Trimellitic Anhydride from Pseudocumene

PEP Report No. 66 presented process and economic information on the manufacture of trimellitic anhydride (TMA) by the catalytic liquid phase air oxidation of pseudocumene. This is the process used in the United States by Amoco Chemicals Corporation. Certain West German firms use a process based on nitric acid oxidation of pseudocumene. The present study summarizes the available information on the latter process, and gives a rough economimc comparison of it with the air oxidation route. The general conclusion is that the nitric acid process does not appear attractice economically.

The chemical reaction in the nitric acid process are as follows: