Method for producing alkylene carbonate and apparatus for producing alkylene carbonate

Abstract

A method for producing an alkylene carbonate, which uses a first reaction vessel in which a reaction solution containing a catalyst and carbon dioxide in a gaseous state are accommodated, said method comprising: a step (A) in which the reaction solution containing a catalyst is introduced into the first reaction vessel; a feed solution containing alkylene oxide is supplied by a nozzle so as to move from the upper part of the first reaction vessel to the lower part of the first reaction vessel along the inner surface, and a feed solution in which carbon dioxide in the first reaction vessel is dissolved is supplied to the reaction solution; and a step (B) for obtaining an alkylene carbonate by reacting an alkylene oxide with carbon dioxide in the catalyst-containing reaction solution in the lower part of the first reaction vessel, the ratio (DL / DT) of the height DL from the liquid level in the first reaction vessel to the discharge port of the nozzle to the height DT from the bottom tangent of the first reaction vessel to the discharge port of the nozzle is 0.1-0.7.

Description

Technical Field

[0001] The present invention relates to a method for producing alkylene carbonate and an apparatus for producing alkylene carbonate. Background Art

[0002] The reaction of obtaining alkylene carbonate from alkylene oxide and carbon dioxide has been extensively studied due to its usefulness, and in order to obtain a sufficient industrial reaction rate, research on catalysts is also actively being conducted. There are many reports using solid acid catalysts, alkali metal salt catalysts, homogeneous organic metal catalysts, etc. For example, there are the following methods: a method for producing alkylene carbonate using a carboxylic acid type cation exchange resin with an alkyl-substituted ammonium cation as a counter cation as a catalyst (Patent Document 1), a method for producing alkylene carbonate using a catalyst containing tungsten oxide or molybdenum oxide (Patent Document 2), a method for producing alkylene carbonate using an anion exchange resin having a tertiary amine functional group or a quaternary ammonium functional group as a catalyst (Patent Document 3), synthesis of aryl-substituted alkylene carbonate using an alkali metal salt as a catalyst (Patent Document 4), a method for producing alkenyl ether carbonate using a phase transfer organic metal complex catalyst (Patent Document 5), a method for producing alkylene carbonate from alkylene oxide and carbon dioxide in the presence of a halide base catalyst (Patent Document 6), etc.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 7-206846

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 7-206847

[0007] Patent Document 3: Japanese Patent Application Laid-Open No. 7-206848

[0008] Patent Document 4: Japanese Patent Application Laid-Open No. 8-53396

[0009] Patent Document 5: U.S. Patent No. 5,095,124

[0010] Patent Document 6: Japanese Patent Application Publication No. 2006-104092 Summary of the invention

[0011] Problems to be solved by the invention

[0012] An object of the present invention is to provide a method and an apparatus for producing alkylene carbonate using alkylene oxide and carbon dioxide as raw materials and showing a high alkylene oxide conversion rate.

[0013] Means used to solve problems

[0014] The present inventors have conducted intensive studies to solve the above-mentioned problems and have found that a reaction showing a high alkylene oxide conversion rate can be achieved by adjusting the ratio of the height DL from the liquid surface in the reaction container to the spout of the nozzle for supplying the raw material liquid to the height DT from the tangent line to the bottom of the reaction container to the spout of the nozzle within a predetermined range, thereby completing the present invention.

[0015] The present invention includes the following embodiments.

[0016] <1> A method for producing an alkylene carbonate, the method comprising using a first reaction container containing a reaction liquid containing a catalyst and gaseous carbon dioxide, wherein the method for producing an alkylene carbonate comprises the following steps:

[0017] Step (A), supplying a raw material liquid containing alkylene oxide from an upper portion of the first reaction container to a lower portion of the first reaction container along an inner surface thereof using a nozzle, and supplying a raw material liquid in which carbon dioxide in the first reaction container is dissolved to the reaction liquid; and

[0018] Step (B), reacting alkylene oxide with carbon dioxide in the reaction liquid containing the catalyst in the lower part of the first reaction vessel to obtain alkylene carbonate,

[0019] A ratio (DL / DT) of a height DL from a liquid surface in the first reaction container to a discharge port of the nozzle to a height DT from a tangent line to the bottom of the first reaction container to the discharge port of the nozzle is 0.1 to 0.7.

[0020] <2> The method for producing an alkylene carbonate according to <1>, wherein two or more of the nozzles are used.

[0021] <3> The method for producing an alkylene carbonate according to <1> or <2>, wherein the reaction liquid contained in the first reaction container is extracted from the bottom of the first reaction container, and a portion of the reaction liquid is supplied to the first reaction container as the raw material liquid,

[0022] The number of cycles of the reaction solution per unit time is 10 to 70 times per hour.

[0023] <4> The method for producing an alkylene carbonate according to any one of <1> to <3>, wherein an operating pressure of the first reaction container is 4 MPa to 12 MPa.

[0024] <5> The method for producing an alkylene carbonate according to any one of <1> to <4>, wherein the ratio (DL / DT) is 0.20 to 0.60.

[0025] <6> The method for producing an alkylene carbonate according to any one of <1> to <5>, wherein the first reaction container has a height / inner diameter ratio of 3 to 7 and an inner diameter of 1 m to 4 m.

[0026] <7> The method for producing an alkylene carbonate according to any one of <1> to <6>, wherein the alkylene oxide is ethylene oxide, and the alkylene carbonate is ethylene carbonate.

[0027] <8> The method for producing an alkylene carbonate according to any one of <1> to <7>, comprising a step (C) of reacting the reaction solution obtained in the step (B) with an alkylene oxide and carbon dioxide in a second reaction vessel to obtain an alkylene carbonate.

[0028] <9> The method for producing an alkylene carbonate according to <8>, further comprising a step (D) of further reacting the reaction solution obtained in the step (C) with an alkylene oxide and carbon dioxide in a third reaction vessel to obtain an alkylene carbonate.

[0029] <10> The method for producing an alkylene carbonate according to any one of <1> to <9>, wherein in the step (A), the raw material liquid is supplied by spraying the raw material liquid onto the wall surface using a nozzle.

[0030] <11> A device for producing an alkylene carbonate, comprising:

[0031] a first reaction container, the first reaction container being used to contain a reaction liquid containing a catalyst;

[0032] a nozzle for supplying a raw material liquid containing alkylene oxide in a manner moving from an upper portion of the first reaction container along an inner surface toward a lower portion of the first reaction container; and

[0033] A carbon dioxide supply unit, the carbon dioxide supply unit is used to introduce carbon dioxide into the first reaction container, wherein

[0034] The alkylene carbonate production apparatus can be controlled to operate so that a ratio (DL / DT) of a height DL from a liquid surface in the reaction container to a discharge port of the nozzle to a height DT from a tangent line to a bottom of the first reaction container to the discharge port of the nozzle is 0.1 to 0.7.

[0035] <12> The device for producing alkylene carbonate according to <11>, further comprising:

[0036] a second reaction container, the second reaction container being used to contain a reaction liquid containing a catalyst;

[0037] a nozzle for supplying the reaction liquid from the first reaction container as a raw material liquid in a manner moving from the upper portion of the second reaction container along the inner surface toward the lower portion of the second reaction container; and

[0038] A carbon dioxide supply unit is used to introduce carbon dioxide into the second reaction container.

[0039] <13> The apparatus for producing alkylene carbonate according to <11> or <12>, further comprising a third reaction vessel for introducing the reaction liquid from the second reaction vessel into the third reaction vessel and further reacting the reaction liquid with alkylene oxide and carbon dioxide.

[0040] <14> The apparatus for producing alkylene carbonate according to any one of <11> to <13>, wherein the ratio (DL / DT) is 0.10 to 0.40.

[0041] <15> The apparatus for producing alkylene carbonate according to any one of <11> to <14>, wherein the nozzle is used to supply the raw material liquid by spraying the raw material liquid onto the wall surface.

[0042] Effects of the Invention

[0043] The present invention can provide a method and an apparatus for producing alkylene carbonate using alkylene oxide and carbon dioxide as raw materials and showing a high alkylene oxide conversion rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic configuration diagram of an alkylene carbonate production apparatus 1 according to the first embodiment.

[0045] Figure 2 It is a schematic configuration diagram of an alkylene carbonate production apparatus 10 according to a second embodiment. DETAILED DESCRIPTION

[0046] Hereinafter, an embodiment of the present invention (hereinafter referred to as "this embodiment") will be described in detail with reference to the accompanying drawings as needed, but the present invention is not limited thereto and can be variously modified within the scope of the gist thereof. It should be noted that in the accompanying drawings, unless otherwise specified, the positional relationships such as up, down, left, and right are based on the positional relationships shown in the accompanying drawings. In addition, the dimensional ratios of the accompanying drawings are not limited to the ratios shown in the drawings.

[0047] The method for producing alkylene carbonate of the present embodiment uses a first reaction container containing a reaction liquid containing a catalyst and gaseous carbon dioxide, and includes the following steps: step (A), supplying a raw material liquid containing alkylene oxide in a manner moving from the upper part of the first reaction container along the inner surface to the lower part of the first reaction container using a nozzle, and supplying a raw material liquid in which carbon dioxide in the first reaction container is dissolved to the reaction liquid; and step (B), reacting alkylene oxide with carbon dioxide in the reaction liquid containing the catalyst in the lower part of the first reaction container to obtain alkylene carbonate, wherein the ratio (DL / DT) of the height DL from the liquid surface in the reaction container to the nozzle outlet relative to the height DT from the bottom tangent of the first reaction container to the nozzle outlet is 0.1 to 0.7.

[0048] By the above configuration, a method for producing alkylene carbonate with alkylene oxide and carbon dioxide as raw materials and showing a high alkylene oxide conversion rate can be provided. In the production method of the present embodiment, a raw material liquid containing alkylene oxide is supplied by a nozzle in a manner of moving from the upper part of the reaction container along the inner surface to the lower part of the reaction container, thereby the reaction liquid and the raw material liquid spread along the wall absorb the carbon dioxide present in the reaction container and supply the reaction liquid at the lower part of the reaction container. It can be considered that in this way, the concentration of carbon dioxide in the reaction liquid becomes higher, and it is easy to obtain the target alkylene carbonate. In particular, it is speculated that by adjusting the ratio (DL / DT) to operate within a specified range, the balance between the absorption amount of carbon dioxide in the raw material liquid and the efficiency of the reaction becomes better, and a reaction showing a high alkylene oxide conversion rate can be achieved. It should be noted that the above is the content of the mechanism for speculating the effect of the production method of the present embodiment, and the present invention is not limited thereto.

[0049] The method for producing alkylene carbonate of the present embodiment may further include, in addition to step (A) and step (B), step (C) of reacting the reaction liquid obtained in step (B) with alkylene oxide and carbon dioxide in a second reaction vessel to obtain alkylene carbonate.

[0050] It should be noted that step (C) may include the following steps:

[0051] A step (C-1) of supplying the reaction liquid obtained in the step (B) as a raw material liquid by moving from the upper part of a second reaction container containing a reaction liquid containing a catalyst and gaseous carbon dioxide along the inner surface to the lower part of the second reaction container using a nozzle, and supplying the raw material liquid in which the carbon dioxide in the second reaction container is dissolved to the reaction liquid; and

[0052] In step (C-2), alkylene oxide is reacted with carbon dioxide in the reaction liquid containing the catalyst in the lower part of the second reaction vessel to obtain alkylene carbonate.

[0053] The method for producing alkylene carbonate of the present embodiment may further include step (D) of further reacting the reaction solution obtained in step (C) with alkylene oxide and carbon dioxide in a third reaction vessel to obtain alkylene carbonate, in addition to step (A), step (B) and step (C).

[0054] By including the above-mentioned configuration, the method for producing an alkylene carbonate according to the present embodiment can further improve the conversion rate of alkylene oxide.

[0055] <Raw Material Liquid>

[0056] The raw material liquid contains an alkylene oxide. Examples of the alkylene oxide include a compound represented by the following formula (1).

[0057]

[0058] (In formula (1), R 1 , R 2 , R 3 and R 4 Each independently represents a hydrogen atom, a linear hydrocarbon group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 8 carbon atoms, or an aromatic hydrocarbon group having 6 to 8 carbon atoms.

[0059] More specifically, examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, vinylethylene oxide, cyclohexene oxide, and styrene oxide. Among them, ethylene oxide and propylene oxide are preferred from the viewpoint of easy availability.

[0060] In the method for producing alkylene carbonate of the present embodiment, in the step of obtaining alkylene carbonate, alkylene oxide is subjected to a reaction with carbon dioxide in the presence of a catalyst to obtain alkylene carbonate (cyclic alkylene carbonate) represented by the following formula (2).

[0061]

[0062] (R in formula (2) 1 , R 2 , R 3 and R 4 As defined in formula (1).

[0063] In the present embodiment, specific examples of the alkylene carbonate include, but are not particularly limited to, ethylene carbonate, propylene carbonate, butylene carbonate, vinyl ethylene carbonate, cyclohexylene carbonate, and phenyl ethylene carbonate, and ethylene carbonate and propylene carbonate are preferred.

[0064] In the method for producing alkylene carbonate, the reaction of obtaining alkylene carbonate from alkylene oxide and carbon dioxide is represented by the following formula (3).

[0065]

[0066] (R in formula (3) 1 , R 2 , R 3 and R 4 As defined in formula (1).

[0067] The catalyst used in the above reaction is not particularly limited as long as it is a catalyst for implementing the reaction of the above formula (3). Specifically, organic catalysts such as tetraethylammonium bromide, halides of 5-membered ring / 6-membered ring hydrocarbons, ammonium thiocyanate or its thermal decomposition products, inorganic catalysts such as bromides or iodides of metals or alkali metals, and catalysts obtained by adding a small amount of alcohols or water to these substances can be used, preferably inorganic catalysts that are easy to recover the catalyst. The amount of the catalyst used is not particularly limited, and is preferably 0.1% to 3% by mass, and more preferably 0.1% to 2% by mass, relative to the raw material liquid.

[0068] [First embodiment]

[0069] <Apparatus for producing alkylene carbonate>

[0070] Figure 1 1 is a schematic diagram of the structure of an alkylene carbonate production apparatus 1 according to the first embodiment. The alkylene carbonate production apparatus 1 according to the present embodiment includes a first reaction vessel 2, a nozzle 3 for supplying a raw material liquid, and a carbon dioxide supply unit 4 for introducing carbon dioxide.

[0071] The first reaction vessel 2 may be a complete mixing reactor or the like. The complete mixing reactor may be equipped with a venturi stirrer.

[0072] The first reaction container 2 contains a reaction solution containing a catalyst. The reaction solution is stored in the lower part of the first reaction container 2 and can be stirred by a stirrer (not shown). In addition, carbon dioxide is introduced into the first reaction container 2 from the carbon dioxide supply unit 4. The upper part of the first reaction container 2 contains gaseous carbon dioxide at a high concentration.

[0073] The nozzle 3 preferably has a structure suitable for dissolving carbon dioxide in the raw material liquid, and an example thereof is a spray nozzle type.

[0074] The nozzle 3 may be connected to the catalyst supply unit 5 and the alkylene oxide supply unit 6 to supply a raw material liquid in which the catalyst and ethylene oxide are mixed. The catalyst is mixed with the raw material liquid after being adjusted to a predetermined concentration.

[0075] The nozzle 3 is provided on the upper part of the first reaction container 2 so as to supply the raw material liquid to the inner wall surface of the first reaction container 2. It is preferred to provide two or more nozzles 3. By having a plurality of nozzles 3, the raw material liquid spreads on the inner surface of the reaction container, which can improve the absorption efficiency of carbon dioxide.

[0076] The height / inner diameter ratio of the reaction container is preferably 3 to 7, more preferably 4 to 6, and even more preferably 4.5 to 5.5. It should be noted that the height of the reaction container herein refers to the distance between the tangent lines of the upper portion and the lower portion.

[0077] The inner diameter of the reaction container is preferably 1 m to 4 m, more preferably 1.2 m to 3.0 m, and even more preferably 1.5 m to 2.5 m.

[0078] like Figure 1 As shown, the manufacturing device of alkylene carbonate preferably has a circulation loop 7 for reusing the reaction liquid from the first reaction container 2 as a raw material liquid. The circulation loop 7 is equipped with an external pump 9 and is configured in a manner that allows the reaction liquid to circulate. It should be noted that, although not shown, the external pump 9 can also be provided with a preparatory machine at the same time. The circulation loop 7 is preferably connected to the process side flow path of the heat exchanger 8 via a pipeline. The heat exchanger 8 is preferably a heat exchanger having a heat exchange side flow path for flowing a heat exchange medium whose temperature is adjusted to a predetermined temperature range, and a process side flow path for flowing a process liquid for heat exchange related to the manufacture of alkylene carbonate. The process liquid refers to a liquid that is processed (i.e., the temperature is adjusted) by a heat exchanger, and the heat exchange medium refers to a medium for adjusting the temperature of the process liquid. Moreover, the heat exchange side flow path of the heat exchanger refers to a flow path for flowing the heat exchange medium, and the process side flow path refers to a flow path for flowing the process liquid.

[0079] The heat exchanger 8 is preferably a heat exchanger that can flow a heat exchange medium having a temperature of 140° C. to 200° C. in the heat exchange side flow path of the heat exchanger and maintain the internal temperature of the process side flow path at 135° C. to 200° C. For example, a serpentine heat exchanger, a double tube heat exchanger, a general multi-tube heat exchanger, etc., which are arranged inside the reactor, can be used alone or in combination. The heat exchanger is preferably a multi-tube heat exchanger that increases the heat transfer area and enables miniaturization of the device.

[0080] When a multi-tube heat exchanger is used, either the tube side or the shell side of the multi-tube heat exchanger can be used as a heat exchange side flow path or a process side flow path for the process liquid and the heat exchange medium. In the case of increasing the total heat transfer coefficient (U) by using a small heat exchanger, or making cleaning easier by passing a fluid that easily adheres to fouling substances into the tube side, it is sufficient to appropriately select which substances are passed into the tube side and the shell side of the heat exchanger according to the needs.

[0081] The heat exchanger 8 preferably functions as both a preheater and a cooler. Such a heat exchanger can be used as a preheater to raise the temperature of the reaction solution to the reaction start temperature during startup, and as a cooler to remove the heat of reaction during steady operation.

[0082] There are no particular restrictions on the material of the process side flow path of the heat exchanger 8 as long as it is resistant to corrosion by the process liquid. Rust causes the formation of polymers of alkylene oxide due to its catalytic action, so stainless steel is preferably used.

[0083] <Method for producing alkylene carbonate>

[0084] Hereinafter, the method for producing alkylene carbonate according to the present embodiment will be described by taking an operation mode using the production apparatus 1 for alkylene carbonate as an example.

[0085] The catalyst and the alkylene oxide are supplied from the catalyst supply unit 5 and the alkylene oxide supply unit 6, respectively, to obtain a raw material liquid containing them. Here, the supply amount of the catalyst can be adjusted to obtain a raw material liquid having a desired catalyst concentration.

[0086] Next, the nozzle 3 supplies the raw material liquid in a manner that moves from the upper part of the first reaction container 2 along the inner surface to the lower part of the first reaction container 2. The raw material liquid spreads into a plane and forms a liquid film while moving along the inner surface, and gaseous carbon dioxide dissolves in the raw material liquid. The raw material liquid in which carbon dioxide is dissolved flows into the reaction liquid containing the catalyst and mixes, thereby supplying alkylene oxide and carbon dioxide to the reaction liquid. Through the above operation, the above step (A) is implemented.

[0087] In step (A), the raw material liquid is preferably supplied by spraying the raw material liquid toward the wall surface using the nozzle 3. By adjusting the direction of the nozzle 3 in this way, the raw material liquid can move along the inner surface of the reactor.

[0088] The ratio of the distance from the nozzle 3 to the wall surface to the inner diameter of the reactor (the nozzle 3 nozzle-wall surface distance / the inner diameter of the reactor) is preferably 0.30 or less, more preferably 0.20 or less, and further preferably 0.10 or less. It should be noted that the distance from the nozzle 3 to the wall surface refers to the distance from the nozzle 3 to the wall surface in the direction of the raw material liquid injection axis of the nozzle 3. For example, when the nozzle 3 is not facing the wall surface, the distance from the nozzle 3 to the wall surface cannot be defined.

[0089] like Figure 1As shown, in the method for producing alkylene carbonate of the present embodiment, the ratio (DL / DT) of the height DL from the liquid surface in the reaction container to the discharge port of the nozzle to the height DT from the bottom tangent line of the first reaction container 2 to the discharge port of the nozzle is 0.1 to 0.7. The ratio (DL / DT) is preferably 0.10 to 0.60, more preferably 0.10 to 0.50, further preferably 0.10 to 0.45, and further preferably 0.10 to 0.40. The smaller the value of the ratio (DL / DT), the smaller the space at the top of the first reaction container 2, and the less likely carbon dioxide is to be absorbed. In the present invention, the raw material liquid is supplied in a manner that moves from the top of the first reaction container along the inner surface to the bottom of the first reaction container, so that the residence time in the upper space can be ensured, and therefore a sufficient amount of carbon dioxide is absorbed in the raw material liquid. On the other hand, a smaller value of the ratio (DL / DT) means a higher liquid level in the first reaction vessel 2. By keeping the ratio (DL / DT) within the above range, a sufficient reaction time can be ensured after the raw material liquid is introduced into the liquid phase, thereby obtaining a high alkylene oxide conversion rate.

[0090] The bottom tangent line refers to the height of the boundary between the straight body portion and the curved surface of the reaction container.

[0091] It should be noted that when multiple nozzles 3 are provided, DT is the average value of the height from the bottom tangent of the first reaction container 2 to the nozzle of each nozzle, and DL is the average value of the height from the liquid surface in the reaction container to the nozzle of each nozzle.

[0092] In the production apparatus of the present embodiment, operation control is performed so that the ratio (DL / DT) is 0.1 to 0.7, for example, by performing cascade control based on a value measured by a liquid level gauge in the reactor and the extraction flow rate of the reactor.

[0093] It should be noted that the above step (B) is carried out in the reaction solution in the lower part of the first reaction container 2 .

[0094] The reaction temperature in step (B) is preferably 100°C to 250°C, more preferably 150°C to 200°C, and even more preferably 160°C to 190°C.

[0095] The average residence time in the reaction container in step (B) is preferably 10 minutes to 6 hours, more preferably 30 minutes to 3 hours, and even more preferably 1 hour to 2 hours.

[0096] The operating pressure of the first reaction vessel 2 is preferably 4 MPa to 12 MPa, more preferably 5 MPa to 11 MPa, and further preferably 8 MPa to 10 MPa.

[0097] The reaction solution contained in the first reaction container 2 is preferably extracted from the bottom of the first reaction container 2, and a part thereof is supplied as a raw material solution to the first reaction container 2. That is, the reaction solution is preferably circulated as a raw material solution via the circulation loop 7 and the external pump 9.

[0098] At this time, the number of cycles per unit time of the reaction solution is preferably 10 to 70 times / hour, more preferably 20 to 50 times / hour. It should be noted that the number of cycles refers to the number of times the reaction solution in the reaction container is replaced per hour, and is represented by the following formula (A).

[0099] Number of cycles = circulation flow rate of external pump / volume of liquid phase at the bottom of the reactor (A)

[0100] When the reaction liquid is circulated, it is preferable to provide a heat exchanger in the middle of the pipeline to remove the heat of reaction, because the cooling capacity of the heat exchanger is improved when a large flow rate is circulated.

[0101] The manufacturing method of the alkylene carbonate of the present embodiment is preferably carried out on an industrial scale. In this specification, the industrial scale refers to the scale of manufacturing the alkylene carbonate at a ratio of 1 t (ton) / hour or more, preferably 2 t (ton) / hour or more, more preferably 3 t (ton) / hour or more, and further preferably 4 t (ton) / hour or more. The upper limit of the industrial scale is not particularly limited, for example, 15 t (ton) / hour or less.

[0102] [Second embodiment]

[0103] Figure 2 1 is a schematic diagram of a manufacturing apparatus 10 for alkylene carbonate according to a second embodiment. The same reference numerals are used for the same structures as those of the manufacturing apparatus 1 for alkylene carbonate and the description thereof is omitted. The characteristic structure of the manufacturing apparatus 10 for alkylene carbonate is described below. The manufacturing apparatus 10 for alkylene carbonate further includes a second reaction vessel 11 and a third reaction vessel 22 in the rear section of the first reaction vessel 2.

[0104] The manufacturing apparatus 10 of alkylene carbonate of this embodiment is provided with a second reaction vessel 11 in addition to the structure shown in the manufacturing apparatus 1 of alkylene carbonate. The reaction liquid containing a catalyst is accommodated in the second reaction vessel 11. The second reaction vessel 11 is provided with: a nozzle 12 for supplying the reaction liquid from the first reaction vessel 2 as a raw material liquid in a manner that it moves from the upper part of the second reaction vessel 11 along the inner surface to the lower part of the second reaction vessel 11; and a carbon dioxide supply unit 16 for introducing carbon dioxide into the second reaction vessel 11.

[0105] In the second reaction vessel 11, the following process is performed: the reaction liquid of the first reaction vessel 2 is supplied by a nozzle in a manner that moves from the upper part of the second reaction vessel 11 along the inner surface to the lower part of the reaction vessel, and the raw material liquid in which the carbon dioxide in the second reaction vessel 11 is dissolved is supplied to the reaction liquid, and the reaction of alkylene oxide and carbon dioxide is further performed. Through the above operation, the above-mentioned step (C) (step (C-1) and step (C-2)) is implemented. In the second reactor 11, carbon dioxide can be supplied from the carbon dioxide supply unit 16, but in the first reactor 2, a sufficient amount of carbon dioxide is dissolved in the reaction liquid, so when the concentration of carbon dioxide in the reaction liquid becomes low, carbon dioxide can be appropriately supplied from the carbon dioxide supply unit 16.

[0106] In the method for producing alkylene carbonate of the present embodiment, the ratio of the height DL' from the liquid surface in the second reaction container 11 to the discharge port of the nozzle to the height DT' from the bottom tangent line of the second reaction container 11 to the discharge port of the nozzle 12 (DL' / DT') is preferably 0.1 to 0.7, more preferably 0.15 to 0.60, and further preferably 0.20 to 0.50.

[0107] When a plurality of nozzles 12 are provided, DT' is the average value of the height from the bottom tangent line of the second reaction container 11 to the nozzle of each nozzle, and DL' is the average value of the height from the liquid surface in the reaction container to the nozzle of each nozzle.

[0108] like Figure 2 As shown, the manufacturing device 10 of alkylene carbonate preferably has a circulation loop 14 for reusing the reaction liquid from the second reaction vessel 11 as a raw material liquid. The circulation loop 14 may have a heat exchanger 13 and an external pump 15. It should be noted that, although not shown, the external pump 15 may be provided with a preparatory machine at the same time. The circulation loop 14 is preferably connected to the process side flow path of the heat exchanger 13 via a pipeline. By having the circulation loop 14, a part of the remaining carbon dioxide is discharged from the second reaction vessel 11.

[0109] The reaction temperature in the second reaction vessel 11 is preferably 100°C to 250°C, more preferably 150°C to 200°C, and further preferably 160°C to 190°C.

[0110] The average residence time in the second reaction vessel 11 is preferably 10 minutes to 6 hours, more preferably 30 minutes to 4 hours, and even more preferably 2 hours to 3 hours.

[0111] The operating pressure in the second reaction vessel 11 is preferably 4 MPa to 12 MPa, more preferably 4 MPa to 8 MPa, and further preferably 4.5 MPa to 6.5 MPa.

[0112] The reaction solution contained in the second reaction vessel 11 is preferably extracted from the bottom of the second reaction vessel 11, and a part of it is supplied as a raw material solution to the second reaction vessel 11. That is, the reaction solution is preferably circulated as a raw material solution via the circulation loop 14 and the external pump 15.

[0113] At this time, the number of circulations of the reaction solution per unit time is preferably 10 to 70 times / hour, and more preferably 15 to 35 times / hour.

[0114] The manufacturing device 10 of alkylene carbonate of this embodiment is equipped with the third reaction container 22 which introduces the reaction liquid from the second reaction container 11 and makes it further react with alkylene oxide and carbon dioxide at the rear stage of the second reaction container 11. The third reaction container 22 is a reaction container for carrying out the reaction of unreacted alkylene oxide and dissolved carbon dioxide, and the reaction liquid obtained by step (C) is further reacted with alkylene oxide and carbon dioxide in the third reaction container 22 to obtain alkylene carbonate. The above-mentioned step (D) is implemented by the above operation. The third reaction container 22 is preferably a full liquid reactor such as a plug flow reactor without external circulation.

[0115] The reaction temperature in the third reaction vessel 22 is preferably 100°C to 250°C, more preferably 150°C to 200°C, and further preferably 160°C to 190°C.

[0116] The operating pressure in the third reaction vessel 22 is preferably 4 MPa to 12 MPa, more preferably 4 MPa to 8 MPa, and further preferably 4.5 MPa to 6.5 MPa.

[0117] Example

[0118] Hereinafter, the present embodiment will be described in more detail with reference to Examples, but the present embodiment is not limited to the following Examples.

[0119] [Example 1]

[0120] use Figure 2 The alkylene carbonate production apparatus 10 shown in the figure produces ethylene carbonate. The first reaction vessel 2 is a stainless steel vertical cylindrical tank with an inner diameter of 1.8 mφ, a straight body length of 8.7 m, and a capacity of 23.6 m 3 In order to disperse the liquid in the upper part of the first reaction vessel 2 to improve the absorption efficiency of the carbon dioxide gas, a distributor having 10 nozzles 3 is arranged at a position (DT) 8.4 m from the tangent line of the lower part of the first reaction vessel 2, and is connected to the process side flow path of the heat exchanger 8 via a pipeline to form a circulation loop 7.

[0121] Ethylene oxide cooled to about 5°C as one of the raw materials was supplied from the alkylene oxide supply unit 6 at 4,780 kg / hour to the first reaction vessel 2. As for carbon dioxide as another raw material, liquefied carbon dioxide was gasified by a carbon dioxide evaporator (not shown) and adjusted to a constant pressure of about 9.5 MPa at a temperature of about 90°C and supplied from the carbon dioxide supply unit 4 to the first reaction vessel 2. The average carbon dioxide supply amount was 4,920 kg / hour.

[0122] Potassium iodide (KI) was used as a catalyst and was mixed in the ethylene carbonate solution in a manner to achieve 5% by mass. The catalyst solution was mixed in a ratio of 9 parts by mass of the recovered catalyst recovered after purifying the ethylene carbonate product and 1 part by mass of the fresh catalyst solution, and supplied to the wall surface of the first reaction vessel 2 via the nozzle 3. The supply amount of the catalyst solution was set to 560 kg / hour by the pump 3 so that the potassium iodide concentration of the circulating liquid (reaction system) reached 0.23% to 0.26% by mass.

[0123] The reaction mixture was discharged from the first reaction vessel 2 so that the distance (DL) from the liquid surface in the first reaction vessel 2 to the nozzle 3 was constant at 2.9 m. The discharge amount of the reaction mixture was adjusted by a discharge regulating valve (not shown). (Ratio (DL / DT) = 0.35)

[0124] The production of ethylene carbonate is carried out under the condition that the reaction temperature measured by the thermometer provided at the bottom of the first reaction vessel 2 is 180°C. During the reaction, while the heat exchange medium is flowing in the heat exchange side flow path of the heat exchanger 8, the reaction liquid is flowing in the circulation loop 7 including the process side flow path of the first reaction vessel 2 and the heat exchanger 8. Specifically, the reaction liquid is extracted from the outlet of the first reaction vessel 2, pressurized by an external pump 9, and sent to the heat exchanger 8. Then, the reaction mixture after adjusting the temperature in the heat exchanger 8 is returned to the reaction vessel 2 from its inlet, thereby circulating in the circulation loop. The circulation amount of the reaction liquid of the first reaction vessel 2 is monitored by a circulation flow meter (not shown) and adjusted to be constant at about 550 tons / hour. The liquid holding amount is 17.5 tons, the average residence time in the first reaction vessel 2 is 1.7 hours, and the number of cycles is 44 times / hour.

[0125] The reaction liquid extracted from the circulation loop 7 of the first reaction vessel 2 is supplied to the second reaction vessel 11. The second reaction vessel 11 is a stainless steel vertical cylindrical tank with an inner diameter of 2.3 mφ, a straight body length of 6.5 m, and a capacity of 33.4 m 3In order to disperse the liquid to improve the absorption efficiency of carbon dioxide gas, a distributor with 10 nozzles is arranged at a position 6.2m away from the tangent line of the lower part of the second reaction container 11 in the upper part of the reaction container, and a circulation loop 14 is formed by connecting with the process side flow path of the heat exchanger 13 via a pipeline. The circulation volume is adjusted in a constant manner of about 405 tons / hour. The reaction temperature is controlled to be 180°C measured by a thermometer arranged at the bottom of the second reaction container 11, and the reaction pressure is controlled to be 5.1MPa. The reaction mixture is discharged from the second reaction container 11 so that the distance from the liquid surface in the second reaction container 11 to the nozzle 12 distributor is constant at 3.1m. (Ratio (DL' / DT') = 0.50)

[0126] Then, the reaction liquid extracted from the circulation loop 14 of the second reaction vessel 11 is supplied to the third reaction vessel 22. The third reaction vessel 22 has an inner diameter of 0.9 mφ, a straight body length of 9.0 m, and a capacity of 6.1 m 3 The reaction temperature was controlled to be 180° C. as measured by a thermometer installed at the bottom of the third reaction vessel 22, and the reaction pressure was controlled to be 5.1 MPa.

[0127] Continuous operation for 180 days under the above conditions achieved stable manufacturing results.

[0128] The output of ethylene carbonate at the outlet of the third reaction vessel 22 was 8,930 Kg / hour, and the conversion rate of ethylene oxide to ethylene carbonate at the outlet of the first reaction vessel 2 was 88.6%. It should be noted that the conversion rate of ethylene oxide to ethylene carbonate at the outlet of the third reaction vessel 22 was 99.3%.

[0129] [Example 2]

[0130] Ethylene carbonate was produced in the same manner as in Example 1 except that the distance (DT) from the liquid surface in the first reaction vessel 2 to the supply position of the nozzle 3 was set to 4.2 m. (Ratio (DL / DT) = 0.50) The liquid holding amount was 15.4 tons, the average residence time in the first reaction vessel 2 was 1.4 hours, and the number of cycles was 52 times / hour.

[0131] Continuous operation for 180 days under the above conditions achieved stable manufacturing results.

[0132] The output of ethylene carbonate at the outlet of the third reaction vessel 22 was 8,730 Kg / hour, and the conversion rate of ethylene oxide to ethylene carbonate at the outlet of the first reaction vessel 2 was 86.5%. It should be noted that the conversion rate of ethylene oxide to ethylene carbonate at the outlet of the third reaction vessel 22 was 99.2%.

[0133] [Example 3]

[0134] Ethylene carbonate was produced in the same manner as in Example 1 except that the distance (DT) from the liquid surface in the first reaction vessel 2 to the supply position of the nozzle 3 was set to 5.5 m. (Ratio (DL / DT) = 0.65) The liquid holding amount was 11.0 tons, the average residence time in the reaction vessel was 1.0 hour, and the number of cycles was 70 times / hour.

[0135] Continuous operation for 180 days under the above conditions achieved stable manufacturing results.

[0136] The output of ethylene carbonate at the outlet of the third reaction vessel 22 was 8,531 kg / hour, and the conversion rate of ethylene oxide to ethylene carbonate at the outlet of the first reaction vessel 2 was 84.5%. It should be noted that the conversion rate of ethylene oxide to ethylene carbonate at the outlet of the third reaction vessel 22 was 99.1%.

[0137] [Example 4]

[0138] Ethylene carbonate was produced in the same manner as in Example 1 except that the number of nozzles 3 of the first reaction vessel 2 was set to 1. The output of ethylene carbonate at the outlet of the third reaction vessel 22 was 8,440 kg / hour, and the conversion rate of ethylene oxide to ethylene carbonate at the outlet of the first reaction vessel 2 was 83.5%. It should be noted that the conversion rate of ethylene oxide to ethylene carbonate at the outlet of the third reaction vessel 22 was 99.0%.

[0139] [Comparative Example 1]

[0140] Ethylene carbonate was produced in the same manner as in Example 1 except that the distance from the liquid surface in the first reaction vessel 2 to the supply position (DT) of the nozzle 3 was set to 0.2 m. (Ratio (DL / DT) = 0.02) The liquid holding amount was 27.5 tons, the average residence time in the reaction vessel was 2.7 hours, and the number of cycles was 28 times / hour.

[0141] The output of ethylene carbonate at the outlet of the third reaction vessel 22 was 8,330 Kg / hour, and the conversion rate of ethylene oxide to ethylene carbonate at the outlet of the first reaction vessel 2 was 82.4%. It should be noted that the conversion rate of ethylene oxide to ethylene carbonate at the outlet of the third reaction vessel 22 was 98.9%.

[0142] [Comparative Example 2]

[0143] Ethylene carbonate was produced in the same manner as in Example 1 except that the distance from the liquid surface in the first reaction vessel 2 to the supply position (DT) of the nozzle 3 was set to 6.7 m. (Ratio (DL / DT) = 0.80) The liquid holding amount was 7.1 tons, the average residence time in the first reaction vessel 2 was 0.7 hours, and the number of cycles was 108 times / hour. The production of ethylene carbonate at the outlet of the third reaction vessel 22 was 7,840 kg / hour, and the conversion rate of ethylene oxide to ethylene carbonate at the outlet of the first reaction vessel 2 was 77.3%. It should be noted that the conversion rate of ethylene oxide to ethylene carbonate at the outlet of the third reaction vessel 22 was 99.0%.

[0144] Industrial Applicability

[0145] The present invention can be suitably used as a method for producing an alkylene carbonate useful as a solvent, an organic synthesis raw material, and a secondary battery electrolyte, and an apparatus used therefor.

[0146] Description of symbols

[0147] 1.10: Apparatus for producing alkylene carbonate

[0148] 2: First reaction vessel

[0149] 3, 12: Nozzle

[0150] 4.16: Carbon dioxide supply unit

[0151] 5: Catalyst supply unit

[0152] 6: Alkylene oxide supply unit

[0153] 7, 14: Circulation loop

[0154] 8, 13: Heat exchanger

[0155] 9, 15: External pump

[0156] 11: Second reaction vessel

[0157] 22: The third reaction vessel

Claims

1. A method for producing an alkylene carbonate, which is a method for producing an alkylene carbonate using a first reaction container containing a reaction liquid containing a catalyst and gaseous carbon dioxide, wherein: The method for producing alkylene carbonate comprises the following steps: Step (A), supplying a raw material liquid containing alkylene oxide from an upper portion of the first reaction container to a lower portion of the first reaction container along an inner surface thereof using a nozzle, and supplying a raw material liquid in which carbon dioxide in the first reaction container is dissolved to the reaction liquid; and Step (B), reacting alkylene oxide with carbon dioxide in the reaction liquid containing the catalyst in the lower part of the first reaction vessel to obtain alkylene carbonate, A ratio (DL / DT) of a height DL from a liquid surface in the first reaction container to a discharge port of the nozzle to a height DT from a tangent line to the bottom of the first reaction container to the discharge port of the nozzle is 0.1 to 0.

7.

2. The method for producing an alkylene carbonate according to claim 1, wherein Two or more of the above nozzles are used.

3. The method for producing an alkylene carbonate according to claim 1, wherein The reaction liquid contained in the first reaction container is extracted from the bottom of the first reaction container, and a part of the reaction liquid is supplied to the first reaction container as the raw material liquid. The number of cycles of the reaction solution per unit time is 10 to 70 times per hour.

4. The method for producing an alkylene carbonate according to claim 1, wherein The operating pressure of the first reaction container is 4 MPa to 12 MPa.

5. The method for producing an alkylene carbonate according to claim 1, wherein The ratio (DL / DT) is 0.10 to 0.

40.

6. The method for producing an alkylene carbonate according to claim 1, wherein The first reaction container has a height / inner diameter ratio of 3 to 7 and an inner diameter of 1 m to 4 m.

7. The method for producing an alkylene carbonate according to claim 1, wherein The alkylene oxide is ethylene oxide, and the alkylene carbonate is ethylene carbonate.

8. The method for producing an alkylene carbonate according to claim 1, wherein The method for producing an alkylene carbonate includes a step (C) of reacting the reaction solution obtained in the step (B) with an alkylene oxide and carbon dioxide in a second reaction vessel to obtain an alkylene carbonate.

9. The method for producing an alkylene carbonate according to claim 8, wherein The method for producing an alkylene carbonate includes a step (D) of further reacting the reaction solution obtained in the step (C) with an alkylene oxide and carbon dioxide in a third reaction vessel to obtain an alkylene carbonate.

10. The method for producing an alkylene carbonate according to any one of claims 1 to 9, wherein In the step (A), the raw material liquid is supplied by spraying the raw material liquid onto the wall surface using a nozzle.

11. A device for producing alkylene carbonate, comprising: a first reaction container for containing a reaction liquid containing a catalyst; a nozzle for supplying a raw material liquid containing alkylene oxide in a manner of moving from an upper portion of the first reaction container along an inner surface to a lower portion of the first reaction container; and a carbon dioxide supply unit for introducing carbon dioxide into the first reaction container, wherein: The alkylene carbonate production apparatus can be controlled to operate so that a ratio (DL / DT) of a height DL from a liquid surface in the reaction container to a discharge port of the nozzle to a height DT from a tangent line to a bottom of the first reaction container to the discharge port of the nozzle is 0.1 to 0.

7.

12. The production apparatus for alkylene carbonate according to claim 11, wherein The alkylene carbonate production device further comprises: a second reaction container, the second reaction container being used to contain a reaction liquid containing a catalyst; a nozzle for supplying the reaction liquid from the first reaction container as a raw material liquid in a manner moving from the upper portion of the second reaction container along the inner surface toward the lower portion of the second reaction container; and A carbon dioxide supply unit is used to introduce carbon dioxide into the second reaction container.

13. The production apparatus for alkylene carbonate according to claim 12, wherein: The alkylene carbonate production apparatus further includes a third reaction container for introducing the reaction liquid from the second reaction container into the third reaction container and further reacting the reaction liquid with an alkylene oxide and carbon dioxide.

14. The apparatus for producing alkylene carbonate according to any one of claims 11 to 13, wherein The ratio (DL / DT) is 0.10 to 0.

40.

15. The apparatus for producing alkylene carbonate according to any one of claims 11 to 13, wherein The nozzle is used to supply the raw material liquid by spraying the raw material liquid toward the wall surface.

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