Parameter evaluation of enhancing glycerol steam reforming for hydrogen production

To understand the enhancing process of autothermal glycerol steam reforming for high efficient hydrogen production, the effects of two enhancing approaches including hydrogen separation and carbon dioxide absorption are evaluated based on Gibbs free energy minimization method. The variation of hydrogen yield, deposited carbon and reaction heat varied with temperature and hydrogen separation fraction are analyzed. The results reveal that the hydrogen separation can promote the hydrogen yield and restrict the methane production, while this process leads to the increase of carbon formation. The hydrogen removal increases the reaction heat, and a higher oxide to glycerol feed ratio is required to achieve the autothermal condition. Calcium oxide absorbs carbon dioxide to generate calcium hydroxide below 750 K, which leads to reduction of hydrogen yield. When the temperature reaches above 800 K, the capacity of sorbents becomes weak owing to the decomposition of calcium carbonate. Hence, the temperature from 750 K to 800 K is suitable for absorption reaction. The autothermal process can be attained with the heat from absorption reaction.