Synthesis and thermal decomposition of alkoxy-, hydroxy-derivatives of Sovol polychlorbiphenyls technical mixture

Important experimental data were obtained for the development of an integrated technology for the destruction of accumulated volumes of environmentally hazardous technical mixtures of polychlorobiphenyls. The proposed technology for the destruction of ecotoxicants includes a chemical and subsequent pyrolytic stages. It was established for the first time that the alkoxy- and hydroxy-derivatives of polychlorobiphenyls obtained by chemical interaction with polyethylene glycols in the presence of alkali and with sodium methoxide contain a reduced amount of chlorine in the structure and are less thermostable compounds in comparison with the initial congeners of the Sovol technical mixture. It was found that heating the Sovol technical mixture leads to the evaporation of toxic polychlorobiphenyl congeners and the release into the atmosphere. During the thermal degradation of the obtained alkoxy- and hydroxy-derivatives of polychlorobiphenyls, there is no evaporation of PCBs congeners, and decomposition to the simplest environmentally acceptable volatile substances (CO2, H2O, HCl, etc.) is observed. Formation of polychlorinated dibenzodioxins and dibenzofurans is not detected. The proposed comprehensive two-stage approach to the destruction of technical mixtures of polychlorobiphenyls requires less energy and is characterized by a significant reduction in the emission of hazardous polychlorobiphenyls.