KR100905655B1 - A preparing method for modified mesoporous materials and a selective isomerization of 2-butene by using the same - Google Patents

Abstract

 The present invention relates to a method for producing a mesoporous material using a nanoparticulate organic compound and a surfactant mixture as a nanoporous template, and more particularly, to a method for producing a silicate molecular sieve having a high surface area and regular mesopores. . Isomerization of 2-butene using this mesoporous material as a catalyst can be converted to 1-butene with high yield and high selectivity.

Cyclodextrins, silicates, molecular sieves, catalysts, 2-butene, 1-butene, isomerization

Description

 A preparing method for modified mesoporous materials and a selective isomerization of 2-butene by using the same}

The present invention relates to a method for producing a mesoporous material using a nanoparticulate organic material and a surfactant mixture as a nanoporous template material, and more specifically, to a mixture of a nanoparticulate organic material such as cyclodextrin and a surfactant using 2 to Silicate molecular sieves with mesopores of 10 nm are prepared. In addition, the present invention relates to a method for converting 2-butene to 1-butene with high yield and high selectivity by isomerizing 2-butene in the presence of a catalyst of such mesoporous material.

As known from U.S. Pat.No. 5,098,684 to Kresge et al. And U.S. Pat.No.5,102,643, a series of mesoporous materials, named M41S family by the researchers of Mobil, for example MCM-41, MCM -48 was developed. These materials have very uniform pore sizes at the nanometer level, and their arrays have a uniform structure as if they were honeycombs. As known from U.S. Patent No. 5,958,368 and U.S. Patent No. 6,541,539, the mesos having various pore structures having a relatively large specific surface area ranging from 500 nm to 1000 m ² / g can be controlled in the nanopore size from 1 nm to 30 nm. Poros materials have been introduced. Studies on catalysts and various other applications are also underway using mesopores of these mesoporous materials. In general, when using porous materials for the application of adsorbents or catalysts, it is very important to have as large a specific surface area as possible. However, these MCM-41 series have a limit of up to about 1000 m ² / g surface area.

On the other hand, the C ₄ residue (butadiene, isobutene, 1-butene, 2-butene, normal butane mixture) separates butadiene from the C ₄ fraction from the naphtha cracking plant, and then reacts isobutene with methanol to make MTBE (methyl C ₄ residue oil II (1-butene, 2-butene, normalbutane mixture) remaining after preparation of tertiary buthyl ether), or C ₄ residue oil III (2-butene, normal) remaining after extracting 1-butene Butane mixture). To date, most of them are used as fuels. The isomerization of 2-butene contained in at least about 13% by weight of these C ₄ residue oil II or residue oil III, which is used as a low-cost fuel, enables the production of 1-butene, which can be used as a raw material for chemicals, to increase its added value. Can be.

There are many known techniques for producing 1-butene by isomerization of 2-butene. In particular, US Pat. No. 4,289,919 discloses pure 2-butene in a fixed bed reactor using a catalyst in which manganese oxide is supported on alumina. A method for producing 1-butene by isomerization has been described. US Pat. No. 4,409,418 describes isomerization of 2-butene in a fixed bed reactor using an oxide catalyst containing zirconium phosphate as an essential component and addition of chromium or thorium. A method for preparing butenes is described. U.S. Patent No. 5,955,640 discloses the yield of 1-butene by isomerization of 2-butene in a C ₄ fraction through butadiene hydrogenation, 1-butene recovery and butane separation using a catalyst in which silicate alumina is modified with sodium oxide. Methods of increasing are described, with low yield and selectivity of 1-butene. On the other hand, U.S. Patent No. 6,242,662 describes a process consisting of a hydro-isomerization process using a palladium catalyst and a distillation process to increase the yield of 1-butene by overcoming the thermodynamic limitation of the isomerization of 2-butene. Although the reaction occurs at a low temperature, the yield of 1-butene was very low.

As a result of the research to solve the problems of the prior art, when the mesoporous material is made by using nanoparticulate organic material as a pore-forming material together with a surfactant that has been traditionally used in the manufacture of the conventional mesoporous material, Silicate molecular sieve of the structure can be prepared, and this mesoporose material can be applied to the isomerization reaction to increase the selectivity and reaction activity of 1-butene to produce 1-butene in high yield to increase productivity. The present invention was completed based on this.

It is therefore an object of the present invention to provide a method for producing a mesoporous material having a high surface area while maintaining a more regular pore structure.

Another object of the present invention is to provide a method for producing 1-butene with high yield and high selectivity by using mesoporous material prepared by the above method as a catalyst for isomerization reaction.

Method for producing a mesoporous material according to the present invention for achieving the above object,

As the pore-forming substance, an ionic or nonionic surfactant and a cyclodextrin derivative represented by the following Chemical Formula 1 are mixed at a mass ratio of 1: 0.01 to 10.

In Formula 1, q = 3 to 12, and R ₁ , R ₂ and R ₃ are the same as or different from each other, a hydrogen atom, an acyl group of C ₂ to C ₃₀ , and C ₁ to C ₂₀ alkyl groups, C ₃ -C ₁₀ alkene groups, C ₃ -C ₂₀ alkyne groups, hydroxy alkyl groups, carboxyl groups, or Carboxy alkyl group.

Method for producing 1-butene for achieving another object of the present invention,

a) filling the reactor with a mesoporos molecular sieve according to the above production method on a fixed catalyst bed; b) providing a 2-butene-containing C ₄ to C ₄ residue or residues Ⅱ Ⅲ as a reactant was passed through the catalyst layer to the step of performing isomerization; And c) obtaining 1-butene.

Hereinafter, the present invention will be described in detail.

As described above, the present invention is to prepare a new silicate molecular sieve having a high surface area while maintaining a regular pore structure by making a mesoporous material by using nanoparticulate organic material as a pore-forming material with a surfactant. The second method relates to a method for preparing 1-butene which improves the yield and selectivity of 1-butene by performing isomerization of 2-butene selectively in the presence of a silicate molecular sieve catalyst having such mesopores compared to the conventional catalyst. will be.

The silicate molecular sieve according to the present invention is a silicate having mesopores having a pore size of 2 to 10 nm. As a pore forming material used in the preparation, a nanoparticulate organic material was mixed with a conventional surfactant. Conventional surfactants may use CTAB (Cetyltrimethylammonium bromide) as an ionic surfactant, and hydrocarbon and polyethylene oxide block copolymers (Brij series) or polyethylene oxide-polypropylene oxide-polyethylene oxide blocks as nonionic surfactants. Polymers of a copolymer (P123 series) can be used. A representative mesoporous material made using CTAB is MCM-41, a mesoporous molecular sieve composed of SiO ₂ and having a pore size of ₂ to 4 nm (20 to 40 microns). It is a catalyst which contains almost no acid point by itself, and has a structure in which the pores are arranged in a hexagonal arrangement of linear pores.

In the present invention, as a pore forming material, a nanoparticulate organic material was mixed with a surfactant such as CTAB, and a representative material of the nanoparticulate organic material is a cyclodextrin (CD) derivative. Cyclodextrin compound is a compound having a cyclic structure in which 6 to 8 glucopyranose groups are connected in the form of α (1 → 4), and can be divided into α, β, and γ types, respectively. β-type cyclodextrin compound has a three-dimensional structure with a maximum radius of about 15.4 mm 3. These cyclodextrin compounds may have strong hydrogen bonding with Si-OH groups in the silicate base walls, which are uniformly dispersed in the form of nano particles in the base walls, and then firing, which is the final step in the preparation of the mesoporous material. In the calculation process, very small nanopores within 2 nm can be formed on the base wall of mesoporous material to maximize the surface area of the material. For reference, β-type cyclodextrin is composed of seven glucopyranose, which may have a total of 21 hydroxyl groups (hydroxyl groups).

The pore-forming material according to the present invention may be preferably a material in which an ionic or nonionic surfactant and the cyclodextrin derivative are mixed in a mass ratio of 1: 0.01-10, more preferably 1: 0.1-1. Mixed materials are used. Here, when the cyclodextrin derivative is mixed at less than 0.01, the surface area improvement effect by the cyclodextrin is hardly exhibited, which is not preferable, and when it is mixed in excess of 10, it is undesirably due to the problem that the structural regularity of the pores collapses. do.

 Formula 1 below represents a cyclodextrin derivative.

<Formula 1>

In Formula 1, q = 3-12 and R ₁ , R ₂ , and R ₃ are the same as or different from each other, a hydrogen atom, an acyl group of C ₂ to C ₃₀ , and a C ₁ to C ₂₀ group. Alkyl group, C ₃ ~ C ₁₀ alkene group, C ₃ ~ C ₂₀ alkyne group, hydroxy alkyl group, carboxyl group, or carboxyalkyl Carboxy alkyl group.

    More preferred nanoparticulate cyclodextrin-based organic materials for implementing the present invention include α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin in a three-dimensional structure as shown in Formulas 2, 3, and 4. The size is a material having a limited three-dimensional structure of about 13 ~ 17Å.

R ₁ , R ₂ , and R ₃ in Formulas 2, 3, and 4 are the same as or different from each other, a hydrogen atom, an acyl group of C ₂ to C ₃₀ , and an alkyl group of C ₁ to C ₂₀ group, C ₃ ~ C ₁₀ alkene group (alkene group), C ₃ ~ C ₂₀ alkyne group (alkyne group), hydroxy alkyl group (hydroxy alkyl group, carboxyl group, or carboxy alkyl group (carboxy alkyl group) group).

More specific cyclodextrins for implementing the present invention can use one or more of the compounds listed below, and the kind of such compounds does not limit the present invention. Hydroxy cyclodextrins such as alpha-cyclodextrin, beta-cyclodextrin, gamma cyclodextrin, hexakis (2,3,6-tri-o-acetyl) -alpha-cyclodextrin [hexakis (2,3, 6-tri-O-acetyl) -α-cyclodextrin], heptakis (2,3,6-tri-o-acetyl) -beta-cyclodextrin [heptakis (2,3,6-tri-O-acetyl)- acetyl, such as β-cyclodextrin, octakis (2,3,6-tri-o-acetyl) -gamma-cyclodextrin, and octakis (2,3,6-tri-O-acetyl) -γ-cyclodextrin. ) Cyclodextrin series, or hexakis (2,3,6-tri-o-methyl) -alpha-cyclodextrin [hexakis (2,3,6-tri-O-metyl) -α-cyclodextrin], heptakis ( Cyclodextrins, such as the alkyl cyclodextrin family such as 2,3,6-tri-o-methyl) -beta-cyclodextrin [heptakis (2,3,6-tri-O-metyl) -β-cyclodextrin] Can be used.

The modified MCM-41 material prepared by using the mixture of the surfactant / nanoparticulate organic material prepared in the present invention as a pore-forming material may be prepared by conventional methods known in the art for silicate molecular sieves having mesopores. In one embodiment of the present invention, a mixture of Cetyltrimethylammonium bromide (CTAB), a cyclodextrin derivative, and sodium silicate may be obtained. The CD modified MCM-41 material thus prepared is either pure 2-butene or C ₄ residue II containing at least 13% by weight of 2-butene, and / or C ₄ residue III remaining after extracting 1-butene from it. Isomerization reaction using as a reactant can be applied under the following reaction conditions.

Isomerization of 2-butene in the present invention is carried out at a reaction temperature of 350 ℃ to 550 ℃, preferably 450 ℃ to 500 ℃, if the reaction temperature is less than 350 ℃ the reaction activity is lowered, exceeding 550 ℃ This can lead to a change in the structure of the CD-modified MCM catalyst, thereby lowering the reaction activity. Incidentally, the ratio of the 2-butene flow rate and catalyst WHSV (weigh hour space velocity) to 10hr ^-1 ~100hr ^-1, and more preferably a WHSV 18hr ^-1 ~70hr ^-1, a side reaction in the US only 10hr ^-1 Selectivity may decrease due to this, and if it exceeds 100hr ⁻¹ , the contact time may be too short, resulting in low activity.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited thereto.

Example 1.

Preparation of CD Modified MCM-41 Family of Mesoporous Materials (10 wt%)

NaOH 66 g and H ₂ O 443 g were dissolved in a water bath at 70-80 ° C., and 500 g of Ludox HS40 was added thereto, followed by stirring until the solution became clear to complete a sodium silicate solution of Na / Si = 0.5. Here, 12.15 g of Cetyltrimethylammonium bromide and 1.215 g of beta-cyclodextrin were mixed, stirred, and dissolved in 140 g of distilled water, followed by stirring while adding 50 g of sodium silicate solution dropwise, and then stirring in a 100 ° C. oven. The reaction was time. After 24 hours, the mixture was adjusted to pH 10 with 50% acetic acid twice, washed with distilled water, filtered and dried, then washed with ethanol, filtered and dried, and then calcined at 550 ° C. for 10 wt% of CD-modified MCM-41. Completed%

Example 2

CD  Deformed MCM -41 series Mesoporos  Preparation of materials (20 wt %)

20 wt% of CD-modified MCM-41 was completed under the same conditions except that 2.430 g of beta-cyclodextrin was used in Example 1.

Comparative Example 1

MCM -41 Mesoporos  Manufacture of substances

In Example 1 mesoporose material was prepared without using beta-cyclodextrin to complete MCM-41.

 catalyst BET XRD V _tot (cc / g) S _BET (m ² / g) Pore size (nm) D-spacing 2 θ Comparative Example 1 MCM-41 1.12 1132 3.02 40.49 2.18 Example 1 β-CD-MCM-41 (10%) 1.18 1212 2.89 39.06 2.26 Example 2 β-CD-MCM-41 (20%) 1.34 1301 3.12 42.23 2.09

VCR fittings were purchased, fabricated and used. The flow rate was controlled by installing a mass flow regulator between the 2-butene storage tank and the reactor. The temperature of the reactor was controlled using a custom-made tubular furnace, and after taking out the liquid product, the gaseous product was analyzed by direct connection with gas chromatography. Conversion rates, selectivity, and yields were calculated by the following equations (1) to (3).

% Conversion = (weight of 2-butene consumed / weight of 2-butene fed) x 100

1-butene selectivity (%) = (weight of produced 1-butene / weight of 2-butene consumed) × 100

1-butene yield (%) = (conversion × 1-butene selectivity) / 100

Example 3

In a fixed bed continuous reactor, 0.5 g of the CD-modified MCM-41 10 wt% catalyst prepared in Example 1 was charged and pure 2-butene 60 ml / min was added to conduct a 2-butene isomerization experiment. Two hours after the start of the reaction, the product was analyzed using gas chromatography. The 2-butene conversion was 28.5%, the selectivity of 1-butene was 99.6%, and the yield of 1-butene was 28.3%.

Example 4

In a fixed bed continuous reactor, 0.5 g of the CD-modified MCM-41 20 wt% catalyst prepared in Example 2 was charged, and pure 2-butene 60 ml / min was added to conduct a 2-butene isomerization experiment. Two hours after the start of the reaction, the product was analyzed using gas chromatography. The 2-butene conversion was 28.7%, the selectivity of 1-butene was 99.2%, and the yield of 1-butene was 28.5%.

Comparative Example 2

In a fixed bed continuous reactor, 0.5 g of the MCM-41 catalyst prepared in Comparative Example 1 was charged and pure 2-butene 60 ml / min was added to conduct a 2-butene isomerization experiment. Two hours after the start of the reaction, the product was analyzed using gas chromatography. The 2-butene conversion was 26.7%, the selectivity of 1-butene was 98.0%, and the yield of 1-butene was 26.2%.

catalyst Reaction temperature (℃) WHSV (hr ^-1 ) 2-butene conversion (%) 1-butene selectivity (%) Yield of 1-butene (%) Comparative Example 2 MCM-41 470 18 26.7 98.0 26.2 Example 3 β-CD-MCM-41 (10%) 470 18 28.5 99.6 28.3 Example 4 β-CD-MCM-41 (20%) 470 18 28.7 99.2 28.5

According to the present invention, as shown in the comparative examples and examples, when the conventional nano-particulate pore-forming material was added, the surface area of the mesoporous material was effectively increased, and as a result of applying this to the isomerization reaction of 2-butene, When the catalyst according to the present invention is used as compared to the MCM-41 catalyst, the conversion of 2-butene is improved, so that the selectivity and yield of 1-butene are improved, and thus it may be industrially useful when applied to the actual process. It is expected.

Claims (7)

Method for producing a mesoporous material, characterized in that for use as a pore-forming material, a cyclodextrin derivative of the general formula (1) is mixed at a mass ratio of 0.01 to 10 times based on an ionic or nonionic surfactant. <Formula 1>

In Formula 1, q = 3 to 12, and R ₁ , R ₂ , and R ₃ are the same as or different from each other, a hydrogen atom, an acyl group of C ₂ to C ₃₀ , and C ₁ to C _An alkyl group of _20, an alkene group of C ₃ -C _10, an alkyne group of C ₃ -C ₂₀ , or a hydroxy alkyl group. The method of claim 1, wherein the ionic surfactant is CTAB (Cetyltrimethylammonium bromide), the non-ionic surfactant is a block copolymer of hydrocarbon and polyethylene oxide or a block copolymer of polyethylene oxide-polypropylene oxide-polyethylene oxide Characterized in that the method for producing a mesoporous material. The method of claim 1, wherein the cyclodextrin derivative of Chemical Formula 1 has a q of 6 to 8. a) providing 2-butene as reactant; b) isomerizing the 2-butene by passing it through a reactor filled with a mesoporos molecular sieve prepared by the method of any one of claims 1 to 3 on a fixed catalyst; And c) obtaining 1-butene from the 2-butene. 5. The method of claim 4, wherein the 2-butene is included in C ₄ residue II or C ₄ residue III. 6. The method of claim 4, wherein the isomerization reaction is performed at a reaction temperature of 350 ° C. to 550 ° C. 6. The method of claim 4, wherein the weight hour space velocity (WHSV) of the isomerization reaction is 10hr ^-1 to 100hr ^-1 .