CN101386572B - Method for separating and purifying acetylacetone - Google Patents
Method for separating and purifying acetylacetone Download PDFInfo
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- CN101386572B CN101386572B CN2008102018447A CN200810201844A CN101386572B CN 101386572 B CN101386572 B CN 101386572B CN 2008102018447 A CN2008102018447 A CN 2008102018447A CN 200810201844 A CN200810201844 A CN 200810201844A CN 101386572 B CN101386572 B CN 101386572B
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Abstract
The invention discloses a method for separating and purifying acetylacetone. The method comprises the following steps: adding an acetylacetone solution containing acetic acid and acetic anhydride to cyclohexane and/or toluene so as to obtain a mixed solution, adding water or an aqueous solution containing salt to the mixed solution, heating the mixed solution for hydrolysis, keeping the mixed solution stand for layering, taking an upper-layer solution, performing batch rectification so as to obtain a crude product and performing continuous rectification and decolorization to the crude product, so as to obtain purified acetylacetone. The method provided by the invention overcomes the defects that the prior acetylacetone purifying process is large in the amount of acetylacetone loss, low in product purity or large in the amount of produced wastewater, high in energy consumption and great in acetylacetone loss. The method has the advantages that the method is high in the purity and yield of the obtained acetylacetone, and obviously reduces the amount of discharged wastewater, energy consumption and the amount of acetylacetone loss.
Description
Technical field
The present invention relates to a kind of method of separating purifying acetylacetone.
Background technology
High-purity acetylacetone is a kind of application organic chemical industry's product extremely widely.It is widely used in fields such as medicine, veterinary drug, fodder additives, catalyzer.
What the processing method employing of production methyl ethyl diketone was more is method of acetic acid.Mainly generate ketene by acetic acid through cracking, the acetone ketene generates isopropenyl acetate, and the high again temp isomerizing of isopropenyl acetate generates methyl ethyl diketone.In reaction, the isopropenyl acetate isomery can produce by product acetic acid and aceticanhydride when turning to the process of methyl ethyl diketone, thereby brings difficulty for the purifying of methyl ethyl diketone.
" in the practical fine chemicals handbook, the methyl ethyl diketone purification process that contains acetic acid is: adopt benzene-aqueous systems as extraction system, acetic acid soluble in water mainly is assigned to water, and methyl ethyl diketone then mainly is dissolved in the benzene, and the content of the methyl ethyl diketone that obtains is about 98%.The purity that this method main drawback is a products obtained therefrom is lower, and the methyl ethyl diketone loss amount is big.
English Patent (GB838142) adopts the method for double tower azeotropic distillation, removes acetic acid and aceticanhydride.In first tower, take methyl ethyl diketone out of quantizer with water as the azeotropic entrainment agent, aceticanhydride is hydrolyzed to acetic acid in tower simultaneously, the water layer of quantizer is back in first tower, the oil reservoir that contains less water is come in second tower and is dewatered, the tower still of second tower can obtain the crude product methyl ethyl diketone, and through decolouring, the crude product methyl ethyl diketone gets product methyl ethyl diketone again.Experimental study shows, the used entrainment agent water yield of azeotropic is that amount of water is will reach 2 times of methyl ethyl diketone the time, most of methyl ethyl diketone could be brought out, simultaneously a large amount of waste water can be drained from the tower still, cause power loss, be dissolved with the part methyl ethyl diketone in addition in the waste water, this part methyl ethyl diketone reclaims relatively difficulty, further cause the loss of methyl ethyl diketone, loss amount is about 2%.And the azeotrope of a large amount of methyl ethyl diketones and water steams from cat head, and required energy consumption is also bigger.Therefore, this method main drawback is: it is bigger to produce a large amount of waste water and energy consumption, and the loss amount of methyl ethyl diketone is more.
Summary of the invention
It is big and purity product is lower or produce a large amount of waste water, energy consumption is bigger and the loss amount of methyl ethyl diketone is more defective that technical problem to be solved by this invention is that the present invention has overcome the methyl ethyl diketone loss amount of existing methyl ethyl diketone purifying technique, and a kind of method of separating purifying acetylacetone is provided.The product purity height of method gained of the present invention, yield height, the loss amount of the wastewater flow rate of discharging, energy consumption and methyl ethyl diketone all obviously reduce.
The method of separation purifying acetylacetone of the present invention is to add in hexanaphthene and/or the toluene by the methyl ethyl diketone solution that will contain acetic acid and aceticanhydride, get mixing solutions, to wherein adding the entry or the saliniferous aqueous solution, heating hydrolysis, standing demix is got upper solution, and then batch fractionating, get crude product, crude product again through the continuous rectification decolouring, is promptly obtained the methyl ethyl diketone (technical process is referring to Fig. 1) of purifying.
Below, further the method to separation purifying acetylacetone of the present invention describes in detail:
(1) will contain in the methyl ethyl diketone solution adding hexanaphthene and/or toluene of acetic acid and aceticanhydride, get mixing solutions, add the entry or the saliniferous aqueous solution therein, heating hydrolysis, standing demix is got upper solution.
Wherein, described hexanaphthene and/or toluene are as the solvent of hydrolysis reaction, and preferable is toluene.That the mass ratio of the consumption of described hexanaphthene and/or toluene and the methyl ethyl diketone solution amount of handling is preferable is 1:1～2:1.
Wherein, the water in the described water or the saliniferous aqueous solution is used for the hydrolysis aceticanhydride, compared to " water is used as extraction solvent in the methyl ethyl diketone purification process of practical fine chemicals handbook, and water consumption of the present invention significantly reduces; Because methyl ethyl diketone has certain solubleness in water, contain salt in the water and can reduce the solubleness of methyl ethyl diketone in water, thereby significantly reduced the loss amount of methyl ethyl diketone again, therefore, the preferable use saliniferous aqueous solution.What described salt was preferable is strong acid and strong base salt, and that better is NaCl or MgCl
2, that best is MgCl
2What the concentration of salt was preferable in the described saliniferous aqueous solution is higher concentration～salt loading concentration, and better is the saturation concentration of salt.The consumption of the described water or the saliniferous aqueous solution according to the mass ratio of water or the saliniferous aqueous solution and aceticanhydride preferable be 2:1～1:1.
Wherein, described heating hydrolysis is the hydrolysis aceticanhydride, and the condition of reacting by heating is the normal condition of hydrolysis aceticanhydride, and preferable reaction conditions is: temperature is 50 a ℃～reflux temperature, if temperature of reaction more the low reaction time long more; Better reaction conditions is: reflux temperature, the reaction times is 4～6 hours.
Wherein, major part is hexanaphthene and/or toluene in the upper solution of standing demix, with the mixing solutions of methyl ethyl diketone, only contains a spot of water and acetic acid; Lower floor's solution is the aqueous solution that contains minute quantity methyl ethyl diketone and acetic acid, does wastewater treatment.
(2) batch fractionating: the upper solution that obtains in the step (1) is carried out batch fractionating by the operational condition of the conventional batch fractionating that uses in this area, the cut of wherein collecting is the layering solution that contains hexanaphthene and/or toluene, acetic acid and water, solution in the tower still of collecting is the crude product methyl ethyl diketone.
The batch fractionating of this step is to utilize in the upper solution that obtains in the step (1), and hexanaphthene and/or toluene, acetic acid and water can form azeotrope, and water in the methyl ethyl diketone and acetic acid are taken out of by hexanaphthene and/or toluene, thereby reaches the purpose of purification.Wherein, in the rectifying, the cut upper strata of collecting is hexanaphthene and/or toluene layer, and lower floor is a water layer.The cut upper strata that this treatment stage obtains is hexanaphthene and/or toluene upper strata, and little acetic acid is removed in the preferable soda lye wash of can using, and recycles.
The batch fractionating of this step is the batch fractionating of this area routine, and preferable is atmospheric pressure batch fractionating, and reflux ratio all is controlled between 2～4.Two cuts are arranged when this reflux ratio: in tower top temperature is 84.0～105.0 ℃, and tower still temperature is 120.9～123.0 ℃, distillates first cut from cat head, and its composition is hexanaphthene and/or toluene, acetic acid, methyl ethyl diketone and water; In tower top temperature is 105.0～111.0 ℃, and tower still temperature is 123.4～124.8 ℃, distillates second cut from cat head, and its composition is hexanaphthene and/or toluene, acetic acid and methyl ethyl diketone.The rectifying tower that described batch fractionating uses is the conventional rectifying tower that uses in this area, and preferable is packing tower, and the better filler for filling is the packing tower of stainless steel metal silk screen filler.
(3) crude product continuous rectification decolouring: wherein, the continuous rectification of this step is the continuous rectification of this area routine, preferable employing decompressing and continuous rectifying, preferable, the pressure of control cat head is 0.03～0.05MPa, and the control tower top temperature is 94～111 ℃, and control tower still temperature is 102～126 ℃.What the theoretical plate number of described continuous rectifying tower was preferable is 20～40.The rectifying tower that described continuous rectification is used is the conventional rectifying tower that uses in this area, and preferable is packing tower, and the better filler for filling is the packing tower of stainless steel metal silk screen filler.
Among the present invention, the optimum condition of each above-mentioned technical characterictic can arbitrary combination, obtains preferred embodiment and is used to separate purifying acetylacetone.
Agents useful for same of the present invention and raw material are all commercially available to be got.
Positive progressive effect of the present invention is: it is big and purity product is lower or produce a large amount of waste water, energy consumption is bigger and the loss amount of methyl ethyl diketone is more defective that the present invention has overcome the methyl ethyl diketone loss amount of existing methyl ethyl diketone purifying technique, and a kind of method of separating purifying acetylacetone is provided.Technology of the present invention makes water or saliniferous aqueous hydrolysis remove aceticanhydride, and the few and saliniferous aqueous solution of water consumption reduces solubleness in the methyl ethyl diketone water, further reduces the loss amount of methyl ethyl diketone; And then batch fractionating, by very a spot of acetic acid and water are taken out of with hexanaphthene and/or toluene,, thereby obviously cut down the consumption of energy compared to patent (GB838142).And batch fractionating distilled hexanaphthene and/or toluene can further be saved resource with recycling after the soda lye wash.The product purity height of method gained of the present invention is greater than 99.5wt%.
Description of drawings
Fig. 1 is the process flow diagram of a preferred embodiment of the present invention.
Embodiment
Mode below by embodiment further specifies the present invention, but does not therefore limit the present invention among the described scope of embodiments.
Among the following embodiment, the specification of used batch fractionating tower and continuous rectifying tower is: tower diameter 25mm; Tower height overall 2m, stripping section 1m wherein, rectifying section 1m, minimum theoretical number of plate are 38; Filler is the Stainless Steel Wire helical packing.
Embodiment 1
47 gram methyl ethyl diketones, 1 gram acetic acid and 2 gram aceticanhydrides are put into 50ml toluene, add the saturated NaCl aqueous solution of 3 grams again, behind the back flow reaction 4h, standing demix, the salt subsurface layer that contains 0.5 gram methyl ethyl diketone emits, upper strata gas chromatographic analysis, analytical results are (disregarding toluene): moisture 1.38wt%, methyl ethyl diketone 92.67wt%, acetic acid 5.93wt%.The solution of preparing 500 grams by the composition on upper strata again carries out batch fractionating, adopts atmospheric pressure batch fractionating, and control of reflux ratio is between 2～4.Collecting the cut of tower top temperature between 84.0～105.0 ℃ is first cut, and collecting the cut of tower top temperature between 105.0 ℃～111.0 ℃ is second cut, and the result of batch fractionating is:
| First cut | Second cut | The tower still | |
| Form | Toluene: 80.20wt% water: 3.80wt% acetic acid: 15.98wt% methyl ethyl diketone: 0.02wt% | Toluene: 99.69wt% acetic acid: 0.09wt% methyl ethyl diketone: 0.22wt% | Methyl ethyl diketone: 99.83wt% acetic acid: 0.17wt% |
Tower still solution is again through the treating tower decolouring, and the pressure of control cat head is 0.03MPa, and tower top temperature is 94～94.5 ℃, and tower still temperature is 102～116 ℃, after the decolouring, obtains the methyl ethyl diketone of purity 99.93wt%.Embodiment 2
47 gram methyl ethyl diketones, 1 gram acetic acid and 2 gram aceticanhydrides are put into the 50ml hexanaphthene, add the saturated NaCl aqueous solution of 3 grams again, behind the back flow reaction 4h, standing demix, the salt subsurface layer that contains 0.6 gram methyl ethyl diketone emits, upper strata gas chromatographic analysis, analytical results are (disregarding hexanaphthene): moisture 1.52wt%, methyl ethyl diketone 92.45wt%, acetic acid 6.03wt%.The solution of preparing 500 grams by the composition on upper strata carries out batch fractionating, adopts atmospheric pressure batch fractionating, and control of reflux ratio is between 2～4.Collecting the cut of tower top temperature between 84.0～105.0 ℃ is first cut, and collecting the cut of tower top temperature between 105.0 ℃～111.0 ℃ is second cut, and the result of batch fractionating is:
| First cut | Second cut | The tower still |
| Form | Hexanaphthene: 90.58wt% water: 1.56wt% acetic acid: 7.81wt% methyl ethyl diketone: 0.05wt% | Hexanaphthene: 99.02wt% acetic acid: 0.13wt% methyl ethyl diketone: 0.85wt% | Methyl ethyl diketone: 99.70wt% acetic acid: 0.30wt% |
Tower still solution passes through treating tower again, and the pressure of control cat head is 0.05MPa, and tower top temperature is 110～110.5 ℃, and tower still temperature is 112～126 ℃, after the decolouring, obtains the methyl ethyl diketone of purity 99.90wt%.
Embodiment 3
47 gram methyl ethyl diketones, 1 gram acetic acid and 2 are restrained the toluene that aceticanhydrides are put into 50ml, add the saturated MgCl of 3 grams again
2Solution, behind the back flow reaction 4h, standing demix, the salt subsurface layer that contains 0.3 gram methyl ethyl diketone emits, the upper strata gas chromatographic analysis, analytical results is (disregarding toluene): moisture 0.80wt%, methyl ethyl diketone 93.78wt%, acetic acid 5.42wt%.The solution of preparing 500 grams by the composition on upper strata carries out batch fractionating, adopts atmospheric pressure batch fractionating, and control of reflux ratio is between 2～4.Collecting the cut of tower top temperature between 84.0～105.0 ℃ is first cut, and collecting the cut of tower top temperature between 105.0 ℃～111.0 ℃ is second cut, and the result of batch fractionating is:
| First cut | Second cut | The tower still | |
| Form | Toluene: 81.43wt% water: 2.99wt% acetic acid: 15.54wt% methyl ethyl diketone: 0.04wt% | Toluene: 98.22wt% acetic acid: 1.48wt% methyl ethyl diketone: 0.30wt% | Methyl ethyl diketone: 99.80wt% acetic acid: 0.20wt% |
Tower still solution passes through treating tower again, and the pressure of control cat head is 0.05MPa, and tower top temperature is 110～110.5 ℃, and tower still temperature is 112～126 ℃, after the decolouring, obtains the methyl ethyl diketone of purity 99.92wt%.
Embodiment 4
47 gram methyl ethyl diketones, 1 gram acetic acid and 2 are restrained the toluene that aceticanhydrides are put into 50ml, add the saturated MgCl of 2 grams again
2Solution, behind the back flow reaction 6h, standing demix, the salt subsurface layer that contains 0.2 gram methyl ethyl diketone emits, the upper strata gas chromatographic analysis, analytical results is (disregarding toluene): moisture 0.45wt%, methyl ethyl diketone 94.69wt%, acetic acid 4.86wt%.The solution of preparing 500 grams by the composition on upper strata carries out batch fractionating, adopts atmospheric pressure batch fractionating, and control of reflux ratio is between 2～4.Collecting the cut of tower top temperature between 84.0～105.0 ℃ is first cut, and collecting the cut of tower top temperature between 105.0 ℃～111.0 ℃ is second cut, and the result of batch fractionating is:
| First cut | Second cut | The tower still |
| Form | Toluene: 81.87wt% water: 1.72wt% acetic acid: 16.38wt% methyl ethyl diketone: 0.03wt% | Toluene: 99.54wt% acetic acid: 0.05wt% methyl ethyl diketone: 0.41wt% | Methyl ethyl diketone: 99.85wt% acetic acid: 0.15wt% |
Tower still solution passes through treating tower again, and the pressure of control cat head is 0.03MPa, and tower top temperature is 94～94.5 ℃, and tower still temperature is 102～116 ℃, after the decolouring, obtains the methyl ethyl diketone of purity 99.95wt%.
Embodiment 5
47 gram methyl ethyl diketones, 1 gram acetic acid and 2 are restrained the toluene that aceticanhydrides are put into 100ml, add the KNO of 4 gram mass per-cents 10% again
3Solution, behind 50 ℃ of reaction 8h, standing demix, the salt subsurface layer that contains methyl ethyl diketone emits, the upper strata gas chromatographic analysis, analytical results is (disregarding toluene): moisture 1.25wt%, methyl ethyl diketone 94.29wt%, acetic acid 4.46wt%.The solution of preparing 500 grams by the composition on upper strata carries out batch fractionating, adopts atmospheric pressure batch fractionating, and control of reflux ratio is between 2～4.Collecting the cut of tower top temperature between 84.0～105.0 ℃ is first cut, and collecting the cut of tower top temperature between 105.0 ℃～111.0 ℃ is second cut, and the result of batch fractionating is:
| First cut | Second cut | The tower still | |
| Form | Toluene: 82.36wt% water: 2.12wt% acetic acid: 15.28wt% methyl ethyl diketone: 0.16wt% | Toluene: 99.30wt% acetic acid: 0.08wt% methyl ethyl diketone: 0.62wt% | Methyl ethyl diketone: 99.42wt% acetic acid: 0.58wt% |
Recycle behind the NaOH solution washing of toluene upper strata with cut with mass percent 10%.Tower still solution passes through treating tower again, and the pressure of control cat head is 0.04MPa, and tower top temperature is 103～104 ℃, and tower still temperature is 105～120 ℃, after the decolouring, obtains the methyl ethyl diketone of purity 99.64wt%.
The comparative example
47 gram methyl ethyl diketones, 1 gram acetic acid and 2 gram aceticanhydrides are dissolved in the 80ml benzene, and with isopyknic distilled water vibration 4 hours, the aceticanhydride hydrolysis generated acetic acid then, and acetic acid soluble in water mainly is assigned to aqueous phase, and methyl ethyl diketone then mainly is dissolved in the benzene.The analytical results on upper strata (disregarding benzene): methyl ethyl diketone 98.85wt%, acetic acid 1.15wt%; Lower floor's (water layer): methyl ethyl diketone 13.23wt%, acetic acid 4.53wt%, moisture 82.24wt%.
Show the method that adopts separation purifying acetylacetone of the present invention by above-mentioned contrast, obviously reduced the loss amount of wastewater flow rate, energy consumption and the methyl ethyl diketone of discharging, products obtained therefrom purity height, yield height.
Claims (12)
1. method of separating purifying acetylacetone, its step is as follows: the methyl ethyl diketone solution that will contain acetic acid and aceticanhydride adds in hexanaphthene and/or the toluene, get mixing solutions, to wherein adding the entry or the saliniferous aqueous solution, heating hydrolysis, standing demix, get upper solution, and then batch fractionating, crude product got, crude product again through the continuous rectification decolouring, is promptly obtained the methyl ethyl diketone of purifying.
2. the method for claim 1 is characterized in that: the consumption of described hexanaphthene and/or toluene is 1: 1～2: 1 with the mass ratio of the methyl ethyl diketone solution amount of handling.
3. the method for claim 1, it is characterized in that: described salt is strong acid and strong base salt; The consumption of the described water or the saliniferous aqueous solution is 2: 1～1: 1 according to the mass ratio of water or the saliniferous aqueous solution and aceticanhydride.
4. as claim 1 or 3 described methods, it is characterized in that: described salt is NaCl or MgCl
2
5. as claim 1 or 3 described methods, it is characterized in that: the concentration of salt is the saturation concentration of salt in the described saliniferous aqueous solution.
6. the method for claim 1, it is characterized in that: the temperature of reaction of described heating hydrolysis is 50 a ℃～reflux temperature.
7. method as claimed in claim 6 is characterized in that: the temperature of described heating hydrolysis is a reflux temperature, and the reaction times is 4～6 hours.
8. the method for claim 1, it is characterized in that: the step of described batch fractionating is as follows: with the upper solution atmospheric pressure batch fractionating of gained, reflux ratio all is controlled between 2～4: tower top temperature is 84.0～105.0 ℃, tower still temperature is 120.9～123.0 ℃, distillates first cut from cat head; Tower top temperature is 105.0 ℃～111.0 ℃, and tower still temperature is 123.4～124.8 ℃, distillates second cut from cat head.
9. method as claimed in claim 8 is characterized in that: the upper strata of described cut is that hexanaphthene and/or toluene are recycled after with soda lye wash; Wherein, described cut comprises first cut and second cut.
10. the method for claim 1, it is characterized in that: the rectifying tower of described batch fractionating or continuous rectification is a packing tower.
11. the method for claim 1 is characterized in that: described continuous rectification is decompressing and continuous rectifying, and condition is: the pressure of cat head is 0.03～0.05MPa, and tower top temperature is 94～111 ℃, and tower still temperature is 102～126 ℃.
12. as claim 1 or 10 described methods, it is characterized in that: the theoretical plate number of the rectifying tower that described continuous rectification is used is 20～40.
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| CN101514151B (en) * | 2009-03-30 | 2012-07-18 | 上海吴泾化工有限公司 | Method for refining acetylacetone |
| WO2018128079A1 (en) * | 2017-01-04 | 2018-07-12 | セントラル硝子株式会社 | DRY ETCHING METHOD AND β-DIKETONE-FILLED CONTAINER |
| WO2018128078A1 (en) | 2017-01-04 | 2018-07-12 | セントラル硝子株式会社 | Etching method and etching device |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1051049A (en) * | 1963-06-03 | 1900-01-01 | ||
| CN1850763A (en) * | 2006-05-25 | 2006-10-25 | 宁波王龙集团有限公司 | Process for preparing high-purity acetylacetone |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1051049A (en) * | 1963-06-03 | 1900-01-01 | ||
| CN1850763A (en) * | 2006-05-25 | 2006-10-25 | 宁波王龙集团有限公司 | Process for preparing high-purity acetylacetone |
Non-Patent Citations (2)
| Title |
|---|
| GB 1051049 A, |
| 徐润华.乙酸法乙酰丙酮的合成及应用.《河南化工》.2003, * |
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