Obtaining phthalic anhydride through oxidation gas phase o-xylene in a main reactor and a postreactor.

摘要

Process for preparing phthalic anhydride by catalytic oxidation in gaseous o-xylene phase in which, in a main reactor, a gaseous mixture of o-xylene and an oxygen-containing gas in a product becomes intermediate gaseous reaction containing o-xylene unconverted products suboxidación of phthalic anhydride and phthalic anhydride, in which the reaction heat obtained in the main reactor is evacuated, at least partially, through the cooling indirectly with heat transfer medium, and the intermediate reaction product is conducted with a temperature below the lowest temperature of the heat carrier medium, a postreactor, wherein the concentration of o-xylene not become the product of intermediate reaction is at least 1% by weight and the sum of the concentrations of products suboxidación of phthalic anhydride in the product reac tion intermediate at least 0.5% by weight, based on the total weight of the organic components in the intermediate reaction product.