Abstract
The use of hydrogen for automotive power is made attractive by its potential unlimited availability and its low emissions. The main obstacles to the use of hydrogen in road vehicles have been, and remain, the storage of hydrogen on board the vehicle, hydrogen handling, hydrogen distribution and cost. For various reasons, such as safety, overall energy considerations and fuel handling, alternatives to compressed or liquid hydrogen must be seriously considered in future applications. It is possible that liquid organic hydrides will become increasingly important for their role as hydrogen carriers in any future hydrogen economy as the transportation and storage of such organic hydrides would exploit existing fuel-distribution infrastructures. For instance, a hydrogen source could be employed to hydrogenate toluene (C7H8) to methylcyclohexane, MCH (C7H14), while, onboard any vehicle employing the system, hydrogen could be liberated through the endothermic reverse reaction.Recently there has been increased interest in developing proton-conducting solid oxide fuel cell (SOFC) technology. Such proton-conducting systems will potentially be able to operate at reduced temperatures compared to more conventional oxygen-ion conducting systems. Furthermore, such systems would be able to exploit any move towards hydrogen-based fuels.Here we report results from the integration of this MTH (methylcyclohexane, toluene, hydrogen) fuel storage system with a novel proton-conducting SOFC operating at 750°C. MCH was vapourised and heated prior to being fed to a dehydrogenation reactor followed by a separation stage where toluene and unreacted MCH were condensed. The vapour phase product from the condenser was fed to the fuel cell. The solid oxide fuel cell (SOFC) was based on a BaCe0.9Y0.1O3 (BCY) proton-conducting electrolyte material with porous platinum electrodes. The performance of the fuel cell was evaluated under hydrogen generated entirely from MCH. At 750°C power outputs of more than 20 mW cm-2 were obtained.
