Method and apparatus for recovering benzene through azeotropic dehydration of maleic anhydride

Abstract

The invention discloses a method for recovering benzene through azeotropic dehydration of maleic anhydride. According to the method, a gas phase above an azeotropic dehydration tower is collected into a first azeotropic condenser; a liquid phase layer in the first azeotropic condenser enters a second azeotropic condenser; and an oil phase, i.e., benzene, in the second azeotropic condenser flows back to a benzene inlet pipe of the azeotropic dehydration tower, and a water phase is discharged out. The invention also discloses an apparatus for recovering benzene. The recovery apparatus comprises the azeotropic dehydration tower, the benzene inlet pipe connected with the azeotropic dehydration tower, the first azeotropic condenser connected with the upper part of the azeotropic dehydration tower via steam pipeline, the second azeotropic condenser connected with the lower end of the first azeotropic condenser via a stop valve, a drain hole formed in the lower end of the second azeotropic condenser and a middle section connected with the benzene inlet pipe via a recovery pipeline. The method provided by the invention can effectively recover gaseous benzene; the first azeotropic condenser is mainly used for steam liquid separation; the second azeotropic condenser realizes separation of the water phase and the oil phase; separated water is discharged out; and the separated oil phase is returned to the benzene inlet pipe, so recycling of benzene is realized.

Description

technical field [0001] The invention relates to a method and a device for producing and recovering chemical products, in particular to a method and a device for recovering benzene through azeotropic dehydration of maleic anhydride. Background technique [0002] Maleic anhydride is also called maleic anhydride, referred to as maleic anhydride, its boiling point is only 202°C, and it is easy to sublime. The most commonly used method for maleic anhydride production is the benzene oxidation method, which produces maleic anhydride under the action of a catalyst by adding benzene and air. The temperature in the reaction tower is very high in the process of oxidation catalysis, and most of the organic phase exists in the gas phase, including the raw material benzene. Therefore, in the process of producing maleic anhydride by benzene oxidation, the consumption of benzene is very serious, and the production cost will be very high if no effective recycling is carried out. Contents ...

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Problems solved by technology

Therefore, the consumption of benzene in the process of producing maleic anhydride by benzene oxidation is very serious, and the production cost will be very high without effective recycling

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