Recycling and depolymerization of waste polyethylene terephthalate bottles by alcohol alkali hydrolysis

Abstract

In this work, a novel alcohol alkali hydrolysis method was explored for the preparation of terephthalic acid (TPA) from waste polyethylene terephthalate (PET). First, a series of single factor experiments on the depolymerization rate of waste PET bottles and the yield of TPA were conducted to determine the optimized experimental conditions, in terms of reaction time, reaction temperature, dosage of ethylene glycol and sodium bicarbonate, amount of distilled water and stirring rate. Then IR spectra and elemental analysis were carried out for the characterization of obtained product. Under optimal experimental conditions, over 98% PET can be depolymerized into the target product (TPA) and the purity and yield of TPA are over 97% and 94%, respectively. Both the experimental and analytical results support a feasible process for the preparation of TPA from waste PET. It is expected that this alcohol alkali hydrolysis method can promise an effective way for the sustainable recycling of waste PET.

Keywords

waste polyethylene terephthalate / terephthalic acid / alcohol alkali hydrolysis / ethylene glycol

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