Device for rapidly capturing carbon dioxide in flue gas by using hydrate method

Abstract

The utility model discloses a device for quickly capturing carbon dioxide in flue gas by using a hydrate method. The device mainly comprises a reaction kettle, a temperature control system, a compressor, a bag-type dust collector, a pressure sensor, a jacket, a gas concentration detector, a temperature sensor, a hand pump and a computer processing and control system. An ultrasonic generator is arranged in the reaction kettle and is used for atomizing water into ultrafine particles to accelerate the hydration reaction rate. And the compressor, the gas concentration detector and the pressure transmitter are connected with a computer signal processing and control system, so that automatic control in the hydrate generation process is realized. The device disclosed by the utility model can automatically control the hydrate generation and decomposition process, fully utilizes a cold source generated by hydrate decomposition to remove heat in flue gas to accelerate the hydrate generation process, quickly realizes the generation and decomposition of carbon dioxide hydrate, and is simple, highly intelligent and automatic.

Description

Technical Field

[0001] This application relates to the field of environmental protection technologies, and particularly to a device for rapidly capturing carbon dioxide in flue gas by using the hydrate method. Background Art

[0002] The exploitation and utilization of fossil energy have promoted the rapid development of science and technology. However, it has caused increasingly severe environmental problems on the earth. The emission of greenhouse gases mainly composed of carbon dioxide is the main reason for the rise in global temperature. Carbon dioxide capture technology, which is used to remove carbon dioxide from gas streams or separate carbon dioxide as a gas product, has received increasing attention.

[0003] In recent years, many scientific research institutions have conducted a large number of studies on capturing carbon dioxide by the hydrate method and designed many experimental devices. Most of them often use methods such as adding hydrate promoters or stirring to accelerate the formation of hydrates. However, most of the devices have disadvantages such as complex design, cumbersome operation process, too slow hydrate formation rate, and high energy consumption. Utility Model Content

[0004] This utility model aims to solve at least one of the above technical problems.

[0005] This utility model provides a device for rapidly capturing carbon dioxide in flue gas by using the hydrate method, which can automatically control the formation and decomposition processes of hydrates, make full use of the cold source generated by the decomposition of hydrates to remove the heat in the flue gas and accelerate the hydrate formation process, and rapidly realize the formation and decomposition of carbon dioxide hydrates. The device is simple, highly intelligent, and automated.

[0006] A device for rapidly capturing carbon dioxide in flue gas by using the hydrate method mainly includes: a bag filter, a compressor, a one-way valve, a heat exchanger, a hand pump, a stirring paddle, an ultrasonic generator, a pressure sensor, a gas concentration detector, a temperature sensor, a computer processing and control system, a temperature control system, a reaction kettle, and a circulation jacket. The gas phase outlet at the top of the reaction kettle is directly connected to the heat exchanger. One ends of the temperature sensor, the gas concentration detector, and the pressure sensor are directly inserted into the reaction kettle, and the other ends are directly connected to the computer signal processing and control system. One end of the circulation jacket is directly connected to the temperature control system, and the other end is connected to the outside of the reaction kettle to form a closed loop. The rotation speed signal of the compressor is directly connected to the computer signal processing and control system.

[0007] Preferably, the temperature control system controls the temperature during the formation and decomposition processes of hydrates by adjusting the cooling coil and heating resistance coil in the reaction kettle.

[0008] Preferably, the inlet end of the compressor is connected to the bag filter, and the outlet end is connected to the one-way valve to adjust the gas phase inlet pressure.

[0009] Preferably, the bag filter is used to remove fine solid particles from the flue gas.

[0010] Preferably, the ultrasonic generator atomizes water into ultrafine particles by emitting ultrasonic waves, accelerating the hydrate formation rate.

[0011] Preferably, the heat exchanger is used to remove heat from the flue gas, reduce the flue gas temperature, and facilitate the hydration reaction.

[0012] Preferably, the concentration detector is located at the upper end of the reaction kettle for detecting the concentration of the gas phase at the upper end of the reaction kettle.

[0013] Preferably, there is a stirring rod in the reaction kettle to accelerate the hydrate formation process.

[0014] Preferably, a liquid phase at 5 - 15 °C is added to the hand pump through a funnel and pressed into the reaction kettle by the hand pump. The liquid phase can be water or other additives, such as a hydrate promoter or a hydrate inhibitor. Adding a hydrate promoter during the formation process accelerates the hydrate formation, and adding a hydrate inhibitor during the decomposition process can accelerate the hydrate decomposition process.

[0015] Preferably, the computer signal processing and control system is connected to the compressor, temperature control system, temperature sensor, pressure sensor, and gas concentration detector. By collecting the values of pressure, temperature, and concentration during the hydrate formation stage and performing corresponding calculation and processing, and then by controlling the temperature control system and the compressor speed, the automatic control during the hydrate formation process is realized.

[0016] The technical solution of the present utility model has the following advantages: After the flue gas of the present utility model is filtered by solid particles through a bag filter, compressed by a compressor, the heat is removed by a heat exchanger, the temperature is reduced and then enters the reaction kettle. Then, a hydrate promoter is added, the stirring rate is increased, and the ultrasonic generator atomizes water into ultrafine particles by emitting ultrasonic waves, significantly increasing the contact area between water and CO2 in the flue gas, and increasing the capture efficiency of CO2 by the hydrate method. The gas concentration detector, compressor, and computer processing and control system can control the feeding by using the concentration to control the compressor speed, with high automation. The pressure transmitter is directly connected to the solenoid valve and the computer processing and control system, which can automatically control the system pressure and test the influence of pressure on the hydrate formation. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0018] Figure 1 It is a schematic diagram of a device for rapidly capturing carbon dioxide in flue gas by using the hydrate method provided by an embodiment of the present application;

[0019] Figure 2 It is a graph showing the change of growth rate with time in an embodiment of the present application;

[0020] Figure 3 It is a graph showing the change of pressure with time in an embodiment of the present application; Specific embodiments

[0021] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present application.

[0022] A device for rapidly capturing carbon dioxide in flue gas by using the hydrate method mainly includes: a bag filter, a compressor, a check valve, a heat exchanger, a hand pump, a stirring paddle, an ultrasonic generator, a pressure sensor, a gas concentration detector, a temperature sensor, a computer processing and control system, a temperature control system, a reaction kettle, and a circulation jacket. The gas phase outlet at the top of the reaction kettle is directly connected to the heat exchanger. One ends of the temperature sensor, the gas concentration detector, and the pressure sensor are directly inserted into the reaction kettle, and the other ends are directly connected to the computer signal processing and control system. One end of the circulation jacket is directly connected to the temperature control system, and the other end is connected to the outside of the reaction kettle to form a closed loop. The rotation speed signal of the compressor is directly connected to the computer signal processing and control system.

[0023] The content of the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0024] The amount of hydrate generated F t-t0 can be expressed as:

[0025] F t-t0 = 18(n t - n t0 )h / 500

[0026] n t , n t0 respectively represent the amount of substance of the gas consumed by the system at time t and time t0 during the test, with the unit of mol; h is the hydrate constant, and the value of methane hydrate is taken as 5.75. The total mass of the liquid inlet in this experimental system is 500.0 g.

[0027] ​​The calculation idea of gas consumption is to calculate the gas consumption after the reaction based on the pressure difference and temperature before and after the reaction, so as to obtain the amount of hydrate generated:

[0028] p t V = Zn t RT t

[0029] In the formula, p t and T t can be accurately measured by a temperature sensor and a pressure sensor; V is a fixed value, obtained from the difference between the volume of the reaction kettle and the volume of the inlet liquid; R is the gas constant, taking 8.3145 J·mol-1·K; Z is the gas compressibility factor, a constant. Through the known or calculated p t 、V、Z、R and T t With these data, the amount of substance n of the gas molecules consumed in the system can be obtained t。 Dividing by the reaction time can calculate the growth rate of the hydrate crystals.

[0030] Example 1

[0031] First, use a hand pump to add 500 g of pure water to the reaction kettle. After the flue gas removes solid particles through a bag filter, it enters the compressor, is pressurized to a certain pressure, enters the heat exchanger through a one-way valve to remove heat, and then enters the reaction kettle. Start stirring at a stirring speed of 700 rpm. Turn on the ultrasonic generator in the kettle to atomize the water into ultrafine particles of 1 - 10 microns, and ensure uniform gas-liquid mixing. Stir for 40 minutes. At the same time, control the temperature in the reaction kettle to slowly decrease through the temperature control system. The cooling rate is generally 8 °C / h, so that the temperature drops to the high supercooling region, and the hydrate starts to nucleate and grow. When enough hydrate is generated, control the temperature to slowly decrease through the temperature control system, with a heating rate of 3 °C / h, and gradually heat up until the hydrate completely decomposes. Record the change of pressure with time during the reaction process and calculate the reaction rate.

[0032] Example 2

[0033] The difference between this Example 2 and Example 1 is only that 500 g of pure water is replaced by 500 g of a 3% mass fraction of tetrahydrofuran (THF) solution.

[0034] Example 3

[0035] The difference between this Example 3 and Example 1 is only that the ultrasonic generator in the kettle is not turned on.

[0036] Example 1 is a pure water system, Example 2 is a 3 wt% tetrahydrofuran (THF) solution system, and Example 3 is a system without turning on the ultrasonic generator in the kettle. Plotting the change of the growth rate with time during the reaction process in Examples 1, 2, and 3 to obtain a scatter plot Figure 2, The changes in pressure over time in Examples 1, 2, and 3 are plotted as a scatter plot to obtain Figure 3 .

[0037] The experimental results show that when the ultrasonic generator is turned on or the tetrahydrofuran solution of the hydrate promoter is added, the hydration rate increases significantly, and the time required for the formation of CO2 hydrate is shorter.

[0038] The above embodiments of the present utility model are merely examples for clearly illustrating the present utility model and are not limitations on the implementation manners of the present utility model. For those of ordinary skill in the art, other different forms of changes can be made based on the above description. It is not necessary and impossible to list all implementation manners here. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included in the protection scope of the claims of the present utility model.

Claims

1. An apparatus for rapidly capturing carbon dioxide in flue gas by using the hydrate method, characterized by mainly comprising: Bag filter (1), compressor (2), check valve (3), heat exchanger (4), hand pump (5), stirring rod (6), ultrasonic generator (7), pressure sensor (9), gas concentration detector (8), temperature sensor (10), computer processing and control system (11), temperature control system (12), reactor (13), circulation jacket (14); The gas phase outlet at the top of the reactor (13) is directly connected to the heat exchanger (4). One ends of the temperature sensor (10), gas concentration detector (8), and pressure sensor (9) are directly inserted into the reactor (13), and the other ends are directly connected to the computer signal processing and control system (11); One end of the circulation jacket (14) is directly connected to the temperature control system (12), and the other end is connected to the outside of the reactor (13) to form a closed loop; The rotational speed signal of the compressor is directly connected to the computer signal processing and control system (11).

2. The device for rapidly capturing carbon dioxide in flue gas by using the hydrate method according to claim 1, wherein, The temperature control system (12) controls the temperature during the hydrate formation and decomposition processes by adjusting the cooling coil and heating resistance coil in the reactor.

3. The device for rapidly capturing carbon dioxide in flue gas by using the hydrate method according to claim 1, wherein The inlet end of the compressor (2) is connected to the bag filter (1), and the outlet end is connected to the check valve (3) to regulate the gas phase inlet pressure.

4. The device for rapidly capturing carbon dioxide in flue gas by using the hydrate method according to claim 1, wherein, The bag filter (1) is used to remove fine solid particles in the flue gas.

5. The device for rapidly capturing carbon dioxide in flue gas by using the hydrate method according to claim 1, wherein The ultrasonic generator (7) atomizes water into ultrafine particles by emitting ultrasonic waves to accelerate the hydrate formation rate.

6. The device for rapidly capturing carbon dioxide in flue gas by the hydrate method according to claim 1, wherein, The heat exchanger (4) is used to remove heat from the flue gas and reduce the flue gas temperature, which is beneficial to the hydration reaction.

7. The device for rapidly capturing carbon dioxide in flue gas by using the hydrate method according to claim 1, wherein, The concentration detector (8) is located at the upper end of the reactor (13) to detect the concentration of the gas phase at the upper end of the reactor.

8. The device for rapidly capturing carbon dioxide in flue gas by using the hydrate method according to claim 1, wherein, There is a stirring rod (6) in the reactor to accelerate the hydrate formation process.

9. The device for rapidly capturing carbon dioxide in flue gas by using the hydrate method according to claim 1, wherein The computer signal processing and control system (11) is connected to the compressor (2), temperature control system (12), temperature sensor (10), pressure sensor (9), and gas concentration detector (8). By collecting the values of pressure, temperature, and concentration during the hydrate formation stage, corresponding calculations are performed, and then by controlling the temperature control system (12) and the rotational speed of the compressor (2), automatic control during the hydrate formation process is achieved.

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