Ethanol steam reforming heated up by molten salt CSP: Reactor assessment

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 20 K, 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 = 1115 h−1, Pressure = 10 bar, steam-to-carbon ratio = 5, inlet reactants temperature = 823 K) and with a 4.5 m long reactor.