A method for preparing carbon dioxide fire extinguisher by using coal-fired flue gas

Abstract

The application discloses a method for preparing carbon dioxide fire extinguisher by using coal-fired flue gas, and the technical scheme is as follows: firstly, the coal-fired flue gas is dedusted, then the dedusted flue gas is introduced into the solution in a reaction kettle to react with the solution in the reaction kettle to generate a cage compound, the cage compound is sent into a separation kettle, the temperature and pressure in the separation kettle are adjusted to make the cage compound decompose into carbon dioxide and water, the carbon dioxide gas is introduced into a gas storage tank from the separation kettle through a dryer and is packed, and finally the carbon dioxide fire extinguisher is prepared. The carbon dioxide and water can form a non-metering cage compound under certain temperature and pressure conditions. When the pressure is reduced and the temperature is increased, the cage compound cannot be maintained and is re-decomposed into water and carbon dioxide. The CO2 gas is separated from the tail flue gas of the coal-fired unit, and the carbon dioxide fire extinguisher is prepared.

Description

Technical Field

[0001] This invention relates to a method for preparing carbon dioxide fire extinguishers using coal-fired flue gas, belonging to the field of air pollution control. Background Technology

[0002] The flue gas from coal-fired power plants contains 12-18% carbon dioxide (CO2). Currently, most of this flue gas is directly released into the atmosphere after treatment, with the CO2 not being reused. Meanwhile, the manufacture of carbon dioxide fire extinguishers requires large amounts of carbon dioxide. Therefore, separating CO2 from the flue gas of coal-fired power plants to produce carbon dioxide fire extinguishers has practical economic and social value. Currently, methods for separating CO2-containing gas mixtures mainly include chemical absorption, pressure swing adsorption, and membrane separation. However, these methods are suitable for continuous, large-scale separation of high-purity carbon dioxide, but they are energy-intensive and costly, making them unsuitable for using the flue gas from coal-fired power plants to produce carbon dioxide fire extinguishers. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method for preparing carbon dioxide fire extinguishers using flue gas from coal-fired power plants. This method is simple, low-cost, and can be widely used in the preparation of carbon dioxide fire extinguishers.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows:

[0005] A method for preparing carbon dioxide fire extinguishers using coal-fired flue gas involves first removing dust from the coal-fired flue gas, then passing the dust-removed flue gas into a solution in a reaction vessel to react with the solution in the reaction vessel to generate cage-like compounds. The cage-like compounds are then sent to a separation vessel, where the temperature and pressure are adjusted to decompose the cage-like compounds into carbon dioxide and water. The carbon dioxide gas then passes through a dryer from the separation vessel into a gas storage tank and is packaged to finally produce carbon dioxide fire extinguishers.

[0006] Furthermore, the solution composition in the reactor is: 0.1-0.3 mol% tetrabutylammonium bromide, 1-3 mol% tetrahydrofuran, 0.2-0.4 mol% disodium hydrogen phosphate, 0.05-0.08 mol% sodium dodecyl sulfonate, with the balance being water.

[0007] Preferably, the solution composition in the reactor is: 0.2-0.3 mol% tetrabutylammonium bromide, 2.5 mol% tetrahydrofuran, 0.3-0.4 mol% disodium hydrogen phosphate, 0.07 mol% sodium dodecyl sulfonate, with the balance being water.

[0008] Furthermore, the water in question is purified water.

[0009] Furthermore, the reaction temperature in the reactor is 10-30℃, and the pressure is 0.2-1 MPa.

[0010] Preferably, the reaction temperature of the reactor is 10°C and the pressure is 1 MPa.

[0011] Furthermore, the temperature in the separation vessel is 15-40℃, and the pressure is atmospheric pressure, i.e., 0.1 MPa.

[0012] Preferably, the temperature in the separation vessel is 15-25℃.

[0013] More preferably, the temperature in the separation vessel is 25°C.

[0014] Beneficial effects:

[0015] This invention utilizes the non-stoichiometric cage-like compound formed by carbon dioxide and water under specific temperature and pressure conditions. When the pressure decreases and the temperature increases, the cage-like compound cannot be maintained and decomposes back into water and carbon dioxide, separating CO2 gas from the tail gas of a coal-fired unit to produce a carbon dioxide fire extinguisher. However, if water and carbon dioxide are reacted directly, the phase equilibrium pressure is high, reaching 10 MPa, which places high demands on the production process. Current research often uses tetrahydrofuran to reduce the phase equilibrium pressure of the cage-like compound and adds kinetic promoters (such as sodium dodecyl sulfonate SDS) to increase the formation rate of the gaseous cage-like compound and shorten the induction time of its formation. In this invention, tetrabutylammonium bromide, as a surfactant, can reduce the time for compound formation. Simultaneously, the synergistic effect of tetrabutylammonium bromide and disodium hydrogen phosphate can further shorten the formation time of the cage-like compound. Disodium hydrogen phosphate can reduce the phase equilibrium pressure of compound formation, and due to its weak alkalinity, it can increase the solubility of carbon dioxide in water, improving the overall reaction rate, thereby reducing production process requirements and costs. This process can be carried out in a batch process using a reactor, making it suitable for small-batch separation and production of carbon dioxide. Detailed Implementation

[0016] The specific embodiments of the present invention will be further described in detail below with reference to examples.

[0017] Example 1

[0018] A method for preparing carbon dioxide fire extinguishers using coal-fired flue gas involves first passing the coal-fired flue gas through a small bag filter for dust removal, then introducing the dust-removed flue gas into a solution in a reaction vessel (the flow is stopped after a fixed volume of flue gas has been introduced). The flue gas reacts with the solution in the reaction vessel at a temperature of 10°C and a pressure of 0.6 MPa to generate cage-like compounds. The cage-like compounds (reaction liquid) are then sent to a separation vessel, where the temperature is adjusted to 15°C and the pressure to atmospheric pressure (0.1 MPa), causing the cage-like compounds to decompose into carbon dioxide and water. The carbon dioxide gas then passes through a dryer from the separation vessel into a gas storage tank and is further packaged to ultimately produce carbon dioxide fire extinguishers.

[0019] The solution in the reactor consists of: 0.2 mol% tetrabutylammonium bromide, 2.5 mol% tetrahydrofuran, 0.3 mol% disodium hydrogen phosphate, 0.07 mol% sodium dodecyl sulfonate, with the remainder being purified water.

[0020] Example 2

[0021] A method for preparing carbon dioxide fire extinguishers using coal-fired flue gas involves first passing the coal-fired flue gas through a small bag filter for dust removal, then introducing the dust-removed flue gas into a solution in a reaction vessel (the flow is stopped after a fixed volume of flue gas has been introduced). The flue gas reacts with the solution in the reaction vessel at a temperature of 10°C and a pressure of 0.2 MPa to generate cage-like compounds. The cage-like compounds (reaction liquid) are then sent to a separation vessel, where the temperature is adjusted to 20°C and the pressure to atmospheric pressure (0.1 MPa), causing the cage-like compounds to decompose into carbon dioxide and water. The carbon dioxide gas then passes through a dryer from the separation vessel into a gas storage tank and is further packaged to ultimately produce carbon dioxide fire extinguishers.

[0022] The solution in the reactor consists of: 0.3 mol% tetrabutylammonium bromide, 2.5 mol% tetrahydrofuran, 0.3 mol% disodium hydrogen phosphate, 0.07 mol% sodium dodecyl sulfonate, with the remainder being purified water.

[0023] Example 3

[0024] A method for preparing carbon dioxide fire extinguishers using coal-fired flue gas involves first passing the coal-fired flue gas through a small filter bag for dust removal, then introducing the dust-removed flue gas into a solution in a reaction vessel (the flow is turned off after a fixed volume of flue gas has been introduced). The flue gas reacts with the solution in the reaction vessel at a temperature of 10°C and a pressure of 1 MPa to generate cage-like compounds. The cage-like compounds (reaction liquid) are then sent to a separation vessel, where the temperature is adjusted to 25°C and the pressure to atmospheric pressure (0.1 MPa), causing the cage-like compounds to decompose into carbon dioxide and water. The carbon dioxide gas then passes through a dryer from the separation vessel into a gas storage tank and is further packaged to ultimately produce carbon dioxide fire extinguishers.

[0025] The solution in the reactor consists of: 0.3 mol% tetrabutylammonium bromide, 2.5 mol% tetrahydrofuran, 0.4 mol% disodium hydrogen phosphate, 0.07 mol% sodium dodecyl sulfonate, with the remainder being purified water.

[0026] Comparative Example

[0027] A method for preparing carbon dioxide fire extinguishers using coal-fired flue gas involves first passing the coal-fired flue gas through a small filter bag for dust removal, then introducing the dust-removed flue gas into a solution in a reaction vessel (the flow is turned off after a fixed volume of flue gas has been introduced). The flue gas reacts with the solution in the reaction vessel at a temperature of 10°C and a pressure of 1 MPa to generate cage-like compounds. The cage-like compounds (reaction liquid) are then sent to a separation vessel, where the temperature is adjusted to 25°C and the pressure to atmospheric pressure (0.1 MPa), causing the cage-like compounds to decompose into carbon dioxide and water. The carbon dioxide gas then passes through a dryer from the separation vessel into a gas storage tank and is further packaged to ultimately produce carbon dioxide fire extinguishers.

[0028] The solution in the reactor consists of: 0.3 mol% tetrabutylammonium bromide, 2.5 mol% tetrahydrofuran, 0.07 mol% sodium dodecyl sulfonate, and the remainder is purified water.

[0029] Under the condition that the same composition and volume of flue gas and the same volume of solution in the reaction vessel were introduced into Examples 1-3 and the Comparative Example, the reaction time (the time from the completion of flue gas introduction to the time when the reaction liquid is about to be sent into the separation vessel), carbon dioxide recovery rate and purity were tested, and the results are shown in the table below.

[0030]

[0031] As can be seen from the table above, the method of the present invention can improve the reaction rate, shorten the reaction time, and at the same time improve the purity and recovery rate of carbon dioxide.

Claims

1. A method for producing carbon dioxide fire extinguisher using coal-fired flue gas, characterized by, The coal-fired flue gas is first dedusted, and then the dedusted flue gas is introduced into the solution in the reaction kettle to react with the solution in the reaction kettle to generate a cage compound, and then the cage compound is sent into a separation kettle, the temperature and pressure in the separation kettle are adjusted to decompose the cage compound into carbon dioxide and water, wherein the carbon dioxide gas is introduced into a gas storage tank from the separation kettle through a dryer and is packed, and finally a carbon dioxide fire extinguisher is prepared; the solution in the reaction kettle comprises 0.1-0.3 mol% tetrabutylammonium bromide, 1-3 mol% tetrahydrofuran, 0.2-0.4 mol% disodium hydrogen phosphate, 0.05-0.08 mol% sodium dodecyl sulfonate, and the balance is water.

2. The method for preparing carbon dioxide fire extinguisher using coal-fired flue gas according to claim 1, characterized in that, The solution in the reaction kettle comprises 0.2-0.3 mol% tetrabutylammonium bromide, 2.5 mol% tetrahydrofuran, 0.3-0.4 mol% disodium hydrogen phosphate, 0.07 mol% sodium dodecyl sulfonate, and the balance is water.

3. The method for preparing carbon dioxide fire extinguisher using coal-fired flue gas according to claim 1 or 2, characterized in that, The water is pure water.

4. The method for preparing carbon dioxide fire extinguisher using coal-fired flue gas according to claim 1, characterized in that, The reaction temperature of the reaction kettle is 10-30 ℃, and the pressure is 0.2-1 Mpa.

5. The method for preparing carbon dioxide fire extinguisher using coal-fired flue gas according to claim 4, characterized in that, The reaction temperature of the reaction kettle is 10 ℃, and the pressure is 1 Mpa.

6. The method for preparing carbon dioxide fire extinguisher using coal-fired flue gas according to claim 1, characterized in that, The temperature in the separation kettle is 15-40 ℃, and the pressure is normal pressure, i.e. 0.1 Mpa.

7. The method for preparing carbon dioxide fire extinguisher using coal-fired flue gas according to claim 6, characterized in that, The temperature in the separation kettle is 15-25 ℃.

8. The method for preparing carbon dioxide fire extinguisher using coal-fired flue gas according to claim 7, characterized in that, The temperature in the separation kettle is 25 ℃.

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