Process and system for the production of 4-methyl-1-pentene

Abstract

The present application relates to the technical field of producing 4-methyl-1-pentene, and discloses a method for preparing 4-methyl-1-pentene, characterized in that the method comprises the following steps: (1) carrying out a hydrogenation reaction on methyl isobutyl ketone and hydrogen gas in the presence of a hydrogenation catalyst to obtain a stream containing methyl isobutyl carbinol; (2) carrying out a dehydration reaction on the stream containing methyl isobutyl carbinol in the presence of a dehydration catalyst to obtain a stream containing 4-methyl-1-pentene. The method provided by the present application can simply and efficiently prepare 4-methyl-1-pentene, the raw material methyl isobutyl ketone is easy to obtain, the reaction condition is relatively mild, the product distribution is simple, and a high-purity 4-methyl-1-pentene product can be prepared.

Description

Technical Field

[0001] This invention relates to the technical field of producing 4-methyl-1-pentene, and more specifically, to a method and system for preparing 4-methyl-1-pentene. Background Technology

[0002] 4-Methyl-1-pentene (4MP1), CAS number 691-37-2, is a C6 olefin with significant application value. Polymerization yields poly(4-methyl-1-pentene) (PMP), which exhibits high transparency, superior heat resistance, mechanical properties, electrical properties, and chemical resistance. It is an important monomer for the polymerization of poly(4-methyl-1-pentene). Furthermore, 4MP1 can be used in the copolymerization of linear low-density polyethylene (LLDPE) resin, which possesses excellent tensile and tear strength as well as good dielectric properties. In recent years, with the continuous improvement of material polymerization technology and application levels, PMP industrial production technology has been developing rapidly, leading to its widespread application in electronics, medical devices, microporous materials, packaging, and blending modification. The usage of PMP is also constantly increasing. In China, with the rapid development of the electronics industry, PMP, due to its release properties, temperature resistance, and very low dielectric constant, has become an excellent mold material for electronic component packaging and a material for high-frequency connector manufacturing, resulting in a significant increase in its usage and a promising market prospect.

[0003] Currently, the 4MP-1 process technology is relatively mature abroad, mainly involving propylene dimerization. Research and improvement efforts primarily focus on the selection of catalysts used in the reaction. Catalysts used in the propylene dimerization reaction can be categorized into three types: acidic catalysts, basic catalysts, and organometallic catalysts. The use of different catalysts significantly affects the 4MP-1 yield. For example, Dow Chemical in the United States uses rare earth metal complexes, such as uranium bis-(polysubstituted cyclopentadiene)-hydrides, as homogeneous catalysts for the highly selective synthesis of 4MP1 from propylene dimerization, reducing operating costs and difficulties in separating C6 byproducts.

[0004] In 1968, Hambling industrialized the dimerization of propylene using a supported metallic sodium catalyst, building the world's first 2000 t / a 4MP1 production unit and achieving a single-pass 4MP1 selectivity of over 87%. Meanwhile, Mitsui Petrochemicals of Japan, using BP's catalyst system and 4MP1 production process, built a 2500 t / a 4MP1 production unit in Japan, with a product composition similar to BP's.

[0005] In the 1980s, Phillips Corporation in the United States developed a novel solid superbase catalyst. It changed the single-component support to a multi-component mixture and dissolved and mixed it instead of simply mechanically mixing it. Then, metallic Na was added as a molten support, and a small amount of co-catalyst was added and diluted with an inert solid to reduce the initial dimerization activity. This catalyst was successfully applied to industrial production, and a production process of 4MP1 with a capacity of tens of thousands of tons was built. The purity of 4MP1 products reached more than 99%.

[0006] Compared to foreign countries, the maturity of 4MP1 technology in China is relatively low. The industry's technology patents are mainly held by Mitsui Chemicals Ltd. of Japan and Phillips Oil Company of the United States. Most of the relevant patent technologies in China are focused on the application of downstream products of poly4MP1. At present, there are no 4MP1 production facilities in China, and domestic consumption is completely dependent on imports.

[0007] Jiang Heng et al. used solid superbase K / K2CO3 as a catalyst and found that: at a reaction temperature of 150℃, a reaction pressure of 8MPa, and a space velocity of 1h... -1 The single-pass conversion of propylene dimerization to 4-methyl-1-pentene was 20%, and the selectivity for 4-methyl-1-pentene was 88%. Sun Hongwei studied the particle size distribution of alkali metal-supported K2CO3 supports and found that the catalyst had high catalytic activity when the particle size range was between 300 and 400 nm. Under certain conditions, the catalytic effect of propylene dimerization to 4MP1 was good, and the selectivity could reach about 85%.

[0008] CN111574317A discloses a synthesis process for 4-methyl-1-pentene, which mainly includes a dimerization reaction of propylene under dehydration and deoxygenation conditions using an alkali metal-supported alkaline salt as a catalyst, followed by a separation process to prepare 4-methyl-1-pentene. The 4-methyl-1-pentene achieves a purity of 99.5%, while also producing α-olefins such as 1-hexene as byproducts, meeting the industrial requirements for the polymerization of 4-methyl-1-pentene.

[0009] In summary, the current main synthesis process for 4MP1 uses propylene dimerization. However, propylene dimerization suffers from drawbacks such as high reaction pressure and numerous oligomerization and isomerization byproducts. Furthermore, no other process routes for producing 4MP1 have been identified. Therefore, methods for preparing 4-methyl-1-pentene that utilize readily available raw materials, operate under mild conditions, and produce easily separable products remain the desired outcome. Summary of the Invention

[0010] In order to overcome the technical problems of the existing propylene dimerization method, such as high reaction pressure and many oligomerization and isomerization byproducts, the present invention provides a method and system for preparing 4-methyl-1-pentene.

[0011] The first aspect of this invention provides a method for preparing 4-methyl-1-pentene, the method comprising the following steps:

[0012] (1) In the presence of a hydrogenation catalyst, methyl isobutyl ketone (MIBK) is mixed with hydrogen to carry out a hydrogenation reaction to obtain a stream containing methyl isobutyl methanol (MIBC).

[0013] (2) In the presence of a dehydration catalyst, the stream containing methyl isobutyl methanol is subjected to a dehydration reaction to obtain a stream containing 4-methyl-1-pentene.

[0014] (3) Optionally, the stream containing 4-methyl-1-pentene described in step (2) is separated to obtain a stream rich in 4-methyl-1-pentene and a stream rich in methyl isobutyl methanol.

[0015] (4) Optionally, the stream containing 4-methyl-1-pentene separated in step (3) is purified to obtain 4-methyl-1-pentene product;

[0016] (5) Optionally, the stream containing methyl isobutyl methanol separated in step (3) can be dehydrated and returned to step (1) or step (2).

[0017] A second aspect of the present invention provides a system for preparing 4-methyl-1-pentene, the system comprising:

[0018] Hydrogenation reactor, dehydration reactor, optional light component removal tower, optional purification tower, and optional dehydration tower; among which,

[0019] The hydrogenation reactor is used to mix methyl isobutyl ketone with hydrogen and, after a first preheating, carry out a hydrogenation reaction to obtain a stream containing methyl isobutyl methanol.

[0020] The dehydration reactor is connected to the hydrogenation reactor and is used to dehydrate the methyl isobutyl methanol stream from the hydrogenation reactor after a second preheating reaction to obtain a stream containing 4-methyl-1-pentene.

[0021] The light-removal tower is connected to the dehydration reactor and is used to separate the 4-methyl-1-pentene-containing stream from the dehydration reactor to obtain a stream rich in 4-methyl-1-pentene and a stream rich in methyl isobutyl methanol.

[0022] The refining tower is connected to the light-light-removal tower and is used to refine the 4-methyl-1-pentene-rich stream from the light-light-removal tower to obtain the 4-methyl-1-pentene product.

[0023] The dehydration tower connects the light-light-removal tower and the hydrogenation reactor, and is used to dehydrate the methyl isobutyl methanol-rich stream from the light-light-removal tower to obtain a methyl isobutyl methanol-containing stream, which is then sent to the hydrogenation reactor.

[0024] Compared with the prior art, the advantages of the present invention include at least the following aspects:

[0025] Compared with existing propylene dimerization production methods, the method provided by this invention can prepare 4-methyl-1-pentene simply and effectively. The methyl isobutyl ketone raw material is readily available, the reaction conditions are relatively mild, the product distribution is simple, and high-purity 4-methyl-1-pentene products can be prepared. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a method and system for preparing 4-methyl-1-pentene according to a specific embodiment of the present invention.

[0027] Explanation of reference numerals in the attached figures

[0028] 1-Hydrogenation reactor; 2-Gas-liquid separator; 3-Dehydration reactor; 4-Light weight removal tower; 5-Refining tower (4MP-1 refining tower); 6-Dehydration tower. Detailed Implementation

[0029] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0030] One specific embodiment of the present invention provides a method for preparing 4-methyl-1-pentene, the method comprising the following steps:

[0031] (1) In the presence of a hydrogenation catalyst, methyl isobutyl ketone is mixed with hydrogen gas to carry out a hydrogenation reaction to obtain a stream containing methyl isobutyl methanol.

[0032] (2) In the presence of a dehydration catalyst, the stream containing methyl isobutyl methanol is subjected to a dehydration reaction to obtain a stream containing 4-methyl-1-pentene.

[0033] (3) Optionally, the stream containing 4-methyl-1-pentene described in step (2) is separated to obtain a stream rich in 4-methyl-1-pentene and a stream rich in methyl isobutyl methanol.

[0034] (4) Optionally, the stream containing 4-methyl-1-pentene separated in step (3) is purified to obtain 4-methyl-1-pentene product;

[0035] (5) Optionally, the stream containing methyl isobutyl methanol separated in step (3) can be dehydrated and returned to step (1) or step (2).

[0036] In this invention, in step (1), before the hydrogenation reaction, 4-methyl-2-pentanone and hydrogen can be mixed and preheated before being introduced into the hydrogenation reactor; there are no particular restrictions on the preheating conditions, as long as 4-methyl-2-pentanone can be completely vaporized, for example, the preheating temperature can be 120-150°C.

[0037] According to some embodiments of the present invention, in step (1), the conditions for the hydrogenation reaction may include: a liquid hourly space velocity (LHSV) of methyl isobutyl ketone of 0.05-3 h⁻¹. -1 The molar ratio of hydrogen to methyl isobutyl ketone is (2-30):1, the temperature of the hydrogenation reaction is 80-160℃, and the pressure of the hydrogenation reaction is atmospheric pressure to 3.5MPa.

[0038] According to some embodiments of the present invention, the conditions for the hydrogenation reaction include: a liquid hourly space velocity (LHSV) of methyl isobutyl ketone of 0.2-2 h⁻¹. -1 The molar ratio of hydrogen to methyl isobutyl ketone is (5-15):1, the temperature of the hydrogenation reaction is 100-140℃, and the pressure of the hydrogenation reaction is 1.0-2.5MPa.

[0039] In this invention, a suitable hydrogenation catalyst is selected from catalysts in which at least two metallic active components are supported on or dispersed in a catalyst support. The metallic active components may be selected from one or more combinations of transition metals from Groups IB, IIB, IIIB, IVB, VB, VIB, VIIB, and VIIIB, lanthanides, and metals from Groups IIIA, IVA, VA, and VIA, such as nickel, cobalt, copper, manganese, ruthenium, tin, iron, tungsten, rhenium, and / or rhodium.

[0040] According to some embodiments of the present invention, the hydrogenation catalyst is a heterogeneous catalyst, and the catalyst comprises Ni and Cu supported on a support; the content of Ni is 10-15 wt% based on the total weight of the hydrogenation catalyst, and the weight ratio of nickel to copper is (4-6):1.

[0041] Preferably, the specific surface area of ​​the hydrogenation catalyst is 140-220 m². 2 / g, pore volume 0.45-0.80mL / g, most probable pore size 5-20nm.

[0042] In this invention, suitable catalyst supports for hydrogenation can be selected from silica, alumina, titanium dioxide, zirconium oxide, magnesium oxide, activated carbon, graphite, or any combination thereof, such as silica-alumina, titanium dioxide-alumina, etc. Preferably, the hydrogenation catalyst support is silica, alumina, activated carbon, zirconium oxide, or any combination thereof. More preferably, the catalyst support is silica, γ-alumina, or a combination thereof.

[0043] According to some embodiments of the present invention, a gas-liquid separation step is further included between step (1) and step (2), wherein the methyl isobutyl methanol stream is subjected to gas-liquid separation to obtain a hydrogen-containing gas phase component and a methyl isobutyl methanol-containing liquid phase component. The methyl isobutyl methanol-containing liquid phase component obtained from the gas-liquid separation is then subjected to a dehydration reaction.

[0044] In this invention, the 4-methyl-1-pentene-containing stream obtained in step (2) contains crude 4-methyl-1-pentene and crude methyl isobutyl methanol.

[0045] According to some embodiments of the present invention, the conditions for the dehydration reaction include: a liquid hourly space velocity (LHSV) of 0.05-1.5 h⁻¹ for methyl isobutyl methanol. -1 The temperature of the dehydration reaction is 250-400℃, and the pressure of the dehydration reaction is atmospheric pressure to 0.5MPa.

[0046] According to some embodiments of the present invention, the liquid hourly space velocity (LHSV) of methyl isobutyl methanol is 0.2-1 h⁻¹. -1 The temperature of the dehydration reaction is 280-340℃, and the pressure of the dehydration reaction is atmospheric pressure to 0.1MPa.

[0047] According to some embodiments of the present invention, the dehydration catalyst comprises Ni and Ce.

[0048] According to some embodiments of the present invention, the Ni content is 0.01-0.5 wt% and the Ce content is 1-5 wt% based on the total weight of the dehydration catalyst.

[0049] Preferably, the support for the dehydration catalyst is zirconium oxide.

[0050] Preferably, the specific surface area of ​​the dehydration catalyst is 30-150 m². 2 / g, pore volume 0.25-0.60mL / g, most probable pore size 10-20nm.

[0051] In this invention, the dehydrogenation catalyst may contain other components besides Ni and Ce, such as Ca, Ba, Zn, Sn, etc.

[0052] According to some embodiments of the present invention, the second carrier is selected from at least one of silicon dioxide, aluminum oxide, titanium dioxide, zirconium oxide, magnesium oxide, activated carbon, and graphite.

[0053] In this invention, the catalysts and catalyst supports suitable for the hydrogenation reaction of methyl isobutyl ketone and the dehydration reaction of methyl isobutyl methanol can be modified and controlled in any way. For example, the pore structure of the support oxide can be adjusted by using pore-expanding agents or hydrothermal treatment to improve the overall selectivity and stability of the catalyst; or, by adding a certain elemental compound during the catalyst preparation process, suitable acidity and basicity can be controlled to improve the catalyst activity and selectivity; or, by adding a certain metal such as lanthanum to the support to exert a synergistic effect with the active components such as nickel and copper, the stability of the catalyst can be improved, which can effectively increase the catalyst lifetime; or, by adjusting the surface properties of the catalyst, the deposition of certain compounds or heavy components on the catalyst surface can be reduced or the dispersion of the active components on the surface can be improved to extend the catalyst lifetime.

[0054] The catalysts involved in this invention (such as catalysts for hydrogenation reactions and dehydration reactions) can be prepared using conventional methods, such as impregnation, ion exchange, blending, kneading, co-precipitation, deposition-precipitation, ammonium evaporation precipitation, melt-filtration, ball milling, and sol-gel methods. More preferred methods include one or more combinations of impregnation, co-precipitation, and sol-gel methods. Most of these catalyst preparation methods are well-known to those skilled in the art as existing mature technologies. For example, a certain amount of support can be weighed, and a precursor of the metal active component can be loaded onto the support using a one-step or multi-step impregnation method, followed by drying, calcination, and reduction to finally obtain the catalyst product. Alternatively, a spraying method can be used to spray the precursor of the active component onto the support, followed by drying, calcination, and reduction to finally obtain the catalyst product. Furthermore, a catalyst powder can be prepared using co-precipitation, followed by drying, decomposition, and then granulation, tableting, and reduction steps to obtain the desired catalyst product.

[0055] The shape and size of the catalyst involved in this invention can be customized arbitrarily, such as spherical, strip, columnar, ring, etc., with a size between approximately 0.3-15 mm, more preferably between 0.5-5 mm; this invention does not impose any particular limitation on the above-mentioned size requirements, but mainly designs the fixed-bed reactor according to this invention to facilitate installation, reduce bed pressure, and other requirements.

[0056] The catalyst of this invention is preferably reduced before use. The reduction is generally performed using a mixture of hydrogen and nitrogen (hydrogen content can be 20-30 vol%). When using pure hydrogen for reduction, the heating rate needs to be strictly controlled. From the perspective of temperature control during catalyst reduction, a mixture with a lower hydrogen content is preferred. During reduction, a higher gas space velocity is better because a higher space velocity allows for rapid removal of the heat generated by the reaction, maintaining a stable catalyst bed temperature and preventing overheating that could damage the catalyst. For example, a gas space velocity of 2000-4000 m / s is preferred. 3 / m 3 ·h -1 The catalyst reduction temperature can be determined based on the specific catalyst composition. For the catalyst described in this invention, the catalyst bed temperature can be gradually increased at a rate of 10-20°C / hour, held at around 200°C (e.g., 180-250°C) for 5-10 hours, and then gradually increased at a rate of 5-20°C / hour until reaching 380-480°C, and maintained at this temperature for 5-20 hours. Then, it is slowly reduced to room temperature, for example, at a rate of 10-20°C / hour. After reaching room temperature, nitrogen is switched to the gas, and dry air is gradually mixed into the nitrogen, gradually increasing the air volume to increase the oxygen content in the mixture. The air volume is adjusted according to changes in the catalyst temperature to avoid the catalyst bed temperature from becoming too high, for example, not exceeding 70°C. Once the catalyst is reduced in situ in the corresponding reactor, and the temperature drops to the reaction temperature after reduction, it can be used as feedstock.

[0057] According to a preferred embodiment, the hydrogenation catalyst is prepared according to the following steps:

[0058] Active component loading: Weigh the γ-Al2O3 support, calculate and weigh the corresponding nickel and copper salts according to the content of nickel and copper loading components, prepare an aqueous solution, add it to the alumina support for equal volume impregnation, let stand for 1-3 hours, dry at 100-120℃ for 3-5 hours, and then calcine in a muffle furnace at 380-420℃ for 3-5 hours to obtain the oxidized catalyst; there are no particular restrictions on the types of nickel and copper salts, as long as they meet the requirements of this invention, the nickel salt can be nickel nitrate hexahydrate; the copper salt can be copper nitrate trihydrate;

[0059] Reduction: The oxidized catalyst obtained above is reduced with a mixture of hydrogen and nitrogen (volume ratio of hydrogen to nitrogen is 1:(2-4)). The reduction heating rate is 100-200℃ / h. The temperature is raised to 200-300℃ and held for 2 hours. Then the temperature is raised to 380-420℃ and held at 380-420℃ for 3-6 hours before the temperature is lowered to room temperature to obtain the hydrogenation catalyst.

[0060] According to a preferred embodiment, the dehydration catalyst is prepared according to the following steps:

[0061] A certain amount of zirconium oxynitrate powder was weighed and dissolved in deionized water to obtain an aqueous solution of zirconium oxynitrate (solution ①). The weights of the corresponding nickel and cerium salts were calculated based on the nickel and cerium content, and then prepared into corresponding aqueous solutions (solution ②). Solutions ① and ② were neutralized in parallel, and the pH (8.0-8.5) and temperature (70-75℃) were controlled during the neutralization process. After neutralization, the solution was aged at 75-90℃ for 1-3 hours, filtered, washed, and then successively dried (100-150℃, 1-10 hours) and calcined (300-400℃, 1-5 hours) to prepare a dehydration catalyst precursor. There are no particular restrictions on the types of nickel and cerium salts, as long as they meet the requirements of this invention. The nickel salt can be nickel nitrate hexahydrate; the cerium salt can be cerium nitrate hexahydrate.

[0062] The dehydration catalyst precursor obtained above was reduced by a mixture of hydrogen and nitrogen (volume ratio of hydrogen to nitrogen of 1:(2-4)). The reduction heating rate was 80-120℃ / h. The temperature was raised to 200-300℃ and held for 1-3 hours. Then the temperature was raised to 400-450℃ and held at that temperature for 2-6 hours. Finally, the temperature was lowered to room temperature to obtain the dehydration catalyst.

[0063] In this invention, various modifications can be made to the catalyst support and preparation method based on the above detailed description. For example, any known hydrogenation catalyst, catalyst support, or modified catalyst support can be used.

[0064] According to some embodiments of the present invention, in step (3), the separation is carried out in a light-weight removal tower.

[0065] The theoretical number of plates in the dehydrogenation tower is 50-75; the feed inlet of the light-light-removal tower is located in the middle and lower part of the light-light-removal tower, the operating temperature at the top of the tower is 50-65℃, and the operating pressure at the top of the tower is 0.05-0.15MPa.

[0066] In this invention, the stream rich in 4-methyl-1-pentene obtained in step (3) also contains a portion of 4-methyl-2-pentene. The stream rich in methyl isobutyl methanol also contains a portion of methyl isobutyl ketone.

[0067] According to some embodiments of the present invention, in step (4), the refining is carried out in a refining tower.

[0068] The theoretical number of trays in the refining column is 40-70. The feed inlet of the refining column is located in the middle and lower part of the refining column. The operating temperature at the top of the column is 45-55℃, and the operating pressure at the top of the column is 0.01-0.15MPa.

[0069] According to some embodiments of the present invention, in step (5), the water removal is carried out in a dehydration tower, the theoretical number of trays of the dehydration tower is 40-60, the feed inlet of the dehydration tower is located in the upper part of the dehydration tower, the operating temperature at the top of the tower is 95-103℃, and the operating pressure at the top of the tower is 0.01-0.20MPa.

[0070] like Figure 1 As shown, a second aspect of the present invention provides a system for preparing 4-methyl-1-pentene, the system comprising:

[0071] Hydrogenation reactor 1, dehydration reactor 3, light component removal tower 4, refining tower 5, and dehydration tower 6; among which,

[0072] The hydrogenation reactor 1 is used to mix methyl isobutyl ketone with hydrogen and, after a first preheating, carry out a hydrogenation reaction to obtain a stream containing methyl isobutyl methanol.

[0073] The dehydration reactor 3 is connected to the hydrogenation reactor 1 and is used to dehydrate the methyl isobutyl methanol stream from the hydrogenation reactor 1 after a second preheating to obtain a stream containing 4-methyl-1-pentene.

[0074] The light-removal tower 4 is connected to the dehydration reactor 3 and is used to separate the stream containing 4-methyl-1-pentene from the dehydration reactor to obtain a stream rich in 4-methyl-1-pentene and a stream rich in methyl isobutyl methanol.

[0075] The refining tower 5 is connected to the light-light-removal tower 4 and is used to refine the 4-methyl-1-pentene-rich stream from the light-light-removal tower 4 to obtain the 4-methyl-1-pentene product.

[0076] The dehydration tower 6 is connected to the light-light-removal tower 4 and the hydrogenation reactor 1. It is used to dehydrate the methyl isobutyl methanol-rich stream from the light-light-removal tower 4 to obtain a methyl isobutyl methanol-containing stream, which is then sent to the hydrogenation reactor 1.

[0077] According to some embodiments of the present invention, a gas-liquid separator 2 is further included between the hydrogenation reactor and the dehydration reactor for separating the methyl isobutyl methanol stream from the hydrogenation reactor 1 into a gas phase component containing hydrogen and a liquid phase component containing methyl isobutyl methanol, and then sending the liquid phase component containing methyl isobutyl methanol into the dehydration reactor 3 for dehydration reaction.

[0078] In this invention, unless otherwise specified, atmospheric pressure refers to "0.1 MPa".

[0079] According to a preferred embodiment, combined with Figure 1The method for preparing 4-methyl-1-pentene according to the present invention, specifically used in the system for preparing 4-methyl-1-pentene according to the present invention, includes the following steps:

[0080] (a) Hydrogenation reaction: In the presence of the above-mentioned hydrogenation catalyst, methyl isobutyl ketone and hydrogen are mixed, preheated, and then fed into hydrogenation reactor 1 to carry out a hydrogenation reaction, thereby obtaining a stream containing methyl isobutyl methanol; the obtained stream containing methyl isobutyl methanol is sent to gas-liquid separator 2 for gas-liquid separation to obtain a gas phase component containing hydrogen and a liquid phase component containing methyl isobutyl methanol; and the gas phase component containing hydrogen is returned to the above-mentioned hydrogenation reactor 1 as the hydrogen source for the hydrogenation reaction;

[0081] (b) Dehydration reaction: In the presence of the above dehydration catalyst, the stream containing methyl isobutyl methanol is preheated and fed into the dehydration reactor 3 to carry out the dehydration reaction, and a stream containing 4-methyl-1-pentene is obtained.

[0082] (c) Light removal: The stream containing 4-methyl-1-pentene is sent to the light removal tower 4 for light removal, and separated into the top product containing 4-methyl-1-pentene (the stream rich in 4-methyl-1-pentene) and the bottom product containing methyl isobutyl methanol (the stream rich in methyl isobutyl methanol).

[0083] (d) 4MP-1 purification: The top product of the light removal tower containing 4-methyl-1-pentene is sent to the 4MP1 purification tower 5 for purification. The 4-methyl-1-pentene product is collected from the top of the tower, and 4-methyl-2-pentene (4MP-2) is collected from the bottom of the tower.

[0084] (e) Dehydration: The product from the bottom of the light removal tower (a stream rich in methyl isobutyl methanol) is sent to the dehydration tower 6. Water is collected from the top of the tower, and methyl isobutyl methanol and methyl isobutyl ketone are collected from the bottom of the tower and returned to the hydrogenation reactor 1 of step (a) as starting material for hydrogenation reaction.

[0085] The present invention will be described in detail below through embodiments.

[0086] The following embodiments will all be combined with Figure 1 The method for preparing 4-methyl-1-pentene according to the present invention is described above. Unless otherwise stated, the specific operation of the process is as described above.

[0087] The specific formulas for conversion rate and selectivity involved in the examples are as follows:

[0088]

[0089]

[0090]

[0091] The following preparation examples illustrate the preparation of hydrogenation catalysts and dehydration catalysts.

[0092] Preparation Example A1

[0093] Active component (Ni, Cu) loading: The γ-Al2O3 support was weighed, and the corresponding weights of nickel nitrate hexahydrate and copper nitrate trihydrate were calculated and weighed according to the content of nickel and copper loading components. The nickel nitrate hexahydrate and copper nitrate trihydrate were prepared into aqueous solutions and added to the alumina support for equal volume impregnation. After standing for 2 hours, it was dried at 110℃ for 4 hours, and then calcined in a muffle furnace at 400℃ for 4 hours to obtain the oxidized hydrogenation catalyst.

[0094] Reduction: The oxidized hydrogenation catalyst obtained above was reduced with a mixed gas containing 25 vol% hydrogen and 75 vol% nitrogen. The reduction heating rate was 150 °C / h. The temperature was raised to 250 °C and held for 2 hours, then raised to 400 °C and held at 400 °C for 5 hours before being cooled to room temperature to obtain the hydrogenation catalyst. The specific composition of the hydrogenation catalyst is as follows: Ni content is 12.5 wt%, Cu content is 2.5 wt%, and the balance is γ-Al₂O₃. The specific surface area of ​​the hydrogenation catalyst is 145 m². 2 / g, pore volume 0.45mL / g, most probable pore size 10.5nm.

[0095] Preparation Example A2

[0096] The preparation method was followed as in Example A1, except that the amounts of nickel nitrate hexahydrate and copper nitrate trihydrate were changed, resulting in a hydrogenation catalyst with the following composition: Ni 14.4 wt%, Cu 2.4 wt%, and the balance γ-Al₂O₃. The specific surface area of ​​the hydrogenation catalyst was 152 m². 2 / g, pore volume 0.47mL / g, most probable pore size 11.8nm.

[0097] Preparation Example A3

[0098] The preparation was carried out in accordance with Example A1, except that the amounts of nickel nitrate hexahydrate and copper nitrate trihydrate were changed, resulting in a hydrogenation catalyst with the following composition: Ni 10.25 wt%, Cu 1.71 wt%, and the balance γ-Al₂O₃. The specific surface area of ​​the hydrogenation catalyst was 136 m². 2 / g, pore volume 0.41mL / g, most probable pore size 11.3nm.

[0099] Preparation Example B1

[0100] A certain amount of zirconium oxynitrate powder was weighed and dissolved in deionized water to obtain an aqueous solution of zirconium oxynitrate (solution ①). The weights of nickel nitrate hexahydrate and cerium nitrate hexahydrate were calculated and weighed according to the contents of nickel and cerium. The nickel nitrate hexahydrate and cerium nitrate hexahydrate were then mixed into an aqueous solution of nickel nitrate hexahydrate and cerium nitrate hexahydrate (solution ②). Solutions ① and ② were neutralized in parallel, and the pH value (8.0-8.5) and temperature (70-75℃) were controlled during the neutralization process. After neutralization, the solution was aged at 85℃ for 2 hours. After filtration and washing, the solution was dried (120℃, 5 hours) and calcined (350℃, 5 hours) to obtain a dehydrated catalyst precursor.

[0101] The catalyst precursor obtained in the previous step was reduced using a mixture of 25 vol% hydrogen and 75 vol% nitrogen at a reduction heating rate of 100 °C / h. The temperature was raised to 250 °C and held for 2 hours, then raised to 420 °C and held at that temperature for 4 hours. The temperature was then lowered to room temperature to obtain the dehydration catalyst. The specific composition of the dehydration catalyst is: Ni content of 0.22 wt%, Ce content of 3.75 wt%, and the balance being zirconium oxide.

[0102] Preparation Example B2

[0103] The preparation was carried out in the same manner as in Example B1, except that the amounts of zirconium oxynitrate, nickel nitrate hexahydrate, and cerium nitrate hexahydrate were changed so that the specific composition of the resulting dehydration catalyst was as follows: Ni content was 0.45 wt%, Ce content was 1.92 wt%, and the balance was zirconium oxide.

[0104] Preparation Example B3

[0105] The preparation was carried out in the same manner as in Example B1, except that the amounts of zirconium oxynitrate, nickel nitrate hexahydrate, and cerium nitrate hexahydrate were changed so that the specific composition of the resulting dehydration catalyst was as follows: Ni content was 0.10 wt%, Ce content was 4.63 wt%, and the balance was zirconium oxide.

[0106] Preparation Example B4

[0107] The preparation was carried out in the same manner as in Example B1, except that the amounts of zirconium oxynitrate, nickel nitrate hexahydrate, and cerium nitrate hexahydrate were changed so that the specific composition of the resulting dehydration catalyst was as follows: Ni content was 1.52 wt%, Ce content was 3.12 wt%, and the balance was zirconium oxide.

[0108] The following examples illustrate a method for preparing 4-methyl-1-pentene.

[0109] Example 1

[0110] (1) Hydrogenation reaction: In the presence of the hydrogenation catalyst obtained in Preparation Example A1 above, methyl isobutyl ketone and hydrogen were mixed, preheated, and then introduced into a hydrogenation reactor to carry out the hydrogenation reaction, obtaining a stream containing methyl isobutyl methanol; wherein, the specific conditions for the hydrogenation reaction were: the liquid hourly space velocity of methyl isobutyl ketone was 1.25 h⁻¹. -1 The molar ratio of hydrogen to methyl isobutyl ketone is 9:1, the hydrogenation reaction temperature is 125℃, and the hydrogenation reaction pressure is 2.0 MPa. The methyl isobutyl methanol stream obtained above is fed into a gas-liquid separator for gas-liquid separation to obtain a hydrogen-containing gas phase component and a methyl isobutyl methanol-containing liquid phase component. The hydrogen-containing gas phase component is returned to the hydrogenation reactor as the hydrogen source for the hydrogenation reaction. The conversion rate of methyl isobutyl ketone is 99.92%, and the selectivity of methyl isobutyl methanol is 100%.

[0111] (2) Dehydration reaction: In the presence of the dehydration catalyst obtained in Preparation Example B1 above, the stream containing methyl isobutyl methanol was preheated and fed into the dehydration reactor for dehydration reaction to obtain a stream containing 4-methyl-1-pentene; the specific process conditions for the dehydration reaction were: the liquid hourly space velocity of methyl isobutyl methanol was 0.75 h⁻¹. -1 The dehydration reaction was carried out at a temperature of 315℃ and a pressure of atmospheric pressure; the conversion rate of methyl isobutyl methanol was 77.5%, and the selectivity of 4-methyl-1-pentene was 81.29%.

[0112] (3) Separation (removal of light components): The stream containing 4-methyl-1-pentene is sent to the removal of light components column to separate it into the top product containing 4-methyl-1-pentene (crude 4-methyl-1-pentene) and the bottom product containing methyl isobutyl methanol (crude methyl isobutyl methanol); the theoretical number of plates in the removal of light components column is 73, the feed inlet is located on the 40th plate, the top temperature is 60℃, and the top pressure is 0.10MPa;

[0113] (4) 4MP1 purification: The top product of the light removal tower containing 4-methyl-1-pentene is sent to the 4MP1 purification tower for purification. 4-methyl-1-pentene product is collected from the top of the tower, and 4-methyl-2-pentene (4MP-2) is collected from the bottom of the tower. The theoretical number of plates in the 4MP-1 purification tower is 65, the feed inlet is located on the 42nd plate, the top temperature is 54℃, and the top pressure is 0.20MPa.

[0114] (5) Dehydration: The product (crude methyl isobutyl methanol) from the bottom of the dehydration tower is sent to the dehydration tower. Water is collected from the top of the tower, and methyl isobutyl methanol and methyl isobutyl ketone are collected from the bottom of the tower and returned to step (1) as starting material for hydrogenation reaction. The theoretical number of plates in the dehydration tower is 52, the feed inlet is located on the 25th plate, the top temperature is 102.2℃, and the top pressure is 0.06MPa.

[0115] The material analysis results for each step (operation unit) are shown in Table 1 below:

[0116] Table 1

[0117]

[0118]

[0119] Example 2

[0120] (1) Hydrogenation reaction: In the presence of the hydrogenation catalyst obtained in Preparation Example A2 above, methyl isobutyl ketone and hydrogen were mixed, preheated, and then introduced into a hydrogenation reactor to carry out the hydrogenation reaction, obtaining a stream containing methyl isobutyl methanol; wherein, the specific conditions for the hydrogenation reaction were: the liquid hourly space velocity of methyl isobutyl ketone was 1.75 h⁻¹. -1 The molar ratio of hydrogen to methyl isobutyl ketone was 6:1, the reaction temperature was 135℃, and the reaction pressure was 1.5MPa. The methyl isobutyl methanol stream obtained above was fed into a gas-liquid separator for gas-liquid separation to obtain a hydrogen-containing gas phase component and a methyl isobutyl methanol-containing liquid phase component. The hydrogen-containing gas phase component was returned to the hydrogenation reactor as the hydrogen source for the hydrogenation reaction. The conversion rate of methyl isobutyl ketone was 99.85%, and the selectivity of methyl isobutyl methanol was 100%.

[0121] (2) Dehydration reaction: In the presence of the dehydration catalyst obtained in Preparation Example B2 above, the stream containing methyl isobutyl methanol was preheated and fed into the dehydration reactor for dehydration reaction to obtain a stream containing 4-methyl-1-pentene; the specific process conditions for the dehydration reaction were: the liquid hourly space velocity of methyl isobutyl methanol was 0.35 h⁻¹. -1 The reaction temperature was 300℃ and the reaction pressure was atmospheric pressure; the conversion rate of methyl isobutyl methanol was 79.02%, and the selectivity of 4-methyl-1-pentene was 86.07%.

[0122] (3) Separation (removal of light components): The stream containing 4-methyl-1-pentene is sent to the removal of light components column to be separated into the top product containing 4-methyl-1-pentene (crude 4-methyl-1-pentene) and the bottom product containing methyl isobutyl methanol (crude methyl isobutyl methanol); the theoretical number of plates in the removal of light components column is 68, the feed inlet is located on the 36th plate, the top temperature is 62℃, and the top pressure is 0.15MPa;

[0123] (4) 4MP1 purification: The top product of the light removal tower containing 4-methyl-1-pentene is sent to the 4MP1 purification tower for purification. 4-methyl-1-pentene product is collected from the top of the tower, and 4-methyl-2-pentene (4MP-2) is collected from the bottom of the tower. The theoretical number of plates in the 4MP-1 purification tower is 68, the feed inlet is located on the 45th plate, the top temperature is 53.4℃, and the top pressure is 0.26MPa.

[0124] (5) Dehydration: The product from the bottom of the light removal tower (crude methyl isobutyl methanol) is sent to the dehydration tower. Water and other components are collected from the top of the tower, and methyl isobutyl methanol and methyl isobutyl ketone are collected from the bottom of the tower and returned to step (1) as starting material for hydrogenation reaction. The theoretical number of plates in the dehydration tower is 58, the feed inlet is located on the 22nd plate, the top temperature is 99.8℃, and the top pressure is 0.09MPa.

[0125] The material analysis results for each step (operation unit) are shown in Table 2 below:

[0126] Table 2

[0127]

[0128] Example 3

[0129] (1) Hydrogenation reaction: In the presence of the hydrogenation catalyst obtained in Preparation Example A3 above, methyl isobutyl ketone and hydrogen were mixed, preheated, and then introduced into a hydrogenation reactor to carry out the hydrogenation reaction, obtaining a stream containing methyl isobutyl methanol; wherein, the specific conditions for the hydrogenation reaction were: the liquid hourly space velocity of methyl isobutyl ketone was 0.5 h⁻¹. -1 The molar ratio of hydrogen to methyl isobutyl ketone was 15:1, the reaction temperature was 114℃, and the reaction pressure was 2.5MPa. The methyl isobutyl methanol stream obtained above was fed into a gas-liquid separator for gas-liquid separation to obtain a hydrogen-containing gas phase component and a methyl isobutyl methanol-containing liquid phase component. The hydrogen-containing gas phase component was returned to the hydrogenation reactor as the hydrogen source for the hydrogenation reaction. The conversion rate of methyl isobutyl ketone was 99.9%, and the selectivity of methyl isobutyl methanol was 100%.

[0130] (2) Dehydration reaction: In the presence of the dehydration catalyst obtained in Preparation Example B3 above, the stream containing methyl isobutyl methanol was preheated and then fed into the dehydration reactor for dehydration reaction to obtain a stream containing 4-methyl-1-pentene; the specific process conditions for the dehydration reaction were: the liquid hourly space velocity of methyl isobutyl methanol was 0.9 h⁻¹. -1 The reaction temperature was 330℃ and the reaction pressure was 0.05MPa; the conversion rate of methyl isobutyl methanol was 84.01%, and the selectivity of 4-methyl-1-pentene was 83.3%.

[0131] (3) Separation (removal of light components): The stream containing 4-methyl-1-pentene is sent to the light component removal tower for removal of light components, separating it into the top product containing 4-methyl-1-pentene (crude 4-methyl-1-pentene) and the bottom product containing methyl isobutyl methanol (crude methyl isobutyl methanol); the light component removal tower has a theoretical number of 59 plates, the feed inlet is located on the 33rd plate, the top temperature is 59℃, and the top pressure is 0.06MPa;

[0132] (4) 4MP1 purification: The top product of the light removal tower containing 4-methyl-1-pentene is sent to the 4MP1 purification tower for purification. 4-methyl-1-pentene product is collected from the top of the tower, and 4-methyl-2-pentene (4MP-2) is collected from the bottom of the tower. The theoretical number of plates in the 4MP-1 purification tower is 52, the feed inlet is located on the 36th plate, the top temperature is 55℃, and the top pressure is 0.1MPa.

[0133] (5) Dehydration: The product (crude methyl isobutyl methanol) from the bottom of the dehydration tower is sent to the dehydration tower. Water is collected from the top of the tower, and methyl isobutyl methanol and methyl isobutyl ketone are collected from the bottom of the tower and returned to step (1) as starting material for hydrogenation reaction. The theoretical number of plates in the dehydration tower is 49, the feed inlet is located on the 19th plate, the top temperature is 97.6℃, and the top pressure is 0.15MPa.

[0134] The material analysis results for each step (operation unit) are shown in Table 3 below:

[0135] Table 3

[0136]

[0137] Example 4

[0138] (1) Hydrogenation reaction: In the presence of the hydrogenation catalyst obtained in Preparation Example A1 above, methyl isobutyl ketone and hydrogen were mixed, preheated, and then introduced into a hydrogenation reactor to carry out the hydrogenation reaction, obtaining a stream containing methyl isobutyl methanol; wherein, the specific conditions for the hydrogenation reaction were: the liquid hourly space velocity of methyl isobutyl ketone was 1.25 h⁻¹. -1 The molar ratio of hydrogen to methyl isobutyl ketone is 9:1, the hydrogenation reaction temperature is 125℃, and the hydrogenation reaction pressure is 2.0 MPa. The methyl isobutyl methanol stream obtained above is fed into a gas-liquid separator for gas-liquid separation to obtain a hydrogen-containing gas phase component and a methyl isobutyl methanol-containing liquid phase component. The hydrogen-containing gas phase component is returned to the hydrogenation reactor as the hydrogen source for the hydrogenation reaction. The conversion rate of methyl isobutyl ketone is 99.92%, and the selectivity of methyl isobutyl methanol is 100%.

[0139] (2) Dehydration reaction: In the presence of the dehydration catalyst obtained in Preparation Example B4 above, the stream containing methyl isobutyl methanol was preheated and fed into the dehydration reactor for dehydration reaction to obtain a stream containing 4-methyl-1-pentene; the specific process conditions for the dehydration reaction were: the liquid hourly space velocity of methyl isobutyl methanol was 0.75 h⁻¹. -1 The dehydration reaction was carried out at a temperature of 315℃ and a pressure of atmospheric pressure; the conversion rate of methyl isobutyl methanol was 88%, and the selectivity of 4-methyl-1-pentene was 28.4%.

[0140] (3) Separation (removal of light components): The stream containing 4-methyl-1-pentene is sent to the removal of light components column to separate it into the top product containing 4-methyl-1-pentene (crude 4-methyl-1-pentene) and the bottom product containing methyl isobutyl methanol (crude methyl isobutyl methanol); the theoretical number of plates in the removal of light components column is 58, the feed inlet is located on the 32nd plate, the top temperature is 58℃, and the top pressure is 0.10MPa;

[0141] (4) 4MP1 purification: The top product of the light removal tower containing 4-methyl-1-pentene is sent to the 4MP1 purification tower for purification. 4-methyl-1-pentene product is collected from the top of the tower, and 4-methyl-2-pentene (4MP-2) is collected from the bottom of the tower. The theoretical number of plates in the 4MP-1 purification tower is 52, the feed inlet is located on the 34th plate, the top temperature is 55℃, and the top pressure is 0.20MPa.

[0142] (5) Dehydration: The product from the bottom of the light removal tower (crude methyl isobutyl methanol) is sent to the dehydration tower. Water is collected from the top of the tower, and methyl isobutyl methanol and methyl isobutyl ketone are collected from the bottom of the tower and returned to step (1) as starting material for hydrogenation reaction. The theoretical number of plates in the dehydration tower is 58, the feed inlet is located on the 32nd plate, the top temperature is 101.8℃, and the top pressure is 0.04MPa.

[0143] The material analysis results for each operating unit are shown in Table 4 below:

[0144] Table 4

[0145]

[0146] Example 5

[0147] (1) Hydrogenation reaction: In the presence of the hydrogenation catalyst obtained in Preparation Example A1 above, methyl isobutyl ketone and hydrogen were mixed, preheated, and then introduced into a hydrogenation reactor to carry out the hydrogenation reaction, obtaining a stream containing methyl isobutyl methanol; wherein, the specific conditions for the hydrogenation reaction were: the liquid hourly space velocity of methyl isobutyl ketone was 1.25 h⁻¹. -1The molar ratio of hydrogen to methyl isobutyl ketone is 9:1, the hydrogenation reaction temperature is 125℃, and the hydrogenation reaction pressure is 2.0 MPa. The methyl isobutyl methanol stream obtained above is fed into a gas-liquid separator for gas-liquid separation to obtain a hydrogen-containing gas phase component and a methyl isobutyl methanol-containing liquid phase component. The hydrogen-containing gas phase component is returned to the hydrogenation reactor as the hydrogen source for the hydrogenation reaction. The conversion rate of methyl isobutyl ketone is 99.92%, and the selectivity of methyl isobutyl methanol is 100%.

[0148] (2) Dehydration reaction: In the presence of the dehydration catalyst obtained in Preparation Example B1 above, the stream containing methyl isobutyl methanol was preheated and fed into the dehydration reactor for dehydration reaction to obtain a stream containing 4-methyl-1-pentene; the specific process conditions for the dehydration reaction were: the liquid hourly space velocity of methyl isobutyl methanol was 0.75 h⁻¹. -1 The dehydration reaction was carried out at a temperature of 255℃ and a pressure of atmospheric pressure; the conversion rate of methyl isobutyl methanol was 57%, and the selectivity of 4-methyl-1-pentene was 35.09%.

[0149] (3) Separation (removal of light components): The stream containing 4-methyl-1-pentene is sent to the removal of light components column to separate it into the top product containing 4-methyl-1-pentene (crude 4-methyl-1-pentene) and the bottom product containing methyl isobutyl methanol (crude methyl isobutyl methanol); the theoretical number of plates in the removal of light components column is 49, the feed inlet is located on the 28th plate, the top temperature is 60℃, and the top pressure is 0.10MPa;

[0150] (4) 4MP1 purification: The top product of the light removal tower containing 4-methyl-1-pentene is sent to the 4MP1 purification tower for purification. 4-methyl-1-pentene product is collected from the top of the tower, and 4-methyl-2-pentene (4MP-2) is collected from the bottom of the tower. The theoretical number of plates in the 4MP-1 purification tower is 51, the feed inlet is located on the 30th plate, the top temperature is 53.5℃, and the top pressure is 0.15MPa.

[0151] (5) Dehydration: The product (crude methyl isobutyl methanol) from the bottom of the light removal tower is sent to the dehydration tower. Water is collected from the top of the tower, and methyl isobutyl methanol and methyl isobutyl ketone are collected from the bottom of the tower and returned to step (1) as starting material for hydrogenation reaction. The theoretical number of plates in the dehydration tower is 45, the feed inlet is located on the 28th plate, the top temperature is 102.5℃, and the top pressure is 0.08MPa.

[0152] The material analysis results for each operating unit are shown in Table 5 below:

[0153] Table 5

[0154]

[0155] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing 4-methyl-1-pentene, characterized in that, The method includes the following steps: (1) In the presence of a hydrogenation catalyst, methyl isobutyl ketone is mixed with hydrogen gas to carry out a hydrogenation reaction to obtain a stream containing methyl isobutyl methanol; (2) In the presence of a dehydration catalyst, the stream containing methyl isobutyl methanol is subjected to a dehydration reaction to obtain a stream containing 4-methyl-1-pentene; (3) Optionally, the stream containing 4-methyl-1-pentene described in step (2) is separated to obtain a stream rich in 4-methyl-1-pentene and a stream rich in methyl isobutyl methanol; (4) Optionally, the stream containing 4-methyl-1-pentene separated in step (3) is purified to obtain 4-methyl-1-pentene product; (5) Optionally, the stream containing methyl isobutyl methanol separated in step (3) can be dehydrated and returned to step (1) or step (2); The hydrogenation reaction temperature is 80-125℃, and the hydrogenation reaction pressure is atmospheric pressure to 3.5MPa; The temperature of the dehydration reaction is 280-330℃, and the pressure of the dehydration reaction is from atmospheric pressure to 0.5MPa; The dehydration catalyst includes Ni and Ce; Based on the total weight of the dehydration catalyst, the Ni content is 0.01-0.5 wt%, and the Ce content is 1-5 wt%. The dehydration catalyst is supported on zirconium oxide; The hydrogenation catalyst is a heterogeneous catalyst, and the catalyst includes a support and Ni and Cu supported on the support; the content of Ni is 10-15 wt% based on the total weight of the hydrogenation catalyst, and the weight ratio of nickel to copper is (4-6):

1. The specific surface area of ​​the hydrogenation catalyst is 140-220 m². 2 / g, pore volume 0.45-0.80mL / g, most probable pore size 5-20nm.

2. The method according to claim 1, wherein, In step (1), the conditions for the hydrogenation reaction include: a liquid hourly space velocity (LHSV) of 0.05-3 h⁻¹ for methyl isobutyl ketone. -1 The molar ratio of hydrogen to methyl isobutyl ketone is (2-30):

1.

3. The method according to claim 1 or 2, wherein, The conditions for the hydrogenation reaction include: a liquid hourly space velocity (LHSV) of 0.2-2 h for methyl isobutyl ketone. -1 The molar ratio of hydrogen to methyl isobutyl ketone is (5-15):1, the temperature of the hydrogenation reaction is 100-125℃, and the pressure of the hydrogenation reaction is 1.0-2.5MPa.

4. The method according to claim 1 or 2, wherein, The step between steps (1) and (2) further includes a gas-liquid separation step, in which the methyl isobutyl methanol stream is subjected to gas-liquid separation to obtain a hydrogen-containing gas phase component and a methyl isobutyl methanol-containing liquid phase component, and the methyl isobutyl methanol-containing liquid phase component obtained by gas-liquid separation is subjected to a dehydration reaction.

5. The method according to claim 1 or 2, wherein, The support for the hydrogenation catalyst is selected from at least one of silica, alumina, activated carbon, and zirconium oxide.

6. The method according to claim 1 or 2, wherein, In step (2), the conditions for the dehydration reaction include: a liquid hourly space velocity (LHSV) of 0.05-1.5 h⁻¹ for methyl isobutyl methanol. -1 .

7. The method according to claim 1 or 2, wherein, The liquid hourly space velocity (LHSV) of methyl isobutyl methanol is 0.2–1 h⁻¹. -1 The dehydration reaction is carried out at pressures ranging from atmospheric pressure to 0.1 MPa.

8. The method according to claim 1 or 2, wherein, In step (3), the separation is carried out in a light-weight removal tower. The theoretical number of trays in the light-light removal tower is 50-75; the feed inlet of the light-light removal tower is located in the middle and lower part of the tower; the operating temperature at the top of the tower is 50-65℃; and the operating pressure at the top of the tower is 0.05-0.15MPa.

9. The method according to claim 1 or 2, wherein, In step (4), the refining is carried out in a refining tower. The theoretical number of trays in the refining column is 40-70. The feed inlet of the refining column is located in the middle and lower part of the refining column. The operating temperature at the top of the column is 45-55℃, and the operating pressure at the top of the column is 0.01-0.15MPa.

10. The method according to claim 1 or 2, wherein, In step (5), the water removal is carried out in a dehydration tower. The dehydration tower has a theoretical number of trays of 40-60, the feed inlet of the dehydration tower is located in the upper middle part of the dehydration tower, the operating temperature at the top of the tower is 95-103℃, and the operating pressure at the top of the tower is 0.01-0.20MPa.

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