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Fuel cell vehicles powered using Hydrogen/air fuel cells have received a lot of attention recently as possible alternatives to internal combustion engine. However, the combined problems of on-board Hydrogen storage and the lack of Hydrogen infrastructure represent major impediments to their wide scale adoption as replacements for IC engine vehicles. On board fuel processors that generate hydrogen from on-board liquid methanol (and other hydrocarbons) have been proposed as possible alternative sources of Hydrogen needed by the fuel cell. This paper focuses on a methanol fuel processor using steam reformation of methanol to generate the Hydrogen required for the fuel cell stack. Since the steam reformation is an endothermic process the thermal energy required is supplied by a catalytic burner.

This paper deals with system level analysis of a methanol fuel processor for an indirect hydrogen-Air based Fuel Cell Vehicle (FCV) based on a Proton Exchange Membrane (PEM) fuel cell stack. This analysis focuses on the performance of the fuel processor from the viewpoint of efficiency and the requirements placed on it by the Fuel Cell Vehicle. It is widely accepted that hydrogen supply is an important issue in PEM-FC vehicle systems. The lack of a well-entrenched hydrogen infrastructure and the nascent state of hydrogen storage technology has led to development of on-board hydrogen generation systems to meet the fuel cell hydrogen demand. The primary fuel is typically a Hydrocarbon (methanol, gasoline) which is then “reformed” in a fuel processor to generate the hydrogen needed by the fuel cell stack. A great deal of effort has been expended in developing fuel processors that would satisfy the rigorous demands of automotive applications.

This paper primarily compares costs and fuel economies of load following direct-hydrogen fuel cell vehicles with battery hybrid variations of the same vehicle. Additional information is included regarding load-following indirect methanol fuel cell vehicles. The key points addressed are as follows: the tradeoff between fuel cell system efficiency and regenerative braking ability; transient effects; and component cost differences. The difference in energy use and costs can vary significantly depending on the assumptions and the hybrid configurations. The mass of the battery pack creates the largest impact in energy use, while system efficiency losses roughly balance out with regenerative braking. For the direct-hydrogen fuel cell system, transient effects are small. These effects are expected to be significant for steam reformer/indirect-methanol systems (analyzed only graphically herein).