Speaker
Description
There is significant recent interest in clean hydrogen production from renewable water electrolysis. However, the costs of green hydrogen are more than twice as expensive as fossil fuel-based production [1]. The largest single-cost component is renewable electricity; thus, plenty of catalysts have been developed to reduce the required electrical energy (i.e., less overpotential). Usually, the alkaline water electrolysis (AWE) operates with a voltage of ca. 2 V due to ohmic and overpotential-derived loss (0.7~0.8 V) [2]. Some promising catalysts, such as Co- and Ni-based metal-oxide catalysts, are known to have a prominent temperature dependence (overpotential decreases at ca. 4 mV/°C) [3], taking this as an advantage, reactivity can be enhanced by providing a heated electrolyte. Our intended solution is to introduce a heat-tolerant electrolyser integrated with a chemically resistant solar thermal collector, allowing the utilisation of low-grade heat directly from solar energy. In this work, we discuss key dimensional design aspects of the thermal collector for alkaline electrolyser, considering the control feasibility of operating temperature and fluidic parameters. Furthermore, we also demonstrate our proof-of-concept experimental results using our alkaline electrolyser integrated with the solar-thermal collector at an elevated temperature.
References
[1] IRENA. Green Hydrogen Cost Reduction. 2020.
[2] E. Amores, J. Rodríguez, J. Oviedo, A. De Lucas-Consuegra, Open Eng 2017, 7,141–152.
[3] B. Zhang, Q. Daniel, M. Cheng, L. Fan, L. Sun, Faraday Discuss 2017, 198, 169–179.
| Keywords | Electrolysis, Alkaline water electrolyser, Solar-thermal energy, Renewable energy, Green hydrogen |
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