Method for strengthening ammoximation reaction of butanone by using supergravity equipment

Abstract

The invention discloses a method for strengthening butanone ammoximation reaction by using supergravity equipment, which comprises the following steps: 1) adding butanone, an organic solvent and a titanium silicalite molecular sieve catalyst into a reaction kettle, heating to 40-55 DEG C, and carrying out heat preservation and stirring for at least 15 minutes; (2) introducing an alkali solution and an oxidizing agent into supergravity equipment, and mixing to obtain a mixed solution; the molar ratio of alkali to butanone in the alkali solution is 0.5-5, and the molar ratio of the oxidant to butanone is 0.5-10; and (3) dropwise adding the mixed solution obtained in the step (2) into the reaction kettle in the step (1), heating to 40-85 DEG C, keeping the temperature for 30-60 minutes, and continuously performing circulating reflux of the reaction solution between the reaction kettle and the supergravity equipment by using a circulating pump in the reaction process. The method can improve the conversion rate of butanone to be greater than or equal to 83%, the selectivity of the product diacetylmonoxime to be greater than or equal to 95%, and the catalytic performance of the catalyst to be improved to be greater than or equal to 51%.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial catalyst preparation, and in particular relates to a method for strengthening butanone ammoximation reaction by using supergravity equipment. Background Art

[0002] Butanone oxime, also known as methyl ethyl ketone oxime, is an important organic synthesis intermediate and metal surface treatment agent as an organic chemical raw material. It is widely used in many fields such as chemical organic synthesis, pharmaceutical research and development, energy research, etc. As an intermediate in the production of silicone cross-linking agents and polyurethane end-capping agents, butanone oxime is in great demand.

[0003] The main processes for the ammoximation of ketones include the Raschig process, the catalytic reduction of nitric oxide, the hydroxylamine process and the ammoximation process. Among them, the ammoximation process has the advantages of simple process, low corrosion resistance requirements and less environmental pollution, and is widely used. Its main production process is: butanone, hydrogen peroxide, ammonia water and tert-butanol are added to the oximation reactor, and the crude butanone oxime is synthesized under the catalysis of titanium silicon molecular sieve, and then after extraction and distillation, the by-products such as isooctyl alcohol and 2-nitrobutane are separated to obtain the pure butanone oxime product. The butanone conversion rate and butanone oxime selectivity need to be further improved, so it is necessary to strengthen the butanone ammoximation reaction.

[0004] During the ammoximation reaction of butanone, H2O2 oxidizes NH3 to hydroxylamine on the Ti active site of the titanium silicalite framework. Hydroxylamine diffuses out of the molecular sieve pores and reacts with butanone to form butanone oxime. However, butanone can also diffuse into the pores and be over-oxidized by H2O2 on the Ti active site to form 2-nitrobutane, resulting in a decrease in product selectivity. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for strengthening the ammoximation reaction of butanone using a supergravity device. The method of the present invention can increase the conversion rate of butanone by ≥83%, the selectivity of the product butanone oxime by ≥95%, and the catalytic performance of the catalyst can be increased by 51%.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows :

[0007] A method for strengthening the ammoximation reaction of butanone using a high gravity device comprises the following steps:

[0008] 1) adding butanone, organic solvent and titanium silicon molecular sieve catalyst into a reaction kettle, heating to 40-55° C. and stirring for at least 15 minutes;

[0009] 2) introducing an alkaline solution and an oxidant into a supergravity device and mixing them to obtain a mixed solution; the molar ratio of the alkali to butanone in the alkaline solution is 0.5-5, and the molar ratio of the oxidant to butanone is 0.5-10;

[0010] 3) The mixed solution obtained in step 2) is added dropwise to the reactor in step 1), and heated to 40-85° C. for 30-60 minutes. During the reaction, a circulating pump is continuously used to circulate the reaction solution between the reactor and the ultra-gravity device.

[0011] Preferably, in step 1), the amount of the organic solvent added is 170-250% of the mass of butanone.

[0012] Preferably, in step 1), the amount of the titanium silicalite catalyst used is 10-14.42 g of catalyst per unit molar amount of butanone.

[0013] Preferably, in step 1), the organic solvent is one of tert-butanol, n-butanol and phenol.

[0014] Preferably, in step 1), the titanium silicon molecular sieve catalyst is a heteroatom molecular sieve having a MOR topological structure in its framework.

[0015] Preferably, in step 2), the alkaline solution is one of aqueous ammonia, NaOH solution and KOH solution.

[0016] Preferably, in step 2), the oxidant is one of hydrogen peroxide, hypochlorous acid, sodium hypochlorite and nitric acid.

[0017] Preferably, in step 2), the rotation speed of the supergravity equipment is 800-2200 rpm; preferably 1500 rpm.

[0018] Preferably, in step 3), the dropwise addition flow rate of the mixed solution is 0.8-1.5 ml / min.

[0019] Preferably, in step 3), the flow rate of the reaction liquid in the circulation pump is 5-10 ml / min.

[0020] Any range described in the present invention includes the end value and any numerical value between the end values ​​and any sub-range formed by the end value or any numerical value between the end values.

[0021] Unless otherwise specified, all raw materials in the present invention can be purchased from the market, and the equipment used in the present invention can adopt conventional equipment in the relevant field or refer to the existing technology in the relevant field.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The method of the present invention can improve the conversion rate of butanone to ≥83%, and the selectivity of the product butanone oxime to ≥95%. Compared with the catalyst without the enhancement effect of the supergravity equipment (the butanone conversion rate is 55%), the catalytic performance of the catalyst under the condition of using the supergravity equipment enhancement (the butanone conversion rate is 83%) can be improved by 51%. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] Figure 1 It is a reaction flow chart of the method of the present invention. DETAILED DESCRIPTION

[0026] In order to explain the present invention more clearly, the present invention is further described below in conjunction with preferred embodiments. It should be understood by those skilled in the art that the following specific description is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0027] As one aspect of the present invention, a method for strengthening the ammoximation reaction of butanone using a high gravity device comprises the following steps:

[0028] 1) adding butanone, organic solvent and titanium silicon molecular sieve catalyst into a reaction kettle, heating to 40-85° C. and stirring for at least 15 minutes;

[0029] 2) introducing an alkaline solution and an oxidant into a supergravity device and mixing them to obtain a mixed solution; the molar ratio of the alkali to butanone in the alkaline solution is 0.5-5, and the molar ratio of the oxidant to butanone is 0.5-10;

[0030] 3) The mixed solution obtained in step 2) is added dropwise to the reactor in step 1), and heated to 40-85° C. for 30-60 minutes. During the reaction, a circulating pump is continuously used to circulate the reaction solution between the reactor and the ultra-gravity device.

[0031] According to certain embodiments of the present invention, in step 1), the amount of the organic solvent added is 170-250% of the mass of butanone.

[0032] According to certain embodiments of the present invention, in step 1), the amount of the titanium silicalite catalyst used is 10-14.42 g of catalyst per unit molar amount of butanone.

[0033] According to some embodiments of the present invention, in step 1), the organic solvent is one of tert-butanol, n-butanol and phenol.

[0034] According to some embodiments of the present invention, in step 1), the titanium silicon molecular sieve catalyst is a heteroatom molecular sieve having a MOR topological structure in the framework. For example, the commercially available mordenite titanium silicon molecular sieve catalyst produced by Henan Shenma Catalysis Technology Co., Ltd. can be selected.

[0035] According to some embodiments of the present invention, in step 2), the alkaline solution is one of ammonia water, NaOH solution and KOH solution.

[0036] According to some embodiments of the present invention, in step 2), the oxidant is one of hydrogen peroxide, hypochlorous acid, sodium hypochlorite, and nitric acid.

[0037] According to some embodiments of the present invention, in step 2), the rotation speed of the supergravity equipment is 800-2200 rpm; preferably 1500 rpm.

[0038] According to some embodiments of the present invention, in step 3), the dropwise addition flow rate of the mixed solution is 0.8-1.5 ml / min.

[0039] According to certain embodiments of the present invention, in step 3), the flow rate of the reaction liquid in the circulation pump is 5-10 ml / min.

[0040] In the present invention:

[0041] The hydrogen peroxide solution may be a commercially available analytically pure 30% hydrogen peroxide solution.

[0042] The ammonia water may be a commercially available ammonia solution with a volume concentration of 28%.

[0043] The tert-butanol can use a commercially available analytically pure 99% tert-butanol solution.

[0044] Example 1

[0045] A method for strengthening the ammoximation reaction of butanone using a high gravity device comprises the following steps:

[0046] 22g of tert-butanol was put into a three-necked flask with a condenser reflux tube, 10g of butanone and 2g of titanium silicalite (A) were added, and the temperature was raised to 55°C with stirring. 12.6g of 28% ammonia water and 19g of 30% hydrogen peroxide were weighed and introduced into the ultra-gravity equipment. After mixing, the mixture was dripped into the three-necked flask at a dripping rate of 0.91ml / min. After the dripping was completed, the reaction was continued for 40 minutes. After the reaction was completed, the reaction liquid was cooled and the catalyst was recovered by centrifugation.

[0047] The reaction solution was analyzed by liquid chromatography and gas chromatography, and the butanone conversion rate was 85%, and the butanone oxime selectivity was 95%.

[0048] Example 2

[0049] A method for strengthening the ammoximation reaction of butanone using a high gravity device comprises the following steps:

[0050] 22g of tert-butanol was put into a three-necked flask with a condenser reflux tube, 10g of butanone and 2g of titanium silicalite (B) were added, and the temperature was raised to 55°C with stirring. 12.6g of 28% ammonia water and 19g of 30% hydrogen peroxide were weighed and introduced into the ultra-gravity equipment. After mixing, the mixture was dripped into the three-necked flask at a dripping rate of 0.91ml / min. After the dripping was completed, the reaction was continued for 40 minutes. After the reaction was completed, the reaction liquid was cooled and the catalyst was recovered by centrifugation.

[0051] The reaction solution was analyzed by liquid chromatography and gas chromatography, and the butanone conversion rate was 83% and the butanone oxime selectivity was 95%.

[0052] Example 3

[0053] A method for strengthening the ammoximation reaction of butanone using a high gravity device comprises the following steps:

[0054] 22g of tert-butanol was put into a three-necked flask with a condenser reflux tube, 10g of butanone and 2g of titanium silicon molecular sieve were added, and the temperature was raised to 50°C with stirring. 19g of 28% ammonia water and 19g of 30% hydrogen peroxide were weighed and introduced into the ultra-gravity equipment. After mixing, they were dripped into the three-necked flask at a dripping rate of 1.2ml / min. After the dripping was completed, the reaction was continued for 50 minutes. After the reaction was completed, the reaction liquid was cooled and the catalyst was recovered by centrifugation.

[0055] The reaction solution was analyzed by liquid chromatography and gas chromatography, and the butanone conversion rate was 99%, and the butanone oxime selectivity was 99%.

[0056] Comparative Example 1

[0057] A method for preparing butanone oxime comprises the following steps:

[0058] 22g of tert-butanol was put into a three-necked flask with a condenser reflux tube, 10g of butanone and 2g of titanium silicalite (A) were added, and the temperature was raised to 55°C with stirring. 12.6g of 28% ammonia water and 19g of 30% hydrogen peroxide were weighed and directly added dropwise to the three-necked flask at a drop rate of 0.41ml / min and 0.62ml / min, respectively. After the dropwise addition was completed, the reaction was continued for 40 minutes. After the reaction was completed, the reaction liquid was cooled and the catalyst was recovered by centrifugation.

[0059] The reaction solution was analyzed by liquid chromatography and gas chromatography, and the butanone conversion rate was 55%, and the butanone oxime selectivity was 82%.

[0060] It can be seen that, compared with Example 1, not using a supergravity device to mix ammonia water and hydrogen peroxide will cause the butanone conversion rate to drop from 85% to 55%, the butanone oxime selectivity to drop from 95% to 82%, and the catalytic performance of the catalyst to drop by 35%.

[0061] Comparative Example 2

[0062] A method for strengthening the ammoximation reaction of butanone using a high gravity device comprises the following steps:

[0063] 30g of tert-butanol was put into a three-necked flask with a condenser reflux tube, 10g of butanone and 2g of titanium silicon molecular sieve were added, and the temperature was raised to 50°C with stirring. 19g of 28% ammonia water and 19g of 30% hydrogen peroxide were weighed and introduced into the ultra-gravity equipment. After mixing, they were dripped into the three-necked flask at a dripping rate of 1.2ml / min. After the dripping was completed, the reaction was continued for 50 minutes. After the reaction was completed, the reaction liquid was cooled and the catalyst was recovered by centrifugation.

[0064] The reaction solution was analyzed by liquid chromatography and gas chromatography, and the butanone conversion rate was 75%, and the butanone oxime selectivity was 92%.

[0065] It can be seen that, compared with Example 3, when too much raw material "tert-butyl alcohol" is added, the butanone conversion rate will drop from 99% to 75%, the butanone oxime selectivity will drop from 99% to 92%, and the catalytic performance of the catalyst will drop by 25%.

[0066] Comparative Example 3

[0067] A method for strengthening the ammoximation reaction of butanone using a high gravity device comprises the following steps:

[0068] 11g of tert-butanol was put into a three-necked flask with a condenser reflux tube, and 10g of butanone and 2g of titanium silicon molecular sieve were added. The temperature was raised to 50°C with stirring. 19g of 28% ammonia water and 19g of 30% hydrogen peroxide were weighed and introduced into the ultra-gravity equipment. After mixing, the mixture was dripped into the three-necked flask at a dripping rate of 1.2ml / min. After the dripping was completed, the reaction was continued for 50 minutes. After the reaction was completed, the reaction liquid was cooled and the catalyst was recovered by centrifugation.

[0069] The reaction solution was analyzed by liquid chromatography and gas chromatography, and the butanone conversion rate was 67% and the butanone oxime selectivity was 96%.

[0070] It can be seen that, compared with Example 3, when the mass ratio of the added solvent tert-butyl alcohol to butanone is lower than 170%, the butanone conversion rate decreases from 99% to 67%, the butanone oxime selectivity decreases from 99% to 96%, and the catalytic performance of the catalyst decreases by 33%.

[0071] Comparative Example 4

[0072] A preparation method of butanone oxime comprises the following steps:

[0073] 22g of tert-butyl alcohol was put into a three-necked flask with a condenser reflux tube, 10g of butanone and 2g of titanium silicalite (B) were added, and the temperature was raised to 55°C with stirring. 3.2g of 28% ammonia water and 19g of 30% hydrogen peroxide were weighed and introduced into the ultra-gravity equipment. After mixing, the mixture was dripped into the three-necked flask at a dripping rate of 0.91ml / min. After the dripping was completed, the reaction was continued for 40 minutes. After the reaction was completed, the reaction liquid was cooled and the catalyst was recovered by centrifugation.

[0074] The reaction solution was analyzed by liquid chromatography and gas chromatography, and the butanone conversion rate was 70% and the butanone oxime selectivity was 89%.

[0075] It can be seen that, compared with Example 2, when the molar ratio of ammonia water to butanone is less than 0.5, the butanone conversion rate decreases from 83% to 70%, the butanone oxime selectivity decreases from 95% to 89%, and the catalytic performance of the catalyst decreases by 16%.

[0076] Comparative Example 5

[0077] A method for strengthening the ammoximation reaction of butanone using a high gravity device comprises the following steps:

[0078] 22g of tert-butanol was put into a three-necked flask with a condenser reflux tube, 10g of butanone and 2g of titanium silicon molecular sieve were added, and the temperature was raised to 50°C with stirring. 19g of 28% ammonia water and 47.2g of 30% hydrogen peroxide were weighed and introduced into the ultra-gravity equipment. After mixing, they were dripped into the three-necked flask at a dripping rate of 2.2ml / min. After the dripping was completed, the reaction was continued for 50 minutes. After the reaction was completed, the reaction liquid was cooled and the catalyst was recovered by centrifugation.

[0079] The reaction solution was analyzed by liquid chromatography and gas chromatography, and the butanone conversion rate was 90%, and the butanone oxime selectivity was 75%.

[0080] It can be seen that compared with Example 3, the added hydrogen peroxide and butanone molar ratio is too high, which will cause the butanone conversion rate to drop from 99% to 90%, the butanone oxime selectivity to drop from 99% to 75%, and the by-products to increase.

[0081] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all implementation methods here. Any obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for strengthening the ammoximation reaction of butanone using a high gravity device, characterized in that: The steps include: 1) adding butanone, organic solvent and titanium silicon molecular sieve catalyst into a reaction kettle, heating to 40-55° C. and stirring for at least 15 minutes; 2) introducing an alkaline solution and an oxidant into a supergravity device and mixing them to obtain a mixed solution; the molar ratio of the alkali to butanone in the alkaline solution is 0.5-5, and the molar ratio of the oxidant to butanone is 0.5-10; 3) The mixed solution obtained in step 2) is added dropwise to the reactor in step 1), and heated to 40-85° C. for 30-60 minutes. During the reaction, a circulating pump is continuously used to circulate the reaction solution between the reactor and the ultra-gravity device.

2. The method for strengthening the butanone ammoximation reaction using a high gravity device according to claim 1, characterized in that: In step 1), the amount of the organic solvent added is 170-250% of the mass of butanone.

3. The method for strengthening the butanone ammoximation reaction using a high gravity device according to claim 1, characterized in that: In step 1), the amount of the titanium silicon molecular sieve catalyst used is 10-14.42 g of catalyst per unit molar amount of butanone.

4. The method for strengthening the butanone ammoximation reaction using a high gravity device according to claim 1, characterized in that: In step 1), the organic solvent is one of tert-butanol, n-butanol and phenol.

5. The method for strengthening the butanone ammoximation reaction using a high gravity device according to claim 1, characterized in that: In step 1), the titanium silicon molecular sieve catalyst is a heteroatom molecular sieve having a MOR topological structure in its framework.

6. The method for strengthening the butanone ammoximation reaction using a high gravity device according to claim 1, characterized in that: In step 2), the alkaline solution is one of ammonia water, NaOH solution and KOH solution.

7. The method for strengthening the butanone ammoximation reaction using a high gravity device according to claim 1, characterized in that: In step 2), the oxidant is one of hydrogen peroxide, hypochlorous acid, sodium hypochlorite and nitric acid.

8. The method for strengthening the butanone ammoximation reaction using a high gravity device according to claim 1, characterized in that: In step 2), the rotation speed of the supergravity equipment is 800-2200 rpm, preferably 1500 rpm.

9. The method for strengthening the butanone ammoximation reaction using a high gravity device according to claim 1, characterized in that: In step 3), the dropwise addition flow rate of the mixed solution is 0.8-1.5 ml / min.

10. The method for strengthening the butanone ammoximation reaction using a high gravity device according to claim 1, characterized in that: In step 3), the flow rate of the reaction liquid in the circulation pump is 5-10 ml / min.

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