Method for producing methyl isobutyl ketone

Abstract

The present invention provides a method for producing methyl isobutyl ketone, comprising reacting mesityl oxide with methyl isobutyl alcohol in the presence of a copper catalyst to produce methyl isobutyl ketone. The present invention uses mesityl oxide and methyl isobutyl alcohol to carry out in situ hydrogen transfer in the presence of a copper catalyst to produce methyl isobutyl ketone in one step. The entire reaction process does not require an external hydrogen gas system, and the reaction is carried out at normal pressure, which has the advantages of a short process flow, high atom utilization rate, and high safety, and is suitable for promoting industrial application.

Description

[Technical field]

[0001] The present invention relates to a method for producing methyl isobutyl ketone, and more particularly to a method for producing methyl isobutyl ketone in one step from mesityl oxide and methyl isobutyl alcohol. [Background technology]

[0002] Methyl isobutyl ketone (MIBK), commonly known as 4-methyl-2-pentanone, is a colorless, stable, flammable liquid with a pleasant odor. Its explosive range in air is 1.4%-7.5%, and it must be kept away from fire sources. It must be stored in a sealed container, kept at low temperature, and long-term contact with the skin must be avoided. MIBK is slightly soluble in water, but completely soluble in several organic solvents, making it an excellent solvent. In recent years, with the rapid development of the automobile industry, its market demand as the main raw material for the synthetic rubber antioxidant 6PPD continues to expand.

[0003] At present, most companies use acetone as raw material, use macroporous acidic resin to support precious metal palladium catalyst, and synthesize MIBK in one step through condensation and hydrogenation in a fixed-bed reactor, and then obtain the final MIBK product through multi-column continuous separation and purification.

[0004] For example, Patent Document 1 provides a process and an apparatus for producing methyl isobutyl ketone, which includes the steps of: (a) sending the raw materials acetone and hydrogen gas to a multi-tubular fixed-bed reactor to react with each other using a B621 catalyst; first condensing and separating the reaction product obtained after the reaction to obtain hydrogen gas; and feeding the condensed solution into a subsequent separation system; (b) sending the solution of the product to a light component tower for separation, and the bottom liquid of the tower flows into an acetone tower for separation; (c) controlling the pressure of the acetone tower to a slightly negative pressure, and sending the heavy component obtained at the bottom of the tower to a dehydration tower to remove moisture; (d) sending the light component obtained at the top of the dehydration tower to a wastewater tower for treatment and obtaining an organic light component; sending the product obtained at the bottom of the dehydration tower to a product tower for purification, and obtaining the product methyl isobutyl ketone at the top of the product tower. Compared with the traditional one-step process, the average conversion rate of acetone has been improved, and the process is simple with fewer by-products, while at the same time improving the maximum recycling rate and energy consumption. However, various parameters in catalyst selection and process engineering have not yet been developed, which still leads to a large amount of energy and material waste, the generation of by-products is still at a high level, the operating temperature and pressure are also high, and equipment investment and safety need to be further improved.

[0005] In Patent Document 2, a strong acid cation exchange resin catalyst treated with palladium acetate is used to optimize the separation process and purify the by-product diisobutyl ketone (DIBK), thereby improving the organic yield and reducing energy consumption. However, because a precious metal palladium catalyst is used, the overall synthesis cost is relatively high, and the reaction pressure is also high, which increases capital investment and increases the overall production cost. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] China Patent Application Publication No. 103274913 [Patent Document 2] China Patent Publication No. 105130778 Summary of the Invention

[0007] In order to solve the shortcomings of the prior art, the present invention provides a novel method for producing methyl isobutyl ketone from raw materials to catalytic system, thereby achieving cost advantage. The present invention uses mesityl oxide (MO) and methyl isobutyl alcohol (MIBC) to carry out in situ hydrogen transfer in the presence of a copper-based catalyst to produce methyl isobutyl ketone in one step. The entire reaction process does not require an external hydrogen gas system, and the reaction is carried out at normal pressure, which has the advantages of short process flow, high atom utilization rate, and high safety, making it suitable for promoting industrial application.

[0008] Specifically, the present invention provides a process for producing methyl isobutyl ketone, comprising reacting mesityl oxide with methyl isobutyl alcohol in the presence of a copper-based catalyst to produce methyl isobutyl ketone.

[0009] In one or more embodiments, the copper-based catalyst comprises copper oxide, and the mass of the copper oxide is 50% or more of the total mass of the copper-based catalyst. In one or more embodiments, the copper-based catalyst is a copper-zinc-aluminum catalyst.

[0010] In one or more embodiments, the copper-zinc-aluminum catalyst comprises copper oxide, zinc oxide, and aluminum oxide. In one or more embodiments, the mass of copper oxide in the copper-zinc-aluminum catalyst is 50% or more of the total mass of the copper-zinc-aluminum catalyst.

[0011] In one or more embodiments, in the copper-zinc-aluminum catalyst, the mass of copper oxide is 50%-70% of the total mass of the copper-zinc-aluminum catalyst, the mass of zinc oxide is 10%-30% of the total mass of the copper-zinc-aluminum catalyst, and the mass of aluminum oxide is 5%-15% of the total mass of the copper-zinc-aluminum catalyst.

[0012] In one or more embodiments, the copper oxide mass in the copper-zinc-aluminum catalyst is 54%-64% of the total mass of the copper-zinc-aluminum catalyst, the zinc oxide mass is 14%-24% of the total mass of the copper-zinc-aluminum catalyst, and the aluminum oxide mass is 7.8%-8% of the total mass of the copper-zinc-aluminum catalyst.

[0013] In one or more embodiments, the molar ratio of mesityl oxide to methyl isobutyl alcohol in the reaction is (0.1-2):1, preferably (0.8-1.2):1.

[0014] In one or more embodiments, methyl isobutyl ketone is added to the reaction at the beginning of the reaction.

[0015] In one or more embodiments, the temperature of the reaction is 140°C-250°C, preferably 180±20°C.

[0016] In one or more embodiments, the reaction pressure is atmospheric. In one or more embodiments, the volumetric space velocity of the reaction is 0.05-0.2 h -1 and preferably 0.1±0.02h -1 It is.

[0017] In one or more embodiments, hydrogen gas is not passed through the reaction process. In one or more embodiments, the reaction is carried out in a fixed bed reactor, such as a single tube reactor. In one or more embodiments, the reaction is carried out under the protection of an inert gas.

[0018] In one or more embodiments, the method includes heating a reactor filled with a copper-based catalyst to a reaction temperature and reacting homogeneously mixed mesityl oxide and methyl isobutyl alcohol by feeding them into the bottom of the reactor and discharging them from the top of the reactor.

[0019] In one or more embodiments, first, a homogeneously mixed mixture of mesityl oxide and methyl isobutyl alcohol is preheated to a reaction temperature and then sent to a reactor to carry out the reaction.

[0020] In one or more embodiments, the reactor is a single tube reactor with a diameter of 20±2 mm and a height of 700±100 mm, and the bed packing height of the copper-based catalyst is 500±50 mm. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a schematic diagram of the one-step production of methyl isobutyl ketone from mesityl oxide and methyl isobutyl alcohol. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] In order to enable those skilled in the art to understand the features and advantages of the present invention, the following provides general explanations and definitions for the terms referred to in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meanings that are understood by those skilled in the art with respect to the present invention, and in the event of any conflict, the definitions herein shall prevail.

[0023] The theories or mechanisms described and disclosed herein, whether correct or incorrect, are not intended to limit the scope of the present invention in any way; that is, the present invention can be practiced without being limited by any particular theory or mechanism.

[0024] As used herein, the terms "comprise", "include", "contain", and similar terms include the meanings "consist essentially of" and "consist of", for example, if "A comprises B and C" is disclosed herein, then "A consists essentially of B and C" and "A consists of B and C" should also be considered to be disclosed herein.

[0025] All features defined herein in the form of numerical or percentage ranges, such as numerical values, quantities, contents, and concentrations, are merely for the sake of brevity and convenience, and thus the description of a numerical or percentage range should be considered to encompass and specifically disclose all possible subranges and individual numerical values ​​(including integers and fractions) within the range.

[0026] In this specification, unless otherwise specified, percentages mean percentages by mass and ratios mean mass ratios.

[0027] It is to be understood that the embodiments or examples described herein are not intended to limit the invention, but on the contrary, all alternatives, modifications, and equivalents of the methods and materials described herein are included within the scope defined by the claims.

[0028] In this specification, in order to simplify the description, not all possible combinations of various technical features in each embodiment or example are described. Therefore, as long as there is no contradiction in the combination of these technical features, each technical feature in each embodiment or example can be arbitrarily combined, and all combinations should be considered to be within the scope of this specification.

[0029] In the present invention, the calculation formula for the conversion rate of methyl isobutyl alcohol (MIBC) is MIBC conversion rate = (1 - MIBC remaining amount / MIBC input amount) x 100%. The calculation formula for the conversion rate of mesityl oxide (MO) is MO conversion rate = (1 - MO remaining amount / MO input amount) x 100%. The calculation formula for the selectivity of methyl isobutyl ketone (MIBK) is MIBK selectivity = MIBK production amount / (MIBC conversion amount x n (MIBK) / n (MIBC) + MO conversion amount x n (MIBK) / n (MO)) x 100%, where n represents the amount of substance.

[0030] The present invention provides a novel method for producing methyl isobutyl ketone from raw materials to catalytic system. As shown in Figure 1, the present invention uses mesityl oxide and methyl isobutyl alcohol to carry out in situ hydrogen transfer in the presence of a copper-based catalyst to produce methyl isobutyl ketone in one step. The entire reaction process does not require an external hydrogen gas system, and the reaction is carried out at normal pressure, which has the advantages of a short process flow, high atom utilization rate, and high safety, making it suitable for promoting industrial application.

[0031] The process for producing methyl isobutyl ketone of the present invention comprises reacting mesityl oxide with methyl isobutyl alcohol in the presence of a copper-based catalyst with in situ transfer of hydrogen.

[0032] In the present invention, the copper-based catalyst comprises copper oxide, and the mass of the copper oxide is 50% or more, for example, more than 50%, 54%, 64% of the total mass of the copper-based catalyst. The copper-based catalyst is preferably a copper-zinc-aluminum catalyst. The main components of the copper-zinc-aluminum catalyst are copper oxide, aluminum oxide, and zinc oxide, and the remaining components may be activated carbon. In some embodiments, the copper-zinc-aluminum catalyst is composed of copper oxide, aluminum oxide, zinc oxide, and activated carbon. In the copper-zinc-aluminum catalyst, the copper oxide content can be 50%-70% of the total mass of the catalyst, for example 52%, 54%, 60%, 64%, 65%, preferably 54%-64%, the zinc oxide content can be 10%-30% of the total mass of the catalyst, for example 12%, 14%, 20%, 24%, 25%, preferably 14%-24%, and the aluminum oxide content can be 5%-15% of the total mass of the catalyst, for example 7%, 8%, 9%, 10%, preferably 7.8%-8%. Maintaining the catalyst composition and proportions in the above ranges is advantageous for in situ hydrogen transfer and short process flow. Copper-based catalysts suitable for the present invention, such as copper-zinc-aluminum catalysts, are commercially available. In some embodiments, the present invention uses a copper-zinc-aluminum catalyst with a copper oxide content of 54%, zinc oxide content of 24%, and aluminum oxide content of 8%, or a copper-zinc-aluminum catalyst with a copper oxide content of 64%, zinc oxide content of 14%, and aluminum oxide content of 7.8%. The catalyst used in the present invention may be cylindrical.

[0033] In the present invention, the molar ratio of mesityl oxide to methyl isobutyl alcohol may be 0.1:1 to 2:1, for example, 0.5:1 to 1.5:1, and is preferably 0.8:1 to 1.2:1, for example, about 1:1. The use of a preferred molar ratio is advantageous in improving the conversion of mesityl oxide to methyl isobutyl alcohol and the selectivity of methyl isobutyl ketone.

[0034] In the present invention, methyl isobutyl ketone may be present in the initial reaction system. For example, mesityl oxide and methyl isobutyl alcohol may be mixed with methyl isobutyl ketone and then subjected to the reaction, or only mesityl oxide and methyl isobutyl alcohol may be mixed and then subjected to the reaction. When methyl isobutyl ketone is contained in the initial reaction system, the initial molar number of methyl isobutyl ketone added may be 0.5 to 2 times, for example, 1 time, of the total molar number of mesityl oxide and methyl isobutyl alcohol charged.

[0035] In the present invention, the reaction pressure can be normal pressure, which is highly safe.

[0036] In the present invention, the reaction temperature may be 140°C-250°C, for example, 140°C, 160°C, 180°C, 200°C, 250°C, and preferably about 180°C. The volumetric space velocity of the reaction is 0.05-0.2h -1 , for example 0.06h -1 , 0.08h -1 , 0.1h -1 , 0.12h -1 , 0.15h -1 and preferably about 0.1 h -1 The above reaction conditions, particularly the preferred reaction conditions, are advantageous in producing methyl isobutyl ketone to improve the conversion of mesityl oxide and methyl isobutyl alcohol and the selectivity of methyl isobutyl ketone.

[0037] In the reaction process of the present invention, it is not necessary to pass hydrogen gas through. The reaction is carried out under the protection of an inert gas such as nitrogen gas. For example, the air in the reactor can be replaced with an inert gas before the reaction.

[0038] The reaction of the present invention is preferably carried out in a fixed bed reactor, i.e., the catalyst is preferably packed in a fixed manner in the reactor, and the reaction is carried out while the fluidized feedstock passes through the catalyst. The fixed bed reactor may be a tubular reactor such as a single tube reactor.

[0039] In the present invention, the reactor filled with the copper catalyst is heated to the reaction temperature, and the homogeneously mixed mesityl oxide and methyl isobutyl alcohol are fed from the bottom of the reactor and discharged from the top of the reactor to react. First, the homogeneously mixed mesityl oxide and methyl isobutyl alcohol are preheated to the reaction temperature and then fed to the reactor to react. A single tube reactor with a diameter of 20±2 mm and a height of 700±100 mm can be used, and the bed filling height of the copper catalyst therein can be 500±50 mm.

[0040] In some embodiments, the method for producing methyl isobutyl ketone of the present invention includes heating a reactor filled with a copper-based catalyst to a reaction temperature, then passing an inert gas through the reactor to purge the reactor, and sending the homogeneously mixed mesityl oxide, methyl isobutyl alcohol, and optional methyl isobutyl ketone to a preheating system to be preheated to a reaction temperature, and then sending the mixture to the reactor for reaction. The rate at which the raw materials enter the preheating system may be 0.125-0.5 mL / min, for example 0.25 mL / min.

[0041] The present invention has the following advantages: 1. The present invention does not require an external hydrogen gas system or high-pressure circulation system, and the entire reaction is carried out under normal pressure, which is highly safe. 2. The present invention uses a relatively inexpensive copper-based catalyst instead of an expensive palladium precious metal catalyst, which greatly reduces production costs. 3. The present invention is a new method for synthesizing MIBK, which is different from the conventional process. The product components are relatively single, and the subsequent separation and purification of the product can be more easily realized. EXAMPLES

[0042] The present invention will be further described below with specific examples. It should be understood that these examples are for illustrative purposes only and do not limit the scope of the present invention. The methods and reagents used in the examples are conventional methods and reagents in the art unless otherwise specified. In the examples described herein, the pillared copper-zinc-aluminum catalyst with a ratio of copper oxide, zinc oxide, and aluminum oxide of 54:24:8 is commercially available and has the model number of Kawaka CB-5; the pillared copper-zinc-aluminum catalyst with a ratio of copper oxide, zinc oxide, and aluminum oxide of 64:14:7.8 is commercially available and has the model number of Kawaka AF104.

[0043] <Example 1> A certain amount of cylindrical copper-zinc-aluminum catalyst (copper oxide content 54%, zinc oxide content 24%, aluminum oxide content 8%) was filled into a single tube reactor with a diameter of 20 mm and a height of 700 mm so that the catalyst bed filling height was 500 mm. The heating system was turned on to heat the reactor. After the temperature reached 140 °C, dry nitrogen gas was passed through the top to purge the reactor for 10 min. MO and MIBC were mixed in a molar ratio of 1:1, and then MIBK, the number of moles of which is the sum of the number of moles of MIBC and MO, was added and mixed uniformly. The mixture was pumped into the preheating system at a rate of 0.25 mL / min by a constant flow pump. After preheating to 140 °C, it was fed from the bottom of the reactor and discharged from the top of the reactor. The reaction volumetric space velocity was 0.1 h -1 After condensation, the mixture was sampled and analyzed by GC. The conversion of MIBC was 82.14%, the conversion of MO was 80.1%, and the selectivity of MIBK was 98.60%.

[0044] <Example 2> A certain amount of cylindrical copper-zinc-aluminum catalyst (copper oxide content 54%, zinc oxide content 24%, aluminum oxide content 8%) was filled into a single tube reactor with a diameter of 20 mm and a height of 700 mm so that the catalyst bed filling height was 500 mm. The heating system was turned on to heat the reactor. After the temperature reached 160 °C, dry nitrogen gas was passed through the top to purge the reactor for 10 min. MO and MIBC were mixed in a molar ratio of 1:1, and then MIBK, the number of moles of which is the sum of the number of moles of MIBC and MO, was added and mixed uniformly. The mixture was pumped into the preheating system at a rate of 0.25 mL / min by a constant flow pump. After preheating to 160 °C, it was fed from the bottom of the reactor and discharged from the top of the reactor. The reaction volumetric space velocity was 0.1 h -1 After condensation, the mixture was sampled and analyzed by GC. The conversion of MIBC was 90.14%, the conversion of MO was 89%, and the selectivity was 98.52%.

[0045] <Example 3> A certain amount of cylindrical copper-zinc-aluminum catalyst (copper oxide content 54%, zinc oxide content 24%, aluminum oxide content 8%) was filled into a single tube reactor with a diameter of 20 mm and a height of 700 mm so that the catalyst bed filling height was 500 mm. The heating system was turned on to heat the reactor. After the temperature reached 180 ° C, dry nitrogen gas was passed through the top to purge the reactor for 10 min. MO and MIBC were mixed in a molar ratio of 1:1, and then MIBK, the number of moles of which is the sum of the number of moles of MIBC and MO, was added and mixed uniformly. The mixture was pumped into the preheating system at a rate of 0.25 mL / min by a constant flow pump. After preheating to 180 ° C, it was fed from the bottom of the reactor and discharged from the top of the reactor. The reaction volumetric space velocity was 0.1 h -1 After condensation, the mixture was sampled and analyzed by GC. The conversion of MIBC was 96.14%, the conversion of MO was 94.23%, and the selectivity was 98.33%.

[0046] <Example 4> A certain amount of cylindrical copper-zinc-aluminum catalyst (copper oxide content 54%, zinc oxide content 24%, aluminum oxide content 8%) was filled into a single tube reactor with a diameter of 20 mm and a height of 700 mm so that the catalyst bed filling height was 500 mm. The heating system was turned on to heat the reactor. After the temperature reached 200 °C, dry nitrogen gas was passed through the top to purge the reactor for 10 min. MO and MIBC were mixed in a molar ratio of 1:1, and then MIBK, the number of moles of which was the sum of the number of moles of MIBC and MO, was added and mixed uniformly. The mixture was pumped into the preheating system at a rate of 0.25 mL / min by a constant flow pump. After preheating to 200 °C, it was fed from the bottom of the reactor and discharged from the top of the reactor. The reaction volumetric space velocity was 0.1 h -1 After condensation, the mixture was sampled and analyzed by GC. The conversion of MIBC was 97.21%, the conversion of MO was 95.72%, and the selectivity was 96.01%.

[0047] <Example 5> A certain amount of cylindrical copper-zinc-aluminum catalyst (copper oxide content 54%, zinc oxide content 24%, aluminum oxide content 8%) was filled into a single tube reactor with a diameter of 20 mm and a height of 700 mm so that the catalyst bed filling height was 500 mm. The heating system was turned on to heat the reactor. After the temperature reached 250 °C, dry nitrogen gas was passed through the top to purge the reactor for 10 min. MO and MIBC were mixed in a molar ratio of 1:1, and then MIBK, the number of moles of which is the sum of the number of moles of MIBC and MO, was added and mixed uniformly. The mixture was pumped into the preheating system at a rate of 0.25 mL / min by a constant flow pump. After preheating to 250 °C, it was fed from the bottom of the reactor and discharged from the top of the reactor. The reaction volumetric space velocity was 0.1 h -1 After condensation, the mixture was sampled and analyzed by GC. The conversion of MIBC was 98.59%, the conversion of MO was 97.31%, and the selectivity was 92.15%.

[0048] <Example 6> A certain amount of cylindrical copper-zinc-aluminum catalyst (copper oxide content 54%, zinc oxide content 24%, aluminum oxide content 8%) was filled into a single tube reactor with a diameter of 20 mm and a height of 700 mm so that the catalyst bed filling height was 500 mm. The heating system was turned on to heat the reactor. After the temperature reached 180 ° C, dry nitrogen gas was passed through the top to purge the reactor for 10 min. MO and MIBC were mixed in a molar ratio of 1:1, and then MIBK, the number of moles of which is the sum of the number of moles of MIBC and MO, was added and mixed uniformly. The mixture was pumped into the preheating system at a rate of 0.25 mL / min by a constant flow pump. After preheating to 180 ° C, it was fed from the bottom of the reactor and discharged from the top of the reactor. The reaction volumetric space velocity was 0.1 h -1 After condensation, the mixture was sampled and analyzed by GC. The conversion of MIBC was 54.32%, the conversion of MO was 99.33%, and the selectivity was 98.15%.

[0049] <Example 7> A certain amount of cylindrical copper-zinc-aluminum catalyst (copper oxide content 54%, zinc oxide content 24%, aluminum oxide content 8%) was filled into a single tube reactor with a diameter of 20 mm and a height of 700 mm so that the catalyst bed filling height was 500 mm. The heating system was turned on to heat the reactor. After the temperature reached 180 ° C, dry nitrogen gas was passed through the top to purge the reactor for 10 min. MO and MIBC were mixed in a molar ratio of 2:1, and then MIBK, the number of moles of which is the sum of the number of moles of MIBC and MO, was added and mixed uniformly. The mixture was pumped into the preheating system at a rate of 0.25 mL / min by a constant flow pump. After preheating to 180 ° C, it was fed from the bottom of the reactor and discharged from the top of the reactor. The reaction volumetric space velocity was 0.1 h -1 After condensation, the mixture was sampled and analyzed by GC. The conversion of MIBC was 99.32%, the conversion of MO was 45.22%, and the selectivity was 97.26%.

[0050] <Example 8> A certain amount of cylindrical copper-zinc-aluminum catalyst (copper oxide content 54%, zinc oxide content 24%, aluminum oxide content 8%) was filled into a single tube reactor with a diameter of 20 mm and a height of 700 mm so that the catalyst bed filling height was 500 mm. The heating system was turned on to heat the reactor. After the temperature reached 180 °C, dry nitrogen gas was passed through the top to purge the reactor for 10 min. MO and MIBC were mixed in a molar ratio of 1:1, and then MIBK, the number of moles of which is the sum of the number of moles of MIBC and MO, was added and mixed uniformly. The mixture was pumped into the preheating system at a rate of 0.125 mL / min by a constant flow pump. After preheating to 180 °C, it was fed from the bottom of the reactor and discharged from the top of the reactor. The reaction volumetric space velocity was 0.05 h -1 After condensation, the mixture was sampled and analyzed by GC. The conversion of MIBC was 98.89%, the conversion of MO was 97.77%, and the selectivity was 96.01%.

[0051] <Example 9> A certain amount of cylindrical copper-zinc-aluminum catalyst (copper oxide content 54%, zinc oxide content 24%, aluminum oxide content 8%) was filled into a single tube reactor with a diameter of 20 mm and a height of 700 mm so that the catalyst bed filling height was 500 mm. The heating system was turned on to heat the reactor. After the temperature reached 180 ° C, dry nitrogen gas was passed through the top to purge the reactor for 10 min. MO and MIBC were mixed in a molar ratio of 1:1, and then MIBK, the number of moles of which is the sum of the number of moles of MIBC and MO, was added and mixed uniformly. The mixture was pumped into the preheating system at a rate of 0.5 mL / min by a constant flow pump. After preheating to 180 ° C, it was fed from the bottom of the reactor and discharged from the top of the reactor. The reaction volumetric space velocity was 0.2 h -1 After condensation, the mixture was sampled and analyzed by GC. The conversion of MIBC was 87.32%, the conversion of MO was 83.15%, and the selectivity was 98.02%.

[0052] <Example 10> A certain amount of cylindrical copper-zinc-aluminum catalyst (copper oxide content 64%, zinc oxide content 14%, aluminum oxide content 7.8%) was filled into a single tube reactor with a diameter of 20 mm and a height of 700 mm so that the catalyst bed filling height was 500 mm. The heating system was turned on to heat the reactor. After the temperature reached 180 ° C, dry nitrogen gas was passed through the top to purge the reactor for 10 min. MO and MIBC were mixed in a molar ratio of 1:1, and then MIBK, the number of moles of which is the sum of the number of moles of MIBC and MO, was added and mixed uniformly. The mixture was pumped into the preheating system at a rate of 0.25 mL / min by a constant flow pump. After preheating to 180 ° C, it was fed from the bottom of the reactor and discharged from the top of the reactor. The reaction volumetric space velocity was 0.1 h -1 After condensation, the mixture was sampled and analyzed by GC. The conversion of MIBC was 97.5%, the conversion of MO was 96.83%, and the selectivity was 98.22%.

[0053] <Example 11> A certain amount of cylindrical copper-zinc-aluminum catalyst (copper oxide content 64%, zinc oxide content 14%, aluminum oxide content 7.8%) was packed into a single tube reactor with a diameter of 20 mm and a height of 700 mm so that the catalyst bed filling height was 500 mm. The heating system was turned on to heat the reactor. After the temperature reached 180 °C, dry nitrogen gas was passed through the top to purge the reactor for 10 min. MO and MIBC were mixed in a molar ratio of 1:1, and the mixture was pumped into the preheating system at a rate of 0.25 mL / min with a constant flow pump. After preheating to 180 °C, it was fed from the bottom of the reactor. The reaction volumetric space velocity was 0.1 h -1 The mixture was discharged from the top of the reactor, condensed, sampled, and analyzed by GC. The conversion of MIBC was 98.72%, the conversion of MO was 97.93%, and the selectivity of MIBK was 98.15%.

[0054] From the results of the above examples, it can be seen that the present invention uses mesityl oxide and methyl isobutyl alcohol to carry out in situ hydrogen transfer in the presence of a copper catalyst to produce methyl isobutyl ketone in one step. The entire reaction process does not require an external hydrogen gas system, the reaction is carried out at normal pressure, the process flow is short, good MIBC conversion, MO conversion and selectivity are achieved, and the atom utilization rate is high and the safety is high, which is suitable for promoting industrial application.

Claims

1. 1. A process for producing methyl isobutyl ketone, comprising reacting mesityl oxide with methyl isobutyl alcohol in the presence of a copper-based catalyst to produce methyl isobutyl ketone.

2. 2. The method of claim 1, wherein the copper-based catalyst comprises copper oxide, and the mass of the copper oxide is 50% or more of the total mass of the copper-based catalyst.

3. 2. The method according to claim 1, wherein the copper-based catalyst is a copper-zinc-aluminum catalyst, preferably the copper-zinc-aluminum catalyst comprises copper oxide, zinc oxide and aluminum oxide.

4. In the copper-zinc-aluminum catalyst, the mass of copper oxide is 50% or more of the total mass of the copper-zinc-aluminum catalyst; Preferably, in the copper-zinc-aluminum catalyst, the mass of copper oxide is 50%-70% of the total mass of the copper-zinc-aluminum catalyst, the mass of zinc oxide is 10%-30% of the total mass of the copper-zinc-aluminum catalyst, and the mass of aluminum oxide is 5%-15% of the total mass of the copper-zinc-aluminum catalyst; More preferably, the method according to claim 3, characterized in that in the copper-zinc-aluminum catalyst, the mass of copper oxide is 54%-64% of the total mass of the copper-zinc-aluminum catalyst, the mass of zinc oxide is 14%-24% of the total mass of the copper-zinc-aluminum catalyst, and the mass of aluminum oxide is 7.8%-8% of the total mass of the copper-zinc-aluminum catalyst.

5. The method according to claim 1, wherein in the reaction, the molar ratio of mesityl oxide to methyl isobutyl alcohol is (0.1-2):1, preferably (0.8-1.2):

1.

6. 2. The method of claim 1, wherein methyl isobutyl ketone is added to the reaction system at the start of the reaction.

7. The reaction has the following characteristics: The temperature of the reaction is 140°C-250°C, preferably 180±20°C; The reaction pressure is atmospheric pressure; The volumetric space velocity of the reaction is 0.05-0.2 h -1 and preferably 0.1±0.02 h -1 and not allowing hydrogen gas to pass through during the reaction; The reaction is carried out in a fixed bed reactor, such as a single tube reactor; 2. The method of claim 1, wherein the reaction is carried out under nitrogen gas protection.

8. 2. The method according to claim 1, comprising heating a reactor filled with a copper-based catalyst to a reaction temperature, feeding homogeneously mixed mesityl oxide and methyl isobutyl alcohol from the bottom of the reactor and discharging them from the top of the reactor to react with each other.

9. The method according to claim 7, characterized in that firstly, the homogeneously mixed mesityl oxide and methyl isobutyl alcohol are preheated to a reaction temperature and then sent to a reactor to carry out the reaction.

10. 8. The method according to claim 7, characterized in that the reactor is a single tube reactor with a diameter of 20±2 mm and a height of 700±100 mm, and the bed loading height of the copper-based catalyst is 500±50 mm.

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