JPH0374082A - Catalyst reactor - Google Patents

Abstract

PURPOSE:To reduce energy loss in heating a catalyst by providing a microwave absorbing layer on a fine hole inner wall of a honey-comb structure composed of a non-microwave-absorbing material, and by providing a catalytic layer on the surface thereof. CONSTITUTION:A catalyst 10 for which a microwave absorbing layer 16 composed of chosen species out of silicon carbide, zinc oxide, and of a group of transition metals oxide, is provided on an inner wall of a fine hole 15a of a honey-comb structure 15 composed of a non-microwave absorbing material, and for which a catalytic layer 17 is provided on the surface of the microwave absorbing layer 16, is arranged in a microwave cavity resonator 9 on which a magnetron 13, a pair of thermal detectors 11, and a magnetron output control circuit 14 are arranged. The microwave generated by the magnetron 13 is absorbed in the microwave absorbing layer 16 of the honey-comb structure 15, whereby the temperature of the catalytic layer is raised. By forming a structure in which a microwave absorbing layer is provided on a fine hole inner wall of a honey-comb structure composed of a non-microwave-absorbing material, increase in temperature is executed at a low energy, requiring a short period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a catalytic reaction apparatus for converting a gaseous substance into another gaseous substance by a catalytic reaction.

BACKGROUND OF THE INVENTION A conventional catalytic reaction apparatus of this type, as shown in FIG.
is heated to a constant temperature, and the gaseous substance 4 is heated to another gaseous substance 5.
When the gaseous substance 4 passes through the pores 6 of the catalyst body 2, a catalytic reaction occurs.

The catalyst body 2 has a honeycomb-like cross-sectional structure as shown in FIG. 2, and a catalyst layer 8 is supported on the walls of the pores 6.

Problems to be Solved by the Invention However, the above configuration has a problem in that energy loss is large because the catalyst body is heated by an external heat source.

The present invention solves such conventional problems and aims to provide a catalytic reaction device with less energy loss.

Means for Solving the Problems In order to solve the above problems, the catalytic reaction apparatus of the present invention includes:
A microwave absorbing layer selected from the group of silicon carbide, zinc oxide, and transition metal oxide is provided on the inner wall of the pores of a honeycomb structure made of a non-microwave absorbing material selected from the group of alumina, mullite, and cordierite. , the catalyst body with the catalyst layer provided on the surface of the microwave absorption layer was placed in a magnetron, 1&
This device has a configuration in which eleven temperature detection elements and a magnetron output control circuit are arranged inside a microwave cavity resonator.

Operation According to the present invention, the microwave generated by the magnetron is absorbed by the microwave absorbing layer of the honeycomb structure, thereby increasing the temperature of the catalyst layer.

A magnetron, a set of temperature detection elements, and a magnetron output control circuit are connected to the microwave cavity resonator in which the catalyst body is arranged, thereby maintaining the temperature of the catalyst body constant. In other words, the gas temperature at the inlet and outlet of the catalyst body is 1
The temperature of the catalyst body is maintained constant by operating the magnetron and magnetron output control circuit while measuring the temperature using a set of temperature detection elements.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings.

In Figure 1a, 9 has an inner diameter of 41 m, an outer diameter of 43 m, and a length of 1
20- stainless steel microwave cavity resonator, which includes a catalyst body 10 inside, a microwave shielding metal 1M11 before and after the catalyst body, and a temperature detection element 12 outside the metal mesh. A magnetron 13 is connected to the magnetron 9, and a magnetron output control circuit 14 is connected to the magnetron.
This circuit is connected to the temperature detection element 12. As shown in FIG.
o ■, length 80m.

A microwave absorbing layer 1 made of zinc oxide whiskers is placed on the inner wall of the pores 15a of the honeycomb structure 15 of 90 cells/1n1.
6, and a cerium oxide catalyst layer 17 is provided on the surface thereof. Cerium oxide exhibits a catalytic effect that oxidizes carbon monoxide and converts it into carbon dioxide gas when the temperature exceeds 150'C. To heat the catalyst body to 150'C with microwaves, a high frequency output of 100W is sufficient. When air balance gas 4 with a carbon monoxide concentration of 1% is flowed at a space velocity of 5 ooo h -t through an 8-catalytic reactor with a rise time of 5 seconds, a reaction gas 5 containing no carbon monoxide is discharged from the outlet. did.

For comparison, in order to achieve the same rise time and the same holding temperature as in this example using the external heating type conventional device shown in Fig. 2, a power of I KW was required for the initial 3 seconds and 400 W thereafter. .

Next, another embodiment of the present invention will be described with reference to FIG. The difference from the above embodiment is that alumina honeycomb is used instead of mullite honeycomb, zinc oxide whiskers are used, and a microwave absorption layer made of carbon silicon is provided instead of a microwave absorption layer, and cerium oxide, manganese oxide, The feature is that a composite perovskite structure catalyst layer made of copper oxide is provided. The catalyst exhibits a catalytic action of oxidizing hydrocarbons such as propylene and converting them into carbon dioxide and water at temperatures above 200°C.

In order to heat the catalyst body to 200° C. using a microwave, a high frequency output of 150 W is sufficient, and the rise time is 7 seconds. Air balance gas with a propylene concentration of 1% was fed into a zero catalytic reactor at a space velocity of 5000 h − When flowing at ', a reaction gas containing no propylene was discharged from the outlet. For comparison, in order to achieve the same rise time and the same holding temperature as in this example using the external heating type conventional device shown in Fig. 2, a power of 1.5 KW is required for the initial 5 seconds and 700 W thereafter. Ta.

Effects of the Invention As described above, the catalytic reaction apparatus of the present invention provides the following effects.

(1) Since the honeycomb structure is made of a non-microwave absorbing material and has a microwave absorbing layer on the inner wall of the pores, it is possible to create a catalytic reaction device that can raise the temperature in a short time with lower energy than conventional methods. be.

■ A set of temperature detection elements is arranged inside the microwave cavity resonator, and connected to the elements, a magnetron output control circuit,
Since a magnetron is connected to the circuit, the chemical reaction rate (therefore, the catalyst temperature) can be controlled based on the difference between the inlet gas temperature and the outlet gas temperature.

[Brief explanation of drawings]

1A and 1B are cross-sectional views of a catalytic reaction apparatus and a catalyst body according to an embodiment of the present invention, and FIGS. 2A and 2B are cross-sectional views of a conventional catalytic reaction apparatus and a catalyst body. 9...Microwave cavity resonator, IO...
- Catalyst body, 11...Temperature detection element, 12...
...Microwave shielding wire mesh, 13...Magnetron, 14...Microwave output control circuit, 1
5...Non-microwave absorbing honeycomb structure, 16
...Microwave absorption layer, 17...Catalyst layer.

Claims (1)

[Claims] A microwave absorbing layer selected from the group of silicon carbide, zinc oxide, and transition metal oxide is provided on the inner wall of the pores of a honeycomb structure made of a non-microwave absorbing material selected from the group of alumina, mullite, and cordierite. , a catalyst body having a catalyst layer on the surface of the microwave absorption layer, a set of microwave blocking wire mesh inside, a set of temperature detection element outside the wire mesh, and a magnetron and a microwave output control circuit outside. A catalytic reaction device placed inside a microwave cavity resonator.