Pure Hydrogen Production from Steam Reforming of Bio-Sources

Abstract

Two synthetic mixtures simulating biogas (CH4 /CO2 = 66.2/33.8) and bioethanol (H2O/EtOH = 13/1) have been used for producing hydrogen by steam reforming reaction in a commercial dense self-supported Pd-Ag membrane reactor. The experimental campaign was subdivided into two parts. Firstly, we studied biogas steam reforming reaction, evaluating the reaction pressure influence (between 200 and 350 kPa) at 450°C, H2O/CH4feed molar ratio = 4/1, GHSV =2370h-1, sweep gas flow rate (N2) = 28.55 mL/min and countercurrent configuration. As best result, we reached 60% CH4 conversion and 40% hydrogen recovery at 350kPa.Successively, we carried out bioethanol steam reforming reaction studying the influence of reaction temperature between 350 and 400°C at 300 kPa of reaction pressure, GHSV=700 h-1 in the presence of sweep gas (N2 = 28.55 mL/min) and countercurrent configuration, obtaining - at 400 °C - maximum ethanol conversion, hydrogen yield and recovery equal to 70%, 50% and 65%, respectively. In addition, we compared the membrane reactor performance with a traditional reactor exercised at the same conditions, only varying the reaction pressure between 200 and 300 kPa. The aim of this work is constituted by the pure hydrogen production from bio-sources exploitation in membrane reactors at bench scale, starting with the utilization of commercial membranes available in the market and in the perspective of scaling up the process for potential industrial development.