FIELD: industrial organic synthesis. SUBSTANCE: oxidation of p-xylene to produce terephthalic acid is conducted using pure or nearly pure oxygen and evaporation-cooling operation. When fulfilling specified operation conditions, generation of by-products and waste is reduced, oxygen usage is increased, and necessity to apply direct- contact heat-exchange surfaces in reactor is avoided. Plant is also provided containing mechanical indirect-contact cooling means, impeller means to maintain liquid recycling stream in reactor, oxygen injection means, gas phase-discharge means, and piping facilities to isolate terephthalic acid. EFFECT: enhanced process efficiency. 20 cl, 4 dwg
