Process of producing monocholo benzen anhydride by continuous liquid phase oxydation

A technology of monochlorinated phthalic anhydride and chlorinated o-xylene, which is applied in the field of liquid phase continuous oxidation to produce monochlorophthalic anhydride, can solve the problems of unstable production index, lack of stirring function, uneven air distribution, etc., and achieve effective increase Production time, avoiding fatigue damage, and high production efficiency

Inactive Publication Date: 2005-01-05
天津市利维科技有限公司
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  • Abstract
  • Description
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  • Application Information

AI Technical Summary

Problems solved by technology

This intermittent oxidation process requires repeated pressure rise and fall and temperature rise and fall. This frequent process of pressure rise and fall and temperature rise and fall not only makes the production index unstable, but also easily causes fatigue damage to the equipment, shortens the service life, and is very unsafe.
The reactor used in the above preparation method is the original bubbling reactor. In this reactor, there is no stirring function, the distribution of air is uneven, the oxidation reaction is incomplete, the energy consumption is high, the yield is low, and the product quality is unstable. , the yield is generally between 97%-103%

Method used

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  • Process of producing monocholo benzen anhydride by continuous liquid phase oxydation

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Embodiment 1

[0023] 1000 kg of monochlorinated o-xylene (wherein the ratio of 3-monochlorinated o-xylene and 4-monochlorinated o-xylene is about 1:1) is pumped into the metering tank. Pump 5000 kg of raw material concentrated acetic acid into another metering tank. Then it is metered and transported to the batching tank with stirring and heating jacket for mixing and dissolving, and then enters the storage tank for storage, and is pumped into the three-stage series oxidation reaction kettle with stirring by a metering pump. 5.2 kg of catalyst cobalt acetate, 5.2 kg of manganese acetate, and 5.2 kg of accelerator tetrabromoethane are added from the mixing batching tank to mix and dissolve evenly with the raw materials, and then enter the oxidation reaction kettle. Compressed air is fed into the three-stage oxidation reactor in parallel, and the flow distribution thereof is controlled separately. For example, if the total amount is 1.0, the ratio of the three stages is controlled to be 0.5 >...

Embodiment 2

[0025] 1000 kg of monochlorinated o-xylene (wherein the ratio of 3-monochlorinated o-xylene and 4-monochlorinated o-xylene is about 1:1) is pumped into the metering tank. Pump 4000-6000 kg raw concentrated acetic acid into another metering tank. Then it is metered and transported to the batching tank with stirring belt and heating jacket, and the mixed solution is then stored in the storage tank, and pumped into the three- or four-stage oxidation reaction kettle in series with a metering pump. The catalyst cobalt acetate is 1-49 kg, the manganese acetate is 1-49 kg, the accelerator tetrabromoethane or hydrogen bromide is 1-49 kg, and the raw materials are evenly mixed and dissolved from the mixing batching tank, and then enter the oxidation reaction kettle. The compressed air is fed into the three or four oxidation reactors in parallel, and the flow distribution is controlled respectively. The oxidation reaction is carried out at a pressure of 0.5 to 4 Mpa (table) and a tempe...

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Abstract

The invention relates to a method of producing monochlorophthalic anhydride by liquid-phase continuous oxidization, using monochloro-ortho-xylene as raw material, using cobalt acetate and manganese acetate as catalyst, using acetylene tetrachloride and hydrogen bromide as accelerant, feeding the above materials in proportion into a multistage serial stirring reaction kettle, and at a certain pressure and temperature, simultaneously charging compressed air to make the liquid-phase continuous oxidization reaction so as to make monochlorophthalic acid, which passes through a medium jar to a flash vaporization tank for temperature and pressure reduction, then obtaining crude anhydride by a multistage serial anhydride-forming reaction kettle dehydrating and deacidifying, continuously rectifying to obtain refined anhydride, and finally flaking to make the finished product. The waste residues are continuously discharged. The acetic acid is rectified and circulates. It adopts multistage serial stirring reaction kettle and multiage anhydride-forming reaction kettle, and the continuity of the reacting steps does not require repeated pressure boost, and temperature increase, and the production indicator is stable.

Description

technical field [0001] The invention relates to a method for producing monochlorinated phthalic anhydride from monochlorinated o-xylene through liquid-phase air oxidation, in particular to a method for producing monochlorinated phthalic anhydride by liquid-phase continuous oxidation. Background technique [0002] Monochlorophthalic anhydride is an important chemical raw material, especially homoanhydride and monoether anhydride can be produced through it to produce downstream products polyimide resin, polyimide resin can be used to manufacture high temperature resistant, high wear-resistant The other parts of aviation machinery are new materials that cannot be replaced by current metal materials. At present, the preparation method of monochlorinated phthalic anhydride has: sodium hypochlorite chlorination method of phthalic anhydride, mononitrophthalic anhydride chlorination method, phthalic anhydride gas phase chlorination method and monochlorinated o-xylene air gas phase c...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D307/89
Inventor 陈维仁卢宝铭王孝曾孙克全
Owner 天津市利维科技有限公司
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