Enhanced ethanol steam reforming by CO2 absorption using CaO, CaO*MgO or Na2ZrO3

This paper presents results of thermodynamic analysis and experimental evaluation of hydrogen production by steam reforming of ethanol (SRE) combined with CO2 absorption using a mixture of a solid absorbent (CaO, CaO*MgO and Na2ZrO3) and a Ni/Al2O3 catalyst. Thermodynamic analysis results indicate that a maximum of 69.5% H2 (dry basis) is feasible at 1 atm, H2O/C2H5OH = 6 (molar ratio) and T = 600 °C. whereas, the addition of a CO2 absorbent at 1 atm, T = 600 °C and H2O/C2H5OH/Absorbent = 6:1:2.5, produced a H2 concentration of 96.6, 94.1, and 92.2% using CaO, CaO*MgO, and Na2ZrO3, respectively. SRE experimental evaluation achieved a maximum of 60% H2. While combining SRE and a CO2 absorbent exhibited a concentration of 96, 94, and 90% employing CaO, CaO*MgO, and Na2ZrO3, respectively at 1 atm, T = 600 °C, SV = 414 h−1 and H2O/C2H5OH/absorbent = 6:1:2.5 (molar ratio).