A hydrotalcite-based strongly basic solid catalyst and a method for catalyzing the propionitrile formation of alcohols

Abstract

The present invention belongs to the field of chemical synthesis, and specifically relates to a hydrotalcite-based strongly basic solid catalyst and a method for catalyzing the propionitrile conversion of alcohols. A strongly basic solid catalyst (MHT) is obtained by using hydrotalcite with strong basicity as a matrix and loading alkaline metal ions such as rubidium, cesium, strontium, and barium. MHT is used as a catalyst, mixed with an alcohol raw material in a certain proportion, and a suitable temperature is controlled. An appropriate amount of acrylonitrile is added at a uniform rate over a certain period of time. After the addition of the acrylonitrile, the temperature is continued to control the reaction for an appropriate time to fully convert the raw material. To suppress the self-polymerization of acrylonitrile, an appropriate polymerization inhibitor is added to the acrylonitrile. After the reaction is completed, the material is filtered to obtain a propionitrile product, and the recovered solid catalyst can be recycled. The present invention simplifies the post-processing process of the alcohol propionitrile conversion reaction, reduces pollutant emissions, and lowers preparation costs.

Description

Technical Field

[0001] The invention belongs to the field of chemical synthesis, and particularly relates to a hydrotalcite-based strongly alkaline solid catalyst and a method for catalyzing the propionitrile formation of alcohols. Background Art

[0002] The propionitrile reaction of alcohols is to react the alcohol hydroxyl group with acrylonitrile in the presence of a catalyst to obtain a propionitrile product.

[0003]

[0004] The resulting propionitrile product can be used as a high-boiling-point aprotic polar solvent and an additive to improve electrolyte conductivity and the dispersion stability of conductive ions. Further catalytic hydrogenation can also yield etheramine compounds, which, as a class of functional chemical products, can be used as curing agents, acid gas absorbents, polymer monomers, and more.

[0005] The addition reaction of alcoholic hydroxyl groups with acrylonitrile is usually catalyzed by strong bases. Tang Xiaodong et al. (Thermosetting Resins, 2014, 29(3): 1-4) reported that KOH, NaOH, sodium methoxide and other catalysts were dissolved in ethylene glycol and ethylene glycol was propionitrile-modified under the catalytic effect of tetrabutylammonium iodide to synthesize 1,2-bispropionitrileoxyethane. For example, using NaOH as a catalyst and tetrabutylammonium iodide as a co-catalyst, ethylene glycol and acrylonitrile were reacted at 50°C for 24 hours, and the conversion rate of ethylene glycol reached 87%. Tang Xiaodong et al. (Thermosetting Resins, 2014, 29(4): 12-15) also reported that propylene glycol and acrylonitrile were reacted at 30°C for 8 hours under the catalytic effect of tetrabutylammonium iodide and sodium methoxide, and the conversion rate of the raw materials was 73%.

[0006] The use of inorganic bases such as KOH and NaOH, or organic bases such as sodium methoxide and potassium tert-butoxide, all have good catalytic effects. These alkaline catalysts are actually dissolved in the reactants during the reaction process, forming a homogeneous catalytic system with a high catalyst utilization rate. However, such a homogeneous catalytic reaction system brings great trouble to product separation. Because these strong alkaline catalysts that dissolve in the reactants will cause the propionitrile product to undergo polymerization and become coke when the product is purified by high-temperature distillation. Therefore, after the reaction is completed, it is necessary to remove the alkaline catalyst by steps such as neutralization, washing, and drying as described in Japanese Patent Application (JP.103505 / 1973). In Chinese Patent Application (CN109134309), more complex post-processing techniques such as anhydride reaction, neutralization, washing, and extraction are used. In short, the complex post-processing operations brought about by these homogeneous catalysis result in high production costs and large pollutant emissions. Summary of the Invention

[0007] The purpose of the present invention is to provide a new catalytic technology to simplify the post-processing process of alcohol propionitrile reaction, reduce pollutant emissions and lower preparation costs.

[0008] To achieve the above object, the technical solution adopted by the present invention is:

[0009] The present invention provides a strong alkaline solid catalyst. The strong alkaline solid material (MHT) is obtained by using hydrotalcite (HT for short) as a matrix and loading alkaline metal ions (M).

[0010] The hydrotalcite matrix is ​​magnesium-aluminum hydrotalcite (HT).

[0011] In the strongly alkaline solid material MHT, M is a heavy alkali metal ion or a heavy alkaline earth metal ion, specifically rubidium (Rb), cesium (Cs), strontium (Sr), barium (Ba), etc. The loading amount of M is 10-20%.

[0012] The loading was carried out by dipping method.

[0013] The impregnation loading process involves impregnating the hydrotalcite substrate with an aqueous solution of a metal hydroxide at 60-90°C for 4-8 hours, followed by drying at 120°C in a nitrogen stream, and then heat-treating at 300-360°C in a nitrogen stream for 2-6 hours. This yields the strongly basic solid catalyst MHT.

[0014] The above-obtained MHT is used as a catalyst, mixed with an alcohol raw material in a certain ratio, and a suitable solvent is added to the reaction system when the viscosity of the alcohol is large or it is a solid. Then, a suitable temperature is controlled, and an appropriate amount of acrylonitrile is added at a uniform speed within a certain period of time. After the acrylonitrile is added, the temperature control reaction is continued for an appropriate time to fully convert the raw materials. To suppress the autopolymerization of acrylonitrile, a suitable polymerization inhibitor is added to the acrylonitrile. After the reaction is completed, the material is filtered, and the resulting liquid is a propionitrile-based product. The recovered solid catalyst can be recycled.

[0015] The weight ratio of the strong alkaline solid catalyst MHT to the reactant alcohol is 5-10:100.

[0016] The alcohol reactant may be a monohydric alcohol having 2 to 8 carbon atoms, such as ethanol, n-butanol, ethylene glycol monomethyl ether, isooctyl alcohol, etc., or a polyhydric alcohol having 2 to 5 carbon atoms, such as ethylene glycol, propylene glycol, pentaerythritol, etc.

[0017] The amount of acrylonitrile used is: the ratio of the molar amount of alcoholic hydroxyl groups in the raw alcohol to the molar amount of acrylonitrile is 1:1.05-1.25.

[0018] The appropriate reaction temperature is 30-55° C. The appropriate addition time of acrylonitrile is 10-20 hours, and the reaction time after addition is 2-4 hours.

[0019] When the alcohol reactant is highly viscous or solid, an aprotic solvent such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, or dimethyl sulfoxide should be added to the reaction system. The appropriate amount of solvent is 50-100% by weight of the starting alcohol.

[0020] The polymerization inhibitor is phenothiazine, p-hydroxyanisole, hydroquinone and its derivatives, and the dosage of the polymerization inhibitor is 0.04% to 0.1% of the weight of acrylonitrile.

[0021] The catalyst recovered by filtration can be directly recycled. It can also be recycled after washing with a solvent. Suitable washing solvents include dichloromethane, 1,2-dichloroethane, chlorobenzene, N,N-dimethylformamide, etc.

[0022] Effects of the invention: The beneficial effects produced by the technical method of the invention include:

[0023] (1) Using hydrotalcite with strong alkalinity as the matrix, by loading alkali metal or alkaline earth metal ions, a strong alkaline solid material MHT is made to replace the traditional soluble alkaline catalyst, so that the propionitrile catalyst can be recycled, reducing catalyst consumption and thus reducing production costs.

[0024] (2) After the reaction, the strong base solid catalyst MHT can be separated from the product by filtration, making the production process simple to operate and the process simplified, thereby improving production efficiency.

[0025] (3) The strong base solid molecular sieve catalyst MH can be easily separated from the product after the reaction and recycled. This avoids the need for neutralization, water washing and other catalyst removal operations required for traditional soluble base catalysts after the reaction, thereby avoiding the discharge of waste salt and wastewater during the post-processing process, making the production process green and clean. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the SEM image of RbHT.

[0027] Figure 2 This is the SEM image of CsHT.

[0028] Figure 3 This is the SEM image of SrHT.

[0029] Figure 4 This is the SEM image of BaHT. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to examples, but is not limited thereto.

[0031] Example 1 Preparation of solid base catalyst RbHT

[0032] 24g of aqueous solution containing 50% rubidium hydroxide was mixed with 76g of water to form a uniform solution. 100g of commercial magnesium aluminum hydrotalcite powder (60-100 mesh, containing about 33% magnesium oxide, 21% aluminum oxide, and a specific surface area of ​​96m 2 / g, pore volume 0.49ml / g. Product of Changzhou Shanye New Material Technology Co., Ltd.) was added thereto, immersed at 60℃ for 4 hours, and dried at 120℃ in a nitrogen flow (about 12 hours). The material was then placed in a tubular furnace and heat treated at 360℃ in a nitrogen flow for 2 hours. The solid base catalytic material RbHT was obtained. Among them, the Rb element content is about 10.0% (relative to the weight of magnesium aluminum hydrotalcite powder). The microstructural parameters measured by the BET method are: specific surface area 72.3m 2 / g, pore volume 0.34ml / g. Its scanning electron microscope (SEM) is shown in Figure 1 .

[0033] Example 2 Preparation of solid base catalyst CsHT-1

[0034] 21.5g of cesium hydroxide monohydrate and 78.5g of water were mixed into a uniform solution, 100g of commercial magnesium aluminum hydrotalcite (same as in Example 1) was added thereto, immersed at 70°C for 8 hours, and dried at 120°C in a nitrogen stream (about 12 hours). The material was then placed in a tube furnace and heat treated at 340°C in a nitrogen stream for 4 hours. A solid base catalytic material CsHT-1 was obtained. The Cs element content was about 17.0% (relative to the weight of magnesium aluminum hydrotalcite). The microstructural parameters measured by the BET method were: specific surface area 79.7m 2 / g, pore volume 0.39ml / g. Its scanning electron microscope (SEM) is shown in Figure 2 .

[0035] Example 3 Preparation of solid base catalyst SrHT

[0036] 39.5 g of strontium hydroxide octahydrate and 60.5 g of water were mixed into a uniform solution, 100 g of commercial magnesium aluminum hydrotalcite (same as in Example 1) was added thereto, immersed at 80°C for 6 hours, and dried at 120°C in a nitrogen stream (about 12 hours). The material was then placed in a tube furnace and heat treated at 320°C in a nitrogen stream for 5 hours. A solid base catalytic material SrHT was obtained. The Sr element content was about 13.0% (relative to the weight of the magnesium aluminum hydrotalcite). The microstructural parameters measured by the BET method were: specific surface area 74.4 m 2 / g, pore volume 0.33ml / g. Its scanning electron microscope (SEM) is shown in Figure 3 .

[0037] Example 4 Preparation of solid base catalyst BaHT

[0038] 47.0 g of barium hydroxide octahydrate and 53.0 g of water were mixed into a uniform solution, 100 g of commercial magnesium aluminum hydrotalcite (same as in Example 1) was added thereto, immersed at 90° C. for 7 hours, and dried at 120° C. in a nitrogen stream (about 12 hours). The material was then placed in a tube furnace and heat treated at 300° C. in a nitrogen stream for 6 hours. A solid base catalytic material BaHT was obtained. The Ba element content was about 20.0% (relative to the weight of the magnesium aluminum hydrotalcite). The microstructural parameters measured by the BET method were: specific surface area 65.2 m 2 / g, pore volume 0.28ml / g. Its scanning electron microscope (SEM) is shown in Figure 4 .

[0039] Example 5 Preparation of solid base catalyst CsHT-2

[0040] 16.4 g of cesium hydroxide monohydrate and 83.6 g of water were mixed into a uniform solution, 100 g of commercial magnesium aluminum hydrotalcite (same as in Example 1) was added thereto, immersed at 70°C for 8 hours, and dried at 120°C in a nitrogen stream (about 12 hours). The material was then placed in a tube furnace and heat treated at 340°C in a nitrogen stream for 4 hours. A solid base catalytic material CsHT-2 was obtained. The Cs element content was about 13.0% (relative to the weight of magnesium aluminum hydrotalcite). The microstructural parameters measured by the BET method were: specific surface area 81.6 m 2 / g, pore volume 0.40ml / g.

[0041] Example 6 Preparation of solid base catalyst CsHT-3

[0042] 25.3g of cesium hydroxide monohydrate and 74.7g of water were mixed into a uniform solution, 100g of commercial magnesium aluminum hydrotalcite (same as in Example 1) was added thereto, immersed at 70°C for 8 hours, and dried at 120°C in a nitrogen stream (about 12 hours). The material was then placed in a tube furnace and heat treated at 340°C in a nitrogen stream for 4 hours. A solid base catalytic material CsHT-3 was obtained. The Cs element content was about 20.0% (relative to the weight of magnesium aluminum hydrotalcite). The microstructural parameters measured by the BET method were: specific surface area 74.8m 2 / g, pore volume 0.37ml / g.

[0043] Example 7: Synthesis of Ethoxypropionitrile by Propanylation of Ethanol Catalyzed by RbHT

[0044] 1.0 mol ethanol (46 g) and 3.68 g solid base catalyst RbHT were added to the reaction flask. At 30 ° C, under sufficient stirring, a solution of 1.05 mol acrylonitrile (56 g) and 0.0224 g phenothiazine was added to the reaction flask at a uniform rate over 20 h through a feed pump, and the reaction was continued with stirring for 4 h. After the reaction, the reaction mass was filtered to separate the solid catalyst. The liquid reaction product was subjected to high vacuum distillation, and the fraction at 60-65 ° C / 4-6 mmHg was collected to obtain 95.6 g of the propionitrile product ethoxypropionitrile, with a gas chromatographic purity of 99.1% and a yield of 95.7%.

[0045] The recycling results of catalyst RbHT are listed in Table 1.

[0046] Table 1 Recycling effect of RbHT catalyst for ethanol propionitrile reaction

[0047] Number of cycles 0 1 2 3 4 5 6 7 8 9 10 Yield, % 95.7 96.2 95.4 93.9 90.8 92.7 87.9 85.4 86.1 83.2 80.3

[0048] Example 8: Synthesis of Butoxypropionitrile by Propanylation of n-Butanol Catalyzed by CsHT-1

[0049] In the reaction flask, add 1.0mol n-butyl alcohol (75g, weight content 99.0%), 5.25g solid base catalyst CsHT-1, under 35 ℃, fully stirring situation, by feed pump with the solution of 1.1mol vinyl cyanide (58.5g) and 0.0351g MEHQ, in 18h, at the uniform velocity add reaction flask, continue stirring reaction 3h subsequently.After finishing, reaction is filtered off with reaction mass suction, isolate solid catalyst.Liquid reaction product carries out high vacuum distillation, collects the cut of 81~89 ℃ / 4~6mmHg, obtains propionitrile product butoxypropionitrile 115.8g, and gas chromatographic analysis purity is 98.6%, yield 89.9%.

[0050] The recycling results of catalyst CsHT-1 are listed in Table 2.

[0051] Table 2 Recycling effect of catalyst CsHT-1 for n-butanol propionitrile reaction

[0052] Number of cycles 0 1 2 3 4 5 6 7 8 9 10 Yield, % 89.9 91.3 91.4 90.9 90.6 89.4 87.1 83.2 83.1 80.2 78.6

[0053] Example 9: Synthesis of Butoxypropionitrile by Propanylation of n-Butanol Catalyzed by CsHT-2

[0054] In the reaction flask, add 1.0mol n-butyl alcohol (75g, weight content 99.0%), 5.25g solid base catalyst CsHT-2, under 35 ℃, fully stirring situation, by feed pump with the solution of 1.1mol vinyl cyanide (58.5g) and 0.0351g MEHQ, in 18h, at the uniform velocity add reaction flask, continue stirring reaction 3h subsequently.After finishing, reaction is filtered off with reaction mass suction, isolate solid catalyst.Liquid reaction product carries out high vacuum distillation, collects the cut of 81~89 ℃ / 4~6mmHg, obtains propionitrile product butoxypropionitrile 104.6g, and gas chromatographic analysis purity is 98.8%, yield 81.3%.

[0055] The recycling results of catalyst CsHT-2 are listed in Table 3.

[0056] Table 3 Recycling effect of catalyst CsHT-2 for n-butanol propionitrile reaction

[0057] Number of cycles 0 1 2 3 4 5 6 7 8 9 10 Yield, % 81.3 81.4 82.5 81.2 80.7 79.6 78.4 72.5 73.4 73.1 72.2

[0058] Comparing Table 3 with Table 2, it can be seen that the CS loading is low and the catalytic performance is poor.

[0059] Example 10: Synthesis of Butoxypropionitrile by Propanylation of n-Butanol Catalyzed by CsHT-3

[0060] In the reaction flask, add 1.0mol n-butyl alcohol (75g, weight content 99.0%), 5.25g solid base catalyst CsHT-3, under 35 ℃, fully stirring situation, by feed pump with the solution of 1.1mol acrylonitrile (58.5g) and 0.0351g MEHQ, in 18h, at the uniform velocity add reaction flask, continue stirring reaction 3h subsequently.After reaction finishes, reaction mass suction filtration is isolated solid catalyst.Liquid reaction product carries out high vacuum distillation, collects the cut of 81~89 ℃ / 4~6mmHg, obtains propionitrile product butoxypropionitrile 119.8g, and gas chromatographic analysis purity is 99.0%, yield 93.4%.

[0061] The recycling results of catalyst CsHT-3 are listed in Table 4.

[0062] Table 4 Recycling effect of catalyst CsHT-3 for n-butanol propionitrile reaction

[0063] Number of cycles 0 1 2 3 4 5 6 7 8 9 10 Yield, % 93.4 92.6 92.5 91.4 90.7 89.2 88.5 86.1 83.2 81.5 78.8

[0064] Comparing Table 4 with Table 2, we can see that the higher the CS loading, the better the initial performance of the catalyst. However, after six cycles, the activity of the high-loading CsHT-3 declined rapidly. This may be because the high loading and high active site density make it easy for coke to form and cover the active sites, causing the rapid decline in catalytic activity.

[0065] Example 11: Synthesis of Butoxypropionitrile by Propanylation of n-Butanol Catalyzed by CsHT-1

[0066] In the reaction flask, add 1.0mol n-butyl alcohol (75g, weight content 99.0%), 3.75g solid base catalyst CsHT-1, under 35 ℃, fully stirring situation, by feed pump with the solution of 1.1mol vinyl cyanide (58.5g) and 0.0351g MEHQ, in 18h, at the uniform velocity add reaction flask, continue stirring reaction 3h subsequently.After reaction finishes, reaction mass suction filtration is isolated solid catalyst.Liquid reaction product carries out high vacuum distillation, collects the cut of 81~89 ℃ / 4~6mmHg, obtains propionitrile product butoxypropionitrile 110.6g, and gas chromatographic analysis purity is 98.7%, yield 86.0%.

[0067] The recycling results of catalyst CsHT-1 are listed in Table 5.

[0068] Table 5 Recycling effect of catalyst CsHT-1 for n-butanol propionitrile reaction

[0069] Number of cycles 0 1 2 3 4 5 6 7 8 9 10 Yield, % 86.0 86.3 85.7 85.1 84.6 83.2 81.5 80.2 79.4 77.6 75.8

[0070] Comparing Table 5 with Table 2, it can be seen that the yield decreases as the catalyst dosage decreases, but the catalyst cyclic activity declines in a similar manner.

[0071] Example 12: Synthesis of Butoxypropionitrile by Propanylation of n-Butanol Catalyzed by CsHT-1

[0072] In the reaction flask, add 1.0mol n-butyl alcohol (75g, weight content 99.0%), 6.75g solid base catalyst CsHT-1, under 35 ℃, fully stirring situation, by feed pump with the solution of 1.1mol acrylonitrile (58.5g) and 0.0351g MEHQ, in 18h, at the uniform velocity add reaction flask, continue stirring reaction 3h subsequently.After reaction finishes, reaction mass suction filtration is isolated solid catalyst.Liquid reaction product carries out high vacuum distillation, collects the cut of 81~89 ℃ / 4~6mmHg, obtains propionitrile product butoxypropionitrile 119.2g, and gas chromatographic analysis purity is 99.3%, yield 93.2%.

[0073] The recycling results of catalyst CsHT-1 are listed in Table 6.

[0074] Table 6 Recycling effect of catalyst CsHT-1 for n-butanol propionitrile reaction

[0075] Number of cycles 0 1 2 3 4 5 6 7 8 9 10 Yield, % 93.2 94.5 93.8 92.6 91.3 91.8 90.7 90.5 89.1 88.4 85.2

[0076] Comparing Table 6 with Table 2, it can be seen that the yield increases with increasing catalyst dosage, but the catalyst cyclic activity declines in a similar manner.

[0077] Example 13: Synthesis of isooctyloxypropionitrile by SrHT-catalyzed propionitrile reaction of isooctyl alcohol

[0078] In reaction flask, add 1.0mol isooctyl alcohol (130g), 6.5g solid base catalyst SrHT, under 40 ℃, fully stirring situation, by feed pump with the solution of 1.15mol vinyl cyanide (61.5g) and 0.0369g MEHQ, in 16h, at the uniform velocity add reaction flask, continue stirring reaction 2h subsequently.After reaction finishes, reaction mass suction filtration is isolated solid catalyst.Liquid reaction product carries out high vacuum distillation, collects the cut of 124~135 ℃ / 4~6mmHg, obtains propionitrile product isooctyloxy propionitrile 169.9g, and gas chromatographic analysis purity is 98.2%, yield 91.2%.

[0079] The catalyst SrHT was washed with ethylene glycol dimethyl ether and dried, and then recycled for use. The results are listed in Table 7.

[0080] Table 7 Effect of recycling of catalyst SrHT for isooctyl alcohol propionitrile reaction

[0081] Number of cycles 0 1 2 3 4 5 6 7 8 9 10 Yield, % 91.2 91.3 91.6 91.9 91.1 89.9 86.6 83.4 82.5 83.6 84.1

[0082] Example 14 BaHT-catalyzed propionitrile reaction of ethylene glycol monomethyl ether

[0083] 1.0 mol of ethylene glycol monomethyl ether (76 g) and 7.6 g of a solid base catalyst, BaHT, were added to a reaction flask. At 50° C. and with sufficient stirring, a solution of 1.2 mol of acrylonitrile (63.6 g) and 0.0636 g of hydroquinone was uniformly added to the reaction flask over 10 hours via a feed pump. The reaction was then stirred for 2 hours. After completion of the reaction, the reaction mass was filtered to separate the solid catalyst. The liquid reaction product was subjected to high vacuum distillation, and a fraction at 68-74° C. / 4-6 mmHg was collected to obtain 121.6 g of a propionitrile product with a gas chromatographic purity of 98.9% and a yield of 93.2%.

[0084] The recycling results of catalyst BaHT are listed in Table 8.

[0085] Table 8 Effect of recycling of BaHT catalyst for propionitrile reaction of ethylene glycol monomethyl ether

[0086] Number of cycles 0 1 2 3 4 5 6 7 8 9 10 Yield, % 93.2 93.7 91.6 92.7 93.4 91.2 89.8 90.2 90.6 88.5 88.9

[0087] Example 15 Synthesis of dioxypropionitrile ethane by RbHT-catalyzed dipropionitrile reaction of ethylene glycol

[0088] In reaction flask, add 1.0mol ethylene glycol (62g), 31g tetrahydrofuran (THF), 3.72g solid base catalyst RbHT, under 35 ℃, fully stirring situation, by feed pump with the solution of 2.1mol vinyl cyanide (112g) and 0.0672g MEHQ, at the uniform velocity add reaction flask in 16h, continue stirring reaction 4h subsequently.After reaction finishes, reaction mass suction filtration is isolated solid catalyst.Liquid reaction product carries out high vacuum distillation, collects the cut of 160~170 ℃ / 4~6mmHg, obtains two propionitrile groups product dioxy propionitrile ethane 157.2g, and gas chromatographic analysis purity is 98.6%, yield 92.3%.

[0089] The recovered catalyst RbHT was washed with dichloromethane and dried, and the results of recycling are listed in Table 9.

[0090] Table 9 Effect of recycling of catalyst RbHT for ethylene glycol dipropionitrile reaction

[0091] Number of cycles 0 1 2 3 4 5 6 7 8 9 10 Yield, % 92.3 92.7 92.8 92.1 90.4 90.7 88.5 86.3 83.6 80.4 80.8

[0092] Example 16 Tripropionitrile Reaction of Glycerol (Glycerol) Catalyzed by CsHT-1

[0093] 1.0 mol glycerol (93 g), 70 g dioxane, and 8.37 g solid base catalyst CsHT-1 were added to the reaction flask. At 45°C and with sufficient stirring, a solution of 3.45 mol acrylonitrile (183 g) and 0.146 g hydroquinone was added to the reaction flask at a uniform rate over 12 hours via a feed pump. The reaction was then stirred and reacted for 3 hours. After the reaction was completed, the reaction mass was filtered to separate the solid catalyst. The liquid reaction product was subjected to high vacuum distillation, and the fraction at 255-265°C / 2-4 mmHg was collected to obtain 213.6 g of 1,2,3-trispropionitrileoxypropane. The purity of the product by gas chromatography was 97.2%, and the yield was 82.7%.

[0094] The recovered catalyst CsHT-1 was washed with chlorobenzene, dried, and then recycled. The results are listed in Table 10.

[0095] Table 10 Effect of recycling of catalyst CsHT-1 for glycerol propionitrile reaction

[0096] Number of cycles 0 1 2 3 4 5 6 Yield, % 82.7 82.6 82.8 81.2 79.8 77.3 73.6

[0097] Product structure analysis:

[0098]

[0099] Mass spectrometry analysis results: m / z: 251.13 (100.0%), 252.13 (13.0%), 252.12 (1.1%).

[0100] NMR analysis results:

[0101] 1 H-NMR:3.48(2H2),3.70(2H3),3.61(2H5),3.70(1H6),3.61(2H7),3.74(2H 10 ),2.85(2H 11 ),3.74(2H 13 ),2.58(2H 14 ).

[0102] 13 C-NMR:157.3(C1),44.2(C2),70.9(C3),64.1(C5),78.7(C6),63.6(C7),65.5(C 10 ),18.9(C 11 ),117.7(C 12 ),63.0(C 13 ),14.8(C 14 ),117.7(C 15 ).

[0103] The results showed that the structure of the obtained product was consistent with that of the target product.

[0104] Example 17 Pentaerythritol Tetrapropionitrile Reaction

[0105] 1.0mol pentaerythritol (138.8g), 138.8g dimethyl sulfoxide (DMSO) and 13.88g solid base catalyst SrHT were added to the reaction flask. At 55°C and under sufficient stirring, a solution of 5.0mol acrylonitrile (265g) and 0.265g p-hydroxyanisole was uniformly added to the reaction flask over a period of 12 hours by a feed pump. The stirring reaction was then continued for 2 hours. After the reaction was completed, the reaction mass was filtered and the solid catalyst was isolated. The filtrate was subjected to high vacuum distillation at 30-80°C to remove volatile matter. After the residual liquid in the still was dissolved with 300g ethyl acetate by heating, it was placed in a refrigerator (approximately -20°C) and crystallized for 24 hours. The solid was filtered and vacuum-dried at 30°C for 12 hours. 291.6 g of light yellow solid product was obtained with a melting point of 43-45° C., which was consistent with the literature report (Lemoine, Truett J. Journal of Gas Chromatography, 1965, 3, (9): 322.), and the product yield was 83.8%.

[0106] The recovered SrHT catalyst was washed with N,N-dimethylformamide, dried, and then recycled. The results are listed in Table 11.

[0107] Table 11 Effect of recycling of catalyst SrHT for propionitrile reaction of pentaerythritol

[0108] Number of cycles 0 1 2 3 4 5 6 Yield, % 83.8 83.1 81.1 80.6 80.9 77.2 74.5

[0109] Product structure analysis:

[0110]

[0111] NMR analysis results:

[0112] 1 H-NMR: 2.58(2H2), 3.74(2H3), 3.79(2H5), 3.79(2H7), 3.79(2H9), 3.74(2H11) , 2.58(2H12), 3.74(2H14), 2.58(2H15), 3.79(2H17), 3.74(2H19), 2.58(2H20).

[0113] 13 C-NMR: 117.7(C1), 18.9(C2), 65.8(C3), 69.9(C5), 44.8(C6), 69.9(C7), 69.9(C9), 65.8(C11), 18.9(C 12), 117.7(C13), 65.8(C14), 18.9(C15), 117.7(C16), 69.9(C18), 65.8(C19), 18.9(C20), 117.7(C21).

[0114] The results showed that the structure of the obtained product was consistent with that of the target product.

[0115] Comparative Example 1: Homogeneous Catalytic Acrylonitrile Reaction of Glycerol by Potassium Tert-Butoxide

[0116] To a reaction flask, 1.0 mol of glycerol (93 g), 70 g of dioxane, and 4.2 g of potassium tert-butoxide were added. At 45°C with thorough stirring, a solution of 3.45 mol of acrylonitrile (183 g) and 0.146 g of hydroquinone was uniformly added via a feed pump over 12 hours. The reaction was then stirred for 3 hours. After the reaction was complete, the alkaline catalyst was neutralized with 3.5 g of phosphoric acid to a pH of 6.0. The solvent, tetrahydrofuran, and volatiles were then distilled off at atmospheric pressure (60-120°C). The mixture was then washed with 150 g of distilled water, allowed to stand and separate, and the salt layer removed. This washing process was repeated twice. A total of 450 g of water was removed, producing 496 g of wastewater containing salt and a small amount of organic matter. The oil layer was dried with 10 g of anhydrous calcium chloride, and the fraction at 255-265° C. / 2-4 mmHg was collected to obtain 218.9 g of 1,2,3-tripropionitrileoxypropane with a purity of 97.7% by gas chromatography and a yield of 85.2%.

[0117] Compared with Example 16, the use of the solid base heterogeneous catalysis of the present invention has obvious advantages: (1) the post-processing operation is simple, which makes the equipment production efficiency relatively high; (2) less auxiliary materials are used, the operation is simplified, and the production cost is reduced; (3) the solid catalyst can be easily recycled, which greatly reduces the "three wastes" emissions in the production process while reducing production costs.

[0118] Comparative Example 2. Tripropionitrile Reaction of Glycerol (Glycerol) Catalyzed by Magnesium-aluminum Hydrotalcite Powder (HT)

[0119] 1.0 mol glycerol (93 g), 70 g dioxane, and 10.0 g magnesium aluminum hydrotalcite (same as in Example 1) were added to the reaction flask. At 45 ° C. and with sufficient stirring, a solution of 3.45 mol acrylonitrile (183 g) and 0.146 g hydroquinone was added to the reaction flask at a uniform rate over 12 h through a feed pump, and then the stirring reaction was continued for 3 h. After the reaction was completed, the reaction mass was filtered to separate the solid catalyst HT. The liquid reaction product was subjected to high vacuum distillation, and the fraction at 255-265 ° C / 2-4 mmHg was collected to obtain 54.8 g of 1,2,3-tripropionitrileoxypropane, with a gas chromatographic purity of 98.3% and a yield of 21.5%.

[0120] The recovered catalyst HT was washed with chlorobenzene, dried, and then recycled. The results are listed in Table 12.

[0121] Table 12 Effect of HT recycling of glycerol propionitrile reaction catalyst

[0122] Number of cycles 0 1 2 3 4 Yield, % 21.5 22.6 20.7 19.8 17.5

[0123] From the data in Table 12, it can be seen that the catalytic activity of the raw magnesium aluminum hydrotalcite powder (HT) is much lower than the catalytic effect of the MHT of the present invention.

[0124] Comparative Example 3 tert-Butoxyhydrotalcite (Mg-Al-O-Bu t -HT)-catalyzed propionitrile reaction of glycerol

[0125] Mg-Al-O-Bu t-HT preparation: Prepared according to the method of reference (Tetrahedron Letters, 1998, 39 (21): 3555-3558). 124g of magnesium nitrate hexahydrate and 60g of aluminum nitrate nonahydrate were dissolved in 400ml of deionized and CO2-free water. 2M NaOH aqueous solution was added to adjust the pH of the solution to 10. The resulting suspension was stirred at room temperature for 2h. The precipitated hydrotalcite was collected by filtration under N2 atmosphere and dried at 80°C overnight to obtain 42.6g of nitrohydrotalcite Mg-AI-NO3-HT. Take 12.5g of nitrohydrotalcite Mg-AI-NO3-HT and exchange it with a solution of 0.1M potassium tert-butoxide in 1000ml of tetrahydrofuran for 24 hours under stirring at room temperature to prepare Mg-Al-O-Bu t -HT. The precipitate was filtered under N2 atmosphere and dried under vacuum to obtain 13.8 g Mg-Al-O-Bu t -HT.

[0126] 1.0 mol glycerol (93 g), 70 g dioxane, 10.0 g prepared Mg-Al-O-Bu t -HT, at 45 ° C, with sufficient stirring, a solution of 3.45 mol of acrylonitrile (183 g) and 0.146 g of hydroquinone was added to the reaction flask at a uniform rate over 12 hours via a feed pump, and the reaction was continued with stirring for 3 hours. After the reaction, the reaction mass was filtered to separate the solid catalyst. The liquid reaction product was subjected to high vacuum distillation, and the fraction at 255-265 ° C / 2-4 mmHg was collected to obtain 219.8 g of 1,2,3-trispropionitrileoxypropane with a gas chromatography purity of 97.8% and a yield of 85.6%.

[0127] Recovered catalyst Mg-Al-O-Bu t -HT was washed with chlorobenzene, dried under vacuum at 60°C, and then recycled. The results are listed in Table 13.

[0128] Table 13 Glycerol propionitrile reaction Mg-Al-O-Bu t -HT cycle effect

[0129] Number of cycles 0 1 2 3 4 5 6 Yield, % 85.6 42.9 27.5 20.8 19.4 20.2 18.7

[0130] From the data in Table 13, it can be seen that tert-butoxylated hydrotalcite Mg-Al-O-Bu t -HT showed good initial catalytic performance. However, performance declined dramatically with repeated cycles. The yield dropped to 20.8% after the third cycle, with no significant change thereafter. This indicates that the tert-butoxy groups on the catalyst surface have disappeared. The catalytic activity of the magnesium-aluminum hydrotalcite matrix is ​​now evident (see data in Table 12).

Claims

1. An application of a hydrotalcite-based strongly basic solid catalyst, characterized in that: The solid catalyst is used for alcohol propionitrile conversion, the solid catalyst is mixed with an alcohol raw material, the temperature is controlled, acrylonitrile is added at a uniform rate, the temperature is continued to control the reaction after the acrylonitrile is added to fully convert the raw material, the material is filtered after the reaction is completed, the obtained liquid is the propionitrile conversion product, and the recovered solid catalyst is recycled; The solid catalyst is based on hydrotalcite and loaded with alkaline metal ions M to obtain a strong alkaline solid catalyst MHT; wherein the hydrotalcite matrix is ​​magnesium aluminum hydrotalcite HT, and the alkaline metal ions M are: rubidium, strontium or barium; The solid catalyst is loaded by impregnation method, and the loading amount of M is 10-20%; The weight ratio of the strong alkaline solid catalyst MHT to the alcohol raw material is 5-10:100; the amount of acrylonitrile used is: the ratio of the molar amount of alcohol hydroxyl group to the molar amount of acrylonitrile is 1:1.05-1.25; The alcohol raw material is a monohydric alcohol with a carbon number of 2 to 8 or a polyhydric alcohol with a carbon number of 2 to 5; The reaction temperature is 30~55℃, the addition time of acrylonitrile is 10~20h, and the reaction time after addition is 2~4h.

2. The use of the hydrotalcite-based strongly basic solid catalyst according to claim 1, characterized in that: The specific process of the impregnation loading method is: using a hydroxide aqueous solution of metal M at 60-90°C to impregnate the hydrotalcite matrix for 4-8 hours, then drying it at 120°C in a nitrogen flow; then heat treating it at 300-360°C in a nitrogen flow for 2-6 hours to obtain a strongly basic solid catalyst MHT.

3. The use of the hydrotalcite-based strongly basic solid catalyst according to claim 1, characterized in that: In order to inhibit the self-polymerization of acrylonitrile, an inhibitor is added to the acrylonitrile; when the viscosity of the alcohol is high or it is solid, a solvent is added to the reaction system.

4. The use of the hydrotalcite-based strongly basic solid catalyst according to claim 3, characterized in that: The polymerization inhibitor is phenothiazine, p-hydroxyanisole or hydroquinone and its derivatives, and the dosage of the polymerization inhibitor is 0.04% to 0.1% of the weight of acrylonitrile; the added solvent is tetrahydrofuran, dioxane, ethylene glycol dimethyl ether or dimethyl sulfoxide, and the dosage of the solvent is 50% to 100% of the weight of the alcohol raw material.

5. The use of the hydrotalcite-based strongly basic solid catalyst according to claim 1, characterized in that: The catalyst recovered by filtration can be directly recycled or washed with a solvent and then recycled.

Images