Link-up of a bench-scale “shift-less” gasoline fuel processor to a polymer electrolyte fuel cell

To demonstrate the “shift-less” fuel processing concept, a test unit was built containing a gasoline reformer and a PROX unit. At GHSV of 3319-19795 h−1 and T = 595-645 °C complete conversion of C2+ was achieved. First, a dual fixed-bed reactor configuration with staged air supply was tested for the PROX. With this configuration hot spots over 280 °C occurred, which made a selective conversion of carbon monoxide impossible. The hot-spot problem was drastically reduced by using an annulus reactor achieving >99.93% carbon monoxide conversion due to the better heat dissipation. The hydrogen conversion in the PROX unit was high at around 27%. This value may be improved by better temperature control of the PROX reactor. Reformate gas with hydrogen concentrations up to 51 vol.% could be produced from sulphur-free gasoline (RON = 95). Reformate gas with 32% H2 and <36 ppmv CO was fed to a 30 cm2 polymer electrolyte fuel cell. A stable cell voltage of 680 mV was obtained at a current density of 500 mA cm−2 for operation with pure O2 as oxidant. Changing the oxidant to air led to a cell voltage decline of 120 mV.