CN114588660A - Hydrophobic deep eutectic solvent and preparation method and application thereof - Google Patents
Hydrophobic deep eutectic solvent and preparation method and application thereof Download PDFInfo
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- CN114588660A CN114588660A CN202210178569.1A CN202210178569A CN114588660A CN 114588660 A CN114588660 A CN 114588660A CN 202210178569 A CN202210178569 A CN 202210178569A CN 114588660 A CN114588660 A CN 114588660A
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- levulinic acid
- eutectic solvent
- deep eutectic
- hydrophobic
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- 239000002904 solvent Substances 0.000 title claims abstract description 80
- 230000002209 hydrophobic effect Effects 0.000 title claims abstract description 77
- 230000005496 eutectics Effects 0.000 title claims abstract description 76
- 238000002360 preparation method Methods 0.000 title abstract description 8
- JOOXCMJARBKPKM-UHFFFAOYSA-N 4-oxopentanoic acid Chemical compound CC(=O)CCC(O)=O JOOXCMJARBKPKM-UHFFFAOYSA-N 0.000 claims abstract description 204
- 229940040102 levulinic acid Drugs 0.000 claims abstract description 101
- 238000000605 extraction Methods 0.000 claims abstract description 58
- 239000007864 aqueous solution Substances 0.000 claims abstract description 47
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 38
- 239000001257 hydrogen Substances 0.000 claims abstract description 38
- 238000000926 separation method Methods 0.000 claims abstract description 14
- 238000000034 method Methods 0.000 claims description 36
- 239000002028 Biomass Substances 0.000 claims description 21
- 239000000413 hydrolysate Substances 0.000 claims description 20
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 claims description 18
- 239000000203 mixture Substances 0.000 claims description 18
- XTAZYLNFDRKIHJ-UHFFFAOYSA-N n,n-dioctyloctan-1-amine Chemical compound CCCCCCCCN(CCCCCCCC)CCCCCCCC XTAZYLNFDRKIHJ-UHFFFAOYSA-N 0.000 claims description 14
- 238000002156 mixing Methods 0.000 claims description 11
- 239000007788 liquid Substances 0.000 claims description 10
- NOOLISFMXDJSKH-UTLUCORTSA-N (+)-Neomenthol Chemical compound CC(C)[C@@H]1CC[C@@H](C)C[C@@H]1O NOOLISFMXDJSKH-UTLUCORTSA-N 0.000 claims description 6
- NOOLISFMXDJSKH-UHFFFAOYSA-N DL-menthol Natural products CC(C)C1CCC(C)CC1O NOOLISFMXDJSKH-UHFFFAOYSA-N 0.000 claims description 6
- 229940041616 menthol Drugs 0.000 claims description 6
- 150000007524 organic acids Chemical class 0.000 claims description 5
- HTZCNXWZYVXIMZ-UHFFFAOYSA-M benzyl(triethyl)azanium;chloride Chemical compound [Cl-].CC[N+](CC)(CC)CC1=CC=CC=C1 HTZCNXWZYVXIMZ-UHFFFAOYSA-M 0.000 claims description 4
- SJWFXCIHNDVPSH-UHFFFAOYSA-N octan-2-ol Chemical compound CCCCCCC(C)O SJWFXCIHNDVPSH-UHFFFAOYSA-N 0.000 claims description 4
- 238000000746 purification Methods 0.000 claims description 4
- NHGXDBSUJJNIRV-UHFFFAOYSA-M tetrabutylammonium chloride Chemical compound [Cl-].CCCC[N+](CCCC)(CCCC)CCCC NHGXDBSUJJNIRV-UHFFFAOYSA-M 0.000 claims description 4
- 238000003756 stirring Methods 0.000 claims description 3
- USFRYJRPHFMVBZ-UHFFFAOYSA-M benzyl(triphenyl)phosphanium;chloride Chemical compound [Cl-].C=1C=CC=CC=1[P+](C=1C=CC=CC=1)(C=1C=CC=CC=1)CC1=CC=CC=C1 USFRYJRPHFMVBZ-UHFFFAOYSA-M 0.000 claims description 2
- LSEFCHWGJNHZNT-UHFFFAOYSA-M methyl(triphenyl)phosphanium;bromide Chemical compound [Br-].C=1C=CC=CC=1[P+](C=1C=CC=CC=1)(C)C1=CC=CC=C1 LSEFCHWGJNHZNT-UHFFFAOYSA-M 0.000 claims description 2
- XKBGEWXEAPTVCK-UHFFFAOYSA-M methyltrioctylammonium chloride Chemical compound [Cl-].CCCCCCCC[N+](C)(CCCCCCCC)CCCCCCCC XKBGEWXEAPTVCK-UHFFFAOYSA-M 0.000 claims description 2
- 235000005985 organic acids Nutrition 0.000 claims description 2
- 230000000694 effects Effects 0.000 abstract description 13
- 239000000243 solution Substances 0.000 abstract description 3
- 238000012360 testing method Methods 0.000 description 24
- 230000000052 comparative effect Effects 0.000 description 16
- 239000000370 acceptor Substances 0.000 description 13
- 238000002474 experimental method Methods 0.000 description 11
- 238000004128 high performance liquid chromatography Methods 0.000 description 10
- 239000012074 organic phase Substances 0.000 description 9
- -1 and meanwhile Substances 0.000 description 7
- 239000003795 chemical substances by application Substances 0.000 description 5
- 238000000638 solvent extraction Methods 0.000 description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 4
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 4
- 239000003153 chemical reaction reagent Substances 0.000 description 4
- 238000000622 liquid--liquid extraction Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000012071 phase Substances 0.000 description 4
- NOEGNKMFWQHSLB-UHFFFAOYSA-N 5-hydroxymethylfurfural Chemical compound OCC1=CC=C(C=O)O1 NOEGNKMFWQHSLB-UHFFFAOYSA-N 0.000 description 3
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 238000003181 co-melting Methods 0.000 description 3
- RJGBSYZFOCAGQY-UHFFFAOYSA-N hydroxymethylfurfural Natural products COC1=CC=C(C=O)O1 RJGBSYZFOCAGQY-UHFFFAOYSA-N 0.000 description 3
- 239000003960 organic solvent Substances 0.000 description 3
- 238000006467 substitution reaction Methods 0.000 description 3
- KBPLFHHGFOOTCA-UHFFFAOYSA-N 1-Octanol Chemical compound CCCCCCCCO KBPLFHHGFOOTCA-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexanone Chemical compound O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 description 2
- 239000007857 degradation product Substances 0.000 description 2
- 239000013067 intermediate product Substances 0.000 description 2
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 1
- NTIZESTWPVYFNL-UHFFFAOYSA-N Methyl isobutyl ketone Chemical compound CC(C)CC(C)=O NTIZESTWPVYFNL-UHFFFAOYSA-N 0.000 description 1
- UIHCLUNTQKBZGK-UHFFFAOYSA-N Methyl isobutyl ketone Natural products CCC(C)C(C)=O UIHCLUNTQKBZGK-UHFFFAOYSA-N 0.000 description 1
- 108010009736 Protein Hydrolysates Proteins 0.000 description 1
- 238000007171 acid catalysis Methods 0.000 description 1
- 239000003463 adsorbent Substances 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 230000000975 bioactive effect Effects 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 1
- 239000012069 chiral reagent Substances 0.000 description 1
- 239000008139 complexing agent Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000006184 cosolvent Substances 0.000 description 1
- XENIIJGPPUHXCO-UHFFFAOYSA-N decanoate;trioctylazanium Chemical compound CCCCCCCCCC([O-])=O.CCCCCCCC[NH+](CCCCCCCC)CCCCCCCC XENIIJGPPUHXCO-UHFFFAOYSA-N 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 239000003085 diluting agent Substances 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- BKAYWXOBNPAGQD-UHFFFAOYSA-N dodecanoate;trioctylazanium Chemical compound CCCCCCCCCCCC([O-])=O.CCCCCCCC[NH+](CCCCCCCC)CCCCCCCC BKAYWXOBNPAGQD-UHFFFAOYSA-N 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000032050 esterification Effects 0.000 description 1
- 238000005886 esterification reaction Methods 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 235000019253 formic acid Nutrition 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- FUZZWVXGSFPDMH-UHFFFAOYSA-N hexanoic acid Chemical compound CCCCCC(O)=O FUZZWVXGSFPDMH-UHFFFAOYSA-N 0.000 description 1
- NUKZAGXMHTUAFE-UHFFFAOYSA-N hexanoic acid methyl ester Natural products CCCCCC(=O)OC NUKZAGXMHTUAFE-UHFFFAOYSA-N 0.000 description 1
- 230000000887 hydrating effect Effects 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 239000000976 ink Substances 0.000 description 1
- 229910017053 inorganic salt Inorganic materials 0.000 description 1
- QXKAIJAYHKCRRA-UHFFFAOYSA-N l-lyxonate Chemical compound OCC(O)C(O)C(O)C(O)=O QXKAIJAYHKCRRA-UHFFFAOYSA-N 0.000 description 1
- 239000002029 lignocellulosic biomass Substances 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 150000002772 monosaccharides Chemical class 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 239000003755 preservative agent Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- STCOOQWBFONSKY-UHFFFAOYSA-N tributyl phosphate Chemical compound CCCCOP(=O)(OCCCC)OCCCC STCOOQWBFONSKY-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D11/00—Solvent extraction
- B01D11/04—Solvent extraction of solutions which are liquid
- B01D11/0492—Applications, solvents used
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
- C07C51/48—Separation; Purification; Stabilisation; Use of additives by liquid-liquid treatment
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention discloses a hydrophobic deep eutectic solvent and a preparation method and application thereof. According to the invention, the hydrophobic deep eutectic solvent is prepared by selecting a specific hydrogen bond donor and a specific hydrogen bond acceptor at a molar ratio of 1: 1-10: 1, and has a good extraction effect, and has an excellent extraction effect on an aqueous solution containing low, medium and high concentrations of levulinic acid. Effectively solves the problems of low extraction efficiency of the solution containing the levulinic acid with medium and high concentration and narrow initial concentration range of the extracted levulinic acid aqueous solution in the prior art. The hydrophobic deep eutectic solvent disclosed by the invention is applied to levulinic acid separation, the extraction process is simple, and the initial levulinic acid concentration range is wide.
Description
Technical Field
The invention belongs to the technical field of separation and purification, and particularly relates to a hydrophobic deep eutectic solvent as well as a preparation method and application thereof.
Background
Levulinic Acid (LA), also known as 4-oxovaleric acid, levogluconic acid or pentonic acid, is an important platform compound, has carboxyl and ketocarbonyl in molecules, can perform various reactions such as esterification, redox, substitution, polymerization and the like, and is widely applied to numerous fields such as chiral reagents, bioactive materials, polymers, lubricants, adsorbents, fillers, batteries, anti-freezing agents, preservatives, surfactants, ink, electronic products and the like. Levulinic acid can be obtained by further hydrating a 5-hydroxymethylfurfural (5-HMF) intermediate product prepared from monosaccharide generated by hydrolysis of lignocellulose biomass resources through acid catalysis. However, the process of converting lignocellulose biomass resources into levulinic acid is a complex reaction process, the levulinic acid and formic acid generated in the process are carboxylic acid substances, have strong affinity and are easy to dissolve in water, and meanwhile, degradation products also contain unreacted sugar, an intermediate product 5-HMF, other small molecular byproducts and high polymer byproducts. Therefore, in order to obtain a product with higher purity, the degradation product mixture must be separated and purified, the levulinic acid is separated from the lignocellulose hydrolysate, and the separation and purification are one of the important links in the process of preparing and producing the levulinic acid.
The prior common separation methods for levulinic acid include a reduced pressure distillation method, an adsorption method, an organic solvent extraction method and the like. The liquid-liquid extraction method has the characteristics of energy conservation, environmental protection, easy operation and the like, and is one of the main technical means for separating organic acid at present. Wherein, the extraction process of single organic solvent is mature, and there are many organic solvents suitable for extracting levulinic acid from aqueous solution, such as cyclohexanone, methyl isobutyl ketone, butyl acetate and the like. However, this method has problems such as low efficiency of extracting levulinic acid and difficulty in separating the extract.
In the prior art, tributyl phosphate is used as a complexing agent, ethyl acetate is used as a cosolvent, toluene is used as a diluent, and sodium chloride is used as an inorganic salt, so that the extraction efficiency of levulinic acid can be effectively improved, but the problem of multiple required reagents exists; in order to solve the problems, the prior art discloses a method for extracting levulinic acid by using a deep eutectic solvent of capric acid-tri-n-octylphosphonium oxide, which can effectively improve the extraction efficiency, but the extraction efficiency is not high, and the method is mainly concentrated in an aqueous solution containing medium-low concentration levulinic acid, and the initial concentration range of the extracted aqueous solution of levulinic acid is narrow (not higher than 15 g/L). Therefore, there is a need to develop an extraction agent with high extraction efficiency, which can effectively extract a wide concentration of levulinic acid solution, and optimize the extraction conditions of the organic acid for the extraction and separation of levulinic acid in biomass resource hydrolysate.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a hydrophobic deep eutectic solvent. The hydrophobic deep eutectic solvent has better extraction performance, and compared with the prior art, the extraction efficiency is improved; the method has good extraction effect on the levulinic acid aqueous solution with low, medium and high concentration, and effectively solves the problem that the initial concentration range of the extracted levulinic acid aqueous solution is narrow in the prior art.
Another object of the present invention is to provide a method for preparing the hydrophobic deep eutectic solvent.
The invention also aims to provide an application of the hydrophobic deep eutectic solvent in separation and purification of organic acid.
In order to achieve the purpose, the invention is realized by the following technical scheme:
the hydrophobic deep eutectic solvent consists of a hydrogen bond donor and a hydrogen bond acceptor, wherein the hydrogen bond donor is one or more of n-butyl alcohol, sec-octyl alcohol and menthol; the hydrogen bond acceptor is one or more of trioctylamine, tetrabutylammonium chloride, benzyltriethylammonium chloride, methyltrioctylammonium chloride, methyltriphenylphosphonium bromide and benzyltriphenylphosphonium chloride;
the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 1: 1-10: 1.
The inventor finds through experiments that the hydrophobic deep eutectic solvent obtained by combining specific hydrogen bond donors and hydrogen bond acceptors according to a specific ratio has excellent extraction effect on organic acids, particularly levulinic acid, and also has good extraction effect on aqueous solutions containing medium and high concentrations of levulinic acid.
Preferably, the hydrogen bond donor is one or more of n-butanol, sec-octanol and menthol, and the hydrogen bond acceptor is trioctylamine.
More preferably, the hydrogen bond donor is n-butanol and the hydrogen bond acceptor is trioctylamine.
Preferably, the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 3: 1-10: 1.
More preferably, the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 8: 1-10: 1.
The preparation method of the hydrophobic deep eutectic solvent comprises the following steps:
and mixing the hydrogen bond donor and the hydrogen bond acceptor, and stirring until the liquid is clear, thus obtaining the hydrophobic deep eutectic solvent.
A method for separating levulinic acid using a hydrophobic deep eutectic solvent, comprising the steps of: mixing the co-melting solvent with low hydrophobicity and depth in the method with the extract liquid to be extracted, and then sequentially extracting, standing and separating, wherein the extract liquid to be extracted is biomass hydrolysate or/and an aqueous solution containing levulinic acid.
If desired, the pH of the biomass hydrolysate or/and the aqueous solution containing levulinic acid can be adjusted. Preferably, the pH value of the biomass hydrolysate or/and the aqueous solution containing levulinic acid is 1-4.
More preferably, the pH value of the biomass hydrolysate or/and the aqueous solution containing levulinic acid is 1-3.
Preferably, the concentration of the levulinic acid in the biomass hydrolysate or/and the aqueous solution containing the levulinic acid is not more than 500 g/L.
More preferably, the concentration of the levulinic acid in the biomass hydrolysate or/and the aqueous solution containing the levulinic acid is 5-150 g/L.
In the invention, the volume ratio range of the extracting agent commonly used in the existing levulinic acid liquid-liquid extraction and biomass hydrolysate or/and aqueous solution containing levulinic acid can be referred to. Preferably, the volume ratio of the hydrophobic deep low-eutectic solvent to the biomass hydrolysate or/and the aqueous solution containing levulinic acid is 2: 1-1: 3.
More preferably, the volume ratio of the hydrophobic low-depth co-melting solvent to the biomass hydrolysate or/and the aqueous solution containing levulinic acid is 2: 1-1: 1.
More preferably, the volume ratio of the hydrophobic low depth co-melting solvent to the biomass hydrolysate or/and the aqueous solution containing levulinic acid is 2: 1.
In the invention, the conventional extraction temperature commonly used in the liquid-liquid extraction of levulinic acid can be referred to. Preferably, the extraction temperature is 20-60 ℃.
More preferably, the extraction temperature is 20-30 ℃.
In the invention, the conventional extraction time for liquid-liquid extraction of levulinic acid can be referred to. Preferably, the extraction time is 0.5-8 h.
More preferably, the extraction time is 0.5-4 h.
Preferably, the acid for adjusting the pH of the biomass hydrolysate or/and the aqueous solution containing levulinic acid is one or more of hydrochloric acid, sulfuric acid and acetic acid, and the alkali is sodium hydroxide.
Compared with the prior art, the invention has the following beneficial effects:
the invention provides a hydrophobic deep eutectic solvent which has excellent extraction effect in the separation of levulinic acid with different initial concentrations, is simple to operate, has easily controlled conditions, has good extraction effect on levulinic acid aqueous solutions with low, medium and high concentrations, and effectively solves the problems of narrow initial concentration range and low extraction efficiency of the levulinic acid aqueous solution extracted in the prior art. The hydrophobic deep eutectic solvent provided by the invention can achieve a balance effect in a short time when being applied to levulinic acid extraction, and can realize rapid and efficient extraction and separation of levulinic acid.
Detailed Description
The present invention is further described in detail below with reference to specific examples, which are provided for illustration only and are not intended to limit the scope of the present invention. The test methods used in the following examples are all conventional methods unless otherwise specified; the materials, reagents and the like used are, unless otherwise specified, commercially available reagents and materials.
Unless otherwise indicated, reagents and materials used in the following examples are commercially available.
The detection method of the extraction effect comprises the following steps: high performance liquid chromatography.
The specific test conditions were: the mobile phase used for the test is a 5mM dilute sulfuric acid solution, and the flow rate is 0.5 mL/min; the chromatographic column is HPX-87H; the test temperature was 55 ℃; the amount of sample was 10. mu.L.
The calculation method of the distribution constant comprises the following steps: the partition constant is mass concentration of levulinic acid in the extract phase/mass concentration of levulinic acid in the raffinate phase. The extraction efficiency calculation method comprises the following steps: the extraction efficiency (mass of levulinic acid in the extraction phase/mass of levulinic acid in the liquid to be separated as the raw material) is 100%.
The following examples and comparative examples were each prepared by preparing a hydrophobic deep eutectic solvent by the following method, and weighing each component in the molar ratio of table 1; the method comprises the following specific steps:
and mixing the hydrogen bond donor and the hydrogen bond acceptor according to a molar ratio, adding the mixture into a flask, and stirring the mixture at 35 ℃ until the liquid is uniform and clear. Subsequently, the obtained homogeneous clear liquid was stored at room temperature (298K) for 24h to obtain a hydrophobic deep eutectic solvent.
Table 1 examples 1 to 9 and comparative examples 1 to 6 kinds and amounts of hydrogen bond donor and hydrogen bond acceptor of hydrophobic deep eutectic solvents
| Hydrogen bond donors | Hydrogen bond acceptors | Hydrogen bond donor: hydrogen bond acceptor molar ratio | |
| Example 1 | N-butanol | Trioctylamine | 3:1 |
| Example 2 | N-butanol | Trioctylamine | 8:1 |
| Example 3 | N-butanol | Trioctylamine | 10:1 |
| Example 4 | N-butanol | Trioctylamine | 1:1 |
| Example 5 | N-butanol | Trioctylamine | 2:1 |
| Example 6 | Sec-octanol | Trioctylamine | 2:1 |
| Example 7 | Menthol | Trioctylamine | 2:1 |
| Example 8 | Paraoctanol (Sec. octanol) | Trioctylamine | 3:1 |
| Example 9 | Menthol | Trioctylamine | 3:1 |
| Comparative example 1 | Lauric acid | Methyl trioctyl ammonium chloride | 2:1 |
| Comparative example 2 | Lauric acid | Trioctylamine | 2:1 |
| Comparative example 3 | Capric acid | Tetrabutyl ammonium chloride | 2:1 |
| Comparative example 4 | Capric acid | Methyl trioctyl ammonium chloride | 2:1 |
| Comparative example 5 | Capric acid | Trioctylamine | 2:1 |
| Comparative example 6 | N-butanol | Trioctylamine | 1:3 |
Test 1
A method for separating levulinic acid using a hydrophobic deep eutectic solvent, comprising the steps of:
mixing an aqueous solution containing 15g/L and 100g/L of levulinic acid with the hydrophobic deep eutectic solvent prepared in examples 1 to 7 and the hydrophobic deep eutectic solvent prepared in comparative examples 1 to 6 according to a volume ratio of 1:1, mixing the mixture at room temperature (298K) by using a vortex mixer, placing the mixture in a shaking table at 30 ℃ and oscillating the mixture at 150rpm for 4 hours, standing the mixture for a period of time, and taking an upper organic phase for high performance liquid chromatography analysis.
Experiment 2 influence of different extraction temperatures on extraction results
A method for separating levulinic acid using a hydrophobic deep eutectic solvent, comprising the steps of:
an aqueous solution containing 15g/L and 100g/L levulinic acid was mixed with the hydrophobic deep eutectic solvent in example 1 at a volume ratio of 1:1, the mixture was mixed with a vortex mixer at room temperature (298K), and then shaken on a shaker at 150rpm for 4 hours at 20 ℃, and after standing for a while, the upper organic phase was taken out and subjected to HPLC analysis.
Tests 3 to 4
The procedure of trial 2 was repeated according to the parameters specified in table 2, and the test results are listed in table 2.
Experiment 5 Effect of adjusting different pH values on extraction Effect
A method for separating levulinic acid using a hydrophobic deep eutectic solvent, comprising the steps of:
adjusting pH of an aqueous solution containing 15g/L levulinic acid to 1 by hydrochloric acid, mixing the aqueous solution with a hydrophobic deep eutectic solvent 1 according to a volume ratio of 1:1, firstly mixing the aqueous solution and the hydrophobic deep eutectic solvent at room temperature (298K) by using a vortex mixer, then placing the mixture in a shaking table at 25 ℃ and oscillating the mixture at 150rpm for 4 hours, standing the mixture for a period of time, and then taking an upper organic phase to perform high performance liquid chromatography analysis.
Tests 6 to 7
The procedure of trial 5 was repeated according to the parameters specified in table 2, and the test results are listed in table 2.
Experiment 8-10 influence of different extraction times on extraction effect
A method for separating levulinic acid using a hydrophobic deep eutectic solvent, comprising the steps of:
an aqueous solution containing 15g/L and 100g/L levulinic acid was mixed with the hydrophobic deep eutectic solvent in example 1 at a volume ratio of 1:1, the mixture was mixed with a vortex mixer at room temperature (298K), and then the mixture was shaken on a shaker at 150rpm for 0.5h, 4h and 8h at 20 ℃ to obtain an upper organic phase, which was then subjected to HPLC analysis.
The procedure of trial 2 was repeated according to the parameters specified in table 2, and the test results are listed in table 2.
Test 11 Effect of aqueous solutions containing levulinic acid at various concentrations on the extraction
A method for separating levulinic acid using a hydrophobic deep eutectic solvent, comprising the steps of:
an aqueous solution containing 1g/L, 5g/L, 30g/L, 150g/L, 300g/L, 400g/L and 500g/L of levulinic acid and the hydrophobic deep eutectic solvent in example 1 were mixed in a volume ratio of 1:1, mixed at room temperature (298K) with a vortex mixer, and then placed on a shaker at 25 ℃ and shaken at 150rpm for 4 hours, and after standing for a while, the upper organic phase was taken out for HPLC analysis.
Experiment 12 influence of volume ratio of different levulinic acid-containing aqueous solutions and hydrophobic deep eutectic solvents on extraction efficiency
A method for separating levulinic acid using a hydrophobic deep eutectic solvent, comprising the steps of:
an aqueous solution containing 15g/L and 100g/L levulinic acid was mixed with the hydrophobic deep eutectic solvent in example 1 at a volume ratio of 1:2, the mixture was mixed with a vortex mixer at room temperature (298K), and then the mixture was shaken on a shaker at 150rpm for 4 hours at 25 ℃ and left for a while, and then the upper organic phase was taken out for HPLC analysis.
Test No. 13
The procedure of trial 13 was repeated with the parameters specified in table 2, but with the volume ratio of the levulinic acid-containing aqueous solution to the hydrophobic deep eutectic solvent of example 1 being 3:1, and the test results are listed in table 2.
Test 14
A method of separating levulinic acid using a hydrophobic deep eutectic solvent, comprising the steps of:
aqueous solutions containing 1g/L, 15g/L, 100g/L and 150g/L levulinic acid were mixed with the hydrophobic deep eutectic solvent of example 8 in a volume ratio of 1:1, mixed with a vortex mixer at room temperature (298K), shaken in a shaker at 150rpm for 4 hours at 25 ℃, and after standing for a while, the upper organic phase was taken out for HPLC analysis.
Test 15
A method for separating levulinic acid using a hydrophobic deep eutectic solvent, comprising the steps of:
aqueous solutions containing 1g/L, 15g/L, 100g/L and 150g/L levulinic acid were mixed with the hydrophobic deep eutectic solvent of example 9 in a volume ratio of 1:1, mixed with a vortex mixer at room temperature (298K), shaken in a shaker at 150rpm for 4 hours at 25 ℃, and after standing for a while, the upper organic phase was taken out for HPLC analysis.
Test 16
A method of separating levulinic acid using a hydrophobic deep eutectic solvent, comprising the steps of:
mixing lignocellulose biomass resource hydrolysate with the hydrophobic deep eutectic solvent in the embodiments 1, 8-9 according to a volume ratio of 1:1, firstly mixing the lignocellulose biomass resource hydrolysate with a vortex mixer at room temperature (298K), then placing the mixture in a shaking table at 25 ℃ and oscillating the mixture at 150rpm for 4 hours, and taking an upper organic phase for high performance liquid chromatography after standing for a period of time; wherein, the concentration of the levulinic acid in the lignocellulose biomass resource hydrolysate is 15.5 g/L.
The test results of tests 1 to 16 are shown in Table 2, and the volume ratio is VThe liquid to be extracted/VExtracting agentThe extract to be extracted is biomass hydrolysate or/and an aqueous solution containing levulinic acid, and the extracting agent is a hydrophobic deep eutectic solvent.
TABLE 2 test results of test 1 to test 16
It can be seen from the results of comparing the hydrophobic deep eutectic solvents in different examples and comparative examples in levulinic acid separation in experiment 1 that the distribution constant and the extraction efficiency of the hydrophobic deep eutectic solvent prepared by the preparation method of the invention applied to levulinic acid separation are significantly higher than those of the hydrophobic deep eutectic solvent prepared by the comparative example applied to levulinic acid-containing aqueous solution separation, which indicates that the hydrophobic deep eutectic solvent prepared by the preparation method of the invention can efficiently extract and separate levulinic acid.
As can be seen from comparative experiments 2 to 4, the distribution constant of the hydrophobic deep eutectic solvent prepared in the embodiment 1 is not lower than 4.95 at different extraction temperatures, the extraction efficiency is not lower than 83.19%, and although the distribution constant and the extraction efficiency are slightly reduced at the extraction temperature of 60 ℃, the distribution constant and the extraction efficiency are still significantly higher than those of the hydrophobic deep eutectic solvent prepared in the comparative examples 1 to 5 when the hydrophobic deep eutectic solvent is applied to separation of an aqueous solution containing levulinic acid.
As can be seen from comparative experiments 5-7, the distribution constant of the hydrophobic deep eutectic solvent prepared in the embodiment 1 of the invention in the aqueous solutions containing levulinic acid with different pH values is not lower than 2.59, the extraction efficiency is not lower than 72.15%, the pH value of the aqueous solution containing levulinic acid is reduced, and the hydrophobic deep eutectic solvent prepared in the embodiment 1 of the invention is more beneficial to extracting levulinic acid.
As can be seen from comparative experiments 8-10, the distribution constants of the hydrophobic deep eutectic solvent prepared in the embodiment 1 of the invention are not lower than 9.14 at different extraction times, the extraction efficiency is not lower than 90.10%, and the hydrophobic deep eutectic solvent prepared by the preparation method of the invention can realize rapid separation of levulinic acid.
It can be seen from experiment 11 that the hydrophobic deep eutectic solvent prepared in example 1 of the present invention has a distribution constant of 2.21 or less and an extraction efficiency of 68.83 or less in the extraction of levulinic acid-containing aqueous solutions of different concentrations, and the distribution constant and the extraction efficiency of the hydrophobic deep eutectic solvent prepared in example 1 of the present invention increase first and then decrease as the initial concentration of the levulinic acid-containing aqueous solution increases.
As can be seen from comparison tests 12 and 13, when the hydrophobic deep eutectic solvent prepared in the embodiment 1 of the invention is used for extracting levulinic acid, the distribution constant is not lower than 5.05 and the extraction efficiency is not lower than 62.86% when different volume ratios of the aqueous solution containing the levulinic acid and the deep eutectic solvent are different, and the distribution constant and the extraction efficiency are obviously higher than those when the hydrophobic deep eutectic solvent prepared in the comparative examples 1-5 is used for separating the levulinic acid.
It can be seen from comparison between test 14 and test 15 that the hydrophobic deep eutectic solvents prepared in examples 8 and 9 of the present invention have distribution constants of not less than 1.97 and extraction efficiencies of not less than 66.29 in the extraction of the levulinic acid-containing aqueous solutions of different concentrations, and the distribution constants and the extraction efficiencies of the hydrophobic deep eutectic solvents prepared in the present invention decrease after increasing with the increase of the initial concentration of the levulinic acid-containing aqueous solution in test 11.
It can be seen from experiment 16 that the hydrophobic deep eutectic solvents prepared in examples 1, 8 and 9 of the present invention are also suitable for separating levulinic acid from hydrolysate of lignocellulosic biomass resources.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.
Claims (10)
1. The hydrophobic deep eutectic solvent is characterized by consisting of a hydrogen bond donor and a hydrogen bond acceptor, wherein the hydrogen bond donor is one or more of n-butyl alcohol, sec-octyl alcohol and menthol; the hydrogen bond acceptor is one or more of trioctylamine, tetrabutylammonium chloride, benzyltriethylammonium chloride, methyltrioctylammonium chloride, methyltriphenylphosphonium bromide and benzyltriphenylphosphonium chloride;
the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 1: 1-10: 1.
2. The hydrophobic deep eutectic solvent of claim 1, wherein the hydrogen bond donor is one of n-butanol, sec-octanol and menthol, and the hydrogen bond acceptor is trioctylamine.
3. The method for preparing the hydrophobic deep eutectic solvent according to any one of claims 1 to 2, comprising the steps of:
and mixing the hydrogen bond donor and the hydrogen bond acceptor, and stirring until the liquid is clear, thus obtaining the hydrophobic deep eutectic solvent.
4. Use of the hydrophobic deep eutectic solvent according to any one of claims 1 to 2 for separation and purification of organic acids.
5. A method for separating levulinic acid by using a hydrophobic deep eutectic solvent is characterized in that the hydrophobic deep eutectic solvent as claimed in any one of claims 1-2 is mixed with an extract to be extracted, and then the mixture is sequentially extracted, kept stand and separated, wherein the extract to be extracted is biomass hydrolysate or/and an aqueous solution containing the levulinic acid.
6. The method for separating levulinic acid according to claim 5, further comprising the following step before the hydrophobic deep eutectic solvent is mixed with the liquid to be extracted: adjusting the pH value of the extract liquid to be 1-4.
7. The method for separating levulinic acid from the hydrophobic deep eutectic solvent according to any one of claims 5 to 6, wherein the concentration of the levulinic acid in the biomass hydrolysate or/and the aqueous solution containing the levulinic acid is not more than 500 g/L.
8. The method for separating levulinic acid by using the hydrophobic deep eutectic solvent as claimed in any one of claims 5 to 6, wherein the mixing volume ratio of the hydrophobic deep eutectic solvent to the levulinic acid in the biomass hydrolysate or/and the levulinic acid-containing aqueous solution is 2: 1-1: 3.
9. The method for separating levulinic acid from a hydrophobic deep eutectic solvent according to any one of claims 5 to 6, wherein the extraction temperature is 20-60 ℃.
10. The method for separating levulinic acid from a hydrophobic deep eutectic solvent according to any one of claims 5 to 6, wherein the extraction time is 0.5 to 8 hours.
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