Application of one-body hybrid solid pellets to sorption-enhanced water gas shift reaction for high-purity hydrogen production

摘要

Interest in hydrogen, regarded as a new clean energy carrier, has been increasing with expectation of the approaching hydrogen economy. In the hydrogen economy, hydrogen will replace the conventional fuels that have caused pollution problems. As one of the methods for the mass production of hydrogen, water gas shift (WGS) reaction (CO + H_2O ⇄ H_2 + CO_2) has been highlighted for synthesis gas feed, which is produced by coal and biomass gasification. Recently, the performance of WGS reaction has been improved significantly through application of the sorption-enhanced WGS (SE-WGS) reaction concept, where WGS reaction and CO_2 sorption are carried out simultaneously. High-purity hydrogen can be directly produced through the SE-WGS reaction, without need for further purification processes. In the SE-WGS reaction, uniform packing of the mixture of catalyst and sorbent is important; however, this is difficult to manage with conventional catalyst and sorbent pellets. In this study, novel one-body hybrid solid pellets consisting of the mixture of catalyst and sorbent were prepared to address this shortcoming and applied to SE-WGS reactions. From experiments, the effect of different ratio of catalyst/sorbent in one-body hybrid solid pellets was studied. A novel multi-section packing concept was also applied to SE-WGS reaction with one-body hybrid solid pellets. The experimental results showed that one-body hybrid solid pellets can be successfully used and that multi-section packing can increase the hydrogen productivity in SE-WGS reaction.