Lifetime Analysis of a Hydrogen Generator by Hydrolysis of Sodium Borohydride

AbstractThe interesting point of this work is to increase the amount of produced H2 in order to improve the energy density of the H2 generator system. For this, one of the main challenges is to increase the NaBH4 concentration of the cartridge solution thus avoiding the drawbacks induced by NaBO2 crystallization, but also to control the stability of this solution, it means add sodium hydroxide to limit the NaBH4 self-decomposition, thus stabilizing the system. This paper shows the two aspects of the cartridge lifetime analysis: the overall order reaction of spontaneous hydrolysis reaction of alkaline aqueous NaBH4 solutions as function of NaOH concentration and the operation temperature range of the cartridge; an unequivocal understanding of the NaBO2 crystallization process and more specifically the delimitation of the homogeneous liquid phase domain in the quaternary system NaBH4-NaBO2-NaOH-H2O