CN117417269A - Preparation method of anhydrous acetonitrile - Google Patents
Preparation method of anhydrous acetonitrile Download PDFInfo
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- CN117417269A CN117417269A CN202311743669.5A CN202311743669A CN117417269A CN 117417269 A CN117417269 A CN 117417269A CN 202311743669 A CN202311743669 A CN 202311743669A CN 117417269 A CN117417269 A CN 117417269A
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- WEVYAHXRMPXWCK-UHFFFAOYSA-N Acetonitrile Chemical compound CC#N WEVYAHXRMPXWCK-UHFFFAOYSA-N 0.000 title claims abstract description 333
- 238000002360 preparation method Methods 0.000 title claims abstract description 49
- 238000000034 method Methods 0.000 claims abstract description 45
- 230000008569 process Effects 0.000 claims abstract description 12
- 239000003795 chemical substances by application Substances 0.000 claims description 104
- 239000000243 solution Substances 0.000 claims description 59
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 58
- 239000007788 liquid Substances 0.000 claims description 53
- 238000003756 stirring Methods 0.000 claims description 46
- 239000000463 material Substances 0.000 claims description 42
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 40
- 239000007787 solid Substances 0.000 claims description 37
- 238000010438 heat treatment Methods 0.000 claims description 36
- 239000002131 composite material Substances 0.000 claims description 32
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 30
- 239000002808 molecular sieve Substances 0.000 claims description 29
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 claims description 29
- 229920001661 Chitosan Polymers 0.000 claims description 28
- 150000001875 compounds Chemical class 0.000 claims description 25
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 23
- 239000001508 potassium citrate Substances 0.000 claims description 21
- 229960002635 potassium citrate Drugs 0.000 claims description 21
- QEEAPRPFLLJWCF-UHFFFAOYSA-K potassium citrate (anhydrous) Chemical compound [K+].[K+].[K+].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O QEEAPRPFLLJWCF-UHFFFAOYSA-K 0.000 claims description 21
- 235000011082 potassium citrates Nutrition 0.000 claims description 21
- 238000006243 chemical reaction Methods 0.000 claims description 20
- 239000008367 deionised water Substances 0.000 claims description 20
- 229910021641 deionized water Inorganic materials 0.000 claims description 20
- 229910021389 graphene Inorganic materials 0.000 claims description 20
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 18
- 239000006087 Silane Coupling Agent Substances 0.000 claims description 17
- HPTYUNKZVDYXLP-UHFFFAOYSA-N aluminum;trihydroxy(trihydroxysilyloxy)silane;hydrate Chemical compound O.[Al].[Al].O[Si](O)(O)O[Si](O)(O)O HPTYUNKZVDYXLP-UHFFFAOYSA-N 0.000 claims description 17
- 239000002071 nanotube Substances 0.000 claims description 17
- PIICEJLVQHRZGT-UHFFFAOYSA-N Ethylenediamine Chemical compound NCCN PIICEJLVQHRZGT-UHFFFAOYSA-N 0.000 claims description 16
- 238000005406 washing Methods 0.000 claims description 16
- SXRSQZLOMIGNAQ-UHFFFAOYSA-N Glutaraldehyde Chemical compound O=CCCCC=O SXRSQZLOMIGNAQ-UHFFFAOYSA-N 0.000 claims description 15
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 claims description 15
- 238000001035 drying Methods 0.000 claims description 15
- 238000001914 filtration Methods 0.000 claims description 15
- 229910052621 halloysite Inorganic materials 0.000 claims description 15
- 239000007864 aqueous solution Substances 0.000 claims description 14
- 230000014759 maintenance of location Effects 0.000 claims description 13
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 12
- 238000007670 refining Methods 0.000 claims description 12
- LZZYPRNAOMGNLH-UHFFFAOYSA-M Cetrimonium bromide Chemical compound [Br-].CCCCCCCCCCCCCCCC[N+](C)(C)C LZZYPRNAOMGNLH-UHFFFAOYSA-M 0.000 claims description 10
- QOSSAOTZNIDXMA-UHFFFAOYSA-N Dicylcohexylcarbodiimide Chemical compound C1CCCCC1N=C=NC1CCCCC1 QOSSAOTZNIDXMA-UHFFFAOYSA-N 0.000 claims description 10
- 238000013329 compounding Methods 0.000 claims description 10
- 238000010992 reflux Methods 0.000 claims description 10
- 238000001816 cooling Methods 0.000 claims description 9
- 235000019441 ethanol Nutrition 0.000 claims description 8
- 238000011068 loading method Methods 0.000 claims description 8
- IDGUHHHQCWSQLU-UHFFFAOYSA-N ethanol;hydrate Chemical compound O.CCO IDGUHHHQCWSQLU-UHFFFAOYSA-N 0.000 claims description 7
- 238000012545 processing Methods 0.000 claims description 7
- 239000012299 nitrogen atmosphere Substances 0.000 claims description 6
- CSDREXVUYHZDNP-UHFFFAOYSA-N alumanylidynesilicon Chemical compound [Al].[Si] CSDREXVUYHZDNP-UHFFFAOYSA-N 0.000 claims description 5
- 238000001354 calcination Methods 0.000 claims description 5
- 239000006185 dispersion Substances 0.000 claims description 5
- 238000000605 extraction Methods 0.000 claims description 5
- 238000004108 freeze drying Methods 0.000 claims description 5
- 238000005087 graphitization Methods 0.000 claims description 5
- 239000000203 mixture Substances 0.000 claims description 5
- 239000002245 particle Substances 0.000 claims description 5
- 239000011148 porous material Substances 0.000 claims description 5
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 238000004321 preservation Methods 0.000 claims 2
- 230000000630 rising effect Effects 0.000 claims 1
- 238000001291 vacuum drying Methods 0.000 claims 1
- 239000012535 impurity Substances 0.000 abstract description 18
- 238000001179 sorption measurement Methods 0.000 abstract description 18
- 239000003463 adsorbent Substances 0.000 abstract description 14
- 238000004064 recycling Methods 0.000 abstract description 10
- 238000009776 industrial production Methods 0.000 abstract description 8
- 238000002835 absorbance Methods 0.000 description 24
- 230000000052 comparative effect Effects 0.000 description 15
- 238000011049 filling Methods 0.000 description 12
- 230000002159 abnormal effect Effects 0.000 description 8
- 238000001704 evaporation Methods 0.000 description 7
- 230000008020 evaporation Effects 0.000 description 7
- 230000007935 neutral effect Effects 0.000 description 4
- 239000002904 solvent Substances 0.000 description 4
- 238000003860 storage Methods 0.000 description 4
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000007800 oxidant agent Substances 0.000 description 3
- 230000001590 oxidative effect Effects 0.000 description 3
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 2
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- XXROGKLTLUQVRX-UHFFFAOYSA-N allyl alcohol Chemical compound OCC=C XXROGKLTLUQVRX-UHFFFAOYSA-N 0.000 description 2
- 239000003575 carbonaceous material Substances 0.000 description 2
- 229940079593 drug Drugs 0.000 description 2
- 239000003814 drug Substances 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- NOESYZHRGYRDHS-UHFFFAOYSA-N insulin Chemical compound N1C(=O)C(NC(=O)C(CCC(N)=O)NC(=O)C(CCC(O)=O)NC(=O)C(C(C)C)NC(=O)C(NC(=O)CN)C(C)CC)CSSCC(C(NC(CO)C(=O)NC(CC(C)C)C(=O)NC(CC=2C=CC(O)=CC=2)C(=O)NC(CCC(N)=O)C(=O)NC(CC(C)C)C(=O)NC(CCC(O)=O)C(=O)NC(CC(N)=O)C(=O)NC(CC=2C=CC(O)=CC=2)C(=O)NC(CSSCC(NC(=O)C(C(C)C)NC(=O)C(CC(C)C)NC(=O)C(CC=2C=CC(O)=CC=2)NC(=O)C(CC(C)C)NC(=O)C(C)NC(=O)C(CCC(O)=O)NC(=O)C(C(C)C)NC(=O)C(CC(C)C)NC(=O)C(CC=2NC=NC=2)NC(=O)C(CO)NC(=O)CNC2=O)C(=O)NCC(=O)NC(CCC(O)=O)C(=O)NC(CCCNC(N)=N)C(=O)NCC(=O)NC(CC=3C=CC=CC=3)C(=O)NC(CC=3C=CC=CC=3)C(=O)NC(CC=3C=CC(O)=CC=3)C(=O)NC(C(C)O)C(=O)N3C(CCC3)C(=O)NC(CCCCN)C(=O)NC(C)C(O)=O)C(=O)NC(CC(N)=O)C(O)=O)=O)NC(=O)C(C(C)CC)NC(=O)C(CO)NC(=O)C(C(C)O)NC(=O)C1CSSCC2NC(=O)C(CC(C)C)NC(=O)C(NC(=O)C(CCC(N)=O)NC(=O)C(CC(N)=O)NC(=O)C(NC(=O)C(N)CC=1C=CC=CC=1)C(C)C)CC1=CN=CN1 NOESYZHRGYRDHS-UHFFFAOYSA-N 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- CSDQQAQKBAQLLE-UHFFFAOYSA-N 4-(4-chlorophenyl)-4,5,6,7-tetrahydrothieno[3,2-c]pyridine Chemical compound C1=CC(Cl)=CC=C1C1C(C=CS2)=C2CCN1 CSDQQAQKBAQLLE-UHFFFAOYSA-N 0.000 description 1
- 102000004877 Insulin Human genes 0.000 description 1
- 108090001061 Insulin Proteins 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 229930012538 Paclitaxel Natural products 0.000 description 1
- 229930003451 Vitamin B1 Natural products 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 239000012847 fine chemical Substances 0.000 description 1
- 239000000796 flavoring agent Substances 0.000 description 1
- 235000019634 flavors Nutrition 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229940125396 insulin Drugs 0.000 description 1
- 239000000543 intermediate Substances 0.000 description 1
- 238000011005 laboratory method Methods 0.000 description 1
- 238000004811 liquid chromatography Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 229960001592 paclitaxel Drugs 0.000 description 1
- 239000012286 potassium permanganate Substances 0.000 description 1
- FVSKHRXBFJPNKK-UHFFFAOYSA-N propionitrile Chemical compound CCC#N FVSKHRXBFJPNKK-UHFFFAOYSA-N 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000006479 redox reaction Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000006722 reduction reaction Methods 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- RCINICONZNJXQF-MZXODVADSA-N taxol Chemical compound O([C@@H]1[C@@]2(C[C@@H](C(C)=C(C2(C)C)[C@H](C([C@]2(C)[C@@H](O)C[C@H]3OC[C@]3([C@H]21)OC(C)=O)=O)OC(=O)C)OC(=O)[C@H](O)[C@@H](NC(=O)C=1C=CC=CC=1)C=1C=CC=CC=1)O)C(=O)C1=CC=CC=C1 RCINICONZNJXQF-MZXODVADSA-N 0.000 description 1
- 229960003495 thiamine Drugs 0.000 description 1
- DPJRMOMPQZCRJU-UHFFFAOYSA-M thiamine hydrochloride Chemical compound Cl.[Cl-].CC1=C(CCO)SC=[N+]1CC1=CN=C(C)N=C1N DPJRMOMPQZCRJU-UHFFFAOYSA-M 0.000 description 1
- 239000011691 vitamin B1 Substances 0.000 description 1
- 235000010374 vitamin B1 Nutrition 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C253/00—Preparation of carboxylic acid nitriles
- C07C253/32—Separation; Purification; Stabilisation; Use of additives
- C07C253/34—Separation; Purification
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Treatment Of Liquids With Adsorbents In General (AREA)
Abstract
The invention provides a preparation method of anhydrous acetonitrile, belonging to the field of anhydrous acetonitrile preparation. The preparation method of the anhydrous acetonitrile comprises the following steps: primary micro-treatment, secondary micro-treatment, tertiary micro-treatment, and quaternary micro-treatment. According to the preparation method of the anhydrous acetonitrile, an adsorption-rectification process is adopted, so that the treatment efficiency and the treatment capacity can be effectively improved, the treatment stability can be improved, the quality of the prepared anhydrous acetonitrile is stable, the impurity and the moisture content are controlled within low levels, and the method can be suitable for the requirements of large-scale industrial production; and further improves the adsorption stability and recycling performance of the adsorbent, and the service life of the adsorbent is long.
Description
Technical Field
The invention relates to the field of anhydrous acetonitrile preparation, in particular to a preparation method of anhydrous acetonitrile.
Background
Acetonitrile is a colorless transparent liquid, and its most important uses are as a solvent, such as a solvent for extracting butadiene and a solvent for organic synthesis. Meanwhile, acetonitrile is an important raw material of medicines (vitamin B1) and flavor intermediates, and high-purity acetonitrile can be used as a mobile phase of liquid chromatography or an important solvent for preparing medicines such as purified insulin, taxol and the like. Although the purity of the industrial grade acetonitrile reaches a higher level, the industrial grade acetonitrile still contains various trace impurities such as propionitrile, acetone, allyl alcohol, acrylic acid, toluene, water and the like, and cannot meet the application requirements of high-end fields such as fine chemical industry, biological pharmacy, biosynthesis, scientific research and development and the like.
In the prior art, aiming at the process for preparing anhydrous acetonitrile by adopting industrial acetonitrile, the anhydrous acetonitrile is prepared by mainly dehydrating industrial acetonitrile, adding an oxidant for oxidation-reduction reaction, removing impurities, rectifying at multiple stages and the like. Wherein the oxidant mainly comprises Taurtrione, poly-methanol, potassium permanganate, sulfuric acid, calcium hydride, ozone, etc. However, the process has the problems of complicated flow, large oxidant residue and difficult equipment maintenance.
Meanwhile, technical schemes for carrying out adsorption refining on industrial acetonitrile by adopting an adsorbent are disclosed in the prior art; however, the existing adsorption-rectification method for preparing anhydrous acetonitrile has the problems of low treatment efficiency, unsatisfactory adsorption stability, high later rectification treatment difficulty and high energy consumption; and the performance of the adopted adsorbent is obviously degraded, and the recycling property of the adsorbent is not ideal; and the comprehensive results in ideal initial operation effect of the adsorption-rectification system, but with the increase of the operation time, the prepared acetonitrile has the problems of unstable quality and substandard impurity content. Furthermore, the existing adsorption-rectification methods are all small-scale laboratory methods, and are affected by a plurality of external factors in the process of capacity expansion, so that the preparation process is more uncontrollable and cannot meet the requirements of large-scale industrial production.
Chinese patent CN105439903a discloses a method for preparing chromatographic acetonitrile by using industrial acetonitrile, which uses graphene oxide as adsorbent, and in heating environment, the industrial acetonitrile is adsorbed and decontaminated, and at the same time distilled to extract fraction, then distilled and purified to obtain anhydrous acetonitrile. However, the invention has the disadvantage of low treatment efficiency for industrial grade acetonitrile; the adsorption effect of the graphene oxide adopted in the heating environment is poor, and the acetonitrile prepared by long-term operation is unstable in quality; meanwhile, the recycling performance of the graphene oxide adsorbent adopted by the method is poor, and the adsorption performance is obviously reduced after the graphene oxide adsorbent is repeatedly used for four times; moreover, the technical scheme of the invention is also a laboratory-scale acetonitrile preparation method, the processing time of the industrial grade acetonitrile of several kilograms is at least more than ten hours (the rectification processing time is counted), and the method cannot be suitable for the requirements of large-scale industrial production.
Disclosure of Invention
In order to solve the technical problems in the prior art, the invention provides a preparation method of anhydrous acetonitrile, which adopts an adsorption-rectification process, can effectively improve the treatment efficiency and the treatment capacity and simultaneously improve the treatment stability, and the prepared anhydrous acetonitrile has stable quality, the impurity and the moisture content are controlled within low levels, and can be suitable for the requirements of large-scale industrial production; and further improves the adsorption stability and recycling performance of the adsorbent, and the service life of the adsorbent is long.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows:
the preparation method of the anhydrous acetonitrile comprises the following steps: primary micro-treatment, secondary micro-treatment, tertiary micro-treatment, and quaternary micro-treatment.
The primary micro-treatment method is that industrial grade acetonitrile is fed into a first micro-reactor of a micro-channel reaction device through a high-level tank at a feeding rate of 0.02-0.03kg/s, the temperature of the first micro-reactor is controlled to be 35-40 ℃, and the material retention time is controlled to be 360-420s, so that a first micro-treatment liquid is obtained.
In the primary micro-treatment, a first micro-treatment agent is filled in a first micro-reactor, and the filling amount of the first micro-treatment agent is 2-2.5wt% of the total weight of the industrial grade acetonitrile;
the first micro-treating agent is a mixture of a 3A molecular sieve and a 4A molecular sieve, and the weight ratio of the 3A molecular sieve to the 4A molecular sieve is 2-2.5:1.
The secondary micro-treatment method comprises the steps of feeding a first micro-treatment liquid obtained by primary micro-treatment into a second micro-reactor of a micro-channel reaction device, controlling the temperature of the second micro-reactor to be 40-45 ℃ and the material residence time to be 300-360s, so as to obtain a second micro-treatment liquid.
In the secondary micro-treatment, a second micro-treatment agent is filled in the second micro-reactor, and the filling amount of the second micro-treatment agent is 2-2.5wt% of the total weight of the industrial grade acetonitrile.
The preparation method of the second micro-treating agent comprises the steps of adding hexadecyl trimethyl ammonium bromide into deionized water, and uniformly stirring; continuously adding ethyl orthosilicate and sodium hydroxide, and uniformly stirring; continuously adding mesoporous activated carbon and Na-MCM-22 molecular sieve, uniformly dispersing by ultrasonic, heating to 40-45 ℃, preserving heat and stirring for 4-5 hours, heating to 145-150 ℃ at a heating rate of 0.8-1 ℃/min, preserving heat for 40-42 hours, and filtering out solid matters; washing solid matters with enough deionized water to be neutral, placing the solid matters in an environment with the vacuum degree of 0.08-0.09MPa, drying the solid matters at the temperature of 80-85 ℃ for 8-10 hours, transferring the solid matters into a roasting furnace, heating the solid matters to 480-500 ℃ at the heating rate of 1.2-1.5 ℃/min, preserving heat and roasting the solid matters for 4-5 hours, naturally cooling the solid matters to normal temperature, and granulating the solid matters to obtain the second micro-treating agent.
In the preparation of the second micro-treating agent, the molar ratio of hexadecyl trimethyl ammonium bromide to tetraethoxysilane to sodium hydroxide to deionized water is 0.48-0.5:1-1.02:0.11-0.12:50-52;
the weight ratio of the mesoporous activated carbon to the Na-MCM-22 molecular sieve to the ethyl orthosilicate is 1.5-2:1.5-2:2.2-2.5;
the particle diameter of the mesoporous activated carbon is 150-200 mu m, and the specific surface area is 1100-1200m 2 Per gram, average pore diameter of 5-10nm, graphitization degree (XDR method) of 55-60%;
the Na-MCM-22 molecular sieve has a silicon-aluminum ratio of 30-32:1 and a crystallinity of 98-99%.
The third micro-treatment method is that the second micro-treatment liquid obtained by the second micro-treatment is fed into a third micro-reactor of a micro-channel reaction device, the temperature of the third micro-reactor is controlled to be 45-50 ℃, and the material retention time is 180-240s, so that the third micro-treatment liquid is obtained.
In the three times of micro-treatment, the third micro-reactor is filled with a compound micro-treating agent, and the filling amount of the compound micro-treating agent is 1-1.2wt% of the total weight of the industrial grade acetonitrile.
The preparation method of the composite micro-treating agent comprises the following steps: preparing a first component, preparing a second component, and compounding.
The method for preparing the first component comprises the steps of putting chitosan into an acetic acid aqueous solution with the concentration of 1.8-2wt percent, uniformly dispersing, and preparing a chitosan solution with the concentration of 1.2-1.5wt percent; then, graphene oxide is put into a chitosan solution, and after uniform dispersion, potassium citrate solution is dripped at the dripping rate of 0.4-0.5mL/min under the stirring condition of 500-600 rpm; continuously stirring for 20-30min after the potassium citrate solution is added dropwise; then adding glutaraldehyde solution, dispersing uniformly, standing for 20-24h, and freeze-drying to obtain freeze-dried substance; transferring the freeze-dried material into a calciner, calcining for 2-3 hours at 700-750 ℃ in a nitrogen atmosphere environment, and naturally cooling to obtain a calcined material; the calcined material is washed by deionized water and dried to prepare a first component.
In the preparation of the first component, the weight ratio of graphene oxide to chitosan is 1:3-3.5;
the concentration of the potassium citrate solution is 18-20wt%;
the concentration of glutaraldehyde solution is 22-23wt%;
the volume ratio of the chitosan solution to the potassium citrate solution to the glutaraldehyde solution is 100:5-5.5:0.5-0.6.
The method for preparing the second component comprises the steps of putting halloysite nanotubes into absolute ethyl alcohol with the weight being 90-100 times that of the halloysite nanotubes, uniformly dispersing, and then dripping ethylenediamine at the dripping rate of 2-2.5mL/min under the stirring condition; after the dripping of the ethylenediamine is completed, continuously stirring for 40-60min, adding dicyclohexylcarbodiimide, heating to 75-80 ℃, preserving heat for 10-12h, filtering out solid matters, washing the solid matters by absolute ethyl alcohol, and drying to obtain a second component.
In the preparation of the second component, the weight ratio of halloysite nanotube, ethylenediamine and dicyclohexylcarbodiimide is 1:13-15:0.5-0.6.
The compounding method comprises the steps of adding the first component and the second component into ethanol water solution, uniformly dispersing, heating to 45-55 ℃, and preserving heat; then dripping the silane coupling agent KH-550 at a dripping rate of 1.5-2mL/min under the stirring condition; after the silane coupling agent KH-550 is added dropwise, continuing to keep the temperature and stir for 6-7 hours, and filtering out solid matters; washing the solid with absolute ethyl alcohol, drying and granulating to obtain the composite micro-treating agent.
In the compounding, the volume concentration of the ethanol water solution is 70-80%;
the weight ratio of the first component to the second component to the silane coupling agent KH-550 to the ethanol aqueous solution is 25-30:8-9:1.2-1.5:250-300.
The four times of micro-treatment method is that third micro-treatment liquid obtained by three times of micro-treatment is fed into a fourth micro-reactor of a micro-channel reaction device, the temperature of the fourth micro-reactor is controlled to be 50-55 ℃, the material retention time is 180-240s, and the fourth micro-treatment liquid is obtained and is introduced into a buffer tank for temporary storage.
In the four times of micro-treatment, a composite micro-treatment agent is filled in a fourth micro-reactor, and the composite micro-treatment agent is the same as the composite micro-treatment agent in the three times of micro-treatment;
the loading of the compound micro-treating agent in the fourth micro-reactor is 0.8-1wt% of the total weight of the industrial grade acetonitrile.
The refining method comprises the steps of introducing the fourth micro-treatment liquid in the buffer tank into a rectifying tower, controlling the pressure in the rectifying tower to be 0.6-0.7MPa, controlling the temperature at the top of the tower to be 95-100 ℃, controlling the temperature at the bottom of the tower to be 110-115 ℃, and carrying out total reflux for 20-30min; starting the lateral line extraction of the product, and controlling the reflux ratio to be 2.3-2.5:1 to prepare the anhydrous acetonitrile.
Compared with the prior art, the invention has the beneficial effects that:
(1) The preparation method of the anhydrous acetonitrile adopts the processes of primary micro-treatment, secondary micro-treatment, tertiary micro-treatment, quaternary micro-treatment and refining; setting a first micro-treating agent consisting of a 3A molecular sieve and a 4A molecular sieve in the primary micro-treatment process, controlling the temperature of a first micro-reactor and the material residence time, and carrying out targeted adsorption on water and a small amount of impurities in industrial acetonitrile; in the secondary micro-treatment process, a second micro-treatment agent prepared by compounding mesoporous activated carbon and Na-MCM-22 molecular sieve is arranged, the temperature of a second micro-reactor and the material residence time are controlled, and the moisture and impurities in the first micro-treatment liquid are subjected to targeted adsorption; in the three times of micro-treatment and four times of micro-treatment, a composite carbon material prepared from graphene oxide and chitosan is arranged, a composite micro-treatment agent prepared by compositing the graphene oxide and a modified halloysite nanotube is arranged, the temperature and the material residence time of a third micro-reactor and a fourth micro-reactor are controlled, and targeted secondary adsorption is carried out on impurities in the second micro-treatment liquid to obtain a fourth micro-treatment liquid; rectifying and refining the fourth micro-treatment liquid to obtain anhydrous acetonitrile; the treatment efficiency and the treatment capacity can be effectively improved, the treatment stability is improved, the quality of the prepared anhydrous acetonitrile is stable, the impurity and the moisture content are controlled within low levels, and the method can be suitable for the requirements of large-scale industrial production; and further improves the adsorption stability and recycling performance of the adsorbent, and the service life of the adsorbent is long.
(2) According to the preparation method of the anhydrous acetonitrile, the purity of the prepared anhydrous acetonitrile exceeds 99.99wt%, the yield is 98.4-98.7%, the moisture content is not more than 0.0015wt%, the acidity is not more than 0.002mmol/L, the alkalinity is not detected, and the evaporation residue is not more than 0.0001wt%; the absorbance at 200nm is 0.009-0.01, the absorbance at 210nm is 0.002-0.003, the absorbance at 220nm is 0, the absorbance at 230nm is 0, the absorbance at 240nm is 0, and the absorbance at 250nm is 0.
(3) Through experiments, the preparation method of the anhydrous acetonitrile is repeatedly carried out for 10 times, the quality of the prepared anhydrous acetonitrile is stable, the purity is over 99.99wt%, the yield, the moisture content and the absorbance at 200nm are free from abnormal fluctuation, the impurity and the moisture content can be controlled within low levels, and the method can be suitable for the requirements of large-scale industrial production.
(4) Through experiments, the preparation method of the anhydrous acetonitrile is adopted, and the second micro-treating agent and the composite micro-treating agent are adopted in a matching way, and the repeated operation is carried out for 20 times, so that the purity of the prepared anhydrous acetonitrile is 99.9957wt%, the yield is 97.3%, the moisture content is 0.0019wt%, and the absorbance at 200nm is 0.012; the second micro-treating agent and the composite micro-treating agent have good adsorption stability and recycling performance and long effective service life.
(5) The preparation method of anhydrous acetonitrile has simple process flow, is easy to control and is suitable for large-scale industrial production.
Detailed Description
Specific embodiments of the present invention will now be described in order to provide a clearer understanding of the technical features, objects and effects of the present invention.
Example 1
The preparation method of the anhydrous acetonitrile specifically comprises the following steps:
1. disposable micro-treatment
Industrial grade acetonitrile is fed into a first micro-reactor of a micro-channel reaction device through an overhead tank at a feeding rate of 0.02kg/s, the temperature of the first micro-reactor is controlled to be 35 ℃, and the material retention time is 360s, so that a first micro-treatment liquid is obtained.
Wherein, the first micro-reactor is filled with a first micro-treating agent, and the filling amount of the first micro-treating agent is 2wt% of the total weight of the industrial grade acetonitrile.
The first micro-treating agent is a mixture of a 3A molecular sieve and a 4A molecular sieve, and the weight ratio of the 3A molecular sieve to the 4A molecular sieve is 2:1.
The technical grade acetonitrile used in this example had a purity of 99.51wt%, a moisture content of 0.13wt%, an acidity of 0.009mmol/L, an alkalinity of 0.006mmol/L and an evaporation residue of 0.011wt%.
2. Secondary micro-treatment
Feeding the first micro-treatment liquid obtained by the primary micro-treatment into a second micro-reactor of a micro-channel reaction device, controlling the temperature of the second micro-reactor to be 40 ℃ and the material residence time to be 300s to obtain the second micro-treatment liquid.
Wherein, the second micro-reactor is filled with a second micro-treating agent, and the filling amount of the second micro-treating agent is 2wt% of the total weight of the industrial grade acetonitrile.
The preparation method of the second micro-treating agent comprises the steps of adding hexadecyl trimethyl ammonium bromide into deionized water, and uniformly stirring; continuously adding ethyl orthosilicate and sodium hydroxide, and uniformly stirring; continuously adding mesoporous activated carbon and Na-MCM-22 molecular sieve, uniformly dispersing by ultrasonic, heating to 40 ℃, preserving heat and stirring for 4 hours, heating to 145 ℃ at a heating rate of 0.8 ℃/min, preserving heat for 40 hours, and filtering out solid matters; washing the solid with enough deionized water to be neutral, placing in an environment with the vacuum degree of 0.08MPa, drying at 80 ℃ for 8 hours, transferring into a roasting furnace, heating to 480 ℃ at the heating rate of 1.2 ℃/min, preserving heat, roasting for 4 hours, naturally cooling to normal temperature, and granulating to obtain the second micro-treating agent.
Wherein, the molar ratio of the cetyl trimethyl ammonium bromide to the tetraethoxysilane to the sodium hydroxide to the deionized water is 0.48:1:0.11:50.
The weight ratio of the mesoporous activated carbon, the Na-MCM-22 molecular sieve and the ethyl orthosilicate is 1.5:1.5:2.2.
The particle diameter of the mesoporous activated carbon is 150 mu m, and the specific surface area is 1100m 2 The average pore diameter was 5nm and the graphitization degree (XDR method) was 55%.
The Na-MCM-22 molecular sieve has a silicon-aluminum ratio of 30:1 and a crystallinity of 98%.
3. Three times of micro-treatment
Feeding the second micro-treatment liquid obtained by the secondary micro-treatment into a third micro-reactor of the micro-channel reaction device, controlling the temperature of the third micro-reactor to be 45 ℃ and the material retention time to be 180s, thus obtaining the third micro-treatment liquid.
Wherein, the third micro-reactor is filled with a compound micro-treating agent, and the filling amount of the compound micro-treating agent is 1 weight percent of the total weight of the industrial grade acetonitrile.
The preparation method of the composite micro-treating agent comprises the following steps:
1) Preparation of the first component
Adding chitosan into acetic acid aqueous solution with the concentration of 1.8 weight percent, uniformly dispersing, and preparing chitosan solution with the concentration of 1.2 weight percent; then, graphene oxide is put into a chitosan solution, and after uniform dispersion, potassium citrate solution is dripped at a dripping rate of 0.4mL/min under the stirring condition of 500 rpm; after the potassium citrate solution is added dropwise, stirring is continued for 20min; then adding glutaraldehyde solution, uniformly dispersing, standing for 20 hours, and freeze-drying to obtain a freeze-dried product; transferring the freeze-dried material into a calciner, calcining for 2 hours at 700 ℃ in a nitrogen atmosphere environment, and naturally cooling to obtain a calcined material; the calcined material is washed by deionized water and dried to prepare a first component.
Wherein the weight ratio of graphene oxide to chitosan is 1:3.
The concentration of the potassium citrate solution was 18wt%.
The glutaraldehyde solution had a concentration of 22wt%.
The volume ratio of the chitosan solution to the potassium citrate solution to the glutaraldehyde solution is 100:5:0.5.
2) Preparation of the second component
Adding halloysite nanotubes into absolute ethyl alcohol with the weight being 90 times that of the halloysite nanotubes, uniformly dispersing, and then dropwise adding ethylenediamine under the stirring condition at the dropwise adding rate of 2mL/min; after the dripping of ethylenediamine is completed, continuously stirring for 40min, adding dicyclohexylcarbodiimide, heating to 75 ℃, preserving heat for 10h, filtering out solid matters, washing the solid matters by absolute ethyl alcohol, and drying to obtain a second component.
Wherein the weight ratio of halloysite nanotube, ethylenediamine and dicyclohexylcarbodiimide is 1:13:0.5.
3) Composite material
Adding the first component and the second component into ethanol water solution, uniformly dispersing, heating to 45 ℃, and preserving heat; then under the stirring condition, dropwise adding a silane coupling agent KH-550 at a dropwise adding rate of 1.5 mL/min; after the silane coupling agent KH-550 is added dropwise, continuing to keep the temperature and stir for 6 hours, and filtering out solid matters; washing the solid with absolute ethyl alcohol, drying and granulating to obtain the composite micro-treating agent.
Wherein the volume concentration of the ethanol aqueous solution is 70%.
The weight ratio of the first component to the second component to the silane coupling agent KH-550 to the ethanol aqueous solution is 25:8:1.2:250.
4. Four times of micro-treatment
And feeding the third micro-treatment liquid obtained by three times of micro-treatment into a fourth micro-reactor of the micro-channel reaction device, controlling the temperature of the fourth micro-reactor to be 50 ℃ and the material retention time to be 180s to obtain the fourth micro-treatment liquid, and introducing the fourth micro-treatment liquid into a buffer tank for temporary storage.
Wherein, the fourth micro-reactor is filled with a compound micro-treating agent which is the same as the compound micro-treating agent in the three times of micro-treatment.
The loading of the composite micro-treating agent in the fourth micro-reactor is 0.8wt% of the total weight of the technical grade acetonitrile.
5. Refining
Introducing the fourth micro-treatment liquid in the buffer tank into a rectifying tower, controlling the pressure in the rectifying tower to be 0.6MPa, the temperature of the top of the tower to be 95 ℃, the temperature of the tower kettle to be 110 ℃, and carrying out total reflux for 20min; starting the lateral line extraction of the product, and controlling the reflux ratio to be 2.3:1 to prepare the anhydrous acetonitrile.
Example 2
The preparation method of the anhydrous acetonitrile specifically comprises the following steps:
1. disposable micro-treatment
Industrial grade acetonitrile is fed into a first micro-reactor of a micro-channel reaction device through an overhead tank at a feeding rate of 0.025kg/s, the temperature of the first micro-reactor is controlled to be 38 ℃, and the material retention time is 400s, so as to obtain a first micro-treatment liquid.
Wherein, the first micro-reactor is filled with a first micro-treating agent, and the filling amount of the first micro-treating agent is 2.3 weight percent of the total weight of the industrial grade acetonitrile.
The first micro-treating agent is a mixture of a 3A molecular sieve and a 4A molecular sieve, and the weight ratio of the 3A molecular sieve to the 4A molecular sieve is 2.2:1.
The technical grade acetonitrile used in this example had a purity of 99.51wt%, a moisture content of 0.13wt%, an acidity of 0.009mmol/L, an alkalinity of 0.006mmol/L and an evaporation residue of 0.011wt%.
2. Secondary micro-treatment
Feeding the first micro-treatment liquid obtained by the primary micro-treatment into a second micro-reactor of a micro-channel reaction device, controlling the temperature of the second micro-reactor to be 42 ℃ and the material residence time to be 330s, thus obtaining the second micro-treatment liquid.
Wherein, the second micro-reactor is filled with a second micro-treating agent, and the filling amount of the second micro-treating agent is 2.2 weight percent of the total weight of the industrial grade acetonitrile.
The preparation method of the second micro-treating agent comprises the steps of adding hexadecyl trimethyl ammonium bromide into deionized water, and uniformly stirring; continuously adding ethyl orthosilicate and sodium hydroxide, and uniformly stirring; continuously adding mesoporous activated carbon and Na-MCM-22 molecular sieve, uniformly dispersing by ultrasonic, heating to 42 ℃, keeping the temperature, stirring for 4.5 hours, heating to 148 ℃ at a heating rate of 0.9 ℃/min, keeping the temperature for 41 hours, and filtering out solid matters; washing the solid with enough deionized water to be neutral, placing in an environment with the vacuum degree of 0.085MPa, drying at 82 ℃ for 9 hours, transferring into a roasting furnace, heating to 490 ℃ at the heating rate of 1.3 ℃/min, roasting at the temperature of 4.5 hours, naturally cooling to normal temperature, and granulating to obtain the second micro-treating agent.
Wherein, the molar ratio of the cetyl trimethyl ammonium bromide to the tetraethoxysilane to the sodium hydroxide to the deionized water is 0.49:1.01:0.115:51.
The weight ratio of the mesoporous activated carbon, the Na-MCM-22 molecular sieve and the ethyl orthosilicate is 1.8:1.7:2.3.
The particle diameter of the mesoporous activated carbon is 170 mu m, and the specific surface area is 1150m 2 The average pore diameter was 7nm and the graphitization degree (XDR method) was 57%.
The Na-MCM-22 molecular sieve has a silicon-aluminum ratio of 31:1 and a crystallinity of 98.5%.
3. Three times of micro-treatment
Feeding the second micro-treatment liquid obtained by the secondary micro-treatment into a third micro-reactor of the micro-channel reaction device, controlling the temperature of the third micro-reactor to be 48 ℃ and the material residence time to be 210s, thus obtaining the third micro-treatment liquid.
Wherein, the third micro-reactor is filled with a compound micro-treating agent, and the filling amount of the compound micro-treating agent is 1.1 weight percent of the total weight of the industrial grade acetonitrile.
The preparation method of the composite micro-treating agent comprises the following steps:
1) Preparation of the first component
Adding chitosan into acetic acid aqueous solution with the concentration of 1.9 weight percent, uniformly dispersing, and preparing chitosan solution with the concentration of 1.4 weight percent; then, graphene oxide is put into a chitosan solution, and after uniform dispersion, potassium citrate solution is dripped at the dripping rate of 0.45mL/min under the stirring condition of 550 rpm; after the potassium citrate solution is added dropwise, stirring is continued for 25min; then adding glutaraldehyde solution, uniformly dispersing, standing for 22 hours, and freeze-drying to obtain a freeze-dried product; transferring the freeze-dried material into a calciner, calcining for 2.5 hours at 720 ℃ in a nitrogen atmosphere environment, and naturally cooling to obtain a calcined material; the calcined material is washed by deionized water and dried to prepare a first component.
Wherein the weight ratio of graphene oxide to chitosan is 1:3.2.
The concentration of the potassium citrate solution was 19wt%.
The glutaraldehyde solution had a concentration of 22.5wt%.
The volume ratio of the chitosan solution to the potassium citrate solution to the glutaraldehyde solution is 100:5.2:0.55.
2) Preparation of the second component
Adding halloysite nanotubes into absolute ethyl alcohol with the weight being 95 times that of the halloysite nanotubes, uniformly dispersing, and then dropwise adding ethylenediamine under the stirring condition at the dropwise adding rate of 2.2 mL/min; after the dripping of ethylenediamine is completed, continuously stirring for 50min, adding dicyclohexylcarbodiimide, heating to 78 ℃, preserving heat for 11h, filtering out solid matters, washing the solid matters by absolute ethyl alcohol, and drying to obtain a second component.
Wherein the weight ratio of halloysite nanotube, ethylenediamine and dicyclohexylcarbodiimide is 1:14:0.55.
3) Composite material
Adding the first component and the second component into ethanol water solution, uniformly dispersing, heating to 50 ℃, and preserving heat; then under the stirring condition, dropwise adding a silane coupling agent KH-550 at a dropwise adding rate of 1.8 mL/min; after the silane coupling agent KH-550 is added dropwise, continuing to keep the temperature and stir for 6.5 hours, and filtering out solid matters; washing the solid with absolute ethyl alcohol, drying and granulating to obtain the composite micro-treating agent.
Wherein the volume concentration of the ethanol aqueous solution is 75%.
The weight ratio of the first component to the second component to the silane coupling agent KH-550 to the ethanol aqueous solution is 28:8.5:1.35:280.
4. Four times of micro-treatment
And feeding the third micro-treatment liquid obtained by three times of micro-treatment into a fourth micro-reactor of the micro-channel reaction device, controlling the temperature of the fourth micro-reactor to be 52 ℃, and the material residence time to be 210s to obtain the fourth micro-treatment liquid, and introducing the fourth micro-treatment liquid into a buffer tank for temporary storage.
Wherein, the fourth micro-reactor is filled with a compound micro-treating agent which is the same as the compound micro-treating agent in the three times of micro-treatment.
The loading of the composite micro-treating agent in the fourth micro-reactor is 0.9wt% of the total weight of the technical grade acetonitrile.
5. Refining
Introducing the fourth micro-treatment liquid in the buffer tank into a rectifying tower, controlling the pressure in the rectifying tower to be 0.65MPa, the temperature at the top of the tower to be 97 ℃, the temperature at the bottom of the tower to be 112 ℃, and carrying out total reflux for 25min; starting the lateral line extraction of the product, and controlling the reflux ratio to be 2.4:1 to prepare the anhydrous acetonitrile.
Example 3
The preparation method of the anhydrous acetonitrile specifically comprises the following steps:
1. disposable micro-treatment
Industrial grade acetonitrile is fed into a first micro-reactor of a micro-channel reaction device through an overhead tank at a feeding rate of 0.03kg/s, the temperature of the first micro-reactor is controlled to be 40 ℃, and the material retention time is controlled to be 420s, so as to obtain a first micro-treatment liquid.
Wherein, the first micro-reactor is filled with a first micro-treating agent, and the filling amount of the first micro-treating agent is 2.5 weight percent of the total weight of the industrial grade acetonitrile.
The first micro-treating agent is a mixture of a 3A molecular sieve and a 4A molecular sieve, and the weight ratio of the 3A molecular sieve to the 4A molecular sieve is 2.5:1.
The technical grade acetonitrile used in this example had a purity of 99.51wt%, a moisture content of 0.13wt%, an acidity of 0.009mmol/L, an alkalinity of 0.006mmol/L and an evaporation residue of 0.011wt%.
2. Secondary micro-treatment
Feeding the first micro-treatment liquid obtained by the primary micro-treatment into a second micro-reactor of a micro-channel reaction device, controlling the temperature of the second micro-reactor to be 45 ℃ and the material residence time to be 360s, thus obtaining the second micro-treatment liquid.
Wherein, the second micro-reactor is filled with a second micro-treating agent, and the filling amount of the second micro-treating agent is 2.5 weight percent of the total weight of the industrial grade acetonitrile.
The preparation method of the second micro-treating agent comprises the steps of adding hexadecyl trimethyl ammonium bromide into deionized water, and uniformly stirring; continuously adding ethyl orthosilicate and sodium hydroxide, and uniformly stirring; continuously adding mesoporous activated carbon and Na-MCM-22 molecular sieve, uniformly dispersing by ultrasonic, heating to 45 ℃, preserving heat and stirring for 5 hours, heating to 150 ℃ at a heating rate of 1 ℃/min, preserving heat for 42 hours, and filtering out solid matters; washing the solid with enough deionized water to be neutral, placing in an environment with the vacuum degree of 0.09MPa, drying at 85 ℃ for 10 hours, transferring into a roasting furnace, heating to 500 ℃ at the heating rate of 1.5 ℃/min, preserving heat and roasting for 5 hours, naturally cooling to normal temperature, and granulating to obtain the second micro-treating agent.
Wherein, the molar ratio of the cetyl trimethyl ammonium bromide to the tetraethoxysilane to the sodium hydroxide to the deionized water is 0.5:1.02:0.12:52.
The weight ratio of the mesoporous activated carbon to the Na-MCM-22 molecular sieve to the ethyl orthosilicate is 2:2:2.5.
The particle diameter of the mesoporous activated carbon is 200 mu m, and the specific surface area is 1200m 2 The average pore diameter was 10nm and the graphitization degree (XDR method) was 60%.
The Na-MCM-22 molecular sieve has a silicon-aluminum ratio of 32:1 and a crystallinity of 99%.
3. Three times of micro-treatment
Feeding the second micro-processing liquid obtained by the secondary micro-processing into a third micro-reactor of the micro-channel reaction device, controlling the temperature of the third micro-reactor to be 50 ℃ and the material retention time to be 240s, thus obtaining the third micro-processing liquid.
Wherein, the third micro-reactor is filled with a compound micro-treating agent, and the filling amount of the compound micro-treating agent is 1.2 weight percent of the total weight of the industrial grade acetonitrile.
The preparation method of the composite micro-treating agent comprises the following steps:
1) Preparation of the first component
Adding chitosan into acetic acid aqueous solution with the concentration of 2wt percent, uniformly dispersing, and preparing chitosan solution with the concentration of 1.5wt percent; then, graphene oxide is put into a chitosan solution, and after uniform dispersion, potassium citrate solution is dripped at the dripping rate of 0.5mL/min under the stirring condition of 600 rpm; after the potassium citrate solution is added dropwise, stirring is continued for 30min; then adding glutaraldehyde solution, dispersing uniformly, standing for 24 hours, and freeze-drying to obtain a freeze-dried substance; transferring the freeze-dried material into a calciner, calcining for 3 hours at 750 ℃ in a nitrogen atmosphere environment, and naturally cooling to obtain a calcined material; the calcined material is washed by deionized water and dried to prepare a first component.
Wherein the weight ratio of graphene oxide to chitosan is 1:3.5.
The concentration of the potassium citrate solution was 20wt%.
The glutaraldehyde solution had a concentration of 23wt%.
The volume ratio of the chitosan solution to the potassium citrate solution to the glutaraldehyde solution is 100:5.5:0.6.
2) Preparation of the second component
Adding halloysite nanotubes into absolute ethyl alcohol with the weight being 100 times that of the halloysite nanotubes, uniformly dispersing, and then dropwise adding ethylenediamine under the stirring condition at the dropwise adding rate of 2.5mL/min; after the dripping of ethylenediamine is completed, continuously stirring for 60min, adding dicyclohexylcarbodiimide, heating to 80 ℃, preserving heat for 12h, filtering out solid matters, washing the solid matters by absolute ethyl alcohol, and drying to obtain a second component.
Wherein the weight ratio of halloysite nanotube, ethylenediamine and dicyclohexylcarbodiimide is 1:15:0.6.
3) Composite material
Adding the first component and the second component into ethanol water solution, uniformly dispersing, heating to 55 ℃, and preserving heat; then under the stirring condition, dropwise adding a silane coupling agent KH-550 at a dropwise adding rate of 2mL/min; after the silane coupling agent KH-550 is added dropwise, continuing to keep the temperature and stir for 7 hours, and filtering out solid matters; washing the solid with absolute ethyl alcohol, drying and granulating to obtain the composite micro-treating agent.
Wherein the volume concentration of the ethanol aqueous solution is 80%.
The weight ratio of the first component to the second component to the silane coupling agent KH-550 to the ethanol aqueous solution is 30:9:1.5:300.
4. Four times of micro-treatment
And feeding the third micro-treatment liquid obtained by three times of micro-treatment into a fourth micro-reactor of the micro-channel reaction device, controlling the temperature of the fourth micro-reactor to be 55 ℃ and the material retention time to be 240s to obtain the fourth micro-treatment liquid, and introducing the fourth micro-treatment liquid into a buffer tank for temporary storage.
Wherein, the fourth micro-reactor is filled with a compound micro-treating agent which is the same as the compound micro-treating agent in the three times of micro-treatment.
The loading of the composite micro-treating agent in the fourth micro-reactor is 1wt% of the total weight of the technical grade acetonitrile.
5. Refining
Introducing the fourth micro-treatment liquid in the buffer tank into a rectifying tower, controlling the pressure in the rectifying tower to be 0.7MPa, the temperature of the top of the tower to be 100 ℃, the temperature of the tower kettle to be 115 ℃, and carrying out total reflux for 30min; starting the lateral line extraction of the product, and controlling the reflux ratio to be 2.5:1 to prepare the anhydrous acetonitrile.
Comparative example 1
The technical scheme of the embodiment 2 is adopted, and the difference is that: 1) In the secondary micro-treatment, the mesoporous activated carbon with the same specification is adopted to replace the second micro-treatment agent in an equivalent way; 2) In the preparation of the composite micro-treating agent, the step of preparing the first component is omitted, and graphene oxide is adopted to replace the first component for the subsequent composite step.
Comparative example 2
The technical scheme of the embodiment 2 is adopted, and the difference is that: 1) In the preparation of the compound micro-treating agent, the steps of preparing the second component and compounding are omitted, and the first component is used as the compound micro-treating agent for three times of micro-treatment; 2) Four micro-processing steps are omitted.
The technical schemes of examples 1-3 and comparative examples 1-2 were used for preparing anhydrous acetonitrile, and the purity, yield, moisture content, acidity, basicity and evaporation residue of the prepared anhydrous acetonitrile, and 200nm absorbance, 210nm absorbance, 220nm absorbance, 230nm absorbance, 240nm absorbance and 250nm absorbance were measured, respectively. The specific results are shown below:
further, the technical schemes of the example 2, the comparative example 1 and the comparative example 2 are adopted to prepare anhydrous acetonitrile, the repeated operation is carried out for 10 times, and whether the purity of the anhydrous acetonitrile prepared in each time is higher than 99.99wt percent is detected; and detecting the yield, the moisture content and the absorbance at 200nm of each prepared anhydrous acetonitrile, and comparing the yield, the moisture content and the absorbance at 200nm with the yield, the moisture content and the absorbance at 200nm of the anhydrous acetonitrile prepared in the previous time respectively to judge whether abnormal fluctuation exists or not so as to verify the stability of the preparation method of the anhydrous acetonitrile.
Wherein, the judgment standard of the abnormal fluctuation of the yield is as follows: [ (previous yield-previous yield)/previous yield ] ×100%; if the calculation result exceeds 2%, it is determined that abnormal fluctuation occurs.
The judgment criteria for abnormal fluctuation of the moisture content were: [ (moisture content of previous time-moisture content of next time)/moisture content of previous time ] ×100%; if the calculation result exceeds 8%, it is determined that abnormal fluctuation occurs.
The judgment standard of the abnormal fluctuation of the absorbance at 200nm is as follows: [ (200 nm absorbance of the previous time-200 nm absorbance of the latter time)/200 nm absorbance of the previous time ] ×100%; if the calculation result exceeds 10%, it is determined that abnormal fluctuation occurs.
The specific results are shown below:
further, the recycling performance of the second and composite micro-treating agents used in example 2, comparative example 1, and comparative example 2 was examined, respectively. Specifically, the preparation methods of the anhydrous acetonitrile of the example 2, the comparative example 1 and the comparative example 2 are adopted, the second micro-treating agent and the compound micro-treating agent adopted in the example 2, the comparative example 1 and the comparative example 2 are respectively matched, the repeated operation is carried out for 20 times, and after each use is completed, the adopted first micro-treating agent, second micro-treating agent and compound micro-treating agent are respectively subjected to heating regeneration treatment; the purity, yield, moisture content and absorbance at 200nm of the anhydrous acetonitrile prepared in example 2, comparative example 1 and comparative example 2 at 20 th time were then examined, and specific results are shown below:
it can be seen that the preparation method of anhydrous acetonitrile of the invention adopts the processes of primary micro-treatment, secondary micro-treatment, tertiary micro-treatment, quaternary micro-treatment and refining; setting a first micro-treating agent consisting of a 3A molecular sieve and a 4A molecular sieve in the primary micro-treatment process, controlling the temperature of a first micro-reactor and the material residence time, and carrying out targeted adsorption on water and a small amount of impurities in industrial acetonitrile; in the secondary micro-treatment process, a second micro-treatment agent prepared by compounding mesoporous activated carbon and Na-MCM-22 molecular sieve is arranged, the temperature of a second micro-reactor and the material residence time are controlled, and the moisture and impurities in the first micro-treatment liquid are subjected to targeted adsorption; in the three times of micro-treatment and four times of micro-treatment, a composite carbon material prepared from graphene oxide and chitosan is arranged, a composite micro-treatment agent prepared by compositing the graphene oxide and a modified halloysite nanotube is arranged, the temperature and the material residence time of a third micro-reactor and a fourth micro-reactor are controlled, and targeted secondary adsorption is carried out on impurities in the second micro-treatment liquid to obtain a fourth micro-treatment liquid; rectifying and refining the fourth micro-treatment liquid to obtain anhydrous acetonitrile; the treatment efficiency and the treatment capacity can be effectively improved, the treatment stability is improved, the quality of the prepared anhydrous acetonitrile is stable, the impurity and the moisture content are controlled within low levels, and the method can be suitable for the requirements of large-scale industrial production; and further improves the adsorption stability and recycling performance of the adsorbent, and the service life of the adsorbent is long.
As can be seen from comparative example 1, the same amount of mesoporous activated carbon was used instead of the second micro-treating agent; in the preparation of the composite micro-treating agent, after graphene oxide is adopted to replace the first component, the adsorption performance of moisture and impurities in industrial acetonitrile is obviously reduced, and the purity of the prepared anhydrous acetonitrile is reduced, the moisture content is obviously increased, and the evaporation residue and the absorbance of 200-230nm are increased (namely the impurity content is increased); meanwhile, the yield of the prepared anhydrous acetonitrile is reduced; the quality stability of the anhydrous acetonitrile prepared in different batches is poor; and deterioration of recycling performance of the second micro-treating agent and the composite micro-treating agent.
As can be seen from comparative example 2, the step of preparing the second component and the compounding step are omitted in the preparation of the compound micro-treating agent; after four times of micro-treatment steps are omitted, the adsorption performance of impurities in the industrial grade acetonitrile is obviously reduced, and the reduction of the adsorption performance of moisture is less obvious; the specific expression is that the purity and yield of the prepared anhydrous acetonitrile are reduced, and the evaporation residue and the absorbance between 200 and 230nm are obviously increased (namely, the impurity content is increased); and the quality stability of the anhydrous acetonitrile prepared in different batches is poor, and the recycling performance of the composite micro-treating agent is obviously degraded.
The percentages used in the present invention are mass percentages unless otherwise indicated.
Finally, it should be noted that: the foregoing description is only a preferred embodiment of the present invention, and the present invention is not limited thereto, but it is to be understood that modifications and equivalents of some of the technical features described in the foregoing embodiments may be made by those skilled in the art, although the present invention has been described in detail with reference to the foregoing embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. The preparation method of the anhydrous acetonitrile is characterized by comprising the following steps of: primary micro-treatment, secondary micro-treatment, tertiary micro-treatment, quaternary micro-treatment and refining;
feeding industrial acetonitrile into a first micro-reactor of a micro-channel reaction device, controlling the temperature of the first micro-reactor to be 35-40 ℃ and the material retention time to be 360-420s to obtain a first micro-treatment liquid;
the first micro-reactor is filled with a first micro-treating agent; the first micro-treating agent is a mixture of a 3A molecular sieve and a 4A molecular sieve;
feeding a first micro-treatment liquid obtained by primary micro-treatment into a second micro-reactor of a micro-channel reaction device, controlling the temperature of the second micro-reactor to be 40-45 ℃ and the material residence time to be 300-360s to obtain a second micro-treatment liquid;
the second micro-reactor is filled with a second micro-treating agent;
the preparation method of the second micro-treating agent comprises the steps of adding hexadecyl trimethyl ammonium bromide into deionized water, and uniformly stirring; continuously adding ethyl orthosilicate and sodium hydroxide, and uniformly stirring; continuously adding mesoporous activated carbon and Na-MCM-22 molecular sieve, dispersing uniformly, heating to 40-45 ℃, keeping the temperature, stirring, heating to 145-150 ℃, keeping the temperature, and filtering out solid matters; washing the solid with deionized water, vacuum drying, and roasting to obtain a second micro-treating agent;
feeding second micro-treatment liquid obtained by the secondary micro-treatment into a third micro-reactor of a micro-channel reaction device, controlling the temperature of the third micro-reactor to be 45-50 ℃ and the material retention time to be 180-240s to obtain third micro-treatment liquid;
the third micro-reactor is filled with a composite micro-treating agent; the compound micro-treating agent comprises the following steps: preparing a first component, preparing a second component and compounding;
the method for preparing the first component comprises the steps of adding chitosan into an acetic acid aqueous solution to prepare a chitosan solution; then, graphene oxide is put into a chitosan solution, and after uniform dispersion, potassium citrate solution is dripped under the stirring condition of 500-600 rpm; after the potassium citrate solution is added dropwise, stirring is continued; then adding glutaraldehyde solution, dispersing uniformly, standing, and freeze-drying to obtain a freeze-dried product; calcining the freeze-dried material at 700-750 ℃ in nitrogen atmosphere, and naturally cooling to obtain a calcined material; washing the calcined material with deionized water, and drying to obtain a first component;
the method for preparing the second component comprises the steps of putting halloysite nanotubes into absolute ethyl alcohol, uniformly dispersing, and dripping ethylenediamine under the stirring condition; continuously stirring after the dripping of the ethylenediamine is completed, adding dicyclohexylcarbodiimide, heating to 75-80 ℃, preserving heat, filtering out solid matters, washing the solid matters by absolute ethyl alcohol, and drying to obtain a second component;
the compounding method comprises the steps of adding the first component and the second component into ethanol water solution, uniformly dispersing, heating to 45-55 ℃, and preserving heat; then dropwise adding a silane coupling agent KH-550 under stirring; after the silane coupling agent KH-550 is added dropwise, continuing to keep the temperature and stir, and filtering out solid matters; washing the solid with absolute ethyl alcohol, drying and granulating to obtain the composite micro-treating agent;
feeding third micro-treatment liquid obtained by three times of micro-treatment into a fourth micro-reactor of a micro-channel reaction device, controlling the temperature of the fourth micro-reactor to be 50-55 ℃ and the material retention time to be 180-240s to obtain fourth micro-treatment liquid;
the fourth micro-reactor is filled with a compound micro-treating agent, and the compound micro-treating agent adopted in the fourth micro-reactor is the same as the compound micro-treating agent in the three times of micro-treatment;
the refining method is that the fourth micro-processing liquid is rectified to prepare anhydrous acetonitrile.
2. The method for producing anhydrous acetonitrile according to claim 1, wherein in the one-time micro-treatment, the feeding rate of industrial grade acetonitrile to the first micro-reactor is 0.02 to 0.03kg/s;
the loading of the first micro-treating agent in the first micro-reactor is 2-2.5wt% of the total weight of the industrial grade acetonitrile;
in the first micro-treating agent, the weight ratio of the 3A molecular sieve to the 4A molecular sieve is 2-2.5:1.
3. The method for preparing anhydrous acetonitrile according to claim 1, wherein the loading amount of the second micro-treating agent in the second micro-reactor is 2-2.5wt% of the total weight of industrial grade acetonitrile;
in the preparation of the second micro-treating agent, the heating rate of the second micro-treating agent to 145-150 ℃ is 0.8-1 ℃/min, and the heat preservation time of the second micro-treating agent to 145-150 ℃ is 40-42h;
roasting at 480-500 deg.c for 4-5 hr;
the temperature rising rate of the roasting to 480-500 ℃ is 1.2-1.5 ℃/min.
4. The method for preparing anhydrous acetonitrile according to claim 1, wherein in the preparation of the second micro-treating agent, the molar ratio of cetyltrimethylammonium bromide, tetraethoxysilane, sodium hydroxide and deionized water is 0.48-0.5:1-1.02:0.11-0.12:50-52;
the weight ratio of the mesoporous activated carbon to the Na-MCM-22 molecular sieve to the ethyl orthosilicate is 1.5-2:1.5-2:2.2-2.5;
the particle diameter of the mesoporous activated carbon is 150-200 mu m, and the specific surface area is 1100-1200m 2 Per gram, the average pore diameter is 5-10nm, and the graphitization degree is 55-60%;
the Na-MCM-22 molecular sieve has a silicon-aluminum ratio of 30-32:1 and a crystallinity of 98-99%.
5. The method for preparing anhydrous acetonitrile according to claim 1, wherein the loading amount of the composite micro-treating agent in the third micro-reactor is 1-1.2wt% of the total weight of industrial grade acetonitrile;
in the fourth micro-reactor, the loading amount of the compound micro-treating agent is 0.8-1wt% of the total weight of the industrial grade acetonitrile.
6. The process for producing anhydrous acetonitrile according to claim 1, wherein the concentration of the acetic acid aqueous solution in the first component is 1.8 to 2wt%;
the concentration of the chitosan solution is 1.2-1.5wt%;
the dropping speed of the potassium citrate solution is 0.4-0.5mL/min;
the freeze-dried material is calcined in nitrogen atmosphere at 700-750 ℃ for 2-3h.
7. The method for preparing anhydrous acetonitrile according to claim 1, wherein in the preparation of the first component, the weight ratio of graphene oxide to chitosan is 1:3-3.5;
the concentration of the potassium citrate solution is 18-20wt%;
the concentration of glutaraldehyde solution is 22-23wt%;
the volume ratio of the chitosan solution to the potassium citrate solution to the glutaraldehyde solution is 100:5-5.5:0.5-0.6.
8. The method for preparing anhydrous acetonitrile according to claim 1, wherein in the second component, the weight ratio of halloysite nanotubes to absolute ethanol is 1:90-100;
the dripping speed of the ethylenediamine is 2-2.5mL/min;
the heat preservation time is 10-12h under the temperature condition of 75-80 ℃;
the weight ratio of halloysite nanotube, ethylenediamine and dicyclohexylcarbodiimide is 1:13-15:0.5-0.6.
9. The method for preparing anhydrous acetonitrile according to claim 1, wherein in the compounding, the dropping rate of the silane coupling agent KH-550 is 1.5-2mL/min;
after the silane coupling agent KH-550 is added dropwise, keeping the temperature and stirring for 6-7h;
the volume concentration of the ethanol water solution is 70-80%;
the weight ratio of the first component to the second component to the silane coupling agent KH-550 to the ethanol aqueous solution is 25-30:8-9:1.2-1.5:250-300.
10. The method for preparing anhydrous acetonitrile according to claim 1, wherein the refining method is that the fourth micro-treatment liquid is led into a rectifying tower, the pressure in the rectifying tower is controlled to be 0.6-0.7MPa, the tower top temperature is 95-100 ℃, the tower bottom temperature is 110-115 ℃, and the total reflux is carried out for 20-30min; starting the lateral line extraction of the product, and controlling the reflux ratio to be 2.3-2.5:1 to prepare the anhydrous acetonitrile.
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