KR20200115064A - Alcohol dehydration catalyst, preparation method the same and method for preparing alpha-olefins using the same - Google Patents

Abstract

The present invention relates to a catalyst for dehydration of a primary alcohol, a method for preparing the same, and a method for preparing alpha-olefins using the same. The catalyst for dehydration of a primary alcohol according to the present invention has excellent dehydration activity, high conversion frequency, and excellent catalyst stability, and thus can provide high-purity linear alpha-olefins with high selectivity even if a relatively small amount of cocatalyst is added compared to a homogeneous catalyst system. The catalyst for dehydration of a primary alcohol includes complex metal oxides of magnesium and aluminum.

Description

Alcohol dehydration catalyst, preparation method the same and method for preparing alpha-olefins using the same}

The present invention relates to a catalyst for dehydration of alcohol, a method for preparing the same, and a method for preparing an alpha-olefin using the same.

Linear alpha-olefins having 4 to 20 carbon atoms are a major feedstock for the production of surfactants, plasticizers, synthetic lubricants and polyolefins. In addition, high-purity linear alpha-olefins are particularly useful for production of low-density polyethylene and oxo processes.

Linear olefins can be prepared through dehydrogenation of linear alkanes or dehydration of linear alcohols. However, most of the products obtained from the above-described manufacturing method consist of internal olefins. Accordingly, research for producing linear alpha-olefins with higher selectivity is continuously being conducted.

Among various linear alpha-olefins, 1-butene, 1-hexene, 1-octene, etc. are hybrid monomers that are polymerized into low-density polyethylene (LDPE) and high-density polyethylene (HDPE) through ethylene and polymer polymerization. Plays a role. Polyethylene is a thermoplastic plastic, light and flexible, and is used in various containers, packaging films, fibers, pipes, packings, and paints in the modern society. In polyethylene, the breaking strength, tear strength, and drop impact strength, which are important properties of the polymer, are affected by the crystallization and crosslink density, which are properties of the polymer. That is, the important required physical properties of polyethylene can be controlled by a combination of various aspects of the hybrid monomer 　 linear alpha-olefin.

Commercial processes for producing these linear alpha-olefins include a method of producing by oligomerization of ethylene and a method of separating and producing olefins from naphtha cracking of petroleum. However, in the commercial process of producing such a linear alpha-olefin, an increase in cost and environmental problems have been pointed out during the fractionation process. Accordingly, there is a need for a commercial process for producing through a dehydration reaction using alcohol converted from biomass, an eco-friendly carbon resource that is renewable and capable of sustained production.

KR 10-2007-0112460 A

An object of the present invention is to provide a catalyst for effective use in the dehydration reaction of primary alcohols and a method for producing the same.

In detail, one object of the present invention is to provide a catalyst for dehydration reaction of a primary alcohol having excellent activity against dehydration reaction, high conversion frequency and excellent catalyst stability, and a method for preparing the same.

In detail, one object of the present invention is to realize high catalytic activity even by introducing a relatively small amount of cocatalyst compared to a homogeneous catalyst system, and to increase selectivity to linear alpha-olefins through dehydration reaction, and to achieve high purity linear alpha. -To provide a catalyst for dehydration of a primary alcohol capable of providing an olefin and a method for producing the same.

Another object of the present invention is to provide a method of converting a primary alcohol to an olefin with high selectivity using the catalyst for dehydration of the primary alcohol described above.

Another object of the present invention is to provide a method for producing a linear alpha-olefin capable of mass production in a very economical manner.

In order to solve the above-described problems, a catalyst for dehydration of a primary alcohol including a composite metal oxide of magnesium (Mg) and aluminum (Al) is provided.

In the catalyst for dehydration of a primary alcohol according to an embodiment of the present invention, the composite metal oxide is magnesium aluminate (MgAl ₂ O ₄ ) and hydrotalcite (Mg _2x Al ₂ (OH)). _4x+4 CO _{3 ·} nH ₂ O) may be selected from.

In the catalyst for dehydration reaction of a primary alcohol according to an embodiment of the present invention, the catalyst for dehydration reaction of the primary alcohol may include the composite metal oxide as a carrier and metal particles supported on the carrier. have.

In the catalyst for dehydration reaction of primary alcohol according to an embodiment of the present invention, the metal particles may be selected from alkaline earth metals and transition metals.

In the catalyst for dehydration reaction of primary alcohol according to an embodiment of the present invention, the metal particles may be tungsten (W) or the like.

In the catalyst for dehydration reaction of primary alcohol according to an embodiment of the present invention, the metal particles may be supported in an amount of 10% by weight or less based on the total weight of the carrier.

In the catalyst for dehydration of a primary alcohol according to an embodiment of the present invention, the primary alcohol may be 1-octanol or the like.

In addition, the present invention comprises the steps of preparing a supported material by impregnating a metal precursor solution on a composite metal oxide of magnesium (Mg) and aluminum (Al); And it provides a method for producing a catalyst for the dehydration reaction of the primary alcohol comprising; and firing the supported material.

In the method for preparing a catalyst for dehydration reaction of a primary alcohol according to an embodiment of the present invention, the metal precursor may be an ammonium-based compound including a metal selected from alkaline earth metals and transition metals.

In the method for producing a catalyst for dehydration reaction of a primary alcohol according to an embodiment of the present invention, the metal precursor is an ammonium tungsten compound selected from ammonium 　 paratungstate, 　 ammonium 　 metatungstate, etc. Can be

In addition, the present invention provides a method of converting a primary alcohol into an olefin using the catalyst for dehydration of the primary alcohol described above.

In addition, the present invention uses the catalyst for dehydration of the primary alcohol described above, converting the primary alcohol into an olefin; And it provides a method for producing a linear alpha-olefin comprising; and fractionating the converted olefin.

In the method for producing a linear alpha-olefin according to an embodiment of the present invention, the converting step may be performed under conditions of 200 to 800°C.

In the method for producing a linear alpha-olefin according to an embodiment of the present invention, the converting step may be to supply the primary alcohol at a liquid hourly space velocity (LHSV) of 3 to 100 h ^-1 . have.

In the method for producing a linear alpha-olefin according to an embodiment of the present invention, the fractionation may be performed through distillation, extraction, adsorption, or ion exchange.

In the method for producing a linear alpha-olefin according to an embodiment of the present invention, the conversion rate of the primary alcohol may be 50% or more, and the selectivity of the linear alpha-olefin may be 60% or more.

According to the present invention, it is possible to provide a heterogeneous catalyst or catalyst system having excellent catalytic activity for dehydration reaction of a primary alcohol, high conversion frequency, and excellent catalytic stability. In addition, high catalytic activity can be achieved with a relatively small amount compared to a liquid homogeneous catalyst system.

In addition, according to the present invention, it is possible to effectively reduce the formation of isomers and satisfy high purity and conversion rate at the same time during dehydration reaction of the primary alcohol by appropriate acid point control.

In addition, according to the present invention, not only can the primary alcohol be converted to olefins with high selectivity, but also linear alpha-olefins can be obtained in high yield, so that mass production of linear alpha-olefins is possible in a very economical manner. . In addition, the use of a solid catalyst or catalyst system facilitates separation of liquid reactants and products.

1 shows a product prepared through dehydration of primary alcohol using catalysts or catalyst systems of Examples and Comparative Examples of the present invention (Sample 1: Comparative Example 5, Sample 2: Comparative Example 4, Sample 3: Example) Example 15, Sample 6: Example 16).

The catalyst for the dehydration reaction of alcohol according to the present invention, a method for preparing the same, and a method for preparing an alpha-olefin using the same will be described below. However, unless otherwise defined in the technical and scientific terms used, the technical field to which the present invention belongs. In the following description, a description of known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted to have the meaning commonly understood by those of ordinary skill in the art.

In the present specification, the term'includes' is an open type description having the meaning equivalent to expressions such as'include','include','have' or'as a feature', and elements not listed further, It does not exclude materials or processes.

As used herein, the term'primary alcohol' means an alcohol in which an alcohol group (-OH) is attached to the terminal. Specifically, the primary alcohol may be an alcohol having 20 or less carbon atoms, more specifically an alcohol having 6 to 20 carbon atoms, and most preferably 1-octanol, an alcohol having 8 carbon atoms.

As used herein, the term'linear alpha-olefin' refers to a hydrocarbon compound in which a double bond exists between carbon 1 and carbon 2 of a hydrocarbon, and examples thereof include 1-hexene and 1-octene.

As used herein, the term'dehydration reaction' refers to a reaction in which water is removed from the primary alcohol, and the product produced therefrom may be an olefin or an ether.

In the present specification, the term'catalyst' is a substrate having the same meaning as a catalyst for dehydration of a primary alcohol. In addition, it may include both a mode in which a plurality of acid points are mixed and a mode in which a cocatalyst is supported.

The singular form used in the present specification may be intended to include the plural form unless otherwise indicated in the context.

Units used in the present specification without special mention are based on weight, for example, the unit of% or ratio means weight% or weight ratio, and weight% means any one component of the total composition unless otherwise defined. It means the weight percent occupied by.

Numerical ranges used herein include lower and upper limits and all values within the range, increments that are logically derived from the shape and width of the defined range, all of which are defined, and upper and lower limits of the numerical range defined in different forms. Includes all possible combinations of.

As mentioned above, when the dehydration reaction is carried out using a primary alcohol, olefins or ethers are produced. Specifically, the reaction in which olefin is generated can be represented by the following Reaction Scheme 1, and the reaction in which ether is generated can be represented by the following Reaction Scheme 2.

[Scheme 1]

ROH → CH ₂ =CH-R' + H ₂ O

[Scheme 2]

2R"OH → R"-OR" + H ₂ O

[In the above Scheme 1 and Scheme 2,

R is C ₂ -C ₂₀ alkyl,

R'is hydrogen or C ₁ -C ₁₈ alkyl,

R" is C ₁ -C ₂₀ alkyl.]

The dehydration reaction as shown in Scheme 1 is an endothermic reaction, where water is removed by a catalyst to generate olefins. In addition, the dehydration reaction as shown in Formula 2 is an exothermic reaction in which dialkyl ether is generated from the reaction of two molecules of primary alcohol.

As described above, in order to produce olefins with high selectivity from primary-alcohol, it is very important to control the catalyst, its composition, and reaction conditions.

As a result of repeating research to produce olefins highly selectively from the dehydration reaction of primary alcohols, the present inventors suppressed side reactions when a composite metal oxide containing magnesium (Mg) and aluminum (Al) is used as a catalyst. The present invention is proposed by confirming that linear alpha-olefins can be produced with high selectivity.

According to the present invention, high-purity linear alpha-olefins useful for production of low-density polyethylene and oxo processes with high added value, using alcohol converted from biomass, which is an eco-friendly carbon resource capable of sustainable and sustainable production, is very economical. It has the advantage that it can be provided in a way.

Further, according to the present invention, catalytic activity for dehydration reaction through a desired endothermic reaction, that is, excellent turnover frequency is realized. Further, when the co-catalyst is supported by using the catalyst as a carrier, the acidity of the catalyst is increased, and the acid point of the catalyst (Lewis acid sites, LAS) can be variously adjusted to realize more improved dehydration reaction characteristics. The improvement of specific dehydration reaction characteristics will be described later.

In addition, according to the present invention, it is possible to achieve high catalytic activity even if a relatively small cocatalyst is added compared to the homogeneous catalyst system, control the acid point that serves as the active point in the dehydration reaction of the primary alcohol, and effectively reduce the formation of isomers. And high selectivity and yield can be satisfied at the same time.

Hereinafter, the present invention will be described in detail.

The present invention provides a catalyst for dehydration of a primary alcohol including a complex metal oxide of magnesium (Mg) and aluminum (Al) in order to achieve the above-described objects and effects. Specifically, the composite metal oxide is differentiated from a mixture of a metal oxide in which magnesium oxide and aluminum oxide are mixed.

The catalyst for dehydration of a primary alcohol according to an embodiment of the present invention is magnesium aluminate (MgAl ₂ O ₄ ) and hydrotalcite (Mg _2x Al ₂ (OH) _4x+4 CO _{3 ·} nH). _It may include a composite metal oxide selected from ₂ O) and the like.

The composite metal oxide mentioned above has a very dense structure, and magnesium and aluminum are uniformly bonded to form a layered structure in a relatively wide range at the atomic level. Accordingly, the dispersibility and uniformity of magnesium and aluminum are very high.

The catalyst for dehydration of the primary alcohol may simultaneously satisfy extremely improved selectivity and yield compared to the case of using magnesium oxide or aluminum oxide alone. Further, considering that when magnesium oxide and aluminum oxide are physically mixed and used, reaction by-products such as internal olefins are excessively produced, and taking into account that it is not possible to provide high-purity linear alpha-olefins, the above-described object according to the present invention and The effect can be expected to result from the structural characteristics of the catalyst containing magnesium and aluminum simultaneously.

As an example, when aluminum oxide having a relatively high acid point intensity is used as a catalyst, it may exhibit a high primary alcohol conversion rate, but various forms of isomers including internal olefins are simultaneously generated, resulting in selectivity and yield for linear alpha-olefins. Is remarkably low.

For example, when magnesium oxide having a relatively low acid point intensity is used as a catalyst, only linear alpha-olefins and dialkyl ethers are obtained to provide high-purity linear alpha-olefins, but selectivity for linear alpha-olefins and The yield is remarkably low.

However, the catalyst for the dehydration of the primary alcohol is selected from magnesium aluminate (MgAl ₂ O ₄ ) and hydrotalcite (Mg _2x Al ₂ (OH) _4x+4 CO _{3 ·} nH ₂ O). As the composite metal oxide is included, extremely improved selectivity and yield can be simultaneously satisfied, and the purity of the linear alpha-olefin obtained therefrom can be increased.

For example, the magnesium aluminate may be used as a commercial magnesium aluminate or a commercial hydrotalcite (Mg _2x Al ₂ (OH) _4x+4 CO ₃ nH ₂ O) in an air atmosphere of 500 to 1100°C. It may be produced by firing under temperature conditions.

As an example, the magnesium aluminate may contain 10 to 300 parts by weight of alumina (Al ₂ O ₃ , aluminum oxide) based on 100 parts by weight of magnesium oxide (MgO). Specifically, the magnesium aluminate may include magnesium oxide (MgO) and alumina (Al ₂ O ₃ ) in a weight ratio of 30:70, 50:50, or 70:30.

For example, in the magnesium aluminate, the weight ratio of magnesium oxide may be appropriately adjusted in order to realize more improved conversion of primary alcohol and selectivity of linear alpha-olefin.

As an example, the hydrotalcite may be a commercial hydrotalcite (Mg ₆ Al ₂ (CO ₃ )(OH) _{16 ·} 4H ₂ O), but is not limited thereto.

The catalyst for dehydration of a primary alcohol according to an exemplary embodiment of the present invention may include the composite metal oxide as a carrier and metal particles supported on the carrier in order to achieve a desired acid point depending on the reactant. At this time, the metal particles serve as a cocatalyst.

The metal particles may be selected from alkaline earth metals and transition metals.

For example, the metal particles may include alkaline earth metals such as beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra); And transition metals such as niobium (Nb), zinc (Zn), cerium (Ce), zirconium (Zr), iron (Fe), molybdenum (Mo), and tungsten (W); It may be one or two or more selected from.

In the catalyst for dehydration reaction of primary alcohol according to an embodiment of the present invention, the metal particle may be a Group 6 transition metal specifically selected from molybdenum (Mo) and 　 tungsten (W), and more specifically, tungsten ( W) can be.

For example, the metal particles may have an atomic-level average diameter (D50) or more. Specifically, the metal particles may be 2 to 10 nm, more specifically 3 to 5 nm. In this case, the average diameter means a value of a particle diameter corresponding to 50% from the smallest particle when the total number of particles is 100%. It goes without saying that D50 can be measured by a method well known to those skilled in the art. For example, it may be measured with a particle size analyzer, or may be measured from a TEM photo or an SEM photo.

For example, the metal particles may be uniformly distributed on the surface or in the pores of the carrier. In this case, both the metal particles distributed on the surface of the carrier and in the pores may be supported.

For example, the metal particles may be supported in an amount of 10% by weight or less based on the total weight of the carrier. The supported amount of the metal particles may be specifically 0.1 to 10% by weight, more specifically 1.0 to 7.5% by weight, and most specifically 4.0 to 6.0% by weight.

As an example, when the catalyst for dehydration reaction of the primary alcohol contains 4.0 to 6.0% by weight of metal particles, it is good in that the conversion rate to the primary alcohol can be extremely improved and a more improved linear alpha-olefin can be provided. . Specifically, in this case, the conversion rate to the primary alcohol may be 80% or more.

For example, the primary alcohol may be a linear or branched alcohol.

For example, the primary alcohol may be a C ₆ -C ₂₀ alcohol, and non-limiting examples thereof include hexanol, heptanol, octanol, nonanol, decanol, and undecanol.

For example, the primary alcohol may most preferably be 1-hexane or 1-octanol.

The catalyst for dehydration of a primary alcohol according to the present invention comprises the steps of preparing a supported material by impregnating a metal precursor solution on a composite metal oxide of magnesium (Mg) and aluminum (Al); And it can be produced through a manufacturing method including; firing the support.

For example, the firing may be performed in a gas atmosphere including one or more gases selected from hydrogen, air, oxygen, and inert gas. In addition, it goes without saying that the composition of the supported metal particles may be adjusted according to the gas atmosphere in the firing step.

For example, the firing may be performed for 3 to 6 hours under conditions of 200 to 800°C.

For example, the support may further include drying at 80 to 110° C. for 6 to 18 hours before the firing step.

In addition, the metal precursor may be an ammonium-based compound including a metal selected from alkaline earth metals and transition metals. Non-limiting examples of the ammonium compound include ammonium 　 paratungstate, 　 ammonium 　 metatungstate, and the like, but the ammonium tungsten compound is not limited thereto.

The catalyst for dehydration reaction of the primary alcohol according to the present invention prepared through the above manufacturing method may contain the metal particles in an amount of 10% by weight or less based on the total weight of the carrier, and may be adjusted to various loading amounts depending on the purpose. Yes, of course.

For example, when the catalyst for dehydration reaction of the primary alcohol contains 4 to 6% by weight of metal particles, a 1-octanol conversion rate of 80% or more may be achieved. In addition, in this case, it is preferable to effectively suppress the generation of reaction by-products to provide high-purity linear alpha-olefins in high yield.

Hereinafter, the use of the catalyst for dehydration of the primary alcohol according to the present invention will be described.

One aspect of the use according to the invention may be a method of converting primary alcohols to olefins. In addition, one aspect of the use according to the invention may be a method of producing a linear alpha-olefin comprising a method of converting a primary alcohol to an olefin.

The method of converting a primary alcohol to an olefin according to an embodiment of the present invention may be performed under conditions of 200 to 800°C. In addition, the method of converting the primary alcohol to olefin may be carried out under a pressure condition of normal pressure to 50 barg.

For more effective conversion to olefins, the catalyst for dehydration reaction of the primary alcohol may be used after pretreatment for 1 to 5 hours at 200°C or higher before use. Specifically, the pretreatment may be performed under conditions of 200 to 800°C, but is not limited thereto.

In addition, in the method of converting the primary alcohol to olefin according to an embodiment of the present invention, the primary alcohol as a reactant may be preheated to a temperature higher than the boiling point (bp) and supplied in a vaporized state. Specifically, the temperature condition for the preheating may be 200°C or higher, more specifically 200 to 500°C, and most specifically 250 to 450°C.

In addition, in the method for converting the primary alcohol to olefin according to an embodiment of the present invention, the primary alcohol as a reactant may be preheated under the above-described conditions and provided in a vaporized state, and it is easier to use a moving gas. It is possible to bring the reactants into contact with the catalyst.

As an example, the moving gas may be used without limitation as long as it does not adversely affect the conversion of primary alcohol to olefin, and non-limiting examples thereof include nitrogen gas, helium gas, and argon gas.

For example, the supply rate of the primary alcohol may be supplied at 20 to 80 mL/min per 0.5 mL of catalyst. In addition, the flow rate of the moving gas may be determined in proportion to the volume of the catalyst, and of course, it may be adjusted under various conditions depending on the purpose.

In addition, the method of converting the primary alcohol to olefin according to an embodiment of the present invention may be to supply the primary alcohol at a liquid hourly space velocity (LHSV) 3 to 100 h ^-1 . The liquid space velocity may be to supply the primary alcohol under conditions of specifically 5 to 80h ^-1 , more specifically 7 to 56h ^-1 .

The product produced through the method of converting a primary alcohol into an olefin according to an embodiment of the present invention may be a combination selected from linear alpha-olefins, internal olefins, dialkyl ethers, and the like.

The method of converting a primary alcohol into an olefin according to an embodiment of the present invention can implement extremely improved selectivity and yield compared to the case of using magnesium oxide or aluminum oxide alone or a mixture of metal oxides in which they are mixed as a catalyst. Has features.

Specifically, according to the above method, the conversion rate is equivalent to or slightly lower than that of aluminum oxide having a relatively high acid point strength as a catalyst, but it effectively suppresses the generation of by-products and highly selectively prepares linear alpha-olefins. It is more commercially advantageous in terms of being able to.

The converted olefin may be fractionated through a conventional fractionation method to finally obtain a linear alpha-olefin.

The fractionation method may be used without limitation as long as it is a conventional method, and non-limiting examples thereof include distillation, extraction, adsorption, ion exchange, etc., and the step may be performed through one or more fractionation methods selected from I can.

At this time, distillation using Soxhlet may be preferable in terms of having an advantage in the process. However, among the products obtained through the step of converting a primary alcohol into an olefin, the linear alpha-olefin and the internal olefin have similar boiling points and are very difficult to separate them. Accordingly, in the step of converting the primary alcohol to olefin, the implementation of high selectivity for the linear alpha-olefin may be a very important factor in the production of high purity linear alpha-olefin.

For example, when using 1-octanol (bp188°C) as a reactant, the olefins converted therefrom are 1-octene (bp121°C), cis-2-octene (bp126°C), trans-2-octene (bp123°C) , cis-3-octene (bp123°C), trans-3-octene (bp121-122°C), trans-4-octene (bp122-123°C), and the like. As mentioned, the boiling point of the desired linear alpha-olefin 1-octene is similar to that of the by-products produced at the same time, and their separation is very difficult.

In the method for producing a linear alpha-olefin according to an embodiment of the present invention, the conversion rate of the primary alcohol may be 50% or more.

Specifically, in the method for producing the linear alpha-olefin, the conversion rate of the primary alcohol may be 50% or more, and the selectivity of the linear alpha-olefin may be 60% or more. More specifically, in the method for producing the linear alpha-olefin, the conversion rate of the primary alcohol may be 70 to 90%, and the selectivity of the linear alpha-olefin may be 65 to 90%. Most specifically, in the method of producing the linear alpha-olefin, the conversion rate of the primary alcohol may be 80 to 90%, and the selectivity of the linear alpha-olefin may be 75 to 90%.

In addition, in the method for producing the linear alpha-olefin, the yield of the linear alpha-olefin may be 45% or more.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples. However, the following Examples and Comparative Examples are only one example for describing the present invention in more detail, and the present invention is not limited by the following Examples and Comparative Examples. Unless otherwise stated in the present invention, all temperature refers to a unit of °C, and unless otherwise stated, the amount used of the composition refers to a unit of weight %.

(Assessment Methods)

1. Identification of product by dehydration reaction

The product obtained from the reactor was converted into a liquid phase in a -2° C. condenser, and the liquid product was collected in a fractionator having a length of 20 cm and a volume of 15 mL. The collected liquid product was analyzed through a GC-FID (Agilent 7890B) equipped with an HP-5 column (Agilent 19091J-413). At this time, the product measurement time was compared based on 3 hours of dehydration reaction.

2. Confirmation of dehydration reaction characteristics

The dehydration properties of Examples and Comparative Examples according to the present invention were calculated through Equations 1 to 4 below.

(Example 1)

Hydrotalcite powder (manufacturer: Sasol, product name: PURAL ^® MG30, MgO:Al ₂ O ₃ =30:70 (wt:wt)) is calcined in an air atmosphere at 850°C for 3 hours in an oven to dehydrate primary alcohol Magnesium aluminate as a catalyst for reaction was prepared.

(Example 2)

Hydrotalcite powder (manufacturer: Sasol, product name: PURAL ^® MG50, MgO:Al ₂ O ₃ =50:50 (wt:wt)) was used. By firing in the same manner as in Example 1, magnesium aluminate, which is a catalyst for dehydration of the primary alcohol, was prepared.

(Example 3)

Hydrotalcite powder (manufacturer: Sasol, product name: PURAL ^® MG70, MgO:Al ₂ O ₃ =70:30 (wt:wt)) was used. By firing in the same manner as in Example 1, magnesium aluminate, which is a catalyst for dehydration of the primary alcohol, was prepared.

(Examples 4 to 7)

Using the magnesium aluminate prepared in Example 1 as a carrier, a catalyst for dehydration of the supported primary alcohol was prepared so that the content of tungsten was 1.0, 2.5, 5.0, or 7.5% by weight (W content).

Specifically, ammonium 　 metatungstate (0.086 g, 0.22 g, 0.43 g or 0.65 g) was added to 10 mL of distilled water so that the content of each tungsten (W) with respect to the total weight of the catalyst satisfies the above-described wt%, and the above Magnesium aluminate (9.9 g, 9.75 g, 9.5 g or 9.25 g) prepared from Example 1 was added. The mixture was mixed for 60 minutes and then calcined in an oven at 500° C. for 4 hours in an air atmosphere to prepare a catalyst for dehydration reaction of the primary alcohol carrying tungsten.

(Example 8)

Using the magnesium aluminate prepared in Example 1 (MgAl ₂ O ₄ , MgO:Al ₂ O ₃ =30:70), a dehydration reaction was performed.

Specifically, the dehydration reaction was performed through a reactor filled with the magnesium aluminate to a height of 0.75 cm in a quartz reactor having a diameter of 3/8 inches. For complete vaporization of the reactant 1-octanol (≥99%, Sigma-Aldrich), it is heated to 280°C through a preheater, and liquid hourly space velocity (LHSV) 7 h ^-1 and 400 using an HPLC pump. The dehydration reaction was performed under conditions of °C.

Analysis of the product by the dehydration reaction was performed through a GC-FID (Agilent 7890B) equipped with an HP-5 column (Agilent 19091J-413). At this time, the product measurement time was compared based on 3 hours of dehydration reaction. In addition, the results are shown in Table 1 below.

(Examples 9 to 14)

Dehydration was performed in the same manner as in Example 8, but the catalysts prepared in Examples 2 to 7 were used instead of the magnesium aluminate prepared in Example 1.

In Example 9, the catalyst prepared in Example 2 was used.

In Example 10, the catalyst prepared in Example 3 was used.

In Example 11, the catalyst prepared in Example 4 was used.

In Example 12, the catalyst prepared in Example 5 was used.

In Example 13, the catalyst prepared in Example 6 was used.

In Example 14, the catalyst prepared in Example 7 was used.

Analysis of the product by the dehydration reaction was also performed in the same manner as in Example 8. In addition, the results are shown in Table 1 below.

(Example 15 and Example 16)

Dehydration was performed in the same manner as in Example 8, but the liquid space velocity and catalyst were adjusted as shown in Table 2 below.

Analysis of the product by the dehydration reaction was also performed in the same manner as in Example 8. In addition, the results are shown in Table 2 below.

(Example 17)

Dehydration was carried out in the same manner as in Example 8, but hydrotalcite (manufacturer: Sasol, product name: PURAL ^® MG30, MgO:Al ₂ O ₃ =30:70 (wt) instead of magnesium aluminate (MgAl ₂ O ₄ ) :wt)) was used as a catalyst.

Analysis of the product by the dehydration reaction was also performed in the same manner as in Example 8.

(Comparative Example 1)

Dehydration was performed in the same manner as in Example 8, but a commercial alumina (manufacturer: Sasol, Al ₂ O ₃ ) was used as a catalyst instead of the magnesium aluminate.

Analysis of the product by the dehydration reaction was performed in the same manner as in Example 8. In addition, the results are shown in Table 1 below.

(Comparative Example 2)

Dehydration was carried out in the same manner as in Example 8, but a commercial magnesium oxide (manufacturer: Sigma Aldrich, MgO) was used as a catalyst instead of the magnesium aluminate.

Analysis of the product by the dehydration reaction was performed in the same manner as in Example 8. In addition, the results are shown in Table 1 below.

(Comparative Example 3)

Dehydration was performed in the same manner as in Example 8, but instead of the magnesium aluminate, commercial alumina (manufacturer: Sasol, Al ₂ O ₃ ) and commercial magnesium oxide (manufacturer: Sigma Aldrich, MgO) were added at 70:30. The mixture mixed in a weight ratio was used as a catalyst.

Analysis of the product by the dehydration reaction was performed in the same manner as in Example 8. In addition, the results are shown in Table 1 below.

(Comparative Examples 4 to 5)

Dehydration was performed in the same manner as in Example 8, but the liquid space velocity and catalyst were adjusted as shown in Table 2 below.

Analysis of the product by the dehydration reaction was also performed in the same manner as in Example 8. In addition, the results are shown in Table 2 below.

As shown in Table 1, it was confirmed that the use of the catalyst according to the present invention exhibited remarkable effects on 1-octene selectivity and 1-octene yield for the dehydration reaction of primary alcohol. Specifically, it was confirmed that Example 8 showed a maximum 1-octene selectivity of 770% or more compared to Comparative Example 2, and showed a remarkable synergistic effect on the 1-octene yield.

In addition, when the catalyst according to the present invention was used, it was possible to achieve a 1-octanol conversion rate of 70% or more, and the selectivity of 1-octene, the final product produced from the dehydration reaction, was very high by effectively suppressing the formation of isomers. I could confirm.

On the other hand, it was confirmed that Comparative Example 2, which had the lowest acid point intensity, showed the lowest 1-octanol conversion rate, mainly produced dioctyl ether, and was not suitable for use in preparing linear alpha-olefins. . On the contrary, in the case of Comparative Example 1 with the highest acid point intensity, 1-octanol conversion was shown, but 1-octene selectivity and yield were low, and the separation of excess isomers was difficult, so the purity of the final product, 1-octene, was remarkably. It was confirmed that it is not suitable for use in producing linear alpha-olefins.

As shown in Table 2 and Fig. 1, in the case of increasing the liquid space velocity using the catalyst according to the present invention, 1-octene is selectively produced and isomers are effectively reduced, while at the same time having a remarkable difference in boiling point. By increasing the selectivity for dioctyl ether, it was confirmed that 1-octene of higher purity can be obtained. Accordingly, according to the present invention, it is possible to selectively generate linear alpha-olefins with a high conversion rate, and easily control product selectivity through dehydration of the primary alcohol, thereby providing a desired linear alpha-olefin with high purity.

The present invention is not limited by the above-described embodiments and the accompanying drawings, and it is common in the technical field to which the present invention pertains that various substitutions, modifications and changes are possible within the scope of the technical spirit of the present invention. It will be obvious to those of knowledge.

Claims (16)

A catalyst for dehydration of a primary alcohol, comprising a complex metal oxide of magnesium and aluminum. The method of claim 1,
The composite metal oxide,
A catalyst for dehydration of a primary alcohol, which is magnesium aluminate, hydrotalcite, or a combination thereof. The method of claim 1,
The catalyst for dehydration reaction of the primary alcohol,
A catalyst for dehydration reaction of a primary alcohol, comprising the composite metal oxide as a carrier and metal particles supported on the carrier. The method of claim 3,
The metal particles,
An alkaline earth metal, a transition metal, or a combination thereof, a catalyst for dehydration of a primary alcohol. The method of claim 3,
The metal particles,
Tungsten phosphorus, a catalyst for dehydration of primary alcohols. The method of claim 3,
The metal particles,
The catalyst for dehydration reaction of the primary alcohol, which is supported in an amount of 10% by weight or less based on the total weight of the support. The method of claim 1,
The primary alcohol,
1-octanol, a catalyst for dehydration of a primary alcohol. Preparing a supported material by impregnating a metal precursor solution on a composite metal oxide of magnesium and aluminum; And
A method for producing a catalyst for dehydration reaction of a primary alcohol comprising; firing the supported material. The method of claim 8,
The metal precursor,
An ammonium-based compound comprising an alkaline earth metal, a transition metal, or a combination thereof, a method for producing a catalyst for dehydration of a primary alcohol. The method of claim 8,
The metal precursor,
Ammonium paratungstate, ammonium metatungstate, or a combination thereof, a method for producing a catalyst for dehydration of a primary alcohol. A method of converting a primary alcohol into an olefin using the catalyst for dehydration of the primary alcohol according to any one of claims 1 to 7. Converting the primary alcohol to an olefin using the catalyst for dehydration of the primary alcohol according to any one of claims 1 to 7; And
A method for producing a linear alpha-olefin comprising; fractionating the converted olefin. The method of claim 12,
The converting step,
The method of producing a linear alpha-olefin is carried out under conditions of 200 to 800°C. The method of claim 12,
The converting step,
A method for producing a linear alpha-olefin, which is to supply the primary alcohol with a liquid space velocity of 3 to 100 h ^-1 . The method of claim 12,
The fractionating step,
A method for producing a linear alpha-olefin, which is carried out through distillation, extraction, adsorption or ion exchange. The method of claim 12,
The conversion rate of the primary alcohol is 50% or more,
The selectivity of the linear alpha-olefin is 60% or more, a method for producing a linear alpha-olefin.

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