Thermodynamic analysis of hydrogen production from glycerol with different reforming processes

Abstract

In this study, a thermodynamic analysis of hydrogen production from glycerol, a by-product of biodiesel production, using different reforming processes, i.e., steam reforming, partial oxidation and autothermal reforming, was investigated. Simulation studies were performed to determine the influence of key operating parameters, i.e., reaction temperature, steam-to-glycerol (S/G) molar feed ratio, and oxygen-to-glycerol (O/G) molar feed ratio, on the performance of a reformer in terms of hydrogen production and heat requirement. The results show that the effect of a side reaction of methanation leads to a decrease in hydrogen production. When a molar feed ratio of S/G increases, the yield of hydrogen and energy demand of the steam reforming process increases. The hydrogen yield also increases with increasing the O/G molar ratio in the partial oxidation process in which the O/G ratio also affects a total heat demand. For the autothermal reforming, it is found that the partial oxidation reaction is more pronounced than the steam reforming reaction. At high temperature, the reverse water gas shift is the dominant reaction. Comparing among different reforming options, the steaming reforming process can produce the highest amount of hydrogen, followed by the autothermal reforming and the partial oxidation processes. However, when considering the total energy demand, the steam reforming is the most requiring energy supply, followed by autothermal reforming process.