Thermal destruction chloride

Thermal destruction systems have become recognized over the past decade as an increasingly desirable alternative to the more traditional methods of disposing of hazardous wastes in landfills and injection wells. What are some of the problems in the combustion of substances such as methylene chloride, chloroform, trichloroethylene, waste oil, phenol, aniline, and hexachloroethane ... 

Experimental and theoretical studies are presented from a laboratory-scale thermal destruction facility on the destructive behavior of surrogate plastic and nonplastic solid wastes. The nonplastic waste was cellulosic while the plastic waste contained compounds such as polyethylene, polyvinyl chloride, polystyrene, polypropylene, nylon, rubber, and polyurethane or any of their desired mixtures. A series of combustion tests was performed with samples containing varying composition of plastic and nonplastic. Experimental results are presented on combustion parameters (CO, excess air, residence time) and toxic emissions (dioxin, furan, metals). 

THERMAL DESTRUCTION OF POLYPROPYLENE, POLYSTYRENE, POLYETHYLENE, AND POLYVINYL CHLORIDE... 

Extensive kinetic investigations have also indicated that the activation energy of the overall thermal-decomposition process is substantially lowered by the addition of sodium chloride and sodium carbonate. Madorsky and coworkers have, therefore, proposed that these salts catalyze the dehydration of cellulose by scission of the C —O bonds (bonds a, b, and c in 1 see p. 438), and that this results in destruction of the hexose units and increases the yield of water and char at the expense of levoglucosan. This theory has found substantial support in subsequent experiments and publications however, it may be noted here that Golova and associates" consider that inorganic salts promote the cleavage of C—C, rather than C—O, bonds in the macromolecule. 

In view of the labile nature of the weak peroxide bond, the cyclization methods must be executed at low temperatures (—30 to + 10°C), but in the case of the thermally more stable derivatives, room temperature (up to -b 30°C) can be tolerated. In the silver ion-catalyzed cyclizations, solvents such as alkanes (pentane, hexane, cyclohexane) and haloalkanes (carbon tetrachloride, methylene chloride, dichlorodifluoromethane) are advantageous. In the base-catalyzed reactions, protic solvents are employed, that is, water and/or methanol and ethanol but heterogeneous solvent systems, for example, aqueous methanol and pentane, are useful. The latter conditions are designed to minimize base-catalyzed destruction of the dioxetane product by extraction into the alkane phase. The preparations of 1,2-dioxetanes via the Kopecky method are collected in Table 1. 

Literature presents numerous data on the syntheses by ML method of oxide layers of titanium, aluminum, chromium, phosphorus, tantalum and series of other elements on silica and alumina surfaces, when appropriate chloride and vapour of water are used as initial reagents [13,35,18,42]. The synthesis thus proceeds without the change of oxidation state of elements. But the stability of Si-O-M bonds in the process of gaseous treatment of element-chloride surface structures is of significant importance. Our researches have shown [44,68], that the strength of Si-O-M bonds is influenced by the thermal stability of element-oxide chloride groups, quantity of their bonds with surfaces (factor m) and series other ones. The reason for the destruction is the hydrogen chloride which educes in the process of vapour hydrolysis [68]. 

As a result of photochemical destruction, the halogen-containing polymers split off low-molecular-weight products having analogous composition to those isolated during thermal-oxidative destruction. For example, as polyvinyl chloride breaks down, the release of hydrogen chloride is observed. 

They destroy thermally labile structural defects. These defects are tertiary ehloride, internal allylie chloride, and polyenyl chloride groups. Their destruction involves the nucleophilic displacement of chloride and possibly the addition of the thiols to polyene double bonds (as in reaction 2, for example). 

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