CN216856676U

CN216856676U - Microwave gas high-temperature reaction device

Info

Publication number: CN216856676U
Application number: CN202220483286.3U
Authority: CN
Inventors: 邓贱牛; 余伟斌; 马剑超
Original assignee: Shenzhen Hongwei Microwave Technology Co ltd
Current assignee: Shenzhen Hongwei Microwave Technology Co ltd
Priority date: 2022-03-08
Filing date: 2022-03-08
Publication date: 2022-07-01
Anticipated expiration: 2032-03-08

Abstract

The utility model discloses a microwave gas high-temperature reaction device which comprises a metal shell and an internal furnace tube, wherein a heat insulation material is filled between the metal shell and the furnace tube, the material of the furnace tube is quartz or ceramic, expanded graphite or an expanded graphite composite material is filled in the furnace tube, screens are arranged at two ends of the furnace tube, a microwave magnetron and an excitation cavity are arranged on the periphery of the metal shell, and the working frequency of the microwave magnetron is 915MHz or 2450 MHz. The device can be used for carrying out reactions such as methane cracking, methane carbon dioxide reforming, VOCs gas treatment and the like under the conditions of normal pressure and no use of noble metal catalyst.

Description

Microwave gas high-temperature reaction device

Technical Field

The utility model belongs to the technical field of microwave reaction devices, and particularly relates to a microwave gas high-temperature reaction device. The high loose permeability of the expanded graphite and the high temperature environment generated by the microwave excitation of the expanded graphite are utilized to carry out the catalytic reaction of the gas.

Background

The microwave gas high-temperature reaction device is mainly applied to catalytic gas high-temperature reactions, such as methane cracking, methane-carbon dioxide reforming, VOCs gas decomposition and the like. In the existing production process equipment, reactions such as methane cracking, methane-carbon dioxide reforming and the like can often occur under harsh conditions such as high temperature, high pressure, use of noble metal catalysts and the like. The noble metal catalyst is mostly attached to the solid material, the contact area with the reaction gas is limited, and the solid product generated by the reaction is deposited on the surface of the solid material, so that the noble metal catalyst cannot be used for a long time.

The expanded graphite is a highly loose carbon material, the expanded graphite can be heated quickly to generate a high-temperature environment after absorbing microwave energy, hot spots with higher temperature can be generated at local positions of the expanded graphite, and the high-temperature environment and the high-temperature hot spots of the expanded graphite can catalyze methane, carbon dioxide and other gases to perform cracking, reforming and other reactions under normal pressure. The device utilizes the microwave to excite the high-temperature environment generated by the expanded graphite to catalyze the gas reaction, so that not only is the construction of reaction conditions simpler, but also a noble metal catalyst is not needed in the reaction process, and the production cost can be obviously reduced. In addition, the expanded graphite has the characteristics of light weight, looseness, large specific surface area and the like, airflow is smoother when passing through, the reaction speed is higher, carbon powder generated by the reaction can absorb microwave, the temperature rise can be continued to generate a catalytic effect, and the continuous and efficient reaction is ensured.

Disclosure of Invention

In order to solve the problems that the conditions required by the current reactions such as cracking and reforming of organic gases are harsh, and noble metal catalysts are easy to inactivate, the utility model provides a microwave gas high-temperature reaction device, which utilizes the high-temperature catalytic environment generated by microwave excitation of expanded graphite to realize the reactions such as methane cracking, methane-carbon dioxide reforming, VOCs gas decomposition and the like under normal pressure without using catalysts, thereby obviously reducing the production cost in the gas reaction process.

In order to achieve the above object, the present invention provides a microwave gas high temperature reaction apparatus, which is characterized by comprising the following structures: the microwave oven comprises a metal shell (1) and a furnace tube (3), wherein a heat insulation material (2) is filled between the metal shell (1) and the furnace tube (3), a filling material (4) is arranged in the furnace tube (3), screens (5) are arranged at two ends of an opening of the furnace tube, a microwave magnetron and an excitation cavity (6) are arranged on the periphery of the metal shell (1), and gas inlets and outlets (7) are arranged at two ends of the metal shell (1); after being excited by microwave, the filling material (4) is converted into a high-temperature bulky state, and the high temperature and the characteristic of large specific surface area of the filling material are utilized to catalyze the gas molecules to carry out cracking and reforming reactions.

Furthermore, the furnace tube (3) is made of quartz or ceramic, two ends of the furnace tube are open, one end of the furnace tube is used for air inlet, and the other end of the furnace tube is used for air outlet;

further, the filling material (4) is one of expanded graphite, expandable graphite, expanded graphite loaded with a catalyst and expandable graphite loaded with a catalyst;

furthermore, the working frequency of the microwave magnetron and the magnetron in the excitation cavity (6) is 915MHz or 2450 MHz.

Compared with the prior equipment, the utility model has the beneficial effects that:

1. obviously reducing the conditions required by the reactions of gas cracking, reforming and the like and reducing the production cost. In the existing production process, reactions such as methane cracking, methane-carbon dioxide reforming, VOCs gas decomposition treatment and the like often need to be carried out under harsh conditions such as high temperature, high pressure, use of noble metal catalysts and the like. The device can realize the reactions of methane cracking, methane-carbon dioxide reforming, VOCs gas treatment and the like under the conditions of normal pressure and no use of noble metal catalyst by utilizing the high temperature and catalytic environment generated by exciting the expanded graphite by microwaves, and can obviously reduce the production cost;

2. the gas contact area is increased, and the reaction rate and efficiency are improved. The expanded graphite is a light and highly loose carbon material, the bulk density of the expanded graphite is 2-5 mg/cm3, the expanded graphite has a large comparative area, when the expanded graphite is filled into a container, gas can freely pass through the container without resistance, the gas can be rapidly diffused and contacted with the expanded graphite, the expanded graphite is heated by the expanded graphite after being excited by microwaves to generate a high-temperature environment, a plurality of high-temperature hot spots can be generated on the surface of the expanded graphite, the high-temperature environment and the high-temperature hot spots can rapidly catalyze reactions such as gas reaction cracking and reforming, and the catalytic efficiency of the expanded graphite per unit mass is far higher than that of a traditional noble metal catalyst;

3. obviously improving the influence of the carbon deposition phenomenon on the reaction. In the existing process equipment, reactions such as methane cracking, methane-carbon dioxide reforming and the like not only require relatively harsh reaction conditions such as high temperature, high pressure, noble metal catalyst and the like, but also carbon generated by the reactions can be deposited on the surface of the noble metal catalyst to cause the catalyst to be deactivated, so that the catalytic effect is greatly reduced and even lost. The catalytic principle of the device is that the expanded graphite can be heated up and generate high-temperature hot spots in a microwave field, the carbon deposition on the surface of the expanded graphite does not influence the heating effect of microwaves on the expanded graphite, and the position of the high-temperature hot spots generated by exciting the expanded graphite by the microwaves is not fixed but can change along with the change of the structure of the expanded graphite, so that the carbon deposition has little influence on the high-temperature catalytic action of the expanded graphite. In addition, carbon deposition generated by the gas cracking reaction can absorb microwaves in a microwave field to increase the temperature, so that a catalytic effect similar to that of expanded graphite is generated, and the subsequent reaction is continuously catalyzed.

Description of the drawings:

FIG. 1 is a schematic view of the structure of the apparatus of the present invention

In the figure: 1. a metal housing; 2. a thermal insulation material; 3. a furnace tube; 4. a filler material; 5. screening a screen; 6. a microwave magnetron and an excitation cavity; 7. and a gas inlet and outlet.

The specific implementation mode is as follows:

the use of the device of the utility model will be more clearly illustrated below with reference to specific application examples, it being clear that the described examples are only a part of the use of the device of the utility model and not all. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, belong to the scope of the present invention.

Example 1: the device is utilized to catalyze the methane cracking to produce hydrogen

1) The device is electrified and the microwave power supply is started, the expanded graphite filled in the furnace tube absorbs microwave radiation to generate a high-temperature environment, and a high-temperature hot spot is generated on the surface of the expanded graphite;

2) the methane gas passes through the device at a certain flow rate, the methane is subjected to catalytic cracking reaction under the catalytic action of a high-temperature environment and a high-temperature hot spot generated by the expanded graphite, and the cracking products are carbon and hydrogen.

Example 2: the device is utilized to catalyze the reforming of methane-carbon dioxide

2) methane and carbon dioxide gas pass through the device at a certain flow rate in a certain proportion, the methane and carbon dioxide gas are subjected to catalytic reforming reaction under the catalytic action of a high-temperature environment and a high-temperature hot spot generated by the expanded graphite, and the reforming reaction products are carbon monoxide and hydrogen.

Example 3: the device is utilized to catalyze the decomposition treatment of VOCs gas

2) pass through this device with the VOCs gas with certain flow, the VOCs gas takes place catalytic decomposition reaction under the catalytic action of the high temperature environment that expanded graphite produced and high temperature hot spot, and the decomposition product is micromolecular inorganic substances such as carbon dioxide, water.

Claims

1. A microwave gas high-temperature reaction device is characterized by comprising the following structures: the microwave oven comprises a metal shell (1) and a furnace tube (3), wherein a heat insulation material (2) is filled between the metal shell (1) and the furnace tube (3), a filling material (4) is arranged in the furnace tube (3), screens (5) are arranged at two ends of an opening of the furnace tube, a microwave magnetron and an excitation cavity (6) are arranged on the periphery of the metal shell (1), and gas inlets and outlets (7) are arranged at two ends of the metal shell (1); after being excited by microwave, the filling material (4) is converted into a high-temperature bulky state, and the high temperature and the characteristic of large specific surface area of the filling material are utilized to catalyze the gas molecules to carry out cracking and reforming reactions.

2. The microwave gas high-temperature reaction device according to claim 1, wherein the furnace tube (3) is made of quartz or ceramic, and is open at two ends, one end is used for gas inlet and the other end is used for gas outlet.

3. A microwave gas high-temperature reaction device according to claim 1, characterized in that the filling material (4) is one of expanded graphite, expandable graphite, catalyst-loaded expanded graphite, catalyst-loaded expandable graphite.

4. A microwave gas high-temperature reaction device according to claim 1, characterized in that the working frequency of the microwave magnetron and the magnetron in the excitation chamber (6) is 915MHz or 2450 MHz.