JPH08103659A - Crystalline titanium-silicalite coated catalyst for epoxidation of olefin compound - Google Patents

Abstract

PURPOSE: To provide a crystalline titanium.silicalite coated catalyst having such strength that it can be industrially and continuously used for a long time and producing an epoxide compd. with high selectivity without causing a side reaction when an olefin compd. is epoxidized with hydrogen peroxide. CONSTITUTION: The surface of a spherical carrier is coated with a crystalline titanium.silicalite layer to obtain the objective crystalline titanium silicalite.coated catalyst.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to the epoxidation of an olefin compound with hydrogen peroxide in a fixed bed, fluidized bed or moving bed type reaction form in a stable and continuous manner for a long time. It relates to a spherical crystalline titanium-silicalite coating catalyst suitable for synthesizing a product having

[0002]

2. Description of the Related Art Crystalline titanium / silicalite is already known as a catalyst for producing an epoxide compound such as ethylene oxide or propylene oxide from hydrogen peroxide and an olefin compound such as ethylene or propylene. Various proposals have been made regarding the mechanism and the catalyst preparation method.

For example, regarding the reaction mechanism, J. C
atal. , 133 , 220 (1992), the epoxide compound is formed in the micropores of crystalline titanium silicalite, and the oxirane ring of the obtained epoxide compound is also opened in the micropores to form glycol and glycol ethers. It is disclosed to be decomposed. Therefore, in order to obtain an epoxide compound with high selectivity,
It is also known that it is indispensable to make the crystalline titanium-silicalite catalyst into a fine spherical shape, shorten the diffusion distance in the pores, and quickly remove the produced epoxide compound from the pores.

Further, a method for preparing a crystalline titanium-silicalite catalyst suitable for synthesizing an epoxide compound from hydrogen peroxide and an olefin compound is disclosed in JP-A-61-1.
83275, JP-A-62-185081, JP-A-6-6
No. 9592, Japanese Examined Patent Publication No. 4-5028, and European Patents 315, 247 and 315, 248, the crystalline titanium-silicalite catalysts disclosed therein are all crystalline. Fine particles of titanium and silicalite alone, which are not suitable for continuous long-term epoxidation reaction in industrially fixed bed, fluidized bed or moving bed type reactors. In order to overcome this, it was necessary to physically form a spherical material having a certain strength.

Further, as a method of physically molding crystalline titanium / silicalite into a spherical material or the like, JP-A-63-1124 is used.
In No. 12, mixed crystalline titanium / silicalite with a binder and spray-dried to obtain a diameter of 5 to 1,000 μm.
A method for obtaining a porous spherical body of m has also been proposed, but the spherical body formed by this method has a short diffusion distance in the catalyst pores as in the case of the above-mentioned fine particles, and the produced epoxide compound can be rapidly produced. Although it is preferable in that it is removed from the inside of the pores and the selectivity is increased, the catalyst used in a fixed bed, fluidized bed or moving bed reactor is a catalyst packed or
It was not practical in terms of easiness of taking out and easiness of flow, and was also insufficient in terms of strength.

[0006]

In view of the above conventional circumstances, the present invention can be industrially suitably applied to a fixed bed, fluidized bed or moving bed type reactor and can be continuously used for a long time. To provide a crystalline titanium-silicalite catalyst having high strength and capable of producing an epoxide compound with a high selectivity without causing a side reaction when epoxidizing an olefin compound with hydrogen peroxide. With the goal.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to achieve the above object, and as a result, by uniformly coating crystalline titanium / silicalite on the surface of an inert spherical carrier, The present invention has been completed by finding that the above object can be achieved and an industrially useful catalyst for epoxidation of olefin compounds can be obtained.

Accordingly, the gist of the present invention resides in a crystalline titanium-silicalite coating catalyst for epoxidation of an olefin compound, characterized in that the surface of a spherical carrier is coated with a crystalline titanium-silicalite layer.

The crystalline titanium silicalite used in the present invention is generally obtained in the form of fine powder.
A known method such as that disclosed in ZEOLITES, 12 , 943 (1992) may be used. For example, titanium tetrabutoxide is added dropwise into a mixture of tetraethylorthosilicic acid and an aqueous solution of tetra-n-propylammonium hydroxide. After preparing the gel, in the autoclave,
It can be obtained by hydrothermal synthesis at 170 ° C. under a generated pressure for 2 to 7 days.

The crystalline titanium / silicalite fine powder thus obtained has a Si / Ti atomic ratio of 7 to 10,000, preferably 10 to 200.

Further, the spherical carrier for coating the crystalline titanium / silicalite fine powder is not particularly limited as long as it has a certain strength and is inert, and examples thereof include spherical silica gel and spherical alumina gel. Appropriate. Also, the size of this spherical carrier is an industrial fixed bed,
Suitable for use in fluidized bed or moving bed reactors,
The diameter is preferably 0.2 to 20.0 mm.

The coating of the crystalline titanium / silicalite on the surface of the spherical carrier is carried out by mixing a fine powder of crystalline titanium / silicalite with a binder to form a slurry solution and spraying it onto the rolling carrier. be able to.

Any binder may be used as long as it can be burned and removed by subsequent firing, and for example, an aqueous solution of glycerin, polyvinylpyrrolidone, methyl cellulose, polyvinyl alcohol, Tween 80 (manufactured by Aldrich) can be used. .

The concentration of the crystalline titanium / silicalite in the slurry solution consisting of the crystalline titanium / silicalite fine powder and the binder is generally 1 to 80% by weight, preferably 2 to
40 wt% is appropriate. In this case, in order to make the bond between the coating layer and the carrier more rigid, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetra-n-propylammonium hydroxide, tetra-i-hydroxide is added to the slurry solution. It is also effective to add 0.1 to 20.0 wt% of a quaternary organic base such as propylammonium and tetra-n-butylammonium hydroxide. Further, in order to reduce the content of crystalline titanium / silicalite in the coating layer, a silica gel fine powder (0.1 to 5.0) was previously added to the slurry solution.
It is also possible to add 0.01 to 5 times by weight, preferably 0.1 to 2 times by weight, to the crystalline titanium / silicalite fine powder.

For the spraying of the slurry solution onto the surface of the spherical carrier, a well-known means such as spraying at a rate of 2 to 50 ml / min with a spray gun while the spherical carrier is rolling on a granulator is used. .

The coating catalyst obtained is from 50 to 12
After drying at 0 ° C for 1-48 hours, 1-1 at 300-550 ° C
Bake for 2 hours.

The thickness of the coating layer after baking is appropriately 0.0001 to 0.1, preferably 0.01 to 0.1, relative to the diameter of the spherical carrier.

The crystalline titanium-silicalite coating catalyst according to the present invention provides an epoxide compound with a high selectivity from hydrogen peroxide and an olefin compound, and further, a fixed bed, fluidized bed or moving bed reactor is used. It is useful as a catalyst for the industrial continuous production method used.

The epoxidation reaction to which the catalyst of the present invention can be applied may be similar to the conventional epoxidation reaction between hydrogen peroxide and an olefin compound.

For example, as a hydrogen peroxide source used as a raw material, commercially available 30 wt% hydrogen peroxide solution or unpurified hydrogen peroxide obtained by oxidizing a secondary alcohol with molecular oxygen can be used as it is. it can. The epoxidized olefin compound is at least 1
Acyclic and cyclic organic compounds having an ethylenic double bond, specifically, ethylene, propylene, 2-butene, isobutene, 1-octene, cyclohexene, allyl alcohol, methyl oleate, diallyl ether and Examples include allyl chloride.

Further, the reaction is a liquid phase reaction and can be carried out under atmospheric pressure, but when the olefin compound is in a gaseous state, it is preferable to keep the pressure sufficient to dissolve it in the liquid phase. The reaction temperature is 0 to 100 ° C., preferably 20 to
It is 80 ° C. Further, the supply rate of the reaction raw material is catalyst volume / raw material supply rate (V / F) = 0.05 to 2.0, preferably 0.05 to 0.5.

[0022]

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

Example 1 50 g of crystalline titanium / silicalite fine powder (Si / Ti atomic ratio = 13) and 150 g of 20 wt% polyvinyl alcohol aqueous solution as a binder were mixed and stirred at room temperature for 1 hour,
A slurry solution was prepared. Next, diameter 1.8-2.0m
250 g of m spherical silica gel (Carriact 10 manufactured by Fuji Silysia Chemical Ltd.) was tumbled on a centrifugal fluidized granulator (CF360S manufactured by Freund Sangyo Co., Ltd.), and the slurry solution was sprayed at 5 ml / min. During this period, air was continuously blown at 150 l / min to facilitate rolling. After spraying, dry at 80 ℃ for 20 hours, 300 ℃
Calcination was carried out for 2 hours and then at 550 ° C. for 2 hours. As a result, a catalyst coated with 0.14 g of crystalline titanium silicalite per 1 g of spherical silica gel was obtained (hereinafter referred to as "catalyst 1").

FIG. 1 shows an electron beam microanalyzer (Shimadzu E
The distribution diagram of titanium of the catalyst cross section analyzed using PMA-8705) with an acceleration voltage of 15 kV, an irradiation current of 50 nA, a spectroscopic crystal PET (pentaerythritol), an analysis range of 3 × 3 mm, and an analysis time of 262 minutes is shown.

The catalyst is spherical, and the crystalline titanium-silicalite coating layer has a thickness of 0.01 to 0.1 mm (coating layer thickness / spherical silica gel diameter = 0.005).
It can be seen that the entire catalyst is completely coated at .about.0.056).

Example 2 20 g of silica gel fine powder and 20 wt% tetra-n hydroxide hydroxide
-Mix 70g of propylammonium aqueous solution and mix at room temperature for 1
Stir for hours. The same crystalline titanium / silicalite fine powder 14 g as in Example 1 and glycerin 4.2 g as a binder were added thereto to prepare a slurry solution. Next, coating, drying, pre-baking and firing were performed in the same manner as in Example 1 except that the above slurry solution was sprayed onto 70 g of the same spherical silica gel as used in Example 1 at 10 ml / min. A catalyst coated with 0.1 g of crystalline titanium-silicalite was obtained (hereinafter referred to as "catalyst 2").

The tetra-n-propylammonium hydroxide used here has a function of dissolving the surface of the silica gel, and as a result, has a function of strengthening the bond between the coating layer and the silica gel.

Comparative Example 1 Silica gel fine powder 6 g, 20 wt% hydroxide tetra-n-
20 g of propylammonium and 8 g of water were mixed, and to this was added 1 g of crystalline titanium / silicalite fine powder as in Example 1.
Was added and kneaded while drying with a kneader until the amount of water that can be formed was obtained, and a wire having an outer diameter of 2 mm was obtained by an extrusion molding machine. Next, in the same manner as in Example 1, drying, calcination, and calcination were performed, and thereafter, the material was cut into a cylindrical shape having a length of 5 mm (hereinafter referred to as "catalyst 3").

Example 3 2.8 m of catalyst 1 was placed on a stainless steel column having an inner diameter of 12 mm.
A reactor filled with 1 was prepared, and 154 g of methyl alcohol, 181 g of isopropanol, 27 mg of disodium dihydrogen pyrophosphate, 30 wt% hydrogen peroxide solution were added to the reactor.
A reaction raw material in which 42 g of propylene was mixed with g was passed through the column at a catalyst volume / raw material supply rate (V / F) = 0.1,
The propylene epoxidation reaction was carried out at a reaction temperature of 60 ° C. As a result, the reaction rate based on hydrogen peroxide was 95%, and the propylene oxide selectivity was 91%.

Example 4 The epoxidation reaction of propylene was carried out in the same manner as in Example 3 except that the catalyst 2 was used instead of the catalyst 1 and the catalyst volume / raw material supply rate (V / F) was 0.2. . As a result, the reaction rate based on hydrogen peroxide was 92%, and the propylene oxide selectivity was 8
It was 9%.

Comparative Example 2 The propylene epoxidation reaction was carried out in the same manner as in Example 3 except that the catalyst 3 was used in place of the catalyst 1 and the catalyst volume / raw material supply rate (V / F) was 0.2. . As a result, the reaction rate based on hydrogen peroxide was 37%, and the propylene oxide selectivity was 6
4%.

Comparative Example 3 The propylene epoxidation reaction was carried out in the same manner as in Example 3 except that the catalyst 3 was used in place of the catalyst 1 and the catalyst volume / raw material supply rate (V / F) was 0.6. . As a result, the reaction rate based on hydrogen peroxide was 63%, and the propylene oxide selectivity was 5
It was 8%. Although the catalyst amount was increased from those of Examples 3 and 4, both the reaction rate and the selectivity were low.

Example 5 2.8 m of catalyst 1 was placed on a stainless steel column having an inner diameter of 12 mm.
A reactor charged with 1 l was prepared, and 335 g of isopropanol, 27 mg of disodium dihydrogen pyrophosphate, 3 mg were added thereto.
A reaction raw material prepared by mixing 56 g of isobutene with 30 g of 0 wt% hydrogen peroxide was used as catalyst volume / raw material supply rate (V / F) =
The solution was passed through the column at 0.2, and the epoxidation reaction of isobutene was performed at a reaction temperature of 60 ° C. As a result, the reaction rate based on hydrogen peroxide was 82% and the isobutene oxide selectivity was 80%.

Comparative Example 4 The epoxidation reaction of isobutene was carried out in the same manner as in Example 5 except that the catalyst 3 was used in place of the catalyst 1 and the catalyst volume / raw material supply rate (V / F) was 0.4. . As a result, the reaction rate based on hydrogen peroxide was 43% and the isobutene oxide selectivity was 6
It was 1%. Although the catalyst amount was increased from that of Example 5, both the reaction rate and the selectivity were low.

Example 6 2.8 m of catalyst 1 was placed on a stainless steel column having an inner diameter of 12 mm.
A reactor charged with 1 l was prepared, and 335 g of isopropanol, 27 mg of disodium dihydrogen pyrophosphate, 3 mg were added thereto.
Allyl alcohol 58 in 30 g of 0 wt% hydrogen peroxide solution
The reaction raw material mixed with g was used as a catalyst volume / raw material supply rate (V /
F) = 0.2 was passed through the column, and the epoxidation reaction of allyl alcohol was performed at a reaction temperature of 60 ° C. as a result,
84% reaction rate based on hydrogen peroxide, glucidol selectivity 7
7%.

Example 7 2.8 m of catalyst 1 was placed on a stainless steel column having an inner diameter of 12 mm.
A reactor filled with 1 l was prepared, and 0.003 wt% of disodium dihydrogen pyrophosphate, 2 wt% of hydrogen peroxide,
Propylene 10 wt%, isopropanol 44 wt%,
38 wt% of methanol and 6 wt% of water were used as reaction raw materials and passed through the column at a catalyst volume / raw material supply rate (V / F) = 0.1, and a continuous reaction was performed at a reaction temperature of 60 ° C. for 100 hours. After the reaction was completed, air was passed through the column at 80 ° C.
The catalyst was regenerated by drying for 2 hours and calcining at 370 ° C. for 13 hours. After allowing this to cool, the same continuous reaction as above was performed again. The above reaction and catalyst regeneration cycles were repeated, and the propylene oxide yield (%) at the reaction time of 20 hours and 100 hours in each cycle reaction [reaction rate based on hydrogen peroxide (%) x propylene oxide selectivity (%) ) ÷ 100] is shown in FIG. The catalyst of the present application is
No deterioration in catalyst performance was observed even after repeating 15 cycles.

[0037]

EFFECTS OF THE INVENTION According to the catalyst of the present invention, an epoxide compound can be economically and industrially produced with a fixed bed, a fluidized bed or a moving bed type reactor for a long period at a high yield and a high selectivity. it can. Further, since the catalyst of the present invention has a high strength, even if it is repeatedly regenerated by firing, it does not undergo a shape change such as miniaturization and maintains a constant shape, and the catalyst activity does not decrease. Therefore, the catalyst of the present invention is very useful in the industrial production of epoxide compounds from hydrogen peroxide and olefin compounds.

[Brief description of drawings]

FIG. 1 is a distribution diagram of titanium atoms by an electron beam microanalyzer of a catalyst 1 having a cross section polished after embedding with an epoxy resin.

FIG. 2 is a diagram showing a propylene oxide yield (%) in each cycle in Example 7.

[Explanation of symbols]

 1 Titanium atom in coating layer 2 Spherical silica gel carrier

Claims (4)

[Claims] 1. A crystalline titanium-silicalite coating catalyst for epoxidation of an olefin compound, characterized in that the surface of a spherical carrier is coated with a crystalline titanium-silicalite layer. 2. The thickness of the crystalline titanium-silicalite layer to the diameter of the spherical carrier is 0.0001-0.
The catalyst according to claim 1, which is 1. 3. The spherical carrier has a diameter of 0.2 to 20.0 m.
The catalyst according to claim 1 or 2, which is m. 4. The catalyst according to claim 1, wherein the spherical carrier is alumina or silica gel.