it is a well known fact that sublimation substances, such as benzoic acid and terephthalic acid, are produced in the thermal decomposition of PET, and this causes problems in plastic recycling plants. However, it is clear that the addition of Ca(OH)(2) affects the high selectivity of benzene without producing sublimation substances. The yield of benzene was 35.85 wt % at 700 degreesC and a 10.0 Ca(OH)(2)/PET molar ratio. This value means that the selectivity of benzene is 78.8% for liquid products, and 85.1 wt % for aromatic ring in input PET.