Thermodynamic investigation on hydrogen production via self-sufficient chemical looping reforming of glycerol (CLRG) using metal oxide oxygen carriers

The self-sufficient chemical looping reforming of glycerol (CLRG) utilizes the same basic principles as chemical looping combustion (CLC), the main difference being that the desired product in CLRG is not heat but H2. Therefore, in the CLR process the O/C ratio is kept low to prevent the complete oxidation of glycerol to H2O. A systematic thermodynamic study of CLRG using metal oxide oxygen carriers (NiO, CuO, CoO, Co3O4, Mn3O4, Mn2O3 and Fe2O3) is performed to analyze the product yield, carbon deposition and energy requirements at different temperatures and pressures. The calculation results show higher temperatures promote, but higher pressures inhibit H2 production. Favorable conditions (800 °C and 1 atm) are obtained for H2 manufacture from CLRG process. CuO is the best performing oxygen carrier followed by Mn-based oxygen carriers, while Fe2O3 is the least preferred oxygen carrier for CLRG. These results obtained in this theoretical study can offer helpful information for CLRG experimental tests.