Reaction parameters influence on the catalytic performance of copper-silica aerogel in the methanol steam reforming

Steam reforming of methanol was carried out on the copper-silica aerogel catalyst. The effects of reaction temperature, feed rate, water to methanol molar ratio and carrier gas flow rate on the H₂ production rate and CO selectivity were investigated. Methanol conversion was increased considerably in the range of about 240-300, after which it increased at a slightly lower rate. The used feed flow rate, steam to methanol molar ratio and carrier gas flow were 1.2-9.0 mL/h, 1.2-5.0 and 20-80 mL/min, respectively. Reducing the feed flow rate increased the H₂ production rate. It was found that an increase in the water to methanol ratio and decreasing the carrier gas flow rate slightly increases the H₂ production rate. Increasing the water to methanol ratio causes the lowest temperature in which CO formation was observed to rise, so that for the ratio of 5.0 no CO formation was detected in temperatures lower than 375 ℃. In all conditions, by approaching the complete conversion, increasing the main product concentration, increasing the temperature and contact time, and decreasing the steam to methanol ratio, the CO selectivity was increased. These results suggested that CO was formed as a secondary product through reverse water-gas shift reaction and did not participate in the methanol steam reforming reaction mechanism.