Nitrogen dioxide disposal

Excess nitrogen dioxide and waste material containing this substance should be placed in an appropriate container, clearly labeled, and handled according to your institution s waste disposal guidelines. For more information on disposal procedures, see Chapter 7 of this volume. ... 

Disposing of such huge quantities of higher hydrocarbon waste gases by incineration impacts on the environment as it releases carbon dioxide, nitric oxide, nitrogen dioxide and sulfur oxide emissions into the atmosphere. 

Dispose of liquid nitrogen dioxide by running the liquid into excess 5-10 percent aqueous sodium hydroxide solution at a moderate rate. Transfer the resulting solution to a plant disposal unit for neutralization and disposal. [2] and [4]... 

Should it become necessary to dispose of nitrogen dioxide from a leaking cylinder, the following procedure may be used. Move the cylinder to a hood or safe out-of-doors area. 

Normal PS requires an adequate amount of eaeh AA to be available in eells. Since some AAs are needed in larger amounts tlian others, the pattern of AAs (relative proportions) in the AA pool is important. AAs present in excess of the amount needed for synthesis are typically utilized for energy by oxidation to carbon dioxide and water, with the nitrogen component disposed of primarily as urea in the urine. 

The increasing number of atomic reactors used for power generation has been questioned from several environmental points of view. A modern atomic plant, as shown in Fig. 28-3, appears to be relatively pollution free compared to the more familiar fossil fuel-fired plant, which emits carbon monoxide and carbon dioxide, oxides of nitrogen and sulfur, hydrocarbons, and fly ash. However, waste and spent-fuel disposal problems may offset the apparent advantages. These problems (along with steam generator leaks) caused the plant shown in Fig. 28-3 to close permanently in 199T. 

In MSO processing, organic wastes are chemically broken down to carbon dioxide, nitrogen gas, and water vapor in a bath of molten salt. The salt may be of various compositions, with variable melting points. Inorganic materials react with the salt mixture, producing ash and salts for subsequent treatment or disposal. The oxidation takes place at lower temperatures than incineration or other combustion technologies. 

While the development of flue gas clean-up processes has been progressing for many years, a satisfactory process is not yet available. Lime/limestone wet flue gas desulfurization (FGD) scrubber is the most widely used process in the utility industry at present, owing to the fact that it is the most technically developed and generally the most economically attractive. In spite of this, it is expensive and accounts for about 25-35% of the capital and operating costs of a power plant. Techniques for the post combustion control of nitrogen oxides emissions have not been developed as extensively as those for control of sulfur dioxide emissions. Several approaches have been proposed. Among these, ammonia-based selective catalytic reduction (SCR) has received the most attention. But, SCR may not be suitable for U.S. coal-fired power plants because of reliability concerns and other unresolved technical issues (1). These include uncertain catalyst life, water disposal requirements, and the effects of ammonia by-products on plant components downstream from the reactor. The sensitivity of SCR processes to the cost of NH3 is also the subject of some concern. 

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