Method for preparing ethylene glycol tert-butyl ether

Abstract

The invention discloses a method for preparing ethylene glycol tert-butyl ether, and belongs to the technical field of petrochemical engineering. According to the method, ethylene glycol or an ethylene glycol aqueous solution, a C4 olefin raw material containing isobutene or methyl tert-butyl ether and a modified solid acid catalyst are subjected to a contact reaction, and ethylene glycol tert-butyl ether is prepared; the modified solid acid catalyst is prepared by the following steps: firstly, loading a hydroxyl pyridine derivative on a molecular sieve, then putting into an acidic aqueous solution for treatment, and roasting. According to the method disclosed by the invention, the selectivity of the ethylene glycol tert-butyl ether can be greatly improved, and the selectivity of the ethylene glycol tert-butyl ether reaches 90% or above; the method is easy to industrially amplify, has a good application prospect and is remarkable in economic benefit.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical technology, and in particular relates to a method for preparing ethylene glycol tert-butyl ether. Background Technology

[0002] Ethylene glycol tert-butyl ether (ETB) is an isomer of ethylene glycol n-butyl ether. Its physical properties are similar to those of ethylene glycol n-butyl ether, but its boiling point is slightly lower, its evaporation rate is slightly faster, and it has good water miscibility. Its aqueous solution is always homogeneous. As a solvent, it exhibits good storage stability in coatings and inks, and has low skin irritation. It is an environmentally friendly alternative to traditional ethylene glycol ether solvents. It is widely used in water-dispersible coatings, and its demand and market share are expected to increase significantly.

[0003] The preparation of ethylene glycol ethers typically involves the following methods: 1. Reaction of sodium glycolate with organic halides, or sodium glycolate with tert-butyl chloride; 2. Etherification reaction of ethylene oxide with tert-butanol to obtain the corresponding ethylene glycol mono-tert-butyl ether and small amounts of diethylene glycol ether and triethylene glycol ether; 3. Ethylene glycol reacting with tert-butanol in the presence of an inorganic acid catalyst to produce ethylene glycol ethers. This method has poor selectivity for ethylene glycol mono-tert-butyl ether and generates some water, forming waste acid with the catalyst, increasing the environmental treatment challenges; 4. Alcohol-olefin method, using saturated alcohols and olefins as raw materials. Under the action of a catalyst, the alcohol and olefin are fully contacted, maintaining a certain temperature and pressure, and the alcohol and olefin undergo an addition reaction to produce the corresponding ether. This method belongs to atomic chemistry, is green and environmentally friendly, and has economical costs. However, this method requires large equipment investment, has high selectivity for alcohols as reactants, and the conversion rate of alcohols with different activities varies greatly with the olefin. To date, this method has been successfully applied to the production of methyl tert-butyl ether.

[0004] The process route for synthesizing ethylene glycol tert-butyl ether (ETB) uses ethylene glycol and isobutylene as raw materials, employing a technique similar to that used in the production of methyl tert-butyl ether (MTBE). Due to the limited catalyst selectivity in the production process, ethylene glycol di-tert-butyl ether is also generated concurrently with ethylene glycol tert-butyl ether.

[0005] Chinese invention patent CN105061160A discloses a method for producing diol tert-butyl ether. The method includes: using saturated diol and liquefied petroleum gas as raw materials, carrying out an addition reaction in a tubular reactor, wherein a multiphase catalyst is fixed in the tubular reactor; the mass percentage concentration of isobutylene in the liquefied petroleum gas is 20-99%, the molar ratio of isobutylene to saturated diol is 1-4:1, and the space velocity of the saturated diol is 0.2-2 h⁻¹. -1The reaction temperature is 50-100℃, and the reaction pressure is 0.5-5.0MPa. Chinese invention patent application CN106397137A discloses a method for preparing di-tert-butyl ether of diols, in which gaseous isobutylene and liquid diol are respectively introduced into a reactive distillation column from the lower and upper parts of a catalyst bed for a countercurrent heterogeneous reaction. This invention's process can suppress the formation of di-tert-butyl ether of diols, thus avoiding the problems of high energy consumption and large investment caused by the azeotropic reaction of di-tert-butyl ether and mono-tert-butyl ether of diols. This invention uses a catalytic distillation reaction, which has problems such as large investment and complex catalyst replacement. In the above inventions, multiple reactors are used for the reaction, resulting in a long reaction process and large equipment investment; catalytic distillation reactions are also used, which have problems such as large investment and complex catalyst replacement. All inventions suffer from the problem that due to the limited selectivity of the catalyst in the production process, a large amount of di-tert-butyl ether of ethylene glycol is generated simultaneously with it.

[0006] The production and utilization of ethylene glycol tert-butyl ether (ETB) abroad is disclosed in the prior art, which is the preparation process of Maruzen Corporation of Japan (Shen Jingyu. Fine Petrochemicals, 1996, 9(5): 45-50). The preparation process uses ethylene glycol to react with isobutylene in the C4 fraction (mixed C4) of naphtha cracking by-products under a strong acid ion exchange resin catalyst. The residence time of the reactants is 1 h, the reactor feed temperature is 90 °C, the pressure is 2.0 MPa, and the molar ratio of raw material ethylene glycol (EG) to isobutylene (IB) is 2.7:1. The outlet temperature of the reaction product gas is 119 °C, and the pressure is 1.7 MPa. Some reaction products are recycled back to the reactor to suppress the generation of by-product ethylene glycol ditert-butyl ether (DBE). The recycling rate is set so that the molar ratio of ETB:IB in the raw material is 1:1, and the molar ratio of DBE:IB is 0.5:1. The IB conversion rate is 81%, and the ETB selectivity can reach 83%. However, this process has problems such as a large DBE cycle ratio, low selectivity of ethylene glycol tert-butyl ether, a large amount of C8 (diisobutylene) byproducts, and high energy consumption.

[0007] Chinese invention patent application CN107434762A discloses a method for preparing and purifying ethylene glycol tert-butyl ether. This method uses ethylene glycol and a mixture of C4 molecules as starting materials in the presence of an acidic catalyst. Tert-butanol is added, and the mixture is then subjected to an etherification reaction in a reactor. The final product is obtained through separation and purification. This invention employs a four-tower separation technique, but it fails to separate the byproduct ethylene glycol tert-butyl ether. Furthermore, because tert-butanol is added in the reaction, it needs to be separated and recycled. Summary of the Invention

[0008] In order to overcome the shortcomings of existing technologies for preparing ethylene glycol tert-butyl ether, the purpose of this invention is to provide a method for preparing ethylene glycol tert-butyl ether with high selectivity and few byproducts.

[0009] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for preparing ethylene glycol tert-butyl ether, which involves reacting ethylene glycol or an aqueous solution of ethylene glycol, a C4 olefin raw material containing isobutylene or methyl tert-butyl ether with a modified solid acid catalyst to obtain ethylene glycol tert-butyl ether. The modified solid acid catalyst is prepared by first loading a hydroxyl-containing pyridine derivative onto a molecular sieve, then treating it in an acidic aqueous solution, and finally calcining it.

[0010] Based on the above technical solution, further, the mass fraction of isobutylene in the C4 olefin raw material is 5~100%, preferably 10~100%; the mass percentage of ethylene glycol in the ethylene glycol aqueous solution is 80~100%, preferably 90~99.9%; the molar ratio of ethylene glycol to isobutylene or methyl tert-butyl ether in the C4 olefin raw material is 1:1~20, preferably 1:2~10.

[0011] Based on the above technical solution, furthermore, the reaction temperature is 50~240℃, preferably 80~180℃; the reaction pressure is 0.5~5.0MPa, preferably 1.0~5.0MPa; and the mass hourly space velocity is 0.1~10h. -1 Preferably, it is 0.5~3.0h. -1 The reactor can be a fixed bed, moving bed, fluidized bed, or batch reactor.

[0012] Based on the above technical solution, the reactor is further described as a single fixed-bed reactor, or two or more fixed-bed reactors connected in series or in parallel.

[0013] Based on the above technical solution, the hydroxypyridine derivative is further defined as one or a combination of two or more of the following derivatives: 2-hydroxypyridine, 3-hydroxypyridine, 4-hydroxypyridine, 2,3-dihydroxypyridine, 2,6-dihydroxypyridine, 3,3'-dihydroxy-2,2'-bipyridine, 3-amino-3'-hydroxy-(2,2')-bipyridine, 4,4'-dihydroxy-2,2'-bipyridine, 5,5'-dihydroxy-2,2'-bipyridine, and 6,6'-dihydroxy-3,3'-bipyridine.

[0014] Based on the above technical solution, the molecular screening self-structure type is one or a combination of two or more of the molecular sieves such as MWW, FER, MFI, MOR, FAU, and BEA.

[0015] Based on the above technical solution, the molecular screening is further selected from one or more combinations of hydrogen-type Beta, hydrogen-type mordenite, hydrogen-type MCM-22, hydrogen-type Y zeolite, hydrogen-type magnesium alkali zeolite, hydrogen-type ZSM-5, hydrogen-type ZSM-11, hydrogen-type ZSM-22, and hydrogen-type ZSM-23.

[0016] Based on the above technical solution, further, the silicon-to-aluminum ratio (Si / Al) in the molecular sieve is 3~300, preferably 5~100.

[0017] Based on the above technical solution, the preparation of the modified solid acid catalyst further includes the following steps: under a protective atmosphere, the molecular sieve is refluxed in a solvent containing a hydroxypyridine derivative; the reflux temperature is 50~200℃, and the time is 2~10h; then, it is filtered, washed, dried, and calcined at 400~600℃ for 2~10h, and the above treatment is repeated 1~5 times; then the obtained sample is placed in an acidic aqueous solution, treated at 30~90℃ for 2~10h, filtered, washed, dried, and calcined at 400~600℃ for 2~10h, and then crushed to obtain the catalyst.

[0018] Based on the above technical solution, the protective atmosphere is further selected from one or more of nitrogen, argon, helium, carbon monoxide and carbon dioxide, preferably nitrogen or argon.

[0019] Based on the above technical solution, the solvent is further selected from one or more combinations of methanol, ethanol, propanol or butanol; the concentration of the hydroxypyridine derivative is 0.1~1 mol / L.

[0020] Based on the above technical solution, the acid is further defined as one or a combination of two or more of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, acetic acid, oxalic acid, and citric acid; the concentration of the acid is 0.1~1.0 mol / L.

[0021] Compared with the prior art, the present invention has the following beneficial effects: This invention first modifies a molecular sieve by loading a hydroxypyridine derivative onto it, then treats it in an acidic aqueous solution and calcines it to obtain a modified solid acid catalyst. This catalyst exhibits excellent conversion and selectivity in the preparation of ethylene glycol tert-butyl ether from ethylene glycol aqueous solution, C4 olefin feedstock containing isobutylene, or methyl tert-butyl ether. This invention is easy to scale up industrially, has good application prospects, and offers significant economic benefits. Detailed Implementation

[0022] The present invention will be described in detail below with reference to the embodiments. However, the implementation of the present invention is not limited thereto. Obviously, the embodiments described below are only some embodiments of the present invention. For those skilled in the art, other similar embodiments can be obtained without creative effort and all fall within the protection scope of the present invention.

[0023] Example 1 Catalyst preparation: 10g of ZSM-5 (Si / Al=30) molecular sieve was added to a 500ml three-necked flask, and 200ml of 0.2mol / L 2-hydroxypyridine ethanol solution was added. The mixture was refluxed at 60℃ for 6 hours, with argon gas being continuously introduced at 40 ml / min during the reflux process. The mixture was then filtered, washed, dried, and calcined at 500℃ for 4 hours. The above process was repeated once. The obtained sample was then placed in 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. The sample was then filtered, washed, dried, and calcined at 500℃ for 4 hours. The sample was then pressed, crushed, and sieved to obtain 20-40 mesh particles, thus obtaining modified catalyst #1, which was used for etherification reaction evaluation.

[0024] Etherification reaction evaluation: 5.0 g of catalyst 1# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 98% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and 50 wt% isobutylene C4 olefin at a rate of 0.50 ml / min (18.0 g / h), with an alcohol-olefin molar ratio of 1:4. The reaction temperature was 120℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1. The alcohol-olefin molar ratio refers to the molar ratio of isobutylene to ethylene glycol in the C4 olefin feedstock.

[0025] Example 2 Catalyst preparation: 10g of Hβ (Si / Al=42) molecular sieve was added to a 500ml three-necked flask, followed by 200ml of 0.2mol / L 2,3-dihydroxypyridine ethanol solution. The mixture was refluxed at 60℃ for 6 hours, with argon gas continuously introduced at 40 ml / min during the reflux process. After filtration, washing, and drying, the sample was calcined at 500℃ for 4 hours. This process was repeated once. The resulting sample was then placed in 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. After filtration, washing, and drying, the sample was calcined at 500℃ for 4 hours. The sample was then pressed into tablets, crushed, and sieved to obtain 20-40 mesh particles, thus obtaining modified catalyst #2, which was used for etherification reaction evaluation.

[0026] Etherification reaction evaluation: 5.0 g of catalyst 2# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 98% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and 50 wt% isobutylene C4 olefin at a rate of 0.50 ml / min (18.0 g / h), with an alcohol-olefin molar ratio of 1:4. The reaction temperature was 120℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1. The alcohol-olefin molar ratio refers to the molar ratio of isobutylene to ethylene glycol in the C4 olefin feedstock.

[0027] Example 3 Catalyst preparation: 10g of HY (Si / Al=7) molecular sieve was added to a 500ml three-necked flask, and 200ml of 0.2mol / L 3-hydroxypyridine ethanol solution was added. The mixture was refluxed at 60℃ for 6 hours, with argon gas being continuously introduced at 40 ml / min during the reflux process. After filtration, washing, and drying, the sample was calcined at 500℃ for 4 hours. The above process was repeated once. Then, the obtained sample was placed in 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. After filtration, washing, and drying, the sample was calcined at 500℃ for 4 hours. The sample was then pressed into tablets, crushed, and sieved to obtain 20-40 mesh particles, thus obtaining modified catalyst #3, which was used for etherification reaction evaluation.

[0028] Etherification reaction evaluation: 5.0 g of catalyst 3# was packed into a high-pressure micro fixed-bed reactor. Ethylene glycol was fed at a rate of 0.038 ml / min (2.5 g / h) and 50 wt% isobutylene C4 olefin was fed at a rate of 0.50 ml / min (18.0 g / h), with an alcohol-olefin molar ratio of 1:4. The reaction temperature was 120℃ and the reaction pressure was 3.0 MPa. The reaction was tested after 20 h, and the results are listed in Table 1. The alcohol-olefin molar ratio refers to the molar ratio of isobutylene to ethylene glycol in the C4 olefin feedstock.

[0029] Example 4 Catalyst preparation: 10g of MCM-22 (Si / Al=35) molecular sieve was added to a 500ml three-necked flask, and 200ml of 0.2mol / L 2,6-dihydroxypyridine ethanol solution was added. The mixture was refluxed at 60℃ for 6 hours, with argon gas being continuously introduced at 40ml / min during the reflux process. After filtration, washing, and drying, the sample was calcined at 500℃ for 4 hours. The above process was repeated once. Then, the obtained sample was placed in 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. After filtration, washing, and drying, the sample was calcined at 500℃ for 4 hours. The sample was then pressed into tablets, crushed, and sieved to obtain 20-40 mesh, thus obtaining modified catalyst #4, which was used for etherification reaction evaluation.

[0030] Etherification reaction evaluation: 5.0 g of catalyst #4 was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 95% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and 50 wt% isobutylene C4 olefin at a rate of 0.50 ml / min (18.0 g / h), with an alcohol-olefin molar ratio of 1:4. The reaction temperature was 120℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1. The alcohol-olefin molar ratio refers to the molar ratio of isobutylene to ethylene glycol in the C4 olefin feedstock.

[0031] Example 5 Catalyst preparation: 10g of magnesium alkali zeolite (Si / Al=62) molecular sieve was added to a 500ml three-necked flask, and 200ml of 0.2mol / L 3,3'-dihydroxy-2,2'-bipyridine ethanol solution was added. The mixture was refluxed at 60℃ for 6 hours, with argon gas being continuously introduced at 40 ml / min during the reflux process. After filtration, washing, and drying, the sample was calcined at 500℃ for 4 hours. The above process was repeated once. Then, the obtained sample was placed in 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. After filtration, washing, and drying, the sample was calcined at 500℃ for 4 hours. The sample was then pressed into tablets, crushed, and sieved to obtain 20-40 mesh particles, thus obtaining modified catalyst #5, which was used for etherification reaction evaluation.

[0032] Etherification reaction evaluation: 5.0 g of catalyst #5 was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 95% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and 50 wt% isobutylene C4 olefin at a rate of 0.50 ml / min (18.0 g / h), with an alcohol-olefin molar ratio of 1:4. The reaction temperature was 120℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1. The alcohol-olefin molar ratio refers to the molar ratio of isobutylene to ethylene glycol in the C4 olefin feedstock.

[0033] Example 6 Catalyst preparation: 10g of ZSM-23 (Si / Al=35) molecular sieve was added to a 500ml three-necked flask, and 200ml of 0.2mol / L 3-amino-3'-hydroxy-(2,2')-bipyridine ethanol solution was added. The mixture was refluxed at 60℃ for 6 hours, with argon gas being continuously introduced at 40 ml / min during the reflux process. The mixture was then filtered, washed, dried, and calcined at 500℃ for 4 hours. The above process was repeated once. The obtained sample was then placed in 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. The sample was then filtered, washed, dried, and calcined at 500℃ for 4 hours. The sample was then pressed into tablets, crushed, and sieved to obtain 20-40 mesh particles, thus obtaining modified catalyst 6#, which was used for etherification reaction evaluation.

[0034] Etherification reaction evaluation: 5.0 g of catalyst 6# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 98% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and 50 wt% isobutylene C4 olefin at a rate of 0.50 ml / min (18.0 g / h), with an alcohol-olefin molar ratio of 1:4. The reaction temperature was 120℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1. The alcohol-olefin molar ratio refers to the molar ratio of isobutylene to ethylene glycol in the C4 olefin feedstock.

[0035] Example 7 Catalyst preparation: 10g of mordenite zeolite (Si / Al=30) molecular sieve was added to a 500ml three-necked flask, and 200ml of 1.0mol / L 4,4'-dihydroxy-2,2'-bipyridine ethanol solution was added. The mixture was refluxed at 60℃ for 6 hours, with argon gas being continuously introduced at 40 ml / min during the reflux process. The mixture was then filtered, washed, dried, and calcined at 500℃ for 4 hours. The above process was repeated once. The obtained sample was then placed in 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. The sample was then filtered, washed, dried, and calcined at 500℃ for 4 hours. The sample was then pressed into tablets, crushed, and sieved to obtain 20-40 mesh particles, thus obtaining modified catalyst #7, which was used for etherification reaction evaluation.

[0036] Etherification reaction evaluation: 5.0 g of catalyst 7# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 98% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and 50 wt% isobutylene C4 olefin at a rate of 0.50 ml / min (18.0 g / h), with an alcohol-olefin molar ratio of 1:4. The reaction temperature was 120℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1. The alcohol-olefin molar ratio refers to the molar ratio of isobutylene to ethylene glycol in the C4 olefin feedstock.

[0037] Example 8 Catalyst preparation: 10g of ZSM-22 (Si / Al=56) molecular sieve was added to a 500ml three-necked flask, followed by 200ml of 0.2mol / L 4,4'-dihydroxy-2,2'-bipyridine ethanol solution. The mixture was refluxed at 60℃ for 6 hours, with nitrogen gas continuously introduced at 40 ml / min during the reflux process. After filtration, washing, and drying, the sample was calcined at 500℃ for 4 hours. This process was repeated once. The resulting sample was then placed in 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. After filtration, washing, and drying, the sample was calcined at 500℃ for 4 hours. The sample was then pressed into tablets, crushed, and sieved to obtain 20-40 mesh particles, yielding modified catalyst #8, which was used for etherification reaction evaluation.

[0038] Etherification reaction evaluation: 5.0 g of catalyst 8# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 98% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and 50 wt% isobutylene C4 olefin at a rate of 0.50 ml / min (18.0 g / h), with an alcohol-olefin molar ratio of 1:4. The reaction temperature was 120℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1. The alcohol-olefin molar ratio refers to the molar ratio of isobutylene to ethylene glycol in the C4 olefin feedstock.

[0039] Example 9 Catalyst preparation: 10g of Hβ (Si / Al=68) molecular sieve was added to a 500ml three-necked flask, followed by 200ml of 0.1mol / L 6,6'-dihydroxy-3,3'-bipyridine ethanol solution. The mixture was refluxed at 60℃ for 6 hours, with nitrogen gas continuously introduced at 40 ml / min during the reflux process. After filtration, washing, and drying, the sample was calcined at 500℃ for 4 hours. This process was repeated once. The resulting sample was then placed in 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. After filtration, washing, and drying, the sample was calcined at 500℃ for 4 hours. The sample was then pressed into tablets, crushed, and sieved to obtain 20-40 mesh particles, yielding modified catalyst #9, which was used for etherification reaction evaluation.

[0040] Etherification reaction evaluation: 5.0 g of catalyst 9# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 98% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and 50 wt% isobutylene C4 olefin at a rate of 0.50 ml / min (18.0 g / h), with an alcohol-olefin molar ratio of 1:4. The reaction temperature was 120℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1. The alcohol-olefin molar ratio refers to the molar ratio of isobutylene to ethylene glycol in the C4 olefin feedstock.

[0041] Example 10 Catalyst preparation: 10g of MCM-22 (Si / Al=25) molecular sieve was added to a 500ml three-necked flask, and 200ml of 0.5mol / L 4-hydroxypyridine ethanol solution was added. The mixture was refluxed at 60℃ for 18 hours, with nitrogen gas being introduced at 40 ml / min throughout the reflux process. The mixture was then filtered, washed, dried, and calcined at 500℃ for 4 hours. The above process was repeated once. The obtained sample was then placed in 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. The sample was then filtered, washed, dried, and calcined at 500℃ for 4 hours. The sample was then pressed into tablets, crushed, and sieved to obtain 20-40 mesh particles, thus obtaining modified catalyst 10#, which was used for etherification reaction evaluation.

[0042] Etherification reaction evaluation: 5.0 g of catalyst 10# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 95% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and 50 wt% isobutylene C4 olefin at a rate of 0.50 ml / min (18.0 g / h), with an alcohol-olefin molar ratio of 1:4. The reaction temperature was 120℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1. The alcohol-olefin molar ratio refers to the molar ratio of isobutylene to ethylene glycol in the C4 olefin feedstock.

[0043] Example 11 Catalyst preparation: 10g of ZSM-11 (Si / Al=40) molecular sieve was added to a 500ml three-necked flask, and 200ml of 0.5 mol / L 4,4'-dihydroxy-2,2'-bipyridine ethanol solution was added. The mixture was refluxed at 60℃ for 6 hours, with nitrogen gas continuously introduced at 40 ml / min during the reflux process. The mixture was then filtered, washed, dried, and calcined at 500℃ for 4 hours. The above process was repeated once. The obtained sample was then placed in 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. The sample was then filtered, washed, dried, and calcined at 500℃ for 4 hours. The sample was then pressed into tablets, crushed, and sieved to obtain 20-40 mesh particles, thus obtaining modified catalyst 11#, which was used for etherification reaction evaluation.

[0044] Etherification reaction evaluation: 5.0 g of catalyst 11# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 95% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and methyl tert-butyl ether at a rate of 0.324 ml / min (14.5 g / h), with an alcohol-ether molar ratio of 1:4. The reaction temperature was 150℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1.

[0045] Example 12 Catalyst preparation: 10g of magnesium alkali zeolite (Si / Al=62) molecular sieve was added to a 500ml three-necked flask, and 200ml of 0.5mol / L 3,3'-dihydroxy-2,2'-bipyridine ethanol solution was added. The mixture was refluxed at 80℃ for 4 hours, with argon gas being continuously introduced at 40 ml / min during the reflux process. The mixture was then filtered, washed, dried, and calcined at 500℃ for 4 hours. The above process was repeated once. The obtained sample was then placed in 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. The sample was then filtered, washed, dried, and calcined at 500℃ for 4 hours. The sample was then pressed into tablets, crushed, and sieved to obtain 20-40 mesh particles, thus obtaining modified catalyst 12#, which was used for etherification reaction evaluation.

[0046] Etherification reaction evaluation: 5.0 g of catalyst 12# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 95% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and methyl tert-butyl ether at a rate of 0.324 ml / min (14.5 g / h), with an alcohol-ether molar ratio of 1:4. The reaction temperature was 150℃ and the reaction pressure was 3.0 MPa. The reaction was tested after 20 h, and the results are listed in Table 1.

[0047] Example 13 Catalyst preparation: 10g of Hβ (Si / Al=42) molecular sieve was added to a 500ml three-necked flask, followed by 200ml of 0.5mol / L 6,6'-dihydroxy-3,3'-bipyridine ethanol solution. The mixture was refluxed at 80℃ for 6 hours, with nitrogen gas continuously introduced at 40 ml / min during the reflux process. The mixture was then filtered, washed, dried, and calcined at 500℃ for 4 hours. This process was repeated once. The resulting sample was then placed in 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. After filtration, washing, and drying, the sample was calcined at 500℃ for 4 hours. The sample was then pressed into tablets, crushed, and sieved to obtain 20-40 mesh particles, yielding modified catalyst 13#, which was used for etherification reaction evaluation.

[0048] Etherification reaction evaluation: 5.0 g of catalyst 13# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 95% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and methyl tert-butyl ether at a rate of 0.324 ml / min (14.5 g / h), with an alcohol-ether molar ratio of 1:4. The reaction temperature was 150℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1.

[0049] Example 14 Catalyst preparation: 10g of HY (Si / Al=7) molecular sieve was added to a 500ml three-necked flask, and 200ml of 0.5mol / L 3-amino-3'-hydroxy-(2,2')-bipyridine ethanol solution was added. The mixture was refluxed at 40℃ for 18 hours, with nitrogen gas being introduced at 40 ml / min throughout the reflux process. The mixture was then filtered, washed, dried, and calcined at 500℃ for 4 hours. The above process was repeated once. The obtained sample was then placed in 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. The sample was then filtered, washed, dried, and calcined at 500℃ for 4 hours. The sample was then pressed into tablets, crushed, and sieved to obtain 20-40 mesh particles, thus obtaining modified catalyst 14#, which was used for etherification reaction evaluation.

[0050] Etherification reaction evaluation: 5.0 g of catalyst 14# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 95% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and methyl tert-butyl ether at a rate of 0.324 ml / min (14.5 g / h), with an alcohol-ether molar ratio of 1:4. The reaction temperature was 150℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1.

[0051] Example 15 Catalyst preparation: 10g of mordenite zeolite (Si / Al=30) molecular sieve was added to a 500ml three-necked flask, and 200ml of 1.0mol / L 2,3-dihydroxypyridine ethanol solution was added. The mixture was refluxed at 60℃ for 6 hours, with nitrogen gas continuously introduced at 40ml / min during the reflux process. The mixture was then filtered, washed, dried, and calcined at 500℃ for 4 hours. The above process was repeated once. The obtained sample was then placed in 200ml of 0.8mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. The sample was then filtered, washed, dried, and calcined at 500℃ for 4 hours. The sample was then pressed into tablets, crushed, and sieved to obtain 20-40 mesh particles, thus obtaining modified catalyst 15#, which was used for etherification reaction evaluation.

[0052] Etherification reaction evaluation: 5.0 g of catalyst 15# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 95% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and methyl tert-butyl ether at a rate of 0.324 ml / min (14.5 g / h), with an alcohol-ether molar ratio of 1:4. The reaction temperature was 150℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1.

[0053] Comparative Example 1 Catalyst preparation: 10g of ZSM-5 (Si / Al=30) molecular sieve was added to 200ml of 0.1mol / L citric acid aqueous solution, treated at 60℃ for 4 hours, filtered, washed, dried, calcined at 500℃ for 4 hours, pressed into tablets, crushed and sieved to obtain 20-40 mesh, and modified catalyst 16# was obtained for evaluation of etherification reaction.

[0054] Etherification reaction evaluation: 5.0 g of catalyst 16# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 98% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and 50 wt% isobutylene C4 olefin at a rate of 0.50 ml / min (18.0 g / h), with an alcohol-olefin molar ratio of 1:4. The reaction temperature was 120℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1. The alcohol-olefin molar ratio refers to the molar ratio of isobutylene to ethylene glycol in the C4 olefin feedstock.

[0055] Comparative Example 2 Catalyst preparation: 10g of Hβ (Si / Al=42) molecular sieve was added to 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. After filtration, washing, drying, and calcination at 500℃ for 4 hours, the catalyst was pressed, crushed, and sieved to obtain 20-40 mesh to obtain modified catalyst 17#, which was used for etherification reaction evaluation.

[0056] Etherification reaction evaluation: 5.0 g of catalyst 17# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 98% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and 50 wt% isobutylene C4 olefin at a rate of 0.50 ml / min (18.0 g / h), with an alcohol-olefin molar ratio of 1:4. The reaction temperature was 120℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1. The alcohol-olefin molar ratio refers to the molar ratio of isobutylene to ethylene glycol in the C4 olefin feedstock.

[0057] Comparative Example 3 Catalyst preparation: 10g of HY (Si / Al=7) molecular sieve was added to 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. After filtration, washing, drying, and calcination at 500℃ for 4 hours, the catalyst was pressed, crushed, and sieved to obtain 20-40 mesh to obtain modified catalyst 18#, which was used for etherification reaction evaluation.

[0058] Etherification reaction evaluation: 5.0 g of catalyst 18# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 98% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and 50 wt% isobutylene C4 olefin at a rate of 0.50 ml / min (18.0 g / h), with an alcohol-olefin molar ratio of 1:4. The reaction temperature was 120℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1. The alcohol-olefin molar ratio refers to the molar ratio of isobutylene to ethylene glycol in the C4 olefin feedstock.

[0059] Comparative Example 4 Catalyst preparation: 10g of MCM-22 (Si / Al=35) molecular sieve was added to 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. After filtration, washing, drying, and calcination at 500℃ for 4 hours, the catalyst was pressed, crushed, and sieved to obtain 20-40 mesh to obtain modified catalyst 19#, which was used for etherification reaction evaluation.

[0060] Etherification reaction evaluation: 5.0 g of catalyst 19# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 98% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and 50 wt% isobutylene C4 olefin at a rate of 0.50 ml / min (18.0 g / h), with an alcohol-olefin molar ratio of 1:4. The reaction temperature was 120℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1. The alcohol-olefin molar ratio refers to the molar ratio of isobutylene to ethylene glycol in the C4 olefin feedstock.

[0061] Comparative Example 5 Catalyst preparation: 10g of magnesium alkali zeolite (Si / Al=62) molecular sieve was added to 200ml of 0.1mol / L citric acid aqueous solution, treated at 60℃ for 4 hours, filtered, washed, dried, calcined at 500℃ for 4 hours, pressed into tablets, crushed and sieved to obtain 20-40 mesh, and modified catalyst 20# was obtained for evaluation of etherification reaction.

[0062] Etherification reaction evaluation: 5.0 g of catalyst 20# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 95% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and 50 wt% isobutylene C4 olefin at a rate of 0.50 ml / min (18.0 g / h), with an alcohol-olefin molar ratio of 1:4. The reaction temperature was 120℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1. The alcohol-olefin molar ratio refers to the molar ratio of isobutylene to ethylene glycol in the C4 olefin feedstock.

[0063] Comparative Example 6 Catalyst preparation: 10g of ZSM-22 (Si / Al=56) molecular sieve was added to 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. After filtration, washing, drying, and calcination at 500℃ for 4 hours, the catalyst was pressed, crushed, and sieved to obtain 20-40 mesh, thus obtaining modified catalyst 21#, which was used for etherification reaction evaluation.

[0064] Etherification reaction evaluation: 5.0 g of catalyst 21# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 95% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and methyl tert-butyl ether at a rate of 0.324 ml / min (14.5 g / h), with an alcohol-ether molar ratio of 1:4. The reaction temperature was 150℃ and the reaction pressure was 3.0 MPa. The reaction was tested after 20 h, and the results are listed in Table 1.

[0065] Comparative Example 7 Catalyst preparation: 10g of mordenite zeolite (Si / Al=62) molecular sieve was added to 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. After filtration, washing, drying, and calcination at 500℃ for 4 hours, the catalyst was pressed, crushed, and sieved to obtain 20-40 mesh to obtain modified catalyst 22#, which was used for etherification reaction evaluation.

[0066] Etherification reaction evaluation: 5.0 g of catalyst 22# was packed into a high-pressure micro fixed-bed reactor. A micro-pump pump was used to feed 95% ethylene glycol aqueous solution at a rate of 0.038 ml / min (2.5 g / h) and methyl tert-butyl ether at a rate of 0.324 ml / min (14.5 g / h), with an alcohol-ether molar ratio of 1:4. The reaction temperature was 150℃, the reaction pressure was 3.0 MPa, and the reaction was tested after 20 h. The reaction results are listed in Table 1.

[0067] Comparative Example 8 Catalyst preparation: 10g of ZSM-11 (Si / Al=40) molecular sieve was added to 200ml of 0.1mol / L citric acid aqueous solution and treated at 60℃ for 4 hours. After filtration, washing, drying, and calcination at 500℃ for 4 hours, the catalyst was pressed, crushed, and sieved to obtain 20-40 mesh to obtain modified catalyst 23#, which was used for etherification reaction evaluation.

[0068] Etherification reaction evaluation: 5.0 g of catalyst 23# was packed into a high-pressure micro fixed-bed reactor. The feed rate of 95% ethylene glycol aqueous solution was 0.038 ml / min (2.5 g / h) and the feed rate of methyl tert-butyl ether was 0.324 ml / min (14.5 g / h), with an alcohol-ether molar ratio of 1:4. The reaction temperature was 150℃ and the reaction pressure was 3.0 MPa. The reaction was tested after 20 h, and the results are listed in Table 1.

[0069] Table 1. Results of etherification reactions in Examples 1-15 and Comparative Examples 1-8

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing ethylene glycol tert-butyl ether, characterized in that, Ethylene glycol tert-butyl ether is prepared by reacting ethylene glycol or an aqueous solution of ethylene glycol, a C4 olefin feedstock containing isobutylene, or methyl tert-butyl ether with a modified solid acid catalyst. The modified solid acid catalyst is prepared by first loading a hydroxyl-containing pyridine derivative onto a molecular sieve, then treating it in an acidic aqueous solution, and finally calcining it.

2. The method according to claim 1, characterized in that, The mass fraction of isobutylene in the C4 olefin raw material is 5-100%, preferably 10-100%; the mass percentage of ethylene glycol in the ethylene glycol aqueous solution is 80-100%, preferably 90-99.9%; the molar ratio of ethylene glycol to isobutylene or methyl tert-butyl ether in the C4 olefin raw material is 1:1-20, preferably 1:2-10.

3. The method according to claim 1, characterized in that, The reaction temperature is 50~240℃, preferably 80~180℃; the reaction pressure is 0.5~5.0MPa, preferably 1.0~5.0MPa; and the mass hourly space velocity is 0.1~10h. -1 Preferably, it is 0.5~3.0h. -1 The reactor can be a fixed bed, moving bed, fluidized bed, or batch reactor.

4. The method according to claim 1, characterized in that, The hydroxypyridine derivatives mentioned are one or a combination of two or more of the following: 2-hydroxypyridine, 3-hydroxypyridine, 4-hydroxypyridine, 2,3-dihydroxypyridine, 2,6-dihydroxypyridine, 3,3'-dihydroxy-2,2'-bipyridine, 3-amino-3'-hydroxy-(2,2')-bipyridine, 4,4'-dihydroxy-2,2'-bipyridine, 5,5'-dihydroxy-2,2'-bipyridine, and 6,6'-dihydroxy-3,3'-bipyridine derivatives.

5. The method according to claim 1, characterized in that, The molecular sieve is a combination of one or more of the following molecular sieve types: MWW, FER, MFI, MOR, FAU, and BEA, and the silicon-to-aluminum ratio (Si / Al) of the molecular sieve is 3 to 300, preferably 5 to 100.

6. The method according to claim 5, characterized in that, The molecular screening is selected from one or more combinations of hydrogen-type Beta, hydrogen-type mordenite, hydrogen-type MCM-22, hydrogen-type Y zeolite, hydrogen-type magnesium alkali zeolite, hydrogen-type ZSM-5, hydrogen-type ZSM-11, hydrogen-type ZSM-22, and hydrogen-type ZSM-23.

7. The method according to claim 1, characterized in that, The preparation of the modified solid acid catalyst includes the following steps: under a protective atmosphere, the molecular sieve is refluxed in a solvent containing a hydroxypyridine derivative; the reflux temperature is 50~200℃ and the time is 2~10h; then, it is filtered, washed, dried, and calcined at 400~600℃ for 2~10h, and the above treatment is repeated 1~5 times; then, the obtained sample is placed in an acidic aqueous solution, treated at 30~90℃ for 2~10h, filtered, washed, dried, and calcined at 400~600℃ for 2~10h, and then crushed to obtain the catalyst.

8. The method according to claim 7, characterized in that, The protective atmosphere is selected from one or more of nitrogen, argon, helium, carbon monoxide and carbon dioxide, preferably nitrogen or argon.

9. The method according to claim 7, characterized in that, The solvent is selected from one or more of methanol, ethanol, propanol or butanol; the concentration of the hydroxypyridine derivative is 0.1~1 mol / L.

10. The method according to claim 7, characterized in that, The acid is one or a combination of two or more of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, acetic acid, oxalic acid, and citric acid; the concentration of the acid is 0.1~1.0 mol / L.

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