A method and device for continuously preparing glycidol

Abstract

The invention discloses a method and device for continuously preparing glycidol, the method comprising the following steps: (1) epichlorohydrin and water are uniformly mixed and flowed through a packed column equipped with a strong acid cation exchange resin, so that epichlorohydrin undergoes a hydrolysis ring-opening reaction to generate 3-chloro-1,2-propylene glycol; (2) the reaction solution directly flows through a packed column equipped with a strong basic anion exchange resin under ultrasonic oscillation, so that 3-chloro-1,2-propylene glycol undergoes a dehydrochlorination ring-closing reaction to generate glycidol, and dehydrates under reduced pressure to obtain glycidol; (3) when the activity of the strong basic anion exchange resin decreases, the strong basic anion exchange resin used in step (2) is regenerated, and the regenerated resin can be reused in step (2), and the anion exchange resin packed column has two or more columns, which are alternately used and regenerated to continuously prepare glycidol. The glycidol preparation method of the present invention can realize continuous operation, and has the advantages of simple operation, high safety, less waste, and green environmental protection.

Description

Technical Field

[0001] The invention relates to a method and a device for continuously preparing glycidol, and belongs to the field of fine chemical raw materials. Background Art

[0002] Glycidol, also known as 2,3-epoxy-1-propanol and glycidol, is an important fine chemical raw material and an important component of organic synthesis intermediates. It is widely used in fine chemicals, biological products, pharmaceutical chemicals and other fields. It can be used to synthesize epoxy resins, surfactants, plastics, paints, fungicides, rubber, food preservatives, antiviral and analgesic drugs, etc.

[0003] Hutchings et al. used methanol as solvent and TS-1 zeolite to catalyze 70% hydrogen peroxide to oxidize allyl alcohol to synthesize glycidol. Wu Peng and Tatsumi used Ti-MWW zeolite as catalyst and 30% hydrogen peroxide as epoxidant to oxidize allyl alcohol to synthesize glycidol. Le Zhiping et al. used water as solvent and self-made W / MCM-41 to catalyze 30% hydrogen peroxide to oxidize allyl alcohol at 50°C for 12 hours to synthesize glycidol. Wang Shifa et al. reacted 3-chloro-1,2-propanediol with aqueous sodium hydroxide solution, then neutralized the excess alkali with hydrochloric acid solution, desalted the resulting solution, and fractionated it under reduced pressure to synthesize glycidol. Li Di et al. used acetic acid to catalyze the reaction of glycerol and hydrochloric acid to first obtain the 3-chloro-1,2-propanediol intermediate, which was then subjected to a ring-closing reaction with sodium hydroxide and then distilled to synthesize glycidol. Cespi et al. used acetic acid as a catalyst and chlorinated glycerol with gaseous HCl to obtain 3-chloro-1,2-propylene glycol intermediate, and then used an alcohol solution of potassium hydroxide to convert 3-chloro-1,2-propylene glycol into glycidol. Bai Rongxian et al. used M(AlO)x as a catalyst, where M is Na, K, etc., to catalyze the one-step reaction of glycerol and dimethyl carbonate to synthesize glycidol. Kostyniuk et al. used SiO2 / Al2O3 on a Cs-ZSM-5 zeolite catalyst to convert glycerol into glycidol in one step.

[0004] The above-mentioned glycidol method has the problems of strict process conditions, low efficiency, large amount of three wastes and residual metal ions. Summary of the invention

[0005] The invention provides a method and a device for continuously preparing glycidol, which solve the problems of strict process conditions, low efficiency, large amount of three wastes and residual metal ions in the existing glycidol method.

[0006] The technical solution adopted by the present invention is:

[0007] A method for continuously preparing glycidol, using epichlorohydrin and water as raw materials, comprises the following steps:

[0008] (1) Epichlorohydrin and water are mixed evenly and flowed through a column filled with a strong acidic cation exchange resin to cause epichlorohydrin to undergo a hydrolysis ring-opening reaction to generate 3-chloro-1,2-propylene glycol;

[0009] (2) The reaction liquid flowing out of the cation exchange resin packed column directly flows through the packed column filled with a strong alkaline anion exchange resin under ultrasonic oscillation, so that 3-chloro-1,2-propanediol undergoes a dehydrochlorination ring-closing reaction to generate glycidol, and the resulting glycidol-containing reaction liquid is dehydrated under reduced pressure to obtain glycidol;

[0010] (3) When the activity of the strong basic anion exchange resin decreases and the yield of glycidol decreases to less than 80% of the initial yield, the strong basic anion exchange resin used in step (2) is regenerated. The regenerated strong basic anion exchange resin can be reused in step (2). There are two or more anion exchange resin filling columns, which are used and regenerated alternately to continuously prepare glycidol.

[0011] Furthermore, in the step (1), when epichlorohydrin and water flow through a packed column filled with a strong acidic cation exchange resin, the volume space velocity is 0.2 to 2 h-1, the temperature in the packed column is 20°C to 80°C, and the pressure in the packed column is normal pressure to 1 MPa.

[0012] Furthermore, in step (2), the frequency of the ultrasound is 20 kHz to 40 kHz, and the ultrasound power per unit volume of the filling column is 10 watts / liter to 100 watts / liter.

[0013] Furthermore, in the step (3), when the reaction liquid flowing out of the cation exchange resin packed column flows through the packed column filled with strong basic anion exchange resin, the volume space velocity is 0.5 to 5 h-1, the temperature in the packed column is 10°C to 50°C, and the pressure in the packed column is normal pressure to 1 MPa.

[0014] Furthermore, in step (4), the regeneration treatment adopts the use of sodium hydroxide solution to regenerate the strong alkaline anion exchange resin used in step (2).

[0015] Furthermore, the concentration of the sodium hydroxide solution is 0.5 mol / L to 2 mol / L, the regeneration temperature is 10° C. to 40° C., the regeneration pressure is normal pressure to 1 MPa, and the volume space velocity of the sodium hydroxide solution during regeneration is 0.5 to 5 h-1.

[0016] Furthermore, the mass ratio of epichlorohydrin to water is 1:2 to 1:20.

[0017] Furthermore, the strongly acidic cation exchange resin is a gel-type sulfonic acid cation exchange resin or a macroporous sulfonic acid cation exchange resin.

[0018] Furthermore, the strong alkaline anion exchange resin is a gel-type quaternary ammonium base anion exchange resin or a porous quaternary ammonium base anion exchange resin.

[0019] The present invention also provides a device for continuously preparing glycidol, comprising a strongly acidic cation exchange resin filled column, a plurality of strongly basic anion exchange resin filled columns and a reduced pressure dehydration device;

[0020] The strong basic anion exchange resin packed column is connected with an ultrasonic generator, the transducer of the ultrasonic generator is arranged inside the strong basic anion exchange resin packed column, the top of the strong basic anion exchange resin packed column is provided with a raw material liquid inlet valve and a regeneration water outlet valve, the bottom of the strong basic anion exchange resin packed column is provided with a product liquid outlet valve and a regeneration water inlet valve, the raw material liquid inlet valve is communicated with the bottom of the strong acid cation exchange resin packed column through a pipeline, the product liquid outlet valve is communicated with the decompression dehydration device through a pipeline, the regeneration water inlet valve is connected to a water supply device through a pipeline, and the regeneration water outlet valve is connected to a wastewater collection device through a pipeline.

[0021] Beneficial effects of the present invention

[0022] The method of the present invention uses a mixture of epichlorohydrin and water to flow through a packed column equipped with a strong acid cation exchange resin, so that epichlorohydrin undergoes a hydrolysis ring-opening reaction to generate 3-chloro-1,2-propylene glycol. The reaction liquid flowing out of the cation exchange resin packed column does not need any treatment, and is further made to flow directly through a packed column equipped with a strong basic anion exchange resin under ultrasonic oscillation, and 3-chloro-1,2-propylene glycol undergoes a dehydrochlorination ring-closing reaction to generate glycidol. The highly toxic intermediate 3-chloro-1,2-propylene glycol does not require extraction, separation, purification, and other operations, nor does it require additional addition of an organic solvent. The strongly basic anion exchange resin after the reaction can be reused after being regenerated with a sodium hydroxide solution. The glycidol preparation process of the present invention can realize continuous operation, and has the advantages of simple operation, high safety, less waste, and green environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 This is a schematic diagram of the reaction principle for preparing glycidol according to the present invention;

[0025] Figure 2 The figure is a schematic diagram of the structure of the device for continuously preparing glycidol according to the present invention.

[0026] In the figure, 1 is a column filled with a strong acid cation exchange resin, 2 is a raw material inlet valve, 3 is a regeneration outlet valve, 4 is a column filled with a strong base anion exchange resin, 5 is an ultrasonic generator, 6 is a regeneration wastewater collection device, 7 is a product outlet valve, 8 is a regeneration inlet valve, 9 is a pressure reducing dehydration device, and 10 is a regeneration liquid supply device. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] like Figure 1 As shown, a method for continuously preparing glycidol, using epichlorohydrin and water as raw materials, comprises the following steps:

[0029] (1) Epichlorohydrin and water are mixed evenly and flowed through a column filled with a strong acidic cation exchange resin to cause epichlorohydrin to undergo a hydrolysis ring-opening reaction to generate 3-chloro-1,2-propylene glycol;

[0030] (2) The reaction liquid flowing out of the cation exchange resin packed column directly flows through the packed column filled with a strong alkaline anion exchange resin under ultrasonic oscillation, so that 3-chloro-1,2-propanediol undergoes a dehydrochlorination ring-closing reaction to generate glycidol, and the resulting glycidol-containing reaction liquid is dehydrated under reduced pressure to obtain glycidol;

[0031] (3) The strongly basic anion exchange resin used in step (2) is regenerated. The regenerated strongly basic anion exchange resin can be reused in step (2). There are two or more anion exchange resin filling columns, which are used and regenerated alternately to continuously prepare glycidol.

[0032] like Figure 2 As shown, a device for continuously preparing glycidol includes a strongly acidic cation exchange resin filling column, a plurality of strongly basic anion exchange resin filling columns and a reduced pressure dehydration device; in this embodiment, there are two strongly basic anion exchange resin filling columns, namely, a strongly basic anion exchange resin filling column A and a strongly basic anion exchange resin filling column B.

[0033] The strong basic anion exchange resin packed column is connected with an ultrasonic generator, the transducer of the ultrasonic generator is arranged inside the strong basic anion exchange resin packed column, the top of the strong basic anion exchange resin packed column is provided with a raw material liquid inlet valve and a regeneration water outlet valve, the bottom of the strong basic anion exchange resin packed column is provided with a product liquid outlet valve and a regeneration water inlet valve, the raw material liquid inlet valve is communicated with the bottom of the strong acid cation exchange resin packed column through a pipeline, the product liquid outlet valve is communicated with the decompression dehydration device through a pipeline, the regeneration water inlet valve is connected to a water supply device through a pipeline, and the regeneration water outlet valve is connected to a wastewater collection device through a pipeline. Example 1

[0034] A method for continuously preparing glycidol, using epichlorohydrin and water as raw materials, comprises the following steps:

[0035] (1) A mixture of epichlorohydrin and water in a mass ratio of 1:8 flows through a column filled with a strong acid cation exchange resin containing a gel-type sulfonic acid cation exchange resin. The volumetric space velocity of the mixture flowing through the column filled with the strong acid cation exchange resin is 0.8 h -1 , the temperature in the filling column is 50°C, the pressure in the filling column is 0.1MPa, epichlorohydrin undergoes hydrolysis and ring-opening reaction to generate 3-chloro-1,2-propylene glycol,

[0036] (2) Open the raw material inlet valve and product outlet valve of the strong basic anion exchange resin packed column A, so that the reaction liquid flowing out of the strong acid cation exchange resin packed column can flow directly through the strong basic anion exchange resin packed column A filled with gel-type quaternary ammonium base anion exchange resin under ultrasonic oscillation. The volume space velocity when flowing through the strong basic anion exchange resin packed column A is 2 hours. -1 , the temperature in the filling column is 30°C, the pressure in the filling column is 0.1MPa, the ultrasonic frequency is 40KHz, and the ultrasonic power per unit volume of the filling column is 50W / L. 3-Chloro-1,2-propylene glycol undergoes a dehydrochlorination ring-closing reaction, and the resulting glycidol-containing reaction liquid is dehydrated under reduced pressure at 40°C and a vacuum degree of 92KPa to 95KPa to obtain the product glycidol. The yield of glycidol is 92% based on the amount of epichlorohydrin.

[0037] (3) When the activity of the strong basic anion exchange resin decreases and the yield of propylene oxide decreases to 75% of the initial yield, close the raw material inlet valve and product outlet valve of the strong basic anion exchange resin column A, and open the raw material inlet valve and product outlet valve of the strong basic anion exchange resin column B at the same time, switch the anion exchange resin column, and allow the reaction liquid flowing out of the cation exchange resin column to flow through the strong basic anion exchange resin column B under the same conditions. Open the regeneration water inlet valve and regeneration water outlet valve, use a 1 mol / L sodium hydroxide aqueous solution at a volume space velocity of 1 hour -1 , under the conditions of temperature of 25°C and pressure of 0.1MPa, the gel-type quaternary ammonium base anion exchange resin used in the reaction of 3-chloro-1,2-propylene glycol dehydrochlorination ring-closing to generate glycidol can be regenerated by flowing through the alkaline anion exchange resin column A, and the regenerated gel-type quaternary ammonium base anion exchange resin can be reused in the reaction of 3-chloro-1,2-propylene glycol dehydrochlorination ring-closing to generate glycidol. Two or more anion exchange resin columns are alternately used and regenerated to continuously prepare glycidol. Example 2

[0038] A method for continuously preparing glycidol, using epichlorohydrin and water as raw materials, comprises the following steps:

[0039] (1) A mixture of epichlorohydrin and water in a mass ratio of 1:20 flows through a column filled with a strong acid cation exchange resin containing a gel-type sulfonic acid cation exchange resin. The volumetric space velocity of the mixture flowing through the column is 0.2 h -1 , the temperature in the filling column is 80°C, the pressure in the filling column is 1MPa, epichlorohydrin undergoes hydrolysis and ring-opening reaction to generate 3-chloro-1,2-propylene glycol,

[0040] (2) Open the raw material inlet valve and product outlet valve of the strongly basic anion exchange resin packed column A, and allow the reaction liquid flowing out of the strongly acidic cation exchange resin packed column to flow directly through the strongly basic anion exchange resin packed column A filled with gel-type quaternary ammonium base anion exchange resin under ultrasonic oscillation. The volume space velocity when flowing through the packed column is 2 hours. -1 , the temperature in the filling column is 30°C, the pressure in the filling column is 0.1MPa, the ultrasonic frequency is 40KHz, and the ultrasonic power per unit volume of the filling column is 50W / L. 3-Chloro-1,2-propylene glycol undergoes a dehydrochlorination ring-closing reaction, and the resulting glycidol-containing reaction liquid is dehydrated under reduced pressure at 40°C and a vacuum degree of 92KPa to 95KPa to obtain the product glycidol. The yield of glycidol is 87% based on the amount of epichlorohydrin.

[0041] (3) When the activity of the strong basic anion exchange resin decreases and the yield of propylene oxide decreases to 75% of the initial yield, close the raw material inlet valve and product outlet valve of the strong basic anion exchange resin column A, and open the raw material inlet valve and product outlet valve of the strong basic anion exchange resin column B at the same time, switch the anion exchange resin column, and allow the reaction liquid flowing out of the cation exchange resin column to flow through the strong basic anion exchange resin column B under the same conditions. Open the regeneration water inlet valve and regeneration water outlet valve, use a 0.5 mol / L sodium hydroxide aqueous solution at a volume space velocity of 0.6 h -1 , under the conditions of temperature of 40°C and pressure of 1MPa, the flow passes through the strong basic anion exchange resin column A of the gel-type quaternary ammonium base anion exchange resin used in the reaction of 3-chloro-1,2-propylene glycol dehydrochlorination ring closure to generate glycidol, so as to achieve the regeneration of the gel-type quaternary ammonium base anion exchange resin used, and the regenerated gel-type quaternary ammonium base anion exchange resin is reused in the reaction of 3-chloro-1,2-propylene glycol dehydrochlorination ring closure to generate glycidol. Two or more anion exchange resin columns are alternately used and regenerated to continuously prepare glycidol. Example 3

[0042] A method for continuously preparing glycidol, using epichlorohydrin and water as raw materials, comprises the following steps:

[0043] (1) A mixture of epichlorohydrin and water in a mass ratio of 1:2 flows through a column filled with a strong acid cation exchange resin containing a gel-type macroporous cation exchange resin. The volumetric space velocity of the mixture flowing through the column is 5 hours. -1 , the temperature in the filling column is 20°C, the pressure in the filling column is normal pressure, epichlorohydrin undergoes hydrolysis and ring-opening reaction to generate 3-chloro-1,2-propylene glycol,

[0044] (2) Open the raw material inlet valve and product outlet valve of the strong basic anion exchange resin packed column A, so that the reaction liquid flowing out of the strong acid cation exchange resin packed column can flow directly through the strong basic anion exchange resin packed column A filled with gel-type quaternary ammonium base anion exchange resin under ultrasonic oscillation. The volume space velocity when flowing through the packed column is 0.5 h -1 , the temperature in the filling column is 30°C, the pressure in the filling column is 0.1MPa, the ultrasonic frequency is 20KHz, and the ultrasonic power per unit volume of the filling column is 100W / L. 3-Chloro-1,2-propanediol undergoes a dehydrochlorination ring-closing reaction, and the resulting reaction liquid containing glycidol is dehydrated under reduced pressure at 40°C and a vacuum degree of 92KPa to 95KPa to obtain the product glycidol. The yield of glycidol is 80% based on the amount of epichlorohydrin.

[0045] (3) When the activity of the strong basic anion exchange resin decreases and the yield of propylene oxide decreases to 78% of the initial yield, close the raw material inlet valve and product outlet valve of the strong basic anion exchange resin column A, and open the raw material inlet valve and product outlet valve of the strong basic anion exchange resin column B at the same time, switch the anion exchange resin column, and allow the reaction liquid flowing out of the cation exchange resin column to flow through the strong basic anion exchange resin column B under the same conditions. Open the regeneration water inlet valve and regeneration water outlet valve, use a 2 mol / L sodium hydroxide aqueous solution at a volume space velocity of 5 hours -1 , under the conditions of temperature of 10°C and pressure of normal pressure, the gel-type quaternary ammonium base anion exchange resin used in the reaction of 3-chloro-1,2-propylene glycol dehydrochlorination ring-closing to generate glycidol is flowed through the strong basic anion exchange resin column A, so that the gel-type quaternary ammonium base anion exchange resin used can be regenerated, and the regenerated gel-type quaternary ammonium base anion exchange resin can be reused in the reaction of 3-chloro-1,2-propylene glycol dehydrochlorination ring-closing to generate glycidol. Two or more anion exchange resin columns are alternately used and regenerated to continuously prepare glycidol. Example 4

[0046] A method for continuously preparing glycidol, using epichlorohydrin and water as raw materials, comprises the following steps:

[0047] (1) A mixture of epichlorohydrin and water in a mass ratio of 1:8 flows through a column filled with a strong acid cation exchange resin containing a gel-type sulfonic acid cation exchange resin. The volumetric space velocity of the mixture flowing through the column filled with the strong acid cation exchange resin is 0.8 h -1 , the temperature in the filling column is 50°C, the pressure in the filling column is 0.1MPa, epichlorohydrin undergoes hydrolysis and ring-opening reaction to generate 3-chloro-1,2-propylene glycol,

[0048] (2) Open the raw material inlet valve and product outlet valve of the strongly basic anion exchange resin packed column A, and allow the reaction liquid flowing out of the strongly acidic cation exchange resin packed column to flow directly through the strongly basic anion exchange resin packed column A filled with gel-type quaternary ammonium base anion exchange resin under ultrasonic oscillation. The volume space velocity when flowing through the packed column is 1 hour. -1 , the temperature in the filling column is 10°C, the pressure in the filling column is 1MPa, the ultrasonic frequency is 40KHz, and the ultrasonic power per unit volume of the filling column is 50W / L. 3-Chloro-1,2-propylene glycol undergoes a dehydrochlorination ring-closing reaction, and the resulting reaction liquid containing glycidol is dehydrated under reduced pressure at 40°C and a vacuum degree of 92KPa to 95KPa to obtain the product glycidol. The yield of glycidol is 95% based on the amount of epichlorohydrin.

[0049] (3) When the activity of the strong basic anion exchange resin decreases and the yield of propylene oxide decreases to 70% of the initial yield, close the raw material inlet valve and product outlet valve of the strong basic anion exchange resin column A, and open the raw material inlet valve and product outlet valve of the strong basic anion exchange resin column B at the same time, switch the anion exchange resin column, and allow the reaction liquid flowing out of the cation exchange resin column to flow through the strong basic anion exchange resin column B under the same conditions. Open the regeneration water inlet valve and regeneration water outlet valve, use a 1 mol / L sodium hydroxide aqueous solution at a volume space velocity of 1 hour -1 , under the conditions of temperature of 25°C and pressure of 0.1MPa, the strong basic anion exchange resin column A of the gel-type quaternary ammonium base anion exchange resin used in the reaction of 3-chloro-1,2-propylene glycol dehydrochlorination ring-closing to generate glycidol can be flowed through, so that the gel-type quaternary ammonium base anion exchange resin used can be regenerated, and the regenerated gel-type quaternary ammonium base anion exchange resin can be reused in the reaction of 3-chloro-1,2-propylene glycol dehydrochlorination ring-closing to generate glycidol. Two or more anion exchange resin columns are alternately used and regenerated to continuously prepare glycidol. Example 5

[0050] A method for continuously preparing glycidol, using epichlorohydrin and water as raw materials, comprises the following steps:

[0051] (1) A mixture of epichlorohydrin and water in a mass ratio of 1:8 flows through a column filled with a strong acid cation exchange resin containing a gel-type sulfonic acid cation exchange resin. The volumetric space velocity of the mixture flowing through the column filled with the strong acid cation exchange resin is 0.8 h -1 , the temperature in the filling column is 50°C, the pressure in the filling column is 0.1MPa, epichlorohydrin undergoes hydrolysis and ring-opening reaction to generate 3-chloro-1,2-propylene glycol,

[0052] (2) Open the raw material inlet valve and product outlet valve of the strongly basic anion exchange resin packed column A, and allow the reaction liquid flowing out of the strongly acidic cation exchange resin packed column to flow directly through the strongly basic anion exchange resin packed column A filled with gel-type quaternary ammonium base anion exchange resin under ultrasonic oscillation. The volume space velocity when flowing through the packed column is 5 hours. -1 , the temperature in the filling column is 50°C, the pressure in the filling column is normal pressure, the ultrasonic frequency is 40KHz, and the ultrasonic power per unit volume of the filling column is 10W / L. 3-Chloro-1,2-propanediol undergoes a dehydrochlorination ring-closing reaction, and the resulting reaction liquid containing glycidol is dehydrated under reduced pressure at 40°C and a vacuum degree of 92KPa to 95KPa to obtain the product glycidol. The yield of glycidol is 75% based on the amount of epichlorohydrin.

[0053] (3) When the activity of the strong basic anion exchange resin decreases and the yield of propylene oxide decreases to 75% of the initial yield, close the raw material inlet valve and product outlet valve of the strong basic anion exchange resin column A, and open the raw material inlet valve and product outlet valve of the strong basic anion exchange resin column B at the same time, switch the anion exchange resin column, and allow the reaction liquid flowing out of the cation exchange resin column to flow through the strong basic anion exchange resin column B under the same conditions. Open the regeneration water inlet valve and regeneration water outlet valve, use a 1 mol / L sodium hydroxide aqueous solution at a volume space velocity of 1 hour -1 , under the conditions of temperature of 25°C and pressure of 0.1MPa, the strong basic anion exchange resin column A of the gel-type quaternary ammonium base anion exchange resin used in the reaction of 3-chloro-1,2-propylene glycol dehydrochlorination ring-closing to generate glycidol can be flowed through, so that the gel-type quaternary ammonium base anion exchange resin used can be regenerated, and the regenerated gel-type quaternary ammonium base anion exchange resin can be reused in the reaction of 3-chloro-1,2-propylene glycol dehydrochlorination ring-closing to generate glycidol. Two or more anion exchange resin columns are alternately used and regenerated to continuously prepare glycidol. Example 6

[0054] A method for continuously preparing glycidol, using epichlorohydrin and water as raw materials, comprises the following steps:

[0055] (1) A mixture of epichlorohydrin and water in a mass ratio of 1:8 flows through a column filled with a strong acid cation exchange resin containing a gel-type sulfonic acid cation exchange resin. The volumetric space velocity of the mixture flowing through the column filled with the strong acid cation exchange resin is 0.8 h -1 , the temperature in the filling column is 50°C, the pressure in the filling column is 0.1MPa, and epichlorohydrin undergoes hydrolysis and ring-opening reaction to generate 3-chloro-1,2-propylene glycol;

[0056] (2) Open the raw material inlet valve and product outlet valve of the strong basic anion exchange resin packed column A, so that the reaction liquid flowing out of the strong acid cation exchange resin packed column can flow directly through the strong basic anion exchange resin packed column A filled with porous quaternary ammonium base anion exchange resin under ultrasonic oscillation. The volume space velocity when flowing through the packed column is 0.5 h -1 , the temperature in the filling column is 10°C, the pressure in the filling column is 1MPa, the ultrasonic frequency is 40KHz, and the ultrasonic power per unit volume of the filling column is 50W / L. The reaction liquid containing glycidol obtained by the dehydrochlorination ring-closing reaction of 3-chloro-1,2-propylene glycol is dehydrated under reduced pressure at 40°C and a vacuum degree of 92KPa to 95KPa to obtain the product glycidol. The yield of glycidol is 83% based on the amount of epichlorohydrin.

[0057] (3) When the activity of the strong basic anion exchange resin decreases and the yield of propylene oxide decreases to 73% of the initial yield, close the raw material inlet valve and product outlet valve of the strong basic anion exchange resin column A, and open the raw material inlet valve and product outlet valve of the strong basic anion exchange resin column B at the same time, switch the anion exchange resin column, and allow the reaction liquid flowing out of the cation exchange resin column to flow through the strong basic anion exchange resin column B under the same conditions. Open the regeneration water inlet valve and regeneration water outlet valve, use a 1 mol / L sodium hydroxide aqueous solution at a volume space velocity of 1 hour -1 , under the conditions of temperature of 25°C and pressure of 0.1MPa, the strong basic anion exchange resin column A of the gel-type quaternary ammonium base anion exchange resin used in the reaction of 3-chloro-1,2-propylene glycol dehydrochlorination ring-closing to generate glycidol can be flowed through, so that the gel-type quaternary ammonium base anion exchange resin used can be regenerated, and the regenerated gel-type quaternary ammonium base anion exchange resin can be reused in the reaction of 3-chloro-1,2-propylene glycol dehydrochlorination ring-closing to generate glycidol. Two or more anion exchange resin columns are alternately used and regenerated to continuously prepare glycidol. Example 7

[0058] A method for continuously preparing glycidol, using epichlorohydrin and water as raw materials, comprises the following steps:

[0059] (1) A mixture of epichlorohydrin and water in a mass ratio of 1:8 flows through a column filled with a strong acid cation exchange resin containing a macroporous sulfonic acid cation exchange resin. The volumetric space velocity of the mixture flowing through the column is 0.8 h -1 , the temperature in the filling column is 50°C, the pressure in the filling column is 0.1MPa, and epichlorohydrin undergoes hydrolysis and ring-opening reaction to generate 3-chloro-1,2-propylene glycol;

[0060] (2) Open the raw material inlet valve and product outlet valve of the strong basic anion exchange resin packed column A, so that the reaction liquid flowing out of the strong acid cation exchange resin packed column can flow directly through the strong basic anion exchange resin packed column A filled with porous quaternary ammonium base anion exchange resin under ultrasonic oscillation. The volume space velocity when flowing through the packed column is 2 hours. -1 , the temperature in the filling column is 30°C, the pressure in the filling column is 0.1MPa, the ultrasonic frequency is 40KHz, and the ultrasonic power per unit volume of the filling column is 50W / L. 3-Chloro-1,2-propanediol undergoes a dehydrochlorination ring-closing reaction, and the resulting reaction liquid containing glycidol is dehydrated under reduced pressure at 40°C and a vacuum degree of 92KPa to 95KPa to obtain the product glycidol. The yield of glycidol is 76% based on the amount of epichlorohydrin.

[0061] (3) When the activity of the strong basic anion exchange resin decreases and the yield of propylene oxide decreases to less than 80% of the initial yield, close the raw material inlet valve and product outlet valve of the strong basic anion exchange resin column A, and open the raw material inlet valve and product outlet valve of the strong basic anion exchange resin column B at the same time, switch the anion exchange resin column, and allow the reaction liquid flowing out of the cation exchange resin column to flow through the strong basic anion exchange resin column B under the same conditions. Open the regeneration water inlet valve and regeneration water outlet valve, use a 1 mol / L sodium hydroxide aqueous solution at a volume space velocity of 1 hour -1 , under the conditions of temperature of 25°C and pressure of 0.1MPa, the strong basic anion exchange resin column A of the gel-type quaternary ammonium base anion exchange resin used in the reaction of 3-chloro-1,2-propylene glycol dehydrochlorination ring-closing to generate glycidol can be flowed through, so that the gel-type quaternary ammonium base anion exchange resin used can be regenerated, and the regenerated gel-type quaternary ammonium base anion exchange resin can be reused in the reaction of 3-chloro-1,2-propylene glycol dehydrochlorination ring-closing to generate glycidol. Two or more anion exchange resin columns are alternately used and regenerated to continuously prepare glycidol. Example 8

[0062] A method for continuously preparing glycidol, using epichlorohydrin and water as raw materials, comprises the following steps:

[0063] (1) A mixture of epichlorohydrin and water in a mass ratio of 1:10 flows through a column filled with a strong acid cation exchange resin containing a macroporous sulfonic acid cation exchange resin. The volumetric space velocity of the mixture flowing through the column is 0.5 h -1 , the temperature in the filling column is 40°C, the pressure in the filling column is 0.1MPa, and epichlorohydrin undergoes hydrolysis and ring-opening reaction to generate 3-chloro-1,2-propylene glycol;

[0064] (2) Open the raw material inlet valve and product outlet valve of the strong basic anion exchange resin packed column A, so that the reaction liquid flowing out of the strong acid cation exchange resin packed column can flow directly through the strong basic anion exchange resin packed column A filled with porous quaternary ammonium base anion exchange resin under ultrasonic oscillation. The volume space velocity when flowing through the packed column is 1 hour. -1 , the temperature in the filling column is 25°C, the pressure in the filling column is 0.1MPa, the ultrasonic frequency is 40KHz, and the ultrasonic power per unit volume of the filling column is 50W / L. 3-Chloro-1,2-propylene glycol undergoes a dehydrochlorination ring-closing reaction, and the resulting reaction liquid containing glycidol is dehydrated under reduced pressure at 40°C and a vacuum degree of 92KPa to 95KPa to obtain the product glycidol. The yield of glycidol is 86% based on the amount of epichlorohydrin.

[0065] (3) When the activity of the strong basic anion exchange resin decreases and the yield of propylene oxide decreases to 80% of the initial yield, close the raw material inlet valve and product outlet valve of the strong basic anion exchange resin column A, and open the raw material inlet valve and product outlet valve of the strong basic anion exchange resin column B at the same time, switch the anion exchange resin column, and allow the reaction liquid flowing out of the cation exchange resin column to flow through the strong basic anion exchange resin column B under the same conditions. Open the regeneration water inlet valve and regeneration water outlet valve, use a 1 mol / L sodium hydroxide aqueous solution at a volume space velocity of 1 hour -1 , under the conditions of temperature of 25°C and pressure of 0.1MPa, the strong basic anion exchange resin column A of the gel-type quaternary ammonium base anion exchange resin used in the reaction of 3-chloro-1,2-propylene glycol dehydrochlorination ring-closing to generate glycidol can be flowed through, so that the gel-type quaternary ammonium base anion exchange resin used can be regenerated, and the regenerated gel-type quaternary ammonium base anion exchange resin can be reused in the reaction of 3-chloro-1,2-propylene glycol dehydrochlorination ring-closing to generate glycidol. Two or more anion exchange resin columns are alternately used and regenerated to continuously prepare glycidol. Comparative Example 1

[0066] The preparation of glycidol using epichlorohydrin and water as raw materials comprises the following steps:

[0067] (1) A mixture of epichlorohydrin and water in a mass ratio of 1:8 flows through a column filled with a strong acid cation exchange resin containing a gel-type sulfonic acid cation exchange resin. The volumetric space velocity of the mixture flowing through the column filled with the strong acid cation exchange resin is 0.8 h -1 , the temperature in the filling column is 50°C, the pressure in the filling column is 0.1MPa, and epichlorohydrin undergoes hydrolysis and ring-opening reaction to generate 3-chloro-1,2-propylene glycol;

[0068] (2) The reaction solution flowing out of the strongly acidic cation exchange resin column further flows through a column filled with a gel-type quaternary ammonium base anion exchange resin. The volume space velocity when flowing through the column is 1 hour. -1 The temperature in the filling column is 10°C, the pressure in the filling column is 1 MPa, and the obtained reaction liquid is decompressed and dehydrated at 40°C and a vacuum degree of 92 KPa to 95 KPa to obtain a product. The yield of glycidol in the product is 8.1% based on the amount of epichlorohydrin. Comparative Example 2

[0069] The preparation of glycidol using epichlorohydrin and water as raw materials comprises the following steps:

[0070] (1) A mixture of epichlorohydrin and water in a mass ratio of 1:8 flows through a column filled with a strong acid cation exchange resin containing a gel-type sulfonic acid cation exchange resin. The volumetric space velocity of the mixture flowing through the column filled with the strong acid cation exchange resin is 0.8 h -1 , the temperature in the filling column is 50°C, the pressure in the filling column is 0.1MPa, and epichlorohydrin undergoes hydrolysis and ring-opening reaction to generate 3-chloro-1,2-propylene glycol;

[0071] (2) The reaction solution flowing out of the strongly acidic cation exchange resin column further flows through a column filled with a porous quaternary ammonium base anion exchange resin at a volume space velocity of 2 hours. -1 The temperature in the filling column is 30°C, the pressure in the filling column is 0.1MPa, and the obtained reaction liquid is decompressed and dehydrated at 40°C and a vacuum degree of 92KPa to 95KPa to obtain a product. The yield of glycidol in the product is 6.5% based on the amount of epichlorohydrin.

[0072] It can be seen from Comparative Examples 1 and 2 that the reaction liquid flowing out of the cation exchange resin packed column of the present invention can significantly improve the yield of the product glycidol by directly flowing it through a packed column filled with a strong basic anion exchange resin under ultrasonic oscillation without any treatment. Comparative Example 3

[0073] The preparation of glycidol using epichlorohydrin and water as raw materials comprises the following steps:

[0074] (1) A mixture of epichlorohydrin and water in a mass ratio of 1:8 flows through a column filled with a strong acid cation exchange resin containing a gel-type sulfonic acid cation exchange resin. The volumetric space velocity of the mixture flowing through the column filled with the strong acid cation exchange resin is 0.8 h -1 , the temperature in the filling column is 50°C, the pressure in the filling column is 0.1MPa, and epichlorohydrin undergoes hydrolysis and ring-opening reaction to generate 3-chloro-1,2-propylene glycol;

[0075] (2) Take 60 ml of porous quaternary ammonium base anion exchange resin and put it into a 200 ml flask. Add 30 g of the reaction solution flowing out of the strong acid cation exchange resin column into the flask under stirring. Stir and react at 30°C for 30 minutes. Use filter paper to separate the solid-liquid mixture consisting of the anion exchange resin and the reaction solution. Decompress and dehydrate the reaction solution at 40°C and a vacuum degree of 92 KPa to 95 KPa to obtain a product. The yield of glycidol in the product is 12.7% based on the amount of epichlorohydrin. Comparative Example 4

[0076] The preparation of glycidol using epichlorohydrin and water as raw materials comprises the following steps:

[0077] (1) A mixture of epichlorohydrin and water in a mass ratio of 1:8 flows through a column filled with a strong acid cation exchange resin containing a gel-type sulfonic acid cation exchange resin. The volumetric space velocity of the mixture flowing through the column filled with the strong acid cation exchange resin is 0.8 h -1 , the temperature in the filling column is 50°C, the pressure in the filling column is 0.1MPa, and epichlorohydrin undergoes hydrolysis and ring-opening reaction to generate 3-chloro-1,2-propylene glycol;

[0078] (2) Take 60 ml of gel-type quaternary ammonium base anion exchange resin and put it into a 200 ml flask. 30 g of the reaction solution flowing out of the strong acid cation exchange resin column is added dropwise into the flask under stirring. The mixture is stirred and reacted at 25°C for 90 minutes. The solid-liquid mixture consisting of the anion exchange resin and the reaction solution is separated into solid and liquid using filter paper. The obtained reaction solution is dehydrated under reduced pressure at 40°C and a vacuum degree of 92 KPa to 95 KPa to obtain a product. The yield of glycidol in the product is 15.8% based on the amount of epichlorohydrin.

[0079] It can be seen from Comparative Examples 3 and 4 that the reaction solution flowing out of the cation exchange resin packed column of the present invention is reacted with a strong basic anion exchange resin in a stirred reactor under stirring conditions without any treatment, and the yield of the product glycidol is not high. Since the solid-liquid mixture composed of the anion exchange resin and the reaction solution needs to be separated into solid and liquid after the reaction, it is not conducive to continuous operation, and there is an operational safety risk due to the high toxicity of the intermediate product.

[0080] Although the embodiments of the present invention have been described above, it will be apparent to those skilled in the art that modifications and substitutions made without departing from the principles and spirit of the present invention are intended to fall within the scope of protection claimed by the present invention.

Claims

1. A method for continuously preparing glycidol, Features: Using epichlorohydrin and water as raw materials, the method comprises the following steps: (1) Epichlorohydrin and water are mixed evenly and flowed through a column filled with a strong acidic cation exchange resin to cause epichlorohydrin to undergo a hydrolysis ring-opening reaction to generate 3-chloro-1,2-propylene glycol; (2) The reaction liquid flowing out of the cation exchange resin packed column directly flows through the packed column filled with a strong alkaline anion exchange resin under ultrasonic oscillation, so that 3-chloro-1,2-propanediol undergoes a dehydrochlorination ring-closing reaction to generate glycidol, and the resulting glycidol-containing reaction liquid is dehydrated under reduced pressure to obtain glycidol; (3) When the activity of the strong basic anion exchange resin decreases and the yield of glycidol decreases to less than 80% of the initial yield, the strong basic anion exchange resin used in step (2) is regenerated, and the regenerated strong basic anion exchange resin can be reused in step (2), and there are two or more anion exchange resin filling columns, which are used and regenerated alternately to continuously prepare glycidol; The strongly acidic cation exchange resin is a gel-type sulfonic acid cation exchange resin or a macroporous sulfonic acid cation exchange resin; the strongly basic anion exchange resin is a gel-type quaternary ammonium base anion exchange resin or a porous quaternary ammonium base anion exchange resin.

2. A method for continuously preparing glycidol according to claim 1, Features: In the step (1), when epichlorohydrin and water flow through a packed column filled with a strong acidic cation exchange resin, the volume space velocity is 0.2 to 2 h-1, the temperature in the packed column is 20°C to 80°C, and the pressure in the packed column is normal pressure to 1 MPa.

3. A method for continuously preparing glycidol according to claim 1, Features: In the step (2), the frequency of the ultrasound is 20 kHz to 40 kHz, and the ultrasound power per unit volume of the filling column is 10 watts / liter to 100 watts / liter.

4. A method for continuously preparing glycidol according to claim 1, Features: In the step (2), when the reaction liquid flowing out of the cation exchange resin packed column flows through the packed column filled with strong basic anion exchange resin, the volume space velocity is 0.5 to 5 h-1, the temperature in the packed column is 10°C to 50°C, and the pressure in the packed column is normal pressure to 1 MPa.

5. A method for continuously preparing glycidol according to claim 1, Features: In the step (3), the regeneration treatment uses a sodium hydroxide solution to regenerate the strongly basic anion exchange resin used in the step (2).

6. A method for continuously preparing glycidol according to claim 5, Features: The concentration of the sodium hydroxide solution is 0.5 mol / L to 2 mol / L, the regeneration temperature is 10°C to 40°C, the regeneration pressure is normal pressure to 1 MPa, and the volume space velocity of the sodium hydroxide solution during regeneration is 0.5 to 5 h-1.

7. A method for continuously preparing glycidol according to claim 1, Features: The mass ratio of epichlorohydrin to water is 1:2 to 1:

20.

8. A method for continuously preparing glycidol according to any one of claims 1 to 7, Features: The device for continuously preparing glycidol comprises a strongly acidic cation exchange resin packed column, a plurality of strongly basic anion exchange resin packed columns and a decompression dehydration device, wherein the strongly basic anion exchange resin packed column is connected to an ultrasonic generator, the transducer of the ultrasonic generator is arranged inside the strongly basic anion exchange resin packed column, the top of the strongly basic anion exchange resin packed column is provided with a raw material liquid inlet valve and a regeneration water outlet valve, the bottom of the strongly basic anion exchange resin packed column is provided with a product liquid outlet valve and a regeneration water inlet valve, the raw material liquid inlet valve is connected to the bottom of the strongly acidic cation exchange resin packed column through a pipeline, the product liquid outlet valve is connected to the decompression dehydration device through a pipeline, the regeneration water inlet valve is connected to a water supply device through a pipeline, and the regeneration water outlet valve is connected to a wastewater collection device through a pipeline.

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