Method for purifying waste gas from production of purified terephthalic acid

Abstract

The present invention discloses a method for purifying waste gas from the production of a purified terephthalic acid. The method comprises: heating oxidation off-gas from the production process of the purified terephthalic acid for temperature rise via a heat exchanger and a preheater; then feeding into a catalytic combustion reactor; after the heat exchange between the exit off-gas of the catalytic combustion reactor and the entrance waste gas of the catalytic combustion reactor, feeding the exit off-gas into an alkaline tower; feeding off-gas from the alkaline tower into an adsorption column for an adsorption drying treatment; and respectively performing reuse or energy recovery to effluent gas after the drying treatment. According to the process adopted by the method of the present invention, only a few changes needed to be made to an existing purified terephthalic acid production apparatus, and production by the apparatus is not affected, so the method is particularly suitable for the transformation of the existing purified terephthalic acid production apparatus for an environmental protection purpose.

Description

technical field [0001] The invention relates to a method for purifying exhaust gas, belonging to the field of exhaust gas purification. This waste gas comes from the oxidation tail gas discharged from the production process of the existing purified terephthalic acid plant, and its main components include benzene, xylene, acetic acid, methyl acetate, dibromoethane, carbon monoxide, etc. Background technique [0002] Purified terephthalic acid (PTA) is an important chemical raw material. In the production process of purified terephthalic acid, the oxidation waste gas produced contains benzene, xylene, acetic acid, methyl acetate, dibromoethane, carbon monoxide and other components. Most of the purified terephthalic acid production facilities built in my country before 2000 produced oxidative waste gas that was directly discharged into the atmosphere without effective treatment, causing great pollution to the atmospheric environment. [0003] CN96195949.5 discloses a waste ga...

AI Technical Summary

Problems solved by technology

Most of the purified terephthalic acid production facilities built in my country before 2000, most of the oxidized waste gas produced by them was directly discharged into the atmosphere without effective treatment, causing great pollution to the atmospheric environment

This technology is also not suitable for the tail gas treatment of existing production equipment

[0005] Most of the purified terephthalic acid production units built in China before 2000 had oxidation tail gas that was directly discharged into the atmosphere without effective treatment.

These two technologies are suitable for newly-built PTA plants, but for existing PTA plants that have not taken effective waste gas treatment measures, the exhaust gas after catalytic combustion needs to meet the requirements of tail gas expansion. Therefore, it is not only difficult in technology and engineering, but also affects the normal production of the purified terephthalic acid unit; if the tail gas expander is re-equipped, the cost of the treatment unit will be greatly increased

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