Conversion of carbon dioxide and methane in biomass synthesis gas for liquid fuels production

The premise of this research is to find whether methane (CH4) and carbon dioxide (CO2) produced during biomass gasification can be converted to carbon monoxide (CO) and hydrogen (H2). Simultaneous steam and dry reforming was conducted by selecting three process parameters (temperature, CO2:CH4, and CH4:steam ratios). Experiments were carried out at three levels of temperature (800 °C, 825 °C and 850 °C), CO2:CH4 ratio (2:1, 1:1 and 1:2), and CH4:steam ratio (1:1, 1:2 and 1:3) at a residence time of 3.5 × 103 gcat min/cc using a custom mixed gas that resembles biomass synthesis gas, over a commercial catalyst. Experiments were conducted using a Box-Behnken approach to evaluate the effect of the process variables. The average CO and CO2 selectivities were 68% and 18%, respectively, while the CH4 and CO2 conversions were about 65% and 48%, respectively. The results showed optimum conditions for maximum CH4 conversion was at 800 °C, CO2:CH4 ratio and CH4:steam ratios of 1:1.

► Simultaneous steam and dry reforming was conducted for hydrogen production.
► A Box-Behnken approach was used to evaluate the effect of the process variables.
► The average CO and CO2 selectivities were 68% and 18%, respectively.
► The average CH4 and CO2 conversions were about 65% and 48%, respectively.