Temperature swing adsorption type device for capturing carbon dioxide in flue gas

Abstract

The utility model provides a temperature swing adsorption type device for capturing carbon dioxide in flue gas, which overcomes the defects of long adsorption time, high equipment cost and low carbon dioxide release efficiency of the existing temperature swing adsorption process equipment, and improves the operation efficiency of the capturing device by adding a cold and heat adjusting air inlet unit. And the carbon dioxide desorption efficiency is improved by using the pressurizing unit, so that the carbon capture efficiency is improved, and the capture cost is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of carbon dioxide gas capture, and in particular relates to a temperature-variable adsorption type flue gas carbon dioxide capture device. Background Art

[0002] As global climate change intensifies, reducing greenhouse gas emissions has become an important issue of global concern. Carbon dioxide is one of the most important greenhouse gases, so the development of carbon dioxide capture technology is of great significance for mitigating climate change. There are three main ways to capture carbon dioxide: pre-combustion capture, oxygen-enriched combustion, and post-combustion capture.

[0003] Post-combustion CO2 capture technology is flexible in operation and has the advantages of high capture rate and low energy consumption compared with other capture technologies. As one of the key carbon capture technologies, post-combustion CO2 capture is an important key factor in achieving the goal of carbon neutrality. There are many types of post-combustion capture technologies, which are highly targeted and mainly include adsorption, absorption, membrane separation and cryogenic distillation.

[0004] At present, the adsorption process mainly includes pressure swing adsorption, vacuum swing adsorption and temperature swing adsorption. For the temperature swing adsorption system, the design of the chemical adsorbent allows CO2 to be absorbed on a large solid surface at room temperature and desorbed at a higher temperature (usually 80℃-150℃). However, the existing temperature swing adsorption process equipment is limited by the heat transfer rate of the system, and the heating and cooling time is relatively long, which leads to a relatively long cycle of temperature swing adsorption of carbon dioxide. At the same time, there is also a problem of low efficiency when releasing carbon dioxide.

[0005] In view of this, the present invention considers it necessary to improve the existing temperature swing adsorption process equipment. Summary of the invention

[0006] The utility model aims to solve the shortcomings of the existing temperature swing adsorption process equipment, such as long adsorption time, high equipment cost and low carbon dioxide release efficiency, and to provide a new temperature swing adsorption flue gas carbon dioxide capture device.

[0007] The inventive concept of the utility model:

[0008] In view of the problem that the existing temperature-swing adsorption process equipment has a long carbon dioxide adsorption cycle, the utility model analyzes the cause of this problem and finds that the main reason for this problem is that after the internal radiation tube in the existing process equipment heats the interior, the temperature of the adsorption structure and the device is too high, and the cooling speed is slow. The adsorption structure with a higher temperature has a poor adsorption effect on carbon dioxide, so it takes a long time to perform normal adsorption; and when releasing carbon dioxide, it only relies on high-temperature desorption, which is a relatively simple method, so there is a problem of low release efficiency. To this end, the utility model intends to improve the operating efficiency of the capture device by using a cold and hot air intake unit, and use a booster device (such as a vacuum pump) to increase the CO2 desorption rate to improve the carbon capture efficiency and reduce the cost of carbon capture.

[0009] Based on the above invention concept, in order to achieve the above purpose, the technical solution provided by the utility model is:

[0010] A temperature-swing adsorption type flue gas carbon dioxide capture device, which is special in that it includes a carbon dioxide adsorption and desorption tank, an adsorption unit, a cold and hot air intake unit, a booster unit and a carbon dioxide storage tank;

[0011] The tank bottom of the carbon dioxide adsorption and desorption tank is provided with a flue gas inlet pipe (for connecting to a flue gas source), the tank top is provided with a first pressure gauge and a residual gas outlet pipe connected to the external atmosphere, and the tank body is provided with a carbon dioxide exhaust pipe connected to a carbon dioxide storage tank;

[0012] A first switch valve is provided on the flue gas inlet pipe; a second switch valve and a carbon dioxide concentration detector are provided on the residual gas outlet pipe along the outlet direction; a third switch valve is provided on the carbon dioxide exhaust pipe; the first switch valve is used to control the entry of flue gas, the second switch valve is used to control the discharge of residual gas, and the third switch valve is used to control the discharge of desorbed carbon dioxide;

[0013] The adsorption unit comprises N partitions filled with carbon dioxide adsorption material, and the N partitions are sequentially arranged from top to bottom in the tank body of the carbon dioxide adsorption and desorption tank; wherein N is a positive integer;

[0014] The shape of the partition is the same as the cross-sectional shape of the carbon dioxide adsorption and desorption tank, and the radial dimension is smaller than the radial dimension of the carbon dioxide adsorption and desorption tank;

[0015] The hot and cold air intake unit comprises a fan, an electric heating chamber, a cold air chamber, a radiation pipe network and a temperature sensor;

[0016] The radiation pipe network is installed on the inner wall of the carbon dioxide adsorption and desorption tank, leaving a gap between the radiation pipe network and the partition net, and is used to heat or cool the carbon dioxide adsorption material in the partition net;

[0017] The fan is used to introduce air into the hot and cold regulating air intake unit, and its outlet is connected to the inlet of the electric heating chamber and the cold air chamber at the same time; the outlets of the electric heating chamber and the cold air chamber are connected to the inlet of the radiation pipe network at the same time, and a fourth switch valve and a fifth switch valve are respectively provided between the outlets of the two and the inlet of the radiation pipe network; the outlet of the radiation pipe network is connected to the external atmosphere, and a sixth switch valve is provided on the air outlet pipe of the radiation pipe network; that is, the external air is introduced through the fan, heated by the electric heating chamber or cooled to a specified temperature by the cold air chamber, and then enters the radiation pipe network to heat or cool the carbon dioxide adsorbent in the partition net so as to desorb and adsorb carbon dioxide; of course, the hot air in the radiation pipe network can also be reused, and the hot air with residual temperature can be returned to the air inlet of the electric heating chamber by designing a return pipe and a switch valve to reduce energy consumption;

[0018] The temperature sensor is arranged on the electric heating chamber and is used to observe the air supply temperature of the electric heating chamber in real time;

[0019] The pressurizing unit is connected to the carbon dioxide adsorption and desorption tank and is used to increase the vacuum degree in the carbon dioxide adsorption and desorption tank to promote the desorption of carbon dioxide.

[0020] The aforementioned carbon dioxide concentration detector is preferably installed at a position near the tank body of the residual gas outlet pipe, so as to judge the adsorption state of the carbon dioxide adsorbent material and the residual carbon dioxide in the flue gas after treatment. When the carbon dioxide content in the residual gas outlet pipe is similar to that in the flue gas, it indicates that the carbon dioxide adsorbent material has reached a saturated state. At this time, it is necessary to close the connection between the device and the flue gas source (i.e., the first switch valve) to desorb the carbon dioxide adsorbent material. In order to avoid misdischarge, the residual gas containing carbon dioxide can also be refluxed to the flue gas inlet pipe for reprocessing by designing a reflux pipe and a switch valve.

[0021] Furthermore, the boosting unit is a vacuum pump.

[0022] Furthermore, the outlets of the electric heating chamber and the cold air chamber are connected to the inlet of the radiation pipe network through a three-way pipe.

[0023] Furthermore, the radiation pipe network is laid along the circumferential inner wall of the carbon dioxide adsorption and desorption tank.

[0024] Furthermore, in order to make the layout of the entire capture device more reasonable, the inlet of the radiation pipe network is located at the lower side of the carbon dioxide adsorption and desorption tank body, and the outlet is located at the upper side of the carbon dioxide adsorption and desorption tank body.

[0025] Furthermore, the carbon dioxide exhaust pipe is located on the upper side of the carbon dioxide adsorption and desorption tank body;

[0026] The tank body of the carbon dioxide storage tank is provided with a second pressure gauge to monitor the pressure inside the tank.

[0027] Furthermore, the pore size of the separator is 10 mm; the carbon dioxide adsorbent filled in the separator is a molecular sieve, using spherical particles with a pore size of 10A. The carbon dioxide adsorbent statically adsorbs CO2 at 25±1°C and desorbs CO2 at around 130°C. At the same time, the adsorption performance of the molecular sieve can be regenerated after high-temperature desorption, so it can be recycled through regeneration treatment; of course, other types of carbon dioxide adsorbents can also be selected.

[0028] Furthermore, the carbon dioxide adsorption and desorption tank is cylindrical, the tank body is made of stainless steel, and is provided with a heat insulation layer, and the maximum pressure resistance is about 10MPa. Different temperatures and pressure conditions have an impact on the pressure resistance of the carbon dioxide adsorption and desorption tank. Accordingly, the partition net is disc-shaped, and the number of layers can be reasonably allocated according to the size of the tank body.

[0029] The advantages of the utility model are:

[0030] 1. The utility model provides a temperature-variable adsorption type flue gas carbon dioxide capture device, which improves the operating efficiency of the capture device by adding a cold and hot regulating air intake unit, solves the problem of long adsorption cycle, combines heat regulation (i.e., heating chamber) with a booster unit to improve the desorption effect of carbon dioxide, and improves the carbon capture efficiency, reduces the carbon capture cost, and improves the utilization rate of thermal energy through the carbon dioxide desorption rate.

[0031] 2. The capture device designed based on the temperature-variable adsorption method of the utility model has a simple structure, is easy to operate, easy to manufacture, and has a low cost. The adsorption of carbon dioxide and the desorption of the solid adsorbent can be completed through a single reactor, which greatly reduces the number of equipment and investment, ensures efficient adsorption effect, and improves the separation efficiency of carbon dioxide.

[0032] 3. In the utility model, the cold and hot air intake unit is reasonably designed to take into account both heating and cooling functions, and assist the carbon dioxide adsorption material to achieve the capture and desorption of carbon dioxide in the flue gas.

[0033] 4. The molecular sieve used as the absorbent in the utility model can be regenerated and recycled, and has a long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the structure of the temperature-swing adsorption type carbon dioxide flue gas capture device of the utility model;

[0035] Figure 2 It is a schematic diagram of the front cross-section structure of the temperature-variable adsorption carbon dioxide flue gas capture device of the utility model.

[0036] The reference numerals are as follows:

[0037] 1-carbon dioxide adsorption and desorption tank, 2-smoke inlet pipe, 3-residual gas outlet pipe, 4-carbon dioxide exhaust pipe, 5-radiation pipe network inlet pipe, 6-radiation pipe network outlet pipe, 7-radiation pipe network, 8-partition net, 9-electric heating chamber, 10-cold air chamber, 11-tee pipe, 12-vacuum pump, 13-fan, 14-first switch valve, 15-second switch valve, 16-third switch valve, 17-fifth switch valve, 18-fourth switch valve, 19-sixth switch valve, 20-carbon dioxide adsorption material, 21-carbon dioxide storage tank, 22-first pressure gauge, 23-carbon dioxide concentration detector, 24-air pump, 25-second pressure gauge. DETAILED DESCRIPTION

[0038] The following is a further detailed description of the present invention in conjunction with the accompanying drawings and specific embodiments:

[0039] like Figure 1 and Figure 2 As shown, the temperature-swing adsorption flue gas carbon dioxide capture device includes a carbon dioxide adsorption and desorption tank, an adsorption unit, a cold and hot regulating air intake unit, a booster unit and a carbon dioxide storage tank.

[0040] The carbon dioxide adsorption and desorption tank is cylindrical, the tank body is made of stainless steel, and is provided with a heat insulation layer, and the maximum pressure resistance is about 10MPa. The bottom of the carbon dioxide adsorption and desorption tank is provided with a flue gas inlet pipe, the top of the tank is provided with a first pressure gauge and a residual gas outlet pipe connected to the external atmosphere, and the upper side of the tank body is provided with a carbon dioxide exhaust pipe connected to the carbon dioxide storage tank. Among them, the flue gas inlet pipe is connected to the flue gas source (i.e., the flue gas generating device), and a first switch valve is provided on it to control the entry of flue gas; the residual gas outlet pipe is provided with a second switch valve for controlling the discharge of residual gas and a carbon dioxide concentration detector for detecting the carbon dioxide concentration in the residual gas. When the carbon dioxide content in the exhaust gas is higher than 5%, the residual gas needs to be connected to the flue gas inlet pipe through a pipeline for secondary adsorption; the carbon dioxide exhaust pipe is provided with a third switch valve and an air pump to control the discharge of the desorbed carbon dioxide into the carbon dioxide storage tank; the carbon dioxide storage tank is provided with a second pressure gauge.

[0041] The adsorption unit includes four (the number can be reasonably allocated according to the size of the tank body) partitions filled with molecular sieves. The four partitions are arranged in the tank body of the carbon dioxide adsorption and desorption tank from top to bottom in sequence. The shape of the partitions is disc-shaped and the radial dimension is smaller than the radial dimension of the carbon dioxide adsorption and desorption tank; the pore size of the partitions is 10mm; the molecular sieve adopts spherical particles with a pore size of 10A, which is an alkali metal aluminosilicate, which statically adsorbs CO2 at 25±1℃ and desorbs CO2 at about 130℃. At the same time, the adsorption performance of the molecular sieve can be regenerated after high-temperature desorption, so it can be recycled through regeneration treatment.

[0042] The heat and cold regulating air intake unit includes a temperature sensor, a fan, an electric heating chamber, a cold air chamber and a radiation pipe network. The radiation pipe network is fully laid along the circumferential inner wall of the carbon dioxide adsorption and desorption tank, and a gap is left between the radiation pipe network and the partition network. The fan is used to introduce air into the cold and hot air intake unit, and its outlet is connected to the inlet of the electric heating chamber and the cold air chamber at the same time; the outlet of the electric heating chamber and the cold air chamber is connected to the inlet of the radiation pipe network through a three-way pipe, and the outlet of the electric heating chamber and the cold air chamber is respectively provided with a fourth switch valve and a fifth switch valve; the outlet pipe of the radiation pipe network can be connected to the air inlet of the electric heating air chamber through a pipeline to reuse the residual heat of the residual air, and the outlet pipe of the radiation pipe network is provided with a sixth switch valve; that is, the external air is introduced through the fan, heated by the electric heating chamber or cooled by the cold air chamber (according to the current weather temperature, when the temperature is low, the external air can be introduced by cooling) to the specified temperature, and then enters the radiation pipe network, and heats or cools the molecular sieve in the partition net (in order to heat the molecular sieve to the desorption temperature or cool it to the adsorption temperature) so as to desorb and adsorb carbon dioxide. The temperature sensor is arranged on the electric heating chamber to observe the air supply temperature of the electric heating chamber in real time.

[0043] The booster unit is used to increase the vacuum degree in the carbon dioxide adsorption and desorption tank to promote carbon dioxide desorption, so as to improve the efficiency of temperature swing adsorption. The booster unit in this embodiment is a vacuum pump, which is connected to the carbon dioxide adsorption and desorption tank.

[0044] In order to make the layout of the entire capture device more reasonable and beautiful, the inlet of the radiation pipe network is located at the lower side of the carbon dioxide adsorption and desorption tank body, and the outlet is located at the upper side of the carbon dioxide adsorption and desorption tank body.

[0045] The capture principle is:

[0046] During adsorption, the flue gas enters the tank, flows through the screen, contacts the adsorbent on it and absorbs the carbon dioxide in the flue gas;

[0047] During desorption, high-temperature gas is transported to the radiation pipe network located in the tank body through the electric heating chamber, so that the radiation pipe network is heated and maintained at about 130°C. At the same time, the tank body is evacuated by a vacuum pump. After the adsorbed carbon dioxide is desorbed and accumulated into high-concentration carbon dioxide gas, the air pump is started to discharge it through the carbon dioxide exhaust port and collected in the carbon dioxide storage tank, thereby achieving the purpose of capturing carbon dioxide.

[0048] The working process is as follows:

[0049] The first switch valve 14 and the second switch valve 15 are opened, and the third switch valve 16, the fourth switch valve 18, the fifth switch valve 17 and the sixth switch valve 19 are closed; the flue gas enters the carbon dioxide adsorption and desorption tank 1, passes through the layers of separation nets 8 and contacts with the molecular sieve to absorb the carbon dioxide in the flue gas;

[0050] When the carbon dioxide concentration detector detects that the carbon dioxide concentration at the residual gas outlet pipe gradually increases, the molecular sieve gradually reaches a saturated state. When the carbon dioxide concentration at the residual gas outlet pipe is equivalent to the carbon dioxide concentration in the flue gas, the molecular sieve reaches a saturated state; at this time, the first switch valve 14 and the second switch valve 15 are closed, the fourth switch valve 18 and the sixth switch valve 19 are opened, and the fan 13 is started, and high-temperature gas is blown into the radiation pipe network 7 inside the carbon dioxide adsorption and desorption tank 1 through the electric heating chamber 9 and the three-way pipe 11 to heat it up and radiate and heat the molecular sieve to the required temperature; thereafter, the fan 13, the fourth switch valve 18 and the sixth switch valve 19 are closed, and the vacuum pump 12 is started at the same time to evacuate (the pressure in the tank is observed through the first pressure gauge) to increase the separation speed of carbon dioxide from the adsorption material; when the first pressure gauge returns to normal and then pressurizes to a certain pressure to be stable, it means that the desorption of carbon dioxide has reached equilibrium, at this time, the third switch valve 16 is opened, and the air pump 24 is started to discharge the carbon dioxide gas into the carbon dioxide storage tank 21.

[0051] Afterwards, the third switch valve 16 is closed, the fifth switch valve 17 and the sixth switch valve 19 are reopened, and the fan 13 is started to transport room temperature gas or cooling gas into the carbon dioxide adsorption and desorption tank 1 through the cold air chamber 10 to quickly cool down the radiation pipe network 7 and the molecular sieve, thereby achieving efficient and high-speed cooling, shortening the cycle, and facilitating the next adsorption.

[0052] The above is a cyclic process for capturing carbon dioxide from flue gas. By repeating the above process, carbon dioxide can be captured from flue gas.

[0053] The above description is only a specific implementation mode of the present utility model, but the protection scope of the present utility model is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present utility model, and these modifications or substitutions should be included in the protection scope of the present utility model.

Claims

1. A temperature swing adsorption type flue gas carbon dioxide capture device, characterized in that: It includes a carbon dioxide adsorption and desorption tank, an adsorption unit, a cold and hot air intake unit, a booster unit and a carbon dioxide storage tank; The tank bottom of the carbon dioxide adsorption and desorption tank is provided with a flue gas inlet pipe, the tank top is provided with a first pressure gauge and a residual gas outlet pipe connected to the external atmosphere, and the tank body is provided with a carbon dioxide exhaust pipe connected to the carbon dioxide storage tank; The flue gas inlet pipe is provided with a first switch valve; the residual gas outlet pipe is provided with a second switch valve and a carbon dioxide concentration detector; the carbon dioxide exhaust pipe is provided with a third switch valve and an air pump; The adsorption unit comprises N partitions filled with carbon dioxide adsorption material, and the N partitions are sequentially arranged from top to bottom in the tank body of the carbon dioxide adsorption and desorption tank; wherein N is a positive integer; The shape of the partition is the same as the cross-sectional shape of the carbon dioxide adsorption and desorption tank, and the radial dimension is smaller than the radial dimension of the carbon dioxide adsorption and desorption tank; The hot and cold air intake unit comprises a fan, an electric heating chamber, a cold air chamber, a radiation pipe network and a temperature sensor; The radiation pipe network is installed on the inner wall of the carbon dioxide adsorption and desorption tank, leaving a gap between the radiation pipe network and the partition net, and is used to heat or cool the carbon dioxide adsorption material in the partition net; The fan is used to introduce air into the cold and hot air intake unit, and its outlet is connected to the inlet of the electric heating chamber and the cold air chamber at the same time; the outlet of the electric heating chamber and the cold air chamber are connected to the inlet of the radiation pipe network at the same time, and a fourth switch valve and a fifth switch valve are respectively provided between the outlets of the two and the inlet of the radiation pipe network; the outlet of the radiation pipe network is connected to the external atmosphere, and a sixth switch valve is provided on the outlet pipe of the radiation pipe network; The temperature sensor is arranged on the electric heating chamber and is used to observe the air supply temperature of the electric heating chamber; The pressurizing unit is connected to the carbon dioxide adsorption and desorption tank, and is used to increase the vacuum degree in the carbon dioxide adsorption and desorption tank and promote the desorption of carbon dioxide.

2. The temperature-swing adsorption flue gas carbon dioxide capture device according to claim 1, characterized in that: The pressurizing unit is a vacuum pump.

3. The temperature-swing adsorption type flue gas carbon dioxide capture device according to claim 1 or 2, characterized in that: The outlets of the electric heating chamber and the cold air chamber are connected to the inlet of the radiation pipe network through a three-way pipe.

4. The temperature-swing adsorption flue gas carbon dioxide capture device according to claim 3 is characterized in that: The radiation pipe network is laid along the circumferential inner wall of the carbon dioxide adsorption and desorption tank.

5. The temperature-swing adsorption type flue gas carbon dioxide capture device according to claim 4, characterized in that: The inlet of the radiation pipe network is located at the lower side of the carbon dioxide adsorption and desorption tank body, and the outlet is located at the upper side of the carbon dioxide adsorption and desorption tank body.

6. The temperature-swing adsorption type flue gas carbon dioxide capture device according to claim 5, characterized in that: The carbon dioxide exhaust pipe is located on the upper side of the carbon dioxide adsorption and desorption tank body; A second pressure gauge is provided on the tank body of the carbon dioxide storage tank.

7. The temperature-swing adsorption type flue gas carbon dioxide capture device according to claim 6, characterized in that: The pore size of the separator is 10 mm; the carbon dioxide adsorbent filled in the separator is a molecular sieve, which is spherical particles with a pore size of 10A.

8. The temperature-swing adsorption type flue gas carbon dioxide capture device according to claim 7, characterized in that: The carbon dioxide adsorption and desorption tank is cylindrical, the tank body is made of stainless steel, and is provided with a heat insulation layer, and the maximum pressure it can withstand is about 10MPa.

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