Experimental investigation and analysis of a hybrid photoelectrochemical hydrogen production system

In this paper, we present both experimental investigation and thermodynamic evaluation of a hybrid chloralkali-photoelectrochemical system built at Clean Energy Research Laboratory of the University of Ontario Institute of Technology. The present hybrid system essentially produces hydrogen via water splitting reaction and converts the by-products into useful industrial products, namely chlorine and sodium hydroxide. More importantly, this hybrid system maximizes the utilized solar spectrum by combining photochemical and electrochemical processes. The system is tested at four different temperatures (20, 40, 60, and 80 °C) and three different light settings (no light, 600 W/m2, and 1200 W/m2). The results show that the reactor responds to the light by generating photocurrent. The hydrogen production rate increases with increasing temperature and light intensity. Under no light conditions at 20 °C, the present system produces about 145 mL/h hydrogen with energy and exergy efficiencies of 25.4% and 18.76%, respectively. At 80 °C under 1200 W/m2 irradiation, the same system generates 295 mL/h hydrogen with energy and exergy efficiencies of 19.6% and 13.72%, respectively.