JPH10314594A - Olefin oxidation catalyst and method for producing olefin oxides using the same - Google Patents

Abstract

(57) [Problem] To provide an olefin oxidation catalyst capable of producing olefin oxides from olefins in excellent yield. SOLUTION: An alkali metal / heavy metal-containing silicate is subjected to ion exchange treatment with an aqueous solution of ammonium nitrate and / or ammonia, and then calcined to carry a nitrate and / or nitrite on a silicate carrier, and microwave irradiation is performed. An olefin oxidation catalyst, comprising:

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an olefin oxidation catalyst and a method for producing olefin oxides using the same.

[0002]

2. Description of the Related Art Olefin oxides are industrially important compounds as intermediates for industrial chemicals, synthetic resins, synthetic rubbers and the like. As a method for producing such olefin oxides, a method of reacting an olefin with a molecular acid in the presence of an olefin oxidation catalyst has been conventionally known. As such an olefin oxidation catalyst, for example, a silver oxide-based catalyst (for example, 53-39404, JP-B-53-12489, U.S. Pat. No. 4,859,786), copper phosphate
Potassium-based catalyst [Journal of the Chemical Society of Japan, 468 (197)
8)], a phosphoric acid or phosphate ester-based catalyst (JP-B-49-33922), a uranium dioxide-based catalyst (JP-B-48-27281), a thallium oxide / cobalt oxide-based catalyst (JP-B-49-39962). Gazette) has been proposed. However, all of these olefin oxidation catalysts have a problem in that carbonyl compounds such as carbon dioxide, aldehydes, and ketones are produced in large amounts as by-products, and the selectivity of the target olefin oxide is low.

As a solution to such a problem, nitrates and / or nitrites are already supported on a siliketo carrier obtained by calcining a solid compound obtained by reacting a silicon compound, a heavy metal compound, a nitrogen-containing organic compound and water. An olefin oxidation catalyst prepared by this method has been proposed (JP-A-7-97378). However, such a catalyst has a problem that the conversion of olefins in the steady state of the reaction is not always sufficient.

[0004]

Under these circumstances, the present inventors have conducted intensive studies to develop an olefin oxidation catalyst capable of producing olefin oxides from olefins in excellent yield. Invented the invention.

[0005]

That is, the present invention provides a silicate support obtained by subjecting an alkali metal / heavy metal-containing silicate to an ion exchange treatment with an aqueous solution of ammonium nitrate and / or ammonia, followed by calcination.
Another object of the present invention is to provide an olefin oxidation catalyst which carries nitrite and is irradiated with microwaves.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The silicate carrier used in the catalyst of the present invention is obtained by subjecting an alkali metal / heavy metal-containing silicate to an ion exchange treatment with an aqueous solution of ammonium nitrate and / or ammonia, followed by calcination. Alkali metal / heavy metal-containing silicate is a crystalline solid composed of alkali metal, heavy metal, silicon and oxygen.As the alkali metal, sodium, potassium,
Cesium and the like are exemplified. Examples of heavy metals include titanium, vanadium, zirconium, gallium, chromium, nickel and the like, and preferably titanium, vanadium and zirconium. Note that other metals may be contained within a range that does not impair the effects of the present invention.

The number of atoms of the alkali metal in the alkali metal / heavy metal-containing silicate (including the number of atoms when another raw material compound contains an alkali metal).
Is usually in the range of 0.01 to 0.1 times the number of silicon atoms, and the number of heavy metal atoms is usually 0.1 times or less, preferably 0.05 times or less, the number of silicon atoms. The number of alkali metal atoms, the number of heavy metal atoms, and the number of silicon atoms can be easily determined by a usual method, for example, a fluorescent X-ray analysis method or a chemical analysis method.

The crystal form of the alkali metal / heavy metal-containing silicate includes, for example, a pentasil type and a mordenite type, and preferably a pentasil type.

Such an alkali metal / heavy metal-containing silicate can be easily produced, for example, by calcining a solid product obtained by reacting a silicon compound, an alkali metal compound, a heavy metal compound, a nitrogen-containing organic compound and water. .

Examples of the silicon compound include tetraalkyl orthosilicates such as tetraethyl orthosilicate, and colloidal silica.

The alkali metal compounds include, for example, halides such as chlorides and bromides of alkali metals, nitrates, sulfides, carbonates, hydroxides and the like. Silicon compounds and heavy metal compounds used as other raw material compounds are exemplified. When a nitrogen-containing organic compound or the like contains an alkali metal component, the alkali metal component is used as it is as a raw material. In the latter case, it is not particularly necessary to use the above alkali metal compound, but the above alkali metal compound may be used for the purpose of adjusting the amount of alkali metal. Such an alkali metal compound has a number of alkali metal atoms (when other raw material compounds contain an alkali metal,
Including the number of atoms. ) Is usually used so as to be at least 0.01 times the number of silicon atoms in the silicon compound.

As the heavy metal compound, a heavy metal compound which can be easily hydrolyzed, for example, a titanium halide such as titanium chloride, a titanium compound such as titanium alkoxide such as tetraisopropyl titanate or tetra-n-butyl titanate, and vanadium trichloride Vanadium halides such as vanadium alkoxides such as vanadium halides, tripropoxyvanadyl, and tributoxyvanadyl;
Zirconium halides such as zirconium oxychloride, zirconium compounds such as zirconium nitrate compounds such as zirconium oxynitrate and the like are used. Such heavy metal compounds are used such that the number of heavy metal atoms is usually 0.1 times or less, preferably 0.05 times or less, of the number of silicon atoms of the silicon compound.

As the nitrogen-containing organic compound, an alkylammonium compound, especially a tetraalkylammonium compound, is preferably used. As such a tetraalkylammonium compound, for example, tetrapropylammonium hydroxide, tetraethylammonium hydroxide,
Examples thereof include tetraalkylammonium hydroxides such as tetra-i-butylammonium hydroxide, and tetraalkylammonium halides in which hydroxylation in each of the above compounds corresponds to chloride, bromide, or iodide. Such a nitrogen-containing organic compound has a nitrogen atom number of usually 0.01 to 2 times, preferably 0.1 to 2 times the number of silicon atoms of the silicon compound.
It is used so as to be in a range of up to 1 times.

The amount of water used is usually in the range of 4 to 200 times, preferably 5 to 100 times the mole of the silicon compound.

In the reaction, for example, a silicon compound, an alkali metal compound, a heavy metal compound, a nitrogen-containing organic compound and water may be mixed and heated under normal pressure or under pressure.
When the silicon compound, the heavy metal compound and the nitrogen-containing organic compound contain an alkali metal component, the silicon compound, the heavy metal compound, the nitrogen-containing organic compound and water may be mixed and heated under normal pressure or under pressure. The reaction temperature is usually 85-
180 ° C, preferably in the range of 100 to 130 ° C.
Such a reaction produces a solid product, which can be easily isolated from the reaction mixture after the reaction by a conventional method, for example, by filtration and washing with water.

Next, the obtained solid product is calcined. The calcining is usually performed in the air, and the calcining temperature is usually 500 ° C. or higher, preferably 500 to 530 ° C. The solid product may be preliminarily calcined in an inert gas such as nitrogen gas or Ar gas in order to prevent rapid heat generation in the early stage of the calcination, and the temperature is the same as the above calcination temperature.

The silicate carrier used in the catalyst of the present invention is obtained by subjecting such a silicate containing an alkali metal and a heavy metal to an ion exchange treatment with an aqueous solution of ammonium nitrate and / or ammonia, followed by calcination.
An aqueous solution of ammonium nitrate used for the ion exchange treatment usually has a concentration of 1 to 20% by weight, and an aqueous solution of ammonia usually has a concentration of 0.1 to 20% by weight.
Those having a range of from 10 to 10% by weight are used, each of which is used alone or in combination. The amount of the aqueous solution of ammonium nitrate and / or ammonia is usually 5 to 5% based on the alkali metal / heavy metal-containing silicate.
The range is 100 times by weight.

At the time of the ion exchange treatment, an alkali metal / heavy metal-containing silicate and an aqueous solution of ammonium nitrate and / or ammonia may be mixed, and the treatment temperature is usually in the range of 50 to 150 ° C.

After the ion exchange treatment, the aqueous solution of ammonium nitrate and / or ammonia is removed by a filtration operation, washing with water, and the like, and then calcined. The calcining may be performed in the same manner as in the above-mentioned solid product. The preliminary firing may be performed in a gas.

The number of alkali metal atoms in the silicate carrier thus obtained is preferably not more than 0.02 times the number of silicon atoms. To this end, the concentration and amount of ammonium nitrate and / or aqueous ammonium solution used in the above-mentioned ion exchange treatment and the treatment temperature are appropriately selected so as to satisfy this condition, and in some cases, the ion exchange of alkali metal / heavy metal silicate is performed. After repeating the treatment, baking may be performed.

The crystal form of the silicate carrier thus obtained is usually a pentasil type, a mordenide type or the like, preferably a pentasil type.

The catalyst of the present invention is obtained by supporting nitrate and / or nitrite on such a silicate carrier. Examples of the nitrate include lithium nitrate, sodium nitrate, potassium nitrate, rubidium nitrate and cesium nitrate. Alkaline earth metal salts such as alkali metal nitrate, barium nitrate, magnesium nitrate, calcium nitrate, strontium nitrate, scandium nitrate, yttrium nitrate, praseodymium nitrate, neodymium nitrate, samarium nitrate, europium nitrate, gadolinium nitrate,
Rare earth metal salts such as yttrium lithium nitrate and silver nitrate, etc., and examples of nitrites include alkali metal nitrites such as sodium nitrite and potassium nitrite and silver nitrite. These nitrates and nitrites are used singly or as a mixture of two or more kinds, and are used in an amount of usually 0.01 to 50 parts by weight, preferably 0.1 to 30 parts by weight based on 100 parts by weight of the silicate carrier. Range.

These nitrates and / or nitrites are easily supported by, for example, mixing an aqueous solution of these salts with a silicate carrier, distilling off water, drying the obtained residue, and irradiating with microwaves. can do. The microwave irradiation output is not particularly limited, but is usually about 100 to about 1200 W, and the irradiation time is usually in the range of about 30 seconds to about 15 minutes. Also,
The catalyst irradiated with microwaves can be calcined under a stream of hydrogen gas. The firing temperature usually ranges from about 100 to about 380C, preferably from about 110 to about 350C. Such a hydrogen gas may be diluted with an inert gas such as carbon dioxide gas, nitrogen gas, helium gas, Ar gas, and water vapor.

Thus, the intended catalyst of the present invention can be obtained. Such a catalyst can produce olefin oxides in good yield by reacting olefins with molecular oxygen in the presence of the catalyst. Excellent selectivity for olefins under pressurized conditions.

Examples of the olefins include those having 1 to 6 carbon atoms such as ethylene, propylene, 1-butene, 2-methylpropene, 2-butene, butadiene, 1-pentene, 2-pentene and 3-methyl-1-butene. Lower olefins and the like are mentioned, and molecular oxygen is usually supplied as oxygen gas, air or the like.

These olefins and molecular oxygen are usually mixed in advance and used as a mixed gas, and the molar ratio between the olefins and molecular oxygen in the mixed gas depends on the type of catalyst, reaction temperature, reaction pressure, and the like. Although it is appropriately selected depending on the like, it is usually in the range of 1: 1000 to 100: 1, preferably 1: 100 to 30: 1. Such a mixed gas may be diluted with a gas inert to a reaction such as carbon monoxide, carbon dioxide, nitrogen, helium, argon, water, a saturated hydrocarbon, and the like. It may contain nitrogen, nitrogen dioxide, aldehydes, ketones, alcohols, halogenated hydrocarbons, esters, nitriles, and the like.

In the reaction, for example, the mixed gas may be brought into contact with the catalyst of the present invention. The reaction pressure may be any of reduced pressure, normal pressure and pressurized, and the reaction temperature is usually 100 to 50.
0 ° C, preferably in the range of 110-250 ° C. The pressurizing condition is not particularly limited, but is usually about 50
Kgf / cm ² G or less, preferably about 20 Kgf / c
m ² G or less.

The desired olefin oxides corresponding to the olefins thus used can be obtained. Examples of such olefin oxides include ethylene oxide and
Examples thereof include propylene oxide, 1-butene oxide, 2-methylpropene oxide, 2-butene oxide, butadiene oxide, 1-pentene oxide, 2-pentene oxide, and 3-methyl-1-butene oxide.

[0029]

According to the present invention, when olefins are oxidized using the olefin oxidation catalyst of the present invention, olefin oxides can be produced in excellent yield.

[0030]

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

Example 1 (Production of silicate containing alkali metal and heavy metal) In a stainless steel autoclave having a content of 2.8 liters, 105 g of an aqueous solution containing 42 g of tetra-n-propylammonium hydroxide (potassium content: 1.18) Wt%), water 51
9 g, 10.6 g of potassium nitrate, an ethanol solution (5 ml) containing 2.56 g of titanium tetraisopropoxide and 187 g of tetraethyl orthosilicate were added in this order, and stirring was continued for 12 hours.
Heat to 05 ° C, and rotate at 400 rpm or more for 9 more.
Stirring was continued for 6 hours. Thereafter, the formed white precipitate was collected by filtration, washed successively with distilled water until the pH of the washing solution was around 7, and the obtained crystals were dried at 120 ° C. for 16 hours. The dried crystal was further calcined at 500 to 530 ° C. for 3 hours under an air flow to obtain an alkali metal / heavy metal-containing silicate as a white powdery crystal.

(Production of silicate carrier) 50 g of the silicate containing the alkali metal and heavy metal obtained above was mixed with 500 g of an aqueous solution of ammonium nitrate (concentration: 7.5% by weight), stirred at 90 ° C. for 1 hour, and the precipitate was collected by filtration. did. The obtained residue was similarly mixed with 500 g of an aqueous ammonium nitrate solution (concentration: 7.5% by weight), stirred at 90 ° C. for 1 hour, and the precipitate was collected by filtration. This operation was repeated once more, and the obtained crystals were dried at 120 ° C. for 16 hours, and then heated under a stream of air at a temperature in the range of 500 to 530 ° C. for 3 hours.
49 g of a silicate carrier were obtained. When the obtained crystal was analyzed by an atomic absorption method, the atomic ratio of Si / Ti was 100. The crystal was analyzed by X-ray analysis to confirm that it was a pentasil type.

(Production of olefin oxidation catalyst) 8 g of the silicate carrier obtained above was mixed with 50 ml of an aqueous solution containing 0.11 g of cesium nitrate and 0.13 g of calcium nitrate tetrahydrate, and heated to 90 ° C. After stirring at the same temperature for 1 hour, the mixture was cooled to room temperature, and water was distilled under reduced pressure at the same temperature to obtain a residue. Microwave irradiation (irradiation output:
500 W, irradiation time: 2 minutes), and then calcined at 200 ° C. for 1 hour in a mixed gas stream of hydrogen and nitrogen (mixing volume ratio 1: 4, flow rate 6000 ml / hour) to obtain an olefin oxidation catalyst A. Was.

(Example 2) In Example 1, instead of setting the firing temperature in a mixed gas stream of hydrogen and nitrogen (mixing volume ratio 1: 4, flow rate 6000 ml / hour) to 200 ° C., 3
An olefin oxidation catalyst B was obtained in the same manner as in Example 1 except that calcination was performed at 00 ° C.

Reference Example 1 An olefin oxidation catalyst C was obtained in the same manner as in Example 1 except that microwave irradiation was not performed.

Reference Example 2 An olefin oxidation catalyst D was obtained in the same manner as in Example 2 except that microwave irradiation was not performed.

Example 3 An olefin oxidation catalyst A was prepared using 24
Pulverized to a mesh of up to 48 meshes, and 8 g thereof was filled in a stainless steel reaction tube (inner diameter 1.5 cm, length 45 cm).
After pressurizing at ² G, the supply of nitrogen gas was stopped, and a mixed gas of propylene and air (mixing volume ratio 1: 4) was supplied at a flow rate of 300.
The solution was supplied at a pressure of 8 kgf / cm ² G at 0 ml / hour.
The temperature of the reaction tube was raised to 160 ° C. over 1 hour while supplying the mixed gas, and when the temperature rose, the reaction was started, and the mixed gas was supplied for 7 hours. After the start of the reaction, the gas after the reaction at the point at which 7 hours had elapsed from the point at which 6 hours had elapsed was collected at the outlet of the reaction tube under atmospheric pressure, and the gas was quantitatively analyzed by gas chromatography. 2.5%, propylene oxide selectivity 75
%Met. Thereafter, the supply of the mixed gas was stopped, and the mixture was cooled while supplying nitrogen gas at normal pressure, and nitrogen gas was supplied at normal pressure at room temperature for 15 hours. Next, after pressurizing with nitrogen gas at a pressure of 8 kgf / cm ² G, the supply of nitrogen gas was stopped, and a mixed gas of propylene and air (mixing volume ratio 1: 4) was flowed at a flow rate of 3000 ml / g.
It was supplied for 8 hours at a pressure of 8 kgf / cm ² G. The temperature of the reaction tube was raised to 160 ° C. over 1 hour while supplying the mixed gas, and when the temperature rose, the reaction was started, and then the mixed gas was supplied for 7 hours. After the start of the reaction, the gas after the reaction at the time when 7 hours have passed from the time when 6 hours have passed,
The sample was collected at the outlet of the reaction tube under atmospheric pressure and quantitatively analyzed by gas chromatography. As a result, the conversion of propylene was 1.0% and the selectivity of propylene oxide was 72%. (This is referred to as Sample-2).
Shown in

(Example 4, Reference Examples 3 and 2) Example 3
In place of catalyst A, catalysts B, C, D
Was carried out in accordance with Example 3 except that 8 g was used. Table 1 shows the results.

[0039]

Table 1 Example of reaction results Catalyst Sample Propylene conversion rate Propylene oxide selectivity (%) (%) Example 3 A 1 2.5 75 Example 3 A 2 1.0 72 Example 4 B 1 1.0 73 Example 4 B 2 1.068 Reference Example 3 C 1 2.068 Reference Example 3 C 2 1.5 67 Reference Example 4 D 1 1.065 Reference Example 4 D 2 1.0 65

Claims (12)

[Claims] An alkali metal / heavy metal-containing silicate is subjected to an ion exchange treatment with an aqueous solution of ammonium nitrate and / or ammonia and then calcined to carry a nitrate and / or a nitrite on a silicate carrier, followed by microwave irradiation. An olefin oxidation catalyst comprising: 2. The olefin oxidation catalyst according to claim 1, which is calcined under a stream of hydrogen gas after irradiation with microwaves. 3. A microwave irradiation output of 100 to 12
The olefin oxidation catalyst according to claim 1 or 2, wherein the irradiation time is 00W and the irradiation time is 30 seconds to 15 minutes. 4. The firing temperature in a hydrogen gas stream is 100.
The olefin oxidation catalyst according to claim 2 or 3, wherein the temperature is from -380 ° C. 5. The alkali metal / heavy metal-containing silicate has an alkali metal atom number of 0.0 to silicon atom number.
The olefin oxidation catalyst according to any one of claims 1 to 4, which is 1 to 0.1 times. 6. The olefin oxidation catalyst according to claim 1, wherein the number of heavy metal atoms in the alkali metal / heavy metal-containing silicate is not more than 0.1 times the number of silicon atoms. 7. The silicate containing an alkali metal and heavy metal,
An alkali metal / heavy metal-containing silicate obtained by calcining a solid product obtained by reacting a silicon compound, an alkali metal compound, a heavy metal compound, a nitrogen-containing compound and water, the silicate according to any one of claims 1 to 6. Olefin oxidation catalyst. 8. The olefin oxidation catalyst according to claim 1, wherein the nitrate is at least one nitrate selected from alkali metal salts, alkaline earth metal salts and rare earth metal salts of nitric acid. 9. A process for producing olefin oxides, comprising reacting olefins with molecular oxygen in the presence of the olefin oxidation catalyst according to claim 1. Description: 10. The process for producing olefin oxides according to claim 9, wherein the olefins and molecular oxygen are in a gaseous state. 11. The process for producing olefin oxides according to claim 9, wherein the olefins are lower olefins. 12. The method for producing olefin oxides according to claim 8, wherein the reaction temperature is 100 to 500 ° C.