Investigation of a novel photoelectrochemical hydrogen production system

The primary aim of this study us to develop an integrated PV/T-photoelectrochemical-chloralkali (PEC-chloralkali) system with multigeneration benefits and evaluate its thermodynamic performance. The key component of the integrated system is the continuous type hybrid H-2 generation reactor, which is also referred to as PEC-chloralkali reactor. The hybrid reactor is capable of converting the byproducts of H-2 production into valuable products for the industry. In addition to hydrogen, the hybrid reactor can produce Cl-2 and NaOH simultaneously. The reason behind using the hybrid reactor together with PV/T in an integrated system is to maximize solar spectrum utilization by combining the advantages of the photoelectrochemical system and PV/T. The electrodes are used as electron donors to drive the photoelectrochemical reaction in the hybrid reactor. As a result, the need for additional chemicals is eliminated and the risk of any potentially harmful waste streams is minimized. The integrated system has five useful products which are hydrogen and chlorine gases, sodium hydroxide solution, heat, and electricity. The performance of the system is evaluated based on hydrogen, chlorine, heat, and electricity production rates, energy and exergy efficiencies, and exergy destruction rates at different ambient temperatures and with different total photoactive area sizes. It is seen that the present innovative hybrid multigenerational system is capable of producing 8.9 g/h H-2 and 244 g/h Cl-2 at energy and exergy efficiencies about 86% and 29%, respectively. (C) 2018 Elsevier Ltd. All rights reserved.