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Adipic acid preparation method and system

A technology of adipic acid and tungstic acid, which is applied in the direction of oxidative preparation of carboxylic acid, chemical instruments and methods, separation/purification of carboxylic acid compounds, etc., which can solve the problems of large mass transfer resistance, high cost of three wastes treatment, and unfavorable separation of adipic acid Purification and other issues, to achieve excellent corrosion resistance, temperature and pressure resistance, improved operability and safety, and avoid serious corrosion of equipment

Pending Publication Date: 2021-08-03
中石油吉林化工工程有限公司
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  • Abstract
  • Description
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  • Application Information

AI Technical Summary

Problems solved by technology

Both of these routes use nitric acid as the oxidant, the equipment is seriously corroded and needs to be replaced regularly, the production cost is high, and a large amount of three wastes will be generated in the production process, and the treatment cost of the three wastes is high. In the process, there are problems such as the use of corrosive nitric acid raw materials and the generation of nitrogen oxides, nitric acid vapor and waste acid that seriously pollute the environment. H2O2 oxidation of cyclohexene to prepare adipic acid has become a research hotspot at home and abroad.
[0004] Proposed in CN102850205B, in the presence of a catalyst, cyclohexene is contacted with hydrogen peroxide to produce 1,2-cyclohexanediol and adipic acid. The catalyst is a roasted product containing heteroatom molecular sieve and zinc compound. Hexene, hydrogen peroxide, acetonitrile and catalyst react under pressure in a high-pressure reactor. After the reaction, the product is analyzed by reaction liquid gas chromatography. The whole reaction is a high-pressure batch reaction, the conversion rate of cyclohexene is low, and the operation safety is low, so it is not suitable industrial application
This process utilizes the efficient mass transfer and heat transfer efficiency of the microchannel reactor to enhance the mass transfer rate between the two-phase materials, stabilize the reaction temperature, and greatly improve the safety and operability of the experiment. In the stage oxidation process, it is difficult to effectively control the oxidation depth, and it is easy to cause uneven distribution of 1,2-cyclohexanediol and adipic acid products in the oxidation system. The adipic acid product has wide regioselectivity and many by-products, which is not conducive to Acid separation and purification
[0007] The research on the preparation of adipic acid by the oxidation of cyclohexene with hydrogen peroxide is relatively mature, but it has not been produced on a large scale. The main reason is that there are still many difficult problems in actual operation, such as the selection of catalysts, the recycling of catalysts, etc., and the self-separation of hydrogen peroxide. Serious solution, large heat of reaction, etc., it needs to be specially pointed out that cyclohexene and hydrogen peroxide are two-phase reaction in the oxidation stage of cyclohexene, and the mass transfer resistance is large; in the intermittent reaction process, the reflux of cyclohexene is large, and the heat of reaction is large, which is easy Charge, even explode

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  • Adipic acid preparation method and system
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  • Adipic acid preparation method and system

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Experimental program
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Effect test

Embodiment approach 1

[0048] to combine Figure 5 and Image 6 , the channel type of this embodiment is (6T1+5S1) cylindrical straight channel and diamond microchannel structure, the reaction molar ratio is determined by the channel volume and flow rate, and the heat exchange medium is heat transfer oil.

[0049] Each raw material storage tank is equipped with cyclohexene and oxidation acid solution (the mass concentration of hydrogen peroxide is 40%, the concentration of tungstic acid is 0.1%, and the concentration of triethylamine is 0.05%). Set the flow control of each metering pump to change the molar ratio of cyclohexene: oxidation acid solution=1:10, control the flow rate of cyclohexene: 1mL / min, control the flow rate of oxidation acid solution: 10mL / min, and inject the materials into each straight-through respectively In the preheating module (preheating module), the reaction temperature is controlled to be 60°C and the pressure is 0.1MPa; the cyclohexene and oxidizing acid solutions are re...

Embodiment approach 2

[0052] to combine Figure 5 and Image 6 , the channel type of this embodiment is (6T1+5S2) cylindrical straight channel and heart-shaped microchannel structure, the reaction molar ratio is determined by the channel volume and flow rate, and the heat exchange medium is heat transfer oil.

[0053] Each raw material storage tank is equipped with cyclohexene and oxidation acid solution (the mass concentration of hydrogen peroxide is 40%, the concentration of tungstic acid is 0.2%, and the concentration of tetraphenylphosphine bromide is 0.05%). Set the flow control of each metering pump to change cyclohexene: oxidizing acid solution molar ratio=1:12, control the flow rate of cyclohexene: 2mL / min, control the flow rate of oxidizing acid solution: 12mL / min, inject the materials into each straight-through respectively In the preheating module (preheating module), the reaction temperature is controlled to be 80°C and the pressure is 0.2MPa; the cyclohexene and oxidizing acid solutio...

Embodiment approach 3

[0056] to combine Figure 5 and Image 6 , the channel type of this embodiment is (6T1+5S3) cylindrical straight channel and triangular microchannel structure, the reaction molar ratio is determined by the channel volume and flow rate, and the heat exchange medium is heat transfer oil.

[0057] Each raw material storage tank is equipped with cyclohexene and oxidation acid solution (the mass concentration of hydrogen peroxide is 50%, the concentration of phosphomolybdenum tungstic acid is 0.3%, and the concentration of tetrabutylammonium bromide is 0.06%). Set the flow control of each metering pump to change cyclohexene: oxidizing acid solution molar ratio=1:15, control the flow rate of cyclohexene: 2mL / min, control the flow rate of oxidizing acid solution: 14mL / min, and inject the materials into each straight-through respectively In the preheating module (preheating module), the reaction temperature is controlled to be 85°C and the pressure is 0.4MPa; the cyclohexene and oxid...

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Abstract

The invention relates to an adipic acid preparation method and system. The method comprises the following steps of a, proportioning cyclohexene and an oxidized acid solution, and respectively preheating the proportioned materials, b, mixing and reacting the preheated materials, and collecting a product obtained by the reaction, and c, recrystallizing and drying the product to obtain an adipic acid product. According to the method, continuous and safe production can be realized, cyclohexene can be completely converted within an extremely short time, the selectivity of adipic acid is high, and the discharge of organic waste liquid can be reduced.

Description

technical field [0001] The invention relates to a method and system for preparing adipic acid. Background technique [0002] Adipic acid is one of the most valuable dibasic acids among aliphatic dicarboxylic acids. It can undergo reactions such as salt formation, esterification and amidation. It is mainly used in the production of nylon 66 and nylon 66 engineering plastics and polyurethane foam plastics. In addition, it can also be used to produce high-grade lubricating oil, food additives, pharmaceutical intermediates, fragrance and flavor control agents, new single crystal materials, plastic foaming agents, coatings, insecticides, adhesives and dyes, etc. very broad. [0003] At present, the main methods for industrial preparation of adipic acid are cyclohexane nitric acid oxidation and cyclohexene hydration nitric acid oxidation. Cyclohexane route, that is, catalytic hydrogenation of pure benzene to generate cyclohexane, cyclohexane is then oxidized by air to generate c...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C51/31C07C51/43C07C55/14B01J19/00
CPCC07C51/31C07C51/43B01J19/0093C07C55/14
Inventor 张茗然刘锦旗滕大君王宝杰赵鑫
Owner 中石油吉林化工工程有限公司