Waste polyester recycling is divided into physical recovery and chemical recovery. Chemical recycling is the depolymerization of solid polymer materials into smaller molecules, intermediate materials, or directly into monomers. For RPET, chemical recovery allows the polyester chain to be broken into low molecular weight ethylene terephthalate (BHET) intermediates or completely degraded to refined terephthalate (PTA) or dimethyl terephthalate (DMT) and ethylene glycol (EG).

Since the use of physically recovered RPET is not allowed in the food field, the progress of polyester chemical recovery technology is very important. Only the development of economic chemical recovery technology can effectively promote the reuse of this resin. At present, the recovery cost of degradation is not competitive with the production of RPET from new raw materials, so it cannot be applied on a large scale. For RPET, the traditional chemical recovery mainly includes the following specific methods: methanolysis, hydrolysis and glycol alcoholysis.