CN110372483B - Process method for preparing glutaraldehyde by catalytic oxidation of cyclopentene - Google Patents

Abstract

The invention relates to a process method for preparing glutaraldehyde by catalytic oxidation of cyclopentene, which comprises mixing hydrogen peroxide solution and reaction solvent, adding tungsten-based molecular sieve catalyst according to the addition amount of the catalyst being 1-4% of the cyclopentene, mixing uniformly, adding cyclopentene, stirring, and carrying out catalytic oxidation reaction in a reaction system to obtain glutaraldehyde product. Compared with the prior art, the method has the advantages of high conversion rate of cyclopentene, high selectivity of pentadiene, high yield, environment-friendly reaction process, simple post-treatment and the like.

Description

A kind of process method of preparing glutaraldehyde by catalytic oxidation of cyclopentene

technical field

The invention relates to a solid-liquid heterogeneous catalytic reaction, in particular to a process for preparing glutaraldehyde by catalytic oxidation of cyclopentene.

Background technique

Glutaraldehyde (abbreviated as GA), a colorless or light yellow oily liquid with a pungent odor, easily soluble in water, ethanol, and benzene, non-flammable, non-volatile, unstable in air. It can be oxidized by air at room temperature, and is also prone to condensation, polymerization and other reactions. It is an important saturated linear aliphatic dialdehyde, an important fine chemical product and intermediate, and has the function of crosslinking and solidifying proteins. It is a high-efficiency and low-toxicity disinfectant, excellent leather tanning agent, color picture tube hardening agent and organic synthesis agent, widely used in biomedical engineering, cell immunology, biochemistry, leather chemistry, histochemistry and microbial industry , environmental protection and other fields.

At present, the main synthesis methods include pyridine method, acrolein method, polyol oxidation method, glutaric acid reduction method and cyclopentene oxidation method. The pyridine method was first used in industrial production, but it was eliminated because of its large consumption of raw materials, high cost, large pollution, and poor product quality. Although the reaction route of the pentanediol oxidation method is short, the possibility of industrialization is not great because the oxidation depth of the oxidation reaction is not easy to control, the yield is low, the raw material is in short supply, and the production cost is high. The cyclopentene oxidation method is a method that has been studied more nowadays, and tungsten-containing molecular sieves are favored by scholars.

At present, the heterogeneous catalysts used for this reaction mainly include heteropolyacid immobilization, composite metal oxides, tungsten-mesoporous molecular sieves, etc. The above-mentioned catalysts are used in the reaction of cyclopentene oxidation to glutaraldehyde with W-SBA-15 , W-MCM-41, W-MCM-48, etc., but tungsten-based molecular sieves have not been proposed for this catalytic oxidation reaction.

Chinese patent CN1680032A discloses a novel heterogeneous tungsten-containing catalyst for the selective oxidation of cyclopentene to prepare glutaraldehyde by using aqueous hydrogen peroxide as an oxidant and a manufacturing method thereof. The new tungsten-containing catalyst is prepared by adding a tungstic acid precursor during the synthesis of HMS-type all-silicon mesoporous molecular sieves, and introducing tungsten oxide components with catalytic oxidation activity into the framework of HMS mesoporous molecular sieves in situ. However, when the catalyst is used to catalyze the oxidation reaction of cyclopentene, the yield of the target product glutaraldehyde is 56.9～75.1%, the selectivity of glutaraldehyde is 73.5～82.0%, and its catalytic effect is not very Well, both catalyst activity and selectivity need to be improved.

Today's environmental problems in China have become serious, and environmental problems have received great attention. Green chemistry has become an inevitable direction for the research and development of the chemical industry. The development of excellent catalysts and optimal process conditions is an important part of the realization of green chemical industry. With the aim of realizing green chemistry, it is of great research significance to synthesize a catalyst with good catalytic activity for the catalytic oxidation of cyclopentene to prepare glutaraldehyde. .

Contents of the invention

The purpose of the present invention is to provide a process for preparing glutaraldehyde by catalytic oxidation of cyclopentene in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions:

A process for preparing glutaraldehyde by catalytic oxidation of cyclopentene, comprising the following steps:

Mix the hydrogen peroxide solution and the reaction solvent, add a tungsten-based molecular sieve catalyst in an amount of 1 to 4% of the mass of cyclopentene as the catalyst, mix evenly, add cyclopentene, stir, and the reaction system carries out catalytic oxidation reaction to obtain pentene dialdehyde product.

Wherein, the reaction solvent is selected from one or more of methanol, ethanol, isopropanol or tert-butanol.

The reaction temperature of the catalytic oxidation reaction is 20-50°C, preferably 25-35°C.

The reaction time of the catalytic oxidation reaction is 12-48 hours, preferably 24-36 hours.

The molar ratio of the cyclopentene to hydrogen peroxide is 1-2.

The mass load of tungsten oxide in the tungsten-based molecular sieve catalyst is 2-15%.

The present invention uses tungsten-based molecular sieves to catalyze the catalytic oxidation of cyclopentene to prepare glutaraldehyde, and optimizes the reaction conditions:

In the reaction process, the amount of catalyst added is very important. When the amount of catalyst added is too much, the conversion rate of cyclopentene is higher, but the selectivity of glutaraldehyde is lower, and too many side reactions are generated, which is not conducive to the reaction raw materials. Utilization, when the addition amount of catalyzer is too low, the conversion ratio of cyclopentene and the selectivity of glutaraldehyde are all lower, are unfavorable for the generation of glutaraldehyde. Compared with the addition of 8 to 17% of the mass of cyclopentene as the catalyst in Chinese patent CN1680032A, the present invention adopts an addition of 1 to 4%, and the yield of glutaraldehyde obtained is as high as 87.1%. The selectivity is as high as 87.1%, which is better than the data of the Chinese patent CN1680032A with a yield of 76% and a selectivity of 77%. By optimizing the amount of catalyst added, the yield of glutaraldehyde is greatly improved, which is beneficial to improve the utilization rate of atoms, and is more economical and environmentally friendly.

If the reaction temperature is too high or too low, the conversion rate of cyclopentene and the selectivity of glutaraldehyde are low, and the catalytic activity is low; the reaction time needs to be controlled at about 24 hours, and the reaction time is short, and cyclopentene has not yet reacted Completely, the conversion rate is too low, the reaction time is long, the product glutaraldehyde is over-converted, and the selectivity of glutaraldehyde decreases, which also leads to a decrease in the final yield of glutaraldehyde, which is not conducive to atom economy.

The tungsten-based molecular sieve catalyst is prepared after in-situ introduction of tungsten oxide active components in the process of synthesizing molecular sieves.

Specifically, the preparation method of the tungsten-based molecular sieve catalyst is:

Material preparation: Weigh the raw materials silicon source, aluminum source, inorganic alkali source, templating agent TPABr, water and tungsten source respectively;

Add the above inorganic alkali source into water, then add the template machine TPABr, after dissolving, add the aluminum source, stir to dissolve, add the tungsten source, stir at room temperature, then add the silicon source, and stir the mixture for aging;

Transfer the aged mixture to a polytetrafluoroethylene reactor for crystallization;

The crystallized mixture is filtered, washed, dried, and calcined to remove the template agent to obtain the tungsten-based molecular sieve catalyst.

During the material preparation process, each raw material component was weighed according to the molar ratio of 100SiO2: _1.0Al2O3 : _8.75Na2O : _12TPABr : _2600H2O : ₁₀ ～ _1.25WO3 ; the silicon source in the raw material was _SiO2 , The aluminum source is aluminum sulfate octadecahydrate, the inorganic alkali source is sodium hydroxide, and the tungsten source is sodium tungstate.

In the aging process, the aging temperature of the mixture is 20-40°C, preferably 30°C, and the aging time is 8-12 hours;

In the crystallization process, the crystallization temperature is 150-220°C, preferably 180°C, and the crystallization time is 30-40 hours, preferably 36 hours;

The calcination temperature of the calcination removal template machine is 450-600°C, preferably 550°C, and the calcination time is 4-8 hours, preferably 6 hours.

Compared with the prior art, the present invention has the following advantages:

(1) In the preparation process, the conversion rate of cyclopentene reaches 100%, the selectivity to the target product glutaraldehyde reaches 87.1%, the yield of glutaraldehyde reaches 87.1%, and the reaction effect is good;

(2) The catalyst in the reaction process has high activity and good stability. After 3 test cycles, in the activity data of the catalyst, the yield of glutaraldehyde does not significantly decrease, indicating that the catalyst structure is stable and reusable; and the catalyst is prepared The process is simple, and it is easy to expand production.

Detailed ways

The present invention will be described in detail below in conjunction with specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

Example 1

A kind of tungsten-based molecular sieve catalyst, its preparation method comprises the following steps:

(1) Add 0.527g NaOH to 36.715g H ₂ O, then add 2.5066g TPABr, after dissolving, add 0.5228g Al ₂ (SO ₄ ) ₃ ·18H ₂ O, stir at room temperature until completely dissolved;

(2) Add 0.4438g Na ₂ WO ₄ , stir at room temperature for 30 minutes, then add 4.707g SiO ₂ , and stir the mixture at 30°C overnight for aging;

(3) The above materials are transferred to a polytetrafluoroethylene reactor for 36 hours at 180°C, filtered, washed, and dried;

(4) The sample was calcined in a muffle furnace at 550° C. for 6 hours to obtain the product.

The raw materials in the preparation process are shown in Table 1.

The raw material reagent source in the preparation process of table 1

Example 2

An application method of a tungsten-based molecular sieve catalyst. The tungsten-based molecular sieve catalyst is used to catalyze the reaction of cyclopentene to catalyze the oxidation value of glutaraldehyde. The specific steps are as follows:

(1) In a 100mL round-bottomed flask, mix 3.89mL of 30%wt hydrogen peroxide solution with 14mL of tert-butanol, then add and weigh 0.1g of the catalyst prepared in Example 1, when the above three substances are fully mixed Afterwards, 5.74 mL of cyclopentene was added, and the reaction was stirred in an oil bath at 35° C. for 24 h.

(2) After the reaction, the mixed solution after the reaction was analyzed with a GC-9790 gas chromatograph (FID, AE PEG-20M 30m×0.32mm×0.5um).

Calculate the conversion rate of cyclopentene and the selectivity and yield of glutaraldehyde according to the analysis results, and the formation test results of the catalyst are shown in Table 2.

Table 2 Example 2 Catalyst Performance Test Results List

From table 2, as can be seen, adopt the catalyzer among the embodiment 1, the conversion rate of cyclopentene conversion rate is up to 100%, the selectivity of glutaraldehyde is 87.1%, and yield is 87.1%, because in Chinese patent CN1680032A The activity data of the catalyst of the present invention shows that the catalyst of the present invention has better catalytic effect.

Example 3

This example is to explore the influence of the reaction solvent on the reaction effect during the reaction process of preparing glutaraldehyde by catalytic oxidation of cyclopentene.

Specific steps are as follows:

(1) Take by weighing 0.1g of the catalyst prepared in Example 1, in a 100mL round bottom flask, 3.89mL, 30%wt hydrogen peroxide solution is mixed with 14mL alcohol solvent, then add the weighed catalyst, when the above three After the substances are completely mixed, add 5.74mL cyclopentene, stir and react at 35°C for 24h to test the catalytic effect of the catalyst in the catalytic oxidation of cyclopentene;

(2) After the reaction under different temperature conditions, the mixed solution after the reaction was analyzed by GC-9790 gas chromatograph (FID, AE PEG-20M 30m×0.32mm×0.5um).

Data analysis was carried out on the reaction effects obtained by using different alcohol solvents, as shown in Table 3.

Catalyst performance test results list under different alcohol solvent conditions of table 3

As can be seen from Table 3, the use of tert-butanol solvent is more conducive to the reaction.

Example 4

This example is to explore the influence of the amount of catalyst on the reaction effect during the reaction process of preparing glutaraldehyde by catalytic oxidation of cyclopentene.

Specific steps are as follows:

(1) Take by weighing 0.05, 0.08, 0.10, 0.15g of the catalyst prepared in Example 1 respectively, in a 100mL round bottom flask, mix 3.89mL of 30%wt hydrogen peroxide solution with 14mL of tert-butanol, then add and weigh After the above three substances are fully mixed, add 5.74mL cyclopentene, stir and react at 35°C for 24h to test the catalytic effect of the catalyst in the catalytic oxidation of cyclopentene;

(2) After the reaction under different temperature conditions, the mixed solution after the reaction was analyzed by GC-9790 gas chromatograph (FID, AE PEG-20M 30m×0.32mm×0.5um).

The data analysis of the reaction effects obtained by adopting different catalyst dosages is shown in Table 4.

Table 4 Catalyst dosage on the influence result list of reaction effect

As can be seen from Table 4, the amount of catalyst used is too high or too low to be unfavorable for the yield of glutaraldehyde, that is, unfavorable for improving catalytic performance.

Example 5

This example is to explore the influence of reaction temperature on the reaction effect during the preparation of glutaraldehyde by catalytic oxidation of cyclopentene.

Specific steps are as follows:

(1) Take by weighing 0.1g of the catalyst prepared in Example 1, in a 100mL round bottom flask, mix the hydrogen peroxide solution of 3.89mL30%wt with 14mL of tert-butanol, then add the weighed catalyst, when the above three substances After complete mixing, add 5.74mL cyclopentene, stir and react at 25°C, 35°C, 45°C, and 55°C for 24 hours to test the catalytic effect of the catalyst in the catalytic oxidation of cyclopentene;

(2) After the reaction under different temperature conditions, the mixed solution after the reaction was analyzed by GC-9790 gas chromatograph (FID, AE PEG-20M 30m×0.32mm×0.5um).

Data analysis was carried out on the reaction effects obtained under different reaction temperature conditions, as shown in Table 5.

List of catalyst performance test results under different reaction temperature conditions in table 5

It can be seen from Table 5 that during the reaction process, too high or too low reaction temperature is not conducive to the smooth progress of the reaction. When the reaction temperature is 35 ° C, the catalyst activity is the best.

Example 6

This example is to explore the influence of reaction time on the reaction effect during the reaction process of preparing glutaraldehyde by catalytic oxidation of cyclopentene.

Specific steps are as follows:

(1) Take by weighing 0.1g of the catalyst prepared in Example 1, in a 100mL round bottom flask, mix the hydrogen peroxide solution of 3.89mL30%wt with 14mL of tert-butanol, then add the weighed catalyst, when the above three substances After complete mixing, add 5.74mL cyclopentene, set the reaction temperature at 35°C, and control the reaction time at 12h, 24h, 36h and 48h, respectively, to compare the catalytic effect of the catalyst in the catalytic oxidation of cyclopentene;

(2) After the reaction, use GC-9790 gas chromatograph (FID, AE PEG-20M 30m×0.32mm×0.5um) to analyze the mixed solution after reaction respectively.

Data analysis was carried out on the reaction effects obtained by adopting different reaction times, as shown in Table 6.

Table 6 Catalyst Performance Test Results List under Different Reaction Time Conditions

As can be seen from Table 6, when the reaction time was 24 hours, the yield of glutaraldehyde reached the highest, and the best yield could be obtained by finishing the reaction now.

Example 7

This example is to explore the influence of the number of cycles of the catalyst on its catalytic performance during the reaction process of preparing glutaraldehyde by catalytic oxidation of cyclopentene, and to explore the stability of the catalyst.

Specific steps are as follows:

(1) Weigh 0.1 g of the catalyst prepared in Example 1 for use.

(2) In a 100mL round-bottomed flask, mix 3.89mL of 30%wt hydrogen peroxide solution with 14mL of tert-butanol, then add and weigh 0.1g of the catalyst prepared above, when the above three substances are fully mixed, then Add 5.74mL cyclopentene, and stir the reaction in an oil bath at 35°C for 24h.

(3) After the reaction, the mixed solution after the reaction was analyzed with a GC-9790 gas chromatograph (FID, AE PEG-20M 30m×0.32mm×0.5um).

(4) After each reaction, see catalyst separation, then repeat above-mentioned steps (2), (3), (4) steps.

The data analysis of the reaction effect obtained by catalysts with different cycle times is shown in Table 7.

Table 7 List of Catalyst Performance Test Results for Different Repeat Times

It can be seen from Table 6 that the catalyst can still maintain good catalytic activity after 3 cycles, and the corresponding glutaraldehyde yield of the catalyst is 73.4%, which shows that the catalyst of the present invention has better stability.

Example 8

A kind of tungsten-based molecular sieve catalyst, in this catalyst, W/Si molar ratio is 0.0125, and its preparation method comprises the following steps:

(1) Add 0.527g NaOH to 36.715g H ₂ O, then add 2.5066g TPABr, after dissolving, add 0.5228g Al ₂ (SO ₄ ) ₃ ·18H ₂ O, stir at room temperature until completely dissolved;

(2) Add 0.2878g Na ₂ WO ₄ , stir at room temperature for 30 minutes, then add 4.707g SiO ₂ , and stir the mixture at 20°C overnight for aging, the specific aging time is 8 hours;

(3) The above-mentioned materials were transferred to a polytetrafluoroethylene reactor for reaction at 150°C for 40 hours, suction filtered, washed, and dried;

(4) The sample was calcined in a muffle furnace at 450° C. for 8 hours to obtain the product.

The raw materials in the preparation process are shown in Table 1.

Calculate the conversion rate of cyclopentene and the selectivity and yield of glutaraldehyde according to the analysis results, and the formation test results of the catalyst are shown in Table 8.

Table 8 embodiment 2 catalyst performance test results list

Example 9

A kind of tungsten-based molecular sieve catalyst, W/Si molar ratio is 0.1 in this catalyst, and its preparation method comprises the following steps:

(1) Add 0.527g NaOH to 36.715g H ₂ O, then add 2.5066g TPABr, after dissolving, add 0.5228g Al ₂ (SO ₄ ) ₃ ·18H ₂ O, stir at room temperature until completely dissolved;

(2) Add 0.2.302g Na ₂ WO ₄ , stir at room temperature for 30 minutes, then add 4.707g SiO ₂ , stir the mixture at 40°C overnight, and the specific aging time is 12 hours;

(3) The above-mentioned materials were transferred to a polytetrafluoroethylene reactor for reaction at 220°C for 30 hours, suction filtered, washed, and dried;

(4) The sample was calcined in a muffle furnace at 600° C. for 8 hours to obtain the product.

The raw materials in the preparation process are shown in Table 1.

The conversion rate of cyclopentene and the selectivity and yield of glutaraldehyde were calculated according to the analysis results, and the formation test results of the catalyst are shown in Table 9.

Table 9 embodiment 2 catalyst performance test results list

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims (5)

1. a process method for preparing glutaraldehyde by catalytic oxidation of cyclopentene, is characterized in that, comprises the following steps: Mix the hydrogen peroxide solution and the reaction solvent, add a tungsten-based molecular sieve catalyst in an amount of 1 to 4% of the mass of cyclopentene as the catalyst, mix evenly, add cyclopentene, stir, and the reaction system performs a catalytic oxidation reaction to obtain pentene dialdehyde products; The reaction solvent is tert-butanol; the reaction temperature of the catalytic oxidation reaction is 25-35°C; the reaction time of the catalytic oxidation reaction is 24-36 hours; The mass loading of tungsten oxide in the tungsten-based molecular sieve catalyst is 2 to 15%, and the preparation method of the tungsten-based molecular sieve catalyst is as follows: Material preparation: Weigh the raw materials silicon source, aluminum source, inorganic alkali source, templating agent TPABr, water and tungsten source respectively; Add the above inorganic alkali source into water, then add the template machine TPABr, after dissolving, add the aluminum source, stir to dissolve, add the tungsten source, stir at room temperature, then add the silicon source, and stir the mixture for aging; Transfer the aged mixture to a polytetrafluoroethylene reactor for crystallization; filtering the crystallized mixture, washing, drying, and roasting to remove the template agent to obtain the tungsten-based molecular sieve catalyst; The calcination temperature of the calcination to remove the template agent is 450-600° C., and the calcination time is 4-8 hours. 2. a kind of cyclopentene catalytic oxidation according to claim 1 prepares the processing method of glutaraldehyde, it is characterized in that, the mol ratio of described cyclopentene and hydrogen peroxide is 1～2. 3. the process method that a kind of cyclopentene catalytic oxidation prepares glutaraldehyde according to claim 1 is characterized in that, according to 100SiO ₂ : 1.0Al ₂ O ₃ : 8.75Na ₂ O: 12TPABr: 2600H ₂ in the preparation process The molar ratio of O: 10～ _1.25W03 takes each raw material component; the silicon source in the raw material is SiO ₂ , the aluminum source is aluminum sulfate octadecahydrate, and the inorganic alkali source is sodium hydroxide, so The tungsten source is sodium tungstate. 4. the process method of preparing glutaraldehyde by catalytic oxidation of a kind of cyclopentene according to claim 1, is characterized in that, in described aging process, the aging temperature of mixture is 20～40 ℃, and aging time is 8～12 Hour; During the crystallization process, the crystallization temperature is 150-220° C., and the crystallization time is 30-40 hours. 5. the process method of preparing glutaraldehyde by catalytic oxidation of a kind of cyclopentene according to claim 4, is characterized in that, in described aging process, the aging temperature of mixture is 30 ℃; In the crystallization process, the crystallization temperature is 180°C, and the crystallization time is 36 hours; The calcination temperature of the calcination to remove the template agent is 550° C., and the calcination time is 6 hours.