Solar-Powered Hydrogen Production

UCF researchers have been conducting solar thermochemical hydrogen production since 2001. Solar-driven thermochemical water splitting cycles (TCWSCs) provide an energy-efficient and environmentally attractive method for generating hydrogen. Solar-powered TCWSCs utilize both thermal (i.e. high temperature heat) and light (i.e. quantum energy) components of the solar resource, thereby boosting the overall solar-to-hydrogen energy conversion efficiency compared to those with heat-only input.

UCF’s patented solar-powered TCWSC, a novel hybrid photo-thermochemical sulfur-ammonia (S-A) cycle, is a modification of the well-known Bowman-Westinghouse (B-W) hybrid cycle wherein the electrochemical step is replaced by a photocatalytic process. The main reaction (unique to UCF’s S-A cycle) is the light-induced photocatalytic production of hydrogen and ammonium sulfate from an aqueous ammonium sulfite solution. Ammonium sulfate product is processed to generate oxygen and recover ammonia and SO₂. Ammonia and sulfur dioxide are then recycled and reacted with water to regenerate ammonium sulfite.

Years of Research: 2001 – 2017

Sponsored by: U.S. Department of Energy; NASA Glen Research Center; Qatar’s National Priority Research Program through the Texas A&M University

Selected Publications

1. Solar hybrid photo-thermochemical sulfur-ammonia water-splitting cycle: Photocatalytic hydrogen production stage
2. Hybrid Photo-thermal Sulfur-Ammonia Water Splitting Cycle: Thermodynamic Analysis of the Thermochemical Steps
3. Particle Model Investigation for the Thermochemical Steps of the Sulfur– Ammonia Water Splitting Cycle
4. Thermal decomposition of (NH₄)₂SO₄in presence of Mn₃O₄
5. A Novel Pd-Cr₂O₃/CdS Photocatalyst for Solar Hydrogen Production Using a Regenerable Sacrificial Donor
6. Development of Efficient Photo-reactors for Solar Hydrogen Production
7. Hydrogen Production via Photolytic Oxidation of Aqueous Sodium Sulfite Solutions

US Patents

• 8,691,068        Solar metal sulfate-ammonia based thermochemical water splitting cycle for hydrogen production, Huang, C.; T-Raissi, A.; Muradov, N.Z. (April 8, 2014)
• 8,207,081        Nanocomposite for photocatalytic hydrogen production and method for its preparation, Huang, C.; Yao, W.; Muradov, N.Z.; T-Raissi, A. (June 26, 2012)

Awards

• 2016 Best Paper Award, at the International Conference on H₂ Production in Hangzhou, China
• 2004 Innovative Technology Award, 15^th World Hydrogen Energy Conf., Yokohama, Japan