Zinc acetate (Zn(Ac)(2)) catalyzed depolymerization of polyethylene terephthalate (PET) in hot compressed water (HCW) was carried out in a batch autoclave reactor, as a potential method for chemical recycling of waste PET. The effects of the ratio of Zn(Ac)(2) to PET (0-3%), temperature (220-300 degrees C), and reaction time (5-60 min) were investigated. The optimal conditions for complete catalytic depolymerization of PET were temperature 240 degrees C, pressure 3.2 MPa, reaction time 30 min, and Zn(Ac)(2)/PET ratio 1.5%. The main products of catalytic depolymerization were identified and quantified as terephthalic acid and ethylene glycol by Fourier-transform infrared spectroscopy, high-performance liquid chromatography, gas chromatography/mass spectrometry, and gas chromatography. The maximum yield of terephthalic acid reached 90.5%. The phase behavior of PET with or without a catalyst in water during heating and cooling was studied in a fused-silica capillary reactor. According to the phase change data, the temperature of PET dissolution in HCW to form a homogeneous aqueous solution was decreased by adding Zn(Ac)(2). (c) 2011 Elsevier B.V. All rights reserved.