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Abstract: In this paper hydrogen production via reforming of ethanol has been studied in a novel hybrid plant consisting in a ethanol reformer and a concentrating solar power (CSP) plant using molten salt as heat carrier fluid. The heat needed for the reforming of ethanol has been supplied to the system by molten salts heated up by solar energy. The molten salt stream temperature drop for supplying hydrogen production process heat duty is less than 20K, making the molten salt stream still suitable for steam and electricity production in a co-generative plant (clean hydrogen and electricity). A 2D mathematical model has been formulated, validated and used in order to simulate the performance of the reformer coupled with heat integration through molten salt. Firstly, the effect of operating conditions on the ethanol conversion and on hydrogen production have been evaluated in order to find the optimal conditions for the solar reforming reaction. Then, a reactor design is proposed in order to achieve almost complete ethanol conversion. The results show that the hybrid plant proposed here is a good solution for “green” hydrogen production. Almost complete conversion (99%) can be achieved with an optimized set of operating conditions (GHSV=1115h−1, Pressure=10 bar, steam-to-carbon ratio=5, inlet reactants temperature=823K) and with a 4.5m long reactor. [Copyright &y& Elsevier]

Abstract: In this paper, specific cases for the interaction between the future electricity-generation mix and a newly-developing hydrogen-production infrastructure is modelled with the model E-simulate. Namely, flexible integrated-gasification combined-cycle units (IGCC) are capable of producing both electricity and hydrogen in different ratios. When these units are part of the electricity-generation mix and when they are not operating at full load, they could be used to produce a certain amount of hydrogen, avoiding the costly installation of new IGCC units for hydrogen production. The same goes for the massive introduction of renewable energies (especially wind), possibly generating excess electricity from time to time, which could then perhaps be used to produce hydrogen electrolytically. However, although contra-intuitive, the interaction between both ‘systems’ turns out to be almost negligible. Firstly, it is shown that it is more beneficial to use IGCC facilities to produce hydrogen with, rather than (excess) wind-generated electricity due to the necessary electrolyser investment costs. But even flexible IGCC facilities do not seem to contribute substantially to the early development of a hydrogen economy. Namely, in most scenarios – which are combinations of a wide range of fuel prices and carbon taxes – one primary-energy carrier (natural gas or coal) seems to be dominant, pushing the other, and the corresponding technologies such as reformers or IGCCs, out of the market. [Copyright &y& Elsevier]