WO2015099053A1

WO2015099053A1 - Cyanopyridine manufacturing method, benzonitrile manufacturing method, carbonate ester manufacturing method, and carbonate ester manufacturing apparatus

Info

Publication number: WO2015099053A1
Application number: PCT/JP2014/084331
Authority: WO
Inventors: 憲治中尾; 鈴木　公仁; 藤本　健一郎; 冨重　圭一; 善直中川; 堂野前　等; 正純田村
Original assignee: 新日鐵住金株式会社
Priority date: 2013-12-27
Filing date: 2014-12-25
Publication date: 2015-07-02
Also published as: TW201531460A; TW201615624A; TWI562988B; TWI593676B

Abstract

[Problem] To provide a method for performing regeneration from picolinamide or benzamide to cyanopyridine or benzonitrile without using strong reagents and while also limiting generation of by-products. [Solution] To solve said problem, one embodiment of the present invention provides a cyanopyridine manufacturing method characterized in that the cyanopyridine is manufactured by heating picolinamide in the presence of a catalyst loaded with an alkali metal oxide and in the presence of an organic solvent to cause a dehydration reaction. Another embodiment of the present invention provides a benzonitrile manufacturing method characterized in that the benzonitrile is manufactured by heating benzamide in the presence of a catalyst in which a metal oxide of a metal species such as molybdenum is loaded on a catalyst support obtained from SiO₂, etc. and in the presence of an organic solvent to cause a dehydration reaction.

Description

Method for producing cyanopyridine, method for producing benzonitrile, method for producing carbonate ester, and apparatus for producing carbonate ester

The present invention relates to a method for producing cyanopyridine, a method for producing benzonitrile, a method for producing carbonate ester, and an apparatus for producing carbonate ester.

Carbonate ester is a general term for compounds in which one or two of hydrogen atoms of carbon dioxide CO (OH) ₂ is substituted with an alkyl group or an aryl group, and RO—C (═O) —OR ′ ( R and R ′ each represents a saturated hydrocarbon group or an unsaturated hydrocarbon group).

Carbonate esters are used as additives for gasoline additives to improve octane number, diesel fuel additives for reducing particles in exhaust gas, etc., and also synthesize polycarbonate and urethane, resins and organic compounds such as pharmaceuticals and agricultural chemicals. It is a very useful compound such as an alkylating agent, a carbonylating agent, a solvent, etc., or as a raw material for a lithium ion battery electrolyte, a lubricant oil raw material, and a deoxidizer for rust prevention of boiler piping. .

As a conventional method for producing a carbonate ester, a method in which phosgene is used as a carbonyl source to directly react with alcohol is the mainstream. This method uses phosgene, which is extremely harmful and highly corrosive, and therefore requires extreme care in handling such as transportation and storage, and it costs a great deal of money to maintain and maintain manufacturing facilities and ensure safety. It was. Moreover, when manufacturing by this method, halogens, such as chlorine, are contained in a raw material and a catalyst, The trace amount halogen which cannot be removed by a simple refinement | purification process is contained in the carbonate ester obtained. In applications for gasoline additives, light oil additives, and electronic materials, there are also concerns that cause corrosion, and therefore a thorough refining process to make trace amounts of halogens extremely small is essential. Furthermore, since phosgene, which is extremely harmful to the human body, has been used recently, administrative guidance has been tightened, such as the establishment of a new production facility for this production method is not permitted, and a new production method that does not use phosgene is strongly desired. It is rare.

Under these circumstances, as described in Non-Patent Document 1, as a method for producing a carbonate ester without using phosgene, a carbonic acid ester is reacted with ethylene oxide to synthesize a cyclic carbonate, and further reacted with methanol to form dimethyl carbonate. A method for obtaining the above has been put into practical use. This method is an environmentally friendly and superior method that can be expected to reduce carbon dioxide, which is expected to be reduced as a global warming gas, with little use or generation of corrosive substances such as hydrochloric acid. It is. However, as described in Patent Document 1, effective use of by-produced ethylene glycol is a major problem. Further, since it is difficult to safely transport ethylene, which is a raw material for ethylene oxide, and ethylene oxide, there is a restriction that a carbonate ester production process plant must be located adjacent to the ethylene and ethylene oxide production process plant.

Further, as described in Patent Document 2, a method for producing dimethyl carbonate by oxidizing methanol and carbon monoxide in a liquid phase in the presence of a cuprous chloride catalyst is also disclosed. However, in this method, carbon monoxide harmful to the human body is handled, and, as in the production method using phosgene, a halogen purification step from the obtained carbonic acid ester is essential by including halogen in the catalyst. Problems such as carbon dioxide by-product have been pointed out.
Furthermore, as described in Non-Patent Document 2, a method for producing dimethyl carbonate from methyl nitrite and carbon monoxide in the presence of a Pd—Cu-based catalyst has been put into practical use. In this method, methyl nitrite, which is a raw material, is supplied by reacting methanol and oxygen with nitric oxide by-produced during the production of dimethyl carbonate. There are issues such as handling harmful carbon monoxide.

In contrast, attempts have been made to directly synthesize carbonate esters by reacting methanol and carbon dioxide in the presence of a solid catalyst (Non-patent Document 3). However, although this reaction is an equilibrium reaction, since the equilibrium is largely biased toward the raw material system, the methanol conversion rate remains at most about 1%, and there is a major problem to be overcome that the reaction rate and productivity are low.

In order to solve the above-mentioned problems, an attempt has been made to remove the reaction restriction by removing water by-produced with carbonate (dimethyl carbonate) out of the system. For example, acetal as a wettable powder with a catalyst (Non-patent Document 4) Research using 2,2-dimethoxypropane (Non-patent Document 5) 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 pressure is extremely high. This is because the hydration reaction of acetal and 2,2-dimethoxypropane is expected to proceed without being catalyzed in the liquid phase, so the reaction rate of the direct synthesis reaction of dimethyl carbonate is not dependent on CO ₂ pressure. It is presumed to determine the overall reaction rate, but because the methanol conversion rate increases at high pressures of 300 atm (30 MPa) and 60 atm (6 MPa), respectively, the motive energy required for pressurization is very large. There was a problem that energy efficiency became worse.

In addition, research using molecular sieves (solid dehydrating agent) (Non-patent Document 6) has been reported, but it is a process that separates and circulates the reaction part (high pressure) and the dehydration part (normal pressure). There was a problem that consumption was large and a large amount of solid dehydrating agent was required.

Solid catalysts used for the direct synthesis reaction of carbonate ester have so far been tin compounds such as dimethoxydibutyltin, thallium compounds such as thallium methoxide, nickel compounds such as nickel acetate, vanadium pentoxide, potassium carbonate and other alkaline carbonates. 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, research on a reaction system for directly synthesizing a cyclic carbonate (propylene carbonate) from propylene glycol and carbon dioxide as a dihydric alcohol in the presence of a solid catalyst has been reported ( Non-patent document 7). However, even in this reaction system, the influence of the reaction pressure is significant, and the reaction proceeds as the reaction pressure increases. The reaction yield is extremely low at low pressure, but the direct synthesis reaction of cyclic carbonate is balanced. In particular, 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 was a problem that the energy efficiency was deteriorated as described above.

The present inventors pay attention to a method of directly synthesizing a carbonate ester from monohydric alcohol and carbon dioxide using a heterogeneous catalyst in the production of carbonate ester, and remove water by-produced with the carbonate ester out of the system. The use of acetonitrile as a compatibilizer eliminates the need for high pressures such as 300 atmospheres and 60 atmospheres as described in Non-Patent

Documents

4 and 5, and it is the first effect that the reaction is promoted under a pressure close to normal pressure. (See Patent Document 3).

WO 2004/014840 EP365,083 JP 2009-132673 A JP 2010-77113 A JP 2012-162523 A JP 2009-213975 A JP 2005-194224 A JP-A-11-35564

The present inventor has further studied the types of wettable powders for further improvement in the amount of carbonate produced, and as a result, by using 2-cyanopyridine or benzonitrile, the production of carbonate ester compared to acetonitrile. It was found that the amount and the production rate were greatly improved, the reaction was likely to proceed under a relatively low pressure close to normal pressure, and the reaction rate was very fast (see Patent Documents 4 and 5). However, the treatment method and utilization method of 2-picolinamide and benzamide as a by-product have not been studied.

Nitriles such as 2-cyanopyridine and benzonitrile, which are wettable powders in the present invention, are generally used in many applications such as solvents, synthetic resins, dyes and pharmaceutical intermediates. Among them, 2-cyanopyridine is a material used as a raw material for pharmaceuticals and agricultural chemicals, and is a material used as a starting material when synthesizing a pyridine or piperidine derivative at the 2-position. Benzonitrile is a material used as a raw material for pharmaceuticals and agricultural chemicals, and is a material used as a starting material when various derivatives are synthesized.

However, the use of 2-picolinamide produced by the reaction of 2-cyanopyridine and water is limited to some medical and agrochemical intermediates. Similarly, the use of benzamide produced by the reaction of benzonitrile with water is limited to some pharmaceutical and agrochemical intermediates. Therefore, in the production of carbonic acid esters using 2-cyanopyridine or benzonitrile as a wettable powder, it is hoped that 2-picolinamide or benzamide produced as a by-product is regenerated and reused as 2-cyanopyridine or benzonitrile. Rarely, this regeneration reaction is highly selective (because by-products are difficult to reuse as a wettable powder), and the yield is high (if the yield is low, the residual amount of 2-picolinamide or benzamide is low). It has been found that this is a problem because the amount of separation treatment with 2-cyanopyridine or benzonitrile increases and the load increases.

In general, nucleophilic substitution reaction with inorganic cyanide is used as one of the methods for synthesizing nitriles, but there is a problem that toxic cyanide is used and halogen salts are by-produced (Non-patent Document 8). ).

In addition, an ammoxidation method (SOHIO method) has been industrialized in a gas phase reaction using air as an oxidant in the presence of ammonia using a Mo—Bi-based or Fe—Sn-based oxide catalyst. A high reaction temperature of 400 ° C. or higher is required, and it is further limited to acrylonitrile and the like (Non-patent Document 9).

On the other hand, there is also nitrile synthesis by amide dehydration, and there are two reports on 2-picolinamide or benzamide dehydration, both of which use homogeneous catalysts, so purification after synthesis, catalyst separation, etc. The subsequent processes are complicated, and a strong reagent (strong acid or strong base) is used, and a large amount of by-products are generated, so that the environmental load is large (Non-Patent Documents 10 and 11). ).

Further, as dehydration reactions of amides using a dehydrating agent,

Patent Documents

7 and 8 disclose phosgene, phosphorus oxychloride, thionyl chloride in a solvent composed of an aliphatic nitrile or an alicyclic nitrile capable of separating an amide from water. Although there is a description on a method for producing a nitrile using thionyl chloride, phosphorus pentachloride, etc., there is a problem that it is necessary to use a highly toxic cyanide or halide.

Further, as a dehydration reaction of an amide using a heterogeneous catalyst, Patent Document 3 describes a catalyst for a dehydration reaction of a primary amide and a method for producing a nitrile using the same. The catalyst is a solid catalyst with vanadium supported on hydrotalcite, and it is said that the primary amide is also active with aromatic amides such as benzamide, amides with heterocycles and aliphatic amides, but the reaction rate is slow. not enough. This is because the amide is generally more stable than the nitrile, and the dehydration reaction of the amide is slower, and the intramolecular hydrogen between the hydrogen atom of the amide group and the nitrogen heteroatom in the amide molecule. This is probably because amides have particularly large intramolecular hydrogen bonds, become stable substances, and are unlikely to undergo dehydration.

As described above, there has been no report on a method for regenerating picolinamide or benzamide to cyanopyridine or benzonitrile without using a powerful reagent and suppressing the generation of by-products.

In view of the above-mentioned problems of the prior art, an object of the present invention is to provide a method for regenerating picolinamide or benzamide to cyanopyridine or benzonitrile without using a powerful reagent and suppressing the generation of by-products. It is to provide.

Conventionally, the dehydration reaction of picolinamide has been carried out only with a homogeneous catalyst, but a heterogeneous catalyst that can suppress separation of by-products and facilitate separation is investigated.

Therefore, first, when dehydration reaction of picolinamide was performed with a heterogeneous catalyst using vanadium which is considered to be effective in the production of benzamide, it was found that cyanopyridine was hardly produced.

Therefore, the inventors have shown that the pyridine ring in picolinamide is weakly basic, so if an acidic catalyst is used, the pyridine ring may be adsorbed and poisoned at the active site of the catalyst, causing a decrease in activity. Therefore, a catalyst using a basic metal as an active species was studied.

As a result, it has been found that the use of a catalyst in which an alkali metal having basic properties is supported on a catalyst carrier is highly active, leading to the invention.

Furthermore, the present inventor also examined a method for producing benzonitrile. Conventionally, the dehydration reaction of benzamide is performed only on metal oxide particles (Non-Patent Document 12), or on a two-dimensional layered inorganic compound carrier called hydrotalcite (Non-Patent Document 13). In particular, the metal-oxygen double bond is presumed that the metal-oxygen double bond in the compound acts as an active species for the dehydration reaction of the amide. We focused on things.

Further, the inventors examined from the viewpoint that the metal oxide is supported in an optimum existence state in consideration of the surface structure, ionicity, and electronic state as the carrier.

As a result, it has been found that when a catalyst in which a specific metal having a double bond between metal and oxygen is supported on a specific catalyst carrier, the catalyst becomes highly active even under relatively mild conditions. It came to.

Furthermore, the present inventor also examined application of the above knowledge to a method for producing a carbonate ester. That is, the present inventors paid attention to a method of directly synthesizing a carbonate ester from a monohydric alcohol and carbon dioxide in the production of the carbonate ester, and used acetonitrile as a hydrating agent to remove water by-produced together with the carbonate ester out of the system. By using benzonitrile, a high pressure such as 30 MPa (300 atm) or 6 MPa (60 atm) as described in

Non-Patent Documents

4 and 5 is unnecessary, and the reaction is accelerated under a pressure close to normal pressure. For the first time, and applied for a patent (Patent Document 3, Patent Document 4). Furthermore, by using 2-cyanopyridine, the production amount and production rate of carbonate ester are greatly improved compared to the case of acetonitrile and benzonitrile, and the reaction is likely to proceed at a relatively low pressure close to normal pressure. And it discovered that reaction rate was very quick, and patent document 5 is carrying out patent publication. Even when any wettable powder is used, a treatment method such as separation or reuse of by-product amide has not been studied, which is a problem.

Based on the above knowledge, the present inventors proceeded with a study on a method for producing a carbonate ester including utilization of by-products, and the reaction was likely to proceed under a relatively low pressure close to normal pressure, and the reaction rate was very high. It was considered to use cyanopyridine or benzonitrile, which has excellent properties as a wettable powder, which is fast and has few by-products, in this production method.

Therefore, as a solid catalyst, intensive studies were conducted by paying attention to the elements constituting the catalyst and the composition. The reaction to produce picolinamide or benzamide was promoted, and dehydration from the reaction system proceeded efficiently, and it was found that carbonate ester can be obtained in high yield without being subjected to reaction equilibrium constraints even under mild conditions of relatively low pressure. It was.

Furthermore, it has been found that among these catalysts, those using a specific catalyst carrier are very effective.

Also, when cyanopyridine or benzonitrile is used as a wettable powder, picolinamide or benzamide is by-produced. These picolinamides or benzamides have a problem that their use is limited and it is difficult to effectively use them. Therefore, the present inventor decided to regenerate picolinamide or benzamide to cyanopyridine or benzonitrile by applying the above-described knowledge to a method for producing carbonate ester. The gist of the present invention is as follows.

(1) Production of cyanopyridine, characterized in that cyanopyridine is produced by heating and dehydrating a picolinamide in the presence of a catalyst supporting an alkali metal oxide and in the presence of an organic solvent. Method.

(2) The method for producing cyanopyridine according to (1), wherein the cyanopyridine is 2-cyanopyridine and the picolinamide is 2-picolinamide.

(3) The catalyst carrying the alkali metal oxide carries one or more alkali metal oxides on a catalyst carrier composed of one or more of SiO ₂ , CeO ₂ and ZrO _2. The method for producing cyanopyridine as described in (1) or (2) above, wherein

(4) The method for producing cyanopyridine according to (3), wherein the catalyst carrier is SiO ₂ .

(5) The production of cyanopyridine as described in any one of (1) to (4) above, wherein the alkali metal oxide is an oxide of Li, K, Na, Rb, or Cs. Method.

(6) The method for producing cyanopyridine according to any one of (1) to (5), wherein the organic solvent is mesitylene.

(7) The method for producing cyanopyridine according to any one of (1) to (6), wherein a dehydrating agent is used in the dehydration reaction.

(8) A monohydric alcohol and carbon dioxide are reacted in the presence of one or both of a solid catalyst of CeO ₂ and ZrO ₂ and cyanopyridine to produce a carbonate and water, and the cyanopyridine and the above A first reaction step of generating picolinamide by a hydration reaction with the generated water;
After the picolinamide is separated from the first reaction step, the picolinamide is dehydrated by heating in the presence of a catalyst carrying an alkali metal oxide and in the presence of an organic solvent, whereby cyano Having a second reaction step to regenerate to pyridine,
A method for producing a carbonic acid ester, wherein the cyanopyridine regenerated in the second reaction step is used in the first reaction step.

(9) A _first catalyst that produces a carbonate ester and a picolinamide by mixing and reacting one or both of a solid catalyst of CeO ₂ and ZrO ₂ , a monohydric alcohol, carbon dioxide, and cyanopyridine. A reaction process;
The carbonate ester, picolinamide, unreacted cyanopyridine, and the solid catalyst discharged from the first reaction step are subjected to solvent extraction with alkane, and then solid-liquid separation is performed to obtain a liquid phase carbonate ester and unreacted cyanopyridine. And a first separation step of separating the alkane and the solid catalyst and picolinamide in solid phase;
A second separation step of separating each of the liquid phase carbonate ester after solid-liquid separation in the first separation step, unreacted cyanopyridine, and alkane;
The solid phase solid catalyst and picolinamide after solid-liquid separation in the first separation step are extracted with a hydrophilic solvent and then solid-liquid separated to obtain a liquid phase picolinamide and a hydrophilic solvent, and a solid phase solid catalyst. A third separation step of separating into
The second reaction in which picolinamide separated in the third separation step is dehydrated by heating in the presence of a catalyst supporting an alkali metal oxide and in the presence of an organic solvent to produce cyanopyridine. Process,
The catalyst loaded with cyanopyridine, unreacted picolinamide, and alkali metal oxide discharged from the second reaction step is filtered to separate the catalyst loaded with the solid phase alkali metal oxide. Separation process of
A fifth separation step for separating cyanopyridine, picolinamide, organic solvent, and water remaining after separation in the fourth separation step, respectively.
The method for producing a carbonate ester according to (8), wherein the cyanopyridine separated in the fifth separation step is used in the first reaction step.

(10) The method according to (9), further comprising a step of regenerating the solid catalyst separated in the third separation step, wherein the regenerated catalyst is used in the first reaction step. Of carbonic acid ester.

(11) Unreacted monohydric alcohol remains in the first reaction step, and carbonate, picolinamide, unreacted monohydric alcohol discharged from the first reaction step in the first separation step Then, the unreacted cyanopyridine and the solid catalyst are subjected to solvent extraction with alkane, followed by solid-liquid separation, and a liquid phase carbonate ester, unreacted monohydric alcohol, unreacted cyanopyridine, and alkane, The method for producing a carbonate ester according to (9) or (10), wherein the solid catalyst and picolinamide are separated.

(12) Carbonate, picoline, which is produced from at least one of methyl picolinate and methyl carbamate as a by-product in the first reaction step and is discharged from the first reaction step in the first separation step. The amide, unreacted cyanopyridine, methyl picolinate, methyl carbamate, and the solid catalyst were subjected to solvent extraction with alkane, followed by solid-liquid separation, and the liquid phase carbonate ester, unreacted cyanopyridine, methyl picolinate, carbamine 12. The method for producing a carbonate ester according to any one of (9) to (11), wherein methyl acid and alkane are separated from the solid catalyst and picolinamide in solid phase.

(13) In the first reaction step, unreacted monohydric alcohol remains and at least one of methyl picolinate and methyl carbamate is generated as a by-product, and in the first separation step, Carbonic acid ester, picolinamide, unreacted monohydric alcohol, unreacted cyanopyridine, methyl picolinate, methyl carbamate and the solid catalyst discharged from the reaction step 1 are subjected to solid-liquid separation after solvent extraction with alkane. And separating into liquid phase carbonate ester, unreacted monohydric alcohol, unreacted cyanopyridine, methyl picolinate, methyl carbamate, and alkane and the solid catalyst and picolinamide in solid phase. The method for producing a carbonate ester according to any one of (9) to (12) above.

(14) The method for producing a carbonate ester as described in any one of (9) to (13) above, wherein the alkane used in the solvent extraction is hexane.

(15) The method for producing a carbonate ester according to any one of (9) to (14), wherein the hydrophilic solvent is acetone.

(16) The method for producing a carbonate ester according to any one of (8) to (15), wherein the cyanopyridine is 2-cyanopyridine and the picolinamide is 2-picolinamide. .

(17) The catalyst carrying the alkali metal oxide carries one or more alkali metal oxides on a catalyst carrier composed of one or more of SiO ₂ , CeO ₂ and ZrO _2. The method for producing a carbonate ester according to any one of (8) to (16) above, wherein

(18) The method for producing a carbonate ester as described in (17) above, wherein the catalyst carrier is SiO ₂ .

(19) The carbonate ester according to any one of (8) to (18), wherein the alkali metal oxide is any one of Li, K, Na, Rb, and Cs. Manufacturing method.

(20) The method for producing a carbonate ester according to any one of (8) to (19), wherein the organic solvent is mesitylene.

(21) The method for producing a carbonate ester as described in any one of (8) to (20) above, wherein a dehydrating agent is used in the dehydration reaction.

(22) The method for producing a carbonate ester according to any one of (8) to (21), wherein the monohydric alcohol is methanol and dimethyl carbonate is produced as a carbonate ester.

(23) The method for producing carbonate ester as described in any one of (8) to (22) above, wherein the monohydric alcohol is ethanol and diethyl carbonate is produced as a carbonate ester.

(24) A production apparatus for use in the method for producing a carbonate according to any one of (8) to (23),
A pressurizing part for pressurizing carbon dioxide;
In the presence of either one or both of CeO ₂ and ZrO ₂ and a cyanopyridine, a monohydric alcohol and carbon dioxide are reacted to produce a carbonate and water, and the cyanopyridine and the produced catalyst. A first reaction part for generating picolinamide by a hydration reaction with water;
The carbonate ester, picolinamide, unreacted cyanopyridine, and the solid catalyst discharged from the first reaction section are subjected to solvent extraction with alkane, and then solid-liquid separation is performed to obtain a liquid phase carbonate ester and unreacted cyanopyridine. And a first separation part for separating the alkane and the solid catalyst and picolinamide in a solid phase;
A second separation part for separating the carbonate, unreacted cyanopyridine, and alkane in the liquid phase after the solid-liquid separation by the first separation part;
The solid catalyst and picolinamide after solid-liquid separation by the first separation unit are extracted with a hydrophilic solvent and then solid-liquid separated to separate into a liquid phase picolinamide and a hydrophilic solvent and a solid phase solid catalyst. A third separation unit
A second reaction for producing cyanopyridine by subjecting picolinamide separated by the third separation part to a dehydration reaction by heating in the presence of a catalyst supporting an alkali metal oxide and in the presence of an organic solvent. And
The catalyst loaded with cyanopyridine, unreacted picolinamide, and alkali metal oxide discharged by the second reaction section is filtered to separate the catalyst loaded with the solid phase alkali metal oxide. A separation part of
A fifth separation unit for separating cyanopyridine, picolinamide, an organic solvent, and water remaining after separation by the fourth separation unit;
An apparatus for producing carbonate ester, comprising: a transport unit that transports the cyanopyridine separated by the fifth separation unit to the first reaction unit.

(25) Any one of molybdenum, tungsten, rhenium, titanium and niobium on a catalyst support composed of one or more of SiO ₂ , TiO ₂ , CeO ₂ , ZrO ₂ , Al ₂ O ₃ and C Benzonitrile is produced by heating and dehydrating benzamide in the presence of a catalyst on which a metal oxide of two or more metal species is supported and in the presence of an organic solvent. A method for producing benzonitrile.

(26) The method for producing benzonitrile according to (25), wherein the benzamide is produced by heating the benzamide to cause a dehydration reaction in a liquid phase state.

(27) The method for producing benzonitrile according to (25) or (26), wherein the catalyst carrier is SiO ₂ .

(28) The method for producing benzonitrile according to any one of (25) to (27), wherein the catalyst is a catalyst in which molybdenum oxide is supported on a SiO ₂ carrier.

(29) The method for producing benzonitrile according to any one of the above (25) to (28), wherein the organic solvent comprises one or more of chlorobenzene, xylene and mesitylene.

(30) The method for producing benzonitrile according to any one of (25) to (29), wherein a dehydrating agent is used in the dehydration reaction.

(31) A monohydric alcohol and carbon dioxide are reacted in the presence of either one or both of CeO ₂ and ZrO ₂ and benzonitrile to produce a carbonate and water, and the benzonitrile A first reaction step of generating benzamide by a hydration reaction between the water and the generated water;
After separating the benzamide from the first reaction step, the benzamide is converted into SiO ₂ , TiO ₂ , a metal oxide of any one or more of molybdenum, tungsten, rhenium, titanium, and niobium. By dehydration reaction by heating in the presence of a catalyst supported on one or more of the catalyst supports of CeO ₂ , ZrO ₂ , Al ₂ O ₃ , and C and in the presence of an organic solvent , Having a second reaction step to regenerate to benzonitrile,
Benzonitrile regenerated in the second reaction step is used in the first reaction step.

(32) A monohydric alcohol and carbon dioxide are reacted in the presence of either one or both of CeO ₂ and ZrO ₂ and benzonitrile to produce a carbonate and water, and the benzonitrile A first reaction step of generating benzamide by a hydration reaction between the water and the generated water;
The carbonate ester, benzamide, unreacted benzonitrile discharged from the first reaction step, and the solid catalyst are subjected to solvent extraction with alkane and then separated into solid and liquid, and the liquid phase carbonate ester, unreacted benzonitrile, And a first separation step of separating the alkane and the solid catalyst and benzamide in a solid phase;
A second separation step of separating the carbonate, unreacted benzonitrile, and alkane in the liquid phase after the solid-liquid separation;
A third separation step in which the solid catalyst and benzamide after the solid-liquid separation are extracted with a hydrophilic solvent, followed by solid-liquid separation, and separated into a liquid phase benzamide and a hydrophilic solvent and a solid phase solid catalyst;
The benzamide separated in the third separation step is a metal oxide of any one or more of molybdenum, tungsten, rhenium, titanium, niobium, or SiO ₂ , TiO ₂ , CeO ₂ , ZrO _2. , And regenerated to benzonitrile by heating and dehydration reaction in the presence of a catalyst supported on one or more catalyst carriers of Al ₂ O ₃ and C and in the presence of an organic solvent. A second reaction step,
The catalyst in which the solid phase metal oxide is supported on the catalyst support is filtered by filtering the catalyst in which the benzonitrile, unreacted benzamide, and metal oxide supported on the catalyst support are discharged from the second reaction step. A fourth separation step of separating
And a fifth separation step for separating benzonitrile, benzamide, organic solvent, and water remaining after the separation,
The method for producing a carbonate ester as described in (31) above, wherein the separated benzonitrile is used in the first reaction step.

(33) The method for producing a carbonate ester according to (32), further comprising a step of regenerating the separated solid catalyst, wherein the regenerated catalyst is used in the first reaction step. .

(34) The method for producing a carbonate ester according to (32) or (33), wherein the alkane used in the solvent extraction is hexane.

(35) The method for producing a carbonate ester according to any one of (32) to (34), wherein the hydrophilic solvent is acetone.

(36) The catalyst support on which the metal oxide is supported is any one or more of SiO ₂ , TiO ₂ , CeO ₂ , and ZrO ₂ (31) to (35), The manufacturing method of carbonate ester of any one of these.

(37) The method for producing carbonate ester as described in (36) above, wherein the catalyst carrier is SiO ₂ .

(38) The method for producing a carbonate ester according to any one of (31) to (37), wherein the metal oxide is molybdenum oxide.

(39) The method for producing a carbonate ester according to any one of (31) to (38), wherein the organic solvent is one or more of chlorobenzene, xylene, and mesitylene. .

(40) The method for producing a carbonate ester as described in any one of (31) to (39) above, wherein a dehydrating agent is used in the second reaction step.

(41) The method for producing a carbonate ester according to any one of (31) to (40), wherein the monohydric alcohol is methanol and dimethyl carbonate is produced as a carbonate ester.

(42) The method for producing a carbonate ester according to any one of (31) to (41), wherein the monohydric alcohol is ethanol and diethyl carbonate is produced as a carbonate ester.

(43) A carbonate ester production apparatus used in the production method according to any one of (31) to (42),
A pressurizing part for pressurizing carbon dioxide;
In the presence of either one or both of CeO ₂ and ZrO ₂ , and benzonitrile, a monohydric alcohol and carbon dioxide are reacted to form a carbonate and water, and the benzonitrile and the above A first reaction part for producing benzamide by a hydration reaction with the produced water;
The carbonate ester, benzamide, unreacted benzonitrile, and the solid catalyst discharged by the first reaction unit are subjected to solvent extraction with alkane, and then solid-liquid separated to obtain a liquid phase carbonate ester, unreacted benzonitrile, And a first separation part for separating the alkane and the solid catalyst and benzamide in a solid phase;
A second separation unit for separating the carbonate, unreacted benzonitrile, and alkane in the liquid phase after the solid-liquid separation;
The solid catalyst and benzamide after the solid-liquid separation are extracted with a hydrophilic solvent, followed by solid-liquid separation, and a third separation unit that separates into a liquid phase benzamide and a hydrophilic solvent and a solid phase solid catalyst;
The separated benzamide is a metal oxide of any one or more of molybdenum, tungsten, rhenium, vanadium, niobium, or a metal oxide of SiO ₂ , TiO ₂ , CeO ₂ , ZrO ₂ , Al ₂ O ₃ , A second reaction section for producing a benzonitrile by heating to cause a dehydration reaction in the presence of a catalyst supported on one or more catalyst supports of C and in the presence of an organic solvent;
The catalyst in which the benzonitrile, unreacted benzamide, and metal oxide supported on the catalyst carrier are discharged by the second reaction unit is filtered to separate the catalyst supporting the solid phase metal oxide. 4 separation parts;
A fifth separation unit for separating benzonitrile, benzamide, an organic solvent, and water remaining after the separation;
A carbonic acid ester producing apparatus, comprising: a conveying unit configured to convey the separated benzonitrile to the first reaction unit.

As described above, according to the present invention, regeneration from picolinamide or benzamide to cyanopyridine or benzonitrile can be performed without using a strong reagent and suppressing the generation of by-products.

It is an example of the manufacturing apparatus of the carbonate ester of this invention. It is a chart which shows the state of each substance in each process of the manufacturing apparatus of FIG. It is another example of the manufacturing apparatus of the carbonate ester of this invention. It is a chart which shows the state of each substance in each process of the manufacturing apparatus of FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

<Production method of 1.2-cyanopyridine>
The method for producing 2-cyanopyridine by the dehydration reaction of 2-picolinamide of the present invention comprises dehydrating 2-picolinamide in the presence of a catalyst supporting a basic metal oxide and an organic solvent to give 2-cyanopyridine. It produces pyridine.

Here, as the catalyst used in the present invention, a basic alkali metal (K, Li, Na, Rb, Cs) oxide can be used, and as the carrier, a substance that generally becomes a catalyst carrier can be used. As a result of studying a suitable support, it was found that SiO ₂ , CeO ₂ , ZrO ₂ , and a catalyst supported on two or more of these (for example, CeO ₂ —ZrO ₂ ) exhibited particularly high performance. .

This is because the pyridine ring in 2-picolinamide is weakly basic, so if an acidic catalyst is used, the pyridine ring may be adsorbed and poisoned at the active site of the catalyst, causing a decrease in activity. Thus, metal oxides having basic properties are preferred. Further, as a result of intensive studies by the present inventor, it is particularly preferable to use a catalyst in which an alkali metal oxide is supported in a highly dispersed state on SiO ₂ , and one or more alkali metal oxides may be supported. Good.

Examples of the carrier production method used here are roughly divided into a dry method and a wet method as general production methods in the case of SiO ₂ . The dry method includes a combustion method, an arc method, etc., and the wet method includes a sedimentation method, a gel method, etc., and it is possible to manufacture a catalyst carrier by any of the manufacturing methods. Since it is technically and economically difficult to form, a gel method is preferred in which silica sol can be easily formed into a spherical shape by spraying in a gas medium or a liquid medium.

In the case of CeO _2, cerium acetylacetonate hydrate and cerium hydroxide, cerium sulfate, cerium acetate, cerium nitrate, cerium ammonium nitrate, cerium carbonate, cerium oxalate, perchlorate cerium, cerium phosphate, cerium stearate These various cerium compounds can be prepared by firing in an air atmosphere. When cerium oxide as a reagent is used, it can be used as it is or by drying or baking in an air atmosphere. Furthermore, it can be used by precipitating from a solution in which cerium is dissolved, filtering, drying, and baking.

On the other hand, in the case of ZrO ₂ , various zirconium compounds such as zirconium ethoxide, zirconium butoxide, zirconium carbonate, zirconium hydroxide, zirconium phosphate, zirconium acetate, zirconium chloride oxide, zirconium dinitrate, zirconium sulfate and the like are fired in an air atmosphere. Can be prepared. When zirconium oxide as a reagent is used, it can be used as it is or by drying or baking in an air atmosphere. Furthermore, it can be used by precipitating from a solution in which zirconium is dissolved, filtering, drying and baking.

In the case of a compound of CeO ₂ and ZrO ₂ , a base is added to a solution containing cerium and zirconium to form a hydroxide by coprecipitation, followed by filtration and washing, followed by drying and firing in an air atmosphere. Can be prepared. Although the powder particles of CeO ₂ and ZrO ₂ can also be prepared by firing the physical mixture, the specific surface area of the final preparation is not high, preferably easily coprecipitation reaction proceeds more.

Specifically, a solid catalyst carrier made of a compound of cerium oxide and zirconium oxide such as CeO ₂ —ZrO ₂ can be obtained by these methods. In addition, including the case where a catalyst carrier made of cerium oxide or a catalyst carrier made of zirconium oxide is prepared, the firing temperature at the time of preparation of each of these catalyst carriers may be selected at a temperature at which the specific surface area of the final preparation is increased. Although it depends on the starting material, for example, 300 ° C. to 1100 ° C. is preferable. Further, the solid catalyst carrier according to the present invention may contain inevitable impurities that are mixed in the catalyst manufacturing process in addition to the above elements, but it is desirable that impurities are not mixed as much as possible.

An example of the method for producing the catalyst of the present invention is as follows. When the support is SiO ₂ , a commercially available powder or spherical SiO ₂ can be used, and 100 mesh (0.15 mm) is used so that the active metal can be uniformly supported. In order to adjust the particle size below and remove moisture, pre-baking is preferably performed in air at 700 ° C. for 1 hour. Also, SiO ₂ has various properties, but a larger surface area is preferable because the active metal can be highly dispersed and the amount of 2-cyanopyridine produced is improved. Specifically, a surface area of 300 m ² / g or more is preferable. However, the surface area of the catalyst after preparation may be lower than the surface area of only SiO ₂ due to the interaction between SiO ₂ and the active metal. In that case, it is preferable that the surface area of the catalyst after manufacture is 150 m ² / g or more. The active metal oxide can be supported by an impregnation method such as an incipient wetness method or an evaporation to dryness method.

The metal salt used as the precursor may be water-soluble, and various compounds such as carbonates, hydrogen carbonates, chloride salts, nitrates, and silicates can be used as long as they are alkali metals. The carrier can be used as a catalyst by impregnating a carrier with an aqueous precursor of a basic metal, and then dried and calcined, and the calcining temperature is preferably 400 to 600 ° C., although it depends on the precursor used.

The supported amount of the catalyst may be set as appropriate. For example, the supported metal amount of the alkali metal oxide is about 0.1 to 1.5 mmol / g, particularly 0.1 to 1 mmol / g based on the total catalyst weight. It is preferable to set at about g. If the loading amount is larger than this, the activity may decrease. Moreover, what is necessary is just to set suitably about the usage-amount of the catalyst at the time of reaction.

Furthermore, the catalyst in the present invention is composed of a catalyst in which one or more alkali metal oxides are supported on a carrier composed of one or more of SiO ₂ , CeO ₂ , and ZrO _2. In addition to the above elements, unavoidable impurities mixed in the catalyst production process or the like may be included. However, it is desirable to prevent impurities from entering as much as possible.

Here, the catalyst in which the metal oxide serving as the active species of the present invention is supported on the support may be in the form of powder or molded body, and in the case of the molded body, it is spherical, pellet-shaped, cylinder-shaped. , Ring shape, wheel shape, granule shape and the like.

Next, the method for producing 2-cyanopyridine using the catalyst of the present invention is not particularly limited as a reaction mode, and is not limited to a batch reactor, a semi-batch reactor, a continuous tank reactor or a tube reactor. Any flow reactor may be used. Moreover, any of a fixed bed, a slurry bed, etc. can be applied to the catalyst.

In the production method of the present invention, it is desirable to carry out while removing the by-product water produced by the dehydration reaction. For example, while removing the by-product water by installing a dehydrating agent such as reflux, distillation or zeolite in the system. It is desirable to carry out the reaction. As a result of intensive studies by the present inventors, using a Soxhlet extraction tube and a cooler, zeolite (molecular sieve) or calcium hydride as a dehydrating agent was installed in the extraction tube, and a catalyst, 2-picolinamide, organic By adding a solvent, refluxing, and reacting at normal pressure, it is possible to improve the amount of 2-cyanopyridine produced.

The organic solvent is preferably a substance having a boiling point of 130 ° C. or higher, and examples thereof include chlorobenzene, (o-, m-, p-) xylene, and mesitylene.

The reaction conditions are preferably selected from the viewpoints of the dehydration reaction rate, the boiling point of the solvent, the amount of CO ₂ emitted during the reaction, and economic efficiency.

The usual reaction conditions in the method for producing 2-cyanopyridine of the present invention can be carried out at a reaction temperature of 160 to 200 ° C., a pressure of normal pressure, and a time of several hours to 500 hours. Is not to be done.

The type and shape of the molecular sieve used as the dehydrating agent are not particularly limited. For example, 3A, 4A, 5A, etc., which are generally highly water-absorbing, such as spherical or pellets are used. it can. Further, it is preferably dried in advance, and is preferably dried at 300 to 500 ° C. for about 1 hour.

In the dehydration reaction of 2-picolinamide, it is considered that picolinic acid and pyridine are by-produced by the decomposition of 2-picolinamide as described above. However, after the dehydration reaction using the catalyst of the present invention, Only a small amount of 2-picolinamide, 2-cyanopyridine as a product, water as a by-product, and an organic solvent are present, and the above-mentioned by-products are hardly generated.

In the case of reflux using a Soxhlet extraction tube and a cooler, the periphery of the reaction tube is heated to 160 to 200 ° C. The melting point of each substance is 110 ° C. (2-picolinamide), 24 ° C. (2-cyanopyridine), −45 ° C. (organic solvent such as mesitylene), and the boiling point is 143 ° C. (2-picolinamide), Since it is 212 ° C. (2-cyanopyridine), 100 ° C. (water), and 165 ° C. (organic solvent such as mesitylene), the reaction phase is all liquid except for the solid catalyst, and is partially vaporized. The 2-picolinamide, by-product water, and the organic solvent are cooled by the cooler, and the by-product water is adsorbed by the dehydrating agent, and the 2-picolinamide and the organic solvent return to the reaction tube and contribute to the reaction again.

Since the boiling point of each substance present in the system after the reaction is different as described above, it can be easily separated by distillation. Further, since the catalyst is a solid, it can be separated and recovered as necessary after the reaction, and can be easily recovered by a solid-liquid separation method such as ordinary filtration.

<Method for producing 2.3, 4-cyanopyridine>
3-Cyanopyridine and 4-cyanopyridine can be synthesized by changing 2-picolinamide, which is a starting material of 2-cyanopyridine, to nicotinamide and isonicotinamide and carrying out the same treatment.

<3. Method for producing benzonitrile>
The method for producing benzonitrile includes the same steps as the method for producing cyanopyridine. Specifically, it is as follows.

The method for producing benzonitrile by dehydration reaction of benzamide according to the present invention is to produce benzonitrile by dehydration reaction of benzamide in the presence of a catalyst supporting a basic metal oxide and an organic solvent.

Here, the catalyst used in the present invention may be an oxide of a basic metal (Mo, W, Re, Ti, Nb), and the support may be a substance that generally becomes a catalyst support. As a result of examining the support, when a catalyst supporting an oxide of an active metal species is used on SiO ₂ , TiO ₂ , CeO ₂ , ZrO ₂ , Al ₂ O ₃ , C, and two or more of these catalyst supports It was found to show particularly high performance.

This is because, when an acidic catalyst is used, a benzene ring is adsorbed and poisoned at the active site of the catalyst, which may cause a decrease in activity. Therefore, a metal oxide having basic properties is preferable. Further, as a result of intensive studies by the present inventors, among SiO ₂ , TiO ₂ , CeO ₂ , ZrO ₂ , Al ₂ O ₃ , and C, any one or two of SiO ₂ , TiO ₂ , CeO ₂ , and ZrO ₂ are used. It is preferable to use more than one type of catalyst support because it shows higher performance. This is because, in the reaction with benzamide, it is considered that the double bond portion between the metal and oxygen may be active, and thus a metal element having a double bond is preferable among the metal oxides. Furthermore, it is particularly preferable to use a catalyst in which the above metal oxide (especially molybdenum) is supported on SiO ₂ in a highly dispersed state, and one or more metal oxides may be supported. A method for producing a metal oxide will be described below.

The general production method in the case of SiO _2, are roughly classified into a dry method and a wet method. The dry method includes a combustion method, an arc method, etc., and the wet method includes a sedimentation method, a gel method, etc., and it is possible to manufacture a catalyst carrier by any of the manufacturing methods. Since it is technically and economically difficult to form, a gel method is preferred in which silica sol can be easily formed into a spherical shape by spraying in a gas medium or a liquid medium.

In the case of ZrO ₂ , various zirconium compounds such as zirconium ethoxide, zirconium butoxide, zirconium carbonate, zirconium hydroxide, zirconium phosphate, zirconium acetate, zirconium chloride oxide, zirconium dinitrate, zirconium sulfate and the like are calcined in an air atmosphere. Can be prepared. When zirconium oxide as a reagent is used, it can be used as it is or by drying or baking in an air atmosphere. Furthermore, it can be used by precipitating from a solution in which zirconium is dissolved, filtering, drying and baking.

Further, in the case of TiO ₂ and _Al 2 _{O 3,} it can be prepared by a general method. C is mainly composed of carbon and may be in any form as long as it does not change during the reaction period. For example, activated carbon is preferable, but it is not limited thereto.

In the case of a compound containing two or more kinds of metal species, a base is added to a solution containing two or more kinds of metal salts to form a hydroxide by coprecipitation, followed by filtration, washing and drying in an air atmosphere. It can be prepared by firing. Moreover, although it can prepare also by physically mixing and baking the powder of 2 or more types of oxides, since the specific surface area of a final preparation does not become high, the coprecipitation method with which reaction progresses more is preferable.

For example, in the case of a compound of CeO ₂ and ZrO ₂ , a base is added to a solution containing cerium and zirconium to form a hydroxide by coprecipitation, followed by filtration and washing, followed by drying and firing in an air atmosphere. Can be prepared.

By such a method, a solid catalyst carrier comprising a compound of cerium oxide and zirconium oxide such as CeO ₂ —ZrO ₂ can be obtained. In addition, including the case where a catalyst carrier made of cerium oxide or a catalyst carrier made of zirconium oxide is prepared, the firing temperature at the time of preparation of each of these catalyst carriers may be selected at a temperature at which the specific surface area of the final preparation is increased. Although it depends on the starting material, for example, 300 ° C. to 1100 ° C. is preferable. Further, the solid catalyst carrier according to the present invention may contain inevitable impurities that are mixed in the catalyst manufacturing process in addition to the above elements, but it is desirable that impurities are not mixed as much as possible.

The carrier selected from one or more of SiO ₂ , TiO ₂ , CeO ₂ , ZrO ₂ , Al ₂ O ₃ , and C can support active metal species in a highly dispersed manner as the surface area increases. This is preferable because the amount of nitrile produced is improved. Specifically, the surface area depends on the type of the carrier, but the surface area is preferably 10 m ² / g or more as measured by the BET method. Whether it is highly dispersed can be confirmed with an image of an electron microscope (SEM, TEM, etc.).

In the production of the catalyst of the present invention, a metal oxide that becomes an active species may be supported on a support by a known method. For example, it can be supported by an impregnation method such as an incipient wetness method or an evaporation to dryness method.

For example, when the carrier is SiO ₂ , commercially available powder or spherical SiO ₂ can be used, and the particle size is adjusted to 100 mesh (0.15 mm) or less to remove the moisture so that the active metal can be uniformly supported. In order to achieve this, it is preferable to perform pre-baking in air at 700 ° C. for 1 hour. Moreover, although SiO ₂ has various properties, it is preferable that the surface area is large because the active metal can be supported in a highly dispersed manner and the amount of benzonitrile produced is improved. Specifically, a surface area of 300 m ² / g or more (BET method) is more preferable. However, the surface area of the catalyst after preparation may be lower than the surface area of only SiO ₂ due to the interaction between SiO ₂ and the active metal. In that case, it is more preferable that the surface area of the catalyst after production is 150 m ² / g or more (BET method).

The metal salt that is a precursor of the metal oxide that becomes the active species may be water-soluble. For example, various compounds such as carbonate, bicarbonate, chloride, nitrate, and silicate can be used. . The carrier can be used as a catalyst by impregnating a carrier with an aqueous precursor of a basic metal, and then dried and calcined, and the calcining temperature is preferably 400 to 600 ° C., although it depends on the precursor used.

The amount of metal oxide supported may be set as appropriate. For example, the amount of metal oxide supported in terms of metal based on the total catalyst weight is about 0.1 to 1.5 mmol / g, particularly 0.1 to 1 mmol. / G, preferably about 0.2 to 0.8 mmol / g. When the loading amount is larger, the activity may be reduced due to the coarsening of the metal oxide. Moreover, what is necessary is just to set suitably about the usage-amount of the catalyst at the time of reaction.

Furthermore, the catalyst in the present invention is one or two kinds of metal oxides on a support composed of one or more of SiO ₂ , TiO ₂ , CeO ₂ , ZrO ₂ , Al ₂ O ₃ , and C. Although it consists of the catalyst which carry | supported only the above, you may contain the unavoidable impurity mixed in a catalyst manufacturing process etc. other than said element. However, it is desirable to prevent impurities from entering as much as possible. In normal cases, the impurities are preferably less than 1% by weight of the total catalyst.

Next, the method for producing benzonitrile using the catalyst of the present invention is not particularly limited as a reaction mode, such as a batch reactor, a semi-batch reactor, a continuous tank reactor or a tube reactor. Any of the flow reactors may be used. Moreover, any of a fixed bed, a slurry bed, etc. can be applied to the catalyst.

The organic solvent is preferably a substance having a boiling point of 130 ° C. or more, and examples thereof include chlorobenzene, (o-, m-, p-) xylene, mesitylene, furfural, heptadecane and the like. , P-) xylene and mesitylene are preferred.

As usual reaction conditions in the method for producing benzonitrile of the present invention, the reaction temperature is 160 to 200 ° C., the pressure is normal pressure, and the time is several hours to 24 hours. It is not a thing.

In the production method of the present invention, in order to react for a long time, it is preferable to remove by-product water generated by the dehydration reaction. For example, a dehydrating agent such as zeolite is installed in the system, and the by-product water is removed. It is desirable to carry out the reaction while removing. As a result of intensive studies by the present inventor, using a Soxhlet extraction tube and a cooler, zeolite (molecular sieve) or calcium hydride was installed in the extraction tube as a dehydrating agent, and a catalyst, benzamide, and an organic solvent were placed in the reaction tube. The amount of benzonitrile produced can be improved by reacting at normal pressure with reflux.

In the dehydration reaction of benzamide, benzoic acid may be produced as a by-product due to the decomposition of benzamide as described above. However, after the dehydration reaction using the catalyst of the present invention, a small amount of benzamide and product remained in the reaction product. There are only some benzonitriles, by-product water, and organic solvents, and these by-products are hardly produced. Moreover, even if it produces | generates, it is very small amount, can isolate | separate by distillation operation and can use it for a pharmaceutical use.

In the case of reflux using a Soxhlet extraction tube and a cooler, the reaction temperature is preferably a condition under which the benzamide dehydration reaction is performed in a liquid phase. Considering the reaction efficiency, it is preferable that the temperature is higher under liquid phase conditions. When the reaction is performed under normal pressure, it is preferable to heat the periphery of the reaction tube to 160 to 200 ° C. The melting point of each substance in a typical reaction system is 127 ° C. (benzamide), −13 ° C. (benzonitrile), −45 ° C. (organic solvent such as mesitylene), and the boiling point is 288 ° C. (benzamide), 188 Since it is ℃ (benzonitrile), 100 ℃ (water), 165 ℃ (organic solvent, for example, mesitylene), at the above temperature, the reaction phase is almost liquid except for the solid catalyst, The partially vaporized benzamide, by-product water, and organic solvent are cooled by a cooler, and the by-product water is adsorbed by the dehydrating agent, and the benzamide and the organic solvent return to the reaction tube and contribute to the reaction again.

<Method for producing carbonate ester using 4.2-cyanopyridine>
As described above, the present inventor was able to conceive of a method for regenerating 2-picolinamide to 2-cyanopyridine without using a powerful reagent and suppressing the generation of by-products. And this inventor was able to think of the manufacturing method of carbonate ester demonstrated below by applying this knowledge to the manufacturing method of carbonate ester.

(First reaction step)
The first reaction step in the method for producing a carbonate ester of the present invention involves directly reacting a monohydric alcohol and carbon dioxide in the presence of one or both of a solid catalyst of CeO ₂ and ZrO ₂ and 2-cyanopyridine. This produces a carbonate ester.

In this process, when monohydric alcohol and carbon dioxide are reacted, water is produced in addition to carbonate ester, but 2-picolinamide is produced by the hydration reaction with the produced water due to the presence of 2-cyanopyridine. And it becomes possible to promote the production | generation of carbonate ester by removing or reducing the produced | generated water from a reaction system.

(Monohydric alcohol)
Here, as the monohydric alcohol, any alcohol selected from one or more of primary alcohol, secondary alcohol, and tertiary alcohol can be used, and methanol, ethanol, 1-propanol can be used. , Isopropanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, allyl alcohol, 2-methyl-1-propanol, cyclohexane methanol, benzyl alcohol This is preferable because the yield of the product is high and the reaction rate is fast. At this time, the produced carbonates are dimethyl carbonate, diethyl carbonate, dipropyl carbonate, diisopropyl carbonate, dibutyl carbonate, dipentyl carbonate, dihexyl carbonate, diheptyl carbonate, dioctyl carbonate, dinonane carbonate, diallyl carbonate, di-2-methyl-propyl carbonate, respectively. To dicyclohexane methyl carbonate and dibenzyl carbonate.

(Carbonate production catalyst)
Moreover, either or both of the solid catalyst of CeO ₂ and ZrO _2, only CeO _2, only ZrO _2, a CeO ₂ and mixtures of ZrO _2, or CeO ₂ solid solution or a composite oxide of ZrO _2, in particular Only CeO ₂ is preferred. Further, CeO ₂ and ZrO ₂ solid solutions and composite oxides are basically based on a mixing ratio of CeO ₂ and ZrO ₂ of 50:50, but the mixing ratio can be changed as appropriate.

As a result of intensive studies by the present inventors, the catalyst used for the direct synthesis of carbonic acid ester is required to have an acid-base complex function, and in particular, has a property of relatively low acidity and relatively high basicity. Is preferred. If the acidity is too high, it is not preferable because a large amount of ether is synthesized rather than carbonate. In the moderate acid base complex function catalyst, RO-M on base point (M catalyst) alcohol dissociates adsorbed in the form of, RO-C (= O) with the CO ₂ -O ... M On the other hand, on the acid point, alcohol is adsorbed in the form of HO—R... M, and RO—C (═O) —OR is generated between both adsorbed species.

This solid catalyst also exhibits catalytic activity for the hydration reaction of water and 2-cyanopyridine, which are by-produced during the synthesis of carbonate ester. Therefore, although both the carbonate ester synthesis reaction and the hydration reaction proceed on the surface of the catalyst, the hydration of 2-cyanopyridine is carried out even under low pressure conditions, which is unfavorably balanced for the carbonate ester synthesis reaction. The reaction proceeds under catalysis, and the water generated as a by-product from the synthesis reaction of the carbonate ester is rapidly eliminated from the catalyst surface, so that the equilibrium of the synthesis reaction of the carbonate ester shifts to the production system and the reaction pressure is low. It is inferred that the carbonate ester synthesis reaction is allowed to have a high reaction rate without being subjected to equilibrium constraints even under mild conditions. On the other hand, under high pressure, a large amount of CO ₂ molecules are adsorbed on the catalyst surface, making it difficult to contact with water molecules generated during the synthesis of carbonic acid ester, so that the hydration reaction with 2-cyanopyridine does not proceed easily. Therefore, it is considered that the carbonate ester can be produced only in a state close to the equilibrium constraint, and as a result, the productivity is not increased under high pressure.

Regarding the above inference, from the viewpoint of the reaction of 2-cyanopyridine, 2-cyanopyridine is catalyzed by the solid catalyst of the present invention in the liquid phase, and the hydration reaction is promoted on the surface thereof. Therefore, when the pressure is increased, the surface of the solid catalyst is covered with CO ₂ , and the hydration reaction rate is reduced because it becomes difficult to be catalyzed by the hydration reaction with water molecules generated in the main reaction. Inferred. On the other hand, acetal and 2,2-dimethoxypropane described in Non-Patent Document 4 and Non-Patent Document 5 do not undergo any catalytic action in the liquid phase and cause a hydration reaction with water molecules generated in the main reaction. Therefore, since the main reaction proceeds predominantly at high pressure, it is presumed that the hydration reaction begins to occur under high pressure.

As for the production method of the catalyst of the present invention, for example, first, in the case of CeO ₂ , cerium acetylacetonate hydrate, cerium hydroxide, cerium sulfate, cerium acetate, cerium nitrate, ammonium cerium nitrate, It can be prepared by firing various cerium compounds such as cerium carbonate, cerium oxalate, cerium perchlorate, cerium phosphate and cerium stearate in an air atmosphere. When cerium oxide as a reagent is used, it can be used as it is or by drying or baking in an air atmosphere. Furthermore, it can be used by precipitating from a solution in which cerium is dissolved, filtering, drying, and baking.

On the other hand, in the case of zirconium oxide (ZrO ₂ ), various zirconium compounds such as zirconium ethoxide, zirconium butoxide, zirconium carbonate, zirconium hydroxide, zirconium phosphate, zirconium acetate, zirconium chloride oxide, zirconium oxide dinitrate, zirconium sulfate and the like are mixed with air. It can be prepared by firing in an atmosphere. When zirconium oxide as a reagent is used, it can be used as it is or by drying or baking in an air atmosphere. Furthermore, it can be used by precipitating from a solution in which zirconium is dissolved, filtering, drying and baking.

In the case of a compound such as a solid solution or composite oxide of CeO ₂ and ZrO ₂ , a base is added to a solution containing cerium and zirconium to form a hydroxide by coprecipitation, followed by filtration and washing with water. It can be prepared by drying and firing in an air atmosphere. Although the powder particles of CeO ₂ and ZrO ₂ can also be prepared by firing the physical mixture, the specific surface area of the final preparation is not high, preferably easily coprecipitation reaction proceeds more.

Specifically, a solid catalyst made of a compound of cerium oxide and zirconium oxide such as CeO ₂ —ZrO ₂ can be obtained by these methods. In addition, including the case of preparing a catalyst made of cerium oxide or a catalyst made of zirconium oxide, it is preferable to select a temperature at which the specific surface area of the final preparation is increased as the firing temperature at the time of preparation of each catalyst. Although it depends on the raw material, for example, 300 ° C. to 1100 ° C. is preferable. Further, the solid catalyst according to the present invention may contain inevitable impurities mixed in the catalyst production process in addition to the above elements, but it is desirable that impurities are not mixed as much as possible.

Here, the catalyst of the present invention may be in any form of powder or molded body, and in the case of a molded body, it may be any of spherical, pellet, cylinder, ring, wheel, granule, etc. .

(carbon dioxide)
Moreover, the carbon dioxide used in the present invention is not limited to those prepared as industrial gases, but can also be used that separated and recovered from exhaust gases from factories, steel mills, power plants, etc. that manufacture each product.

(Solid-liquid separation)
Under the conditions where the conversion rate of monohydric alcohol is 100% and no by-products such as methyl picolinate and methyl carbamate are formed, carbonate ester as the main product, 2-picolinamide as the by-product after the reaction, It becomes a solid catalyst such as unreacted 2-cyanopyridine, CeO ₂ or the like. In order to separate them, first, a liquid component (carbonate ester, 2-cyanopyridine) is extracted in an extraction step using an organic solvent, and can be separated from a fixed component (2-picolinamide and a fixed catalyst) and a filter. The organic solvent used here is preferably an alkane that can dissolve the carbonate, and more preferably hexane, octane, nonane, decane, and undecane.

(Separation of liquid components)
Next, the separated liquid component contains carbonate ester, 2-cyanopyridine, and an organic solvent. The melting point and boiling point of each substance are 4 ° C and 90 ° C (dimethyl carbonate). -43 ° C and 128 ° C (diethyl carbonate), -41 ° C and 167 ° C (dipropyl carbonate), 25 ° C or less and 207 ° C (dibutyl carbonate), and 24 ° C and 215 ° C (2-cyanopyridine) , −95 ° C. and 69 ° C. (for example, hexane), the carbonate ester can be separated by distillation, and the product carbonate ester can be recovered with high purity. In addition to distillation, it is also possible to filter and recover what is solidified by cooling stepwise to below the melting point.

(Separation of solid components)
Further, 2-picolinamide and solid catalyst separated as solid components can be separated from the solid catalyst and a filter by extracting only 2-picolinamide with a hydrophilic solvent. The hydrophilic solvent used here is preferably acetone, ethanol, ether, or water in view of ease of handling and separation at a later stage. The 2-picolinamide dissolved in the hydrophilic solvent can be separated by distillation, and the by-produced 2-picolinamide can be purified with high purity.

(Regeneration treatment of the separated solid catalyst)
The separated solid catalyst is regenerated in the step of regenerating the catalyst and can be reused in the first reaction step. The catalyst regeneration step is a step in which impurities on the solid catalyst are heated to burn off, and is baked at 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 rapid temperature rise, it is better to consider the drying step before firing, and it is preferable to dry at 110 ° C. for about 2 hours.

(Residual components)
In addition, when unreacted monohydric alcohol remains, or the reaction temperature is as high as 130 ° C. or higher, or the reaction time is as long as 24 hours or more, by-products such as methyl picolinate and methyl carbamate are formed. If they are produced, the melting point and boiling point are -97 ° C and 65 ° C (methanol), -114 ° C and 78 ° C (ethanol), -126 ° C and 97 ° C (1-propanol) for monohydric alcohols, respectively. ), −90 ° C. and 117 ° C. (1-butanol) and the like, and 103 ° C. and 233 ° C. (methyl picolinate), 52 ° C. and 177 ° C. (methyl carbamate). By gradually increasing the temperature to about 0 ° C., monohydric alcohol, organic solvent, carbonate ester, methyl carbamate, methyl picolinate, and 2-sia Can separate and pyridine, followed by cooling to 30 ~ 100 ° C., the solidified picolinate by the filter, it can be separated from 2-cyanopyridine.

Since most of monohydric alcohols and organic solvents are organic solvents, they can be reused in the extraction process with organic solvents. However, it is preferable that there are few by-products because it is difficult for the processing step after separation to the outside of the system to occur.

(Second reaction step)
Next, in the second reaction step of the present invention, 2-picolinamide by-produced in the first reaction step is separated from the system after the carbonic acid ester formation reaction, and then 2-cyanopyridine is converted by dehydration reaction. To manufacture. The second reaction step corresponds to the above-described method for producing 2-cyanopyridine.

In the production of 2-cyanopyridine, 2-picolinamide is dehydrated in the presence of a catalyst supporting a basic metal oxide and an organic solvent to produce 2-cyanopyridine.

Here, as the catalyst used in the present invention, a catalyst in which an oxide of a basic alkali metal (K, Li, Na, Rb, Cs) is generally supported on a substance serving as a catalyst carrier can be used. As a result of studying various supports, particularly high performance is exhibited when a catalyst supported on SiO ₂ , CeO ₂ , ZrO ₂ , or two or more of these (for example, CeO ₂ —ZrO ₂ ) is used. found.

This is because the pyridine ring in 2-picolinamide is weakly basic, so if an acidic catalyst is used, the pyridine ring may be adsorbed and poisoned at the active site of the catalyst, causing a decrease in activity. A metal having basic properties is preferable. In addition, as a result of intensive studies by the present inventors, it is particularly preferable to use a catalyst in which an alkali metal is supported on SiO ₂ in a highly dispersed state, and one or more alkali metals may be supported.

Further, the catalyst according to the present invention may contain inevitable impurities that are mixed in the catalyst manufacturing process in addition to the above-mentioned elements, but it is desirable that impurities are not mixed as much as possible.

Here, the catalyst supported on the carrier of the present invention may be in the form of a powder or a molded body. In the case of a molded body, a spherical shape, a pellet shape, a cylinder shape, a ring shape, a wheel shape, a granule Any shape may be used.

(Reaction format)
Next, the method for producing 2-cyanopyridine using the catalyst of the present invention is not particularly limited as a reaction mode, and is not limited to a batch reactor, a semi-batch reactor, a continuous tank reactor or a tube reactor. Any flow reactor may be used. Moreover, any of a fixed bed, a slurry bed, etc. can be applied to the catalyst.

(dehydration)
In the second reaction step of producing (regenerating) 2-cyanopyridine from 2-picolinamide by-produced in the production method of the present invention, as well as by-product water produced by the dehydration reaction, It is desirable to carry out the reaction while removing it. For example, it is desirable to carry out the reaction while removing by-product water by installing a dehydrating agent such as reflux, distillation or zeolite in the system. As a result of intensive studies by the present inventors, using a Soxhlet extraction tube and a cooler, zeolite (molecular sieve) or calcium hydride as a dehydrating agent was installed in the extraction tube, and a catalyst, 2-picolinamide, organic By adding a solvent, refluxing, and reacting at normal pressure, it is possible to improve the amount of 2-cyanopyridine produced.

(Organic solvent)
The organic solvent used for the dehydration reaction is preferably a substance having a boiling point of 130 ° C. or higher, and examples thereof include chlorobenzene, (o-, m-, p-) xylene, mesitylene and the like, and mesitylene is particularly preferable.

(Reaction conditions)
In the method for producing 2-cyanopyridine using the catalyst of the present invention, the reaction conditions are preferably selected from the viewpoints of the dehydration reaction rate, the boiling point of the solvent, the amount of CO ₂ generated during the reaction, and economic efficiency. For example, the reaction temperature may be 160 to 200 ° C., the reaction pressure may be normal pressure, and the reaction time may be several hours to 500 hours, but is not particularly limited thereto.

(Reaction product)
In the dehydration reaction of 2-picolinamide, it is considered that picolinic acid and pyridine are by-produced by the decomposition of 2-picolinamide as described above. However, after the dehydration reaction using the catalyst of the present invention, Only a small amount of 2-picolinamide, 2-cyanopyridine as a product, water as a by-product, and an organic solvent are present, and the above-mentioned by-products are hardly generated.

(Reuse of 2-cyanopyridine)
The 2-cyanopyridine regenerated in the second reaction step can be reused in the first reaction step.

<5. Carbonate ester production equipment>
Next, the production apparatus of the present invention will be described in more detail with reference to specific examples. FIG. 1 is an example of a suitable facility of the present invention. Moreover, the state of each substance in each process in this equipment in FIG. 1 is shown in FIG. This equipment can be used in the case of reaction conditions in which the conversion rate of monohydric alcohol is 100% and by-products of methyl picolinate and methyl carbamate are not generated.

(First reaction step)
In the first reaction step, in the first reaction column 1 (first reaction section), one or both of the solid catalyst (solid phase) of CeO ₂ and ZrO ₂ , the monohydric alcohol 12 (liquid phase), Carbon dioxide (gas phase) is charged through 2-cyanopyridine 13 (liquid phase) and pressure blower 10 (pressure part). As the solid catalyst, a solid catalyst 14 (solid phase) newly charged before the reaction or regenerated in the regeneration tower 6 can be used. In addition, although 2-cyanopyridine is a new one at the start of the reaction, it is purified by unreacted 2-cyanopyridine 20 (liquid phase) purified in the first distillation column 3 and in the third distillation column 9. 2-Cyanopyridine regenerated from picolinamide can be reused.

Next, the carbon dioxide ester direct synthesis apparatus using the solid catalyst of either or both of CeO ₂ and ZrO ₂ of the present invention is a batch reactor, a semi-batch reactor, a continuous tank reactor, a tube type, or the like. Any flow reactor such as a reactor may be used.

(Reaction temperature)
The reaction temperature in the first reaction column 1 is preferably 50 to 300 ° C. When the reaction temperature is less than 50 ° C., the reaction rate is low, the carbonate ester synthesis reaction and the hydration reaction with 2-cyanopyridine hardly proceed, and the carbonate ester productivity tends to be low. On the other hand, when the reaction temperature exceeds 150 ° C., the reaction rate of each reaction increases, but decomposition and modification of the carbonate ester, and 2-picolinamide easily react with the monohydric alcohol, resulting in a low carbonate ester yield. Tend to be. More preferably, it is 100 to 150 ° C. However, since this temperature is considered to vary depending on the type and amount of the solid catalyst and the amount and ratio of the raw materials (monohydric alcohol, 2-cyanopyridine), it is desirable to set optimum conditions appropriately. Since the preferable reaction temperature is 100 to 150 ° C., it is desirable to preheat the raw material (monohydric alcohol, 2-cyanopyridine) with steam or the like before the first reaction column.

(Reaction pressure)
The reaction pressure is preferably 0.1 to 5 MPa (absolute pressure). When the reaction pressure is less than 0.1 MPa (absolute pressure), a pressure reducing device is required, and not only the equipment is complicated and expensive, but also the motive energy for reducing the pressure is required, resulting in poor energy efficiency. On the other hand, when the reaction pressure exceeds 5 MPa, the hydration reaction with 2-cyanopyridine is difficult to proceed and not only the yield of the carbonate ester is deteriorated, but also the kinetic energy necessary for pressurization is required and the energy efficiency is poor. Become. Further, from the viewpoint of increasing the yield of carbonate ester, the reaction pressure is more preferably 0.1 to 4 MPa (absolute pressure), and further preferably 0.2 to 2 MPa (absolute pressure).

(2-cyanopyridine dose)
The 2-cyanopyridine used for the hydration reaction is desirably introduced into the reactor in advance at a rate of 0.1 to 1 times the volume of the starting alcohol prior to the reaction. If it is introduced at less than 0.1 times, the yield of carbonate ester may be deteriorated because of the small amount of 2-cyanopyridine contributing to the hydration reaction. On the other hand, when it is introduced more than 1 time, there is no particular problem because it can be easily separated from the product after the completion of the reaction and reused. Furthermore, the amount of monohydric alcohol and 2-cyanopyridine with respect to the solid catalyst is considered to vary depending on the type and amount of the solid catalyst, the type of monohydric alcohol and the ratio with 2-cyanopyridine. It is desirable.

(Reaction product separation)
The reaction liquid 15 after the reaction in the first reaction tower 1 is separated into a liquid phase and a solid phase in the first extraction tower 2 (first separation section). The substances contained in the reaction solution 15 are carbonate ester (liquid phase), unreacted 2-cyanopyridine (liquid phase) and 2-picolinamide (solid phase), solid catalyst (solid phase), and organic solvent (liquid phase). Phase). Alkane is suitable for the organic solvent used here, and hexane, octane, nonane, decane, and undecane are preferable from the viewpoint of ease of separation by distillation in the subsequent stage. In order to reduce energy consumption, the extraction process in the first extraction column 2 is preferably performed at room temperature, but the temperature is lower than the boiling point of the organic solvent (for example, in the case of hexane, the boiling point is 69 ° C.). If it is heated to about 50 ° C., the extraction time can be shortened by heating.

The extract 17 extracted in the first extraction tower 2 contains carbonate ester, unreacted 2-cyanopyridine, and alkane. The boiling point of each substance in the first distillation column 3 (second separation section) is 90 ° C. (for example, dimethyl carbonate), 215 ° C. (2-cyanopyridine), 69 ° C. (for example, hexane). The product is distilled into carbonic acid ester 19, unreacted 2-cyanopyridine 20, and alkane 16 used for extraction.

On the other hand, the solid phase 18 separated in the first extraction tower 2 contains 2-picolinamide and a solid catalyst, and is separated in the second extraction tower 4 (third separation section). As the solvent used here, a hydrophilic solvent (liquid phase) capable of dissolving 2-picolinamide is suitable, and acetone, ethanol, ether, and water are preferable because they are easily separated by distillation at a later stage. The extraction step in the second extraction tower 4 is also preferably performed at room temperature for extraction in order to suppress energy consumption. However, the temperature is lower than the boiling point of the hydrophilic solvent (for example, in the case of acetone, the boiling point is 56.56). If it is 5 [deg.] C. and heated to about 40 [deg.] C.), the extraction time can be shortened by heating.

The extract solution 21 containing 2-picolinamide and a hydrophilic solvent is distilled in the second distillation column 5 so that the boiling points of the substances are 143 ° C. (2-picolinamide) and 57 ° C. (for example, in the case of acetone). To be separated.

Further, the solid catalyst 22 (solid phase) separated in the second extraction tower 4 can be regenerated in the catalyst regeneration tower 6 and returned to the first reaction tower 1. The catalyst regeneration is a step of heating to burn off impurities on the solid catalyst, and is fired at 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 rapid temperature rise, it is better to consider the drying step before firing, and it is preferable to dry at 110 ° C. for about 2 hours.

The 2-picolinamide 23 (solid phase) purified in the second distillation column 5 is transferred to the second reaction column 7 (second reaction section) for regeneration to 2-cyanopyridine. In order to avoid blockage, it is desirable to heat the pipe to a melting point of 103 ° C. or higher with low-pressure steam or the like.

The solution after the reaction can be recovered as a used catalyst 26 by separating only the solid catalyst by filtering with a filter in the catalyst separation device 8. At this time, it can be easily recovered by a solid-liquid separation method such as normal filtration. Since the boiling point of each substance present in the system is different as described above after the catalyst separation, 2-cyanopyridine, organic solvent, 2-picolinamide, water are distilled by distillation in the third distillation column 9. The organic solvent 27 and 2-picolinamide 28 can be recycled for the dehydration reaction of 2-picolinamide. The purified 2-cyanopyridine 13 can be reused in a reaction for producing a carbonate ester.

(Second reaction step)
In the second reaction step, 2-cyanopyridine is produced in the second reaction column 7 by the dehydration reaction of 2-picolinamide. The production apparatus of the present invention is an apparatus for producing 2-cyanopyridine by dehydrating 2-picolinamide in the presence of a catalyst supporting a basic metal oxide and an organic solvent. The reaction format is not particularly limited, and any of a batch reactor, a semi-batch reactor, a flow reactor such as a continuous tank reactor and a tubular reactor may be used. Moreover, any of a fixed bed, a slurry bed, etc. can be applied to the catalyst. The temperature of the second reaction column 7 can be changed according to the reaction mode, but in the case of reflux using a Soxhlet extraction tube and a cooler, it is preferable to heat the periphery of the reaction tube to 160 to 200 ° C. In the production apparatus of the present invention, it is desirable to carry out while removing the by-product water produced by the dehydration reaction. For example, a dehydrating agent such as reflux, distillation or zeolite is installed in the system to remove the by-product water. It is desirable to carry out the reaction. As a result of intensive studies by the present inventors, using a Soxhlet extraction tube and a cooler, zeolite (molecular sieve) or calcium hydride as a dehydrating agent was installed in the extraction tube, and a catalyst, 2-picolinamide, organic By adding a solvent, refluxing, and reacting at normal pressure, it is possible to improve the amount of 2-cyanopyridine produced. The organic solvent is preferably a substance having a boiling point of 130 ° C. or higher, and examples thereof include chlorobenzene, (o-, m-, p-) xylene, mesitylene and the like.

The solution after the reaction is recovered as a used catalyst 26 by separating only the catalyst in the catalyst separation column 8 (fourth separation section) while being heated to 103 ° C. or higher, which is the melting point of 2-picolinamide, with low-pressure steam or the like. To do. At this time, it can be easily recovered by a solid-liquid separation method such as normal filtration. After the catalyst separation, the boiling points of the substances present in the system are different from each other as described above. Therefore, by distilling in the third distillation column 9 (fifth separation part), 2-cyanopyridine 13, The organic solvent 27, 2-picolinamide 28 and water 29 can be easily separated, and the organic solvent 27 and 2-picolinamide 28 can be returned to the previous stage of the third reaction column 7 and recycled. . The purified 2-cyanopyridine 13 is transported to the first reaction column 1 where the carbonate ester is produced by the transport unit, and is reused in the first reaction column 1.

(Other examples of carbonic acid ester production method and apparatus)
FIG. 3 shows another example of the preferred equipment of the present invention, and FIG. 4 shows the state of each substance in each process in the equipment of FIG. This equipment can also be used in the case of reaction conditions where unreacted monohydric alcohol remains and byproducts of methyl picolinate and methyl carbamate are generated. The basic configuration is the same as in the case of FIG. 1 described above, but the extract 17 extracted in the first extraction tower 2 includes carbonate ester, unreacted 2-cyanopyridine, alkane, and monohydric alcohol. Contains methyl carbamate and methyl picolinate. The boiling point of each substance in the first distillation column 3 is 90 ° C. (for example, dimethyl carbonate), 215 ° C. (2-cyanopyridine), 69 ° C. (for example, hexane), 65 ° C. (for example, methanol), Utilizing the fact that it is 177 ° C (methyl carbamate) and 233 ° C (methyl picolinate), it was distilled by gradually increasing the temperature to about 180 ° C, and was used as a product, carbonate 19, The mixture is separated into a mixture 33 of alkane and unreacted monohydric alcohol 33 and methyl carbamate 32. Further, after distillation, cooling to about 30 to 100 ° C. solidifies methyl picolinate having a melting point of 103 ° C., so that it can be separated into solid and liquid with a filter 30 or the like, and unreacted 2-cyanopyridine. 20 and methyl picolinate 31. Moreover, since the mixture 33 of alkane and monohydric alcohol is mostly alkane, it can be reused as a solvent for extraction.

<Manufacturing method and manufacturing apparatus for carbonate ester using 3-, 4-cyanopyridine>
In the carbonic acid ester production method and production apparatus described above, 3-cyanopyridine or 4-cyanopyridine may be used instead of 2-cyanopyridine.

<7. Method for producing carbonate ester using benzonitrile>
As described above, the present inventor was able to conceive of a method for regenerating benzamide to benzonitrile without using a strong reagent and suppressing the generation of by-products. And this inventor was able to think of the manufacturing method of carbonate ester demonstrated below by applying this knowledge to the manufacturing method of carbonate ester.

(First reaction step)
The first reaction step in the method for producing a carbonate ester of the present invention involves directly reacting a monohydric alcohol and carbon dioxide in the presence of one or both of a solid catalyst of CeO ₂ and ZrO ₂ and benzonitrile to produce carbonic acid. An ester is produced.

In this step, when monohydric alcohol and carbon dioxide are reacted, water is produced in addition to the carbonate ester. However, the presence of benzonitrile produces benzamide by hydration reaction with the produced water. It becomes possible to promote the production | generation of carbonate ester by removing or reducing from a reaction system.

(Carbonate production catalyst)
Moreover, either or both of the solid catalyst of CeO ₂ and ZrO _2, only CeO _2, only ZrO _2, a CeO ₂ and mixtures of ZrO _2, or CeO ₂ solid solution or a composite oxide of ZrO _2, in particular Only CeO ₂ is preferred. As for the CeO ₂ and ZrO ₂ solid solution or a composite oxide, the mixing ratio of CeO ₂ and ZrO ₂ (molar ratio) is not particularly limited, for example, 1:99 to 99: it can be a 1, For example, the molar ratio may be 50:50.

This solid catalyst also exhibits catalytic activity for the hydration reaction of water and benzonitrile by-produced during the synthesis of the carbonate ester. Therefore, although both carbonate synthesis reaction and hydration reaction proceed on the surface of this catalyst, the hydration reaction of benzonitrile does not occur even under low pressure conditions, which is unfavorably balanced for the synthesis reaction of carbonate ester. The reaction proceeds under catalysis, and water generated as a by-product in the synthesis reaction of the carbonate ester is quickly eliminated from the catalyst surface, so that the equilibrium of the synthesis reaction of the carbonate ester shifts to the production system, and the mild reaction pressure is low. It is presumed that the carbonic acid ester synthesis reaction enables a high reaction rate of the carbonic acid ester without being subjected to equilibrium constraints even under conditions. On the other hand, under high pressure, a large amount of CO ₂ molecules are adsorbed on the catalyst surface, making it difficult to contact with water molecules generated during the synthesis of the carbonic acid ester, making it difficult for the hydration reaction with benzonitrile to proceed. Carbonic acid ester can only be produced under conditions close to equilibrium constraints, and as a result, it is considered that productivity does not increase under high pressure.

Regarding the above inference, from the viewpoint of the reaction of benzonitrile, benzonitrile is catalyzed by the solid catalyst in the present invention in the liquid phase, and the hydration reaction is promoted on the surface thereof. Therefore, when the pressure is increased, the surface of the solid catalyst is covered with CO ₂ , and the hydration reaction rate is reduced because it becomes difficult to be catalyzed by the hydration reaction with water molecules generated in the main reaction. Inferred. On the other hand, acetal and 2,2-dimethoxypropane described in Non-Patent Document 4 and Non-Patent Document 5 do not undergo any catalytic action in the liquid phase and cause a hydration reaction with water molecules generated in the main reaction. Therefore, since the main reaction proceeds predominantly at high pressure, it is presumed that the hydration reaction begins to occur under high pressure.

Further, with respect to the method for producing the catalyst of the present invention, the following examples are given. First, in the case of cerium oxide (CeO ₂ ), cerium acetylacetonate hydrate, cerium hydroxide, cerium sulfate, cerium acetate, cerium nitrate It can be prepared by firing various cerium compounds such as ammonium cerium nitrate, cerium carbonate, cerium oxalate, cerium perchlorate, cerium phosphate and cerium stearate in an air atmosphere. When cerium oxide as a reagent is used, it can be used as it is or by drying or baking in an air atmosphere. Furthermore, it can be used by precipitating from a solution in which cerium is dissolved, filtering, drying, and baking.
On the other hand, in the case of zirconium oxide (ZrO ₂ ), various zirconium compounds such as zirconium ethoxide, zirconium butoxide, zirconium carbonate, zirconium hydroxide, zirconium phosphate, zirconium acetate, zirconium chloride oxide, zirconium oxide nitrate, zirconium sulfate, etc. It can be prepared by firing in an atmosphere. When zirconium oxide as a reagent is used, it can be used as it is or by drying or baking in an air atmosphere. Furthermore, it can be used by precipitating from a solution in which zirconium is dissolved, filtering, drying and baking.

Specifically, a solid catalyst made of a compound of cerium oxide and zirconium oxide such as CeO ₂ —ZrO ₂ can be obtained by these methods. In addition, including the case of preparing a catalyst made of cerium oxide or a catalyst made of zirconium oxide, it is preferable to select a temperature at which the specific surface area of the final preparation is increased as the firing temperature at the time of preparation of each catalyst. Although it depends on the raw material, for example, 300 to 1100 ° C. is preferable. Further, the solid catalyst according to the present invention may contain inevitable impurities mixed in the catalyst production process in addition to the above elements, but it is desirable that impurities are not mixed as much as possible. The impurities are preferably less than 1% by mass with respect to the catalyst.

(Solid-liquid separation)
Under the conditions where the conversion rate of monohydric alcohol is 100% and no by-products such as methyl benzoate and methyl carbamate are produced, the main product carbonate ester, by-product benzamide, unreacted It becomes a solid catalyst such as benzonitrile and CeO ₂ . In order to separate them, first, a liquid component (carbonate ester, benzonitrile) is extracted in an extraction step using an organic solvent, and can be separated from a solid component (benzamide and a fixed catalyst) with a filter. The organic solvent used here is preferably an alkane that can dissolve the carbonate, and more preferably hexane, octane, nonane, decane, and undecane.

(Separation of liquid components)
Next, the separated liquid component contains carbonate ester, benzonitrile, and organic solvent. The melting point and boiling point of each substance are 4 ° C and 90 ° C (dimethyl carbonate), -43 ℃ and 128 ℃ (diethyl carbonate), -41 ℃ and 167 ℃ (dipropyl carbonate), 25 ℃ or less and 207 ℃ (dibutyl carbonate), -13 ℃ and 188 ℃ (benzonitrile), -95 ℃ And 69 ° C. (for example, hexane), the carbonate ester can be separated by distillation, and the product carbonate ester can be recovered with high purity. In addition to distillation, it is also possible to filter and recover what is solidified by cooling stepwise to below the melting point.

(Separation of solid components)
The benzamide and the solid catalyst separated as solid components can be separated from the solid catalyst and the filter by extracting only benzamide with a hydrophilic solvent. The hydrophilic solvent used here is preferably acetone, ethanol, ether, or water in view of ease of handling and separation at a later stage. The benzamide dissolved in the hydrophilic solvent can be separated by distillation, and the by-product benzamide can be purified with high purity.

In addition to the separation of benzamide dissolved in a hydrophilic solvent, it is also possible to collect the benzamide that has cooled to a melting point or lower and solidified by cooling with a liquid hydrophilic solvent, in addition to distillation.

(Regeneration treatment of the separated solid catalyst)
The separated solid catalyst is regenerated in the step of regenerating the catalyst and can be reused in the first reaction step. The catalyst regeneration step is a step of heating to burn off impurities etc. on the solid catalyst, and is preferably calcined at 400 to 700 ° C., more preferably at 500 to 600 ° C. for about 3 hours. In order to prevent structural destruction of the solid catalyst due to rapid temperature rise, it is better to consider the drying step before firing, and it is preferable to dry at 110 ° C. for about 2 hours.

(Residual components)
Further, when unreacted monohydric alcohol remains, or the reaction temperature is as high as 130 ° C. or higher, or the reaction time is as long as 24 hours or longer, by-products such as methyl benzoate and methyl carbamate are formed. If it has been produced, the melting point and boiling point are -97 ° C and 65 ° C (methanol), -114 ° C and 78 ° C (ethanol), -126 ° C and 97 ° C (1-propanol), -90 ° C and 117 ° C (1-butanol), etc., and -15 ° C and 198 ° C (methyl benzoate), 52 ° C and 177 ° C (methyl carbamate). By gradually increasing to a certain extent, monohydric alcohol, organic solvent, carbonate, and methyl carbamate, methyl benzoate, and benzonitrile Can release, then, by cooling, the solidified methylbenzoic acid by the filter, can be separated from the benzonitrile.

(Second reaction step)
Next, in the second reaction step of the present invention, the benzamide produced as a by-product in the first reaction step is separated from the system after the carbonic acid ester formation reaction, and then benzonitrile is produced by a dehydration reaction. The second reaction step corresponds to the above-described method for producing benzonitrile.

In the production of benzonitrile, benzamide is produced by dehydrating benzamide in the presence of a catalyst supporting a basic metal oxide and an organic solvent.

(Benzonitrile production catalyst)
Here, the catalyst used in the present invention is generally an oxide (metal oxide) of a metal species (molybdenum, tungsten, rhenium, titanium, niobium) having a double bond between the metal and oxygen as a catalyst carrier. Although a catalyst supported on a substance can be used, as a result of examining various supports, a catalyst composed of one or more of SiO ₂ , TiO ₂ , CeO ₂ , ZrO ₂ , Al ₂ O ₃ , and C is used. It has been found that high performance is exhibited when a catalyst supported on a carrier is used.

In particular, it is preferable to use any one or two or more catalyst carriers of SiO ₂ , TiO ₂ , CeO ₂ , and ZrO ₂ because higher performance is exhibited. This is because, in the reaction with benzamide, it is considered that the double bond portion between the metal and oxygen may be active, and thus a metal element having a double bond is preferable among the metal oxides.

Further, as a result of intensive studies by the present inventors, it is particularly preferable to use a catalyst in which molybdenum is supported on SiO ₂ in a highly dispersed state. Whether it is highly dispersed can be confirmed with an image of an electron microscope (SEM, TEM, etc.).

In the case of ZrO ₂ , various zirconium compounds such as zirconium ethoxide, zirconium butoxide, zirconium carbonate, zirconium hydroxide, zirconium phosphate, zirconium acetate, zirconium chloride oxide, zirconium dinitrate, zirconium sulfate and the like are calcined in an air atmosphere. Can be prepared. When zirconium oxide as a reagent is used, it can be used as it is or by drying or baking in an air atmosphere. Furthermore, it can be used by precipitating from a solution in which zirconium is dissolved, filtering, drying and baking.
In the case of TiO ₂ or Al ₂ O ₃ , it can be produced by a general method. C is mainly composed of carbon and may be in any form as long as it does not change during the reaction period. For example, activated carbon is preferable, but it is not limited thereto.

In the case of a compound containing two or more metal species, a base is added to a solution containing two or more metal salts to form a hydroxide by coprecipitation, followed by filtration and washing in an air atmosphere. Can be prepared by drying and baking. Moreover, although it can prepare also by physically mixing and baking the powder of 2 or more types of oxides, since the homogeneity of the component of a final preparation does not become high, the coprecipitation method with which reaction progresses more is preferable.

The carrier selected from one or more of SiO ₂ , TiO ₂ , CeO ₂ , ZrO ₂ , Al ₂ O ₃ , and C can support active metal species in a highly dispersed manner as the surface area increases. This is preferable because the amount of nitrile produced is improved. Specifically, the surface area depends on the type of the carrier, but the surface area is preferably 10 m ² / g or more as measured by the BET method.

In the production method of the catalyst of the present invention, a metal oxide that becomes an active species may be supported on a support by a known method. In addition to the precipitation loading method using a general solution, for example, it can be loaded by an impregnation method such as an incipient wetness method or an evaporation to dryness method.

Preferred examples are given below. When the carrier is SiO ₂ , a commercially available powder or spherical SiO ₂ can be used, and pre-baking is performed to adjust the particle size to 100 mesh (0.15 mm) or less and to remove moisture so that the active metal can be uniformly supported. It is preferable to carry out at 700 degreeC in air for 1 hour. Moreover, although SiO ₂ has various properties, it is preferable that the surface area is large because the active metal can be highly dispersed and the amount of benzonitrile produced is improved. Specifically, a surface area of 300 m ² / g or more is more preferable. However, the surface area of the catalyst after preparation may be lower than the surface area of only SiO ₂ due to the interaction between SiO ₂ and the active metal. In that case, it is more preferable that the surface area of the catalyst after manufacture is 150 m ² / g or more.

The metal salt that is the precursor of the metal oxide that becomes the active species only needs to have high solubility in various solvents. For example, carbonate, bicarbonate, chloride, nitrate, sulfate, silicate, acetate Various compounds such as can be used. After impregnating the precursor solution of the metal compound into the support, it can be used as a catalyst by drying and firing, and the firing temperature is preferably 400 to 600 ° C., although it depends on the precursor used.

(Organic solvent)
As the organic solvent used in the dehydration reaction, various substances having a boiling point of 130 ° C. or higher are preferably used. Among them, chlorobenzene, (o-, m-, p-) xylene, mesitylene, and the like are more preferably used, and in particular, mesitylene. Is preferred.

(Reaction conditions)
In the method for producing benzonitrile using the catalyst of the present invention, the reaction conditions are preferably selected from the viewpoints of the dehydration reaction rate, the boiling point of the solvent, the amount of CO ₂ emitted during the reaction, and the economy. The reaction temperature may be 160 to 200 ° C., the reaction pressure may be normal pressure, and the reaction time may be several hours to 24 hours, but is not particularly limited thereto.

(Reaction format)
Next, the method for producing benzonitrile using the catalyst of the present invention is not particularly limited as a reaction format, and is distributed as a batch reactor, a semi-batch reactor, a continuous tank reactor or a tubular reactor. Any of the type reactors may be used. Moreover, any of a fixed bed, a slurry bed, etc. can be applied to the catalyst.

(dehydration)
In the second reaction step of producing (regenerating) benzonitrile from the by-produced benzamide in the production method of the present invention, it is carried out while removing the by-product water produced by the dehydration reaction, as in the step of producing carbonate ester. For example, it is desirable to install a dehydrating agent such as zeolite in the system and perform the reaction while removing by-product water. As a result of intensive studies by the present inventor, using a Soxhlet extraction tube and a cooler, zeolite (molecular sieve) or calcium hydride was installed in the extraction tube as a dehydrating agent, and a catalyst, benzamide, and an organic solvent were placed in the reaction tube. The amount of benzonitrile produced can be improved by reacting at normal pressure with reflux.

(Reaction product)
In the dehydration reaction of benzamide, benzoic acid may be produced as a by-product due to the decomposition of benzamide as described above. However, after the dehydration reaction using the catalyst of the present invention, a small amount of benzamide and product remained in the reaction product. There are only some benzonitriles, by-product water, and organic solvents, and these by-products are hardly produced.

(Reuse of benzonitrile)
The benzonitrile regenerated in the second reaction step can be reused in the first reaction step.

<8. Carbonate ester production equipment>
Next, a specific example is shown below and the example of the manufacturing apparatus and operation conditions (reaction conditions) used with the manufacturing method of the carbonate ester of this invention is demonstrated still in detail. Here, the apparatus for producing carbonate ester using benzonitrile has substantially the same configuration as the apparatus for producing 2-cyanopyridine. Schematically, an apparatus for producing a carbonate ester using benzonitrile is such that 2-cyanopyridine and 2-picolinamide in FIG. 1 and the like are replaced with benzonitrile and benzamide. Therefore, in the following, an apparatus for producing a carbonate using benzonitrile will be described with reference to FIGS.

FIG. 1 is an example of a suitable facility of the present invention. Moreover, the state of each substance in each process in this equipment in FIG. 1 is shown in FIG. This equipment can be used in the case of reaction conditions in which the conversion rate of monohydric alcohol is 100% and byproducts of methyl benzoate and methyl carbamate are not generated.

(First reaction step)
In the first reaction step, in the first reaction column 1 (first reaction section), one or both of the solid catalyst (solid phase) of CeO ₂ and ZrO ₂ , the monohydric alcohol 12 (liquid phase), Carbon dioxide (gas phase) is filled through the benzonitrile 13 (liquid phase) and the pressure booster 10 (pressure part). As the solid catalyst, a solid catalyst 14 (solid phase) newly charged before the reaction or regenerated in the regeneration tower 6 can be used. Also, a new benzonitrile is used at the start of the reaction, but the unreacted benzonitrile 20 (liquid phase) purified in the first distillation column 3 and the benzamide regenerated from the benzamide purified in the third distillation column 9 are used. Nitriles can be reused.

(Reaction temperature)
The reaction temperature in the first reaction column 1 is preferably 50 to 300 ° C. When the reaction temperature is less than 50 ° C., the reaction rate is low, the carbonate ester synthesis reaction and the hydration reaction with benzonitrile hardly proceed, and the carbonate ester productivity tends to be low. When the reaction temperature exceeds 150 ° C., the reaction rate of each reaction increases, but decomposition and modification of the carbonate ester, and benzamide easily react with the monohydric alcohol, so that the yield of the carbonate ester tends to decrease. is there. More preferably, it is 100 to 150 ° C. However, since this temperature is considered to vary depending on the type and amount of the solid catalyst and the amount and ratio of the raw materials (monohydric alcohol and benzonitrile), it is desirable to appropriately set the optimum conditions. Since the preferred reaction temperature is 100 to 150 ° C., it is desirable to preheat the raw material (monohydric alcohol, benzonitrile) with steam or the like before the first reaction column.

(Reaction pressure)
The reaction pressure is preferably 0.1 to 5 MPa (absolute pressure). When the reaction pressure is less than 0.1 MPa (absolute pressure), a pressure reducing device is required, and not only the equipment is complicated and expensive, but also the motive energy for reducing the pressure is required, resulting in poor energy efficiency. On the other hand, when the reaction pressure exceeds 5 MPa, the hydration reaction by benzonitrile is difficult to proceed and not only the yield of the carbonate ester is deteriorated, but also the kinetic energy necessary for pressurization is required and the energy efficiency is deteriorated. Further, from the viewpoint of increasing the yield of carbonate ester, the reaction pressure is more preferably 0.1 to 4 MPa (absolute pressure), and further preferably 0.2 to 2 MPa (absolute pressure).

(Dose of benzonitrile)
The benzonitrile used for the hydration reaction is preferably introduced into the reactor in advance at a rate of 0.1 to 1 times the volume of the starting alcohol prior to the reaction. If it is introduced at less than 0.1 times, the yield of the carbonate ester may be deteriorated because there is little benzonitrile contributing to the hydration reaction. On the other hand, when it is introduced more than 1 time, there is no particular problem because it can be easily separated from the product after the completion of the reaction and reused. Furthermore, the amount of monohydric alcohol and benzonitrile with respect to the solid catalyst is considered to vary depending on the type and amount of the solid catalyst, the type of monohydric alcohol and the ratio with benzonitrile, and therefore it is desirable to appropriately set optimum conditions.

(Reaction product separation)
The reaction liquid 15 after the reaction in the first reaction tower 1 is separated into a liquid phase and a solid phase in the first extraction tower 2 (first separation section). The substances contained in the reaction solution 15 are carbonate ester (liquid phase), unreacted benzonitrile (liquid phase), benzamide (solid phase), and solid catalyst (solid phase), and are extracted with an organic solvent (liquid phase). . Alkane is suitable for the organic solvent used here, and hexane, octane, nonane, decane, and undecane are preferable from the viewpoint of ease of separation by distillation in the subsequent stage. In order to reduce energy consumption, the extraction process in the first extraction column 2 is preferably performed at room temperature, but the temperature is lower than the boiling point of the organic solvent (for example, in the case of hexane, the boiling point is 69 ° C.). If it is heated to about 50 ° C., the extraction time can be shortened by heating.

The extract 17 extracted in the first extraction tower 2 contains carbonate ester, unreacted benzonitrile, and alkane. Utilizing that the boiling point of each substance is 90 ° C. (for example, dimethyl carbonate), 188 ° C. (benzonitrile), 69 ° C. (for example, hexane) in the first distillation column 3 (second separation section). The product is then distilled and separated into the product carbonate 19, unreacted benzonitrile 20, and alkane 16 used for extraction.

On the other hand, the solid phase 18 separated in the first extraction tower 2 contains benzamide and a solid catalyst, and is separated in the second extraction tower 4 (third separation section). As the solvent used here, a hydrophilic solvent (liquid phase) capable of dissolving benzamide is suitable, and acetone, ethanol, ether, and water are preferable because they are easily separated by distillation at a later stage. The extraction step in the second extraction tower 4 is also preferably performed at room temperature for extraction in order to suppress energy consumption. However, the temperature is lower than the boiling point of the hydrophilic solvent (for example, in the case of acetone, the boiling point is 56.56). If it is 5 [deg.] C. and heated to about 40 [deg.] C.), the extraction time can be shortened by heating.

The extract 21 containing benzamide and a hydrophilic solvent is distilled in the second distillation column 5, and the boiling point of each substance is separated into 127 ° C. (benzamide) and 57 ° C. (for example, in the case of acetone).
Further, the solid catalyst 22 (solid phase) separated by the second extraction tower 4 can be regenerated by the catalyst regeneration tower 6 and returned to the first reaction tower 1. The catalyst regeneration is a step of heating to burn off impurities on the solid catalyst, and is fired at 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 rapid temperature rise, it is better to consider the drying step before firing, and it is preferable to dry at 110 ° C. for about 2 hours.

The benzamide 23 (solid phase) purified in the second distillation column 5 is transferred to the second reaction column 7 (second reaction part) for regeneration to benzonitrile, but in order to avoid blockage in the piping. The piping is preferably heated to 127 ° C. or higher, which is the melting point, with low pressure steam or the like.

The solution after the reaction can be recovered as a used catalyst 26 by separating only the solid catalyst by filtering with a filter in the catalyst separation device 8. At this time, it can be easily recovered by a solid-liquid separation method such as normal filtration. Since the boiling point of each substance present in the system is different as described above after the catalyst separation, it can be easily separated into benzonitrile, organic solvent, benzamide, and water by distillation. The organic solvent 27 and the benzamide 28 can be recycled for the dehydration reaction of benzamide. The purified benzonitrile 13 can be reused in a reaction for producing a carbonate ester.

(Second reaction step)
In the second reaction step, benzonitrile is generated in the second reaction column 7 by a dehydration reaction of benzamide. The production apparatus of the present invention is an apparatus for producing benzonitrile by dehydrating benzamide in the presence of a catalyst supporting a metal oxide having a double bond and an organic solvent. The reaction format is not particularly limited, and any of a batch reactor, a semi-batch reactor, a flow reactor such as a continuous tank reactor and a tubular reactor may be used. Moreover, any of a fixed bed, a slurry bed, etc. can be applied to the catalyst. The temperature of the second reaction column can be changed according to the reaction mode, but in the case of reflux using a Soxhlet extraction tube and a cooler, the periphery of the reaction tube is preferably heated to 160 to 200 ° C. In the production apparatus of the present invention, it is desirable to carry out while removing the by-product water produced by the dehydration reaction. For example, a dehydrating agent such as reflux, distillation or zeolite is installed in the system to remove the by-product water. It is desirable to carry out the reaction. As a result of intensive studies by the present inventor, using a Soxhlet extraction tube and a cooler, zeolite (molecular sieve) or calcium hydride was installed in the extraction tube as a dehydrating agent, and a catalyst, benzamide, and an organic solvent were placed in the reaction tube. The amount of benzonitrile produced can be improved by reacting at normal pressure with reflux. The organic solvent is preferably a substance having a boiling point of 130 ° C. or higher, and examples thereof include chlorobenzene, (o-, m-, p-) xylene, mesitylene and the like.

In the case of reflux using a Soxhlet extraction tube and a cooler, the periphery of the reaction tube is heated to 160 to 200 ° C. The melting point of each substance is 127 ° C. (benzamide), −13 ° C. (benzonitrile), −45 ° C. (organic solvent such as mesitylene), and the boiling point is 288 ° C. (benzamide), 188 ° C. (benzonitrile), Since the reaction phase is 100 ° C. (water) and 165 ° C. (organic solvent such as mesitylene), the reaction phase is all liquid except for the solid catalyst, and partially evaporated benzamide, by-product water, Cooled by a cooler, by-product water is adsorbed by a dehydrating agent, and benzamide and the organic solvent return to the reaction tube and contribute to the reaction again.

The solution after the reaction is recovered as a used catalyst 26 by separating only the catalyst in the catalyst separation tower 8 (fourth separation section) while being heated to 288 ° C. or higher, which is the melting point of benzamide, with low-pressure steam or the like. At this time, it can be easily recovered by a solid-liquid separation method such as normal filtration. After the catalyst separation, the boiling point of each substance present in the system is different as described above. Therefore, by distilling in the third distillation column 9 (fifth separation section), the benzonitrile 13 and the organic solvent are separated. 27, benzamide 28, and water 29 can be easily separated, and the organic solvent 27 and benzamide 28 can be returned to the previous stage of the third reaction column 7 and recycled. Further, the purified benzonitrile 13 is transported to the first reaction column 1 where the carbonate is produced by the transport unit, and is reused in the first reaction column 1.

(Other examples of carbonic acid ester production method and apparatus)
FIG. 3 shows another example of the preferred equipment of the present invention, and FIG. 4 shows the state of each substance in each process in the equipment of FIG. This equipment can also be used in the case of reaction conditions in which unreacted monohydric alcohol remains and by-products of methyl benzoate and methyl carbamate are generated. The basic configuration is the same as in the case of FIG. 1 described above, but the extract 17 extracted in the first extraction tower 2 includes carbonate, unreacted benzonitrile, alkane, methyl carbamate and benzoic acid. Contains methyl acid. The boiling point of each substance in the first distillation column 3 is 90 ° C. (for example, dimethyl carbonate), 215 ° C. (benzonitrile), 69 ° C. (for example, hexane), 65 ° C. (for example, methanol), 177 ° C. (Methyl carbamate) 233 ° C. (methyl benzoate), which is distilled by gradually increasing the temperature up to about 180 ° C., and the product carbonate 19 and the alkane used for extraction The mixture is separated into a mixture 33 of unreacted monohydric alcohol and methyl carbamate 32. Further, after distillation, cooling to about 30 to 100 ° C. solidifies methyl benzoate having a melting point of 103 ° C., so that it can be separated into solid and liquid with the filter 30 or the like, and unreacted benzonitrile 20, It can be separated into methyl benzoate 31. Moreover, since the mixture 33 of alkane and monohydric alcohol is mostly alkane, it can be reused as a solvent for extraction.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. First, the Example and comparative example of the manufacturing method of cyanopyridine are demonstrated.

Example 1
SiO _{2 as a} carrier (manufactured by Fuji Silysia, CARiACT, G-6, surface area: 535 m ² / g) was sized to 100 mesh or less and pre-baked at 700 ° C. for about 1 hour. Thereafter, in order to carry the Na as the alkali metal, finally _Na 2 CO ₃ as Na amount of metal supported is 0.5 mmol / g (manufactured by Kanto Kagaku, special grade) was used to adjust the aqueous solution, SiO ₂ Impregnated. Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 hours _to obtain a Na ₂ O / SiO 2 catalyst.

Therefore, a magnetic stir bar, the above catalyst (0.1 g), 2-picolinamide (2-PA, 1 mmol), and mesitylene (20 ml) were introduced into a test tube, and molecular sieve 4A (preliminarily dried at 300 ° C. for 1 hour). A filled Soxhlet extractor and Liebig condenser were connected, the temperature of the condenser was set to 10 ° C., and the magnetic stirrer was set to about 200 ° C. and 600 rpm. After purging the cooler, the Soxhlet extraction tube, and the inside of the test tube with Ar gas, the reaction start time was defined as the time when the solution started to evaporate, and the reaction was performed for 24 hours.
After the reaction, the test tube (solution) is cooled to room temperature, 20 ml of ethanol and anthracene (0.1 g) as an internal standard substance are added to the reaction solution, a sample is taken, and GC-MS (gas chromatograph-mass spectrometer) And quantitative analysis by FID-GC. As a result, as shown in Table 1, 0.42 mmol of 2-cyanopyridine (2-CP) was produced. The byproduct was only water, yield was 42%, and selectivity was 100%.

(Example 2)
Is similar to Example 1, the catalyst preparation, eventually Li metal support amount 0.5 mmol / g and composed as _Li 2 CO ₃ (manufactured by Kanto Kagaku, special grade) to adjust the aqueous solution with, SiO ₂ was impregnated. Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 hours _to obtain a Li ₂ O / SiO 2 catalyst. 2-CP was produced from 2-PA in the same manner as in Example 1 except that a Li ₂ O / SiO ₂ catalyst was used. As a result, as shown in Table 1, 0.43 mmol of 2-CP was produced. By-product was only water, yield was 43%, and selectivity was 100%.

Example 3
As in Example 1, but in the catalyst preparation, an aqueous solution was prepared using K ₂ CO ₃ (manufactured by Kanto Chemical Co., Ltd., special grade) so that the amount of supported K metal was 0.5 mmol / g, and SiO 2 It was impregnated to _2. Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 hours _to obtain K ₂ O / SiO 2 catalyst. 2-CP was produced from 2-PA in the same manner as in Example 1 except that a K ₂ O / SiO ₂ catalyst was used. As a result, as shown in Table 1, 0.42 mmol of 2-CP was produced. The byproduct was only water, yield was 42%, and selectivity was 100%.

Example 4
Is similar to Example 1, the catalyst preparation, finally Rb amount of metal supported is adjusted aqueous solution using a _Rb 2 CO ₃ (manufactured by Kanto Chemical) as a 0.5 mmol / g, the SiO ₂ Impregnated. Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 hours _to obtain Rb ₂ O / SiO 2 catalyst. 2-CP was produced from 2-PA in the same manner as in Example 1 except that the Rb ₂ O / SiO ₂ catalyst was used. As a result, as shown in Table 1, 0.43 mmol of 2-CP was produced. By-product was only water, yield was 43%, and selectivity was 100%.

(Example 5)
Although it is the same as that of Example 1, in the catalyst preparation, the aqueous solution was adjusted using Cs ₂ CO ₃ (manufactured by Kanto Chemical Co., 4N) so that the Cs metal loading was finally 0.5 mmol / g, and SiO 2 ₂ was impregnated. Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 hours _to obtain Cs ₂ O / SiO 2 catalyst. Cs but using ₂ O / SiO ₂ catalyst was prepared 2-CP from 2-PA as in Example 1. As a result, as shown in Table 1, 0.45 mmol of 2-CP was produced. The byproduct was only water, yield was 45%, and selectivity was 100%.

(Example 6)
As in Example 1, but in the catalyst preparation, Na ₂ CO ₃ (manufactured by Kanto Chemical Co., Ltd., special grade) and K are used so that the total amount of Na metal loading and K metal loading is finally 0.5 mmol / g. _{Using 2} CO ₃ (manufactured by Kanto Chemical Co., Ltd., special grade), the molar ratio was changed to prepare an aqueous solution, and SiO ₂ was impregnated. Thereafter, it was dried at 110 ° C. for about 6 hours and calcined at 500 ° C. for about 3 hours to obtain a Na ₂ O—K ₂ O / SiO ₂ catalyst. 2-CP was produced from 2-PA in the same manner as in Example 1 except that a Na ₂ O—K ₂ O / SiO ₂ catalyst was used. As a result, as shown in Table 2, 2-CP was produced at any molar ratio, the byproduct was only water, the yield was 41 to 43%, and the selectivity was 100%. From the above results, it was found that the amount of alkali metal used can be changed according to the market price.

(Comparative Example 1)
Example 1 except that only SiO ₂ (Fuji Silysia, CARiACT, G-6, surface area: 535 m ² / g) preliminarily calcined at 700 ° C. for about 1 hour was used as the catalyst. And so on. As a result, as shown in Table 3, 2-CP produced only 0.03 mmol and was very low in activity.

(Comparative Example 2)
The same procedure as in Example 1 was performed except that 1 mmol of Na ₂ CO ₃ (manufactured by Kanto Chemical Co., Ltd., special grade) was used as the catalyst. As a result, as shown in Table 3, 2-CP was not generated at all.

(Comparative Example 3)
The same procedure as in Example 1 was performed except that 1 mmol of Li ₂ CO ₃ (manufactured by Kanto Chemical Co., Ltd., special grade) was used as the catalyst. As a result, as shown in Table 3, 2-0.01 produced 2-CP only.

(Comparative Example 4)
The same procedure as in Example 1 was conducted except that 1 mmol of K ₂ CO ₃ (manufactured by Kanto Chemical Co., Ltd., special grade) was used as the catalyst. As a result, as shown in Table 3, 2-CP was not generated at all.

(Comparative Example 5)
The same procedure as in Example 1 was carried out except that 1 mmol of Rb ₂ CO ₃ (manufactured by Kanto Chemical) was used as the catalyst. As a result, as shown in Table 3, 2-CP was hardly generated.

(Comparative Example 6)
The same procedure as in Example 1 was performed except that 1 mmol of Cs ₂ CO ₃ (manufactured by Kanto Chemical Co., 4N) alone was used as the catalyst. As a result, as shown in Table 3, 2-CP produced only 0.01 mmol, and its activity was very low.
From the above results, it was found that a catalyst having an alkali metal oxide supported on a SiO ₂ carrier is effective.

(Example 7)
In the catalyst preparation, the final amount of Na metal supported was as shown in Table 4, and 5 mmol of 2-picolinamide (PA) was introduced, and the reaction time was 4 hours. The results are shown in Table 4.

From the above results, it was found that the amount of Na supported was high at 0.1 to 1 mmol / g, and about 0.5 mmol / g was particularly suitable.

(Example 8)
In the catalyst preparation, Examples were used except that CeO ₂ (manufactured by 1st rare element, HS, surface area: 74 m ² / g) was sized to 100 mesh or less and pre-fired at 500 ° C. for about 3 hours. Same as 5. As a result, as shown in Table 5, 0.11 mmol of 2-CP was produced. The byproduct was only water, yield was 11%, and selectivity was 100%.

Example 9
In the preparation of the catalyst, the same procedure as in Example 5 was performed except that ZrO ₂ (manufactured by the first rare element, surface area: 88 m ² / g) was sized to 100 mesh or less and used without preliminary firing. As a result, as shown in Table 5, 0.10 mmol of 2-CP was produced. The byproduct was only water, yield was 10%, and selectivity was 100%.

(Example 10)
In the catalyst preparation, for using the _CeO 2 -ZrO ₂ solid solution as a carrier, Ce _(NO _{3) 3} (manufactured by Kanto Chemical Co., Inc.) and Zr _(NO _{3) 4} dissolved (manufactured by Kanto Chemical) and so Ce is 20 atomic weight% An aqueous NaOH solution was introduced into the resulting solution to form a precipitate, which was filtered, washed with water, fired at 1000 ° C. in an air atmosphere for 3 hours, and then powdered solid solution (surface area: 65 m ² / g ) This solid solution was sized to 100 mesh or less, and the same procedure as in Example 5 was used except that a pre-baked product was used at 500 ° C. for about 3 hours. As a result, as shown in Table 5, 0.11 mmol of 2-CP was produced. The byproduct was only water, yield was 11%, and selectivity was 100%.

(Comparative Example 7)
In catalyst preparation, α-Al ₂ O ₃ (manufactured by Sumitomo Chemical Co., Ltd., KHO-24, surface area: 10 m ² / g) is sized to 100 mesh or less and pre-calcined at 1150 ° C. for about 3 hours. Were the same as in Example 5. As a result, as shown in Table 5, 2-CP produced only 0.03 mmol, and the activity was very low.

(Comparative Example 8)
In the catalyst preparation, MgO (Ube Industries, 500A, surface area: 30 m ² / g) was sized to 100 mesh or less and used in the same manner as in Example 5 except that it was used without preliminary firing. As a result, as shown in Table 5, 2-CP produced only 0.004 mmol and hardly reacted.

(Example 11)
Example 1 was repeated except that 5 mmol of 2-picolinamide (2-PA) as a reaction product was introduced and the reaction time was as shown in Table 6. The results are shown in Table 6.

From the above results, it was confirmed that the longer the reaction was, the more 2-cyanopyridine was produced, and when the reaction was carried out for 500 hours, the yield was 90% and the selectivity was 99%.

Example 12
Except for using o-xylene, m-xylene and p-xylene as solvents, the reaction was carried out under the same conditions as in Example 1 to produce 2-CP from 2-PA. As a result, as shown in Table 4, a certain amount of 2-CP was produced with any carrier.

(Example 13)
The reaction was carried out under the same conditions as in Example 1 except that nicotinamide and isonicotinamide were used as reactants instead of 2-PA, and 3-cyanopyridine (3-CP), 4-cyanopyridine (4-CP) ) Was manufactured. As a result, as shown in Table 8, regardless of whether nicotinamide or isonicotinamide was used as the reaction product, CP was generated, and the catalyst having the alkali metal oxide of the present invention supported on SiO ₂ or the like was It was found to be effective for the production of cyanopyridine by dehydration reaction.

(Comparative Example 9)
In the catalyst preparation, finally CaCO ₃ as Ca amount of metal supported is 0.5 mmol / g (manufactured by Kanto Kagaku, special grade) to adjust the aqueous solution was used to impregnate the SiO _2. Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 hours to obtain a CaO / SiO ₂ catalyst. Example 1 was repeated except that a CaO / SiO ₂ catalyst was used. As a result, as shown in Table 8a, 2-CP produced only 0.06 mmol and was very low in activity.
(Comparative Example 10)
In the catalyst preparation, an aqueous solution was prepared using BaCO ₃ (manufactured by Kanto Chemical Co., Ltd., special grade) so that the final supported amount of Ba metal was 0.5 mmol / g, and impregnated with SiO ₂ . Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 hours to obtain a BaO / SiO ₂ catalyst. Example 1 was repeated except that a BaO / SiO ₂ catalyst was used. As a result, as shown in Table 8a, 2-CP produced only 0.07 mmol and was very low in activity.
From the above results, it can be confirmed that the catalyst supporting the alkaline earth metal oxide that is basic as well as the alkali metal oxide has low activity, and the catalyst supporting the alkali metal oxide on SiO ₂ is effective. I found out that
(Comparative Example 11)
In the catalyst preparation, an aqueous solution was prepared using NH ₄ VO ₃ (manufactured by Sigma-Aldrich) so that the V metal loading was finally 0.5 mmol / g, and SiO ₂ was impregnated. Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 _hours, to obtain a V _₂ O 5 / SiO ₂ catalyst. Example 1 was repeated except that a V ₂ O ₅ / SiO ₂ catalyst was used. As a result, as shown in Table 8a, 2-CP is 0.06mmol only not produce very activity was lower in the case of the same level of only SiO ₂ of Comparative Example 1.

From the above results, it was found that even when a V-type catalyst having high activity in the dehydration reaction of benzamide was used for the dehydration reaction of 2-picolinamide, the reaction hardly proceeded.
In the above example, only 2-cyanopyridine and water were produced as by-products, and no other by-products were produced. Therefore, by distillation, 2-cyanopyridine, which is the desired product, The reacted 2-picolinamide can be recovered alone, and the unreacted 2-picolinamide can be used again as a reactant.

(Example 14)
Next, examples and comparative examples of benzonitrile will be described. SiO _{2 as a} carrier (manufactured by Fuji Silysia, CARiACT, G-6, surface area: 535 m ² / g) was sized to 100 mesh or less and pre-baked at 700 ° C. for about 1 hour. Thereafter, in order to support Mo as a metal, an aqueous solution was prepared using (NH ₄ ) ₆ Mo ₇ O ₂₄ (manufactured by Kanto Kagaku, special grade) so that the Mo support amount was finally 0.5 mmol / g. And impregnated with SiO ₂ . Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 _hours, to obtain a MoO 3 / SiO ₂ catalyst.

Therefore, a magnetic stir bar, the above catalyst (0.1 g), benzamide (hereinafter referred to as BA. 20 mmol), and mesitylene (20 ml) were introduced into a test tube, and molecular sieve 4A (pre-dried at 300 ° C. for 1 hour) was filled. The Soxhlet extractor and Liebig condenser were connected, the temperature of the condenser was set to 10 ° C., and the magnetic stirrer was set to about 200 ° C. and 600 rpm. After purging the cooler, the Soxhlet extraction tube, and the inside of the test tube with Ar gas, the reaction start time was defined as the time when the solution started to evaporate, and the reaction was performed for 24 hours.

After the reaction, the test tube (solution) is cooled to room temperature, 20 ml of ethanol and anthracene (0.1 g) as an internal standard substance are added to the reaction solution, a sample is taken, and GC-MS (gas chromatograph-mass spectrometer) And quantitative analysis by FID-GC. As a result, as shown in Table 9, 5 mmol of benzonitrile (hereinafter referred to as BN) was produced. The byproduct was only water, yield was 25%, and selectivity was 100%.

(Example 15)
Similar to Example 14, but in the catalyst preparation, an aqueous solution was used using (NH ₄ ) ₆ W ₁₂ O ₄₁ (manufactured by Kanto Chemical Co., Ltd., deer grade 1) so that the final W loading was 0.5 mmol / g. Was prepared and impregnated with SiO ₂ . Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 hours _to obtain WO 3 / SiO ₂ catalyst. BN was produced from BA in the same manner as in Example 14 except that a WO ₃ / SiO ₂ catalyst was used. As a result, as shown in Table 9, 3 mmol of BN was generated. By-product was only water, yield was 15%, and selectivity was 100%.

(Example 16)
As in Example 14, but in the catalyst preparation, the aqueous solution was adjusted using NH ₄ ReO ₄ (manufactured by Mitsuwa Chemicals) so that the final amount of Re supported was 0.5 mmol / g, and SiO ₂ Impregnated. Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 hours _to obtain a Re _₂ O 7 / SiO ₂ catalyst. Benzonitrile (BN) was produced from benzamide (BA) in the same manner as in Example 14 except that the Re ₂ O ₇ / SiO ₂ catalyst was used. As a result, as shown in Table 9, 1 mmol of BN was generated. The byproduct was only water, yield was 5%, and selectivity was 100%.

(Example 17)
As in Example 14, except that in the catalyst preparation, an aqueous solution was prepared using TiCl ₃ (manufactured by Kanto Chemical Co., Ltd., deer grade 1) so that the Ti loading amount was finally 0.5 mmol / g, and the SiO ₂ Impregnated. Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 hours _to obtain a TiO 2 / SiO ₂ catalyst. BN was produced from BA in the same manner as in Example 14 except that a TiO ₂ / SiO ₂ catalyst was used. As a result, as shown in Table 9, 1 mmol of BN was generated. The byproduct was only water, yield was 5%, and selectivity was 100%.

(Example 18)
As in Example 14, but in the catalyst preparation, (NH ₄ ) ₃ (NbO (C ₂ O ₄ ) ₃ ) (manufactured by Sigma-Aldrich, so that the Nb supported amount is finally 0.5 mmol / g, The aqueous solution was prepared using 4N) and impregnated with SiO ₂ . Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 hours _to obtain a Nb ₂ O 5 / SiO ₂ catalyst. BN was produced from BA in the same manner as in Example 14 except that the Nb ₂ O ₅ / SiO ₂ catalyst was used. As a result, as shown in Table 9, 1 mmol of BN was generated. The byproduct was only water, yield was 5%, and selectivity was 100%.

(Example 19)
SiO ₂ (manufactured by Fuji Silysia, CARiACT, G-3, surface area: 700 m ² / g) serving as a carrier was sized to 100 mesh or less and pre-baked at 700 ° C. for about 1 hour. Thereafter, in catalyst preparation, SiO ₂ was impregnated using (NH ₄ ) ₆ Mo ₇ O ₂₄ (manufactured by Kanto Chemical Co., Ltd., special grade) so that the Mo loading amount finally became as shown in Table 10. Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 _hours, to obtain a MoO 3 / SiO ₂ catalyst. BN was produced from BA in the same manner as in Example 14 except that the supported amount of the MoO ₃ / SiO ₂ catalyst was changed. As a result, as shown in Table 10, at any molar ratio, BN is generated, the byproduct is only water, and the amount of generation increases as the amount of Mo loaded increases, but there is a tendency to saturate above a certain level. It was.

(Example 20)
Carrier TiO ₂ (manufactured by Nippon Aerosil Co., P25, surface ^{area: 50m 2 / g), ZrO} 2 ( Daiichi Kigenso made, surface ^{area: 88m 2 / g), CeO} 2 ( Daiichi Kigenso made, surface area: ^74m 2 / g), Al ₂ O ₃ (manufactured by Sumitomo Chemical Co., Ltd., KHO, surface area: 10 m ² / g), carbon black (manufactured by Cabot, Vulcan, XC-72, surface area: 254 m ² / g), and the amount of supported Mo is 0. Each support was impregnated with (NH ₄ ) ₆ Mo ₇ O ₂₄ (manufactured by Kanto Chemical Co., Ltd., special grade) so as to be 19 mmol / g. BN was produced from BA in the same manner as in Example 14 using the catalyst thus prepared. As a result, as shown in Table 11, a fixed amount of BN was produced with any carrier.

(Example 21)
Except for using o-xylene, m-xylene, p-xylene and chlorobenzene as the solvent, the reaction was carried out under the same conditions as in Example 14 to produce BN from BA. As a result, as shown in Table 12, a fixed amount of BN was produced with any carrier.

(Example 22)
Evaluation was performed in the same manner as in Example 14 except that no dehydrating agent was used. As a result, after the reaction for 24 hours, the yield was 10% and the selectivity was almost 100%.

(Comparative Example 12)
Except carrying 0.5 mmol of Mn, Ce, and Zr as respective catalysts using respective aqueous solutions of Mn (NO ₃ ) ₂ , Ce (NH ₄ ) ₂ (NO ₃ ) ₆ , and ZrO (NO ₃ ) ₂ Same as Example 14. As a result, BN was not detected in any case and showed no activity.

(Comparative Example 13)
An aqueous solution was prepared using NH ₄ VO ₃ (manufactured by Sigma-Aldrich) as a catalyst, and V ₂ was impregnated with SiO ₂ . Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 _hours, to obtain a V _₂ O 5 / SiO ₂ catalyst. The same operation as in Example 14 was performed except that a V ₂ O ₅ / SiO ₂ catalyst was used. As a result, BN produced only 0.01 mmol and was very low in activity. From these results, it was found that even with a V-type catalyst as described in Non-Patent Document 5, the benzamide dehydration reaction hardly progressed under mild conditions such as the present reaction conditions.

(Comparative Example 14)
The same procedure as in Example 14 was performed, except that only MgO (sized by Ube Industries, 500A, surface area: 28 m ² / g) which had been sized to 100 mesh or less and pre-fired at 700 ° C. for about 1 hour was used as the catalyst. As a result, BN was not generated at all.

In the above examples, benzonitrile and water were only produced as by-products, but no other by-products were produced. Therefore, by distillation, the target product, benzonitrile, by-product water, and unreacted benzamide were obtained. It can be recovered alone and unreacted benzamide can be used again as a reactant.

(Example 23)
Next, the Example of the manufacturing method of carbonate ester using cyanopyridine is demonstrated. Carbonate was produced using the production apparatus shown in FIG. CeO ₂ (manufactured by the first rare element: impurity concentration of 0.02% or less) was calcined at 873 K in an air atmosphere for 3 hours to obtain a powdered solid catalyst. Therefore, a magnetic stirrer, the above solid catalyst (1 mmol), methanol (100 mmol) and 2-cyanopyridine (2-CP, 50 mmol) were introduced into a 190 ml autoclave (reactor), and about 5 g of CO ₂ in the autoclave. After purging air three times, a predetermined amount of CO ₂ was introduced and pressurized. The autoclave was heated to 120 ° C. with a band heater and a hot stirrer, and the time when the target temperature was reached was defined as the reaction start time. After reacting at 120 ° C. for 12 hours, the autoclave was cooled with water, and after cooling to room temperature, the pressure was reduced and 0.2 mL of 1-hexanol as an internal standard substance was added, and the product was collected and analyzed by GC (gas chromatography). . In this way, test Nos. Shown in Table 13 were performed by changing the amount of CO ₂ introduced and the reaction pressure. 37-40 experiments were performed.

As a result, dimethyl carbonate (DMC) was produced even at 0.08 MPa below normal pressure, and the DMC yield based on methanol was 34.8% at 0.08 MPa, 44.4% at 0.2 MPa, 58 at 1 MPa. %, It was confirmed that it was obtained at 86% at 5 MPa. The amount of by-product 2-picolinamide (2-PA) produced was almost the same as DMC, and no other by-products were detected.

Here, the yield based on methanol (alcohol) was calculated by the following formula because the stoichiometric ratio was alcohol: carbonate = 2: 1.

Next, 200 ml of hexane was added to the solid-liquid coexisting substance after each test, and the mixture was stirred, extracted with a solvent, and filtered through a filter to separate a liquid and a solid. The liquid includes DMC, 2-CP, methanol, and hexane, and the solid includes 2-PA and CeO ₂ . The liquid component after solvent extraction with hexane can be separated into DMC, 2-CP, hexane and methanol by distillation that gradually increases the temperature to about 120 ° C., and DMC with a purity of 96% or more can be recovered. It was. In addition, 2-PA and CeO ₂ in the solid component are dissolved in 200 ml of acetone and filtered through a filter to separate CeO ₂ , 2-PA and acetone, and 2-PA and acetone are separated by distillation. As a result, 2-PA having a purity of 97% or more was recovered.

Subsequently, the recovery from the recovered 2-PA to 2-CP will be described below. SiO _{2 as a} carrier (manufactured by Fuji Silysia, CARiACT, G-6, surface area: 535 m ² / g) was sized to 100 mesh or less and pre-baked at 700 ° C. for about 1 hour. Thereafter, in order to carry the Na as the alkali metal, finally _Na 2 CO ₃ as Na amount of metal supported is 0.5 mmol / g (manufactured by Kanto Kagaku, special grade) was used to adjust the aqueous solution, SiO ₂ Impregnated. Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 hours _to obtain a Na ₂ O / SiO 2 catalyst. Therefore, a magnetic stir bar, the above catalyst (0.1 g), 2-PA produced as a byproduct of DMC generation, and mesitylene (20 ml) were introduced into a test tube, and molecular sieve 4A (pre-dried at 300 ° C. for 1 hour) was filled. A Soxhlet extractor and a Liebig condenser were connected, the temperature of the condenser was set to 10 ° C., and the magnetic stirrer was set to about 200 ° C. and 600 rpm. After purging the cooler, the Soxhlet extraction tube, and the test tube with Ar gas, the reaction start time was defined as the time when the solution started to evaporate, and the reaction was performed for 500 hours. After the reaction, the test tube (solution) is cooled to room temperature, 20 ml of ethanol and anthracene (0.1 g) as an internal standard substance are added to the reaction solution, a sample is taken, and GC-MS (gas chromatograph-mass spectrometer) And quantitative analysis by FID-GC. In this way, as shown in Table 13, the test No. When 37 to 40 were carried out, 2-CP was produced at 16.1, 20.7, 26.6, and 37.8 mmol, respectively. In all experiments, water was the only byproduct, yield was 90%, and selectivity was 100%.

The solid-liquid coexisting substance after the above test was filtered with a filter under heating at 120 ° C. to separate the liquid and the solid (catalyst). Liquids include 2-CP, water, unreacted 2-PA, and mesitylene. This liquid component is separated into 2-CP, water, unreacted 2-PA, and mesitylene by distillation that gradually increases the temperature to about 180 ° C., and 2-CP having a purity of 98% or more is recovered. I was able to. The separated unreacted 2-PA and mesitylene can be recycled again for 2-PA dehydration reaction.

A second DMC production reaction was performed using 2-CP regenerated in this way. The reaction conditions were the same, and a small amount of new 2-CP was added to 2-CP that was regenerated and 2-CP that had not been reacted in the first reaction, so that the amount of 2-CP was 50 mmol. did. As a result, as in the first time, it was confirmed that DMC was obtained in a high yield, and the amount of 2-PA produced as a by-product was almost the same as DMC, and other by-products were not detected at all. There wasn't.

From the above results, 50 mmol of new 2-CP is required at the start of the reaction, but it can be recovered by reusing from separated unreacted 2-CP and by-produced 2-PA to 2-CP. Conventionally, it is possible to reduce most of 2-CP required for generating DMC. In addition, 2-PA can be used as an intermediate for medicines and agrochemicals, but the amount used is not so much, and the disposal cost was high, and it was possible to reduce more than 90%. Furthermore, since the temperature is raised to about 180 ° C. when regenerated and distilled from 2-PA to 2-CP, this can be achieved by supplying it through a heated pipe when reusing it for DMC production. Heat can be used.

(Example 24)
Example 23 was repeated except that ethanol (100 mmol) was used as a monohydric alcohol.

From the results shown in Table 14, in the case of diethyl carbonate (DEC), the DEC yield based on ethanol is 32.8% at 0.08 MPa, 41.8% at 0.2 MPa, 50 at 1 MPa. % And 5 MPa, it was confirmed to be obtained at 81%. The amount of 2-PA produced as a by-product was almost the same as DEC, and no other by-products were detected.

Next, in the same manner as in Example 23, 200 ml of hexane was added to the solid-liquid coexisting substance after each test, followed by stirring, solvent extraction, and filtration through a filter to separate the liquid and the solid. Liquids, DEC, 2-CP, ethanol, hexane, the solid, include 2-PA and CeO _2. The liquid component after solvent extraction with hexane can be separated into DEC, 2-CP, hexane and ethanol by distillation that gradually increases the temperature to about 130 ° C, and DEC with a purity of 96% or more can be recovered. It was. In addition, 2-PA and CeO ₂ in the fixed component are dissolved in 200 ml of acetone and filtered through a filter to separate CeO ₂ , 2-PA and acetone, and 2-PA and acetone are separated by distillation. As a result, 2-PA having a purity of 97% or more was recovered.

Subsequently, regeneration from the recovered 2-PA to 2-CP was performed in the same manner as in Example 23. As a result, as shown in Table 14, test no. When 41 to 44 were carried out, 2-CP was produced at 15.5, 19.9, 21.8, and 39.1 mmol, respectively. In all experiments, the byproduct was only water, yield was 90% or more, and selectivity was 100%.

As for the solid-liquid coexisting substance after the above test, each liquid and solid was separated in the same manner as in Example 1, and 2-CP having a purity of 98% or more could be recovered.

Using the 2-CP regenerated in this way, a second DEC generation reaction was performed. The reaction conditions were the same as in Example 1, and a small amount of new 2-CP was added to 2-CP obtained by regeneration with unreacted 2-CP so that the amount of 2-CP was 50 mmol. did. As a result, as in the first time, it was confirmed that DEC was obtained in a high yield, and the amount of 2-PA produced as a by-product was almost the same as DEC, and other by-products were not detected at all. There wasn't.

Even when the monohydric alcohol is ethanol and the product is DEC, it is possible to reduce most of the 2-CP required to produce DEC, and reduce 90% or more of 2-PA, which has been discarded. It has become possible. Furthermore, since the temperature is increased to about 180 ° C when regenerating and distilling from 2-PA to 2-CP, this can be achieved by supplying it through a heated pipe when reusing it for DEC production. Heat can be used.

(Example 25)
The same procedure as in Example 23 was performed except that 1-propanol (100 mmol) was used as the monohydric alcohol and the reaction was performed for 24 hours.

From the results in Table 15, the yield of DPrC based on 1-propanol is 18.2% at 0.08 MPa, 23.2% at 0.2 MPa, 1 MPa, although not as much as DMC in the case of dipropyl carbonate (DPrC). It was confirmed that it was sometimes obtained at 30.8% and at 45 MPa at 5 MPa. The amount of 2-PA produced as a by-product was almost the same as DPrC, and no other by-products were detected.

Next, in the same manner as in Example 23, 200 ml of hexane was added to the solid-liquid coexisting substance after each test, followed by stirring, solvent extraction, and filtration through a filter to separate the liquid and the solid. The liquid contains DPrC, 2-CP, 1-propanol and hexane, and the solid contains 2-PA and CeO ₂ . The liquid component after solvent extraction with hexane is separated into DPrC, 2-CP, hexane, and 1-propanol by distillation that gradually increases the temperature to about 170 ° C., and DPrC having a purity of 96% or more is recovered. I was able to. In addition, 2-PA and CeO ₂ in the fixed component are dissolved in 200 ml of acetone and filtered through a filter to separate CeO ₂ , 2-PA and acetone, and 2-PA and acetone are separated by distillation. As a result, 2-PA having a purity of 97% or more was recovered.
Subsequently, regeneration from the recovered 2-PA to 2-CP was performed in the same manner as in Example 1. As a result, as shown in Table 15, test no. When 45 to 48 were carried out, 2-CP was produced at 9.5, 12.2, 15.4 and 21.4 mmol, respectively. In all experiments, the byproduct was only water, yield was 90% or more, and selectivity was 100%.

Using the 2-CP regenerated in this way, a second DPrC production reaction was performed. The reaction conditions were the same as in Example 1, and a small amount of new 2-CP was added to 2-CP obtained by regeneration with unreacted 2-CP so that the amount of 2-CP was 50 mmol. did. As a result, as in the first time, it was confirmed that DPrC was obtained in high yield, and the amount of 2-PA produced as a by-product was almost the same as DPrC, and other by-products were not detected at all. There wasn't.

Even when the monohydric alcohol is 1-propanol and the product is DPrC, it is possible to reduce most of the 2-CP required for the production of DPrC. More reductions were possible. Furthermore, since the temperature is raised to about 180 ° C. when regenerated and distilled from 2-PA to 2-CP, this can be achieved by supplying it through a heated pipe when reusing it for DPrC production. Heat can be used.

(Example 26)
Example 23 was repeated except that 2-propanol (100 mmol) was used as a monohydric alcohol and the reaction was performed for 24 hours.

From the results shown in Table 16, in the case of diisopropyl carbonate (DiPrC), the DPrC yield based on 2-propanol was 4.4% at 0.08 MPa and 5.6 at 0.2 MPa. %, 1 MPa, 7.2%, and 5 MPa, 10.8%. The amount of 2-PA produced as a by-product was almost the same as DiPrC, and no other by-products were detected.

Next, in the same manner as in Example 23, 200 ml of hexane was added to the solid-liquid coexisting substance after each test, followed by stirring, solvent extraction, and filtration through a filter to separate the liquid and the solid. The liquid includes DiPrC, 2-CP, 2-propanol, and hexane, and the solid includes 2-PA and CeO ₂ . The liquid component after solvent extraction with hexane is separated into DiPrC, 2-CP, hexane, and 2-propanol by distillation that gradually increases the temperature to about 170 ° C., and DiPrC having a purity of 96% or more is recovered. I was able to. In addition, 2-PA and CeO ₂ in the fixed component are dissolved in 200 ml of acetone and filtered through a filter to separate CeO ₂ , 2-PA and acetone, and 2-PA and acetone are separated by distillation. As a result, 2-PA having a purity of 97% or more was recovered.

Subsequently, regeneration from the recovered 2-PA to 2-CP was performed in the same manner as in Example 23. As a result, as shown in Table 16, test no. When 49 to 52 were conducted, 2-CP was produced in 2.1, 2.7, 3.4, and 4.7 mmol, respectively. In all experiments, the byproduct was only water, yield was 90% or more, and selectivity was 100%.

As for the solid-liquid coexisting substance after the above test, each liquid and solid was separated in the same manner as in Example 23, and 2-CP having a purity of 98% or more could be recovered.

Using the 2-CP regenerated in this way, a second DiPrC production reaction was performed. The reaction conditions were the same as in Example 23, and a small amount of new 2-CP was added to 2-CP obtained by regeneration with unreacted 2-CP so that the amount of 2-CP was 50 mmol. did. As a result, as in the first time, it was confirmed that DiPrC was obtained in a high yield, and the amount of 2-PA produced as a by-product was almost the same as DiPrC, and other by-products were not detected at all. There wasn't.

Even when the monohydric alcohol is 2-propanol and the product is DiPrC, it is possible to reduce most of the 2-CP required for the production of DiPrC. More reductions were possible. Furthermore, since the temperature is raised to about 180 ° C. when regenerated and distilled from 2-PA to 2-CP, this can be achieved by supplying it through a heat-insulated pipe when reused for DiPrC production. Heat can be used.

(Example 27)
Example 23 was repeated except that 1-butanol (100 mmol) was used as a monohydric alcohol and the reaction was performed for 24 hours.

From the results shown in Table 17, the yield of DBtC based on 1-butanol is 16.4% at 0.08 MPa, 21.0% at 0.2 MPa, 1 MPa, although not as high as DMC in the case of dibutyl carbonate (DBtC). It was confirmed that 29.0% was sometimes obtained and 40.6% was obtained at 5 MPa. The amount of 2-PA produced as a by-product was almost the same as DBtC, and no other by-products were detected.

Next, in the same manner as in Example 23, 200 ml of hexane was added to the solid-liquid coexisting substance after each test, followed by stirring, solvent extraction, and filtration through a filter to separate the liquid and the solid. The liquid contains DBtC, 2-CP, 1-butanol and hexane, and the solid contains 2-PA and CeO ₂ . The liquid component after solvent extraction with hexane first separates hexane and 1-butanol by distillation that gradually increases the temperature to about 120 ° C., and then cools to about 0 ° C. As a result, DBC having a purity of 96% or more was recovered. In addition, 2-PA and CeO ₂ in the fixed component are dissolved in 200 ml of acetone and then filtered through a filter to separate CeO ₂ , 2-PA and acetone, and 2-PA and acetone are separated by distillation. The 2-PA having a purity of 97% or more was recovered.

Subsequently, regeneration from the recovered 2-PA to 2-CP was performed in the same manner as in Example 23. As a result, as shown in Table 17, test no. When 53 to 56 were conducted, 2-CP was produced at 8.8, 11.3, 14.1, and 20.3 mmol, respectively. In all experiments, the byproduct was only water, yield was 90% or more, and selectivity was 100%.

Using the 2-CP regenerated in this way, a second DBtC production reaction was performed. The reaction conditions were the same as in Example 23, and a small amount of new 2-CP was added to 2-CP obtained by regeneration with unreacted 2-CP so that the amount of 2-CP was 50 mmol. did. As a result, as in the first time, it was confirmed that DBtC was obtained in high yield, and the amount of 2-PA produced as a by-product was almost the same as DBtC, and other by-products were not detected at all. There wasn't.

Even in the case where the monohydric alcohol is 1-butanol and the product is DBtC, it is possible to reduce most of the 2-CP required for the production of DBtC. More reductions were possible. Furthermore, since the temperature is increased to about 180 ° C. when regenerating and distilling from 2-PA to 2-CP, this can be achieved by supplying it through a heated pipe when reusing it for DBtC production. Heat can be used.

(Example 28)
The same procedure as in Example 23 was performed except that allyl alcohol (100 mmol) was used as a monohydric alcohol and the reaction was performed for 24 hours.

From the results of Table 18, the case of diallyl carbonate (DAC) is not as high as that of DMC, but the DAC yield based on allyl alcohol is 8.8% at 0.08 MPa, 11.2% at 0.2 MPa, and 1 MPa at 0.2 MPa. It was confirmed that it was obtained at 21.6% at 14.6% and 5 MPa. The amount of 2-PA produced as a by-product was almost the same as that of DAC, and no other by-products were detected.

Next, in the same manner as in Example 23, 200 ml of hexane was added to the solid-liquid coexisting substance after each test, followed by stirring, solvent extraction, and filtration through a filter to separate the liquid and the solid. The liquid contains DAC, 2-CP, allyl alcohol, and hexane, and the solid contains 2-PA and CeO ₂ . The liquid component after solvent extraction with hexane first separates hexane and allyl alcohol by distillation that gradually increases the temperature to about 120 ° C, and then cools to about 0 ° C to precipitate 2-CP. As a result, DAC having a purity of 96% or more was recovered. In addition, 2-PA and CeO ₂ in the fixed component are dissolved in 200 ml of acetone and then filtered through a filter to separate CeO ₂ , 2-PA and acetone, and 2-PA and acetone are separated by distillation. The 2-PA having a purity of 97% or more was recovered.

Subsequently, regeneration from the recovered 2-PA to 2-CP was performed in the same manner as in Example 23. As a result, as shown in Table 18, test no. When 57 to 60 were carried out, 4.1, 5.3, 6.8, and 9.5 mmol of 2-CP were produced, respectively. In all experiments, the byproduct was only water, yield was 90% or more, and selectivity was 100%.

Using the 2-CP regenerated in this way, a second DAC generation reaction was performed. The reaction conditions were the same as in Example 23, and a small amount of new 2-CP was added to 2-CP obtained by regeneration with unreacted 2-CP so that the amount of 2-CP was 50 mmol. did. As a result, as in the first time, it was confirmed that DAC was obtained in high yield, and the amount of 2-PA produced as a by-product was almost the same as DAC, and other by-products were not detected at all. There wasn't.

Even when the monohydric alcohol is allyl alcohol and the product is DAC, it is possible to reduce most of the 2-CP required to produce DAC, and more than 90% of 2-PA that has been disposed of in the past. It became possible to reduce. Furthermore, since the temperature is raised to about 180 ° C. when regenerated and distilled from 2-PA to 2-CP, this can be achieved by supplying it through a heated pipe when reusing it for DAC production. Heat can be used.

(Example 29)
The same procedure as in Example 23 was performed except that benzyl alcohol (100 mmol) was used as a monohydric alcohol and the reaction was performed for 24 hours.

From the results in Table 19, the yield of DBnC based on benzyl alcohol is 13.0% at 0.08 MPa, 16.6% at 0.2 MPa, 16.6% at 1 MPa, and 1 MPa at the time of dibenzyl carbonate (DBnC). It was confirmed that it was obtained at 31.8% at 21.8% and 5 MPa. The amount of 2-PA produced as a by-product was almost the same as that of DBnC, and no other by-products were detected.

Next, in the same manner as in Example 23, 200 ml of hexane was added to the solid-liquid coexisting substance after each test, followed by stirring, solvent extraction, and filtration through a filter to separate the liquid and the solid. Liquids, DBnC, 2-CP, benzyl alcohol, hexane, the solid, include 2-PA and CeO _2. The liquid component after solvent extraction with hexane first separates hexane and benzyl alcohol by distillation that gradually increases the temperature to about 120 ° C, and then cools to about 0 ° C to precipitate 2-CP. DBnC having a purity of 96% or higher was recovered. In addition, 2-PA and CeO ₂ in the fixed component are dissolved in 200 ml of acetone and then filtered through a filter to separate CeO ₂ , 2-PA and acetone, and 2-PA and acetone are separated by distillation. The 2-PA having a purity of 97% or more was recovered.

Subsequently, regeneration from the recovered 2-PA to 2-CP was performed in the same manner as in Example 23. As a result, as shown in Table 19, test no. When 61 to 64 were conducted, 2-CP was produced in 6.2, 7.9, 10.2, and 14.2 mmol, respectively. In all experiments, the byproduct was only water, yield was 90% or more, and selectivity was 100%.

Using the 2-CP regenerated in this way, a second DBnC production reaction was performed. The reaction conditions were the same as in Example 23, and a small amount of new 2-CP was added to 2-CP obtained by regeneration with unreacted 2-CP so that the amount of 2-CP was 50 mmol. did. As a result, as in the first time, it was confirmed that DBnC was obtained in a high yield, and the amount of 2-PA produced as a by-product was almost the same as DBnC, and other by-products were not detected at all. There wasn't.

Even when the monohydric alcohol is benzyl alcohol and the product is DBnC, it is possible to reduce most of the 2-CP required for the production of DBnC. It became possible to reduce. Furthermore, since the temperature is raised to about 180 ° C. when regenerated and distilled from 2-PA to 2-CP, this can be achieved by supplying it through a heated pipe when reusing it for DAC production. Heat can be used.

(Example 30)
In the catalyst preparation in reproduction from the recovered 2-PA to 2-CP, the other catalyst was a _{_{_{_{Li 2 O / SiO 2, K}}}} 2 O / SiO 2, Rb 2 O / SiO 2, Cs 2 O / SiO 2 Is the same test No. as in Example 23. 65-72 was performed. The catalyst carrier described above was used, and the catalyst was supported on the catalyst carrier according to the method described above.

From the results in Table 20, it was found that even when the alkali metal was Li, K, Rb, or Cs, the yield was around 90% and the selectivity was 100%.

(Example 31)
In the catalyst preparation in the regeneration from the recovered 2-PA to 2-CP, Na ₂ CO ₃ (manufactured by Kanto Chemical Co., Ltd.) so that the total amount of the Na metal loading and the K metal loading is finally 0.5 mmol / g. , Special grade) and K ₂ CO ₃ (manufactured by Kanto Chemical Co., Ltd., special grade) were used to adjust the aqueous solution by changing the molar ratio and impregnated with SiO ₂ . Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 hours to obtain a _{_{Na 2 O-K 2 O /}} SiO 2 catalyst. As in Example 23, except that a Na ₂ O—K ₂ O / SiO ₂ catalyst was used, NO. 73-80 tests were conducted. As a result, as shown in Table 21, 2-CP was produced at any molar ratio, the by-product was only water, the yield was around 90%, and the selectivity was 100%. From the above results, it was found that the amount of alkali metal used can be changed according to the market price.

(Example 32)
In the catalyst preparation in the regeneration from recovered 2-PA to 2-CP, NO is the same as in Example 23 except that the final amount of supported Na metal is as shown in Table 22 and the reaction pressure is only 1 MPa. . 81-88 tests were conducted. As a result, as shown in Table 22, it was found that Na supported amount showed high activity at 0.1 to 1 mmol, and about 0.5 mmol was a suitable supported amount. On the other hand, it is confirmed that when the loading amount is too large, the activity is lowered. This is because the structure of the SiO ₂ carrier is changed due to the loading of a large amount of Na oxide, and the surface area is greatly reduced. It was assumed that the oxide was also a large aggregate.

In Examples 23 to 29, Na ₂ O / SiO ₂ catalyst was used in the regeneration reaction from 2-PA to 2-CP, but any of Li, Na, K, Rb, and Cs was used as the alkali metal. One or two of these are prepared by adjusting the aqueous solution so that the final concentration is 0.5 mmol / g, then impregnating with SiO ₂ , drying at 110 ° C. for about 6 hours, and baking at 500 ° C. for about 3 hours. Even when a catalyst was used, the same effect was obtained. In addition to SiO ₂ , the same effect was obtained when CeO ₂ , ZrO ₂ , or CeO ₂ —ZrO ₂ was used in addition to SiO ₂ .

(Comparative Example 15)
In the DMC production reaction, the same procedure as in Example 23 was performed except that acetonitrile (AN, 300 mmol) was introduced as a wettable powder and the reaction was performed at 150 ° C. for 24 hours.

From the results of Table 23, when AN is used, the amount of DMC produced is about 1/10 lower than that of 2-CP, and the DMC yield based on methanol is 8.2% at 0.5 MPa. The best results indicate that the present invention is more efficient. The amount of by-product acetamide (AA) produced was almost the same as that of DMC, and no other by-products were detected.

Next, in the same manner as in Example 23, 200 ml of hexane was added to the solid-liquid coexisting substance after each test, followed by stirring, solvent extraction, and filtration through a filter to separate the liquid and the solid. The liquid contains DMC, unreacted AN, methanol, and hexane, and the solid contains AA and CeO ₂ . Since the liquid component after solvent extraction with hexane has a melting point and boiling point of AN of -45 ° C and 82 ° C, respectively, DMC and AN cannot be separated by distillation, so it is once cooled to -30 to 0 ° C It is possible to separate the precipitated DMC. Thereafter, when distillation is performed by raising the temperature to about 70 ° C., a mixture of methanol and hexane and unreacted AN can be separated. The unreacted AN can be reused for the DMC formation reaction. Since the concentration of methanol contained in the mixture is high, it is difficult to reuse it as a solvent for extraction, and it is necessary to dispose of it. In addition, AA and CeO ₂ in the fixed component are dissolved in 100 ml of acetone and filtered through a filter to separate CeO ₂ , AA and acetone, and AA and acetone are separated by distillation heated to about 70 ° C. As a result, AA having a purity of 95% or more was recovered.

Subsequently, regeneration from the collected AA to AN was performed in the same manner as in Example 23. As a result, as shown in Table 23, the test No. When 89 to 91 were performed, there was almost no reaction. This is considered that since the solid catalyst is basic while AA is acidic, AA poisons the active sites on the solid catalyst and the reaction does not proceed.

Therefore, since the AA produced as a by-product could not be dehydrated and the AN could not be regenerated, the second DMC formation reaction was performed by adding new AN to the unreacted AN so that the amount of AN was 300 mmol. The reaction was conducted in the same manner as in Example 23 except that the reaction was performed at 150 ° C. for 24 hours. As a result, as in the first time, the amount of DMC produced was reduced to about 1/10 compared to the case of 2-CP, and the DMC yield based on methanol was the highest at 8.0% at 0.5 MPa. It became.

(Comparative Example 16)
Test NO. 2 was conducted under the same conditions as in Example 23 except that the regeneration step from 2-PA to 2-CP and the separation step after the regeneration step were not performed. 92 and 93 were performed. As a result, DMC with a purity of 96% or more and 2-PA with a purity of 97% or more could be recovered, but 2-PA had almost no use and was treated as industrial waste. In addition, the second DMC production reaction newly required at least 29.2 or 42.0 mmol of 2-CP, leading to an increase in raw material costs.

(Comparative Example 17)
In the regeneration reaction from the recovered 2-PA to 2-CP, SiO ₂ (size of 100 mesh or less and pre-calcined at 700 ° C. for about 1 hour as a catalyst (carried by Fuji Silysia, CARiACT, G-6, surface area: 535 m ² / g) was used, and the same procedure as in Example 23 was performed except that the reaction pressure was only 1 MPa. As a result, as shown in Table 25 (NO. 94), 2-CP produced only 0.05 mmol, and its activity was very low.

(Comparative Example 18)
In the regeneration reaction from recovered 2-PA to 2-CP, the same as Example 23, except that only 1 mmol of Na ₂ CO ₃ (manufactured by Kanto Chemical Co., Ltd., special grade) was used as the catalyst, and the reaction pressure was only 1 MPa. I made it. As a result, as shown in Table 25 (NO. 95), 2-CP was not produced at all.

(Comparative Example 19)
In the regeneration reaction from recovered 2-PA to 2-CP, the same as Example 23, except that 1 mmol of K ₂ CO ₃ (manufactured by Kanto Chemical Co., Ltd., special grade) was used as the catalyst, and the reaction pressure was only 1 MPa. I made it. As a result, as shown in Table 25 (NO. 96), 2-CP was not produced at all.

(Comparative Example 20)
In the regeneration reaction from recovered 2-PA to 2-CP, the same procedure as in Example 23 was performed except that 1 mmol of Rb ₂ CO ₃ (manufactured by Kanto Chemical Co., Inc.) was used as the catalyst and the reaction pressure was only 1 MPa. . As a result, 2-CP was hardly generated as shown in Table 25 (NO. 97).

(Comparative Example 21)
In the regeneration reaction from recovered 2-PA to 2-CP, the same as Example 23, except that only 1 mmol of Cs ₂ CO ₃ (manufactured by Kanto Chemical Co., 4N) was used as the catalyst, and the reaction pressure was only 1 MPa. I made it. As a result, as shown in Table 25 (NO. 98), 2-CP produced only 0.01 mmol, and its activity was very low.

From the above results, it was found that a catalyst in which an alkali metal oxide was supported on a SiO ₂ carrier was effective for the regeneration from 2-PA to 2-CP.

(Comparative Example 22)
In the regeneration reaction from recovered 2-PA to 2-CP, an aqueous solution was prepared using CaCO ₃ (manufactured by Kanto Chemical Co., Ltd., special grade) so that the amount of Ca metal supported was 0.5 mmol / g in the catalyst preparation. Prepared and impregnated with SiO ₂ . Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 hours to obtain a CaO / SiO ₂ catalyst. The same procedure as in Example 23 was performed except that a CaO / SiO ₂ catalyst was used and the reaction pressure was only 1 MPa. As a result, as shown in Table 26 (NO. 99), 2-CP produced only 0.11 mmol and was very low in activity.

(Comparative Example 23)
In the regeneration reaction from the recovered 2-PA to 2-CP, an aqueous solution was prepared using BaCO ₃ (manufactured by Kanto Chemical Co., Ltd., special grade) so that the final amount of supported Ba metal was 0.5 mmol / g in the catalyst preparation. Prepared and impregnated with SiO ₂ . Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 hours to obtain a BaO / SiO ₂ catalyst. The same procedure as in Example 23 was performed except that a BaO / SiO ₂ catalyst was used and the reaction pressure was only 1 MPa. As a result, as shown in Table 26 (NO. 100), 2-CP produced only 0.13 mmol and was very low in activity.
From the above results, it can be confirmed that the catalyst supporting the alkaline earth metal oxide that is basic as well as the alkali metal oxide has low activity, and the catalyst supporting the alkali metal oxide on SiO ₂ is effective. I found out that

(Comparative Example 24)
In the regeneration reaction from recovered 2-PA to 2-CP, in catalyst preparation, finally V metal support amount with _NH 4 VO ₃ (manufactured by Sigma-Aldrich) as a 0.5 mmol / g solution Was adjusted and impregnated with SiO ₂ . Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 _hours, to obtain a V _₂ O 5 / SiO ₂ catalyst. The same procedure as in Example 23 was performed except that a V ₂ O ₅ / SiO ₂ catalyst was used and the reaction pressure was only 1 MPa. As a result, as shown in Table 26 (NO. 101), 2-CP produced only 0.11 mmol, and the activity was very low at the same level as in the case of only SiO _{2 of} Comparative Example 17.

From the above results, it was found that even when a V-type catalyst having high activity in the dehydration reaction of benzamide was used for the dehydration reaction of 2-picolinamide, the reaction hardly proceeded.

(Example 33)
In catalyst preparation by regeneration from recovered 2-PA to 2-CP, CeO ₂ (manufactured by 1st rare element, HS, surface area: 74 m ² / g) is sized to 100 mesh or less at a carrier, and about 500 ° C. The same material as Example 30 (NO. 71) was used after pre-baking for 3 hours. As a result, 3.3 mmol of 2-CP was produced as shown in Table 27 (NO. 102). The byproduct was only water, yield was 11.2%, and selectivity was 100%.

(Example 34)
In catalyst preparation by regeneration from recovered 2-PA to 2-CP, ZrO ₂ (manufactured by Daiichi Rare Element, HS, surface area: 88 m ² / g) is sized to 100 mesh or less on the support, and about 500 ° C. The same material as Example 30 (NO. 71) was used after pre-baking for 3 hours. As a result, as shown in Table 27 (NO. 103), 3.0 mmol of 2-CP was produced. The byproduct was only water, yield was 10.2%, and selectivity was 100%.

(Example 35)
Ce (NO ₃ ) ₃ (manufactured by Kanto Chemical Co., Ltd.) and Zr (NO ₃ ) ₄ (Kanto) are used in the catalyst preparation in the regeneration from the recovered 2-PA to 2-CP, because CeO ₂ —ZrO ₂ solid solution is used as a support. (Chemical) was dissolved in a solution of Ce at 20 atomic% to introduce an aqueous NaOH solution to form a precipitate. The precipitate was filtered and washed with water at 1000 ° C. in an air atmosphere for 3 hours. After firing, a powdered solid solution (surface area: 65 m ² / g) was obtained. This solid solution was sized to 100 mesh or less, pre-baked at 500 ° C. for about 3 hours, and the same as in Example 30 (NO. 71). As a result, 3.2 mmol of 2-CP was produced as shown in Table 27 (NO. 104). The byproduct was only water, yield was 10.8%, and selectivity was 100%.

From the above results, it was found that it is effective to use CeO ₂ , ZrO ₂ , or CeO ₂ —ZrO ₂ as a support as a catalyst for regeneration and fixation from 2-PA to 2-CP.

(Example 36)
In the recovery step from recovered 2-PA to 2-CP, the same procedure as in Example 1 was performed except that o-xylene (20 ml) was used instead of mesitylene as the organic solvent and the reaction pressure was only 1 MPa. As a result, as shown in Table 28 (NO. 105), 9.5 mmol of 2-CP was produced. By-product was only water, yield was 32.2%, and selectivity was 100%.

From the above results, even when o-xylene is used as the organic solvent, as shown in Comparative Examples 17 to 24, only the SiO ₂ carrier, only the alkali metal (carbonate), the alkaline earth metal-supported SiO ₂ catalyst, V system It was found that the reaction was higher in yield than the catalyst. Similar effects were obtained with m-xylene and p-xylene.

(Example 37)
Next, Examples and Comparative Examples of the method for producing carbonate ester using benzonitrile will be described. Carbonate ester was produced using the production apparatus shown in FIG. CeO ₂ (manufactured by the first rare element: impurity concentration of 0.02% or less) was calcined at 873 K in an air atmosphere for 3 hours to obtain a powdered solid catalyst. Therefore, a magnetic stirrer, the solid catalyst (1 mmol), methanol (100 mmol) and benzonitrile (BN, 50 mmol) were introduced into a 190 ml autoclave (reactor), and the air in the autoclave was blown 3 times with about 5 g of CO _2. After purging, a predetermined amount of CO ₂ was introduced and pressurized. The autoclave was heated up to 150 ° C. with a band heater and a hot stirrer, and the time when the target temperature was reached was defined as the reaction start time. After reacting at 150 ° C. for 12 hours, the autoclave was cooled with water, and when cooled to room temperature, the pressure was reduced and 2-propanol as an internal standard substance was added, and the product was collected and analyzed by GC (gas chromatography). Thus, test No. shown in Table 1 was changed by changing the amount of CO ₂ introduced and the reaction pressure. Experiments 106-112 were conducted.

As a result, a large amount of dimethyl carbonate (DMC) is produced even at a relatively low pressure of 0.08 or 0.1 MPa, and a DMC yield based on methanol is obtained at 6% at 0.1 MPa and 8% at 5 MPa. It was confirmed. The amount of by-product benzamide (BA) produced was almost the same as DMC, and no other by-products were detected.

Next, 200 ml of hexane was added to the solid-liquid coexisting substance after each test, and the mixture was stirred, extracted with a solvent, and filtered through a filter to separate a liquid and a solid. The liquid contains DMC, BN, methanol, and hexane, and the solid contains BA and CeO ₂ . The liquid component after solvent extraction with hexane was separated into DMC, BN, hexane and methanol by distillation that gradually increased the temperature to about 120 ° C., and DMC with a purity of 96% or more could be recovered. Further, BA and CeO ₂ in the fixed component are dissolved in 200 ml of acetone and then filtered through a filter to separate CeO ₂ , BA and acetone, and further, BA and acetone are separated by distillation, respectively, and purity is 97% or more. Of BA could be recovered.

Subsequently, regeneration from the recovered BA to BN will be described below. SiO _{2 as a} carrier (manufactured by Fuji Silysia, CARiACT, G-6, surface area: 535 m ² / g) was sized to 100 mesh or less and pre-baked at 700 ° C. for about 1 hour. Thereafter, in order to support Mo as a metal, an aqueous solution is prepared using (NH ₄ ) ₆ Mo ₇ O ₂₄ (manufactured by Kanto Kagaku, special grade) so that the amount of Mo metal supported is finally 0.5 mmol / g. and it was impregnated in SiO _2. Thereafter, about 6 hours drying at 110 ° C., and calcined at 500 ° C. for about 3 _hours, to obtain a MoO 3 / SiO ₂ catalyst. So, a magnetic stir bar, the above catalyst (0.1 g), BA produced as a by-product of DMC generation, and mesitylene (20 ml) were introduced into a test tube, and Soxhlet extraction was packed with molecular sieve 4A (pre-dried at 300 ° C. for 1 hour). The temperature of the cooler was set to 10 ° C., and the magnetic stirrer was set to about 200 ° C. and 600 rpm. After purging the cooler, the Soxhlet extraction tube, and the test tube with Ar gas, the reaction start time was defined as the time when the solution started to evaporate, and the reaction was performed for 500 hours. After the reaction, the test tube (solution) is cooled to room temperature, 20 ml of ethanol and anthracene (0.1 g) as an internal standard substance are added to the reaction solution, a sample is taken, and GC-MS (gas chromatograph-mass spectrometer) And quantitative analysis by FID-GC. In this way, as shown in Table 29, the test No. When 106 to 112 were performed, BN was produced in a proportion of 1.5 mmol, 2.6 mmol, 3.3 mmol, 5.1 mmol, 6.3 mmol, 6.0 mmol, and 3.5 mmol, respectively. In all experiments, water was the only byproduct, yield was about 90%, and selectivity was almost 100%.

The solid-liquid coexisting substance after the above test was filtered with a filter under heating at 120 ° C. to separate the liquid and the solid (catalyst). The liquid includes BN, water, unreacted BA, and mesitylene. This liquid component was separated into BN, water, unreacted BA, and mesitylene by distillation that gradually increased the temperature to about 180 ° C., and BN having a purity of 98% or more could be recovered. The separated unreacted BA and mesitylene can be recycled again for the dehydration reaction of BA.

Using the BN regenerated in this way, a second DMC production reaction was performed. The reaction conditions were the same, and a small amount of new BN was added to the BN obtained by regeneration and the unreacted BN in the first reaction so that the amount of BN was 50 mmol. As a result, as in the first time, it was confirmed that DMC was obtained in a high yield, and the amount of BA produced as a by-product was almost the same as DMC, and no other by-products were detected. .

From the above results, 50 mmol of new BN is required at the start of the reaction. However, it is conventionally necessary to generate DMC by reusing and reusing separated unreacted BN and by-product BA to BN. Most BN can be reduced. In addition, BA may be used as an intermediate for medicines and agrochemicals, but the amount used is not so much, and it was possible to reduce more than 90% of the place where disposal costs were high. Furthermore, when regenerating and distilling from BA to BN, the temperature is increased to about 180 ° C., so this heat is used by supplying it through a heated pipe when reusing it for DMC production. be able to.

(Example 38)
Example 37 was repeated except that ethanol (100 mmol) was used as a monohydric alcohol.

From the results in Table 30, it was confirmed that the DEC yield based on ethanol was 13% at 1 MPa and 7% at 5 MPa, although not as high as DMC in the case of diethyl carbonate (DEC). The amount of BA produced as a by-product was almost the same as that of DEC, and no other by-products were detected.

Next, in the same manner as in Example 37, 200 ml of hexane was added to the solid-liquid coexisting substance after each test, and the mixture was stirred, extracted with a solvent, and filtered through a filter to separate a liquid and a solid. The liquid includes DEC, BN, ethanol, and hexane, and the solid includes BA and CeO ₂ . The liquid component after solvent extraction with hexane was separated into DEC, BN, hexane and ethanol by distillation that gradually increased the temperature to about 130 ° C., and DEC having a purity of 96% or more could be recovered. Further, BA and CeO ₂ in the fixed component are dissolved in 200 ml of acetone and then filtered through a filter to separate CeO ₂ , BA and acetone, and further, BA and acetone are separated by distillation, respectively, and purity is 97% or more. Of BA could be recovered.

Subsequently, regeneration from the recovered BA to BN was performed in the same manner as in Example 37. As a result, as shown in Table 30, test no. When 113 to 114 were performed, BN produced 6.0 mmol and 3.2 mmol, respectively. In all experiments, the only by-product was water, yield was about 90% or more, and selectivity was almost 100%.

As for the solid-liquid coexisting substance after the test, each liquid and solid was separated in the same manner as in Example 37, and BN having a purity of 98% or more could be recovered.

Using the BN regenerated in this way, a second DEC generation reaction was performed. The reaction conditions were the same as in Example 37, and a small amount of new BN was added to BN obtained by regeneration with unreacted BN so that the amount of BN was 50 mmol. As a result, as in the first time, it was confirmed that DEC was obtained in high yield, and the amount of BA produced as a by-product was almost the same as DEC, and no other by-products were detected. .

Even when the monohydric alcohol is ethanol and the product is DEC, it has become possible to reduce most of the BN conventionally required for the production of DEC and to reduce the amount of BA that has been disposed of by more than 90%. . Furthermore, when regenerating and distilling from BA to BN, the temperature is raised to about 180 ° C., so this heat is used by supplying it through the insulated pipe when reusing it for DEC production. be able to.

(Example 39)
The same procedure as in Example 37 was performed, except that 1-propanol (100 mmol) was used as a monohydric alcohol and the reaction was performed for 24 hours.

From the results in Table 31, it is confirmed that the yield of DPrC based on 1-propanol is 12.4% at 1 MPa and 6.4% at 5 MPa, although not as much as DMC in the case of dipropyl carbonate (DPrC). It was done. The amount of BA produced as a by-product was almost the same as DPrC, and no other by-products were detected.

Next, in the same manner as in Example 37, 200 ml of hexane was added to the solid-liquid coexisting substance after each test, and the mixture was stirred, extracted with a solvent, and filtered through a filter to separate a liquid and a solid. The liquid includes DPC, BN, 1-propanol, and hexane, and the solid includes BA and CeO ₂ . The liquid component after solvent extraction with hexane can be separated into DPC, BN, hexane, and 1-propanol by distillation that gradually increases the temperature to about 170 ° C., and DPC with a purity of 96% or more can be recovered. It was. Further, BA and CeO ₂ in the fixed component are dissolved in 200 ml of acetone and then filtered through a filter to separate CeO ₂ , BA and acetone, and further, BA and acetone are separated by distillation, respectively, and purity is 97% or more. Of BA could be recovered.

Subsequently, regeneration from the recovered BA to BN was performed in the same manner as in Example 37. As a result, as shown in Table 31, test no. When 115 and 116 were performed, BN produced | generated 5.9 mmol and 2.8 mmol, respectively. In all experiments, the only by-product was water, yield was about 90% or more, and selectivity was almost 100%.

Using the BN thus regenerated, a second DPC generation reaction was performed. The reaction conditions were the same as in Example 37, and a small amount of new BN was added to BN obtained by regeneration with unreacted BN so that the amount of BN was 50 mmol. As a result, as in the first time, it was confirmed that DPC was obtained in high yield, the amount of BA produced as a by-product was almost the same as DPC, and no other by-products were detected. .

Even in the case where the monohydric alcohol is 1-propanol and the product is DPC, it is possible to reduce most of the BN required for the production of DPC, and to reduce the amount of BA that has been disposed of by 90% or more. became. Furthermore, when regenerating and distilling from BA to BN, the temperature is raised to about 180 ° C., so this heat is used by supplying it through a heated pipe when reusing it for DPC production. be able to.

(Example 40)
The same procedure as in Example 37 was performed, except that 1-butanol (100 mmol) was used as a monohydric alcohol and the reaction was performed for 24 hours.

From the results of Table 32, it is confirmed that the yield of DBC based on 1-butanol is 11.4% at 1 MPa and 5.8% at 5 MPa, although not as high as DMC in the case of dibutyl carbonate (DBC). It was done. The amount of BA produced as a by-product was almost the same as that of DBC, and no other by-products were detected.

Next, in the same manner as in Example 37, 200 ml of hexane was added to the solid-liquid coexisting substance after each test, and the mixture was stirred, extracted with a solvent, and filtered through a filter to separate a liquid and a solid. The liquid contains DBC, BN, 1-butanol and hexane, and the solid contains BA and CeO ₂ . The liquid component after solvent extraction with hexane first separates hexane and 1-butanol by distillation that gradually increases the temperature to about 120 ° C., and then cools to about 0 ° C. to precipitate BN. It was possible to recover DBC having a purity of 96% or more. Further, BA and CeO ₂ in the fixed component are dissolved in 200 ml of acetone and then filtered through a filter to separate CeO ₂ , BA and acetone, and further, BA and acetone are separated by distillation, respectively, and purity is 97% or more. Of BA could be recovered.

Subsequently, regeneration from the recovered BA to BN was performed in the same manner as in Example 37. As a result, as shown in Table 32, Test No. When 117 and 118 were performed, 5.5 mmol and 2.6 mmol of BN were formed, respectively. In all experiments, the only by-product was water, yield was about 90% or more, and selectivity was almost 100%.

Using the BN regenerated in this way, a second DBC production reaction was performed. The reaction conditions were the same as in Example 37, and a small amount of new BN was added to BN obtained by regeneration with unreacted BN so that the amount of BN was 50 mmol. As a result, as in the first time, it was confirmed that DBC was obtained in a high yield, and the amount of BA produced as a by-product was almost the same as DBC, and no other by-products were detected. .

Even in the case where the monohydric alcohol is 1-butanol and the product is DBC, it is possible to reduce most of the BN conventionally required for DBC generation, and the amount of BA that has been disposed of can be reduced by 90% or more. became. Furthermore, when regenerating and distilling from BA to BN, the temperature is increased to about 180 ° C., so this heat is used by supplying it through a heated pipe when reusing it for DBC production. be able to.

(Example 41)
The same procedure as in Example 37 was performed except that 100 mmol each of benzyl alcohol, allyl alcohol, and 2-propanol was used as a monohydric alcohol and the reaction was performed for 24 hours.

From the results shown in Table 33, although a series of carbonic acid esters (EC) are not as much as DMC, the EC yield based on each alcohol of benzyl alcohol, allyl alcohol, and 2-propanol is 6.0% at 1 MPa, respectively. It was confirmed that 5.6% and 13.4% were obtained. The amount of BA produced as a by-product was almost the same as that of each EC, and no other by-products were detected.

Next, in the same manner as in Example 37, 200 ml of hexane was added to the solid-liquid coexisting substance after each test, and the mixture was stirred, extracted with a solvent, and filtered through a filter to separate a liquid and a solid. The liquid contains EC, BN and each alcohol component, and hexane, and the solid contains BA and CeO ₂ . The liquid component after solvent extraction with hexane first separates hexane and each alcohol by distillation that gradually increases the temperature to about 120 ° C., and then cools to about 0 ° C. to precipitate BN, EC with a purity of 96% or more could be recovered. Further, BA and CeO ₂ in the fixed component are dissolved in 200 ml of acetone and then filtered through a filter to separate CeO ₂ , BA and acetone, and further, BA and acetone are separated by distillation, respectively, and purity is 97% or more. Of BA could be recovered.

Subsequently, regeneration from the recovered BA to BN was performed in the same manner as in Example 37. As a result, as shown in Table 33, test No. When 119 to 121 were performed, BN was produced in 2.6 mmol, 2.5 mmol, and 6.5 mmol, respectively. In all experiments, the only by-product was water, yield was about 90% or more, and selectivity was almost 100%.

Using the BN regenerated in this way, a second EC generation reaction was performed. The reaction conditions were the same as in Example 37, and a small amount of new BN was added to BN obtained by regeneration with unreacted BN so that the amount of BN was 50 mmol. As a result, as in the first time, it was confirmed that EC was obtained in a high yield, the amount of BA produced as a by-product was almost the same as that of EC, and no other by-products were detected. .

(Example 42)
In the catalyst preparation in the regeneration from the recovered BA to BN, the catalyst was MoO ₃ / TiO ₂ , Re ₂ O ₇ / CeO ₂ , WO ₃ / SiO ₂ , Nb ₂ O ₅ / ZrO ₂ Test NO. 122-129 were performed. The catalyst carrier described above was used, and the catalyst was supported on the catalyst carrier according to the method described above.

From the results of Table 34, it was found that the yield was around 90% and the selectivity was almost 100% even when the metal element was Mo, Re, W, or Nb.

(Example 43)
In the catalyst preparation in the regeneration from the recovered BA to BN, NO. Is the same as in Example 37 except that the final Mo loading is as shown in Table 35 and the reaction pressure is only 1 MPa. 130-135 tests were performed. As a result, as shown in Table 35, it was found that Mo loading was high at 0.1 to 1 mmol, and about 0.6 mmol was a suitable loading amount. On the other hand, when the loading amount was excessively increased, the activity was relatively lowered. This is because the Mo oxide on the SiO ₂ carrier becomes a large aggregate because the Mo oxide is loaded in a large amount. Inferred.

In Examples 37 to 41, the MoO ₃ / SiO ₂ catalyst was used in the regeneration reaction from BA to BN, but one or two of W, Re, and Nb were used as metal elements in the final reaction. The same effect can be obtained by using a catalyst obtained by adjusting an aqueous solution to 0.5 mmol / g, then impregnating with SiO ₂ , drying at 110 ° C. for about 6 hours, and calcining at 500 ° C. for about 3 hours. was gotten. In addition to SiO ₂ , the same effect was obtained when CeO ₂ , ZrO ₂ , or CeO ₂ —ZrO ₂ was used in addition to SiO ₂ .

(Example 44)
In the recovered BA to BN regeneration step, the procedure was the same as Example 37, except that o-xylene (20 ml) was used instead of mesitylene as the organic solvent, and the reaction pressure was only 1 MPa. As a result, as shown in Table 36 (NO. 136), 3.2 mmol of BN was generated. By-product was only water, yield was 42.7%, and selectivity was almost 100%.

From the above results, it was found that even when o-xylene was used as the organic solvent, the reaction was performed in a high yield. Similar effects were obtained with m-xylene and p-xylene.

(Comparative Example 25)
In the DMC production reaction, the same procedure as in Example 37 was carried out except that acetonitrile (AN, 300 mmol) was introduced as a wettable powder and allowed to react at 150 ° C. for 24 hours.

From the results in Table 37, when AN is used, the amount of DMC produced is about 1/10 lower than that of BN, and the DMC yield based on methanol is highest at 8.2% at 0.5 MPa. From this, it was found that the present invention is more efficient. The amount of by-product acetamide (AA) produced was almost the same as that of DMC, and no other by-products were detected.

Next, in the same manner as in Example 37, 200 ml of hexane was added to the solid-liquid coexisting substance after each test, and the mixture was stirred, extracted with a solvent, and filtered through a filter to separate a liquid and a solid. The liquid contains DMC, unreacted AN, methanol, and hexane, and the solid contains AA and CeO ₂ . Since the liquid component after solvent extraction with hexane has a melting point and boiling point of AN of -45 ° C and 82 ° C, respectively, DMC and AN cannot be separated by distillation, so it is once cooled to -30 to 0 ° C It is possible to separate the precipitated DMC. Thereafter, when the temperature is increased to about 70 ° C. and distillation is performed, a mixture of methanol and hexane can separate the unreacted AN, and the unreacted AN can be reused for the DMC formation reaction. Since the concentration of methanol contained in the mixture is high, it is difficult to reuse as a solvent for extraction and it is necessary to dispose of it. In addition, AA and CeO ₂ in the fixed component are dissolved in 100 ml of acetone and filtered through a filter to separate CeO ₂ , AA and acetone, and AA and acetone are separated by distillation heated to about 70 ° C. As a result, AA having a purity of 95% or more was recovered.

Subsequently, regeneration from the collected AA to AN was performed in the same manner as in Example 37. As a result, as shown in Table 37, test No. When 137 and 138 were performed, there was almost no reaction. This is considered that since the solid catalyst is basic while AA is acidic, AA poisons the active sites on the solid catalyst and the reaction does not proceed.

Therefore, since the AA produced as a by-product could not be dehydrated and the AN could not be regenerated, the second DMC formation reaction was performed by adding new AN to the unreacted AN so that the amount of AN was 300 mmol. The reaction was conducted in the same manner as in Example 37 except that the reaction was performed at 150 ° C. for 24 hours. As a result, as in the first time, the amount of DMC produced was reduced to about 1/10 compared to the case of BN, and the DMC yield based on methanol reached 1.7% at 0.5 MPa. It was.

(Comparative Example 26)
Except that the regeneration step from BA to BN (and the separation step after the regeneration step) is not performed, the test NO. 139 and 140 were performed. As a result, DMC with a purity of 96% or more and BA with a purity of 97% or more could be recovered, but a large amount of by-produced BA had little use and was treated as industrial waste. In addition, at least 7.7 or 4.3 mmol of BN was newly required for the second DMC production reaction, which led to an increase in raw material costs.

(Comparative Example 27)
In the regeneration reaction from the recovered BA to BN, a catalyst as shown in Table 39 was prepared and used as the catalyst, and the same reaction as in Example 37 was performed except that the reaction pressure was only 1 MPa. As a result, as shown in Table 39 (NO. 141 to 143), the amount of BN produced was small and the activity was low.

The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

1 first reaction tower, 2 first extraction tower, 3 first distillation tower, 4 second extraction tower, 5 second distillation tower, 6 catalyst regeneration tower, 7 second reaction tower, 8 catalyst separation tower, 9 third distillation Tower, 10 CO ₂ pressure blower, 11 CO ₂ , 12 monohydric alcohol, 13 2-cyanopyridine, benzonitrile, 14 solid catalyst, 15 reaction solution, 16 alkane, 17, 21 extract, 18 solid phase material, 19 carbonic acid Ester, 20 Unreacted 2-cyanopyridine, Unreacted benzonitrile, 22 Used solid catalyst, 23 2-Picolinamide, Benzamide, 24 Hydrophilic solvent, 25 Solid catalyst, 26 Used solid catalyst, 27 Organic solvent, 28 Not yet used Reaction 2-picolinamide, unreacted benzamide, 29 water, 30 filtration tower, 31 methyl picolinate, methyl benzoate, 32 methyl carbamate, 33 alkane and unreacted one Alcohol

Claims

A process for producing cyanopyridine, characterized in that cyanopyridine is produced by heating and dehydrating picolinamide in the presence of a catalyst supporting an alkali metal oxide and in the presence of an organic solvent.
The method for producing cyanopyridine according to claim 1, wherein the cyanopyridine is 2-cyanopyridine and the picolinamide is 2-picolinamide.
The catalyst carrying the alkali metal oxide is a catalyst carrying one or more alkali metal oxides on a catalyst carrier composed of one or more of SiO 2 , CeO 2 and ZrO 2. The method for producing cyanopyridine according to claim 1 or 2, wherein:
The method for producing cyanopyridine according to claim 3, wherein the catalyst support is SiO 2 .
The method for producing cyanopyridine according to any one of claims 1 to 4, wherein the alkali metal oxide is an oxide of Li, K, Na, Rb, or Cs.
The method for producing cyanopyridine according to any one of claims 1 to 5, wherein the organic solvent is mesitylene.
The method for producing cyanopyridine according to any one of claims 1 to 6, wherein a dehydrating agent is used in the dehydration reaction.
In the presence of one or both of the solid catalyst of CeO 2 and ZrO 2 and cyanopyridine, a monohydric alcohol and carbon dioxide are reacted to generate a carbonate and water, and the cyanopyridine and the generated water A first reaction step of generating picolinamide by a hydration reaction with
After the picolinamide is separated from the first reaction step, the picolinamide is dehydrated by heating in the presence of a catalyst carrying an alkali metal oxide and in the presence of an organic solvent, whereby cyano Having a second reaction step to regenerate to pyridine,
A method for producing a carbonic acid ester, wherein the cyanopyridine regenerated in the second reaction step is used in the first reaction step.
A first reaction step in which one or both of CeO 2 and ZrO 2 , a monohydric alcohol, carbon dioxide, and cyanopyridine are mixed and reacted to produce carbonate and picolinamide; ,
The carbonate ester, picolinamide, unreacted cyanopyridine, and the solid catalyst discharged from the first reaction step are subjected to solvent extraction with alkane, and then solid-liquid separation is performed to obtain a liquid phase carbonate ester and unreacted cyanopyridine. And a first separation step of separating the alkane and the solid catalyst and picolinamide in solid phase;
A second separation step of separating each of the liquid phase carbonate ester after solid-liquid separation in the first separation step, unreacted cyanopyridine, and alkane;
The solid phase solid catalyst and picolinamide after solid-liquid separation in the first separation step are extracted with a hydrophilic solvent and then solid-liquid separated to obtain a liquid phase picolinamide and a hydrophilic solvent, and a solid phase solid catalyst. A third separation step of separating into
The second reaction in which picolinamide separated in the third separation step is dehydrated by heating in the presence of a catalyst supporting an alkali metal oxide and in the presence of an organic solvent to produce cyanopyridine. Process,
The catalyst loaded with cyanopyridine, unreacted picolinamide, and alkali metal oxide discharged from the second reaction step is filtered to separate the catalyst loaded with the solid phase alkali metal oxide. Separation process of
A fifth separation step for separating cyanopyridine, picolinamide, organic solvent, and water remaining after separation in the fourth separation step, respectively.
The method for producing a carbonate ester according to claim 8, wherein the cyanopyridine separated in the fifth separation step is used in the first reaction step.
The carbonate ester according to claim 9, further comprising a step of regenerating the solid catalyst separated in the third separation step, wherein the regenerated catalyst is used in the first reaction step. Production method.
Unreacted monohydric alcohol remains in the first reaction step, and carbonate ester, picolinamide, unreacted monohydric alcohol and unreacted discharged from the first reaction step in the first separation step. The cyanopyridine and the solid catalyst were subjected to solvent extraction with alkane and then solid-liquid separation, and the liquid phase carbonate ester, unreacted monohydric alcohol, unreacted cyanopyridine, and alkane, and the solid catalyst in the solid phase The method for producing a carbonate ester according to claim 9 or 10, wherein the carbonate ester is separated into picolinamide.
In the first reaction step, at least one of methyl picolinate and methyl carbamate is generated as a by-product, and in the first separation step, a carbonate ester, picolinamide, unreacted product discharged from the first reaction step is formed. The reaction cyanopyridine, methyl picolinate, methyl carbamate, and the solid catalyst were subjected to solvent extraction with alkane, followed by solid-liquid separation, and a liquid phase carbonate ester, unreacted cyanopyridine, methyl picolinate, methyl carbamate, The method for producing a carbonate ester according to any one of claims 9 to 11, wherein the carbonic acid ester and alkane are separated into the solid catalyst and picolinamide in solid phase.
In the first reaction step, unreacted monohydric alcohol remains and at least one of methyl picolinate and methyl carbamate is generated as a by-product, and in the first separation step, the first reaction Carbonate ester, picolinamide, unreacted monohydric alcohol, unreacted cyanopyridine, methyl picolinate, methyl carbamate, and the solid catalyst discharged from the process are subjected to solvent extraction with alkane, followed by solid-liquid separation. A phase carbonate ester, unreacted monohydric alcohol, unreacted cyanopyridine, methyl picolinate, methyl carbamate, and alkane, and the solid catalyst and picolinamide in solid phase are separated. The method for producing a carbonate ester according to any one of 9 to 12.
The method for producing a carbonate ester according to any one of claims 9 to 13, wherein the alkane used in the solvent extraction is hexane.
The method for producing a carbonate ester according to any one of claims 9 to 14, wherein the hydrophilic solvent is acetone.
The method for producing a carbonate ester according to any one of claims 8 to 15, wherein the cyanopyridine is 2-cyanopyridine and the picolinamide is 2-picolinamide.
The catalyst carrying the alkali metal oxide is a catalyst carrying one or more alkali metal oxides on a catalyst carrier composed of one or more of SiO 2 , CeO 2 and ZrO 2. The method for producing a carbonate ester according to any one of claims 8 to 16, wherein:
The method for producing a carbonate ester according to claim 17, wherein the catalyst support is SiO 2 .
The method for producing a carbonate ester according to any one of claims 8 to 18, wherein the alkali metal oxide is any one of Li, K, Na, Rb, and Cs.
The method for producing a carbonate ester according to any one of claims 8 to 19, wherein the organic solvent is mesitylene.
The method for producing a carbonate ester according to any one of claims 8 to 20, wherein a dehydrating agent is used in the dehydration reaction.
The method for producing a carbonate ester according to any one of claims 8 to 21, wherein the monohydric alcohol is methanol and dimethyl carbonate is produced as a carbonate ester.
The method for producing a carbonate ester according to any one of claims 8 to 22, wherein the monohydric alcohol is ethanol and diethyl carbonate is produced as a carbonate ester.
A production apparatus for use in the method for producing a carbonate ester according to any one of claims 8 to 23,
A pressurizing part for pressurizing carbon dioxide;
In the presence of either one or both of CeO 2 and ZrO 2 and a cyanopyridine, a monohydric alcohol and carbon dioxide are reacted to produce a carbonate and water, and the cyanopyridine and the produced catalyst. A first reaction part for generating picolinamide by a hydration reaction with water;
The carbonate ester, picolinamide, unreacted cyanopyridine, and the solid catalyst discharged from the first reaction section are subjected to solvent extraction with alkane, and then solid-liquid separation is performed to obtain a liquid phase carbonate ester and unreacted cyanopyridine. And a first separation part for separating the alkane and the solid catalyst and picolinamide in a solid phase;
A second separation part for separating the carbonate, unreacted cyanopyridine, and alkane in the liquid phase after the solid-liquid separation by the first separation part;
The solid catalyst and picolinamide after solid-liquid separation by the first separation unit are extracted with a hydrophilic solvent and then solid-liquid separated to separate into a liquid phase picolinamide and a hydrophilic solvent and a solid phase solid catalyst. A third separation unit
A second reaction for producing cyanopyridine by subjecting picolinamide separated by the third separation part to a dehydration reaction by heating in the presence of a catalyst supporting an alkali metal oxide and in the presence of an organic solvent. And
The catalyst loaded with cyanopyridine, unreacted picolinamide, and alkali metal oxide discharged by the second reaction section is filtered to separate the catalyst loaded with the solid phase alkali metal oxide. A separation part of
A fifth separation unit for separating cyanopyridine, picolinamide, an organic solvent, and water remaining after separation by the fourth separation unit;
An apparatus for producing carbonate ester, comprising: a transport unit that transports the cyanopyridine separated by the fifth separation unit to the first reaction unit.
On a catalyst support composed of one or more of SiO 2 , TiO 2 , CeO 2 , ZrO 2 , Al 2 O 3 , and C, any one or two of molybdenum, tungsten, rhenium, titanium, and niobium Benzonitrile is produced by heating and dehydrating benzamide in the presence of a catalyst on which a metal oxide of at least one metal species is supported and in the presence of an organic solvent. Manufacturing method.
26. The method for producing benzonitrile according to claim 25, wherein the benzonitrile is produced by heating the benzamide to cause a dehydration reaction in a liquid phase state.
The catalyst support, a manufacturing method of benzonitrile according to claim 25 or 26, characterized in that a SiO 2.
The method for producing benzonitrile according to any one of claims 25 to 27, wherein the catalyst has molybdenum oxide supported on a support of SiO 2 .
The method for producing benzonitrile according to any one of claims 25 to 28, wherein the organic solvent comprises one or more of chlorobenzene, xylene and mesitylene.
The method for producing benzonitrile according to any one of claims 25 to 29, wherein a dehydrating agent is used in the dehydration reaction.
In the presence of either one or both of CeO 2 and ZrO 2 and benzonitrile, a monohydric alcohol and carbon dioxide are reacted to produce a carbonate and water, and the benzonitrile and the production. A first reaction step of producing benzamide by hydration reaction with purified water;
After separating the benzamide from the first reaction step, the benzamide is converted into SiO 2 , TiO 2 , a metal oxide of any one or more of molybdenum, tungsten, rhenium, titanium, and niobium. By dehydration reaction by heating in the presence of a catalyst supported on one or more of the catalyst supports of CeO 2 , ZrO 2 , Al 2 O 3 , and C and in the presence of an organic solvent , Having a second reaction step to regenerate to benzonitrile,
Benzonitrile regenerated in the second reaction step is used in the first reaction step.
In the presence of either one or both of CeO 2 and ZrO 2 and benzonitrile, a monohydric alcohol and carbon dioxide are reacted to produce a carbonate and water, and the benzonitrile and the production. A first reaction step of producing benzamide by hydration reaction with purified water;
The carbonate ester, benzamide, unreacted benzonitrile discharged from the first reaction step, and the solid catalyst are subjected to solvent extraction with alkane and then separated into solid and liquid, and the liquid phase carbonate ester, unreacted benzonitrile, And a first separation step of separating the alkane and the solid catalyst and benzamide in a solid phase;
A second separation step of separating the carbonate, unreacted benzonitrile, and alkane in the liquid phase after the solid-liquid separation;
A third separation step in which the solid catalyst and benzamide after the solid-liquid separation are extracted with a hydrophilic solvent, followed by solid-liquid separation, and separated into a liquid phase benzamide and a hydrophilic solvent and a solid phase solid catalyst;
The benzamide separated in the third separation step is a metal oxide of any one or more of molybdenum, tungsten, rhenium, titanium, niobium, or SiO 2 , TiO 2 , CeO 2 , ZrO 2. , And regenerated to benzonitrile by heating and dehydration reaction in the presence of a catalyst supported on one or more catalyst carriers of Al 2 O 3 and C and in the presence of an organic solvent. A second reaction step,
The catalyst in which the solid phase metal oxide is supported on the catalyst support is filtered by filtering the catalyst in which the benzonitrile, unreacted benzamide, and metal oxide supported on the catalyst support are discharged from the second reaction step. A fourth separation step of separating
And a fifth separation step for separating benzonitrile, benzamide, organic solvent, and water remaining after the separation,
32. The method for producing a carbonate ester according to claim 31, wherein the separated benzonitrile is used in the first reaction step.
33. The method for producing a carbonate ester according to claim 32, further comprising a step of regenerating the separated solid catalyst, wherein the regenerated catalyst is used in the first reaction step.
The method for producing a carbonate ester according to claim 32 or 33, wherein the alkane used in the solvent extraction is hexane.
The method for producing a carbonate ester according to any one of claims 32 to 34, wherein the hydrophilic solvent is acetone.
The catalyst support on which the metal oxide is supported is one or more of SiO 2 , TiO 2 , CeO 2 , and ZrO 2 , according to any one of claims 31 to 35, The manufacturing method of carbonate ester of description.
The method for producing a carbonate ester according to claim 36, wherein the catalyst support is SiO 2 .
The method for producing a carbonate ester according to any one of claims 31 to 37, wherein the metal oxide is molybdenum oxide.
The method for producing a carbonate ester according to any one of claims 31 to 38, wherein the organic solvent comprises one or more of chlorobenzene, xylene, and mesitylene.
The method for producing a carbonate ester according to any one of claims 31 to 39, wherein a dehydrating agent is used in the second reaction step.
The method for producing a carbonate ester according to any one of claims 31 to 40, wherein the monohydric alcohol is methanol and dimethyl carbonate is produced as a carbonate ester.
The method for producing a carbonate ester according to any one of claims 31 to 41, wherein the monohydric alcohol is ethanol and diethyl carbonate is produced as a carbonate ester.
An apparatus for producing a carbonate ester used in the production method according to any one of claims 31 to 42,
A pressurizing part for pressurizing carbon dioxide;
In the presence of either one or both of CeO 2 and ZrO 2 , and benzonitrile, a monohydric alcohol and carbon dioxide are reacted to form a carbonate and water, and the benzonitrile and the above A first reaction part for producing benzamide by a hydration reaction with the produced water;
The carbonate ester, benzamide, unreacted benzonitrile, and the solid catalyst discharged by the first reaction unit are subjected to solvent extraction with alkane, and then solid-liquid separated to obtain a liquid phase carbonate ester, unreacted benzonitrile, And a first separation part for separating the alkane and the solid catalyst and benzamide in a solid phase;
A second separation unit for separating the carbonate, unreacted benzonitrile, and alkane in the liquid phase after the solid-liquid separation;
The solid catalyst and benzamide after the solid-liquid separation are extracted with a hydrophilic solvent, followed by solid-liquid separation, and a third separation unit that separates into a liquid phase benzamide and a hydrophilic solvent and a solid phase solid catalyst;
The separated benzamide is a metal oxide of any one or more of molybdenum, tungsten, rhenium, vanadium, niobium, or a metal oxide of SiO 2 , TiO 2 , CeO 2 , ZrO 2 , Al 2 O 3 , A second reaction section for producing a benzonitrile by heating to cause a dehydration reaction in the presence of a catalyst supported on one or more catalyst supports of C and in the presence of an organic solvent;
The catalyst in which the benzonitrile, unreacted benzamide, and metal oxide supported on the catalyst carrier are discharged by the second reaction unit is filtered to separate the catalyst supporting the solid phase metal oxide. 4 separation parts;
A fifth separation unit for separating benzonitrile, benzamide, an organic solvent, and water remaining after the separation;
A carbonic acid ester producing apparatus, comprising: a conveying unit configured to convey the separated benzonitrile to the first reaction unit.