Thermal Removal Of Mercury From Spent Powdered Activated Carbon (Pac) Sorbent In Coal-fired Electric Power Plants

The US Environmental Protection Agency (EPA) issued the first ever federal rule to permanently cap and reduce mercury emissions from coal-fired power plants on March 15, 2005. The rule referred to as The Clean Air Mercury Rule (CAMR) when fully implemented, will reduce utility emissions of mercury from 48 tons a year to 15 tons by 2018, a reduction of nearly 70%. These mandatory declining caps coupled with significant penalties for noncompliance, will ensure that mercury reduction requirements are achieved and sustained. In anticipation of this rule, scientists and organizations in collaboration with EPA and US Department of Energy (DOE) are carrying out research to understand the science of mercury speciation, and its fate and transport within the atmosphere, in order to develop more efficient and cost-effective mercury control technologies and devices. This research develops and demonstrates a technology to liberate mercury adsorbed onto powdered activated carbon (PAC) sorbent by the TOXECON TM process, and recommends further evaluation of the regenerated PAC. The TOXECONTM process is the patent of Electric Power Research Institute (EPRI). It involves injecting activated carbon downstream of an existing primary particulate control device and upstream of a iiisecond particulate control device. The pilot scale (Air Scale) apparatus removed 65%, 83% and 92% of mercury without addition of catalysts when run at 900 o F, 1000 o F, and