ABSTRACT
Durene is obtained from complex mixtures of aromatics from oil-refining processes (“reformate gasoline”) or from cracking processes in olefin manufacture (“pyrolysis gasoline”). More recently the methanol to gasoline process, which went on-stream in New Zealand in 1986, has been found to produce large quantities of durene as a by-product. It is estimated that as much as 60 million pounds of durene may be isolated from this source. Normally, one of the disadvantages of homogeneous catalysis is the separation of the products from the catalyst. With durene (as well as with a number of other methylaromatic compounds) this is not a problem. Upon cooling to room temperature, 93% to 95% of the pyromellitic acid precipitates in the reactor and is removed by filtration. Zirconium is a remarkable substance in autoxidations since, with the proper experimental conditions, it results in much higher activity and yields to desired products.
