Development of dehydrogenation catalyst for hydrogen generation in organic chemical hydride method

Abstract

The utilization of the organic chemical hydride method (OCH method) for hydrogen storage and transportation using hydrogenation and dehydrogenation chemical reactions with aromatic compounds has been investigated since the 1980s. This method provides for both high gravimetric and volumetric hydrogen densities, and the potential risk is very small due to the storage and transportation in the liquid state under ambient pressure. It also has the advantage that hydrogen storage and transportation is carried out as a conventional petrochemical product. However, this method has not been technically established because the dehydrogenation catalyst does not have a sufficient stability and performance. We have developed a dehydrogenation catalyst using a simple fixed-bed reactor that has a high stability and sufficient performance. This catalyst can generate hydrogen from methylcyclohexane (MCH: 99.9%) with a conversion > 95 % , toluene selectivity > 99.9 % , hydrogen generation rate > 1000 Nm 3 / h / m 3 cat under the reasonable conditions of 593 K, ambient pressure, LHSV:2.0/h and co-feed hydrogen 5–20 mol% in the feed. The estimated production cost at a hydrogen station for fuel cell vehicle (FCV) is around 64.7 ¥ / Nm 3 H 2 ( 59 ¢ / Nm 3 H 2 ) . Two possible applications of this method are introduced. One is the utilization of low-grade hydrogen including impurities. The other is a future vision of the global hydrogen energy chain.