Experimental investigation and analysis of a new light-based hydrogen production system

Abstract

Due to the world’s increasing population and the rising standard of living, global energy demand is expected to keep increasing. The limited nature of fossil fuels and their non-homogenous global distribution along with the emissions related to their utilization have caused renewable energies to be considered as a key to sustainability. However, renewable energy sources such as solar energy are intermittent, due to which it has to be stored in an alternate form, such as electricity or hydrogen. Hydrogen is a highly versatile fuel that may become one of the key pillars to support the future energy infrastructure. The photoelectrochemical water splitting cycle is one of the supreme attractive alternative photoelectrochemical cycles for clean hydrogen production due to its lower temperature requirement and better overall efficiency. The key objective of this master’s research is to develop, theoretically analyse and experimentally investigate a continuous type hybrid hydrogen production system that photoelectrochemically splits water and electrolyses chloralkali to convert the by–products of H2 production into useful industrial commodities. This hybrid system maximizes the utilized solar spectrum by combining photochemical and electrochemical hydrogen production in a photoelectrochemical system. In addition, CFD simulations are performed for various models to determine optimum design parameters for the present PEC reactor. Furthermore, by using electrodes as electron donors to drive photochemical hydrogen production, the hybrid system minimises the potential pollutants. The proposed system has the advantage to eliminate generating waste by converting the by-products into commercially viable products. In addition to hydrogen, the system generates Cl2 and NaOH which are desired by various industries. The proposed system has an annual production capacity of 2.8 kg hydrogen per square meter of heliostat with a production cost of 1$/kg hydrogen produced. In addition to converting by-products into usable commodities, the system does not emit GHG during operation.