Low CO content hydrogen production from bio-ethanol using a combined plasma reforming–catalytic water gas shift reactor

Abstract

Bio-ethanol reforming was studied using a plasma-catalytic reactor for hydrogen production at low temperature and atmospheric pressure without diluent gas or external heating. The plasma applied was a DC pulse discharge (corona) plasma. The water gas shift (WGS) catalyst was put just below the cathode electrode. The discharge generated heat was effectively used for feed vaporization and the WGS reaction. The large amounts of CO (∼30%) in the H2 rich gas formed in plasma reforming of ethanol (H2O/ethanol=6) was successfully reduced to ∼0.8% when a Pt/TiO2 and Pt–Re/TiO2 stacked bed were used for in situ WGS catalysis with a gas hourly space velocity up to 12,000cm3g−1h−1. The resultant gases contain ∼73% H2 and ∼23% CO2, with small amounts of CO, CH4, and C2H6, that is suitable for H2 fuel cell use after residual CO removal. Stability tests with daily startup–shutdown showed both plasma and catalyst are stable. The plasma-catalytic system is promising for low CO content H2 production, and could be extended to other applications.