Catalytic conversion of carbon dioxide and coal/biomass pyrolysis byproduct (char) to carbon monoxide and hydrogen

The intent of this study was to convert CO2 and char to useful products CO and H2. High surface area coal and biomass chars impregnated with sodium carbonate (Na2CO3) were studied independently in a fixed bed reactor varying catalyst loading between 0 and 5 wt% Na2CO3 and temperatures 800-1,000 °C to determine the optimum conditions for conversion of CO2 to CO (CO2+C→ 2CO), and also H2 in the presence of H2O (H2O+C→CO+H 2). Using the shrinking core model of gasification with a controlling surface reaction, activation energies and frequency factors were evaluated with and without addition of Na2CO3. The addition of catalyst and water reduced activation energies and frequency factors in most cases. The addition of 5 wt% Na2CO3 and water was found to reduce reactor temperatures by nearly 100 °C in coal chars and around 150 °C in biomass chars. Successfully indicating Na2CO 3 is an attractive option for development.