Anode Concepts for SO2 Crossover Reduction in the HyS Electrolyzer

The idea of a hydrogen-fueled future is positive on many levels (better air quality, increased energy efficiency), but its realization depends critically on finding a non-carbon, or at least renewable, source of hydrogen. Thermochemical cycles, such as the Hybrid Sulfur (HyS) process, have the potential of providing hydrogen from nuclear energy at high efficiency with minimal environmental impact. This project will develop an innovative, HyS electrolyzer design to correct the SO2 crossover problem inherent to current HyS electrolyzers. This approach, which involves the regulation of SO2 gas delivery to the HyS electrolyzer anode, will help to minimize the activity of SO2 at the anode-membrane interface, thereby diminishing the driving force for diffusion of SO2 to the electrolyzer cathode. Phase I will focus on reducing SO2 crossover by at least 50% while maintaining high electrochemical performance. Phase II will demonstrate the scaling up of this technology to a hydrogen production rate of 1.6 lbs H2/day. Commercial Applications and other Benefits as described by the awardee: The wide-scale deployment of hydrogen energy technologies is a potential answer to the crises of air pollution, global warming, energy efficiency, and security. The technology should have a significant positive effect on the prospect of a successful integrated laboratory scale (ILS) or pilot plant demonstration.