Hydrolysis of PET-waste

Although aromatic polyesters are rather resistant to water under atmospheric conditions, compared with other polymers, they can be completely hydrolyzed by water at higher temperatures (and) under pressure. For practical purposes, however, particularly to speed up the process, use has to be made of catalysts. Acidic as well as alkaline catalysts have been studied and worked out in practice. 

PET has a calorific value of ca. 30.2 MJ/kg, which is about equivalent to that of coal. It is thus ideally suited for the incineration process. The combustion of plastics, however, requires 3 to 5 times more oxygen than for conventional incineration, produces more soot, develops more excessive heat, and incineration equipment had to be adapted in order to cope with these problems. 

At present it seems that most problems arising during incineration of PET can be resolved however, quite a few residual hurdles will have to be taken before an economically feasible and ecologically accepted industrial technical process will be available. 

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