FUEL 102 |
| Ammonia borane (AB) is a promising hydrogen storage material for fuel-cell vehicle applications owing to its high hydrogen density and stability under typical ambient conditions. The Department of Energy has defined technical targets for on-board storage systems including operating ambient temperatures up to 60°C. The thermal stability of solid AB from 40 to 60°C is investigated experimentally and computationally. Isothermal differential scanning calorimetry results from 70 to 90°C, in which hydrogen is released thermolytically and exothermically (deltaH ~ -22 kJ/mol), are characterized by modified Avrami kinetics, and the derived rate constants are fit to an Arrhenius expression (Ea ~160 kJ/mol). The results are used to project hydrogen release as a function of temperature, time, and initial AB conversion during isothermal and adiabatic storage. These calculations are compared to data obtained in the ARC® (Accelerated Rate Calorimeter), which is used to determine if the reaction is self-propagating under adiabatic storage conditions. |
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Progress in Computational and Experimental Studies of Materials for Hydrogen Storage
1:30 PM-5:10 PM, Monday, 11 September 2006 Palace -- Mendocino Room, Oral
Division of Fuel Chemistry |