Synthesis and thermal decomposition of alkoxy-, hydroxy-derivatives of Sovol polychlorbiphenyls technical mixture
- PDF / 1,164,865 Bytes
- 9 Pages / 595.276 x 790.866 pts Page_size
- 46 Downloads / 182 Views
ORIGINAL ARTICLE
Synthesis and thermal decomposition of alkoxy‑, hydroxy‑derivatives of Sovol polychlorbiphenyls technical mixture A. V. Maiorova1,2 · A. P. Safronov2 · T. V. Kulikova1,2 · T. I. Gorbunova3 · M. G. Pervova3 · K. Yu. Shunyaev1,2 Received: 24 January 2020 / Accepted: 20 April 2020 © Springer Japan KK, part of Springer Nature 2020
Abstract 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. Keywords Polychlorobiphenyls · Congeners · Technical mixtures · Nucleophilic substitution · Conversion · Thermal degradation · Gas phase
Introduction Polychlorinated biphenyls (PCBs) belong to the class of persistent organic pollutants and are the precursors for the formation of even more dangerous compounds, namely, polychlorinated dibenzodioxins and dibenzofurans (PCDD and PCDF) [1, 2]. PCBs are characterized by low dielectric constant and high boiling point, which made them widely used as a dielectric liquid in electrical condensers and electrical transformers [3]. In addition, technical mixtures based * T. V. Kulikova [email protected] 1
Institute of Metallurgy of the Ural Branch, Russian Academy of Sciences, Amundsena st. 101, Yekaterinburg 620016, Russia
2
Ural Federal University, Mira st. 19, Yekaterinburg 620002, Russia
3
I.Ya, Postovskii Institute of Organic Synthesis of the Ural Branch, Russian Academy of Sciences, S. Kovalevskoy st., 22, Yekaterinburg 620990, Russia
on PCBs were used in the composition of varnishes, waxes, synthetic resins, epoxy paints, paints for underwater parts of ships, coatings, lubricating and cooling emulsions, etc.[4]. According to the Stockholm Convention (2001), the complete destruction of PCBs stockpiles should be
Data Loading...
