PROCESS FOR RECYCLING PET BOTTLE

摘要

PROBLEM TO BE SOLVED: To prepare a polyester product having a high purity by converting a recovered PET bottle into bis-β-hydroxyethyl terephthalate which is an intermediate material for preparing polyester products. SOLUTION: PET bottle wastes are pretreated and converted into crude polyester flakes, which are added with an excess of purified ethylene glycol and depolymerized in the presence of a catalyst to obtain crude bis-β- hydroxyethyl terephthalate(BHET). Then, compounds other than polyester resins such as polyethylene or the like are removed. Purified BHET, obtained through a hydrogenation process wherein a mixture solution of the obtained crude BHET and crude ethylene glycol is added with water to obtain a mixture solution of crude BHET, ethylene glycol and water, a foreign matter removal process, a crude BHET crystallization separation process and a BHET purification process, is melt polycondensed to obtain a highly pure polyester polymer.