25.8 THEORETICAL STUDY OF CONVERSION OF HALON CBrClF2 INTO ENVIRONMENTAL FRIENDLY SUBSTANCES

UDC 621.039.7.001.2 📖 Issue 25 / 2016 • 74-81 pages

 

V. Kukueva

V. Kukueva Ph. D., Postdoctoral Reseacher SI «Institute of Environmental Geochemistry NAS of Ukraine», v_kukueva@mail.ru

Abstract

The paper considers the problem of disposal of environmentally hazardous chemicals that were used in the past as effective extinguishing agents. The urgency of the issue is related to the large number of herbicides, pesticides, Freon and other hazardous chemicals, which are already out of use, or even banned for use, but in large quantities are stored in warehouses and require disposal. Experienced way to find effective methods of disposal of toxic substances is dangerous and economically inexpedient. The paper shows the possibility of using quantum chemical methods for the theoretical study of possible ways of chemical transformations of the freon CBrClF2 into the useful for industry substance difluoroethen CF2 = CH2, which manifests extinguishing properties, but does not apply to ozone-depleting compounds. It is shown that the conversion of CBrClF2 with the addition of methane is more energetically favorable than with the addition of hydrogen and likely than direct thermal decomposition. Among the by-products of the conversion as a result of quantum chemical calculations were detected such particles as the CF2 :, involved in many of the elementary stages of minimum energy and trifluorometane CF3H, which itself exhibits inhibitory properties with respect to the flame and in many studies is offered as an alternative extinguishing agent. In addition, it serves as a precursor for other, more effective flame retardant CF3I, which best can replace banned Freon CF3Br, as exhibits similar physical properties.

 

Key words: environmentally hazardous substances, halons, flame retardants, quantum-chemical calculation.

 

Article



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