Dimethyl Terephthalate

Abstract

This process also called Dynamit-Witten-Nobel process involves the oxidation of para-xylene in an oxidation reactor maintained at 15 bar and 190oC. The oxidation catalyst used may be a 0.1-0.5 percent cobaltous-manganese salt mixture used as the acetate. The oxidate is contacted with methanol and catalyst (para-toluene sulphonic acid) at 1500C in the esterification reactor. Subsequent purification steps remove methanol, water plus other impurities. Crude DMT is vacuum crystallised, washed and centrifuged. The DMT is thereafter liquefied and sent to a DMT column for final purification. DMT may be stored or shipped as a liquid. Alternatively, it can also be handled as solid product, a flaking and an inert gas conveying system to transfer the DMT product would be required in addition.