Tubular adsorption fixed bed for capturing carbon dioxide

Abstract

The utility model discloses a tubular adsorption fixed bed for capturing carbon dioxide, which comprises a barrel and a material tube bundle, and the bottom of the barrel is provided with a discharge port, a gas inlet, a cold medium inlet and a hot medium outlet; a baffling tube plate is arranged at the middle section of the barrel; a hot medium inlet, a cold medium outlet, a gas outlet, a filling opening and a fixed tube plate are arranged at the top of the barrel; the material tube bundle is arranged in the middle of the cylinder body; based on an existing adsorption fixed bed, redesign is carried out, a shell-and-tube structure is adopted, the heat exchange efficiency can be effectively improved, a large temperature gradient cannot be generated, meanwhile, the problems of gas short circuit and non-uniform gas distribution in an adsorption bed layer are effectively solved, and the gas-solid contact efficiency is improved.

Description

Technical Field

[0001] The utility model relates to chemical equipment and environmental protection equipment for separation and purification processes, and in particular to a tube-in-tube adsorption fixed bed for capturing carbon dioxide. Background Art

[0002] A report by the International Energy Agency (IEA) shows that in the next 50 years, the use of CCUS technology to transform chemical, steel and cement plants can reduce carbon dioxide emissions by 600 billion tons, equivalent to 17 times the current annual emissions.

[0003] In carbon capture technology, the adsorption separation method has great potential in industrial carbon capture applications due to its advantages such as simple equipment, convenient operation, high degree of automation, no equipment corrosion and environmental pollution, low investment and low consumption. However, the traditional adsorption bed has poor heat exchange effect, uneven distribution of gas in the bed during adsorption, and easy short circuit. At present, there are two methods to solve the poor heat exchange effect in industry: setting a heater inside or outside the adsorption bed for indirect heating, and heating the purge gas without adsorbent after heating and passing it into the adsorbent bed for direct heating. In the above two methods, indirect heating has the problem of poor thermal conductivity and large temperature gradient in the bed; direct heating has the problem of secondary separation after carbon dioxide desorption. For the problem of uneven distribution of gas in the bed and easy short circuit, the industry usually adopts the method of reasonably setting gas distributors and controlling gas velocity. This method reduces the occurrence of this phenomenon to a certain extent, but it still needs to be further transformed through technology to solve the problem of gas short circuit and improve the contact efficiency of gas and solid.

[0004] In view of the shortcomings of the existing technology, it is necessary to develop a tube-in-tube adsorption fixed bed for carbon dioxide capture to address the problems of poor heat and mass transfer in traditional adsorption beds. Utility Model Content

[0005] Based on the above content, the purpose of the utility model is to provide a tube-in-tube adsorption fixed bed for carbon dioxide capture, which redesigns the structure based on the existing adsorption fixed bed and greatly improves the heat transfer and mass transfer effects of the equipment.

[0006] The technical solution adopted by the utility model is as follows: a tube-in-tube adsorption fixed bed for carbon dioxide capture, characterized in that it includes a cylinder and a material tube bundle; the bottom of the cylinder is provided with a discharge port, a gas inlet, and a gas distributor, and the gas distributor is fixedly connected to the gas inlet; the space at the bottom of the cylinder is filled with glass beads; the bottom of the cylinder is also provided with a cold medium inlet and a hot medium outlet, which are distributed at 180° intervals; the middle section of the cylinder is evenly arranged with baffle tube plates; the top of the cylinder is provided with a hot medium inlet and a cold medium outlet, which are distributed at 180° intervals; the top of the cylinder is also provided with a gas outlet and a filler port;

[0007] The material tube bundle is distributed inside the cylinder, the middle section of the material tube bundle is connected to the baffle tube sheet, and both ends are fixedly connected to the fixed tube sheet.

[0008] The bottom of the cylinder adopts a triangular head to facilitate unloading; the glass beads filled in the head space at the bottom of the cylinder are used to evenly distribute the gas.

[0009] The shell space between the cylinder and the material tube bundle provides a heat exchange space.

[0010] The material tube bundle is filled with adsorbent to provide adsorption and desorption space.

[0011] Radial fins may also be provided on the outside of the material tube bundle to improve the heat transfer effect.

[0012] The fixed tube sheet of the adsorption fixed bed is connected and fixed to the outer cylinder by welding.

[0013] The baffle tube plates of the adsorption fixed bed are arched baffle plates, which are used to increase the flow rate of cold and hot fluids, enhance the heat transfer effect, and support the material tube bundle.

[0014] The gas outlet is provided with a bypass for connecting a carbon dioxide detector.

[0015] The working process of the process device of the utility model is explained as follows:

[0016] (1) During the adsorption operation, the heat medium inlet and the heat medium outlet are closed, and the gas inlet and the gas outlet are opened, and the gas is introduced into the material tube bundle to fully contact with the adsorbent for adsorption, and the adsorbed gas is discharged from the gas outlet, and then the cold medium inlet and the cold medium outlet are opened, and room temperature fluid is introduced to keep the bed temperature of the fixed bed constant during the adsorption process;

[0017] (2) When performing the desorption operation, the gas inlet, gas outlet, cold medium inlet and cold medium outlet are closed, the hot medium outlet and hot medium inlet are opened, and hot fluid is introduced to heat the adsorbent in the material tube bundle to the desorption temperature. Subsequently, the hot medium outlet and hot medium inlet are closed, the cold medium outlet and cold medium inlet are opened, and fluid at the desorption temperature is introduced to keep the temperature of the fixed bed layer constant during the desorption process. The gas outlet is opened, and the desorbed carbon dioxide enters the downstream operation unit through the gas outlet.

[0018] The advantages of the utility model are:

[0019] 1. The utility model adopts a shell-and-tube structure, which can increase the heat transfer area per unit volume. The baffle tube sheet in the utility model can increase the turbulence of the fluid, improve the heat transfer efficiency, and support the material tube bundle. Therefore, the utility model can effectively improve the heat exchange efficiency of the adsorption bed while achieving uniform temperature inside the bed without generating a large temperature gradient.

[0020] 2. The hot medium inlet and outlet and the cold medium inlet and outlet of the utility model can achieve a constant bed temperature during the desorption process by introducing hot and cold fluids.

[0021] 3. The utility model adopts a material tube bundle as the gas-solid contact space, which effectively solves the problems of gas short circuit and uneven gas distribution in the adsorption bed and improves the gas-solid contact efficiency.

[0022] 4. The lower end cap of the utility model adopts a conical end cap and is provided with a discharge port, which can improve the discharge efficiency and make the adsorbent unload more fully.

[0023] 5. The air intake space of the utility model is filled with glass beads, which can achieve uniform gas distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are described as follows:

[0025] Figure 1 This is a schematic diagram of the structure of an adsorption fixed bed for capturing carbon dioxide in the utility model;

[0026] In the figure, 1-discharging port, 2-glass beads, 3-cold medium inlet, 4-outer cylinder, 5-hot medium inlet, 6-filling port, 7-gas outlet, 8-fixed tube sheet, 9-cold medium outlet, 10-baffle tube sheet, 11-material tube bundle, 12-hot medium outlet, 13-gas inlet. DETAILED DESCRIPTION

[0027] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0028] The following is a specific embodiment to illustrate the implementation method of the present invention. People familiar with the technology can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0029] Referring to the drawings, the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the utility model, so they have no substantial technical significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the effects and purposes that can be achieved by the utility model, should still fall within the scope of the technical content disclosed by the utility model. At the same time, the position limiting terms quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the utility model. The change or adjustment of the relative relationship, without substantial change in the technical content, should also be regarded as the scope of the implementation of the utility model.

[0030] Figure 1 The structure diagram of the carbon dioxide capture adsorption fixed bed of the utility model; the carbon dioxide capture tube-type adsorption fixed bed of the utility model comprises a cylinder 4 and a material tube bundle 11; the bottom of the cylinder 4 is provided with a discharge port 1, a gas inlet and a gas distributor 13, and the gas distributor is fixedly connected to the gas inlet; the bottom space of the cylinder 4 is filled with glass beads 2; the bottom of the cylinder 4 is also provided with a cold medium inlet 3 and a hot medium outlet 12, which are distributed at 180° intervals; the middle section of the cylinder 4 is evenly arranged with baffle tube plates 10; the top of the cylinder 4 is provided with a hot medium inlet 5 and a cold medium outlet 9, which are distributed at 180° intervals; the top of the cylinder 4 is also provided with a gas outlet 7 and a filler port 6; the material tube bundle 11 is distributed inside the cylinder 4, the middle section of the material tube bundle 11 is connected to the baffle tube plate 10, and the two ends are fixedly connected to the fixed tube plate 8. The material tube bundle 11 is filled with adsorbent.

[0031] The working process of the fixed bed adsorption for carbon dioxide capture of the utility model is as follows:

[0032] (1) When performing adsorption operation, the hot medium inlet 5, the hot medium outlet 11, the cold medium inlet 3, and the cold medium outlet 8 are closed, and the gas inlet 1 and the gas outlet 6 are opened, and the gas is passed into the material tube bundle 10 to fully contact with the adsorbent for adsorption. The adsorbed gas is discharged from the gas outlet 6, and then the cold medium inlet 3 and the cold medium outlet 8 are opened, and room temperature fluid is passed to keep the bed temperature of the fixed bed constant during the adsorption process;

[0033] (2) When performing the desorption operation, the gas inlet 1, the gas outlet 6, the cold medium inlet 3 and the cold medium outlet 8 are closed, the hot medium inlet 5 and the hot medium outlet 11 are opened, and a hot fluid is introduced to heat the adsorbent in the material tube bundle 10 to the desorption temperature. Subsequently, the hot medium inlet 5 and the hot medium outlet 11 are closed, the cold medium outlet 8 and the cold medium inlet 3 are opened, and a fluid at the desorption temperature is introduced to keep the temperature of the fixed bed layer constant during the desorption process. The gas outlet 6 is opened, and the desorbed carbon dioxide enters the downstream operation unit through the gas outlet 6.

[0034] Although the specific implementation methods of the utility model are described above in conjunction with the accompanying drawings, they are not limited to the protection scope of the utility model. Technical personnel in the relevant field should understand that based on the technical solution of the utility model, technical personnel in this field can modify or deform various equivalent structures or equivalent processes of the utility model without creative work, or directly or indirectly apply them to other related technical fields, which still falls within the protection scope of the utility model.

Claims

1. A tube-in-tube fixed bed for carbon dioxide capture, comprising a cylinder (4) and a material tube bundle (11); characterized in that: The bottom of the cylinder is provided with a discharge port (1), a gas inlet and a gas distributor (13), and the gas inlet is fixedly connected to the gas distributor; the bottom head space of the cylinder (4) is filled with glass beads (2); the bottom of the cylinder (4) is also provided with a cold medium inlet (3) and a hot medium outlet (12), which are distributed at an interval of 180 degrees; the top of the cylinder (4) is provided with a hot medium inlet (5) and a cold medium outlet (9), which are distributed at an interval of 180 degrees; the material tube bundle (11) is distributed in parallel in multiple tubes inside the cylinder (4), the middle section of the material tube bundle (11) is connected to the baffle tube sheet (10), and the two ends are fixedly connected to the fixed tube sheet (8).

2. The tube-type adsorption fixed bed for carbon dioxide capture according to claim 1, characterized in that The top end of the cylinder (4) is provided with a filling port (6) and a gas outlet (7).

3. The tube-type adsorption fixed bed for carbon dioxide capture according to claim 1, characterized in that The baffle tube plates (10) are evenly arranged in the middle section of the cylinder (4).

4. The tube-type adsorption fixed bed for carbon dioxide capture according to claim 1 is characterized in that The baffle tube plate (10) is mutually supported by the cylinder (4) and the material tube bundle (11).

5. The tube-type adsorption fixed bed for carbon dioxide capture according to claim 1 is characterized in that The fixed tube sheet (8) is fixedly connected to the cylinder (4).

6. The tube-type adsorption fixed bed for carbon dioxide capture according to claim 1, characterized in that The bottom end cap of the cylinder (4) is filled with glass beads (2).

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