Design and optimization of advanced materials and processes for efficient hydrogen storage

This work presents a systematic approach for the optimal design and optimization of metal-hydride materials and processes for efficiency hydrogen storage. Techniques for the synthesis and characterization of novel metal-hydride materials are presented in a view of designing material to enhance storage efficiency. More specifically the synthesis of a composite intermetallic hydride by using theoretical and experimental procedures is investigated and a pseudobinary Zr-Ti-Cr-Ni-V compound has been developed. The X-ray diffraction pattern analysis revealed two Laves phases and a Rietveld analysis has been performed for the determination of the structural characteristics. A unique composite structure is responsible for the desorbed similar to 280 ml of H-2 per gram of the material obtained after 15 min at 100 degrees C A small-scale metal-hydride tank has been designed in order to investigate its capacity and efficiency from 20 degrees C to 100 degrees C. Then, a dynamic model that has developed previously by the authors provides the basis for investigating systematic optimization and online control studies. The objective is to find the optimal process design (e.g. cooling systems design) and online operating strategy (e.g. cooling fluid profile over time) so as to minimize the storing time, while satisfying, a number of operating constraints. Optimization results indicate that significant improvement on the storage time can be achieved, compared the case where the system is not optimized and control. Trade-offs between various objectives, alternative design options and optimal cooling control policies are systematically revealed illustrating the potential offered by modern optimization and control techniques. (C) 2008 Elsevier Ltd. All rights reserved.