(509a) Conceptual Design and Techno-Economic Analysis of a Solar Hybrid Sulfur Process

The hybrid sulfur (HyS) cycle is the only practical two-step thermochemical water-splitting cycle with all fluid reactants. It is also one of the most advanced of the thermochemical water-splitting cycles, with both reaction steps having been experimentally validated and with detailed system designs having been proposed for hydrogen production from a continuous heat source like an advanced, high-temperature reactor. This presentation describes the conceptual design of a HyS process based on a variable heat source, specifically concentrated solar energy, which is only available for part of the day. The presentation will address how the diurnal variation was accommodated by the design of the plant and will lay out a techno-economic analysis for a hypothetical 50-MT/d solar hydrogen plant in the southwestern US. It will conclude with a development path toward hydrogen production at $2/kg H₂, the renewable hydrogen production cost target set by the DOE Office of Energy Efficiency and Renewable Energy.