CN114751382B - Carbon dioxide decomposition device - Google Patents

Abstract

The invention provides a carbon dioxide decomposition device, which belongs to the technical field of carbon dioxide conversion, and comprises: the side wall of the main pipe is respectively provided with an air inlet and an air outlet which are suitable for carbon dioxide to enter and exit; the branch pipe is arranged on the main pipe between the air inlet and the air outlet; the conductive metal rod is arranged in the main pipe; a ground electrode provided outside the main pipe; the magnetic field generating device is arranged on the outer side of the main pipe and is used for generating a magnetic field so as to separate oxygen generated by decomposing the carbon dioxide in the main pipe from the branch pipe. According to the carbon dioxide decomposition device, the acting force of the magnetic field generated by the magnetic field generating device on oxygen is utilized to enable the oxygen path to deflect and separate from the branch pipe, so that the oxygen is continuously extracted and separated in the carbon dioxide decomposition process, the recombination of the oxygen and carbon monoxide is avoided, and the carbon dioxide conversion efficiency is improved.

Description

A carbon dioxide decomposition device

Technical Field

The present invention relates to the technical field of carbon dioxide conversion, and in particular to a carbon dioxide decomposition device.

Background technique

In response to climate change, my country has proposed goals such as "striving to peak carbon dioxide emissions before 2030 and striving to achieve carbon neutrality before 2060". Against this background, carbon dioxide capture, utilization and storage (CCUS) has gradually attracted people's attention as an effective and sustainable method to limit carbon dioxide emissions. This technology can effectively mitigate the greenhouse effect and is considered a feasible method to reduce greenhouse gas emissions on a large scale and slow down global warming in the future.

As we all know, carbon dioxide is a special renewable resource with abundant reserves, safety, low cost and easy access. Through chemical transformation, _CO2 can be used as a resource to obtain high value-added energy, materials and chemical products. Therefore, since the mid-1970s, the research on the activation and transformation of carbon dioxide has been a hot topic pursued by people. The related research involves various fields of modern chemical synthesis, including fine chemicals, bulk chemistry, drug development, bio-based polymers, etc. However, in the process of research, it was found that _CO2 often exhibits thermodynamic stability and kinetic relative inertness in its chemical transformation, and the structure of _CO2 chemical transformation products is single and the conversion efficiency is not high.

Plasma is rich in various ions, electrons, excited atoms, molecules and free radicals and other highly active species. The energy of high-energy particles in plasma is generally several to tens of electron volts, which is enough to provide the activation energy required for chemical reactions. In addition, since low-temperature plasma is in a non-equilibrium state, and this non-equilibrium characteristic is very beneficial to chemical reactions, it can break the restrictions of thermodynamic equilibrium on reactions. Therefore, high-energy particles generated by gas discharge can be used to decompose carbon dioxide into carbon monoxide and oxygen, thereby using discharge to convert carbon dioxide. In the prior art, the more common methods of improving gas conversion efficiency by using plasma to decompose carbon dioxide include: changing the material and morphology of the high-voltage electrode, or changing the intake speed, reaction environment temperature, or adding adsorption materials, etc. These methods are based on changing external conditions, and the carbon dioxide conversion efficiency is not significantly improved, and the subsequent oxygen needs to be further purified.

Summary of the invention

The problem solved by the present invention is that the existing method of improving the carbon dioxide conversion efficiency by changing the external conditions has low conversion efficiency.

In order to solve at least one aspect of the above problems, the present invention provides a carbon dioxide decomposition device, comprising:

A main pipe, the side walls of which are respectively provided with an air inlet and an air outlet suitable for the inflow and outflow of carbon dioxide;

A branch pipe, the branch pipe being arranged on the main pipe between the air inlet and the air outlet;

A conductive metal rod, the conductive metal rod being disposed inside the main pipe;

A grounding electrode, the grounding electrode being arranged outside the main pipe;

A magnetic field generating device is arranged outside the main pipe and is used to generate a magnetic field to separate the oxygen generated by the decomposition of the carbon dioxide in the main pipe from the branch pipe.

Preferably, there are a plurality of branch pipes, and the plurality of branch pipes are arranged at intervals on the outer wall of the main pipe along the axial direction of the main pipe.

Preferably, the magnetic field generating device comprises an iron rod and a conductive coil wound around the iron rod, the iron rod is arranged on the outside of the main pipe, and the conductive coil is suitable for connecting to a DC power supply.

Preferably, the number of the iron rods is the same as the number of the branch pipes, and a plurality of the iron rods are connected in parallel in a DC circuit.

Preferably, the magnetic field generating device further comprises a sliding rheostat, the sliding rheostat is connected in series with the iron rod, and a plurality of the sliding rheostats are connected in parallel in the DC circuit.

Preferably, the iron rod is arranged opposite to the connection between the branch pipe and the main pipe.

Preferably, the diameter of the iron rod is the same as the diameter of the connection between the branch pipe and the main pipe.

Preferably, the angle between the branch pipe and the main pipe is 25°-40°.

Preferably, the ground electrode comprises an ITO film disposed on the outer wall of the main pipe.

Preferably, the magnetic field generating device comprises a magnet, the magnet is arranged parallel to the main pipe, and a side of the magnet close to the main pipe is an S pole.

The advantages of the present invention compared to the prior art are:

The carbon dioxide decomposition device of the present invention utilizes the force of the magnetic field generated by the magnetic field generating device on oxygen, so that the oxygen path is deflected and separated from the branch pipe, thereby realizing continuous extraction and separation of oxygen during the carbon dioxide decomposition process, avoiding the recombination of oxygen and carbon monoxide, and thus improving the carbon dioxide conversion efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the overall structure of a carbon dioxide decomposition device according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the overall structure of a carbon dioxide decomposition device in another embodiment of the present invention.

Description of reference numerals:

1-main pipe; 2-ground electrode; 3-conductive metal rod; 4-air inlet; 5-air outlet; 6-branch pipe; 7-sliding rheostat; 8-iron rod; 9-magnet.

Detailed ways

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

Referring to FIG. 1 , a carbon dioxide decomposition device according to an embodiment of the present invention includes:

A main pipe 1, the side walls of which are respectively provided with an air inlet 4 and an air outlet 5 suitable for the inlet and outlet of carbon dioxide;

A branch pipe 6, which is arranged on the main pipe 1 between the air inlet 4 and the air outlet 5;

A conductive metal rod 3, which is arranged inside the main pipe 1;

A grounding electrode 2, wherein the grounding electrode 2 is arranged outside the main pipe 1;

The magnetic field generating device is arranged outside the main pipe 1 and is used to generate a magnetic field to separate the oxygen generated by the decomposition of carbon dioxide in the main pipe 1 from the branch pipe 6.

The high-energy particles generated by gas discharge can decompose carbon dioxide into carbon monoxide and oxygen. In this embodiment, the main pipe 1, the conductive metal rod 3 and the ground electrode 2 form a dielectric barrier discharge device, wherein the conductive metal rod 3 includes a brass rod as a high-voltage electrode, and of course it can also be other metal electrodes. It should be understood that the two ends of the main pipe 1 are sealed with vacuum pipe joints, and the carbon dioxide gas flow enters the main pipe 1 from the air inlet 4, performs dielectric barrier discharge, and decomposes into carbon monoxide and oxygen. However, since oxygen and carbon monoxide are extremely unstable, carbon monoxide and oxygen will be compounded into stable carbon dioxide during the discharge process, thereby reducing the conversion efficiency of carbon dioxide.

The carbon dioxide decomposition device of this embodiment continuously separates oxygen during the carbon dioxide decomposition process. Compared with the prior art method of improving the carbon dioxide conversion efficiency based on changing external conditions (such as increasing the filling medium, changing the material morphology of the high-voltage electrode, etc.), it greatly simplifies the operation of later oxygen purification and avoids the recombination of carbon monoxide and oxygen decomposed from carbon dioxide, thereby improving the carbon dioxide conversion efficiency.

Due to the presence of a single electron in the oxygen molecule, it exhibits paramagnetism, while carbon dioxide and carbon monoxide both exhibit diamagnetic properties under magnetic field conditions. According to relevant research, assuming that the relative magnetic susceptibility of oxygen is 100, the relative magnetic susceptibility of carbon dioxide is -0.57. Therefore, carbon dioxide is extremely difficult to magnetize, while oxygen is an easily magnetizable body. Therefore, a magnetic field can be used to separate oxygen from carbon monoxide and carbon dioxide.

In this embodiment, a branch pipe 6 is provided on the main pipe 1 , and a magnetic field is provided outside the main pipe 1 , so that the Lorentz force generated by the magnetic field on oxygen is used to deflect the airflow path of oxygen, and then separate it from the branch pipe 6 .

Therefore, unlike the traditional dielectric barrier discharge device for decomposing carbon dioxide, the carbon dioxide decomposition device of this embodiment uses the magnetic field generated by the magnetic field generating device to exert force on oxygen, so that the oxygen path is deflected and separated from the branch pipe 6, thereby realizing continuous extraction and separation of oxygen during the carbon dioxide decomposition process, avoiding the recombination of oxygen and carbon monoxide, and thus improving the carbon dioxide conversion efficiency.

In some embodiments, the magnetic field generating device includes an iron rod 8 and a conductive coil wound on the iron rod 8, the conductive coil is suitable for connecting to a DC power supply, and the conductive coil is preferably a copper coil. The iron rod 8 is arranged on the outside of the main pipe 1. Preferably, the iron rod 8 is arranged opposite to the connection between the branch pipe 6 and the main pipe 1. By winding the copper coil on the iron rod 8 and energizing the copper coil to generate current, a magnetic field is formed. And because the iron rod 8 is opposite to the connection between the branch pipe 6 and the main pipe 1, that is, the iron rod 8 is perpendicular to the main pipe 1, a vertical magnetic field is formed, and the magnetic field force on the oxygen gas flow in the main pipe 1 is the largest. When the oxygen generated by decomposition in the main pipe 1 passes through the connection between the branch pipe 6 and the main pipe 1, the oxygen path is deflected by the vertical magnetic field and enters the branch pipe 6. Preferably, the diameter of the iron rod 8 is the same as the diameter of the connection between the branch pipe 6 and the main pipe 1. Thus, it is ensured that the oxygen can be separated out in time under the force of the magnetic field.

In some of the embodiments, two straight pipe channels are respectively provided at a certain distance near both ends of the main pipe 1 as an air inlet 4 and an air outlet 5. Since the distance that carbon dioxide passes through in the main pipe 1 is relatively long, a plurality of branch pipes 6 are spaced apart along the axial direction of the main pipe 1 so that oxygen can be separated at different stages of the carbon dioxide decomposition process. In addition, the number of iron rods 8 is the same as that of branch pipes 6, and a plurality of iron rods 8 are connected in parallel in the DC circuit, so that each branch pipe 6 can be subjected to the magnetic field at the connection with the main pipe 1.

In some implementations, since the concentration of oxygen is constantly decreasing during the separation process, it is necessary to adjust the corresponding magnetic field strength to maintain the separation efficiency, so the magnetic field strength needs to be increased accordingly as the oxygen concentration decreases. Therefore, the magnetic field generating device in this embodiment also includes a sliding rheostat 7, which is connected in series with the iron rod 8, and multiple sliding rheostats 7 are connected in parallel in the DC circuit. Therefore, by changing the resistance value of each sliding rheostat 7 in the parallel circuit, the current in each parallel circuit can be changed to achieve a gradient current, thereby achieving a gradient magnetic field.

The magnetic field generating device of this embodiment includes an iron rod 8, a conductive coil and a sliding rheostat 7. By connecting the iron rod 8 and the sliding rheostat 7 in series and then connecting them in parallel to a DC circuit, during the decomposition process of carbon dioxide, the magnetic field strength can be adjusted accordingly according to the change in oxygen concentration in the main pipe 1, thereby achieving a higher oxygen separation efficiency throughout the process.

When the carbon dioxide gas flow rate is 30-50 ml/min, the vertical magnetic field generates a Lorentz force on the oxygen to deflect its path. Relevant calculations show that the curvature of the oxygen deflection is about 25°-40°. Therefore, preferably, the angle between the branch pipe 6 and the main pipe 1 is set to 25°-40° to be consistent with the oxygen deflection angle for better oxygen separation.

In some embodiments, as shown in Fig. 2, the magnetic field generating device may also include a magnet 9, which is arranged parallel to the main pipe 1, and the side of the magnet 9 close to the main pipe 1 is an S pole. Preferably, the magnet 9 is a neodymium iron boron magnet.

In some of the embodiments, the ground electrode 2 includes an ITO (tin-doped indium oxide) film disposed on the outer wall of the main pipe 1. Since the ITO film is transparent, the present embodiment uses the ITO film as the ground electrode 2 to visualize the discharge process of carbon dioxide. Thus, the emission spectra of different positions of the main pipe 1 are collected using an emission spectrometer, and the dynamic conversion law of carbon dioxide is analyzed by analyzing the strength of the characteristic peaks in the emission spectrum. The conventional method of analyzing the carbon dioxide conversion product usually requires analysis by a gas chromatography-mass spectrometer, which requires a precise pumping device and is too large and expensive to be suitable for industrialization. The present device has a simple structure and can be dynamically monitored by a portable emission spectrometer, and has good portability.

The following is an explanation through specific embodiments.

Example 1

As shown in FIG. 1 , the main pipe 1 in FIG. 1 is a quartz glass tube with a length of 1000 mm, an outer diameter of 50 mm, and an inner diameter of 45 mm. A layer of ITO film with a thickness of 0.05 mm is attached to the outer side of the glass tube as a ground electrode 2. A brass rod with a length of 1200 mm and a diameter of 20 mm is inserted in the middle of the glass tube as a high-voltage electrode. The copper rod and the glass tube are sealed by a vacuum pipe joint to form a dielectric barrier discharge device. Two straight tube channels with an outer diameter of 30 mm and a wall thickness of 2 mm are opened at 50 mm near the pipe joint of the glass rod as an air inlet 4 and an air outlet 5. A thin glass tube with a certain angle to the glass tube is opened on one side of the glass tube between the air inlet 4 and the air outlet 5 as a branch pipe 6 for separating oxygen. The thin glass tube is 100 mm long, 10 mm in outer diameter, and 2 mm in wall thickness. The interval between each thin glass tube is 150 mm.

A magnetic field is set on one side of the separation point between each thin glass tube and the main tube 1 for separating oxygen. The magnetic field is formed by winding a copper coil on an iron rod 8 and giving the copper coil current. The diameter of the iron rod 8 is consistent with the diameter of the main tube 1 and the thin glass tube at the angle. At a distance of 5 cm from the thin glass tube, the iron rod 8 is perpendicular to the main tube 1 and all the iron rods 8 are connected in parallel in a DC circuit. A gradient current is realized by a sliding rheostat 7, and finally a gradient magnetic field is realized.

Example 2

The difference between this embodiment and embodiment 1 lies in the difference in the magnetic field generating device. As shown in FIG2 , the NdFeB magnet is located on the side of the glass tube close to the thin glass tube and parallel to the glass tube. The magnetic field strength of the magnet 9 is 0.5 Tesla, and the side close to the glass tube is the S pole. A thin glass tube with an angle of 30° with the glass tube is opened on one side of the glass tube between the air inlet 4 and the air outlet 5.

Although the disclosure is disclosed as above, the protection scope of the disclosure is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the disclosure, and these changes and modifications will fall within the protection scope of the present invention.

Claims (10)

1. A carbon dioxide decomposition device, comprising:

the main pipe (1), the sidewall of the main pipe (1) is provided with an air inlet (4) and an air outlet (5) which are suitable for carbon dioxide to enter and exit respectively;

the branch pipe (6) is arranged on the main pipe (1) between the air inlet (4) and the air outlet (5);

A conductive metal rod (3), wherein the conductive metal rod (3) is arranged inside the main pipe (1);

A ground electrode (2), wherein the ground electrode (2) is arranged outside the main pipe (1);

the magnetic field generating device is arranged on the outer side of the main pipe (1) and is used for generating a magnetic field so as to separate oxygen generated by decomposing the carbon dioxide in the main pipe (1) from the branch pipe (6).

2. The carbon dioxide decomposition apparatus according to claim 1, wherein the number of the branch pipes (6) is plural, and the plurality of branch pipes (6) are provided at intervals in the axial direction of the main pipe (1) on the outer wall of the main pipe (1).

3. The carbon dioxide decomposition apparatus according to claim 2, wherein the magnetic field generating means comprises an iron rod (8) and a conductive coil wound around the iron rod (8), the iron rod (8) being provided outside the main pipe (1), the conductive coil being connected to a direct current power supply.

4. A carbon dioxide decomposition apparatus according to claim 3, wherein the number of the iron rods (8) is the same as the branch pipe (6), and a plurality of the iron rods (8) are connected in parallel in a direct current circuit.

5. The carbon dioxide decomposition apparatus according to claim 4, wherein the magnetic field generating apparatus further comprises a slide rheostat (7), the slide rheostat (7) is connected in series with the iron rod (8), and a plurality of the slide rheostats (7) are connected in parallel in the direct current circuit.

6. A carbon dioxide decomposition apparatus according to claim 3, wherein the iron rod (8) is disposed directly opposite to the junction of the branch pipe (6) and the main pipe (1).

7. The carbon dioxide decomposition apparatus according to claim 6, wherein the diameter of the iron rod (8) is the same as the diameter of the junction of the branch pipe (6) and the main pipe (1).

8. The carbon dioxide decomposition device according to claim 1, wherein the angle between the branch pipe (6) and the main pipe (1) is 25 ° -40 °.

9. The carbon dioxide decomposition apparatus according to any one of claims 1 to 8, wherein the ground electrode (2) comprises an ITO thin film provided on an outer wall of the main tube (1).

10. The carbon dioxide decomposition apparatus according to claim 1, wherein the magnetic field generating means comprises a magnet (9) which is disposed parallel to the main pipe (1), and one side of the magnet near the main pipe (1) is an S-pole.