Dehydration catalyst for preparing olefin by alcohol dehydration, method for preparing the same, and method for preparing olefin by alcohol dehydration

Abstract

The present application relates to the technical field of alcohol dehydration to prepare olefins, and discloses a dehydration catalyst for alcohol dehydration to prepare olefins, a preparation method of the dehydration catalyst and a method for alcohol dehydration to prepare olefins. The dehydration catalyst comprises a main component, an alkaline earth metal oxide and metallic cobalt, and the main component is selected from at least one of zirconium oxide, silicon oxide and aluminum oxide. The dehydration catalyst provided by the present application has proper selective hydrogenation capacity, can inhibit the generation of aldehydes or ketones and does not hydrogenate the olefins, the alcohol dehydration reaction can effectively reduce various side reactions caused by alcohol dehydrogenation, improve the reaction selectivity, reduce the impurities and types of reaction products, greatly reduce the polymers and gums generated by the condensation of aldehydes or ketones, significantly delay the carbon deposition and deactivation of the catalyst, make the catalyst have a longer service life, and reduce the material consumption and energy consumption of the reaction.

Description

Technical Field

[0001] The present invention relates to the technical field of preparing olefins by dehydrating alcohols, and in particular to a dehydration catalyst for preparing olefins by dehydrating alcohols, a preparation method thereof, and a method for preparing olefins by dehydrating alcohols. Background Art

[0002] The main methods for producing olefins include paraffin cracking, solvent extraction, ethylene oligomerization, Fischer-Tropsch synthesis, and alcohol dehydration. Paraffin cracking and solvent extraction methods have stringent operating conditions, complex reaction processes, low product purity, and numerous by-products, and have been gradually phased out. Ethylene oligomerization, however, offers a simple process and mature technology, producing high-purity, high-quality products with minimal waste, and is a method monopolized by global oil giants. Fischer-Tropsch synthesis, which uses coal as a raw material, offers low industrial costs, but product separation is costly and challenging. Alcohol dehydration offers a simple process, mild reaction conditions, high product purity, concentrated distribution, and ease of separation. It is a relatively clean production process, with low energy consumption during distillation, making it a competitive synthetic route.

[0003] Among olefins, α-olefins occupy a crucial position and are widely used. α-olefins are olefins with a terminal carbon-carbon double bond, and their general molecular formula is CH2=CH-R (R is an alkyl group). They are very important petrochemical raw materials and are widely used in various fields, such as as comonomers, intermediates, plasticizers, fungicides, emulsifiers, oil additives, and in the production of surfactants, plastics, and various fine organic chemicals.

[0004] Alcohol dehydration catalysts can be divided into two categories. One is the redox catalyst, which has many side reactions, low selectivity for the target product, and difficult product separation; the other is the acid-base bifunctional catalyst, whose surface acidic and basic sites synergistically catalyze the reactants, showing better activity, selectivity and longer service life, and has unique catalytic performance in dehydration reactions.

[0005] US20180009725A1 discloses a method for producing ethylene by vapor-phase dehydration of ethanol using a heteropolyacid catalyst supported on a composite oxide carrier. The carrier is composed of zirconium oxide and different transition metal oxides.

[0006] CN101940938A discloses a heteropolyacid-modified alumina ethanol dehydration catalyst and its preparation method. The catalyst comprises the following components, by weight: a) 0.5-30 parts of a heteropolyacid and b) 70-99.5 parts of alumina. This method primarily addresses the high cost and low ethylene yield issues of existing ethanol dehydration catalysts. However, the heteropolyacid-modified alumina ethanol dehydration catalyst is difficult to separate from the product, making catalyst recovery difficult.

[0007] CN112275315A discloses a sulfur-modified metal-supported molecular sieve catalyst, its preparation method, and its application in the preparation of isosorbide. The sulfur-modified metal-supported molecular sieve catalyst is obtained by sequentially modifying an H-type molecular sieve with a metal salt and a sulfur-containing compound. The catalyst promotes the efficient dehydration reaction of sorbitol, but the catalyst modified with sulfate ions has poor thermal stability, a short service life, is easily deactivated by carbon deposition, and SO4 2- It is easy to lose in liquid phase reactions, resulting in a decrease in catalytic activity, thus limiting its application in industrial production.

[0008] EP3233765B1 discloses a heteropolyacid catalyst supported on a mixed oxide and its use in the dehydration of ethanol to produce ethylene. The supported heteropolyacid catalyst comprises the following components: i) a mixed oxide of silicon dioxide and a transition metal oxide as a support; or ii) a mixed oxide of zirconium oxide and different transition metal oxides as a support. Compared to conventional supported heteropolyacid catalysts, this catalyst exhibits a longer catalyst life in the alcohol dehydration reaction. However, the heteropolyacid catalyst has a smaller specific surface area, which limits its catalytic activity.

[0009] CN108745422A discloses a 1,4-butanediol dehydration catalyst with tunable surface acidity and alkalinity, as well as a preparation method and application. In this method, a support selected from a zirconium oxide support is used to load the active component onto the zirconium oxide support to obtain a supported catalyst. This catalyst is used to dehydrate 1,4-butanediol to produce 3-butene-1-ol. However, the catalyst preparation process and composition are complex, resulting in relatively low 1,4-butanediol conversion and 3-butene-1-ol selectivity.

[0010] From the perspective of existing alcohol dehydration technology, the industrial application of catalytic alcohol dehydration to produce olefins still has problems such as many side reactions, severe carbon deposition and easy catalyst deactivation. Summary of the Invention

[0011] The present invention aims to overcome the problems of numerous side reactions, severe carbon deposition, and easy catalyst deactivation in the prior art catalytic alcohol dehydration technology for producing olefins. A dehydration catalyst for producing olefins by dehydrating alcohols, a preparation method thereof, and a method for producing olefins by dehydrating alcohols are provided. The dehydration catalyst introduces a small amount of metallic cobalt for the first time, and is combined with a main component and an alkaline earth metal oxide. The catalyst is applied to the dehydration reaction of producing olefins by dehydrating alcohols, has few side reactions, significantly delays carbon deposition and deactivation of the catalyst, and thus has a longer catalyst life.

[0012] The inventors of the present invention have found in the process of studying the production of olefins by dehydration of alcohols that, in addition to olefins, the reaction product also contains corresponding aldehydes or ketones generated by dehydrogenation of alcohols. On the one hand, the condensation of aldehydes or ketones will cause the dehydration catalyst to deactivate, and on the other hand, it will increase the difficulty of separation and energy consumption. In the process of dehydration of alcohols to produce olefins, it is generally believed that introducing a component with hydrogenation ability into the dehydration catalyst will cause the olefins to be hydrogenated to produce alkanes, thereby reducing the selectivity and yield of the product. If the hydrogenation ability of the catalyst is stronger, it will indeed cause the olefins to be hydrogenated to produce alkanes, but the inventors of the present invention have found that appropriate selective hydrogenation ability can suppress the generation of aldehydes or ketones without hydrogenating olefins. The present invention, by introducing metallic cobalt into the dehydration catalyst and coordinating the main component and alkaline earth metal oxide, can significantly reduce side reactions and significantly slow down carbon deposition.

[0013] In order to achieve the above objectives, the first aspect of the present invention provides a dehydration catalyst for dehydrating alcohols to prepare olefins, wherein the dehydration catalyst comprises a main component, an alkaline earth metal oxide and metallic cobalt, and the main component is selected from at least one of zirconium oxide, silicon oxide and aluminum oxide.

[0014] The second aspect of the present invention provides a method for preparing the dehydration catalyst described in the first aspect, the method comprising:

[0015] (1) providing a solution containing a main component precursor, an alkaline earth metal precursor, and a cobalt source, and then precipitating the solution with a precipitant to obtain a precipitated product;

[0016] (2) calcining the precipitated product to obtain a calcined product;

[0017] (3) heat-treating the calcined product in a reducing atmosphere;

[0018] Wherein, the main component matrix is ​​selected from at least one of a zirconium source, a silicon source and an aluminum source.

[0019] A third aspect of the present invention provides a method for preparing olefins by dehydrating alcohol, the method comprising: contacting alcohol with the dehydration catalyst described in the first aspect to carry out a dehydration reaction.

[0020] By the above technical solution, the dehydration catalyst provided by the present invention has an appropriate selective hydrogenation ability. When the alcohol dehydration reaction is carried out, the alcohol undergoes a dehydrogenation reaction to form an aldehyde or ketone and produces hydrogen. In the absence of additional hydrogen, this part of hydrogen causes the aldehyde or ketone to be hydrogenated to form an alcohol under the selective hydrogenation of the dehydration catalyst, thereby suppressing the generation of the aldehyde or ketone. In the presence of external hydrogen, the generation of the aldehyde or ketone can be further suppressed. In addition, the metallic cobalt contained in the dehydration catalyst as an effective component can suppress the generation of the aldehyde or ketone while not hydrogenating the olefin. The cobalt is combined with the main component and alkaline earth metal oxide in the dehydration catalyst to effectively reduce the various side reactions caused by the alcohol dehydrogenation, improve the reaction selectivity, reduce the impurities and types of the reaction products, and also significantly reduce the polymers and colloids produced by the condensation of the aldehyde or ketone, significantly delaying the carbon deposition deactivation of the catalyst, so that the catalyst has a longer life, and the material consumption and energy consumption of the reaction are reduced. DETAILED DESCRIPTION

[0021] The endpoints of the ranges and any values ​​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 endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0022] The term "optional" as used herein means that a certain component may be contained or not contained, or a certain operation may be performed or not performed.

[0023] A first aspect of the present invention provides a dehydration catalyst for dehydrating alcohol to prepare olefins. The dehydration catalyst comprises a main component, an alkaline earth metal oxide, and metallic cobalt. The main component is selected from at least one of zirconium oxide, silicon oxide, and aluminum oxide.

[0024] The inventors of the present invention, while studying the process of producing olefins by dehydrating alcohols, observed through extensive experiments that dehydrogenation reactions also occur during the alcohol dehydration reaction to produce aldehydes or ketones. On the one hand, the condensation of aldehydes or ketones will cause the dehydration catalyst to deactivate, and on the other hand, it will increase the difficulty of separation and energy consumption. The inventors of the present invention unexpectedly discovered that by introducing metallic cobalt rather than cobalt oxide into the dehydration catalyst, the dehydration catalyst can be given an appropriate selective hydrogenation ability, significantly inhibiting the dehydrogenation reaction. While suppressing the production of aldehydes or ketones, it does not hydrogenate olefins. The combination of the main component and alkaline earth metal oxide in the dehydration catalyst can significantly slow carbon deposition and improve the stability of the catalyst. In addition, the prior art has not yet recorded the introduction of metallic cobalt into the dehydration catalyst for producing olefins by dehydrating alcohols. In the alcohol dehydration reaction, alcohol dehydrogenation produces aldehydes or ketones, which are hydrogenated into alcohols under the action of metallic cobalt, thereby suppressing the production of aldehydes or ketones.

[0025] According to some embodiments of the present invention, the dehydration catalyst includes a main component selected from at least one of zirconium oxide, silicon oxide, and aluminum oxide.

[0026] According to some embodiments of the present invention, the dehydration catalyst further comprises an alkaline earth metal oxide; in order to improve the selectivity of secondary alcohol to α-olefin, preferably, the alkaline earth metal oxide is selected from at least one of magnesium oxide, calcium oxide, strontium oxide and barium oxide.

[0027] According to some embodiments of the present invention, preferably, relative to 100 parts by weight of the main component, the content of the alkaline earth metal oxide is 0.1-10 parts by weight, for example, it can be 0.1 parts by weight, 0.2 parts by weight, 0.5 parts by weight, 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, or any value in the range formed by any two of the above values, preferably 0.2-8 parts by weight.

[0028] According to some embodiments of the present invention, the dehydration catalyst further comprises metallic cobalt. Typically, existing dehydration catalyst components are all oxides, and no catalyst using metallic components, especially metallic components with hydrogenation capabilities, has been found. The inventors of the present invention creatively introduced metallic cobalt into the dehydration catalyst, which enables the dehydration catalyst to have a certain selective hydrogenation capability to suppress the generation of aldehydes or ketones while not hydrogenating olefins. Experiments have shown that metallic cobalt has a higher selectivity for carbonyl hydrogenation than for carbon-carbon double bond hydrogenation, while metallic nickel or copper has an opposite hydrogenation selectivity. Therefore, in order to enable the dehydration catalyst to have a certain selective hydrogenation capability while suppressing the generation of aldehydes or ketones while not hydrogenating olefins, the dehydration catalyst further comprises metallic cobalt. More preferably, the dehydration catalyst does not include nickel and copper.

[0029] According to some embodiments of the present invention, preferably, relative to the main component of 100 weight parts, the content of cobalt is 0.01-0.1 weight part, for example, it can be 0.01 weight part, 0.015 weight part, 0.02 weight part, 0.025 weight part, 0.03 weight part, 0.035 weight part, 0.04 weight part, 0.045 weight part, 0.05 weight part, 0.06 weight part, 0.07 weight part, 0.08 weight part, 0.09 weight part, 0.1 weight part, or any value in the scope of any two numerical values, preferably 0.01-0.035 weight part, more preferably 0.015-0.035 weight part. Adopting the above-mentioned preferred embodiment is conducive to further suppressing aldehyde or ketone generation, prevents aldol condensation from causing polymer to produce, and avoids olefin hydrogenation to generate alkane simultaneously. Metallic cobalt content is too low, and hydrogenation ability is too weak, and content is too high, then hydrogenation ability is too strong, causes olefin hydrogenation.

[0030] According to some embodiments of the present invention, in order to further improve the performance of the catalyst, preferably, the dehydration catalyst further includes a modifier; more preferably, the modifier is selected from at least one of lanthanum oxide, potassium oxide, cerium oxide and zinc oxide.

[0031] According to some embodiments of the present invention, preferably, relative to 100 parts by weight of the main component, the content of the modifier is 0.1-6 parts by weight, for example, it can be 0.1 parts by weight, 0.2 parts by weight, 0.5 parts by weight, 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, or any value in the range formed by any two of the above values, preferably 0.2-4 parts by weight.

[0032] According to a preferred embodiment of the present invention, the dehydration catalyst comprises a main component, an alkaline earth metal oxide, and metallic cobalt; wherein the main component is selected from at least one of zirconium oxide, silicon oxide, and aluminum oxide; the alkaline earth metal oxide is selected from at least one of magnesium oxide, calcium oxide, strontium oxide, and barium oxide; the alkaline earth metal oxide is present in an amount of 0.1-10 parts by weight relative to 100 parts by weight of the main component; and the cobalt content is 0.01-0.1 parts by weight. This preferred embodiment advantageously inhibits the formation of aldehydes or ketones, prevents polymer formation caused by aldol condensation, and avoids olefin hydrogenation.

[0033] According to a preferred embodiment of the present invention, the dehydration catalyst includes a main component, an alkaline earth metal oxide, metallic cobalt and a modifier, so that the dehydration catalyst has appropriate selective hydrogenation ability, suppressing the formation of aldehydes or ketones while not hydrogenating olefins. In addition, the main component and metallic cobalt in the dehydration catalyst are combined with the alkaline earth metal oxide and the modifier, so that acidic sites and basic sites are simultaneously present on the surface of the dehydration catalyst, and the acidic sites and basic sites can play a synergistic role in catalyzing the alcohol dehydration reaction; on the one hand, the simultaneous presence of the alkaline earth metal oxide and the modifier can better maintain the number of acidic sites on the surface of the main component while improving the alkalinity of the dehydration catalyst, so that more acid-base synergistic active centers are generated on the catalyst surface, which is conducive to the formation of α-olefins and inhibits the formation of β-olefins, thereby improving the selectivity of α-olefins; on the other hand, controlling the acidic groups and basic groups on the surface of the dehydration catalyst within a certain range can improve the adsorption-desorption performance of the catalyst, thereby promoting the diffusion of the reaction system, accelerating the reaction rate, reducing carbon deposition, and slowing down pore blockage.

[0034] According to a preferred embodiment of the present invention, the dehydration catalyst comprises a main component, an alkaline earth metal oxide, metallic cobalt, and a modifier; wherein the main component is selected from at least one of zirconium oxide, silicon oxide, and aluminum oxide; the alkaline earth metal oxide is selected from at least one of magnesium oxide, calcium oxide, strontium oxide, and barium oxide; and the modifier is selected from at least one of lanthanum oxide, potassium oxide, cerium oxide, and zinc oxide. With respect to 100 parts by weight of the main component, the alkaline earth metal oxide is present in an amount of 0.1-10 parts by weight; the cobalt content is 0.01-0.1 parts by weight; and the modifier content is 0.1-6 parts by weight. Adoption of this preferred embodiment facilitates the production of more α-olefins and further reduces carbon deposits.

[0035] According to some embodiments of the present invention, in order to further optimize the selectivity and service life of the dehydration catalyst for α-olefins, preferably, the ammonia adsorption capacity of the dehydration catalyst is 0.15-0.4 mmol·g -1 , preferably 0.18-0.28 mmol·g -1 .

[0036] According to some embodiments of the present invention, in order to further optimize the selectivity and service life of the dehydration catalyst for α-olefins, preferably, the carbon dioxide adsorption capacity of the dehydration catalyst is 0.16-0.4 mmol·g -1 , preferably 0.18-0.35mmol·g -1 .

[0037] According to some embodiments of the present invention, in order to further improve the catalytic performance of the dehydration catalyst, preferably, the specific surface area of ​​the dehydration catalyst is 40-150m 2 ·g -1 , preferably 50-130m 2 ·g -1 ;

[0038] According to some embodiments of the present invention, in order to further improve the catalytic performance of the dehydration catalyst, preferably, the pore volume of the dehydration catalyst is 0.05-0.2 mL·g -1 , preferably 0.1-0.2 mL·g -1 .

[0039] According to some embodiments of the present invention, there is no particular limitation on the introduction mode of the alkaline earth metal oxide, the metallic cobalt and the modifier, and the alkaline earth metal oxide, the metallic cobalt and the modifier can be loaded on the main component or can be dispersed in the main component. In order to better bring into play the effect of alkaline earth metal oxide, the metallic cobalt and the modifier, improve the stability and selectivity of the catalyst, preferably, at least one of the alkaline earth metal oxide, the metallic cobalt and the modifier is introduced in the preparation process of the main component. The preparation process generally refers to the process of precipitating the main component matrix to generate a precipitated product, such as using zirconyl nitrate as the process of synthesizing basic zirconium carbonate as raw material, the process of synthesizing pseudo-boehmite (i.e. hydrated aluminum oxide, hydrated aluminum hydroxide) with carbon dioxide, etc. by aluminum nitrate.

[0040] According to some embodiments of the present invention, the dehydration catalyst can be prepared using an existing method that can obtain an ammonia adsorption amount and a carbon dioxide adsorption amount that meet the above ranges, and obtaining a dehydration catalyst with an ammonia adsorption amount and a carbon dioxide adsorption amount that meet the above ranges can be implemented by those skilled in the art.

[0041] The second aspect of the present invention provides a method for preparing the dehydration catalyst described in the first aspect, the method comprising:

[0042] (1) providing a solution containing a main component precursor, an alkaline earth metal precursor, and a cobalt source, and then precipitating the solution with a precipitant to obtain a precipitated product;

[0043] (2) calcining the precipitated product to obtain a calcined product;

[0044] (3) heat-treating the calcined product in a reducing atmosphere;

[0045] Wherein, the main component matrix is ​​selected from at least one of a zirconium source, a silicon source and an aluminum source.

[0046] According to some embodiments of the present invention, in the method, those skilled in the art will understand that: if the raw material providing the main component matrix already contains the required amount of alkaline earth metal elements, cobalt elements and modifier metal elements, then only such raw material needs to be used for molding; if the raw material providing the main component matrix does not contain alkaline earth metal elements, cobalt elements and modifier metal elements or the content of the elements is low (insufficient), then additional alkaline earth metal elements, cobalt elements and modifier metal elements can be introduced.

[0047] According to some embodiments of the present invention, preferably, the zirconium source is selected from at least one of zirconium oxychloride, zirconium nitrate, zirconyl nitrate and zirconyl sulfate.

[0048] According to some embodiments of the present invention, preferably, the silicon source is selected from tetraethyl orthosilicate and / or silica sol.

[0049] According to some embodiments of the present invention, preferably, the aluminum source is selected from at least one of sodium metaaluminate, aluminum nitrate, aluminum sulfate and aluminum isopropoxide.

[0050] According to some embodiments of the present invention, the precipitant is preferably selected from at least one of carbon dioxide, nitric acid, ammonia, urea, sodium carbonate, sodium bicarbonate, ammonium carbonate, and ammonium bicarbonate. When carbon dioxide is the precipitant, it is preferably provided in the form of a mixed gas; more preferably, the concentration of carbon dioxide in the mixed gas is 20-30 mol%. When the precipitant is selected from at least one of nitric acid, ammonia, urea, sodium carbonate, sodium bicarbonate, ammonium carbonate, and ammonium bicarbonate, it may be provided in the form of an aqueous solution; more preferably, the concentration of the precipitant in the aqueous solution is 20-30 wt%. When synthesizing the main component precursor, the pH value at the synthesis endpoint can be controlled within a normal range. For example, when synthesizing the alumina precursor pseudo-boehmite, the pH value is controlled to be 10-10.5.

[0051] According to some embodiments of the present invention, the solution contains a main component precursor, an alkaline earth metal precursor and a cobalt source; preferably, the solvent in the solution is selected from water and / or ethanol, more preferably water.

[0052] According to some embodiments of the present invention, the alkaline earth metal precursor is preferably selected from an alkaline earth metal salt, preferably selected from at least one of alkaline earth metal nitrates, alkaline earth metal formates, alkaline earth metal oxalates, and alkaline earth metal lactates; more preferably, the alkaline earth metal salt is selected from at least one of magnesium nitrate, calcium nitrate, strontium nitrate, and barium nitrate. Further preferably, the alkaline earth metal precursor can be provided in the form of an alkaline earth metal salt solution. The solvent in the solution is selected from water and / or ethanol, preferably water.

[0053] According to some embodiments of the present invention, preferably, the cobalt source can be selected from a wide range of types, without particular limitation. For example, the cobalt source can be a soluble cobalt salt conventionally used in the art, preferably selected from at least one of cobalt nitrate, cobalt acetate, cobalt formate, basic cobalt carbonate, cobalt citrate, cobalt chloride, cobalt sulfate, and cobalt phosphate.

[0054] According to some embodiments of the present invention, preferably, the solution further contains a modifier precursor.

[0055] According to some embodiments of the present invention, preferably, the modifying agent precursor is selected from at least one of lanthanum nitrate, potassium hydroxide, potassium nitrate, potassium carbonate, cerium nitrate, and zinc nitrate. More preferably, the modifying agent precursor can be provided in the form of a metal salt solution. The solvent in the solution is selected from water and / or ethanol, preferably water.

[0056] According to some embodiments of the present invention, there is no special limitation on the order of adding the alkaline earth metal matrix, cobalt source and modifier matrix. The alkaline earth metal matrix, cobalt source and modifier matrix can be mixed and added to the system containing the main component matrix, or the alkaline earth metal matrix, cobalt source and modifier matrix can be added separately to the system containing the main component matrix.

[0057] According to some embodiments of the present invention, preferably, the precipitation is carried out under stirring. Preferably, the precipitation temperature is 5-80°C, for example, 5°C, 8°C, 10°C, 12°C, 15°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, or any value within a range formed by any two of the foregoing values.

[0058] According to some embodiments of the present invention, preferably, step (1) further comprises the step of aging the precipitated product. Aging generally refers to a process of continuously stirring the precipitated product for a period of time at a temperature slightly higher than the precipitation temperature (e.g., 5-20°C higher than the precipitation temperature) or allowing the precipitated product to stand at a constant temperature for a period of time.

[0059] According to some embodiments of the present invention, preferably, the aging conditions include: a temperature of 30-90° C., preferably 50-90° C.; and a time of 10-120 min, preferably 20-120 min.

[0060] According to some embodiments of the present invention, preferably, the method further comprises the steps of washing and drying the precipitated product, wherein the washing is generally performed with deionized water to wash the precipitated product until it is neutral; the drying time can be reasonably selected according to the drying temperature, the amount of material and the type of drying equipment. Under preferred conditions, the drying is performed at 70-150°C for 2-20 hours.

[0061] According to some embodiments of the present invention, the method preferably further comprises the step of shaping the dried product. The shaping can be performed by conventional methods such as ball rolling, kneading and extruding to process the dried product into a certain shape, such as a bar or a sphere.

[0062] According to some embodiments of the present invention, calcination generally refers to the process of removing water of crystallization at high temperature, often accompanied by crystal transformation and decomposition to form oxides. Preferably, the calcination conditions include: a temperature of 400-800°C, preferably 450-650°C; a time of 1-20 hours, preferably 2-10 hours; and a heating rate of 1-5°C / min, preferably 1.5-5°C / min.

[0063] According to some embodiments of the present invention, in step (3), the calcined product is subjected to a heat treatment in a reducing atmosphere to at least partially reduce the cobalt oxide in the calcined product to metallic cobalt.

[0064] According to some embodiments of the present invention, preferably, the reducing atmosphere is provided by a reducing gas containing hydrogen and optionally an inert gas (such as nitrogen and / or argon); more preferably, the content of hydrogen in the reducing gas is 10-30 vol%.

[0065] According to some embodiments of the present invention, when performing the heat treatment, the temperature of the heat treatment is gradually increased, and the temperature increase should not be too fast, for example, the heating rate does not exceed 20°C / hour. The heat treatment time can be determined by monitoring the production of H2O in the reduction system. That is, when the reduction system no longer produces new H2O, the heat treatment is terminated. Those skilled in the art can select the heat treatment time accordingly. Preferably, the heat treatment temperature is 100-450°C, preferably 200-450°C; the time is 1-24 hours, preferably 2-8 hours.

[0066] A third aspect of the present invention provides a method for preparing olefins by dehydrating alcohol, the method comprising: contacting alcohol with the dehydration catalyst described in the first aspect to carry out a dehydration reaction.

[0067] According to some embodiments of the present invention, preferably, the conditions of the dehydration reaction include: a reaction temperature of 240-370°C, for example, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, or any value in the range consisting of any two of the above values, preferably 260-330°C; and / or a reaction pressure of 0.085-0.3 MPa, for example, 0.085 MPa, 0.09 MPa, 0.1 MPa, 0.15 MPa, 0.2 MPa, 0.25 MPa, 0.3 MPa, or any value in the range consisting of any two of the above values, preferably 0.1-0.2 MPa; and / or a liquid phase volume space velocity of the alcohol of 0.1-1.2 h -1 , for example, it can be 0.1h -1 , 0.2h -1 , 0.3h -1 , 0.4h -1 , 0.5h -1 , 0.6h -1 , 0.7h -1 , 0.8h -1 , 0.9h -1 , 1h -1 , 1.1h -1, 1.2h -1 , or any value in the range of any two of the above values, preferably 0.2-1h -1 The above preferred embodiment is beneficial for improving olefin selectivity, reducing the amount of aldehyde or ketone generated, and reducing carbon deposits. Excessively high reaction temperatures can easily generate aldehydes or ketones or initiate olefin polymerization. Excessively low alcohol liquid phase volumetric space velocity can prolong the material's residence time in the catalyst bed, easily initiating olefin polymerization.

[0068] According to some embodiments of the present invention, alcohols can generally be dehydrated to produce olefins, such as primary alcohols, secondary alcohols, and tertiary alcohols. The dehydration catalyst can be used for the dehydration of various alcohols to produce olefins, which can achieve the purpose of the present invention to a certain extent.

[0069] According to some embodiments of the present invention, preferably, the alcohol is selected from alcohols having 2-18 carbon atoms, for example, alcohols having 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 carbon atoms, or any value in the range formed by any two of the above values. From the perspective of olefin use, primary alcohols having 2-18 carbon atoms and / or secondary alcohols having 3-18 carbon atoms are preferred; more preferably, the hydroxyl group of the secondary alcohol is located on the second carbon atom of the carbon chain.

[0070] According to some embodiments of the present invention, preferably, the alcohol is selected from at least one of ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, 2-propanol, 2-butanol, 2-pentanol, 2-hexanol, 2-heptanol, 2-octanol, 4-methyl-2-pentanol, 2-ethyl-1-hexanol, 2-propyl-1-heptanol and 1,4-butanediol.

[0071] According to some embodiments of the present invention, preferably, the olefin is an α-olefin.

[0072] According to some embodiments of the present invention, when a secondary alcohol in which the hydroxyl group is located on the second carbon atom of the carbon chain undergoes a dehydration reaction, the dehydration of such secondary alcohol can produce α-olefins and β-olefins, and at the same time, the dehydrogenation can also produce the corresponding ketones. When the dehydration catalyst provided by the present invention is used in the dehydration reaction of such secondary alcohols, it is beneficial to inhibit the formation of ketones and further improve the selectivity of α-olefins.

[0073] According to a preferred embodiment of the present invention, the dehydration catalyst is particularly suitable for the dehydration of methyl isobutyl carbinol (MIBC) to produce 4-methyl-1-pentene. It has higher selectivity for the target product and significantly delays the carbon deposition and deactivation of the catalyst, so that the catalyst exhibits a longer service life.

[0074] In the present invention, normal pressure refers to 1 standard atmosphere.

[0075] In the present invention, the pressures mentioned are all absolute pressures.

[0076] The present invention will be described in detail below through examples.

[0077] In the following examples, the specific surface area and pore volume of the catalysts were measured by the nitrogen adsorption-desorption method (BET). The test conditions were: experimental gas: N2 (purity 99.999%); degassing conditions: 10°C·min -1 The temperature was raised to 350°C and vacuumed for 4 h. Instrument name: Automatic Micropore & Chemisorption Analyzer; Instrument model: ASAP 2420, MICROMERITICS (USA);

[0078] The acidic sites (ammonia adsorption capacity) of the catalyst were obtained by NH3-TPD test. The test method is as follows: accurately weigh about 0.1g of sample and put it into the sample tube. -1 Raise to 600℃, stay for 1h, then reduce to 120℃, change the gas to 10% NH3-He mixed gas, adsorb for 60min, then change to He gas purge for 1h, start counting after the baseline is stable, and calculate at 10℃·min -1 The temperature was raised to 600°C and maintained for 30 minutes. The recording was stopped, and the experiment was completed. The peak area was integrated to calculate the NH3 desorption amount (acidic sites of the catalyst). The testing instrument was an Automated Catalyst Characterization System (Autochem 2920, manufactured by MICROMERITICS, USA).

[0079] The basicity of the catalyst (CO2 adsorption capacity) was tested by CO2-TPD. The test conditions were as follows: accurately weigh about 0.1g of sample into a sample tube, and then measure the sample at 10℃·min under He gas purge. -1 Raise to 600℃, stay for 1h, then reduce to 120℃, change the gas to 10% CO2-He mixture, adsorb for 60min, then change to He purge for 1h, start counting after the baseline is stable, and calculate at 10℃·min -1 The temperature was raised to 600°C and maintained for 30 minutes. The recording was stopped, completing the experiment. The peak area was integrated to calculate the CO2 desorption amount (catalyst basicity). The instrument used was an Automated Catalyst Characterization System (Autochem 2920, manufactured by MICROMERITICS, USA).

[0080] The elemental compositions of the main components and catalysts were analyzed by plasma emission spectrometry.

[0081] The carbon deposits on the catalyst were measured using an O2-TPO test. The test conditions were as follows: 0.2 g of sample was accurately weighed, and argon was used as the carrier gas at a flow rate of 40 mL / min. The sample was pretreated at 150°C for 60 minutes, then cooled to 100°C. A mixture of oxygen and argon (20% oxygen by volume) was used as the analytical gas at a flow rate of 40 mL / min. The sample was then subjected to a temperature-programmed oxidation process at a rate of 10°C / min to 900°C. The CO2 and CO gas signals were detected during the temperature-programmed oxidation process. The test instrument was a fully automatic temperature-programmed chemical adsorption instrument (AutoChem II 2920, manufactured by Micromeritics, USA).

[0082] Examples 1-5 are used to illustrate the dehydration catalyst and its preparation method of the present invention

[0083] Example 1

[0084] 400 g of sodium aluminate, 9.5 g of calcium nitrate tetrahydrate and 0.2 g of cobalt nitrate hexahydrate were weighed and dissolved in 3 L of deionized water to prepare a mixed solution; carbon dioxide gas (i.e., a mixture of CO2 and N2 containing 25 mol% CO2) was introduced into the mixed solution under stirring in a 12°C water bath to adjust the pH to 10.5, and the pH was maintained for 20 minutes after the introduction of carbon dioxide gas was stopped; the obtained precipitate was then filtered to obtain a precipitate product; the precipitate was washed with deionized water to a pH of 7.0, dried at 80°C for 8 h, and then dried at 120°C for 4 h; the dried powder was formed using a kneader and an extruder, and placed in a muffle furnace at 5°C·min -1 The temperature was raised to 650°C at a rate of 0.5°C and calcined at this temperature for 3 h. The catalyst was reduced with hydrogen at 440°C for 2 h to obtain dehydration catalyst C-1. The test results are shown in Table 1.

[0085] Example 2

[0086] 375 g of zirconium oxynitrate, 9.5 g of calcium nitrate tetrahydrate, and 0.1 g of cobalt nitrate were weighed and dissolved in 3 L of deionized water to prepare a mixed solution; an ammonia solution (25 wt%) was added dropwise to the mixed solution in a 60° C. water bath with stirring to adjust the pH to 7.2, and then maintained for 30 minutes; centrifugation was performed to obtain a precipitated product; the precipitated product was washed with deionized water to a pH of 6.8, and the filter cake was dried at 120° C. for 3 h; and the dried product was precipitated in a muffle furnace at 2° C. min -1The temperature was raised to 550°C and calcined at this temperature for 4 h. The catalyst was reduced with hydrogen at 400°C for 3 h to obtain dehydration catalyst C-2. The test results are shown in Table 1.

[0087] Example 3

[0088] 800 g of zirconium oxynitrate, 40 g of calcium nitrate tetrahydrate, and 0.3 g of cobalt nitrate were weighed and dissolved in 6 L of deionized water to prepare a mixed solution; sodium carbonate solution (25 wt %) was added dropwise to the mixed solution in a 60° C. water bath with stirring to adjust the pH to 7.0, and then maintained for 40 minutes; centrifugation was performed to obtain a precipitated product; the precipitated product was washed with deionized water to a pH of 7.0, and the filter cake was dried at 120° C. for 3 h; and the dried product was precipitated in a muffle furnace at 1.5° C. min -1 The temperature was raised to 580°C at a rate of 1000 ℃ and calcined at this temperature for 4 h. The catalyst was reduced with hydrogen at 420°C for 3 h to obtain dehydration catalyst C-3. The test results are shown in Table 1.

[0089] Example 4

[0090] 860 g of zirconium oxynitrate, 60 g of calcium nitrate tetrahydrate, 0.4 g of cobalt nitrate and 18.3 g of lanthanum nitrate hexahydrate were weighed and dissolved in 6 L of deionized water to prepare a mixed solution; sodium carbonate solution (25 wt %) was added dropwise to the mixed solution in a 60 ° C water bath with stirring, and the pH was adjusted to 7.0, and then maintained for 40 minutes; centrifugation was performed to obtain a precipitated product; the precipitated product was washed with deionized water to pH = 7.0, and the filter cake was dried at 120 ° C for 3 h; finally, the dried product was precipitated in a muffle furnace at 1.5 ° C·min -1 The catalyst was heated to 580°C at a heating rate and calcined at this temperature for 4 hours. It was reduced with a mixture of hydrogen and nitrogen containing 20 vol% hydrogen at 420°C for 3 hours to obtain dehydration catalyst C-4. The test results are shown in Table 1.

[0091] Example 5

[0092] 800 g of zirconium oxynitrate, 6 g of calcium nitrate tetrahydrate, 0.2 g of cobalt nitrate and 5.67 g of lanthanum nitrate hexahydrate were weighed and dissolved in 6 L of deionized water to prepare a mixed solution; sodium carbonate solution (25 wt %) was added dropwise to the mixed solution in a 60 ° C water bath with stirring, and the pH was adjusted to 7.0, and then maintained for 40 minutes; centrifugation was performed to obtain a precipitated product; the precipitated product was washed with deionized water to pH = 7.0, and the filter cake was dried at 120 ° C for 3 h; finally, the dried product was precipitated in a muffle furnace at 1.5 ° C·min -1The catalyst was heated to 580°C at a heating rate and calcined at this temperature for 4 hours. The catalyst was reduced with a mixture of hydrogen and nitrogen containing 20 vol% hydrogen at 420°C for 3 hours to obtain dehydration catalyst C-5. The test results are shown in Table 1.

[0093] Example 6

[0094] 800 g of zirconium oxynitrate, 6 g of calcium nitrate tetrahydrate, 1.26 g of cobalt nitrate and 5.67 g of lanthanum nitrate hexahydrate were weighed and dissolved in 6 L of deionized water to prepare a mixed solution; sodium carbonate solution (25 wt %) was added dropwise to the mixed solution in a 60 ° C water bath with stirring, and the pH was adjusted to 7.0, and then maintained for 40 minutes; centrifugation was performed to obtain a precipitated product; the precipitated product was washed with deionized water to pH = 7.0, and the filter cake was dried at 120 ° C for 3 h; finally, the dried product was precipitated in a muffle furnace at 1.5 ° C·min -1 The catalyst was heated to 580°C at a heating rate and calcined at this temperature for 4 hours. It was reduced with a mixture of hydrogen and nitrogen containing 20 vol% hydrogen at 420°C for 3 hours to obtain dehydration catalyst C-6. The test results are shown in Table 1.

[0095] Comparative Example 1

[0096] 500 g of zirconium oxynitrate was weighed and dissolved in 3 L of deionized water to prepare a solution; an ammonia solution (20 wt%) was added dropwise to the solution in a 50 ° C water bath with stirring until the pH reached 10.0, and the resulting mixture was allowed to stand at 60 ° C for 2.0 h, and then centrifuged to obtain a precipitated product; the precipitated product was then washed with deionized water to a pH of 6.8, the filter cake was dried at 120 ° C for 2 h, and the dried product was precipitated in a muffle furnace at 5 ° C min -1 The heating rate was raised to 550°C and calcined at this temperature for 2 hours to obtain dehydration catalyst D-1. The test results are shown in Table 1.

[0097] Table 1

[0098]

[0099] Note: * Alkaline earth refers to alkaline earth metal oxides

[0100] Test Examples 1-5 are used to illustrate the method of preparing olefins by dehydrating alcohols of the present invention, specifically, to prepare 4-methyl-1-pentene by dehydrating methyl isobutyl carbinol (4-methyl-2-pentanol, abbreviated as MIBC) as a raw material.

[0101] 50 mL of each of the dehydration catalysts C-1 to C-6 prepared in Examples 1-6 was placed in a fixed-bed reactor and preheated with nitrogen at 200°C for 1 h. Methyl isobutyl carbinol (MIBC) was then fed into the upper end of the reactor using a metering pump for dehydration reaction. The liquid phase volumetric space velocity of MIBC was 0.25 h-1. -1 The reaction temperature was 290°C and the reaction pressure was normal pressure. When the reaction was stable (i.e., after 100 hours of reaction), the reaction liquid was sampled and analyzed. The analysis results are listed in Table 2.

[0102] The sampling and analysis method is gas chromatography, which is calibrated by preparing correction factors of standard samples;

[0103] The conversion rate and selectivity were calculated based on the molar content of each component in the reaction solution (4-methyl-1-pentene is abbreviated as 4MP1, 4-methyl-2-pentene is abbreviated as 4MP2, 4-methyl-2-pentanone is abbreviated as MIBK, and 2-methylpentane is abbreviated as HA). The amount of carbon deposits was not taken into account when calculating the conversion rate and selectivity. In Table 2, the selectivity of the oligomer is the remainder.

[0104] MIBC conversion rate = 100% - n1 / [(n1+n2+n3+n4+n5)+2×n6]×100%

[0105] 4MP1 selectivity = n2 / [(n2+n3+n4+n5)+2×n6]×100%

[0106] 4MP2 selectivity = n3 / [(n2+n3+n4+n5)+2×n6]×100%

[0107] MIBK selectivity = n4 / [(n2+n3+n4+n5)+2×n6]×100%

[0108] HA selectivity = n5 / [(n2+n3+n4+n5)+2×n6]×100%

[0109] Wherein, n1 is the molar content of MIBC in the reaction solution; n2 is the molar content of 4MP1 in the reaction solution; n3 is the molar content of 4MP2 in the reaction solution; n4 is the molar content of MIBK in the reaction solution; n5 is the molar content of HA in the reaction solution; and n6 is the molar content of oligomers (calculated as dimers of 4-methylpentene) in the reaction solution.

[0110] Comparative test example

[0111] The method of Test Example 1 was followed, except that the dehydration catalyst C-1 was replaced with the dehydration catalyst D-1 prepared in Comparative Example 1. The rest was the same as in Test Example 1. The reaction solution was sampled and analyzed, and the analysis results are listed in Table 2.

[0112] Table 2

[0113]

[0114] Note: ** Carbon deposit refers to the amount of carbon deposit after 600 hours of continuous reaction

[0115] The above results show that, after 600 hours of continuous reaction, the carbon deposits in Examples 1-6 were all below 4.5 wt%, while the carbon deposit in Comparative Example 1 was 5.8 wt%. This demonstrates that the method provided by the present invention for dehydrating alcohols to olefins achieves higher selectivity for the target product and significantly delays catalyst deactivation due to carbon deposition, resulting in a longer catalyst life. Furthermore, the cobalt content in the dehydration catalyst prepared in Example 6 exceeds the preferred range. While this reduces ketone formation, it also results in the hydrogenation of some olefins to alkanes.

[0116] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A dehydration catalyst for dehydrating alcohols to produce olefins, characterized in that: The dehydration catalyst comprises a main component, an alkaline earth metal oxide and metallic cobalt, wherein the main component is selected from at least one of zirconium oxide, silicon oxide and aluminum oxide; The content of the alkaline earth metal oxide is 0.1-10 parts by weight relative to 100 parts by weight of the main component; The content of cobalt is 0.01 to 0.1 parts by weight relative to 100 parts by weight of the main component.

2. The dehydration catalyst according to claim 1, wherein The alkaline earth metal oxide is selected from at least one of magnesium oxide, calcium oxide, strontium oxide and barium oxide.

3. The dehydration catalyst according to claim 1, wherein The content of the alkaline earth metal oxide is 0.2-8 parts by weight relative to 100 parts by weight of the main component.

4. The dehydration catalyst according to claim 1, wherein The content of cobalt is 0.01 to 0.035 parts by weight relative to 100 parts by weight of the main component.

5. The dehydration catalyst according to claim 4, wherein The content of cobalt is 0.015 to 0.035 parts by weight relative to 100 parts by weight of the main component. The dehydration catalyst according to claim 1 , wherein The dehydration catalyst also includes a modifier.

7. The dehydration catalyst according to claim 6, wherein The modifier is selected from at least one of lanthanum oxide, potassium oxide, cerium oxide and zinc oxide.

8. The dehydration catalyst according to claim 6, wherein The content of the modifier is 0.1-6 parts by weight relative to 100 parts by weight of the main component.

9. The dehydration catalyst according to claim 8, wherein The content of the modifier is 0.2-4 parts by weight relative to 100 parts by weight of the main component.

10. The dehydration catalyst according to claim 6, wherein At least one of the alkaline earth metal oxide, metallic cobalt and a modifier is introduced during the preparation of the main component.

11. The dehydration catalyst according to any one of claims 1 to 10, wherein The ammonia adsorption capacity of the dehydration catalyst is 0.15-0.4 mmol·g -1 .

12. The dehydration catalyst according to claim 11, wherein The ammonia adsorption capacity of the dehydration catalyst is 0.18-0.28 mmol·g -1 .

13. The dehydration catalyst according to any one of claims 1 to 10, wherein The carbon dioxide adsorption capacity of the dehydration catalyst is 0.16-0.4 mmol·g -1 .

14. The dehydration catalyst according to claim 13, wherein The carbon dioxide adsorption capacity of the dehydration catalyst is 0.18-0.35 mmol·g -1 .

15. The dehydration catalyst according to any one of claims 1 to 10, wherein The specific surface area of ​​the dehydration catalyst is 40-150 m 2 ·g -1 .

16. The dehydration catalyst according to claim 15, wherein The specific surface area of ​​the dehydration catalyst is 50-130m 2 ·g -1 .

17. The dehydration catalyst according to any one of claims 1 to 10, wherein The pore volume of the dehydration catalyst is 0.05-0.2 mL·g -1 .

18. The dehydration catalyst according to claim 17, wherein The pore volume of the dehydration catalyst is 0.1-0.2 mL·g -1 .

19. A method for preparing the dehydration catalyst according to any one of claims 1 to 18, characterized in that: The method includes: (1) providing a solution containing a main component precursor, an alkaline earth metal precursor, and a cobalt source, and then precipitating the solution with a precipitant to obtain a precipitated product; (2) calcining the precipitated product to obtain a calcined product; (3) heat-treating the calcined product in a reducing atmosphere; Wherein, the main component matrix is ​​selected from at least one of a zirconium source, a silicon source and an aluminum source.

20. The method according to claim 19, wherein The zirconium source is selected from at least one of zirconium oxychloride, zirconium nitrate, zirconyl nitrate and zirconyl sulfate.

21. The method according to claim 19, wherein The silicon source is selected from tetraethyl orthosilicate and / or silica sol.

22. The method according to claim 19, wherein The aluminum source is selected from at least one of sodium metaaluminate, aluminum nitrate, aluminum sulfate and aluminum isopropoxide.

23. The method according to claim 19, wherein The precipitant is selected from at least one of carbon dioxide, nitric acid, ammonia water, urea, sodium carbonate, sodium bicarbonate, ammonium carbonate and ammonium bicarbonate.

24. The method according to claim 19, wherein The alkaline earth metal precursor is selected from alkaline earth metal salts.

25. The method according to claim 24, wherein The alkaline earth metal salt is selected from at least one of alkaline earth metal nitrates, alkaline earth metal formates, alkaline earth metal oxalates and alkaline earth metal lactates.

26. The method according to claim 25, wherein The alkaline earth metal salt is selected from at least one of magnesium nitrate, calcium nitrate, strontium nitrate and barium nitrate.

27. The method according to claim 19, wherein The cobalt source is selected from at least one of cobalt nitrate, cobalt acetate, cobalt formate, basic cobalt carbonate, cobalt citrate, cobalt chloride, cobalt sulfate and cobalt phosphate.

28. The method according to claim 19, wherein The solution also contains a modifying agent precursor.

29. The method according to claim 28, wherein The modifier matrix is ​​selected from at least one of lanthanum nitrate, potassium hydroxide, potassium nitrate, potassium carbonate, cerium nitrate and zinc nitrate.

30. The method according to any one of claims 19 to 29, wherein: Step (1) also includes the step of aging the precipitated product.

31. The method according to claim 30, wherein The aging conditions include: temperature of 30-90° C.; time of 10-120 min.

32. The method according to claim 31, wherein The aging conditions include: temperature of 50-90° C.; time of 20-120 min.

33. The method according to any one of claims 19 to 29, wherein: In step (2), the calcination conditions include: temperature of 400-800°C; time of 1-20h; and heating rate of 1-5°C / min.

34. The method according to claim 33, wherein In step (2), the calcination conditions include: temperature of 450-650°C; time of 2-10 hours; and heating rate of 1.5-5°C / min.

35. The method according to any one of claims 19 to 29, wherein: In step (3), the reducing atmosphere is provided by a reducing gas containing hydrogen and optionally an inert gas.

36. The method according to claim 35, wherein The content of hydrogen in the reducing gas is 10-30 vol%.

37. The method according to any one of claims 19 to 29, wherein: The heat treatment temperature is 100-450° C. and the time is 1-24 hours.

38. The method according to claim 37, wherein The heat treatment temperature is 200-450° C. and the time is 2-8 hours.

39. A method for preparing olefins by dehydrating alcohols, characterized in that: The method comprises: contacting alcohol with the dehydration catalyst according to any one of claims 1 to 18 to carry out a dehydration reaction.

40. The method of claim 39, wherein The dehydration reaction conditions include: temperature of 240-370°C; pressure of 0.085-0.3 MPa; liquid phase volume space velocity of 0.1-1.2 h -1 .

41. The method according to claim 40, wherein The dehydration reaction conditions include: temperature of 260-330°C; pressure of 0.1-0.2 MPa; liquid phase volume space velocity of 0.2-1 h -1 .

42. The method according to any one of claims 39 to 41, wherein: The alcohol is selected from alcohols having 2 to 18 carbon atoms.

43. The method according to claim 42, wherein The alcohol is selected from primary alcohols having 2 to 18 carbon atoms and / or secondary alcohols having 3 to 18 carbon atoms.

44. The method according to claim 43, wherein The hydroxyl group of the secondary alcohol is located on the second carbon atom of the carbon chain.

45. The method according to any one of claims 39 to 41, wherein: The alcohol is selected from at least one of ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, 2-propanol, 2-butanol, 2-pentanol, 2-hexanol, 2-heptanol, 2-octanol, 4-methyl-2-pentanol, 2-ethyl-1-hexanol, 2-propyl-1-heptanol and 1,4-butanediol.

46. ​​The method according to any one of claims 39 to 41, wherein: The olefin is an α-olefin.

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