JPH0441326Y2 - - Google Patents

Description

[Detailed explanation of the idea]

This invention uses a catalyst to react raw material gas,
The present invention relates to a catalytic reaction experimental device that can be advantageously implemented for determining the reaction rate equation at that time. In the prior art, a reaction tube in which a catalyst is housed and a raw material gas is passed through is surrounded by a heating means such as an electric heater. For example, in the case of a methanation reaction, when a ruthenium catalyst on an alumina carrier is used to produce methane from a mixed gas of carbon monoxide and hydrogen as the main components, a large amount of heat is generated and the internal temperature of the catalyst varies. This results in a temperature difference of, for example, about ±10°C. If the reaction temperature is 10°C higher, the reaction rate increases by about 1.5 times.
Therefore, it was difficult to determine the reaction rate equation. The present invention consists of (a) a reaction tube 1 formed on a straight tube extending vertically and to which raw material gas is supplied from above; (b) an annular first space 6a concentrically surrounding the reaction tube 1;
(c) a second annular space 6b concentrically surrounding the reaction tube 1;
a second electric heater 4 which is formed in an annular shape with an opening therebetween and extends downward from approximately the upper end position 2a of the catalyst 2 to the lower end position of the first electric heater 3 to near the lower end position 2b of the catalyst 2; (d) reaction; An annular third space 6c surrounds the tube 1 concentrically.
(e) a first space 6a, a second space 6b; , third space 6c
are connected in a substantially uniform shape vertically to form a space 6, and the inner circumferential surfaces of the first electric heater 3, the second electric heater 4, and the third electric heater 5 are continuous vertically, Furthermore, (f) is fixed to the upper end portion 31 of the first electric heater 3;
an upper end plate 7 that closes the first space 6a; (g) fixed to the lower end 51 of the third electric heater 5;
a lower end plate 9 forming an exhaust port 8 having an inner diameter smaller than the inner diameter of the third space 6c concentrically with the reaction tube 1; (h) a lower end plate 9 connected to the upper end plate 7 to supply cooling gas to the first space 6a; (i) the first flow control valve 11 interposed in the middle of the first pipe line 10; (j) the second electric heater 4 at a substantially central position in the height direction of the second electric heater 4; (k) a second flow control valve 13 interposed in the middle of the second pipe line 12; (l) First electric heater 3, second electric heater 4, third electric heater
Electric power amount of electric heater 5 and first flow control valve 1
1. A catalytic reaction experimental apparatus characterized by including a control circuit 17 that controls the opening degree of the second flow control valve 13. Further, the present invention is characterized in that the cooling gas is nitrogen or air. An object of the present invention is to provide a catalytic reaction experimental apparatus that allows the temperature distribution of the catalyst to be set uniformly. FIG. 1 is a sectional view of an embodiment of the present invention.
For example, in the case of a methanation reaction, a mixed gas of carbon monoxide and hydrogen, which are the main components, is supplied from above the reaction tube 1, and this raw material gas is fed to the alumina gas stored in the center portion 1a of the reaction tube 1. The methanation reaction takes place through a catalyst 2 made of ruthenium as a carrier. The generated methane is passed down in FIG. On the outside of the reaction tube 1, there is a first annularly formed annular space 6 concentric with the reaction tube 1.
An electric heater 3, a second electric heater 4, and a third electric heater 5 are arranged vertically adjacent to each other in the axial direction of the reaction tube 1. The space 6 and the upper end 31 of the first electric heater 3 are closed by an upper end plate 7. The space 6 and the lower end 51 of the third electric heater 5 include a space 6
A lower end plate 9 is attached having an exhaust port 8 with an inner diameter smaller than the inner diameter of the lower end plate 9. The upper end plate 7 is provided with a first conduit 10 through which cooling air is supplied. A first flow control valve 11 is interposed in the first conduit 10 . The second electric heater 4 and the second conduit 12 provided radially through the second electric heater 4 at a substantially central position in the height direction thereof are connected to a portion of the reaction tube 1 in which the catalyst 2 is housed. Facing 1a. This second
Cooling air is supplied to the pipe line 12 via a second flow control valve 13 . Inside the catalyst 2, temperature detectors 14 are installed at equal intervals along the axial direction of the reaction tube 1.
15 and 16 are embedded. FIG. 2 is a block diagram of one embodiment of the present invention. The outputs from the temperature detectors 14, 15, 16 are:
The signal is input to the control circuit 17. The control circuit 17 controls the first electric heater 3, the second electric heater 4, and the third electric heater so that all measured values of temperature detected by the temperature detectors 14, 15, and 16 are equal to a predetermined value. The power amount of the heater 5 is controlled, and the opening degrees of the first flow control valve 11 and the second flow control valve 13 are controlled. The electric power of the first electric heater 3, the first flow control valve 11 provided in the first conduit 10, and the second conduit are adjusted so that the temperature detected by the temperature detector 14 becomes a predetermined value. The opening degree of the second flow control valve 13 provided in the flow rate control valve 12 is controlled. Also,
The electric power of the second electric heater 4, the first flow control valve 11 provided in the first conduit 10 and the second conduit are adjusted so that the temperature detected by the temperature detector 15 becomes a predetermined temperature. The second one provided at 12
The opening degree of the flow rate control valve 13 is controlled. In addition, in order to prevent a temperature drop due to heat transfer from the reaction tube section, the electric power amount of the third electric heater 5 and the first pipe line are adjusted so that the temperature displayed by the temperature detector 16 does not become lower than a predetermined temperature. The first flow control valve 11 provided in the flow control valve 10 and the second flow control valve provided in the second pipe line 12
Controls the flow rate control valve 13. In this way, the temperature within the catalyst 2 can be maintained uniformly at a predetermined constant temperature. Therefore, it becomes easy to determine the reaction rate equation of the catalyst 2, etc. Example According to the inventor's experiment, the inner diameter of the reaction tube 1 is
10 mmφ, the layer length h of the catalyst 2 along the axial direction of the reaction tube 1 is 3 cm, the first pipe line 10, the second pipe line 12
The inner diameter of each is 1 mmφ, the reaction temperature is 250℃,
When the pressure of the gas was 10 Kg/cm ² and the reaction rate was 20%, the experimental results shown in Table 1 were obtained.
The raw material gas consists of N ₂ , H ₂ and CO, and the catalyst 2
This is a Ru/Al ₂ O ₃ catalyst, and a methanation reaction occurs with this catalyst 2, which generates heat. According to the experimental results of the present invention, temperature detectors 14, 15, 16
For example, the difference in temperature detected by
±1.1℃. Comparative example: The electric heater is not divided into the first electric heater 3, the second electric heater 4, and the third electric heater 5,
In the prior art in which the first conduit 10 and the second conduit 12 are not provided and the space 6 is not formed, ±7 to ±15°C
temperature difference occurs. It is thus understood that according to the invention it is possible to maintain the temperature of the catalyst uniformly and precisely at a desired value.

[Table] As another embodiment of the present invention, instead of the cooling air introduced from the first pipe line 10 and the second pipe line 12, the cooling gas may be nitrogen gas, or other non-containing gas may be used. Activated gases may also be used. As described above, according to the present invention, a space 6 is formed between the inner peripheral surfaces of the first electric heater 3, second electric heater 4, and third electric heater 5 and the reaction tube 1, and this space 6 is uniform in the vertical direction; in other words, the inner surfaces of the first to third electric heaters 3, 4, and 5 are continuous in the vertical direction. By changing the amount of electric power of the first electric heater 3, the second electric heater 4, and the third electric heater 5 by the control circuit 7, the reaction tube 1 can be heated quickly and accurately by radiation heat transfer. can. Further, the first electric heater 3 serves to heat the raw material gas supplied to the reaction tube 1 to a predetermined temperature and also to prevent temperature changes in the upper part of the catalyst 2. The third electric heater 5 prevents temperature changes in the lower part of the catalyst 2. With these things, it is possible to maintain a constant temperature with uniform temperature distribution across the top and bottom of the catalyst 2. Further, a first conduit 10 is attached to the upper end plate 7, and cooling gas is supplied from this first conduit.
The cooling gas is forced into the space 6, and the flow rate of this cooling gas is controlled by the first flow rate control valve 11, so that the outer surface of the reaction tube 1 is not allowed to accumulate in the space 6. The cooling gas can flow smoothly along the lower part. Therefore, the temperature distribution of the catalyst 2 over the height h of the central portion 1a of the reaction tube 1 can be maintained as uniform as possible. Further, the cooling gas from the second conduit 12 provided radially through the second electric heater 4 at a substantially central position in the height direction of the second electric heater 4 is
The gas from line 10 flows downward. Further, these cooling gases are controlled by the first flow control valve 11 or the second flow control valve 13, and the center of the reaction tube 1 filled with the catalyst 2 is controlled by the total flow rate or the flow rate ratio thereof. It is possible to more reliably maintain the temperature in the range of the height h of the portion 1a at a uniform, predetermined temperature. Further, since the lower end plate 9 has an exhaust port 8 having an inner diameter smaller than the inner diameter of the space 6 formed concentrically with the reaction tube 1, the first pipe line 10 and the second pipe line 12 in the space 6 are Since the supplied cooling gas flows in uniform contact with the outer surface of the reaction tube 1, it maintains a uniform temperature within the height h range of the central portion 1a of the reaction tube 1 filled with the catalyst 2. It is possible to maintain the temperature even more reliably.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a block diagram of the embodiment shown in FIG. DESCRIPTION OF SYMBOLS 1... Reaction tube, 2... Catalyst, 3... First electric heater, 4... Second electric heater, 5... Third electric heater, 6... Space, 10... First pipe line, 12... …
Second pipe line, 11...first flow control valve, 13...second flow control valve, 14, 15, 16...temperature detector, 17...control circuit.

Claims (1)

[Claims for Utility Model Registration] (1) (a) A reaction tube 1 formed on a straight tube extending vertically and to which raw material gas is supplied from above,
The catalyst 2 is filled in the center of the reaction tube 1 to a predetermined height h along the tube axis direction.
Such a reaction tube 1, (b) an annular first space 6 concentrically surrounding the reaction tube 1;
(c) a first electric heater 3 which is formed in an annular shape with a space a apart and extends upward from approximately the upper end position 2a of the catalyst 2; (c) a second annular space 6 which concentrically surrounds the reaction tube 1;
It is formed in an annular shape with a gap 2a apart, and extends downward from approximately the upper end position 2a of the catalyst 2 to the lower end position of the first electric heater 3, and extends downward from the lower end position 2b of the catalyst 2.
(d) a third annular space 6 concentrically surrounding the reaction tube 1;
(e) a first space 6a, a second space; 6b, third space 6
c has a substantially uniform shape vertically and is connected to form a space 6, which includes a first electric heater 3,
The inner peripheral surfaces of the second electric heater 4 and the third electric heater 5 are vertically continuous, and (f) an upper end plate 7 fixed to the upper end 31 of the first electric heater 3 and closing the first space 6a. , (g) a lower end plate 9 fixed to the lower end 51 of the third electric heater 5 and forming an exhaust port 8 concentrically with the reaction tube 1 and having an inner diameter smaller than the inner diameter of the third space 6c; (h) an upper part; A first pipe line 10 connected to the end plate 7 and supplying cooling gas to the first space 6a, (i) a first flow control valve 11 interposed in the middle of the first pipe line 10, (j) a second electric A second conduit 12 is provided to radially penetrate the second electric heater 4 at a substantially central position in the height direction of the heater 4, opens into the second space 6b, and supplies cooling gas. (k) The second flow control valve 13 interposed in the middle of the second pipe line 12 and (l) the electric power of the first electric heater 3, the second electric heater 4, and the third electric heater 5; A catalytic reaction experimental device characterized by including a control circuit 17 that controls the opening degree of a flow control valve 13. (2) The catalytic reaction experimental apparatus according to claim 1, wherein the cooling gas is nitrogen or air.