Plastics recycling - Part 4 – The physicochemical recycling methods Solvent extraction, chemolysis, thermolysis

The mechanical recycling, useful for sorted plastics, is unsuitable for the considerable stream of mixed plastics included in municipal solid wastes and shredders coming from end-of-life vehicles or electric & electronic equipment. For those, mass-recycling methods are more suitable. Physicochemical methods can be used to recover either a very pure polymer or, at the opposite, basic components or monomers or oligomers. These opposite strategies lead to very different products, results and economic balances. * Solvent extraction leading to pure polymers directly reprocessable, * Chemolysis leading to monomers and oligomers to be used for polymerization of new virgin polymers from the same original structure or a different one, * Thermolysis leading to oils, gases or basic components reusable as feedstocks for chemical industry or as alternative fuels. Obviously, the increase in value rises the more so as the by-products are sophisticated, the recovery as alternative fuels being not very exciting.