Hydrogen production by coupling pressurized high temperature electrolyser with solar tower technology. (11th May 2017)

• Record Type: Journal Article
• Authors: Monnerie, N.; von Storch, H.; Houaijia, A.; Roeb, M.; Sattler, C.
• Is Part Of: International journal of hydrogen energy. Volume 42:Number 19(2017)
• Page Start: 13498
• Page End: 13509
• Publication Date: 2017-05-11
• Subjects: High temperature electrolysis -- Hydrogen -- Solar energy -- CSP; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2016.11.034
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Solar hydrogen production by coupling of pressurized high temperature electrolyser with concentrated solar tower technology is studied. As the high temperature electrolyser requires constant temperature conditions, the focus is made on a molten salt solar tower due to its high storage capacity. A flowsheet was developed and simulations were carried out with Aspen Plus 8.4 software for MW-scale hydrogen production plants. The solar part was laid out with HFLCAL software. Two different scenarios were considered: the first concerns the production of 400 kg/d hydrogen corresponding to mobility use (fuel station). The second scenario deals with the production of 4000 kg/d hydrogen for industrial use. The process was analyzed from a thermodynamic point of view by calculating the overall process efficiency and determining the annual production. It was assumed that a fixed hydrogen demand exists in the two cases and it was assessed to which extent this can be supplied by the solar high temperature electrolysis process including thermal storage as well as hydrogen storage. For time periods with a potential over supply of hydrogen, it was considered that the excess energy is sold as electricity to the grid. For time periods where the hydrogen demand cannot be fully supplied, electricity consumption from the grid was considered. It was assessed which solar multiple is appropriate to achieve low consumption of grid electricity and low excess energy. It is shown that the consumption of grid electricity is reduced for increasing solar multiple but the efficiency is also reduced. At a solar multiple of 3.0 an annual solar-to-H2 efficiency greater than 14% is achieved at grid electricity production below 5% for the industrial case (4000 kg/d). In a sensitivity study the paramount importance of electrolyser performance, i.e. efficiency and conversion, is shown. Highlights: Coupling of a high temperature electrolyser with molten salts solar tower. Two different scenarios depending of the end-use of hydrogen were considered. Flow-sheets and simulations were carried out in MW-range. Annual production of solar high temperature electrolyser is determined. Influence of electrolyser performance on process performance is assessed.