(546c) Effect of Water Transport On the Hybrid Sulfur Electrolyzer

Efficient production of clean hydrogen on a large scale is necessary for the transition to a hydrogen economy. Traditional methods of hydrogen production use fossil fuels, which are not renewable and contribute to greenhouse gas emissions. In addition, the hydrogen produced by traditional methods may contain impurities. The hybrid sulfur thermochemical cycle, because it does not require fossil fuels, can potentially produce large quantities of hydrogen without contributing to greenhouse gas emissions. Its high-temperature step makes this process ideally suited to be used with advanced nuclear reactors. Researchers at the University of South Carolina have identified the critical design and operating parameters of the electrolysis step of the hybrid sulfur cycle. Realizing that water transport in the polymer electrolyte membrane is critical to electrolyzer operation, a mathematical model has been developed and coupled with experimental data to identify the key components of water transport. Here we present the water transport model, and discuss the effects of water transport on electrolyzer operation via its influence on reversible voltage and sulfuric acid concentration.