METHOD FOR PRODUCING TEREPHTHALIC ACID, AND METHOD FOR PRODUCING RECYCLED POLYETHYLENE TEREPHTHALATE

摘要

This method for producing terephthalic acid includes: a first hydrolysis step in which an object to be processed including polyethylene terephthalate is loaded into a sealed container, and subsequently exposed to an atmosphere having a pressure ranging from normal pressure to saturated water vapour pressure to hydrolyse the polyethylene terephthalate, and obtain a hydrolysate including terephthalic acid and/or an oligomer (an ethylene terephthalate oligomer) comprising terephthalic acid and ethylene glycol; and a second hydrolysis step in which the ethylene terephthalate oligomer obtained in the first hydrolysis step is hydrolysed in hot water having a temperature of 150-300˚C to obtain crude terephthalic acid.