In contrast to processes that remove mercury from utility flue gas, WRI’s patented process removes mercury from coal prior to combustion.
WRI’s two-stage process is integrated into a power plant’s design, thereby improving plant efficiency, reducing freshwater consumption through water recovery, and reducing emissions of mercury and other pollutants. In a report prepared for the U.S. Department of Energy (DOE), the WRI Pre-Combustion Mercury Removal Process was shown to remove up to 80 percent of the mercury in Powder River Basin (PRB) coal. With native mercury removal from normal combustion taken into account, more than 90 percent removal has been documented. The WRI technology has been shown to be competitive with post-combustion process on a cost basis and, it has been shown to increase plant efficiency by three to four percent for PRB coal plants.
The WRI process is compatible with both pulverized coal power plants, as well as advanced gasification/Integrated Gasification Combined Cycle (IGCC) plants.
A large-scale demonstration of the technology is proceeding under a DOE grant that focuses on field-testing advanced mercury control technologies. The project criteria require that the technology is capable of achieving at least a 50 percent increase over baseline in mercury removal at 50 percent or less of the baseline cost.
WRI's pre-combustion mercury removal process is the subject of a DOE-sponsored research project initiated in 2006. It is supported by utilities in both the U.S. and Canada. Project partners include the Energy and Environmental Research Center (EERC), Etaa Energy, Iowa State University, Washington Group International, and Foster Wheeler Development Corp. Industry-affiliated co-sponsors are the Electric Power Research Institute, Southern Company, Basin Electric Power Cooperative, North Dakota Industrial Commission, Montana-Dakota Utilities, Detroit Edison and SaskPower.