction of high quality syngas (H-2/CO similar to 2.0), C-2 + hydrocarbons and C-1 + oxygenates with 5.10% CO2 and 12.65% CH4 conversions, 21.76% liquid selectivity and unsaturated over saturated hydrocarbons ratio close to 1.