Gas Purification in the Manufacture of PET and PTA

Inert gases are used in the thermal post-treatment of polymer raw materials, for instance in the SSP process (Solid State Polycondensation) for polyester materials. The impurities, which are enriched in the inert gas, are organic compounds, such as aldehydes, glycols and oligomers. These impurities are removed from the inert gas in circulation by means of catalytic oxidation.

Heraeus-catalysts can be used in this process with a minimum (stoichiometric) excess of oxygen. The purified gas can be fed back into the circulation immediately after a subsequent drying step.

Heraeus-catalysts are not only used in the purification of inert gas in the SSP reactor, but also in the purification of exhaust gases in PTA equipment.