Investigation of efficient electro chemical reactor utilizing hydrogen

Hydrogen is regarded as one of the most important energy sources to Produce heat, electricity, power energy and in dustries in the near future.One efficient utilization of hydregen is an application to fuel cells (FC_s)which have been act ively investigated as an efficient power generationsystem for the future application. The present investigation focused o n the chemical reaction at the fuel side of solid oxide fuel cells (SOFC_s) andpolymer electrolyte fuel cells (PEFC_s). Ni-YSZ (yttria-stabilized zirconia) cermet has been most popularlyemployed as a fuel electrode material in the SOF C system. Since the SOFC is operated around 1000ﾟC, it allows reforming of hydrocarbons within the fuelcell (internal ref orming). Hydrogen and carbon monoxide, produced throughthe internal reforming reaction, can react with oxide ions and be directlyused as the fuel. Information on the internal reforming was obtained from the gas phase analysis during the power generation experiments. Al thoughsteam reforming and CO2 reforming of methane are suitable way to generateelectrical power from methane fueled SOFC, carbon deposition on the anodeleads to deactivation of the catalyst when the concentration of C H4 is excess to steam or CO2. The carbon deposition and deterioration of the power generation was also observed in the case of ethylene and ethane fueled SOFC.However, this deterioration was irreversible and the performance of the cell was not recovered after removal of the deposited carbon on theanode. Methanol fueled SOFC demonstrated excellent performance with out the carbon deposition Methanol is regarded as most desirable chemical existing as liquid at ambient temperature for PEFC applications. S team reforming of methanol is established as hydrogen production technology. However, a small amount of CO in the reformed fuel deteriorates a Pt electrode in the PEFC and the cell performance is lowered heavily. Cu/A12O3-ZnO demonstratedexcelle nt activity for CO removal in the methanol steam reformed gas viawater gas shift reaction (WGSR). However, the catalytic activity is insufficient at low temperature to attain the situation close to the equilibrium. This indicates that removal o f the slight amount of CO in the reformed gas is difficult only through WGSR.A small amount of 02 additionto the post-met hanol reforming gas was effective to enhance the CO removalthrough CO oxidation.