METHOD FOR PRODUCING TEREPHTHALIC ACID AND METHOD FOR PRODUCING REGENERATED POLYETHYLENE TEREPHTHALATE

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a terephthalic acid that processes a material to be processed including polyethylene terephthalate by a chemical recycling technology without requiring a large-scale apparatus and a high cost and can recover a terephthalic acid as a synthetic raw material for the polyethylene terephthalate with a high quality and to provide a method for producing a regenerated polyethylene terephthalate produced by using the resultant terephthalic acid.SOLUTION: The method for producing a terephthalic acid has a first hydrolysis step of hydrolyzing polyethylene terephthalate upon exposure to an atmosphere of a normal pressure to a saturated water vapor pressure after storage of a material to be processed including polyethylene terephthalate in a closed vessel to produce a terephthalic acid and/or an ethylene terephthalate oligomer and a second hydrolysis step of hydrolyzing the ethylene terephthalate oligomer produced in the first hydrolysis step in hot water to produce a terephthalic acid. The weight of hot water in the second hydrolysis step is two or more times as much as the weight of the material to be processed for use in the first hydrolysis step.SELECTED DRAWING: Figure 1