Preparation method of high-selectivity ethylene glycol monoethyl ether

Abstract

The application belongs to the field of chemical synthesis, and particularly relates to a preparation method of high-selectivity ethylene glycol monoethyl ether, and reaction steps comprise: under the protection of inert gas, etherification reaction of ethylene glycol and ethanol is generated to form ethylene glycol monoethyl ether in the presence of heteropolyacid salt / molecular sieve supported catalyst. The supported catalyst used by the application has a special structure, and has very high selectivity to the generation of ethylene glycol monoethyl ether. In addition, the application still has high conversion rate and selectivity under large-scale production (ten kilogram level), and the reaction condition is more moderate compared with the prior art, and is suitable for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of chemical synthesis, specifically relating to a method for preparing highly selective ethylene glycol monoethyl ether. Background Technology

[0002] Ethylene glycol monoethyl ether is a general-purpose solvent. Due to the presence of both ether and hydroxyl groups in its structure, it possesses excellent properties such as low freezing point, good miscibility, rapid penetration, strong diffusion, and good solubility and dilution. It is commonly used as a solvent for nitrocellulose, synthetic resins, and paints. For example, in the coatings industry, it is used to formulate paint thinners, paint removers, and as a raw material for spray paint manufacturing; in the leather industry, it is used as a colorant, emulsion stabilizer, ink solvent, and refined solvent for vitamin B12; in the textile industry, it is used to manufacture fiber dyes; and in organic chemicals, it is used to manufacture acetate esters and emulsion stabilizers.

[0003] Currently, the main methods for producing ethylene glycol ether compounds include the Williamson synthesis, ethylene oxide ring-opening etherification, and ethylene addition. Among these, the Williamson synthesis is a commonly used method in industrial production; however, it generates large amounts of sodium chloride, causing severe environmental pollution and presenting significant challenges in post-processing, thus becoming a bottleneck in current industrial production.

[0004] CN101190876B discloses a method for preparing ethylene glycol ethers by reacting ethylene oxide with low-carbon fatty alcohols, wherein the ethylene glycol conversion rate is greater than 99% and the monohydric selectivity of ethylene glycol is greater than 82%. The ethylene addition method uses ethylene, hydrogen peroxide, and alcohol as raw materials to synthesize ethanol ethers; the ethylene addition method is essentially an extension of the ethylene oxide ring-opening etherification method.

[0005] CN104250206B discloses a method for preparing ethylene glycol ethers. Ethylene glycol is used as a raw material, low-carbon fatty alcohols as etherifying agents and reaction solvents, and an acid as a catalyst; however, the selectivity for single ethers is low.

[0006] CN100554231C describes a one-step reaction of ethylene, hydrogen peroxide, and n-butanol using Tween 80, aluminum isopropoxide, and Sphene 80-modified titanium silicate molecular sieves to produce ethylene glycol monobutyl ether. The hydrogen peroxide utilization rate is approximately 80%, and the ethylene glycol monobutyl ether production rate can reach 100%. Essentially, these routes are petrochemical routes based on ethylene as the primary substrate and ethylene oxide as the intermediate. Given the increasingly scarce oil reserves, there is an urgent need to develop non-petroleum-based feedstocks for the preparation of ethylene glycol ethers to supplement petrochemical processes.

[0007] CN102452908B discloses a method for producing ethylene glycol monoether from ethylene. In the presence of a titanium-silicon molecular sieve composite catalyst, ethylene, hydrogen peroxide, and a lower alcohol undergo a one-step reaction involving epoxidation and ring-opening etherification to obtain the ethylene glycol ether. The catalyst consists of a titanium-silicon molecular sieve, an acidic molecular sieve, and a resin. However, this method suffers from harsh reaction conditions and low selectivity.

[0008] CN 112479832 B discloses a method for preparing ethylene glycol monoether using titanium silicate molecular sieve as a catalyst. This method uses ethylene glycol and low-carbon fatty alcohols as raw materials, with titanium silicate molecular sieve as the catalyst. The titanium silicate molecular sieve is treated with allyl chloride before catalyzing the reaction to obtain the product, ethylene glycol monoether. However, this method requires harsh reaction conditions, with reaction temperatures exceeding 200°C.

[0009] Given the problems of environmental pollution, low selectivity of ethylene glycol monoethers, and harsh reaction conditions in existing technologies, there is an urgent need to develop a method for preparing ethylene glycol monoethers suitable for industrial production. Summary of the Invention

[0010] In view of the problems existing in the prior art, the purpose of this invention is to provide a highly selective method for preparing ethylene glycol monoethyl ether, so as to solve the problems of harsh reaction conditions and poor selectivity in the prior art. This invention is achieved through the following technical solution:

[0011] A method for preparing highly selective ethylene glycol monoethyl ether, characterized in that, under inert gas protection, ethylene glycol and ethanol undergo an etherification reaction in the presence of a heteropolyacid salt / molecular sieve supported catalyst to generate ethylene glycol monoethyl ether;

[0012] The heteropolyacid salt / molecular sieve supported catalyst is selected from [TPHBS]3PMo. 12 O 40 / HMCM-22 or [TPHBS]3PMo 12 O 40 / HMCM-22;

[0013] [TPHBS]3PW 12 O 40 The structural formula is: ;

[0014] [TPHBS]3PMo 12 O 40 The structural formula is: .

[0015] In some embodiments, the preparation method of the heteropolyacid salt / molecular sieve supported catalyst includes the following steps:

[0016] HMCM-22 molecular sieve, [TPHBS]3PW 12 O 40 Or [TPHBS]3PMo 12 O 40 The catalyst is added to an alcohol solvent and impregnated under ultrasonic treatment for 5-10 hours. Then, the impregnated catalyst is vacuum dried at 100-150℃ to obtain the final product.

[0017] In some embodiments, the HMCM-22 molecular sieve is combined with [TPHBS]3PW 12 O 40 The mass ratio is 1:(0.05~0.15); the HMCM-22 molecular sieve and [TPHBS]3PMo 12 O 40 The mass ratio is 1:(0.05~0.15).

[0018] In some embodiments, the alcohol solvent is selected from methanol, ethanol, or isopropanol.

[0019] In some embodiments, the molar ratio of ethylene glycol to ethanol is 1:(1.1~2.0); the mass ratio of ethylene glycol to heteropolyacid salt / molecular sieve supported catalyst is 1:(0.05~0.1).

[0020] In some implementation schemes, the reaction temperature is 60-90°C and the reaction time is 1-5 hours.

[0021] Some implementation schemes include the following specific steps:

[0022] At room temperature, ethylene glycol, ethanol, and [TPHBS]3PW were added to a high-pressure reactor. 12 O 40 / HMCM-22, after sealing, the gas in the high-pressure reactor was replaced with nitrogen three times, and then the temperature was raised to 80℃ and stirred for 2 hours; after the reaction was completed, the reactants in the reactor were cooled to ambient temperature to obtain ethylene glycol monoethyl ether.

[0023] Some implementation schemes include the following specific steps:

[0024] Ethylene glycol, ethanol, and [TPHBS]3PMo were added to a high-pressure reactor at room temperature. 12 O 40 / HMCM-22, after sealing, the gas in the high-pressure reactor was replaced with nitrogen three times, and then the temperature was raised to 80℃ and stirred for 2 hours; after the reaction was completed, the reactants in the reactor were cooled to ambient temperature to obtain ethylene glycol monoethyl ether.

[0025] The present invention has achieved the following beneficial effects:

[0026] 1) The [TPHBS]3PMo used in this invention 12 O 40 / HMCM-22 or [TPHBS]3PMo 12 O 40 The / HMCM-22 molecular sieve supported catalyst has a unique structure and exhibits high selectivity for the formation of ethylene glycol monoethyl ether. The conversion rate of ethylene glycol reaches up to 99.8%, and the selectivity for ethylene glycol monoethyl ether reaches up to 99.0%.

[0027] 2) The present invention still has a high conversion rate and selectivity under large-scale production (ten kilograms level), and the reaction conditions are milder than those of the prior art, making it suitable for industrial production. Detailed implementation method:

[0028] The following non-limiting embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way. The following content is merely an exemplary description of the scope of protection claimed by the present invention, and those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, and such changes should also fall within the scope of protection claimed by the present invention.

[0029] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0030] The present invention will be further described below by way of specific embodiments. Unless otherwise specified, all chemical reagents used in the embodiments of the present invention are obtained through conventional commercial means.

[0031] Among them, [TPHBS]3PW 12 O4、[TPHBS]3PMo 12 O4 can be prepared according to the method disclosed in CN112076783B.

[0032] Preparation Example 1: Heteropolyacid [TPHBS]3PW 12 O 40 Preparation of HMCM-22 molecular sieve supported catalyst

[0033] Step 1: Heteropolyacid salt [TPHBS]3PW 12 O 40 Preparation

[0034]

[0035] 0.1 mol of 1,4-butanesulfonate lactone was added to 100 mL of toluene and mixed thoroughly. Then, 0.12 mol of triphenylphosphine was slowly added, and the mixture was heated to 100 °C and stirred under reflux for 12 h. After the reaction was complete, the crude solid product was filtered, washed three times with diethyl ether, and dried under vacuum at 60 °C for 12 h to obtain a white TPHBS powder with a yield of 91.5%.

[0036]

[0037] Phosphotungstic acid (0.1 mol), TPHBS (0.3 mol), and ethanol (100 mL) were added to a reactor and mixed thoroughly. The mixture was then heated to 80 °C and stirred under reflux for 10 h. After the reaction was complete, the mixture was vacuum dried at 80 °C for 12 h to obtain the heteropolyacid salt [TPHBS]3PW. 12 O 40 The yield was 95.8%.

[0038] Step 2: Heteropolyacid salt [TPHBS]3PW 12 O 40 Preparation of HMCM-22 molecular sieve supported catalyst

[0039] 100g of HMCM-22 molecular sieve (purchased from Tianjin Yuanli Chemical Co., Ltd., with a silica-to-alumina ratio of 25) and heteropolyacid [TPHBS]3PW were added. 12 O 40 10 g of the catalyst was added to 100 mL of methanol and impregnated under ultrasonic treatment at room temperature for 10 h. The impregnated catalyst was then vacuum dried at 120 °C for 24 h to obtain the heteropolyacid salt [TPHBS]3PW. 12 O 40 / HMCM-22 molecular sieve supported catalyst, with heteropolyacid acid loading of 10wt%.

[0040] Preparation Example 2: Heteropolyacid [TPHBS]3PMo 12 O 40 Preparation of HMCM-22 molecular sieve supported catalyst

[0041]

[0042] Based on Preparation Example 1, the phosphotungstic acid described in step 1 was replaced with phosphomolybdic acid, and other operating conditions were the same as in Preparation Example 1, to obtain the heteropolyacid salt [TPHBS]3PMo. 12 O 40 / HMCM-22, with a heteropolyacid acid loading of 10wt%.

[0043] Example 1

[0044] At room temperature, ethylene glycol (10 kg, 161.29 mol), ethanol (11 kg, 239.13 mol), and the heteropolyacid salt [TPHBS]3PW obtained in Preparation Example 1 were added to a high-pressure reactor. 12 O 40 The catalyst supported on HMCM-22 molecular sieve (0.5 kg) was sealed, and the gas in the high-pressure reactor was purged with nitrogen three times. The reactor was then heated to 80°C and stirred for 2 hours. After the reaction was complete, the reactants in the reactor were cooled to ambient temperature, the reactor was opened, and samples were taken for analysis. The conversion rate of ethylene glycol was 99.8%, and the selectivity for ethylene glycol monoethyl ether was 99.0%.

[0045] Example 2

[0046] At room temperature, ethylene glycol (10 kg, 161.29 mol), ethanol (11 kg, 239.13 mol), and the heteropolyacid salt [TPHBS]3PMo obtained in Preparation Example 2 were added to a high-pressure reactor. 12 O 40 The catalyst supported on HMCM-22 molecular sieve (0.5 kg) was sealed, and the gas in the high-pressure reactor was purged with nitrogen three times. The reactor was then heated to 80°C and stirred for 2 hours. After the reaction was complete, the reactants in the reactor were cooled to ambient temperature, the reactor was opened, and samples were taken for analysis. The conversion rate of ethylene glycol was 99.4%, and the selectivity for ethylene glycol monoethyl ether was 98.8%.

[0047] Comparative Example 1

[0048] Based on Example 1, the heteropolyacid salt [TPHBS]3PW 12 O 40 The catalyst supported on HMCM-22 molecular sieves was replaced with HMCM-22 molecular sieves. The specific procedure is as follows:

[0049] At room temperature, ethylene glycol (10 kg, 161.29 mol), ethanol (11 kg, 239.13 mol), and HMCM-22 molecular sieve (0.5 kg) were added to a high-pressure reactor. After sealing, the reactor was purged with nitrogen three times, and then the temperature was raised to 80 °C and the mixture was stirred for 2 hours. After the reaction was complete, the reactants in the reactor were cooled to ambient temperature, the reactor was opened, and samples were taken for analysis. The conversion rate of ethylene glycol was 95.6%, and the selectivity for ethylene glycol monoethyl ether was 70.9%.

[0050] Comparative Example 2

[0051] Based on Preparation Example 1, [TPHBS]3PW 12 O 40 Replace with H3PW 12 O 40Other operating conditions and steps are the same as in Preparation Example 1, to obtain the heteropolyacid salt H3PW 12 O 40 / HMCM-22 molecular sieve supported catalyst.

[0052] At room temperature, ethylene glycol (10 kg, 161.29 mol), ethanol (11 kg, 239.13 mol), and H3PW were added to a high-pressure reactor. 12 O 40 The catalyst supported on HMCM-22 molecular sieve (0.5 kg) was sealed, and the gas in the high-pressure reactor was purged with nitrogen three times. The reactor was then heated to 80°C and stirred for 2 hours. After the reaction was complete, the reactants in the reactor were cooled to ambient temperature, the reactor was opened, and samples were taken for analysis. The conversion rate of ethylene glycol was 97.2%, and the selectivity for ethylene glycol monoethyl ether was 81.7%.

[0053] The above embodiments are merely illustrative examples and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing highly selective ethylene glycol monoethyl ether, characterized in that, Under inert gas protection, ethylene glycol and ethanol undergo an etherification reaction in the presence of a heteropolyacid salt / molecular sieve supported catalyst to produce ethylene glycol monoethyl ether; The heteropolyacid salt / molecular sieve supported catalyst is selected from [TPHBS]3PW. 12 O 40 / HMCM-22 or [TPHBS]3PMo 12 O 40 / HMCM-22; [TPHBS]3PW 12 O 40 The structural formula is: ; [TPHBS]3PMo 12 O 40 The structural formula is: .

2. The preparation method according to claim 1, characterized in that, The preparation method of the heteropolyacid salt / molecular sieve supported catalyst includes the following steps: HMCM-22 molecular sieve, [TPHBS]3PW 12 O 40 Or [TPHBS]3PMo 12 O 40 The catalyst is added to an alcohol solvent and impregnated under ultrasonic treatment for 5-10 hours. Then, the impregnated catalyst is vacuum dried at 100-150℃ to obtain the final product.

3. The preparation method according to claim 2, characterized in that, The HMCM-22 molecular sieve and [TPHBS]3PW 12 O 40 The mass ratio is 1:(0.05~0.15); the HMCM-22 molecular sieve and [TPHBS]3PMo 12 O 40 The mass ratio is 1:(0.05~0.15).

4. The preparation method according to claim 2, characterized in that, The alcohol solvent is selected from methanol, ethanol or isopropanol.

5. The preparation method according to claim 1, characterized in that, The molar ratio of ethylene glycol to ethanol is 1:(1.1~2.0); the mass ratio of ethylene glycol to heteropolyacid salt / molecular sieve supported catalyst is 1:(0.05~0.1).

6. The preparation method according to claim 1, characterized in that, The reaction temperature is 60~90℃ and the reaction time is 1~5h.

7. The preparation method according to claim 1, characterized in that, The specific steps include the following: At room temperature, ethylene glycol, ethanol, and [TPHBS]3PW were added to a high-pressure reactor. 12 O 40 / HMCM-22, after sealing, the gas in the high-pressure reactor was replaced with nitrogen three times, and then the temperature was raised to 80℃ and stirred for 2 hours; after the reaction was completed, the reactants in the reactor were cooled to ambient temperature to obtain ethylene glycol monoethyl ether.

8. The preparation method according to claim 1, characterized in that, The specific steps include the following: Ethylene glycol, ethanol, and [TPHBS]3PMo were added to a high-pressure reactor at room temperature. 12 O 40 / HMCM-22, after sealing, the gas in the high-pressure reactor was replaced with nitrogen three times, and then the temperature was raised to 80℃ and stirred for 2 hours; after the reaction was completed, the reactants in the reactor were cooled to ambient temperature to obtain ethylene glycol monoethyl ether.

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