Highly Efficient Removal of Mercury from Industrial Flue Gas

Coal-fired utilities emit 48 tons of elemental mercury into the atmosphere each year. Rising costs and escalating energy demands are expected to increase our reliance on energy produced by these facilities. However, with the Clean Air Mercury Rule (CAMR), mercury emissions from these utilities must ultimately be decreased to 15 tons for Phase II by 2018. To meet this mission cap, new technologies must be realized that reduce the output mercury with minimal implementation and operational costs. The first phase of CAMR, required in 2010, encourages mercury control technologies based on “co-benefit” reductions. Frontier’s SBIR technology is intended as a “co-benefit” technology and involves a method and product for reducing persistent elemental mercury present in the flue-gas at coal-fired utilities. The technology prescribes a water-soluble organic compound as a simple amendment, which is added as a liquid to the utility’s existing wet flue-gas desulphurization (FGD) unit. The amendment forms an insoluble precipitate, sequestering the elemental mercury, which is readily separated from the produced gypsum with little or no additional capital investment. Phase I results demonstrated that the proposed organic compounds are capable of removing elemental mercury from a synthetic flue-gas using a pilot-scale, Venturi scrubber. Under optimized conditions, 95 percent of elemental mercury present in the gas phase can be removed and greater than 99 percent of this mercury can be simultaneously complexed in the scrubber water. The product also will remove greater than 99 percent of dissolved or inorganic mercury. The technology has been shown to work effectively over the pH range of a typical wet FGD scrubber (pH 5-8). The primary goal of Phase II research is to translate the technology from the Phase I pilot system to a beta-scale test at a working coal-fired utility. To accomplish this, investigations into the mechanism of operation, fate of mercury in the by-product, and compatibility of the proposed technology within installation requirements will be made. The Southern Company has offered its Mercury Research Center at Plant Crist in Pensacola as a beta site, and Black and Veatch are interested in sponsoring the Commercialization Option of the proposal should the initial Phase II results show promise. CCI, a domestic chemical manufacturer, has prepared to produce the organic compound on a commercial scale at a market competitive price.