JP2549799B2 - Catalyst for producing carbonic acid diester and method for producing carbonic acid diester using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a catalyst for producing a carbonic acid diester and a method for producing a carbonic acid diester using the catalyst, and more specifically, to reacting an alcohol with carbon monoxide and oxygen to produce a carbonic acid diester for a long period of time. TECHNICAL FIELD The present invention relates to a catalyst for producing a carbonic acid diester capable of maintaining activity for a long time and a method for producing a carbonic acid diester using the same.

[0002]

BACKGROUND OF THE INVENTION Carbonic acid diesters such as dimethyl carbonate are widely used as extenders for gasoline, octane number improvers and organic solvents, and in recent years produce isocyanates, polycarbonates and various pharmaceuticals, agricultural chemicals and the like. At the same time, it is used as an alternative raw material for phosgene, and its application is expanding more and more.

The method for producing this carbonic acid diester is as follows:
A liquid phase method is known in which alcohol, carbon monoxide and oxygen are reacted in the liquid phase in the presence of a copper halide catalyst. Further, various copper-based or palladium-based catalysts have been studied to improve the liquid phase method.

However, in such a liquid phase method, (1) the water generated during the reaction markedly reduces the catalytic activity,
(2) Since the catalyst halide is used in solution, the reactor material is corroded, (3) It takes time to separate the carbonic acid diester from the reaction mixture obtained by the reaction, and it dissolves in the reaction mixture. There is a problem that it is difficult to separate the existing catalyst.

As an alternative to the liquid phase method, a method of producing a carbonic acid diester by a gas phase reaction has been proposed. For example, international application publication WO87 / 07601
The publication discloses a method for producing a carbonic acid diester by reacting alcohol, carbon monoxide and oxygen in a gas phase in the presence of a catalyst in which a copper halide is supported on a porous carrier such as activated carbon. . Further, in JP-A-4-89458, a catalyst formed by supporting a chloride of a platinum group metal and a compound of a metal selected from iron, copper, bismuth, cobalt, nickel and tin on a porous carrier, such as PdCl ₂ -BiC
Disclosed is a method for producing a carbonic acid diester, which comprises subjecting carbon monoxide and a nitrite ester to a gas phase catalytic reaction in the presence of l ₃ / C.

However, the catalysts disclosed in these publications do not necessarily have sufficient catalytic activity such as low conversion of alcohol or low selectivity of carbonic acid diester, and therefore, the high activity catalyst for producing carbonic acid diester. Was expected.

[0007] By the way, the applicant of the present invention has previously published the international application W
O90 / 15791, carbonic acid characterized by reacting alcohol, carbon monoxide and oxygen in the presence of a catalyst containing a copper halide and a tertiary organic phosphorus compound having a phenyl group or an alkyl group. A method for producing diester was proposed. The catalyst disclosed in this publication is preferably used by supporting a catalyst component on a porous carrier such as activated carbon.

Such a catalyst for producing carbonic acid diester is
Although it has a high alcohol conversion rate and a high carbonic acid diester selectivity and a high activity, the advent of a carbonic acid diester-producing catalyst capable of maintaining a high activity for a long period of time is desired.

As a result of earnest research in view of the above-mentioned prior art, the present inventor has found that copper halide and alkali metal hydroxide or alkaline earth metal hydroxide, or copper halide and phenyl group. Further, it was found that a catalyst obtained by supporting a tertiary organic phosphorus compound having an alkyl group on a porous carrier having a specific particle size shows high activity for a long period of time when producing a carbonic acid diester. As a result, the present invention has been completed.

[0010]

An object of the present invention is to provide a catalyst for producing a carbonic acid diester which exhibits high activity for a long period of time when an alcohol is reacted with carbon monoxide and oxygen to produce a carbonic acid diester, and a carbonic acid diester using the same. It is intended to provide a way.

[0011]

SUMMARY OF THE INVENTION A catalyst for producing a carbonic acid diester according to the present invention comprises (i) a copper halide and (ii) an alkali metal hydroxide or an alkaline earth metal hydroxide, or (i) a copper halide. And (iii) a tertiary organic phosphorus compound having a phenyl group or an alkyl group is supported on a porous carrier having a particle size of 1.0 mm or less.

This porous carrier has a particle size of 0.02-1.
It is preferably 0 mm. The method for producing a carbonic acid diester according to the present invention is characterized by reacting an alcohol with carbon monoxide and oxygen in the presence of a catalyst as described above, preferably under gas phase reaction conditions, to produce a carbonic acid diester. There is.

[0013]

DETAILED DESCRIPTION OF THE INVENTION First, the catalyst for producing carbonic acid diester according to the present invention will be explained. The catalyst for producing carbonic acid diester according to the present invention is for reacting alcohol with carbon monoxide and oxygen to produce carbonic acid diester, and (i) copper halide and (ii) alkali metal hydroxide. Or alkaline earth metal hydroxide, or (i)
A copper halide and (iii) a tertiary organic phosphorus compound having a phenyl group or an alkyl group are supported on a porous carrier having a specific particle size.

As such (i) copper halide, 1
Examples of divalent or divalent copper halides include copper chloride (CuCl, CuCl ₂ ), copper bromide (CuB).
r, CuBr ₂ ), copper iodide (CuI, CuI ₂ ), and copper fluoride. These may be used alone or in combination. Of these, cupric halide is preferable, and cupric chloride (CuCl ₂ ) is particularly preferable.

(Ii) Alkali metal hydroxides and alkaline earth metal hydroxides include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, barium hydroxide, calcium hydroxide and the like. Examples thereof include alkaline earth metal hydroxides.

These may be used alone or in combination. Further, (iii) as the tertiary organic phosphorus compound having a phenyl group or an alkyl group, specifically, an alkylarylphosphine such as triphenylphosphine, triphenylphosphite, or dimethylphenylphosphine,
Examples thereof include trimethyl phosphite and trialkyl phosphite such as triethyl phosphite, and trialkyl phosphite such as trimethyl phosphate and triethyl phosphite.

The catalyst for producing carbonic acid diester used in the present invention comprises (i) a copper halide and (ii) an alkali metal hydroxide and an alkaline earth metal hydroxide as described above, or (ii) A copper halide and (iii) a tertiary organic phosphorus compound having a phenyl group or an alkyl group are supported on a porous carrier having a particle size of 1.0 mm or less.

This porous carrier has a surface area of 10 m ² / g
As described above, it is preferably 30 to 1000 m ² / g. Specific examples include activated carbon, titanium oxide, niobium oxide, silica, zirconium oxide, magnesium oxide and alumina. In the present invention, activated carbon is particularly preferably used as the porous carrier.

In the present invention, such a porous carrier has a particle size of 1.0 mm or less, preferably 0.02 to 1.0.
mm, and more preferably 0.06 to 0.8 mm.

The catalyst for producing carbonic acid diester according to the present invention comprises (i) copper halide and (ii) alkali metal hydroxide or alkaline earth metal hydroxide, or (i) copper halide and ( iii) It is prepared by supporting a tertiary organic phosphorus compound having a phenyl group or an alkyl group on a porous carrier.

In preparing the catalyst, these (i) and
The component (ii) or the components (i) and (iii) is dissolved as it is or in an appropriate solvent and brought into contact with and carried by the porous carrier in a solution state. When used in a solution state, for example, (i) copper halide as a solution of ethanol, methanol, water, etc., (ii) an alkali metal hydroxide or alkaline earth metal hydroxide as an aqueous solution, (i)
ii) The tertiary organic phosphorus compound having a phenyl group or an alkyl group is used as a solution of alcohol or the like.

When supporting these catalyst components on the porous carrier, (i) copper halide and (ii) are used as catalyst components.
When an alkali metal hydroxide or an alkaline earth metal hydroxide is supported on the porous carrier, first, (i) a copper halide is supported, and then (ii) an alkali metal hydroxide or an alkaline earth metal. You may carry a metal hydroxide,
Further, (ii) an alkali metal hydroxide or an alkaline earth metal hydroxide may be supported, and then (i) a cupric halide may be supported, or these (i) and (ii) components may be simultaneously added. It may be supported. Further, for example, the components (i) and (ii) may be mixed in advance in a solution state and then simultaneously supported on the porous carrier.

Such preparation is preferably carried out under the flow of an inert gas (nitrogen, argon, helium, etc.). For loading on such a porous carrier, an impregnation method, a kneading method, a coprecipitation method, or the like is appropriately adopted.

The catalyst obtained by impregnating the components (i) and (ii) in this way may be washed with water or the like. Further, it may be dried with an inert gas such as nitrogen. More specifically, the impregnation method for supporting the above-mentioned catalyst component on the porous carrier will be explained. For example, (i) after the cupric halide solution is impregnated into the porous carrier, the impregnation method is carried out in an air atmosphere or under a vacuum. It is dried at 80 to 100 ° C. while circulating an active gas, and then this porous carrier is impregnated with a solution of (ii) an alkali metal hydroxide or an alkaline earth metal hydroxide, and then under an air atmosphere or under an inert atmosphere. The heat treatment may be performed at 80 to 400 ° C. while circulating the active gas.

In the preparation of such a catalyst, the amount of the components (i) and (ii) loaded on the porous carrier may be any amount so long as the resulting catalyst has activity in the synthesis reaction of carbonic acid diester. Although not limited, usually (i) the copper halide is preferably 1.5 to 20% by weight, more preferably 5 to 15% by weight as Cu / (copper halide + porous carrier).
It is supported in an amount of wt%. Further, (ii) alkali metal hydroxide or alkaline earth metal hydroxide is (i) Cu in copper halide in terms of hydroxyl group (OH group) equivalent in hydroxide.
It is supported in an amount of preferably 0.3 to 2, more preferably 0.5 to 1.5 in terms of molar ratio ((OH group) / Cu) with respect to the atom.

As described above, the catalyst for producing carbonic acid diester according to the present invention comprises (i) copper halide and (ii) alkali metal hydroxide or alkaline earth metal hydroxide supported on a porous carrier. In this catalyst, the component (i) and
It is considered that (ii) forms a double salt and / or a decomposition product thereof. For example, cupric halide (CuC
l ₂ ) and NaOH supported catalyst, CuCl ₂ ·
3Cu (OH) ₂ double salt and its decomposed product Cu ₂
It is considered that a metal oxide halide of OCl ₂ is formed.

Further, (i) copper halide and (i
ii) When supporting a tertiary organic phosphorus compound having a phenyl group or an alkyl group on a porous carrier, (i)
Alternatively, either component (iii) may be loaded first, and then the remaining components may be loaded, or these components (i) and (iii) may be loaded simultaneously.

Alternatively, a copper complex may be previously synthesized from (i) and (iii) and supported on a carrier. Such a copper complex is represented by the following general formula, for example. Cu (PPh _{3) n} X [wherein PPh ₃ is _{P (C 6 H 5) 3} , X is halogen, n represents 1, 2 or 3. Specifically, it is supported by the method described in WO90 / 15791.

In the preparation of such a catalyst, the amount of the components (i) and (iii) loaded on the porous carrier is (i) the copper halide is Cu (Cu / porous / porosity) in the copper halide with respect to the carrier. As a solid carrier), preferably in an amount of 2 to 10% by weight, and
(iii) The tertiary organic phosphorus compound having a phenyl group or an alkyl group is (i) with respect to the Cu atom in the copper halide,
The molar ratio is preferably 0.06 to 0.4.

When a copper complex is previously synthesized from the components (i) and (iii) and is supported on a porous carrier, the copper complex in the catalyst is converted to Cu in the copper complex in the carrier ( C
u / porous carrier), preferably 2 to 10% by weight.

The catalyst for producing a carbonic acid diester according to the present invention has a high alcohol conversion rate and a high carbonic acid diester selectivity when a carbonic acid diester is produced by reacting an alcohol with carbon monoxide and oxygen. Moreover, high activity can be maintained over a long period of time.

Next, the method for producing the carbonic acid diester according to the present invention will be described. In the present invention, the method for producing a carbonic acid diester produces a carbonic acid diester by reacting an alcohol with carbon monoxide and oxygen under gas phase reaction conditions in the presence of the catalyst for producing a carbonic acid diester as described above. .

Examples of the alcohol as a reaction raw material used in the present invention include aliphatic alcohols having 1 to 6 carbon atoms, alicyclic alcohols and aromatic alcohols. Specifically, methanol, ethanol, propyl alcohol, butanol, pentanol, hexanol,
Examples are monohydric alcohols such as cyclopropanol, cyclobutanol, cyclopentanol, cyclohexanol and benzyl alcohol. These may be used alone or in combination. Of these, methanol and ethanol are particularly preferable.

In the present invention, 1 is used as the alcohol.
The use of different alcohols gives symmetrical carbonic diesters, and the use of different alcohols in combination gives symmetrical or asymmetric carbonic diesters.

In the above reaction system, carbon monoxide is in a molar ratio to alcohol (CO / alcohol).
And usually about 0.01 to 100, preferably 0.5 to 2
0, more preferably used in an amount of 1 to 10, and oxygen is a molar ratio to alcohol (O ₂ / alcohol).
And 0.01 to 2.0, preferably 0.05 to 1.0,
More preferably, it is used in an amount of 0.05 to 0.5.

The carbon monoxide and oxygen are usually in a molar ratio (CO / O ₂ ) of 1 to 1000, preferably 10 to 10.
It is used in an amount of 0, more preferably 20 to 50. In the reaction system as described above, oxygen is pure molecular oxygen,
Alternatively, it is diluted with an inert gas such as nitrogen or argon and supplied.

The carbon monoxide may be not only pure but also a mixture with a gas inert to the reaction such as hydrogen. For example, a mixed gas of carbon monoxide and hydrogen obtained by a decomposition reaction of methanol can be used.

When methanol is used as the raw material alcohol, it is also possible to use a decomposition product gas in which at least a part thereof is introduced into the decomposition reaction step and the decomposition rate of methanol is appropriately adjusted.

In the present invention, when the above reaction is carried out under gas phase reaction conditions, specifically, the reaction temperature is usually 70 to 350 ° C, preferably 80 to 250 ° C, more preferably 100 to 200 ° C. The reaction pressure is usually normal pressure to 35 kg / cm ² G, preferably ^{2 to 20} kg / cm ² G, and more preferably 5 to 15 kg / cm ² G.

The gas phase reaction is not limited to a fixed bed type, a fluidized bed type, or the like. As the carbonic acid diester obtained in the present invention, specifically, dimethyl carbonate, diethyl carbonate, dipropyl carbonate,
Dibutyl carbonate, dipentyl carbonate, dihexyl carbonate, dicyclopropyl carbonate,
Examples thereof include dicyclobutyl carbonate, dicyclopentyl carbonate, dicyclohexyl carbonate, dibenzyl carbonate, methyl ethyl carbonate, methyl propyl carbonate and ethyl propyl carbonate.

[0041]

EFFECT OF THE INVENTION The catalyst for producing carbonic acid diester according to the present invention comprises a specific component supported on a porous carrier having a specific particle size as described above, and an alcohol is reacted with carbon monoxide and oxygen. When producing a carbonic acid diester, high activity can be maintained over a long period of time.

According to the method for producing a carbonic acid diester of the present invention, the carbonic acid diester can be produced in a high yield over a long period of time. Next, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

[0043]

【Example】

(Solution preparation) (1) Add 25.0 g of cupric chloride to 100 ml of distilled water,
A cupric chloride solution was prepared. (2) 22.3 g of sodium hydroxide was added to 100 ml of distilled water to prepare an aqueous sodium hydroxide solution.

(Catalyst preparation example 1) Particle size 0.7 mm to 1.0 mm
8 g of the above cupric chloride solution was impregnated into 15 g of activated carbon, and then 100% while circulating an inert gas (nitrogen).
It dried at 3 degreeC for 3 hours. After cooling, perform the above two steps
I did it once. Next, activated carbon carrying cupric chloride was impregnated with 8 ml of the above sodium hydroxide aqueous solution, and then dried at 100 ° C. for 3 hours while circulating an inert gas (nitrogen). In this way, catalyst A (Cu loading 13.5
% By weight, OH / Cu = 1) was prepared.

(Catalyst Preparation Example 2) Catalyst B was prepared in the same manner as in Preparation Example 1 except that 15 g of activated carbon having a particle size of 0.7 mm to 0.75 mm was used in Catalyst Preparation Example 1 above.

(Catalyst Preparation Example 3) Catalyst C was prepared in the same manner as in Preparation Example 1 except that 15 g of activated carbon having a particle size of 0.3 mm to 0.35 mm was used in Catalyst Preparation Example 1 above.

(Catalyst Preparation Example 4) Catalyst D was prepared in the same manner as in Preparation Example 1 except that 15 g of activated carbon having a particle size of 2.8 mm to 4.0 mm was used in Catalyst Preparation Example 1 above.

(Catalyst Preparation Example 5) Catalyst E was prepared in the same manner as in Preparation Example 1 except that 15 g of activated carbon having a particle size of 1.7 mm to 2.4 mm was used in Catalyst Preparation Example 1.

(Catalyst Preparation Example 6) A catalyst F was prepared in the same manner as in Preparation Example 1 except that 15 g of activated carbon having a particle size of 1.0 mm to 1.7 mm was used in Catalyst Preparation Example 1.

[0050]

Example 1 Dimethyl carbonate (DMC) was produced as follows using a high pressure fixed bed reactor. That is, 7 ml of a catalyst A was filled in a stainless steel reaction tube having an inner diameter of 16 mm, and the reaction pressure was 6 kg / cm ² G and the reaction temperature was 130 ° C. under the conditions of methanol 5 g / hour, carbon monoxide 57.8 ml / minute,
DMC was produced by introducing oxygen at a rate of 3.6 ml / min.

Table 1 shows the respective catalyst activities after a lapse of a predetermined time (3 hours, 50 hours, 100 hours) after the start of the reaction. In Table 1, the upper column shows the methanol conversion rate (%), and the lower column shows the methanol selectivity to DMC (%).

[0052]

[Example 2] The catalyst B was replaced with the catalyst B in Example 1.
Dimethyl carbonate (DMC) was produced in the same manner as in Example 1 except that was used.

The results are shown in Table 1.

[0054]

Example 3 In Example 1, instead of the catalyst A, the catalyst C was used.
Dimethyl carbonate (DMC) was produced in the same manner as in Example 1 except that was used.

The results are shown in Table 1.

[0056]

Comparative Examples 1 to 3 Dimethyl carbonate (DMC) was produced in the same manner as in Example 1 except that the catalyst A was replaced by the catalysts D, E and F, respectively.

Table 1 shows the results.

[0058]

[Table 1]

In Table 1, Cu content = [Cu weight /
(Weight of copper halide + weight of carrier)] × 100 (%).

As is clear from Table 1 above, the particle size is 1.
The catalyst supported on the porous carrier having a diameter of 0 mm or less retains its catalytic activity for a long period of time. On the other hand, the particle size is 1.0
The catalyst supported on the porous carrier having a size larger than mm showed a marked decrease in catalytic activity with the lapse of time after the start of the reaction.

The change with time of the methanol conversion rate (%) shown in Table 1 for each catalyst is shown in the figure. (Table 2)

[0062]

[Table 2]

(Catalyst Preparation Example 7) Cupric chloride and triphenylphosphine [P (C ₆ H ₅ ) ₃ ; hereinafter abbreviated as PPh ₃ ]
To 3.751 g of the complex Cu (PPh ₃ ) Cl obtained from the above, 20 g of activated carbon having a particle size of 0.3 mm to 0.35 mm and an ethanol solvent were added and mixed, and after drying, while flowing an inert gas, 2
Catalyst G was prepared by treating at 50 ° C. for 3 hours.

(Catalyst Preparation Example 8) A catalyst H was prepared in the same manner as in Preparation Example 7 except that 20 g of activated carbon having a particle size of 1.7 mm to 2.4 mm was used in Catalyst Preparation Example 7.

[0065]

[Example 4] The catalyst G was replaced with the catalyst G in Example 1.
Dimethyl carbonate (DMC) was produced in the same manner as in Example 1 except that was used.

The results are shown in Table 3.

[0067]

Comparative Example 4 Dimethyl carbonate (DMC) was produced in the same manner as in Example 1 except that the catalyst H was used instead of the catalyst A.

The results are shown in Table 3. In Table 3, the upper part shows the methanol conversion rate (%), and the lower part shows the methanol selectivity to DMC (%).

Cu content (wt%) = [Cu weight /
Carrier weight] × 100 (%).

[0070]

[Table 3]

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location C07C 68/00 9546-4H C07C 68/00 B 69/96 9546-4H 69/96 Z (72) Inventor Yama Nobuhiro Ta, 2-110, Sakinomachi, Handa, Aichi Prefecture, Kinuura Research Laboratories, JGC Co., Ltd. (56) Reference: JP-A-3-190846 (JP, A)

Claims (6)

(57) [Claims] 1. (i) copper halide and (ii) alkali metal hydroxide or alkaline earth metal hydroxide, or (i) copper halide and (iii) phenyl group or alkyl group And a tertiary organophosphorus compound having: are supported on a porous carrier having a particle size of 1.0 mm or less, and an alcohol is reacted with carbon monoxide and oxygen to produce a carbonic acid diester. For the production of carbonic acid diesters. 2. The porous carrier has a particle size of 0.02-1.
It is 0 mm, The catalyst for carbonic acid diester manufacture of Claim 1 characterized by the above-mentioned. 3. The catalyst for carbonic acid diester production according to claim 1, wherein the porous carrier is activated carbon. 4. (i) a copper halide and (ii) an alkali metal hydroxide or an alkaline earth metal hydroxide, or (i) a copper halide and (iii) a phenyl group or an alkyl group. With a tertiary organophosphorus compound having the following formula: Alcohol is reacted with carbon monoxide and oxygen under gas phase reaction conditions in the presence of a catalyst supported on a porous carrier having a particle size of 1.0 mm or less. A method for producing a carbonic acid diester, comprising: 5. The particle size of the porous carrier is 0.02-1.
It is 0 mm, The manufacturing method of the carbonic acid diester of Claim 4 characterized by the above-mentioned. 6. The method for producing a carbonic acid diester according to claim 4 or 5, wherein the porous carrier is activated carbon.