CN113461644A - Method for recovering tetrahydrofuran from waste solvent - Google Patents
Method for recovering tetrahydrofuran from waste solvent Download PDFInfo
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- CN113461644A CN113461644A CN202110824504.5A CN202110824504A CN113461644A CN 113461644 A CN113461644 A CN 113461644A CN 202110824504 A CN202110824504 A CN 202110824504A CN 113461644 A CN113461644 A CN 113461644A
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- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 title claims abstract description 230
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 title claims abstract description 115
- 238000000034 method Methods 0.000 title claims abstract description 36
- 239000010887 waste solvent Substances 0.000 title claims abstract description 23
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims abstract description 114
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 claims abstract description 96
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 46
- 238000004821 distillation Methods 0.000 claims abstract description 38
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 17
- 238000011084 recovery Methods 0.000 claims abstract description 15
- 239000002904 solvent Substances 0.000 claims abstract description 11
- 238000004064 recycling Methods 0.000 claims abstract description 9
- 239000012528 membrane Substances 0.000 claims description 25
- 239000000243 solution Substances 0.000 claims description 24
- 238000000926 separation method Methods 0.000 claims description 21
- 238000010992 reflux Methods 0.000 claims description 14
- 239000011259 mixed solution Substances 0.000 claims description 13
- 230000002572 peristaltic effect Effects 0.000 claims description 12
- 238000005373 pervaporation Methods 0.000 claims description 12
- FELGDWYLIIVCRC-UHFFFAOYSA-N oxolan-2-ylmethanol;hydrate Chemical compound O.OCC1CCCO1 FELGDWYLIIVCRC-UHFFFAOYSA-N 0.000 claims description 11
- 239000007788 liquid Substances 0.000 claims description 10
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 claims description 9
- 229920000767 polyaniline Polymers 0.000 claims description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 8
- 238000010438 heat treatment Methods 0.000 claims description 6
- 229910052757 nitrogen Inorganic materials 0.000 claims description 4
- 230000005484 gravity Effects 0.000 claims description 3
- 238000005086 pumping Methods 0.000 claims description 3
- 239000000203 mixture Substances 0.000 abstract description 5
- 125000004122 cyclic group Chemical group 0.000 abstract description 4
- 239000002920 hazardous waste Substances 0.000 abstract description 3
- 238000000746 purification Methods 0.000 abstract description 3
- 238000011027 product recovery Methods 0.000 abstract 1
- 239000002994 raw material Substances 0.000 abstract 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 16
- 239000000463 material Substances 0.000 description 13
- 238000009835 boiling Methods 0.000 description 7
- 238000006243 chemical reaction Methods 0.000 description 7
- PAYRUJLWNCNPSJ-UHFFFAOYSA-N Aniline Chemical compound NC1=CC=CC=C1 PAYRUJLWNCNPSJ-UHFFFAOYSA-N 0.000 description 6
- 239000004372 Polyvinyl alcohol Substances 0.000 description 6
- 229920002451 polyvinyl alcohol Polymers 0.000 description 6
- 239000000047 product Substances 0.000 description 6
- 230000018044 dehydration Effects 0.000 description 5
- 238000006297 dehydration reaction Methods 0.000 description 5
- 235000019441 ethanol Nutrition 0.000 description 5
- 238000000605 extraction Methods 0.000 description 5
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 4
- 239000002253 acid Substances 0.000 description 4
- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium persulfate Chemical compound [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 description 4
- 238000001816 cooling Methods 0.000 description 4
- 239000008367 deionised water Substances 0.000 description 4
- 229910021641 deionized water Inorganic materials 0.000 description 4
- 238000001514 detection method Methods 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 238000000895 extractive distillation Methods 0.000 description 3
- 239000012847 fine chemical Substances 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- 238000003786 synthesis reaction Methods 0.000 description 3
- 238000001132 ultrasonic dispersion Methods 0.000 description 3
- 239000002699 waste material Substances 0.000 description 3
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 2
- 229910001870 ammonium persulfate Inorganic materials 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 238000003889 chemical engineering Methods 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000006731 degradation reaction Methods 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- WXHLLJAMBQLULT-UHFFFAOYSA-N 2-[[6-[4-(2-hydroxyethyl)piperazin-1-yl]-2-methylpyrimidin-4-yl]amino]-n-(2-methyl-6-sulfanylphenyl)-1,3-thiazole-5-carboxamide;hydrate Chemical compound O.C=1C(N2CCN(CCO)CC2)=NC(C)=NC=1NC(S1)=NC=C1C(=O)NC1=C(C)C=CC=C1S WXHLLJAMBQLULT-UHFFFAOYSA-N 0.000 description 1
- NNBFNNNWANBMTI-UHFFFAOYSA-M brilliant green Chemical compound OS([O-])(=O)=O.C1=CC(N(CC)CC)=CC=C1C(C=1C=CC=CC=1)=C1C=CC(=[N+](CC)CC)C=C1 NNBFNNNWANBMTI-UHFFFAOYSA-M 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000003431 cross linking reagent Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- DXXIJMQJQDPMFJ-UHFFFAOYSA-N furan-2-ylmethanol hydrate Chemical compound O.OCc1ccco1 DXXIJMQJQDPMFJ-UHFFFAOYSA-N 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- FPYJFEHAWHCUMM-UHFFFAOYSA-N maleic anhydride Chemical compound O=C1OC(=O)C=C1 FPYJFEHAWHCUMM-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000003880 polar aprotic solvent Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 239000010865 sewage Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000000967 suction filtration Methods 0.000 description 1
- 238000001291 vacuum drying Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
- C07D307/02—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings
- C07D307/04—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having no double bonds between ring members or between ring members and non-ring members
- C07D307/06—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having no double bonds between ring members or between ring members and non-ring members with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, directly attached to ring carbon atoms
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
Abstract
The invention relates to the technical field of purification and recovery of hazardous waste solvents, in particular to a method for purifying and recovering tetrahydrofuran, and particularly relates to a method for recovering tetrahydrofuran from a waste solvent. The raw materials are preheated and then sent into an atmospheric distillation tower with ethylene glycol as an extracting agent, an azeotrope of tetrahydrofuran and methanol is obtained at the top of the atmospheric distillation tower, and a product obtained at the bottom of the tower is a mixture of water, methanol and ethylene glycol. The mixture enters an extractant recovery tower, and the extractant is recovered for recycling. The azeotrope enters a high-pressure tower, tetrahydrofuran with higher purity is obtained at the tower bottom, the azeotrope containing a small amount of tetrahydrofuran and methanol is obtained at the tower top of a high-pressure rectifying tower, and the azeotrope at the tower top is sent to normal-pressure extractive rectification for cyclic rectification, so that the product recovery rate is improved.
Description
Technical Field
The invention relates to the technical field of purification and recovery of hazardous waste solvents, in particular to a method for purifying and recovering tetrahydrofuran, and particularly relates to a method for recovering tetrahydrofuran from a waste solvent.
Background
At present, Tetrahydrofuran (THF) as a polar aprotic solvent has the characteristics of clarity, low viscosity, low boiling point, strong stability and good fluidity, and has good solubility for a plurality of organic matters, so that THF can be widely applied to the chemical industry, especially the organic synthesis, pharmaceutical synthesis and polymer synthesis industries.
Tetrahydrofuran can be mutually soluble with water in any ratio, is a solvent which is easy to absorb water, has great influence on chemical reaction after absorbing water, has high dehydration cost for recycling tetrahydrofuran, and reduces the economy of recycling tetrahydrofuran. In addition, the boiling point (66.5 ℃) of tetrahydrofuran is very similar to that (64.7 ℃) of methanol, in the recovery of tetrahydrofuran waste liquid, because tetrahydrofuran is easy to form ternary azeotropic boiling with methanol and water, the rectification recovery process of tetrahydrofuran needs very high number of tower plates to support the full separation of materials, the equipment investment cost is very high, the energy consumption is very large, the economy of tetrahydrofuran recovery is greatly reduced, only degradation use can be realized, and part of tetrahydrofuran with poor quality can only be subjected to harmless treatment through incineration and biochemical sewage degradation technologies.
The existing recovery technology mainly comprises three methods of extractive distillation, pressure swing distillation and membrane separation. The pure THF extraction rectification method uses an extractant in the rectification process, the use cost of the extractant is higher, the used extractant becomes secondary hazardous waste, and secondary pollution to the environment is easily caused by improper disposal. The pressure difference of the pressure-swing distillation is changed by changing the air pressure during distillation, so that the azeotropic proportion of tetrahydrofuran and other materials is changed by pressure change, the tetrahydrofuran can reach the index of a qualified product after the azeotrope of the tetrahydrofuran and other solvents is effectively separated, and the comprehensive recovery cost is far less than the price of the qualified product.
In view of the above-mentioned drawbacks, the present invention is to provide a method for recovering tetrahydrofuran from waste solvent, which is more valuable in industrial application.
Disclosure of Invention
The invention aims to solve the technical problems of complex process, high cost, low yield and purity and the like of the existing dangerous waste solvent in the process of purifying and recovering tetrahydrofuran, and provides a process for purifying and recovering tetrahydrofuran with high purity, which has the advantages of simple process, convenient operation, low cost, environmental protection and high yield.
The invention relates to a method for recovering tetrahydrofuran from a waste solvent, which comprises the following specific recovery steps:
s1, feeding the waste solvent containing tetrahydrofuran into an atmospheric distillation tower through a peristaltic pump, wherein the feeding position is the 25 th tower plate of the atmospheric distillation tower, adding ethylene glycol serving as an extracting agent into the atmospheric distillation tower, the feeding position of the extracting agent is the 30 th tower plate of the distillation tower, adjusting the reflux ratio to be 6, extracting an azeotrope containing a large amount of tetrahydrofuran and a small amount of methanol from the top of the tower, and extracting methanol, water and ethylene glycol from the bottom of the tower;
s2, conveying an azeotrope of tetrahydrofuran and methanol extracted from the tower top into a high-pressure rectifying tower at a 28 th tower plate of the normal-pressure rectifying tower by using a peristaltic pump, controlling the reflux ratio to be 3, extracting the azeotrope of tetrahydrofuran and methanol from the tower top, extracting high-purity tetrahydrofuran from a tower kettle of the high-pressure rectifying tower, and extracting a mixed solution of methanol, water and ethylene glycol from the tower kettle of the high-pressure rectifying tower;
s3, separating glycol, water and methanol extracted from the tower bottom of the atmospheric distillation tower, and feeding the separated glycol into the atmospheric distillation tower by a peristaltic pump for recycling;
s4, pumping the extracted and valence difference rectified and separated high-purity tetrahydrofuran solution into a device provided with a hydrophilic polyaniline pervaporation membrane by a pump, and heating the tetrahydrofuran solution by a heater in the transportation process to enable the liquid temperature to reach 55 ℃; controlling the temperature in the membrane separation device within the range of 50-60 ℃, wherein in the membrane separation device, hydrophilic polyaniline pervaporation membrane hydrophilic side, the solution falls freely by gravity, and the other side of the pervaporation membrane is vacuumized and protected by nitrogen to prevent tetrahydrofuran from absorbing moisture in the air.
Further, in the S1, the mass of the extracting agent ethylene glycol is 1.5-2 times of the mass of the tetrahydrofuran-containing waste solvent, and the temperature of the tower kettle of the atmospheric distillation tower is controlled at 70-80 ℃.
Further, in S1, the waste solvent containing tetrahydrofuran is a tetrahydrofuran-methanol-water mixed solution, and the waste solvent contains, by mass: 25-70% of tetrahydrofuran, 25-70% of methanol and 5-10% of water, wherein the feeding flow rate of the tetrahydrofuran-containing waste solvent is 1000-1500 kg/h.
Further, in the S1, the number of plates of the atmospheric distillation column is 55.
Further, in the S2, the pressure of the high-pressure rectifying tower is 10atm, and the temperature of the tower kettle of the high-pressure rectifying tower is 95-115 ℃.
Further, in the S2, the number of plates of the high-pressure rectification column is 38.
Further, in the S1, the final tower bottom temperature of the atmospheric distillation tower is 75 ℃.
Further, in the S2, the tower bottom temperature of the high-pressure rectifying still is 100 ℃.
By the scheme, the invention at least has the following advantages:
the extraction agent selected by the invention is glycol, the price is low, the extraction agent can be recycled and reused, secondary pollution is avoided, the harm to human bodies and the environment is reduced, a safe and recyclable production mode is provided, the purification efficiency of the tetrahydrofuran is high, and the purity of the tetrahydrofuran is good. The traditional method is single differential pressure rectification, extractive rectification and salt rectification, and is combined in a small number, the materials in the fine chemical industry are relatively single and clear, the materials to be treated are not mixed, an azeotrope is more, and tetrahydrofuran absorbs water, the materials to be treated are complex, the feed is a mixture of tetrahydrofuran, water and methanol, the three materials are azeotropic and are difficult to separate, the traditional method mainly uses tetrahydrofuran and water for separation, and the tetrahydrofuran, the ethanol or the tetrahydrofuran, the water and the ethanol have boiling points which are closer to the boiling point of the tetrahydrofuran and only have a difference of 1.8 ℃, so that the separation difficulty is high. The recovery process of the invention can achieve the following process parameters: the recovery rate reaches more than 92 percent, the purity reaches 99.95 percent, and the water content is less than 200 ppm.
The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate a certain embodiment of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
FIG. 1 is a schematic diagram of a process for separating and purifying tetrahydrofuran by combining the extraction of tetrahydrofuran-methanol-water system with ethylene glycol as an extractant and tetrahydrofuran as a product and a pressure difference rectification process;
wherein, in the figure;
1. a normal pressure rectifying tower; 2. a high pressure rectification column; 3. an extractant regeneration tower; 4. a reflux tank; 5. a pervaporation membrane module; 6. a tetrahydrofuran receiving tank; 7. a water receiving tank; 8. and a nitrogen tank.
Detailed Description
The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
Referring to fig. 1, a method for recovering tetrahydrofuran from a waste solvent according to a preferred embodiment of the present invention includes the following steps:
s1, feeding the tetrahydrofuran-containing waste solvent into an atmospheric distillation tower through a peristaltic pump, wherein the feeding position is the 25 th tower plate of the atmospheric distillation tower, adding ethylene glycol serving as an extracting agent into the atmospheric distillation tower, the feeding position of the extracting agent is the 30 th tower plate of the distillation tower, the quality of the extracting agent ethylene glycol is ensured to be 1.5-2 times of that of the tetrahydrofuran-containing waste solvent, the temperature of a tower kettle of the atmospheric distillation tower is controlled to be 70-80 ℃, the reflux ratio is adjusted, the reflux ratio of the atmospheric distillation tower is controlled to be 6, an azeotrope containing a large amount of tetrahydrofuran and a small amount of methanol is extracted from the top of the tower, and methanol, water and ethylene glycol are extracted from the tower kettle; the waste solvent containing tetrahydrofuran is tetrahydrofuran-methanol-water mixed solution; wherein the mass percentage composition is as follows: tetrahydrofuran 25-70 wt%, methanol 25-70 wt% and water 5-10 wt%; the feeding flow rate of the tetrahydrofuran-containing waste solvent is 1000-1500 kg/h; the number of the tower plates of the atmospheric distillation tower is 55;
s2, conveying an azeotrope of tetrahydrofuran and methanol extracted from the top of the tower into a high-pressure rectifying tower at a 28 th tower plate of the normal-pressure rectifying tower by using a peristaltic pump, controlling the pressure of the high-pressure rectifying tower to be 10atm, controlling the temperature of a tower kettle to be 95-115 ℃, controlling the reflux ratio to be 3, extracting the azeotrope of tetrahydrofuran and methanol from the top of the tower, extracting high-purity tetrahydrofuran from the tower kettle of the high-pressure rectifying tower, and extracting a mixed solution of methanol, water and glycol from the tower kettle of the high-pressure rectifying tower; the number of the tower plates of the high-pressure rectifying tower is 38;
s3, separating glycol, water and methanol extracted from the tower bottom of the atmospheric distillation tower, and feeding the separated glycol into the atmospheric distillation tower by a peristaltic pump for recycling;
s4, pumping the extracted and valence difference rectified and separated high-purity tetrahydrofuran solution into a device provided with a hydrophilic polyaniline pervaporation membrane by a pump, and heating the tetrahydrofuran solution by a heater during transportation to enable the temperature of the tetrahydrofuran solution to reach about 55 ℃; controlling the temperature in the membrane separation device within the range of 50-60 ℃, wherein in the membrane separation device, hydrophilic polyaniline pervaporation membrane hydrophilic side, the solution falls freely by gravity, and the other side of the pervaporation membrane is vacuumized and protected by nitrogen to prevent tetrahydrofuran from absorbing moisture in the air.
The preparation method of the hydrophilic polyaniline pervaporation membrane comprises the following steps:
adding deionized water into a reaction kettle, adding aniline with the mass of 10-15% of the deionized water into the reaction kettle, continuously stirring, mixing sulfuric acid and sulfosalicylic acid according to the molar ratio of 1:4 to obtain mixed acid, adding excessive mixed acid into the reaction kettle, reacting aniline and acid to generate soluble sulfate, dropwise adding an ammonium persulfate solution with the mass of 1.5 times of that of aniline into the generated sulfate solution at the speed of 5mL/min under the condition of continuously stirring, gradually changing the solution color from light yellow to green after adding ammonium persulfate, gradually deepening the solution color along with the continuous reaction to finally change into emerald green, controlling the reaction temperature to polymerize at 20 ℃ for 6h, after the reaction is finished, performing suction filtration by using a funnel, sequentially washing and filtering by using composite acid, absolute ethyl alcohol and distilled water until the filtrate is basically colorless, and then drying at the constant temperature of 60 ℃ for 24h in a vacuum drying oven, grinding to obtain polyaniline solid powder;
adding deionized water into a beaker, adding polyvinyl alcohol with the mass of 5-10% of that of the deionized water into the beaker, dissolving to prepare polyvinyl alcohol solution, keeping the temperature at 75-95 ℃ for 3-4 hours, cooling to normal temperature, and filling into a bottle for later use;
adding polyaniline powder accounting for 1-5% of the mass of the polyvinyl alcohol solution into the polyvinyl alcohol solution, adding maleic anhydride accounting for 5% of the mass of the polyvinyl alcohol solution as a cross-linking agent, adding sulfuric acid accounting for 2% of the mass of the polyvinyl alcohol solution as a catalyst, uniformly stirring, performing ultrasonic dispersion, controlling the temperature during ultrasonic dispersion by using an ice bath method, and performing ultrasonic dispersion for 6 hours to finally obtain a uniformly dispersed casting solution;
casting the prepared membrane liquid on a clean glass plate prepared in advance to be scraped into a membrane, putting the membrane liquid into a drying box with the temperature of 100-115 ℃, and drying for 24 hours to prepare the pervaporation tetrahydrofuran dehydration composite membrane.
Examples
Example 1:
the tetrahydrofuran-methanol-water mixed solution has the feed flow of 1000kg/h and comprises the following components in percentage by mass: tetrahydrofuran 70%, methanol 25% and water 5%. The solution is preheated to 60 ℃ by a heater and then is added into a normal pressure rectifying tower for extraction and rectification. Ethylene glycol was added as an extractant. The feeding ratio of the extracting agent to the tetrahydrofuran-methanol-water mixed solution is 1.5:1, the reflux ratio is controlled to be 6, the heating temperature of a tower kettle is 75 ℃, and the temperature of a tower top is 64.7 ℃. The number of tower plates of the atmospheric distillation tower is 55, the number of tower plates of the high-pressure distillation tower is 38, the extracting agent is ethylene glycol, the discharged material at the top of the tower is an azeotrope containing a large amount of tetrahydrofuran and a small amount of methanol, and the discharged material at the bottom of the tower is ethylene glycol, methanol and water. And (3) feeding the ethylene glycol at the bottom of the tower into a separation tower for separation, and recycling the ethylene glycol. Feeding the azeotrope discharged from the top of the tower into a high-pressure rectifying tower, wherein the pressure of the high-pressure rectifying tower is 10atm, the temperature of a tower kettle is 100 ℃, the temperature of the top of the tower is 91.5 ℃, the reflux ratio is adjusted to be 3, tetrahydrofuran with higher purity is taken at the bottom of the tower, a small amount of azeotrope is extracted from the top of the tower, and the azeotrope is fed into an extractive rectifying tower for cyclic distillation. And finally, conveying the tetrahydrofuran with higher purity into a membrane separation treatment device by using a peristaltic pump for dehydration, after cooling, extracting a small amount of water from the upper end of the device, collecting and collecting a tetrahydrofuran finished product from the lower end of the device, wherein the purity of the extracted tetrahydrofuran can reach 99.98 percent through detection, and the water content of the tetrahydrofuran is 104 ppm.
Example 2
The feeding flow of the tetrahydrofuran-methanol-water mixed solution is 1200kg/h, the tetrahydrofuran-methanol-water mixed solution is preheated to 60 ℃ by a heater, and the tetrahydrofuran-methanol-water mixed solution comprises the following components in percentage by mass: 50% of tetrahydrofuran, 40% of methanol and 10% of water. The feeding ratio of the extracting agent to the tetrahydrofuran-methanol-water mixed solution is 2:1, the normal pressure rectification is carried out, the reflux ratio is controlled to be 6, the number of tower plates of a normal pressure rectification tower is 55, the number of tower plates of a high pressure rectification tower is 38, the heating temperature of a tower kettle is 78 ℃, the temperature of a tower top is 63.4 ℃, the extracting agent is ethylene glycol, the discharge of the tower top is an azeotrope containing a large amount of tetrahydrofuran and a small amount of methanol, and the discharge of the tower bottom is ethylene glycol, methanol and water. And (3) feeding the ethylene glycol at the bottom of the tower into a separation tower for separation, and recycling the ethylene glycol. Feeding the azeotrope discharged from the top of the tower into a high-pressure rectifying tower, wherein the pressure of the high-pressure rectifying tower is 10atm, the heating temperature of a tower kettle is 110 ℃, the temperature of the top of the tower is 94.6 ℃, the reflux ratio is adjusted to be 3, tetrahydrofuran with higher purity is obtained at the bottom of the tower, a small amount of azeotrope is extracted from the top of the tower, and the azeotrope is fed into an extractive rectifying tower for cyclic distillation. And finally, conveying the tetrahydrofuran with higher purity into a membrane separation treatment device by using a peristaltic pump for dehydration, after cooling, extracting a small amount of water from the upper end of the device, collecting and collecting a tetrahydrofuran finished product from the lower end of the device, wherein the purity of the extracted tetrahydrofuran can reach 99.97 percent through detection, and the water content is 118 pm.
Example 3
The feed flow of the mixed liquid of the hydrogen furan-methanol-water is 1500kg/h, the mixed liquid is preheated to 60 ℃ by a heater, the pressure is 1atm, and the mixed liquid comprises the following components in percentage by mass: tetrahydrofuran 25%, methanol 70% and water 5%. The feeding ratio of the extracting agent to the tetrahydrofuran-methanol-water mixed solution is 2.5:1, the operating pressure of the extractive distillation tower is 1atm, the reflux ratio is 6, the number of tower plates of the extractive distillation tower is 55, the number of tower plates of the high-pressure distillation tower is 38, the temperature of a tower kettle is 76 ℃, the temperature of a tower top is 64.7 ℃, the extracting agent is ethylene glycol, the discharging material at the tower top is an azeotrope containing a large amount of tetrahydrofuran and a small amount of methanol, and the discharging material at the tower bottom is ethylene glycol, methanol and water. And (3) feeding the ethylene glycol at the bottom of the tower into a separation tower for separation, and recycling the ethylene glycol. Feeding the azeotrope discharged from the top of the tower into a high-pressure rectifying tower, wherein the pressure of the high-pressure rectifying tower is 10atm, the temperature of a tower kettle is 103.8 ℃, the temperature of the top of the tower is 95.2 ℃, the reflux ratio is adjusted to be 3, tetrahydrofuran with high purity is arranged at the bottom of the tower, a small amount of azeotrope is extracted from the top of the tower, and the azeotrope is fed into an extractive rectifying tower for cyclic distillation. And finally, conveying the tetrahydrofuran with higher purity into a membrane separation treatment device by using a peristaltic pump for dehydration, after cooling, extracting a small amount of water from the upper end of the device, collecting and collecting a tetrahydrofuran finished product from the lower end of the device, wherein the purity of the extracted tetrahydrofuran can reach 99.96 percent through detection, and the water content of the extracted tetrahydrofuran is 146 ppm.
It can be seen from the above examples that the recovery purity and water content index of tetrahydrofuran in example 1 of the present invention are optimal, because the whole process has the optimal parameter ratio, the optimal recovery effect can be achieved only under the process parameters of example 1, which is also laterally confirmed that the technical scheme of the present invention can be implemented, in addition, the components of the recovered materials processed by the present invention are relatively complex, the traditional methods are basically fine chemical engineering, and have different fields, the traditional methods are single pressure difference rectification, extractive rectification, salt rectification, combined rectification does not occur, the components of the materials in the fine chemical engineering are simple, unlike the materials to be processed by the present invention, which have complex components and many azeotropes, and the tetrahydrofuran absorbs water, the feed is a mixture of tetrahydrofuran, water and methanol, all of which are boiling, and difficult to separate, the existing literature reports that there are few waste liquids of this type, the most reports are that tetrahydrofuran and water are separated, tetrahydrofuran and ethanol are separated, or tetrahydrofuran, water and ethanol are separated, but the boiling point of methanol in the waste liquid is closer to that of tetrahydrofuran compared with ethanol, the difference is only 1.8 ℃, the separation difficulty is larger, and by using the separation process, the final recovery rate reaches more than 92%, the purity reaches 99.95%, the moisture content is below 200ppm, the requirements of industrial-grade superior tetrahydrofuran are met, and the application prospect is wide.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, it should be noted that, for those skilled in the art, many modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.
Claims (8)
1. A method for recovering tetrahydrofuran from a waste solvent is characterized by comprising the following specific recovery steps:
s1, feeding the waste solvent containing tetrahydrofuran into an atmospheric distillation tower through a peristaltic pump, wherein the feeding position is the 25 th tower plate of the atmospheric distillation tower, adding ethylene glycol serving as an extracting agent into the atmospheric distillation tower, the feeding position of the extracting agent is the 30 th tower plate of the distillation tower, adjusting the reflux ratio to be 6, extracting an azeotrope containing a large amount of tetrahydrofuran and a small amount of methanol from the top of the tower, and extracting methanol, water and ethylene glycol from the bottom of the tower;
s2, conveying an azeotrope of tetrahydrofuran and methanol extracted from the tower top into a high-pressure rectifying tower at a 28 th tower plate of the normal-pressure rectifying tower by using a peristaltic pump, controlling the reflux ratio to be 3, extracting the azeotrope of tetrahydrofuran and methanol from the tower top, extracting high-purity tetrahydrofuran from a tower kettle of the high-pressure rectifying tower, and extracting a mixed solution of methanol, water and ethylene glycol from the tower kettle of the high-pressure rectifying tower;
s3, separating glycol, water and methanol extracted from the tower bottom of the atmospheric distillation tower, and feeding the separated glycol into the atmospheric distillation tower by a peristaltic pump for recycling;
s4, pumping the extracted and valence difference rectified and separated high-purity tetrahydrofuran solution into a device provided with a hydrophilic polyaniline pervaporation membrane by a pump, and heating the tetrahydrofuran solution by a heater in the transportation process to enable the liquid temperature to reach 55 ℃; controlling the temperature in the membrane separation device within the range of 50-60 ℃, wherein in the membrane separation device, hydrophilic polyaniline pervaporation membrane hydrophilic side, the solution falls freely by gravity, and the other side of the pervaporation membrane is vacuumized and protected by nitrogen to prevent tetrahydrofuran from absorbing moisture in the air.
2. The method for recovering tetrahydrofuran from a used solvent according to claim 1, wherein: in the S1, the mass of the extractant glycol is 1.5-2 times of the mass of the tetrahydrofuran-containing waste solvent, and the temperature of a tower kettle of the atmospheric distillation tower is controlled at 70-80 ℃.
3. The method for recovering tetrahydrofuran from a used solvent according to claim 1, wherein: in the step S1, the waste solvent containing tetrahydrofuran is a tetrahydrofuran-methanol-water mixed solution, and the waste solvent contains, by mass: 25-70% of tetrahydrofuran, 25-70% of methanol and 5-10% of water, wherein the feeding flow rate of the tetrahydrofuran-containing waste solvent is 1000-1500 kg/h.
4. The method for recovering tetrahydrofuran from a used solvent according to claim 1, wherein: in the S1, the number of the atmospheric distillation tower trays is 55.
5. The method for recovering tetrahydrofuran from a used solvent according to claim 1, wherein: in the S2, the pressure of the high-pressure rectifying tower is 10atm, and the temperature of a tower kettle of the high-pressure rectifying tower is 95-115 ℃.
6. The method for recovering tetrahydrofuran from a used solvent according to claim 1, wherein: in the S2, the number of the high-pressure rectifying tower plates is 38.
7. The method for recovering tetrahydrofuran from a used solvent according to claim 1, wherein: in the S1, the final tower kettle temperature of the atmospheric distillation tower is 75 ℃.
8. The method for recovering tetrahydrofuran from a used solvent according to claim 1, wherein: in the S2, the tower bottom temperature of the high-pressure rectifying kettle is 100 ℃.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114200900A (en) * | 2021-11-29 | 2022-03-18 | 合肥工业大学 | Dispersion control system for THF recovery device |
| CN114315546A (en) * | 2021-12-18 | 2022-04-12 | 常州锦益辉化工有限公司 | Method for treating waste electron solvent containing water, propylene glycol methyl ether and cyclopentanone |
| CN114437001A (en) * | 2022-01-19 | 2022-05-06 | 上海天汉环境资源有限公司 | Method for recovering tetrahydrofuran in wastewater |
| CN115181080A (en) * | 2022-07-22 | 2022-10-14 | 扬州贝尔新环境科技有限公司 | Separation process of methyl tert-butyl ether-tetrahydrofuran-ethanol-water azeotropic system |
| CN115197177A (en) * | 2022-07-01 | 2022-10-18 | 扬州贝尔新环境科技有限公司 | Environment-friendly tetrahydrofuran extractive distillation separation process |
| CN116041285A (en) * | 2022-12-08 | 2023-05-02 | 杰特(宁夏)科技有限公司 | Novel tetrahydrofuran dehydration process |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202336224U (en) * | 2011-10-11 | 2012-07-18 | 南京蓝星化工新材料有限公司 | Azeotropic distillation system for mixture of carbinol and tetrahydrofuran |
| CN103012332A (en) * | 2012-12-07 | 2013-04-03 | 江苏阿尔法药业有限公司 | Method for separating waste solvent of tetrahydrofuran-methanol-water through rectification with packed tower |
-
2021
- 2021-07-21 CN CN202110824504.5A patent/CN113461644A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202336224U (en) * | 2011-10-11 | 2012-07-18 | 南京蓝星化工新材料有限公司 | Azeotropic distillation system for mixture of carbinol and tetrahydrofuran |
| CN103012332A (en) * | 2012-12-07 | 2013-04-03 | 江苏阿尔法药业有限公司 | Method for separating waste solvent of tetrahydrofuran-methanol-water through rectification with packed tower |
Non-Patent Citations (3)
| Title |
|---|
| 夏德万等: "渗透汽化膜分离研究的新进展", 《高分子通报》 * |
| 杨座国编著: "《膜科学技术过程与原理》", 31 August 2009, 华东理工大学出版社 * |
| 郑智纯等: "精馏回收制药废液中四氢呋喃和甲醇工艺的模拟与实验", 《化工进展》 * |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114200900A (en) * | 2021-11-29 | 2022-03-18 | 合肥工业大学 | Dispersion control system for THF recovery device |
| CN114315546A (en) * | 2021-12-18 | 2022-04-12 | 常州锦益辉化工有限公司 | Method for treating waste electron solvent containing water, propylene glycol methyl ether and cyclopentanone |
| CN114315546B (en) * | 2021-12-18 | 2024-01-23 | 张家港市飞翔环保科技有限公司 | Method for treating waste electronic solvent containing water, propylene glycol methyl ether and cyclopentanone |
| CN114437001A (en) * | 2022-01-19 | 2022-05-06 | 上海天汉环境资源有限公司 | Method for recovering tetrahydrofuran in wastewater |
| CN114437001B (en) * | 2022-01-19 | 2023-12-26 | 上海天汉环境资源有限公司 | Recovery method of tetrahydrofuran in wastewater |
| CN115197177A (en) * | 2022-07-01 | 2022-10-18 | 扬州贝尔新环境科技有限公司 | Environment-friendly tetrahydrofuran extractive distillation separation process |
| CN115181080A (en) * | 2022-07-22 | 2022-10-14 | 扬州贝尔新环境科技有限公司 | Separation process of methyl tert-butyl ether-tetrahydrofuran-ethanol-water azeotropic system |
| CN115181080B (en) * | 2022-07-22 | 2023-08-22 | 扬州贝尔新环境科技有限公司 | Separation process of methyl tertiary butyl ether-tetrahydrofuran-ethanol-water azeotropic system |
| CN116041285A (en) * | 2022-12-08 | 2023-05-02 | 杰特(宁夏)科技有限公司 | Novel tetrahydrofuran dehydration process |
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