| abstract |
1373230 Terephthalic acid MITSUI PETROCHEMICAL INDUSTRIES Ltd 23 Dec 1971 59918/71 Heading C2C In an otherwise known process for the production of terephthalic acid in which p-xylene is oxidized in the liquid phase in the presence of acetic acid with either molecular oxygen or a gas containing molecular oxygen and in the presence of a cobalt containing catalyst the improvement wherein the vapour effluent from the reactor, which contains a non-condensable gas, steam and acetic acid vapour, is fractionally distilled to recover acetic acid which is recycled to the reactor and terephthalic acid is crystallized and removed from the liquid reaction product the resultant mother liquor being recycled, without distillation, to the reaction. Crystallization of terephthalic acid may be achieved by cooling or by flashing the hot reaction product. The vapour obtained by flashing is an acetic acid solution which may be used to wash the crystalline product prior to drying. |