JPH10130206A - Production of carbonate diester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a carbonate diester, capable of efficiently producing the carbonate diester and inhibiting the deterioration in the activity of a catalyst, even when profitable carbon monoxide containing one or more sulfur components is used. SOLUTION: This method for producing a carbonate diester comprises reacting an alcohol with carbon monoxide and oxygen in the presence of a catalyst comprising at least a copper compound. Therein, the carbon monoxide containing one or more sulfur components is used. The content of one or more sulfur components in the carbon monoxide is approximately 0.01-5000ppm (ppm: mg/Nm<3> ), and the sulfur components include H2 S, COS, CS2 , SO and SO2 . The catalyst may be a copper compound, a mixture of the copper compound with one or more other metals or their compounds, or further a solid catalyst produced by carrying the catalyst on a carrier.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a carbonic acid diester by oxidative carbonylation of an alcohol and a method for suppressing a decrease in catalytic activity due to a sulfur component.

[0002]

2. Description of the Related Art Carbonic esters are used as gasoline bulking agents, octane improvers, organic solvents and reactants in place of phosgene (for example, isocyanates, carbonates, carbamates, urethanes, and various agricultural chemicals and pharmaceutical intermediates). The compound is important as a reactant in the above. In a carbonyl oxide reaction in which an alcohol is reacted with carbon monoxide and oxygen, there has been proposed a method of producing a carbonate ester using only metallic copper as a catalyst (Japanese Patent Application Laid-Open No. 2-210).
No. 2566651). However, a metal copper catalyst is applied to an industrial production method, and industrial CO produced by naphtha steam reforming, partial oxidation of asphalt, etc.
When gas is used, a marked decrease in catalytic activity is observed.

[0003] On the other hand, it is known that in a methanation reaction of CO gas and a steam reforming reaction of naphtha and natural gas using a Ru metal catalyst, a trace amount of sulfur of 0.1 ppm or less poisons the catalyst. (Catalyst Magazine, Vol. 35, No. 4 (199
3), p224-p230). Also, generally, noble metals, periodic table VIII
It is said that a catalyst using a group metal, Cu, Ag or the like is poisoned by sulfur. Therefore, in a process using a catalyst composed of these metals, sulfur poisoning of the catalyst is prevented by incorporating a desulfurization process as a step of purifying the raw material. However, complete desulfurization is not possible in the existing desulfurization process, and 0.05 to 0.1 ppm (ppm:
mg / Nm ³ ) levels of sulfur slip into the wake.
In addition, equipment costs and operating costs increase significantly depending on the degree of desulfurization. In recent years, a high-order desulfurization technique capable of reducing the sulfur content to the ppb level or less has been developed (Japanese Patent Laid-Open No.
238389). However, in this technology, it is necessary to install an adsorption tower containing a zinc-based desulfurizing agent and an adsorption tower containing a copper-based adsorbent in addition to the conventional hydrodesulfurization equipment having high equipment costs. It will be large.

At present, carbon monoxide gas is industrially produced by partial oxidation of vacuum residue, naphtha steam reforming, natural gas steam reforming, partial oxidation of coal, decomposition of methanol, and the like. Among these methods, the carbon monoxide gas containing no sulfur compound can be generated only by a method of decomposing high-purity methanol, and in other methods, the carbon compound gas generated by the sulfur compound contained in the raw material is not limited. The sulfur component is also contained in the carbon monoxide gas. However, in the method of producing extremely high-purity carbon monoxide gas by decomposition of methanol, the unit price of methanol is higher than that of vacuum residue oil, naphtha, natural gas, etc., so the produced carbon monoxide gas is inevitable. Becomes expensive. Therefore, it is difficult to economically produce a carbonate ester.

It should be noted that JP-A-6-239975, JP-A-6-218284, and JP-A-6-192183.
Japanese Patent Application Publication No. JP-A-2005-26464 and the like disclose a method of producing a carbonic acid diester by reacting an alcohol, carbon monoxide and oxygen using a copper compound as a catalyst. However, these documents do not describe a method for suppressing the deactivation of a copper catalyst in association with carbon monoxide.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for efficiently producing a carbonic diester without using a carbon monoxide containing a sulfur component, without reducing the catalytic activity. is there. Another object of the present invention is to
It is an object of the present invention to provide a method for producing a carbonic acid diester economically and inexpensively without highly purifying carbon monoxide gas. Still another object of the present invention is to provide a method for producing a carbonic diester with high conversion and selectivity using economically advantageous carbon monoxide. Another object of the present invention is to provide a method capable of suppressing a decrease in catalytic activity even using carbon monoxide containing a sulfur component.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, it
By using a catalyst composed of at least a copper compound, it has been found that the sulfur poisoning resistance of the catalyst is greatly improved, and that a carbonate can be efficiently produced industrially, and the present invention has been completed. That is, the method of the present invention is a method for producing a carbonic acid diester by a reaction between alcohol, carbon monoxide and oxygen in the presence of a catalyst composed of at least a copper compound, and uses carbon monoxide containing a sulfur component. .
The content of the sulfur component in carbon monoxide is 0.01 to 500.
It may be about 0 ppm (ppm: mg / Nm ³ ), and the sulfur component is H ₂ S, COS, CS ₂ , SO and S
O ₂ or the like may be used. The catalyst may be composed of a copper compound, may be composed of a copper compound and another metal or a compound thereof, or may be a solid catalyst in which a catalyst is supported on a carrier.

Further, the present invention provides a method for producing a carbonic acid diester by reacting an alcohol, carbon monoxide containing a sulfur component, and oxygen in the presence of a catalyst, wherein at least a copper compound is used as the catalyst. There is also included a method of using a structured catalyst to suppress a decrease in catalytic activity. In the present specification, a component constituting a catalyst in combination with a copper compound may be referred to as a “cocatalyst component”, and the “copper compound” and the “cocatalyst component” may be collectively referred to as a “catalyst”.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION

[Catalyst] Examples of copper compounds constituting the catalyst include copper hydroxide (cuprous hydroxide, cupric hydroxide), copper oxide (cuprous oxide, cupric oxide), and copper halide (fluorine). Cuprous chloride,
Cuprous chloride, cuprous bromide, cuprous halide of cuprous iodide; cupric fluoride, cupric chloride, cupric bromide, cupric halide of cupric iodide Copper), copper oxyhalide (C
u ₂ OCl ₂ , Cu ₄ O ₃ Cl ₂ etc.), inorganic acid salts (sulfuric acid,
Salts with inorganic acids such as nitric acid, carbonic acid, boric acid and phosphoric acid), organic acid salts (salts with aliphatic carboxylic acids such as formic acid, acetic acid, propionic acid, pivalic acid, oxalic acid, malonic acid, glycolic acid, Salts with oxycarboxylic acids such as lactic acid, malic acid, tartaric acid, and citric acid; salts with aromatic carboxylic acids such as benzoic acid, toluic acid, salicylic acid, and phthalic acid; salts with heterocyclic carboxylic acids such as nicotinic acid ), Metal oxoacid salts (salts with metal oxoacids such as vanadic acid, stannic acid, antimonic acid, bismuthic acid, molybdic acid, tungstic acid), coordinating compounds (ligands containing phosphorus or nitrogen atoms,
For example, amines such as ethylenediamine, nitrogen-containing heterocyclic compounds such as imidazole and pyridine, organic phosphorus compounds such as triphenylphosphine and trimethylphosphite, nitriles such as benzonitrile, isonitriles, and hexamethylphosphorous triamide. And phosphorous amides). These copper compounds can be used alone or in combination of two or more. Preferred copper compounds include, for example, copper oxide, copper halides (eg, copper chloride such as cuprous chloride and cupric chloride), inorganic acid salts (eg, inorganic strong acid salts such as copper nitrate,
Inorganic carbonates such as copper carbonate and copper borate; organic acid salts (eg, C _1-6 organic acid salt such as copper acetate and copper oxalate); complexes (eg, amine complexes, amide complexes, nitrogen-containing compounds) A heterocyclic compound complex, a phosphine complex, a phosphite complex, a nitrile complex, an isonitrile complex, a phosphorous amide complex, and the like.

The copper compound may be used alone or in combination with another metal or a compound thereof (a cocatalyst component). Examples of the co-catalyst component that can be combined with the copper compound include, for example, transition metals (copper, iron, nickel, cobalt, palladium, platinum, rhodium, iridium, ruthenium, etc.) or transition metal compounds (salts with the inorganic acids described above). , A salt with an organic acid exemplified above, a halide, an oxide,
Hydroxides, complexes, etc., alkali metal compounds (halides such as lithium chloride, sodium chloride, potassium chloride and potassium fluoride), hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, lithium carbonate, carbonate Carbonates such as sodium and potassium carbonate, lithium bicarbonate, sodium bicarbonate, bicarbonate such as potassium bicarbonate, lithium oxalate, sodium oxalate,
Oxalates such as potassium oxalate, acetates such as lithium acetate, sodium acetate, potassium acetate, etc., alkaline earth metal compounds (halides such as magnesium chloride, calcium chloride, strontium bromide, magnesium hydroxide, hydroxide) Hydroxides such as calcium, strontium hydroxide and barium hydroxide, carbonates such as magnesium carbonate, calcium carbonate, strontium carbonate and barium carbonate, hydrogen carbonates such as magnesium hydrogen carbonate, calcium hydrogen carbonate and strontium hydrogen carbonate, oxalic acid Oxalates such as magnesium, calcium oxalate and strontium oxalate, and acetates such as magnesium acetate, calcium acetate and strontium acetate), boric acid and borate. As the transition metal or a compound thereof, for example, palladium, platinum,
Platinum group metals or platinum group metal compounds such as rhodium are preferred. The amount of the cocatalyst component to be used can be selected within a range capable of improving the catalytic activity, and is 1 mol or less (about 0.0001 to 0.5 mol), preferably 0.1 mol to 1 mol of the copper compound.
It is 1 mol or less (about 0.0001 to 0.05 mol).

The above-mentioned catalyst can be used as a solid catalyst supported on a carrier. Examples of the carrier include activated carbon, silica-alumina, alumina, silica, zeolite, clay, magnesia, titania, vanasia, zirconia, and ion exchange resin. The shape of the carrier is
There is no particular limitation, and for example, any of powder, granule, fiber, pellet, and honeycomb shapes may be used. Although the specific surface area of the carrier is not particularly limited, it is usually 10 m
² / g or more, preferably about 100 to 3000 m ² / g. The specific surface area of activated carbon, which is a preferred carrier, is, for example, 500 m ² / g or more (preferably 700 to 3000).
m ² / g, more preferably 900~3000m ² / g
Degree). The average pore diameter of the activated carbon is, for example, 5-1.
00 Å, preferably about 10 to 50 Å.

The amount of the catalyst to be supported can be appropriately selected. For example, the amount of the copper compound to be supported is usually about 0.1 as Cu / support.
5 to 60% by weight, preferably 1 to 40% by weight, more preferably about the saturated adsorption amount of the carrier (for example, about 2 to 20% by weight in the case of activated carbon). Can be selected from the range of the ratio with the copper compound. The loading of the catalyst on the carrier can be carried out by a method such as an impregnation method, a kneading method, a coating method, a spray method, an adsorption method, a precipitation method, and a coprecipitation method. For example, when copper halide is supported by impregnation, after the carrier is impregnated with a solution of copper halide (such as cupric halide), the carrier is heated at 80 to 400 ° C. in an air atmosphere or under a flow of an inert gas. Heat treatment may be performed. The catalyst is preferably highly dispersed on the support. The carrier supporting the catalyst may be formed into an appropriate shape, for example, a spherical shape, a cylindrical shape, a polygonal column shape, a hollow shape, a honeycomb shape, or the like, depending on the type of the reactor and the reaction type.

[Reaction components] In the method of the present invention, an alcohol, carbon monoxide and oxygen are reacted in the presence of the above-mentioned catalyst to form a carbonic acid diester. Examples of the alcohol include saturated aliphatic alcohols such as methanol, ethanol, 1-propanol, 2-propanol and 1-butanol, unsaturated aliphatic alcohols such as allyl alcohol, and alicyclic alcohols such as cyclohexanol. And polyhydric alcohols such as ethylene glycol, propylene glycol, neopentyl glycol and polyethylene glycol, and aromatic alcohols such as phenols and benzyl alcohol. These alcohols may be used alone or in combination. Preferred alcohols include monohydric saturated or unsaturated alcohols (eg, C _1-6 alcohols, especially C _1-4 alcohols),
Particularly, methanol, ethanol, and especially methanol are included.

The oxygen may be pure molecular oxygen,
It may be diluted with an inert gas (nitrogen, argon, helium, carbon dioxide, etc.). Further, air may be used as an oxygen source.

In the present invention, the use of the above-mentioned catalyst makes
Monoxide containing sulfur components easily available at low cost
Can reduce the catalytic activity
High conversion and selectivity while maintaining high catalytic activity
Carbonic diester can be produced at a high rate. Especially,
Highly purified even with carbon monoxide containing sulfur components
Maintains almost the same high catalytic activity as when using carbon monoxide
it can. Therefore, highly purified expensive carbon monoxide
There is no need to use it, and it is industrially extremely advantageous.
It has high value as an industrial production method for steles. Carbon monoxide
Examples of the sulfur component contained in the raw gas include hydrogen sulfide and
Its derivative (H_TwoS, mercaptans, thioethers
Etc.), carbon sulfide and its derivatives (COS, CS, CS
_Two, H_TwoCS _Three), Sulfur oxides and their derivatives (SO,
SO_Two, S_TwoO_Three, SO_Three), Sulfur halide (S_TwoC
l_Two, SCl_Two, SCl_FourEtc.), sulfur oxyhalides
(SOCl_Two, SO_TwoCl_TwoEtc.), including monoxide
Carbon contains one or more of these sulfur components.
You may. The sulfur component is H_TwoS, COS, CS_Two, SO,
SO_TwoOften it is. Sulfur component in carbon monoxide
Is, for example, 0.01 to 5000 ppm (pp
m: mg / Nm^Three), Preferably 1 to 5000 ppm
(For example, 5 to 4000 ppm), and more preferably 1
0 to 5000 ppm (for example, 50 to 4000 ppm)
It is about. Improved sulfur poisoning resistance in the present invention
Although the reason is not clear, 1) Copper catalyst is used instead of copper metal
Compound, the affinity of the sulfur component for copper
It is considered that the power became weak. 2) Higher catalyst on carrier
When dispersing, the saturated adsorption amount for sulfur components increases.
It seems to be due to the addition.

The method of the present invention can be applied to any of a liquid phase reaction and a gas phase reaction, but a gas phase reaction is preferable in order to efficiently remove heat of reaction from a reactor. The liquid phase reaction may be performed in the absence of a solvent or in the presence of a solvent inert to the reaction. The amount of the catalyst to be used is, for example, 0.001 to 5 g atom / L, preferably 0.1 g in terms of copper atom in the reaction solution.
01 to 3 gram atoms / L, more preferably 0.1 to
It is about 2.5 gram atoms / L. The reaction temperature is usually
The reaction pressure is usually about 30 to 200 ° C., preferably about 50 to 150 ° C., and the reaction pressure is usually about normal pressure to 200 atm, preferably about normal pressure to 60 atm. Also, the carbon monoxide partial pressure is
For example, the pressure is about 0.1 to 200 atm, preferably about 1 to 60 atm. The oxygen partial pressure is usually selected within a range that does not form an explosive mixture, and is, for example, 0.1 to 20 atm, preferably about 0.5 atm. About 10 to 10 atm.

In the gas phase reaction, the reaction temperature is usually 7
The reaction pressure is usually from normal pressure to 35 kg / cm ² G, preferably from ^{2 to} 20 kC, at 0 to 350 ° C, preferably about 80 to 250 ° C, more preferably about 100 to 200 ° C.
g / cm ² G, more preferably 5 to 15 kg / cm ²
G. The molar ratio of carbon monoxide to alcohol (C
O / alcohol) is usually about 0.01 to 100, preferably about 0.5 to 20, and more preferably about 1 to 10, and the molar ratio of oxygen to alcohol (O ₂ / alcohol) is usually about 0.1. 01-2.0, preferably 0.05
To 1.0, more preferably about 0.05 to 0.5. The space velocity of the raw material gas is, for example, 10 to 10000
0 h ^-1 , preferably about 50 to 10000 h ^-1 , more preferably about 100 to 5000 h ^-1 . The gas phase reaction is
It can be implemented in any type of fixed bed, fluidized bed or moving bed.

The process of the present invention can be carried out in any of a batch system, a semi-batch system, and a continuous system.
By treating in accordance with a conventional method such as distillation, a carbonic acid diester corresponding to the starting alcohol can be obtained.

[0019]

According to the present invention, even when carbon monoxide containing a sulfur component is used as a reaction component, a diester carbonate can be efficiently produced while suppressing a decrease in catalytic activity. for that reason,
The carbonic acid diester can be produced economically and inexpensively without highly purifying the carbon monoxide gas. Further, even when carbon monoxide containing a sulfur component is used, a carbonic acid diester can be produced with high conversion and selectivity, as in the case of using highly purified carbon monoxide. Therefore, a large equipment cost for desulfurization from carbon monoxide gas and a large operation cost for desulfurization are not required, and carbon monoxide obtained from inexpensive raw materials and which is inexpensive and economically advantageous is converted to carbonic acid diester. Available for the manufacture of Further, in the method of the present invention, since a catalyst composed of at least a copper compound is used, even if carbon monoxide containing a sulfur-containing component is used as a reaction component, a decrease in catalytic activity can be suppressed, and a high catalytic activity can be maintained over a long period of time. Can be maintained.

[0020]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but the present invention is not limited to these Examples. Example 1 2.5 g of cupric chloride anhydride and 10.6 g of copper nitrate trihydrate
Was dissolved in 100 ml of methanol.
40 g of activated carbon [Shirasagi C2X (average pore diameter: 17 angstroms) manufactured by Takeda Pharmaceutical Co., Ltd.] degassed at 0 ° C. and 10 Torr for 1 hour was stirred at 30 ° C. for 2 hours to carry out impregnation. After the liquid phase portion was separated by filtration from the activated carbon after the impregnation and loading, it was dried at 130 ° C. for 18 hours under a nitrogen atmosphere, and further calcined at 240 ° C. for 6 hours to obtain a catalyst. The copper content was 4.3% by weight [Cu content (wt%) = (Cu weight / carrier weight) × 100]. A stainless steel reaction tube having an inner diameter of 27 mm and a length of 450 mm was filled with the catalyst so as to have a layer length of 35 mm, and the reaction temperature was set at 140 ° C., and then carbon monoxide (CO) / O ₂ / methanol = 82.
/ 2/16 (volume ratio) mixed gas at a space velocity (SV) of 5
It circulated at 00 / h for 4 hours. In this reaction, the concentration of the sulfur component in the CO gas was 2000 ppm, and the gauge pressure in the reaction tube was kept at 7 kg / cm ² . The reaction product gas flowing from the outlet of the reaction tube was cooled to −70 ° C. to be condensed and analyzed by gas chromatography. As a result, dimethyl carbonate (DMC) was found to be present in an amount of 2.0% per liter of the catalyst.
Mol / h and a methanol conversion rate of 17
%, Selectivity of dimethyl carbonate based on methanol 9
8%.

Example 2 The reaction was carried out in the same manner as in Example 1 except that CO gas having a sulfur component concentration of 100 ppm was used. The production rate of dimethyl carbonate (DMC) was 2.0 mol / h per liter of the catalyst. At a conversion of methanol of 17%,
99% selectivity for dimethyl carbonate based on methanol
Met.

EXAMPLE 3 2.5 g of cupric chloride anhydride and 10.6 g of copper nitrate trihydrate
Activated carbon obtained by preliminarily degassing a solution prepared by dissolving 2.5 g of sodium carbonate in 100 ml of methanol at 150 ° C. and 10 Torr for 1 hour [Shirasagi C2X manufactured by Takeda Pharmaceutical Co., Ltd.]
(Average pore diameter 17 angstroms)]
The mixture was stirred at 30 ° C. for 2 hours to carry out impregnation. The liquid phase was filtered off from the activated carbon after the impregnation, and then dried at 130 ° C. for 18 hours under a nitrogen atmosphere. Further, the catalyst was baked at 240 ° C. for 6 hours to prepare a catalyst. And the sulfur component concentration is 100p
When the reaction was carried out in the same manner as in Example 1 using CO gas of pm, dimethyl carbonate (DMC) was converted to 1 L of catalyst.
The yield was 2.05 mol / h, and the conversion of methanol was 17% and the selectivity for dimethyl carbonate based on methanol was 98.5%.

Example 4 15 g of activated carbon was impregnated with 8 ml of a cupric chloride solution obtained by dissolving 12.9 g of cupric chloride in 100 ml of ethanol, and dried at 100 ° C. for 3 hours while flowing nitrogen gas. After cooling, the activated carbon carrying cupric chloride was impregnated with 8 ml of an aqueous sodium hydroxide solution obtained by dissolving 3.8 g of sodium hydroxide in 100 ml of distilled water, and then at 100 ° C. for 3 hours while flowing nitrogen gas. The catalyst was prepared by drying. High pressure fixed bed reactor (inner diameter 12
mm) with 7 ml of the prepared catalyst and a reaction pressure of 6 k.
g / cm ² G, reaction temperature 150 ° C., methanol 5 g / hr, carbon monoxide 57.8 ml / min, oxygen 3.
It was introduced at a rate of 6 ml / min to synthesize dimethyl carbonate (DMC). Sulfur component concentration in carbon monoxide is 100ppm
Met. Three hours after the start of the reaction, a reaction result with a methanol conversion of 16.7% and a DMC selectivity of 93% was obtained.

Example 5 15 g of activated carbon was impregnated with 8 ml of a cupric chloride solution obtained by dissolving 12.9 g of cupric chloride in 100 ml of ethanol, and dried at 100 ° C. for 3 hours while flowing nitrogen gas. After cooling, the activated carbon supporting cupric chloride was impregnated with 8 ml of an aqueous potassium hydroxide solution in which 5.3 g of potassium hydroxide was dissolved in 100 ml of distilled water, and then at 100 ° C. for 3 hours while flowing nitrogen gas. After drying, a catalyst was prepared. A high-pressure fixed-bed reactor (12 mm in inner diameter) was charged with 7 ml of the prepared catalyst, and under the conditions of a reaction pressure of 6 kg / cm ² G and a reaction temperature of 150 ° C., methanol 5 g / hr, carbon monoxide 57.8 ml / min, Dimethyl carbonate (DMC) was synthesized by introducing oxygen at a rate of 3.6 ml / min. The sulfur component concentration in carbon monoxide was 100 ppm. After 3 hours from the start of the reaction, the methanol conversion was 18.5.
%, And a DMC selectivity of 93%.

Comparative Example 1 The reaction was carried out in the same manner as in Example 1 except that CO gas having a sulfur component concentration of 0 ppm (concentration below the lower detection limit in gas chromatography analysis) was used.
Dimethyl carbonate (DMC) was added at a rate of 2.
It is produced at a production rate of 1 mol / h and has a methanol conversion rate of 18
%, Selectivity of dimethyl carbonate based on methanol 9
8%. As is clear from the comparison with Example 1,
As in Comparative Example 1 using carbon monoxide containing no sulfur component, Example 1 using carbon monoxide containing a sulfur component can also produce dimethyl carbonate at a high conversion and selectivity, and is economical. And it is very advantageous industrially.

Comparative Example 2 [Preparation and Reaction Example of Activated Carbon Catalyst Supported on Metallic Copper] 2.5 g of cupric chloride dihydrate was dissolved in 22 ml of pure water.
20 g of the activated carbon used in Example 1 was added to this solution,
After immersion for an hour, the water was evaporated with a hot air drier at 80 ° C. for 16 hours with occasional stirring. Then, it was heat-treated at 400 ° C. for 2 hours in a hydrogen atmosphere to prepare a catalyst. 15 ml (6.5 g, 4.8 (Cu) mmol) of the prepared catalyst was charged into a U-shaped high-pressure gas-phase reaction tube, and heated at 150 ° C.
20.4 atm, space velocity of 10700 / h, CO / O
₂ / N ₂ / methanol = 37/3/57/3 (volume ratio)
Was reacted for 2 hours. The concentration of the sulfur component in the CO gas was below the lower detection limit by gas chromatography analysis. As a result, 0.29 mol / h of dimethyl carbonate was obtained per liter of the catalyst.

Comparative Example 3 The reaction was carried out in the same manner as in Comparative Example 2 except that CO gas having a sulfur component concentration of 100 ppm was used.
0.09 mol / h of dimethyl carbonate was formed per unit. From this result, it can be seen that the catalyst is remarkably deactivated by a trace amount of sulfur component in the CO gas.

Claims (6)

[Claims] 1. A method for producing a carbonic diester by reacting an alcohol, carbon monoxide and oxygen in the presence of a catalyst composed of at least a copper compound, the method comprising using carbon monoxide containing a sulfur component. Manufacturing method. 2. The content of a sulfur component in carbon monoxide is 0.1%.
^{01~5000ppm (ppm: mg / Nm 3} ) in a process according to claim 1, carbonic diester according. 3. The sulfur component of carbon monoxide is H ₂ S, CO
S, CS _2, SO and at least one a is method for producing a carbonic diester according to claim 1, wherein selected from SO _2. 4. The method for producing a carbonic acid diester according to claim 1, wherein the catalyst comprises a copper compound, or a copper compound and another metal or a compound thereof. 5. The method for producing a carbonic acid diester according to claim 1, wherein a solid catalyst having a catalyst supported on a carrier is used. 6. A method for producing a carbonic acid diester by reacting an alcohol, carbon monoxide containing a sulfur component and oxygen in the presence of a catalyst, wherein a catalyst composed of at least a copper compound is used as the catalyst, A method for suppressing a decrease in catalyst activity.