Method for producing aromatic nitrile compound and method for producing carbonate ester

Abstract

Provided is a method for producing an aromatic nitrile compound, with which it is possible to obtain an aromatic nitrile compound with high yield selectivity while shortening the reaction time by using an aromatic amide compound, and with which it is possible to suppress the generation of by-products. The above-mentioned problem is solved by the following method for producing an aromatic nitrile compound. Namely, the method for producing an aromatic nitrile compound according to the present invention comprises a dehydration reaction for dehydrating an aromatic amide compound, the dehydration reaction having a contact step for bringing the aromatic amide compound and a diluent into contact with a catalyst in a gas phase, the temperature at which the aromatic amide compound and the diluent are in contact with the catalyst is 300 DEG C or above.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for producing an aromatic nitrile compound including a step of dehydrating an aromatic amide compound in a gas phase, and a method for producing a carbonate. BACKGROUND

[0002] A carbonate is a general term for a compound in which one or both of the two hydrogen atoms of carbonic acid CO(OH)2 is / are substituted with an alkyl group or an aryl group, and is a compound having a structure of RO-C(=O)-OR' (R, R' represents a saturated hydrocarbon group or an unsaturated hydrocarbon group).

[0003] A carbonate is a very useful compound, which is used as a gasoline additive for increasing octane number, a diesel fuel additive for reducing particulates in exhaust gas, an alkylating agent, a carbonylating agent, a solvent, or the like in the synthesis of resins / organic compounds such as polycarbonates, polyurethanes, pharmaceuticals / pesticides, and the like, an electrolyte of a lithium ion battery, a lubricating oil raw material, a raw material of an oxygen scavenger for preventing rust of a boiler pipe, and the like, in addition to the above.

[0004] As a method for producing a carbonate, a method including a step of reacting water generated as a by-product in the reaction of an alcohol and carbon dioxide with a nitrile compound is known (Patent Documents 1, 2, and the like). In these methods for producing a carbonate, a step of dehydrating an amide compound generated from water and a nitrile compound, thereby regenerating the nitrile compound, is included.

[0005] However, according to such a conventional method for producing a carbonate, it is not necessarily possible to selectively regenerate a nitrile compound in a short time and with a high yield, and it is not easy to efficiently produce a target compound, a carbonate.

[0006] PRIOR ART DOCUMENTS PATENT DOCUMENTS Patent Document 1: WO2015 / 099053 Patent Document 2: WO2020 / 022416 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION The present application relates to a method for producing an aromatic nitrile compound including a step of dehydrating an aromatic amide compound in a gas phase, and a method for producing a carbonate.

[0008] TECHNICAL SOLUTION FOR SOLVING THE PROBLEMS The inventors of the present application have studied a method for producing an aromatic nitrile compound by dehydration of an aromatic amide compound, and as a result, have found that by bringing an aromatic amide compound and a diluent into contact with a catalyst in the gas phase at a high temperature, not only can the reaction rate be greatly increased and the reaction time be shortened, but also the generation of by-products can be suppressed, and the target compound can be selectively obtained in a high yield.

[0009] According to the present application, the regeneration rate from an aromatic amide compound to an aromatic nitrile compound by dehydration reaction can be increased. Moreover, it has been confirmed that the production method of the present application, which introduces a dehydration reaction step, for producing a carbonate by using carbon dioxide and an alcohol has an excellent effect of efficiently producing a carbonate or the like.

[0010] The present application includes, for example, the following.

[0011] [1] A method for producing an aromatic nitrile compound, wherein the method comprises a dehydration reaction of dehydrating an aromatic amide compound, The dehydration reaction has a contact step of bringing the aromatic amide compound and a diluent into contact with a catalyst in the gas phase, and the temperature at the time when the aromatic amide compound and the diluent are brought into contact with the catalyst in the contact step is 300°C or higher.

[0012] [2] The method for producing an aromatic nitrile compound according to the above [1], wherein the diluent contains at least one of a solvent and an inert gas.

[0013] [3] The method for producing an aromatic nitrile compound according to the above [2], wherein the solvent contains at least an aromatic compound.

[0014] [4] The method for producing an aromatic nitrile compound according to the above [3], wherein the aromatic compound is represented by the following formula (1), In formula (1), R1is independently selected from an alkyl group having 1 to 10 carbon atoms which can have a substituent, an alkoxy group having 1 to 10 carbon atoms which can have a substituent, an aryl group having 6 to 30 carbon atoms which can have a substituent, and an aryloxy group having 6 to 30 carbon atoms which can have a substituent, and a is an integer of 1 to 6.

[0015] [5] The method for producing an aromatic nitrile compound according to any one of the above [3] and [4], for example, the above [3], wherein the aromatic compound has one or two aromatic rings and one or more groups selected from an alkyl group, an alkoxy group, and an aryloxy group.

[0016] [6] The method for producing an aromatic nitrile compound according to any one of the above [3] to [5], for example, the above [3], wherein the aromatic compound has a self-ignition temperature of 300°C or higher.

[0017] [7] The method for producing an aromatic nitrile compound according to any one of the above [3] to [6], for example, the above [3], wherein the aromatic compound contains at least any one of 1,3,5-trimethylbenzene, p-cymene, phenyl ether, and anisole.

[0018] [8] The method for producing an aromatic nitrile compound according to any one of the above [1] to [5], for example, the above [1], wherein the pressure of the reaction system in the contacting step is 101.3 kPa or lower.

[0019] [9] The method for producing an aromatic nitrile compound according to any one of the above [1] to [8], for example, the above [1], wherein the aromatic amide compound contains at least a heteroaryl amide compound, and the aromatic nitrile compound contains at least a heteroaryl nitrile compound.

[0020]

[10] The method for producing an aromatic nitrile compound according to the above [9], wherein the heteroaryl amide compound contains 2-picolinamide, and the heteroaryl nitrile compound contains 2-cyanopyridine.

[0021]

[11] The method for producing an aromatic nitrile compound according to any one of the above [1] to

[10] , for example, the above [1], wherein an inert gas in a gaseous state is used in the contacting step.

[0022]

[12] The method for producing an aromatic nitrile compound according to any one of the above [3] to

[11] , for example, the above

[11] , wherein the inert gas contains at least nitrogen.

[0023]

[13] The method for producing an aromatic nitrile compound according to any one of the above [1] to

[12] , for example, the above [1], wherein the catalyst contains an alkali metal.

[0024]

[14] The method for producing an aromatic nitrile compound according to any one of the above [2] to

[13] , for example, the above [2], wherein the solvent is compatible with the aromatic amide compound.

[0025]

[15] The method for producing an aromatic nitrile compound according to any one of the above [1] to

[14] , for example, the above [1], wherein the aromatic amide compound is contacted with the catalyst in a gaseous phase for a time of 0.001 seconds or more and less than 10 seconds.

[0026]

[16] A method for producing a carbonate, comprising a first reaction step and a second reaction step, The first reaction step includes a carbonate production reaction in which an alcohol is reacted with carbon dioxide in the presence of an aromatic nitrile compound to produce a carbonate and water, and a hydration reaction in which the produced water is hydrated with the aromatic nitrile compound to produce an aromatic amide compound, The second reaction step regenerates the aromatic nitrile compound from the aromatic amide compound by a dehydration reaction, the dehydration reaction dehydrating the aromatic amide compound after the aromatic amide compound is separated from a reaction system of the first reaction step, and the dehydration reaction has the contact step described in any one of [1] to

[15] , At least a part of the aromatic nitrile compound regenerated in the second reaction step is used in the first reaction step.

[0027]

[17] The method for producing a carbonate according to the above

[16] , wherein a catalyst containing cerium oxide is used in the carbonate production reaction.

[0028]

[18] The method for producing a carbonate according to the above

[16] or

[17] , wherein the alcohol contains an alcohol having 1 to 6 carbon atoms.

[0029] Effects of the Invention According to the present invention, the production (regeneration) of an aromatic nitrile compound such as cyanopyridine from an aromatic amide compound such as picolinamide (picolinamide and nicotinamide, etc.), benzamide, etc. can be efficiently performed. That is, in the dehydration reaction of the aromatic amide compound used for the regeneration, the generation of a by-product can be suppressed, and the target compound can be selectively obtained at a high yield, and the reaction rate can be increased.

[0030] Therefore, according to the present invention, the reaction time of the dehydration reaction for regenerating the aromatic nitrile compound can be greatly shortened compared to the conventional method. Also, in the dehydration step using a gas phase reaction at a high temperature, the reaction vessel can be miniaturized compared to the conventional dehydration step of the amide compound performed by a liquid phase reaction or a gas phase reaction at a low temperature. Therefore, according to the present invention, the industrialization of the step for regenerating the corresponding aromatic nitrile compound from the aromatic amide compound can be easily achieved.

[0031] Further, according to the present invention, by producing the aromatic nitrile compound as described above, an effective method for producing a carbonate can also be achieved. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 An example of a device for producing a carbonate.

[0033] Figure 2 A brief schematic diagram of a manufacturing apparatus for an aromatic nitrile compound in an example employing a solvent.

[0034] Figure 3 A brief schematic diagram of a manufacturing apparatus for an aromatic nitrile compound in an example employing an inert gas.

[0035] Figure 4 A graph showing the relationship between the reaction temperature in the dehydration reaction and the yield of the aromatic nitrile compound (2-cyanopyridine (2-CP)) in the example employing a solvent and the comparative example.

[0036] Figure 5 A graph showing the relationship between the reaction temperature in the dehydration reaction and the by-product generation rate of the by-product pyridine (Py) in the example employing a solvent and the comparative example. DETAILED DESCRIPTION

[0037] The preferred embodiments of the present application are described in detail below.

[0038] <1. Method for manufacturing aromatic nitrile compound> In the method for manufacturing an aromatic nitrile compound of the present application, an aromatic amide compound such as a pyridine carboxamide (2-pyridinecarboxamide, 3-pyridinecarboxamide, or 4-pyridinecarboxamide) is dehydrated by being brought into contact with a catalyst such as a basic metal oxide-supporting catalyst in the gas phase at a high temperature, thereby converting into an aromatic nitrile compound such as a cyanopyridine. That is, the method for manufacturing an aromatic nitrile compound of the present application is a process in which a dehydration reaction is caused by bringing an aromatic amide compound into contact with a catalyst such as a basic metal oxide-supporting catalyst in the gas phase at a high temperature in a contact step, thereby generating an aromatic nitrile compound. (Reaction substrate) As the aromatic amide compound used in the method for manufacturing an aromatic nitrile compound, an amide compound having an aromatic hydrocarbon ring such as a benzene ring, a naphthalene ring, an anthracene ring, or an amide compound having a heteroaryl ring can be given. Among these aromatic amide compounds, a compound having a heteroaryl ring, i.e., a heteroaryl amide compound is preferably used. As the heteroaryl amide compound, an amide compound having a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, a pyrrole ring, a furan ring, a thiophene ring, an imidazole ring, a pyrazole ring, an oxazole ring, or the like can be given.

[0039] As a preferred specific example of the heteroaryl amide compound, a compound having a pyridine ring such as the above-described pyridine carboxamide (2-pyridinecarboxamide, 3-pyridinecarboxamide, and 4-pyridinecarboxamide) can be given.

[0040] The aromatic nitrile compound produced by the production method of the present application is a product of a dehydration reaction of the above-described aromatic amide compound as understood from the above reaction formula. Therefore, as a specific example of the aromatic nitrile compound which is the object of the production method of the present application, a heteroaryl nitrile compound can be given. As a preferred specific example of the heteroaryl nitrile compound, a compound having a pyridine ring such as cyanopyridine (2-cyanopyridine, 3-cyanopyridine and 4-cyanopyridine) can be given.

[0041] (Catalyst) In the present application, the catalyst used in the above-described dehydration reaction of the present application preferably contains an oxide of an alkali metal (K, Li, Na, Rb, Cs). It is particularly preferable to use an oxide containing at least any one of Na, K, Rb and Cs (cerium) as the catalyst used in the above-described reaction. Further, as a support of the above-described catalyst, a substance generally used as a catalyst support can be used, and as a result of studies on various supports, it is preferable to contain at least any one of SiO2 and ZrO2.

[0042] As a production method of the catalyst used in the above-described dehydration reaction of the present application, the following examples can be given. In the case where the support is SiO2, commercially available powdered or spherical SiO2 can be used, and in order to be able to uniformly support the active metal, the whole is granulated to, for example, 4.0 mm or less; and in order to remove moisture, pre-baking in air at a temperature of, for example, 700°C for about 1 hour is preferable. In addition, although there are various products of SiO2, a product having a large specific surface area is preferable because the larger the specific surface area, the higher the dispersibility of the active metal, and the higher the yield of the aromatic nitrile compound. Specifically, a specific surface area of 300 m 2 / g or more is preferable. However, the specific surface area of the catalyst after preparation is sometimes lower than that of SiO2 alone due to the interaction between SiO2 and the active metal or the like. In this case, the specific surface area of the catalyst after production is preferably 150 m 2 / g or more. The support of the metal oxide as the active species can be achieved by an impregnation method such as an incipient wetness method or an evaporation drying method.

[0043] As the metal salt of the catalyst precursor, various compounds can be used as long as they are water-soluble compounds, and in the case of an alkali metal, various compounds such as carbonate, bicarbonate, chloride, nitrate, silicate and the like can be used. After impregnating the water solution of the precursor of the alkali metal in the support, by drying and firing, it can be used as a catalyst, and although the firing temperature also depends on the precursor used, it is preferably 400 to 600°C.

[0044] Further, as the catalyst used in the present application, a catalyst in which only one or two or more kinds of alkali metal oxides are supported on a carrier containing either one or both of SiO2and ZrO2is preferred, but it can also contain unavoidable impurities mixed in during catalyst production processes and the like other than the above-mentioned elements. However, it is preferred that impurities are not mixed in as much as possible.

[0045] The catalyst in which a metal oxide is supported on a carrier as an active species used in the present application can be in any of a powder or a shaped body, and in the case of a shaped body, it can be in any of a spherical shape, a pellet shape, a cylindrical shape, a ring shape, a wheel shape, a granular shape, and the like. In addition, it can also be used in a state in which the catalyst is fixed to a support structure such as a honeycomb.

[0046] The size of the carrier is not limited, and in the case of using a spherical carrier, the average particle diameter of the catalyst particles (carrier particle diameter) is preferably in the range of 0.01 to 8.0 mm, more preferably 0.03 to 6.0 mm, and further preferably 0.05 to 5.0 mm. By using a catalyst in which the carrier particle diameter is relatively large compared to the average particle diameter of the catalyst particles (carrier particle diameter) used in the liquid phase reaction, the flow path of the reaction substrate in the gas phase reaction can be ensured, and a high space velocity can be ensured. In the case of using a fluidized bed in the gas phase reaction, a catalyst with a relatively small particle diameter is preferred in order to stir the catalyst with a small gas flow rate; and in the case of using a fixed bed in the gas phase reaction, a relatively large particle diameter or shape is preferred in order to not cause pressure loss as much as possible.

[0047] Note that the carrier particle diameter, i.e., the average particle diameter of the catalyst particles, is the average particle diameter of the particles of the entire catalyst including the active component and the carrier of the catalyst. The carrier particle diameter of the catalyst is a measured value measured according to the sieving test method general rules or the like specified in sieving method: JIS Z8815.

[0048] In addition, the support amount of the catalyst can be appropriately set, and the metal equivalent (converted) support amount of the active species such as alkali metal oxides based on the total weight of the catalyst is preferably 0.05 to 2.0 mmol / g, more preferably 0.10 to 1.5 mmol / g, and further preferably 0.30 to 1.0 mmol / g. In addition, the catalyst usage amount at the time of the reaction can also be appropriately set.

[0049] (Reaction form and reaction vessel) In the production method of the aromatic nitrile compound of the present application, a gas phase reaction in which the gaseous or misty amide compound is made to flow through a catalyst layer together with a diluent is preferably employed, and for example, a gas phase reaction apparatus using a fixed bed or a fluidized bed can be applied. In the contacting step in which the aromatic amide compound is contacted with the catalyst in a gas phase, although it is preferable to use the aromatic amide compound in a completely gasified state, the aromatic amide compound in a state in which a part of the liquid droplets (mist) are contained in the gas can also be used.

[0050] The production method of the aromatic nitrile compound is preferably performed while removing the generated by-product water through dehydration reaction. As a result of intensive studies by the inventors of the present application, it has been found that the yield of the aromatic nitrile compound can be increased and the generation of by-products can be suppressed by installing a gasification chamber at the top of the reaction tube to which the catalyst is added, and by dropping the aromatic amide compound into the gasification chamber so that the amide compound passes through the catalyst layer in a gas phase in a short time.

[0051] (Diluent) In the above dehydration reaction, a diluent is preferably used, and particularly preferably at least either one of an inert gas and a solvent described in detail below is used as the diluent in the dehydration reaction. The diluent is mainly used to reduce the frequency of contact of the water generated when the aromatic amide compound is gasified and reacts with the catalyst with the unreacted aromatic amide compound, the aromatic nitrile compound as the reaction product, and the like, and to reduce the generation of by-products such as pyridine.

[0052] Accordingly, the inert gas can also be used as the diluent. Furthermore, if the diluent is one that is soluble in the aromatic amide compound in a liquid phase, in the step of gasifying the aromatic amide compound, by previously mixing the aromatic amide compound with the soluble diluent and feeding the liquid, it is also possible to prevent the clogging problem due to the precipitation of the aromatic amide compound. That is, as the diluent, either an inert gas or a liquid that is not soluble in the aromatic amide compound as the object of the dehydration reaction can be used, but a liquid that is soluble in the aromatic amide compound is more preferable. The diluent that is soluble in the aromatic amide compound in a liquid phase includes not only a diluent that can be mixed with the aromatic amide compound in an arbitrary ratio, but also a diluent that can only dissolve the object aromatic amide compound up to a prescribed solubility, and that dissolves the aromatic amide compound up to a concentration below the upper limit of the solubility at a prescribed temperature.

[0053] (Inert gas) As described above, it is preferable that, in the dehydration reaction, the inert gas is contacted with the catalyst in a gas phase together with the aromatic amide compound. That is, the inert gas is used in the dehydration reaction in a gasified state. As a specific example of the inert gas used in the dehydration reaction, nitrogen gas and noble gases such as helium gas and argon gas can be given, and nitrogen gas is preferably used. The flow rate and the like of the inert gas are described later.

[0054] (Solvent) In the above dehydration reaction, a solvent is preferably used. In particular, as described above, in the process of vaporizing the aromatic amide compound, by previously mixing the aromatic amide compound with a compatible solvent and feeding the liquid, the problem of clogging due to precipitation of the aromatic amide compound can be prevented. That is, as the solvent, a solvent compatible with the aromatic amide compound which is the object of the dehydration reaction is preferable. The solvent compatible with the aromatic amide compound includes not only a solvent which can be mixed with the aromatic amide compound in any ratio, but also a solvent which can only dissolve the object aromatic amide compound up to a prescribed solubility, and dissolve the aromatic amide compound at a prescribed temperature up to a concentration of the upper limit of the solubility.

[0055] The solvent preferably contains at least an aromatic compound, and as the aromatic compound, a compound represented by the following formula (1) is preferably used. In formula (1), R1is independently selected from an alkyl group having 1 to 10 carbon atoms which can have a substituent, an alkoxy group having 1 to 10 carbon atoms which can have a substituent, an aryl group having 6 to 30 carbon atoms which can have a substituent, and an aryloxy group having 6 to 30 carbon atoms which can have a substituent.

[0056] R1in formula (1) is preferably an alkyl group having 1 to 6 carbon atoms which can have a substituent, an alkoxy group having 1 to 6 carbon atoms which can have a substituent, or an aryl group having 6 to 18 carbon atoms which can have a substituent. R1is more preferably any of an alkyl group having 1 to 4 carbon atoms which can have a substituent, an alkoxy group having 1 to 3 carbon atoms which can have a substituent, or an aryl group having 6 to 12 carbon atoms which can have a substituent. Further preferably, R1is any of an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 or 2 carbon atoms which can have a substituent, or an aryl group having 6 to 8 carbon atoms which can have a substituent.

[0057] In formula (1), a is an integer of 1 to 6, and a is preferably an integer of 1 to 4, and more preferably an integer of 1 to 3.

[0058] As the above substituent, a halogen atom, a hydroxyl group, a carboxyl group, a cyano group, an amido group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and the like can be mentioned. Note that the number of carbon atoms mentioned in formula (1) is the total number of carbon atoms including the number of carbon atoms of the substituent.

[0059] The aromatic compound as the solvent preferably has one or two aromatic rings, and one or more selected from the group consisting of an alkyl group, an alkoxy group, and an aryloxy group, more preferably has a total of 1 to 3 alkyl groups and / or alkoxy groups. In addition, the aromatic compound preferably has two or more aromatic rings, such as benzene rings, bonded by an ether bond.

[0060] The aromatic compound used as the solvent for the dehydration reaction preferably includes at least any one of, for example, 1,3,5-trimethylbenzene, p-cymene, phenyl ether, and anisole. In addition, as other specific examples of the solvent, aromatic compounds including pyridine compounds and the like, ketone compounds, ether compounds, ester compounds, alcohols, and the like can be given, and the above-described aromatic compounds are preferably used.

[0061] In addition, the pyridine compound as the solvent, that is, a compound having a pyridine skeleton, can include 2-alkylpyridine, 3-alkylpyridine, 4-alkylpyridine, and the like, for example, 4-methylpyridine, and pyridine. In particular, in the dehydration reaction in which pyridine is likely to be produced as a by-product, if a pyridine compound is used as the solvent after being set to appropriate conditions in advance, a removal process of the main by-product pyridine can be omitted.

[0062] In addition, the ketone compound as the solvent can include, for example, cyclic ketone compounds such as cyclopentanone and cyclohexanone, and acetone.

[0063] Note that, as the solvent for the dehydration reaction, although it is preferable to use a solvent composed only of one or more selected from the above-described compounds, it can also be a mixed solvent containing other compounds.

[0064] The solvent is preferably vaporized together with the aromatic amide compound for the dehydration reaction (contacting process). Thus, a solvent that is vaporized and used for the dehydration reaction is preferably used. In addition, as described in detail later, since it is used in the dehydration reaction performed at a high temperature, the solvent as the aromatic compound preferably has a relatively high autoignition temperature. For example, the solvent preferably has an autoignition temperature of 300°C or higher, 340°C or higher, 380°C or higher, or 400°C or higher, more preferably has an autoignition temperature of 430°C or higher or 450°C or higher, further preferably has an autoignition temperature of 470°C or higher or 500°C or higher, and particularly preferably has an autoignition temperature of 550°C or higher.

[0065] In addition, the boiling point of the solvent as the aromatic compound is not particularly limited, and the boiling point at normal pressure is, for example, 20°C or higher and 300°C or lower, preferably 80°C or higher and 250°C or lower, and further preferably 110°C or higher and 200°C or lower.

[0066] (Conditions of the dehydration reaction including the contacting process) The method for producing an aromatic nitrile compound as described above has a contacting step in which the aromatic amide compound is contacted with the catalyst in the gas phase in the dehydration reaction.

[0067] In the contacting step, the temperature at which the aromatic amide compound and a diluent such as a solvent are contacted with the catalyst is, for example, a temperature of 285°C or higher, and is preferably 300°C or higher. The contacting temperature is more preferably 300°C or higher and 550°C or lower, further preferably 320°C or higher and 520°C or lower, and particularly preferably 350°C or higher and 490°C or lower.

[0068] Note that the temperature at which the aromatic amide compound and the like are contacted with the catalyst is the temperature in the vicinity of the catalyst layer in a reaction tube (reaction vessel) in which the catalyst is fixed, for example, as described later.

[0069] The time during which the aromatic amide compound is contacted with the catalyst in the contacting step (catalytic contacting time) and the catalytic contacting time of a mixed gas of these gaseous compositions in the case where the gaseous compositions contain an inert gas, a solvent, and the like in addition to the aromatic amide compound are preferably 0.001 seconds or more or 0.005 seconds or more, and are, for example, preferably 0.01 seconds or more and less than 10 seconds. The catalytic contacting time is more preferably 0.1 seconds or more and less than 5 seconds, and further preferably 0.5 seconds or more and less than 2 seconds.

[0070] Note that the catalytic contacting time refers to the average time during which the gas of the aromatic amide compound or the mixed gas passes through the catalyst layer, and is calculated from the catalytic contacting time (seconds) = catalyst layer height in the reactor (cm) ÷ gas linear velocity in the reactor (cm / second).

[0071] In the contacting step, the molar ratio of the flow rate of the aromatic amide compound to the flow rate of the gaseous composition is preferably 1:0 to 1:200, more preferably 1:1 to 1:100, and further preferably 1:1 to 1:20.

[0072] The space velocity (SV) of all the gas components in the contacting step is preferably 1000 to 50000 (h ﹣1 ), more preferably 1500 to 30000 (h ﹣1 ), and further preferably 2000 to 25000 (h ﹣1 ). In addition, in the case where the contacting step is performed under reduced pressure, the space velocity (SV) of all the gas components is preferably 1000 to 1000000 (h ﹣1 ), more preferably 1500 to 700000 (h ﹣1 ), and further preferably 1900 to 504000 (h ﹣1 ).

[0073] As the conditions of the dehydration reaction, it can be carried out under a pressure of pressurization (e.g., 506.5 (kPa)) to normal pressure (101.3 (kPa)) or reduced pressure (e.g., 101.3 to 1.0 (kPa) or less, 101.3 to 1.0 (kPa) to 0.1 (kPa), etc.), although it is not particularly limited, but it is preferable that the dehydration reaction be carried out under reduced pressure.

[0074] The reaction pressure in the dehydration reaction is preferably 101.3 (kPa) or less, more preferably 90 (kPa) to 1.0 (kPa) or 80 (kPa) to 5.0 (kPa), further preferably 70 (kPa) to 10 (kPa) or 60 (kPa) to 20 (kPa), particularly preferably 50 (kPa) to 30 (kPa).

[0075] Further, the aromatic amide compound is preferably subjected to dehydration in advance in a liquid state before vaporization. In the case where a molecular sieve is used as the dehydration agent, there is no particular limitation on the kind, shape, etc., and a product having a generally high water absorption such as 3A, 4A, 5A, etc. can be used, and a spherical or pellet-like product can be used. For example, ZEORAM® manufactured by Tosoh Corporation can be suitably used.

[0076] (Examples of by-products in the dehydration reaction) In the dehydration reaction of the aromatic amide, it is considered that a by-product pyridine is generated via an aromatic carboxylic acid due to the decomposition of the aromatic amide compound as described above. However, in the reaction liquid after the dehydration reaction of the present application which employs the contact step, the by-product pyridine or the like represented by the above formula is hardly contained.

[0077] <2. Method for producing carbonate using aromatic nitrile compound> In the regeneration from the aromatic amide compound to the aromatic nitrile compound using the dehydration reaction, by providing the contact step under the gas phase, it is possible to greatly increase the reaction speed and greatly shorten the reaction time. Thereby, it is possible to balance the regeneration speed from the aromatic amide compound to the aromatic nitrile compound using the dehydration reaction and the synthesis speed of the synthesis of the carbonate from CO2 and alcohol using the aromatic nitrile compound, and it is possible to establish these reactions as a series of commercial processes. Thereby, the inventors of the present application were able to conceive the method for producing carbonate described below by applying the above knowledge to the method for producing carbonate.

[0078] (First reaction step) The first reaction step in the method for producing carbonate of the present application includes a reaction (carbonate generation reaction) in which an alcohol is directly reacted with carbon dioxide in the presence of a solid catalyst including, for example, CeO2 (cerium oxide) or the like and an aromatic nitrile compound to generate a carbonate.

[0079] In this process, although water is generated in addition to the carbonate when the alcohol is reacted with carbon dioxide, the aromatic amide compound is generated by the hydration reaction of the aromatic nitrile compound present in the reaction system with the generated water, and the generated water can be removed or reduced from the reaction system. Therefore, by effectively removing the water from the reaction system, the generation of the carbonate can be promoted. For example, as shown in the following formula. (alcohol) In the present application, as the alcohol, any alcohol selected from one or two or more of a primary alcohol, a secondary alcohol, and a tertiary alcohol can be used. For example, when methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, allyl alcohol, 2-methyl-l-propanol, cyclohexanemethanol, benzyl alcohol, ethylene glycol, 1,2-propanediol, and 1,3-propanediol are used, they are preferable because the product yield is high and the reaction rate is also fast. At this time, the generated carbonates are dimethyl carbonate, diethyl carbonate, dipropyl carbonate, diisopropyl carbonate, dibutyl carbonate, dipentyl carbonate, dihexyl carbonate, diheptyl carbonate, dioctyl carbonate, dinonyl carbonate, diallyl carbonate, di(2-methylpropyl) carbonate, dicyclohexanemethyl carbonate, dibenzyl carbonate, vinyl carbonate, 1,2-propanediol carbonate, and 1,3-propanediol carbonate.

[0080] In addition, in the first reaction process, an alcohol having 1 to 6 carbon atoms is preferably used, and an alcohol having 2 to 4 carbon atoms is more preferably used. In particular, when the obtained carbonate is used as a raw material of a diaryl carbonate, it is preferable to adjust the number of carbon atoms of the alcohol to the above range.

[0081] Further, in the first reaction process, a monohydric alcohol or a dihydric alcohol is preferably used.

[0082] (carbonate production catalyst) In addition, in the first reaction process of producing the carbonate, a solid catalyst of either one of Ce02and Zr02or both is preferably used. For example, Ce02alone, Zr02alone, a mixture of Ce02and Zr02, or a solid solution or a composite oxide of Ce02and Zr02, or the like is preferable, and the use of Ce02alone is particularly preferable. Further, the mixing ratio of Ce02to Zr02in the solid solution or the composite oxide of Ce02and Zr02is basically set to 50:50, but the mixing ratio can be appropriately set.

[0083] In the present application, the catalyst used in the first reaction process can be in any of a powder form or a molded body form, and in the case of a molded body, it can be in any of a spherical shape, a pellet shape, a cylindrical shape, a ring shape, a wheel shape, a granular shape, or the like.

[0084] (carbon dioxide) The carbon dioxide used in the present application can be not only a product prepared as an industrial gas, but also carbon dioxide separated and recovered from exhaust gas of a plant for manufacturing various products, a steel mill, a power plant, and the like.

[0085] (Solvent in carbonic ester generation reaction) In the carbonic ester generation reaction, a solvent having a higher boiling point than the generated amide compound is preferably used. More preferably, the solvent in the carbonic ester generation reaction contains at least one of a dialkylbenzene, an alkyl naphthalene, and a diphenylbenzene, and as specific examples, there can be mentioned Barrel Process Oil B28AN and Barrel Process Oil B30 (Matsunushi Oil Manufacturing) containing components such as a dialkylbenzene, an alkyl naphthalene, and a diphenylbenzene, and the like.

[0086] (Distillation separation) After the reaction, distillation separation is performed on the carbonic ester as a main product, the aromatic amide compound as a by-product, the unreacted aromatic nitrile compound, the solid catalyst such as CeO2, and the like, and the products can be recovered.

[0087] (Second reaction step) Next, the second reaction step of the present application will be described. In the second reaction step, after the by-product aromatic amide compound in the first reaction step is preferably separated from the system after the carbonic ester generation reaction, an aromatic nitrile compound is manufactured by a dehydration reaction. The second reaction step corresponds to the above-mentioned method for manufacturing an aromatic nitrile compound. That is, in the second reaction step for generating a carbonic ester, an aromatic nitrile compound can be manufactured from an aromatic amide compound by the method described in the above-mentioned method for manufacturing an aromatic nitrile compound section, and thus the aromatic nitrile compound is regenerated. Therefore, detailed description of the second reaction step is omitted.

[0088] (Reuse of aromatic nitrile compound) The aromatic nitrile compound regenerated by the second reaction step can be reused in the first reaction step (hydration reaction).

[0089] According to the present application, as described above, by performing the reaction in a gas phase in the dehydration reaction of the aromatic amide compound, not only the generation of a by-product can be suppressed, but also the aromatic nitrile compound can be effectively regenerated from the aromatic amide compound. Further, by fixing the catalyst in the reaction tube, for example, not only a solid-liquid separation step of the catalyst is not necessary, but also the recovery of the aromatic nitrile compound is facilitated. Thus, in the present application, not only the aromatic nitrile compound can be selectively regenerated from the aromatic amide compound, but also by distillation separation alone without the solid-liquid separation of the catalyst, each component can be separated and a series of reactions can be performed, and thus an effective process as described in detail later can be achieved.

[0090] <3. Carbonic ester manufacturing apparatus> Next, a carbonic acid ester production apparatus used in the present application will be described in more detail using the following specific example. Figure 1 An example of an applicable device.

[0091] (First reaction step) In the first reaction step, an alcohol (1-propanol (PrOH); liquid phase) as a raw material, 2-cyanopyridine (2-CP; liquid phase), and carbon dioxide (CO2; liquid phase, supplied via a booster pump) are continuously supplied to the buffer tank 1 via the raw material feed pipe 31, the CO2 recovery column overhead CO2 delivery pipe (CO2 delivery pipe on the overhead side of the CO2 recovery column) 15, the carbonic acid ester recovery column overhead liquid delivery pipe (liquid delivery pipe on the overhead side of the carbonic acid ester recovery column) 19, and the amide separation column overhead liquid delivery pipe (liquid delivery pipe on the overhead side of the amide separation column) 21. The raw material mixture is circulated between the fixed bed flow-through carbonic acid ester reactor 2 (first reaction section) in which a solid catalyst (solid phase) such as either or both of CeO2and ZrO2is fixed to a support material and the buffer tank 1 via the first reaction liquid circulation pipe 11 and the second reaction liquid circulation pipe 12 by means of a pump (not shown), thereby synthesizing dipropyl carbonate (DPrC). The reaction liquid containing DPrC is continuously extracted from the second reaction liquid circulation pipe 12 in an amount equivalent to the raw material supply amount supplied to the buffer tank 1, and is recovered by the pipe 13 to be sent to the DPrC recovery step. PrOH and CO2 are recovered from the reaction liquid and delivered to the buffer tank 1 via the carbonic acid ester recovery column overhead liquid delivery pipe 19 and the CO2 recovery column overhead CO2 delivery pipe 15, respectively, to enable reuse. As the 2-cyanopyridine, for example, a fresh product is used at the start of the reaction, but 2-cyanopyridine regenerated from 2-picolinamide can also be separated and purified in the amide separation column 6, delivered to the buffer tank 1 via the amide separation column overhead liquid delivery pipe 21, and reused.

[0092] Note that, as the carbonic acid ester direct synthesis apparatus (carbonic acid ester reactor 2) in which, for example, CeO2and ZrO2or the like are used as a solid catalyst, any of a flow-type reactor such as a batch reactor, a semi-batch reactor, a continuous tank reactor, or a pipe reactor can be used, and if the catalyst is fixed to the reaction apparatus, there is no need to filter and separate the catalyst, and thus a fixed bed reactor is preferable.

[0093] (Reaction liquid temperature) The reaction liquid temperature in the carbonate reactor 2 is preferably set to 50 to 300°C. When the reaction liquid temperature is lower than 50°C, the reaction rate is low, and the synthesis reaction of the carbonate and the hydration reaction using 2-cyanopyridine hardly proceed, and the productivity of the carbonate tends to be low. In addition, when the reaction liquid temperature exceeds 300°C, although the reaction rate of each reaction increases, the carbonate tends to be easily decomposed or modified, and aromatic amide compounds such as 2-picolinamide tend to react with alcohol, and thus the yield of the carbonate tends to be low. The reaction liquid temperature is further preferably 100 to 150°C. However, since the ideal reaction liquid temperature varies depending on the kind and amount of the solid catalyst, the amount and ratio of the raw materials (alcohol, 2-cyanopyridine), it is necessary to appropriately set to the optimum condition. In addition, since the preferable reaction liquid temperature is 100 to 150°C, it is preferable to preheat the raw materials (alcohol, 2-cyanopyridine, etc.) with steam or the like in the preceding stage of the carbonate reactor.

[0094] (Reaction pressure) The reaction pressure in the carbonate reactor 2 is preferably set to 0.1 to 20 MPa (absolute pressure). When the reaction pressure is lower than 0.1 MPa (absolute pressure), a pressure reducing device is required, and not only the equipment tends to be complicated, but also the cost increases, and in addition, a power source for pressure reduction is required, and thus the energy efficiency becomes poor. In addition, when the reaction pressure exceeds 20 MPa, the hydration reaction using 2-cyanopyridine hardly proceeds, and not only the yield of the carbonate becomes poor, but also a power source for pressure increase is required, and thus the energy efficiency becomes poor. In addition, from the viewpoint of improving the yield of the carbonate, the reaction pressure is more preferably 0.5 to 15 MPa (absolute pressure), and further preferably 1.0 to 10 MPa (absolute pressure).

[0095] (Amount of aromatic nitrile compound (2-cyanopyridine, etc.)) The aromatic nitrile compound such as 2-cyanopyridine used in the hydration reaction is preferably introduced into the reactor in a molar amount of 0.1 times or more and 5 times or less of the theoretical molar amount of the by-product water generated by the reaction of the raw material alcohol with CO2 before the reaction. More preferably, the molar amount of the aromatic nitrile compound such as 2-cyanopyridine is 0.2 times or more and 3 times or less, and particularly preferably 0.3 times or more and 1.5 times or less of the theoretical molar amount of the by-product water generated by the reaction of the raw material alcohol with CO2. When the molar amount of the aromatic nitrile compound such as 2-cyanopyridine is too small, the 2-cyanopyridine or the like participating in the hydration reaction is small, and thus the yield of the carbonate can be poor. On the other hand, when the aromatic nitrile compound such as 2-cyanopyridine is introduced in a molar amount exceeding that of the raw material alcohol, since the side reaction of 2-cyanopyridine or the like increases, it is not preferable. In addition, since the ideal amount of the alcohol and 2-cyanopyridine or the like with respect to the solid catalyst varies depending on the kind and amount of the solid catalyst, the kind of the alcohol, and the ratio to 2-cyanopyridine, it is necessary to appropriately set to the optimum condition.

[0096] Separation of reaction products The separation of the reaction products is preferably carried out exclusively by distillation. The reaction liquid 13 after the reaction in the carbonate reactor 2 is fed to the CO2 recovery column 3, from the bottom of which a mixture of PrOH, DPrC, 2-cyanopyridine, 2-picolinamide is recovered via the bottom liquid feed line 14 of the CO2 recovery column 3, and from the top of which CO2 is recovered via the top CO2 feed line 15 of the CO2 recovery column. The recovered CO2 is fed to the buffer tank 1 and recycled in the reaction in the carbonate reactor 2.

[0097] The mixture recovered from the CO2 recovery column 3 is fed via the bottom liquid feed line 14 of the CO2 recovery column to the dehydrating agent separation column 4, from the bottom of which a mixture of 2-cyanopyridine and 2-picolinamide is recovered via the bottom liquid feed line 16 of the dehydrating agent separation column, and from the top of which PrOH and DPrC are recovered via the top liquid feed line 17 of the dehydrating agent separation column.

[0098] The mixture recovered from the bottom of the dehydrating agent separation column 4 is fed via the bottom liquid feed line 16 of the dehydrating agent separation column to the amide separation column 6, from the bottom of which 2-picolinamide (20) is recovered, and from the top of which 2-cyanopyridine is recovered. The recovered 2-cyanopyridine is fed via the top liquid feed line 21 of the amide separation column to the buffer tank 1 and recycled in the reaction in the carbonate reactor 2.

[0099] PrOH and DPrC recovered from the top of the dehydrating agent separation column 4 are fed via the top liquid feed line 17 of the dehydrating agent separation column to the carbonate recovery column 5, from the bottom of which DPrC is recovered via the bottom liquid feed line 18 of the carbonate recovery column, and from the top of which PrOH is recovered via the top liquid feed line 19 of the carbonate recovery column. The recovered PrOH is fed to the buffer tank 1 and recycled in the reaction in the carbonate reactor 2.

[0100] Second reaction process In the second reaction process, 2-cyanopyridine is produced by the dehydration reaction of 2-picolinamide using the nitrile regeneration gas phase reactor 8.

[0101] The 2-picolinamide recovered by the amide separation column 6 is fed to the gasification device 7 via the amide separation column bottom liquid feed pipe 20, preferably mixed with an inert gas such as nitrogen, and further heated to the vicinity of the boiling point of the amide compound, thereby forming a gas or a mixed gas of gas and liquid droplets, which is fed to the nitrile regeneration gas phase reactor 8 via the gasification device-nitrile regeneration gas phase reactor connecting pipe 22. The form of the gasification device 7 for gasifying the amide compound is not particularly limited, and any one of a jet-type gasifier, a contact-type gasifier, a bubbling device, etc. can be used.

[0102] In the nitrile compound production device (nitrile regeneration gas phase reactor 8) used in the present application, the 2-picolinamide, and preferably together with an inert gas such as nitrogen, is brought into contact with a catalyst on which a basic metal oxide is supported in the gas phase, thereby initiating a dehydration reaction of the 2-picolinamide. By this dehydration reaction, 2-cyanopyridine is produced. Note that during the feeding of the amide compound, the amide compound can also be fed as a liquid by dissolving it in a feed solvent for the purpose of preventing clogging. When an amide feed solvent is used, it is preferable that the solvent is also gasified together with the amide, and a nitrile regeneration gas phase reaction is performed, in which case, solvent vapor can be used instead of the inert gas.

[0103] The form of the nitrile regeneration gas phase reactor 8 is not particularly limited, and a gas phase reaction in which a gaseous or misty amide compound is caused to flow through a catalyst layer together with an inert gas, etc. can be performed using a fixed bed or a fluidized bed, etc. as a gas phase reaction device.

[0104] Thus, in order to cause the 2-picolinamide to come into contact with a catalyst, etc. in the gas phase and effectively perform a dehydration reaction, various reaction conditions described above in relation to the dehydration reaction or the reaction conditions described in the Examples section below can be appropriately used.

[0105] The mixed gas containing 2-cyanopyridine is fed from the gas phase reactor 8 to the H2O separation device 9 via the gas phase reaction product feed pipe 23. Water and nitrogen are separated from the mixed gas by the H2O separation device 9, and the recovered 2-cyanopyridine and 2-picolinamide are fed from the H2O separation device 9 to the amide separation column 6 via the H2O separation device high-boiling substance feed pipe 24. Also, the 2-picolinamide is recovered from the bottom of the amide separation column 6 and fed to the gasification device 7 via the amide separation column bottom liquid feed pipe 20, and the 2-cyanopyridine is recovered from the top of the amide separation column 6. The recovered 2-cyanopyridine is fed to the buffer tank 1 via the amide separation column top liquid feed pipe 21, and recycled in the reaction in the carbonate reactor 2.

[0106] The nitrogen gas and water separated by the H2O separation device 9 are sent to the N2 recovery device 10 via the light-ends delivery pipe 25 of the H2O separation device, and the water is separated and the nitrogen gas is recovered in the N2 recovery device 10. The water separated by the N2 recovery device 10 is sent to the outside of the carbonate device via the water delivery pipe 26 of the N2 recovery device. The nitrogen gas recovered by the N2 recovery device 10 is delivered to the gasification device 7 via the N2 delivery pipe 27 of the N2 recovery device, and thus can be used in the gas phase reaction. In the case where a delivery solvent of an amide compound is used, a solvent recovery process can be provided separately, and thus can be reused in the delivery of the amide compound. The forms of the H2O recovery device 9 and the N2 recovery device 10 are not particularly limited, and any one of a cooling device, a membrane separation device, and the like can be used.

[0107] As described above, in the present application, not only the dehydration of the amide compound can be performed by the contact process under the gas phase, but also the reaction product and the reused compound can be separated by distillation separation or the like without performing the solid-liquid separation. Therefore, according to the present application, not only the device simplification can be achieved, but also the carbonate can be effectively manufactured with fewer manufacturing processes.

[0108] Example The present application is further explained in detail by examples below, but the present application is not limited to these examples. First, examples and comparative examples of the manufacturing method of the cyanopyridine are described.

[0109] Example 1 (Example using a solvent as a diluent) A support SiO2 (CARiACT, G-6 (support particle diameter 0.010 mm) manufactured by FUJI SILYSIA CHEMICAL LTD.) was subjected to a pre-burning at a temperature of 700°C for 1 hour. Then, in order to support Cs as an alkali metal, an aqueous solution of CsNO3 (manufactured by Wako Pure Chemical Industries, Ltd.) was prepared, and the SiO2 was impregnated with the solution in such a manner that the final Cs metal support amount reached 0.5 mmol / g. Then, drying was performed at a temperature of 110°C for 6 hours, and firing was performed at a temperature of 500°C for 3 hours, and thus a Cs2O / SiO2 catalyst was obtained.

[0110] The catalyst manufactured by the above manufacturing method was filled into a reaction tube 36 made of SUS316 having an inner diameter of 10.8 mm and a length of 35 cm (see Figure 2 A gasification chamber 33 made of SUS316 having an inner diameter of 10.8 mm and a length of 35 cm was provided just above the reaction tube 36, and the gasification chamber 33 was filled with a Raschig ring.

[0111] A mixture of 2-picolinamide (2-PA) 203 g and a solvent for transportation, mesitylene (200 g), was heated and mixed in an oil bath at 140°C, and the resulting mixed solution of 2-PA and mesitylene was transferred to the raw material container 30.

[0112] The gasification chamber 33 and the reaction tube 36 connected to the raw material container 30 were heated by the tube furnaces 34 and 35 (see Fig. 1). Figure 2 The outlet side piping of the reaction tube 36 was heat-insulated at 180°C. In order to recover the reaction product, a dry ice / methanol cold trap container 37 and a trap container 38 were provided, and the outlet side piping of the trap container 38 was connected to a vacuum pump 39, and the gasification chamber 33 and the reaction tube 36 were depressurized to 40 (KPa).

[0113] After the temperature of the gasification chamber and the reaction tube was stabilized at 337°C, the plunger pump 32 was started, and the reaction was performed for the time shown in the catalytic contact time column of Table 1 below.

[0114] Examples 2 to 10 and Comparative Examples 1 to 7 The dehydration reaction of 2-picolinamide was performed in the same manner as in Example 1, using the same reaction apparatus, except that the reaction conditions were changed as shown in Table 1 below.

[0115] The conditions of the above contact reaction (dehydration reaction) are shown in Table 1. Then, after the reaction was completed, the reaction product was recovered and analyzed by GC-FID.

[0116] The analysis conditions of the results of the contact reaction (dehydration reaction) are shown below. [Analysis Conditions] (GC-FID) Shimadzu GC-2014, column: TC-17 (length 30 m, inner diameter 0.25 mm ID, liquid phase film thickness 0.25 μm), Gasification chamber temperature: 250°C, detector: 250°C, carrier gas N2: 175 kPa, column flow rate: 10.3 mL / min, split ratio: 5.0 Temperature program: [hold at 40°C for 10 minutes] → [raise to 250°C at 12°C / min] → [hold at 250°C for 5 minutes] [24-hour yield per 1 g of catalyst (mmol / 24 hr·g)] = (amount of product recovered after 24 hours of reaction, mmol) / (amount of catalyst, g) [Space velocity: SV (hr ﹣1 )] = (amount of gas passing through the catalyst layer (L·hr ﹣1 )) / (amount of catalyst (L)) Gas amount: total gas volume of nitrogen, 2-PA, and solvent (L·hr ﹣1 ) [Catalyst packing height (height of catalyst layer in reactor)] : height of catalyst packed into the reactor tube (cm) [Catalytic contact time (sec)] = [Catalyst packing height (cm)] / [Linear velocity (gas linear velocity in reactor) (cm / sec)] [Catalyst support particle size] The catalyst support particle size is a measured value measured according to the general rules for sieve test methods specified in JIS Z 8815.

[0117] [Autoignition temperature of solvent] The autoignition temperature of the solvent used in the examples and comparative examples is a measured value or a literature value. The measured value of the autoignition temperature is a value measured by the ignition point test according to ASTM E659-15.

[0118] [Gasification chamber and reactor tube temperature and reaction temperature (contact temperature)] According to the reaction apparatus schematic diagram of, for example, Figure 2 and Figure 3 , a SUS316 sheath tube with an internal thermometer was inserted from the lower part of the reaction tube exemplified by the reaction tube 36 to a position just below the catalyst layer, and the gasification chamber and reactor tube temperature and the reaction temperature in the dehydration reaction were measured. That is, the temperature just below the catalyst layer was measured, the temperature before the passage of the raw material stream was taken as the temperature of the gasification chamber and reactor tube, and the temperature when the raw material stream was passed was taken as the reaction temperature (contact temperature).

[0119] [Detection of unknown components] Detection was performed according to the relevant measurement methods of the contact reaction (dehydration reaction) product described in the [Analysis conditions] section above, and cases where compounds with indeterminate molecular structures (unknown components) were detected were recorded as “yes”, and cases where no unknown components were detected were recorded as “no”.

[0120] [Table 1] Example 11 (Example using solvent as diluent) A support SiO2(CARiACT, G-6 (support particle size 0.010 mm) manufactured by Fuji Silysia Chemical Ltd.) was subjected to a pre-baking at a temperature of 700°C for 1 hour. Then, in order to support Cs as an alkali metal in such a manner that the final Cs metal support amount would be 0.5 mmol / g, an aqueous solution was prepared using CsNO3(manufactured by Wako Pure Chemical Industries, Ltd.) and was impregnated in the SiO2. Then, drying was performed at a temperature of 110°C for 6 hours and firing was performed at a temperature of 500°C for 3 hours, thereby obtaining a Cs2O / SiO2 catalyst.

[0121] The catalyst manufactured by the above manufacturing method was filled into a reaction tube 36 made of SUS316 having an inner diameter of 10.8 mm and a length of 35 cm (see FIG. 1). Figure 2 A gasification chamber 33 made of SUS316 having an inner diameter of 10.8 mm and a length of 35 cm was provided immediately above the reaction tube 36, and the gasification chamber 33 was filled with a Rasching ring.

[0122] 2-picolinamide (2-PA) 170 g was mixed with a solvent for transportation, p-cymene (187 g), in an oil bath at 140°C, and the resulting 2-PA and p-cymene mixed solution was transferred to the raw material container 30.

[0123] The gasification chamber 33 and the reaction tube 36 connected to the raw material container 30 were heated by the tube furnaces 34 and 35 (see FIG. 1). Figure 2 The outlet side piping of the reaction tube 36 was heat-insulated at 180°C. In order to recover the reaction product, a dry ice / methanol cold trap container 37 and a trap container 38 were provided, and the outlet side piping of the trap container 38 was connected to a vacuum pump 39, and the gasification chamber 33 and the reaction tube 36 were depressurized to 40 (KPa).

[0124] After the temperature of the gasification chamber and the reaction tube was stabilized at 382°C, the plunger pump 32 was started, and the reaction was performed for the time shown in the catalytic contact time column of Table 2 below.

[0125] Examples 12 to 13 and Comparative Examples 8 to 15 The dehydration reaction of 2-picolinamide was performed in the same manner as in Example 11 using the same reaction apparatus as in Example 11, except that the reaction conditions were changed as shown in Table 2 below.

[0126] Example 14 A support SiO2(CARiACT, G-6 (support particle size 0.010 mm) manufactured by Fuji Silysia Chemical Ltd.) was pre-burned at a temperature of 700°C for 1 hour. Then, in order to support K (potassium) as an alkali metal, in such a manner that the final K metal support amount would be 0.5 mmol / g, an aqueous solution prepared using KNO3(manufactured by Wako Pure Chemical Industries, Ltd.) was impregnated in the SiO2. Then, drying was performed at a temperature of 110°C for 6 hours, and firing was performed at a temperature of 500°C for 3 hours, to obtain a K2O / SiO2 catalyst.

[0127] The catalyst manufactured by the above manufacturing method was filled into a reaction tube 36 made of SUS316 having an inner diameter of 10.8 mm and a length of 35 cm (see FIG. 1). Figure 2 A gasification chamber 33 made of SUS316 having an inner diameter of 10.8 mm and a length of 35 cm was provided directly above the reaction tube 36, and the gasification chamber 33 was filled with a Raschig ring.

[0128] 2-picolinamide (2-PA) 203 g and a solvent for transport, mesitylene (200 g), were mixed by heating in an oil bath at 140°C, and the resulting mixed solution of 2-PA and mesitylene was transferred to the raw material container 30.

[0129] The gasification chamber 33 and the reaction tube 36 connected to the raw material container 30 were heated to 511.2°C by the tube furnaces 34 and 35 (see FIG. 1). Figure 2 The outlet side piping of the reaction tube 36 was heat-insulated at 180°C. In order to recover the reaction product, a dry ice / methanol cold trap container 37 and a trap container 38 were provided, and the outlet side piping of the trap container 38 was connected to a vacuum pump 39, and the gasification chamber 33 and the reaction tube 36 were depressurized to 40 (KPa).

[0130] After the temperature of the catalyst layer was stabilized, the plunger pump 32 was activated, and the reaction was performed for the time indicated in the catalytic contact time column of Table 2 below.

[0131] Example 15 A support SiO2(CARiACT, G-6 (support particle size 0.010 mm) manufactured by Fuji Silysia Chemical Ltd.) was pre-burned at a temperature of 700°C for 1 hour. Then, in order to support Na as an alkali metal, in such a manner that the final Na metal support amount would be 0.5 mmol / g, an aqueous solution prepared using NaNO3(manufactured by Wako Pure Chemical Industries, Ltd.) was impregnated in the SiO2. Then, drying was performed at a temperature of 110°C for 6 hours, and firing was performed at a temperature of 500°C for 3 hours, to obtain a Na2O / SiO2 catalyst.

[0132] The catalyst manufactured by the above manufacturing method was filled into a SUS316-made reaction tube 36 having an inner diameter of 10.8 mm and a length of 35 cm (see FIG. 1). Figure 2 A gasification chamber 33 made of SUS316 having an inner diameter of 10.8 mm and a length of 35 cm was provided just above the reaction tube 36, and the gasification chamber 33 was filled with Raschig rings.

[0133] The dehydration reaction of 2-picolinamide was performed in the same manner as in Example 14, except that the reaction conditions other than the catalyst were changed as shown in Table 2 below, using the same reaction apparatus as in Example 14.

[0134] Example 16 (Example using inert gas (nitrogen) as diluent) A support SiO2(CARiACT Q-6 (support particle size: 0.075 to 0.15 mm) manufactured by Fuji Silysia Chemical Ltd.) was subjected to pre-baking at a temperature of 700°C for 1 hour. Then, in order to support Cs as an alkali metal, an aqueous solution prepared using CsNO3(manufactured by Wako Pure Chemical Industries, Ltd.) was impregnated in the SiO2in such a manner that the final Cs metal support amount reached 0.5 mmol / g. Then, drying was performed at a temperature of 110°C for 6 hours, and firing was performed at a temperature of 500°C for 3 hours, to obtain a Cs2O / SiO2catalyst.

[0135] The catalyst manufactured by the above manufacturing method was filled into a SUS316-made reaction tube 36 having an inner diameter of 10.8 mm and a length of 35 cm (see Figure 3 A gasification chamber 33 made of SUS316 having an inner diameter of 10.8 mm and a length of 35 cm was provided just above the reaction tube 36, and the gasification chamber 33 was filled with Raschig rings.

[0136] 2-picolinamide (2-PA) 100 g was dissolved in an oil bath at 140°C, and the 2-PA was transferred to the raw material container 30 without using a solvent.

[0137] The gasification chamber 33 and the reaction tube 36 connected to the raw material container 30 were heated by the tube furnaces 34 and 35 (see FIG. 1). Figure 3 The outlet side of the reaction tube 36 was heat-insulated at 180°C. In order to recover the reaction product, a dry ice / methanol cold trap container 37 and a trap container 38 were provided. The outlet side of the trap container 38 was opened to the atmosphere.

[0138] After the temperature of the gasification chamber and the reaction tube was stabilized at 516°C, the plunger pump 32 was started, and nitrogen was introduced as a diluent, and the reaction was performed for the time shown in the catalytic contact time column of Table 2 below.

[0139] Comparative Example 16 The dehydration reaction of 2-picolinamide was performed in the same manner as in Example 16, using the same reaction apparatus, except that the reaction conditions were changed as shown in Table 2 below.

[0140] [Table 2] From the results of the examples and the comparative examples, it was confirmed that the higher the reaction temperature in the gas phase dehydration reaction, the higher the yield of the aromatic nitrile compound and the more the generation of the by-product pyridine was suppressed (see Tables 1, 2 and 3 above). Figure 4 and Figure 5 In addition, in some examples, although relatively large amounts of by-products were produced, the overall evaluation of all the examples was good because of the high yield of the aromatic nitrile compound.

[0141] The preferred embodiments of the present application are described in detail above with reference to the accompanying drawings, but the present application is not limited to the related examples. Obviously, those having ordinary knowledge in the technical field to which the present application pertains can conceive various modified examples or corrected examples within the scope of the technical idea recited in the scope of the claims, and these modified examples or corrected examples are naturally to be understood as belonging to the technical scope of the present application.

[0142] Explanation of symbols 30: raw material container 32: plunger pump 33: vaporization chamber 34: heat medium double pipe / tube furnace 35: heat medium double pipe / tube furnace / cannula heater 36: reaction tube 37: cold trap container 38: trap container 39: vacuum pump 40: nitrogen introduction pipe

Claims

1. A method for manufacturing an aromatic nitrile compound, characterized in that: This includes dehydration reactions that dehydrate aromatic amide compounds. The dehydration reaction includes a contact step in which the aromatic amide compound and the diluent come into contact with the catalyst in the gas phase. In the contact process, the temperature at which the aromatic amide compound and the diluent come into contact with the catalyst is above 300°C.

2. The method for manufacturing aromatic nitrile compounds according to claim 1, characterized in that: The diluent comprises at least one of a solvent and an inert gas.

3. The method for manufacturing aromatic nitrile compounds according to claim 2, characterized in that: The solvent contains at least an aromatic compound.

4. The method for manufacturing aromatic nitrile compounds according to claim 3, characterized in that: The aromatic compound is represented by the following formula (1), In formula (1), R1 is independently selected from alkyl groups having 1 to 10 carbon atoms that may have substituents, alkoxy groups having 1 to 10 carbon atoms that may have substituents, aryl groups having 6 to 30 carbon atoms that may have substituents, and aryloxy groups having 6 to 30 carbon atoms that may have substituents, and a is an integer from 1 to 6.

5. The method for manufacturing aromatic nitrile compounds according to claim 3, characterized in that: The aromatic compound has one or two aromatic rings and one or more groups selected from alkyl, alkoxy and aryloxy groups.

6. The method for producing the aromatic nitrile compound according to claim 3, characterized in that: The aromatic compound has an auto-ignition temperature of over 300°C.

7. The method for producing the aromatic nitrile compound according to claim 3, characterized in that: The aromatic compound comprises at least one of 1,3,5-trimethylbenzene, p-isopropyltoluene, phenyl ether, and anisole.

8. The method for producing the aromatic nitrile compound according to claim 1, characterized in that: The pressure of the reaction system in the contact process is below 101.3 kPa.

9. The method for producing the aromatic nitrile compound according to claim 1, characterized in that: The aromatic amide compound contains at least a heteroaryl amide compound, and the aromatic nitrile compound contains at least a heteroaryl nitrile compound.

10. The method for producing the aromatic nitrile compound according to claim 9, characterized in that: The heteroaryl amide compound contains 2-picolinamide, and the heteroaryl nitrile compound contains 2-cyanopyridine.

11. The method for producing the aromatic nitrile compound according to claim 1, characterized in that: In the contact process, an inert gas in a vaporized state is used.

12. The method for producing the aromatic nitrile compound according to claim 11, characterized in that: The inert gas contains at least nitrogen.

13. The method for producing the aromatic nitrile compound according to claim 1, characterized in that: The catalyst contains alkali metals.

14. The method for producing the aromatic nitrile compound according to claim 1, characterized in that: The solvent is miscible with the aromatic amide compound.

15. The method for producing the aromatic nitrile compound according to claim 1, characterized in that: The aromatic amide compound is in contact with the catalyst in the gas phase for a time of 0.001 seconds or more and less than 10 seconds.

16. A method for manufacturing carbonate, characterized in that: Including the first reaction process and the second reaction process, The first reaction step includes a carbonate formation reaction in which an alcohol reacts with carbon dioxide in the presence of an aromatic nitrile compound to produce carbonate and water; and a hydration reaction in which the generated water is hydrated with the aromatic nitrile compound to produce an aromatic amide compound. The second reaction step utilizes a dehydration reaction to regenerate the aromatic nitrile compound from the aromatic amide compound. This dehydration reaction occurs after the aromatic amide compound has been separated from the reaction system of the first reaction step, and includes a contact step as described in any one of claims 1 to 15. At least a portion of the aromatic nitrile compound regenerated in the second reaction step is used in the first reaction step.

17. The method for manufacturing carbonate according to claim 16, characterized in that: In the carbonate formation reaction, a catalyst containing cerium oxide is used.

18. The method for manufacturing carbonate according to claim 16, characterized in that: The alcohols include alcohols with 1 to 6 carbon atoms.

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