A Feasible Hybrid Fuel Cell Vehicle for the Hydrogen Economy

The pollution from greenhouse emissions from current energy production sources is directing the world towards a hydrogen economy. A design that integrates hydrogen production (produced either at the fuel depot site or at a centralized location, i.e., refinery), hydrogen odorization, fuel depot storage, an onboard odorant adsorber, onboard vehicle storage, and hydrogen utilization in a fuel cell system, was presented. The transportation sector was selected as a basis for the design, since it is expected that this sector would see substantial growth in hydrogen utilization over the next decade. However, the design could be modified for stationary fuel cell systems. The design feasibility was proven quantitatively. The process started by removing a hydrogen odorant through adsorbers. The hydrogen was then stored in a metal hydride unit. After the fueling process, the battery stack might heat the hydride unit releasing hydrogen. The fuel cell stack produced useful electricity from this hydrogen. Based on the reaction kinetics for the release of hydrogen from magnesium hydride, the temperature for the release of hydrogen was in the range 562-581 K for a range of 500-60,000 rpm.