Volume 20: Sustainable Energy Solutions for a Post-COVID Recovery towards a Better Future: Part III

Solar hydrogen production under combined solar light and thermal effect at mid-and-low temperature –experimental and thermodynamic analysis Buchu Lu,Xiangyu Yan,Qibin Liu

Abstract

The efficient use of solar energy to produce hydrogen by thermochemical and photochemical reactions is quite challenging and promising. Solar thermochemical processes can make use of full spectrum sunlight but ignore the energy quality differences between spectrums, while photochemical processes can convert light into chemical energy but use part of the solar spectrum. To explore the possibility of combining solar light and heat, an experimental study of photo-thermochemical methanol steam reforming reaction is conducted in a fixed bed reactor. Photochemical and thermochemical reactions are carried out simultaneously on Cu/ZnO/Al2O3 catalyst. Compared to thermochemical reactions (TRs), the photo-thermochemical reaction (PTR) shows an increased conversion rate, especially at low temperature. At 188℃, the PTR improves the yield of hydrogen by 32.9%. According to the characterization results, the photo-generated electrons contribute to the enhancement of the PTR. The mechanism for the increased conversion rate is further discussed from the thermodynamics perspective. These findings provide a reference for future integrated use of light and heat at mid-and-low temperatures.

Keywords photo-thermochemical reaction,methanol steam reforming,photo-generated electron,hydrogen production