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Show INCINERATION OF NITROGEN-BEARING WASTES Incineration is perhaps the safest and most effective method for the disposal of many industrial wastes. Practically all organic compounds can be incinerated with an assured level of destruction. When burning hydrocarbons, the combustion process produces an, H20 and some "allowable" quantities of un burnt hydrocarbons, CO and oxides of nitrogen (NOx). Single-stage burning of wastes containing bound nitrogen can produce NOx emissions exceeding those dictated by environmental concerns or mandated by regulatory agencies. The incineration of nitrogen-bearing wastes, thus, requires a specialized approach. John Zink Company's NOxidizer' " incinerator employs a proprietary three-stage incineration process that limits NOx formation when burning these wastes. Wastes The NOxidizer'" system is capable of incinerating a wide variety of bound nitrogen-containing gas and liquid wastes. Nitrogen in the chemical waste can be in the organic or inorganic form; examples of the fonner are amines, nitriles, and nitroaromatics; examples of the latter are ammonia, HCN and even NOx. A small process stream containing some quantity of NOx can be treated to produce a cleaner stream that contains comparably less NOx than the original waste. It should be noted that the NOxidizer'" system is not suitable for NOx reduction in flue gases from large combustion processes like those of utilities. It is also not an appropriate method for waste streams containing large quantities of air, water, or inerts due to the large amount of auxiliary fuel it would take to operate such units. Wastes can be primarily organic or aqueous, gaseous or liquid. These may contain chlorinated or sulfonated hydrocarbons which will necessitate the removal of acid gases downstream of the incinerator. Process The NOxidizerlll system provides a means of effectively disposing of nitrogen-bearing wastes in a three-stage combustion process (Fig. 1) with limited NOx emissions. In the first stage, the waste and fuel are burned with less than the stoichiometic requirement of oxygen. Usually the oxygen is supplied by combustion air, but may be supplied by the NOx or oxygen contained in the waste gas stream. The temperature in this stage is controlled at or above 2200-F with a residence time of about 2.0 seconds. The combustion process under starved-air conditions produces CO2, H20, and a certain quantity of combustibles (CO and H2). To limit NOx formation, the level of combustibles maintained is dependent on the type of nitrogen-bearing waste being burned. For instance, ammonia or acrylonitrile may require 8 to 10 percent combustibles by volume whereas a NOx-containing stream may require 16 to 18 percent 1 |