KR102090402B1 - A method for producing the higher alkene from butene by using desilicated pentasil structure zeolite catalyst - Google Patents

Abstract

The present invention relates to a method of producing a higher alkene through an oligomerization reaction of butene, and more specifically, to a method of producing a higher alkene of a jet fuel range by promoting the oligomerization reaction of butane by using a desilicated pentasil structure-type zeolite catalyst. A method of producing a C_8-C_16 alkene from butane according to the present invention comprises the steps of: preparing the desilicated pentasil structure-type zeolite catalyst; filling the desilicated pentasil structure-type zeolite catalyst as a fixed catalyst phase in a reactor; passing butane through the reactor to induce the oligomerization reaction; and obtaining the C_8-C_16 alkene through the oligomerization reaction. According to the present invention, the desilicated pentasil structure-type zeolite catalyst is effective in improvements of conversion ratio of butane and yield of the higher alkene of the jet fuel range (C_8-C_16 alkene), and improvement of catalyst lifetime compared to catalysts which have been conventionally used. The method according to the present invention is expected to be industrially useful by exhibiting an excellent performance in the process of producing the higher alkene of the jet fuel range (C_8-C_16 alkene) by oligomerizing butene.

Description

A method for producing the higher alkene from butene by using desilicated pentasil structure zeolite catalyst}

The present invention relates to a method for producing a high-grade alkene through a small polymerization reaction of butene, and more specifically, by using a desilica pentasil-structured zeolite catalyst to promote the small polymerization reaction of butene to prepare a high-grade alkene in the aviation oil region. How to do.

Studies on the synthesis of aviation oil using biomass as a raw material are attracting attention. The Alcohol to Jet (ATJ) process for producing alcohol using biomass as a raw material and manufacturing aviation oil from alcohol has recently begun to draw attention. In particular, the process of manufacturing aviation oil using butanol as a raw material has attracted attention, and this process produces butene through dehydration reaction of butanol, and high-grade alkene in the range of aviation oil by small polymerization reaction of produced butene (C ₈ ~ C ₁₆ Range of olefins) and hydrogenation of higher alkenes.

For the small polymerization reaction of butene, a homogeneous catalyst or a heterogeneous acid catalyst such as zeolite can be used. U.S. Patent No. 8,395,007 reported that bis (cyclopentadienyl) zirconium chloride was used as a catalyst to synthesize high-grade alkenes ranging from 1-butene to diesel oil, and U.S. Patent No. 9,732,295 reported that zirconium metal was used as a catalyst. Using Sen, it has been reported that high-grade alkenes in the range of diesel oil from 1-butene were synthesized, but there is a problem in that it is difficult to recover and reuse the catalyst because a homogeneous catalyst is used.

U.S. Patent Nos. 4,227,992 and 4,211,640 reported that other microporous zeolites such as ZSM-11, ZSM-12, ZSM-21 and mordenite can be used as catalysts for the olefin subpolymerization process. British Patents 2,106,131 and British Patent 2,106,533 have reported methods of using microporous zeolites ZSM-5 and ZSM-11 for the small polymerization reaction of light olefins. In WO93 / 082780, a method for performing a small polymerization reaction of butene using microporous zeolite ZSM-23 as a catalyst is proposed. U.S. Patent No. 9,550,706 describes a method for producing higher grade alkenes from butenes using the ITQ-39 catalyst, a microporous zeolite.

However, the above-mentioned microporous zeolite catalysts have a problem in that since the pore size is small, diffusion of reactants and products within the pores is likely to be limited and the possibility of coke formation is large.

U.S. Patent No. 8,395,007 U.S. Patent No. 9,732,295 U.S. Patent No. 4,227,992 U.S. Patent No. 4,211,640 British Patent No. 2,106,131 British Patent No. 2,106,533 U.S. Patent No. 9,550,706 WO 93/082780

Accordingly, in order to solve the above-mentioned problems, the present invention provides a desilica-type pentasil structure-type zeolite catalyst that is a heterogeneous catalyst, and promotes the small polymerization reaction of butene by using a desilica-type zeolite catalyst to promote high-grade alkene (C ₈ ~ C ₁₆ range of alkene) is intended to be produced in high yield.

In addition, another object of the present invention is to provide a method for producing high-grade alkenes in the aviation oil region by promoting depolymerization reaction of butene by using a desilica pentasil-structured zeolite catalyst.

In order to achieve the above object, the present invention comprises the steps of preparing a desilica pentasil structured zeolite catalyst, filling the desilica pentasil structured zeolite in a reactor with a fixed catalyst, and passing the butene through the reactor to undergo small polymerization. It provides a method for producing an alkene ranging from C ₈ to C ₁₆ from butene, characterized in that it comprises the step of inducing a reaction and obtaining an alkene ranging from C ₈ to C ₁₆ through the small polymerization reaction.

The butene may be selected from one or more of 1-butene and 2-butene, and the small-polymerization reaction is butene in the range of WHSV (weight hour space velocity) 1 to 50hr ^-1 at a reaction temperature of 200 to 550 ° C. It is possible to prepare alkenes ranging from C ₈ to C ₁₆ .

The desilica-type pentasil-structured zeolite catalyst is composed of a ZSM-5 unit structure, and the pentasil-structured zeolite catalyst can be prepared by treating the pentasil-structured zeolite under a basic aqueous solution having a concentration of 0.2 to 0.5M. The basic aqueous solution is not particularly limited, and may be an aqueous sodium hydroxide solution, etc.,

The desilica pentasil-structured zeolite catalyst has a medium pore size in the range of 4 to 25 nm, and a specific surface area of 450 to 500 m ² / g.

According to the present invention, since the pore size of the desilica pentasil-structured zeolite catalyst is 4 to 25 nm, diffusion of butene molecules or butene oligomer molecules in the catalyst pores is quick, so it is easy to reach the surface active point in the catalyst pores, and coke It is possible to prepare a catalyst that can delay the phenomenon of pore clogging due to the production of.

Accordingly, the conversion rate of butene and the high-grade alkene (alkenes in the range of C ₈ to C ₁₆ ) in the aviation oil area are improved compared to the catalysts used in the past, and it is effective in extending the life of the catalyst.

Therefore, the method according to the present invention is expected to be useful industrially because it shows excellent performance in preparing high-grade alkenes (alkenes in the C ₈ to C ₁₆ range) in the aviation oil area by small polymerization of butenes.

1 is a graph showing the pore size distribution of a desilica pentasil structured zeolite catalyst according to the present invention.

Hereinafter, the present invention will be described in more detail based on the following examples. However, the following examples are only intended to illustrate the present invention and are not limited.

The present invention relates to a method for producing high-grade alkenes (alkenes in the range of C ₈ to C ₁₆ ) from the butenes by performing a small polymerization reaction by passing butene as a reactant through a reactor in which the catalyst is filled with a fixed catalyst bed.

The catalyst in the present invention is a desilica pentasil-structured zeolite catalyst. The desilica pentasil-structured zeolite catalyst according to the present invention has a specific surface area of 450 to 500 m ² / g, and is composed of a pentasil-structured zeolite unit structure, and thus has a scattering point, so it can promote small polymerization reaction, and Since the size is in the range of 4 to 25 nm, there is an advantage that the diffusion of butene molecules or butene oligomer molecules in the catalytic pores is fast, and thus it is easy to reach the surface active point in the catalytic pores.

The desilica pentasil-structured zeolite catalyst is desilica-treated in a pentasil-structured zeolite under an aqueous sodium hydroxide solution. If the sodium hydroxide concentration is lower than 0.1 M, it does not form a sufficient degree of intermediate pores. Excess desilica progresses to break down the microstructure of the pentasil-structured zeolite itself, which can significantly reduce the reaction activity. Therefore, the sodium hydroxide concentration is preferably 0.1 to 1.0M, and more preferably, it is characterized in that the desilica treatment of the pentasil-structured zeolite is performed under an aqueous solution of 0.2 to 0.5M sodium hydroxide.

The desilica-type pentasil-structured zeolite catalyst can be applied in the following reaction conditions to a small polymerization reaction using 1-butene, 2-butene, or a mixture of 1-butene and 2-butene as reactants.

In the present invention, the reaction for producing high-grade alkenes in the aviation oil region by promoting the depolymerization reaction of butenes by using the desilica pentasil-structured zeolite catalyst is 200 to 550 ° C. by passing the butenes as reactants in a reactor filled with a fixed catalyst bed. , It is preferably carried out at a reaction temperature of 250 to 450 ° C. If the reaction temperature is less than 200 ° C, the reaction activity decreases, and if it exceeds 550 ° C, the change in the structure of the intermediate pore catalyst may decrease the reaction activity.

In addition, the ratio of the flow rate of the butene and the catalyst is 1 to 50 hr ^-1 as a WHSV (weigh hour space velocity), more preferably, the WHSV is 5 to 30 hr ^-1 , and the selectivity decreases due to a side reaction under ¹ hr ^-1 . If it exceeds 30hr ^-1 , the contact time is too short, and the activity may be lowered.

In the present invention, the reactor used for the reaction for producing high-grade alkenes in the aviation oil region by promoting the depolymerization reaction of butenes using the desilica pentasil-structured zeolite catalyst is stainless steel having an inner diameter of 1/4 inch (inch) and a length of 10 cm. It was manufactured and used as a steel tube. A mass flow regulator was installed between the butene storage tank and the reactor to control the flow. The temperature of the reactor was adjusted using a custom-made tube furnace, and after receiving the liquid product, the gaseous product was analyzed by directly connecting to gas chromatography. Conversion rate, selectivity and yield were calculated by the following equations 1 to 3.

[Equation 1]

Butene conversion (%) = (weight of butene consumed / weight of butene fed) × 100

[Equation 2]

Alken selectivity in the range of C ₈ to C ₁₆ (%) = (Alken / consumed butene weight in the range of C ₈ to C ₁₆ generated) × 100

[Equation 3]

Alkene yield (%) in the range of C ₈ ~ C ₁₆ = (butene conversion × air oil selectivity) / 100

Hereinafter, the present invention will be described in more detail through examples, but the scope of the present invention is not limited thereto.

Preparation of desilica pentasil structured zeolite catalyst

It is to perform a small polymerization reaction of a butene mixture by using a desilica pentasil-structured zeolite catalyst. The desilica-type pentasil-structured zeolite catalyst was used, and the method for preparing the de-silica-type pentasil-structured zeolite catalyst was prepared by removing silica from the zeolite skeleton using a zeolite and a basic aqueous solution to prepare a material for the intermediate pores. Method was used.

First, a 0.2 M sodium hydroxide solution was prepared by dissolving 4.8 g of sodium hydroxide in 600 g of distilled water, and 10 g of ZSM-5 zeolite (molar ratio of silica and alumina of 80) was mixed with the aqueous sodium hydroxide solution. Desilicazed ZSM-5 (DS-ZSM-5) was synthesized while reflux cooling for 30 minutes at ℃. The precipitate thus obtained was obtained by vacuum filtration, washed with distilled water, and dried in an oven at 100 ° C. for 24 hours. Subsequently, the ion exchange was carried out using an aqueous solution of 0.1 M ammonium chloride to convert to an ammonium-substituted material, and desilica ZSM having an intermediate pore of 4 to 25 nm converted to a hydrogen-substituted material through a calcination process at 500 ° C. for 3 hours. -5 (DS-ZSM-5, a molar ratio of silica and alumina of 53) was obtained.

Porosity was measured by specific surface area and pore size through the results of nitrogen adsorption-desorption isotherm analysis, and FIG. 1 shows the results of pore size change before and after desilica reaction.

Referring to FIG. 1, which shows the pore size distribution of the catalyst, it can be seen that the intermediate pore size of the desilica ZSM-5 catalyst has a wide range of 4 to 25 nm compared to ZSM-5, and the specific surface area is also silica. It was confirmed that the specific surface area before the reaction increased from 430 m ² / g to 484 m ² / g after the desilica reaction.

Example

In a fixed bed continuous reactor, 1 g of desilica ZSM-5 catalyst having the intermediate pores prepared above was charged, and a butene mixture in which 1-butene and 2-butene was mixed in a weight ratio of 1: 1.3 was added at a flow rate of 10 ^{hr -1} . Then, a small polymerization reaction experiment was performed at 350 ° C and 15 bar.

After 3 hours from the start of the reaction, the product was analyzed using gas chromatography, butene conversion was 82.9%, the selectivity of the alkene in the range of C ₈ to C ₁₆ was 68.7%, and the yield of the alkene in the range of C ₈ to C ₁₆ was 57.0%. Was.

After 40 hours from the start of the reaction, the product was analyzed using gas chromatography to find that the butene conversion rate was 84.9%, the selectivity of alkenes in the range of C ₈ to C ₁₆ was 70.9%, and the yield of alkenes in the range of C ₈ to C ₁₆ was 60.2%. Was.

Comparative example

A fixed bed continuous reactor was charged with 1 g of HZSM-5 catalyst, a type of pentasil-structured zeolite, and a butene mixture in which 1-butene and 2-butene was mixed in a weight ratio of 1: 1.3 was introduced at a flow rate of 10 ^{hr -1} , and 350 ° C. , A small polymerization reaction experiment was conducted at 15 bar.

After 3 hours from the start of the reaction, the product was analyzed using gas chromatography, butene conversion was 81.4%, the selectivity of the alkene in the range of C ₈ to C ₁₆ was 65.6%, and the yield of the alkene in the range of C ₈ to C ₁₆ was 53.4%. Was.

When the product was analyzed using gas chromatography 40 hours after the start of the reaction, the butene conversion rate was 68.6%, the selectivity of the alkene in the range of C ₈ to C ₁₆ was 68.2%, and the yield of the alkene in the range of C ₈ to C ₁₆ was 46.5%. Was.

Table 1 shows the reaction conditions and analysis results comprehensively.

catalyst Reaction temperature
(℃) Reaction pressure (bar) WHSV
(hr ^-1 ) Reaction time (hr) Butene
Conversion rate
(%) Alken selectivity in the range of C ₈ to C ₁₆ (%) C ₈ ~ C ₁₆ range
Alken yield (%) Example DS-ZSM-5 350 15 10 3 82.9 68.7 57.0 40 84.9 70.9 60.2 Comparative example HZSM-5 350 15 10 3 81.4 65.6 53.4 40 68.6 68.2 46.5

As shown in the Examples and Comparative Examples in Table 1, when using the catalyst according to the present invention compared to the catalyst used for the small polymerization reaction of the conventional butene, the alkene selectivity has 68% or more and the yield is 54% or more. In particular, after the reaction time has elapsed, it can be seen that both the conversion rate of butenes of the desilica pentasil structured zeolite catalyst and the yield of alkenes in the range of C ₈ to C ₁₆ are improved. It can be seen that the increase was significantly greater than the existing pentasil-structured zeolite catalyst.

Claims (8)

Preparing a desilica pentasil structured zeolite catalyst prepared by treating a pentasil structured zeolite under a basic aqueous solution having a concentration of 0.2 to 0.5M,
Filling the reactor with a fixed catalyst on the desilica pentasil-structured zeolite,
Inducing a small polymerization reaction by passing butene through the reactor, and
The step of obtaining an alken in the range of C8 ~ C16 through the small polymerization reaction,
The desilica pentasil-structured zeolite catalyst is composed of a ZSM-5 unit structure, has an intermediate pore size of 4 to 25 nm, and a specific surface area of 450 to 500 m ² / g, from a butene to a range of C8 to C16 alkenes. Method of manufacturing. According to claim 1,
The butene is a method for producing alkene in the range of C ₈ to C ₁₆ from butene, characterized in that at least one of 1-butene and 2-butene is selected. According to claim 1,
The small polymerization reaction is a method of producing alkenes ranging from C ₈ to C ₁₆ from butene, which is performed at a reaction temperature of 200 to 550 ° C. According to claim 1,
The method for producing alkenes ranging from C ₈ to C ₁₆ from butene, characterized in that the weight hour space velocity (WHSV) of the small polymerization reaction is 1-50 hr ⁻¹ . delete delete delete delete

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