A 5 kwel propylene glycol microchannel fuel processor as hydrogen source for fuel cells
The reforming of biomass-derived oxygenates such as ethanol or glycerol has been deeply studied. However, the stability of catalyst formulations developed for glycerol reforming was not the main focus of this development work to date. In the case of propylene glycol, few studies have been addressed to date. Propylene glycol serves as coolant in many mobile applications nowadays and therefore a distribution grid already exists. The practical processing of larger amounts of polyalcohols such as propylene glycol to synthesis gas for fuel cell applications in reactors larger than laboratory scale suited for distributed applications has not been adequately addressed to date. The current work deals with (a) the development of stable catalyst formulations for propylene glycol reforming and (b) reformer and fuel processor development for the steam reforming of propylene glycol in the power range exceeding 17 kWthermal of the synthesis gas product. A self developed stable catalyst formulation was incorporated into a plate heat-exchanger reformer. The energy required to drive the endothermic steam reforming reaction was foreseen to originate from the combustion of fuel cell anode off-gas and additional propylene glycol in a future technical process. Therefore the demonstrator was composed of layers for energy supply carrying a micro-structured catalytic burner, which was fed with anode off-gas surrogate and reaction layers which carried catalyst for the oxidative steam reforming of propylene glycol. A complete integrated and compact fuel processor is under development including start-up burner and CO clean-up. It is to the authors' knowledge the first fuel processor for steam reforming of polyalcohols of that size presented in open literature.