Abstract

The fixed-bed chemical-looping hydrogen (CLH) process offers the possibility of decentralised small-scale hydrogen production and storage from local available renewable hydrocarbon sources like biogas. The detailed process simulation indicated the ability of converting a broad range of different bio-based feedstocks into hydrogen."br" Experiments for hydrogen production in a lab-scale reactor showed the ability to release high-pressurized hydrogen with up to 50 bar from the fixed-bed production system without an additional gas compression step. Hydrogen with a purity up to 99.999% was produced in the performed lab-scale experiments to meet the stringent requirements for FCEVs. Detailed process simulations for combined loading and unloading of the oxygen carrier with a typical biogas feedstock are presented. The thermodynamic analyses revealed a high influence of the reformer synthesis gas composition and also of the internal recirculation on the overall process efficiency."br" The previously loaded oxygen carrier is appropriate as process-integrated storage solution to cover fluctuating demands during the day i.e. for use in fuel stations. A long-term storage and distribution is possible due to the easy handling and the very high volumetric storage capacity compared to conventional tube trailer transportation.