High-Capacity Sorbent for Removal of Mercury from Flue Gas

In December 2000, EPA announced its intent to regulate the emission of mercury from coal-fired power plants. ADA Technologies, Inc., is developing a family of new disposable sorbents for this application. The sorbents consist of a natural silicate doped with chemicals to capture and immobilize vapor-phase mercury and mercury compounds. Laboratory testing in Phase I has shown the new materials to have two to three times the capacity for mercury compared to activated carbon, with projected costs lower than those for activated carbon. In Phase II, a reproducible preparation process that can be scaled to mass production will be developed. Additional laboratory tests will be run to characterize the relative mercury removal performances of the several candidate dopant chemicals. Once the optimum formulation has been identified, a test will be run in which sorbent is injected into the exhaust gas from a pilot coal combustor. The project team includes an architect/engineering firm and a major supplier of the natural silicate raw material. One project team member has committed to a cash investment to secure Option funding for Phase II, when prototype sorbent performance milestones are met. In the Option task, the project team will set up a pilot test system at an operating power plant, and will evaluate performance of the new sorbent on a slipstream of flue gas from the plant. A joint venture will be established in parallel with the Phase II project to commercialize the new sorbent. EPA is due to issue draft regulations for mercury control in 2003, and finalize them in 2004. By 2007, a total of 1,100 power plants in the United States will be required to control mercury emissions. Estimated control costs using activated carbon range from $2 billion to $5 billion annually, with carbon costs comprising well over $1 billion of that total. The high-performance ADA sorbent will be a drop-in replacement for activated carbon, with similar low capital equipment and installation costs. The joint-venture partners will bring experience in the utility industry, production of the raw material, and development of mercury control technologies to the new entity. The joint venture will market a mercury control solution to the utility industry - one that includes equipment, sorbent, and installation/startup elements. Additional applications for the new sorbent include replacement of activated carbon in municipal waste and medical waste incinerators, and in industrial processes where mercury control is an issue, such as precious metals production.