Manufacturing of Material-Based Hydrogen Fuel for Lightweight Vehicles

Vehicles powered by hydrogen fuel cells store hydrogen as a cooled liquid at 20 degrees kelvin or a compressed gas at 10,000 pounds per square inch. An alternative that eliminates the need for these extremes of temperature and pressure is to heat a compound containing covalently bonded hydrogen, causing it to release the hydrogen to the fuel cell. Ammonia borane, which is stable at ambient conditions, requires minimal energy for dehydrogenation, and is rich in hydrogen, is a possible storage medium for hydrogen. If a viable storage system could be engineered, demand for ammonia borane as a source of hydrogen would increase. The goal of this project is to develop a processing plant and to optimize design specifications for scaling up processing of ammonia borane through the metathesis reaction pathway. Optimization of individual unit operations was determined using quality-by-design concepts, which allowed the team to confirm scalability, design limitations, and competitive market pricing. The final design involves the application of two mixers, two reactors, and four separators. The plant design should yield 99 percent pure ammonia borane.