JP2812418B2 - Method for producing ester compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention performs gas phase catalytic carbonylation using carbon monoxide and nitrite in the presence of a solid catalyst and a trace amount of chlorine compounds such as hydrogen chloride, chlorine and chloroformate. In a reaction such as a carbonate ester synthesis reaction and a dicarboxylic acid diester synthesis reaction, a trace amount of chloroformate (by-product or additive) in the reaction gas derived from the reaction system while generating an ester compound in the reaction system And a method for producing an ester compound which decomposes and removes the same. INDUSTRIAL APPLICABILITY The present invention can be used, for example, to sufficiently reduce chloroformate in a separation and purification step of a carbonylation reaction to prevent contamination of a product with chlorine and corrosion of equipment.

[0002]

2. Description of the Related Art Carbonyl monoxide and nitrite are brought into contact with each other in the gas phase in the presence of a solid catalyst to effect carbonylation, for example, a carbonate ester synthesis reaction and a dicarboxylic acid diester synthesis reaction. Since the activity of the solid catalyst supporting chlorides gradually decreases during the reaction, industrially, trace amounts of chlorine compounds such as hydrogen chloride, chlorine and chloroformate are continuously supplied to the reaction system. (Japanese Patent Publication No. 58-42859, Japanese Patent Application Laid-Open No. 4-89458, Japanese Patent Application No. 5-21371, or Japanese Patent Application No. No. 5-101228).

At this time, the gas derived from the carbonylation reaction system contains, in addition to the desired ester compound such as a carbonic acid ester and a dicarboxylic acid diester, carbon monoxide, nitrite, nitrogen monoxide and nitrogen. Since there is a trace amount of chloroformate by-produced in the reaction system or a trace amount of chloroformate added to the reaction system, the chloroformate is also brought into the separation and purification step along with the target ester compound. Was. If chloroformate, which is susceptible to hydrolysis or alcoholysis, is brought into the separation and purification process, contamination of the chlorine content of the product and corrosion of the equipment will be a major problem. In the past, there were significant disadvantages in terms of cost and productivity due to trace amounts of chlorine compounds, such as the specialization of

However, with respect to a trace amount of chloroformate derived from such a carbonylation reaction system, no economical method for efficiently decomposing the chloroformate has been known at all. That is, as a method of decomposing a chloroformate, a method of heating a chloroformate to an alkyl chloride in the presence of a Lewis acid such as boron trifluoride is disclosed in J. Am. Chem. Soc., 77, 5033 (1955). ), And a method for producing an alkyl chloride by heating a chloroformate in an aprotic solvent such as N-methylpyrrolidone is disclosed in DE-A 25 45 659. It takes a long time to decompose the chloroformate of alcohol and the decomposition rate is low.The latter requires a solvent tank for the liquid phase method using a special solvent. It was not an economical way to do it.

[0005]

As described above, any of the conventionally known methods for decomposing chloroformate is economical to employ industrially for the removal of chloroformate in the production of the above-mentioned ester compound. Is not a conventional method, but also decomposes and removes trace chloroformate derived from the reaction system of gas-phase catalytic carbonylation in which carbon monoxide and nitrite are reacted in the presence of a solid catalyst and a trace amount of chlorine compound. In the above carbonylation reaction, a very small amount of chloroformate introduced into the separation and purification step has caused a serious problem of chlorine contamination in the product and corrosion of the apparatus. An object of the present invention is an economical method capable of efficiently decomposing and removing chloroformate in a gas-phase catalytic carbonylation reaction using carbon monoxide and a nitrite in the presence of a solid catalyst and a trace amount of a chlorine compound. ,
It is an object of the present invention to provide a method capable of decomposing and removing a trace amount of chloroformate derived from the reaction system while generating an ester compound in the carbonylation reaction system, thereby preventing deterioration of product quality and corrosion of equipment.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems in the conventionally known methods for decomposing chloroformate, the present inventors have keenly developed an economical method for efficiently decomposing chloroformate. As a result of the investigation, they have found that the chloroformate can be decomposed into an alkyl chloride at an extremely high rate by bringing the chloroformate into gaseous contact with activated carbon or a metal oxide-based carrier substance, and completed the present invention. That is, the present invention provides a gas phase catalytic carbonylation reaction between carbon monoxide and a nitrite in the presence of a solid catalyst and a trace amount of a chlorine compound to produce an ester compound, and the reaction gas derived from the reaction system is activated carbon. Alternatively, the present invention relates to a method for producing an ester compound, which comprises bringing a chloroformate ester in the reaction gas into gaseous phase by contacting with a metal oxide-based carrier substance in a gas phase to remove the chloroformate.

Hereinafter, the method of the present invention will be described in detail. The chloroformate used in the present invention is a solid catalyst and hydrogen chloride, chlorine, and carbon monoxide and nitrite.
Gas phase catalytic carbonylation reaction used in the presence of a trace amount of a chlorine compound such as chloroformate, for example, a carbonate ester synthesis reaction, a dicarboxylic acid diester synthesis reaction (JP-B-58-42859, JP-A-4-89458, Japanese Patent Application No. 5-21371, Japanese Patent Application No. 5-101228
) Is a trace amount of chloroformate in the reaction gas derived from the reaction system such as methyl chloroformate, ethyl chloroformate, n- (or i-) propyl chloroformate, n-chloroformate. (Or i-, sec-) lower aliphatic monovalent alcohol chloroformate having 1 to 4 carbon atoms such as butyl. Further, the alkyl chloride produced by the decomposition reaction of the chloroformate of the present invention is
Methyl chloride, ethyl chloride, n- (or i-) propyl chloride, n- (or i-, sec-) butyl chloride, etc. corresponding to the chloroformate derived from the reaction system of the carbonylation reaction, respectively. And an alkyl chloride having a lower aliphatic alkyl group having 1 to 4 carbon atoms.

In the present invention, the activated carbon used for decomposing a chloroformate into an alkyl chloride includes:
Those used as general catalyst carriers, adsorbents and decolorizing agents are sufficient, but those having a specific surface area of 300 m ² / g or more are particularly preferable. Further, the metal oxide-based carrier material is not particularly limited as long as it is used as a general catalyst carrier, for example, α-alumina,
Alumina such as γ-alumina, η-alumina, X type, Y
And natural zeolites such as soda-fluorite and morden-fluorite, molecular sieves, silica alumina, silica, titania, zirconia and the like.

The metal component such as a platinum group metal used in the carbonylation reaction is supported in a small amount on the above-mentioned activated carbon or metal oxide-based carrier material in an amount that is not effective in the carbonylation reaction. Although it does not matter, in the present invention, the platinum group metal is preferably less than 0.1% by weight, particularly preferably about 0 to 0.05% by weight, based on the activated carbon or the metal oxide-based carrier material used for the decomposition reaction. Further, it is preferable that the platinum group metal is not substantially present.

The decomposition reaction of the chloroformate of the present invention into an alkyl chloride is preferably carried out in a gas phase and continuously. At this time, the form of the activated carbon or the metal oxide-based carrier substance may be either a fixed bed or a fluidized bed, and it is not necessary to pay particular attention to its shape as long as it can sufficiently contact the gas to be fed. For example, those having a shape such as granules, pellets, and honeycombs can be used.

In the present invention, a reaction layer (hereinafter, referred to as a decomposition reaction layer) filled with activated carbon or a metal oxide-based carrier substance for decomposing chloroformate is subjected to a reaction temperature,
Since the amount of chloroformate produced varies depending on the amount of chlorine compound added, the composition and amount of the gas used in the carbonylation reaction, and the like, a reaction layer filled with a solid catalyst for performing the carbonylation reaction (hereinafter referred to as a carbonylation reaction layer) Is called)
0.02 to 5 times by volume, preferably 0.05 to
It is desirable that the volume be twice the volume, particularly preferably 0.1 to 0.5 times the volume.

The place where the above-mentioned decomposition reaction layer is formed is simply and preferably formed in a part of the carbonylation reaction reactor on the outlet side of the carbonylation reaction layer. The reactor is equipped with an outgassing line for carbonylation reaction, for example, as disclosed in Japanese Patent Application No. 3-269950 (EP523)
728 A2) Installed in a part of the conduit from the carbonylation reactor to the absorption tower in the production of dimethyl carbonate shown in A2), and filled with activated carbon or a metal oxide-based carrier material used in the above-mentioned decomposition reaction to decompose A reaction layer can also be formed. In this case, the decomposition reaction is a reaction with a small amount of gas in view of the amount of gas used for the carbonylation reaction, and does not involve a large amount of heat. The shape may be acceptable.

Although the decomposition reaction of the chloroformate to the alkyl chloride of the present invention occurs at a low temperature of about 0 ° C., the space velocity (GHSV) of the gas to be fed is 1000 to 30.
000 hr ^-1 , preferably 2000 to 10000 hr ^-1
Under the above conditions, it is desirable that the temperature of the decomposition reaction is maintained in the range of 50 to 200 ° C., preferably 70 to 150 ° C. in order to increase the decomposition rate. In addition, since this reaction does not largely depend on pressure, the reaction is performed under normal pressure or under pressure (for example, 1 to 1).
20 kg / cm ² , preferably in the range of ^{2 to} 5 kg / cm ² ).

As the gas fed to the above-mentioned decomposition reaction, the above-mentioned carbonylation reaction containing a chloroformate formed from hydrogen chloride or chlorine added to the reaction system of the carbonylation reaction or a chloroformate added to the reaction system is used. It is preferable to use the reaction gas derived from the reaction system as it is. Therefore, the gas fed to the decomposition reaction, in addition to chloroformate, carbonic acid ester, the target product of the carbonylation reaction such as dicarboxylic acid diester, by-products such as oxalic acid diester, carbon monoxide, nitrite, Although nitrogen monoxide, carbon dioxide, nitrogen and the like are contained, the decomposition reaction of the present invention can be carried out without any problem even when these substances coexist.

By providing the decomposition reaction layer as in the present invention, the chlorine compound added in the carbonylation reaction effectively acts on maintaining the activity of the solid catalyst catalyzing the carbonylation reaction in the carbonylation reaction layer. However, the decomposition reaction layer decomposes into alkyl chloride which is harmless to the material of the apparatus and is easily separated and removed, and can be led out of the reaction system. For example, in the case of dimethyl carbonate synthesis (Japanese Patent Application No. 3-26)
A decomposition reaction layer newly installed in a part of a reactor (a carbonylation reactor) or a part of a conduit from the reactor to an absorption tower;
The reaction gas of the carbonylation reaction is obtained by distilling a trace amount of chloroformate into methyl chloride, absorbing and condensing it in the absorption tower, and then connecting the bottom of the absorption tower with a distillation purification step ( (For example, an extractive distillation column, a multi-stage distillation column, etc.), and first, methyl chloride is discharged from the top of the extractive distillation column, and the crude product stream containing dimethyl carbonate is reduced in chlorine content from the bottom of the extractive distillation column. And further refined into a product. At this time, the target product of the carbonylation reaction such as a carbonate ester and a dicarboxylic acid diester is led out of the system without any change in the decomposition reaction layer. Furthermore, in the present invention, as shown in Examples and Comparative Examples, chlorine compounds such as hydrogen chloride derived in an unreacted state in the carbonylation reaction can be reduced. Corrosion can be prevented.

The reaction of the present invention for producing an ester compound by subjecting carbon monoxide and a nitrite to a gas phase catalytic carbonylation reaction in the presence of a solid catalyst and a trace amount of a chlorine compound is disclosed in JP-B-58-42859. Gazette, JP-A-4-8
No. 9458, and a method disclosed in Japanese Patent Application No. Hei.
No. 21371 and Japanese Patent Application No. 5-101228 can be easily carried out. Examples of the ester compound obtained by these methods include dimethyl carbonate and diethyl carbonate. And dicarboxylic acid diesters such as esters, dimethyl succinate and diethyl succinate.

The above-mentioned method of gas phase catalytic carbonylation reaction can be incorporated as a part of the present specification.
The dimethyl carbonate synthesis reaction can be carried out by the following method. That is, examples of the nitrite used in the dimethyl carbonate synthesis reaction include methyl nitrite, ethyl nitrite, n- (or i-) propyl nitrite, and n- (or i-, sec-) butyl nitrite. Nitrite esters of lower aliphatic monohydric alcohols having 1 to 4 carbon atoms can be mentioned. Among them, methyl nitrite and ethyl nitrite are preferably used. In the carbonylation reaction, chloroformate is formed from hydrogen chloride or chlorine corresponding to these nitrites, and is derived from the reaction system.

The solid catalyst used in the dimethyl carbonate synthesis reaction includes chlorides of platinum group metals such as palladium, platinum, iridium, ruthenium and rhodium, and iron, copper, bismuth, cobalt, nickel and tin. It is preferable that at least one selected metal compound is supported on a carrier such as activated carbon, alumina, diatomaceous earth, silicon carbide, or titania.

Specific examples of the chlorides of the platinum group metals include palladium chloride, platinum chloride, iridium chloride, ruthenium chloride and rhodium chloride. Among them, palladium chloride, ruthenium chloride and rhodium chloride are preferred.
Further, palladium chloride is most preferred. The amount of the platinum group metal chloride carried on the carrier is 0.1 to 10% by weight, particularly 0.1 to 10% by weight, based on the platinum group metal.
It is preferably from 5 to 2% by weight.

Of course, the chloride of the platinum group metal in the present invention is not limited to the above-mentioned ones. In the presence of hydrogen chloride, the above-mentioned chloride or a complex in which chlorine participates in the reaction is used. It may be a platinum group metal or a compound of said metal that can form a body. Examples of such a compound of the platinum group metal include halogen compounds such as bromate, iodate and fluorate of the metal, inorganic salts such as nitrate, sulfate and phosphate, acetate and oxalate. And organic acid salts such as benzoate, and more specifically, palladium bromide, palladium iodide, palladium fluoride, palladium nitrate, palladium sulfate, palladium phosphate, palladium acetate, palladium oxalate, benzoate Palladium acid and the like.

On the other hand, compounds of metals such as iron, copper, bismuth, cobalt, nickel and tin include halogen compounds such as chloride, bromide, iodide and fluoride of these metals, nitrates, sulfates and phosphates. And the like, and organic acid salts such as acetate, etc., among which the above-mentioned halogen compounds are particularly preferred. The loading amount of these metal compounds is preferably 1 to 50 gram atomic equivalents, more preferably 1 to 10 gram atomic equivalents, based on the amount of these metals, relative to the platinum group metal.

As a trace amount of a chlorine compound used in the dimethyl carbonate synthesis reaction, hydrogen chloride is preferably anhydrous, and the amount thereof is 1 to 50 per unit time with respect to the platinum group metal in the solid catalyst. Mol%, preferably 5 to
Desirably, it is 20 mol%. Specifically, in a fixed bed reactor, the gas hourly space velocity (GHSV) is 3000 hr.
^-1 reaction, 10%
~ 500 ppm by volume, preferably 20-100 ppm by volume
It is preferable to add m of hydrogen chloride and to continuously supply the solid catalyst layer. The dimethyl carbonate synthesis reaction can be performed by supplying chlorine or chloroformate as a chlorine compound to the reaction system.

At this time, it is desirable that carbon monoxide and nitrite in the raw material gas fed are diluted with an inert gas such as nitrogen gas and then fed to the reactor. The composition is not particularly limited from the viewpoint of the reaction, but the concentration of nitrite is not more than 20% by volume, preferably 5 to 20% by volume from the viewpoint of safety, and the concentration of carbon monoxide is economical. From the viewpoint of, it is desirable that the content is 5 to 20% by volume. Further, the use ratio of carbon monoxide to nitrite is such that carbon monoxide is 0.1 mol per mol of nitrite.
It is desirably in the range of 10 to 10 mol, preferably 0.25 to 1 mol. The space velocity (GHSV) of the raw material gas fed to the reactor is 500 to 20,000 hr.
^-1 , preferably in the range of 2000 to 10000 hr ^-1 .

The synthesis reaction of an ester compound such as dimethyl carbonate is carried out under very mild reaction conditions, for example, from 0 to 200
C., preferably at a temperature of 50 to 120.degree. C. and at normal pressure. Of course, the reaction is possible even under pressure, 1 to 20 kg / c
It can be carried out at a pressure of m ² G and a temperature of 50 to 150 ° C. The form of this reaction is preferably a gas phase or a continuous type, and the solid catalyst may be present in the reaction system either in a fixed bed or a moving bed.
In the case of granular, about 4 to 200 mesh, and in the case of powder, 20 to 100 μm which is usually used is suitable.

According to a specific example of the reaction according to the above-mentioned method, the reaction for synthesizing dimethyl carbonate is described in JP-A-4-8.
As disclosed in Japanese Patent No. 9458, a gas-phase reaction tube filled with granular activated carbon (catalyst for producing dimethyl carbonate) supporting palladium chloride and bismuth chloride is placed under normal pressure under pressure.
At 0 ° C., methyl nitrite: 15% by volume, carbon monoxide: 10
The raw material gas consisting of 3% by volume of nitric oxide, 3% by volume of nitric oxide, 6% by volume of methanol, 100% by volume of hydrogen chloride and 66% by volume of nitrogen was supplied at a space velocity of 3000 hr ^-1 (GHS
It can be carried out by the method of supplying in V).

The reaction for synthesizing dimethyl succinate as an ester compound is described, for example, in JP-B-58-4285.
As disclosed in Japanese Patent Publication No. 9-145, a gas-phase reaction tube filled with silica beads (catalyst for producing dimethyl succinate) supporting palladium metal and cupric chloride is placed under normal pressure under a pressure of 145.
At a temperature of 700 ° C., a raw material gas consisting of 20% by volume of ethylene, 22% by volume of carbon monoxide, 5% by volume of nitric oxide and 30% by volume of oxygen was supplied at a rate of 700 ml / min. Is evaporated to 40 ml
/ Min and a rate of 0.5 to 2 ml / min (a space velocity (GHSV) of the whole raw material gas: 2500 hr ^-1 ).

In the present invention, for example, a gas phase catalytic carbonylation reaction using carbon monoxide and a nitrite in the presence of a solid catalyst and hydrogen chloride (which may be a trace amount of a chlorine compound such as chlorine or chloroformate) ( For example, a reaction to produce an ester compound such as a carbonate ester such as dimethyl carbonate or a dicarboxylic acid diester such as dimethyl succinate) is performed, and unreacted carbon monoxide is added together with the target dimethyl carbonate and dimethyl succinate from the reaction system. , Methyl nitrite, then a carbonylation reaction gas comprising nitric oxide, carbon dioxide, inert gas, etc., and contacting the reaction gas with activated carbon or a metal oxide-based carrier material; and The reaction gas in a state where methyl acid is decomposed and removed and hydrogen chloride is reduced at the same time is derived, and this After cooling the response gas, it is possible to obtain a chlorine content reduced product performed by a conventional method for separation and purification such as distillation from the condensate (ester compound of dimethyl carbonate, dimethyl succinate).

[0028]

EXAMPLES Next, the method of the present invention will be specifically described with reference to examples and comparative examples, but these do not limit the method of the present invention at all. Example 1 A stainless steel reaction tube (with an outer jacket) having an inner diameter of 27 mm and a length of 500 mm was vertically fixed, and the reaction tube was filled with 3.5 ml of granular activated carbon (Shirasagi: Takeda Pharmaceutical) to form a decomposition reaction layer. Then, 25 ml of a solid catalyst supported on granular activated carbon (Shirasagi: manufactured by Takeda Pharmaceutical Co., Ltd.) at a ratio of 1% by weight and 1.2% by weight of palladium chloride and cupric chloride, respectively, in terms of metal, was charged into the upper part of the mixture. An oxidation reaction layer was formed. A heating medium was circulated through the jacket of the reaction tube to control the heating so that the temperature in both reaction layers became 100 ° C. From the top of the reaction tube, methyl nitrite: 10% by volume, carbon monoxide: 20% by volume , Nitric oxide: 4% by volume, methanol:
A source gas diluted with nitrogen containing 8% by volume and 50 ppm by volume of hydrogen chloride was supplied at a flow rate of 100 Nl / hr (a space velocity (GHSV) based on a cracking reaction layer (GHSV) of 28600 hr ^-1 , and a reaction pressure of 3 kg / cm ² G). The carbonylation reaction and the decomposition reaction were performed for 10 hours at this time, and the temperature of the carbonylation reaction layer was 105 to 115 ° C. and the temperature of the decomposition reaction layer was 110.
° C.

When methyl chloroformate and methyl chloride in the reactor outlet gas were analyzed by gas chromatography,
Methyl chloroformate could not be confirmed, and the concentration of methyl chloride was 4
It was 7 ppm by volume. Further, the reaction product collected through ice-cooled methanol was analyzed by ion chromatography, and it was found that chlorine compounds (methyl chloroformate and hydrogen chloride) except for methyl chloride were contained at 1 ppm by volume in terms of concentration in gas. I was The dimethyl carbonate was produced at a space-time yield (STY) of 380 g / l · hr and a selectivity of 88% based on carbon monoxide.

The space-time yield of dimethyl carbonate (S
(TY) (g / l · hr) indicates the contact reaction time between carbon monoxide and methyl nitrite as θ (hr), the amount of dimethyl carbonate generated during the reaction as a (g), and carbonylation in the reaction tube. The reaction layer is determined by the following equation as b (l), and the same applies to the following Examples and Comparative Examples.

[0031]

STY (g / 1 · hr) = a / (b × θ)

The selectivity (X) (%) of dimethyl carbonate in Examples and Comparative Examples is the selectivity based on the supplied carbon monoxide, and the dimethyl carbonate and oxalic acid formed at the above θ (hr) The amounts of dimethyl and carbon dioxide are each c
(Mol), d (mol) and e (mol) were determined by the following equations. The same applies hereinafter.

[0033]

X (%) = {c / (c + 2 × d + e)} × 100

Example 2 Example 1 was repeated except that the reactor was filled with 3.5 ml of γ-alumina (KHA-24: manufactured by Sumitomo Chemical) in place of the granular activated carbon in Example 1 to form a decomposition reaction layer. The reaction was carried out in the same manner as described above. As a result, the concentration of methyl chloroformate in the output gas from the reactor was 4 ppm by volume, and the concentration of methyl chloride was 43 ppm.
The volume was ppm. Further, chlorine compounds (methyl chloroformate and hydrogen chloride) except for methyl chloride in the reaction product collected through ice-cooled methanol contained 5 ppm by volume in terms of gas concentration. Note that dimethyl carbonate was produced at a space-time yield (STY) of 375 g / l · hr and a selectivity of 90% based on carbon monoxide.

Comparative Example 1 Except that no decomposition reaction layer was formed in Example 1,
The reaction was carried out in the same manner as in Example 1, and the product was analyzed. As a result, the concentration of methyl chloroformate in the outlet gas of the reactor was 18 ppm by volume, and the concentration of methyl chloride was 27 ppm by volume.
Met. The chlorine compounds (methyl chloroformate and hydrogen chloride) in the reaction product collected through ice-cooled methanol were 25 ppm by volume in terms of gas concentration. The dimethyl carbonate was produced at a space-time yield (STY) of 377 g / l · hr and a selectivity of 88% based on carbon monoxide.

Example 3 Instead of the catalyst in Example 1, a reaction tube was filled with 5 ml of γ-alumina (KHA-24: manufactured by Sumitomo Chemical Co., Ltd.) to form a decomposition reaction layer. KHA-
24: Sumitomo Chemical Co., Ltd.)
2 (DE 4123603), a carbonylation reaction layer was formed by filling 25 ml of a dimethyl carbonate production catalyst carrying 1.5% by weight of lithium chloropalladate in terms of metal, and the concentration of methyl nitrite in the raw material gas was reduced to 18%. capacity%
The reaction was carried out in the same manner as in Example 1 except that the concentration of hydrogen chloride was changed to 1000 ppm by volume. At this time, the temperature of the carbonylation reaction layer was 108 to 120 ° C, and the temperature of the decomposition reaction layer was 114 ° C.

After the reaction, the product was analyzed in the same manner.
The concentration of methyl chloroformate in the reactor outlet gas is 15
At pm, the concentration of methyl chloride was 970 ppm by volume. Chlorine compounds (methyl chloroformate and hydrogen chloride) in the reaction product collected through ice-cooled methanol, excluding methyl chloride, are 20 ppm by volume in terms of gas concentration.
Was included. Dimethyl carbonate has a space-time yield (ST
Y) 570 g / l · hr, selectivity 88 based on carbon monoxide
%.

Comparative Example 2 Except that no decomposition reaction layer was provided in Example 3,
The reaction was carried out in the same manner as in Example 3, and the product was analyzed. As a result, the concentration of methyl chloroformate in the reactor outlet gas was 53
7 ppm by volume, the concentration of methyl chloride is 455 ppm by volume
Met. The chlorine compounds (methyl chloroformate and hydrogen chloride) in the reaction product collected through ice-cooled methanol were 550 ppm by volume in terms of gas concentration. Note that dimethyl carbonate was produced at a space-time yield (STY) of 565 g / l · hr and a selectivity of 88% based on carbon monoxide.

Example 4 Instead of the catalyst in Example 1, a reaction tube was filled with 3 ml of γ-alumina (KHA-24: manufactured by Sumitomo Chemical Co., Ltd.) to form a decomposition reaction layer. KHA-
24: manufactured by Sumitomo Chemical Co., Ltd.) and filled with 15 ml of a catalyst for producing dimethyl succinate supporting 1% by weight and 1.2% by weight of palladium chloride and cupric chloride in terms of metal, respectively, to form a carbonylation reaction layer. The composition of the raw material gas was methyl nitrite: 5% by volume, carbon monoxide: 20% by volume, ethylene: 15% by volume, nitric oxide: 4% by volume, methano-
The reaction was carried out in the same manner as in Example 1 except that the mixture was supplied at a flow rate of 50 Nl / hr (a space velocity (GHSV) based on a decomposition reaction layer of 16700 hr ^-1 ) instead of 8 vol% of hydrogen and 800 ppm of hydrogen chloride. Was. At this time, the temperature of the carbonylation reaction layer was 105 to 115 ° C, and the temperature of the decomposition reaction layer was 108 ° C.

When methyl chloroformate and methyl chloride in the reactor outgas were analyzed by gas chromatography,
The concentration of methyl chloroformate was 10 ppm by volume and the concentration of methyl chloride was 770 ppm by volume. Further, the reaction product collected through ice-cooled methanol was analyzed by ion chromatography, and it was found that chlorine compounds (methyl chloroformate and hydrogen chloride) other than methyl chloride were contained at 15 ppm by volume in terms of gas concentration. I was The dimethyl succinate was produced with a space-time yield (STY) of 230 g / l · hr and a selectivity of 93% based on carbon monoxide. Example 1
Table 1 summarizes the results of Comparative Examples 1 to 4 and Comparative Examples 1 and 2.

[0041]

[Table 1]

The space-time yield of dimethyl succinate (ST
Y) (g / l · hr) indicates the contact reaction time between carbon monoxide and ethylene and methyl nitrite as θ (hr), the amount of dimethyl succinate generated during the reaction as f (g), and The carbonylation reaction layer was determined as b (l) by the following equation.

[0043]

STY (g / 1 · hr) = f / (b × θ)

The selectivity of dimethyl succinate (Y)
(%) Is the selectivity based on the supplied carbon monoxide, and the amounts of dimethyl succinate, dimethyl oxalate, dimethyl carbonate and carbon dioxide generated at the above θ (hr) are respectively expressed in g (mol), h (mol), i (mol), j
(Mol) was determined by the following equation.

[0045]

Y (%) = {2 × g / (2 × g + 2 × h + i + j)} × 100

[0046]

The present invention provides a gas-phase catalytic carbonylation reaction in which carbon monoxide and a nitrite are reacted in the presence of a solid catalyst and hydrogen chloride (or a trace amount of a chlorine compound such as chlorine or chloroformate). A trace amount of chloroformate (by-product or additive) present together with ester compounds such as carbonic acid diester and dicarboxylic acid diester produced in the above is decomposed into alkyl chloride to substantially remove the chloroformate from the reaction gas. This is an industrially excellent method for producing an ester compound, which can reduce hydrogen chloride, and at the same time, can prevent chlorine content from contaminating a product and corrosion of a purification device.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C07C 68/00 C07C 68/00 A 68/08 68/08 69/34 69/34 // C07B 61/00 300 C07B 61/00 300 C07C 17/00 C07C 17/00 19/03 19/03 (72) The inventor, Masato Murakami 5 at 1978 Kogushi, Ube City, Ube, Yamaguchi Prefecture Ube Industries, Ltd. Ube Research Laboratory (72) Inventor, Toshio Kurato Yamaguchi Prefecture Ube City, 1978 Kogushi, 5 Ube Industries, Ltd. Ube Research Laboratory Examiner Hiroko Fujiwara (56) References JP-A-4-89458 (JP, A) JP-A-54-100312 (JP, A) 6-329597 (JP, A) U.S. Pat. No. 4,814,524 (US, A) West German Patent Application Publication No. 2545659 (DE, A1) (58) Fields investigated (Int. Cl. ⁶ , DB name) C07C 69/96 C07C 67 / 36 C07C 67/60 C07C 68/00 C07C 68/08 C07C 69/34 C 07C 17/00 C07C 19/03 CA (STN)

Claims (1)

(57) [Claims] Claims: 1. A gas phase catalytic carbonylation reaction of carbon monoxide and a nitrite in the presence of a solid catalyst and a trace amount of a chlorine compound to produce an ester compound, and the reaction gas derived from the reaction system is activated carbon or A method for producing an ester compound, comprising subjecting a gaseous contact with a metal oxide-based carrier substance to decompose and remove chloroformate in the reaction gas into alkyl chloride.