JP2003299947A - Hydrogenation apparatus and method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that the fluidized state of a hydrogen gas and liquid benzene becomes non-uniform because a reaction pipe is non-uniformly filled with catalyst particles, in a perfusate type fixed bed reactor being one embodiment of a conventional hydrogeneration apparatus and reaction is not performed because the contact of the catalyst with a substrate is not performed at a certain part in the reaction pipe and, therefore, the utilization efficiency of a catalyst is low and, further, the optimum reaction temperature Topt required for achieving a high reaction speed is not prescribed especially. <P>SOLUTION: In this hydrogenation apparatus, the temperature of a monolithic catalyst is held to the optimum reaction temperature higher than the boiling point of a dehydrogenation reaction product, and the reaction product is uniformly supplied to the upper part of the monolithic catalyst from a despersion device in each of stages. A required amount of a hydrogen gas is uniformly supplied to the upper part of the monolithic catalyst of the first stage from a hydrogen gas supply part, and the supply volume ratio of the hydrogen gas and the reaction product is regulated in each stage to perform hydrogenation reaction. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an apparatus and method for adding hydrogen gas to a dehydrogenation reaction product.

[0002]

2. Description of the Related Art Utilization of hydrogen energy is expected due to depletion of fossil fuels or pollution problems caused by fossil fuels. As part of this, fuel cell power generation using hydrogen gas in automobiles, houses, etc. is currently under consideration, but in this case, hydrogen gas needs to be stored, transported to a demanded place, and supplied. As its method, hydrogen gas is stored in a high-pressure cylinder, transported, and supplied from the cylinder when necessary, a method of storing and transporting hydrogen gas in the form of methanol, and supplying hydrogen gas by reforming when necessary, cyclohexane, There is a method of storing and transporting hydrogen gas in the form of an organic compound such as methylcyclohexane, decalin and 2-propanol, and generating and supplying hydrogen gas by a dehydrogenation reaction when necessary.

Among these methods, hydrogen gas is stored and transported in the form of organic compounds such as cyclohexane, methylcyclohexane, decalin and 2-propanol, that is, in the form of so-called organic hydride, and hydrogen gas is dehydrogenated by a dehydrogenation reaction when necessary. In the method of generating and supplying hydrogen, for example, when cyclohexane is used as an organic hydride, hydrogen gas and benzene, which is a dehydrogenation reaction product, are generated by a dehydrogenation reaction at a demand site, and hydrogen gas is separated from a mixture thereof. Then, after supplying to the fuel cell or the like, the residual benzene is returned from the demanding place to the hydrogen gas supply source, cyclohexane is produced by the hydrogenation reaction, and the hydrogen gas can be stored in the form of an organic hydride. The same organic hydride can be transported to the demand area again, and hydrogen gas can be generated and supplied by the dehydrogenation reaction. The method of storing, transporting and supplying hydrogen gas in the form of the above organic hydride is illustrated in FIG.

This method has the advantage that existing fossil fuel equipment such as tank trucks and pipelines can be used for storage and transportation of the organic hydride and the dehydrogenation reaction product of the organic hydride used, It also has the advantage that the organic hydride can be recycled. Due to these advantages, this method is the most promising means for supplying hydrogen gas.

In this method, hydrogen gas is stored and transported in the form of organic hydride, and when the hydrogen gas is generated by a dehydrogenation reaction and supplied, the dehydrogenation reaction product of the organic hydride is supplied from the demand area. The process of returning to the source and converting it to an organic hydride again by the hydrogenation reaction is essential.
Conventionally, such a hydrogenation reaction has mainly used a countercurrent contact type continuous hydrogenation apparatus and method. As such a hydrogenation reactor, for example, the one shown in FIG. 12 is known (Japanese Patent Laid-Open No. 02-56238).

This relates to a perfusion type fixed bed reactor, in which a plurality of reaction tubes 104 filled with a catalyst 103 are arranged between two upper and lower tube plates 101 and 102, and the fixed beds are housed. Reaction vessel 105, a raw material inlet 106 provided on the upper portion of the reaction vessel 105 for supplying hydrogen gas and a benzene liquid phase, a disperser 108 for uniformly dispersing the fed raw material liquid into a plurality of reaction tubes 104, a reaction vessel 105 A heat exchange medium in a space 109 formed between a reaction product discharge port 107 provided in the lower portion and an outer wall of the reaction tube 104 and an inner wall of the reaction vessel 105 and divided by two upper and lower tube plates 101 and 102. Inlet 110 and outlet 111 for circulating
Is equipped with. Further, a fixed bed 112 of a single tube filled with the catalyst 103a is provided below the fixed bed, and the liquid from the plurality of reaction tubes 104 in the upper part is collected by a collecting plate 113 and a redispersion plate 114.
And then uniformly dispersed in the catalyst layer of the fixed bed 112. The nozzle 115 is for extracting a reaction product gas or introducing a raw material gas.

However, in such a conventional hydrogenation reaction apparatus, the reaction tube 104 and the fixed bed 112 are used.
Since the catalysts 103 and 103a are non-uniformly filled therein, the flow state of hydrogen gas and liquid benzene becomes non-uniform, and the catalysts 103 and 103a and the substrate are mixed with each other in a part of the reaction tube 104 and the fixed bed 112. Contact is not performed and the reaction is not performed. Therefore, the utilization efficiency of the catalysts 103 and 103a is low. Further, since a pressure loss of hydrogen gas occurs, it is necessary to pressurize the hydrogen gas to be supplied, which requires a pressurizing device. Further, the optimum reaction temperature Topt required for achieving a high reaction rate is not particularly specified. Further, cyclohexane produced by the catalyst 103 in the reaction tube 104 may inhibit the hydrogenation reaction in the catalyst 103a in the fixed bed 112.

[0008]

The present invention has been made in view of such conventional technical problems, and has the following structure. The invention of claim 1 comprises a monolith catalyst, a hydrogen gas supply unit, a dehydrogenation reaction product supply unit, an organic hydride recovery unit, a disperser, a disperser main valve, and a recovery unit valve, and the monolith catalyst is a gas flow path. Is a hydrogenation device in which a hydrogenation reaction catalyst is supported on a monolithic carrier composed of a plurality of cells that divide into a plurality of cells. The invention of claim 2 is
Multiple cells consisting of a monolith catalyst, a hydrogen gas supply unit, a dehydrogenation reaction product supply unit, an organic hydride recovery unit, a disperser, a disperser source valve, and a recovery unit valve, and the monolith catalyst divides the gas flow path into multiple cells. In a hydrogenation device, which is a monolithic carrier consisting of a hydrogenation reaction catalyst supported thereon,
The temperature of the monolith catalyst is maintained at an optimum reaction temperature higher than the boiling point of the dehydrogenation reaction product at the pressure inside the hydrogenation device, and the dehydrogenation reaction product is uniformly supplied to the upper part of the monolith catalyst from the disperser in each stage. At the same time, the required amount of hydrogen gas is uniformly supplied from the hydrogen gas supply unit to the upper part of the first stage monolith catalyst, and the supply volume flow rate ratio of hydrogen gas and dehydrogenation reaction product is adjusted in each stage. Is a hydrogenation method.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION FIG. 3 shows an embodiment of a hydrogenation apparatus according to the present invention. In the figure, reference numeral 1 is a tower reactor, which is a monolith catalyst 2, a hydrogen gas supply unit 3, a dehydrogenation reaction product supply unit 4, an organic hydride recovery unit 5, a disperser 6, a disperser main valve 7, and a recovery unit. It is composed of a partial valve 8. The monolith catalyst 2 is a product in which a hydrogenation reaction catalyst 11 is supported on a monolith carrier 9 composed of a plurality of cells 10 dividing a gas flow path into a plurality of cells as shown in FIG.

The hydrogenation device is a tower type reactor 1,
Inside it, a flow path for hydrogen gas from the top to the bottom is formed. In the tower reactor 1, monolith catalysts 2 which are integral catalysts are arranged in a plurality of stages at predetermined vertical intervals to divide the flow path into a plurality of spaces in the vertical direction. An opening 6 for supplying hydrogen gas is provided at the upper end of the tower reactor 1.
1 is formed. In the tower reactor 1, the disperser 6 of the dehydrogenation reaction product supply unit 4 and the collector 12 of the organic hydride recovery unit 5 are associated with each monolith catalyst 2.
Is provided.

The opening 61 of the tower reactor 1 is connected to one end of a pipe 62 having a valve 60 having an opening / closing function and a flow rate adjusting function, and the other end of the pipe 62 is a hydrogen gas storing hydrogen gas. The supply unit 3 is connected. Therefore, by adjusting the opening degree of the valve 60, the hydrogen gas from the hydrogen gas supply unit 3 is supplied into the upper end portion of the tower reactor 1 from the opening portion 61 at a required volume flow rate, and the uppermost first stage. It can be uniformly supplied to the monolith catalyst 2 of the eye.

The dehydrogenation reaction product supply unit 4 is arranged in the tower reactor 1 in correspondence with the dehydrogenation reaction product source 4a for storing the liquid phase dehydrogenation reaction product and each monolith catalyst 2. And a disperser 6 serving as a supply unit, one end of which is connected to the dehydrogenation reaction product source 4a and the other end of which is provided with a disperser main valve 7 having an opening / closing function and a flow rate adjusting function.
And a pipe 70 connected to the. The dispersers 6 are arranged above the monolith catalysts 2 at the respective stages. Therefore, by adjusting the opening of each disperser main valve 7,
The dehydrogenation reaction product from the dehydrogenation reaction product source 4a flows into each monolith catalyst 2 from above while being dispersed by each disperser 6 with a required volume flow rate.

The organic hydride recovery unit 5 is a recovery unit 12 disposed in the tower reactor 1 corresponding to each monolith catalyst 2.
(Recovery part), organic hydride recovery container 5a for storing organic hydride, and recovery part valve 8 having one end connected to organic hydride recovery container 5a and the other end having an opening / closing function and a flow rate adjusting function. It has the piping 80 which connects with each collection | recovery device 12 through it.

The collectors 12 are respectively disposed below the monolith catalysts 2 at the respective stages, and receive all of the liquid-phase organic hydride dropped from the monolith catalysts 2, but the flow path in the tower reactor 1 Hydrogen gas is allowed to pass around the collector 12 without being blocked. In the illustrated example, an annular receiving plate 12a is arranged below the monolith catalyst 2 so as to be in close contact with the inner wall of the tower reactor 1 to receive a part of the organic hydride dropped from the lower portion of the monolith catalyst 2. It is adapted to be dropped along the plate 12 a and be received by the collector 12. The hydrogen gas that has passed through the monolith catalyst 2 is supplied to the next stage monolith catalyst 2 through the flow path between the receiving plate 12a and the collector 12.

However, by adjusting the opening of each recovery part valve 8, the organic hydride recovered in the recovery device 12 flows out to the organic hydride recovery container 5a at a required flow rate. However, the opening of each recovery part valve 8 blocks the outflow of the gas in the tower reactor 1 from the recovery device 12 and the pipe 80, and allows only the organic hydride recovered in the recovery device 12 to flow out. To do. Therefore, the collector 1
The pipe 80 is joined to the lower end of the pipe 2, and a small amount of the organic hydride is always left in the recovery unit 12, and each recovery is performed so that the opening 13 to the pipe 80 is covered with the liquid organic hydride. The outflow of gas in the tower reactor 1 is prevented by adjusting the opening of the partial valve 8.

The monolith catalyst 2 at each stage, the corresponding disperser 6, and the corresponding collector 12 cause the hydrogenation reaction of the dehydrogenation reaction product in the presence of hydrogen gas to produce an organic hydride. It constitutes an organic hydride generation device for generating.

Each monolith catalyst 2 is provided with a temperature adjusting means 20. Each temperature adjusting means 20 maintains the monolith carrier 9 of the corresponding monolith catalyst 2 at a required temperature. That is, not only the function of raising the temperature of the monolith catalyst 2 to a required temperature before starting the hydrogenation reaction and heating for supplementing the amount of heat released to the atmosphere during the hydrogenation reaction, but also with the exothermic reaction It has a function of cooling the monolith catalyst 2 which is heated to lower the temperature to a required temperature.

The dehydrogenation reaction product uniformly supplied from above each monolith catalyst 2 from each disperser 6 and the hydrogen gas uniformly supplied above each monolith catalyst 2 from the opening 61 have a supply volume flow rate ratio. Adjust to an appropriate value. The supply volumetric flow rate of hydrogen gas is obtained by adjusting the opening degree of the valve 60, and the supply volumetric flow rate of the dehydrogenation reaction product is obtained by adjusting the opening degree of each disperser main valve 7.

Further, the supply volume flow rate of the dehydrogenation reaction product supplied from the disperser 6 at each stage is set to an appropriate amount according to the temperature of the monolith catalyst 2 given by the temperature adjusting means 20. That is, the dehydrogenation reaction product uniformly supplied from the disperser 6 of each stage to above the corresponding monolith catalyst 2 is:
All the dehydrogenation reaction products react with hydrogen gas in the presence of the monolith catalyst 2 in the corresponding monolith catalyst 2 of each stage, and are provided so as to be converted into an organic hydride.

As an example of the organic hydride, cyclohexane is used and benzene is used as the dehydrogenation reaction product, and the operation of the tower reactor 1 will be specifically described.

First, the main valve 7 of the disperser (first stage) is opened, and benzene is uniformly supplied from the disperser 6 (first stage) to the upper portion of the monolith catalyst 2 (first stage). In addition, a required amount of hydrogen gas is supplied from the hydrogen gas supply unit 3 to the monolith catalyst 2
Supply evenly to the top of (first stage). At this time, when the opening degree of the distributor main valve 7 (first stage) is large and a large amount of benzene is supplied, the above hydrogen gas is also supplied, so that the surface of the cell 10 is exposed to the state shown in FIG. The bubbly flow shown by is formed. In this case, the amount of hydrogen gas passing through benzene and diffusing to the surface of the hydrogenation reaction catalyst 11 is low,
Hydrogenation reaction rate is low. On the other hand, by reducing the opening degree of the main valve 7 of the disperser (first stage), reducing the supply amount of benzene, and adjusting the supply volume flow ratio of hydrogen gas and benzene to an appropriate value, the monolith carrier 9 An annular flow shown in FIG. 5 is formed on the surface of the internal cell 10. In the same flow mode, benzene moves on the surface of the cell 10 in a liquid film state,
Hydrogen gas moves in the center of the cell 10. Therefore, hydrogen gas can easily pass through the liquid film of benzene in the hydrogenation reaction catalyst 1.
It diffuses to the surface of No. 1 and easily undergoes hydrogenation reaction with benzene. Moreover, since benzene spreads evenly on the surface of the cell 10, the entire amount of the hydrogenation reaction catalyst 11 supported on the surface of the monolith carrier 9 is used. Therefore, the utilization efficiency of the catalyst is high.

On the other hand, in a perfusion type fixed bed reactor which is an example of a conventional hydrogenation apparatus, the reaction tube is filled with catalyst particles, and benzene flows down on the surface of these particles. Further, while the hydrogen gas flows down through the gap between the liquid benzene and the catalyst particles, the hydrogen gas diffuses in the liquid benzene to the surface of the catalyst to carry out a hydrogenation reaction with benzene. However, since the catalyst particles are non-uniformly filled, the flow state of the hydrogen gas and liquid benzene becomes non-uniform, and the catalyst and the substrate do not come into contact with each other in a certain part of the reaction tube, and the reaction is not performed. Absent. Therefore, the utilization efficiency of the catalyst is low as compared with the hydrogenation method of the present invention.

Further, in the hydrogenation method of the present invention, the pressure loss of hydrogen gas does not occur due to the monolith catalyst, but the pressure loss of hydrogen gas does not occur in the perfusion type fixed bed reactor which is an example of the conventional hydrogenation apparatus. Occurs. Therefore, it is necessary to pressurize the hydrogen gas to be supplied, and a pressurizing device is required.

In the hydrogenation method of the present invention, the monolith catalyst 2 is then maintained at a desired reaction temperature by using heating means such as electric heating. At this time, if the temperature of the monolith catalyst 2 is maintained at a temperature T1 which is significantly lower than the boiling point of benzene at the pressure inside the tower reactor 1, benzene is a liquid, so that the inside of the hydrogenation reaction catalyst 11 is Into the catalyst surface, and the concentration of benzene on the surface of the catalyst becomes sufficiently high. However, the reaction rate is low due to the significantly low reaction temperature.

Therefore, the reaction temperature is raised and maintained at a temperature T2 which is lower than the boiling point of benzene and is in the vicinity thereof. In this case, as in the above case, since benzene is a liquid, it sufficiently penetrates into the hydrogenation reaction catalyst 11, the concentration on the catalyst surface is sufficiently high, and the reaction temperature is high, so that a high reaction rate is achieved. . In this case, the benzene moves on the surface of the cell 10 in a liquid film state over an appropriate distance, and since the hydrogenation reaction is an exothermic reaction, it is heated by the generated heat and evaporated.

When the reaction temperature is further raised and maintained at an appropriate temperature T _opt higher than the boiling point of benzene, benzene is moving on the surface of the cell 10 in a liquid film state as described above, and hydrogen gas is used. Blows benzene onto the surface of the cell 10, so that the above moving distance is maintained.
Therefore, the concentration of benzene on the catalyst surface is also sufficiently high and the reaction temperature is higher so that a higher reaction rate is achieved. In this case, by using the monolith catalyst 2 having an appropriate reaction rate, the disperser 6 (first stage)
All of the benzene supplied can be converted to cyclohexane, which is the corresponding organic hydride.

However, when the reaction temperature is further raised to the temperature T3, benzene moving in the liquid film state on the surface of the cell 10 starts to evaporate, and the above moving distance becomes short. Therefore, the area of liquid benzene covering the surface of the cell 10 is reduced, and the concentration of benzene on the catalyst surface is reduced, so that the reaction rate is reduced.

When the reaction temperature is further raised to the temperature T4, benzene moving in the liquid film state on the surface of the cell 10 is further evaporated, so that the above moving distance is further shortened. Therefore, the area of liquid benzene covering the surface of the cell 10 is further reduced, and the concentration of benzene on the catalyst surface is further reduced, so that the reaction rate is further reduced.

The relationship between the temperature of the monolith catalyst 2 and the concentration of benzene on the catalyst surface described above is illustrated in FIG. As shown in FIG. 4 (1), when hydrogen gas and benzene flow in the cell 10, the temperature of the monolith catalyst 2 is maintained at a temperature T1 which is significantly lower than the boiling point of benzene at the pressure inside the tower reactor 1. If the temperature of the monolith catalyst 2 is maintained at a temperature T2 near the boiling point of the benzene and lower, and if the temperature of the monolith catalyst 2 is higher than the boiling point of the benzene, a suitable temperature T
_When it is held in _opt , the concentration of benzene on the surface of the hydrogenation reaction catalyst 11 becomes sufficiently high as shown in FIGS. 4 (2)-(a).

When the reaction temperature is further raised to the temperature T3, the concentration of benzene on the surface of the hydrogenation reaction catalyst 11 becomes low as shown in FIG. 4 (2)-(b).

When the reaction temperature is further raised to the temperature T4, the concentration of benzene on the surface of the hydrogenation reaction catalyst 11 is further lowered as shown in FIGS. 4 (2)-(c).

Therefore, the supply volume flow rate ratio of hydrogen gas and benzene is adjusted as described above, and the temperature of the monolith catalyst 2 is maintained at the optimum temperature T _opt higher than the boiling point of benzene at the pressure inside the tower reactor 1. Thereby, a high reaction rate is achieved. In this case, by using the monolith catalyst 2 having an appropriate reaction rate, the disperser 6 (first stage)
All of the benzene supplied can be converted to cyclohexane, which is the corresponding organic hydride. Since the conversion rate to cyclohexane is 100%, the step of separating benzene as a raw material from the reaction product can be omitted.

On the other hand, in the perfusion type fixed bed reactor which is an example of the conventional hydrogenation device, the above-mentioned optimum reaction temperature Topt required for achieving a high reaction rate is not particularly specified. . Therefore the reaction temperature is not optimal.

Next, the cyclohexane produced by the monolith catalyst 2 (first stage) is dropped from the lower part of the monolith catalyst 2 (first stage) to the recovery unit 12 (first stage) and recovered. The unreacted hydrogen gas is similarly recovered from the lower part of the monolith catalyst 2 (first stage) and then uniformly supplied to the upper part of the monolith catalyst 2 (second stage). At this time, in order to prevent unreacted hydrogen gas from mixing in the organic hydride recovery part 5, the opening of the recovery part valve 8 (first stage) is adjusted,
A cyclohexane liquid phase 14 (first stage) having a constant depth is always formed on the upper surface of the collector 12 (first stage), and the opening 13 (first stage) is cut off from the gas phase.

In the second stage, as in the first stage,
The main valve 7 (second stage) of the disperser is opened, and benzene is uniformly supplied from the disperser 6 (second stage) to the upper portion of the monolith catalyst 2 (second stage). As in the case of the first stage, adjusting the supply volume flow rate ratio of hydrogen gas and benzene to maintain the temperature of the monolith catalyst 2 at an appropriate temperature T _opt higher than the boiling point of benzene at the pressure inside the tower reactor 1. Thus, the entire amount of benzene supplied from the disperser 6 (second stage) can be converted into cyclohexane. The cyclohexane is recovered from the recovery unit 12 (second stage) as in the first stage. Similarly, for unreacted hydrogen gas, the monolith catalyst 2
It is uniformly supplied to the upper part of (third stage). The opening 13 (second stage) is blocked from the gas phase by the cyclohexane liquid phase 14 (second stage).

In the hydrogenation method of the present invention, the entire amount of cyclohexane produced in the monolith catalyst of each stage is recovered using the recovery device provided in each stage as described above. Therefore, it does not hinder the hydrogenation reaction in the lower monolith catalyst.

On the other hand, the above-mentioned recovery mechanism is not provided in the perfusion type fixed bed reactor, which is an example of the conventional hydrogenation apparatus. Therefore, cyclohexane produced by the upper catalyst 103 may hinder the hydrogenation reaction in the lower catalyst 103a.

As described above, in the hydrogenation method of the present invention, the same operation is repeated in each stage of the monolith catalyst 2, and a required amount of hydrogen gas is subjected to hydrogenation reaction with benzene to produce cyclohexane. can do.

In the hydrogenation reaction of benzene represented by the reaction formula of Chemical formula 1, first, in the batch reactor, when the temperature of the catalyst layer is kept lower than the boiling point of benzene and in the vicinity thereof, a high reaction rate is achieved. This was confirmed using the experimental apparatus shown in FIG.

[0040]

[Chemical 1]

FIG. 7 shows the experimental apparatus. 21 is a Schlenk tube which is a batch-type reaction device and has a capacity of 50 ml.
Is. 22 is a heater used to maintain the reaction device 21 at the reaction temperature. An oil bath was used when the reaction temperature was lower than 200 ° C, and a salt bath was used when the reaction temperature was 200 ° C or higher. A temperature controller 23 keeps the temperature of the heater 22 at the reaction temperature. A cooling pipe 24 cools and condenses the reaction mixture that evaporates from the reaction device 21 by the refrigerant flowing through the internal spiral pipe, and causes the reaction mixture to flow back into the reaction device 21 to advance the reaction. A cooler 25 cools the refrigerant flowing through the spiral pipe inside the cooling pipe 24. Reference numeral 26 is a hydrogen supply line used to supply hydrogen, which is a reaction product, into the reactor 21. 27 is a burette having a capacity of 1000 ml, which measures the volume of added hydrogen. 28
Is a catalyst layer.

As the catalyst, 0.5 g of carbon-supported platinum catalyst was used. The amount of platinum supported is 3.82 wt% on a dry basis.

When carrying out the hydrogenation reaction of benzene, the above catalyst which has been activated by performing drying and hydrogen reduction treatment is previously prepared.
A catalyst layer 28 was formed by laying layers on the bottom surface of the reactor 21 at room temperature. Similarly, the reaction device 21 and the cooling pipe 24, the pipe connecting the cooling pipe 24 and the buret 27, and the inside of the buret 27 were filled with hydrogen as a reactant from the hydrogen supply line 26. Next, 1.0 ml (11 mmol) of benzene, which is a reaction product, was charged into the reaction device 21 through a branch pipe of the reaction device 21 using a syringe. Then, the reaction device 21 at room temperature is quickly replaced by the heater 22.
Then, the reaction was started. This time was defined as a reaction time of 0. The volume of hydrogen added was measured using a buret 27.

FIG. 8 shows changes with time in the hydrogenation volume at each reaction temperature. In addition, these values are for the reactor 2
The amount of thermal expansion of the gas present inside 1 is corrected. When the reaction time is 0, the reaction product benzene is not supplied to the catalyst layer 28 from above the catalyst layer 28.
However, at the reaction time of 20 min, the reaction mixture evaporated from the reaction device 21 was cooled and condensed by the cooling pipe 24 and continuously supplied to the catalyst layer 28 inside the reaction device 21 from above.

Then, when the reaction rate at the reaction time of 20 min is calculated for each reaction temperature, it becomes as shown in FIG.

From FIG. 9, the temperature of the catalyst layer 28 is determined by the reaction device 2
1 The boiling point of benzene at the internal pressure (atmospheric pressure) (35
When the temperature is kept higher than 3.3 K), the reaction rate of the hydrogenation reaction is low. On the other hand, when the temperature of the catalyst layer 28 is maintained at a temperature significantly lower than the same boiling point, the reaction rate is similarly low. However, when the temperature of the catalyst layer 28 is maintained at a temperature near the boiling point of the above-mentioned benzene, a high reaction rate is achieved.

Next, the hydrogenation reaction of benzene, which is represented by the reaction formula of Chemical formula 1, is similarly performed using a monolith catalyst, and the reaction temperature of the monolith catalyst is higher than the boiling point of benzene at the pressure inside the flow system reactor. It was confirmed that a high reaction rate was achieved by keeping the temperature at T _opt .

FIG. 10 shows an experimental apparatus using a monolith catalyst. Reference numeral 31 is a flow reactor. 32 is a monolith catalyst. The monolith catalyst 32 has a diameter of 15 mm and a length of 75.
mm round type catalyst, and the catalyst substrate is stainless steel. Alumina is thinly coated as a carrier on the surface of the catalyst substrate, and 0.02 g of platinum is carried. Reference numeral 33 is a heater used to keep the monolith catalyst 32 at a required temperature. Reference numeral 34 is a thermocouple for measuring and adjusting the temperature of the heater 33. Reference numeral 35 is a heat insulating material. Reference numeral 36 denotes a dehydrogenation reaction product supply unit, to which benzene is supplied as a dehydrogenation reaction product. Reference numeral 37 denotes a disperser, which uses benzene supplied from the dehydrogenation reaction product supply unit 36 as the monolith catalyst 3
2 is uniformly supplied to the upper part. 38 is a hydrogen gas supply part, 39 is a hydrogen gas dispersion plate. The hydrogen gas supplied from the hydrogen gas supply unit 38 is uniformly supplied to the upper portion of the monolith catalyst 32 by the hydrogen gas dispersion plate 39. A cooling trap 40 collects unreacted dehydrogenation reaction products and hydrogenation reaction products. The cooling trap 40 is cooled using a suitable coolant 43 such as water. Unreacted hydrogen gas is recovered from the vent port 42.

When carrying out the hydrogenation reaction of benzene using the flow reactor 31, first the heater 33 was used to hold the monolith catalyst 32 at the reaction temperature. Next, hydrogen gas was supplied from the hydrogen gas supply unit 38 at a volume flow rate of 65 cm ³ / min (25 ° C.), and benzene was supplied from the dehydrogenation reaction product supply unit 36 at a volume flow rate of 0.1 cm ³ / min.
The benzene supplied from the dehydrogenation reaction product supply unit 36 was uniformly supplied to the upper portion of the monolith catalyst 32 by the disperser 37. After reacting for 2 hours, cool trap 40
The liquid collected in the column is sampled from the sample port 41 and subjected to gas chromatography (column: J & W Scientif).
ic DB-WAX, detector: FID, column temperature 10
When analyzed at 0 ° C. and carrier gas: He), the conversion rate to cyclohexane at each reaction temperature was as shown in FIG. When the reaction temperature was 150 ° C, the conversion rate showed a maximum value of 99.0%.

Since the boiling point of benzene at the pressure inside the flow reactor (atmospheric pressure) is 80.2 ° C., the optimum reaction temperature Topt capable of achieving a high reaction rate Topt
It was confirmed that (in this case, 150 ° C) exists above the boiling point.

[0051]

As can be understood from the above description,
According to the hydrogen adding device and method of the present invention, the following effects can be achieved. (1) In each stage of the monolith catalyst, by adjusting the supply volume flow rate ratio of hydrogen gas and benzene to an appropriate value,
An annular flow is formed on the surface of the cells inside the monolith support. In the same flow mode, benzene moves in a liquid film state on the surface of the cell, and hydrogen gas moves in the center of the cell. Therefore,
Hydrogen gas easily diffuses in the liquid film of benzene to the surface of the hydrogenation reaction catalyst, and easily causes hydrogenation reaction with benzene. Moreover, since benzene spreads uniformly on the surface of the cell, the entire amount of the hydrogenation reaction catalyst supported on the surface of the monolith carrier is used. Therefore, the utilization efficiency of the catalyst is high.

(2) Since the monolith catalyst is used, pressure loss of hydrogen gas does not occur. Therefore, it is not necessary to pressurize the hydrogen gas to be supplied, and a pressurizing device is not required, as compared with the perfusion type fixed bed reactor which is an example of the conventional hydrogenation device.

(3) When the temperature of the monolith catalyst is kept at the optimum reaction temperature Topt which is higher than the boiling point of benzene at the pressure inside the tower type reactor, it is necessary that benzene moves on the surface of the cell in a liquid film state. Since hydrogen gas blows benzene to the surface of the cell, the concentration of benzene on the catalyst surface is sufficiently high and the reaction temperature is also sufficiently high, so that a high reaction rate is achieved. In this case, by using a monolith catalyst having an appropriate reaction rate, the entire amount of benzene supplied from the disperser in each stage can be converted to cyclohexane which is the corresponding organic hydride. Moreover, since the conversion rate to cyclohexane is 100%, the step of separating benzene as a raw material from the reaction product can be omitted.

(4) The entire amount of cyclohexane produced in the monolith catalyst of each stage is recovered using the recovery device provided in each stage. Therefore, it does not hinder the hydrogenation reaction in the lower monolith catalyst.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a method of storing, transporting and supplying hydrogen gas in the form of an organic hydride.

FIG. 2 is a sectional view showing a monolith catalyst used in the present invention.

FIG. 3 is a sectional view showing a hydrogenation device according to the present invention.

FIG. 4 shows the relationship between the temperature of the monolith catalyst and the concentration of benzene on the catalyst surface. (1) is a schematic diagram of the monolith catalyst, (2) (a) is the temperature of the monolith catalyst and the pressure inside the tower reactor. At a temperature T1 significantly lower than the boiling point of benzene in the above; when the temperature of the monolith catalyst is lower than the boiling point of benzene and at a temperature near T2; the temperature of the monolith catalyst is higher than the boiling point of benzene. A diagram showing the case where the temperature is maintained at an appropriate temperature T _opt , (2) and (B) show the reaction temperature further increased to the temperature T3
And (2) and (c) are diagrams showing the case where the reaction temperature is further raised to the temperature T4.

FIG. 5 is a schematic view showing an annular flow.

FIG. 6 is a schematic diagram showing a bubbly flow.

FIG. 7 is a diagram showing an experimental device.

FIG. 8 is a diagram showing a time-dependent change in hydrogenation volume at each reaction temperature.

FIG. 9 is a diagram showing a reaction rate at a reaction time of 20 min at each reaction temperature.

FIG. 10 is a view showing an experimental apparatus using a monolith catalyst.

FIG. 11 is a diagram showing the conversion rate to cyclohexane at each reaction temperature.

FIG. 12 is a cross-sectional view showing a perfusion type fixed bed reactor which is an example of a conventional hydrogenation device.

[Explanation of symbols]

1: Tower type reactor, 2: Monolith catalyst, 3: Hydrogen gas supply part, 4: Dehydrogenation reaction product supply part, 5: Organic hydride recovery part, 6: Disperser, 7: Disperser main valve, 8 : Recovery part valve, 9: monolith carrier, 10: cell, 11: hydrogenation reaction catalyst, 12: recovery device, 20: temperature control means, 2
1: Schlenk tube which is a reaction device, 22: heater, 23: temperature controller, 24: cooling pipe, 25: cooler,
26: Hydrogen supply line, 27: Burette, 28: Catalyst layer, 31: Flow reactor, 32: Monolith catalyst, 3
3: Heater, 34: Thermocouple, 35: Heat insulating material, 36: Dehydrogenation reaction product supply part, 37: Disperser, 38: Hydrogen gas supply part, 39: Hydrogen gas dispersion plate, 40: Cooling trap, 4
2: Vent port, 43: Refrigerant.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4G075 AA14 BA06 BD03 BD17 CA02                       CA54 DA01 DA20 EE33 FB02                       FB03                 4H006 AA02 AA04 AC11 BA26 BA55                       BC10 BC30 BD20 BD21 BD80                       BE20                 4H039 CA40 CB10

Claims (2)

[Claims] 1. A monolith catalyst, a hydrogen gas supply unit, a dehydrogenation reaction product supply unit, an organic hydride recovery unit, a disperser, a disperser main valve, and a recovery unit valve, wherein the monolith catalyst has a plurality of gas flow paths. A hydrogenation device in which a hydrogenation reaction catalyst is supported on a monolith carrier composed of a plurality of cells divided into two. 2. A monolith catalyst, a hydrogen gas supply unit, a dehydrogenation reaction product supply unit, an organic hydride recovery unit, a disperser, a disperser main valve, and a recovery unit valve, wherein the monolith catalyst has a plurality of gas flow paths. In a hydrogenation device in which a hydrogenation reaction catalyst is supported on a monolith carrier composed of a plurality of cells, the temperature of the monolith catalyst is higher than the boiling point of the dehydrogenation reaction product at the pressure inside the hydrogenation device. While maintaining the reaction temperature, in each stage the dehydrogenation reaction product is uniformly supplied to the upper portion of the monolith catalyst from the disperser,
Hydrogen that consists of supplying the required amount of hydrogen gas from the hydrogen gas supply unit to the upper part of the first stage monolith catalyst uniformly, and adjusting the supply volume flow rate ratio of hydrogen gas and dehydrogenation reaction product in each stage. How to add.