Water and Heat Balance in a Fuel Cell Vehicle with a Sodium Borohydride Hydrogen Fuel Processor

The National Renewable Energy Laboratory (NREL) collaborated with Millennium Cell and DaimlerChrysler to study heat and water management in a sodium borohydride (NaBH₄) storage/processor used to supply hydrogen to a fuel cell in an automotive application. Knowledge of heat and water flows in this system is necessary to maximize the storage concentration of NaBH₄, which increases vehicle range. This work helps evaluate the NaBH₄ system's potential to meet the FreedomCAR program technical target of 6 wt% hydrogen for hydrogen storage technologies. This paper also illustrates the advantages of integrating the NaBH₄ hydrogen processor with the fuel cell.