Preparation method of novel supported solid base catalyst and application of novel supported solid base catalyst in alkyl glycoside

Abstract

The invention discloses a preparation method of a novel supported solid base catalyst and application of the novel supported solid base catalyst in alkyl glycoside, and belongs to the field of organic synthesis catalysis technology and green chemistry. The novel supported solid base catalyst has the advantages that the alkaline site density is high, the catalytic efficiency is improved by 25-40% or above compared with that of KOH, and the reaction time is shortened by 20-30%; by adjusting the ratio of alkaline earth metal to rare earth metal in the catalyst, the average addition number of epoxybutane can be accurately controlled, and the content of a target product is greater than or equal to 95%; the reaction kettle is green, environment-friendly, environment-friendly and non-corrosive, the service life of the reaction kettle is prolonged, and the industrialization cost is reduced; compared with the traditional process, the initial height of the synthesized product foam is reduced by 60-80%, and the residual quantity of foam in 5 minutes is less than 20 mL. The prepared novel supported solid base catalyst is applied to alkyl glycoside to generate alkyl glycoside polyoxybutylene ether, some excellent performance of alkyl glycoside is reserved, the alkyl glycoside polyoxybutylene ether has obvious low-foam performance, a large amount of industrial water can be saved, and the requirements for fast decontamination, easy rinsing, environmental protection and the like can be met.

Description

Technical Field

[0001] The present invention relates to the fields of organic synthesis catalysis technology and green chemistry, and specifically to a preparation method of a novel supported solid base catalyst and its application in alkyl glycosides, and especially to a green synthesis process in which a solid base is used to replace a traditional base catalyst. Background Art

[0002] Alkyl polyglycoside (APG) is currently internationally recognized as a "green" functional surfactant. It has low surface tension, no cloud point, adjustable HLB value, strong wetting power, strong detergency, strong compatibility, is non-toxic, harmless, and non-irritating to the skin. It biodegrades quickly and thoroughly and can be compounded with any type of surfactant with obvious synergistic effects. It also produces rich, delicate, and stable foam.

[0003] In large-scale industrial cleaning and dyeing, foam not only affects decontamination but also makes rinsing difficult, leaving residue and even overflowing the cleaning equipment, resulting in waste. Furthermore, foam can carry away some surfactants from the cleaning liquid, reducing surfactant concentration and detergency. Therefore, defoamers or low-foaming cleaning products are necessary. Surfactants are the primary factor in foam generation in cleaning agents. Surfactants that do not produce foam or whose foam is unstable and disappears quickly under these conditions, known as low-foaming surfactants, are widely used.

[0004] Alkyl polyglycoside products currently on the market experience foam accumulation, particularly in industrial cleaning and textile printing and dyeing, where excessive foam can significantly reduce their effectiveness. Studies have shown that low-foaming surfactants can be effectively developed through the targeted polyhydroxyl modification of the glycosyl backbone. However, existing technologies have limitations: CN109503824A introduces the use of ethylene oxide groups to modify the alkyl polyglycoside backbone, but the hydrophilic nature of ethylene oxide results in high foaming power for the product; and although CN110894290B patent uses propylene oxide for structural modification to obtain alkyl polyoxypropylene ethers, its foam suppression effect still fails to meet the expected standards.

[0005] Alkyl polyoxybutylene ether is a specialty surfactant that combines low-foaming properties with environmental friendliness. Its synthesis process uses alkyl polyoxybutylene ether (APG0810) and butylene oxide (BO) as raw materials, and is prepared through a chain growth reaction under the action of a catalytic system. Traditional processes often use strong base catalysts such as KOH and NaOH, but have four major shortcomings:

[0006] ① Hidden dangers of strong corrosion: The high corrosiveness of the catalyst can easily lead to serious damage to equipment such as reactors and pipelines, significantly increasing the frequency of equipment maintenance and production costs;

[0007] ② Complex post-processing: After the reaction, the catalyst residue must be removed through neutralization and refining processes, which not only greatly increases the pressure on waste treatment, but also runs counter to the concept of green chemistry;

[0008] ③ Difficulty in directional control: Existing catalytic systems make it difficult to achieve precise control of the average addition number of butylene oxide (1 to 4), resulting in a wide molecular weight distribution of the product and insufficient structural uniformity;

[0009] ④ Poor recycling: The one-way consumption characteristics of the catalyst lead to low utilization, causing serious waste of resources and rising production costs.

[0010] In summary, constructing an innovative supported solid base catalytic system that is efficient, stable, environmentally compatible and recyclable has become an important research direction to break through the technical bottleneck of alkyl glycoside polyoxybutylene ether synthesis, realize catalyst recycling and promote the sustainable development of the surfactant industry. Summary of the Invention

[0011] The purpose of the present invention is to provide a novel supported solid base catalyst to overcome the deficiencies of existing catalysts and improve the efficiency of the synthesis reaction and the quality of the product.

[0012] A method for preparing a novel supported solid base catalyst, wherein the supported solid base catalyst is an alkaline earth metal-rare earth metal composite oxide solid base, comprises the following steps:

[0013] S1. Precursor preparation: Dissolve the metal nitrate corresponding to the active component and the carrier precursor in deionized water in proportion, add 2-4 mol / L NaOH solution dropwise under stirring at 50-70°C, and adjust the pH to 9-11 to form a suspension;

[0014] The active component is composed of alkaline earth metal oxide and rare earth metal oxide in a mass ratio of (3-5): (1-2), accounting for 60% to 85% of the total mass. The carrier is mesoporous SiO2, Al2O3 or TiO2 with a specific surface area of ​​≥200m 2 / g, pore volume ≥ 0.5cm 3 / g, accounting for 15% to 40% by mass;

[0015] S2. Aging and washing: The suspension was aged for 2 to 4 hours, filtered, washed with deionized water until free of Cl-, and tested with silver nitrate to obtain a solid product;

[0016] S3. Drying and calcining: drying the solid product at 100-120° C. for 12-24 hours, and calcining it in a muffle furnace at 500-700° C. for 3-5 hours at a heating rate of 5° C. / min to obtain a solid base catalyst.

[0017] Furthermore, the alkaline earth metal oxide in step S1 is one of MgO and CaO, the rare earth metal oxide is one of La2O3 and CeO2, and the metal nitrate corresponding to the active component is Mg(NO3)2, Ca(NO3)2, La(NO3)3 and Ce(NO3)3.

[0018] Furthermore, the carrier in step S1 is mesoporous SiO2, Al2O3 or TiO2, with a specific surface area of ​​≥200m 2 / g, pore volume ≥ 0.5cm 3 / g, accounting for 15% to 40% by mass.

[0019] Furthermore, the supported solid base catalyst is a granular solid with a basic site density of ≥2.0 mmol / g and an average particle size of 20 to 50 μm.

[0020] A novel supported solid base catalyst is used in alkyl glycosides. The prepared novel supported solid base catalyst is applied to alkyl glycosides. Under the action of the solid base catalyst, the polyhydroxyl groups on the saccharide skeleton of alkyl glycoside APG0810 undergo a ring-opening addition reaction with butylene oxide to generate alkyl glycoside polyoxybutylene ether. The reaction formula is as follows:

[0021]

[0022] The addition number of butylene oxide is 1 to 4.

[0023] Furthermore, the novel supported solid base catalyst is applied to the synthesis of alkyl glycoside polyoxybutylene ether, comprising the following steps:

[0024] a. In a reactor, melt-mix the crude alkyl glycoside product APG0810 and the solid base catalyst in a mass ratio of (50-200):1, replace with high-purity nitrogen three times, and heat to 130°C in the absence of oxygen for dehydration reaction;

[0025] b. Then BO is introduced and the reaction is completed at a temperature of 130-180°C for 3-5 hours. After aging and cooling to 80°C, the solid base catalyst is filtered out and recycled;

[0026] c. Finally, adjust the pH value of the system to 6.5-7.0 with an acidic neutralizer, and filter the product to obtain alkyl glycoside polyoxybutylene ether.

[0027] Furthermore, the solid base catalyst can be recycled 5 to 8 times.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The novel supported solid base catalyst obtained by the present invention has the following advantages:

[0030] (1) High efficiency catalysis: high basic site density, catalytic efficiency is 25-40% higher than KOH, and reaction time is shortened by 20%-30%;

[0031] (2) Precise control: By adjusting the ratio of alkaline earth metal to rare earth metal in the catalyst, the average addition number of butylene oxide can be precisely controlled, and the target product content is ≥95%;

[0032] (3) Green and environmentally friendly: the catalyst can be reused, no wastewater is discharged, and it complies with EU REACH regulations;

[0033] (4) Equipment friendly: non-corrosive, prolongs the service life of the reactor and reduces industrialization costs;

[0034] (5) Excellent low-foaming performance: The initial foam height of the synthetic product is 60-80% lower than that of the traditional process, and the foam residue after 5 minutes is less than 20 mL.

[0035] The novel supported solid base catalyst prepared by the present invention is applied to alkyl glycoside to generate alkyl glycoside polyoxybutylene ether, which not only retains some excellent properties of alkyl glycoside but also has obvious low-foaming performance, can save a large amount of industrial water, and can meet the requirements of fast decontamination, easy rinsing and environmental protection. DETAILED DESCRIPTION

[0036] The present invention is further illustrated below by way of examples, but is not limited to these examples and application examples.

[0037] Example 1: MgO-La2O3 / SiO2 solid base catalyst

[0038] 21.4g of Mg(NO3)2·6H2O and 43.3g of La(NO3)3·6H2O were weighed and dissolved in 200mL of water. 71mL of a sodium silicate solution containing 15g of SiO2 was added, and 3mol / L of NaOH was added dropwise to a pH of 10. The mixture was aged for 3 hours. After filtration and washing, the mixture was dried at 110°C for 16 hours and calcined at 600°C for 4 hours to obtain a catalyst with a mass ratio of MgO:La2O3:SiO2 of 7:3:3. The sodium silicate solution containing 15g of SiO2 was prepared as follows: 100g of industrial sodium silicate with a modulus of 3.3, in which SiO2 accounts for 75%, was weighed and dissolved in deionized water and diluted to 500mL to obtain a 20% sodium silicate solution with a density of 1.4g / mL.

[0039] Example 2: CaO-CeO2 / Al2O3 solid base catalyst

[0040] Weigh 16.4 g of Ca(NO3)2·4H2O and 32.0 g of Ce(NO3)3·6H2O, dissolve them in 150 mL of water, add 28.6 mL of sodium aluminate solution containing 20 g of Al2O2, add NaOH dropwise until the pH is 9, and age for 4 hours; after filtering and washing, dry at 110°C for 16 hours and then calcine at 550°C for 5 hours to obtain a CaO:CeO2:Al2O3=8:2:2 (mass ratio) catalyst, wherein the sodium aluminate solution containing 20 g of Al2O3 is prepared as follows: weigh 40 g of industrial sodium aluminate (Al2O3 content 50%), dissolve it in deionized water and dilute to 100 mL to obtain a 40% sodium aluminate solution with a density of 1.4 g / mL.

[0041] Example 3: MgO-CeO2 / TiO2 solid base catalyst

[0042] 21.4g of Mg(NO3)2·4H2O and 32.0g of Ce(NO3)3·6H2O were weighed and dissolved in 150mL of water. 139mL of a titanyl sulfate aqueous solution containing 20g of TiO2 was added, and NaOH was added dropwise until the pH reached 11. The mixture was aged for 2 hours. After filtration and washing, the mixture was dried at 110°C for 16 hours and calcined at 550°C for 5 hours to obtain a catalyst with a mass ratio of MgO:CeO2:TiO2 of 7:2:2. The titanyl sulfate aqueous solution containing 20g of TiO2 was prepared by dissolving 15g of titanium sulfate in 85g of deionized water to obtain a 15% titanium sulfate aqueous solution with a density of 1.2g / mL.

[0043] Application Example 1

[0044] In an autoclave, 380 kg of crude alkyl glycoside APG0810 and 3.8 kg of MgO-La2O3 / SiO2 solid base catalyst were melt-mixed, replaced with high-purity nitrogen three times, and heated to 130°C in the absence of oxygen for dehydration reaction for 1 hour. Then, 70 kg of BO was introduced and the reaction system was reacted at 160°C for 3.2 hours (until the butylene oxide conversion rate was ≥99%) at a reaction rate of 21.9 kg BO / h. The reaction system was then aged at 160°C for 1 hour, cooled to 80°C, and the solid base catalyst was filtered out. Finally, citric acid was added to adjust the pH of the system to 6.5-7.0 to obtain alkyl glycoside polyoxybutylene ether APG0810BO. The addition number was tested to be 1.0. After several uses, the addition number for the sixth time became 1.8, indicating that the MgO-La2O3 / SiO2 solid base catalyst can be recycled 5 times.

[0045] In Application Example 1, the catalytic efficiency reached 21.9 kg BO / h, which was 40.4% higher than that of the KOH catalyst (15.6 kg BO / h); the reaction time was shortened to 3.2 hours, which was 28.9% shorter than that of KOH (4.5 hours).

[0046] Application Example 2

[0047] In an autoclave, 380 kg of crude alkyl glycoside APG0810 and 3.8 kg of CaO-CeO2 / Al2O3 solid base catalyst were melt-mixed, replaced with high-purity nitrogen three times, heated to 130°C in the absence of oxygen for dehydration reaction for 1 hour, then introduced 140 kg of BO, reacted at 160°C for 4.0 hours (until the butylene oxide conversion rate was ≥99%), with a reaction rate of 35.0 kg BO / h, and then aged at 160°C for 1 hour. The mixture was cooled to 80°C, the solid base catalyst was filtered out, and citric acid was added to adjust the pH of the system to 6.5-7.0 to obtain alkyl glycoside polyoxybutylene ether APG0810BO2. The addition number was found to be 2.1. After several uses, the addition number for the ninth time became 2.7. The CaO-CeO2 / Al2O3 solid base catalyst can be recycled 8 times.

[0048] Application Example 3

[0049] In an autoclave, 380 kg of crude alkyl glycoside APG0810 and 3.8 kg of MgO-La2O3 / SiO2 solid base catalyst were melt-mixed, replaced with high-purity nitrogen three times, heated to 130°C in the absence of oxygen for dehydration reaction for 1 hour, then introduced 210 kg of BO, reacted at 160°C for 4.5 hours (until the butylene oxide conversion rate was ≥99%), with a reaction rate of 46.7 kg BO / h, and then aged at 160°C for 1 hour. The mixture was cooled to 80°C, the solid base catalyst was filtered out, and citric acid was added to adjust the pH of the system to 6.5-7.0 to obtain alkyl glycoside polyoxybutylene ether APG0810BO3. The addition number was found to be 3.1. After several uses, the addition number for the eighth time became 3.8. The MgO-La2O3 / SiO2 solid base catalyst can be recycled 7 times.

[0050] Application Example 4

[0051] In an autoclave, 380 kg of crude alkyl glycoside APG0810 and 3.8 kg of MgO-La2O3 / SiO2 solid base catalyst were melt-mixed, replaced with high-purity nitrogen three times, heated to 130°C in the absence of oxygen for dehydration reaction for 1 hour, then introduced 280 kg of BO, reacted at 160°C for 5.0 hours (until the butylene oxide conversion rate was ≥99%), at a reaction rate of 56.0 kg BO / h, then aged at 160°C for 1 hour, cooled to 80°C, filtered out the solid base catalyst, and finally added citric acid to adjust the pH of the system to 6.5-7.0 to obtain alkyl glycoside polyoxybutylene ether APG0810BO4. The addition number was found to be 4.0. After several uses, the addition number for the seventh time became 4.6. The MgO-La2O3 / SiO2 solid base catalyst can be recycled 6 times.

[0052] The data show that the high efficiency of the catalyst has been verified in the synthesis of BO1 to BO4.

[0053] Comparative Example 1

[0054] In a high-pressure reactor, 380 kg of crude alkyl glycoside product APG0810 and 4.4 kg of traditional catalyst KOH were melt-mixed, replaced with high-purity nitrogen three times, and heated to 130°C under anaerobic conditions for dehydration reaction for 1 hour. Then, 70 kg of BO was introduced and the reaction system was reacted at a temperature of 160°C for 4.5 hours (until the butylene oxide conversion rate was ≥99%) at a reaction rate of 15.6 kg BO / h. The reaction was then maintained at 160°C for aging for 1 hour, cooled to 80°C, and finally, citric acid was added to adjust the pH value of the system to 6.5-7.0 to obtain alkyl glycoside polyoxybutylene ether APG0810BO. The addition number was found to be 1.8, but 500 L of wastewater was produced during the reaction.

[0055] Comparative Example 2

[0056] The same operation as in Comparative Example 1 was carried out, except that 380 kg of APG0810 and 4.4 kg of KOH were melt mixed in an autoclave. After nitrogen displacement, the mixture was heated to 130°C for dehydration for 1 hour. 140 kg of BO was then introduced, and the mixture was reacted at 160°C for 5.0 hours (until the conversion was ≥99%) at a reaction rate of 28.0 kg of BO / h. After aging, the mixture was cooled and neutralized to obtain a product with an addition number of 2.8, generating 500 L of wastewater.

[0057] Comparative Example 3

[0058] The same operation was carried out, but 210 kg of BO was introduced and the reaction was carried out for 5.6 hours (until the conversion rate was ≥99%). The reaction rate was 37.3 kg of BO / h, and a product with an addition number of 3.5 was obtained, generating 500 L of wastewater.

[0059] Comparative Example 4

[0060] The same operation was carried out, but 280 kg of BO was introduced and the reaction was carried out for 6.2 hours (until the conversion rate was ≥99%). The reaction rate was 44.8 kg of BO / h, and a product with an addition number of 4.2 was obtained, generating 500 L of wastewater.

[0061] The test method of the addition number in the application examples and comparative examples is as follows: The addition number (n) is determined by nuclear magnetic resonance hydrogen spectrum ( 1 The average value was calculated based on the integrated area ratio of the anomeric hydrogen of the glycosyl terminal (δ≈4.5-5.5 ppm) to the methyl hydrogen of the polyoxybutylene chain terminal (δ≈1.0-1.2 ppm) or the methylene hydrogen (δ≈3.3-3.7 ppm).

[0062] The product parameters of application examples 1-4 and comparative examples are shown in Table 1:

[0063] Table 1

[0064]

[0065] The surface tension and foam performance test results of application examples 1-4 and comparative example samples are shown in Table 2:

[0066] Table 2

[0067]

[0068]

[0069] Note: The foam performance test method is Ross-Miles method.

[0070] The efficiency comparison of application examples 1-4 and comparative samples is shown in Table 3:

[0071] Table 3

[0072]

[0073] From the data analysis in Table 2, it can be seen that the series of alkyl glycoside polyoxybutylene ether samples prepared using the catalyst of the present invention are low-foaming nonionic surfactants, and their initial foam height is significantly reduced compared with APG0810; although the performance of the products obtained by the reaction using traditional catalysts does not change much, the amount of catalyst used will increase. For example, the amount of KOH used using the traditional catalyst is about 1.16 times the amount of solid base used, which increases by about 15.8%, and a large amount of wastewater will be generated.

[0074] Analysis of the data in Table 3 shows that, at the same BO feed rate, the solid base catalyst of the present invention has a significantly higher reaction rate than KOH (increased by 25% to 40%). The time required to complete the reaction at the same scale is shortened by 20% to 30%. The efficiency advantage remains stable as the reaction scale increases (BO 70 → 280 kg). The solid base catalyst achieves precise control (addition number deviation ≤ 0.1), while the KOH product addition number deviates from the target value by 0.7 to 1.8.

[0075] In summary, the above is only a preferred embodiment of the present invention and is not intended to limit the scope of implementation of the present invention. All equivalent changes and modifications of the shape, structure, characteristics and spirit described in the scope of the claims of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a novel supported solid base catalyst, characterized in that: The supported solid base catalyst is an alkaline earth metal-rare earth metal composite oxide solid base, comprising the following steps: S1. Precursor preparation: Dissolve the metal nitrate corresponding to the active component and the carrier precursor in deionized water in proportion, add 2-4 mol / L NaOH solution dropwise under stirring at 50-70°C, and adjust the pH to 9-11 to form a suspension; The active component is composed of alkaline earth metal oxide and rare earth metal oxide in a mass ratio of (3-5): (1-2), accounting for 60% to 85% of the total mass. The carrier is mesoporous SiO2, Al2O3 or TiO2 with a specific surface area of ​​≥200m 2 / g, pore volume ≥ 0.5cm 3 / g, accounting for 15% to 40% by mass; S2. Aging and washing: The suspension was aged for 2 to 4 hours, filtered, washed with deionized water until free of Cl-, and tested with silver nitrate to obtain a solid product; S3. Drying and calcining: drying the solid product at 100-120° C. for 12-24 hours, and calcining it in a muffle furnace at 500-700° C. for 3-5 hours at a heating rate of 5° C. / min to obtain a solid base catalyst.

2. The method for preparing a novel supported solid base catalyst according to claim 1, wherein: The alkaline earth metal oxide in step S1 is one of MgO and CaO, the rare earth metal oxide is one of La2O2 and CeO2, and the metal nitrate corresponding to the active component is Mg(NO3)2, Ca(NO3)2, La(NO2)2 and Ce(NO2)3.

3. The method for preparing a novel supported solid base catalyst according to claim 1, wherein: The carrier in step S1 is mesoporous SiO2, Al2O3 or TiO2 with a specific surface area of ​​≥200m 2 / g, pore volume ≥ 0.5cm 3 / g, accounting for 15% to 40% by mass.

4. The method for preparing a novel supported solid base catalyst according to claim 1, wherein: The supported solid base catalyst is in the form of solid particles, has a basic site density of ≥2.0 mmol / g, and an average particle size of 20 to 50 μm.

5. Use of a novel supported solid base catalyst prepared by the method according to any one of claims 1 to 4 in alkyl glycosides, characterized in that: The prepared new supported solid base catalyst was applied to alkyl glycoside. Under the action of the solid base catalyst, the polyhydroxyl groups on the saccharide skeleton of alkyl glycoside APG0810 reacted with butylene oxide to undergo a ring-opening addition reaction to generate alkyl glycoside polyoxybutylene ether. The reaction formula is as follows: The addition number of butylene oxide is 1 to 4.

6. The use of a novel supported solid base catalyst in alkyl glycosides according to claim 5, characterized in that: The novel supported solid base catalyst is used to synthesize alkyl glycoside polyoxybutylene ether, comprising the following steps: a. In a reactor, melt-mix the crude alkyl glycoside product APG0810 and the solid base catalyst in a mass ratio of (50-200):1, replace with high-purity nitrogen three times, and heat to 130°C in the absence of oxygen for dehydration reaction; b. Then BO is introduced and the reaction is completed at a temperature of 130-180°C for 3-5 hours. After aging and cooling to 80°C, the solid base catalyst is filtered out and recycled; c. Finally, adjust the pH value of the system to 6.5-7.0 with an acidic neutralizer, and filter the product to obtain alkyl glycoside polyoxybutylene ether.

7. The use of a novel supported solid base catalyst in alkyl glycosides according to claim 6, characterized in that: The solid base catalyst can be recycled 5 to 8 times.

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