1. A method of making bis(2-hydroxyethyl) terephthalate (BHET) from polyethylene terephthalate (PET), comprising:(a) combining PET with ethylene glycol and a catalyst system to produce a heterogeneous reaction mixture, wherein the catalytic system comprises a catalyst and a microwave absorber, with the catalyst being selected from the group consisting of: zinc acetate, zinc chloride, manganese acetate, 1, 5, 7-triazabicyclo [4.4. 0] dec-5-ene (TBD), 1, 8-diazabicyclo [5. 4. 0]undec-7-ene (DBU), magnesium acetate, 4-dimethylaminopyridine (DMAP), and combinations thereof, and with the microwave absorber being selected from the group consisting of a sodium salt, lithium salt, potassium salt, calcium salt, a magnesium salt, or combination thereof; and then
(b) heating by microwave irradiation the reaction mixture to produce a reaction product comprising BHET.