JP2023108403A - Method for recovering acetone and method for producing methyl isobutyl ketone - Google Patents

Abstract

To provide a method for recovering acetone that can recover acetone at a high recovery rate from a process liquid containing methyl oxide after dehydration of diacetone alcohol in the production of methyl isobutyl ketone.SOLUTION: Provided is a method for recovering acetone from a solution containing mesityl oxide that includes distilling the solution in the presence of an alkali metal hydroxide to recover an acetone-containing fraction. Also provided is a method for producing methyl isobutyl ketone in which methyl isobutyl ketone is produced using the method for recovering acetone.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for recovering acetone and a method for producing methyl isobutyl ketone.

A well-known method for producing a saturated carbonyl-containing product is to condense a carbonyl-containing reactant and then hydrogenate the resulting unsaturated carbonyl-containing compound to obtain a saturated carbonyl-containing product. One of such production methods is a method of producing methyl isobutyl ketone (MIBK) from acetone.

As a method for producing this methyl isobutyl ketone (MIBK), for example, two molecules of acetone are condensed in the presence of a basic solid catalyst to form diacetone alcohol (DAA), then DAA is dehydrated to produce mesityl oxide ( MSO) is obtained, and this MSO is hydrogenated to obtain MIBK.
In such a method for manufacturing MIBK, acetone is recovered from the process solution and reused from the viewpoint of improving the raw material unit consumption.

As a method for recovering acetone from a process solution in the production of MIBK, for example, Patent Document 1 discloses that an alkaline solution is added to the aqueous phase by-produced in the process of recovering MIBK, distillation is performed, and an acetone-containing fraction is recovered. A technique for doing so is disclosed.
Further, Patent Documents 2 and 3 disclose techniques for recovering acetone from a process solution containing unreacted acetone after condensation reaction and hydrogenation reaction of acetone.

JP-A-11-228464 Japanese translation of PCT publication No. 2009-519319 Japanese translation of PCT publication No. 2009-519320

However, Patent Documents 1 to 3 do not mention recovery of acetone from the process solution containing MSO after dehydration of DAA.

The present invention has been made in view of the prior art as described above, and in the production of MIBK, it is possible to recover acetone at a high recovery rate from the process solution containing MSO after dehydrating DAA. An object of the present invention is to provide a method for recovering acetone and a method for producing methyl isobutyl ketone using this method for recovering acetone.

As a result of repeated studies to solve the above problems, the present inventors found that the above problems can be solved by distilling the process liquid containing MSO after dehydrating DAA in the presence of an alkali metal hydroxide. I found

That is, the first gist of the present invention is a method for recovering acetone from a solution containing mesityl oxide, wherein the solution is distilled in the presence of an alkali metal hydroxide to recover an acetone-containing fraction. A method for recovering acetone comprising:
A second gist of the present invention is a method for producing methyl isobutyl ketone, comprising the following steps (1) to (5).
(1) a condensation step of condensing acetone in the presence of a basic solid catalyst to produce a reaction product containing diacetone alcohol and acetone; (2) distilling the reaction product produced in step (1); a recovery step (3) for recovering diacetone alcohol; a dehydration step (4) for producing a reaction product liquid containing mesityl oxide by dehydrating the diacetone alcohol recovered in the step (2); A portion of the produced reaction product liquid is distilled in the presence of an alkali metal hydroxide according to the acetone recovery method of the present invention to recover an acetone-containing fraction, and the recovered acetone-containing fraction is subjected to the above step. Acetone recovery step introduced in (3) (5) Recovery of methyl isobutyl ketone in which mesityl oxide contained in the reaction product liquid produced in step (3) is hydrogenated and then distilled to recover methyl isobutyl ketone. process

According to the present invention, it is possible to provide a method for recovering acetone with excellent acetone recovery rate in the production of MIBK.
Furthermore, according to the present invention, it is possible to provide a method for producing MIBK, in which acetone can be effectively used.

It is a process schematic which shows an example of the process which manufactures MIBK from acetone.

Although the present invention will be described in detail below, the present invention is not limited to the following description, and can be arbitrarily modified without departing from the gist of the present invention.

In addition, unless otherwise specified, the numerical range represented by using "~" in this specification means a range including the numerical values described before and after "~" as lower and upper limits, and "A ~ B" means greater than or equal to A and less than or equal to B.

[Acetone recovery method]
The method for recovering acetone of the present invention is characterized by distilling a solution containing MSO (mesityl oxide) in the presence of an alkali metal hydroxide to recover an acetone-containing fraction.

In the solution containing MSO from which acetone is to be recovered (hereinafter referred to as "MSO-containing solution"), the lower limit of the content of MSO is not particularly limited. 10% by mass or more is preferable, 20% by mass or more is more preferable, and 30% by mass or more is even more preferable with respect to 100% by mass of the total mass of the containing solution. On the other hand, the upper limit of the MSO content is not particularly limited, but is usually 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less. The above upper and lower limits can be combined arbitrarily. For example, the MSO content of the MSO-containing solution is preferably 10 to 50% by mass, more preferably 20 to 45% by mass, and even more preferably 30 to 40% by mass with respect to 100% by mass of the total mass of the MSO-containing solution. .
Examples of components other than MSO in the MSO-containing solution include triacetone alcohol.

The MSO-containing solution described above is preferably a reaction product solution containing MSO obtained in step (3) in the method for producing methyl isobutyl ketone of the present invention, which will be described later. The composition of the MSO-containing solution, which is the reaction product liquid, is not particularly limited, but an MSO-containing solution having the following composition can be used.
(Composition of MSO-containing solution)
Acetone: 0 to 5% by mass
MSO: 10 to 50% by mass
Triacetone alcohol: 10 to 30% by mass
Other components (by-products, high boiling point components): 15 to 80% by mass

In the method for recovering acetone of the present invention, an alkali metal hydroxide is added to the MSO-containing solution, and distillation is performed in the presence of the alkali metal hydroxide to alkali hydrolyze the MSO in the MSO-containing solution. can be converted to acetone at high recovery rates.

Alkali metal hydroxides to be added include alkali metal hydroxides such as lithium hydroxide, potassium hydroxide and sodium hydroxide. Among these, sodium hydroxide and potassium hydroxide are preferred. Alkali metal hydroxides may be used alone or in combination of two or more.

In the method for recovering acetone of the present invention, the distillation of the MSO-containing solution is preferably carried out in the presence of an alkali metal hydroxide and water in order to carry out alkaline hydrolysis of MSO within the distillation system.
Water for alkaline hydrolysis can be added separately from the alkali metal hydroxide, but it is efficient to add the alkali metal hydroxide as an aqueous solution.

In the aqueous alkali metal hydroxide solution described above, the concentration of the alkali metal hydroxide is not particularly limited, but is usually 1 to 1 with respect to 100% of the total mass of the aqueous alkali metal hydroxide solution. It is 40% by mass, and particularly in the present invention, it can be 3 to 20% by mass.

In the distillation of the MSO-containing solution described above, the content ratio of the alkali metal hydroxide in the solution subjected to distillation is not particularly limited, but the total mass of the solution subjected to distillation is 100% by mass. 6 to 30% by mass is preferable, and 1 to 10% by mass is more preferable.
If the content of the alkali metal hydroxide in the solution subjected to distillation is at least the above lower limit, the alkaline hydrolysis of MSO can be carried out efficiently and the acetone recovery rate can be increased. Further, if the content is equal to or less than the above upper limit, it is not necessary to add alkali more than necessary, so that the cost of using alkali can be reduced.

In addition, in the above-described distillation of the MSO-containing solution, the content of water in the solution subjected to distillation is not particularly limited, but it is 5 to 60 mass% with respect to 100 mass% of the total mass of the solution subjected to distillation. %, more preferably 10 to 40% by mass.
If the content of water in the solution to be distilled is at least the above lower limit, alkaline hydrolysis of MSO can be efficiently carried out and the recovery rate of acetone can be increased. Further, if the content is equal to or less than the above upper limit, the size of the distillation column can be kept small.

Distillation of the MSO-containing solution to which an alkali metal hydroxide, preferably an aqueous alkali metal hydroxide solution has been added, can be carried out according to conventional methods, for example at a temperature of 90-120° C. to obtain a distillate (acetone-containing fraction ) can be done while collecting.

[Method for producing methyl isobutyl ketone]
The method for producing methyl isobutyl ketone of the present invention includes the following steps (1) to (5).
(1) a condensation step of condensing acetone in the presence of a basic solid catalyst to produce a reaction product containing diacetone alcohol and acetone; (2) distilling the reaction product produced in step (1); a recovery step (3) for recovering diacetone alcohol; a dehydration step (4) for producing a reaction product liquid containing mesityl oxide by dehydrating the diacetone alcohol recovered in the step (2); A portion of the produced reaction product liquid is distilled in the presence of an alkali metal hydroxide according to the acetone recovery method of the present invention to recover an acetone-containing fraction, and the recovered acetone-containing fraction is subjected to the above step. Acetone recovery step introduced into (3) (5) MIBK recovery step of recovering MIBK by hydrogenating MSO contained in the reaction product liquid produced in step (3) and then distilling it

Each step of the MIBK manufacturing method according to the present invention will be specifically described below with reference to FIG. FIG. 1 is a process chart showing an example of a process for producing MIBK from acetone.

<Step (1)>
Raw material acetone is introduced into the condensation reactor 1 through the pipe L1. Acetone separated in the first distillation column 2 and the third distillation column 5 in the latter stage is returned to this raw material acetone via the pipe L2.

The condensation reactor 1 is filled with a basic solid catalyst, and acetone is condensed by contact with the basic solid catalyst to produce DAA (diacetone alcohol).

Examples of basic solid catalysts include insoluble basic compounds of alkaline earth metals such as magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium oxide, calcium oxide, strontium oxide and barium oxide. Solid catalysts are mentioned. These basic solid catalysts can be used singly or in combination of two or more. Further, the basic compound constituting the active component of the basic solid catalyst can be used alone as a catalyst, but it can also be used by supporting it on a carrier. As the carrier used in this case, it is preferable to use a carrier with low solubility in water.

The basic solid catalyst is obtained by calcining at a low temperature a mixture of basic solid catalyst-forming components, particularly containing an alkaline earth metal hydroxide such as calcium hydroxide and a silicon compound such as sodium metasilicate. It is preferred to use a catalyst.

The basic solid catalyst can be packed in the condensation reactor 1 in a fixed bed, fluidized bed, moving bed, or other form and brought into contact with acetone. is preferred.

Acetone and the basic solid catalyst may be brought into contact with each other at least once, but a plurality of reactors similar to the condensation reactor 1 are arranged in series to bring acetone and the basic solid catalyst into contact two or more times. Thus, the production rate of DAA can be improved.

A reaction product containing DAA and acetone, in which at least part of the acetone is converted to DAA by contact with the basic solid catalyst in the condensation reactor 1, is introduced into the first distillation column 2 through the pipe L3.

<Step (2)>
In the first distillation column 2, acetone and DAA are separated by utilizing the difference in boiling points between them. The obtained DAA (containing a small amount of water, acetone, etc.) is introduced into the dehydrator 3 through the pipe L4. On the other hand, the separated unreacted acetone is returned to the condensation reactor 1 through the pipe L2 and reused as raw material acetone.

<Step (3)>
In the dehydrator 3, a dehydration reaction occurs by bringing DAA into contact with a catalyst to produce MSO (mesityl oxide). Sulfuric acid, phosphoric acid, etc. are mentioned as a catalyst used here.

A part of the reaction product liquid containing MSO produced by the dehydration reaction is withdrawn from the pipe L5 and fed to the second distillation column 4 . The other part of this reaction product liquid is fed to the third distillation column 5 through the pipe L6.

<Step (4)>
In the second distillation column 4, the reaction product liquid containing MSO from the dehydrator 3 is subjected to distillation in the presence of an alkali metal hydroxide according to the above-described acetone recovery method of the present invention.
Specifically, the aforementioned aqueous solution of alkali metal hydroxide is added through pipe L7, and distillation is performed in the presence of alkali metal hydroxide according to the above-described method for recovering acetone of the present invention to obtain an acetone-containing fraction. to recover.

The acetone-containing fraction recovered in the second distillation column 4 is returned to the dehydrator 3 of step (3) through the pipe L8.
On the other hand, the bottom liquid of the second distillation column 4 (distillation residue containing water, alkali metal hydroxides and other high-boiling substances) is discharged from the system through the pipe L9.

<Step (5)>
MIBK is recovered by further distilling the reaction product liquid containing MSO extracted from the dehydrator 3 through the pipe L6 after the hydrogenation reaction. Distillation may be performed in the third distillation column 5 for recovery, and the acetone-containing fraction distilled by the distillation may be returned to the condensation reactor 1 via the pipe L2 and reused as raw material acetone.

The other fraction extracted from the acetone-containing fraction in the third distillation column 5 is fed to the hydrogenation reactor 6 through the pipe L10, and the contained MSO is hydrogenated to produce MIBK.

In the hydrogenation reactor 6, MSO and hydrogen are brought into contact in the presence of a hydrogenation catalyst to produce MIBK.
As the hydrogenation catalyst, conventionally known hydrogenation catalysts such as nickel, Raney nickel, platinum black, platinum oxide, palladium and palladium black are used.

The reaction product liquid containing MIBK produced in the hydrogenation reactor 6 is sent through the pipe L11 to the fourth distillation column 7 where it is further distilled, and the MIBK fraction is extracted and recovered through the pipe L12.

According to the method for producing MIBK of the present invention, through the above steps (1) to (5), acetone can be efficiently recovered from the process solution at a high recovery rate and reused as raw material acetone. can be improved.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Acetone, sodium hydroxide, and potassium hydroxide used in Reference Experimental Example 1, Examples, and Comparative Examples were reagents manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.

[Reference Experimental Example 1]
Acetone was condensed using the basic solid catalyst disclosed in JP-A-2004-323375 to obtain a reaction product containing diacetone alcohol and acetone. Next, the obtained reaction product was distilled, and the recovered diacetone alcohol was dehydrated to obtain a reaction product liquid containing mesityl oxide.

The composition of the obtained reaction product liquid was analyzed by the gas chromatography internal standard method using a gas chromatograph measuring device with an FID detector (type: GC-2014, manufactured by Shimadzu Corporation), and the results were as follows. .
(Composition of reaction product liquid)
Acetone 0.8% by mass
Mesityl oxide 31.4% by mass
Triacetone alcohol 16.9% by mass
Other components (by-products, high boiling point components) 50.9% by mass

[Example 1]
A 200 mL distillation flask equipped with a thermometer, a Liebig condenser, a stirring blade and an oil bath is charged with 50 g of the reaction product liquid obtained in Reference Experimental Example 1 and 30 g of a 3% by mass sodium hydroxide aqueous solution. When the temperature was raised from room temperature (20°C), distillation started when the temperature reached 140°C, and the distillate was collected in a 10 mL eggplant flask for 60 minutes while maintaining the temperature at 140°C. The content of sodium hydroxide in the contents of the flask immediately after the start of simple distillation was 1.13% by mass.
The composition of the obtained distillate was analyzed by the gas chromatography internal standard method using a gas chromatograph measuring device with an FID detector (type: GC-2014, manufactured by Shimadzu Corporation). The recovery rates of acetone and mesityl oxide with respect to the obtained reaction product liquid were determined. The analysis results are shown in Table 1.

[Example 2]
Distillation of the reaction product liquid obtained in Reference Experimental Example 1 was performed under the same conditions as in Example 1, except that a 5% by mass aqueous sodium hydroxide solution was used instead of the 3% by mass aqueous sodium hydroxide solution. The content of sodium hydroxide in the contents of the flask immediately after the start of simple distillation was 1.88% by mass. Table 1 shows the analysis results of the obtained distillate.

[Example 3]
Distillation of the reaction product liquid obtained in Reference Experimental Example 1 was performed under the same conditions as in Example 1, except that a 15% by mass aqueous sodium hydroxide solution was used instead of the 3% by mass aqueous sodium hydroxide solution. The content of sodium hydroxide in the contents of the flask immediately after the start of simple distillation was 5.63% by mass. Table 1 shows the analysis results of the obtained distillate.

[Example 4]
Distillation of the reaction product liquid obtained in Reference Experimental Example 1 was performed under the same conditions as in Example 1, except that a 15% by mass aqueous potassium hydroxide solution was used instead of the 3% by mass aqueous sodium hydroxide solution. The content of potassium hydroxide in the contents of the flask immediately after the start of simple distillation was 5.63% by mass. Table 1 shows the analysis results of the obtained distillate.

[Comparative Example 1]
Distillation of the reaction product liquid obtained in Reference Experimental Example 1 was performed under the same conditions as in Example 1, except that pure water was used instead of the 3% by mass sodium hydroxide aqueous solution. Table 1 shows the analysis results of the obtained distillate.

In Examples 1 to 4, since the distillation was performed in the presence of an alkali metal hydroxide, acetone could be recovered in a high yield from the reaction product liquid containing MSO.
On the other hand, in Comparative Example 1, since distillation was performed without adding an alkali metal hydroxide, the recovery rate of acetone was low.

According to the method for recovering acetone of the present invention, mesityl oxide in a solution containing mesityl oxide is distilled in the presence of an alkali metal hydroxide to convert mesityl oxide into acetone through alkaline hydrolysis. acetone can be recovered in an industrially advantageous manner at a high yield, which is industrially valuable and remarkable.

1 condensation reactor 2 first distillation column 3 dehydrator 4 second distillation column 5 third distillation column 6 hydrogenation reactor 7 fourth distillation column

Claims (7)

In a method for recovering acetone from a solution containing mesityl oxide,
A method of recovering acetone, comprising distilling the solution in the presence of an alkali metal hydroxide to recover an acetone-containing fraction. A method for recovering acetone according to claim 1, wherein said distillation is carried out in the presence of water and an alkali metal hydroxide. 3. The method for recovering acetone according to claim 1 or 2, wherein said alkali metal hydroxide is sodium hydroxide and/or potassium hydroxide. The method for recovering acetone according to any one of claims 1 to 3, wherein the content of mesityl oxide in the solution is 10% by mass or more with respect to 100% of the total mass of the solution. The content of the alkali metal hydroxide in the solution is 0.6% by mass or more and 30.0% by mass or less with respect to 100% of the total mass of the solution, according to any one of claims 1 to 4 Method for recovering acetone as described. A solution containing mesityl oxide is
condensing acetone in the presence of a basic solid catalyst to give a reaction product comprising diacetone alcohol and acetone;
Distilling the obtained reaction product, dehydrating the recovered diacetone alcohol to obtain a reaction product liquid containing mesityl oxide,
The method for recovering acetone according to any one of claims 1 to 5, wherein the obtained reaction product liquid is an oil phase liquid obtained by oil-water separation. A method for producing methyl isobutyl ketone, comprising the following steps (1) to (5).
(1) a condensation step of condensing acetone in the presence of a basic solid catalyst to produce a reaction product containing diacetone alcohol and acetone; (2) distilling the reaction product produced in step (1); a recovery step (3) for recovering diacetone alcohol; a dehydration step (4) for producing a reaction product liquid containing mesityl oxide by dehydrating the diacetone alcohol recovered in the step (2); A part of the produced reaction product liquid is distilled in the presence of an alkali metal hydroxide according to the method for recovering acetone according to any one of claims 1 to 5, thereby recovering an acetone-containing fraction. and acetone recovery step (5) in which the recovered acetone-containing fraction is introduced into the step (3). Mesityl oxide contained in the reaction product liquid produced in the step (3) is hydrogenated and then distilled to obtain methyl Methyl isobutyl ketone recovery process for recovering isobutyl ketone

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