A comprehensive thermodynamic analysis of hydrogen and synthesis gas production from steam reforming of propionic acid: Effect of O2 addition and CaO as CO2 sorbent

Abstract

A thermodynamic analysis was performed for the production of synthesis gas and hydrogen gas from steam reforming of propionic acid, one of the constituents of the bio-oil, using ASPEN Plus v8.8. The aim of the study was to perform a global analysis on steam reforming of propionic acid focusing on several parameters such as steam-to-propionic acid ratio, reaction temperature, addition of O2 in the feed stream and presence of CaO as a CO2 sorbent in the reaction environment. The results showed that higher amounts of steam/propionic acid ratio resulted in higher H2 and CO2 yields. It was also observed that high H2O/PA molar ratios led to reduced coke production as WGS reaction was favored with excess steam, causing CO in the reaction mixture to be consumed through the WGS reaction rather than the Boudouard reaction. Addition of O2 in the reaction environment was observed to negatively affect yield of H2. Yet, coke formation was deprived and increasing the O2 amount in the feed stream decreased the energy required for the process. Furthermore, the presence of CaO enhanced H2 yield and energy requirements of the process compared to conventional steam reforming process. 100 % yield of H2 production with a heat generation of −83.4 MJ/kmol of PA and almost zero formation of CO2, CO, CH4 and coke is achieved at 600 °C for sorption enhanced steam reforming of propionic acid.