JP3405125B2 - Process for producing epoxidized olefins - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing epoxidized olefins. More specifically, the present invention relates to a method for producing epoxidized olefins by reacting olefins with hydrogen peroxide in an alcoholic medium.

[0002]

2. Description of the Related Art Epoxy compounds of olefins, especially propylene oxide, is one of important industrial products as a raw material for propylene glycol, polypropylene glycol and the like. The chlorohydrin method, the Halcon method, the peracetic acid method, etc. are known as general industrial methods for producing propylene oxide. However, these methods have a problem that it is necessary to secure a market for co-produced products because a large amount of by-products are co-produced.

On the other hand, the method using hydrogen peroxide in the presence of a titanium compound is advantageous in that it does not produce a large amount of by-products (for example, Japanese Patent Publication No. 4-5028 and US Pat. No. 5,354,875). Specification etc.). For example
5028 discloses that by using crystalline titanosilicate as a catalyst in an alcoholic medium, hydrogen peroxide can be used as an oxidant to epoxidize an olefin with high yield and high selectivity. There is a problem that hydrogen oxide is used.

When the medium of the raw material hydrogen peroxide is an aqueous medium, it is necessary to dilute it with an organic solvent such as alcohol which is an efficient medium in the process of producing an epoxide. For example, it is conceivable to dilute a 30 wt% hydrogen peroxide aqueous solution with methanol and use it as a 5 wt% hydrogen peroxide solution containing methanol as a main solvent in the epoxide production process. Therefore, in order to secure the concentration of hydrogen peroxide used in the epoxidized product manufacturing process at a certain level, it was necessary to manufacture an aqueous solution of hydrogen peroxide having a higher concentration than that in advance.

A high-concentration aqueous hydrogen peroxide solution requires a concentration step, which complicates the process and makes it expensive. In addition, there are risks associated with high concentrations,
There are many problems such as the need for a step of diluting with alcohol and the addition of a large amount of water, resulting in an increase in by-products such as glycol in the epoxide production process.

By the way, the most general industrial method for producing hydrogen peroxide at present is by the autoxidation method using alkylanthraquinone. But the problem with this method is that
It requires many steps such as reduction of alkyl anthraquinone, oxidation and extraction / separation of produced hydrogen peroxide, purification and concentration, which makes the process complicated. In addition, loss of alkyl anthraquinone and deterioration of the reduction catalyst are also problems.

In order to solve these problems, there has been proposed a method in which hydrogen and oxygen are brought into contact with each other in an aqueous medium in the presence of a platinum group metal to directly synthesize hydrogen peroxide (Japanese Patent Publication No. 55-55-55). No. 18646, Japanese Patent Publication No. 1-2340
No. 1, JP-A-63-156005, etc.). For example, in JP-A-63-156005, a hydrogen peroxide aqueous solution having a somewhat high concentration can be produced from hydrogen and oxygen in an aqueous medium containing an acid and a halide ion in the presence of a platinum group metal supported on a support. I am trying. However, all of them produce hydrogen peroxide in an aqueous medium, and since they must be diluted with an organic solvent to be used as a raw material for epoxidation of olefins, it is necessary to produce a higher concentration of hydrogen peroxide. I had to do it.

Further, in these methods, in order to obtain a hydrogen peroxide aqueous solution having a concentration as high as possible, it was necessary to carry out the reaction under high pressure conditions. The production of hydrogen peroxide under a high pressure condition is industrially disadvantageous because the construction cost of various equipment is high. Furthermore, considering the reaction of a combination of hydrogen and oxygen, which is likely to cause an explosive reaction, the high-pressure condition is not preferable in terms of safety. It is important to establish a method for efficiently producing hydrogen peroxide even under a low pressure condition, and to further effectively use it for producing an epoxidized olefin compound.

JP-A-57-92506 describes that alcohol, ketone, ether, ester, amide and the like can be used as a reaction medium, but methanol is particularly excellent. However, in order to obtain a hydrogen peroxide solution with a certain degree of efficiency, it was necessary to make formaldehyde coexist in the reaction medium in order to suppress decomposition of hydrogen peroxide produced. Therefore, there is a problem that a step for adding this and a purification step for removing it are required, the process is complicated, and formaldehyde may suppress the catalytic activity.

[0010]

The problem to be solved by the present invention, that is, the object of the present invention, is to produce a large amount of by-products without the need for a highly concentrated aqueous hydrogen peroxide solution. It is an object of the present invention to provide a method for producing an epoxidized olefin compound with high selectivity.

[0011]

DISCLOSURE OF THE INVENTION The inventors of the present invention have conducted intensive studies in view of the above situation and completed the present invention. That is, the present invention is a solution of hydrogen peroxide in an alcoholic medium by catalytically reacting hydrogen and oxygen in an alcoholic medium.
And a method for producing an epoxidized product of olefins, wherein the solution is used in the next step to oxidize olefins in the presence of an oxidation catalyst.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. (1) Production of hydrogen peroxide In the present invention, an alcoholic medium is used as a reaction medium during the production of hydrogen peroxide. The alcoholic medium as referred to in the present invention refers to alcohol or a mixed liquid containing alcohol as a main component, and other components in the case of a mixed liquid containing alcohol as a main component include ketone, ether, ester,
Examples include amide and water. More preferably, an alcohol simple medium is used as the alcoholic medium. As the alcohol, methanol, ethanol, isopropanol, butanol, ethylene glycol and the like are used, but methanol and ethanol are preferable, and methanol is more preferable.

In the present invention, when hydrogen peroxide is produced by catalytically reacting hydrogen and oxygen, it is preferable to carry out the reaction in the presence of a platinum group metal or a compound of the platinum group metal.

Preferably, the hydrogen peroxide of the present invention is produced by catalytically reacting hydrogen and oxygen in an alcoholic medium in the presence of a halogen compound of a platinum group metal. If this is the case, epoxidized olefins can be obtained without the need for a high-concentration aqueous hydrogen peroxide solution, and without adding an acid, a compound that dissociates to produce a halide ion, or formaldehyde. It is preferable because hydrogen peroxide suitable as a manufacturing reagent can be manufactured.

Examples of the platinum group metal in the halogen compound of the platinum group metal include rhodium, iridium, platinum and palladium. Platinum or palladium is preferable, and palladium is more preferably used. As the halogen compound, a fluorine compound, a chlorine compound, a bromine compound or an iodine compound is used, but a chlorine compound or a bromine compound is preferably used. Specific examples of the halogen compound of the platinum group metal include rhodium chloride, rhodium bromide, iridium chloride, iridium bromide, platinum chloride, platinum bromide, palladium fluoride, palladium chloride, palladium bromide, palladium iodide, dichloro. Examples include diammine palladium and the like. Particularly preferred is palladium chloride or palladium bromide.

The reaction may be either continuous or batch type, and the reaction apparatus may be a suspension bed type, a fixed bed type or the like. The amount of the halogen compound of the platinum group metal used is not particularly limited, but in the case of the suspension bed system, the reaction medium 100 is usually used.
1 mg to 10 g per ml, preferably 10 m
It is carried out in the range of g to 10 g. The halogen compound of the platinum group metal may be in any form such as fine powder and pellets, but fine powder is preferable and its surface area is 0.01-
The one having 10000 m ² / g is more preferably used.
The halogen compound of the platinum group metal may be used as it is,
It is also possible to use it by supporting it on a suitable carrier. In general, the yield of hydrogen peroxide per weight of metal is higher when supported.

Examples of the carrier include alumina, silica, titania, magnesia, zirconia, ceria, zeolite, graphite, activated carbon, silica gel, hydrous silicic acid, silicon carbide and the like. Alumina, silica, titania, zeolite, graphite or activated carbon. Is preferably used. As a method of loading on a carrier, for example,
The carrier is suspended in a solution of a halogen compound of a platinum group metal,
There is no particular limitation as long as it can be supported, such as a method of evaporating to dryness.

The hydrogen peroxide of the present invention is obtained by catalytically reacting hydrogen and oxygen in an alcoholic medium containing an acid and a halide of an alkali metal or an alkaline earth metal in the presence of a platinum group metal. The produced one can also produce hydrogen peroxide suitable as a reagent for producing epoxidized olefins without requiring a high-concentration aqueous hydrogen peroxide solution and further without adding an additive such as formaldehyde. Therefore, it is preferable.

Specific examples of the platinum group metal include rhodium, iridium, platinum, palladium and the like, with palladium being preferred. The platinum group metal may be used as it is, or may be used by being supported on various carriers such as activated carbon. Various types of such supported platinum group metals are commercially available.

The platinum group metal may be in any form such as fine powder and pellets, and the reaction may be either continuous type or batch type, and the reaction apparatus may be a suspension bed type or a fixed bed type. . These are not particularly limited. The amount of platinum group metal used is not particularly limited, but in the case of the suspension bed type, it is usually 1 mg per 100 ml of the reaction medium.
The amount is 10 g or more and preferably 10 mg or more and 10 g or less.

The acid referred to here is sulfuric acid, hydrochloric acid,
Phosphoric acid or the like can be used. It is also possible to use a mixture of these acids. Acid concentration is 0.001-
It is usually carried out at 1N, but is preferably 0.01 to 1N.

Specific examples of the alkali metal or alkaline earth metal halides include sodium fluoride, sodium chloride, sodium bromide, sodium iodide, potassium chloride, potassium bromide, magnesium chloride, and the like.
Examples include magnesium bromide, calcium chloride, calcium bromide and the like. Alkali metal chlorides, bromides or iodides are preferably used, more preferably alkali metal chlorides or bromides. Most preferably, it is an alkali metal bromide. The amount of alkali metal or alkaline earth metal halide used is
It is usually 1 × 10 ⁻⁶ to 1 × 10 ⁻³ N, preferably 1 ×
It is carried out at 10 ⁻⁵ to 1 × 10 ⁻³ N.

Hydrogen peroxide produced by catalytically reacting hydrogen and oxygen in an alcoholic medium containing an acid and a halide of an alkali metal or an alkaline earth metal in the presence of such a platinum group metal is It is preferable to perform a neutralization treatment with a base before using it in the next step of producing an epoxidized product of olefins, since the selectivity of the epoxidized product becomes high. The base is preferably an alkali metal or alkaline earth metal hydroxide solution, and specific examples thereof include sodium hydroxide, potassium hydroxide, calcium hydroxide and rubidium hydroxide, and more preferably alkali metal Hydroxide is used. These bases are usually used in an aqueous solution or an alcohol solution, and a solution having a high concentration, for example, 1 to 20 N is preferable so that the hydrogen peroxide concentration after the neutralization treatment is not significantly lowered. The amount of the base is preferably as close to the equivalence point.

In the reaction for producing hydrogen peroxide according to the present invention, the partial pressure ratio of oxygen and hydrogen is usually 1/50 to 50: 1.
It can be carried out in the range of. It is possible to carry out the reaction by diluting with an inert gas, or to carry out the reaction using air instead of oxygen. For safety, it is preferable to carry out the reaction outside the explosion range. The reaction temperature is generally in the range of 5 ° C to 60 ° C, preferably 10 ° C to 50 ° C. The reaction pressure is not particularly limited, but is atmospheric pressure to 150 kg / cm ²
・ G, especially in the range of 5 to 50 kg / cm ² · G.

In the present invention, the solution of hydrogen peroxide thus obtained in an alcoholic medium is used in the next step, which is a process for producing an epoxidized olefin compound,
Usually, the solid components in the reaction medium are removed and then used in the next step. The method for removing the solid component is not particularly limited, and any suitable method such as decantation or filtration may be used.

(2) Epoxidation of olefins The catalyst used for propylene oxide synthesis in the present invention is M
oO ₃ , V ₂ O ₅ , WO ₃ , titanosilicate, SiO
It can be used as the TiO ₂ supported on a carrier such as _2, preferably titanosilicate. The titanosilicate referred to here is crystalline S having a zeolite structure.
It is obtained by substituting a part of silicon forming the crystal lattice of iO ₂ with titanium. The present invention is not particularly limited to the method for synthesizing titanosilicate, but synthetic examples include, for example, JP-A-56-96720. Si / Ti in titanosilicate
The atomic ratio of 10 to 1000 is used.

In the present invention, the amount of the oxidation catalyst used is not particularly limited. In the case of the suspension bed type, the reaction medium 1 is usually used.
It is used in the range of 1 mg to 10 g per 00 ml. The catalyst may be in any form such as fine powder and pellets, and the reaction may be either continuous or batch type, and the reaction apparatus may be a suspension bed type or a fixed bed type. These are not particularly limited.

The olefins epoxidized by the method of the present invention are, for example, ethylene, propylene, allyl chloride, 2-butene, 1-octene, 1-tridecene, mesityl oxide, isoprene, cyclooctene, and cyclohexene. . Ethylene and propylene are preferred, and propylene is more preferred.

The reaction temperature is 5 ° C to 150 ° C, preferably 3 ° C.
It is generally carried out in the range of 0 ° C. to 100 ° C., but when the reaction is carried out at a temperature higher than the boiling point of the medium, it needs to be carried out under pressure. When a gaseous olefin is used, the reaction pressure is not particularly limited, but atmospheric pressure to 100 kg / cm.
It is carried out in the range of ² · G, especially 3 to 30 kg / cm ² · G.

[0030]

The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

The hydrogen peroxide concentration in the examples was determined by the iodometric titration method. For the titration, an automatic potentiometer AT-310 manufactured by Kyoto Electronics Manufacturing Co., Ltd. was used.

The epoxidation reaction product was quantified using a gas chromatograph, and the propylene oxide selectivity was calculated from the following formula. (Propylene oxide selectivity%) = (moles of propylene oxide produced) / (moles of hydrogen peroxide consumed) x 100

The conversion rate of hydrogen peroxide was calculated from the following formula. (Conversion rate of hydrogen peroxide) = (Number of moles of hydrogen peroxide consumed) / (Number of moles of hydrogen peroxide before reaction) x 100

The specific surface area was measured using a Flowsorb II2300 type manufactured by Micromeritics.

Example 1 (1) Production of hydrogen peroxide PdBr ₂ (manufactured by Nacalai Tesque, Inc .: specific surface area of 0.
4 m ² / g) 30 mg and 120 ml of methanol were charged into a glass inner cylinder having an inner volume of 300 ml and an inner volume of 400 m.
It was attached to an autoclave of 1 l. Hydrogen gas 80ml / min, oxygen gas 800ml / min.
Each flowed in at min. 2500m nitrogen gas in the gas phase
Introduced at 1 / min, autoclave internal pressure is 9kg / c
The pressure was kept at m ² · G and the reactor was kept at 20 ° C by external cooling. The hydrogen peroxide concentration in the reaction solution after 2 hours from the start of the reaction was 0.15 wt%.

(2) Production of Propylene Oxide 48 g of the hydrogen peroxide methanol solution obtained in (1) and 200 mg of titanosilicate (manufactured by NE Chemcat Corporation: Si / Ti atomic ratio of 50) are 125
Prepared in a ml autoclave and fed propylene gas 4k
It was press-fitted so that it would be g / cm ² · G. Reaction temperature 40 ℃
The hydrogen peroxide conversion after stirring for 1 hour at 99% was 99%, and the propylene oxide selectivity was 70%.

Example 2 (1) Production of hydrogen peroxide 30 mg of Pd powder (manufactured by Tanaka Kikinzoku International Co., Ltd .: specific surface area 10.8 m ² / g) and 0.0012 N-Na
A glass inner cylinder having an inner volume of 300 ml charged with a mixed methanol solution of 5 ml of Br methanol solution, 5 ml of 1.2N—H ₂ SO ₄ methanol solution and 110 ml of methanol,
It was attached to an autoclave having an internal volume of 400 ml. Hydrogen gas was introduced at 80 ml / min and oxygen gas was introduced at 800 ml / min through a gas blowing tube. For safety, nitrogen gas was introduced into the gas phase portion at 2500 ml / min and diluted. The pressure was maintained so that the internal pressure of the autoclave was 9 kg / cm ² · G, and the reactor was kept at 20 ° C by external cooling. The hydrogen peroxide concentration in the reaction solution 2 hours after the start of the reaction was 0.35 wt%.

(2) Production of propylene oxide 2N--N was added to the hydrogen peroxide methanol solution obtained in (1).
48 g of a solution in which 3.1 ml of an aOH aqueous solution was added and stirred
Then, it was charged together with 200 mg of titanosilicate (manufactured by NE Chemcat Co., Ltd .: Si / Ti atomic ratio of 50) into an autoclave having an internal volume of 125 ml, and propylene gas was injected under pressure to 4 kg / cm ² · G. After stirring for 1 hour at a reaction temperature of 40 ° C., the conversion rate of hydrogen peroxide was 65% and the selectivity of propylene oxide was 95%.
Met.

Example 3 Using a solution obtained by adding 2.5 ml of a 2N-NaOH aqueous solution to a hydrogen peroxide methanol solution obtained under the same conditions as in Example 2 (1) and stirring the mixture, Example 2 (2) The reaction was carried out under the same conditions as. After 1 hour from the start of the reaction, the conversion rate of hydrogen peroxide was 98% and the selectivity of propylene oxide was 27%.

[0040]

EFFECTS OF THE INVENTION According to the present invention, inexpensive low-concentration hydrogen peroxide that does not need to be concentrated can be effectively used without requiring a high-concentration hydrogen peroxide solution, and epoxidation proceeds with high selectivity. To do. As a result, it becomes possible to inexpensively produce an epoxidized olefin compound, for example, propylene oxide, without producing a large amount of by-products.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification symbol FI // C07B 61/00 300 C07B 61/00 300 (72) Inventor Toshio Sasaki 6 Kitahara, Tsukuba, Ibaraki Sumitomo Chemical Co., Ltd. (56) References JP-A-57-92506 (JP, A) JP 2000-506060 (JP, A) German patent application publication 4425672 (DE, A 1) (58) Fields investigated (Int.Cl. ⁷⁾ , DB name) C07D 301/12 C07D 303/04

Claims (14)

(57) [Claims] 1. A method of catalytically reacting hydrogen and oxygen in an alcoholic medium to produce an alcoholic medium solution of hydrogen peroxide.
Then, in the next step, the solution is used to oxidize olefins in the presence of an oxidation catalyst. 2. The method for producing an epoxidized olefin compound according to claim 1, wherein the oxidation catalyst is titanosilicate. 3. The method for producing an epoxidized olefin according to claim 1, wherein the olefin is propylene. 4. An alcoholic solution of hydrogen peroxide produced by catalytically reacting hydrogen and oxygen in an alcoholic medium in the presence of a platinum group metal or a compound of a platinum group metal. A method for producing an epoxidized olefin compound according to any one of claims 1 to 3, wherein the method is an ionic medium solution. 5. An alcoholic medium solution of hydrogen peroxide produced by catalytically reacting hydrogen and oxygen in an alcoholic medium in the presence of a halogen compound of a platinum group metal. The method for producing an epoxidized olefin compound according to any one of claims 1 to 3, wherein 6. The method for producing an epoxidized olefin compound according to claim 5, wherein the halogen compound of the platinum group metal is supported on a carrier. 7. The method for producing an epoxidized olefin compound according to claim 5, wherein the platinum group metal halogen compound is a palladium or platinum halogen compound. 8. The method for producing an epoxidized olefin compound according to claim 5, wherein the halogen compound of the platinum group metal is palladium chloride or palladium bromide. 9. A solution of hydrogen peroxide in an alcoholic medium, wherein hydrogen and oxygen are catalytically contacted with each other in an alcoholic medium containing an acid and an alkali metal or alkaline earth metal halide in the presence of a platinum group metal. The method for producing an epoxidized olefin compound according to any one of claims 1 to 3, which is an alcoholic medium solution of hydrogen peroxide produced by the reaction. 10. A solution of hydrogen peroxide in an alcoholic medium,
An acid in the presence of a platinum group metal, and an alcoholic medium solution of hydrogen peroxide produced by catalytically reacting hydrogen and oxygen in an alcoholic medium containing an alkali metal or alkaline earth metal halide, The method for producing an epoxidized olefin compound according to any one of claims 1 to 3, which is a solution neutralized with a base. 11. The method for producing an epoxidized olefin compound according to claim 9, wherein the platinum group metal is supported on a carrier. 12. The method for producing an epoxidized olefin compound according to any one of claims 9 to 11, wherein the platinum group metal is palladium. 13. The method for producing an epoxidized olefin compound according to claim 10, wherein the base is a hydroxide solution of an alkali metal or an alkaline earth metal. 14. The method for producing an epoxidized olefin compound according to any one of claims 1 to 13, wherein the alcoholic medium is methanol.