A method for continuously producing ethylene glycol series ether derivatives at normal pressure

Abstract

The application discloses a method for continuously producing ethylene glycol series ether derivatives under normal pressure, and belongs to the technical field of organic synthesis. The steps of the preparation method comprise the following steps: mixing ethylene glycol monoalkyl ether or diethylene glycol monoalkyl ether with a dialkyl carbonate to prepare a reaction solution; and feeding the reaction solution into a reactor provided with a solid-phase metal phosphate catalyst, and obtaining the ethylene glycol series ether derivatives after heating reaction. The raw material used in the preparation method has low toxicity, the reaction does not require special conditions, the safety is high, the experimental device is simple, the by-products are few, and the preparation method meets the requirements of green chemistry. The ethylene glycol series ether derivatives are prepared from the cheap and easily available alkyl carbonate, ethylene glycol monoalkyl ether and diethylene glycol monoalkyl ether, and the method has high economic benefits.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a method for continuous production of ethylene glycol series ether derivatives under normal pressure. Background Technology

[0002] Ethylene glycol dimethyl ether, also known as 1,2-dimethoxyethane, is an organic compound, a colorless and transparent liquid, soluble in water, ethanol, and hydrocarbons. CAS: 110-71-4, molecular formula C4H 10 O2, molecular weight 90.121, melting point -58℃, boiling point 82 to 83℃, relative density 0.867 g / cm³ 3 Ethylene glycol dimethyl ether is an important raw material and organic solvent in organic synthesis. It is commonly used as a gas absorbent, extractant, and paint remover. It is also used in electrochemistry, polymer materials, organic compounds, pharmaceutical intermediates synthesis, industrial additives, cleaning agent formulations, adhesive formulations, and in the preparation of borides and organometallic compounds.

[0003] Ethylene glycol diethyl ether, also known as 1,2-diethoxyethane, is an organic compound, a colorless and transparent liquid, soluble in water, ethanol, and hydrocarbons. CAS: 629-14-1, molecular formula: C6H 14 O2, molecular weight 118.174, melting point -74℃, boiling point 121℃, relative density 0.842 g / cm³ 3 It is mainly used as a solvent, cleaning agent, diluent, and reaction medium for organic synthesis.

[0004] Ethylene glycol ethyl methyl ether, also known as 1-ethoxy-2-methoxyethane, is an organic compound, a colorless and transparent liquid, soluble in water, ethanol, and hydrocarbons. CAS: 5137-45-1, molecular formula: C5H 12 O2, molecular weight 104.15, boiling point 101.999℃, relative density 0.841 g / cm³ 3 It is an important intermediate in organic synthesis.

[0005] Ethylene glycol dibutyl ether, also known as 1,2-dibutoxyethane, is an organic compound, a colorless and transparent liquid, soluble in water, ethanol, and hydrocarbons. CAS: 112-48-1, molecular formula: C 10 H 22 O2, molecular weight 174.28, melting point -69.1℃, boiling point 203℃, relative density 0.8365 g / cm³ 3It is mainly used as a solvent, cleaning agent, diluent, and reaction medium in organic synthesis. It is stable to alkalis, but the ether bond breaks upon reaction with strong acids. It can form peroxides in the presence of oxygen in the air. It is miscible with acetone, ethanol, 1,2-dichloroethane, ethyl acetate, toluene, diethyl ether, heptane, castor oil, pine oil, isopropyl ether, etc. It is used as a dispersant, and also for the extraction of fatty acids from dilute fatty acid solutions, the separation and purification of alkyl phosphates, and as an inert solvent in uranium ore extraction.

[0006] Current methods for synthesizing ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and ethylene glycol dibutyl ether involve long reaction times, low yields, and high costs. Furthermore, the raw materials used involve strong acids and alkalis, posing significant risks to equipment corrosion and experimental hazards.

[0007] The synthesis of ethylene glycol series ether derivatives generally employs the traditional Williamson process, which involves reacting metallic sodium with dimethyl carbonate to produce sodium dimethyl carbonate, then reacting it with ethylene glycol monoether to produce sodium ethylene glycol monoether, which is then reacted with BuBr (or BuI). Alternatively, solid NaOH is refluxed with dimethyl carbonate, then reacted with ethylene glycol monomethyl ether, and finally refluxed with BuBr. The former method, using metallic sodium, is costly and hazardous, while the latter method has an excessively long reaction time. The industrial production of ethylene glycol series diethers still primarily relies on the Williamson process. Besides the unavoidable handling of the byproduct NaCl, the cost and recovery of the catalyst are currently the biggest challenges in production costs.

[0008] Dimethyl carbonate (DMC) is a colorless, flammable liquid with a sweet taste. CAS: 616-38-6, molecular formula C3H6O3, molecular weight 90.08, melting point 2-4℃, boiling point 90℃, density 1.069 g / mL at 25℃. DMCC is an important solvent and intermediate in many industrial and chemical applications. It has good dissolving power and is widely used in coatings, dyes, pharmaceuticals, and electronic materials. Furthermore, DMCC can be used as a raw material for the manufacture of polycarbonate (a type of plastic), methyl oxalate, and glycerol. Compared to other carbonates, DMCC has lower toxicity and volatility, making it relatively environmentally friendly and human-friendly.

[0009] Diethyl carbonate is a colorless, transparent liquid with a characteristic odor. It is insoluble in water but soluble in organic solvents such as alcohols and ethers. CAS: 105-58-8, Molecular formula C5H 10O3, molecular weight 118.13, melting point -43℃, boiling point 126-128℃, density 0.975 g / mL at 25℃. Diethyl carbonate is used as a solvent for nitrocellulose, natural and synthetic resins. It is also an important intermediate in organic synthesis, used in the synthesis of phenobarbital and pyrethroids, and as a coating for cathodes in electron tubes. Diethyl carbonate is commonly used as a solvent in organic synthesis, particularly in the manufacture of coatings, inks, and adhesives. Diethyl carbonate can also be used as a solvent and cleaning agent, such as for cleaning printed circuit boards in the electronics industry.

[0010] Diethylene glycol monoethyl ether, also known as diethylene glycol monoethyl ether, is a colorless, hygroscopically stable liquid. It has a moderately pleasant odor. CAS: 111-90-0, molecular formula: C6H 14 O3, with a molecular weight of 134.17, a melting point of -80℃, and a boiling point of 202℃, is an important solvent widely used in the chemical industry for the preparation of resins, paints, coatings, detergents, and dyes. Diethylene glycol monoethyl ether can also be used in the synthesis of catalysts, plastic elastomers, lubricants, and surfactants.

[0011] Diethylene glycol diethyl ether is a transparent, colorless liquid commonly used as a solvent in organic synthesis. CAS: 112-36-7, molecular formula: C8H 18 O3, with a molecular weight of 162.23, a melting point of -44.3℃, and a boiling point of 190.2℃, is a diethylene glycol diethyl ether. It possesses high polarity and low volatility, and is commonly used as a solvent in organic synthesis reactions, particularly those involving organometallic compounds, such as hydride reduction and organometallic catalysis. Diethylene glycol diethyl ether can be used as a raw material for the synthesis of fluorescent dyes, dye intermediates, and surfactants. It can also be used as an additive in certain coatings, inks, and fluorescent adhesives.

[0012] Current methods for synthesizing diethylene glycol diethyl ether have long reaction times, low yields, and high costs. Furthermore, the raw materials used involve strong acids and bases, posing problems such as equipment corrosion and significant experimental hazards.

[0013] The synthesis of diethylene glycol diethyl ether generally employs the traditional Williamson process. This involves first reacting diethylene glycol monoethyl ether with sodium hydroxide to obtain sodium diethylene glycol ethyl ether. The resulting sodium diethylene glycol ethyl ether is then used as a phase-transfer catalyst, and a synthesis reaction is carried out in the presence of chloroethane to produce diethylene glycol diethyl ether. In this reaction, chloroethane is a highly hazardous substance, being flammable and explosive; sodium hydroxide is highly corrosive and poses a significant hazard, making mass production difficult. Summary of the Invention

[0014] The purpose of this invention is to provide a method for the continuous production of ethylene glycol ether derivatives under normal pressure. This method uses ethylene glycol ether compounds or diethylene glycol ether compounds and dialkyl carbonate as raw materials, and prepares ethylene glycol ether derivatives through an etherification reaction catalyzed by a solid-phase metal phosphate. This method has advantages such as fast reaction rate, high reaction efficiency, simple and convenient reaction, low reaction cost, and continuous production capability.

[0015] To achieve the above objectives, the present invention provides the following technical solution:

[0016] A method for preparing diethylene glycol dimethyl ether via a continuous gas-solid phase reaction includes the following steps:

[0017] Ethylene glycol monoalkyl ether or diethylene glycol monoalkyl ether is mixed with dialkyl carbonate to prepare a reaction solution. The reaction solution is fed into a reactor containing a solid metal phosphate catalyst and heated to react, yielding ethylene glycol series ether derivatives.

[0018] The raw material combination of the reaction solution does not include diethylene glycol monomethyl ether and dimethyl carbonate.

[0019] Preferably, the ethylene glycol monoalkyl ether is ethylene glycol monomethyl ether or ethylene glycol monoethyl ether.

[0020] Preferably, the diethylene glycol monoalkyl ether is diethylene glycol monoethyl ether or diethylene glycol butyl ether.

[0021] Preferably, the dialkyl carbonate is dimethyl carbonate, diethyl carbonate, or dibutyl carbonate.

[0022] Preferably, the metal phosphate is one or more selected from aluminum phosphate, lanthanum phosphate, zirconium phosphate, cerium phosphate, zinc phosphate, calcium phosphate, and magnesium phosphate.

[0023] The ethylene glycol series ether derivatives disclosed in this invention can be prepared by combining various raw materials, such as:

[0024] Ethylene glycol monomethyl ether is prepared by reacting ethylene glycol monomethyl ether with dimethyl carbonate;

[0025] Ethylene glycol monoethyl ether is prepared by reacting ethylene glycol monoethyl ether with diethyl carbonate;

[0026] Ethylene glycol monoethyl ether is prepared by reacting ethylene glycol monoethyl ether with dimethyl carbonate;

[0027] Diethylene glycol diethyl ether is prepared by reacting diethylene glycol monoethyl ether with diethyl carbonate;

[0028] Diethylene glycol dibutyl ether is prepared by reacting diethylene glycol butyl ether with dibutyl carbonate;

[0029] Diethylene glycol ethyl ether and dimethyl carbonate are used to prepare diethylene glycol methyl ether, etc.

[0030] Taking the preparation of ethylene glycol dimethyl ether from ethylene glycol monomethyl ether and dimethyl carbonate as an example:

[0031] The molar ratio of ethylene glycol monomethyl ether to dimethyl carbonate is 1:(0.2-6), preferably 1:3; the rate at which the reaction solution passes through each gram of catalyst per minute is 0.02-0.25 mL, preferably 0.10 mL / min; the reaction temperature is 240-330℃, preferably 280℃; the metal phosphate is more preferably one or more of aluminum phosphate, lanthanum phosphate, and magnesium phosphate; most preferably aluminum phosphate and / or magnesium phosphate.

[0032] Taking the preparation of diethylene glycol diethyl ether from diethylene glycol monoethyl ether and diethyl carbonate as an example:

[0033] The molar ratio of diethylene glycol monoethyl ether to diethyl carbonate is 1:(2-7), preferably 1:6; the rate at which the reaction solution passes through each gram of catalyst per minute is 0.1-0.4 mL, preferably 0.2 mL / min; the reaction temperature is 200-250℃, preferably 240℃; the metal phosphate is more preferably one or more of aluminum phosphate, lanthanum phosphate, and cerium phosphate; most preferably aluminum phosphate and / or lanthanum phosphate.

[0034] Taking the preparation of diethylene glycol methyl ether from diethylene glycol monoethyl ether and dimethyl carbonate as an example:

[0035] The molar ratio of diethylene glycol monoethyl ether to dimethyl carbonate is 1:(2-7), preferably 1:6; the rate at which the reaction solution passes through each gram of catalyst per minute is 0.1-0.5 mL, preferably 0.3 mL / min; and the reaction temperature is 200-260℃, preferably 250℃.

[0036] Diethylene glycol dibutyl ether is produced by reacting diethylene glycol butyl ether with dibutyl carbonate:

[0037] The molar ratio of diethylene glycol butyl ether to dibutyl carbonate is 1:(2-7), preferably 1:6; the rate at which the reaction solution passes through each gram of catalyst per minute is 0.1-0.4 mL, preferably 0.2 mL / min; and the reaction temperature is 200-250℃, preferably 240℃.

[0038] The beneficial technical effects of the present invention are as follows:

[0039] This invention provides a method for preparing ethylene glycol series ether derivatives via etherification reactions using ethylene glycol monoalkyl ethers, diethylene glycol monoalkyl ethers, and dialkyl carbonates as raw materials under the catalysis of solid-phase metal phosphates. The raw materials used are of low toxicity, the reaction requires no special conditions, is highly safe, the experimental apparatus is simple, and there are few byproducts, meeting the requirements of green chemistry. This invention utilizes inexpensive and readily available alkyl carbonates, ethylene glycol monoalkyl ethers, and diethylene glycol monoalkyl ethers to prepare ethylene glycol series ether derivatives, resulting in high economic benefits. Specifically, when preparing ethylene glycol methyl ethyl ether from a combination of ethylene glycol monoethyl ether and dimethyl carbonate, the selectivity of the product ethylene glycol methyl ethyl ether can reach 95%; when preparing ethylene glycol dimethyl ether from a combination of ethylene glycol monoethyl ether and dimethyl carbonate, the selectivity of the product ethylene glycol dimethyl ether can reach 85%; when preparing ethylene glycol diethyl ether from a combination of ethylene glycol monoethyl ether and diethyl carbonate, the selectivity of the product ethylene glycol diethyl ether can reach 70%; and when preparing diethylene glycol diethyl ether from a combination of diethylene glycol monoethyl ether and diethyl carbonate, the selectivity of the reactant diethylene glycol monoethyl ether can reach 70%. The conversion rate of ether can reach 99.9%, and the selectivity of the product diethylene glycol diethyl ether can reach 92%. When diethylene glycol dibutyl ether is prepared by combining diethylene glycol butyl ether and dibutyl carbonate, the conversion rate of the reactant diethylene glycol butyl ether can reach 99.9%, and the selectivity of the product diethylene glycol dibutyl ether can reach 91%. When diethylene glycol ethyl ether is prepared by combining diethylene glycol ethyl ether and dimethyl carbonate, the conversion rate of the reactant diethylene glycol ethyl ether can reach 99.8%, and the selectivity of the product diethylene glycol methyl ethyl ether can reach 90%. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the self-made fixed-bed reaction device used in the embodiments of the present invention, wherein 1 is a nitrogen cylinder, 2 is a flow stabilizing valve, 3 is a rotor flow meter, 4 is a reaction tube, 5 is a heating furnace, 6 is a catalyst bed, 7 is a power cord, 8 is a thermocouple, 9 is a programmable temperature control cabinet, 10 is a cold trap, 11 is a collection bottle, 12 is a horizontal flow pump, and 13 is a container for holding the reaction liquid. Detailed Implementation

[0041] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.

[0042] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0043] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar to or equivalent to those described herein may be used in the implementation or testing of this invention.

[0044] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0045] Examples 1-21 of the present invention use Figure 1 The self-made fixed-bed reaction apparatus shown continuously prepares ethylene glycol series ether derivatives. Ethylene glycol monoalkyl ethers or diethylene glycol monoalkyl ethers are mixed with dialkyl carbonates in different molar ratios in a reaction solution container to obtain a reaction solution. A solid metal phosphate catalyst (20-40 mesh) is placed in a reaction tube (inner diameter 1.55 cm). Nitrogen gas released from a nitrogen cylinder is used to purge the air from the reaction tube. The heating furnace is heated to the required reaction temperature by a programmed temperature control cabinet. The nitrogen gas supply device is disassembled, and a horizontal flow pump is connected to inject the reaction solution. The reaction solution is heated in the reaction tube and passes through the catalyst to obtain ethylene glycol series ether derivatives. A collection bottle placed in a cold trap is connected to the end of the reaction tube.

[0046] Examples 1-7 describe the preparation of ethylene glycol dimethyl ether from ethylene glycol monomethyl ether and dimethyl carbonate.

[0047] Example 1

[0048] Preparation of ethylene glycol dimethyl ether:

[0049] In this embodiment, ethylene glycol monomethyl ether and dimethyl carbonate were mixed at a molar ratio of 1:3 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 270°C under a nitrogen atmosphere. The reaction solution was then fed into the fixed-bed reactor at a flow rate of 0.10 mL / min using a horizontal pump, allowing the etherification reaction of ethylene glycol monomethyl ether and dimethyl carbonate to occur under the action of the aluminum phosphate catalyst. After the reaction was completed, the product ethylene glycol dimethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant ethylene glycol monomethyl ether was 99%, the selectivity for ethylene glycol dimethyl ether was 83%, and the other byproducts were 17%.

[0050] The above steps were repeated to investigate the catalytic effects of equal masses of lanthanum phosphate, zirconium phosphate, cerium phosphate, zinc phosphate, calcium phosphate, and magnesium phosphate. The results showed that lanthanum phosphate and aluminum phosphate had comparable effects, followed by cerium phosphate, and then zirconium phosphate, calcium phosphate, magnesium phosphate, and zinc phosphate.

[0051] Example 2

[0052] Preparation of ethylene glycol dimethyl ether:

[0053] In this embodiment, ethylene glycol monomethyl ether and dimethyl carbonate were mixed at a molar ratio of 1:3 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 280°C under a nitrogen atmosphere. The reaction solution was then fed into the fixed-bed reactor at a flow rate of 0.10 mL / min using a horizontal pump, allowing the etherification reaction of ethylene glycol monomethyl ether and dimethyl carbonate to occur under the action of the aluminum phosphate catalyst. After the reaction was completed, the product ethylene glycol dimethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant ethylene glycol monomethyl ether was 99%, the selectivity for ethylene glycol dimethyl ether was 85%, and the other byproducts were 15%.

[0054] Example 3

[0055] Preparation of ethylene glycol dimethyl ether:

[0056] In this embodiment, ethylene glycol monomethyl ether and dimethyl carbonate were mixed at a molar ratio of 1:3 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 290°C under a nitrogen atmosphere. The reaction solution was then fed into the fixed-bed reactor at a flow rate of 0.10 mL / min using a horizontal pump, allowing the etherification reaction of ethylene glycol monomethyl ether and dimethyl carbonate to occur under the action of the aluminum phosphate catalyst. After the reaction was completed, the product ethylene glycol dimethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant ethylene glycol monomethyl ether was 99%, the selectivity for ethylene glycol dimethyl ether was 82%, and the other byproducts were 18%.

[0057] Example 4

[0058] Preparation of ethylene glycol dimethyl ether:

[0059] In this embodiment, ethylene glycol monomethyl ether and dimethyl carbonate were mixed at a molar ratio of 1:3 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 280°C under a nitrogen atmosphere. The reaction solution was then fed into the fixed-bed reactor at a flow rate of 0.15 mL / min using a horizontal pump, allowing the etherification reaction of ethylene glycol monomethyl ether and dimethyl carbonate to occur under the action of the aluminum phosphate catalyst. After the reaction was completed, the product ethylene glycol dimethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant ethylene glycol monomethyl ether was 99%, the selectivity for ethylene glycol dimethyl ether was 82%, and the other byproducts were 18%.

[0060] Example 5

[0061] Preparation of ethylene glycol dimethyl ether:

[0062] In this embodiment, ethylene glycol monomethyl ether and dimethyl carbonate were mixed at a molar ratio of 1:3 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 280°C under a nitrogen atmosphere. The reaction solution was then fed into the fixed-bed reactor at a flow rate of 0.20 mL / min using a horizontal pump, allowing the etherification reaction of ethylene glycol monomethyl ether and dimethyl carbonate to occur under the action of the aluminum phosphate catalyst. After the reaction was completed, the product ethylene glycol dimethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant ethylene glycol monomethyl ether was 99%, the selectivity for ethylene glycol dimethyl ether was 81%, and the other byproducts were 19%.

[0063] Example 6

[0064] Preparation of ethylene glycol dimethyl ether:

[0065] In this embodiment, ethylene glycol monomethyl ether and dimethyl carbonate were mixed at a molar ratio of 3:1 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 280°C under a nitrogen atmosphere. The reaction solution was then fed into the fixed-bed reactor at a flow rate of 0.10 mL / min using a horizontal pump, allowing the etherification reaction of ethylene glycol monomethyl ether and dimethyl carbonate to occur under the action of the aluminum phosphate catalyst. After the reaction was completed, the product ethylene glycol dimethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant ethylene glycol monomethyl ether was 42%, the selectivity for ethylene glycol dimethyl ether was 29%, and the selectivity for other byproducts was 71%.

[0066] Example 7

[0067] Preparation of ethylene glycol dimethyl ether:

[0068] In this embodiment, ethylene glycol monomethyl ether and dimethyl carbonate were mixed at a molar ratio of 1:6 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 280°C under a nitrogen atmosphere. The reaction solution was then fed into the fixed-bed reactor at a flow rate of 0.10 mL / min using a horizontal pump, allowing the etherification reaction of ethylene glycol monomethyl ether and dimethyl carbonate to occur under the action of the aluminum phosphate catalyst. After the reaction was completed, the product ethylene glycol dimethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant ethylene glycol monomethyl ether was 99%, the selectivity for ethylene glycol dimethyl ether was 84%, and the other byproducts were 16%.

[0069] Examples 8-10 describe the preparation of ethylene glycol diethyl ether from ethylene glycol monoethyl ether and diethyl carbonate.

[0070] Example 8

[0071] Preparation of ethylene glycol diethyl ether:

[0072] In this embodiment, ethylene glycol monoethyl ether and diethyl carbonate were mixed at a molar ratio of 1:6 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 210°C under a nitrogen atmosphere. The reaction solution was then fed into the fixed-bed reactor at a flow rate of 0.10 mL / min using a horizontal pump, allowing the etherification reaction of ethylene glycol monoethyl ether and diethyl carbonate to occur under the action of the aluminum phosphate catalyst. After the reaction was completed, the product ethylene glycol diethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant ethylene glycol monoethyl ether was 99%, the selectivity for ethylene glycol diethyl ether was 65%, and the selectivity for other byproducts was 35%.

[0073] Example 9

[0074] Preparation of ethylene glycol diethyl ether:

[0075] In this embodiment, ethylene glycol monoethyl ether and diethyl carbonate were mixed at a molar ratio of 1:6 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 220°C under a nitrogen atmosphere. The reaction solution was then fed into the fixed-bed reactor at a flow rate of 0.10 mL / min using a horizontal pump, allowing the etherification reaction of ethylene glycol monoethyl ether and diethyl carbonate to occur under the action of the aluminum phosphate catalyst. After the reaction was completed, the product ethylene glycol diethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant ethylene glycol monoethyl ether was 99%, the selectivity for ethylene glycol diethyl ether was 70%, and the other byproducts were 30%.

[0076] Example 10

[0077] Preparation of ethylene glycol diethyl ether:

[0078] In this embodiment, ethylene glycol monoethyl ether and diethyl carbonate were mixed at a molar ratio of 1:6 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 230°C under a nitrogen atmosphere. The reaction solution was then fed into the fixed-bed reactor at a flow rate of 0.10 mL / min using a horizontal pump, allowing the etherification reaction of ethylene glycol monoethyl ether and diethyl carbonate to occur under the action of the aluminum phosphate catalyst. After the reaction was completed, the product ethylene glycol diethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant ethylene glycol monoethyl ether was 99%, the selectivity for ethylene glycol diethyl ether was 69%, and the other byproducts were 31%.

[0079] Examples 11-15 describe the preparation of ethylene glycol methyl ether from ethylene glycol monoethyl ether and dimethyl carbonate.

[0080] Example 11

[0081] Preparation of ethylene glycol methyl ethyl ether:

[0082] In this embodiment, ethylene glycol monoethyl ether and dimethyl carbonate were mixed at a molar ratio of 1:6 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 270°C under a nitrogen atmosphere. The reaction solution was then fed into the fixed-bed reactor at a flow rate of 0.50 mL / min using a horizontal pump, allowing the etherification reaction of ethylene glycol monoethyl ether and dimethyl carbonate to occur under the action of the aluminum phosphate catalyst. After the reaction was completed, the product ethylene glycol methyl ethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant ethylene glycol monoethyl ether was 95%, the selectivity for ethylene glycol methyl ethyl ether was 91%, and the other byproducts were 9%.

[0083] Example 12

[0084] Preparation of ethylene glycol methyl ethyl ether:

[0085] In this embodiment, ethylene glycol monoethyl ether and dimethyl carbonate were mixed at a molar ratio of 1:6 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 260°C under a nitrogen atmosphere. The reaction solution was then fed into the fixed-bed reactor at a flow rate of 0.40 mL / min using a horizontal pump, allowing the etherification reaction of ethylene glycol monoethyl ether and dimethyl carbonate to occur under the action of the aluminum phosphate catalyst. After the reaction was completed, the product ethylene glycol methyl ethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant ethylene glycol monoethyl ether was 99%, the selectivity for ethylene glycol methyl ethyl ether was 90%, and the other byproducts were 10%.

[0086] Example 13

[0087] Preparation of ethylene glycol methyl ethyl ether:

[0088] In this embodiment, ethylene glycol monoethyl ether and dimethyl carbonate were mixed at a molar ratio of 1:6 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 250°C under a nitrogen atmosphere. The reaction solution was then fed into the fixed-bed reactor at a flow rate of 0.30 mL / min using a horizontal pump, allowing the etherification reaction of ethylene glycol monoethyl ether and dimethyl carbonate to occur under the action of the aluminum phosphate catalyst. After the reaction was completed, the product ethylene glycol methyl ethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant ethylene glycol monoethyl ether was 98%, the selectivity for ethylene glycol methyl ethyl ether was 90%, and the other byproducts were 10%.

[0089] Example 14

[0090] Preparation of ethylene glycol methyl ethyl ether:

[0091] In this embodiment, ethylene glycol monoethyl ether and dimethyl carbonate were mixed at a molar ratio of 1:6 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 240°C under a nitrogen atmosphere. The reaction solution was then fed into the fixed-bed reactor at a flow rate of 0.20 mL / min using a horizontal pump, allowing the ethylene glycol monoethyl ether and dimethyl carbonate to undergo an etherification reaction under the action of the aluminum phosphate catalyst. After the reaction was completed, the product ethylene glycol methyl ethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant ethylene glycol monoethyl ether was 97%, the selectivity for ethylene glycol methyl ethyl ether was 92%, and the other byproducts were 8%.

[0092] Example 15

[0093] Preparation of ethylene glycol methyl ethyl ether:

[0094] In this embodiment, ethylene glycol monoethyl ether and dimethyl carbonate were mixed at a molar ratio of 1:6 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 230°C under a nitrogen atmosphere. The reaction solution was then fed into the fixed-bed reactor at a flow rate of 0.10 mL / min using a horizontal pump, allowing the etherification reaction of ethylene glycol monoethyl ether and dimethyl carbonate to occur under the action of the aluminum phosphate catalyst. After the reaction was completed, the product ethylene glycol methyl ethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant ethylene glycol monoethyl ether was 98%, the selectivity for ethylene glycol methyl ethyl ether was 90%, and the other byproducts were 10%.

[0095] Examples 16-19 describe the preparation of diethylene glycol diethyl ether from diethylene glycol monoethyl ether and diethyl carbonate.

[0096] Example 16

[0097] Preparation of diethylene glycol diethyl ether:

[0098] In this embodiment, diethylene glycol monoethyl ether and diethyl carbonate were mixed at a molar ratio of 1:7 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 240°C under a nitrogen atmosphere. The reaction solution was then pumped into the fixed-bed reactor at a space velocity of 0.2 mL / min using a horizontal flow pump, allowing the diethylene glycol monoethyl ether and diethyl carbonate to undergo an etherification reaction under the action of the aluminum phosphate catalyst. After the reaction was completed, the product diethylene glycol diethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant diethylene glycol monoethyl ether was 99.7%, the selectivity of diethylene glycol diethyl ether was 89%, and the other byproducts were 11%.

[0099] Example 17

[0100] Preparation of diethylene glycol diethyl ether:

[0101] In this embodiment, diethylene glycol monoethyl ether and diethyl carbonate were mixed at a molar ratio of 1:6 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 240°C under a nitrogen atmosphere. The reaction solution was then pumped into the fixed-bed reactor at a space velocity of 0.2 mL / min using a horizontal flow pump, allowing the diethylene glycol monoethyl ether and diethyl carbonate to undergo an etherification reaction under the action of the aluminum phosphate catalyst. After the reaction was completed, the product diethylene glycol diethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant diethylene glycol monoethyl ether was 99.9%, the selectivity of diethylene glycol diethyl ether was 92%, and the other byproducts were 8%.

[0102] The above steps were repeated to investigate the effects of mixing diethylene glycol monoethyl ether and diethyl carbonate in molar ratios of 1:5, 1:4, 1:3, and 1:2. The optimal molar ratio of diethylene glycol monoethyl ether to diethyl carbonate was 1:6.

[0103] Example 18

[0104] Preparation of diethylene glycol diethyl ether:

[0105] In this embodiment, diethylene glycol monoethyl ether and diethyl carbonate were mixed at a molar ratio of 1:6 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 240°C under a nitrogen atmosphere. The reaction solution was then pumped into the fixed-bed reactor at a space velocity of 0.1 mL / min using a horizontal flow pump, allowing the diethylene glycol monoethyl ether and diethyl carbonate to undergo an etherification reaction under the action of the aluminum phosphate catalyst. After the reaction was completed, the product diethylene glycol diethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant diethylene glycol monoethyl ether was 99.9%, the selectivity of diethylene glycol diethyl ether was 91%, and the other byproducts were approximately 9%.

[0106] The above steps were repeated to examine the results at space velocities of 0.2 mL / min, 0.3 mL / min, and 0.4 mL / min, with the optimal space velocity being 0.2 mL / min.

[0107] Example 19

[0108] Preparation of diethylene glycol diethyl ether:

[0109] In this embodiment, diethylene glycol monoethyl ether and diethyl carbonate were mixed at a molar ratio of 1:6 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 230°C under a nitrogen atmosphere. The reaction solution was then pumped into the fixed-bed reactor at a space velocity of 0.2 mL / min using a horizontal flow pump, allowing the diethylene glycol monoethyl ether and diethyl carbonate to undergo an etherification reaction under the action of the aluminum phosphate catalyst. After the reaction was completed, the product diethylene glycol diethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant diethylene glycol monoethyl ether was 99.7%, the selectivity of diethylene glycol diethyl ether was 90%, and the other byproducts were approximately 10%.

[0110] The above steps were repeated, and the reaction was examined at temperatures of 200℃, 210℃, 220℃, 240℃ and 250℃. The optimal reaction temperature was found to be 240℃.

[0111] Example 20 describes the preparation of diethylene glycol methyl ether from diethylene glycol monoethyl ether and dimethyl carbonate.

[0112] Example 20

[0113] Preparation of diethylene glycol methyl ethyl ether:

[0114] In this embodiment, diethylene glycol monoethyl ether and dimethyl carbonate were mixed at a molar ratio of 1:6 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 250°C under a nitrogen atmosphere. The reaction solution was then pumped into the fixed-bed reactor at a space velocity of 0.3 mL / min using a horizontal flow pump, allowing the diethylene glycol monoethyl ether and dimethyl carbonate to undergo an etherification reaction under the action of the aluminum phosphate catalyst. After the reaction was completed, the product diethylene glycol methyl ethyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant diethylene glycol monoethyl ether was 99.8%, the selectivity of diethylene glycol methyl ethyl ether was 90%, and the other byproducts were 10%.

[0115] The effects of a molar ratio of diethylene glycol monoethyl ether to dimethyl carbonate of 1:(2–7), a space velocity of 0.1–0.5 mL / min, and a reaction temperature of 200–260 °C were also investigated. Ultimately, it was determined that a molar ratio of 1:6 for diethylene glycol monoethyl ether and dimethyl carbonate, a space velocity of 0.3 mL / min, and a reaction temperature of 250 °C yielded the best reaction results.

[0116] Example 21 describes the preparation of diethylene glycol dibutyl ether from diethylene glycol butyl ether and dibutyl carbonate.

[0117] Example 21

[0118] Preparation of diethylene glycol dibutyl ether:

[0119] In this embodiment, diethylene glycol butyl ether and dibutyl carbonate were mixed at a molar ratio of 1:6 to prepare a reaction solution. An aluminum phosphate catalyst was placed in a fixed-bed reactor, and the reactor was heated to 250°C under a nitrogen atmosphere. The reaction solution was then pumped into the fixed-bed reactor at a space velocity of 0.2 mL / min using a horizontal flow pump, allowing the diethylene glycol butyl ether and dibutyl carbonate to undergo an etherification reaction under the action of the aluminum phosphate catalyst. After the reaction was completed, the product diethylene glycol dibutyl ether and other byproducts were collected. In this embodiment, the conversion rate of the reactant diethylene glycol butyl ether was 99.9%, the selectivity of diethylene glycol dibutyl ether was 91%, and the other byproducts were 9%.

[0120] The effects of a molar ratio of diethylene glycol butyl ether to dibutyl carbonate of 1:(2-7), a space velocity of 0.1-0.4 mL / min, and a reaction temperature of 200-250 °C were also investigated. Ultimately, it was determined that a molar ratio of 1:6 for diethylene glycol butyl ether and dibutyl carbonate, a space velocity of 0.2 mL / min, and a reaction temperature of 240 °C yielded the best reaction results.

[0121] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for continuous production of ethylene glycol series ether derivatives under normal pressure, characterized in that, Includes the following steps: Ethylene glycol monoalkyl ether or diethylene glycol monoalkyl ether is mixed with dialkyl carbonate to prepare a reaction solution. The reaction solution is fed into a reactor containing a solid metal phosphate catalyst and heated to react, yielding ethylene glycol series ether derivatives. The raw material combination of the reaction solution does not include diethylene glycol monomethyl ether and dimethyl carbonate; The metal phosphate is one or more of aluminum phosphate, lanthanum phosphate, zirconium phosphate, cerium phosphate, zinc phosphate, calcium phosphate, and magnesium phosphate.

2. The method for continuous production of ethylene glycol series ether derivatives under normal pressure according to claim 1, characterized in that, The ethylene glycol monoalkyl ether is ethylene glycol monomethyl ether or ethylene glycol monoethyl ether.

3. The method for continuous production of ethylene glycol series ether derivatives under normal pressure according to claim 1, characterized in that, The diethylene glycol monoalkyl ether is diethylene glycol monoethyl ether or diethylene glycol butyl ether.

4. The method for continuous production of ethylene glycol series ether derivatives under normal pressure according to claim 1, characterized in that, The dialkyl carbonate is dimethyl carbonate, diethyl carbonate, or dibutyl carbonate.

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