Pathways of Chemical Recycling of Polyvinyl Chloride: Part 1
E. M. Zakharyan, Н. Н. Петрухина, А. Л. Максимов
Abstract
An increase in the level of production and consumption of polyvinyl chloride leads to the formation of a large volume of chlorinated waste, mostly as a component of municipal plastics waste. Incineration of such waste to produce energy results in emission of toxic gases (SO2, NOx) and of heavy metals and solid particles with flue gases, and also in formation of polychlorinated dibenzodioxins and dibenzofurans and of other aggressive chlorinated organic compounds. Therefore, recycling of waste containing chlorinated organic polymers becomes a serious problem. The review considers modern commercial processes for sorting municipal plastics waste, including various procedures for polymer waste separation. Procedures based on pyrolysis and gasification for chlorinated waste recycling are analyzed. Approaches to chemical recycling of polyvinyl chloride and of polymer mixtures and municipal waste containing polyvinyl chloride, namely, pyrolysis and low-temperature catalytic dechlorination, are described. The influence of the composition and kind of polymer waste on the degree of dechlorination is analyzed. Principles and mechanisms of mechanochemical processing of polyvinyl chloride waste in a mixture with chemical sorbents and with biological and technical wastes are presented.