Reforming of Carbon Dioxide to Methane and Methanol by Electric Impulse Low-Pressure Discharge with Hydrogen

Basic phenomena of the reduction of carbon dioxide to reusable organic materials including methane and methanol were investigated by using a radio frequency impulse discharge in a low gas pressure range without catalysis. The discharge took place under different discharge parameters such as voltage, gas flow rate, gas-mixing ratio, and gas residence time, where the carbon dioxide was mixed with hydrogen at total gas pressure of 1-10 Torr. Organic materials such as methane and methanol were observed. Carbon monoxide was a major product from carbon dioxide. Methane was the dominant organic species produced by the discharge. The concentration of methane increased with discharge voltage, and its volume fraction attained 10-20% of the products containing carbon that came from carbon dioxide. This fraction was also dependent on the mixing ratio of carbon dioxide and hydrogen. We also observed the formation of methanol, though its fraction was low, a few %, compared with methane.