Plastic wastes tertiary recycling

This chapter deals exclusively with tertiary recycling by pyrolysis and catalytic cracking of plastics waste alone and by coprocessing with petroleum residue or heavy oils to... 

TECHNOLOGIES FOR TERTIARY RECYCLING OF MIXED PLASTIC WASTE (MPW)... 

Pyrolysis is a tertiary or feedstock recycling technique capable of converting plastic waste into fuels, monomers, or other valuable materials by thermal and catalytic cracking processes. This method can be applied to transform both thermoplastics and thermosets in high-quality fuels and chemicals. Moreover it allows the treatment of mixed, unwashed plastic wastes. 

The severe limitations on the mechanical recycling of plastic wastes highlight the interest and potential of feedstock recycling, also called chemical or tertiary recycling.17,18 It is based on the decomposition of polymers by means of heat, chemical agents and catalysts to yield a variety of products ranging from the starting monomers to mixtures of compounds, mainly hydrocarbons, with possible applications as a source of chemicals or fuels. The products derived from the plastic decomposition exhibit properties and quality similar to those of their counterparts prepared by conventional methods. 

Tertiary recycling is the production of basic chemicals or fuels from segregated plastic scrap or plastic material that is part of a municipal waste stream or other source. ... 

T. R. Curlee and S. Das, "Back to Basics The Viability of Recycling Plastics by Tertiary Processes , Working Paper 5, Yale Program on Solid Waste Policy, Yale University, New Haven, CT, Sept. 1996... 

Data relating to the nature and quantities of plastics wastes arising from industrial processes and municipal refuse have been reviewed [1,2], together with a consideration of the economics and appropriateness of primary, secondary, tertiary and quaternary recycling respectively. 

Tertiary or quaternary recycling, (recovery of chemicals or energy), should only be considered when other types of recycling are not economically or technologically feasible. In tertiary recycling, waste plastics are converted to either monomers or fuels or petrochemical feedstocks. Conversion to monomers by solvolytic methods is feasible for condensation polymers but often requires pure polymer streams. Sorting and cleaning of the waste stream increases the cost of the process. 

Tertiary recycling The process of producing chemicals, fuels or similar products from waste plastics. 

Vasile, Roy and Deanin [100-103] proposed a locked loop between the tertiary and secondary recycling of plastic waste. A part of the plastic waste... 

Tertiary recycling Waste plastic is used as the feedstock in a process that generates chemicals and fuels. An example of tertiary recycling is the glycolysis of PET into diols and dimethyl terephthalate that can then be used to make virgin PET. 

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