The Environmental Protection Agency (EPA) in December 2011 finalized a rule to reduce emissions of toxic air pollutants from power plants. Specifically, these Mercury and Air Toxics Standards (MATS) for power plants will reduce emissions from new and existing coal- and oil-fired electric utility steam generating units.
The goal of MATS is to reduce emissions of heavy metals, including mercury, arsenic, chromium, and nickel; and acid gases, including hydrochloric acid and hydrofluoric acid.
The EPA believes about 40 percent of coal-fired units covered by the rule do not have advanced controls in place. MATS applies to plants larger than 25 megawatts (MW) that 'burn coal or oil for the purpose of generating electricity for sale and distribution through the national electric grid to the public'.
For all existing and new coal-fired plants, the rule establishes numerical emission limits for mercury, for toxic non-mercury metals, and HCl/toxic acid gases. Plants may also show compliance with the HCl and HF limits by limiting the moisture content of their oil.
The rule also establishes emission standards for SO2 (as an alternate to HCl) for certain subcategories of power plants.
Breen provides demonstrations of a range of economically feasible technologies including dry sorbent injection to help meet MATS standards.