Method for simultaneously producing 2-pentanone and methyl isobutyl ketone

Abstract

The invention belongs to the technical field of organic chemical industry, and provides a method for simultaneously producing 2-pentanone and methyl isobutyl ketone, which comprises the following steps: (1) mixing ethanol, acetone and an activated carbon metal catalyst, and carrying out condensation reaction to obtain a mixed system; and (2) in a hydrogen atmosphere, carrying out a hydrogenation reaction on the mixed system to complete simultaneous production of 2-pentanone and methyl isobutyl ketone. The high-efficiency co-generation of 2-pentanone and MIBK is realized through condensation-hydrogenation cascade reaction in the same reaction system by precisely regulating and controlling the raw material ratio and optimizing the catalyst composition and reaction parameters. Compared with the traditional sectional production process, the method not only simplifies the production process, reduces the equipment investment and operation cost, but also realizes the accurate control of the product composition through the flexible adjustment of the raw material ratio, and provides an innovative technical solution for the industrial co-production of 2-pentanone and MIBK.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of organic chemical technology, and in particular to a method for simultaneously producing 2-pentanone and methyl isobutyl ketone. BACKGROUND

[0002] In the field of chemical industry, 2-pentanone and methyl isobutyl ketone (MIBK) as key organic chemical raw materials, occupy an important position in many fields such as medicine manufacturing, pesticide synthesis, perfume blending and paint production.

[0003] 2-pentanone as a compound that can be used as a solvent and an intermediate, is slightly soluble in water but can form a homogeneous system with organic solvents such as ethanol and diethyl ether, which makes it widely used in paint formulation optimization, ink dispersion, resin modification and perfume compounding. In addition, 2-pentanone meets the use standard of food additives in China (GB 2760), can be used as a food flavor to simulate the aroma characteristics of tropical fruits such as bananas and pineapples, and can be used as a selective solvent in lubricating oil dewaxing process, and plays a key role in the synthesis of pharmaceutical intermediates and pesticide precursors.

[0004] Methyl isobutyl ketone (MIBK) as another important ketone compound, is mainly used in the paint and paint industry. As a medium-boiling organic solvent, MIBK can effectively dissolve various resin systems, pigment particles and functional additives, and significantly improve the decoration and durability of the end product by adjusting the rheological properties and adhesion of the coating. With the acceleration of the standardization process of the global construction industry and the growing demand for lightweight new energy vehicles, the market demand for MIBK is showing a sustained expansion trend. In addition, MIBK has potential application prospects in the fields of green chemical material development, synthesis of pharmaceutical active ingredients and bio-based chemical conversion.

[0005] The traditional 2-pentanone production process has obvious technical bottlenecks in the control of side reactions and product separation. Although the ethanol conversion process represented by cerium oxide-based catalyst system can achieve a target product selectivity of 90%, trace amounts of by-products are still generated during the reaction process, which not only increases the complexity of the subsequent refining process, but also leads to high overall process energy consumption, which is inconsistent with the current green chemistry principles. In the field of MIBK production, the acetone one-step method as the mainstream process, inevitably generates isopropyl alcohol (IPA), diacetone alcohol (DAA) and other by-products in the reaction network, which directly reduces the yield of the target product and significantly increases the difficulty and cost of product rectification separation. Although existing technologies (such as CN200000108059.8 and CN201010145278.X) have realized the co-production of MIBK and diisobutyl ketone (DIBK), the product selectivity still needs to be improved; and the process disclosed in patent CN201910060664.X can obtain high-purity products, but it cannot dynamically adjust the production scale of DIBK according to market demand. SUMMARY

[0006] The present application aims to overcome the problems of high by-product ratio (30%-40%), high energy consumption for separation and low resource utilization rate in the production process of 2-pentanone in the prior art, and provides a method for simultaneously producing 2-pentanone and methyl isobutyl ketone.

[0007] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions: The present application provides a method for simultaneously producing 2-pentanone and methyl isobutyl ketone, comprising the following steps: (1) mixing ethanol, acetone and activated carbon metal catalyst to perform condensation reaction to obtain a mixed system; (2) performing hydrogenation reaction on the mixed system in a hydrogen atmosphere to complete the simultaneous production of 2-pentanone and methyl isobutyl ketone.

[0008] As a preferred, the molar ratio of ethanol and acetone in step (1) is 1-5:1-5.

[0009] As a preferred, the mass of the activated carbon metal catalyst in step (1) is 3-16% of the mass sum of ethanol and acetone.

[0010] As a preferred, the temperature of the condensation reaction in step (1) is 150-250℃.

[0011] As a preferred, the time of the condensation reaction in step (1) is 1-8h.

[0012] As a preferred, the pressure of the condensation reaction in step (1) is 1.7-7.5MPa.

[0013] As a preferred, the time of the hydrogenation reaction in step (2) is 1-20min.

[0014] The present application provides a method for simultaneously producing 2-pentanone and methyl isobutyl ketone, comprising the following steps: (1) mixing ethanol, acetone and activated carbon metal catalyst to perform condensation reaction to obtain a mixed system; (2) performing hydrogenation reaction on the mixed system in a hydrogen atmosphere to complete the simultaneous production of 2-pentanone and methyl isobutyl ketone. Through precise control of raw material ratio, optimization of catalyst composition and reaction parameters, high-efficiency co-production of 2-pentanone and MIBK is realized in the same reaction system through "condensation-hydrogenation" series reaction. Relying on activated carbon supported metal catalyst and combining with optimized temperature control strategy, high-purity target product can be obtained. Compared with the traditional segmented production process, this method not only simplifies the production process, reduces equipment investment and operation cost, but also realizes precise control of product composition through flexible adjustment of raw material ratio, which provides an innovative technical solution for industrialized co-production of 2-pentanone and MIBK. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 Mass spectrum of the product of Example 1. DETAILED DESCRIPTION

[0016] The present application provides a method for simultaneously producing 2-pentanone and methyl isobutyl ketone, comprising the following steps: (1) mixing ethanol, acetone and activated carbon metal catalyst to carry out condensation reaction to obtain a mixed system; (2) carrying out hydrogenation reaction on the mixed system in a hydrogen atmosphere to complete the simultaneous production of 2-pentanone and methyl isobutyl ketone.

[0017] In the present application, the molar ratio of ethanol to acetone in step (1) is preferably 1-5:1-5, further preferably 2-4:2-4, and more preferably 2.5-3:2.5-3.

[0018] In the present application, the activated carbon metal catalyst is prepared according to patent CN119016052A.

[0019] In the present application, the mass of the activated carbon metal catalyst in step (1) is preferably 3-16% of the mass sum of ethanol and acetone, further preferably 5-13%, and more preferably 8-10%.

[0020] In the present application, the temperature of the condensation reaction in step (1) is preferably 150-250°C, further preferably 160-240°C, and more preferably 180-220°C.

[0021] In the present application, the time of the condensation reaction in step (1) is preferably 1-8h, further preferably 2-7h, and more preferably 3-6h.

[0022] In the present application, the pressure of the condensation reaction in step (1) is preferably 1.7-7.5MPa, further preferably 2-7MPa, and more preferably 4-5MPa.

[0023] In the present application, the condensation reaction in step (1) is carried out under a protective atmosphere, and the protective atmosphere is nitrogen, argon or helium.

[0024] In the present application, the time of the hydrogenation reaction in step (2) is preferably 1-20min, further preferably 5-15min, and more preferably 8-12min.

[0025] The technical solutions provided by the present application will be described in detail below in conjunction with examples, but they should not be understood as limiting the scope of protection of the present application.

[0026] In this invention, the Ni-Cu / AC catalyst uses nickel formate and copper formate supported on activated carbon, which is impregnated in a mixture of ammonia and water and then calcined to obtain the catalyst; wherein, the concentration of ammonia is 25%, and the mass ratio of nickel formate, copper formate, activated carbon, ammonia and water is 5:1:100:100:100; the impregnation temperature is 30°C and the time is 5h; the calcination temperature is 350°C and the time is 3h.

[0027] In this invention, the Pt-Ni / AC catalyst uses nickel formate and platinum formate supported activated carbon, which is impregnated in a mixture of ammonia and water and then calcined to obtain the catalyst; wherein, the concentration of ammonia is 25%, and the mass ratio of nickel formate, platinum formate, activated carbon, ammonia and water is 5:1:100:100:100; the impregnation temperature is 35°C and the time is 4h; the calcination temperature is 300°C and the time is 4h.

[0028] In this invention, the Pd-Ni / AC catalyst uses nickel formate and palladium formate supported on activated carbon, which is impregnated in a mixture of ammonia and water and then calcined to obtain the catalyst; wherein, the concentration of ammonia is 25%, and the mass ratio of nickel formate, palladium formate, activated carbon, ammonia and water is 5:1:50:50; the impregnation temperature is 50°C and the time is 28h; the calcination temperature is 300°C and the time is 2h.

[0029] In this invention, the Co-Pt / AC catalyst uses cobalt formate and platinum formate supported activated carbon, which is impregnated in a mixture of ammonia and water and then calcined to obtain the catalyst; wherein, the concentration of ammonia is 25%, and the ratio of cobalt formate, platinum formate, activated carbon, ammonia and water is 5:1:100:50:50; the impregnation temperature is 20°C and the time is 12h; the calcination temperature is 300°C and the time is 3h.

[0030] In this invention, the Ru / AC catalyst uses ruthenium formate-supported activated carbon, which is impregnated in a mixture of ammonia and water and then calcined to obtain the catalyst; wherein, the ammonia concentration is 25%, and the ratio of ruthenium formate, activated carbon, ammonia and water is 5:1:50:50; the impregnation temperature is 60°C and the time is 5h; the calcination temperature is 300°C and the time is 2h.

[0031] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0032] Example 1

[0033] Anhydrous ethanol (9.21 g, 0.2 mol) and acetone (11.62 g, 0.2 mol) were added sequentially to a stainless steel autoclave at a molar ratio of n1:n2 = 1:1. A Ni-Cu / AC catalyst (1.04 g, 5% of the total mass of ethanol and acetone) was then added. After sealing, the mixture was purged with nitrogen three times and heated to 200 °C. The reaction was carried out at 5.13 MPa for 4 hours. Samples were taken through the built-in sampling valve. GC analysis showed an ethanol conversion rate of 92.3% and an acetone conversion rate of 85.6%. Subsequently, a hydrogen generator was connected, and H2 was introduced for 5 minutes. After cooling, the autoclave was opened to obtain a pale yellow liquid. The mass spectrum of the product is shown below. Figure 1 As shown, 2-pentanone and methyl isobutyl ketone were successfully synthesized; the yield of 2-pentanone was 68.4% (selectivity 74.2%), the yield of methyl isobutyl ketone was 21.3% (selectivity 23.1%), and the total ketone selectivity was 97.3%.

[0034] Example 2

[0035] Ethanol and acetone were added to a stainless steel autoclave at a feed ratio of n1:n2 = 2:1 (18.42 g ethanol, 0.4 mol; 11.62 g acetone, 0.2 mol). A Ni-Cu / AC catalyst (3.00 g, 10% of the total mass of ethanol and acetone) was added, and the reaction was carried out under a nitrogen atmosphere at 180 °C and 4.26 MPa for 6 h. Sampling was performed using a built-in sampling valve, showing an ethanol conversion of 88.7% and an acetone conversion of 79.2%. Subsequently, a hydrogen generator was connected, and H2 was introduced for 10 min. The selectivity of 2-pentanone increased to 81.5% (yield 65.2%), while the selectivity of methyl isobutyl ketone decreased to 15.8% (yield 12.7%), with unreacted intermediates accounting for 2.1%.

[0036] Example 3

[0037] In a stainless steel autoclave, a molar ratio of n1:n2 = 5:1 (46.05 g ethanol, 1.0 mol; 11.62 g acetone, 0.2 mol) was used, with 1.44 g of 3% Ni-Cu / AC catalyst (2.5% of the total mass of ethanol and acetone). The reaction was carried out at 250 °C and 7.45 MPa under a nitrogen atmosphere for 2 hours. Samples were taken through a built-in sampling valve, showing an ethanol conversion of 76.4% and an acetone conversion of 58.3%. Subsequently, a hydrogen generator was connected, and H2 was introduced for 3 minutes. The product composition was 89.6% 2-pentanone (62.3% yield), only 3.2% methyl isobutyl ketone (2.1% yield), and the byproduct 4-pentanone accounted for 5.1%.

[0038] Example 4

[0039] In a stainless steel autoclave, a molar ratio of n1:n2 = 1:5 (9.21 g ethanol, 0.2 mol; 58.10 g acetone, 1.0 mol) was used with a Ni-Cu / AC catalyst (10.38 g, accounting for 15.4% of the total mass of ethanol and acetone). The reaction was carried out at 150 °C and 6.78 MPa under a helium atmosphere for 8 h. Samples were taken through the built-in sampling valve, and the conversion rates of ethanol and acetone were 98.2% and 91.4%, respectively. Subsequently, a hydrogen generator was connected, and H2 was introduced for 15 min. The selectivity of methyl isobutyl ketone was 78.9% (yield 67.3%), the selectivity of 2-pentanone was 19.8% (yield 16.5%), and the rearrangement product 3-pentanone accounted for 1.3%.

[0040] Example 5

[0041] In a stainless steel autoclave, a molar ratio of n1:n2 = 1:2 was used (9.21 g ethanol, 0.2 mol; 23.24 g acetone, 0.4 mol), with Ni-Cu / AC catalyst (2.60 g, accounting for 8% of the total mass of ethanol and acetone). The reaction was carried out at 220 °C and 6.18 MPa under a helium atmosphere for 3 h. Sampling was performed using a built-in sampling valve, and the ethanol conversion rate was 94.1%, and the acetone conversion rate was 87.5%. Subsequently, a hydrogen generator was connected, and H2 was introduced for 4 min. The total yield of the two ketones was 85.7%, of which 2-pentanone accounted for 58.3%, methyl isobutyl ketone accounted for 27.4%, and the byproduct 2-hexanone accounted for 4.3%.

[0042] Example 6

[0043] In a stainless steel autoclave, a molar ratio of n1:n2 = 3:1 was used (ethanol 27.63 g, 0.6 mol; acetone 11.62 g, 0.2 mol), with a catalyst dosage of Ni-Cu / AC (4.71 g, accounting for 12% of the total mass of ethanol and acetone). The reaction was carried out at 190 °C and 5.06 MPa under a helium atmosphere for 5 h. Samples were taken through the built-in sampling valve, and the ethanol conversion rate was 90.8% and the acetone conversion rate was 82.1%. Subsequently, a hydrogen generator was connected, and H2 was introduced for 7 min. The product distribution was: 2-pentanone 71.2% (yield 63.4%), methyl isobutyl ketone 24.6% (yield 21.8%), and no obvious rearrangement products were detected.

[0044] Example 7

[0045] In a stainless steel autoclave, a molar ratio of n1:n2 = 1:1 (9.21 g ethanol + 11.62 g acetone) was used, with a Pt-Ni / AC catalyst (1.40 g, accounting for 6.7% of the total mass of ethanol and acetone). The reaction was carried out at 190 °C and 4.91 MPa under a helium atmosphere for 1.5 h. Sampling was performed using a built-in sampling valve, and the ethanol conversion rate was 85.4%, while the acetone conversion rate was 76.8%. Subsequently, a hydrogen generator was connected, and H2 was introduced for 2 min. The total yield of the two ketones was 82.1%, of which 2-pentanone accounted for 61.5%, methyl isobutyl ketone accounted for 20.6%, and the byproduct methyl pentyle ketone accounted for 17.9%.

[0046] Example 8

[0047] Ethanol (13.82 g, 0.3 mol) and acetone (11.62 g, 0.2 mol) were added to an autoclave at a molar ratio of n1:n2 = 3:2. A Pd-Ni / AC catalyst (2.00 g, 8 wt% of the system) was used. The reaction was carried out at 210 °C and 5.87 MPa under an argon atmosphere for 4 h. Samples were taken through the built-in sampling valve, and the conversion rates of ethanol and acetone were 93.1% and 86.4%, respectively. Subsequently, a hydrogen generator was connected, and H2 was introduced for 6 min, yielding 72.6% 2-pentanone (78.3% selectivity), 23.4% methyl isobutyl ketone (25.1% selectivity), and 1.2% 2-hexanone as a byproduct. The total ketone selectivity was 99.1%, and no obvious rearrangement products were detected.

[0048] Example 9

[0049] Ethanol and acetone were added to a high-pressure reactor at a ratio of n1:n2 = 1:3 (9.21 g ethanol, 0.2 mol; 34.86 g acetone, 0.6 mol). A Co-Pt / AC catalyst (5.50 g, 12.5 wt% of the system) was used. The reaction was carried out at 160 °C and 3.88 MPa under an argon atmosphere for 4 h. Samples were taken through the built-in sampling valve, and the conversion rates of ethanol and acetone were 97.8% and 94.2%, respectively. Subsequently, a hydrogen generator was connected, and H2 was introduced for 20 min. The selectivity of methyl isobutyl ketone reached 83.7% (yield 71.2%), the selectivity of 2-pentanone was 14.1% (yield 12.3%), and the byproduct 3-pentanone accounted for 2.4%.

[0050] Example 10

[0051] In a high-pressure reactor, an N1:N2 ratio of 2.5:1 (23.03 g ethanol, 0.5 mol; 11.62 g acetone, 0.2 mol) was added, along with a Ru / AC catalyst (1.39 g, 4 wt% of the system). The reaction was carried out at 160 °C and 3.83 MPa under an argon atmosphere for 1 h. Samples were taken using a built-in sampling valve, showing an ethanol conversion of 79.2% and an acetone conversion of 63.5%. Subsequently, a hydrogen generator was connected, and H2 was purged for 1 min. The product composition was 91.4% 2-pentanone (65.8% yield), only 2.7% methyl isobutyl ketone (1.9% yield), 5.3% 4-pentanone (byproduct), and 7.0% unreacted intermediates.

[0052] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for simultaneously producing 2-pentanone and methyl isobutyl ketone, characterized in that, Includes the following steps: (1) Ethanol, acetone and activated carbon metal catalyst are mixed and subjected to condensation reaction to obtain a mixed system; (2) In a hydrogen atmosphere, the mixed system is subjected to a hydrogenation reaction to achieve the simultaneous production of 2-pentanone and methyl isobutyl ketone.

2. The method for simultaneously producing 2-pentanone and methyl isobutyl ketone as described in claim 1, characterized in that, In step (1), the molar ratio of ethanol to acetone is 1~5:1~5.

3. The method for simultaneously producing 2-pentanone and methyl isobutyl ketone as described in claim 2, characterized in that, The mass of the activated carbon metal catalyst in step (1) is 3 to 16% of the combined mass of ethanol and acetone.

4. The method for simultaneously producing 2-pentanone and methyl isobutyl ketone as described in claim 3, characterized in that, The temperature of the condensation reaction in step (1) is 150~250℃.

5. The method for simultaneously producing 2-pentanone and methyl isobutyl ketone as described in claim 4, characterized in that, The condensation reaction in step (1) takes 1 to 8 hours.

6. The method for simultaneously producing 2-pentanone and methyl isobutyl ketone as described in claim 5, characterized in that, The pressure of the condensation reaction in step (1) is 1.7~7.5 MPa.

7. The method for simultaneously producing 2-pentanone and methyl isobutyl ketone as described in claim 6, characterized in that, The hydrogenation reaction in step (2) takes 1 to 20 minutes.

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