Treatment of low‐concentration hydrogen by use of proton exchange membrane

The proton exchange membrane fuel cell (PEMFC) cannot react 100% of fuel, because the cell potential becomes zero if all of the fuel is consumed in the PEMFC. Therefore, a small amount of fuel is always released from the PEMFC. The exhausted H2 should be treated for safety. The VCell–iave characteristics were measured while varying the hydrogen concentration from 99.99% to 1%. In addition the VCell of the constant voltage control was selected with reference to the measured VCell–Iave characteristics. It was found that low-concentration hydrogen could be treated at VCell = 0.15 to 0.3 V by the hydrogen pump and at VCell = 0.4 to 0.6 V by PEMFC. The exhaust hydrogen concentration was reduced to several tens of ppm. © 2011 Wiley Periodicals, Inc. Electron Comm Jpn, 94(3): 51–59, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10292