JP2021151986A - Method and device for producing carbonate ester - Google Patents

Abstract

To provide a method for producing a carbonate ester with high efficiency while removing by-product water from a reaction field without using a dehydrating agent or a chemical hydration agent under mild reaction pressure and to provide a device for producing a carbonate ester.SOLUTION: There are provided a method and a device for producing a carbonate ester in which a carbonate ester and by-product water are produced by reacting carbon dioxide and at least one alcohol selected from the group consisting of monovalent and divalent alcohols having a boiling point of more than 100°C under the conditions of a reaction temperature of 100°C or more and equal to or below the boiling point of the alcohols and the solvent in the presence of at least one solid catalyst selected from the group consisting of cerium oxide, zirconium oxide, lanthanum oxide, samarium oxide, praseodymium oxide, tin oxide, dysprosium oxide, gadolinium oxide and europium oxide and a solvent and the by-product water is removed from a reaction field by vaporization.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for producing a carbonic acid ester and an apparatus for producing a carbonic acid ester.

Carbonate ester is a general term for compounds in which one or two of the two hydrogen atoms of HO-C (= O) -OH carbonate is substituted with an alkyl group or an aryl group, and RO-C (= O). It has a structure of −OR'(R, R'represents a saturated hydrocarbon group or an unsaturated hydrocarbon group).

Carbonate esters are used as additives such as gasoline additives for improving octane value and diesel fuel additives for reducing particles in exhaust gas, and also synthesize resins and organic compounds such as polycarbonate, polyurethane, pharmaceuticals and pesticides. It is a very useful compound as it is used as an alkylating agent, a carbonylating agent, a solvent, etc., or as a raw material for an electrolytic solution of a lithium battery, a raw material for lubricating oil, and a deoxidizing agent for rust prevention of a boiler pipe.

As a conventional method for producing a carbonic acid ester, a method of directly reacting with alcohol using phosgene as a carbonyl source is the mainstream. Since this method uses phosgene, which is extremely harmful and highly corrosive, it is necessary to pay close attention to its transportation and storage, and it costs a lot of money to maintain and manage the manufacturing equipment and ensure safety. Was there. Further, in the case of production by this method, halogens such as chlorine are contained in the raw materials and the catalyst, and the obtained carbonic acid ester contains a trace amount of halogen that cannot be removed by a simple purification step. In applications for gasoline additives, light oil additives, and electronic materials, there is a concern that it may cause corrosion, so a thorough refining process is essential to reduce the amount of halogen present in trace amounts to a very small amount. Furthermore, recently, since phosgene, which is extremely harmful to the human body, is used, administrative guidance has been strict, such as not permitting the construction of new manufacturing equipment using this manufacturing method, and there is a strong desire for a new manufacturing method that does not use phosgene. It is rare.

Under these circumstances, as described in Non-Patent Document 1, as a method for producing a carbonic acid ester without using phosgene, carbon dioxide is reacted with ethylene oxide or the like to synthesize a cyclic carbonate, which is further reacted with methanol to form dimethyl carbonate. The method of obtaining the ester has been put into practical use. This method uses or hardly generates corrosive substances such as hydrochloric acid, and is an excellent environment-friendly method that can be expected to have a reduction effect by adding carbon dioxide, which is required to be reduced as a greenhouse gas, into the skeleton. Is. However, as described in Patent Document 1, effective utilization of ethylene glycol produced as a by-product is a major issue. In addition, since it is difficult to safely transport ethylene, which is a raw material of ethylene oxide, and ethylene oxide, there is a restriction that a plant for the carbonic acid ester production process must be located adjacent to the plant for the production process of ethylene and ethylene oxide.

Further, as described in Patent Document 2, Patent Document 3, and Patent Document 4, a method for synthesizing a carbonic acid ester (polyether carbonate polyol or polycarbonate polyol) by reacting carbon dioxide with an alkylene oxide or epoxiside is disclosed. ing. These methods are also excellent environmentally friendly methods that can be expected to have a reduction effect by incorporating carbon dioxide, which is required to be reduced as a greenhouse gas, into the skeleton. However, since a complex catalyst is used as the catalyst, there are restrictions on the upper limit of the operating temperature so that the complex catalyst does not decompose, it is not easy to separate the product from the catalyst after the reaction, and the reaction pressure is 2 MPa to 6 MPa. There was a problem that the higher the pressure, the more advantageous it was.

Further, as described in Patent Document 5, a method for producing dimethyl carbonate by oxygen-oxidizing methanol and carbon monoxide in the liquid phase in the presence of a cuprous chloride catalyst is also disclosed. However, in this method, it is essential to handle carbon monoxide, which is harmful to the human body, and to purify halogen from the carbon dioxide ester obtained by containing halogen in the catalyst, as in the production method using phosgene. Problems such as carbon dioxide being produced as a by-product have been pointed out.
On the other hand, Patent Document 6 discloses a method for producing urethane or carbonate from carbon dioxide and divalent alcohol, but the method uses a strongly basic nitrogen-containing compound as a catalyst and has a high environmental load. Was the problem.

In order to solve the above problems, an attempt has been made to remove the water produced as a by-product together with the carbonic acid ester (dimethyl carbonate) to the outside of the system to release the reaction restriction. For example, acetal as a wettable powder together with a catalyst (Non-Patent Document 2). , 2,2-Dimethoxypropane (Non-Patent Document 3) has been reported. However, this method has a characteristic that the reaction proceeds as the reaction pressure increases, the reaction yield is very low at low pressure, and high productivity cannot be obtained unless the reaction pressure is extremely high. This is because the hydration reaction of acetal and 2,2-dimethoxypropane is expected to proceed in the liquid phase without being catalyzed, so the reaction rate of the dimethyl carbonate direct synthesis reaction is independent of the _{CO 2 pressure.} It is presumed that this is to determine the overall reaction rate, but since the reaction pressure is as high as 300 atm (30 MPa) and 60 atm (6 MPa), the methanol conversion rate is high, so the power energy required for boosting is very large. There were problems such as poor energy efficiency.

In addition, studies using molecular sieves (solid dehydrating agents) (Patent Document 7, Non-Patent Document 4) have been reported, but in the process of separating and circulating the reaction part (high pressure) and the dehydration part (normal pressure). Therefore, there is a problem that energy consumption is large and a large amount of solid dehydrating agent is required. The solid catalyst used in the direct synthesis reaction of carbonic acid ester has been a tin compound such as dimethoxydibutyltin, a tarium compound such as talliummethoxydo, a nickel compound such as nickel acetate, and an alkali carbonate such as vanadium pentoxide and potassium carbonate. Various compounds such as salts and Cu / SiO _{2 have been studied.}

On the other hand, as a reaction using acetonitrile as a wettable powder, studies on a reaction system for directly synthesizing cyclic carbonate (propylene carbonate) from divalent alcohols propylene glycol and carbon dioxide in the presence of a solid catalyst have been reported. (Non-Patent Document 5).
However, even in this reaction system, the influence of the reaction pressure is remarkable, and the reaction proceeds as the reaction pressure increases. At low pressure, the reaction yield is extremely low, but the direct synthesis reaction of the cyclic carbonate is in equilibrium. It was confirmed that the yield increased at a particularly advantageous high pressure, and the reaction pressure was preferably 100 atm or more, and there were problems such as poor energy efficiency as described above.

In the production of carbonic acid ester, the present inventors focused on a method of directly synthesizing carbonic acid ester from monovalent alcohol and carbon dioxide using a heterogeneous catalyst, and remove water produced as a by-product together with carbonic acid ester to the outside of the system. By using acetonitrile and benzonitrile as the wettable powder, high pressures such as 300 atm and 60 atm as described in Non-Patent Documents 2 and 3 are unnecessary, and the reaction is promoted under a pressure close to normal pressure. For the first time, we found the effect (see Patent Documents 8 and 9). However, when acetonitrile is used as the wettable powder, by-products such as acetamide are generated and their uses are limited. Therefore, by adopting benzonitrile as the wettable powder, the same as in the case of acetonitrile In addition, it was found that the reaction proceeded more when the pressure of the reaction system was close to the normal pressure, and that the number of by-products was small. In addition, benzamide itself, which is a main by-product, has been found to have many uses and has been invented.

Furthermore, the present inventor diligently examined the type of wettable powder in order to further improve the amount of carbonic acid ester produced, and found that 2-cyanopyridine or benzonitrile was used as the wettable powder in order to further improve the amount of carbonic acid ester produced. By using, the amount and rate of carbonic acid ester production are greatly improved as compared with the case of acetonitrile and benzonitrile, the reaction is easy to proceed under a relatively low pressure close to normal pressure, and the reaction rate is very high. It was found to be fast (see Patent Documents 10, 11, 12, and 13). However, a process of regenerating and reusing the by-produced 2-picoline amide or benzamide was required (see Patent Documents 10, 11, 12, and 13).

WO2004 / 014840 WO2006 / 103213 JP-A-2015-28182 WO2013 / 010986 EP365,083 Japanese Unexamined Patent Publication No. 5-117222 Japanese Unexamined Patent Publication No. 2001-247519 Japanese Unexamined Patent Publication No. 2009-132673 Japanese Unexamined Patent Publication No. 2010-77113 Japanese Unexamined Patent Publication No. 2012-162523 Japanese Unexamined Patent Publication No. 2009-23975 Japanese Unexamined Patent Publication No. 2016-216361 Japanese Unexamined Patent Publication No. 2016-216363

Chemical Engineering, 68 (1) (2004) 41 Polyhedron, 19 (2000) 573 Appl. Catal. A Gen, 237 (2002) 103 Eco Industry, 6 (2001) 11 Catal. Lett., 112, (2006) 187

As described above, alcohol and carbon dioxide are reacted in the presence of a solid catalyst under a mild reaction pressure such as normal pressure, and by-product water is used without using a dehydrating agent or a chemical wettable powder. Was removed from the reaction field to synthesize carbon dioxide ester in high yield.

Therefore, an object of the present invention is to produce carbonic acid under mild reaction pressure with high efficiency while removing by-product water from the reaction field without using a dehydrating agent or a chemical wettable powder. The present invention provides a method for producing an ester and an apparatus for producing a carbonic acid ester.

The means for solving the problem includes the following aspects.
[1]
Carbon dioxide in the presence of at least one solid catalyst and solvent selected from the group consisting of cerium oxide, zirconium oxide, lanthanum oxide, samarium oxide, placeodym oxide, tin oxide, displosium oxide, gadrinium oxide, and europium oxide. And at least one alcohol selected from the group consisting of monohydric and divalent alcohols having a boiling point of more than 100 ° C. and a reaction temperature of 100 ° C. or higher and lower than the boiling point of the alcohol and the solvent. A method for producing a carbonic acid ester, which is reacted below to produce a carbon dioxide ester and by-product water, and the by-product water is removed from the reaction field by evaporation.
[2]
The method for producing a carbonic acid ester according to [1], wherein the evaporated by-product water is removed from the reaction field by an air flow of carbon dioxide.
[3]
The method for producing a carbonic acid ester according to [1] or [2], wherein the alcohol is a monohydric alcohol having 4 to 10 carbon atoms.
[4]
The method for producing a carbonic acid ester according to [1] or [2], wherein the alcohol is a divalent alcohol having 2 to 10 carbon atoms.
[5]
The method for producing a carbonic acid ester according to [4], wherein the divalent alcohol is a divalent alcohol having 4 to 6 carbon atoms.
[6]
The method for producing a carbonic acid ester according to any one of [1] to [5], wherein the solvent is an ether solvent.
[7]
The method for producing a carbonic acid ester according to any one of [1] to [6], wherein the solvent is a hydrophobic solvent.
[8]
In a reactor in which at least one solid catalyst and solvent selected from the group consisting of cerium oxide, zirconium oxide, lanthanum oxide, samarium oxide, placeodium oxide, tin oxide, displosium oxide, gadolinium oxide, and europium oxide are present. Carbon dioxide and at least one alcohol selected from the group consisting of monohydric and divalent alcohols having a boiling point of more than 100 ° C. are supplied, the reaction temperature is 100 ° C. or higher, and the alcohol and the solvent are used. A reaction step of reacting the carbon dioxide with the alcohol to produce a carbonic acid ester and by-product water under the conditions below the boiling point of
The unreacted carbon dioxide, the unreacted alcohol, the by-product water, and the solvent discharged as the gas phase from the reactor in the reaction step are cooled, and the unreacted dioxide is used as the gas phase. A first cooling step of separating the carbon into the unreacted alcohol, the by-product water and the solvent as a liquid phase.
The unreacted alcohol, the by-product water and the solvent separated as the liquid phase in the first cooling step are distilled to obtain the by-product water as the gas phase and the unreacted product as the liquid phase. A first distillation step of separating into the alcohol and the solvent, and
The carbonic acid ester, the unreacted alcohol and the solvent discharged as the liquid phase from the reactor in the reaction step are distilled to prepare the unreacted alcohol and the solvent as the gas phase and the liquid phase. The carbonic acid ester, the unreacted alcohol, and the solvent discharged as a liquid phase from the reactor in the second distillation step of separating into the carbonic acid ester and the reaction step are cooled. A second cooling step of separating the unreacted alcohol and the solvent as the liquid phase and the carbonic acid ester as the solid phase.
Have,
The unreacted carbon dioxide separated in the first cooling step, the unreacted alcohol and the solvent separated in the first distillation step, and the second distillation step or the second cooling. The unreacted alcohol and the solvent separated in the step are reused in the reaction step.
Method for producing carbonic acid ester.
[9]
A separation step of separating the solid catalyst discharged as a solid phase together with the liquid phase from the reactor in the reaction step from the liquid phase.
A catalyst regeneration step of regenerating the solid catalyst separated in the separation step, and a catalyst regeneration step.
Have more
The method for producing a carbonic acid ester according to [8], wherein the solid catalyst regenerated in the catalyst regeneration step is reused in the reaction step.
[10]
It has a reactor in which at least one solid catalyst and solvent selected from the group consisting of cerium oxide, zirconium oxide, lanthanum oxide, samarium oxide, placeodium oxide, tin oxide, displosium oxide, gadolinium oxide, and europium oxide are present. Then, carbon dioxide and at least one alcohol having a boiling point of more than 100 ° C. and selected from the group consisting of monohydric and divalent alcohols are supplied to the reactor, and the reaction temperature is 100 ° C. or higher. A reaction tower that produces carbonic acid ester and by-product water by reacting the carbon dioxide with the alcohol under conditions below the boiling point of the alcohol and the solvent.
The unreacted carbon dioxide, the unreacted alcohol, the by-product water, and the solvent discharged as the gas phase from the reactor in the reaction tower are cooled, and the unreacted dioxide is used as the gas phase. A first cooling tower that separates carbon into, as a liquid phase, the unreacted alcohol, the by-product water, and the solvent.
The unreacted alcohol, the by-product water and the solvent separated as the liquid phase in the first cooling column are distilled to form the gas phase with the by-product water and the liquid phase with the unreacted product. A first distillation column that separates into the alcohol and the solvent,
The carbonic acid ester, the unreacted alcohol and the solvent discharged as a liquid phase from the reactor in the reaction tower are distilled, and the unreacted alcohol and the solvent are used as a gas phase as a liquid phase. The carbonic acid ester, the unreacted alcohol, and the solvent discharged as a liquid phase from the second distillation column separated into the carbonic acid ester and the reactor in the reaction column are cooled. A second cooling tower that separates the unreacted alcohol and the solvent as the liquid phase and the carbonic acid ester as the solid phase.
With
The unreacted carbon dioxide separated in the first cooling tower, the unreacted alcohol and the solvent separated in the first distillation column, and the second distillation column or the second cooling column. The unreacted alcohol and the solvent separated in the above are reused in the reaction column.
Carbonate ester manufacturing equipment.
[11]
A separation tower that separates the solid catalyst discharged as a solid phase together with the liquid phase from the reactor in the reaction tower from the liquid phase.
A catalyst regeneration tower that regenerates the solid catalyst separated by the separation tower, and a catalyst regeneration tower.
With more
The carbonic acid ester production apparatus according to [10], wherein the solid catalyst regenerated in the catalyst regeneration tower is reused in the reaction tower.

According to the present invention, a carbonic acid ester that produces a carbonic acid ester with high efficiency under mild reaction pressure without using a dehydrating agent or a chemical wettable powder while removing by-product water from the reaction field. A method for producing a carbonic acid ester and an apparatus for producing a carbonic acid ester can be provided.

It is a schematic block diagram which shows the carbonic acid ester production apparatus which concerns on 1st Embodiment. It is a schematic block diagram which shows the carbonic acid ester production apparatus which concerns on 2nd Embodiment.

Hereinafter, the present invention will be described.
In the present specification, the numerical range represented by using "~" means a range including the numerical values before and after "~" as the lower limit value and the upper limit value.
In the numerical range described stepwise, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the upper limit value or the lower limit value of another numerical range described stepwise.
In the numerical range, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the value shown in the examples.
The term "process" is included in this term as long as the intended purpose of the process is achieved, not only in an independent process but also in cases where it cannot be clearly distinguished from other processes.
The "combination of preferred embodiments" is a more preferred embodiment.

The method for producing a carbonic acid ester of the present invention is at least one solid catalyst selected from the group consisting of cerium oxide, zirconium oxide, lanthanum oxide, samarium oxide, placeodym oxide, tin oxide, disprosium oxide, gadolinium oxide, and europium oxide. In the presence of and a solvent, carbon dioxide and at least one alcohol having a boiling point of more than 100 ° C. and selected from the group consisting of monohydric and divalent alcohols have a reaction temperature of 100 ° C. or higher and a reaction temperature of 100 ° C. or higher. This is a method in which a carbon dioxide ester and by-product water are produced by reacting under conditions below the boiling point of an alcohol and a solvent (see the scheme below), and the by-product water is removed from the reaction field by evaporation.

In the method for producing a carbonic acid ester of the present invention, the above method is used to remove by-product water from the reaction field under mild reaction pressure without using a dehydrating agent or a chemical wettable powder, and to achieve high efficiency. Can produce carbonic acid esters.
The method for producing a carbonic acid ester of the present invention has been found based on the following findings.

The present inventors have focused on a method for directly synthesizing a carbonic acid ester from alcohol and carbon dioxide having a boiling point of more than 100 ° C. in the production of the carbonic acid ester. Then, the inventors obtained the following findings.
Carbon dioxide in the presence of at least one solid catalyst and solvent selected from the group consisting of cerium oxide, zirconium oxide, lanthanum oxide, samarium oxide, placeodym oxide, tin oxide, displosium oxide, gadolinium oxide, and europium oxide. By reacting with alcohol while introducing the above, by-product water produced as a by-product with carbon dioxide ester can be removed from the reaction field by utilizing the difference in boiling point without using a dehydrating agent or a chemical wettable powder. As a result, high pressures such as 3 MPa (30 atm) and 6 MPa (60 atm) as described in Non-Patent Documents 2 and 3 are unnecessary, and carbon dioxide is carbon dioxide under mild reaction pressure such as under normal pressure. And the reaction with alcohol proceed.

Based on the above findings, the method for producing a carbonic acid ester of the present invention is highly efficient under mild reaction pressure while removing by-product water from the reaction field without using a dehydrating agent or a chemical wettable powder. It was found that carbonic acid esters can be produced in.

Further, in the method for producing a carbonic acid ester of the present invention, the solid catalyst is selected from the group consisting of cerium oxide, zirconium oxide, lanthanum oxide, samarium oxide, placeodym oxide, tin oxide, displosium oxide, gadolinium oxide, and europium oxide. By using at least one of them, it is possible to solve the problems that the conventional complex catalyst is difficult to separate from the product after the reaction and that the upper limit of the reaction temperature is restricted so that the catalyst itself does not undergo thermal decomposition.

Hereinafter, the method for producing a carbonic acid ester of the present invention will be described in more detail.

In the method for producing a carbon dioxide ester of the present invention, in the reaction step, at least one selected from the group consisting of cerium oxide, zirconium oxide, lanthanum oxide, samarium oxide, placeodym oxide, tin oxide, disprosium oxide, gadolinium oxide, and europium oxide. In the presence of a seed solid catalyst and a solvent, an alcohol having a boiling point of more than 100 ° C. and carbon dioxide are directly reacted to produce a carbonic acid ester.
In this reaction step, when carbon dioxide is reacted with alcohol having a boiling point of more than 100 ° C., by-product water is produced in addition to carbonic acid ester.

When the reaction conditions at this time are such that the reaction temperature is 100 ° C. or higher (that is, the boiling point of water or higher) and the boiling point of the alcohol and the solvent or lower, the solvent and the alcohol remain liquid and the by-product water evaporates. Therefore, it is removed from the reaction field, and it becomes possible to promote the formation of carbonic acid ester.
In addition, the evaporated by-product water may be removed from the reaction field by a stream of carbon dioxide.

Here, "removing the by-product water from the reaction field by evaporation" means removing all the by-product water from the reaction field where the carbonic acid ester is generated (that is, the region where the alcohol, the solid catalyst and the solvent are present). In addition, it also includes the fact that some by-product water remains in the reaction field. The by-product water remaining in the reaction field can be separated by distillation.

(carbon dioxide)
As carbon dioxide, not only carbon dioxide prepared as an industrial gas but also carbon dioxide separated and recovered from exhaust gas from factories, steelworks, power plants, etc. that manufacture each product can be used.

(alcohol)
As the alcohol, at least one alcohol selected from the group consisting of monohydric and divalent alcohols is applied.

Examples of the monohydric alcohol include 1-butanol, isobutyl alcohol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol and the like.
Examples of the divalent alcohol include ethylene glycol, propylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, and 1, Examples thereof include 5-pentanediol, 1,6-hexanediol, 1,10-decanediol, trans-1,4-cyclohexenedimethanol and the like.

Among these, the monohydric and divalent alcohols are appropriately selected according to the properties required for the carbonic acid ester which is the target product, and the boiling point and the ratio of carbon dioxide incorporated into the product are used. From the viewpoint, an alcohol having 2 to 10 carbon atoms is preferable, and an alcohol having 4 to 6 carbon atoms is more preferable.
Of the monohydric and divalent alcohols, monohydric alcohol is preferable from the viewpoint of producing polycarbonate and its intermediate, and divalent alcohol is preferable from the viewpoint of producing polyurethane intermediate (polycarbonate diol). ..
Here, from the viewpoint of producing carbonic acid ester with high efficiency, a particularly preferable monohydric alcohol is a monohydric alcohol having 4 to 10 carbon atoms. On the other hand, from the same viewpoint, a particularly preferable divalent alcohol is a divalent alcohol having 2 to 10 carbon atoms (preferably 4 to 6 carbon atoms).

The boiling point of alcohol is more than 100 ° C., but it is preferably 101 to 300 ° C., more preferably 110 to 250 ° C., from the viewpoint of separability by distillation of alcohol and by-product water.

(Solid catalyst)
As the solid catalyst, at least one selected from the group consisting of cerium oxide, zirconium oxide, lanthanum oxide, samarium oxide, placeodymium oxide, tin oxide, disprosium oxide, gadolinium oxide, and europium oxide is applied.
Here, the catalyst used for the direct synthesis of the carbonic acid ester needs to have an acid-base complex function. In particular, the catalyst preferably has properties of relatively low acidity and relatively high basicity. If the acidity is too high, a large amount of ether will be synthesized rather than a carbonate ester. In an appropriate acid-base complex function catalyst, alcohol is dissociated and adsorbed in the form of ROOM (M is a catalyst, R is a group other than "-OH" of alcohol) on the base point, and is between _{CO 2 and CO 2.} Formed RO-C (= O) -O ... M on the other hand, adsorbed in the form of HO-R ... M on the acid point, and RO-C (= O) -OR was generated between the two adsorbed species. The mechanism to be used is conceivable. Suitable catalysts for exhibiting this mechanism are cerium oxide, zirconium oxide, lanthanum oxide, samarium oxide, placeodymium oxide, tin oxide, disprosium oxide, gadolinium oxide, and europium oxide.
In addition, since cerium oxide, zirconium oxide, lanthanum oxide, samarium oxide, praseodymium oxide, tin oxide, disprosium oxide, gadolinium oxide, and europium oxide are solid catalysts, there is no restriction on the upper limit of the reaction temperature, and separation after the reaction is possible. Is also easy.
For the above reasons, as the solid catalyst, at least one selected from the group consisting of cerium oxide, zirconium oxide, lanthanum oxide, samarium oxide, placeodymium oxide, tin oxide, disprosium oxide, gadolinium oxide, and europium oxide is applied. NS.

An example of a method for producing cerium oxide is as follows.
Cerium oxide is a cerium compound (cerium acetylacetonate hydrate, cerium hydroxide, cerium sulfate, cerium acetate, cerium nitrate, ammonium cerium nitrate, cerium carbonate, cerium oxalate, cerium perchlorate, cerium phosphate, cerium stearate, etc.) Can be produced by firing in an air atmosphere.
Solid catalysts other than cerium oxide can be produced in the same manner.

When the solid catalyst of the reagent is used, the reagent may be used as it is, or a dried product obtained by drying the reagent in an air atmosphere or a calcined product obtained by calcining the reagent may be used.
In addition, a solid catalyst produced by precipitating from a solution in which cerium is dissolved, filtering, drying, and firing can be used.

The form of the solid catalyst may be either a powder or a molded product. The solid catalyst of the molded body is only a catalyst, and may be molded into a spherical shape, a pellet shape, a cylinder shape, a ring shape, a wheel shape, a granule shape, or the like. Further, the solid catalyst of the molded body may be a molded body in which the solid catalyst is applied to a supported body (honeycomb made of cordierite, stainless steel, etc.).

The solid catalyst is used in a form dispersed or immobilized in a solvent. Here, to immobilize the solid catalyst in a solvent means, for example, immersing a molded body in which the solid catalyst is applied to a supported body (honeycomb made of cordierite or stainless steel, etc.) in the solvent and arranging the solid catalyst. show.

When the catalyst performance deteriorates, it can be regenerated by taking out the catalyst from the reactor, washing it with alcohol such as methanol or ethanol, and then drying it in air at a temperature of about 100 ° C.

(solvent)
The solvent is a solvent for dispersing or immobilizing the solid catalyst and dissolving the alcohol as the reaction substrate.
As the solvent, a solvent that does not affect the reaction between carbon dioxide and alcohol is applied.
The solvent may have a boiling point of more than 100 ° C., and examples thereof include aliphatic hydrocarbons, aromatic hydrocarbons, ether-based solvents, secondary amines, and tertiary amines.
Among these, the solvents include toluene, decane, dodecane, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, dipropylene glycol dimethyl ether, and tripropylene glycol from the viewpoint of high dispersibility and boiling point of the catalyst without reacting with the catalyst or alcohol. Preferably, dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, tetralin, diphenylmethane, phenylcyclohexene and diphenyl ether.
In particular, from the viewpoint of producing carbonic acid ester with high efficiency, the solvent is preferably an ether solvent (solvent having an ether bond) or a hydrophobic solvent. Further, as the solvent, an ether solvent and a hydrophobic solvent may be mixed and used.
_{Here, the hydrophobic solvent is a solvent exhibiting solubility (g / L—H 2} O) in which the amount dissolved in 1 L of water at 25 ° C. is 10 g or less.

(Reaction condition)
The reaction conditions between carbon dioxide and alcohol are such that the reaction temperature is 100 ° C. or higher (that is, the boiling point of water or higher) and the boiling point of the alcohol and the solvent or lower.
The reaction temperature depends on the boiling points of the alcohol and the solvent, but is preferably 101 to 300 ° C., more preferably 110 to 260 ° C., from the viewpoint of highly efficient carbonic acid ester production.

The reaction pressure may be normal pressure (1 atm) or may be pressurized. When pressurizing, the wall thickness of the reactor is required, so the reaction pressure is preferably less than 2 MPa from the viewpoint of equipment cost. The reaction pressure is more preferably less than 1 MPa because it does not correspond to high-pressure gas equipment.

The reaction between carbon dioxide and alcohol is carried out, for example, by introducing carbon dioxide into a solvent in which a solid catalyst is dispersed or fixed as a reaction field and the alcohol is dissolved. It is preferable to introduce carbon dioxide while bubbling using, for example, a bubbling device.

For example, in a beaker scale at the laboratory level, carbon dioxide may be blown into a beaker containing a solvent from a tube having an inner diameter of about 2 mm. A bubbler may be installed at the end of the tube. On a real-world scale, spargers can be used to facilitate the introduction of carbon dioxide and the flow within the reactor.

The amount of carbon dioxide, alcohol, catalyst, and solvent introduced is preferably adjusted as appropriate according to the capacity of the reactor.

Each component after the reaction of carbon dioxide and alcohol may be separated by cooling, distillation or the like and reused in the reaction, or may be discharged as it is. Carbon dioxide can be selected from the viewpoint of life cycle assessment (LCA) depending on whether carbon dioxide is circulated or discharged as it is.

Next, the method and apparatus for producing the carbonic acid ester of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic configuration diagram showing a carbonic acid ester production apparatus according to the first embodiment.
The carbonic acid ester production apparatus according to the first embodiment includes, for example, as shown in FIG. 1, a reaction tower 10 that reacts carbon dioxide with the alcohol to produce a carbonic acid ester and by-product water.
Then, in the reaction tower 10, the reaction step is carried out.

Further, the carbon dioxide ester production apparatus according to the first embodiment is, for example, a cooling tower 11 (first cooling) for cooling and distilling, separating and regenerating each component discharged as a gas phase from the reaction tower 10. An example of a tower), a distillation tower 12 (an example of a second distillation tower), a cooling tower 13, and a separation tower 14 are provided.
Then, in each tower, a cooling step (an example of a first cooling step), a distillation step (an example of a first distillation step), a cooling step, and a separation step are carried out.

Further, the carbonic acid ester production apparatus according to the first embodiment has, for example, a distillation column 21 and a separation column 22 for distilling and cooling, separating and regenerating each component discharged as a liquid phase from the reaction column 10. And.
Then, in each tower, a distillation step (an example of a second distillation step) and a separation step are carried out.

In FIG. 1, 100 indicates the alcohol ROH to be introduced into the reaction column 10.
_{100A represents carbon dioxide CO 2} to be introduced into the reaction tower 10.
Reference numeral 100B indicates the solvent Sol to be introduced into the reaction column 10.
100C shows a gas phase discharged from reactor 10 (unreacted carbon dioxide CO _2, unreacted alcohol ROH, product water _{H 2} O and solvent Sol).
_{Reference numeral 101 denotes a gas phase (unreacted carbon dioxide CO 2} ) discharged from the cooling tower 11 (an example of the first cooling tower).
103 shows a cooling tower 11 the liquid phase discharged from (first example of a cooling tower) (unreacted alcohol ROH, product water _{H 2} O and solvent Sol).
104 is discharged from the distillation column 12 (one example of a second distillation column) shows the gas phase (product water _H 2 O).
Reference numeral 105 denotes a liquid phase (unreacted alcohol ROH and solvent Sol) discharged from the distillation column 12 (an example of the second distillation column).
106 shows the liquid phase discharged from the cooling tower 13 (product water _H 2 O).
Reference numeral 107 denotes a liquid phase (unreacted alcohol ROH) discharged from the separation column 14.
Reference numeral 108 denotes a liquid phase (solvent Sol) discharged from the separation tower 14.
Reference numeral 201 denotes a liquid phase (carbonate ester C-ester, unreacted alcohol ROH, and solvent Sol) discharged from the reaction column 10.
Reference numeral 202 denotes a gas phase (unreacted alcohol ROH and solvent Sol) discharged from the distillation column 21 (an example of the second distillation column).
Reference numeral 203 denotes a liquid phase (carbonic acid ester C-ester) discharged from the distillation column 21 (an example of the second distillation column).
Reference numeral 204 denotes a liquid phase (unreacted alcohol ROH) discharged from the separation tower 22.
Reference numeral 205 denotes a liquid phase (solvent Sol) discharged from the separation tower 22.
Although not shown, each tower is connected by piping.

(Reaction tower 10: Reaction process)
In the reaction column 10, the reaction step is carried out.
In the reaction step, at least one selected from the group consisting of carbon dioxide and monohydric and dihydric alcohols having a boiling point of more than 100 ° C. in a reactor 10A in which a solid catalyst as a solid catalyst and a solvent are present. The alcohol is supplied and the reaction temperature is 100 ° C. or higher, and the carbon dioxide and the alcohol are reacted under the conditions of the alcohol and the boiling point of the solvent or less to produce a carbon dioxide ester and by-product water.

Specifically, the reactor 10A contains a solvent in which a solid catalyst is immobilized. A liquid phase alcohol is supplied to the solvent in the reactor 10A from above, and carbon dioxide at normal pressure (gas phase) is introduced from below while bubbling. Then, the inside of the reactor 10A is set to a predetermined reaction temperature and reaction pressure. As a result, carbon dioxide and alcohol are reacted to produce carbonic acid ester and by-product water.

For the reactor 10 (the reactor 10A), for example, any reactor such as a batch reactor, a semi-batch reactor, or a flow reactor (continuous tank reactor, tube reactor, etc.) can be applied. good.

(Cooling tower 11 (an example of the first cooling tower))
In the cooling tower 11, a cooling step (first cooling step) is carried out.
In the cooling step, unreacted carbon dioxide and unreacted alcohol (a part of the unreacted alcohol in the reactor 10A of the reaction tower 10) discharged as a vapor phase from the reactor 10A in the reaction tower (reaction step). The vaporized alcohol), the by-product water (evaporated by-product water), and the solvent (the solvent in which a part of the solvent in the reactor 10A of the reaction tower 10 is vaporized) are cooled. At this time, the unreacted alcohol, by-product water, and solvent are discharged from the reaction tower 10 on the stream of unreacted carbon dioxide.
As a result, it is separated into unreacted carbon dioxide as a gas phase and unreacted alcohol, by-product water and a solvent as a liquid phase. Then, these components are discharged from the cooling tower 11.

Here, the cooling temperature in the cooling tower 11 (cooling step) is set to be less than unreacted alcohol, by-product water and solvent (specifically, less than 100 ° C.).

(Distillation column 12 (an example of a second distillation column))
In the distillation column 12, a distillation step (first distillation step) is carried out.
In the distillation step, unreacted alcohol, by-product water and solvent separated as a liquid phase are distilled in the cooling tower 11 (cooling step).
As a result, it is separated into by-product water as a gas phase and unreacted alcohol and solvent as a liquid phase. Then, these components are discharged from the distillation column 12.

Here, the distillation temperature in the distillation column 12 (distillation step) is set to be equal to or higher than the boiling point of the by-product water and lower than the boiling point of the unreacted alcohol and the solvent.

(Cooling tower 13)
In the cooling tower 13, a cooling step is carried out.
In the cooling step, the by-product water discharged as the gas phase is cooled from the distillation column 12 (distillation step). As a result, the by-product water is liquefied. Then, the by-product water is discharged from the cooling tower 13 as a liquid phase.

(Separation tower 14)
In the separation tower 14, for example, a separation step of separating unreacted alcohol and solvent is carried out by a distillation column and a cooling tower.
In the distillation and cooling steps, unreacted alcohol and solvent discharged as a liquid phase from the distillation column 12 (distillation step) are distilled and cooled so as to be separated and liquefied by utilizing the difference in boiling points between them.
As a result, the liquid phase is separated into an unreacted alcohol and a solvent. Then, these components are discharged from the distillation and cooling tower 14.

(Distillation column 21 (an example of a second distillation column))
In the distillation column 21, a distillation step (an example of a second distillation step) is carried out.
In the distillation step, the carbonic acid ester, unreacted alcohol and solvent discharged as a liquid phase are distilled from the reactor 10A in the reaction column 10 (reaction step).
As a result, the gas phase is separated into an unreacted alcohol and solvent, and the liquid phase is separated into a carbonic acid ester. Then, the unreacted alcohol and solvent are discharged from the distillation column 21, and the target carbonic acid ester is recovered from the distillation column 21.

Here, the distillation temperature in the distillation column 21 (distillation step) is set to be equal to or higher than the boiling point of the unreacted alcohol and solvent and lower than the boiling point of the carbonic acid ester.

(Separation tower 22)
In the separation tower 22, for example, a separation step of separating the unreacted alcohol and the solvent is carried out by two cooling towers.
In the separation step, for example, unreacted alcohol and solvent discharged as a gas phase from the distillation column 21 (distillation step) are cooled so as to be separated and liquefied by utilizing the difference in boiling points between them.
As a result, the liquid phase is separated into an unreacted alcohol and a solvent. Then, these components are discharged from the separation tower 24.

(Reuse)
In the carbonic acid ester production apparatus according to the first embodiment, unreacted carbon dioxide (gas phase) separated in the cooling tower 11 (distillation step), unreacted alcohol and solvent separated in the separation tower 14, and the like. The unreacted alcohol and solvent separated in the separation tower 22 are reused in the reaction tower 10 (reaction step).
The unreacted alcohol and solvent separated in the distillation columns 12 and 21 (that is, a mixed solution of unreacted alcohol and solvent) are reused as they are in the reaction column 10 (reaction step) without separation. You may.

Through the above process, the carbonic acid ester is produced in the carbonic acid ester producing apparatus according to the first embodiment.

[Second Embodiment]
FIG. 2 shows a schematic configuration diagram showing a carbonic acid ester production apparatus according to the second embodiment.
As shown in FIG. 2, the carbonic acid ester production apparatus according to the second embodiment further includes a separation tower 31 and a catalyst regeneration tower 32 in the carbonic acid ester production apparatus according to the first embodiment, for example.
The carbonic acid ester production apparatus according to the second embodiment has the same configuration as the carbonic acid ester production apparatus according to the first embodiment, except that the separation tower 31 and the catalyst regeneration tower 32 are provided.

In FIG. 2, 301 shows the solid catalyst Cat discharged as a solid phase together with the liquid phase (carbonate ester C-ester, unreacted alcohol ROH, and solvent Sol).
Reference numeral 302 denotes a solid catalyst Cat separated by the separation tower 31.
Reference numeral 302 denotes a solid catalyst Cat regenerated in the catalyst regeneration tower 32.
Other than that, the reference numerals indicate the same objects as the reference numerals given in FIG. However, 201 indicates the liquid phase (carbonate ester C-ester, unreacted alcohol ROH, and solvent Sol) separated by the separation column 31.

(Separation tower 31)
In the separation tower 31, the separation step is carried out.
In the separation step, the solid catalyst discharged as a solid phase together with the liquid phase (carbonate ester, the unreacted alcohol, and the solvent) is separated from the liquid phase.
Specifically, a filter or the like is used to separate the solid catalyst from the liquid phase. The separated solid catalyst is discharged from the separation tower 31 as a slurry containing the solid catalyst.
Then, the liquid phase (carbonic acid ester, the unreacted alcohol, and the solvent) separated from the solid catalyst is discharged from the separation column 31 and sent to the distillation column 21.

(Catalyst regeneration tower 32)
In the catalyst regeneration tower 32, the catalyst regeneration step is carried out.
In the catalyst regeneration step, the solid catalyst separated in the separation tower 31 (separation step) is regenerated.
Specifically, in the catalyst regeneration step, for example, the solid catalyst is regenerated by firing the solid catalyst to burn off impurities and the like on the solid catalyst.
The firing is carried out at, for example, 400 to 700 ° C. (preferably 500 to 600 ° C.) for about 3 hours. In order to prevent structural destruction of the solid catalyst due to a rapid temperature rise, it is preferable to dry the solid catalyst at 110 ° C. for about 2 hours before firing.

(Reuse)
Then, in the carbonic acid ester production apparatus according to the second embodiment, the solid catalyst regenerated in the catalyst regeneration tower 32 (catalyst regeneration step) is reused in the reaction tower 10 (reaction step).

[Other forms]
In the carbonic acid ester production apparatus (or production method) according to the first and second embodiments, the carbonic acid ester, unreacted alcohol and solvent separated as a liquid phase are distilled in the distillation tower 21 (distillation step). The form of separation into an unreacted alcohol and solvent as a gas phase and a carbonic acid ester as a liquid phase has been described.
However, the carbonic acid ester production apparatus (or production method) according to the present embodiment includes a cooling tower (an example of a second cooling tower) instead of the distillation tower 21, and is a liquid phase in the distillation tower 21 (distillation step). The carbonate ester, the unreacted alcohol and the solvent separated as above may be cooled and separated into the unreacted alcohol and the solvent as the liquid phase and the carbonic acid ester as the solid phase.

In this form of carbonic acid ester production apparatus (or production method), the carbonic acid ester is cooled to below the melting point of the carbonic acid ester, the carbonic acid ester is solidified, and then recovered by a filter or the like.

In the carbonic acid ester production apparatus (or production method) according to the first and second embodiments, a trace amount of by-product water may be contained in the component as a liquid phase discharged from the reaction tower 10. In that case, a distillation column (distillation step) and a cooling column (cooling step) for separating the by-product water from the components discharged from the reaction column 10 may be provided.
However, it is difficult to separate a trace amount of by-product water from the liquid phase component discharged from the reaction tower 10, and a large amount of energy is required. Therefore, it is preferable not to separate the trace amount of by-product water.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the conditions in the Examples are one condition example adopted for confirming the feasibility and effect of the present invention, and the present invention is the one condition. It is not limited to the example. In the present invention, various conditions can be adopted as long as the gist of the present invention is not deviated and the object of the present invention is achieved.

(Comparative Example 1)
In a batch type, 190 mL autoclave (with magnetic stir bar), CeO ₂ : 0.17 g (1 mmol) as a solid catalyst and 1,6-hexanediol: 10 mmol (1.2 g, 1.1 mL) as alcohol were introduced, and about The air in the autoclave was purged 3 times with 5 g of CO _2.
Then, CO ₂ (0.4 g, 9.1 mmol @ 130 ° C.) was introduced into the autoclave and the pressure was increased (0.1 MPa).
The temperature was raised while stirring the inside of the autoclave to a reaction temperature of 130 ° C. Then, the time when the reaction temperature was reached was defined as the reaction start time, and CO ₂ and 1,6-hexanediol were reacted for 12 hours. Then, the autoclave was cooled with water, and when it was cooled to room temperature, the pressure was reduced to add 2-propanol, which is an internal standard substance, and the product was collected and analyzed by GC (gas chromatography).
As a result, 0.001 mmol of chain carbonic acid ester was produced, and the yield of carbonic acid ester was 0.016%.

(Example 1)
In a circulation type, eggplant-shaped flask 200 mL (upper cooling temperature 4 ° C.), CeO ₂ : 0.6 g (3.5 mmol) as a solid catalyst, 1,6-hexanediol: 85 mmol (10 g, 9 mL) as an alcohol, and toluene as a solvent. : 80 mL (70 g) was introduced.
Thereafter, the pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min was introduced into the flask, reaction temperature 110 ° C. (boiling point of toluene, the heating is 130 ° C.), with a reaction time 12h, CO ₂ 1,6 -Reacted with hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
As a result, 1.35 mmol of the chain carbonate ester dimer was produced, 0.01 mmol of the chain carbonate ester trimmer was produced, and the yield of the chain carbonate ester was 3.18%.

(Example 2)
In a circulation type, eggplant-shaped flask 200 mL (upper cooling temperature 4 ° C.), CeO ₂ : 0.6 g (3.5 mmol) as a solid catalyst, 1,6-hexanediol: 85 mmol (10 g, 9 mL) as an alcohol, and toluene as a solvent. : 80 mL (70 g) was introduced.
Thereafter, the pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min was introduced into the flask, reaction temperature 110 ° C. (boiling point of toluene, the heating is 130 ° C.), with a reaction time 48h, CO ₂ 1,6 -Reacted with hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
As a result, 2.68 mmol of the chain carbonate ester dimer was produced, 0.02 mmol of the chain carbonate ester trimmer was produced, and the yield of the chain carbonate ester was 6.31%.

(Example 3)
In a circulation type, eggplant-shaped flask 200 mL (upper cooling temperature 4 ° C.), CeO ₂ : 0.4 g (2.3 mmol) as a solid catalyst, 1,6-hexanediol: 85 mmol (10 g, 9 mL) as an alcohol, and toluene as a solvent. : 30 mL (NO.1), 80 mL (NO.2), or 110 mL (NO.3) was introduced.
Thereafter, the pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min was introduced into the flask, reaction temperature 110 ° C. (boiling point of toluene, the heating is 130 ° C.), with a reaction time 4h, CO ₂ 1,6 -Reacted with hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 1. From the results in Table 1, it was found that the yield of carbonic acid ester was 1.6 to 1.7%, and there was no influence of the amount of solvent.

(Comparative Example 2)
_{CeO 2} : 0.4 g (2.3 mmol) as a solid catalyst and 1,6-hexanediol: 85 mmol (10 g, 9 mL) as an alcohol were introduced into 200 mL of a flow-type eggplant-shaped flask (upper cooling temperature 4 ° C.).
Then introduced to a pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min the flask, reaction temperature 130 ° C., with a reaction time 4h, allowed to react with CO ₂ and 1,6-hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
As a result, 1,6-hexanediol as a reaction substrate was solidified, and the yield of carbonic acid ester was 0%. Therefore, it was found that a solvent is required for the formation of carbonic acid ester.

(Example 4)
In a circulation type, eggplant-shaped flask 200 mL (upper cooling temperature 4 ° C.), CeO ₂ : 0.4 g (2.3 mmol) as a solid catalyst, 1,6-hexanediol: 85 mmol (10 g, 9 mL) as an alcohol, n as a solvent. -Decan: 30 mL was introduced.
_{Then, CO 2} was introduced into the flask while bubbling at a pressure of 0.1 MPa and a flow rate of 200 mL / min, and the reaction temperatures were 110 ° C. (NO.1), 140 ° C. (NO.2), 150 ° C. (NO.3). _{Alternatively, CO 2} and 1,6-hexanediol were reacted at 170 ° C. (NO.4) at a reaction time of 4 hours.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 2. From the results in Table 2, it can be seen that the higher the reaction temperature, the higher the yield of carbonic acid ester.

(Example 5)
In a circulation type, eggplant-shaped flask 200 mL (upper cooling temperature 4 ° C.), CeO ₂ : 0.4 g (2.3 mmol) as a solid catalyst, 1,6-hexanediol: 85 mmol (10 g, 9 mL) as an alcohol, n as a solvent. -Decan: 30 mL was introduced.
Thereafter, pressure 0.1 MPa, introducing CO ₂ into the flask while bubbling at a flow rate of 200 mL / min, reaction temperature 140 ° C. (NO.1), or 0.99 ° C. (NO.2), a reaction time 20h, CO ₂ Was reacted with 1,6-hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 3. From the results in Table 3, it can be seen that the yield of carbonic acid ester is improved by increasing the reaction time.

(Example 6)
In a circulation type, eggplant-shaped flask 200 mL (upper cooling temperature 4 ° C.), CeO ₂ : 0.4 g (2.3 mmol) as a solid catalyst, 1,6-hexanediol: 85 mmol (10 g, 9 mL) as an alcohol, n as a solvent. -Dodecane: 30 mL was introduced.
_{Then, CO 2} was introduced into the flask while bubbling at a pressure of 0.1 MPa and a flow rate of 200 mL / min, and the reaction temperature was 140 ° C. (NO.1), 150 ° C. (NO.2), or 170 ° C., and the reaction time was 20 h. , CO ₂ was reacted with 1,6-hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 4. From the results in Table 4, it can be seen that the yield of carbonic acid ester is improved by further increasing the reaction temperature.

(Example 7)
In a circulation type, eggplant-shaped flask 200 mL (upper cooling temperature 4 ° C.), CeO ₂ : 0.4 g (2.3 mmol) as a solid catalyst, 1,6-hexanediol: 85 mmol (10 g, 9 mL) as an alcohol, Table 5 shows. The solvent shown: 30 mL was introduced.
Then introduced to a pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min in the flask, the reaction temperature 0.99 ° C., with a reaction time 20h, allowed to react with CO ₂ and 1,6-hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 5. From the results in Table 5, it can be seen that the dispersibility of the solid catalyst in the solvent was low and the yield of carbonic acid ester was lowered.

(Example 8)
In a circulation type, eggplant-shaped flask 200 mL (upper cooling temperature 4 ° C.), CeO ₂ : 0.4 g (2.3 mmol) as a solid catalyst, 1,6-hexanediol: 85 mmol (10 g, 9 mL) as an alcohol, and diethylene glycol as a solvent. Diethyl ether: 1 mL (No. 1), 5 mL (No. 2), or 30 mL (No. 3) was introduced.
Then introduced to a pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min the flask, reaction temperature 170 ° C., with a reaction time 20h, allowed to react with CO ₂ and 1,6-hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 6. From the results in Table 6, it can be seen that the yield of carbonic acid ester is improved when diethylene glycol diethyl ether is used as the solvent. However, it can also be seen that if the amount of the solvent is too large, the dispersibility of the solid catalyst deteriorates and the yield decreases.

(Example 9)
In a circulation type, eggplant-shaped flask 200 mL (upper cooling temperature 4 ° C.), CeO ₂ : 0.4 g (2.3 mmol) as a solid catalyst, 1,6-hexanediol: 85 mmol (10 g, 9 mL) as an alcohol, and diethylene glycol as a solvent. Diethyl ether: 5 mL was introduced.
Thereafter, pressure 0.1 MPa, was introduced into the flask while bubbling CO ₂ at a flow rate of 200 mL / min, reaction temperature 170 ° C., with a reaction time 48h, allowed to react with CO ₂ and 1,6-hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
As a result, 7.3 mmol of the chain carbonate ester dimer was produced, 0.14 mmol of the chain carbonate ester trimmer was produced, and the yield of the chain carbonate ester was 18%.
It can be seen that the yield of carbonic acid ester is further improved by long-term reaction using diethylene glycol diethyl ether as a solvent.

(Example 10)
_{CeO 2} : 0.4 g (2.3 mmol) as a solid catalyst, alcohol: 85 mmol shown in Table 7, and diethylene glycol diethyl ether: 5 mL as a solvent were introduced into 200 mL of a flow-type flask (upper cooling temperature 4 ° C.).
Then introduced to a pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min in the flask, the reaction temperature 0.99 ° C., with a reaction time 20h, allowed to react with each alcohol CO _2.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 7. From the results in Table 7, it can be seen that when a divalent alcohol having 2 to 10 carbon atoms is used as the alcohol, a carbonic acid ester can be produced with high efficiency.

(Example 11)
_{CeO 2} : 0.4 g (2.3 mmol), 1,10-decanediol: 85 mmol as a solid catalyst, and diethylbenzene: 10 mL as a solvent were introduced into 200 mL of a flow-type eggplant-shaped flask (upper cooling temperature 4 ° C.).
Thereafter, pressure 0.1 MPa, was introduced into the flask while bubbling CO ₂ at a flow rate of 200 mL / min, reaction temperature 0.99 ° C., with a reaction time 20h, allowed to react with CO ₂ and 1,10-decanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
As a result, the yield of the chain carbonate ester was 3.4%.

(Comparative Example 3)
_{CeO 2} : 0.4 g (2.3 mmol) and propylene glycol: 85 mmol (10 g, 9 mL) were introduced as solid catalysts into 200 mL of a flow-type eggplant-shaped flask (upper cooling temperature 4 ° C.).
_{Then, CO 2} was introduced into the flask while bubbling at a pressure of 0.1 MPa and a flow rate of 200 mL / min _{, and CO 2} and propylene glycol were reacted at a reaction temperature of 150 ° C. and a reaction time of 20 h.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
As a result, since no solvent was used _{, the reaction between CO 2} and propylene glycol did not proceed, and the yield of carbonic acid ester was 0%.

(Example 12)
_{CeO 2} : 0.4 g (2.3 mmol) as a solid catalyst, alcohol: 85 mmol shown in Table 8, and diethylene glycol diethyl ether: 5 mL as a solvent were introduced into 200 mL of a flow-type flask (upper cooling temperature 4 ° C.).
Thereafter, the pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min was introduced into the flask, the reaction temperature shown in Table 8, reaction time 20h, allowed to react with each alcohol CO _2.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 8. From the results in Table 8, it can be seen that when a monohydric alcohol having a boiling point of more than 100 ° C. and having 4 to 10 carbon atoms is used as the alcohol, a carbonic acid ester can be produced with high efficiency.

(Comparative Example 4)
_{CeO 2} : 0.4 g (2.3 mmol) as a solid catalyst, alcohol: 85 mmol shown in Table 9, and diethylene glycol diethyl ether: 5 mL as a solvent were introduced into 200 mL of a flow-type flask (upper cooling temperature 4 ° C.).
Thereafter, the pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min was introduced into the flask at the reaction temperature and reaction time shown in Table 9, was reacted with each alcohol CO _2.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 9. From the results in Table 9, it can be seen that when a monohydric alcohol having a boiling point of 100 ° C. or lower is used as the alcohol, the reaction temperature cannot be raised at a boiling point of 100 ° C. or lower, so that a carbonic acid ester cannot be produced.

(Comparative Example 5)
_{CeO 2} : 0.4 g (2.3 mmol) as a solid catalyst, glycerin: 85 mmol, and diethylene glycol diethyl ether: 5 mL as a solvent were introduced into 200 mL of a flow-type flask (upper cooling temperature 4 ° C.).
_{Then, CO 2} was introduced into the flask while bubbling at a pressure of 0.1 MPa and a flow rate of 200 mL / min _{, and CO 2} and glycerin were reacted at the reaction temperature and reaction time of 20 h shown in Table 10.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 10. From the results in Table 10, it can be seen that when glycerin, which is a trihydric alcohol, is used, glycerin is insoluble in the solvent, so that carbonic acid ester cannot be produced even if the reaction temperature is raised.

(Example 13)
_{CeO 2} : 0.4 g (2.3 mmol), 1,6-hexanediol: 34 mmol, and the solvent shown in Table 11: 5 mL were introduced into 50 mL of a flow-type eggplant-shaped flask (upper cooling temperature 4 ° C.) as a solid catalyst. ..
Then introduced to a pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min the flask, reaction temperature 170 ° C., with a reaction time 24h, allowed to react with CO ₂ and 1,6-hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 11. From the results in Table 11, it can be seen that a carbonic acid ester can be produced with high efficiency by using a solvent having a boiling point of more than 100 ° C., particularly an ether solvent.

(Example 14)
_{CeO 2} : 0.4 g (2.3 mmol), 1,6-hexanediol: 34 mmol, and the solvent shown in Table 12: 5 g were introduced into 50 mL of a flow-type eggplant-shaped flask (upper cooling temperature 20 ° C.) as a solid catalyst. ..
Then introduced to a pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min the flask, reaction temperature 190 ° C., with a reaction time 4h, allowed to react with CO ₂ and 1,6-hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 12. From the results in Table 12, it can be seen that a carbonic acid ester can be produced with high efficiency by using a solvent having a boiling point of more than 100 ° C., particularly an ether solvent.

(Example 15)
_{CeO 2} : 0.1 g (0.6 mmol), 1,6-hexanediol: 17 mmol as a solid catalyst in a flow-type, eggplant-shaped flask 50 mL (upper cooling temperature 24 ° C.), shown in Table 13 with solubility in water. Solvent: 3 g was introduced.
Then introduced to a pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min the flask, reaction temperature 200 ° C., with a reaction time 1h, allowed to react with CO ₂ and 1,6-hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 13. From the results in Table 13, it can be seen that a carbonic acid ester can be produced with high efficiency by using a solvent having a boiling point of more than 100 ° C., particularly an ether solvent or a hydrophobic solvent.

(Example 16)
In a flow type, eggplant-shaped flask 50 mL (upper cooling temperature 24 ° C.), CeO ₂ : 0.1 g (0.6 mmol) as a solid catalyst, 1,6-hexanediol: 17 mmol, tri as the first solvent shown in Table 14. 2 g of ethylene glycol dimethyl ether and 3 g of each solvent as a second solvent were introduced.
Then introduced to a pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min the flask, reaction temperature 200 ° C., with a reaction time 1h, allowed to react with CO ₂ and 1,6-hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 14. From the results in Table 14, it can be seen that carbonic acid ester can be produced with high efficiency even when an ether solvent and a hydrophobic solvent are mixed and used in a solvent having a boiling point of more than 100 ° C.

(Example 17)
In a flow type, eggplant-shaped flask 50 mL (upper cooling temperature 24 ° C.), CeO ₂ : 0.1 g (0.6 mmol) as a solid catalyst, 1,6-hexanediol: 17 mmol, tri as the first solvent shown in Table 15. 1 to 4 g of ethylene glycol dimethyl ether and 3 g of diphenyl ether as a second solvent were introduced.
Then introduced to a pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min the flask, reaction temperature 200 ° C., with a reaction time 1h, allowed to react with CO ₂ and 1,6-hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 15. From the results in Table 15, it can be seen that carbonic acid esters can be produced with high efficiency even when a hydrophilic solvent and a hydrophobic solvent are mixed and used in an ether solvent with a solvent having a boiling point of more than 100 ° C. ..

(Example 18)
In a flow type, eggplant-shaped flask 50 mL (upper cooling temperature 24 ° C.), CeO ₂ : 0.1 g (0.6 mmol) as a solid catalyst, 1,6-hexanediol: 17 mmol, tri as the first solvent shown in Table 16. 2 g of ethylene glycol dimethyl ether and 1 to 5 g of diphenyl ether as a second solvent were introduced.
Then introduced to a pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min the flask, reaction temperature 200 ° C., with a reaction time 1h, allowed to react with CO ₂ and 1,6-hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 16. From the results in Table 16, it can be seen that carbonic acid esters can be produced with high efficiency even when a hydrophilic solvent and a hydrophobic solvent are mixed and used in an ether solvent with a solvent having a boiling point of more than 100 ° C. ..

(Example 19)
In a circulation type, eggplant-shaped flask 50 mL (upper cooling temperature 24 ° C.), CeO ₂ : 0.1 g (0.6 mmol) as a solid catalyst, various alcohols shown in Table 17: 17 mmol, and triethylene glycol dimethyl ether as a first solvent 2 g. And 3 g of diphenyl ether was introduced as a second solvent.
Thereafter, pressure 0.1 MPa, is introduced into a flow rate 200 mL / min of CO ₂ while bubbling in a flask, the reaction temperature shown in Table 17, reaction time 48h, to react the CO ₂ and various alcohols.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 17. From the results in Table 17, a solvent having a boiling point of more than 100 ° C., a hydrophilic solvent and a hydrophobic solvent are mixed and used in an ether solvent, and the alcohol has a boiling point of 100 ° C. or higher and has 3 to 10 carbon atoms. It can be seen that carbonic acid ester can be produced with high efficiency by using a divalent alcohol or a monohydric alcohol having 8 to 10 carbon atoms.

(Example 20)
In a flow type, eggplant-shaped flask 50 mL (upper cooling temperature 24 ° C.), CeO ₂ : 0.1 g (0.6 mmol) as a solid catalyst, 1,6-hexanediol: 17 mmol, and triethylene glycol dimethyl ether as a first solvent 2 g. And 3 g of diphenyl ether was introduced as a second solvent.
Then introduced to a pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min in the flask, the reaction temperature shown in Table 18, reaction time 4h, allowed to react with CO ₂ and 1,6-hexanediol ..
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 18. From the results in Table 18, it can be seen that when triethylene glycol dimethyl ether and diphenyl ether are used in a solvent having a boiling point of more than 100 ° C., a carbonic acid ester can be produced with high efficiency at a reaction temperature of 180 to 215 ° C.

(Example 21)
_{CeO 2} (No. 1), ZrO ₂ (No. 2), La ₂ O ₃ (No. 3), Sm shown in Table 22 as solid catalysts in a flow-type, eggplant-shaped flask 50 mL (upper cooling temperature 20 ° C.). ₂ O ₃ (No. 4), Pr ₆ O ₁₁ (No. 5), SnO ₂ (No. 6), Dy ₂ O ₃ (No. 7), Gd ₂ O ₃ (No. 8), Eu ₂ O _{0.4 g of 3} (No. 9), 1,6-hexanediol: 34 mmol, and diphenyl ether: 5 g as a solvent were introduced.
Then introduced to a pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min the flask, reaction temperature 190 ° C., with a reaction time 4h, allowed to react with CO ₂ and 1,6-hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 19. From the results in Table 19, _{ZrO 2} (No. 2), La ₂ O ₃ (No. 3), Sm ₂ O ₃ (No. 4), Pr ₆ O ₁₁ (No. 1) other than _{CeO 2 (No. 1).} 5), SnO ₂ (No. 6), Dy ₂ O ₃ (No. 7), Gd ₂ O ₃ (No. 8), Eu ₂ O ₃ (No. 9) are high even when used as solid catalysts. It can be seen that carbonic acid ester can be produced efficiently.

(Comparative Example 6)
The reaction was carried out under the same conditions as in Example 14 except that 0.4 g of each catalyst shown in Table 20 was used as the solid catalyst.
The results are shown in Table 20. From the results in Table 20, SiO ₂ (No. 1), SiO _2- Al ₂ O ₃ (No. 2), γ-Al ₂ O ₃ (No. 3), MgO (No. 4), TiO ₂ (No. 2) It _{can be seen that when HfO 2} (No. 6), Y ₂ O ₃ (No. 7), and ZnO (No. 8) are used as solid catalysts, the reactivity is small or hardly reacts.

(Example 22)
In a circulation type, eggplant-shaped flask 50 mL (upper cooling temperature 20 ° C.), _{0.4 g (2.3 mmol) of CeO 2} as a solid catalyst, 1,6-hexanediol: 34 mmol, and diphenyl ether: 1 g (No. 1) as a solvent. , 3 g (No. 2), 5 g (No. 3, the same as No. 1 of Example 14), 7 g (No. 4), and 10 g (No. 5) were introduced.
Then introduced to a pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min the flask, reaction temperature 190 ° C., with a reaction time 4h, allowed to react with CO ₂ and 1,6-hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 21. From the results in Table 21, it can be seen that the amount of diphenyl ether used as the solvent does not significantly affect the yield of carbonic acid ester, and carbonic acid ester can be produced with high efficiency in any amount.

(Comparative Example 7)
_{0.4 g (2.3 mmol) of CeO 2} and 34 mmol of 1,6-hexanediol were introduced as a solid catalyst into 50 mL of a flow-type eggplant-shaped flask (upper cooling temperature 20 ° C.), but no solvent was introduced. (0 g).
Then introduced to a pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min the flask, reaction temperature 190 ° C., with a reaction time 4h, allowed to react with CO ₂ and 1,6-hexanediol.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
When no solvent was used, the yield of carbonic acid ester was 3.8%, but 1,6-hexanediol and the produced carbonic acid ester adhered to and solidified in the cooling part at the top of the flask, resulting in CO ₂ and by-products. It was found that the solvent was essential because the water flow path was blocked and it was difficult to continue the reaction.

(Example 23)
_{0.4 g (2.3 mmol) of CeO 2} as a solid catalyst, 34 mmol of 1,6-hexanediol as a solid catalyst, and 5 g of diphenyl ether as a solvent were introduced into 50 mL of a flow-type flask (upper cooling temperature 20 ° C.).
_{Then, CO 2} was introduced into the flask while bubbling at a pressure of 0.1 MPa and a flow rate of 200 mL / min, and the reaction temperatures were 110 ° C. (NO.1), 150 ° C. (NO.2), 170 ° C. (NO.3). _{CO 2} and 1,6-hexanediol were reacted at 190 ° C. (NO.4) or 210 ° C. (NO.5) with a reaction time of 16 hours.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 22. From the results in Table 22, it can be seen that the higher the reaction temperature, the higher the yield of carbonic acid ester.

(Example 24)
_{0.4 g (2.3 mmol) of CeO 2} as a solid catalyst, 34 mmol of 1,6-hexanediol as a solid catalyst, and 5 g of diphenyl ether as a solvent were introduced into 50 mL of a flow-type flask (upper cooling temperature 20 ° C.).
_{Then, CO 2} was introduced into the flask while bubbling at a pressure of 0.1 MPa and a flow rate of 200 mL / min, and the reaction temperature was 190 ° C. and the reaction time was 16 to 480 h to react CO ₂ with 1,6-hexanediol. rice field.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 23. From the results in Table 23, it can be seen that the yield of carbonic acid ester increases as the reaction time increases.

(Example 25)
In a circulation type, eggplant-shaped flask 50 mL (upper cooling temperature 24 ° C.), _{0.1 g (0.6 mmol) of CeO 2} as a solid catalyst, 17 mmol of 1,6-hexanediol, and 2 g of triethylene glycol dimethyl ether as a first solvent. And 3 g of diphenyl ether was introduced as a second solvent.
_{Then, CO 2} was introduced into the flask while bubbling at a pressure of 0.1 MPa and a flow rate of 200 mL / min, and the reaction temperature was 210 ° C. and the reaction time was 4 to 96 h to react CO ₂ with 1,6-hexanediol. rice field.
Then, when the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 24. From the results in Table 24, it can be seen that the yield of carbonic acid ester increases as the reaction time increases. It can also be seen that the average molecular weight of the product can be increased.

(Example 26)
In a circulation type, eggplant-shaped flask 50 mL (upper cooling temperature 24 ° C.), _{0.1 g (0.6 mmol) of CeO 2} as a solid catalyst, 17 mmol of 1,6-hexanediol, and 2 g of triethylene glycol dimethyl ether as a first solvent. And 3 g of diphenyl ether was introduced as a second solvent.
Then introduced to a pressure 0.1 MPa, while bubbling CO ₂ at a flow rate of 200 mL / min the flask, reaction temperature 210 ° C., the reaction time as 4h, allowed to react with CO ₂ and 1,6-hexanediol. After washing the catalyst after the reaction with ethanol, a regeneration step of drying at 110 ° C. for 12 hours was performed, and the reaction was repeated at the number of reactions shown in Table 25.
After each reaction, the flask was air-cooled and cooled to room temperature, the product was collected and analyzed by GC (gas chromatography).
The results are shown in Table 25. From the results in Table 25, it can be seen that the activity can be maintained even if the catalyst is regenerated and used repeatedly.

From the above, in this example, the carbonic acid ester can be produced with high efficiency under mild reaction pressure without using a dehydrating agent or a chemical wettable powder while removing by-product water from the reaction field. I understand.

10 Reaction tower 11 Cooling tower (an example of the first cooling tower)
12 Distillation column (an example of the first distillation column)
13 Cooling tower 14 Separation tower 21 Distillation column (Example of first distillation column)
22 Separation tower

Claims (11)

Carbon dioxide in the presence of at least one solid catalyst and solvent selected from the group consisting of cerium oxide, zirconium oxide, lanthanum oxide, samarium oxide, placeodym oxide, tin oxide, displosium oxide, gadrinium oxide, and europium oxide. And at least one alcohol selected from the group consisting of monohydric and divalent alcohols having a boiling point of more than 100 ° C. and a reaction temperature of 100 ° C. or higher and lower than the boiling point of the alcohol and the solvent. A method for producing a carbonic acid ester, which is reacted below to produce a carbon dioxide ester and by-product water, and the by-product water is removed from the reaction field by evaporation. The method for producing a carbonic acid ester according to claim 1, wherein the evaporated by-product water is removed from the reaction field by a stream of carbon dioxide. The method for producing a carbonic acid ester according to claim 1 or 2, wherein the alcohol is a monohydric alcohol having 4 to 10 carbon atoms. The method for producing a carbonic acid ester according to claim 1 or 2, wherein the alcohol is a divalent alcohol having 2 to 10 carbon atoms. The method for producing a carbonic acid ester according to claim 4, wherein the divalent alcohol is a divalent alcohol having 4 to 6 carbon atoms. The method for producing a carbonic acid ester according to any one of claims 1 to 5, wherein the solvent is an ether solvent. The method for producing a carbonic acid ester according to any one of claims 1 to 6, wherein the solvent is a hydrophobic solvent. In a reactor in which at least one solid catalyst and solvent selected from the group consisting of cerium oxide, zirconium oxide, lanthanum oxide, samarium oxide, placeodium oxide, tin oxide, displosium oxide, gadolinium oxide, and europium oxide are present. Carbon dioxide and at least one alcohol selected from the group consisting of monohydric and divalent alcohols having a boiling point of more than 100 ° C. are supplied, the reaction temperature is 100 ° C. or higher, and the alcohol and the solvent are used. A reaction step of reacting the carbon dioxide with the alcohol to produce a carbonic acid ester and by-product water under the conditions below the boiling point of
The unreacted carbon dioxide, the unreacted alcohol, the by-product water, and the solvent discharged as the gas phase from the reactor in the reaction step are cooled, and the unreacted dioxide is used as the gas phase. A first cooling step of separating the carbon into the unreacted alcohol, the by-product water and the solvent as a liquid phase.
The unreacted alcohol, the by-product water and the solvent separated as the liquid phase in the first cooling step are distilled to obtain the by-product water as the gas phase and the unreacted product as the liquid phase. A first distillation step of separating into the alcohol and the solvent, and
The carbonic acid ester, the unreacted alcohol and the solvent discharged as the liquid phase from the reactor in the reaction step are distilled to prepare the unreacted alcohol and the solvent as the gas phase and the liquid phase. The carbonic acid ester, the unreacted alcohol, and the solvent discharged as a liquid phase from the reactor in the second distillation step of separating into the carbonic acid ester and the reaction step are cooled. A second cooling step of separating the unreacted alcohol and the solvent as the liquid phase and the carbonic acid ester as the solid phase.
Have,
The unreacted carbon dioxide separated in the first cooling step, the unreacted alcohol and the solvent separated in the first distillation step, and the second distillation step or the second cooling. The unreacted alcohol and the solvent separated in the step are reused in the reaction step.
Method for producing carbonic acid ester. A separation step of separating the solid catalyst discharged as a solid phase together with the liquid phase from the reactor in the reaction step from the liquid phase.
A catalyst regeneration step of regenerating the solid catalyst separated in the separation step, and a catalyst regeneration step.
Have more
The method for producing a carbonic acid ester according to claim 8, wherein the solid catalyst regenerated in the catalyst regeneration step is reused in the reaction step. It has a reactor in which at least one solid catalyst and solvent selected from the group consisting of cerium oxide, zirconium oxide, lanthanum oxide, samarium oxide, placeodium oxide, tin oxide, displosium oxide, gadolinium oxide, and europium oxide are present. Then, carbon dioxide and at least one alcohol having a boiling point of more than 100 ° C. and selected from the group consisting of monohydric and divalent alcohols are supplied to the reactor, and the reaction temperature is 100 ° C. or higher. A reaction tower that produces carbonic acid ester and by-product water by reacting the carbon dioxide with the alcohol under conditions below the boiling point of the alcohol and the solvent.
The unreacted carbon dioxide, the unreacted alcohol, the by-product water, and the solvent discharged as the gas phase from the reactor in the reaction tower are cooled, and the unreacted dioxide is used as the gas phase. A first cooling tower that separates carbon into, as a liquid phase, the unreacted alcohol, the by-product water, and the solvent.
The unreacted alcohol, the by-product water and the solvent separated as the liquid phase in the first cooling column are distilled to form the gas phase with the by-product water and the liquid phase with the unreacted product. A first distillation column that separates into the alcohol and the solvent,
The carbonic acid ester, the unreacted alcohol and the solvent discharged as a liquid phase from the reactor in the reaction tower are distilled to form a gas phase with the unreacted alcohol and the solvent as a liquid phase. The carbonic acid ester, the unreacted alcohol, and the solvent discharged as a liquid phase from the second distillation column separated into the carbonic acid ester and the reactor in the reaction column are cooled. A second cooling tower that separates the unreacted alcohol and the solvent as the liquid phase and the carbonic acid ester as the solid phase.
With
The unreacted carbon dioxide separated in the first cooling tower, the unreacted alcohol and the solvent separated in the first distillation column, and the second distillation column or the second cooling column. The unreacted alcohol and the solvent separated in the above are reused in the reaction column.
Carbonate ester manufacturing equipment. A separation tower that separates the solid catalyst discharged as a solid phase together with the liquid phase from the reactor in the reaction tower from the liquid phase.
A catalyst regeneration tower that regenerates the solid catalyst separated by the separation tower, and a catalyst regeneration tower.
With more
The carbonic acid ester production apparatus according to claim 10, wherein the solid catalyst regenerated in the catalyst regeneration tower is reused in the reaction tower.

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