Process and system for preparing 4-methyl-1-pentene from 4-methyl-2-pentanol

Abstract

The present application relates to the technical field of 4-methyl-1-pentene preparation, and discloses a method and system for preparing 4-methyl-1-pentene from 4-methyl-2-pentanol. The method comprises: in the presence of a dehydration catalyst, dehydrating a stream containing 4-methyl-2-pentanol to obtain a stream containing 4-methyl-1-pentene; the dehydration catalyst comprises calcium oxide and zirconium oxide, wherein the content of calcium oxide in terms of metal elements is 0.1-6 wt% based on the total weight of the dehydration catalyst. The method for preparing 4-methyl-1-pentene from 4-methyl-2-pentanol can be used to simply and effectively prepare 4-methyl-1-pentene product, the raw material 4-methyl-2-pentanol is easy to obtain, the reaction conditions are relatively mild, the product distribution is simple, and high-purity 4-methyl-1-pentene product can be prepared.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of 4-methyl-1-pentene preparation, in particular, to a method and system for preparing 4-methyl-1-pentene from 4-methyl-2-pentanol. BACKGROUND

[0002] In recent years, with the expansion of the application and consumption field of materials, the industrial production technology of poly-4-methyl-2-pentene (PMP) has developed rapidly. Currently, Philips Company and Japan Mitsui Company both have their industrialized products TPX, which are widely used in the fields of electronic appliances, medical devices, microporous materials, packaging, and blending modification. In China, with the rapid development of the electronic industry, PMP has become an excellent mold material for electronic component packaging and a high-frequency connector manufacturing material due to its shapeability, temperature resistance, and low dielectric constant, and its demand has increased significantly, showing a good market prospect.

[0003] The polymerization monomer of PMP is 4-methyl-1-pentene (4MP1), which is a good α-olefin organic compound. Through its own polymerization, poly-4-methyl-1-pentene (PMP) with high transparency, excellent heat resistance, mechanical properties, electrical properties, and chemical resistance can be obtained. In addition, 4MP1 can also be used for the copolymerization of linear low-density polyethylene resin (LLDPE), which has excellent tensile and tear resistance and good dielectric properties. At present, the production process technology of 4MP1 abroad is relatively mature, and the main process is propylene dimerization.

[0004] In 1968, Hambling used a supported metal Na catalyst to realize the industrial production of propylene dimerization reaction, and built the world's first 2000 t / a 4MP1 production device with a single pass 4MP1 selectivity higher than 87%. At the same time, Japan Mitsui Chemical Company obtained a technology patent license from British ICI Company, and began production and entered the market in 1973. At present, Japan Mitsui Chemical Company is the only PMP resin manufacturer in the world.

[0005] In the 1980s, the United States Phillips Company developed a novel solid superbase catalyst, which changed the single-component carrier to a multi-component mixture and dissolved the mixture instead of simple mechanical mixing, then added a small amount of cocatalyst and was diluted by an inert solid to reduce the initial dimerization activity. The catalyst was successfully applied to industrial production, and a 10,000-ton 4MP1 production process was built, with a 4MP1 product purity of more than 99%.

[0006] Compared with foreign countries, the maturity of 4MP1 technology in China is low, and the industry technology patent is mainly mastered by Japan's Mitsui Chemical Corporation and the United States' Phillips Petroleum Company. The domestic related patent technology is mostly focused on the application of 4MP1 downstream products. At present, there is no 4MP1 production device in China, and domestic consumption is completely dependent on imports.

[0007] Sun Hongwei studied the particle size distribution of K2CO3 carrier loaded with alkali metal, and found that when the particle size range was between 300-400 nm, the catalyst had higher catalytic activity. At this time, 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 of 4-methyl-1-pentene, mainly including dimerization reaction of propylene under the condition of alkali metal loaded basic salt as catalyst on the basis of dehydration and deoxidation, and then preparing 4-methyl-1-pentene through a separation process. The purity of the 4-methyl-1-pentene can reach 99.5%, and the by-product is 1-hexene and other alpha-olefins, which meets the requirements of industrial 4-methyl-1-pentene polymerization reaction.

[0009] In summary, the current 4MP1 synthesis process mainly adopts propylene dimerization method, which has the disadvantages of high reaction pressure, many oligomerization and isomerization by-products, etc. At present, there is no other process route for producing 4MP1. Therefore, the method for preparing 4-methyl-1-pentene with easy-to-obtain raw materials, mild conditions and easy-to-separate products is still the goal pursued by people. SUMMARY

[0010] The purpose of the present application is to solve the technical problems of high reaction pressure, many oligomerization and isomerization by-products, etc. in the propylene dimerization method in the prior art. The present application provides a method and system for preparing 4-methyl-1-pentene from 4-methyl-2-pentanol.

[0011] In order to achieve the above-mentioned purpose, the first aspect of the present application provides a method for preparing 4-methyl-1-pentene from 4-methyl-2-pentanol, which comprises: carrying out dehydration reaction on a stream containing 4-methyl-2-pentanol in the presence of a dehydration catalyst to obtain a stream containing 4-methyl-1-pentene.

[0012] The second aspect of the present application provides a system for preparing 4-methyl-1-pentene from 4-methyl-2-pentanol, which comprises: a dehydration reactor, a first refining column, a second refining column and a hydrogenation reactor, wherein,

[0013] The dehydration reactor is used for carrying out dehydration reaction on a stream containing 4-methyl-2-pentanol to obtain a stream containing 4-methyl-1-pentene;

[0014] The first purification tower is connected to the dehydration reactor and is used to perform a first purification on the stream containing 4-methyl-1-pentene from the dehydration reactor to obtain 4-methyl-1-pentene product and crude 4-methyl-2-pentene product;

[0015] The second purification tower is connected to the first purification tower and is used to perform a second purification on the crude 4-methyl-2-pentene from the first purification tower to obtain a product rich in 4-methyl-2-pentene and a crude product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone.

[0016] The hydrogenation reactor is connected to the second purification tower and is used to hydrogenate the crude product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone from the second purification tower to obtain crude 4-methyl-2-pentanol.

[0017] Compared with existing propylene dimerization production methods, the method for preparing 4-methyl-1-pentene from 4-methyl-2-pentanol provided by this invention can be used simply and effectively to prepare 4-methyl-1-pentene products. 4-methyl-2-pentanol 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

[0018] Figure 1 This is a schematic diagram of a method and system for preparing 4-methyl-1-pentene from 4-methyl-2-pentanol according to a specific embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures

[0020] 1-Dehydration reactor; 2-First purification tower (4MP1 purification tower); 3-Second purification tower (4MP2 purification tower); 4-Hydrogenation reactor; 5-Gas-liquid separator. Detailed Implementation

[0021] 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.

[0022] One specific embodiment of the present invention provides a method for preparing 4-methyl-1-pentene from 4-methyl-2-pentanol (MIBC), the method comprising:

[0023] The stream containing 4-methyl-2-pentanol is subjected to a dehydration reaction in the presence of a dehydration catalyst to obtain a stream containing 4-methyl-1-pentene;

[0024] The dehydration catalyst preferably comprises calcium oxide and zirconium oxide, wherein the content of calcium oxide, in terms of metal elements, is 0.1-6 wt% (0.1 wt%, 0.5 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt% or any value between the above values) based on the total weight of the dehydration catalyst.

[0025] In the present application, the specific surface area of the dehydration catalyst can be 45-90 m 2 / g, the pore volume is 0.25-0.5 mL / g, and the most probable pore diameter is 3.5-6 nm.

[0026] In the present application, the dehydration catalyst can also comprise other metal active components, such as nickel, barium, zinc, etc., and the zirconium oxide can also be a zirconium oxide carrier that has been appropriately modified, for example, by adding an appropriate amount of other metal oxides such as titanium dioxide, tin oxide, neodymium oxide, thorium oxide, etc. during molding or co-precipitation.

[0027] According to some embodiments of the present application, the conditions of the dehydration reaction can include that the liquid phase volume space velocity of 4-methyl-2-pentanol is 0.05-1.5 h -1 , the temperature of the dehydration reaction is 250-410℃, and the pressure of the dehydration reaction is normal pressure to 0.3 MPa.

[0028] Preferably, the conditions of the dehydration reaction include that the liquid phase volume space velocity of 4-methyl-2-pentanol is 0.2-1.0 h -1 , the temperature of the dehydration reaction is 290-350℃, and the pressure of the dehydration reaction is normal pressure to 0.1 MPa.

[0029] In the present application, before the dehydration reaction, the stream containing 4-methyl-2-pentanol can be preheated and then introduced into the dehydration reactor; wherein the conditions of the preheating are not particularly limited as long as the 4-methyl-2-pentanol can be completely vaporized, for example, the temperature of the preheating can be 110-160℃.

[0030] According to some embodiments of the present application, the method further comprises subjecting the stream containing 4-methyl-1-pentene to a first refining to obtain 4-methyl-1-pentene product and 4-methyl-2-pentene crude product.

[0031] In the present application, the content of 4-methyl-2-pentanol in the stream containing 4-methyl-2-pentanol in step (1) is greater than 95 wt%. The stream containing 4-methyl-1-pentene obtained is a mixture containing 4-methyl-1-pentene, 4-methyl-2-pentene, 4-methyl-2-pentanol and 4-methyl-2-pentanone (MIBK). According to some embodiments of the present application, the first refining is carried out in a first refining column.

[0032] According to some embodiments of the present application, the first refining column has a theoretical plate number of 50-60, the feed inlet of the first refining column is located in the middle-lower part of the first refining column, the operating temperature at the top of the column is 45-60°C, preferably 50-55°C, and the operating pressure at the top of the column is 0.01-0.2 MPa, preferably 0.01-0.15 MPa.

[0033] In the present application, the crude 4-methyl-2-pentene obtained by the first refining is a mixture containing 4-methyl-2-pentene, 4-methyl-2-pentanol and 4-methyl-2-pentanone, and a small amount of 4-methyl-1-pentene.

[0034] According to some embodiments of the present application, the method further comprises a second refining of the crude 4-methyl-2-pentene to obtain a product (and water) rich in 4-methyl-2-pentene, and a crude product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone. The 4MP2 product and water are obtained at the top of the column, and the crude product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone is obtained at the bottom of the column.

[0035] According to some embodiments of the present application, the second refining is carried out in a second refining column.

[0036] According to some embodiments of the present application, the second refining column has a theoretical plate number of 60-80, the feed inlet of the second refining column is located in the middle-lower part of the second refining column, the operating temperature at the top of the column is 65-100°C, preferably 75-90°C, and the operating pressure at the top of the column is 0.01-0.2 MPa, preferably 0.01-0.15 MPa.

[0037] According to some embodiments of the present application, the method can further comprise a hydrogenation reaction of the crude product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone obtained by the second refining after mixing with hydrogen in the presence of a hydrogenation catalyst to obtain a crude 4-methyl-2-pentanol.

[0038] Preferably, the conditions of the hydrogenation reaction can include a liquid phase volume space velocity of 4-methyl-2-pentanone of 0.05-3.0 h -1The molar ratio of hydrogen to 4-methyl-2-pentanone is (2-30): 1, the temperature of the hydrogenation reaction is 80-160°C, and the pressure of the hydrogenation reaction is normal pressure to 3.5 MPa.

[0039] More preferably, the liquid phase volume space velocity of 4-methyl-2-pentanone is 0.2-2 h -1 The molar ratio of hydrogen to 4-methyl-2-pentanone is (5-15): 1, the temperature of the hydrogenation reaction is 100-140°C, and the pressure of the hydrogenation reaction is 1.0-2.5 MPa.

[0040] In the present application, the hydrogenation reaction can be carried out under gas phase or liquid phase conditions. Preferably, the reaction raw material is hydrogenated with hydrogen in a gas phase manner in a catalyst bed. 4-methyl-2-pentanone is hydrogenated to form 4-methyl-2-pentanol, but some side reactions may also occur when the catalyst or process conditions are not suitable, such as the condensation of 4-methyl-2-pentanone or the further hydrogenation of the condensation product to form heavy components, the intramolecular dehydration of 4-methyl-2-pentanol to form carbon hexane, and the chain breaking reaction of 4-methyl-2-pentanone and 4-methyl-2-pentanol. The occurrence of the above reactions may be caused by the nature or performance of the catalyst itself, or by the extreme process conditions. Therefore, the selection of a suitable catalyst and moderate process conditions can achieve the desired effect.

[0041] In the present application, the suitable hydrogenation catalyst is selected from a catalyst in which at least two metal active components are supported on a catalyst or dispersed by a catalyst carrier. The metal active component can be selected from one or more than two combinations of IB, IIB, IIIB, IVB, VB, VIB, VIIB, VIIIB group transition metals, lanthanide series metals, and IIIA, IVA, VA, VIA group metals in the periodic table, such as nickel, cobalt, copper, manganese, ruthenium, tin, iron, tungsten, rhenium, and / or rhodium, etc.

[0042] According to some embodiments of the present application, the hydrogenation catalyst is a heterogeneous catalyst.

[0043] More preferably, the hydrogenation catalyst comprises the active component Ni and the carrier oxide, and the content of Ni is 10-15 wt% based on the total weight of the hydrogenation catalyst.

[0044] Preferably, the specific surface area of the hydrogenation catalyst is 145-175 m 2 / g, the pore volume is 0.50-0.80 mL / g, and the most probable pore diameter is 6.0-10.0 nm.

[0045] In the present invention, the hydrogenation catalyst carrier can be selected from silica, alumina, titania, zirconia, magnesia, activated carbon, graphite or any combination thereof, such as silica-alumina, titania-alumina, etc. Preferably, the hydrogenation catalyst carrier is silica, alumina, activated carbon, zirconia or any combination thereof. More preferably, the catalyst carrier is silica, γ-alumina or a combination thereof.

[0046] wherein the second carrier is selected from at least one of alumina, silica and titania.

[0047] In the present invention, the catalyst and catalyst carrier used in the hydrogenation of 4-methyl-2-pentanone and the dehydration of 4-methyl-2-pentanol can be modified in any way. For example, the pore structure of the carrier oxide can be adjusted by using a pore-expanding agent or hydrothermal treatment to improve the selectivity and stability of the overall catalyst; alternatively, the appropriate acidity or basicity can be adjusted by adding certain element compounds during catalyst preparation to improve the activity and selectivity of the catalyst; alternatively, the stability of the catalyst can be improved by adding certain metals such as cerium to the carrier to synergize with the active components nickel and copper, which can effectively improve the service life of the catalyst; alternatively, the surface properties of the catalyst can be adjusted to reduce the deposition of certain compounds or heavy components on the catalyst surface or to improve the surface dispersion of the active components to extend the service life of the catalyst.

[0048] The catalysts (such as catalysts for hydrogenation and dehydration) according to the present invention can be prepared by conventional methods, such as impregnation, ion exchange, blending, kneading, coprecipitation, deposition-precipitation, ammonium vapor deposition, melt-extraction, ball milling and sol-gel methods. More preferably, the catalysts are prepared by one or more of impregnation, coprecipitation and sol-gel methods. The above-mentioned catalyst preparation methods are well known to those skilled in the art as existing mature technologies. For example, a certain amount of carrier is weighed, and the active component precursor is loaded on the carrier by one or more steps of impregnation, followed by drying, calcination, reduction and finally obtaining the catalyst product; alternatively, the active component precursor can be sprayed on the carrier by spraying, followed by drying, calcination, reduction and finally obtaining the catalyst product; alternatively, the catalyst raw powder can be prepared by coprecipitation, followed by drying, decomposition, granulation, tabletting, reduction and other steps to obtain the desired catalyst product.

[0049] The shape and size of the catalysts according to the present invention can be arbitrarily customized, such as spherical, strip-shaped, columnar, ring-shaped, etc., with a size of about 0.3-10 mm, more preferably 0.5-5 mm. The present invention does not have a particular limitation on the above-mentioned size, which is mainly designed according to the fixed bed reactor described in the present invention to facilitate installation, reduce bed pressure and other requirements.

[0050] The catalyst of the present application is preferably reduced before use. The catalyst is generally reduced using hydrogen and / or nitrogen. When reduced using pure hydrogen, the temperature increase rate needs to be strictly controlled. From the perspective of temperature control during reduction of the catalyst, a mixed gas with a low hydrogen content is preferred. The greater the gas space velocity during reduction, the better, because the greater the gas space velocity, the faster the heat generated by the reaction can be removed, thereby maintaining the temperature of the catalyst bed steady and avoiding damage to the catalyst caused by a rapid temperature increase. For example, the gas space velocity of the mixed gas is 1000-3000 m 3 / m 3 ·h -1 The temperature at which the catalyst is reduced can be determined according to the composition of the catalyst. For the catalyst described in the present application, the temperature of the catalyst bed can be gradually increased at a rate of 10-20°C / h, held at about 180°C (e.g. 160-200°C) for 5-10 hours, then gradually increased at a rate of 5-20°C / h until 300-450°C, and held at this temperature for 10-15 hours. Then, the temperature is slowly decreased to room temperature, for example, at a rate of 10-20°C / h. After the temperature is decreased to room temperature, the nitrogen is switched to a mixture of dry air and nitrogen, and the amount of air is gradually increased to increase the oxygen content in the mixed gas. The amount of air is adjusted in real time according to the change in the temperature of the catalyst to avoid a too high temperature of the catalyst bed, for example, not more than 50°C. When the catalyst is reduced in situ in the corresponding reactor, the temperature of the catalyst after reduction is decreased to the reaction temperature, and the catalyst can be used after the reaction is started.

[0051] According to a preferred embodiment, the dehydration catalyst is prepared according to the following steps:

[0052] A certain amount of zirconyl nitrate powder is dissolved in deionized water to obtain a zirconyl nitrate aqueous solution (solution ①). The weight of the calcium salt is calculated according to the calcium content, and a calcium salt aqueous solution (solution ②) is prepared. The solution ① and the solution ② are subjected to concurrent neutralization, and the pH value (8.5-9.0) and the temperature (75-80°C) of the neutralization process are controlled. After the neutralization is completed, the solution is aged at 80-100°C for 1-3h, filtered and washed, and then dried (100-150°C, 1-10h), calcined (300-400°C, 1-6h) in sequence to obtain a dehydration catalyst precursor. There is no particular limitation to the type of the calcium salt as long as it meets the requirements of the present application. For example, the calcium salt can be calcium nitrate tetrahydrate;

[0053] The dehydration catalyst precursor obtained above is reduced using hydrogen. The temperature increase rate during reduction is 120-160°C / h, the temperature is held at 200-250°C for 1-5h, then the temperature is increased to 400-450°C for 1-10h, and then the temperature is decreased to room temperature to obtain the dehydration catalyst.

[0054] According to a preferred embodiment of the present application, the hydrogenation catalyst is prepared by the following steps:

[0055] Active component (Ni) loading: The γ-Al2O3 carrier is weighed, the weight of the nickel salt corresponding to the content of the nickel loading component is calculated and weighed, and an aqueous solution of the nickel salt is prepared. The above aqueous solution is added to the γ-Al2O3 carrier for equal volume impregnation, and after standing for 1-3 h, it is dried at 100-150℃ for 1-3 h, and then calcined and decomposed at 340-380℃ in a muffle furnace for 1-6 h to obtain an oxidation state hydrogenation catalyst; wherein the type of the nickel salt is not particularly limited as long as it meets the requirements of the present application, and the nickel salt can be nickel nitrate hexahydrate.

[0056] Reduction: The oxidation state hydrogenation catalyst obtained above is reduced with a mixed gas containing hydrogen and nitrogen (the volume ratio of hydrogen to nitrogen is 1:(2-4)), the reduction temperature is raised at a rate of 100-150℃ / h, the temperature is raised to 220-280℃ and held for 1-6 hours, then the temperature is raised to 400-450℃ and held for 1-10 hours, then the temperature is lowered to room temperature to obtain the hydrogenation catalyst.

[0057] In the present application, various changes can be made to the catalyst carrier and the preparation method of the present application according to the inspiration from the above detailed description. For example, any known hydrogenation catalyst, catalyst carrier or modified catalyst carrier can be used.

[0058] In the present application, before the hydrogenation reaction, 4-methyl-2-pentanone and hydrogen can be mixed and preheated before being introduced into the hydrogenation reactor; wherein the conditions for preheating are not particularly limited, as long as the 4-methyl-2-pentanone is completely vaporized, for example, the preheating temperature can be 120-150℃.

[0059] According to a preferred embodiment of the present application, the method can further comprise: subjecting the 4-methyl-2-pentanol crude obtained by the hydrogenation reaction to gas-liquid separation to obtain a gas phase component containing hydrogen and a liquid phase component containing 4-methyl-2-pentanol, and using the liquid phase component containing 4-methyl-2-pentanol as the raw material for the dehydration reaction. Wherein, before the gas-liquid separation, it further comprises the step of cooling the 4-methyl-2-pentanol crude.

[0060] The second aspect of the present application provides a system for preparing 4-methyl-1-pentene from 4-methyl-2-pentanol, the system comprising: a dehydration reactor 1, a first rectification column 2, a second rectification column 3 and a hydrogenation reactor 4, wherein,

[0061] The dehydration reactor 1 is used for carrying out a dehydration reaction on a stream containing 4-methyl-2-pentanol to obtain a stream containing 4-methyl-1-pentene;

[0062] The first refining column 2 is connected to the dehydration reactor 1, and is used to perform first refining on the 4-methyl-1-pentene-containing stream from the dehydration reactor 1 to obtain 4-methyl-1-pentene product and 4-methyl-2-pentene crude product;

[0063] The second refining column 3 is connected to the first refining column 2, and is used to perform second refining on the 4-methyl-2-pentene crude product from the first refining column 2 to obtain 4-methyl-2-pentene product and crude product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone;

[0064] The hydrogenation reactor 4 is connected to the second refining column 3, and is used to perform hydrogenation reaction on the crude product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone from the second refining column 3 to obtain 4-methyl-2-pentanol crude product.

[0065] According to some embodiments of the present application, the system comprises a gas-liquid separator 5 connected to the dehydration reactor 1 and the hydrogenation reactor 4, which is used to perform gas-liquid separation on the 4-methyl-2-pentanol crude product from the hydrogenation reactor 4, and then return the obtained liquid phase component to the dehydration reactor 1 for dehydration reaction.

[0066] In the present application, normal pressure refers to "0.1 MPa" unless otherwise specified.

[0067] According to a preferred embodiment, in combination with Figure 1 The method for preparing 4-methyl-1-pentene from 4-methyl-2-pentanol of the present application specifically comprises the following flow in the use of the system for preparing 4-methyl-1-pentene from 4-methyl-2-pentanol of the present application:

[0068] (a) Dehydration reaction: the 4-methyl-2-pentanol-containing stream is preheated and then introduced into the dehydration reactor 1 in the presence of the above-mentioned dehydration catalyst to perform dehydration reaction, and 4-methyl-2-pentanol is dehydrated to form a 4-methyl-1-pentene-containing stream (crude product of 4-methyl-1-pentene (4MP1));

[0069] (b) 4MP1 refining (first refining): the above-mentioned crude product of 4-methyl-1-pentene is sent to the 4MP1 refining column to perform first refining 2, and the 4-methyl-1-pentene product is separated from the top of the column, and the 4-methyl-2-pentene (4MP2) crude product is separated from the bottom of the column;

[0070] (c) 4MP2 refining (second refining): the above-mentioned 4-methyl-2-pentene (4MP2) crude product from the bottom of the 4MP1 refining column 2 is sent to the 4MP2 refining column 3 to perform second refining, and the product containing rich 4MP2 and water is separated from the top of the column, and the crude product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone is separated from the bottom of the column;

[0071] (d) hydrogenation reaction: the column bottom product from the 4MP2 refining column 3 containing the crude product of 4-methyl-2-pentanol and 4-methyl-2-pentanone is mixed with hydrogen gas and preheated, and then introduced into the hydrogenation reactor 4 in the presence of the hydrogenation catalyst described above, to perform a hydrogenation reaction, so that the 4-methyl-2-pentanone therein is hydrogenated to form 4-methyl-2-pentanol, after cooling, the product is introduced into the gas-liquid separator 5 to perform gas-liquid separation, to obtain a gas phase component containing hydrogen gas and a liquid phase component containing 4-methyl-2-pentanol, and the obtained liquid phase component containing 4-methyl-2-pentanol is returned to the dehydration reactor 1 as the raw material for the dehydration reaction, and the gas phase component containing hydrogen gas is introduced into the hydrogenation reactor 4 as the hydrogen source for the hydrogenation reaction described above.

[0072] The present application will be described in detail below by way of examples.

[0073] The following examples will illustrate the method for preparing 4-methyl-1-pentene from 4-methyl-2-pentanol according to the present application in combination with Figure 1 Unless otherwise specified, the specific operations of the flow are as described above.

[0074] The conversion rate and selectivity involved in the examples are specifically formulated as follows:

[0075]

[0076]

[0077]

[0078] The following preparation examples are used to illustrate the preparation of the dehydration catalyst and the hydrogenation catalyst

[0079] Preparation Example Al

[0080] A certain amount of zirconium oxynitrate powder is dissolved with deionized water to obtain an aqueous solution of zirconium oxynitrate (solution ①), the corresponding amount of calcium nitrate tetrahydrate is calculated according to the calcium content, and the calcium nitrate tetrahydrate is prepared into an aqueous solution of calcium nitrate tetrahydrate (solution ②), the solution ① and the solution ② are subjected to concurrent neutralization, and the pH value (8.5-9.0) and the temperature (75-80℃) of the neutralization process are controlled, after the neutralization is completed, aging is performed at 90℃ for 2h, and after filtration and washing, drying (120℃, 5h) and calcination (350℃, 5h) are performed in sequence, to obtain the dehydration catalyst precursor;

[0081] The dehydration catalyst precursor obtained above is reduced with hydrogen gas, the reduction temperature is raised at a rate of 150℃ / h, the temperature is raised to 220℃ and held for 4h, then the temperature is raised to 450℃ and held for 6h, and then the temperature is reduced to room temperature, to obtain the dehydration catalyst. The specific composition of the dehydration catalyst is: the content of Ca is 1.93wt%, and the balance is zirconia.

[0082] Preparation Example A2

[0083] Preparation Example A1 was performed except that the amount of calcium nitrate tetrahydrate was changed, and the obtained dehydrated catalyst had the following specific content composition: the content of Ca was 0.45 wt%, and the balance was zirconia.

[0084] Preparation Example A3

[0085] Preparation Example A1 was performed except that the amount of calcium nitrate tetrahydrate was changed, and the obtained dehydrated catalyst had the following specific content composition: the content of Ca was 4.65 wt%, and the balance was zirconia.

[0086] Preparation Example A4

[0087] Preparation Example A1 was performed except that the amount of calcium nitrate tetrahydrate was changed, and the obtained dehydrated catalyst had the following specific content composition: the content of Ca was 3.81 wt%, and the balance was zirconia.

[0088] Preparation Example A5

[0089] Preparation Example A1 was performed except that the amount of calcium nitrate tetrahydrate was changed, and the obtained dehydrated catalyst had the following specific content composition: the content of Ca was 5.56 wt%, and the balance was zirconia.

[0090] Preparation Example B1

[0091] Active component (Ni) loading: γ-Al2O3 support was weighed, the weight of nickel nitrate hexahydrate corresponding to the content of the nickel loading component was calculated according to the content of the nickel loading component, and the nickel nitrate hexahydrate was prepared into a nickel nitrate hexahydrate aqueous solution. The above solution was added to the γ-Al2O3 support for equal-volume impregnation, and after standing for 2 h, drying was performed at 120°C for 2 h, and then calcination and decomposition were performed at 360°C for 4 h in a muffle furnace to obtain an oxidized hydrogenation catalyst;

[0092] Reduction: the oxidized hydrogenation catalyst obtained above was reduced with a mixed gas containing 25 vol% hydrogen and 75 vol% nitrogen, the reduction temperature was increased at a rate of 120°C / h, the temperature was increased to 250°C and maintained for 3 h, and then the temperature was increased to 420°C and maintained for 8 h, and then the temperature was decreased to room temperature to obtain a hydrogenation catalyst. The specific composition of the hydrogenation catalyst was as follows: the content of Ni was 10.4 wt%, and the balance was γ-Al2O3. The specific surface area of the hydrogenation catalyst was 156 m 2 / g, the pore volume was 0.58 ml / g, and the most probable pore diameter was 8.5 nm.

[0093] Preparation Example B2

[0094] Preparation Example B1 was followed, except that the amount of nickel nitrate hexahydrate was changed, so that the hydrogenation catalyst obtained had the following specific content composition: the content of Ni was 12.7wt%, and the balance was γ-Al2O3. The specific surface area of the hydrogenation catalyst was 152m 2 / g, the pore volume was 0.55ml / g, and the most probable pore diameter was 8.8nm.

[0095] Preparation Example B3

[0096] Preparation Example B1 was followed, except that the amount of nickel nitrate hexahydrate was changed, so that the hydrogenation catalyst obtained had the following specific content composition: the content of Ni was 14.6wt%, and the balance was γ-Al2O3. The specific surface area of the hydrogenation catalyst was 159m 2 / g, the pore volume was 0.6ml / g, and the most probable pore diameter was 8.2nm.

[0097] Preparation Example B4

[0098] Preparation Example B1 was followed, except that the amount of nickel nitrate hexahydrate was changed, so that the hydrogenation catalyst obtained had the following specific content composition: the content of Ni was 13.5wt%, and the balance was γ-Al2O3. The specific surface area of the hydrogenation catalyst was 164m 2 / g, the pore volume was 0.59ml / g, and the most probable pore diameter was 8.0nm.

[0099] Example 1

[0100] (1) Dehydration reaction: the stream containing 4-methyl-2-pentanol was preheated and then introduced into the dehydration reactor in the presence of the dehydration catalyst obtained in the above Preparation Example Al, so as to carry out the dehydration reaction, and 4-methyl-2-pentanol was dehydrated to produce a stream containing 4-methyl-l-pentene (crude product of 4-methyl-l-pentene (4MPI)); the specific process conditions of the dehydration reaction were as follows: the liquid phase volume space velocity of 4-methyl-2-pentanol was 0.82h -1 , the reaction temperature was 345°C, and the reaction pressure was normal pressure; wherein the conversion rate of methyl isobutyl carbinol was 87.01%, and the selectivity of 4-methyl-l-pentene was 81.61%;

[0101] (2) 4MPI refining (first refining): the crude product of 4-methyl-l-pentene was sent to the 4MPI refining column to carry out the first refining, so as to separate the 4-methyl-l-pentene product at the top of the column and the 4-methyl-2-pentene (4MP2) crude product at the bottom of the column; wherein the theoretical plate number of the 4MPI refining column was 58, the feed inlet was located at the 34th plate, the operating temperature at the top of the column was 54.3°C, and the operating pressure at the top of the column was 0.12MPa;

[0102] (3) 4MP2 refining (second refining): the 4-methyl-2-pentene (4MP2) crude product from the 4MP1 refining column is sent to the 4MP2 refining column for second refining, and the overhead product containing 4MP2 product and water and the column bottom product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone crude product are separated; the 4MP2 refining column has 64 theoretical plates, the feed inlet is located at the 35th plate, the operating temperature at the top of the column is 79.4°C, and the operating pressure at the top of the column is 0.08 MPa;

[0103] (4) hydrogenation reaction: the column bottom product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone crude product obtained from the 4MP2 refining column is mixed with hydrogen and preheated, and then introduced into a hydrogenation reactor in the presence of the hydrogenation catalyst obtained in the above Preparation Example B1, to perform hydrogenation reaction, so that the 4-methyl-2-pentanone therein is hydrogenated to form 4-methyl-2-pentanol, after cooling, the product is sent to a gas-liquid separator to perform gas-liquid separation, to obtain a gas phase component containing hydrogen and a liquid phase component containing 4-methyl-2-pentanol, and the obtained liquid phase component containing 4-methyl-2-pentanol is returned to the dehydration reactor as the raw material for dehydration reaction, and the gas phase component containing hydrogen is used as the hydrogen source for the above hydrogenation reaction. The specific conditions for the above hydrogenation reaction are as follows: the liquid phase volume space velocity of 4-methyl-2-pentanone is 1.84 h -1 , the molar ratio of hydrogen to 4-methyl-2-pentanone is 14:1, the reaction temperature is 136°C, and the reaction pressure is 1.5 MPa; wherein the conversion rate of methyl isobutyl ketone is 99.93%, and the selectivity of methyl isobutyl carbinol is 100%.

[0104] The material analysis results of each operation unit are shown in Table 1 below:

[0105] Table 1

[0106]

[0107] Example 2

[0108] (1) dehydration reaction: the stream containing 4-methyl-2-pentanol is preheated and introduced into a dehydration reactor in the presence of the dehydration catalyst obtained in the above Preparation Example A2, to perform dehydration reaction, to dehydrate 4-methyl-2-pentanol to form a stream containing 4-methyl-1-pentene (4-methyl-1-pentene (4MP1) crude product); the specific process conditions for the dehydration reaction are as follows: the liquid phase volume space velocity of 4-methyl-2-pentanol is 0.54 h -1 , the reaction temperature is 320°C, and the reaction pressure is 0.04 MPa; wherein the conversion rate of methyl isobutyl carbinol is 80.5%, and the selectivity of 4-methyl-1-pentene is 84.47%;

[0109] (2) 4MP1 refining (first refining): the crude product of 4-methyl-1-pentene above is sent to a 4MP1 refining column for first refining, to separate 4-methyl-1-pentene product at the top and 4-methyl-2-pentene (4MP2) crude product at the bottom; wherein the 4MP1 refining column has 55 theoretical plates, the feed inlet is at the 30th plate, the operating temperature at the top is 55.1°C, and the operating pressure at the top is 0.14 MPa;

[0110] (3) 4MP2 refining (second refining): the 4-methyl-2-pentene (4MP2) crude product at the bottom of the 4MP1 refining column above is sent to a 4MP2 refining column for second refining, to separate the product containing 4MP2 at the top and the product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone at the bottom; wherein the 4MP2 refining column has 78 theoretical plates, the feed inlet is at the 42nd plate, the operating temperature at the top is 84.8°C, and the operating pressure at the top is 0.12 MPa;

[0111] (4) hydrogenation reaction: the product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone at the bottom of the 4MP2 refining column above is mixed with hydrogen and preheated, and then fed into a hydrogenation reactor in the presence of the hydrogenation catalyst prepared in Preparation B2 above, to perform hydrogenation reaction, so that 4-methyl-2-pentanone is hydrogenated to form 4-methyl-2-pentanol; after cooling, the product is fed into a gas-liquid separator to perform gas-liquid separation, to obtain gaseous components containing hydrogen and liquid components containing 4-methyl-2-pentanol, and the liquid components containing 4-methyl-2-pentanol are returned to the dehydration reactor as raw material for dehydration reaction, and the gaseous components containing hydrogen are used as hydrogen source for the hydrogenation reaction above. The specific conditions for the hydrogenation reaction above are as follows: the liquid space velocity of 4-methyl-2-pentanone is 0.25 h-1, the molar ratio of hydrogen to 4-methyl-2-pentanone is 6:1, the reaction temperature is 115°C, and the reaction pressure is 2.5 MPa; wherein the conversion rate of methyl isobutyl ketone is 99.9%, and the selectivity of methyl isobutyl carbinol is 100%. -1

[0112] The material analysis results of each operation unit are shown in Table 2 below:

[0113] Table 2

[0114]

[0115] Example 3

[0116] ​(1) Dehydration reaction: the stream containing 4-methyl-2-pentanol obtained in the above Preparation Example A3 was preheated and then introduced into a dehydration reactor in the presence of the dehydration catalyst obtained in the above Preparation Example A3 to perform a dehydration reaction, so that 4-methyl-2-pentanol was dehydrated to produce a stream containing 4-methyl-l-pentene (crude product of 4-methyl-l-pentene (4MP1)); the specific process conditions of the dehydration reaction were as follows: the liquid space velocity of 4-methyl-2-pentanol was 0.35 h -1 -1, the reaction temperature was 295°C, and the reaction pressure was 0.06 MPa; wherein the conversion rate of methyl isobutyl carbinol was 89.03%, and the selectivity of 4-methyl-l-pentene was 84.26%;

[0117] (2) 4MP1 refining (first refining): the crude product of 4-methyl-l-pentene obtained in the above was sent to a 4MP1 refining column to perform first refining, so that 4-methyl-l-pentene product was separated at the top of the column and 4-methyl-2-pentene (4MP2) crude product was separated at the bottom of the column; wherein the theoretical plate number of the 4MP1 refining column was 52, the feed inlet was located at the 29th plate, the operating temperature at the top of the column was 53.2°C, and the operating pressure at the top of the column was 0.08 MPa;

[0118] (3) 4MP2 refining (second refining): the 4-methyl-2-pentene (4MP2) crude product obtained at the bottom of the 4MP1 refining column in the above was sent to a 4MP2 refining column to perform second refining, so that the top product containing 4MP2 product and water was separated and the bottom product containing crude product of 4-methyl-2-pentanol and 4-methyl-2-pentanone was separated; wherein the theoretical plate number of the 4MP2 refining column was 73, the feed inlet was located at the 40th plate, the operating temperature at the top of the column was 89.1°C, and the operating pressure at the top of the column was 0.04 MPa;

[0119] (4) Hydrogenation reaction: the bottom product of the crude product of 4-methyl-2-pentanol and 4-methyl-2-pentanone obtained in the 4MP2 refining column in the above was mixed with hydrogen and then preheated and introduced into a hydrogenation reactor in the presence of the hydrogenation catalyst obtained in the above Preparation Example B3 to perform a hydrogenation reaction, so that 4-methyl-2-pentanone in the bottom product was hydrogenated to produce 4-methyl-2-pentanol; after cooling, the product was sent to a gas-liquid separator to perform gas-liquid separation, so that the gas phase component containing hydrogen and the liquid phase component containing 4-methyl-2-pentanol were obtained, and the liquid phase component containing 4-methyl-2-pentanol was returned to the dehydration reactor as raw material for the dehydration reaction, and the gas phase component containing hydrogen was used as the source of hydrogen for the hydrogenation reaction in the above; wherein the specific conditions of the hydrogenation reaction were as follows: the liquid space velocity of 4-methyl-2-pentanone was 1.0 h -1 -1, the molar ratio of hydrogen to 4-methyl-2-pentanone was 8:1, the reaction temperature was 128°C, and the reaction pressure was 2.0 MPa; wherein the conversion rate of methyl isobutyl ketone was 99.91%, and the selectivity of methyl isobutyl carbinol was 100%.

[0120] The results of the material analysis of each operation unit are shown in Table 3 below.

[0121] Table 3

[0122]

[0123] Example 4

[0124] (1) Dehydration reaction: The stream containing 4-methyl-2-pentanol was preheated and then introduced into a dehydration reactor in the presence of the dehydration catalyst obtained in Preparation Example A4, to perform a dehydration reaction, thereby dehydrating 4-methyl-2-pentanol to produce a stream containing 4-methyl-1-pentene (crude product of 4-methyl-1-pentene (4MP1)); the specific process conditions of the dehydration reaction were as follows: the liquid phase volume space velocity of 4-methyl-2-pentanol was 0.64 h -1 -1, the reaction temperature was 312°C, and the reaction pressure was normal pressure; wherein the conversion rate of methyl isobutyl carbinol was 87.03%, and the selectivity of 4-methyl-1-pentene was 83.91%;

[0125] (2) 4MP1 refining (first refining): The crude product of 4-methyl-1-pentene was introduced into a 4MP1 refining column to perform first refining, thereby separating 4-methyl-1-pentene product at the top of the column and 4-methyl-2-pentene (4MP2) crude product at the bottom of the column; wherein the theoretical plate number of the 4MP1 refining column was 60, the feed inlet was located at the 39th plate, the operating temperature at the top of the column was 52.7°C, and the operating pressure at the top of the column was 0.04 MPa;

[0126] (3) 4MP2 refining (second refining): The 4-methyl-2-pentene (4MP2) crude product at the bottom of the 4MP1 refining column was introduced into a 4MP2 refining column to perform second refining, thereby separating column top product containing 4MP2 product and water, and column bottom product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone crude product; wherein the theoretical plate number of the 4MP2 refining column was 67, the feed inlet was located at the 37th plate, the operating temperature at the top of the column was 87.2°C, and the operating pressure at the top of the column was 0.1 MPa;

[0127] (4) Hydrogenation reaction: the column bottom product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone crude product obtained from the 4MP2 refining column was mixed with hydrogen and preheated, and then introduced into a hydrogenation reactor to perform hydrogenation reaction, so that 4-methyl-2-pentanone in the column bottom product was hydrogenated to form 4-methyl-2-pentanol. After cooling, the column bottom product was introduced into a gas-liquid separator to perform gas-liquid separation, so as to obtain a gas phase component containing hydrogen and a liquid phase component containing 4-methyl-2-pentanol. The liquid phase component containing 4-methyl-2-pentanol was returned to the dehydration reactor as the raw material for dehydration reaction, and the gas phase component containing hydrogen was used as the hydrogen source for the hydrogenation reaction. The specific conditions of the hydrogenation reaction were as follows: the liquid phase volume space velocity of 4-methyl-2-pentanone was 1.45 h-1, the molar ratio of hydrogen to 4-methyl-2-pentanone was 12:1, the reaction temperature was 120°C, and the reaction pressure was 1.0 MPa. The conversion rate of methyl isobutyl ketone was 99.92%, and the selectivity of methyl isobutyl carbinol was 100%. -1 -1

[0128] The material analysis results of each operation unit are shown in Table 4 below.

[0129] Table 4

[0130]

[0131] Example 5

[0132] (1) Dehydration reaction: the stream containing 4-methyl-2-pentanol was preheated and introduced into a dehydration reactor to perform dehydration reaction, so as to dehydrate 4-methyl-2-pentanol to form a stream containing 4-methyl-1-pentene (4-methyl-1-pentene (4MP1) crude product). The specific process conditions of the dehydration reaction were as follows: the liquid phase volume space velocity of 4-methyl-2-pentanol was 0.82 h-1, the reaction temperature was 345°C, and the reaction pressure was normal pressure. The conversion rate of methyl isobutyl carbinol was 85.02%, and the selectivity of 4-methyl-1-pentene was 36.47%.

[0133] (2) 4MP1 refining (first refining): the 4-methyl-1-pentene crude product was introduced into a 4MP1 refining column to perform first refining, so as to separate 4-methyl-1-pentene product at the top of the column and 4-methyl-2-pentene (4MP2) crude product at the bottom of the column. The theoretical tray number of the 4MP1 refining column was 45, the feed inlet was located at the 27th tray, the operating temperature at the top of the column was 55.1°C, and the operating pressure at the top of the column was 0.10 MPa.

[0134] ​​(3) 4MP2 refining (second refining): the 4-methyl-2-pentene (4MP2) crude product from the 4MP1 refining column is sent to the 4MP2 refining column for second refining, and the overhead product containing 4MP2 product and water and the column bottom product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone crude product are separated; the 4MP2 refining column has 68 theoretical plates, the feed inlet is located at the 39th plate, the operating temperature at the top of the column is 79.8°C, and the operating pressure at the top of the column is 0.06 MPa;

[0135] (4) hydrogenation reaction: the column bottom product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone crude product obtained from the 4MP2 refining column is mixed with hydrogen and preheated, and then introduced into a hydrogenation reactor in the presence of the hydrogenation catalyst obtained in the above Preparation Example B1, to perform hydrogenation reaction, so that the 4-methyl-2-pentanone therein is hydrogenated to form 4-methyl-2-pentanol, after cooling, the product is sent to a gas-liquid separator to perform gas-liquid separation, to obtain a gas phase component containing hydrogen and a liquid phase component containing 4-methyl-2-pentanol, and the obtained liquid phase component containing 4-methyl-2-pentanol is returned to the dehydration reactor as the raw material for dehydration reaction, and the gas phase component containing hydrogen is used as the hydrogen source for the above hydrogenation reaction. The specific conditions for the above hydrogenation reaction are as follows: the liquid phase volume space velocity of 4-methyl-2-pentanone is 1.84 h -1 , the molar ratio of hydrogen to 4-methyl-2-pentanone is 14:1, the reaction temperature is 136°C, and the reaction pressure is 1.5 MPa; wherein, the conversion rate of methyl isobutyl ketone is 99.89%, and the selectivity of methyl isobutyl carbinol is 100%. The material analysis results of each operation unit are as shown in Table 5:

[0136] Table 5

[0137]

[0138]

[0139] Example 6

[0140] (1) dehydration reaction: the stream containing 4-methyl-2-pentanol is preheated and introduced into a dehydration reactor in the presence of the dehydration catalyst obtained in the above Preparation Example A5, to perform dehydration reaction, to dehydrate 4-methyl-2-pentanol to form a stream containing 4-methyl-1-pentene (4-methyl-1-pentene (4MP1) crude product); the specific process conditions for the dehydration reaction are as follows: the liquid phase volume space velocity of 4-methyl-2-pentanol is 0.82 h -1 , the reaction temperature is 345°C, and the reaction pressure is atmospheric pressure; wherein, the conversion rate of methyl isobutyl carbinol is 85.5%, and the selectivity of 4-methyl-1-pentene is 50.29%;

[0141] (2) 4MP1 refining (first refining): the crude product of 4-methyl-1-pentene is sent to a 4MP1 refining column for first refining, and 4-methyl-1-pentene product is separated at the top of the column and 4-methyl-2-pentene (4MP2) crude product is separated at the bottom of the column; wherein the 4MP1 refining column has 55 theoretical plates, the feed inlet is located at the 32nd plate, the operating temperature at the top of the column is 55.4°C, and the operating pressure at the top of the column is 0.10 MPa;

[0142] (3) 4MP2 refining (second refining): the 4-methyl-2-pentene (4MP2) crude product at the bottom of the 4MP1 refining column is sent to a 4MP2 refining column for second refining, and the top product containing 4MP2 product and water and the bottom product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone crude product are separated; wherein the 4MP2 refining column has 70 theoretical plates, the feed inlet is located at the 41st plate, the operating temperature at the top of the column is 80.2°C, and the operating pressure at the top of the column is 0.07 MPa;

[0143] (4) hydrogenation reaction: the bottom product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone crude product obtained from the 4MP2 refining column is mixed with hydrogen and preheated, and then introduced into a hydrogenation reactor in the presence of the hydrogenation catalyst obtained in the preparation example B1, to perform hydrogenation reaction, so that 4-methyl-2-pentanone in the product is hydrogenated to form 4-methyl-2-pentanol, after cooling, the product is sent to a gas-liquid separator to perform gas-liquid separation, to obtain a gas phase component containing hydrogen and a liquid phase component containing 4-methyl-2-pentanol, and the obtained liquid phase component containing 4-methyl-2-pentanol is returned to the dehydration reactor as the raw material for dehydration reaction, and the gas phase component containing hydrogen is used as the hydrogen source for the hydrogenation reaction. The specific conditions of the hydrogenation reaction are as follows: the liquid phase volume space velocity of 4-methyl-2-pentanone is 1.5 h-1, the molar ratio of hydrogen to 4-methyl-2-pentanone is 14:1, the reaction temperature is 136°C, and the reaction pressure is 1.5 MPa. Among them, the conversion rate of methyl isobutyl ketone is 99.86%, and the selectivity of methyl isobutyl carbinol is 100%. The material analysis results of each operation unit are shown in Table 6. -1

[0144] Table 6

[0145]

[0146] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application and fall within the protection scope of the present application.​

Claims

1. A process for the preparation of 4-methyl- 1-pentene from 4-methyl-2-pentanol, characterized in that, The method comprises: dehydration of a stream containing 4-methyl-2-pentanol in the presence of a dehydration catalyst to obtain a stream containing 4-methyl-1-pentene; The dehydration catalyst contains calcium oxide and zirconium oxide, wherein the content of calcium oxide, in terms of metal elements, is 0.1-5wt% based on the total weight of the dehydration catalyst.

2. The method of claim 1, wherein, The conditions of the dehydration reaction include: the liquid phase volume space velocity of 4-methyl-2-pentanol is 0.05-1.5h -1 -1, the temperature of the dehydration reaction is 250-410℃, and the pressure of the dehydration reaction is normal pressure to 0.3MPa.

3. The method of claim 2, wherein, The conditions of the dehydration reaction include: the liquid phase volume space velocity of 4-methyl-2-pentanol is 0.2-1.0h -1 , the temperature of the dehydration reaction is 290-350℃, and the pressure of the dehydration reaction is normal pressure to 0.1MPa.

4. The method of claim 1, wherein, The method further comprises first refining the stream containing 4-methyl-1-pentene to obtain 4-methyl-1-pentene product and 4-methyl-2-pentene crude product.

5. The method of claim 4, wherein, The first refining is carried out in a first refining column, the number of theoretical plates of the first refining column is 50-60, the feed inlet of the first refining column is located in the middle-lower part of the first refining column, the operating temperature at the top of the column is 45-60℃, and the operating pressure at the top of the column is 0.01-0.2MPa.

6. The method of claim 5, wherein, The operating temperature at the top of the column is 50-55℃, and the operating pressure at the top of the column is 0.01-0.15MPa.

7. The method of any of claims 4-6, wherein, The method further comprises second refining the 4-methyl-2-pentene crude product to obtain a product rich in 4-methyl-2-pentene and a crude product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone.

8. The method of claim 7, wherein, The second refining is carried out in a second refining column, the number of theoretical plates of the second refining column is 60-80, the feed inlet of the second refining column is located in the middle-lower part of the second refining column, the operating temperature at the top of the column is 65-100℃, and the operating pressure at the top of the column is 0.01-0.2MPa.

9. The method of claim 8, wherein, The operating temperature at the top of the column is 75-90℃, and the operating pressure at the top of the column is 0.01-0.15MPa.

10. The method of claim 7, wherein, The method further comprises: hydrogenation of the crude product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone obtained by second refining after mixing with hydrogen in the presence of a hydrogenation catalyst to obtain 4-methyl-2-pentanol crude product.

11. The method of claim 10, wherein, The conditions of the hydrogenation reaction include: the liquid phase volume space velocity of 4-methyl-2-pentanone is 0.05-3.0h -1 The molar ratio of hydrogen to 4-methyl-2-pentanone is (2-30):1, the temperature of the hydrogenation reaction is 80-160℃, and the pressure of the hydrogenation reaction is normal pressure to 3.5MPa.

12. The method of claim 11, wherein, 4-methyl-2-pentanone is 0.2-2 h -1 The molar ratio of hydrogen to 4-methyl-2-pentanone is (5-15):1, the temperature of the hydrogenation reaction is 100-140℃, and the pressure of the hydrogenation reaction is 1.0-2.5 MPa.

13. The method of claim 10, wherein, The hydrogenation catalyst comprises active component Ni and carrier oxide, and the content of Ni is 10-15wt% based on the total weight of the hydrogenation catalyst. The carrier oxide is selected from at least one of alumina, silica and titania.

14. The method of claim 13, wherein, The method further comprises: gas-liquid separation of the 4-methyl-2-pentanol crude product obtained by hydrogenation to obtain a gas phase component containing hydrogen and a liquid phase component containing 4-methyl-2-pentanol, and the liquid phase component containing 4-methyl-2-pentanol is used as the raw material for the dehydration reaction.

15. The method of any one of claims 1-6, wherein, The 4-methyl-1-pentene is prepared in a system, wherein the system comprises: a dehydration reactor (1), a first refining column (2), a second refining column (3) and a hydrogenation reactor (4), wherein, The dehydration reactor (1) is used for dehydration of a stream containing 4-methyl-2-pentanol to obtain a stream containing 4-methyl-1-pentene; The first refining column (2) is connected to the dehydration reactor (1) and is used for first refining of the stream containing 4-methyl-1-pentene from the dehydration reactor (1) to obtain 4-methyl-1-pentene product and 4-methyl-2-pentene crude product; The first refining column (2) is connected to the dehydration reactor (1) and is used for first refining of the stream containing 4-methyl-1-pentene from the dehydration reactor (1) to obtain 4-methyl-1-pentene product and 4-methyl-2-pentene crude product; The second refining column (3) is connected to the first refining column (2) and is used for second refining of the 4-methyl-2-pentene crude product from the first refining column (2) to obtain a product rich in 4-methyl-2-pentene and a crude product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone; The hydrogenation reactor (4) is connected to the second refining column (3) and is used for hydrogenation reaction of the crude product containing 4-methyl-2-pentanol and 4-methyl-2-pentanone from the second refining column (3) to obtain a 4-methyl-2-pentanol crude product.

16. The method of claim 15, wherein, The system comprises a gas-liquid separator (5) connected to the dehydration reactor (1) and the hydrogenation reactor (4), which is used for gas-liquid separation of the 4-methyl-2-pentanol crude product from the hydrogenation reactor (4) and then returning the obtained liquid phase component to the dehydration reactor (1) for dehydration reaction.

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