This paper reports new data on the production of hydrogen from water vapor plus NaBH4, or NaBH4 þ 10% CoCl2. Data were collected with the aid of an isothermal semi-batch reactor with in-situ H2 rate measurement. The reaction of NaBH4 to generate H2 proceeds via three steps: deliquescence, dissolution and reaction. The deliquescence regime of NaBH4 in the presence of 10 weight percent CoCl2 is defined. The H2 yield is quantified at various reaction conditions (reaction temperature 70-120 C, relative humidity 31-69%). CoCl2 significantly accelerates the rate of H2 production compared to deliquescence + reaction of pure NaBH4. It is also found that a combination of high temperature and high relative humidity contributes to high H2 rate and yield, and either of the two factors dominates the reaction at different conditions. A two-part reactor model accounting for the mechanism of the steam hydrolysis by NaBH4 is developed. The model captures the dissolution + reaction step as well as reaction-only step and was validated by experimental data.
Published in International Journal of Hydrogen Energy, Volume 39, Issue 8, 2014, pages 3830-3836.
© International Journal of Hydrogen Energy 2014, Elsevier.
Yu, Lin & Matthews, M. A. (2014). A Reactor Model for Hydrogen Generation from Sodium Borohydride and Water Vapor. International Journal of Hydrogen Energy 2014, 39 (8), 3830-3836. http://dx.doi.org/10.1016/j.ijhydene.2013.12.147