Acetone recovery method and methyl isobutyl ketone production method

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

[Technical Field]

[0001] The present invention relates to a method for recovering acetone and a method for producing methyl isobutyl ketone. [Background technology]

[0002] Well-known methods for producing saturated carbonyl-containing products include condensing carbonyl-containing reactants and then hydrogenating the resulting unsaturated carbonyl-containing compound to produce the saturated carbonyl-containing product, such as the production of methyl isobutyl ketone (MIBK) from acetone.

[0003] A known method for producing methyl isobutyl ketone (MIBK) is, for example, to condense two molecules of acetone in the presence of a basic solid catalyst to form diacetone alcohol (DAA), which is then dehydrated to obtain mesityl oxide (MSO), which is then hydrogenated to obtain MIBK. In this type of MIBK manufacturing method, acetone is recovered from the process liquid and reused in order to improve the raw material consumption rate.

[0004] As a method for recovering acetone from a process liquid in the production of MIBK, for example, Patent Document 1 discloses a technology in which an alkaline solution is added to an aqueous phase by-produced in an MIBK recovery step, followed by distillation to recover an acetone-containing fraction. Furthermore, Patent Documents 2 and 3 disclose techniques for recovering acetone from a process liquid containing unreacted acetone after the condensation reaction and hydrogenation reaction of acetone. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-228464 [Patent Document 2] Special Publication No. 2009-519319 [Patent Document 3] Special Publication No. 2009-519320 Summary of the Invention [Problem to be solved by the invention]

[0006] However, Patent Documents 1 to 3 make no mention of recovering acetone from the process liquid containing MSO after dehydration of DAA.

[0007] The present invention has been made in view of the above-described conventional techniques, and an object of the present invention is to provide a method for recovering acetone, which is capable of recovering acetone at a high recovery rate from a process solution containing MSO remaining after dehydration of DAA in the production of MIBK, and a method for producing methyl isobutyl ketone using this method for recovering acetone. [Means for solving the problem]

[0008] As a result of extensive investigations aimed at solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by distilling a process solution containing MSO after dehydration of DAA in the presence of an alkali metal hydroxide.

[0009] That is, a first gist of the present invention resides in a method for recovering acetone from a solution containing mesityl oxide, the method comprising distilling the solution in the presence of an alkali metal hydroxide to recover an acetone-containing fraction. A second gist of the present invention resides in a method for producing methyl isobutyl ketone, which includes the following steps (1) to (5): (1) A condensation step in which acetone is condensed in the presence of a basic solid catalyst to produce a reaction product containing diacetone alcohol and acetone. (2) A recovery step of distilling the reaction product produced in the step (1) to recover diacetone alcohol. (3) A dehydration step in which the diacetone alcohol recovered in the step (2) is dehydrated to produce a reaction product liquid containing mesityl oxide. (4) an acetone recovery step in which a part of the reaction product liquid produced in the step (3) is distilled in the presence of an alkali metal hydroxide according to the method for recovering acetone of the present invention to recover an acetone-containing fraction, and the recovered acetone-containing fraction is introduced into the step (3). (5) A methyl isobutyl ketone recovery step in which mesityl oxide contained in the reaction product solution produced in the step (3) is hydrogenated and then distilled to recover methyl isobutyl ketone. [Effects of the Invention]

[0010] According to the present invention, a method for recovering acetone with an excellent acetone recovery rate in the production of MIBK can be provided. Furthermore, the present invention can provide a method for producing MIBK that can effectively utilize acetone. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a process schematic diagram showing an example of a process for producing MIBK from acetone. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described in detail below, but the present invention is not limited to the following description and can be practiced with any modifications within the scope of the gist of the present invention.

[0013] Unless otherwise specified, in this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits, and "A to B" means A or more and B or less.

[0014] [Method for recovering acetone] 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.

[0015] In an MSO-containing solution from which acetone is to be recovered (hereinafter referred to as an "MSO-containing solution"), the lower limit of the MSO content is not particularly limited, but from the viewpoint of MSO recovery efficiency, it is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, relative to the total mass of the MSO-containing solution (100% by mass). 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 arbitrarily combined. 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, relative to the total mass of the MSO-containing solution (100% by mass). Components other than MSO in the MSO-containing solution include triacetone alcohol.

[0016] The MSO-containing solution is preferably a reaction product liquid containing MSO obtained in step (3) of the method for producing methyl isobutyl ketone of the present invention, which will be described later. The composition of this reaction product liquid, i.e., the MSO-containing solution, 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: 10~50% by mass Triacetone alcohol: 10 to 30% by mass Other components (by-products, high boiling point components): 15 to 80% by mass

[0017] 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. This allows the MSO in the MSO-containing solution to be alkaline hydrolyzed and converted into acetone, and acetone can be recovered at a high recovery rate.

[0018] Examples of the alkali metal hydroxide to be added include alkali metal hydroxides such as lithium hydroxide, potassium hydroxide, and sodium hydroxide, with sodium hydroxide and potassium hydroxide being preferred. Only one type of alkali metal hydroxide may be used, or two or more types may be mixed and used.

[0019] 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 in the distillation system. Although water for alkaline hydrolysis can be added separately from the alkali metal hydroxide, it is more efficient to add the alkali metal hydroxide as an aqueous solution.

[0020] In the aqueous solution of alkali metal hydroxide described above, the concentration of the alkali metal hydroxide is not particularly limited, but is usually 1 to 40 mass % relative to 100% of the total mass of the aqueous solution of alkali metal hydroxide, and particularly in the present invention, can be 3 to 20 mass %.

[0021] In the distillation of the MSO-containing solution described above, the alkali metal hydroxide content of the solution to be distilled is not particularly limited, but is preferably 0.6 to 30 mass% and more preferably 1 to 10 mass% relative to the total mass of the solution to be distilled (100 mass%). If the content of alkali metal hydroxide in the solution to be distilled is equal to or greater than the lower limit, the alkaline hydrolysis of MSO can be carried out efficiently, increasing the recovery rate of acetone. Furthermore, if the content is equal to or less than the upper limit, there is no need to add more alkali than necessary, thereby reducing the cost of using alkali.

[0022] In the distillation of the MSO-containing solution described above, the water content of the solution to be distilled is not particularly limited, but is preferably 5 to 60 mass %, and more preferably 10 to 40 mass %, relative to 100 mass % of the total mass of the solution to be distilled. If the water content in the solution to be distilled is equal to or greater than the lower limit, the alkaline hydrolysis of MSO can be carried out efficiently, increasing the recovery rate of acetone. If the water content is equal to or less than the upper limit, the size of the distillation column can be kept small.

[0023] Distillation of the MSO-containing solution to which an alkali metal hydroxide, preferably an aqueous solution of an alkali metal hydroxide, has been added can be carried out according to a conventional method, for example, at a temperature of 90 to 120°C while recovering the distillate (acetone-containing fraction).

[0024] [Method of 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 in which acetone is condensed in the presence of a basic solid catalyst to produce a reaction product containing diacetone alcohol and acetone. (2) A recovery step of distilling the reaction product produced in the step (1) to recover diacetone alcohol. (3) A dehydration step in which the diacetone alcohol recovered in the step (2) is dehydrated to produce a reaction product liquid containing mesityl oxide. (4) an acetone recovery step in which a part of the reaction product liquid produced in the step (3) is distilled in the presence of an alkali metal hydroxide according to the method for recovering acetone of the present invention to recover an acetone-containing fraction, and the recovered acetone-containing fraction is introduced into the step (3). (5) A MIBK recovery step in which the MSO contained in the reaction product liquid produced in the step (3) is hydrogenated and then distilled to recover MIBK.

[0025] Each step of the method for producing MIBK according to the present invention will be specifically described below with reference to Fig. 1. Fig. 1 is a process diagram showing an example of a process for producing MIBK from acetone.

[0026] <Process (1)> Raw acetone is introduced into the condensation reactor 1 through a pipe L1. Acetone separated in the first distillation column 2 and the third distillation column 5 at the downstream side is returned to this raw acetone through a pipe L2.

[0027] The condensation reactor 1 is filled with a basic solid catalyst, and acetone is condensed by contacting with the basic solid catalyst to produce DAA (diacetone alcohol).

[0028] Examples of basic solid catalysts include solid catalysts containing 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. These basic solid catalysts can be used alone or in combination of two or more. The basic compounds constituting the active components of the basic solid catalysts can be used alone as catalysts or can be supported on a carrier. In this case, it is preferable to use a carrier with low solubility in water.

[0029] As the basic solid catalyst, it is particularly preferable to use a catalyst obtained by low-temperature calcination of a mixture of basic solid catalyst-forming components including an alkaline earth metal hydroxide such as calcium hydroxide and a silicon compound such as sodium metasilicate.

[0030] The basic solid catalyst can be filled in the condensation reactor 1 in the form of a fixed bed, a fluidized bed, a moving bed, or the like, and brought into contact with acetone, but it is preferable to bring the basic solid catalyst into contact with acetone in a fixed bed.

[0031] It is sufficient that the acetone is brought into contact with the basic solid catalyst at least once. However, the production rate of DAA can be improved by arranging a plurality of reactors similar to the condensation reactor 1 in series and bringing the acetone into contact with the basic solid catalyst two or more times.

[0032] The reaction product containing acetone and DAA, in which at least a portion of the acetone has been converted to DAA upon contact with the basic solid catalyst in the condensation reactor 1, is introduced into the first distillation column 2 through the pipe L3.

[0033] <Process (2)> In the first distillation column 2, acetone and DAA are separated by utilizing the difference in their boiling points. The resulting DAA (containing small amounts of water, acetone, etc.) is introduced into the dehydrator 3 through pipe L4. Meanwhile, the separated unreacted acetone is returned to the condensation reactor 1 through pipe L2 and reused as raw acetone.

[0034] <Process (3)> In the dehydrator 3, DAA is brought into contact with a catalyst to cause a dehydration reaction, producing MSO (mesityl oxide). Examples of the catalyst used here include sulfuric acid and phosphoric acid.

[0035] A portion of the reaction product liquid containing MSO produced by the dehydration reaction is extracted through pipe L5 and fed to second distillation column 4. The other portion of this reaction product liquid is fed to third distillation column 5 through pipe L6.

[0036] <Process (4)> In the second distillation column 4, the reaction product liquid containing MSO from the dehydrator 3 is distilled in the presence of an alkali metal hydroxide according to the above-mentioned method for recovering acetone of the present invention. Specifically, the aforementioned aqueous solution of alkali metal hydroxide is added through pipe L7, and distillation is carried out in the presence of the alkali metal hydroxide according to the aforementioned method for recovering acetone of the present invention, to recover an acetone-containing fraction.

[0037] The acetone-containing fraction recovered in the second distillation column 4 is returned to the dehydrator 3 in step (3) via 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 points) is discharged to the outside of the system through a pipe L9.

[0038] <Process (5)> The reaction product liquid containing MSO and extracted from the dehydrator 3 via pipe L6 is further distilled after the hydrogenation reaction to recover MIBK. However, prior to this, in order to further recover acetone from the reaction product liquid containing MSO, distillation may be carried out in the third distillation column 5, and the acetone-containing fraction distilled by this distillation may be returned to the condensation reactor 1 via pipe L2 and reused as the raw acetone.

[0039] The remaining fraction after the acetone-containing fraction extracted in the third distillation column 5 is fed to a hydrogenation reactor 6 via a pipe L10, where MIBK is produced by a hydrogenation reaction of the contained MSO.

[0040] In the hydrogenation reactor 6, MSO is brought into contact with hydrogen 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 can be used.

[0041] The reaction product liquid containing MIBK produced in the hydrogenation reactor 6 is fed to the fourth distillation column 7 via the pipe L11 and further distilled, and the MIBK fraction is extracted and recovered via the pipe L12.

[0042] According to the MIBK production method of the present invention, acetone can be efficiently recovered from the process liquid at a high recovery rate through the above steps (1) to (5) and reused as raw material acetone, thereby improving the raw material consumption rate. [Example]

[0043] The present invention will be explained in more detail below by way of examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention.

[0044] The 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.

[0045] [Reference Experimental Example 1] Acetone was condensed using a basic solid catalyst disclosed in JP 2004-323375 A to obtain a reaction product containing diacetone alcohol and acetone. The reaction product was then distilled, and the recovered diacetone alcohol was dehydrated to obtain a reaction product liquid containing mesityl oxide.

[0046] The composition of the resulting reaction product liquid was analyzed by the gas chromatography internal standard method using a gas chromatograph measuring device with an FID detector (model: GC-2014, manufactured by Shimadzu Corporation), and was found to be 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

[0047] [Example 1] 50 g of the reaction product liquid obtained in Reference Experimental Example 1 and 30 g of a 3 mass % aqueous sodium hydroxide solution were placed in a 200 mL distillation flask equipped with a thermometer, a Liebig condenser, a stirring blade, and an oil bath, and the temperature of the oil bath was raised from room temperature (20°C). Distillation began when the temperature reached 140°C, and the distillate was collected in a 10 mL recovery flask for 60 minutes while maintaining the temperature at 140°C. The sodium hydroxide content of the contents of the flask immediately after the start of simple distillation was 1.13 mass %. The composition of the obtained distillate was analyzed by the gas chromatography internal standard method using a gas chromatograph measuring device equipped with an FID detector (model: GC-2014, manufactured by Shimadzu Corporation), and the recovery rates of acetone and mesityl oxide relative to the reaction product liquid obtained in Reference Experimental Example 1 were determined. The analytical results are shown in Table 1.

[0048] [Example 2] The reaction product liquid obtained in Reference Experimental Example 1 was distilled under the same conditions as in Example 1, except that a 5% by mass aqueous solution of sodium hydroxide was used instead of a 3% by mass aqueous solution of sodium hydroxide. The sodium hydroxide content of the contents in the flask immediately after the start of simple distillation was 1.88% by mass. The analytical results of the obtained distillate are shown in Table 1.

[0049] [Example 3] The reaction product liquid obtained in Reference Experimental Example 1 was distilled under the same conditions as in Example 1, except that a 15% by mass aqueous solution of sodium hydroxide was used instead of a 3% by mass aqueous solution of sodium hydroxide. The sodium hydroxide content of the contents in the flask immediately after the start of simple distillation was 5.63% by mass. The analytical results of the obtained distillate are shown in Table 1.

[0050] [Example 4] The reaction product liquid obtained in Reference Experimental Example 1 was distilled under the same conditions as in Example 1, except that a 15% by mass aqueous solution of potassium hydroxide was used instead of a 3% by mass aqueous solution of sodium hydroxide. The potassium hydroxide content of the contents in the flask immediately after the start of simple distillation was 5.63% by mass. The analytical results of the obtained distillate are shown in Table 1.

[0051] [Comparative Example 1] The reaction product liquid obtained in Reference Experimental Example 1 was distilled under the same conditions as in Example 1, except that pure water was used instead of the 3 mass % aqueous sodium hydroxide solution. The analytical results of the obtained distillate are shown in Table 1.

[0052] [Table 1]

[0053] In Examples 1 to 4, since the distillation was carried out in the presence of an alkali metal hydroxide, acetone could be recovered in high yield from the reaction product liquid containing MSO. On the other hand, in Comparative Example 1, the distillation was carried out without adding an alkali metal hydroxide, and therefore the recovery rate of acetone was low.

[0054] According to the method for recovering acetone of the present invention, mesityl oxide in a solution containing mesityl oxide can be distilled in the presence of an alkali metal hydroxide, whereby mesityl oxide can be converted into acetone by alkaline hydrolysis, and acetone can be recovered in a high yield in an industrially advantageous manner that has not been achieved before, thereby achieving a remarkable industrially valuable effect. [Explanation of symbols]

[0055] 1. Condensation reactor 2. First distillation tower 3 Dehydrator 4. Second distillation tower 5. Third distillation tower 6. Hydrogenation reactor 7 Fourth Distillation Tower

Claims

1. 1. A method for recovering acetone from a solution containing mesityl oxide, comprising: distilling the solution in the presence of an alkali metal hydroxide to recover an acetone-containing fraction; The solution containing mesityl oxide is condensing acetone in the presence of a basic solid catalyst to obtain a reaction product containing diacetone alcohol and acetone; The obtained reaction product is distilled, and the recovered diacetone alcohol is dehydrated to obtain a reaction product liquid containing mesityl oxide. A method for recovering acetone, which is an oil phase liquid obtained by oil-water separation of the reaction product liquid obtained.

2. 2. The method for recovering acetone according to claim 1, wherein the distillation is carried out in the presence of water and an alkali metal hydroxide.

3. 3. The method for recovering acetone according to claim 1 or 2, wherein the alkali metal hydroxide is sodium hydroxide and / or potassium hydroxide.

4. 4. The method for recovering acetone according to claim 1, wherein the content of mesityl oxide in the solution is 10% by mass or more, relative to 100% by total mass of the solution.

5. 5. The method for recovering acetone according to claim 1, wherein the content of alkali metal hydroxide in the solution is 0.6% by mass or more and 30.0% by mass or less, relative to 100% by total mass of the solution.

6. A method for producing methyl isobutyl ketone, comprising the following steps (1) to (5): (1) A condensation step in which acetone is condensed in the presence of a basic solid catalyst to produce a reaction product containing diacetone alcohol and acetone. (2) A recovery step of distilling the reaction product produced in the step (1) in a first distillation column to recover diacetone alcohol. (3) A dehydration step in which the diacetone alcohol recovered in the step (2) is dehydrated in a dehydrator to produce a reaction product liquid containing mesityl oxide. (4) An acetone recovery step in which a part of the reaction product liquid containing mesityl oxide produced in the step (3) is distilled in a second distillation column 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 the recovered acetone-containing fraction is introduced into the dehydrator of the step (3). (5) A methyl isobutyl ketone recovery step in which the other part of the reaction product liquid produced in the step (3) is subjected to a hydrogenation reaction to hydrogenate the mesityl oxide contained therein in a hydrogenation reactor, and then distilled in a fourth distillation column to recover methyl isobutyl ketone.

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