CN115724880A - Preparation method of ionic liquid for separating ethyl formate-methanol azeotropic system - Google Patents
Preparation method of ionic liquid for separating ethyl formate-methanol azeotropic system Download PDFInfo
- Publication number
- CN115724880A CN115724880A CN202211681178.8A CN202211681178A CN115724880A CN 115724880 A CN115724880 A CN 115724880A CN 202211681178 A CN202211681178 A CN 202211681178A CN 115724880 A CN115724880 A CN 115724880A
- Authority
- CN
- China
- Prior art keywords
- ionic liquid
- methanol
- ethyl formate
- azeotropic system
- ethyl
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000002608 ionic liquid Substances 0.000 title claims abstract description 167
- MONIGHCKZUNWTN-UHFFFAOYSA-N ethyl formate;methanol Chemical compound OC.CCOC=O MONIGHCKZUNWTN-UHFFFAOYSA-N 0.000 title claims abstract description 54
- 238000002360 preparation method Methods 0.000 title claims abstract description 20
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims abstract description 170
- 238000000926 separation method Methods 0.000 claims abstract description 57
- 238000000034 method Methods 0.000 claims abstract description 41
- XBDQKXXYIPTUBI-UHFFFAOYSA-M Propionate Chemical compound CCC([O-])=O XBDQKXXYIPTUBI-UHFFFAOYSA-M 0.000 claims abstract description 24
- ZDIRKWICVFDSNX-UHFFFAOYSA-N diethyl phosphate 1-ethyl-3-methyl-1,2-dihydroimidazol-1-ium Chemical compound P(=O)(OCC)(OCC)O.C(C)N1CN(C=C1)C ZDIRKWICVFDSNX-UHFFFAOYSA-N 0.000 claims abstract description 24
- WBJINCZRORDGAQ-UHFFFAOYSA-N formic acid ethyl ester Natural products CCOC=O WBJINCZRORDGAQ-UHFFFAOYSA-N 0.000 claims abstract description 24
- MCTWTZJPVLRJOU-UHFFFAOYSA-N 1-methyl-1H-imidazole Chemical compound CN1C=CN=C1 MCTWTZJPVLRJOU-UHFFFAOYSA-N 0.000 claims abstract description 15
- 230000000694 effects Effects 0.000 claims abstract description 15
- DQWPFSLDHJDLRL-UHFFFAOYSA-N triethyl phosphate Chemical compound CCOP(=O)(OCC)OCC DQWPFSLDHJDLRL-UHFFFAOYSA-N 0.000 claims abstract description 11
- 239000001257 hydrogen Substances 0.000 claims abstract description 10
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 10
- 238000005185 salting out Methods 0.000 claims abstract description 10
- 239000000126 substance Substances 0.000 claims abstract description 8
- 239000012808 vapor phase Substances 0.000 claims abstract description 8
- 238000007614 solvation Methods 0.000 claims abstract description 7
- 230000009471 action Effects 0.000 claims abstract description 5
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 claims description 20
- 239000000376 reactant Substances 0.000 claims description 19
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 14
- -1 diethyl phosphate anion Chemical class 0.000 claims description 12
- 239000003208 petroleum Substances 0.000 claims description 10
- 239000003795 chemical substances by application Substances 0.000 claims description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 8
- 229910052757 nitrogen Inorganic materials 0.000 claims description 7
- 238000002390 rotary evaporation Methods 0.000 claims description 7
- 238000002604 ultrasonography Methods 0.000 claims description 6
- 238000009833 condensation Methods 0.000 claims description 5
- 230000005494 condensation Effects 0.000 claims description 5
- 238000001035 drying Methods 0.000 claims description 5
- 238000010992 reflux Methods 0.000 claims description 5
- 238000005303 weighing Methods 0.000 claims description 5
- 150000001450 anions Chemical class 0.000 claims description 4
- UNLFUFQHYWLHRE-UHFFFAOYSA-N P(=O)(OCC)(OCC)O.C(CCC)N1CN(C=C1)C Chemical compound P(=O)(OCC)(OCC)O.C(CCC)N1CN(C=C1)C UNLFUFQHYWLHRE-UHFFFAOYSA-N 0.000 claims description 3
- UCQFCFPECQILOL-UHFFFAOYSA-N diethyl hydrogen phosphate Chemical compound CCOP(O)(=O)OCC UCQFCFPECQILOL-UHFFFAOYSA-N 0.000 claims 1
- 238000000605 extraction Methods 0.000 abstract description 6
- 238000010850 salt effect Methods 0.000 abstract description 6
- 125000000129 anionic group Chemical group 0.000 abstract 1
- 238000004519 manufacturing process Methods 0.000 abstract 1
- 238000001291 vacuum drying Methods 0.000 abstract 1
- HQWOEDCLDNFWEV-UHFFFAOYSA-M diethyl phosphate;1-ethyl-3-methylimidazol-3-ium Chemical compound CC[N+]=1C=CN(C)C=1.CCOP([O-])(=O)OCC HQWOEDCLDNFWEV-UHFFFAOYSA-M 0.000 description 20
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 10
- RAXXELZNTBOGNW-UHFFFAOYSA-N imidazole Natural products C1=CNC=N1 RAXXELZNTBOGNW-UHFFFAOYSA-N 0.000 description 10
- 238000006243 chemical reaction Methods 0.000 description 9
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 8
- 239000002904 solvent Substances 0.000 description 8
- 238000000895 extractive distillation Methods 0.000 description 7
- RJUFJBKOKNCXHH-UHFFFAOYSA-N Methyl propionate Chemical compound CCC(=O)OC RJUFJBKOKNCXHH-UHFFFAOYSA-N 0.000 description 6
- 229940017219 methyl propionate Drugs 0.000 description 6
- 239000000243 solution Substances 0.000 description 6
- 238000009835 boiling Methods 0.000 description 5
- HZAXFHJVJLSVMW-UHFFFAOYSA-N 2-Aminoethan-1-ol Chemical compound NCCO HZAXFHJVJLSVMW-UHFFFAOYSA-N 0.000 description 4
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 4
- 239000000460 chlorine Substances 0.000 description 4
- 229910052801 chlorine Inorganic materials 0.000 description 4
- 150000001875 compounds Chemical class 0.000 description 4
- 230000007797 corrosion Effects 0.000 description 4
- 238000005260 corrosion Methods 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 238000003786 synthesis reaction Methods 0.000 description 4
- 238000005406 washing Methods 0.000 description 4
- 230000027455 binding Effects 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000003993 interaction Effects 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 238000001308 synthesis method Methods 0.000 description 3
- WSLDOOZREJYCGB-UHFFFAOYSA-N 1,2-Dichloroethane Chemical compound ClCCCl WSLDOOZREJYCGB-UHFFFAOYSA-N 0.000 description 2
- LSQKDIHYWWWCTQ-UHFFFAOYSA-M 1-(2-chloroethyl)-3-methylimidazol-3-ium;chloride Chemical compound [Cl-].C[N+]=1C=CN(CCCl)C=1 LSQKDIHYWWWCTQ-UHFFFAOYSA-M 0.000 description 2
- IBZJNLWLRUHZIX-UHFFFAOYSA-N 1-ethyl-3-methyl-2h-imidazole Chemical compound CCN1CN(C)C=C1 IBZJNLWLRUHZIX-UHFFFAOYSA-N 0.000 description 2
- PMUNIMVZCACZBB-UHFFFAOYSA-N 2-hydroxyethylazanium;chloride Chemical compound Cl.NCCO PMUNIMVZCACZBB-UHFFFAOYSA-N 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 150000001412 amines Chemical class 0.000 description 2
- XENVCRGQTABGKY-ZHACJKMWSA-N chlorohydrin Chemical compound CC#CC#CC#CC#C\C=C\C(Cl)CO XENVCRGQTABGKY-ZHACJKMWSA-N 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000004821 distillation Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- IDGUHHHQCWSQLU-UHFFFAOYSA-N ethanol;hydrate Chemical compound O.CCO IDGUHHHQCWSQLU-UHFFFAOYSA-N 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 229910052736 halogen Inorganic materials 0.000 description 2
- 239000005457 ice water Substances 0.000 description 2
- 125000002883 imidazolyl group Chemical group 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000002329 infrared spectrum Methods 0.000 description 2
- 229910017053 inorganic salt Inorganic materials 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 238000000622 liquid--liquid extraction Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- TZIHFWKZFHZASV-UHFFFAOYSA-N methyl formate Chemical compound COC=O TZIHFWKZFHZASV-UHFFFAOYSA-N 0.000 description 2
- 239000011259 mixed solution Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 239000010452 phosphate Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000001737 promoting effect Effects 0.000 description 2
- 230000035484 reaction time Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 238000001577 simple distillation Methods 0.000 description 2
- 238000000638 solvent extraction Methods 0.000 description 2
- 238000000194 supercritical-fluid extraction Methods 0.000 description 2
- 230000002194 synthesizing effect Effects 0.000 description 2
- 238000010189 synthetic method Methods 0.000 description 2
- JSNMGAXVEHDHEO-UHFFFAOYSA-N 1-ethyl-3-methyl-2H-imidazol-1-ium-1,2-dicarbonitrile Chemical class C(C)[N+]1(C(N(C=C1)C)C#N)C#N JSNMGAXVEHDHEO-UHFFFAOYSA-N 0.000 description 1
- NJMWOUFKYKNWDW-UHFFFAOYSA-N 1-ethyl-3-methylimidazolium Chemical compound CCN1C=C[N+](C)=C1 NJMWOUFKYKNWDW-UHFFFAOYSA-N 0.000 description 1
- 208000035859 Drug effect increased Diseases 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910002056 binary alloy Inorganic materials 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- ZYBWTEQKHIADDQ-UHFFFAOYSA-N ethanol;methanol Chemical compound OC.CCO ZYBWTEQKHIADDQ-UHFFFAOYSA-N 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
- ZHUXMBYIONRQQX-UHFFFAOYSA-N hydroxidodioxidocarbon(.) Chemical compound [O]C(O)=O ZHUXMBYIONRQQX-UHFFFAOYSA-N 0.000 description 1
- 239000002917 insecticide Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- QZJVWTNHFOMVHX-UHFFFAOYSA-N methanol;methyl acetate Chemical compound OC.COC(C)=O QZJVWTNHFOMVHX-UHFFFAOYSA-N 0.000 description 1
- NIQQIJXGUZVEBB-UHFFFAOYSA-N methanol;propan-2-one Chemical compound OC.CC(C)=O NIQQIJXGUZVEBB-UHFFFAOYSA-N 0.000 description 1
- 150000004702 methyl esters Chemical class 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 230000009149 molecular binding Effects 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 238000010587 phase diagram Methods 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 235000013599 spices Nutrition 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Images
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
A process for preparing ionic liquid used for separating ethyl formate-methanol azeotropic system features that the anionic group of the ionic liquid synthesized has P-O double bond. The preparation method comprises the following steps: firstly, N-methylimidazole reacts with triethyl phosphate to prepare 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid, and the ionic liquid is extracted, rotary evaporated and purified by vacuum drying to obtain methanol which contains phosphorus-oxygen double bonds and can be selectively combined with a binary azeotropic system, and through the action of chemical affinity, hydrogen bond force and ionic electrostatic attraction, a nonvolatile ionic liquid-methanol association is formed to generate a solvation effect and reduce the methanol vapor pressure and volatility, so that the vapor phase partial pressure and relative volatility of ethyl formate are increased, and a salting-out phenomenon is generated, thereby realizing the separation of the ethyl formate-methanol azeotropic system. The method is simple, and the prepared ionic liquid is stable, environment-friendly, strong in salt effect, high in extraction efficiency and capable of being recycled for multiple times.
Description
Technical Field
The invention relates to the field of material science of ionic liquid synthesis, in particular to a method for preparing ionic liquid for selective separation of an ethyl formate-methanol azeotropic system.
Background
Ethyl formate, also known as ethyl formate, has a boiling point of 54.7 ℃ at normal pressure, is an important organic raw material, and is widely applied to various fields such as food, agriculture, medicine and the like as a spice, an insecticide, a solvent and the like. Methanol is a common chemical basic raw material, and the boiling point of the methanol at normal pressure is 64.7 ℃. Methanol has been produced by ethyl formate catalysis in recent years, but ethyl formate and methanol form an azeotrope at atmospheric pressure. In a binary system of ethyl formate and methanol at standard atmospheric pressure, an azeotropic point exists at a mole fraction of 0.697 of ethyl formate, and the azeotropic temperature is 50.6 ℃.
The ethyl formate-methanol azeotrope cannot be completely separated using common simple distillation. In recent years, researchers have studied many separation methods, such as distillation, salt-added distillation, membrane separation, liquid-liquid extraction, and supercritical extraction. Although the common salt-adding rectification has the advantages of low energy consumption and small dosage, the inorganic salt has the problems of corrosion, blockage of equipment, difficult transportation and the like. Therefore, the compound which is a green and environment-friendly azeotropic separation system and has both soluble salt and a solvent is urgently expected to be found. The Ionic Liquid (IL) is environment-friendly, almost has no saturated vapor pressure and has a salting-out effect. Therefore, in combination with the advantages and disadvantages of various separation methods in industrial separation, the ionic liquid is used as an extracting agent for separating the ethyl formate-methanol azeotropic system.
In recent years, ionic liquids have been widely used as extractants in the field of special rectification, and have attracted the interest of a large number of researchers. In the field of azeotropic separation, there are a number of reports on the separation of water-ethanol azeotropic systems: (Korean J. Chem.Eng.2013， 30， 1681-1686; ACS Sym. Ser.2012， 1117， 239-257; J. Chem. Eng. Data 2009， 54， 1004-1008; J. Chem. Eng. Data 2006， 51， 2178-2181; J. Chem. Eng. Data 2003， 48, 1315-1317). The invention patent (CN 201410004279) "synthetic method of ionic liquid with high separation performance" is disclosed in Shenxiu et al, shenyang chemical university Li Wen, 2014. The invention relates to a synthesis method of chlorohydrin-containing amine ionic liquid, which is characterized by being prepared by the following steps: adding a monoethanolamine solution into a reaction kettle in an ice water bath, adding concentrated hydrochloric acid into a constant-pressure dropping funnel according to a molar ratio of 1.3, and stirring and reacting the monoethanolamine solution and the concentrated hydrochloric acid in a slow dropping manner, wherein the reaction temperature is controlled to be 0-3 ℃ and the reaction time is 20 hours. And purifying through the steps of washing, rotary evaporation and the like to obtain the wine red monoethanolamine chloride ionic liquid. The invention also provides application of the ionic liquid in an azeotropic system for separating methanol and acetone by extractive distillation. The ionic liquid has simple synthesis and high separation efficiency, can be recycled for more than 10 times, and the obtained product has the characteristics of non-volatilization of the ionic liquid, good stability and good separation of strong polar azeotrope systems. An invention patent (CN 201410004533) disclosed in 2014 relates to a preparation method of an ionic liquid, which is characterized by being prepared by the following method, and comprising the following specific steps: under the protection of nitrogen, N-methylimidazole and 1, 2-dichloroethane are mixed according to a molar ratio of 1:1.2 adding into a reaction kettle, stirring and reacting for 6 h at 75 ℃, and purifying by washing and other steps to obtain white 1- (2-chloroethyl) -3-methylimidazolium chloride crystals. The method introduces chlorine into imidazole ions, so that the obtained product has the characteristics of no volatilization of ionic liquid, good stability, salt effect and good separation performance of chlorine, can improve the separation capability of the ionic liquid, and avoids aggravated equipment corrosion caused by excessive halogen anions. The invention also provides the application of the ionic liquid in an azeotropic system of methanol-methyl acetate separated by extractive distillation, and the ionic liquid can be repeatedly used for more than 20 times. 2017 Jumbo et al, the university of Qingdao science and technology, disclose an invention patent (CN 107445817B) a method for separating acetone and methanol by ionic liquid extraction and rectification, which adoptsThe method for separating the binary azeotropic system of acetone and methanol by extracting, rectifying and separating the ionic liquid 1-ethyl-3-methylimidazolium dinitrile salt reduces the using amount of an extracting agent while obtaining a high-purity product. The invention discloses a patent (CN 108997084A) for promoting separation of methanol and methyl propionate by using an ionic liquid solvent, namely Lijinlong and Lijiawei two people at university of Hezhou in 2018, provides a bis-trifluoromethanesulfonimide imidazole ionic liquid which can effectively eliminate azeotropic properties of a mixture solution of methanol and methyl propionate, and can obtain high-purity methanol and methyl propionate products by an extractive distillation double-tower process method. The invention discloses a method for separating methanol-ethyl formate azeotrope by ionic liquid extractive distillation (CN 113214047A) of Zhaohong kang, et al, beijing university of industry, 2021, and the invention selects ionic liquid 1-ethyl-3-methylimidazolium acetate- [ EMIM][OAC]As an extractant, experiments prove that when the dosage of the extractant and the dosage of the raw material mixed solution are 0.04 (molar ratio), the azeotrope between methanol and ethyl formate can be eliminated, the extractant is a better extractant, and high-purity methanol and high-purity ethyl formate can be obtained by extraction, rectification and separation.
So far, reports of separating the ethyl formate-methanol binary azeotropic system by using ionic liquid as an entrainer are rare. The methods only prepare the ionic liquid capable of separating the azeotropic system, but no group carrying specificity and to be grouped and separated is found, and no literature reports about the preparation method for selectively separating the ionic liquid of the ethyl formate-methanol system. Therefore, the preparation method for synthesizing the green solvent 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid is researched, and the necessity of realizing the selective separation of the ethyl formate-methanol azeotropic system is realized.
In the present invention, we report the preparation of ionic liquid for the selective separation of ethyl formate-methanol from 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid. The 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid contains phosphorus-oxygen double bonds, and the ionic liquid is particularly suitable to be used as a green organic separation solvent of an azeotropic separation system. Because diethyl phosphate anion in the ionic liquid has phosphorus-oxygen double bond, and reacts with methanol molecules through the action of chemical affinity, hydrogen bond force and ionic electrostatic attraction to form ionic liquid-methanol association which is difficult to volatilize, thereby reducing the proportion of the methanol molecules in a vapor phase, reducing the vapor pressure, increasing the vapor partial pressure of ethyl formate, increasing the relative volatility, further showing the salting-out phenomenon and realizing the separation of ethyl formate-methanol. .
Disclosure of Invention
The purpose of the invention is as follows: aiming at the defects of the conventional ethyl formate-methanol separation azeotropic system, the invention uses a water bath ultrasonic method to prepare 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid as an extracting agent to separate the ethyl formate-methanol system.
The technical scheme of the invention is as follows: the ionic liquid of 1-ethyl-3-methylimidazole diethyl phosphate synthesized by the method contains phosphorus-oxygen double bonds, and the ionic liquid is particularly suitable for being used as a green organic separation solvent of an ethyl formate-methanol azeotropic system. Because the phosphorus-oxygen double bond in the diethyl phosphate anion in the ionic liquid and the component methanol in the ethyl formate-methanol azeotropic system have selective and solvation reaction with methanol molecules under the action of chemical affinity, hydrogen bond force and ionic electrostatic attraction, the ionic liquid-methanol association complex which is difficult to volatilize is formed, thereby reducing the specific gravity of the methanol molecules in a vapor phase, reducing the vapor pressure, increasing the vapor phase partial pressure of the ethyl formate, increasing the relative volatility, further showing the salting-out phenomenon and realizing the separation of the ethyl formate-methanol.
The preparation process of the invention comprises the following two steps:
1.1 Preparation of 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid: firstly, weighing reactants of 44.2364 g-51.6092 g of N-methylimidazole and 16.6 g-19.3780 g of triethyl phosphate, sequentially placing the reactants in a 250 mL round-bottom flask, introducing nitrogen for 10 minutes, connecting a condensation reflux device, and reacting for 2 hours-3 hours under water bath ultrasound at 80-90 ℃ to obtain 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid containing unreacted reactants;
1.2 Purifying 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid: using petroleum ether as an extracting agent, repeatedly extracting 1-ethyl-3-methylimidazole diethyl phosphate for 3 times, removing unreacted reactants, performing rotary evaporation by using a rotary evaporator to remove the petroleum ether, transferring the obtained ionic liquid into a 150 mL beaker, placing the beaker in a vacuum oven at the temperature of 60-70 ℃, and drying for 18-24 hours to remove unreacted N-methylimidazole and triethyl phosphate, thus obtaining the 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid.
As a further improvement on the prior art, the 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid has the advantages of non-volatilization, good stability, selective salt effect and small corrosivity; the synthesized imidazole ionic liquid anion group contains functional phosphorus-oxygen double bonds; the synthesized ionic liquid is combined with methanol molecules to generate a nonvolatile ionic liquid-methanol association complex, and the separation of an azeotropic system can be realized. The preparation operation of the synthesized ionic liquid is simple and controllable, and the prepared ionic liquid has obvious characteristics and excellent selectivity.
Compared with the prior art, the method has the beneficial effects that:
the common simple distillation cannot completely separate the ethyl formate-methanol azeotropic system. In recent years, researchers have studied various separation methods, such as rectification, salt-added rectification, membrane separation, liquid-liquid extraction, supercritical extraction and other technologies. Although the common salt-adding rectification has the advantages of low energy consumption and small dosage, the inorganic salt has the problems of corrosion, blockage of equipment and difficult transportation. Therefore, the method has urgent need of finding a green and environment-friendly azeotropic separation system compound with both soluble salt and solvent. The Ionic Liquid (IL) is environment-friendly, almost has no saturated vapor pressure and has a salting-out effect. Therefore, in combination with the advantages and disadvantages of various separation methods in industrial separation, the ionic liquid is used as an extracting agent for separating the ethyl formate-methanol azeotropic system.
In recent years, ionic liquids have been widely used as extractive agents in the field of special rectification, and have attracted the interest of a large number of researchers. In azeotropic separationIn the field, there are a number of reports on the separation of water-ethanol azeotropic systems (Korean J. Chem. Eng. 2013， 30， 1681-1686; ACS Sym. Ser. 2012， 1117， 239-257; J. Chem. Eng. Data 2009， 54， 1004-1008; J. Chem. Eng. Data 2006， 51， 2178-2181; J. Chem. Eng. Data 2003， 48, 1315-1317). The invention patent (CN 201410004279) "synthetic method of ionic liquid with high separation performance" is disclosed in Shenxiu et al, shenyang chemical university Li Wen, 2014. The invention relates to a synthesis method of chlorohydrin-containing amine ionic liquid, which is characterized by being prepared by the following steps: adding a monoethanolamine solution into a reaction kettle in an ice water bath, adding concentrated hydrochloric acid into a constant-pressure dropping funnel according to a molar ratio of 1.3, and stirring and reacting the monoethanolamine solution and the concentrated hydrochloric acid in a slow dropping manner, wherein the reaction temperature is controlled to be 0-3 ℃ and the reaction time is 20 hours. And purifying through washing, rotary evaporation and other steps to obtain the wine red monoethanolamine chloride ionic liquid. The invention also provides application of the ionic liquid in an azeotropic system of methanol-acetone by extractive distillation and separation. The ionic liquid has simple synthesis and high separation efficiency, can be recycled for more than 10 times, and the obtained product has the characteristics of no volatilization of the ionic liquid, good stability and good separation of a strong-polarity azeotrope system. An invention patent (CN 201410004533) disclosed in 2014 relates to a preparation method of an ionic liquid, which is characterized by being prepared by the following method, and comprising the following specific steps: under the protection of nitrogen, N-methylimidazole and 1, 2-dichloroethane are mixed according to a molar ratio of 1:1.2 adding into a reaction kettle, stirring and reacting for 6 h at 75 ℃, and purifying through steps such as washing and the like to obtain white 1- (2-chloroethyl) -3-methylimidazolium chloride crystal. The synthesis method provided by the invention is simple and completed in one step, and chlorine is introduced into imidazole ions, so that the obtained product has the characteristics of non-volatilization of ionic liquid, good stability, salt effect and good chlorine separation performance, the separation capability of the ionic liquid can be improved, and the phenomenon that equipment corrosion is aggravated due to excessive halogen anions is avoided. The invention also provides a method for separating methanol-ethanol from the ionic liquid by extractive distillationThe application of the methyl ester can be repeatedly used for more than 20 times. 2017, rongma university of Qingdao science and technology, discloses an invention patent (CN 107445817B) of a method for separating acetone and methanol by ionic liquid extraction and rectification, and the invention adopts a method for separating an acetone and methanol binary azeotropic system by ionic liquid 1-ethyl-3-methylimidazol diaminonitrile salt extraction and rectification, so that a high-purity product is obtained and the using amount of an extracting agent is reduced. The invention discloses a patent (CN 108997084A) for promoting separation of methanol and methyl propionate by using an ionic liquid solvent, namely Lijinlong and Lijiawei two people at university of Hezhou in 2018, provides a bis-trifluoromethanesulfonimide imidazole ionic liquid which can effectively eliminate azeotropic properties of a mixture solution of methanol and methyl propionate, and can obtain high-purity methanol and methyl propionate products by an extractive distillation double-tower process method. The invention discloses Zhaohongkang et al (CN 113214047A) of Beijing university of industry in 2021, a method for separating methanol-ethyl formate azeotrope by ionic liquid extractive distillation, and ionic liquid 1-ethyl-3-methylimidazole acetate- [ EMIM][OAC]As an extractant, experiments prove that when the dosage of the extractant and the dosage of the raw material mixed solution are 0.04 (molar ratio), azeotrope between methanol and ethyl formate can be eliminated, the extractant is a better extractant, and high-purity methanol and high-purity ethyl formate can be obtained by extraction, rectification and separation.
So far, reports of separating the ethyl formate-methanol binary azeotropic system by using ionic liquid as an entrainer are rare. The methods only prepare the ionic liquid capable of separating the azeotropic system, but no group carrying specificity and to be grouped and separated is found, and no literature reports about the preparation method for selectively separating the ionic liquid of the ethyl formate-methanol system. Therefore, the preparation method for synthesizing the green solvent 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid is researched, and the necessity of realizing the selective separation of the ethyl formate-methanol azeotropic system is realized.
The invention prepares 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid: firstly, weighing reactants of 44.2364 g-51.6092 g of N-methylimidazole and 16.6000 g-19.3780 g of triethyl phosphate, sequentially placing the reactants in a 250 mL round-bottom flask, introducing nitrogen for 10 minutes, connecting a condensation reflux device, and reacting for 2 hours-3 hours under water bath ultrasound at 80-90 ℃ to obtain 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid containing unreacted reactants; purification of 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid: using petroleum ether as an extractant, repeatedly extracting 1-ethyl-3-methylimidazole diethyl phosphate for 3 times, removing unreacted reactants, performing rotary evaporation by using a rotary evaporator to remove the petroleum ether, transferring the obtained ionic liquid into a 150 mL beaker, placing the beaker in a vacuum oven at the temperature of 60-70 ℃, and drying for 18-24 hours to remove unreacted N-methylimidazole and triethyl phosphate, thus obtaining the 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid. Has the performance of selective separation of an ethyl formate-methanol azeotropic system.
In summary, the 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid synthesized by water bath ultrasound, especially the ionic liquid with selectively combined phosphorus-oxygen double bonds, not only increases the acting force between the ionic liquid and methanol, but also increases the molecular binding sites, and improves the selectivity and the binding property.
And the second step is as follows: compared with the ionic liquid prepared by the traditional method, the ionic liquid has selective binding sites, improves the selective binding to methanol molecules, is easy to have solvation reaction, improves the volatility of ethyl formate to methanol, and enables a salting-out effect to occur, thereby realizing the separation of the azeotropic system.
And thirdly: the method provided by the invention is simple and controllable to operate, and the prepared ionic liquid has obvious characteristics and excellent selectivity.
Fourthly, the method comprises the following steps: the ionic liquid prepared by the water-bath ultrasonic synthesis reaction of N-methylimidazole and phosphate ester has the following advantages: (1) The ionic liquid prepared by the method has the advantages of non-volatilization, good stability and selective salt effect; (3) Can be selectively combined with methanol in an ethyl formate-methanol system to carry out solvation reaction and separate an azeotropic system; and (4) the paint is harmless to the environment and can be recycled.
Drawings
FIG. 1 shows the IR spectrum of 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid synthesized by the present invention.
FIG. 2 is the space structure of the theoretical research of the compound formed by the interaction of the synthesized 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid and ethyl formate-methanol.
FIG. 3 shows that the 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid synthesized by the invention corresponds to different mole fractionsy 1 -x 1 ’ And (4) gas-liquid balance.
FIG. 4 shows the relative volatility of the synthesized 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid at different mole fractions.
FIG. 5 shows that the 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid synthesized by the invention corresponds to different mole fractionsT-x-yDrawing.
The embodiments are further explained with reference to the drawings
FIG. 1 is an infrared spectrum of 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid synthesized by the method. 2970 cm -1 ～ 2 700 cm -1 The absorption band of (A) is caused by saturated C-H stretching vibration, and the wave number is 1630 cm -1 Is caused by C = C stretching vibration, 1540 cm -1 And 1400 cm -1 1370cm caused by flexural vibration of methyl group C-H in the absorption band of (1) -1 is-CH 3 Symmetric bending vibration with wavenumber of 1140 cm -1 Is the stretching vibration of imidazole ring, 1270 cm -1 And 994 cm -1 And (2) is the stretching vibration of O = P-O.
FIG. 2 is the space structure of the theoretical research of the compound formed by the interaction of the synthesized 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid and ethyl formate-methanol. The 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid can react with methanol molecules and affect the charge distribution of the methanol molecules, the methanol molecules are attracted by the ionic liquid, carboxyl oxygen of methanol and hydrogen atoms of methyl on imidazole rings form C-H8230, an O hydrogen bond with the hydrogen bond length of 2.1228, and meanwhile, carboxyl hydrogen of the methanol and oxygen atoms on 1-ethyl-3-methylimidazolium diethyl phosphate anions form hydrogen bonds with the distance of 1.70279, so that when the ionic liquid is added into an azeotropic system, the ionic liquid can form hydrogen bonds with the methanol, so that the relative volatility of the methanol is reduced, the relative volatility of ethyl formate is improved, a salting-out effect is generated, and the separation of the ethyl formate-methanol azeotropic system is realized.
FIG. 3 shows that 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid synthesized by the invention corresponds to different mole fractionsy 1 -x 1 ’ And (4) gas-liquid balance. Measurement of Ethyl formate mole fraction at different mole fractions of an Ionic liquid Using a Fischer Labodest VLE-602/VLLE-602 boiling point apparatusx 1 ’ Andy 1 calculating the corresponding temperature from 0 to 1 by using an NRTL model correlationy 1 And make ay 1 -x 1 ’ Vapor-liquid equilibrium phase diagram. In contrast to the blank test, the separation effect increased as the ionic liquid mole fraction increased. When the molar fraction is 5%, the separation effect can be substantially achieved, and obviously, when the molar fraction is more than 8%,x 1 the azeotropic point at =0.697 can be completely removed, the azeotropic phenomenon disappears, and the separation effect is good.
FIG. 4 shows the relative volatility of the synthesized 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid at different mole fractions. The addition of IL may alter the azeotropic effect of the system. When the IL mole fraction is 1%, there is a part of the relative volatilityα 12 Less than 1; at the azeotropic point when the IL mole fraction is 5% and 8%x 1 Relative volatility at =0.679α 12 When the boiling point is more than 1, the azeotropic point is broken, and the system achieves the separation effect. As the polarity of methanol molecules is far greater than that of ethyl formate, the interaction force between IL and methanol is far greater than that between IL and ethyl formate with the increase of IL concentration, so that methanol molecules are more gathered around anions and cations of the ionic liquid, the activity coefficient of methanol is reduced, a solvation effect is formed, and the methanol molecules and the methyl formate are subjected to a solvation reactionThe ethyl formate shows a salting-out effect, so that the relative volatility of the ethyl formate to the methanol is obviously improved.
FIG. 5 shows that the 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid synthesized by the invention corresponds to different mole fractionsT-x 1 ’ -y 1 Drawing. Addition of ionic liquid to azeotropic system ethyl formate-methanolT-x 1 ’ -y 1 A significant effect is produced. When the molar fraction of the ionic liquid is increased by 1%,5% and 8%,T-x 1 ’ -y 1 the figure is translated in its entirety upwards. When the ionic liquid mole fraction is 5%, the intersection point (azeotropic point) of the liquid phase line and the gas phase line is separated, and when the ionic liquid mole fraction is 8%, the distance between the gas phase line and the liquid phase line is more and more obvious. As the mole fraction of the ionic liquid increases, the higher boiling point material is added and therefore more energy is required to reach the new equilibrium, the equilibrium temperature increases.
The specific implementation mode is as follows: the synthesized 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid contains phosphorus-oxygen double bonds, and the ionic liquid is particularly suitable to be used as a green organic separation solvent of an ethyl formate-methanol azeotropic separation system. Because the phosphorus-oxygen double bond in the diethyl phosphate anion in the ionic liquid and the component methanol in the ethyl formate-methanol azeotropic system form ion liquid-methanol associated complex which is difficult to volatilize under the action of chemical affinity, hydrogen bond force and ionic electrostatic attraction, the specific gravity of methanol molecules in a vapor phase is reduced, the vapor pressure is reduced, the vapor phase partial pressure of ethyl formate is increased, the relative volatility is increased, the salting-out phenomenon is further shown, and the separation of ethyl formate-methanol is realized, the preparation process comprises the following two steps:
1.1 Preparation of 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid: firstly, weighing reactants of 44.2364 g-51.6092 g of N-methylimidazole and 16.6000 g-19.3780 g of triethyl phosphate, sequentially placing the reactants in a 250 mL round-bottom flask, introducing nitrogen for 10 minutes, connecting a condensation reflux device, and reacting for 2 hours-3 hours at 80 ℃ -90 ℃ under water bath ultrasound to obtain 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid containing unreacted substances;
1.2 Purifying 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid: using petroleum ether as an extractant, repeatedly extracting 1-ethyl-3-methylimidazole diethyl phosphate for 3 times, removing unreacted reactants, performing rotary evaporation by using a rotary evaporator to remove the petroleum ether, transferring the obtained ionic liquid into a 150 mL beaker, placing the beaker in a vacuum oven at the temperature of 60-70 ℃, and drying for 18-24 hours to remove unreacted N-methylimidazole and triethyl phosphate, thus obtaining the 1-butyl-3-methylimidazole diethyl phosphate ionic liquid. The ionic liquid and an ethyl formate-methanol azeotropic system are mixed in a molar ratio of 1: when the ionic liquid is mixed at the ratio of 19, the azeotropic point of an azeotropic system can be broken, and the ionic liquid can be recycled for multiple times.
As a further improvement on the prior art, the 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid has the advantages of non-volatilization, good stability, selective salt effect and small corrosivity; the synthesized imidazole ionic liquid anion group contains functional phosphorus-oxygen double bonds; the synthesized ionic liquid is combined with methanol molecules to generate a nonvolatile ionic liquid-methanol association complex, so that the azeotropic system separation can be realized. The preparation of the synthesized ionic liquid is simple and controllable, and the prepared ionic liquid has obvious characteristics and excellent selectivity.
Example (b): n-methylimidazole, phosphate and the like are used as reactants, the ionic liquid is prepared by a water bath ultrasonic method, and the phosphorus-oxygen double bond can be selectively combined with the component methanol in an ethyl formate-methanol system to realize the separation of the ethyl formate-methanol binary azeotropic system.
Preparation of 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid: firstly, weighing reactants of 47.9228 g of N-methylimidazole and 17.989 g of triethyl phosphate, sequentially placing the reactants in a 250 mL round-bottom flask, introducing nitrogen for 10 minutes, connecting a condensation reflux device, and reacting for 2.5 hours in water bath ultrasound at 85 ℃ to obtain 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid containing unreacted substances;
and (2) purifying the 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid: using petroleum ether as an extracting agent, repeatedly extracting 1-ethyl-3-methylimidazole diethyl phosphate for 3 times, removing unreacted reactants, performing rotary evaporation by using a rotary evaporator to remove the petroleum ether, transferring the obtained ionic liquid into a 150 mL beaker, placing the beaker in a vacuum oven at 65 ℃, and drying for 21 hours to remove unreacted N-methylimidazole and triethyl phosphate, thus obtaining the 1-butyl-3-methylimidazole diethyl phosphate ionic liquid. The ionic liquid and an ethyl formate-methanol azeotropic system are mixed in a molar ratio of 1: when the ionic liquid is mixed at the ratio of 19, the azeotropic point of an azeotropic system can be broken, and the ionic liquid can be recycled for multiple times.
Claims (8)
1. A preparation method of ionic liquid for separating ethyl formate-methanol azeotropic system is disclosed, the synthesized ionic liquid anion is diethyl phosphate, and the method is characterized in that: the ionic liquid is characterized in that a diethyl phosphate anion in the ionic liquid has a phosphorus-oxygen double bond, and generates a difficultly volatile ionic liquid-methanol association complex with a component methanol in an ethyl formate-methanol azeotropic system under the action of chemical affinity, hydrogen bond force and ionic electrostatic attraction, the number of molecules of the methanol in a balance vapor phase in the component is reduced, the vapor pressure of the methanol is reduced, the vapor phase partial pressure of the ethyl formate is increased, and the separation of the ethyl formate-methanol azeotropic system is realized, wherein the preparation process of the ionic liquid comprises the following two steps:
1.1 Preparation of 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid: firstly, weighing reactants of 44.2364 g-51.6092 g of N-methylimidazole and 16.6000 g-19.3780 g of triethyl phosphate, sequentially placing the reactants in a 250 mL round-bottom flask, introducing nitrogen for 10 minutes, connecting a condensation reflux device, and reacting for 2 hours-3 hours under water bath ultrasound at 80-90 ℃ to obtain 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid containing unreacted reactants;
1.2 Purifying 1-ethyl-3-methylimidazole diethyl phosphate ionic liquid: using petroleum ether as an extracting agent, repeatedly extracting 1-ethyl-3-methylimidazole diethyl phosphate for 3 times, removing unreacted reactants, performing rotary evaporation by using a rotary evaporator to remove the petroleum ether, transferring the obtained ionic liquid into a 150 mL beaker, placing the beaker in a vacuum oven at the temperature of 60-70 ℃, and drying for 18-24 hours to remove unreacted N-methylimidazole and triethyl phosphate, thus obtaining the 1-butyl-3-methylimidazole diethyl phosphate ionic liquid.
2. The method for preparing ionic liquid for separating ethyl formate-methanol azeotropic system as described in claim 1, wherein said method comprises the following steps: the ionic liquid has selective separation on an ethyl formate-methanol azeotropic system.
3. The method for preparing ionic liquid for separating ethyl formate-methanol azeotropic system as described in claim 1, wherein said method comprises the following steps: the component with stronger polarity in the ionic liquid and ethyl formate-methanol system is methanol.
4. The method for preparing the ionic liquid for the separation of the ethyl formate-methanol azeotropic system according to claim 1, which is characterized in that: the ionic liquid forms a solvation effect with component methanol in an ethyl formate-methanol azeotropic system.
5. The method for preparing ionic liquid for separating ethyl formate-methanol azeotropic system as described in claim 1, wherein said method comprises the following steps: the ionic liquid reduces the volatility of the component methanol in an ethyl formate-methanol azeotropic system.
6. The method for preparing ionic liquid for separating ethyl formate-methanol azeotropic system as described in claim 1, wherein said method comprises the following steps: the ionic liquid improves the relative volatility of the component ethyl formate in an ethyl formate-methanol azeotropic system.
7. The method for preparing ionic liquid for separating ethyl formate-methanol azeotropic system as described in claim 1, wherein said method comprises the following steps: the ionic liquid enables ethyl formate to show a salting-out effect in a solution in an ethyl formate-methanol azeotropic system.
8. The method for preparing the ionic liquid for the separation of the ethyl formate-methanol azeotropic system according to claim 1, which is characterized in that: the molar content of the ionic liquid in an ethyl formate-methanol azeotropic system is 5-10%, and the separation temperature is 50-70 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211681178.8A CN115724880A (en) | 2022-12-27 | 2022-12-27 | Preparation method of ionic liquid for separating ethyl formate-methanol azeotropic system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211681178.8A CN115724880A (en) | 2022-12-27 | 2022-12-27 | Preparation method of ionic liquid for separating ethyl formate-methanol azeotropic system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115724880A true CN115724880A (en) | 2023-03-03 |
Family
ID=85301984
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211681178.8A Pending CN115724880A (en) | 2022-12-27 | 2022-12-27 | Preparation method of ionic liquid for separating ethyl formate-methanol azeotropic system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115724880A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107501187A (en) * | 2016-06-14 | 2017-12-22 | 赢创德固赛有限公司 | The method for preparing high-purity imidazole salts |
-
2022
- 2022-12-27 CN CN202211681178.8A patent/CN115724880A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107501187A (en) * | 2016-06-14 | 2017-12-22 | 赢创德固赛有限公司 | The method for preparing high-purity imidazole salts |
Non-Patent Citations (5)
| Title |
|---|
| JUN CAO ET AL: "Determination of Vapor−Liquid Equilibrium of Methyl Acetate + Methanol + 1 ‑Alkyl-3-methylimidazolium Dialkylphosphates at 101.3 kPa", J. CHEM. ENG. DATA, vol. 62, pages 816 * |
| MARIE F. THOMAS ET AL: "Enzyme activity in dialkyl phosphate ionic liquids", BIORESOURCE TECHNOLOGY, vol. 102, pages 11200, XP028108841, DOI: 10.1016/j.biortech.2011.09.069 * |
| ZHIGANG ZHANG ET AL: "Isobaric Vapor−Liquid Equilibria for Ethyl Acetate + Methanol + Ionic Liquids Ternary Systems at 101.3 kPa", J. CHEM. ENG. DATA, vol. 61, pages 772 * |
| 卢向军;窦辉;戴耀东;陈达;: "磷酸酯盐离子液体的微波辅助合成及其在Knoevenagel反应中的应用", 南京航空航天大学学报, no. 03, pages 414 - 417 * |
| 陶伟娜;王少君;李飞;: "微晶纤维素在EMIM-DEP中的溶解与再生", 现代化工, no. 12, pages 41 - 45 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TW467893B (en) | Process for the chemical reaction of substances in a reaction column | |
| CN100334056C (en) | Production of unsaturated ketone | |
| US20150197473A1 (en) | Process for Producing Alpha-Fluoroaldehydes | |
| CN1073541C (en) | Process for separation of dimethyl ether and chloromethane in mixtures | |
| CN115724880A (en) | Preparation method of ionic liquid for separating ethyl formate-methanol azeotropic system | |
| US20120071690A1 (en) | Production of formamides | |
| CN107406469A (en) | For extracting C from aqueous stream1To C4The season aryl carboxylic acid salt composite of carboxylic acid | |
| JP3495541B2 (en) | Preparation of alkyl chloride | |
| CN1636422B (en) | Process for preparing beta-diketone compound and process for preparing metal complex thereof | |
| JP5211876B2 (en) | Method for producing high purity 2'-trifluoromethylpropiophenone | |
| CN106397080A (en) | Preparation method of alpha, beta-unsaturated ketone | |
| JP3502523B2 (en) | Continuous production of alkyl halides. | |
| CN102367230A (en) | Method for synthesizing nitrile from aldoxime | |
| JP2010037286A (en) | Method for producing n-propyl acetate | |
| US6429340B1 (en) | Process for producing 2,4,5,-trialkylbenzaldenhydes | |
| US3655745A (en) | Preparation of methacrylic acid | |
| CN106986746A (en) | A kind of method extracted with flash distillation integrated separation normal propyl alcohol and normal heptane mixture | |
| CN107628943B (en) | Preparation method of 5-chlorovaleryl chloride | |
| WO2003091222A1 (en) | Process for producing n-alkyl-n'-alkylimidazolium salt | |
| KR20160149440A (en) | Method for separating 3-hydroxypropionic acid and Acrylic Acid | |
| CN114539090B (en) | Method for preparing primary amide by heterogeneous catalysis of inorganic ammonium salt and olefin | |
| CN109206304A (en) | A kind of preparation method of 2,2- dimethoxy propane | |
| CN109851522B (en) | Method for preparing N-ethyl-L-menthyl formamide by inversion of N-ethyl-neo-menthyl formamide configuration | |
| CN109721064B (en) | Method for producing titanium silicalite molecular sieve, titanium silicalite molecular sieve produced by method and ammoximation reaction method | |
| CN115819207A (en) | Method for nickel catalytic synthesis of 1,1-disubstituted allene |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |