Vanadium-nickel-magnesium ternary catalyst, preparation method and application thereof

Abstract

The application discloses a vanadium-nickel-magnesium ternary catalyst and a preparation method and application thereof, raw materials of the catalyst include: 50-70 parts of aluminum-nickel alloy, 10-20 parts of vanadium oxide, 20-30 parts of talcum powder, 80-120 parts of 30% sodium hydroxide solution, 150-300 parts of distilled water, the raw material aluminum-nickel alloy, talcum powder and vanadium oxide are added into the sodium hydroxide solution to be mixed into a slurry, the filter cake after heat preservation reaction is washed with water, and the vanadium-nickel-magnesium ternary catalyst is obtained through drying and calcination, the preparation method is simple, easy to operate and easy to control; the catalyst is also used for preparing N-ethylaniline, ethanol, aniline and the catalyst are added into a reaction kettle to react at normal temperature and normal pressure, the reaction is mild, the requirement for equipment is low, the selectivity of N-ethylaniline is high, when the mass ratio of ethanol, aniline and the catalyst is 1:2:0.2, the reaction time is 5h, and the selectivity of N-ethylaniline can reach more than 86%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of amine N-alkylation synthesis, in particular to a vanadium-nickel-magnesium ternary catalyst, a preparation method thereof and application of the vanadium-nickel-magnesium ternary catalyst in efficient preparation of N-ethylaniline under normal pressure. BACKGROUND

[0002] N-ethylaniline is an important intermediate of azo dyes and triphenylmethane dyes, and can also be used in rubber additives, explosives, photographic materials and other fine chemical intermediates. In recent years, it has also been applied to the gasoline industry as an anti-explosion agent and an antioxidant.

[0003] In the prior art, the preparation process of N-ethylaniline mainly includes: 1) liquid phase preparation, aniline and ethanol are reacted in the presence of a catalyst to generate N-ethylaniline under high temperature and high pressure, the catalysts mainly include potassium tert-butoxide, sodium ethoxide, phosphorus oxychloride, aluminum oxide and a special catalyst loaded with one or two metals such as nickel, cobalt, titanium and zirconium, the reaction temperature is generally 150-250 DEG C, the pressure is generally 2-3.5 Mpa, and the reaction time is generally 16-48 hours, the product obtained by the reaction includes about 20% of aniline, about 60% of N-ethylaniline and about 10% of N,N-diethylaniline, three main fractions are collected by rectification, the first fraction is aniline, which is recycled and used, the second fraction is N-ethylaniline, and the third fraction is N,N-diethylaniline; 2) gas phase preparation, aniline and ethanol are gasified and then reacted in the presence of a catalyst loaded on SBA-15 to obtain a catalyst for synthesis, the method has high requirements on equipment, and industrialization has not been realized; 3) excess ethanol and aniline are refluxed in the presence of a large amount of Raney nickel under a hydrogen atmosphere, the reaction temperature is 80 DEG C, and the refluxing time is 15 hours, the conversion rate of aniline reaches 98%, but the selectivity is not high, and N-ethylaniline is only about 60%. SUMMARY

[0004] In view of the above problems in the prior art, the present application aims to provide a vanadium-nickel-magnesium ternary catalyst, a preparation method thereof and application of the vanadium-nickel-magnesium ternary catalyst in efficient preparation of N-ethylaniline under normal pressure, by using the catalyst, the reaction is mild, the requirements on equipment are low, the selectivity of N-ethylaniline is high, and the catalyst is suitable for industrialized popularization and application.

[0005] The present application defines a vanadium-nickel-magnesium ternary catalyst, raw materials of the catalyst include the following components in parts by weight: aluminum-nickel alloy 50-70 parts, vanadium oxide 10-20 parts, talcum powder 20-30 parts, 30% sodium hydroxide solution 80-120 parts and distilled water 150-300 parts, preferably: aluminum-nickel alloy 60 parts, vanadium oxide 15-20 parts, talcum powder 25-30 parts, 30% sodium hydroxide solution 100 parts and distilled water 200 parts.

[0006] Further, the present application also limits the preparation method of the vanadium-nickel-magnesium ternary catalyst, which comprises the following steps: according to the feeding ratio, the aluminum-nickel alloy, talcum powder and vanadium oxide are added into 30% sodium hydroxide solution to mix into slurry, and the temperature is increased to 50-80°C under stirring to react for 5-7 hours, after the reaction is completed, centrifugal treatment is carried out, the obtained filter cake is washed with distilled water, and the vanadium-nickel-magnesium ternary catalyst is obtained through drying and calcination.

[0007] Further, the present application also limits the preparation method of the vanadium-nickel-magnesium ternary catalyst, which comprises the following steps: according to the feeding ratio, the aluminum-nickel alloy, talcum powder and vanadium oxide are added into 30% sodium hydroxide solution to mix into slurry, and the temperature is increased to 50-80°C under stirring to react for 5-7 hours, after the reaction is completed, centrifugal treatment is carried out, the obtained filter cake is washed with distilled water, and the vanadium-nickel-magnesium ternary catalyst is obtained through drying and calcination.

[0008] Further, the present application also limits the preparation method of the vanadium-nickel-magnesium ternary catalyst, which comprises the following steps: according to the feeding ratio, the aluminum-nickel alloy, talcum powder and vanadium oxide are added into 30% sodium hydroxide solution to mix into slurry, and the temperature is increased to 50-80°C under stirring to react for 5-7 hours, after the reaction is completed, centrifugal treatment is carried out, the obtained filter cake is washed with distilled water, and the vanadium-nickel-magnesium ternary catalyst is obtained through drying and calcination.

[0009] Further, the present application also limits the preparation method of the vanadium-nickel-magnesium ternary catalyst, which comprises the following steps: according to the feeding ratio, the aluminum-nickel alloy, talcum powder and vanadium oxide are added into 30% sodium hydroxide solution to mix into slurry, and the temperature is increased to 50-80°C under stirring to react for 5-7 hours, after the reaction is completed, centrifugal treatment is carried out, the obtained filter cake is washed with distilled water, and the vanadium-nickel-magnesium ternary catalyst is obtained through drying and calcination.

[0010] 1) the vanadium-nickel-magnesium ternary catalyst is prepared according to the limited method, and the preparation method is simple, easy to operate and control;

[0011] 2) ethanol, aniline and the vanadium-nickel-magnesium ternary catalyst are added into a reaction kettle to react under stirring at normal temperature and pressure, after the reaction is completed, standing is carried out, the upper layer reaction clear liquid is transferred into a rectifying kettle, the fraction with a temperature of 110-115°C is collected, and the product N-ethyl aniline is obtained, and the reaction equation is as follows:

[0012]

[0013] Further, the present application also limits the reaction time to be 4-5 hours.

[0014] Further, the present application also limits the feeding mass ratio of ethanol, aniline and the vanadium-nickel-magnesium ternary catalyst to be 1:2:0.04-0.4, and preferably 1:2:0.2.

[0015] Further, the present application also limits that the vanadium-nickel-magnesium ternary catalyst can be repeatedly used.

[0016] Through the above technology, the present application has the following beneficial effects:

[0017] 1) the vanadium-nickel-magnesium ternary catalyst is prepared according to the limited method, and the preparation method is simple, easy to operate and control;

[0018] 2)The vanadium-nickel-magnesium ternary catalyst prepared by the application is used for preparing N-ethyl aniline, and the reaction can be completed by stirring at normal temperature and pressure, the reaction is mild, the requirement for equipment is low, and the selectivity of N-ethyl aniline is high; when the mass ratio of ethanol, aniline and the catalyst is 1:2:0.2, and the reaction time is 5 hours, the selectivity of N-ethyl aniline can reach 86%. DETAILED DESCRIPTION

[0019] The application will be further described in combination with specific examples, but the protection scope of the application is not limited to the examples:

[0020] The vanadium-nickel-magnesium ternary catalyst is prepared by the following method: according to the feeding ratio, 50-70 parts of aluminum-nickel alloy, 10-20 parts of vanadium oxide and 20-30 parts of talcum powder are added into 80-120 parts of 30% sodium hydroxide solution to mix into a slurry, the slurry is heated to 65-75 DEG C under stirring and kept for 5-7 hours, after the reaction is completed, the slurry is centrifuged, the obtained filter cake is washed with 150-300 parts of distilled water, and after drying, the filter cake is calcined at 500-800 DEG C for 5-10 hours to obtain the vanadium-nickel-magnesium ternary catalyst.

[0021] The application also limits a preparation method of N-ethyl aniline, specifically, ethanol, aniline and the vanadium-nickel-magnesium ternary catalyst are added into a reaction kettle, and the reaction is stirred at normal temperature and pressure for 4-5 hours, after the reaction is completed, the reaction liquid is transferred to a rectifying kettle, and the fraction of 110-115 DEG C is collected by vacuum distillation, which is N-ethyl aniline, and the reaction equation is as follows:

[0022]

[0023] Example 1: Preparation of vanadium-nickel-magnesium ternary catalyst

[0024] According to the feeding ratio, 60 parts of aluminum-nickel alloy, 18 parts of vanadium oxide and 25 parts of talcum powder are added into 100 parts of 30% sodium hydroxide solution to mix into a slurry, the slurry is heated to 70 DEG C under stirring and kept for 5 hours, after the reaction is completed, the slurry is centrifuged, the obtained filter cake is washed with 200 parts of distilled water, and after drying, the filter cake is calcined at 600 DEG C for 8 hours, and after cooling, the filter cake is crushed to obtain the vanadium-nickel-magnesium ternary catalyst, which is recorded as catalyst 1, wherein the weight ratio of nickel:vanadium:magnesium is 6:2:0.9.

[0025] Example 2-5: Preparation of vanadium-nickel-magnesium ternary catalyst

[0026] The preparation process is the same as that in example 1, the feeding ratio and reaction conditions are shown in Table 1, and the vanadium-nickel-magnesium ternary catalyst is obtained, which is recorded as catalyst 2, catalyst 3, catalyst 4 and catalyst 5 respectively.

[0027] Table 1: Feeding ratio of raw materials and reaction conditions of examples 2-5

[0028]

[0029]

[0030] Example 6-10 Synthesis of N-ethylaniline

[0031] 1) Synthesis of N-ethylaniline: Aniline 1000 g, catalyst 100 g (catalyst 1, catalyst 2, catalyst 3, catalyst 4, catalyst 5) prepared in Example 1-5 were added into a normal pressure reaction kettle, and 500 g of ethanol was added dropwise under stirring at 25 °C for 3 hours, and then reacted for another 2 hours. After the reaction, the supernatant was sampled and analyzed. The main components were ethanol 4%, aniline 4%, ethylaniline 85%, and N, N-diethylaniline 5% by gas chromatography.

[0032] 2) Rectification: The supernatant 1400 g (containing 12% water) was added into a rectification kettle, and ethanol, water, aniline, N-ethylaniline, and N, N-diethylaniline were separated by vacuum rectification (20 mmHg). Specifically, ethanol and water 220 g were collected at a temperature less than 80 °C, aniline 50 g was collected at a temperature of 80-105 °C, N-ethylaniline 1040 g was collected at a temperature of 105-115 °C, and N, N-diethylaniline 55 g was collected at a temperature of 115-125 °C.

[0033] Table 2 Analysis results of the supernatant in Example 6-10

[0034] Catalyst N-ethylaniline selectivity Example 6 Catalyst 1 85％ Example 7 Catalyst 2 76％ Example 8 Catalyst 3 79％ Example 9 Catalyst 4 83％ Example 10 Catalyst 5 82％

[0035] Example 11-16 Synthesis of N-ethylaniline

[0036] By adjusting the amount of catalyst 1 and the reaction time, other conditions were the same as in Example 10. Specifically, aniline 1000 g was used, and 500 g of ethanol was added dropwise under stirring at 25 °C for 3 hours, and then reacted for another 2 hours to synthesize N-ethylaniline. The reaction parameters and results are shown in Table 3.

[0037] Table 3 Reaction data of Example 11-16

[0038]

[0039]

[0040] According to the above data, it can be seen that as the amount of catalyst increases, the selectivity of N-ethylaniline increases, and when the amount of ethanol continues to increase, the selectivity decreases. When the amount of ethanol is 500 g and the amount of aniline is 1000 g, the optimal amount of catalyst is 100 g.

[0041] Example 17

[0042] 1) Synthesis of N-ethylaniline: Charge ratio: 1000 g of aniline was charged into the atmospheric reactor containing catalyst 1 (reused once) from Example 6. The temperature was controlled at 25°C and 500 g of ethanol was added dropwise with stirring. The reaction was continued for 2 hours. The catalyst was allowed to settle and a sample was analyzed. The main components of the crude product were: 5% ethanol, 10% water, 3% aniline, 86% N-ethylaniline, and 5% N,N-diethylaniline.

[0043] 2) Rectification: The supernatant was charged into a rectification column and the ethanol, water, aniline, N-ethylaniline, and N,N-diethylaniline were separated by vacuum distillation (20 mm Hg). The ethanol and water were collected at a temperature less than 80°C, 235 g; the aniline was collected at a temperature less than 80-105°C, 55 g; the N-ethylaniline was collected at a temperature less than 105-115°C, 1115 g; and the N,N-diethylaniline was collected at a temperature less than 115-125°C, 55 g.

[0044] Examples 18-22

[0045] The catalyst from Example 17 was reused (Example 18 was reused twice, Example 19 was reused three times, Example 20 was reused four times, and Example 21 was reused five times, and in Example 21, 7 g of catalyst 1 was added. The reaction was the same as in Example 17 and the results are shown in Table 4.

[0046] Table 4 Results of Examples 18-21

[0047] Number of runs Reaction completion time h N-ethylaniline selectivity 0 (Example 6) 5 85％ 1 (Example 17) 5 86％ 2 (Example 18) 5 85％ 3 (Example 19) 5 85％ 4 (Example 20) 5 85％ 5 (Example 21) 6 85％

[0048] As can be seen from Table 4, the selectivity of the catalyst for N-ethylaniline remained unchanged when the catalyst was reused four times. When the catalyst was reused a fifth time, the reaction time was almost unchanged by adding 7 g of catalyst 1.

Claims

1. The application of a vanadium-nickel-magnesium ternary catalyst in the preparation of N-ethylaniline, wherein the raw materials for the vanadium-nickel-magnesium ternary catalyst comprise the following components in parts by weight: 50-70 parts of aluminum-nickel alloy, 10-20 parts of vanadium oxide, 20-30 parts of talc powder, 80-120 parts of 30% sodium hydroxide solution, and 150-300 parts of distilled water; the method for preparing the vanadium-nickel-magnesium ternary catalyst is characterized by... The process includes the following steps: according to the feeding ratio, aluminum-nickel alloy, talc powder and vanadium oxide are added to a 30% sodium hydroxide solution and mixed into a slurry. The mixture is heated to 70°C and kept at that temperature for 5 hours under stirring. After the reaction is completed, the mixture is centrifuged. The resulting filter cake is washed with distilled water, dried and calcined to obtain a vanadium-nickel-magnesium ternary catalyst. The calcination temperature is 500-800°C and the calcination time is 5-10 hours.

2. The application according to claim 1, characterized in that... The catalyst raw materials include the following components in parts by weight: 60 parts aluminum-nickel alloy, 15-20 parts vanadium oxide, 25-30 parts talc, 100 parts 30% sodium hydroxide solution, and 200 parts distilled water.

3. A method for preparing N-ethylaniline, characterized in that... Includes the following steps: 1) According to the weight ratio, add 50-70 parts of aluminum-nickel alloy, 20-30 parts of talc powder and 10-20 parts of vanadium oxide to 80-120 parts of 30% sodium hydroxide solution and mix into a slurry. Under stirring, heat to 50-80℃ and keep it at that temperature for 5-7 hours. After the reaction, centrifuge and wash the resulting filter cake with distilled water, dry and calcine to obtain vanadium-nickel-magnesium ternary catalyst. The calcination temperature is 500-800℃ and the calcination time is 5-10 hours. 2) Ethanol, aniline, and the vanadium-nickel-magnesium ternary catalyst obtained in step 1) were added to a reaction vessel and stirred at room temperature and pressure. After the reaction was completed, the mixture was allowed to stand, and the supernatant was transferred to a distillation vessel. The fraction collected at 110-115℃ and 20 mmHg was obtained to yield the product N-ethylaniline. The reaction equation is as follows: 。 4. The method for preparing N-ethylaniline according to claim 3, characterized in that... The reaction time is 4-5 hours.

5. The method for preparing N-ethylaniline according to claim 3, characterized in that... The mass ratio of ethanol, aniline, and vanadium-nickel-magnesium ternary catalyst is 1:2:0.04-0.

4.

6. The method for preparing N-ethylaniline according to claim 3, characterized in that... The mass ratio of ethanol, aniline, and vanadium-nickel-magnesium ternary catalyst is 1:2:0.

2.

7. A method for preparing N-ethylaniline according to any one of claims 3-6, characterized in that... Vanadium-nickel-magnesium ternary catalysts can be reused.

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