In a program funded by the Department of Energy, Physical Sciences Inc. (PSI) has begun the development of a mercury sorbent using a zeolite material with a proprietary agent for improved capture of elemental mercury in utility power plants.

Previous research has shown the feasibility of using zeolites for mercury capture. Several sorbents were tested in the laboratory by flowing coal combustion flue gases with known concentrations of mercury through a heated filter containing a thin bed of each sorbent. Results showed that a zeolite treated with a proprietary agent performed as well as a treated activated carbon in removing elemental mercury from the gas stream.

This paper will present the latest work in this development program. It will focus on further laboratory work in which the zeolite sorbent with additive is injected into coal combustion flue gases that contain known concentrations of mercury. The objective of this effort is to evaluate sorbent efficiency under conditions that approximate full-scale utilities with electro-static precipitators. As in the previous fixed bed work, mercury concentration and speciation are measured using the modified Ontario Hydro Method. The test matrix will also include an acti-vated carbon sorbent so that a comparison can be made with the zeolite sorbent. Future work will include pilot-scale testing at a utility power plant.