Thermodynamic Analysis of Glycerol Steam Reforming using Calcium Oxide and Iron Oxide for High-Purity Hydrogen Production

Abstract

Abstract A thermodynamic analysis of glycerol steam reforming in the presence of a CO2 adsorbent (CaO) and solid oxygen transfer material (Fe2O3) for high-purity hydrogen production was performed using the Gibbs free energy minimization method. CO in reformate gas was reduced via CO oxidation by Fe2O3 into CO2 coupled with in situ CO2 capture by CaO. The high-purity hydrogen produced without using a downstream reactor has potential application in proton exchange membrane fuel cells (PEMFCs). The influence of temperature (300–1000 °C), pressure (0.1–1.0 MPa), and mole ratios of H2O/glycerol (1–10), CaO/glycerol (0–6), and Fe2O3/glycerol (0–6) on equilibrium gas compositions and carbon formation was evaluated. The produced gas (99.8 mol% H2 and 12.8 ppm CO) was obtained without carbon formation under the optimal conditions (450 °C, 0.1 MPa, CaO/glycerol mole ratio of 3, Fe2O3/glycerol mole ratio of 3 and H2O/glycerol mole ratio of 10), and can be directly used in PEMFCs. However, further optimizations are needed.