Since 1990, our combined emissions of sulfur dioxide and nitrogen oxides are down more than 30 percent, while electricity generation has increased more than 40 percent to serve growing demand. Performance »
Through 2008, Southern Company:
- Invested about $6.3 billion in environmental controls. Planning to spend additional $3.1 billion through 2011 to further reduce emissions of nitrogen oxide, sulfur dioxide and mercury.
- Developed, with U.S. Department of Energy and KBR, the TRIG™ advanced coal gasification technology. This technology turns coal into gas that can be used to generate electricity more cleanly than traditional coal-fired power plants.
- Advanced one-of-a-kind, clean coal power generation, in partnership with the U.S. Department of Energy at the National Carbon Capture Center in Wilsonville, Alabama.
Particulate Matter and Air Quality Research
- SEARCH (Southeastern Aerosol Research and Characterization)
- ARIES (Aerosol Research and Inhalation Epidemiological Study)
Southern Company participates in data collection and research studies. Two leading studies, SEARCH and ARIES have provided an empirical foundation for air quality policy, practices, and emerging issues.
SEARCH monitors the relationship of myriad compounds comprising particulate matter to health effects. ARIES investigates associations between specific air pollution components and human health.
Together, this ongoing research provides data to help establish causal relationships between chemicals in the air and their effects on people, and ultimately air quality standards to safeguard human health.
Scrubbers and SCRs
At the end of 2008, Southern Company will have installed scrubbers at 11 of its coal units and SCRs at 15 of its coal units. Over the next few years, Southern Company has plans to add scrubbers at more than 15 units, SCRs to at least four units, and baghouses at three units.
How Scrubbers Work
Emissions from burning coal contain sulfur dioxide. The scrubber sprays the combustion emissions with a water and limestone mixture. The sulfur dioxide reacts with the limestone to form gypsum, a reusable compound. The clean gas rises out of the stack. This system removes up to 95 percent of the sulfur dioxide.
How Selective Catalytic Reduction Systems Work
SCRs remove up to 85 percent of nitrogen oxides, another emission from burning coal. An SCR, or selective catalytic reduction system, adds ammonia to the gases exiting the boiler. A catalyzed chemical reaction breaks the nitrogen oxides down to harmless nitrogen and water. Catalytic converters in autos are similar devices. Performance of Southern Company's first 13 SCRs was judged to be the best in the industry, according to a study by the Electric Power Research Institute.
Particulate Removal
Baghouses collect flyash and other particulate matter. Baghouses work like vacuum cleaners, forcing the flue gas through filter bags, which collect more than 99 percent of the dust particles.
Devices like SCRs, scrubbers, and baghouses require energy to operate. Typically emission-control devices reduce generation by about 2.5 percent.
Privacy Policy and Terms of Use | Cautionary Notice About Forward-Looking Statements
