Hydrogen storage has proved to be the greatest obstacle preventing hydrogen from replacing fossil fuels. Hence, a safe, efficient and economical method of storing hydrogen must be available to turn viable a hydrogen economy based on renewable resources . Hydrogen can be stored in chemical hydrides such as sodium borohydride (NaBH4), with large theoretical H2 content of 10,9 wt%. With the aid of catalysts, and at room temperatures, the alkaline hydrolysis of NaBH4 can be enhanced . In this work, a 100 L innovative reactor for hydrogen production was designed, based on the optimized layout of a laboratorial scale reactor , as part of a project financed by the Portuguese financial support program NSRF. The developed system has the capability to feed a 5 kW PEM fuel cell with a maximum hydrogen consumption of 75 slpm. The NaBH4 solution is stored in a 50 L reservoir from where seven consecutive 7,0 L injections to the reactor are possible. The Ni-Ru based catalyst applied can be re-used several times without losing its performance  and because of this capacity its replacement will be done, manually, every seven NaBH4 solution injections (simultaneously with the residual solution removal and the reactor cleaning). The catalyst should then be recovered for further utilization. Additionally to the reactor...
Modelling of a hydro-pneumatic energy storage system is presented in this paper. Hydro pneumatic storage aims to combine the good efficiency of hydraulic energy conversion and the space flexibility of pneumatic storage. The project aims to model a prototype which uses a rotodynamic multi-stage pump-turbine to displace a virtual liquid piston to compress air. To facilitate mass and heat transfers between both phases, there is no separation between the water and the air.
A dynamic model of the storage system is developed using block diagram methodology. It takes into account characteristic curves of the pump-turbine and thermodynamic equations. Modelling results show that vapour diffusion contributes to reducing compression final temperature. This implies an increase of storage efficiency. A test rig construction will begin at the end of autumn 2011. It will be electrically connected to the “Distributed Energies” platform of ‘’Arts et Métiers Paristech’’ in Lille.; ademe
Modelling of a hydro-pneumatic energy storage system is the main aim of this paper. The project aims to model a prototype that uses a rotodynamic multi-stage pump-turbine to displace a virtual liquid piston for air compression. A dynamic model of the storage system is developed using the block diagram methodology. Two driving strategies are also developed in order to manage the constant variation of operating point due to pressure variation: maximum efficiency strategy and power demand response strategy.; ADEME