An overview of the hybrid sulfur cycle process for solar hydrogen production

Abstract

Hybrid sulfur (HyS) cycle or Westinghouse cycle is among the main candidates for full-scale solar hydrogen production. This cycle is one of the most attractive and simplest thermochemical processes, because it comprises only two global reaction steps and has only fluid reactants. It consists of an endothermal high temperature step of 800-1200 °C and slightly exothermal electrochemical reaction operating at about 80 °C. In this process, the water is dissociated indirectly by means of auxiliary substances, which are recycled. The aim of this work is discuss the possible introduction of solar source into the sulfuric acid decomposition. The study is limited to the case of Algeria. In the first part, the concept of thermochemical cycle to split water is briefly reported. The main concept of the hybrid sulfur thermochemical cycle are then described. Finally, some information about the potential of solar Algerian source are provided and the potential of hydrogen production using HyS cycle discussed.