CN117209354B - Method for producing ethylene glycol from ionic liquid ethylene carbonate waste - Google Patents
Method for producing ethylene glycol from ionic liquid ethylene carbonate waste Download PDFInfo
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- CN117209354B CN117209354B CN202311214292.4A CN202311214292A CN117209354B CN 117209354 B CN117209354 B CN 117209354B CN 202311214292 A CN202311214292 A CN 202311214292A CN 117209354 B CN117209354 B CN 117209354B
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- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 title claims abstract description 352
- 239000002699 waste material Substances 0.000 title claims abstract description 76
- 239000002608 ionic liquid Substances 0.000 title claims abstract description 51
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical group C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 title claims abstract description 33
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 22
- 238000006243 chemical reaction Methods 0.000 claims abstract description 137
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 96
- 239000000047 product Substances 0.000 claims abstract description 70
- 239000003054 catalyst Substances 0.000 claims abstract description 63
- 239000000463 material Substances 0.000 claims abstract description 43
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 claims abstract description 27
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 claims description 59
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 48
- 239000002994 raw material Substances 0.000 claims description 39
- 239000001569 carbon dioxide Substances 0.000 claims description 24
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 24
- 238000003756 stirring Methods 0.000 claims description 24
- 239000007806 chemical reaction intermediate Substances 0.000 claims description 21
- 238000010438 heat treatment Methods 0.000 claims description 17
- 238000010992 reflux Methods 0.000 claims description 16
- 239000011521 glass Substances 0.000 claims description 12
- 239000013067 intermediate product Substances 0.000 claims description 12
- 238000012856 packing Methods 0.000 claims description 12
- 239000007864 aqueous solution Substances 0.000 claims description 8
- 238000004064 recycling Methods 0.000 claims description 7
- 238000001816 cooling Methods 0.000 claims description 6
- 239000007788 liquid Substances 0.000 claims description 6
- 230000035484 reaction time Effects 0.000 claims description 6
- 238000007670 refining Methods 0.000 claims description 6
- 238000003860 storage Methods 0.000 claims description 6
- 230000001502 supplementing effect Effects 0.000 claims description 6
- 238000005303 weighing Methods 0.000 claims description 6
- 238000004090 dissolution Methods 0.000 claims description 2
- IJRHDFLHUATAOS-DPMBMXLASA-M sodium ricinoleate Chemical compound [Na+].CCCCCC[C@@H](O)C\C=C/CCCCCCCC([O-])=O IJRHDFLHUATAOS-DPMBMXLASA-M 0.000 claims 1
- 150000003839 salts Chemical class 0.000 abstract description 7
- 239000012043 crude product Substances 0.000 abstract 2
- 238000010586 diagram Methods 0.000 description 45
- 238000000034 method Methods 0.000 description 14
- 230000000694 effects Effects 0.000 description 8
- 239000000945 filler Substances 0.000 description 8
- 238000001704 evaporation Methods 0.000 description 6
- 238000006703 hydration reaction Methods 0.000 description 6
- 230000036571 hydration Effects 0.000 description 5
- 238000006460 hydrolysis reaction Methods 0.000 description 5
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 description 4
- 238000009835 boiling Methods 0.000 description 4
- 230000008020 evaporation Effects 0.000 description 4
- 239000006260 foam Substances 0.000 description 4
- 230000007062 hydrolysis Effects 0.000 description 4
- 238000000926 separation method Methods 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 239000003513 alkali Substances 0.000 description 3
- 238000005265 energy consumption Methods 0.000 description 3
- 238000001914 filtration Methods 0.000 description 2
- 239000000543 intermediate Substances 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 239000002920 hazardous waste Substances 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
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- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention is applicable to the field of application of ethylene carbonate waste, and provides a method for producing ethylene glycol by using ionic liquid ethylene carbonate waste, which comprises the following steps: the mass ratio of desalted water, reaction material ionic liquid ethylene carbonate waste and catalyst is controlled at 500-1000:100-500:1-5, the temperature is controlled at 120-160 ℃, the pressure is normal pressure, the reaction is carried out in a reaction kettle for 3-6 hours to obtain a crude product of ethylene glycol, and then the crude product of ethylene glycol is refined by an ethylene glycol rectifying tower to obtain the ethylene glycol product. The invention can recycle the ethylene carbonate in the ionic liquid catalyst waste to obtain the ethylene glycol product with high added value, and solves the problem that a large amount of salt in the waste blocks equipment and pipelines.
Description
Technical Field
The invention belongs to the field of application of ethylene carbonate waste, and particularly relates to a method for producing ethylene glycol from ionic liquid ethylene carbonate waste.
Background
The ethylene carbonate of one of the existing electrolytic solutions is produced by adopting an ionic liquid catalytic process, and the process can generate a part of catalyst waste containing low-concentration ethylene carbonate, and the waste has high viscosity and is generally used as hazardous waste or incineration treatment. The waste contains 20-70% of ethylene carbonate, so that the recycling value is high.
The ethylene glycol production method is divided into two processes of ethylene oxide direct pressurized hydration and ethylene oxide indirect hydration. The direct hydration method is to carry out hydration reaction of ethylene oxide and water in a tubular reactor in a certain molar ratio to generate ethylene glycol, the concentration of the product ethylene glycol is low, and a large amount of water is required to be evaporated for later purification, so that the process flow is long and the energy consumption is high. The working principle of the indirect hydration method is as follows: ethylene oxide and carbon dioxide generate ethylene carbonate under the action of an ionic liquid catalyst, and ethylene carbonate and water generate hydrolysis reaction under the action of an alkaline catalyst to generate ethylene glycol and carbon dioxide.
The present invention adopts indirect hydration method, uses organic alkali catalyst-sodium ricinoleate, its molecular formula contains hydroxyl group, carboxyl group and long-chain alkyl group, and because of having hydrophilic and lipophilic groups, it is completely mutually soluble in water, ionic liquid EC waste material and product glycol. Similar to the invention, the catalyst of flake alkali (sodium hydroxide and potassium hydroxide) reacts with the dead catalyst of ionic liquid, and the product after the reaction contains glycol, water and unreacted flake alkali and carbonate, which are not dissolved in glycol and can be gradually separated out in the process of dehydration of glycol, thus blocking equipment and pipelines and affecting the stable operation of the device.
Therefore, in view of the above-mentioned current situation, there is an urgent need to develop a method for producing ethylene glycol by using the waste of ethylene carbonate in ionic liquid catalyst, which can recycle the ethylene carbonate in the waste of ionic liquid catalyst to obtain ethylene glycol product with high added value, and meanwhile, solve the problem that the waste contains a large amount of salt to block equipment and pipelines, so as to overcome the defects in the current practical application.
Disclosure of Invention
The embodiment of the invention aims to provide a method for producing ethylene glycol by using ionic liquid ethylene carbonate waste, which aims to solve the problems that ethylene carbonate in ionic liquid catalyst waste is recovered and a large amount of salt is contained in the waste to block equipment and pipelines.
The embodiment of the invention is realized in such a way that the method for producing the ethylene glycol by using the ionic liquid ethylene carbonate waste comprises the following steps:
Step 1, preparing a catalyst
Calculating and weighing the dosage of each batch of catalyst, and putting the catalyst into a reaction kettle; injecting desalted water into a desalted water raw material tank, and adding desalted water into the reaction kettle through a reaction kettle water supplementing line by the desalted water raw material tank; then, a stirrer of the reaction kettle is started to mix water and the catalyst to form an aqueous solution of the catalyst for later use;
Step 2, raw material input
Adding ionic liquid ethylene carbonate waste into a reaction kettle, wherein the mass ratio of desalted water to the ionic liquid ethylene carbonate waste to the catalyst is 500-1000:100-500:1-5;
The stirrer of the reaction kettle continuously stirs, the temperature is raised by utilizing heat conduction oil, the oil inlet temperature of the heat conduction oil is 230 ℃, the oil return temperature of the heat conduction oil is 200 ℃, and the temperature in the reaction kettle is controlled to be not more than 100 ℃;
The stirrer continues stirring until the materials are fully mixed;
Step 3, reaction stage
Starting heat conducting oil to heat, continuously stirring in the heating process, controlling the temperature in the reaction kettle to 120-160 ℃ and controlling the pressure to be normal pressure;
In the reaction process, ethylene carbonate is hydrolyzed to generate ethylene glycol and carbon dioxide, carbon dioxide gas is discharged to a desalted water raw material tank through a reaction kettle emptying line, and the carbon dioxide gas is discharged from a desalted water raw material tank top emptying line;
Step 4, constant temperature stage
Keeping the reaction kettle at the constant temperature of 120-160 ℃, continuously stirring, reacting at the constant temperature for 3-6 hours, reducing or prolonging the reaction time according to the amount of bubbles generated in the reaction, stopping heating after no bubbles are generated in the reaction, cooling the reaction kettle to 50-80 ℃, conveying a crude ethylene glycol product into a reaction intermediate product tank for temporary storage through a reaction intermediate product pump, wherein the conversion rate of ethylene carbonate is 80-99%, and the selectivity of ethylene glycol is 60-90%;
Step 5, refining the product
The crude ethylene glycol product is conveyed to an ethylene glycol rectifying tower by a bottom pump of a reaction intermediate product, tower top materials enter a reflux tank through a tower top condenser, a part of materials at the outlet of the bottom pump of the reflux tank forcedly reflux to the ethylene glycol rectifying tower, a part of materials return to a desalted water raw material tank, and a part of materials return to a waste material tank; the material in the glycol rectifying tower kettle is pumped to a waste tank through a glycol rectifying tower kettle, waste is conveyed to a waste tank area through a waste tank bottom pump, a glycol product is extracted from the tower side line of the glycol rectifying tower and enters a glycol intermediate product tank, and after being checked to be qualified, the glycol product is pumped to a glycol product tank area through a glycol intermediate product, wherein the glycol content in the product is more than or equal to 99 percent.
In the further technical scheme, in the step 1, the desalted water in a desalted water raw material tank is maintained at 30% -70% of liquid level; and observing the dissolution state of the catalyst through a sight glass on the reaction kettle, and forming an aqueous solution of the catalyst for later use after the catalyst is completely dissolved.
In the step 2, whether the materials are fully mixed is judged by observing the reaction kettle sight glass.
In the further technical scheme, in the step 3, a cold water circulation is further arranged on the emptying line of the reaction kettle, and the water vapor is condensed and then returned to the reaction kettle for recycling.
In the step 5, the glycol rectifying tower consists of CY700 plate ripple structured packing and trays, the rectifying section consists of two sections of packing, the number of the trays is 10-50, the stripping section is a tray tower, and the number of the trays is 20-50.
In the further technical scheme, in the step 5, the tower top condenser is cooled by 28 ℃ circulating incoming water and 32 ℃ circulating return water.
In a further technical scheme, in the step 5, a reboiler is further arranged at the bottom of the ethylene glycol rectifying tower for heating, and heat conduction oil is used as a heat source.
According to the method for producing ethylene glycol by using the ionic liquid ethylene carbonate waste, provided by the embodiment of the invention, ethylene carbonate in the ionic liquid waste is recovered and converted into ethylene glycol with high added value, and the conversion rate of ethylene carbonate and the selectivity of ethylene glycol are both high, so that the method has the advantages of high conversion rate and high selectivity; compared with other existing catalyst treatment processes, the method reduces the generation of salt insoluble substances, correspondingly reduces treatment equipment of the salt insoluble substances, such as filtering and evaporating equipment, and saves equipment cost, operation cost and energy consumption cost.
Drawings
Fig. 1 is a schematic diagram of the principle of ethylene glycol production from the ionic liquid ethylene carbonate waste provided in the embodiment of the invention.
In the figure: 1-desalted water raw material tank, 2-reaction kettle, 3-reaction intermediate pump, 4-reaction intermediate tank, 5-reaction intermediate tank bottom pump, 6-glycol rectifying tower, 7-tower top condenser, 8-reflux tank, 9-reflux tank bottom pump, 10-reboiler, 11-glycol rectifying tower bottom pump, 12-waste tank, 13-waste tank bottom pump, 14-glycol intermediate tank, 15-glycol intermediate pump.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
Specific implementations of the invention are described in detail below in connection with specific embodiments.
As shown in fig. 1, a method for producing ethylene glycol from ionic liquid ethylene carbonate waste according to an embodiment of the present invention includes the following steps:
Step 1, preparing a catalyst
Calculating and weighing the dosage of each batch of catalyst, and putting the catalyst into a reaction kettle 2; injecting desalted water (S1 in the corresponding diagram) into a desalted water raw material tank 1, and maintaining the liquid level at 30% -70%; the desalted water raw material tank 1 adds desalted water with a certain mass into the reaction kettle 2 through a reaction kettle water supplementing line (S6 in the corresponding diagram); then, a stirrer of the reaction kettle 2 is started to mix water and the catalyst, the dissolved state of the catalyst is observed through a sight glass on the reaction kettle 2, and after the catalyst is completely dissolved, an aqueous solution of the catalyst is formed for later use;
Step 2, raw material input
Adding ionic liquid ethylene carbonate waste material (corresponding to S2 in the figure) in a corresponding proportion into a reaction kettle 2, wherein the mass ratio of desalted water to the ionic liquid ethylene carbonate waste material to the catalyst is 500-1000:100-500:1-5; the stirrer of the reaction kettle 2 continuously stirs, the temperature is raised by utilizing heat conduction oil, the oil inlet temperature of the heat conduction oil is 230 ℃, the oil return temperature of the heat conduction oil is 200 ℃ (oil inlet and oil return respectively correspond to S3 and S4 in the drawing), and in order to prevent large water evaporation loss, the temperature in the reaction kettle 2 is controlled to be not more than 100 ℃; the stirrer continues stirring, and the sight glass of the reaction kettle 2 is observed until the materials are fully mixed;
Step 3, reaction stage
Starting heat conduction oil to heat, controlling the temperature in the reaction kettle 2 to 120-160 ℃, keeping the pressure at normal pressure, and continuously stirring in the heating process; in the reaction process, ethylene glycol and carbon dioxide are generated by hydrolysis of ethylene carbonate, carbon dioxide gas is discharged to a desalted water raw material tank 1 through a reaction kettle emptying line (corresponding to S7 in the figure), carbon dioxide gas is discharged from a top emptying line (corresponding to S5 in the figure) of the desalted water raw material tank 1, cold water circulation is further arranged on the reaction kettle emptying line, and water vapor is condensed and then returned to a reaction kettle 2 for recycling; in order to avoid the reaction to be too severe, the generated carbon dioxide gas entrains materials to form a large amount of foam, and the reaction temperature rise speed and the rotation speed of a stirrer motor are strictly controlled;
Step 4, constant temperature stage
Keeping the reaction kettle 2 at the constant temperature of 120-160 ℃, continuously stirring, reacting for 3-6 hours at the constant temperature, and properly reducing or prolonging the reaction time according to the amount of bubbles generated by the reaction; after no bubble is generated basically in the reaction, stopping heating, cooling the reaction kettle 2 to 50-80 ℃, conveying a crude ethylene glycol product (S8 in the corresponding diagram) into the reaction intermediate product tank 4 through the reaction intermediate product pump 3 for temporary storage, wherein the conversion rate of ethylene carbonate is 80-99%, and the selectivity of ethylene glycol is 60-90%;
Step 5, refining the product
The crude ethylene glycol product (S9 in the corresponding diagram) is conveyed into an ethylene glycol rectifying tower 6 by a reaction intermediate product tank bottom pump 5, the ethylene glycol rectifying tower 6 is composed of CY700 plate ripple structured packing and trays, a rectifying section is composed of two sections of packing, the theoretical plate number is 10-50 layers, a stripping section is a tray tower, and the theoretical plate number is 20-50 layers. The purpose of this design is because ionic liquid boiling point is high, and viscosity is big, and the stripping section sets up the tower tray and can prevent ionic liquid jam, and because the separation effect of filler is good, sets up the filler in the rectifying section and can improve the refined effect of product. The tower top material (S11 in the corresponding diagram) enters a reflux tank 8 through a tower top condenser 7, the tower top condenser 7 is cooled by 28 ℃ circulating incoming water (S14 in the corresponding diagram) and 32 ℃ circulating backwater (S13 in the corresponding diagram), a part of the material at the outlet of a reflux tank bottom pump 9 is forcedly refluxed to an ethylene glycol rectifying tower 6 (S12 in the corresponding diagram), a part of the material is returned to a desalted water raw material tank 1 (S10 in the corresponding diagram), and a part of the material is returned to a waste material tank 12 (S16 in the corresponding diagram); the tower kettle of the glycol rectifying tower 6 is provided with a reboiler 10 for heating, and heat conduction oil is used as a heat source (a connecting line S17, an oil inlet S18 and an oil return S19 in the corresponding diagram); the material in the tank of the glycol rectifying tower 6 is sent to a waste tank 12 (corresponding to S20 in the figure) through a tank bottom pump 13, the waste is sent to a waste tank area (corresponding to S22 in the figure), the glycol product is extracted from the side line of the glycol rectifying tower 6 (corresponding to S15 in the figure) and enters a glycol intermediate product tank 14, after being checked, the glycol product is sent to the glycol product tank area (corresponding to S23 in the figure) through a glycol intermediate product pump 15, and the glycol content in the product is more than or equal to 99%.
Example 1
As shown in fig. 1, a method for producing ethylene glycol from ionic liquid ethylene carbonate waste according to an embodiment of the present invention includes the following steps:
Step 1, preparing a catalyst
Calculating and weighing the dosage of each batch of catalyst, and putting the catalyst into a reaction kettle 2; injecting desalted water (S1 in the corresponding diagram) into the desalted water raw material tank 1, and maintaining the desalted water at a 30% liquid level; the desalted water raw material tank 1 adds desalted water with a certain mass into the reaction kettle 2 through a reaction kettle water supplementing line (S6 in the corresponding diagram); then, a stirrer of the reaction kettle 2 is started to mix water and the catalyst, the dissolved state of the catalyst is observed through a sight glass on the reaction kettle 2, and after the catalyst is completely dissolved, an aqueous solution of the catalyst is formed for later use;
Step 2, raw material input
Adding ionic liquid ethylene carbonate waste material (corresponding to S2 in the figure) in a corresponding proportion into a reaction kettle 2, wherein the mass ratio of desalted water to the ionic liquid ethylene carbonate waste material to the catalyst is 500:100:1; the stirrer of the reaction kettle 2 continuously stirs, the temperature is raised by utilizing heat conduction oil, the oil inlet temperature of the heat conduction oil is 230 ℃, the oil return temperature of the heat conduction oil is 200 ℃ (oil inlet and oil return respectively correspond to S3 and S4 in the drawing), and in order to prevent large water evaporation loss, the temperature in the reaction kettle 2 is controlled to be not more than 100 ℃; the stirrer continues stirring, and the sight glass of the reaction kettle 2 is observed until the materials are fully mixed;
Step 3, reaction stage
Starting heat conduction oil to heat, controlling the temperature in the reaction kettle 2 to 120 ℃, keeping the pressure at normal pressure, and continuously stirring in the heating process; in the reaction process, ethylene glycol and carbon dioxide are generated by hydrolysis of ethylene carbonate, carbon dioxide gas is discharged to a desalted water raw material tank 1 through a reaction kettle emptying line (corresponding to S7 in the figure), carbon dioxide gas is discharged from a top emptying line (corresponding to S5 in the figure) of the desalted water raw material tank 1, cold water circulation is further arranged on the reaction kettle emptying line, and water vapor is condensed and then returned to a reaction kettle 2 for recycling; in order to avoid the reaction to be too severe, the generated carbon dioxide gas entrains materials to form a large amount of foam, and the reaction temperature rise speed and the rotation speed of a stirrer motor are strictly controlled;
Step 4, constant temperature stage
Keeping the reaction kettle 2 at the constant temperature of 120 ℃, continuously stirring, reacting for 3 hours at the constant temperature, and properly reducing or prolonging the reaction time according to the amount of bubbles generated by the reaction; after no bubble is generated basically in the reaction, stopping heating, cooling the reaction kettle 2 to 50 ℃, conveying a crude ethylene glycol product (S8 in the corresponding diagram) into the reaction intermediate product tank 4 through the reaction intermediate product pump 3 for temporary storage, wherein the conversion rate of ethylene carbonate is 80%, and the ethylene glycol selectivity is 60%;
Step 5, refining the product
The crude ethylene glycol product (S9 in the corresponding diagram) is conveyed into an ethylene glycol rectifying tower 6 by a reaction intermediate product tank bottom pump 5, the ethylene glycol rectifying tower 6 is composed of CY700 plate ripple structured packing and trays, a rectifying section is composed of two sections of packing, the theoretical plate number is10 layers, a stripping section is a tray tower, and the theoretical plate number is 20 layers. The purpose of this design is because ionic liquid boiling point is high, and viscosity is big, and the stripping section sets up the tower tray and can prevent ionic liquid jam, and because the separation effect of filler is good, sets up the filler in the rectifying section and can improve the refined effect of product. The tower top material (S11 in the corresponding diagram) enters a reflux tank 8 through a tower top condenser 7, the tower top condenser 7 is cooled by 28 ℃ circulating incoming water (S14 in the corresponding diagram) and 32 ℃ circulating backwater (S13 in the corresponding diagram), a part of the material at the outlet of a reflux tank bottom pump 9 is forcedly refluxed to an ethylene glycol rectifying tower 6 (S12 in the corresponding diagram), a part of the material is returned to a desalted water raw material tank 1 (S10 in the corresponding diagram), and a part of the material is returned to a waste material tank 12 (S16 in the corresponding diagram); the tower kettle of the glycol rectifying tower 6 is provided with a reboiler 10 for heating, and heat conduction oil is used as a heat source (a connecting line S17, an oil inlet S18 and an oil return S19 in the corresponding diagram); the material in the tank of the glycol rectifying tower 6 is sent to a waste tank 12 (corresponding to S20 in the figure) through a tank bottom pump 11, the waste is sent to a waste tank area (corresponding to S22 in the figure) through a tank bottom pump 13, the glycol product is extracted from the side line of the glycol rectifying tower 6 (corresponding to S15 in the figure) and enters a glycol intermediate product tank 14, after being checked, the glycol product is sent to the glycol product tank area (corresponding to S23 in the figure) through a glycol intermediate product pump 15, and the glycol content in the product is 99.2%.
Example 2
As shown in fig. 1, a method for producing ethylene glycol from ionic liquid ethylene carbonate waste according to an embodiment of the present invention includes the following steps:
Step 1, preparing a catalyst
Calculating and weighing the dosage of each batch of catalyst, and putting the catalyst into a reaction kettle 2; injecting desalted water (S1 in the corresponding diagram) into the desalted water raw material tank 1, and maintaining the liquid level at 50%; the desalted water raw material tank 1 adds desalted water with a certain mass into the reaction kettle 2 through a reaction kettle water supplementing line (S6 in the corresponding diagram); then, a stirrer of the reaction kettle 2 is started to mix water and the catalyst, the dissolved state of the catalyst is observed through a sight glass on the reaction kettle 2, and after the catalyst is completely dissolved, an aqueous solution of the catalyst is formed for later use;
Step 2, raw material input
Adding ionic liquid ethylene carbonate waste material (corresponding to S2 in the figure) in a corresponding proportion into a reaction kettle 2, wherein the mass ratio of desalted water to the ionic liquid ethylene carbonate waste material to the catalyst is 1000:300:2; the stirrer of the reaction kettle 2 continuously stirs, the temperature is raised by utilizing heat conduction oil, the oil inlet temperature of the heat conduction oil is 230 ℃, the oil return temperature of the heat conduction oil is 200 ℃ (oil inlet and oil return respectively correspond to S3 and S4 in the drawing), and in order to prevent large water evaporation loss, the temperature in the reaction kettle 2 is controlled to be not more than 100 ℃; the stirrer continues stirring, and the sight glass of the reaction kettle 2 is observed until the materials are fully mixed;
Step 3, reaction stage
Starting heat conduction oil to heat, controlling the temperature in the reaction kettle 2 to 140 ℃, keeping the pressure at normal pressure, and continuously stirring in the heating process; in the reaction process, ethylene glycol and carbon dioxide are generated by hydrolysis of ethylene carbonate, carbon dioxide gas is discharged to a desalted water raw material tank 1 through a reaction kettle emptying line (corresponding to S7 in the figure), carbon dioxide gas is discharged from a top emptying line (corresponding to S5 in the figure) of the desalted water raw material tank 1, cold water circulation is further arranged on the reaction kettle emptying line, and water vapor is condensed and then returned to a reaction kettle 2 for recycling; in order to avoid the reaction to be too severe, the generated carbon dioxide gas entrains materials to form a large amount of foam, and the reaction temperature rise speed and the rotation speed of a stirrer motor are strictly controlled;
Step 4, constant temperature stage
Keeping the reaction kettle 2 at the constant temperature of 140 ℃, continuously stirring, reacting for 4 hours at the constant temperature, and properly reducing or prolonging the reaction time according to the amount of bubbles generated by the reaction; after no bubble is generated basically in the reaction, stopping heating, cooling the reaction kettle 2 to 70 ℃, conveying a crude ethylene glycol product (S8 in the corresponding diagram) into the reaction intermediate product tank 4 through the reaction intermediate product pump 3 for temporary storage, wherein the conversion rate of ethylene carbonate is 98.8%, and the ethylene glycol selectivity is 90%;
Step 5, refining the product
The crude ethylene glycol product (S9 in the corresponding diagram) is conveyed into an ethylene glycol rectifying tower 6 by a reaction intermediate product tank bottom pump 5, the ethylene glycol rectifying tower 6 is composed of CY700 plate ripple structured packing and trays, a rectifying section is composed of two sections of packing, the theoretical plate number is 30 layers, a stripping section is a tray tower, and the theoretical plate number is 30 layers. The purpose of this design is because ionic liquid boiling point is high, and viscosity is big, and the stripping section sets up the tower tray and can prevent ionic liquid jam, and because the separation effect of filler is good, sets up the filler in the rectifying section and can improve the refined effect of product. The tower top material (S11 in the corresponding diagram) enters a reflux tank 8 through a tower top condenser 7, the tower top condenser 7 is cooled by 28 ℃ circulating incoming water (S14 in the corresponding diagram) and 32 ℃ circulating backwater (S13 in the corresponding diagram), a part of the material at the outlet of a reflux tank bottom pump 9 is forcedly refluxed to an ethylene glycol rectifying tower 6 (S12 in the corresponding diagram), a part of the material is returned to a desalted water raw material tank 1 (S10 in the corresponding diagram), and a part of the material is returned to a waste material tank 12 (S16 in the corresponding diagram); the tower kettle of the glycol rectifying tower 6 is provided with a reboiler 10 for heating, and heat conduction oil is used as a heat source (a connecting line S17, an oil inlet S18 and an oil return S19 in the corresponding diagram); the material in the tank of the glycol rectifying tower 6 is sent to a waste tank 12 (corresponding to S20 in the figure) through a tank bottom pump 11, the waste is sent to a waste tank area (corresponding to S22 in the figure) through a tank bottom pump 13, the glycol product is extracted from the side line of the glycol rectifying tower 6 (corresponding to S15 in the figure) and enters a glycol intermediate product tank 14, after being checked, the glycol product is sent to the glycol product tank area (corresponding to S23 in the figure) through a glycol intermediate product pump 15, and the glycol content in the product is 99.7%.
Example 3
As shown in fig. 1, a method for producing ethylene glycol from ionic liquid ethylene carbonate waste according to an embodiment of the present invention includes the following steps:
Step 1, preparing a catalyst
Calculating and weighing the dosage of each batch of catalyst, and putting the catalyst into a reaction kettle 2; the desalted water (S1 in the corresponding diagram) is injected into the desalted water raw material tank 1 and is maintained at the 70% liquid level; the desalted water raw material tank 1 adds desalted water with a certain mass into the reaction kettle 2 through a reaction kettle water supplementing line (S6 in the corresponding diagram); then, a stirrer of the reaction kettle 2 is started to mix water and the catalyst, the dissolved state of the catalyst is observed through a sight glass on the reaction kettle 2, and after the catalyst is completely dissolved, an aqueous solution of the catalyst is formed for later use;
Step 2, raw material input
Adding ionic liquid ethylene carbonate waste material (corresponding to S2 in the figure) in a corresponding proportion into a reaction kettle 2, wherein the mass ratio of desalted water to the ionic liquid ethylene carbonate waste material to the catalyst is 1000:500:5; the stirrer of the reaction kettle 2 continuously stirs, the temperature is raised by utilizing heat conduction oil, the oil inlet temperature of the heat conduction oil is 230 ℃, the oil return temperature of the heat conduction oil is 200 ℃ (oil inlet and oil return respectively correspond to S3 and S4 in the drawing), and in order to prevent large water evaporation loss, the temperature in the reaction kettle 2 is controlled to be not more than 100 ℃; the stirrer continues stirring, and the sight glass of the reaction kettle 2 is observed until the materials are fully mixed;
Step 3, reaction stage
Starting heat conduction oil to heat, controlling the temperature in the reaction kettle 2 to 160 ℃, keeping the pressure at normal pressure, and continuously stirring in the heating process; in the reaction process, ethylene glycol and carbon dioxide are generated by hydrolysis of ethylene carbonate, carbon dioxide gas is discharged to a desalted water raw material tank 1 through a reaction kettle emptying line (corresponding to S7 in the figure), carbon dioxide gas is discharged from a top emptying line (corresponding to S5 in the figure) of the desalted water raw material tank 1, cold water circulation is further arranged on the reaction kettle emptying line, and water vapor is condensed and then returned to a reaction kettle 2 for recycling; in order to avoid the reaction to be too severe, the generated carbon dioxide gas entrains materials to form a large amount of foam, and the reaction temperature rise speed and the rotation speed of a stirrer motor are strictly controlled;
Step 4, constant temperature stage
Keeping the reaction kettle 2 at the constant temperature of 160 ℃, continuously stirring, reacting for 6 hours at the constant temperature, and properly reducing or prolonging the reaction time according to the amount of bubbles generated by the reaction; after no bubble is generated basically in the reaction, stopping heating, cooling the reaction kettle 2 to 80 ℃, conveying a crude ethylene glycol product (S8 in the corresponding diagram) into the reaction intermediate product tank 4 through the reaction intermediate product pump 3 for temporary storage, wherein the conversion rate of ethylene carbonate is 99%, and the ethylene glycol selectivity is 80%;
Step 5, refining the product
The crude ethylene glycol product (S9 in the corresponding diagram) is conveyed into an ethylene glycol rectifying tower 6 by a reaction intermediate product tank bottom pump 5, the ethylene glycol rectifying tower 6 is composed of CY700 plate ripple structured packing and trays, a rectifying section is composed of two sections of packing, the theoretical plate number is 50 layers, a stripping section is a tray tower, and the theoretical plate number is 50 layers. The purpose of this design is because ionic liquid boiling point is high, and viscosity is big, and the stripping section sets up the tower tray and can prevent ionic liquid jam, and because the separation effect of filler is good, sets up the filler in the rectifying section and can improve the refined effect of product. The tower top material (S11 in the corresponding diagram) enters a reflux tank 8 through a tower top condenser 7, the tower top condenser 7 is cooled by 28 ℃ circulating incoming water (S14 in the corresponding diagram) and 32 ℃ circulating backwater (S13 in the corresponding diagram), a part of the material at the outlet of a reflux tank bottom pump 9 is forcedly refluxed to an ethylene glycol rectifying tower 6 (S12 in the corresponding diagram), a part of the material is returned to a desalted water raw material tank 1 (S10 in the corresponding diagram), and a part of the material is returned to a waste material tank 12 (S16 in the corresponding diagram); the tower kettle of the glycol rectifying tower 6 is provided with a reboiler 10 for heating, and heat conduction oil is used as a heat source (a connecting line S17, an oil inlet S18 and an oil return S19 in the corresponding diagram); the material in the tank of the glycol rectifying tower 6 is sent to a waste tank 12 (corresponding to S20 in the figure) through a tank bottom pump 13, the waste is sent to a waste tank area (corresponding to S22 in the figure), the glycol product is extracted from the side line of the glycol rectifying tower 6 (corresponding to S15 in the figure) and enters a glycol intermediate product tank 14, after being checked, the glycol product is sent to the glycol product tank area (corresponding to S23 in the figure) through a glycol intermediate product pump 15, and the glycol content in the product is 99%.
The embodiment of the invention provides a method for producing ethylene glycol by using ionic liquid ethylene carbonate waste, which is characterized in that ethylene carbonate in the ionic liquid waste is recovered and ethylene glycol with high added value is produced, the conversion rate of ethylene carbonate and the selectivity of ethylene glycol are both high, and the method has the advantages of high conversion rate and high selectivity; compared with other existing catalyst treatment processes, the method reduces the generation of salt insoluble substances, correspondingly reduces treatment equipment of the salt insoluble substances, such as filtering and evaporating equipment, and saves equipment cost, operation cost and energy consumption cost.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The foregoing examples illustrate only a few embodiments of the invention and are described in detail herein without thereby limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.
Claims (7)
1. The method for producing the ethylene glycol by using the ionic liquid ethylene carbonate waste is characterized by comprising the following steps of:
Step 1, preparing a catalyst
Calculating and weighing the dosage of each batch of catalyst, and putting the catalyst into a reaction kettle; wherein, the catalyst adopts sodium ricinoleate;
Injecting desalted water into a desalted water raw material tank, and adding desalted water into the reaction kettle through a reaction kettle water supplementing line by the desalted water raw material tank;
then, a stirrer of the reaction kettle is started to mix water and the catalyst to form an aqueous solution of the catalyst for later use;
Step 2, raw material input
Adding ionic liquid ethylene carbonate waste into a reaction kettle, wherein the mass ratio of desalted water to the ionic liquid ethylene carbonate waste to the catalyst is 500-1000:100-500:1-5;
The stirrer of the reaction kettle continuously stirs, the temperature is raised by utilizing heat conduction oil, the oil inlet temperature of the heat conduction oil is 230 ℃, the oil return temperature of the heat conduction oil is 200 ℃, and the temperature in the reaction kettle is controlled to be not more than 100 ℃;
The stirrer continues stirring until the materials are fully mixed;
Step 3, reaction stage
Starting heat conducting oil to heat, continuously stirring in the heating process, controlling the temperature in the reaction kettle to 120-160 ℃ and controlling the pressure to be normal pressure;
In the reaction process, ethylene carbonate is hydrolyzed to generate ethylene glycol and carbon dioxide, carbon dioxide gas is discharged to a desalted water raw material tank through a reaction kettle emptying line, and the carbon dioxide gas is discharged from a desalted water raw material tank top emptying line;
Step 4, constant temperature stage
Keeping the reaction kettle at the constant temperature of 120-160 ℃, continuously stirring, reacting at the constant temperature for 3-6 hours, reducing or prolonging the reaction time according to the amount of bubbles generated in the reaction, stopping heating after no bubbles are generated in the reaction, cooling the reaction kettle to 50-80 ℃, conveying a crude ethylene glycol product into a reaction intermediate product tank for temporary storage through a reaction intermediate product pump, wherein the conversion rate of ethylene carbonate is 80-99%, and the selectivity of ethylene glycol is 60-90%;
Step 5, refining the product
The crude ethylene glycol product is conveyed to an ethylene glycol rectifying tower by a bottom pump of a reaction intermediate product, tower top materials enter a reflux tank through a tower top condenser, a part of materials at the outlet of the bottom pump of the reflux tank forcedly reflux to the ethylene glycol rectifying tower, a part of materials return to a desalted water raw material tank, and a part of materials return to a waste material tank;
The material in the glycol rectifying tower kettle is pumped to a waste tank through a glycol rectifying tower kettle, waste is conveyed to a waste tank area through a waste tank bottom pump, a glycol product is extracted from the tower side line of the glycol rectifying tower and enters a glycol intermediate product tank, and after being checked to be qualified, the glycol product is pumped to a glycol product tank area through a glycol intermediate product, wherein the glycol content in the product is more than or equal to 99 percent.
2. The method for producing ethylene glycol from ionic liquid ethylene carbonate waste according to claim 1, wherein in step 1, the desalted water in the desalted water raw material tank is maintained at a liquid level of 30% to 70%;
and observing the dissolution state of the catalyst through a sight glass on the reaction kettle, and forming an aqueous solution of the catalyst for later use after the catalyst is completely dissolved.
3. The method for producing ethylene glycol from the ionic liquid ethylene carbonate waste according to claim 1, wherein whether the materials are sufficiently mixed is judged by observing a reaction kettle sight glass.
4. The method for producing ethylene glycol by using the ionic liquid ethylene carbonate waste according to claim 1, wherein a cold water circulation is further arranged on a reaction kettle emptying line, and water vapor is condensed and returned to the reaction kettle for recycling.
5. The method for producing ethylene glycol by using the waste ionic liquid ethylene carbonate according to claim 1, wherein in the step 5, the ethylene glycol rectifying tower consists of CY700 plate ripple structured packing and trays, the rectifying section consists of two sections of packing, the number of the trays is 10-50, the stripping section is a tray tower, and the number of the trays is 20-50.
6. The method for producing ethylene glycol by using the waste ionic liquid ethylene carbonate according to claim 1 or 5, wherein in the step 5, the top condenser is cooled by 28 ℃ circulating water and 32 ℃ circulating water.
7. The method for producing ethylene glycol from the waste ionic liquid ethylene carbonate according to claim 6, wherein in step 5, a reboiler is further provided to heat the bottom of the ethylene glycol rectifying tower, and heat transfer oil is used as a heat source.
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| CN104761429A (en) * | 2015-02-12 | 2015-07-08 | 中国科学院过程工程研究所 | Dimethyl carbonate and ethylene glycol production process |
| CN109678653A (en) * | 2017-10-19 | 2019-04-26 | 中国石油化工股份有限公司 | Technique for alkylene carbonates offal treatment |
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| RO115051B1 (en) * | 1992-04-07 | 1999-10-29 | Mircea Scurtu | Process for recovering waste resulted from ethylene carbonate distillation |
| CN103664627B (en) * | 2012-09-26 | 2015-11-18 | 辽宁港隆化工有限公司 | A kind of method of Catalysts of Preparing Methyl Ethyl Carbonate and production equipment special |
| CN110105174B (en) * | 2019-05-22 | 2021-10-08 | 胜华新能源科技(东营)有限公司 | Method for producing ethylene glycol by using ethylene carbonate and methanol as raw materials |
| CN116239444A (en) * | 2023-01-09 | 2023-06-09 | 山东海科新源材料科技股份有限公司 | Device and method for recycling waste liquid of ethylene carbonate device |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104761429A (en) * | 2015-02-12 | 2015-07-08 | 中国科学院过程工程研究所 | Dimethyl carbonate and ethylene glycol production process |
| CN109678653A (en) * | 2017-10-19 | 2019-04-26 | 中国石油化工股份有限公司 | Technique for alkylene carbonates offal treatment |
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