Microwave-assisted dry reforming of methane

The microwave-assisted dry reforming of methane over an activated carbon, which acted as catalyst and microwave receptor, was investigated. As a preliminary study, the CO₂ reforming of CH₄ was carried out using conventional heating and microwave heating in order to compare both heating devices. Higher conversions of CH₄ and CO₂ were achieved by microwave heating. Under microwave heating, various operating variables were studied in order to determine the best conditions for performing dry reforming with high conversions and the most suitable H₂/CO ratio. Thus, the dry reforming reaction was studied at different temperatures. An optimum range of working temperatures (between 700 °C and 800 °C) was established. In this range of temperatures, the dry reforming reaction is believed to take place as a combination of CH₄ decomposition and CO₂ gasification. Carbonaceous deposits from CH₄ decomposition are gasified by CO₂ and, as a result, active centres for the dry reforming reaction are constantly regenerated. The effect of the proportion of CO₂ fed in on the CH₄ and CO₂ conversions was also investigated. Small increases in the percentage of CO₂ fed in gave rise to large increases in both conversions, but especially in the case of CH₄. The volumetric hourly space velocity was also studied. It was found that the lower the space velocity, the higher the conversions obtained.