Bench-Scale Testing of Attrition Resistant Moving Bed Sorbents

Integrated Gasification Combined Cycle (IGCC) systems with cold-gas cleanup have now reached the early stages of commercialization. The foundation for this was successful completion of the Cool Water Coal Gasification Program several years ago. Destec Energy, Inc., a subsidiary of Dow Chemical Company, has a plant in operation in Louisiana, and the 2 Wabash River Plant in Indiana is now starting up. A similar plant based on the Shell gasification technology is operating in the Netherlands. In two new plants now under construction, the Tampa Electric Plant in Florida and the Sierra Pacific Power Plant in Nevada, incorporating hot-gas cleanup technology is desirable. Unfortunately, some nagging problems remain with both sulfur sorbent and particle filter technology that may result in the use of cold-gas, rather than hot-gas, cleanup in these plants. With sulfur sorbents, the main problems are with mechanical property degradation and/or loss of sulfur capacity over many sulfidation-regeneration cycles. The sorbents receiving the most attention are all zinc based. They include various zinc titanate formulations and proprietary materials developed by the U.S. Department of Energy/Morgantown Energy Technology Center (DOE/METC) staff and the Phillips Petroleum Company. The investigators on this project are now completing their third year of effort on a superstrong zinc titanate sorbent. Prior to this year, various formulations were prepared and evaluated for their potential use in fixed- and fluidized-bed hot-gas desulfurization systems. A unique feature, the reason for the high strength, is that the zinc titanate is contained in a matrix of titanium dioxide. Its crush strength is more than 6 times that prior investigators achieved.