Nitrogen dioxide control systems

Pollutants. The problems posed by ak pollutants are very serious. Within a museum, measures can be taken to remove harmful substances as efficiently as possible by means of the installation of appropriate filter systems in the ventilation equipment. Proposed specification values for museum climate-control systems requke filtering systems having an efficiency for particulate removal in the dioctyl phthalate test of 60—80%. Systems must be able to limit both sulfur dioxide and nitrogen dioxide concentrations <10 /ig/m, and ozone to <2 /ig/m. ... 

Most industrial operations today now have pollution control systems, like the one shown in this chemical plant, to reduce the levels of sulfur dioxide and oxides of nitrogen released to the atmosphere. (Maximilian Stock Ltd./Photo Researchers, Inc.)... 

Chemical absorption in scrubbers, which employ any of water, nitric acid, alkaline solutions, or solutions of urea in water can reduce tail gas NOx concentrations to below 200 ppm [55]. Physical adsorption on molecular sieves is also a feasible control method. Activated carbon cannot be used because of oxidation hazards. Chemical and physical adsorption were improved if both nitric oxide and nitrogen dioxide were present in the tail gas rather than just nitric oxide, perhaps from the formation of dinitrogen trioxide (N2O3). An advantage of any absorption or adsorption system is that the NOx collected is recovered in some form. 

Local regulations require that the emissions of sulfur dioxide be less than 200 ppm (by moles) from your plant. They also require you to reduce nitrogen dioxide emissions to less than 50 ppm. You decide that the most economical method for control of these for your plant is to utilize ammonia-based processes. The proposed system is as follows ... 

The most common airborne pollutants are carbon monoxide, benzene, 1,3-butadiene, sulphur dioxide, nitrogen dioxide and lead. Air pollution is currently monitored by Integrated Pollution Control (IPC). This is a system established by Part 1 of the EPA which introduced two tiers of pollution control ... 

Huang, H., Allen, J.W., and Livengood, C. D., 1988, Combined Nitrogen Oxides/Sulfur Dioxide Control in a Spray-Dryer/Fabric-Filter System, ANL/ESD TM-8, Argonne National Laboratory, Argonne, IL, November. 

J. Lanier and co-workers, "Sulfur Dioxide and Nitrogen Oxide Emissions Control in a Coal-Eked MHD System," ASME Winter Annual Meeting Adanta, Ga., Dec. 1979. 

TTte most cost-effective methods of reducing emissions of NO are the use of low-NO burners and the use of low nitrogen fuels such as natural gas. Natural gas has the added advantage of emitting almost no particulate matter or sulfur dioxide when used as fuel. Other cost-effective approaches to emissions control include combustion modifications. These can reduce NO emissions by up to 50% at reasonable cost. Flue gas treatment systems can achieve greater emissions reductions, but at a much higher cost. 

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