Combustion of chlorinated hydrocarbons

Mere destruction of the original hazardous material is not, however, an adequate measure of the performance of an incinerator. Products of incomplete combustion can be as toxic as, or even more toxic than, the materials from which they evolve. Indeed, highly mutagenic PAHs are readily generated along with soot in fuel-rich regions of most hydrocarbon flames. Formation of dioxins in the combustion of chlorinated hydrocarbons has also been reported. We need to understand the entire sequence of reactions involved in incineration in order to assess the effectiveness and risks of hazardous waste incineration. 

Senkan, S. Combustion of chlorinated hydrocarbons. In Pollutants in Combustion Vovelle, C., Ed. NATO Science Ser. C 547, 2000a 303. 

Hydrogen chloride and small amounts of chlorine from the combustion of chlorinated hydrocarbons... 

In addition to the Wacker oxidation catalysts, supported eutectic molten salt CuCl/KCl-based catalyst systems have also been examined for other processes including, for example, production of synthesis gas from methanol for the use as on-board hydrogen production in vehicles [57] and quantitative combustion of chlorinated hydrocarbons to COx and HCI/CI2 at ambient pressure (200-500 °C) with silica-based systems [58,59]. 

Lopez-Fonseca R, Gutierrez-Ortiz JI, Gonzdlez-Velasco JR. Catalytic Combustion of Chlorinated Hydrocarbons Over H-BETA and PdO/H-BETA Zeolite Catalysts. Appl Catal A Gen 2004 271 39-46. 

Everaert K, Mathieu M, Baeyens J, Vansant E. Combustion of Chlorinated Hydrocarbons in Catalyst-coated Sintered Metal Eleece Reactors. J Chem Technol Biotechnol 2003 78 167-172. 

Blankenship A, Chang DPY, Jones AD, et al. 1994. Toxic combustion by-products from the incineration of chlorinated hydrocarbons and plastics. Chemosphere 28 183-196. 

Ahling B.. Bjorseth, A., and Lunde, G. Formation of chlorinated hydrocarbons during combustion of polyvinyl chloride. Chemosphere, 7(10) 799-806, 1978. 

PCBs are mixtures of chlorinated hydrocarbons. Regarding the source of contamination, they can be divided into two main groups intentional (commercial products) and unintentional (by-products of combustion, such as an incinerator trace amounts of PCBs have been reported in agricultural chemicals or chemical products as impurities) (UNEP Chemicals, 2002). PCBs were produced commercially in the United States from 1929 to 1977. Due to their chemical inertness, heat resistance, a high dielectric constant and nonflammable properties, they have been used extensively for a variety of industrial purposes, such as dielectrics in transformers and large capacitors as heat exchange fluids and in plastics (WHO, 1993). 

Not identified Kuopion University, Department of Environmental Sciences Kuopion University Formation of Chlorinated Hydrocarbons in Combustion of Waste Materials Ministry of Trade and Industry, Helsinki (Finland)... 

The incineration of chlorinated hydrocarbons is an interesting field of the catalytic offgas-cleaning because the needed process temperatures are lower than in thermal combustion. 

Senkan, S. Gupta, A. Robinson, J.M. Sooting limits of chlorinated-hydrocarbon methane air premixed flames. Combust. Flame 1983, 49, 305-314. 

Valeiras, H. Gupta, A.K. Senkan, S.M. Laminar burning velocities of chlorinated hydrocarbon-methane-air flames. Combust. Sci. Tech. 1984, 36, 123-133. 

Manganese oxides have long been known to be catalysts for a variety of gas clean-up reactions. Manganese/copper mbced oxide (Hopcalite) is the catalytically active component in gas mask filters for CO CO is converted to CO2 at room temperature [4]. Further applications of manganese oxide catalysts are the NH3 oxidation to N2 [5], the combustion of VOC [6,7] and methane [8], the oxidation of methanol [7], the O3 decomposition [9] and the NOx reduction [14]. Perovskite-type oxide catalysts (e.g. LaMnOs) have been proven to be effective catalysts for the total oxidation of chlorinated hydrocarbons [10]. Several studies have shown that besides preparation method and calcination temperature the kind... 

Among various natural sources, the largest amounts of chlorinated hydrocarbons are supplied into the air by forest fires. In the combustion of cellulose, 2.2 mg of methyl chloride are formed per 1 g of substance burnt. Anthropogenic sources include the combustion of PVC (polyvinyl chloride) wastes, burning of plants in agriculture and uncontrolled fires resulting from human activity. 

Chlorinated hydrocarbons. The total amount of chlorinated hydrocarbons in the atmosphere may be determined by a combustion method (combustion at 850 to 900°C Pt catalyst). The combustion products are absorbed in a sodium arsenite solution. The chloride formed is determined... 

All compounds were combusted with the required efficiency, with the exception of chlorinated hydrocarbons, which were seen to partially deactivate the catalyst. Chlorinated hydrocarbons are frequently difficult to destroy, with both chlorinated reagents and products acting as catalyst poisons and thus causing catalyst deactivation, resulting in a decrease in activity. A similar situation is seen for fluorinated VOCs. 

Ahling, B., A. Bjdrseth, and G. Lunde. 1978. Formation of chlorinated hydrocarbons during combustion of poly(vinyl chloride). Chemosphere 1 799-806. 

Combustion by Utilization of Chlorinated Hydrocarbon Side Products. 81... 

The crude gas mixture to be treated contains, in addition to hydrogen chloride and chlorine, considerable quantities of chlorinated hydrocarbons and other organic chlorine compounds. The mixture is subjected to a two-stage thermal treatment. It is fed into a first combustion chamber supplied with suflScient fuel and air. (Under some circumstances, replacing the combustion air either completely or partially with oxygen can be advantageous in this stage of the combustion process.)... 

Chlorinated hydrocarbon liquid streams from the oxychlorination process (this chapter), containing flnely divided carbonaceous solids and metallic corrosion products in solution and suspension are pumped into the lower portion of the fluidized bed. Air is used to fluidize the bed and to oxidize the feed. The reaction occurs at below 540° C. Combustion of the feed is essentially complete with no significant breakthrough of elemental chlorine and only minor breakthrough of chlorinated hydrocarbons (Benson, 1979). The heat of combustion is recovered by generating medium to high pressure steam inside coils placed in the bed. The pro-... 

In addition to the combustion of the hydrocarbon part, the catalytic oxidation of chlorinated aromatics also leads to HQ and CI2 that may generate the catalysts deactivation. Working with these mixed oxide catalysts eliminates this disadvantage due to at least partial chlorination of the surface component cations. 

Both CI2 and HCl have been shown to chlorinate hydrocarbons on fly ash particles. Pilot-scale data involving the injection of fly ash from municipal waste combustion (33) show that intermediate oxygen concentrations (4—7%) produce the highest levels of PCDD and PCDF. These data also show significant reductions in PCDD and PCDF emissions with the upstream injection of Ca(OH)2 at about 800°C. 

Flame Retardants. Because PVC contains nearly half its weight of chlorine, it is inherently flame-retardant. Not only is chlorine not a fuel, but it acts chemically to inhibit the fast oxidation in the gas phase in a flame. When PVC is diluted with combustible materials, the compound combustibiHty is also increased. Por example, plastici2ed PVC with > 30% plastici2er may require a flame retardant such as antimony oxide, a phosphate-type plastici2er, or chlorinated or brominated hydrocarbons (145,146). 

BPR [By-Product Recycle] A process for recycling the chlorine-containing by products from the manufacture of vinyl chloride, 1,2-dichloroethane, and other chlorinated hydrocarbons. Combustion with oxygen converts 90 percent of the chlorine to anhydrous hydrogen chloride, and 10 percent to aqueous hydrochloric acid. Developed by BASF and licensed by European Vinyl Corp. 

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