JPH10291986A - Epoxidation of olefinic hydrocarbon and its halide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit the deterioration of a titanium silicalite catalyst for a long period by controlling the concentration of sodium in a reaction system within a specific range, when various kinds of olefins are epoxidized with hydrogen peroxide in the presence of the catalyst. SOLUTION: This olefinic hydrocarbon or its halide is epoxidized with hydrogen peroxide in the presence of a titanium-containing zeolite expressed by the composition formula: xTiO2 .(1-x)SiO2 [0.0005<(x)<0.5] and having a MFI crystal structure in a solvent. Therein, it is important that the concentration of sodium in the epoxidation reaction system is <=1 ppm. When the raw material hydrogen peroxide having a sodium concentration of <=2 ppm is used, the above-described sodium concentration is thereby achieved. The profitability of the method is excellent, because the production of the epoxide per unit catalyst is increased and further because the deterioration of the catalyst is inhibited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for epoxidizing an olefinic hydrocarbon or its halide with hydrogen peroxide in the presence of a titanium silicalite catalyst having an MFI crystal structure. The present invention relates to a method for suppressing excessive deterioration.

[0002]

2. Description of the Related Art Among the methods for epoxidizing olefin compounds, the method using hydrogen peroxide as an oxidizing agent is characterized in that hydrogen peroxide has a high active oxygen content per unit weight and is relatively inexpensive, However, many studies have been made because water is only water and has advantages such as low environmental load. However, only a very limited number of these have reached industrial practice. The presence of water, which is a diluting solvent for hydrogen peroxide, and water generated by the reaction make it difficult to contact the highly hydrophobic olefin compound with hydrogen peroxide, so that the reaction rate is slow and the generated epoxy ring is hydrolyzed. Is promoted and the yield is reduced. As a solution to this problem, hydrogen peroxide is previously reacted with a carboxylic acid such as acetic acid or propionic acid to convert it to a corresponding peracid, and a substantially anhydrous peracid solution is obtained by extraction or the like, and this is used. A method of performing an epoxidation reaction (Japanese Patent Laid-Open No. 51-13321)
0, JP-A-51-143604) or arsenic, boron,
In the presence of oxide catalysts such as molybdenum and selenium, use high-concentration hydrogen peroxide of 70 wt% or more, remove water generated during the reaction by some means, and perform the reaction while reducing the water concentration in the system as much as possible. A method is known (JP-A-53-68707).
No., JP-A-53-95901). However, the former method has a complicated process and basically requires handling a high concentration of peracid, which has an inherent danger of explosion.The latter method has a problem of catalyst recycling, and both methods are industrially implemented. Has not been reached. In recent years, titanium silicalite, a zeolite in which part of silicon in the crystal lattice of silicalite having an MFI or MEL structure is replaced with titanium, is a very effective catalyst for epoxidation of olefins using hydrogen peroxide as an oxidizing agent. Something was found (JP-A-59-51273). The method using this catalyst enables efficient epoxidation even with a low concentration of hydrogen peroxide solution of about 30 wt%, and is easy to separate from the reaction system because it is a solid catalyst.
This is an industrially promising method that has solved the above-mentioned disadvantages of the conventional method.

[0003]

DISCLOSURE OF THE INVENTION The present inventors have studied in detail the epoxidation reaction of various olefins with hydrogen peroxide using the above titanium silicalite catalyst.
Although the reaction itself proceeds well and gives the corresponding epoxide with relatively good performance, the activity of the catalyst is rapidly degraded, and regenerating operation by known means such as calcination or washing with a solvent is indispensable at a considerable frequency. There was found. It is considered that an epoxidation reaction can be carried out many times by this regeneration operation, and an economically advantageous process can be constructed if the amount of epoxide produced per unit catalyst weight can be increased. However, according to the study of the present inventors, the activity gradually decreases as such reaction and regeneration are repeated many times over a long period of time, and at some point it may be degraded to an extent that it can no longer be used. It was revealed. The catalyst with reduced activity is discarded because it is no longer possible to reuse it.
It has been found that the loss of this expensive titanium silicalite catalyst results in high production costs for the epoxide, and the process is completely economically ineffective. The present invention relates to a method for producing an epoxide by epoxidizing an olefin compound with hydrogen peroxide in the presence of a titanium silicalite catalyst having an MFI structure, in which the regeneration of the catalyst, which is a disadvantage of the conventional method, is repeated for a long time. The object of the present invention is to provide a method for epoxidizing an olefin compound which overcomes the decrease in catalytic activity, increases the amount of epoxide produced per unit catalyst, and therefore has a low cost of the catalyst in the production cost and is excellent in economic efficiency.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, it has been found that a trace amount of sodium present in the reaction system is crucial for the long-term deterioration of the catalyst. I found out that I was playing a role. As a result, under the condition that the sodium concentration in the reaction system is lower than a certain value, the inventors have found a surprising fact that no deterioration of the catalyst is observed even by repetition of regeneration, and have completed the present invention. . That is, the method of the present invention uses the composition formula xTiO2. (1-x) SiO2 (0.0005 <x <
0.5) and present in the reaction system in the epoxidation of olefin compounds in which olefin compounds are reacted with hydrogen peroxide in the presence of titanium-containing zeolites having the MFI crystal structure and one or more solvents. Is characterized in that the concentration of sodium is less than 1 ppm.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The titanium silicalite used in the present invention has a composition formula xTiO2. (1-x) SiO2 (0.0005 <x
<0.5, preferably 0.0005 <x <0.04), and ZSM-5
Has the same MFI structure (IUPAC code name). Such a titanium silicalite catalyst can be obtained by a known method (for example, US Pat.
P4, 410, 501). That is, using tetraethyl orthosilicate as a silicon oxide source and tetraethyl orthotitanate as a titanium oxide source,
A sol is prepared using tetrapropylammonium hydroxide (TPAOH) as a base, and titanium silicalite crystals are obtained by hydrothermal synthesis. At this time, it is known that if the used TPAOH contains an alkali metal, only titanium silicalite having a low catalytic activity can be obtained (B. Notari, Stud. Surf. Sci. Catal., 37 343 (19)
91)) and therefore TP substantially free of alkali metals
The use of AOH is important for obtaining good initial activity. Further, the titanium silicalite catalyst thus prepared is further treated with a water-soluble base such as sodium acetate, sodium hydrogen phosphate, and sodium carbonate to neutralize acid sites on the catalyst, thereby producing an epoxy product. A known method such as suppression of hydrolysis or solvolysis (Japanese Patent Publication No. 8-16105) can be used, but is not essential. Regardless of the presence or absence of such treatment, the concentration of sodium contained in the catalyst is desirably 100 ppm or less.

[0006] The amount of titanosilicate catalyst can vary considerably depending on the reaction mode, but when used in a slurry system, it is usually appropriate that the concentration in the reaction mixture be in the range of 0.1 to 20% by weight, more preferably , 0.5 to 10% by weight. In a fixed bed flow reaction system, an apparently larger amount of catalyst will be used.

[0007] The reaction solvent is selected from a group of substances which are phase solvents for water and hydrogen peroxide and the olefin compound and are inert to the reaction. Examples of such a substance include alcohols, ketones, ethers, and glycols.Specifically, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, acetone, methyl ethyl ketone, Diethyl ketone,
Methyl isopropyl ketone, methyl isobutyl ketone,
Ethyl isopropyl ketone, tetrahydrofuran, 1,
Examples thereof include 4-dioxane and ethylene glycol. Further, a mixture of these substances at an appropriate ratio can be used as a solvent.

[0008] There is an appropriate range for the amount of solvent. If the amount of the solvent is too small, the reaction mixture is separated into an organic layer and an aqueous layer with the progress of the reaction, and the effect of the hydrolysis reaction of the epoxy compound, which mainly proceeds in the aqueous layer, is not preferable. On the other hand, if the amount of the solvent is too large, the reaction rate decreases and the concentration of the epoxy compound in the reaction solution decreases, so that the energy cost for removing a large amount of the solvent becomes too large, which is not economical. Therefore, it is preferable that the amount of the solvent is the minimum amount required to maintain the reaction results. The amount of such a solvent may vary depending on the olefin compound used and the molar ratio of the olefin compound to hydrogen peroxide, but is usually in the range of 5 to 80% by weight, more preferably 15 to 50% by weight, based on the total amount of the reaction mixture. Is selected from

In the present invention, the sodium concentration in the reaction solution is
It is characterized by being in the range of 1 ppm or less. Solvents, olefin compounds, hydrogen peroxide, catalysts, reactors, and the like can be used as sources of sodium contamination. If the total concentration of these is 1 ppm or less, the effect can be obtained. Among these, the largest contribution of sodium mixed in from the raw material hydrogen peroxide continuously added to the reaction system,
In many cases, the above-mentioned sodium concentration in the solution is achieved by using a raw material having a sodium concentration of 2 ppm or less in hydrogen peroxide. In general, industrially available concentrations of 35% by weight, 60% by weight, 70% by weight of hydrogen peroxide solution include:
Various stabilizers have been added for the purpose of suppressing the catalytic decomposition of hydrogen peroxide. As typical stabilizers, for example,
Sodium pyrophosphate, sodium stannate and the like are known (Kirk-Othmer, Encyclopedia of Chemical Technolog
y, 3rd ed., vol. 13, p.14). In the present invention, by using hydrogen peroxide such that the sodium concentration derived from these stabilizers and the like is 2 ppm or less, more preferably 1 ppm or less, regeneration over a long period of time, deterioration of the catalyst activity even by repeated reaction is reduced. There is almost no catalyst, so that the ratio of the catalyst to the production cost is small, and the process can be economically excellent.

[0010] Such a hydrogen peroxide solution having a small content of the sodium compound is obtained by the following method. That is, by distilling industrial hydrogen peroxide containing a sodium compound or the like, a hydrogen peroxide solution substantially free of a sodium compound or the like is obtained, and by adjusting it to an appropriate concentration by a known method, the present invention is achieved. Hydrogen peroxide that can be used for the above purpose. Alternatively, as a simpler method, hydrogen peroxide from which dissolved cations such as sodium have been removed can be obtained by a known method of passing an industrial hydrogen peroxide solution through an appropriate ion exchange resin.

The olefin compounds to be epoxidized according to the invention are acyclic and cyclic organic compounds having at least one ethylenically unsaturated functional group. Preferred olefin compounds are those containing 3 to 20 carbon atoms. Examples of olefin compounds include propylene,
Examples thereof include 1-butene, 2-butene, isoprene, 1-hexene, 1-octene, 1-octadecene, and allyl alcohol. These may be used alone or in combination of two or more.

[0012] The amount of hydrogen peroxide to be added can be used in excess in molar ratio with respect to the olefin compound, or the olefin compound can be used in excess. The preferred range of the olefin compound / hydrogen peroxide molar ratio is 0.9 to 5
And more preferably 1.5 to 3. The present invention provides a catalyst,
A so-called batch reaction system in which a solvent and an olefin compound are put into a reactor and hydrogen peroxide is added thereto to start a reaction, or a so-called batch reaction method can be used, or a solvent, an olefin compound and hydrogen peroxide are continuously fed into the reactor A so-called continuous reaction system in which the reaction solution is introduced and the reaction solution is simultaneously withdrawn is also possible.

In the present invention, the epoxidation reaction can be carried out under atmospheric pressure, but when the olefin compound is gaseous at the reaction temperature, it is necessary to maintain a pressure sufficient to dissolve it in the liquid phase. Preferably, it is usually carried out at 1 to 100 atm. The reaction temperature is preferably in the range of 0 to 150 ° C, more preferably 20 to 100 ° C.

The catalyst gradually degrades each time it is used in the reaction,
Since it does not show the initial activity, it is subjected to a reproducing operation. As the regeneration operation, baking or washing with a solvent is known, but it is difficult to completely restore the initial activity only by washing with a solvent. Therefore, a regeneration method by baking, or a combination of solvent washing and baking is used. preferable. In the regeneration by calcination, the active component adhering to the catalyst filtered from the reaction solution is recovered by washing, dried, and then regenerated by calcination at 400 to 600 ° C. in an oxygen-containing gas atmosphere. If the firing temperature is higher than 600 ° C., the crystal structure of zeolite may be destroyed, and a so-called sintering phenomenon may occur. On the other hand, at temperatures lower than 400 ° C., regeneration of the catalyst is not sufficient.
The preferred temperature range is 500-550 ° C.

[0015]

EXAMPLES The present invention will be described below in detail with reference to examples, but the contents of the present invention are not limited in any way by these examples. Reference Example (Method for Preparing Titanosilicate Catalyst) 375 g of tetraethylorthosilicate and 10.3 g of tetraethylorthotitanate were placed in a three-liter four-neck separable flask, and 20% by weight of tetrapropylammonium was added using a dropping pump under a nitrogen stream. Hydroxide aqueous solution 648
g was dropped at a rate of 5.4 g / min. During the addition, the temperature of the reaction solution was adjusted to be constant at 20 ° C. Stirring is continued for a while after the completion of the dropwise addition, and the hydrolysis is allowed to proceed completely.
The reaction temperature was heated to 80 ° C., and ethanol produced by the hydrolysis was distilled off from the reaction solution to obtain a transparent sol. 290 g of distilled water was added to the obtained sol, and the total weight of the solution was 885 g, and
A 3 liter autoclave made of US316 was filled at a filling rate of 30%. After the gas in the autoclave was replaced with nitrogen, the autoclave was closed and heated to 170 ° C. for 2 days, and then heated to 210 ° C. for 2
After maintaining at 210 ° C. for a day, it was cooled to room temperature. The liquid containing the white solid was centrifuged at 3000 rpm for 20 minutes using a centrifugal separator to separate an almost transparent supernatant liquid and white titanosilicate particles. The obtained white titanosilicate particles are washed with distilled water, dried, and heated in an electric furnace at 550 ° C. in air.
The calcining treatment was performed for 6 hours to obtain 91.7 g of a titanosilicate catalyst. The Si / Ti ratio in the obtained crystalline titanosilicate was 66 as determined by X-ray fluorescence.

Example 1 In a 200 ml flask, 3.56 g of the catalyst prepared in the above reference example, 1-
Octene 50.0 g, methanol 30.0 g, and methyl ethyl ketone 30.0 g were charged, fitted with a stirrer, a thermometer, and a reflux condenser, and heated in a 61 ° C. water bath. When the temperature of the solution reached 60 ° C., the sodium concentration obtained by distilling the industrial hydrogen peroxide was started to be dropped at 60% by weight of a hydrogen peroxide solution having a concentration of 0.1 ppm of 0.1 ppm, and 5.05 g was added over 40 minutes. It was dropped. After stirring was continued for another 10 minutes after the completion of the dropwise addition, the catalyst was filtered to terminate the reaction. The filtrate was analyzed and quantified for residual hydrogen peroxide and 1-octene oxide by iodine titration and gas chromatography, respectively. Filtered catalyst in air 55
It was baked at 0 ° C. for 2 hours to perform a regeneration treatment, and used for the next reaction. Table 1 shows the results. Catalyst activity (hydrogen peroxide conversion)
Does not show any change from 1 batch to 3 batches and does not deteriorate with time. Also, no decrease in the selectivity of the reaction was observed.

Comparative Example 1 The same operation as in Example 1 was performed except that 60% by weight of hydrogen peroxide containing 25 ppm of sodium was used. The sodium concentration in the solution was 1.2 ppm. As shown in Table 1, the conversion of hydrogen peroxide after calcination was remarkably reduced, and did not return to the original characteristics by calcination.

[0018]

[Table 1]

Example 2 In a 200 ml flask, 3.16 g of the catalyst prepared in the above Reference Example, 1-
Hexene (40.0 g), methanol (30.0 g), and methyl ethyl ketone (30.0 g) were charged, fitted with a stirrer, a thermometer, and a reflux condenser, and heated in a 60 ° C. water bath. At the time when the temperature of the solution reached 50 ° C., the sodium concentration obtained by distilling the industrial hydrogen peroxide was 0.1 ppm, and the dropping of 60% by weight aqueous hydrogen peroxide was started, and 5.45 g was added over 60 minutes. It was dropped. After stirring was continued for another 30 minutes after the completion of the dropwise addition, the catalyst was filtered to terminate the reaction. The filtrate was analyzed and quantified for residual hydrogen peroxide and 1-hexene oxide by iodine titration and gas chromatography, respectively. Filtered catalyst in air 55
It was baked at 0 ° C for 2 hours to perform a regeneration treatment, and used for the next reaction. Table 2 shows the results. By the calcination, the catalyst was completely restored to the original characteristics.

Comparative Example 2 The same operation as in Example 2 was performed except that 60% by weight of hydrogen peroxide containing 25 ppm of sodium was used. The sodium concentration in the solution was 1.3 ppm. As shown in Table 2, the conversion of hydrogen peroxide gradually decreased with each firing, and deterioration of the catalyst was observed.

[0021]

[Table 2]

Example 3 2.9 Catalyst prepared in the above reference example in a 200 ml flask
0 g, 50.0 g of allyl chloride, and 25.0 g of methanol, and equipped with a stirrer, a thermometer, and a reflux condenser.
Heated in a water bath. When the solution started to reflux at about 50 ° C., the sodium concentration obtained by distilling the industrial hydrogen peroxide started dropping 0.1 ppm of 60% by weight aqueous hydrogen peroxide, and it took 40 minutes. 18.5 g was added dropwise. After stirring was continued for another 10 minutes after the completion of the dropwise addition, the catalyst was filtered to terminate the reaction. The remaining hydrogen peroxide and epichlorohydrin were analyzed and quantified by iodine titration and gas chromatography, respectively. The filtered catalyst was used as it was in another batch reaction, and then calcined in air at 550 ° C. for 2 hours to perform a regeneration treatment, and used in the next cycle. Table 3 shows the results. By the calcination, the catalyst was completely restored to the original characteristics.

Comparative Example 3 The same operation as in Example 3 was performed, except that 60% by weight of hydrogen peroxide containing 5 ppm of sodium was used. The sodium concentration in the solution was 1.3 ppm. As shown in Table 3, the conversion of hydrogen peroxide in the second batch in each cycle was significantly reduced, and the effect of sodium was remarkably observed.

[0024]

[Table 3]

[0025]

According to the present invention, when an olefinic hydrocarbon is epoxidized with hydrogen peroxide in the presence of a titanium silicalite catalyst to produce an epoxy compound, the sodium concentration in the reaction solution or the hydrogen peroxide used as a raw material is reduced. By setting the content of the sodium compound contained to a specific value or less, the deterioration of the catalyst is suppressed, so that the method is excellent in economic efficiency.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Takanobu Okamoto 22 Wadai, Tsukuba, Ibaraki Pref.

Claims (4)

[Claims] 1. The composition formula xTiO2. (1-x) SiO2 (0.0005 <x
<0.04) In the method of epoxidizing an olefinic hydrocarbon or its halide with hydrogen peroxide in the presence of a titanium-containing zeolite represented by <0.04), the concentration of sodium present in the reaction system is 1 ppm or less. Epoxidation of olefinic hydrocarbons or halides thereof. 2. The raw material hydrogen peroxide has a sodium concentration of 2 p.
2. The method of claim 1, wherein the value is less than or equal to pm. 3. The olefinic hydrocarbon or its halide is selected from the group consisting of propylene, 1-butene, 2-butene, isoprene, 1-hexene, 1-octene, 1-octadecene, allyl alcohol and allyl chloride. Done 1
2. The method of claim 1, wherein the method is more than one species. 4. The composition formula xTiO2. (1-x) SiO2 (0.0005 <x
The method according to claim 1, wherein the titanium-containing zeolite represented by <0.04) has an MFI crystal structure.