Mitsui Chemicals, Inc.

Mitsui Petrochemical Industries, Ltd.

Toshiyuki Sakata

Hiroshi Suzuki

Etsuro Okamoto

Ryoichi Yamamoto

Shigeru Isayama

Hideaki Iwata

Satoshi Murakami

Process for producing aromatic dicarboxylic acid

A process and an apparatus for producing an aromatic carboxylic acid by a liquid phase oxidation of an alkyl aromatic compound with a molecular oxygen-containing gas in the presence of an oxidation catalyst in a reaction solvent in an oxidation reactor, which process can afford to suppress the amount of non-condensing gas lost in accompaniment with the withdrawn slurry of the formed aromatic carboxylic acid crystals from the oxidation reactor to thereby increase the utilization efficiency of the molecular oxygen-containing gas, wherein a deflector 10 is arranged on the inner surface of the reactor wall at a portion downstream from the opening 9 for the slurry withdrawal line 8 in the flow path of the stirring stream 11 of the reaction liquor and the oxidation is conducted while stirring the reaction liquor by a stirrer 3 and while withdrawing the resulting slurry containing the formed aromatic carboxylic acid crystals from the reactor, by feeding the alkyl aromatic compound together with the reaction solvent and with the catalyst to the reactor via a raw material feed line 6 while supplying the molecular oxygen-containing gas thereto via a gas supply line 7, whereby the amount of the non-condensing gas entrained in the withdrawn slurry from the reactor is suppressed.

Process for producing aromatic carboxylic acid and apparatus therefor

A method for recovering crystals from a crystal-containing slurry, which comprises supplying the slurry to a rotary filter having a rotating cylindrical filter medium, filtering the supplied slurry in a filtering region to retain the crystals on the filter medium and washing the filter cake formed on the rotating filter medium repeatedly in a plurality of washing regions by spraying a washing liquid onto the cake in each region by supplying any one of washing regions on the aft side in the rotating direction of the filter medium with the spent washing liquid of the washing region adjacent to said one washing region on the fore side in the rotating direction.

Method for recovering crystals from slurry with wash water recycle means

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Ohtake, Japan

Toshiyuki Sakata