Incineration method

Hexachloroethane and waste containing hexachloroethane are classified as hazardous wastes by EPA. Generators of waste containing this contaminant must conform to EPA regulations for treatment, storage, and disposal (see Chapter 7). Rotary kiln or fluidized bed incineration methods are acceptable disposal methods for these wastes. Underground injection may also be used (HSDB 1995). 

For either plant type, incineration, or fuel type, these factors must be empirically determined and controlled. Because dioxins as effluents are concerned, it is possible to reduce I-TE values from about 50 ng/m to about 1 ng/m. Additional secondary measures (filter techniques) are therefore necessary for obtaining the lower limit value of 0.1 ng/m. Secondary measures are special filter techniques for pollutants formed in nongreen processes, also called end-of-pipe technology. The main part of technical incineration plants consists of filter devices, mostly coke as adsorbent is used, which must be decontaminated later by itself by burning in hazardous-waste incinerators. The inhibition technology, discussed later, is related on principles of primary (green) measures for a clean incineration method. 

According to the U.S. DOD, the capital costs for PWC are similar to the costs for conventional incineration methods (D213605, p. 242). In contrast, operation and maintenance (O M) costs are believed to be 15 to 20% higher for PWC than for incineration. Insufficient data existed, however, to perform an in-depth comparison of total O M costs for the two technologies... 

The electrochemical combustion (or electrochemical incineration) method, in which the organics are completely mineralized (i.e., oxidized to C02 and inorganic ions). 

Table V lists the air pollutants contained in the exhaust gas from the systems. The values vary to some extent with the properties of the refuse that is processed. The HC1, NOx and SOx concentrations obtained from the inflammable gas recovery and direct combustion methods are considerably lower than their concentrations in the conventional incinerator method.

On account of the rapid poisoning of the catalyst in the catalytic incineration method, the thermal incineration has been most widely employed. The combustion heat is used, for example, to preheat the air in paint shop dryers [14.165], [14.166]. 

In Germany, arsenicals such as Lewisite, Adamsite, Clark I and II, Sulphur- and Nitrogen mustards are destroyed by a special incineration method. Agents are drained into polyethylene barrels and incinerated directly at 1000°C [2]. Arsenicals are precipitated out of the incinerator scrubber water as FeAs04. The arsenic sludge is buried in drums in a waste dump (former salt mine). Since operation began in 1980, 73 tonnes of concentrated chemical weapon agents and 600 tonnes of contaminated materials have been destroyed. The cost estimate for Sulphur mustard is about 100 DM/kg. 

The incineration method for determining the residual matter in the binder extract is used by some extraction methods for residual binder content as an alternative method (see Figure 9.1). 

Tire rubber can be transformed into energy via the incineration method. This process is advocated by a number of the major tire and rubber companies and also by the major utility companies. Tire-derived fuel can be in the... 

Snow has reviewed (53 references) a number of different methods for reducing the volume of nuclear steam generator wastes. Disposal methods that are mostly mechanical that were considered include direct solidification, thermal degradation, incineration, and evaporation. Direct solidification methods include addition of a cement binder and solidification with a vinyl ester binder. The latter method was used to solidify the NS-1 waste from the decontamination of Dresden-1 after partial evaporation to reduce the volume. Thermal degradation and incineration methods require a large amount of equipment to ensure destruction of the very stable EDTA molecule, which must be subjected to temperature >200°C (392°F) to cause rapid degradation. 

While incineration is the preferred method of disposal for wastes containing high concentrations of organics, it becomes expensive for aqueous wastes with low concentrations of organics because auxiliary fuel is required, making the treatment expensive. Weak aqueous solutions of organics are better treated by wet oxidation (see Sec. 11.5). 

Compounds having low vapor pressures at room temperature are treated in water-cooled or air-cooled condensers, but more volatile materials often requite two-stage condensation, usually water cooling followed by refrigeration. Minimising noncondensable gases reduces the need to cool to extremely low dew points. Partial condensation may suffice if the carrier gas can be recycled to the process. Condensation can be especially helpful for primary recovery before another method such as adsorption or gas incineration. Both surface condensers, often of the finned coil type, and direct-contact condensers are used. Direct-contact condensers usually atomize a cooled, recirculated, low vapor pressure Hquid such as water into the gas. The recycle hquid is often cooled in an external exchanger. 

Disposal of exhausted soHds can be easily overlooked at the plant design stage, particularly when these have no intrinsic value alternative disposal methods might include landfiU of inert material or incineration, hydrolysis, or pyrolysis of organic materials. Liquid, soHd, and gaseous emissions are aU subject to the usual environmental considerations. 

When disposed of, all the nitroparaffins are considered to be hazardous waste. AH have the characteristic of ignitabHity however, 2-nitropropane also is a Hsted hazardous waste (U171) because of its toxicity. The preferred method of disposal is by incineration. GeneraHy, the nitroparaffins must be... 

Low Level Waste Treatment. Methods of treatment for radioactive wastes produced in a nuclear power plant include (/) evaporation (qv) of cooling water to yield radioactive sludges, (2) filtration (qv) using ion-exchange (qv) resins, (J) incineration with the release of combustion gases through filters while retaining the radioactively contaminated ashes (see Incinerators), (4) compaction by presses, and (5) solidification in cement (qv) or asphalt (qv) within metal containers. 

The common treatment methods are acidification, neutralization, and incineration. When oxahc acid is heated slightly in sulfuric acid, it is converted to carbon monoxide, carbon dioxide, and water. Reaction with acid potassium permanganate converts it to carbon dioxide. Neutralization with alkahes, such as caustic soda, yields soluble oxalates. Neutralization with lime gives practically insoluble calcium oxalate, which can be safely disposed of, for instance, by incineration. 

Scrap from municipal refuse may be in the form of source-separated steel cans, a mixed ferrous fraction, metal magnetically separated from mixed waste or incinerator ash, and C D debris. An ASTM specification (E1134-86) was developed in 1991 for source-separated steel cans. The Steel Recycling Institute has a descriptive steel can specification entitled "Steel Can Scrap Specifications". PubHshed standards for municipal ferrous scrap also include ASTM E701-80, which defines chemical and physical test methods, and ASTM E702-85 which covers the chemical and physical requirements of ferrous scrap for several scrap-consurning industries. 

Incineration in an approved combustion plant is the preferred method of disposal. Wastewater from succinic acid processes is suitable for biological degradation by activated sludge (188). Polymeric sorbents (189) and ferric chloride treatment processes (190) can also be used for wastes containing... 

Ash and Inorganic Constituents. Ash may be measured gravimetdcaHy by incineration in the presence of sulfudc acid or, more conveniendy, by conductivity measurement. The gravimetric result is called the sulfated ash. The older carbonate ash method is no longer in use. Ash content of sugar and sugar products is approximated by solution conductivity measurements using standardized procedures and conversion factors. 

Although there are minor differences in the HCl—vinyl chloride recovery section from one vinyl chloride producer to another, in general, the quench column effluent is distilled to remove first HCl and then vinyl chloride (see Eig. 2). The vinyl chloride is usually further treated to produce specification product, recovered HCl is sent to the oxychlorination process, and unconverted EDC is purified for removal of light and heavy ends before it is recycled to the cracking furnace. The light and heavy ends are either further processed, disposed of by incineration or other methods, or completely recycled by catalytic oxidation with heat recovery followed by chlorine recovery as EDC (76). 

Gaseous vent streams from the different unit operations may contain traces (or more) of HCl, CO, methane, ethylene, chlorine, and vinyl chloride. These can sometimes be treated chemically, or a specific chemical value can be recovered by scmbbing, sorption, or other method when economically justified. Eor objectionable components in the vent streams, however, the common treatment method is either incineration or catalytic combustion, followed by removal of HCl from the effluent gas. 

Wet Air Oxidation. With wet air oxidation, increased temperature and pressure are used to oxidize dilute concentrations of organics and some inorganics, such as cyanide, in aqueous wastes that contain too much water to be incinerated, but are too toxic to be treated biologically. In general, wet air oxidation provides primary treatment for wastewaters that are subsequendy treated by conventional methods. This technology can be used with wastes that are pumpable (slurries andUquids). 

Thermal Desorption. Thermal desorption is an innovative treatment that has been appHed primarily to soils. Wastes are heated to temperatures of 200 to 600°C to increase the volatilization of organic contaminants. Volatilized organics in the gas stream are removed by a variety of methods including incineration, carbon adsorption, and chemical reduction. 

One physical method that has attracted some commercial interest is evaporation several evaporative plants were installed in Japan in the early 1970s, nearly all followed by incinerators for the sludge produced (60). They are, however, expensive in both capital and operating costs. The most recent evaporation systems use a process known as vapor recompression, which has the claimed advantage of much lower operating costs than the eadier evaporative processes used in the wool industry. Capital costs of these processes are still high. 

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