Method for producing polymerizable compound, and apparatus for producing polymerizable compound

Abstract

To provide a method for producing a polymerizable compound and an apparatus for producing a polymerizable compound, enabling suppression of a decline in production efficiency of the polymerizable compound.SOLUTION: A method for producing a polymerizable compound comprises a step of contacting a polymerization inhibitor with an inner surface F1 of a condenser 30 that condenses a to-be-condensed gas G1 containing a polymerizable compound to yield a condensate L1. An apparatus for producing a polymerizable compound comprises a condenser 30 that condenses a to-be-condensed gas G1 containing a polymerizable compound to yield a condensate L1, wherein a polymerization inhibitor is contacted with an inner surface F1 of the condenser 30.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a method for producing a polymerizable compound, an apparatus for producing a polymerizable compound, and the like.

Background Art

[0002] A polymerizable compound can be used to obtain various high molecular compounds. When producing a polymerizable compound, after reacting raw materials in a reactor to obtain a gas containing the polymerizable compound, the gas is condensed in a condenser to obtain a condensate containing the polymerizable compound. Regarding the method for producing a polymerizable compound, various production methods have been studied (for example, see Patent Document 1 below).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When producing a polymerizable compound, solids may be formed on the inner surface of a condenser that condenses a gas containing the polymerizable compound to obtain a condensate. When such solids are formed, it hinders the transfer of the gas and condensate containing the polymerizable compound, and the production efficiency of the polymerizable compound decreases.

[0005] An object of the present invention is to provide a method for producing a polymerizable compound and an apparatus for producing a polymerizable compound that can suppress a decrease in the production efficiency of the polymerizable compound.

Means for Solving the Problems

[0006] The present invention relates to the following [1] to

[14] and the like in some aspects. [1] A method for producing a polymerizable compound, comprising a step of bringing a polymerization inhibitor into contact with the inner surface of a condenser that condenses a gas containing a polymerizable compound to obtain a condensate. [2] The method for producing a polymerizable compound according to [1], wherein the polymerization inhibitor is brought into contact with the inner surface of the condenser while supplying the gas to the condenser. [3] The method for producing a polymerizable compound according to [1] or [2], wherein the inner surface of the condenser has a portion at a temperature equal to or lower than the condensation temperature of the polymerizable compound. [4] The method for producing a polymerizable compound according to any one of [1] to [3], wherein the inner surface of the condenser has a portion at a temperature of 75°C or lower. [5] The method for producing a polymerizable compound according to any one of [1] to [4], wherein the condenser has a piping portion with a closed downstream end in the gas flow path direction, and the inner surface of the condenser includes the surface located at the downstream end of the piping portion. [6] The method for producing a polymerizable compound according to any one of [1] to [5], wherein the condenser has a first vent portion and a second vent portion connected to the first vent portion on the downstream side in the gas flow path direction relative to the first vent portion, and the space between the first vent portion and the second vent portion is partitioned by a partition portion having an opening, and the inner surface of the condenser includes the surface on the first vent portion side in the partition portion. [7] The method for producing a polymerizable compound according to [6], wherein the second vent portion is an air fin cooler portion. [8] The method for producing a polymerizable compound according to any one of [1] to [7], wherein the polymerization inhibitor is supplied to the inner surface of the condenser from a position facing the inner surface of the condenser. [9] The method for producing a polymerizable compound according to any one of [1] to [8], wherein the polymerization inhibitor is brought into contact with the inner surface of the condenser using a nozzle in a state where the central axis of the injection hole of the nozzle is perpendicular to the inner surface of the condenser.

[10] The method for producing a polymerizable compound according to any one of [1] to [9], wherein a mixed liquid containing the polymerization inhibitor and water is brought into contact with the inner surface of the condenser.

[11] The method for producing a polymerizable compound according to any one of [1] to

[10] , wherein the polymerization inhibitor contains at least one selected from the group consisting of phenolic compounds, oxyl compounds, phenylenediamine compounds, hydroxylamine compounds, catechol compounds, pyrogallol compounds, phenothiazine compounds, and nitrosyl radicals.

[12] The method for producing a polymerizable compound according to any one of [1] to

[11] , wherein the polymerization inhibitor contains 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl.

[13] The method for producing a polymerizable compound according to any one of [1] to

[12] , wherein the polymerizable compound contains styrene.

[14] A production apparatus for a polymerizable compound, comprising a condenser for condensing a gas containing the polymerizable compound to obtain a condensate, and bringing a polymerization inhibitor into contact with the inner surface of the condenser. [Effect of the Invention]

[0007] According to the present invention, it is possible to provide a method for producing a polymerizable compound and a production apparatus for a polymerizable compound that can suppress a decrease in the production efficiency of the polymerizable compound. [Brief Description of the Drawings]

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

[0009] Hereinafter, embodiments for carrying out the present invention will be described. However, the present invention is not limited to the following embodiments.

[0010] The method for producing a polymerizable compound according to this embodiment includes a step (contact step) of bringing a polymerization inhibitor into contact with the inner surface of a condenser (at least a part of the inner surface: the surface of the internal space of the condenser) that condenses a gas containing the polymerizable compound (hereinafter, sometimes referred to as "gas to be condensed". It may be referred to as a gas phase component, a gas fluid, etc.) to obtain a condensate. The production apparatus for a polymerizable compound according to this embodiment includes a condenser that condenses a gas to be condensed to obtain a condensate, and brings a polymerization inhibitor into contact with the inner surface of the condenser (at least a part of the inner surface: the surface of the internal space of the condenser). The production apparatus for a polymerizable compound according to this embodiment can be used in the method for producing a polymerizable compound according to this embodiment. According to the method and apparatus for producing a polymerizable compound according to this embodiment, by bringing a polymerization inhibitor into contact with the inner surface of the condenser, it is possible to suppress the formation of solids on the inner surface of the condenser, and thus suppress a decrease in the production efficiency of the polymerizable compound.

[0011] Examples of the solids that can be formed on the inner surface of the condenser include polymers of the polymerizable compound to be produced (for example, styrene polymers), polymers of raw materials (residues) for obtaining the polymerizable compound to be produced, and polymers of side reaction products in the reaction for obtaining the polymerizable compound to be produced (for example, divinylbenzene polymers). Examples of the raw materials for the polymerizable compound include acetylene, butadiene, etc., which are raw materials for chloroprene.

[0012] The gas to be condensed and the condensate contain a polymerizable compound and may contain components other than the polymerizable compound. Examples of the components other than the polymerizable compound in the gas to be condensed include water (water vapor), a polymerization inhibitor, a corrosion inhibitor, a raw material (residue) for obtaining the polymerizable compound to be produced, and side reaction products in the reaction for obtaining the polymerizable compound to be produced. Examples of the components other than the polymerizable compound in the condensate include water, a polymerization inhibitor, a corrosion inhibitor, a polymer of the polymerizable compound to be produced, a polymer of a raw material (residue) for obtaining the polymerizable compound to be produced, and a polymer of a side reaction product in the reaction for obtaining the polymerizable compound to be produced.

[0013] The polymerizable compound may include compounds that can be used as raw materials for polymer compounds and may include compounds having a carbon-carbon double bond in the molecule. Examples of the polymerizable compound include aromatic vinyl compounds such as styrene, α-methylstyrene, and vinyltoluene; conjugated dienes such as 1,3-butadiene, isoprene, and chloroprene; ethylenically unsaturated carboxylic acids such as (meth)acrylic acid, maleic acid, and itaconic acid; (meth)acrylic compounds such as alkyl (meth)acrylate, aryl (meth)acrylate, (meth)acrylamide, and (meth)acrylonitrile; and vinyl esters of carboxylic acids such as vinyl acetate and vinyl propionate. For example, the polymerizable compound may include styrene.

[0014] In the method and apparatus for producing a polymerizable compound according to this embodiment, the inner surface of the condenser may be brought into contact with a polymerization inhibitor alone or a mixture containing a polymerization inhibitor. The mixture containing a polymerization inhibitor may contain, as components other than the polymerization inhibitor, water, an organic solvent, a corrosion inhibitor, and other additives. In the method and apparatus for producing a polymerizable compound according to this embodiment, from the viewpoint of removing (washing away) the solid matter when the solid matter is generated on the inner surface of the condenser and from the viewpoint of easily bringing the polymerization inhibitor into contact with the inner surface of the condenser, a mixed solution containing a polymerization inhibitor and water (for example, an aqueous solution of a polymerization inhibitor) may be brought into contact with the inner surface of the condenser.

[0015] Examples of polymerization inhibitors include phenolic compounds such as hydroquinone (also known as p-dihydroxybenzene), 2-sec-butyl-4,6-dinitrophenol, 2,4-dinitro-6-sec-butylphenol, 4-tert-butylcatechol, p-methoxyphenol, 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, pentaerythritol, and tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate); nitroxyl compounds such as 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl, and bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate; phenylenediamine compounds such as N,N'-diisopropyl-p-phenylenediamine, N,N'-di-2-naphthyl-p-phenylenediamine, N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine, N,N'-bis(1,4-dimethylphenyl)-p-phenylenediamine, and N-(1,4-dimethylphenyl)-N'-phenyl-p-phenylenediamine; hydroxylamine compounds; catechol compounds; pyrogallol compounds; phenothiazine compounds; nitrosyl radicals, etc. The polymerization inhibitor may contain at least one selected from the group consisting of phenolic compounds, nitroxyl compounds, phenylenediamine compounds, hydroxylamine compounds, catechol compounds, pyrogallol compounds, phenothiazine compounds, and nitrosyl radicals, and may contain 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl. When the polymerizable compound contains styrene, the polymerization inhibitor may contain nitroxyl compounds such as 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl, and bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate. The polymerization inhibitor may contain a stable radical compound.

[0016] In the method and apparatus for producing a polymerizable compound according to this embodiment, a polymerization inhibitor can be brought into contact with any inner surface of the condenser. The inner surface (inner surface of the condenser: hereinafter, sometimes referred to as the "surface to be treated") to which the polymerization inhibitor is brought into contact in the condenser may be a surface of any shape such as a flat surface, a concavo-convex surface, or a curved surface. There is no particular limitation on the size of the surface to be treated, and it is sufficient that the surface to be treated has a portion capable of bringing the polymerization inhibitor into contact.

[0017] In the method and apparatus for producing a polymerizable compound according to this embodiment, the surface to be treated may include any inner surface in the condenser where the gas to be condensed tends to stay. Hereinafter, "upstream" and "downstream" mean the upstream and downstream in the flow path direction of the gas to be condensed and the condensate. When there is a shielding object on the downstream side in the one direction in the space where the gas to be condensed flows from the upstream side in one direction, the gas to be condensed tends to stay in the vicinity of the shielding object. Therefore, the surface to be treated may include a surface existing on the downstream side in the one direction in the internal space of the condenser where the gas to be condensed flows from the upstream side in one direction.

[0018] In the method and apparatus for producing a polymerizable compound according to this embodiment, the surface to be treated may have a portion where a condensate containing the polymerizable compound can be generated, and may have a portion at a temperature equal to or lower than the condensation temperature of the polymerizable compound. In the portion where the condensate can be generated, the gas to be condensed may be naturally cooled, or the gas to be condensed may be cooled by a cooling means.

[0019] As the temperature T of the portion where the condensate can be generated or the condensation temperature of the polymerizable compound, the temperature T may be in the following range. From the viewpoint of easily obtaining the condensate, the temperature T may be 100°C or lower, 90°C or lower, 80°C or lower, or 75°C or lower. The temperature T may be 0°C or higher, 10°C or higher, 20°C or higher, 30°C or higher, 40°C or higher, 50°C or higher, or 60°C or higher. From these viewpoints, the temperature T may be 0 to 100°C.

[0020] In the method and apparatus for producing a polymerizable compound according to this embodiment, a polymerization inhibitor can be brought into continuous, intermittent, or discontinuous contact with the surface to be treated. It can be confirmed from the heat distribution of the surface to be treated that solids have been generated on the surface to be treated, and the supply time, supply amount, etc. of the polymerization inhibitor can be adjusted.

[0021] In the method and apparatus for producing a polymerizable compound according to this embodiment, while supplying a gas to be condensed to a condenser, a polymerization inhibitor can be brought into contact with the surface to be treated, and in a state where the gas to be condensed is not supplied to the condenser (a state where the supply of the gas to be condensed is stopped), a polymerization inhibitor can be brought into contact with the surface to be treated.

[0022] In the method and apparatus for producing a polymerizable compound according to this embodiment, a polymerization inhibitor can be supplied to the surface to be treated from a position facing the surface to be treated, and a polymerization inhibitor can be supplied to the surface to be treated from a position not facing the surface to be treated. As means for bringing the polymerization inhibitor into contact, any means can be used. For example, in the method and apparatus for producing a polymerizable compound according to this embodiment, the polymerization inhibitor can be sprayed onto the surface to be treated, and the polymerization inhibitor can be brought into contact with the surface to be treated (for example, sprayed) using a nozzle. The apparatus for producing a polymerizable compound according to this embodiment includes a supply means (for example, a spraying means) for the polymerization inhibitor and may include a nozzle. The supply means (for example, a nozzle) for the polymerization inhibitor may be arranged at only one location or at a plurality of locations.

[0023] As the nozzle, any nozzle can be used, such as a single-fluid nozzle or a two-fluid nozzle. As the spray pattern of the nozzle, any spray pattern can be used, such as a full cone, a hollow cone, a flat (fan-shaped), or a straight pattern. From the perspective of being easy to suppress the generation of solids, the spray pattern may be a full cone. The nozzle may be a swirl nozzle that injects the ejecta by swirling the ejecta inside the nozzle to form a swirling flow. The nozzle may have one injection hole or may have a plurality of injection holes with different injection directions. From the perspective of being easy to simplify the shape and thus easy to suppress the generation of solids in the nozzle, the nozzle may have one injection hole. Examples of the material of the nozzle include metal materials such as stainless steel (SUS), aluminum, and brass. The pressure, flow rate, shape of the injection hole, hole diameter of the injection hole, etc. in the nozzle are not particularly limited.

[0024] In the method and apparatus for producing a polymerizable compound according to this embodiment, the surface to be treated may be present at the position where the central axis of the injection hole of the nozzle extends, or the surface to be treated may not be present at the position where the central axis of the injection hole of the nozzle extends. When the surface to be treated is present at the position where the central axis of the injection hole of the nozzle extends, the polymerization inhibitor may be brought into contact with the surface to be treated using the nozzle in a state where the central axis of the injection hole of the nozzle is perpendicular to the surface to be treated (the portion where the central axis of the injection hole extends on the surface to be treated), or the polymerization inhibitor may be brought into contact with the surface to be treated using the nozzle in a state where the central axis of the injection hole of the nozzle is inclined with respect to the surface to be treated (the portion where the central axis of the injection hole extends on the surface to be treated). When the surface to be treated is not present at the position where the central axis of the injection hole of the nozzle extends (for example, when the opening of the flow path is located at the position where the central axis of the injection hole of the nozzle extends), the polymerization inhibitor can be brought into contact with the inner surface around the position where the central axis of the injection hole of the nozzle extends by injecting the polymerization inhibitor, for example, radially from the injection hole of the nozzle.

[0025] The spray angle at the injection hole of the nozzle may be in the following range. From the viewpoint of easily suppressing the generation of solids, the spray angle may be 60° or more, 90° or more, or 120° or more. The spray angle may be 170° or less, 160° or less, 150° or less, 140° or less, 130° or less, 120° or less, 110° or less, or 100° or less. From these viewpoints, the spray angle may be 60 to 170°.

[0026] The distance between the injection hole of the nozzle and the surface to be treated (the portion where the central axis of the injection hole on the surface to be treated extends) may be in the following range. The distance may be 0.1 m or more, 0.3 m or more, 0.5 m or more, 0.8 m or more, or 1.0 m or more. The distance may be 3.0 m or less, 2.5 m or less, 2.0 m or less, 1.5 m or less, or 1.0 m or less. From these viewpoints, the distance may be 0.1 to 3.0 m.

[0027] In the method and apparatus for producing a polymerizable compound according to the present embodiment, when the polymerization inhibitor is brought into contact with the surface to be treated using a nozzle, for example, 50% by mass or more (70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, etc.) of the polymerization inhibitor sprayed from the nozzle may come into contact with the surface to be treated.

[0028] The configuration of the condenser can be any configuration as long as it can condense the gas to be condensed to obtain a condensate. Examples of the condenser include an air fin cooler, a multi-tube heat exchanger, a double-tube heat exchanger, and a plate heat exchanger. As the condenser, it is possible to use a device without heating means, and a device different from a distiller (such as a distillation column) can be used.

[0029] The condenser may have a pipe section through which the gas to be condensed flows inside. The gas to be condensed may flow from the upstream end of the pipe section (the end on the upstream side in the flow path direction) to the downstream end of the pipe section (the end on the downstream side in the flow path direction). The downstream end of the pipe section may be closed (shielded) and may be opened and connected to subsequent equipment. The method and apparatus for producing a polymerizable compound according to the present embodiment may be such that the condenser has a pipe section with a closed downstream end (the downstream end in the flow path direction of the gas to be condensed), and the surface to be treated of the condenser may include the surface located at the downstream end of the pipe section. In this case, since the gas to be condensed stays at the downstream end of the pipe section and solids are likely to be generated, it is easy to suppress the generation of solids by bringing a polymerization inhibitor into contact with the surface located at the downstream end of the pipe section.

[0030] The condenser may have a first ventilation section and a second ventilation section connected to the first ventilation section on the downstream side in the flow path direction of the gas to be condensed relative to the first ventilation section, and the gas to be condensed may flow from the first ventilation section into the second ventilation section. In the method and apparatus for producing a polymerizable compound according to the present embodiment, the space between the first ventilation section and the second ventilation section is partitioned by a partition section having an opening (through hole: for example, a plurality of openings), and the surface to be treated of the condenser may include the surface on the first ventilation section side in the partition section. In this case, since the gas to be condensed stays in the first ventilation section and solids are likely to be generated, it is easy to suppress the generation of solids by bringing a polymerization inhibitor into contact with the surface on the first ventilation section side in the partition section. The dimensions, shapes, etc. of the first ventilation section, the second ventilation section, and the partition section are not particularly limited. The number, shape, dimensions, arrangement, etc. of the openings in the partition section are not particularly limited.

[0031] The second ventilation section may be a cooling section for cooling the gas to be condensed. As the cooling section, it is sufficient to have a cooling means for cooling the gas to be condensed and be able to obtain a condensate containing a polymerizable compound. The second ventilation section may be, for example, an air fin cooler section. The second ventilation section may have a flow path (for example, a plurality of flow paths) extending from the upstream end to the downstream end of the second ventilation section as a flow path for transferring the gas to be condensed and the condensate, and may be configured to cool the flow path.

[0032] In addition to the first vent portion and the second vent portion, the condenser may have a third vent portion connected to the second vent portion on the downstream side in the flow path direction from the second vent portion, and the gas to be condensed and the condensate may flow into the third vent portion from the second vent portion. The space between the second vent portion and the third vent portion may be partitioned by a partition portion having an opening (through hole: for example, a plurality of openings). The dimensions, shape, etc. of the third vent portion and the partition portion are not particularly limited. The number, shape, dimensions, arrangement, etc. of the openings in the partition portion are not particularly limited.

[0033] The method for producing a polymerizable compound according to this embodiment may include a reaction step of reacting a raw material of the polymerizable compound to obtain a gas to be condensed (a gas containing the polymerizable compound). The apparatus for producing a polymerizable compound according to this embodiment may include a reactor that reacts a raw material of the polymerizable compound to obtain a gas to be condensed (a gas containing the polymerizable compound). As the raw material of the polymerizable compound, any raw material can be used, and examples include ethylbenzene which is a raw material of styrene.

[0034] In the method and apparatus for producing a polymerizable compound according to this embodiment, based on the temperature of the reactor for obtaining the gas to be condensed (for example, the inlet temperature of the reactor), the relative amount of the polymerization inhibitor with respect to the polymerizable compound can be adjusted. For example, in the method and apparatus for producing a polymerizable compound according to this embodiment, the temperature T1 of the reactor is acquired, and the relative amount of the polymerization inhibitor with respect to the polymerizable compound is adjusted to the relative amount corresponding to the temperature T1 in a linear equation showing the relationship between the temperature of the reactor and the relative amount of the polymerization inhibitor with respect to the polymerizable compound (the relative amount of the adjustment target).

[0035] In the method and apparatus for producing a polymerizable compound according to this embodiment, the supply amount of the polymerization inhibitor may be adjusted based on the flow rate of the polymerization inhibitor in the flow path between the supply means (for example, a nozzle) of the polymerization inhibitor and the storage portion of the polymerization inhibitor. The supply amount of the polymerization inhibitor can be adjusted by a valve or the like arranged in the flow path. The flow rate of the polymerization inhibitor may be adjusted based on the flow rate of a mixture containing the polymerization inhibitor (for example, a mixed liquid containing the polymerization inhibitor and water).

[0036] The method for producing a polymerizable compound according to this embodiment may include a temperature adjustment step of adjusting the temperature of the gas to be condensed after the reaction step. The production apparatus for a polymerizable compound according to this embodiment may include a temperature adjuster for adjusting the temperature of the gas to be condensed. As the means for adjusting the temperature of the gas to be condensed, any temperature adjustment means can be used. The gas to be condensed may be cooled or heated. The gas to be condensed whose temperature has been adjusted can be transferred to a condenser.

[0037] The method for producing a polymerizable compound according to this embodiment may include a separation step of separating the polymerizable compound from the condensate containing the polymerizable compound. The production apparatus for a polymerizable compound according to this embodiment may include a separator for separating the polymerizable compound from the condensate containing the polymerizable compound. As the means for separating the polymerizable compound, any separation means can be used. Only the polymerizable compound may be separated, or a mixture containing the polymerizable compound and other components may be separated.

[0038] The method for producing a polymerizable compound according to this embodiment may include steps different from the above-described steps. For example, it may include a purification step of purifying the polymerizable compound separated by a separator. The production apparatus for a polymerizable compound according to this embodiment may include equipment different from the above-described equipment. For example, it may include a purifier for purifying the polymerizable compound separated by a separator.

[0039] Examples of the method for producing a polymerizable compound and the production apparatus according to this embodiment will be described with reference to FIGS. 1 to 4.

[0040] FIG. 1 is a schematic diagram for explaining the manufacturing procedure of a polymerizable compound. A manufacturing apparatus 100 used for manufacturing the polymerizable compound includes, in order from upstream to downstream in the flow path direction, a reactor 10, a heat exchanger 20, condensers (a condenser (first condenser) 30 and a condenser (second condenser) 40), and a separator 50. In the manufacturing apparatus 100, a condensable gas G1 containing the polymerizable compound is generated in the reactor 10, and the condensable gas G1 is transferred from the reactor 10 to the condenser 30 via the heat exchanger 20. In the condenser 30, a part of the condensable gas G1 is condensed to obtain a condensate L1 containing the polymerizable compound, and the remaining condensable gas G2 of the condensable gas G1 is transferred to the condenser 40. In the condenser 40, the condensable gas G2 is condensed to obtain a condensate L2 containing the polymerizable compound. The condensate L1 of the condenser 30 and the condensate L2 of the condenser 40 are transferred to the separator 50, and the polymerizable compound is separated from the condensate L1 and the condensate L2 in the separator 50.

[0041] In the reactor 10, raw materials of the polymerizable compound are reacted to obtain a condensable gas G1 containing the polymerizable compound. The reactor 10 is connected to the heat exchanger 20. The condensable gas G1 obtained in the reactor 10 is transferred to the heat exchanger 20.

[0042] In the heat exchanger 20, the condensable gas G1 is cooled. The heat exchanger 20 is connected to the condenser 30. The condensable gas G1 cooled in the heat exchanger 20 is transferred to the condenser 30.

[0043] FIG. 2 is a schematic end view for explaining the condenser 30. FIGS. 3 and 4 are schematic end views for explaining the condenser 30 and the condenser 40. In FIGS. 2 to 4, a rectangular coordinate system S defined by an X axis, a Y axis, and a Z axis (vertical direction) orthogonal to each other is shown. In FIGS. 2 to 4, for the sake of convenience, illustration of some members is omitted.

[0044] The condenser 30 has a long first pipe section 32, a second pipe section 34 connected to the first pipe section 32 and a plurality of flow paths 36, and a nozzle 38. The first pipe section 32 and the second pipe section 34 have an internal space for the gas G1 to be condensed, the condensed liquid L1, etc. to flow through. The material, dimensions, shape, etc. of the first pipe section 32 and the second pipe section 34 are not particularly limited. The dimensions, shape, etc. of the internal space of the first pipe section 32 and the second pipe section 34 are not particularly limited.

[0045] The upstream end 32a of the first pipe section 32 is an open end, and the downstream end 32b of the first pipe section 32 is a closed end. The gas G1 to be condensed cooled in the heat exchanger 20 flows into the first pipe section 32 from the upstream end 32a of the first pipe section 32. A liquid phase component may flow into the first pipe section 32 together with the gas G1 to be condensed. As the inner surface F1 of the condenser 30, the inner surface of the downstream end 32b of the first pipe section 32 is a curved surface that curves toward the outside of the first pipe section 32.

[0046] The second pipe section 34 is connected to the first pipe section 32 at a position on the bottom side (vertically downward side) in the vicinity of the downstream end 32b of the first pipe section 32. One end of the second pipe section 34 is connected to the first pipe section 32, and the other end of the second pipe section 34 is connected to the separator 50.

[0047] The plurality of flow paths 36 are flow paths for transferring the gas G2 to be condensed to the condenser 40. The flow paths 36 are connected in plurality along the longitudinal direction (Y-axis direction in FIGS. 2 to 4) of the first pipe section 32 on one side surface of the first pipe section 32, and are connected in plurality along the longitudinal direction of the first pipe section 32 on the other side surface of the first pipe section 32. The flow paths 36 extend vertically upward.

[0048] The nozzle 38 is a nozzle for bringing the polymerization inhibitor into contact with the inner surface F1, and is disposed in the vicinity of the downstream end 32b of the first pipe section 32. The nozzle 38 is suspended from vertically above, and brings an aqueous solution of the polymerization inhibitor into contact with the inner surface F1.

[0049] In the condenser 30, after the gas G1 to be condensed flows into the first pipe section 32 from the upstream end 32a of the first pipe section 32, a part of the gas G1 to be condensed, i.e., the gas G2 to be condensed, flows out from the flow path 36 and is transferred to the condenser 40, while the remaining part of the gas G1 to be condensed flows from the upstream end 32a to the downstream end 32b and stays at the downstream end 32b. The gas G1 to be condensed contacts the inner surface such as the inner surface F1 of the first pipe section 32 and is cooled, thereby condensing to generate the condensate L1. The condensate L1 flows into the second pipe section 34 along the bottom side (vertically downward side) of the first pipe section 32 and is transferred to the separator 50.

[0050] The condenser 40 is composed of two condensers having the same configuration. Each of the condensers 40 is arranged above the condenser 30 in the vertical direction such that the two condensers 40 face each other with the condenser 30 in between when viewed from above in the vertical direction. Each of the condensers 40 has a first vent section 42, a second vent section 44 connected to the first vent section 42 on the downstream side of the first vent section 42, a third vent section 46 connected to the second vent section 44 on the downstream side of the second vent section 44, a plurality of nozzles 48, and a flow path 49 connected to the third vent section 46 on the downstream side of the third vent section 46. The first vent section 42, the second vent section 44, and the third vent section 46 have an internal space for the gas G2 to be condensed, the condensate L2, etc. to flow through.

[0051] The space between the first vent section 42 and the second vent section 44 is partitioned by a partition section 42a having a plurality of openings. The space between the second vent section 44 and the third vent section 46 is partitioned by a partition section 44a having a plurality of openings.

[0052] The first ventilation part 42 has a long internal space extending in the horizontal direction (Y-axis direction in FIGS. 2 to 4). The gas G2 to be condensed flowing out from the first piping part 32 of the condenser 30 flows into the first ventilation part 42 of the condenser 40 via the flow path 36. The gas G2 to be condensed flows into the second ventilation part 44 through the opening of the partition part 42a. The gas G2 to be condensed before flowing into the second ventilation part 44 stays in the first ventilation part 42 and contacts, as the inner surface F2 of the condenser 40, the surface on the first ventilation part 42 side in the partition part 42a.

[0053] The second ventilation part 44 has a long internal space extending in the horizontal direction and is an air fin cooler part that cools the gas G2 to be condensed. The second ventilation part 44 has a plurality of flow paths (not shown) extending from the opening of the partition part 42a to the opening of the partition part 44a, and the flow paths are cooled in the second ventilation part 44. In the second ventilation part 44, when the gas G2 to be condensed condenses, a condensate L2 containing a polymerizable compound is obtained, and the condensate L2 and the non-condensed gas phase component of the gas G2 to be condensed flow into the third ventilation part 46 from the second ventilation part 44 through the opening of the partition part 44a.

[0054] The third ventilation part 46 has a long internal space extending in the horizontal direction. The condensate L2 flowing into the third ventilation part 46 from the second ventilation part 44 is transferred from the third ventilation part 46 to the separator 50 via the flow path 49. The non-condensed gas phase component of the gas G2 to be condensed is transferred from the third ventilation part 46 to subsequent equipment (not shown) other than the separator 50 via the flow path 49.

[0055] The nozzle 48 is a nozzle for bringing a polymerization inhibitor into contact with the inner surface F2 of the condenser 40, and a plurality of nozzles 48 are arranged along the longitudinal direction of the first ventilation part 42 inside the first ventilation part 42. In the condenser 40, a plurality of nozzles 48 are arranged so that the polymerization inhibitor partially contacts the inner surface F2, but a plurality of nozzles 48 may be arranged so that the polymerization inhibitor contacts substantially the entire inner surface F2. The nozzle 48 supplies an aqueous solution of the polymerization inhibitor to the inner surface F2 from the upper surface side of the first ventilation part 42 and brings the aqueous solution of the polymerization inhibitor into contact with the inner surface F2.

[0056] In the condenser 40, after the gas G2 to be condensed flows into the first vent portion 42 from the flow path 36, the gas G2 to be condensed flows into the second vent portion 44 through the opening of the partition portion 42a. In the second vent portion 44, a part of the gas G2 to be condensed is cooled and condensed to generate a condensate L2. The condensate L2 flows into the third vent portion 46 from the second vent portion 44 through the opening of the partition portion 44a, and is transferred from the third vent portion 46 to the separator 50 via the flow path 49.

[0057] In the separator 50, the polymerizable compound is separated and recovered from the condensates L1 and L2.

[0058] In the manufacturing apparatus 100, the gas G1 to be condensed flows in the longitudinal direction of the first piping portion 32. Since the inner surface F1 exists in the longitudinal direction, the gas G1 to be condensed tends to stay in the vicinity of the inner surface F1. Further, in the manufacturing apparatus 100, the gas G2 to be condensed flows in the direction from the first vent portion 42 toward the second vent portion 44. Since the inner surface F2 exists in this direction, the gas G2 to be condensed tends to stay in the vicinity of the inner surface F2. In such a manufacturing apparatus 100, by bringing a polymerization inhibitor into contact with the inner surface F1 of the condenser 30, it is possible to suppress the generation of solids on the inner surface F1, and by bringing a polymerization inhibitor into contact with the inner surface F2 of the condenser 40, it is possible to suppress the generation of solids on the inner surface F2. Thereby, in the manufacturing apparatus 100, it is possible to suppress a decrease in the production efficiency of the polymerizable compound.

[0059] Further, in the manufacturing apparatus 100, by bringing an aqueous solution of a polymerization inhibitor into contact with the inner surfaces F1 and F2, even when solids are generated on the inner surfaces of the condenser 30 and the condenser 40, the solids can be removed (washed away).

[0060] The method and apparatus for producing a polymerizable compound according to this embodiment are not limited to the aspects described with reference to FIGS. 1 to 4. For example, in the production apparatus 100, a polymerization inhibitor may be brought into contact with any inner surface of the condenser 30 and the condenser 40, such as an inner surface other than the inner surface F1 in the first pipe section 32, the inner surface of the second pipe section 34, the inner surface of the flow path 36, an inner surface other than the inner surface F2 in the first ventilation section 42, the inner surface of the second ventilation section 44, and the inner surface of the third ventilation section 46. Further, in the production apparatus 100, a polymerization inhibitor may be brought into contact with only one of the inner surface F1 of the condenser 30 and the inner surface F2 of the condenser 40. In the condensers 30 and 40, in addition to the inner surfaces F1 and F2, a polymerization inhibitor may be brought into contact with inner surfaces other than the inner surfaces F1 and F2, or a polymerization inhibitor may be brought into contact with only the inner surfaces other than the inner surfaces F1 and F2 in the condensers 30 and 40. In the method and apparatus for producing a polymerizable compound according to this embodiment, in addition to the inner surface of the condenser, a polymerization inhibitor may be brought into contact with the inner surface of equipment other than the condenser.

Examples

[0061] Hereinafter, the content of the present invention will be described in more detail using examples and comparative examples, but the present invention is not limited to the following examples.

[0062] (Example) Using the production apparatus 100 of FIGS. 1 to 4, a condensate containing styrene (styrene monomer) was obtained.

[0063] First, in the reactor 10, ethylbenzene and steam were subjected to a dehydrogenation reaction under high temperature and reduced pressure to obtain a gas G1 to be condensed containing styrene. Next, the gas G1 to be condensed was transferred to the heat exchanger 20 and cooled by supplying water to the heat exchanger 20. Subsequently, the gas G1 to be condensed was transferred to the condenser 30.

[0064] In the condenser 30, while supplying the gas G1 to be condensed from the upstream end 32a of the first pipe section 32 to the first pipe section 32, an aqueous solution of a polymerization inhibitor (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl) was sprayed onto the inner surface F1 of the condenser 30 using the nozzle 38. As the nozzle 38, a full-cone type spiral nozzle (material: SUS) was used. The content of the polymerization inhibitor in the aqueous solution of the polymerization inhibitor was 6 to 40 ppm with respect to 1 kg of styrene, and was 0.1 to 1.0% by mass based on the total mass of the aqueous solution. The injection amount of the aqueous solution of the polymerization inhibitor was 4000 kg / h, the spray angle was 60 to 100°, and the distance between the injection hole of the nozzle 38 and the inner surface F1 of the condenser 30 (the portion where the central axis of the injection hole extends on the inner surface F1) was 1.0 m. The nozzle 38 was arranged in a state where the central axis of the injection hole of the nozzle 38 was perpendicular to the approximate center of the inner surface F1. The condensate L1 obtained by condensing a part of the gas G1 to be condensed in the first pipe section 32 was transferred from the second pipe section 34 to the separator 50. The remaining gas G2 to be condensed was transferred from the flow path 36 to the condenser 40.

[0065] In the condenser 40, while supplying the gas G2 to be condensed from the flow path 36 to the first vent section 42, an aqueous solution of a polymerization inhibitor (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl) was sprayed onto the inner surface F2 of the condenser 40 using the nozzle 48. As the nozzle 48, a flat spray nozzle (material: SUS) was used. The content of the polymerization inhibitor in the aqueous solution of the polymerization inhibitor was 6 to 40 ppm with respect to 1 kg of styrene, and was 0.1 to 1.0% by mass based on the total mass of the aqueous solution. The injection amount of the aqueous solution of the polymerization inhibitor was 40 kg / h. The nozzle 48 was arranged on the upper surface side of the first vent section 42 in a state where the central axis of the injection hole of the nozzle 48 was inclined with respect to the inner surface F2. A plurality of nozzles 48 were arranged along the longitudinal direction of the first vent section 42. The gas G2 to be condensed was transferred from the opening of the partition section 42a to the second vent section 44, and the condensate L2 was obtained by cooling the gas G2 to be condensed in the second vent section 44. After the condensate L2 was transferred from the opening of the partition section 44a to the third vent section 46, the condensate L2 was transferred to the separator 50 via the flow path 49.

[0066] In the separator 50, styrene was separated and recovered from the condensate L1 and the condensate L2.

[0067] After operating the above-described production apparatus 100 for 350 days, the inner surface F1 of the condenser 30 and the inner surface F2 of the condenser 40 were observed. No formation of solids was confirmed on the inner surface F1 and the inner surface F2. FIG. 5 is a diagram showing the observation results of the inner surface of the condenser, and shows the observation results of the inner surface F2 after operation.

[0068] (Comparative Example) After performing the same operation as in the example except that the production apparatus 100 was operated for 350 days without spraying the aqueous solution of the polymerization inhibitor on the inner surface F1 and the inner surface F2, the inner surface F1 and the inner surface F2 were observed. Formation of solids was confirmed on the inner surface F1 and the inner surface F2. FIG. 6 is a diagram showing the observation results of the inner surface of the condenser, and shows the observation results of the inner surface F2 after operation.

Explanation of Signs

[0069] 10... reactor, 20... heat exchanger, 30, 40... condensers, 32... first piping section, 32a... upstream end, 32b... downstream end, 34... second piping section, 36, 49... flow paths, 38, 48... nozzles, 42... first vent section, 42a, 44a... partition sections, 44... second vent section, 46... third vent section, 50... separator, 100... production apparatus, F1, F2... inner surfaces, G1, G2... gases to be condensed, L1, L2... condensates, S... rectangular coordinate system.

Claims

1. A method for producing a polymerizable compound, comprising a step of bringing a polymerization inhibitor into contact with the inner surface of a condenser that condenses a gas containing a polymerizable compound to obtain a condensate.

2. The method for producing a polymerizable compound according to claim 1, wherein the polymerization inhibitor is brought into contact with the inner surface of the condenser while the gas is being supplied to the condenser.

3. The method for producing a polymerizable compound according to claim 1, wherein the inner surface of the condenser has a portion at a temperature equal to or lower than the condensation temperature of the polymerizable compound.

4. The method for producing a polymerizable compound according to claim 1, wherein the inner surface of the condenser has a portion at a temperature of 75°C or lower.

5. The condenser has a piping portion with a closed downstream end in the gas flow path direction, The method for producing a polymerizable compound according to claim 1, wherein the inner surface of the condenser includes the surface located at the downstream end of the piping portion.

6. The condenser has a first vent portion and a second vent portion connected to the first vent portion on the downstream side of the first vent portion in the gas flow path direction, The space between the first vent portion and the second vent portion is partitioned by a partition portion having an opening, The method for producing a polymerizable compound according to claim 1, wherein the inner surface of the condenser includes the surface on the first vent portion side of the partition portion.

7. The method for producing a polymerizable compound according to claim 6, wherein the second vent portion is an air fin cooler portion.

8. The method for producing a polymerizable compound according to claim 1, wherein the polymerization inhibitor is supplied to the inner surface of the condenser from a position facing the inner surface of the condenser.

9. The method for producing a polymerizable compound according to claim 1, wherein the polymerization inhibitor is brought into contact with the inner surface of the condenser using a nozzle in a state where the central axis of the injection hole of the nozzle is perpendicular to the inner surface of the condenser.

10. The method for producing a polymerizable compound according to claim 1, wherein a mixed solution containing the polymerization inhibitor and water is brought into contact with the inner surface of the condenser.

11. The method for producing a polymerizable compound according to claim 1, wherein the polymerization inhibitor contains at least one selected from the group consisting of phenolic compounds, oxyl compounds, phenylenediamine compounds, hydroxylamine compounds, catechol compounds, pyrogallol compounds, phenothiazine compounds, and nitrosyl radicals.

12. The method for producing a polymerizable compound according to claim 1, wherein the polymerization inhibitor contains 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl.

13. The method for producing a polymerizable compound according to any one of claims 1 to 12, wherein the polymerizable compound contains styrene.

14. A production apparatus for a polymerizable compound, comprising a condenser that condenses a gas containing the polymerizable compound to obtain a condensate, wherein a polymerization inhibitor is brought into contact with the inner surface of the condenser.

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