How are emissions from the combustion process controlled?
While the specific pollution controls used vary from plant to plant, all facilities are equipped with systems for reducing levels of nitrogen oxides (NOx), sulfur dioxide (SO2) and various chemicals. At all facilities, a scrubber neutralizes acid gases. Electrostatic precipitators, fabric filters or a combination of these systems trap fly ash and other particles. Carbon is also injected into combustion gases to further reduce concentrations of mercury and organic chemicals. These control technologies combine to significantly reduce emissions of gases, heavy metals and soot so they will not exceed the limits established by MassDEP regulations and individual facility permits. With state-of-the-art controls in place, combustion facilities emit considerably less toxic and smog-causing pollution than they did even a few years ago. It is important to note, however, that no combination of technologies available today can completely eliminate emissions from combustion.
