System and method for producing hydrogen by electrolyzing salt-containing wastewater and coupling carbon fixation
阅读说明：本技术 一种含盐废水电解制氢耦合固碳系统及其方法 (System and method for producing hydrogen by electrolyzing salt-containing wastewater and coupling carbon fixation ) 是由 余智勇 王金意 王凡 张畅 任志博 王鹏杰 于 2021-08-25 设计创作，主要内容包括：本发明提出了一种含盐废水电解制氢耦合固碳系统以及方法,包括预处理系统、电解槽、气液反应塔、蒸发结晶塔。含盐废水经过预处理后进入电解槽；在阴极生成氢气和NaOH溶液,氢气作为能源物质回收,NaOH溶液进入气液反应塔与富碳烟气接触反应,固定烟气中的二氧化碳,并生成NaHCO-(3)溶液；通过低温空气蒸发结晶,分离溶液中NaHCO-(3),剩余的含盐溶液重新进入电解反应。本发明该系统设计合理,实现了废水的处理、资源化回收以及能源物质的生产。(The invention provides a system and a method for hydrogen production coupling carbon fixation through electrolysis of salt-containing wastewater. The salt-containing wastewater enters an electrolytic cell after pretreatment; generating hydrogen and NaOH solution at the cathode, recovering the hydrogen as an energy substance, allowing the NaOH solution to enter a gas-liquid reaction tower to contact and react with the carbon-rich flue gas, fixing carbon dioxide in the flue gas, and generating NaHCO 3 A solution; separating NaHCO from the solution by low-temperature air evaporation crystallization 3 And the residual salt-containing solution enters the electrolysis reaction again. The system is reasonable in design, and realizes the treatment of wastewater, resource recovery and the production of energy substances.)
1. A coupled carbon fixation system for electrolytic hydrogen production from salt-containing wastewater is characterized by comprising
An electrolytic cell in which anode chambers and cathode chambers are alternately arranged and a diaphragm separating the anode chambers and the cathode chambers;
the gas-liquid reaction tower is arranged at the downstream of the electrolytic cell and used for receiving alkali liquor in the cathode chamber and is externally connected with carbon-rich flue gas; the alkali liquor and the carbon-rich flue gas are contacted with a filler contact layer arranged in the gas-liquid reaction tower to carry out carbon fixation reaction;
and the evaporative crystallization tower is arranged at the downstream of the gas-liquid reaction tower and used for receiving the solution after the carbon fixation reaction, and meanwhile, the evaporative crystallization tower is externally connected with low-temperature air to concentrate and crystallize the solution after the carbon fixation reaction.
2. The system of claim 1, wherein the electrolyzer is an ion exchange membrane electrolyzer; the diaphragm is a cation exchange membrane.
3. The system of claim 1, wherein the cathode chamber is provided with a brine inlet, a lye outlet and a hydrogen outlet; the alkali liquor outlet is connected with the gas-liquid reaction tower.
4. The system of claim 3, wherein the gas-liquid reaction tower is a gas-liquid countercurrent spray tower and comprises an alkali liquor inlet, a solution outlet, a water collecting tank arranged at the bottom in the gas-liquid reaction tower, a filler contact layer in the middle and a spray layer at the upper part; circularly spraying the liquid in the water collecting tank from top to bottom; the alkali liquor inlet is connected with the alkali liquor outlet; the bottom of the water collecting tank is provided with a first gas distribution pipe, and the first gas distribution pipe is externally connected with the carbon-rich flue gas.
5. The system as claimed in claim 4, wherein the evaporative crystallization tower is a gas-liquid countercurrent spray tower, and comprises a solution inlet, a liquid collecting tank arranged at the bottom in the evaporative crystallization tower, and a spray liquid layer arranged at the upper part; circularly spraying liquid in the liquid collecting pool from top to bottom; the solution inlet is connected with the solution outlet; a second air distribution pipe is arranged above the liquid level in the liquid collecting pool; the second air distribution pipe is externally connected with low-temperature air.
6. The system of any one of claims 1-5, wherein the carbon sequestration system further comprises a pretreatment system comprising a wastewater inlet, a wastewater outlet, and a wastewater decontamination system; the wastewater outlet is respectively connected with the anode chamber and the cathode chamber; the waste water inlet is connected with the evaporative crystallization tower.
7. The system of claim 6, wherein the anode chamber is provided with a brine inlet, a brine outlet, and a chlorine outlet; the brine outlet is connected with the wastewater inlet; the waste water outlet is connected with the brine inlet.
8. The system of claim 6, wherein the evaporative crystallization tower is further provided with a concentrate outlet and a crystallized salt discharge outlet; the concentrated solution outlet is connected with the waste water inlet.
9. The method for coupling carbon sequestration through hydrogen production by electrolysis of saline wastewater, which is characterized in that the system of any one of claims 1 to 8 is used for coupling carbon sequestration through hydrogen production by electrolysis of saline wastewater, and comprises the following steps:
(1) introducing the salt-containing wastewater with the mass percentage of 2-26.5% into an electrolytic cell, generating chlorine gas and Na simultaneously in an anode chamber+Passing through a cation exchange membrane into the cathode chamber; hydrogen gas produced in the cathode compartment, OH-With Na+Forming NaOH solution, and controlling the pH value of the solution to be more than 13;
(2) the solution of NaOH is circularly sprayed in a gas-liquid reaction tower, and generates a carbon fixation reaction with a filler contact layer and carbon-rich flue gas, and the pH value is controlled to be 7-8 to generate NaHCO3The solution of (1);
(3) said NaHCO3The solution is sprayed circularly in an evaporation crystallization tower and contacts with low-temperature air at 50-60 ℃, the concentration ratio is 2-5 times, and NaHCO is used3Crystallizing and separating out;
(4) step (3) NaHCO3And refluxing the solution after crystallization to the electrolytic bath.
10. The method according to claim 9, wherein before the salt-containing wastewater with the mass percentage of 2-26.5% is introduced into the electrolytic cell, suspended matters and heavy metals are removed through an activated carbon filter by a pretreatment system, and calcium, magnesium and heavy metal ions are removed through an ion resin filter; step (4) NaHCO3And refluxing the solution after crystallization to the pretreatment system.
Technical Field
The invention relates to the technical field of wastewater treatment, in particular to a system and a method for hydrogen production and carbon fixation through electrolysis of salt-containing wastewater.
Background
Under the conditions of water resource shortage and increasingly serious water pollution, the treatment and recycling efficiency of water is improved, the near zero emission of wastewater is gradually emphasized, and the engineering implementation of the near zero emission of the wastewater is developed in the industries of electric power, coal chemical industry and the like. At present, the near-zero discharge of wastewater mainly adopts pretreatment, concentration, crystallization or drying processes, wherein the pretreatment is mainly to remove organic matters, heavy metals, calcium, magnesium and other hardness ions in the wastewater, finally, the residual pollutants in the wastewater are mainly sodium salts and potassium salts, and anions are mainly chloride ions. The salt-containing wastewater finally forms waste salt after concentration and crystallization, or is mixed with solid wastes such as coal ash and the like, and is not fully utilized. With the promotion of zero discharge of wastewater in the future, a large amount of strong brine brings secondary environmental problems.
The strong brine can be used as an important electrolyte in the electrolysis process, and is mainly used for electrolyzing the strong brine to generate energy substances such as hydrogen, and the hydrogen is a green and efficient secondary energy and has wide application space in the fields of traffic, electric power, chemical industry and the like. Therefore, the concentrated brine can be used as an important raw material in the hydrogen production process by electrolysis. Therefore, the hydrogen production by electrolyzing the salt-containing wastewater has larger application potential.
Therefore, the technical problem that needs to be solved by the technical personnel in the field is how to provide a system and a method for producing hydrogen by electrolyzing salt-containing wastewater, so as to realize comprehensive utilization of the salt-containing wastewater through an electrolysis process and generate green energy substance hydrogen.
Disclosure of Invention
The invention aims to solve at least one of the technical problems in the related technology to a certain extent, and provides a system and a method for coupling and fixing carbon by electrolyzing salt-containing wastewater.
In view of the above, according to the first object of the present invention, there is provided a coupled carbon sequestration system for hydrogen production by electrolysis of saline wastewater, comprising
An electrolytic cell in which anode chambers and cathode chambers are alternately arranged and a diaphragm separating the anode chambers and the cathode chambers;
the gas-liquid reaction tower is arranged at the downstream of the electrolytic cell and used for receiving alkali liquor in the cathode chamber and is externally connected with carbon-rich flue gas; the alkali liquor and the carbon-rich flue gas contact with a filler contact layer arranged in the gas-liquid reaction tower to carry out carbon fixation reaction;
and the evaporative crystallization tower is arranged at the downstream of the gas-liquid reaction tower and used for receiving the solution after the carbon fixation reaction, and meanwhile, the evaporative crystallization tower is externally connected with low-temperature air to concentrate and crystallize the solution after the carbon fixation reaction.
The system for preparing hydrogen by electrolyzing the salt-containing wastewater and coupling carbon fixation is characterized in that an electrolytic cell is an ion exchange membrane electrolytic cell; the diaphragm is a cation exchange membrane.
The cathode chamber is provided with a brine inlet, an alkali liquor outlet and a hydrogen outlet; the alkali liquor outlet is connected with the gas-liquid reaction tower.
In the system for coupling the hydrogen production by electrolyzing the salt-containing wastewater with the carbon fixation, the gas-liquid reaction tower is a gas-liquid countercurrent spray tower and comprises an alkali liquor inlet, a solution outlet, a water collecting tank arranged at the bottom in the gas-liquid reaction tower, a filler contact layer arranged in the middle and a spray layer arranged at the upper part; circularly spraying the liquid in the water collecting tank from top to bottom; the alkali liquor inlet is connected with the alkali liquor outlet; the bottom of the water collecting tank is provided with a first gas distribution pipe which is externally connected with the carbon-rich flue gas.
Preferably, the first air distribution pipe is also arranged above the liquid level of the water collecting tank.
In the invention, alkali liquor in a water collecting tank of the gas-liquid reaction tower is circularly sprayed by a circulating water pump, and the bottom of the water collecting tank and above the liquid level are both provided with a first gas distribution pipe.
In the system for coupling the hydrogen production by electrolyzing the salt-containing wastewater with the carbon fixation, the evaporation crystallization tower is a gas-liquid countercurrent spray tower and comprises a solution inlet, a liquid collecting tank arranged at the bottom in the evaporation crystallization tower and a spray liquid layer arranged at the upper part; circularly spraying liquid in the liquid collecting pool from top to bottom; the solution inlet is connected with the solution outlet; a second air distribution pipe is arranged above the liquid level in the liquid collecting tank; the second air distribution pipe is externally connected with low-temperature air.
In the invention, the solution in the liquid collecting tank of the evaporative crystallization tower is circularly sprayed by the circulating water pump.
The saliferous wastewater electrolysis hydrogen production coupling carbon fixation system further comprises a pretreatment system, wherein the pretreatment system comprises a wastewater inlet, a wastewater outlet and a wastewater impurity removal system; the waste water outlet is respectively connected with the anode chamber and the cathode chamber; the waste water inlet is connected with the evaporative crystallization tower.
Wherein, the waste water outlet of the invention is connected with the brine inlet on the cathode chamber.
In the system for coupling the electrolytic hydrogen production and carbon sequestration of the salt-containing wastewater, the anode chamber is provided with a brine inlet, a brine outlet and a chlorine outlet; the saline water outlet is connected with the waste water inlet; the waste water outlet is connected with the brine inlet.
The waste water impurity removal system comprises a coagulating sedimentation tank, a quartz sand filter, an activated carbon filter and an ion exchange resin filter; the salt-containing wastewater is treated by a coagulating sedimentation tank and a quartz sand filter to remove particle precipitates such as coagulation blocks, quartz sand and the like, then treated by an activated carbon filter to remove suspended matters and heavy metals, and finally treated by an ion resin filter to remove calcium, magnesium and partial heavy metal ions.
In the saliferous wastewater electrolysis hydrogen production coupling carbon sequestration system, the evaporative crystallization tower is also provided with a concentrated solution outlet and a crystallized salt outlet; the concentrated solution outlet is connected with the waste water inlet.
According to the second purpose of the invention, the method for fixing carbon by electrolytic hydrogen production coupling of the salt-containing wastewater is provided, and the method for fixing carbon by electrolytic hydrogen production coupling of the salt-containing wastewater by using the system comprises the following steps:
(1) introducing the salt-containing wastewater with the mass percentage of 2-26.5% into an electrolytic cell, generating chlorine gas in an anode chamber, and simultaneously introducing Na+Passing through a cation exchange membrane into the cathode chamber; hydrogen gas produced in the cathode compartment, OH-With Na+Forming NaOH solution, and controlling the pH value of the solution to be more than 13;
(2) the NaOH solution is circularly sprayed in the gas-liquid reaction tower, and generates carbon fixation reaction with the filler contact layer and the carbon-rich flue gas, the pH is controlled to be 7-8, and NaHCO is generated3The solution of (1);
(3)NaHCO3the solution is sprayed circularly in an evaporation crystallization tower and contacts with low-temperature air at 50-60 ℃, the concentration ratio is 2-5 times, and NaHCO is used3Crystallizing and separating out;
(4) step (3) NaHCO3The solution after crystallization is refluxed to the electrolytic bath.
The salt-containing wastewater is introduced into an electrolytic cell, and an anode chamber reacts as follows:
Cl--2e-→Cl2
the cathode compartment reacts as follows:
H++2e-→H2
hydrogen generated in cathode chamber of electrolytic cell is collected and utilized, H+OH remaining after electrolysis-And Cl-Cannot enter the anode chamber through the cation exchange membrane, and thus, OH-With Na permeating through the cation exchange membrane+And Na in the electrolyte+NaOH is formed. The carbon-rich flue gas with carbon dioxide content of 10% and nitrogen and oxygen as the rest is introduced from the first gas distribution pipe of the gas-liquid reaction tower, contacts with the sprayed NaOH solution in the space inside the gas-liquid reaction tower and the middle filler contact layer, and undergoes a carbon fixation reaction to generate NaHCO3Solution:
CO2+2NaOH→Na2CO3+H2O
CO2+Na2CO3+H2O→2NaHCO3
NaHCO3the solution is circularly sprayed in the evaporative crystallization tower, and low-temperature air at 50-60 ℃ enters from a second air distribution pipe of the evaporative crystallization tower and is mixed with sprayed NaHCO3The solution is contacted with the space in the tower, NaHCO3In solutionThe water is taken out of the evaporation crystallization tower, the solution is gradually concentrated, and NaHCO is used3And (4) precipitating.
Before the salt-containing wastewater with the mass percentage of 2-26.5% is introduced into an electrolytic cell, suspended matters and heavy metals are removed through an activated carbon filter by a pretreatment system, and calcium, magnesium and heavy metal ions are removed through an ion resin filter; step (4) NaHCO3And refluxing the solution after crystallization to a pretreatment system.
Through the technical scheme, the invention provides a system and a method for coupling carbon fixation by electrolyzing salt-containing wastewater to produce hydrogen, and the system and the method have the following technical effects:
(1) the method uses the salt-containing wastewater as the electrolytic solution, so that the treatment and resource utilization of the wastewater are realized; meanwhile, an energy substance hydrogen is generated, so that the preparation of green energy is realized;
(2) the method synchronously fixes the carbon dioxide in the carbon-rich flue gas by using the solution of NaOH generated in the electrolysis process to realize carbon capture;
(3) after carbon fixation reaction, crystallization is carried out to obtain NaHCO through separation3Meanwhile, the sodium chloride in the solution can be reused for the electrolysis reaction.
Drawings
The foregoing and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
fig. 1 is a schematic structural diagram of a system for producing hydrogen by electrolyzing salt-containing wastewater and coupling carbon fixation in the prior art.
The system comprises a pretreatment system-1, an electrolytic cell-2, a gas-liquid reaction tower-3, an evaporative crystallization tower-4, carbon-rich flue gas-5, low-temperature air-6, chlorine-7 and hydrogen-8.
Detailed Description
In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings. It should be noted that the embodiments of the present invention and features of the embodiments may be combined with each other without conflict.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.
Example 1
Referring to fig. 1, this embodiment provides a system for fixing carbon by coupling hydrogen production through electrolysis of saline wastewater, which includes
An electrolytic cell 2 in which anode chambers and cathode chambers are alternately arranged and a diaphragm for separating the anode chambers and the cathode chambers;
the gas-liquid reaction tower 3 is arranged at the downstream of the electrolytic bath 2 and used for receiving alkali liquor in the cathode chamber, and is externally connected with carbon-rich flue gas 5; the alkali liquor and the carbon-rich flue gas 5 contact with a filler contact layer arranged in the gas-liquid reaction tower 3 to carry out carbon fixation reaction;
and the evaporative crystallization tower 4 is arranged at the downstream of the gas-liquid reaction tower 3 and used for receiving the solution after the carbon fixation reaction, and is externally connected with low-temperature air 6 to concentrate and crystallize the solution after the carbon fixation reaction.
Wherein the electrolytic bath 2 in the embodiment is an ion exchange membrane electrolytic bath 2; the diaphragm is a cation exchange membrane.
In order to further optimize the embodiment, the cathode chamber is provided with a brine inlet, an alkali liquor outlet and a hydrogen outlet; the alkali liquor outlet is connected with the gas-liquid reaction tower 3.
In order to further optimize the embodiment, the gas-liquid reaction tower 3 is a gas-liquid countercurrent spray tower and comprises an alkali liquor inlet, a solution outlet, a water collecting tank arranged at the bottom in the gas-liquid reaction tower 3, a filler contact layer arranged in the middle and a spray layer arranged at the upper part; circularly spraying the liquid in the water collecting tank from top to bottom; the alkali liquor inlet is connected with the alkali liquor outlet; the bottom of the water collecting tank is provided with a first gas distribution pipe which is externally connected with the carbon-rich flue gas 5.
Preferably, the first air distribution pipe is also arranged above the liquid level of the water collecting tank.
In this embodiment, the alkali liquor in the water collecting tank of the gas-liquid reaction tower 3 is circularly sprayed by the circulating water pump, and the bottom of the water collecting tank and above the liquid level are both provided with the first gas distribution pipes.
In order to further optimize the embodiment, the evaporative crystallization tower 4 is a gas-liquid countercurrent spray tower, and comprises a solution inlet, a liquid collecting tank arranged at the bottom in the evaporative crystallization tower 4 and a spray liquid layer arranged at the upper part; circularly spraying liquid in the liquid collecting pool from top to bottom; the solution inlet is connected with the solution outlet; a second air distribution pipe is arranged above the liquid level in the liquid collecting tank; the second air distribution pipe is externally connected with low-temperature air 6.
In this embodiment, the solution in the liquid collecting tank of the evaporative crystallization tower 4 is sprayed by the circulating water pump in a circulating manner.
In order to further optimize the embodiment, the carbon sequestration system further comprises a pretreatment system 1, wherein the pretreatment system 1 comprises a wastewater inlet, a wastewater outlet and a wastewater impurity removal system; the waste water outlet is respectively connected with the anode chamber and the cathode chamber; the waste water inlet is connected with the evaporative crystallization tower 4.
Wherein, the waste water outlet in this embodiment is connected with the brine inlet on the cathode chamber.
In order to further optimize the embodiment, the anode chamber is provided with a brine inlet, a brine outlet and a chlorine outlet; the saline water outlet is connected with the waste water inlet; the waste water outlet is connected with the brine inlet.
The waste water impurity removal system in the embodiment comprises a coagulating sedimentation tank, a quartz sand filter, an activated carbon filter and an ion exchange resin filter; the salt-containing wastewater is treated by a coagulating sedimentation tank and a quartz sand filter to remove particle precipitates such as coagulation blocks, quartz sand and the like, then treated by an activated carbon filter to remove suspended matters and heavy metals, and finally treated by an ion resin filter to remove calcium, magnesium and partial heavy metal ions.
In order to further optimize the embodiment, the evaporative crystallization tower 4 is also provided with a concentrated solution outlet and a crystallized salt outlet; the concentrated solution outlet is connected with the waste water inlet.
The method for carrying out the coupled carbon fixation of the hydrogen production by electrolyzing the saline wastewater by using the system to carry out the coupled carbon fixation by electrolyzing the saline wastewater comprises the following steps:
(1) the salt-containing wastewater with the mass percentage of 2-26.5 percent is introduced into an electrolytic cell 2, chlorine gas 7 is generated in an anode chamber, and Na is simultaneously added+Passing through a cation exchange membrane into the cathode chamber; hydrogen 8, and OH produced in the cathode compartment-With Na+Forming NaOH solution, and controlling the pH value of the solution to be more than 13;
(2) the NaOH solution is circularly sprayed in the gas-liquid reaction tower 3, and is subjected to carbon fixation reaction with the filler contact layer and the carbon-rich flue gas 5, the pH is controlled to be 7-8, and NaHCO is generated3The solution of (1);
(3)NaHCO3the solution is circularly sprayed in an evaporation crystallization tower 4 and contacts with low-temperature air 6 at the temperature of 50-60 ℃, the concentration ratio is 2-5 times, and NaHCO is used3Crystallizing and separating out;
(4) step (3) NaHCO3The solution after the crystallization is refluxed to the electrolytic bath 2.
To facilitate understanding of the method of this example the salt-containing wastewater of this example was passed into an electrolytic cell 2, the anode compartment was subjected to the following reaction:
Cl--2e-→Cl2
the cathode compartment reacts as follows:
H++2e-→H2
hydrogen 8 produced in the cathode chamber of the electrolytic cell 2 is collected and utilized, H+OH remaining after electrolysis-And Cl-Cannot enter the anode chamber through the cation exchange membrane, and thus, OH-With Na permeating through the cation exchange membrane+And Na in the electrolyte+NaOH is formed. The carbon-rich flue gas 5 enters from a first gas distribution pipe of the gas-liquid reaction tower 3, contacts with the sprayed NaOH solution in the inner space of the gas-liquid reaction tower 3 and the middle filling contact layer, and undergoes the following carbon fixation reaction to generate NaHCO3Solution:
CO2+2NaOH→Na2CO3+H2O
CO2+Na2CO3+H2O→2NaHCO3
NaHCO3the solution is circularly sprayed in the evaporative crystallization tower 4, low-temperature air 6 at 50-60 ℃ enters from a second air distribution pipe of the evaporative crystallization tower 4 and is mixed with sprayed NaHCO3The solution is contacted with the space in the tower, NaHCO3The water content in the solution is carried out of the evaporative crystallization tower 4, the solution is gradually concentrated, and NaHCO is used3And (4) precipitating.
For further optimizing the embodiment, before the salt-containing wastewater with the mass percentage of 2-26.5% is introduced into the electrolytic cell 2, suspended matters and heavy metals are removed through the pretreatment system 1 by the activated carbon filter, and calcium, magnesium and heavy metal ions are removed through the ion resin filter; step (4) NaHCO3The solution after crystallization is refluxed to the pretreatment system 1.
The embodiment specifically includes: the salt-containing wastewater with the mass percentage of 2-26.5%, in this embodiment, the salt-containing wastewater has a mass percentage selected from 2%, and is subjected to a coagulation sedimentation tank and a quartz sand filter by a pretreatment system 1 to remove particle precipitates such as coagulation blocks and quartz sand therein, and is subjected to an activated carbon filter to remove suspended matters and heavy metals, and finally subjected to an ion resin filter to remove calcium, magnesium and part of heavy metal ions, and then is introduced into brine inlets of an anode chamber and a cathode chamber of an electrolytic cell 2 through a wastewater outlet to perform electrolytic hydrogen production, wherein the anode chamber performs the following reactions: cl--2e-→Cl2(ii) a The cathode compartment reacts as follows: h++2e-→H2(ii) a Na of anode chamber under the action of electric field+Enters the cathode chamber through a cation exchange membrane; OH of the cathode compartment-And Cl-Cannot enter the anode chamber through the cation exchange membrane, OH-With Na permeating through the cation exchange membrane+And Na in the electrolyte+A NaOH solution is formed, the pH of which is greater than 13. The salt solution in the anode chamber of the electrolytic cell 2 is returned to the wastewater inlet of the pretreatment system 1 through the brine outlet.
NaOH solution in a cathode chamber of the electrolytic cell 2 is connected with an alkali liquor inlet of the gas-liquid reaction tower 3 through an alkali liquor outlet and discharged to a water collecting tank, and is sprayed downwards from a spraying layer at the upper part in the tower through a circulating water pump; the carbon-rich flue gas 5 enters from a first gas distribution pipe of a gas-liquid reaction tower 3, contacts with a sprayed NaOH solution in a space in the tower and a middle filling contact layer in the tower to carry out the following carbon fixation reaction, controls the pH value to be 7-8, preferably 8.0, and generates NaHCO3A solution; NaHCO after carbon-fixing reaction3The solution enters a solution inlet of an evaporative crystallization tower 4 through a solution outlet and is sprayed downwards from a spraying layer at the upper part in the tower through a circulating water pump; 50-60The low temperature air 6 at 50 ℃ in the embodiment enters from the second air distribution pipe of the evaporative crystallization tower 4 and is sprayed with NaHCO3The solution is contacted with the space in the tower, NaHCO3The water in the solution is taken out of the evaporation crystallization tower 4, the solution is gradually concentrated, the concentration ratio is 2-5 times, the concentration ratio is 3 times in the embodiment, and NaHCO is used3The crystallized salt is discharged from a crystallized salt discharge port at the bottom, and the residual solution returns to a wastewater inlet of the pretreatment system 1 through a concentrated solution outlet.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
- 上一篇：一种医用注射器针头装配设备
- 下一篇：一种水电容器高频分解系统