PRODUCTION OF NAPHTHALENE CARBOXYLIC ACID

摘要

PURPOSE:To suppress local raising of temperature in a reactor and subsidiary reaction followed thereby and obtain the high-quality title compound in high yield by simple treatment circulating a discharge gas to a specific position of a reactor in liquid phase oxidation of a substituted naphthalene. CONSTITUTION:When a substituted naphthalene is oxidized with a molecular oxygen-containing gas in the presence of a catalyst containing at least one kind of metal selected from cerium, cobalt and manganese and bromine in a solvent containing a lower fatty acid monocarboxylic acid in an oxidation reactor to provide the aimed naphthalene carboxylic acid, a discharge gas discharged from a path 7 is cooled by a heat exchanger 9 and a condensing component is condensed and the treated discharge gas is then fed to a storage tank 10. The oxidation reaction is carried out while circulating part of the gas from which the condensed component is removed through a path 11 to the position of depth 0.01-0.5 times deeper than that of liquid from the surface of liquid phase part of the reactor by a blower 12 and the reaction temperature is controlled by control of circulation amount of the discharge gas.