Production of hydrogen by dry reforming of ethanol over alumina supported nano-NiO/SiO2 catalyst

Abstract

Hydrogen was produced with very high yield by dry reforming of ethanol over alumina supported nano-NiO catalyst in silica synthesized using sol-gel method. The activity of the prepared nano-catalyst was assessed in terms of ethanol conversion, carbon dioxide conversion, carbon monoxide yield and hydrogen yield. The catalyst activity as well as distribution of products was observed to vary with Ni loading in the catalyst and the reaction conditions. Catalyst containing 10% Ni showed good activity among the screened catalyst for ethanol dry reforming. Detailed experimental investigations were carried out over a wide range of operating parameters such as reforming temperature from 500°C–850°C, feed carbon dioxide to ethanol molar ratio from 0.5 to 2 and space-time from 19.0 to 41.8kg cat h/kmol of ethanol fed. The catalyst was found to be active within the range of parameters studied at atmospheric pressure. However, the most favorable reaction conditions were established at 750°C with CO2/EtOH molar ratio of 1.4 and space-time of 24.90kgcath/kmol of ethanol fed. Under the optimum condition, almost complete conversion of ethanol, 76.0% conversion of CO2 and 100% yield of hydrogen were obtained. The space-time–conversion data in the temperature range of 500–600°C were fitted into a power law model and the activation energy of the ethanol dry reforming reaction was determined to be 97.87kJ/mol.