Terephthalic acid is produced by oxidation of paraxylene by oxygen in air. The oxidation is conducted using acetic acid and a metallized catalyst, composed of cobalt and manganese salts. Impurities are removed by hydrogenation of a hot aqueous solution, which is then cooled to crystallize highly pure terephthalic acid (PTA). PTA is a commodity chemical, used principally to produce polyester PET to make clothing and plastic bottles.

VRV has developed and supplied several components for PTA production plants worldwide in accordance with the INVISTA license and specification. In particular, VRV has supplied the following types of equipment:

• Solvent Dehydration Column
• High Pressure Dissolver
• Crystallizer

The Solvent Dehydration Column and the Crystallizer are usually fabricated in solid duplex stainless steel Tp 2205, while the High Pressure Dissolver is fabricated in low-alloy steel, weld overlaid in stainless steel Tp 347.