Apparatus and method for producing acenaphthylene

Abstract

To provide an apparatus and a method for producing acenaphthylene which improve preheating means of raising the temperature of acenaphthene to a reaction temperature in a catalyst layer, thereby achieves a high yield of acenaphthylene, and prevent precipitation of only acenaphthene having a high boiling point, and enable stable continuous production of acenaphthylene.SOLUTION: An apparatus 1 for producing acenaphthylene includes: a preheating device 3 for raising the temperature of acenaphthene, a solvent and superheated vapor up to a temperature range of ±20°C of a reaction temperature in a catalyst layer 6e; and a reactor 6 for bringing the acenaphthene whose the temperature has been raised up to the reaction temperature in the catalyst layer 6e by the preheating device 3 into contact with the catalyst layer 6e together with the solvent and the superheated vapor, and dehydrogenating the mixture. The preheating device 3 includes: a first preheater 4 for raising the temperature of the mixture of the acenaphthene, the solvent and the superheated vapor up to a temperature vaporizing the acenaphthene and the solvent; and a second preheater 5 for raising the temperature of the mixture whose the temperature has been raised by the first preheater 4 up to a temperature range of ±20°C of the reaction temperature in the catalyst layer 6e.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an apparatus and method for producing acenaphthylene. [Background technology]

[0002] Conventionally, methods for producing acenaphthylene include catalytic reactions in the gas phase and isotopic reactions in the liquid phase. In the gas phase reaction of acenaphthylene, acenaphthene is dehydrogenated by contacting it with a catalyst in a gaseous state to produce acenaphthylene. It is known that in the gas phase reaction of acenaphthylene, if iron oxide or titanium oxide is used as a catalyst and the catalytic reaction is carried out at about 600°C, the yield of acenaphthylene can be increased and the catalyst can have a long life. Acenaphthene used as a raw material is a solid at room temperature, and it is difficult to continuously charge it into the catalyst bed as a single substance. Therefore, it is charged into the catalyst bed in the form of a solution dissolved in a solvent such as benzene. In addition, steam is charged into the catalyst bed together with the raw material to prevent coking on the catalyst.

[0003] Here, as conventional methods for producing acenaphthylene by a gas-phase reaction of acenaphthylene, for example, those shown in Patent Documents 1 to 3 are known. The method for producing acenaphthylene shown in Patent Document 1 involves contacting acenaphthene in a gaseous state with titanium oxide. Patent Document 1 describes that when acenaphthene is introduced into titanium oxide as a catalyst layer, it can be diluted with a gas inert to the catalyst (nitrogen, water vapor, carbon dioxide gas, and aromatic hydrocarbons such as benzene, toluene, and xylene) and then introduced into the catalyst layer. Patent Document 1 also describes that when acenaphthene is introduced into the catalyst layer, it is heated to the reaction temperature (600°C) in the catalyst layer. By heating acenaphthene to the reaction temperature in the catalyst layer when introducing it into the catalyst layer, it is possible to suppress a drop in the reaction temperature in the catalyst layer and reduce the amount of unreacted raw material (acenaphthene).

[0004] Furthermore, the method for producing acenaphthylene shown in Patent Document 2 involves contacting acenaphthene in a gaseous state with a catalyst containing iron oxide, titanium oxide, and a potassium compound at a temperature of 500 to 750° C. to dehydrogenate it. Patent Document 2 also describes that when acenaphthene and water vapor are introduced into the catalyst layer, it is preferable to heat the acenaphthene and water vapor in advance to a reaction temperature (500 to 750° C.) similar to that of the catalyst.

[0005] Furthermore, the method for producing acenaphthylene shown in Patent Document 3 involves dehydrogenating acenaphthenes in a gas phase in the presence of steam by contacting them with an iron oxide-based catalyst containing iron oxide, an alkali metal compound, and a chromium group metal compound. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 47-25165 [Patent Document 2] Japanese Patent Application Publication No. 63-316746 [Patent Document 3] Japanese Patent Application Publication No. 1-139538 Summary of the Invention [Problem to be solved by the invention]

[0007] Here, in conventional methods for producing acenaphthylene, such as the methods for producing acenaphthylene shown in Patent Documents 1 to 3, improvements have been made to increase the yield of acenaphthylene and extend the life of the catalyst in the gas-phase reaction of acenaphthylene by focusing only on the composition of the catalyst. On the other hand, even if a high-performance catalyst is used, depending on the preheating method for raising the temperature of acenaphthene to the reaction temperature in the catalyst layer, acenaphthene may not reach the reaction temperature or temperature unevenness may occur, resulting in a low yield and a low recovery rate.

[0008] In addition, when acenaphthene is preheated to increase its temperature, if the solvent, for example, benzene and acenaphthene, is not vaporized all at once, only acenaphthene, which has a high boiling point, will precipitate and cause blockages in the equipment, which may make it difficult to stably and continuously produce acenaphthylene. Therefore, the present invention has been made to solve these conventional problems, and an object of the present invention is to provide an apparatus and method for producing acenaphthylene which improves the preheating means for raising the temperature of acenaphthene to the reaction temperature in the catalyst layer, thereby increasing the yield of acenaphthylene and preventing the precipitation of only acenaphthene, which has a high boiling point, thereby enabling stable continuous production of acenaphthylene. [Means for solving the problem]

[0009] In order to solve the above problems, an apparatus for producing acenaphthylene according to one embodiment of the present invention is an apparatus for producing acenaphthylene comprising a preheating device which heats acenaphthene, a solvent and superheated steam to a temperature range of ±20°C of the reaction temperature in the catalyst bed, and a reactor which brings the acenaphthene heated in the preheating device into contact with the catalyst bed together with the solvent and superheated steam for dehydrogenation, wherein the preheating device comprises a first preheater which heats a mixture of acenaphthene, the solvent and superheated steam to a temperature at which the acenaphthene and the solvent are vaporized, and a second preheater which heats the mixture heated in the first preheater to a temperature range of ±20°C of the reaction temperature in the catalyst bed.

[0010] Furthermore, a method for producing acenaphthylene according to another embodiment of the present invention is a method for producing acenaphthylene including a preheating step of heating acenaphthene, a solvent, and superheated steam to a temperature range of ±20°C of the reaction temperature in the catalyst layer, and a reaction step of dehydrogenating the acenaphthene heated in the preheating step by contacting the acenaphthene heated in the preheating step together with the solvent and superheated steam with the catalyst layer, wherein the preheating step includes a first preheating step of heating a mixture of acenaphthene, the solvent, and superheated steam to a temperature at which the acenaphthene and the solvent are vaporized, and a second preheating step of heating the mixture heated in the first preheating step to a temperature range of ±20°C of the reaction temperature in the catalyst layer. Effect of the Invention

[0011] According to the apparatus and method for producing acenaphthylene of the present invention, by improving the preheating means for raising the temperature of acenaphthene to the reaction temperature in the catalyst layer, it is possible to provide an apparatus and method for producing acenaphthylene that increases the yield of acenaphthylene and prevents the precipitation of only acenaphthene, which has a high boiling point, thereby enabling stable continuous production of acenaphthylene. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic diagram of an apparatus for producing acenaphthylene according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic view of the vicinity of an inlet of a first preheater in the acenaphthylene production apparatus shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an apparatus and method for producing acenaphthylene according to an embodiment of the present invention will be described with reference to the drawings. The embodiments shown below are merely examples of an apparatus and method for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention is not limited to the following embodiments in terms of the material, shape, structure, arrangement, etc. of the components. In addition, the drawings are schematic, and therefore, it should be noted that the relationship between thickness and planar dimensions, ratios, etc. may differ from the actual relationship between thickness and planar dimensions, and the drawings may include parts in which the relationship between dimensions and ratios differ from one another.

[0014] FIG. 1 shows a schematic configuration of an apparatus for producing acenaphthylene according to one embodiment of the present invention. The acenaphthylene production apparatus 1 shown in FIG. The steam heater 2 heats steam (water vapor) to produce superheated steam. The steam heater 2 is configured by disposing an electric heater 2b in a container 2a closed by a lid 2c, and produces superheated steam by heating the steam introduced into the container 2a with the electric heater 2b. The temperature of the superheated steam produced by the steam heater 2 is about 400°C.

[0015] A heating steam pipe 2d for leading the superheated steam in the container 2a to the outside is installed on the cover 2c of the steam heater 2. As shown in Fig. 1 and Fig. 2, the heating steam pipe 2d is connected to an inlet 4e of a tube 4a of a first preheater 4 (described later) of the preheating device 3, and the superheated steam produced by the steam heater 2 is charged into the inlet 4e of the tube 4a of the first preheater 4. The preheating device 3 heats the raw material acenaphthene, the solvent benzene, and the superheated steam to a temperature range of ±20° C. of the reaction temperature in the catalyst layer 6e in the reactor 6. The "reaction temperature" will be described later.

[0016] The preheating device 3 includes a first preheater 4 which heats a mixture of a solution of acenaphthene in benzene (hereinafter also referred to as an acenaphthene-benzene solution) and superheated steam to a temperature at which acenaphthene and benzene are vaporized in one go, and a second preheater 5 which heats the mixture of acenaphthene, benzene, and superheated steam heated and vaporized in the first preheater 4 to a reaction temperature in the catalyst layer 6e.

[0017] In the first preheater 4, as shown in Fig. 2, superheated steam produced by the steam heater 2 is charged from the superheated steam pipe 2d to the inlet 4e of the tube 4a, and an acenaphthene benzene solution is charged from the charging pipe 4f to the inlet 4e of the tube 4a into the superheated steam, and the acenaphthene benzene solution is temporarily heated. Then, the first preheater 4 heats the mixture of the acenaphthene benzene solution charged at the inlet 4e and the superheated steam with an electric heater 4b installed on the outer periphery of the tube 4a, thereby raising the temperature of the mixture of the acenaphthene benzene solution and the superheated steam to a temperature at which acenaphthene and benzene are vaporized at once. In other words, the mixture is heated to a temperature (about 400°C) above the boiling point of acenaphthene, which vaporizes acenaphthene and benzene at once. The temperature rise rate of acenaphthene in the first preheating step (the temperature rise rate of acenaphthene from the inlet of the first preheating step to the outlet of the first preheating step) is preferably 400 to 2000°C / sec. If the temperature rise rate is slower than 400°C / sec, acenaphthene may precipitate in the device. On the other hand, if the temperature rise rate is faster than 2000°C / sec, the device becomes large and the manufacturing cost increases.

[0018] By using the structure of the first preheater 4 as shown in FIG. 2, acenaphthene and benzene are vaporized at once, and clogging of the equipment due to precipitation of acenaphthene, which has a high boiling point, is suppressed, enabling stable continuous production of acenaphthylene. The structure of the inlet portion of the first preheater 4 will be described in detail with reference to Fig. 2. The inlet 4g of the charging pipe 4f, which charges the acenaphthene benzene solution into the inlet 4e of the tube 4 of the first preheater 4, has a submerged tube structure. Specifically, the inlet 4g of the charging pipe 4f is located near the superheated steam pipe 2d and inside the tube 4a, so that acenaphthene can be charged directly from the inlet 4f into the superheated steam charged from the superheated steam pipe 2d to the inlet 4e of the tube 4a. This makes it possible to prevent precipitation of acenaphthene at the liquid outlet of the charging pipe 4f.

[0019] A lid 4c is provided at the end (upper end) of the tube 4a on the inlet 4e side, and a charging pipe 4f is installed in the lid 4c. A lid 4d is provided at the end (lower end) of the tube 4a on the outlet side, and a discharge pipe 4h is installed in the lid 4d to discharge a mixture of acenaphthene, benzene, and superheated steam that has been heated and vaporized in the first preheater 4. The discharge pipe 4h is connected to the inlet of the tube 5a of the second preheater 5 of the preheating device 3, which will be described later.

[0020] The second preheater 5 heats the mixture of acenaphthene, benzene, and superheated steam, which is heated and vaporized in the first preheater 4, to a temperature range of ±20°C of the reaction temperature in the catalyst layer 6e, and includes a tube 5a into which the mixture of vaporized acenaphthene, benzene, and superheated steam is charged from a discharge pipe 4h, and an electric heater 5b that is installed on the outer periphery of the tube 5a and heats the mixture to the reaction temperature in the catalyst layer 6e. A cover 5c that closes the inlet end (upper end) of the tube 5a is provided, and the discharge pipe 4h is inserted into the cover 5c. The outlet end (lower end) of the tube 5a is provided with an outlet 5d that discharges the heated mixture toward the reactor 6.

[0021] By heating the mixture to a temperature range of ±20° C. from the reaction temperature in the catalyst layer 6e using the second preheater 5, it is possible to suppress a drop in the reaction temperature and local heating in the catalyst layer 6e. This makes it possible to reduce unreacted acenaphthene and over-reacted products, and to obtain acenaphthylene in a high yield. Furthermore, by performing preheating to raise the temperature to the reaction temperature in the catalyst layer 6e in two stages, that is, by preheating using the first preheater 4 and then by preheating using the second preheater 5, the mixture of acenaphthene, benzene, and superheated steam can reliably reach the reaction temperature without temperature unevenness, resulting in a high yield and a high production rate of acenaphthylene.

[0022] Here, the reaction temperature in the catalyst layer 6e is about 600°C, and the preheating temperature by the second preheater 5 is −20°C to +20°C with respect to the reaction temperature. If the preheating temperature by the second preheater 5 is set lower than −20°C with respect to the reaction temperature, the temperature of the mixture does not reach the reaction temperature, and the decrease in the reaction temperature and local heating in the catalyst layer 6e cannot be suppressed, and unreacted acenaphthene and over-reaction products cannot be reduced, so that acenaphthylene cannot be obtained in high yield. On the other hand, even if the preheating setting temperature by the second preheater 5 is set higher than +20°C with respect to the reaction temperature, acenaphthylene cannot be obtained in high yield.

[0023] The reactor 6 dehydrogenates acenaphthene, which has been heated to a temperature range of ±20°C of the reaction temperature in the catalyst layer 6e by the preheating device 3, by contacting it with the catalyst layer 6e together with benzene and superheated steam. The reactor 6 includes a tube 6a housing the catalyst layer 6e therein and an electric heater 6b that is installed on the outer periphery of the tube 6a and heats the catalyst layer 6e to the aforementioned reaction temperature. In the reactor 6, before acenaphthene is brought into contact with the catalyst layer 6e together with benzene and superheated steam, the catalyst layer 6e is heated by the electric heater 6b to the aforementioned reaction temperature. Then, in the reactor 6, acenaphthene is brought into contact with the heated catalyst layer 6e together with benzene and superheated steam to dehydrogenate it, thereby producing acenaphthylene. An inlet 6c is provided at the end (upper end) of the inlet side of the tube 6a to introduce the mixture heated in the second preheater 5 into the tube 6a. Furthermore, an outlet port 6d for discharging the produced acenaphthylene is provided at the outlet end (lower end) of the tube 6a.

[0024] The catalyst for the catalyst layer 6e is a conventional catalyst such as titanium oxide or iron oxide. As described above, in the acenaphthylene production apparatus 1 according to this embodiment, the preheating device 3 includes a first preheater 4 which heats a mixture of acenaphthene, benzene and superheated steam to a temperature at which the acenaphthene and benzene are vaporized, and a second preheater 5 which heats the mixture heated in the first preheater 4 to a temperature range of the reaction temperature in the catalyst layer 6e ±20°C.

[0025] By using the first preheater 4 to heat the mixture of acenaphthene, benzene and superheated steam to a temperature at which acenaphthene and benzene are vaporized, acenaphthene and benzene are vaporized all at once, which prevents the precipitation of acenaphthene, which has a high boiling point, from causing blockage of the equipment, thereby enabling stable continuous production of acenaphthylene. In addition, by raising the temperature of the mixture described above to a temperature range of ±20° C. of the reaction temperature in the catalyst layer 6e using the second preheater 5, it is possible to suppress a decrease in the reaction temperature and local heating in the catalyst layer 6e, reduce unreacted acenaphthene and over-reacted products, and obtain acenaphthylene in a high yield.

[0026] Furthermore, by carrying out preheating to raise the temperature to the reaction temperature in the catalyst layer 6e in two stages, that is, by preheating using the first preheater 4 and then by preheating using the second preheater 5, the mixture of acenaphthenebenzene and superheated steam reliably reaches the reaction temperature without temperature unevenness, resulting in a high yield and a high yield of acenaphthylene. As a result, by improving the preheating means for raising the temperature of acenaphthene to the reaction temperature in the catalyst layer 6e, it is possible to provide an acenaphthylene production apparatus 1 that increases the yield of acenaphthylene and prevents the precipitation of only acenaphthene, which has a high boiling point, thereby enabling stable continuous production of acenaphthylene.

[0027] Next, a method for producing acenaphthylene using the acenaphthylene production apparatus 1 will be described with reference to FIGS. First, steam is heated by the steam heater 2 to produce superheated steam (steam heating step). In this steam heating step, the temperature of the superheated steam produced is about 400°C. Next, the preheating device 3 heats the raw material acenaphthene, the solvent benzene, and the superheated steam to a temperature range of the reaction temperature in the catalyst layer 6e ±20° C. (preheating step).

[0028] Here, this preheating step includes a first preheating step by a first preheater 4, which heats a mixture of acenaphthene-benzene solution and superheated steam to a temperature at which acenaphthene and benzene are vaporized all at once, and a second preheating step by a second preheater 5, which heats the mixture of acenaphthene, benzene, and superheated steam that has been heated and vaporized in the first preheating step to a temperature range of ±20°C of the reaction temperature in the catalyst layer 6e.

[0029] In the first preheating step, an acenaphthene benzene solution is charged from a charging pipe 4f into superheated steam produced by the steam heater 2, which is charged from the heating steam pipe 2d to the inlet 4e of the tube 4a. This temporarily raises the temperature of the acenaphthene benzene solution. In addition, in the first preheating step, the mixture of the acenaphthene benzene solution charged at the inlet 4e and the superheated steam is heated by an electric heater 4b installed on the outer periphery of the tube 4a, thereby raising the temperature of the mixture of the acenaphthene benzene solution and the superheated steam to a temperature at which acenaphthene and benzene are vaporized at once. In other words, the mixture is heated to a temperature equal to or higher than the boiling point of acenaphthene (e.g., 400°C) at which acenaphthene and benzene are vaporized at once.

[0030] As a result, acenaphthene and benzene vaporize all at once, preventing the clogging of equipment due to precipitation of acenaphthene, which has a high boiling point, and enabling stable continuous production of acenaphthylene. In the second preheating process, the mixture of acenaphthene, benzene, and superheated steam that was heated and vaporized in the first preheating process and charged into the tube body 5a from the exhaust pipe 4h is heated by an electric heater 5b installed on the outer periphery of the tube body 5a to a temperature range of ±20°C of the reaction temperature in the catalyst layer 6e.

[0031] This makes it possible to suppress a decrease in the reaction temperature and local heating in the catalyst layer 6e, reduce unreacted acenaphthene and over-reaction products, and obtain acenaphthylene in a high yield. Furthermore, by carrying out preheating to raise the temperature to the reaction temperature in the catalyst layer 6e in two stages, the first preheating step and the second preheating step, the mixture of acenaphthene, solvent, and superheated steam can reliably reach the reaction temperature without temperature unevenness, resulting in a high yield and a high yield of acenaphthylene.

[0032] Next, after the preheating step, in the reactor 6, acenaphthene, which has been heated to a temperature range of the reaction temperature in the catalyst layer 6e ±20°C in the preheating step, is brought into contact with the catalyst layer 6e together with benzene and superheated steam and dehydrogenated (reaction step). Thus, according to the method for producing acenaphthylene in this embodiment, the preheating process includes a first preheating process in which a mixture of acenaphthene, benzene and superheated steam is heated to a temperature at which acenaphthene and benzene are vaporized, and a second preheating process in which the mixture heated in the first preheating process is heated to the reaction temperature in the catalyst layer 6e.

[0033] In the first preheating process, the mixture of acenaphthene, benzene and superheated steam is heated to a temperature at which acenaphthene and benzene are vaporized, causing acenaphthene and benzene to vaporize all at once. This prevents the precipitation of acenaphthene, which has a high boiling point, from causing blockage of equipment, enabling stable, continuous production of acenaphthylene. Furthermore, by raising the temperature of the mixture to a temperature range of ±20° C. of the reaction temperature in the catalyst layer 6e in the second preheating step, it is possible to suppress a decrease in the reaction temperature and localized heating in the catalyst layer 6e, reduce unreacted acenaphthene and over-reacted products, and obtain acenaphthylene in a high yield.

[0034] Furthermore, by carrying out preheating to raise the temperature to the reaction temperature in the catalyst layer 6e in two stages, that is, preheating in a first preheating step and preheating in a second preheating step, the mixture of acenaphthene, benzene and superheated steam reliably reaches the reaction temperature without temperature unevenness, resulting in a high yield and a high yield of acenaphthylene. As a result, by improving the preheating method for raising the temperature of acenaphthene to the reaction temperature in the catalyst layer 6e, it is possible to provide a method for producing acenaphthylene that increases the yield of acenaphthylene and prevents the precipitation of only acenaphthene, which has a high boiling point, thereby enabling stable continuous production of acenaphthylene.

[0035] Although the embodiment of the present invention has been described above, the present invention is not limited to this and various modifications and improvements can be made. For example, the reaction temperature in the catalyst layer 6e is set to about 600°C, but may be within the range of 550 to 630°C. The temperature above the boiling point of acenaphthene at which acenaphthene and benzene are vaporized at once is set to about 400° C., but may be in the range of 300° C. to the reaction temperature.

[0036] Although benzene is used as the solvent, other solvents such as toluene and xylene that do not decompose at high temperatures and do not react with the acenaphthylene produced may also be used. EXAMPLES

[0037] In order to verify the effects of the present invention, acenaphthylene was produced by the production methods of Comparative Examples 1 to 4 and Invention Examples 1 to 3 shown in Table 1, and the yield and the rate of increase in differential pressure after 24 hours were investigated. The production conditions and the investigation results for each production method are shown in Table 1.

[0038] [Table 1]

[0039] In the production method of Comparative Example 1, the acenaphthenebenzene solution was brought into contact with the catalyst layer without preheating and dehydrogenated to produce acenaphthylene. In the production method of Comparative Example 2, the acenaphthene-benzene solution was heated to the reaction temperature in the catalyst layer (600°C) + 0°C in a single preheating stage, and the heated acenaphthene and benzene were brought into contact with the catalyst layer for dehydrogenation to produce acenaphthylene.

[0040] In the manufacturing method of Comparative Example 3, a mixture of acenaphthene benzene solution and superheated steam was heated to the reaction temperature in the catalyst layer (600°C) + 0°C in one stage of preheating, and the heated acenaphthene, benzene and superheated steam were brought into contact with the catalyst layer for dehydrogenation to produce acenaphthylene. During preheating, the inlet for charging the acenaphthene benzene solution was of a submerged tube structure. In the manufacturing method of Comparative Example 4, the mixture of acenaphthene-benzene solution and superheated steam was heated in two stages, namely, the first preheating step to heat the mixture to a temperature at which acenaphthene and benzene were vaporized at once, and the second preheating step to heat the mixture of vaporized acenaphthene, benzene and superheated steam to the reaction temperature (600°C) -25°C, and the heated acenaphthene, benzene and superheated steam were brought into contact with a catalyst layer for dehydrogenation to produce acenaphthylene. During preheating, the charging port for charging the acenaphthene-benzene solution had a submerged tube structure.

[0041] On the other hand, in the production method of Example 1 of the present invention, the mixture of acenaphthene-benzene solution and superheated steam was heated in two preheating stages, namely, the first preheating stage in which the mixture of acenaphthene and benzene was heated to a temperature at which acenaphthene and benzene were vaporized all at once, and the second preheating stage in which the mixture of vaporized acenaphthene, benzene and superheated steam was heated to the reaction temperature (600°C) + 0°C in the catalyst layer, and the heated acenaphthene, benzene and superheated steam were brought into contact with the catalyst layer for dehydrogenation to produce acenaphthylene. During preheating, the charging port for charging the acenaphthene-benzene solution had a submerged tube structure.

[0042] In the production method of Example 2 of the present invention, the mixture of acenaphthene-benzene solution and superheated steam was heated in two preheating steps, namely, the first preheating step to heat the mixture to a temperature at which acenaphthene and benzene were vaporized all at once, and the second preheating step to heat the mixture of vaporized acenaphthene, benzene and superheated steam to the reaction temperature (600°C) -5°C in the catalyst layer, and the heated acenaphthene, benzene and superheated steam were brought into contact with the catalyst layer for dehydrogenation to produce acenaphthylene. During preheating, the charging port for charging the acenaphthene-benzene solution had a submerged tube structure.

[0043] In the production method of Example 3 of the present invention, the mixture of acenaphthene-benzene solution and superheated steam was heated in two stages: first preheating to a temperature at which acenaphthene and benzene were vaporized at once, and second preheating to a temperature of 20°C above the reaction temperature (600°C) in the catalyst layer. The heated acenaphthene, benzene, and superheated steam were brought into contact with the catalyst layer for dehydrogenation to produce acenaphthylene. During preheating, the charging port for charging the acenaphthene-benzene solution had a submerged tube structure.

[0044] As shown in Table 1, in the manufacturing method of the invention examples 1 to 3, the yield of the produced acenaphthylene after 24 hours was 93% or more, and the rate of increase of the differential pressure was 1 (kPa / year) or less, and good results were obtained. In the case of the invention examples 1 to 3, the preheating temperature was set to the reaction temperature (600°C) +0°C, -5°C, and +20°C, respectively, and since the preheating was performed in two stages, the temperature of the actual acenaphthenebenzene solution after preheating reached the reaction temperature, there was no temperature unevenness, and it is considered that the yield of the produced acenaphthylene after 24 hours was large at 93% or more. The differential pressure is the pressure difference from before the first preheating to after the catalyst layer.

[0045] In contrast, in the manufacturing method of Comparative Example 1 in which preheating was not performed, the yield of the produced acenaphthylene after 24 hours was low at 60%, and the rate of increase in the differential pressure was high at over 10 (kPa / year), and good results were not obtained. In Comparative Example 2, in which the acenaphthenebenzene solution was heated to the reaction temperature in the catalyst layer (600°C) + 0°C in a single preheating step, the yield of the produced acenaphthylene after 24 hours was as low as 90%, and the rate of increase in the differential pressure was as high as 10 (kPa / year) or more, and good results were not obtained. In the case of Comparative Example 2, the preheating temperature during preheating was set to the reaction temperature (600°C) + 0°C, but since it was a single preheating step, it is believed that the temperature of the actual acenaphthenebenzene solution after preheating did not reach the reaction temperature or there was temperature unevenness, which is why the yield of the produced acenaphthylene after 24 hours was as low as 90%.

[0046] Similarly, in Comparative Example 3, in which the acenaphthene benzene solution is heated to the reaction temperature (600°C) + 0°C in the catalyst layer by one-stage preheating, the yield of the produced acenaphthylene after 24 hours was as low as 90%, and good results were not obtained. In the case of Comparative Example 3, the preheating temperature is set to the reaction temperature (600°C) + 0°C, but since it is a one-stage preheating, it is considered that the temperature of the actual acenaphthene benzene solution after preheating does not reach the reaction temperature or there is temperature unevenness, which is why the yield of the produced acenaphthylene after 24 hours is as low as 90%. In the production method of Comparative Example 3, the acenaphthene benzene solution is mixed with superheated steam to be heated to the reaction temperature in the catalyst layer, and the heated acenaphthene, benzene, and superheated steam are brought into contact with the catalyst layer to dehydrogenate, so the differential pressure increase rate was as low as 1 (kPa / year) or less.

[0047] The mixture of acenaphthene benzene solution and superheated steam is heated in two stages, but in the case of Comparative Example 4, in which the preheating temperature was the reaction temperature (600°C) -25°C, the temperature of the actual acenaphthene benzene solution after preheating was too low compared to the reaction temperature, so the yield of the produced acenaphthylene after 24 hours was only 90%, and good results were not obtained. However, even in the case of the production method of Comparative Example 4, the acenaphthene benzene solution was mixed with superheated steam to be heated to the reaction temperature in the catalyst layer, and the heated acenaphthene, benzene and superheated steam were brought into contact with the catalyst layer to dehydrogenate, so the rate of increase in differential pressure was low at 1 (kPa / year) or less. [Explanation of symbols]

[0048] 1 Acenaphthylene manufacturing equipment 2 Steam heater 2a container 2b Electric heater 2c Lid body 2d Superheated steam piping 3 Preheating device 4. First preheater 4a Body 4b Electric heater 4c Lid body 4d lid body 4e entrance 4f Charging pipe 4g loading port 4h discharge tube 5. Second preheater 5a Body 5b Electric heater 5c Lid body 5d outlet 6. Reactor 6a Body 6b Electric heater 6c Introduction 6d outlet 6e catalyst layer

Claims

1. An apparatus for producing acenaphthylene, comprising: a preheating device for heating acenaphthene, a solvent, and superheated steam to a temperature range of ±20° C. of a reaction temperature in a catalyst bed; and a reactor for dehydrogenating the acenaphthene heated in the preheating device by contacting the acenaphthene heated in the preheating device together with the solvent and superheated steam with the catalyst bed, The preheating device is characterized in that it comprises a first preheater which heats a mixture of acenaphthene, a solvent and superheated steam to a temperature at which the acenaphthene and the solvent are vaporized, and a second preheater which heats the mixture heated in the first preheater to a temperature within a temperature range of ±20°C of the reaction temperature in the catalyst layer.

2. 2. The apparatus for producing acenaphthylene according to claim 1, further comprising a steam heater for heating steam to produce the superheated steam, the first preheater comprising a pipe for superheated steam for charging the superheated steam produced by the steam heater into an inlet of a tube body, and a charging pipe having an inlet disposed in the vicinity of the pipe for superheated steam and within the tube body, for charging acenaphthene and a solvent from the inlet into the tube body, and heating the mixture of acenaphthene, solvent and superheated steam charged and mixed at the inlet of the tube to raise the temperature of the mixture to a temperature at which acenaphthene and the solvent are vaporized.

3. A method for producing acenaphthylene, comprising: a preheating step of heating acenaphthene, a solvent, and superheated steam to a temperature range of a reaction temperature in a catalyst layer ±20° C.; and a reaction step of contacting the acenaphthene heated in the preheating step, together with the solvent and the superheated steam, with the catalyst layer to dehydrogenate the acenaphthene, The method for producing acenaphthylene, wherein the preheating step includes a first preheating step of heating a mixture of acenaphthene, a solvent and superheated steam to a temperature at which the acenaphthene and the solvent are vaporized, and a second preheating step of heating the mixture heated in the first preheating step to a temperature within a temperature range of ±20°C of the reaction temperature in the catalyst layer.

4. 4. The method for producing acenaphthylene according to claim 3, further comprising a steam heating step of producing the superheated steam by heating steam prior to the first preheating step, wherein in the first preheating step, the acenaphthene and the solvent are charged into and mixed with the superheated steam produced in the steam heating step, and the mixture is heated to raise the temperature of the mixture to a temperature at which the acenaphthene and the solvent are vaporized.

5. The method for producing acenaphthylene according to claim 3 or 4, characterized in that the temperature rise rate of acephtenane in the first preheating step is 400 to 2000° C. / sec.

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