Crude terephthalic acid (CTA) is produced through catalytic oxidation of
paraxylene by oxygen in compressed air. At the next stage, through catalytic
hydrogenation of impurities present in CTA, high quality purified terephthalic
acid (PTA) is obtained.
Purified terephthalic acid (PTA) is used mainly as feedstock in the production
of polyethylene terephthalate (PET), polyester fibres and polyamide fibres with
excellent tensile strength.