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None Provided Zero Emissions Technology: Current Technologies and Future Developments in Electrostatic Precipitators Zero Emissions Technology is a company located in New Durham, NH. They develop new technologies targeted at coal fired power plants. They have recently developed a new air emissions technology that will meet current and pending air pollution regulations. Their product, Electro-Catalytic Oxidation Technology, allow the combined removal of particulates in the air waste stream. The new technology can be retrofitted onto existing electrostatic precipitators (ESP), according to the industry, is not as expensive as other air pollution control technologies. The Electro-Catalytic Oxidation Technology also has many technological advantages to more conventional ESPs. Zero Emissions Technology (ZET) is a company who develops new technologies in air pollution control technologies to meet the demands of new regulations on air emissions. In the past, their focus has been on air pollution control technology for large stationary sources, such as coal fired power plants. In the future, their research will be to discover new technologies not only for air pollution, but also in water and solid waste. (ZET, 1999). Zero Emissions Technology has developed a new technology that focuses on the combined removal of particulates for coal fired power plants. Electro-Catalytic Oxidation Technology is a product by Zero Emissions Technology (ZET). This new technology that ZET is has developed will enable the combined removal of nitrogen oxides (NOx), sulfur dioxide (SO2), mercury (Hg), and fine particulate matter (PM2.5) from the flue gas of coal fired power plants. This new technology will collect at least 70% of NOx, 50% of SO2, 70% of mercury (Hg), and 90% of PM2.5 in a single unit that can be retrofitted into the last fields of existing electrostatic precipitators (ESP) (ZET, 1999). This will allow coal fired plants to meet new air emission requirements with minimal impact on their generating costs. It can be retrofitted into the last fields of existing ESP. Electo-Catalytic Oxidatin Technology uses a proprietary gas discharge technology to convert NOx and SO2 to acid mists, and to oxidize elemental mercury. It also uses advances in wet ESP technology to remove acid mists and other fine particles without saturating flue gas. The Electro-Catalytic Oxidation system consists of three sections: gas converter, condensing wet ESP, and acid recovery (ZET, 1999). The Gas Converter is used for the electrical oxidation of NOx, SO2 and Hg. As the flue gas enters the Gas Converter, it is exposed to a high voltage discharge which creates ionized species to oxidize pollutants. The oxidized pollutants then form the following particulates: • NOx gas forms nitric acid (HNO3) aerosol mist • SO2 gas forms sulfuric acid (H2SO4) aerosol mist • Elemental mercury vapor forms mercuric oxide (HgO) particulate Chemical reactions are initiated by collisions of high energy electrons with water and oxygen molecules present in the flue gas stream. This leads to the formation of oxygen and OH radicals. The oxygen and OH radicals then act to oxidize particulates that are present in the gas stream, particularly NOx, SO2, and Hg. Reactions subsequent to oxidation which produce acids take place in the discharge reactor or after the gas exits the reactor. All of the reactions can be made to occur at low temperature (150-300°̊F). The second part of the Electro-Catalytic Oxidation system is the Condensing Wet ESP. The Condensing Wet ESP is used for acid aerosol and fine particulate collection. Wet electrostatic precipitators have been used successfully in industrial applications to collect acid mists for over 50 years, particularly in metallurgical plants and in sulfuric acid manufacturing. Wet ESPs have also shown to be very efficient collectors of PM2.5 and hazardous air pollutants, such as HgO. In the Electro-Catalytic Oxidation system, the condensing wet ESP serves two primary objectives: to remove acid mist from the gas stream; and to act as a "scrubber" to remove additional NO2 and SO2 which is not converted directly to acids by the Gas Converter. At the exit of the condensing wet ESP, approximately 20% of the NOx and 50% of the SO2 will remain in the flue gas to be emitted from the stack. The wet ESP effluent which includes nitric and sulfuric acids, ash, and heavy metals will be directed to the Acid Recovery System for further processing. The Acid Recovery System treats effluent from the wet ESP. The wet ESP effluent will consist of approximately ten percent ash, nitric and sulfuric, and heavy metals. Conventional technology can separate the ash and acids, and concentrate nitric and sulfuric acids, leaving a salable byproduct. Technological Advantages of Electro-Catalytic Oxidation Technology are as follows: • No reagents to purchase or handle • No new waste streams requiring landfill disposal • Flue gas remains above saturation • Low system pressure drop (use existing fan) • Uses existing plant systems (steam, water) and footprint • Uses conventional materials and power supplies • Should meet or exceed pending emissions limits for Hg and PM2.5 • Produces valuable byproducts Zero Emissions Technology. (Spring 1997). New Technology Demonstration: Pilot Installation for Full-Scale Arc Snubber Power Supply. Breakthrough - A Zero Emissions Technology Technical Journal. New Durham, NH. Zero Emissions Technology. (Spring 1997). Combined removal of nitrogen oxides (NOx), sulfur dioxide (SO2), mercury (Hg), and fine particulate matter (PM2.5) from the flue gas of coal fired power plants. Breakthrough - A Zero Emissions Technology Technical Journal. New Durham, NH. Larry S. Monroe. Testing of a Combined Dry and Wet Electrostatic Precipitator for Control of Fine Particulate Emissions from a Coal-Fired Boiler. Southern Research Institute. Bibliography:

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