A system and method for producing alkali using industrial waste gas and industrial waste brine.

Abstract

This invention provides a system and method for producing alkali using industrial waste gas and industrial waste brine. The system includes a waste liquid pipeline, a waste gas pipeline, an ammonia pipeline, a heat exchanger, an oxidation reaction tower, a dust removal tower, a preliminary carbonization reaction tower, and a deep carbonization reaction tower. The outlet of the waste liquid pipeline is connected to the oxidation reaction tower, and the heat exchanger is installed on the waste liquid pipeline. The oxidation products generated in the waste liquid pipeline are transported to the preliminary carbonization reaction tower via a first conveying pipeline. The waste gas pipeline is connected to the dust removal tower via the heat exchanger, and the dust removal products obtained in the waste gas pipeline are transported to the preliminary carbonization reaction tower via a second conveying pipeline. The ammonia pipeline is connected to the preliminary carbonization reaction tower, and a third conveying pipeline is connected to the bottom outlet of the preliminary carbonization reaction tower. The outlet of the third conveying pipeline is connected to the deep carbonization reaction tower. This system realizes a carbon-negative, green, and low-energy-consumption environmentally friendly alkali production process, meeting the needs of green and sustainable industrial production.

Description

Technical Field

[0001] This invention relates to the field of soda ash preparation technology, and more specifically, to a system and method for producing soda ash using industrial waste gas and industrial waste brine. Background Technology

[0002] The chemical principle of the "Hou's process for alkali production 1.0" mainly includes the following three chemical reaction steps:

[0003] (1) NH3 + H2O + CO2 = NH4HCO3

[0004] (2)NH4HCO3+NaCl=NH4Cl+NaHCO3↓

[0005] (3) 2NaHCO3 = Na2CO3 + CO2↑ + H2O (thermal decomposition)

[0006] Of the three reaction steps mentioned above, steps (1) and (2) are carried out in a carbonization reactor (commonly known as a carbonization tower), while step (3) is carried out in a calcining furnace. Compared with the "Solvay process", the "Hou's process 1.0" combines an ammonia plant and an alkali plant, with the ammonia plant supplying the alkali plant with the ammonia and carbon dioxide raw materials required for the reaction. The reaction not only produces the precursor compound NaHCO3 of the target product Na2CO3, but also produces ammonium chloride that can be recycled as a chemical product or fertilizer, instead of the large amount of solid waste CaCl2 produced in the "Solvay process". This improves atom economy and significantly enhances the value of the production process.

[0007] However, in the current Hou-style combined alkali production process, the raw materials used to produce soda ash, such as NH3, CO2, and NaCl, all need to be purchased. The raw materials for ammonia synthesis mainly come from coal-based ammonia synthesis, and the various energy sources used in the production process are mostly fossil fuels, not renewable green energy sources. The CO2 used in the "Hou's Soda Ash Process 1.0" comes from high-concentration CO2 (85%-90%) obtained from ammonia synthesis gasification and shift conversion processes, rather than the low-concentration flue gas CO2 released from other production processes. The former is used in the "Hou's Soda Ash Process 1.0" production process, and its overall carbon balance remains that of a high-carbon production process. Furthermore, the characteristics of combined alkali production require the alkali plant to be built near the ammonia synthesis plant, increasing production costs.

[0008] Furthermore, in the current chemical industry, petrochemical and coal chemical industries, such as oil cracking and coal-to-methanol production, emit large amounts of CO2 in their waste gas. The gas composition is simple and easy to separate. This CO2 is emitted directly without being recovered, causing environmental problems and wasting resources. Meanwhile, industries such as pharmaceutical, pesticide, and fertilizer plants discharge industrial wastewater containing high concentrations of NaCl. Currently, many factories use costly wastewater treatment technologies, and once the wastewater meets standards, it is discharged directly without generating any economic value.

[0009] In view of this, the present invention is hereby proposed. Summary of the Invention

[0010] The primary objective of this invention is to provide a system for producing alkali using industrial waste gas and industrial waste brine. This method uses industrial waste brine and industrial waste gas as reaction raw materials to produce alkali, achieving a carbon-negative, green, and low-energy-consumption environmentally friendly alkali production process. Furthermore, by combining an enhanced mass transfer reactor with the alkali production process section (i.e., the preliminary carbonization reaction tower and the deep carbonization reaction tower), the reaction efficiency and utilization rate of the raw materials can be effectively improved, thereby increasing the alkali production efficiency.

[0011] The second objective of this invention is to provide a method for producing alkali using industrial waste gas and industrial waste brine. This method uses industrial waste brine and industrial waste gas as reaction raw materials to produce alkali, and has the characteristics of being carbon-negative, green, low-energy consumption, and environmentally friendly. It also has low production costs and high raw material utilization.

[0012] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0013] This invention provides a system for producing alkali using industrial waste gas and industrial waste brine, comprising: waste liquid pipeline, waste gas pipeline, ammonia pipeline, heat exchanger, oxidation reaction tower, dust removal tower, preliminary carbonization reaction tower and deep carbonization reaction tower;

[0014] The outlet of the waste liquid pipeline is connected to the oxidation reaction tower, and the heat exchanger is installed on the waste liquid pipeline; the industrial waste brine in the waste liquid pipeline undergoes a wet oxidation reaction in the oxidation reaction tower, and the generated oxidation products are transported to the preliminary carbonization reaction tower via the first conveying pipeline.

[0015] The exhaust gas pipeline is connected to the dust removal tower via the heat exchanger. After the industrial exhaust gas in the exhaust gas pipeline is dusted in the dust removal tower, the dust removal product is transported to the preliminary carbonization reaction tower via the second conveying pipeline.

[0016] The ammonia pipeline is connected to the preliminary carbonization reaction tower, and the bottom outlet of the preliminary carbonization reaction tower is connected to a third conveying pipeline, the outlet of which is connected to the deep carbonization reaction tower.

[0017] The deep carbonization reaction tower is equipped with a first enhanced mass transfer reactor and a second enhanced mass transfer reactor. The first enhanced mass transfer reactor and the second enhanced mass transfer reactor are respectively located on opposite side walls of the deep carbonization reaction tower, and their outlets are opposite to each other. Both the first enhanced mass transfer reactor and the second enhanced mass transfer reactor are connected to the second conveying pipeline. The dust removal product is dispersed and broken into micron-sized microbubbles by the first enhanced mass transfer reactor and the second enhanced mass transfer reactor, and then reacts with the material conveyed by the third conveying pipeline to realize the production of alkali using a negative carbon production process.

[0018] In the above scheme, the industrial waste brine in the waste liquid pipeline undergoes real-time oxidation in the oxidation reaction tower to obtain a high-concentration brine (i.e., oxidation product); by using a dust removal tower to remove dust from the industrial waste gas, high-purity CO2 gas (i.e., dust removal product) can be obtained; the oxidation product, dust removal product, and ammonia water can react sequentially in the preliminary carbonization reaction tower and the deep carbonization reaction tower to produce NaHCO3. Simultaneously, by setting up a first enhanced mass transfer reactor and a second enhanced mass transfer reactor, the CO2 gas can be dispersed and broken into micron-sized microbubbles, increasing the gas-liquid mass transfer area; by positioning the outlets of the first and second enhanced mass transfer reactors opposite each other, the two microbubble streams can be counteracted, further dispersing and breaking down the microbubbles, which helps to further increase the gas-liquid mass transfer area. It is understandable that the CO2 concentration in the dust removal products of purified industrial waste gas is typically low (less than 70%). This solution combines the alkali production process with enhanced mass transfer technology and specifically positions the enhanced mass transfer reactor, ensuring good alkali production efficiency even at low CO2 concentrations. Furthermore, this alkali production solution is carbon-negative, green, low-energy, and environmentally friendly, meeting the needs of green and sustainable industrial production. In addition, because this solution increases the interphase mass transfer area between the gas and liquid phases through enhanced mass transfer technology, the required transport pressure of the gaseous feedstock can be reduced, allowing for low-pressure CO2 transport, which further helps to reduce production energy consumption.

[0019] Preferably, the system further includes a stirrer, which comprises a stirring motor, a stirring shaft, and stirring blades. The stirring motor is connected to the stirring shaft, and the stirring blades are positioned at the end of the stirring shaft away from the stirring motor. The end of the stirring shaft away from the stirring motor passes through the deep carbonization reaction tower and extends into its interior. The stirring blades are vertically positioned above the first and second enhanced mass transfer reactors, and horizontally positioned between them. This design, by using a stirrer, ensures uniform distribution of microbubbles through agitation. Simultaneously, positioning the stirring blades vertically above the first and second enhanced mass transfer reactors reduces the impact of the stirring blades on the opposing flow of the two microbubbles, thereby further increasing the gas-liquid mass transfer area and improving raw material utilization. Furthermore, this arrangement also reduces the impact of the stirring blades on the products already reacted at the bottom of the tower, preventing product backmixing and ensuring stable output of the bottom product.

[0020] Preferably, a distribution pipe is provided between the outlet of the first enhanced mass transfer reactor and the outlet of the second enhanced mass transfer reactor; the distribution pipe has multiple distribution holes on its wall near the stirring blade. In this design, the distribution pipe can provide relatively independent space for the opposing of the two microbubble streams, avoiding the influence of the stirrer on the opposing effect. Simultaneously, by providing multiple distribution holes near the stirring blade, the microbubbles that are further broken up after opposing can be fed into the vicinity of the stirring blade through the distribution holes and uniformly dispersed under the stirring of the stirring blade. This helps to further prevent bubble aggregation and improve the uniformity of microbubble dispersion.

[0021] Preferably, the deep carbonization reaction tower is further equipped with a third enhanced mass transfer reactor, which is positioned above the liquid surface of the deep carbonization reaction tower. The outlet of the third enhanced mass transfer reactor is connected to an extension pipe that extends into the liquid surface of the deep carbonization reaction tower, and the outlet of the extension pipe is located above the first and second enhanced mass transfer reactors. The outlet of the third conveying pipeline is connected to the third enhanced mass transfer reactor. In this configuration, the material in the third conveying pipeline can entrain unreacted gas from the top of the tower into the third enhanced mass transfer reactor for further dispersion and crushing, and then return to the tower to continue participating in the reaction, which helps to further improve the raw material conversion rate.

[0022] Preferably, a circulation pipeline is provided on one side of the deep carbonization reaction tower. The inlet of the circulation pipeline is connected to the side wall of the deep carbonization reaction tower, and the outlet is connected to the third enhanced mass transfer reactor. The inlet of the circulation pipeline is located vertically between the liquid surface of the first enhanced mass transfer reactor and the deep carbonization reaction tower. On the one hand, the circulation pipeline can stir the liquid in the deep carbonization reaction tower, improving the reaction efficiency. On the other hand, placing the inlet of the circulation pipeline vertically between the liquid surface of the first enhanced mass transfer reactor and the deep carbonization reaction tower can reduce the impact of the stirring of the circulation pipeline on the products that have already reacted at the bottom of the tower, avoid product backmixing, and ensure the stable output of the bottom product. At the same time, the circulating material in the circulation pipeline can be fed into the third enhanced mass transfer reactor together with the material in the third conveying pipeline. That is, the two materials simultaneously provide the driving force for dispersion and breakage, which helps to improve the degree of microbubble breakage, reduce the size of microbubbles, and thus further increase the phase boundary mass transfer area.

[0023] Preferably, the primary carbonization reaction tower is equipped with a fourth enhanced mass transfer reactor and a fifth enhanced mass transfer reactor. The fourth enhanced mass transfer reactor is located below the liquid level in the primary carbonization reaction tower, and the fifth enhanced mass transfer reactor is located above the liquid level in the primary carbonization reaction tower. The outlet of the fifth enhanced mass transfer reactor is connected to a first connecting pipe, and the outlet of the first connecting pipe is connected to the fourth enhanced mass transfer reactor. The first conveying pipeline is connected to the fifth enhanced mass transfer reactor. The ammonia pipeline and the second conveying pipeline are both connected to the fourth enhanced mass transfer reactor. This scheme utilizes a fourth enhanced mass transfer reactor to disperse and break down ammonia and CO2 in the second delivery pipeline into micron-sized microbubbles, increasing the phase-interface mass transfer area. The fifth enhanced mass transfer reactor, located above, entrains unreacted gas from the top of the column, disperses and breaks it down, and then returns it to the column to participate in the reaction again, thus improving the feed conversion rate. Furthermore, the microbubbles dispersed and broken down in the fifth enhanced mass transfer reactor are fed into the fourth enhanced mass transfer reactor via the first connecting pipe, where they undergo further dispersion and breaking down. This material can also impact the microbubble flow dispersed and broken down in the fourth enhanced mass transfer reactor itself, further enhancing the degree of microbubble dispersion and breaking down. Simultaneously, the first connecting pipe also provides support for the fifth enhanced mass transfer reactor, improving the overall structural strength.

[0024] Preferably, a backmixing pipeline is provided on one side of the preliminary carbonization reaction tower. The inlet of the backmixing pipeline is connected to the side wall of the preliminary carbonization reaction tower, and the outlet is connected to the fifth enhanced mass transfer reactor. The inlet of the backmixing pipeline is located vertically between the liquid surface of the fourth enhanced mass transfer reactor and the preliminary carbonization reaction tower. This design, by setting up a backmixing pipeline, can stir the material inside the tower, improving reaction efficiency and the uniformity of microbubble distribution. Simultaneously, the material in the backmixing pipeline is fed into the fifth enhanced mass transfer reactor along with the material in the first conveying pipeline; that is, both streams of material simultaneously provide the driving force for dispersion and breakup. This helps to improve the degree of microbubble breakup, reduce the size of microbubbles, and thus further increase the phase boundary mass transfer area.

[0025] Preferably, the preliminary carbonization reaction tower is provided with multiple layers of baffles arranged alternately, and the baffles are located below the fourth enhanced mass transfer reactor. The product of the preliminary carbonization reaction tower is output from the bottom of the tower. By arranging multiple layers of baffles alternately below the fourth enhanced mass transfer reactor, it is helpful to avoid product backmixing and ensure that the product is stably and orderly fed into the next stage reaction tower (i.e., the deep carbonization reaction tower).

[0026] Preferably, the dust removal tower is equipped with a sixth enhanced mass transfer reactor and a seventh enhanced mass transfer reactor. Both the sixth and seventh enhanced mass transfer reactors are located below the liquid level within the dust removal tower, and are respectively positioned on opposite sidewalls within the dust removal tower. Both reactors are connected to the waste gas pipeline. In this design, by setting up the sixth and seventh enhanced mass transfer reactors, the industrial waste gas can be dispersed and broken into micron-sized microbubbles, thereby increasing the gas-liquid mass transfer area and improving the dust removal effect. By positioning the sixth and seventh enhanced mass transfer reactors on opposite sidewalls within the dust removal tower, the outlets of the two enhanced mass transfer reactors face each other, allowing the microbubbles output from the two reactors to counteract each other, further dispersing and breaking down the waste gas.

[0027] Preferably, a sprayer is installed inside the dust collection tower, and the sprayer is connected to a dust collection liquid pipeline; the sprayer is vertically positioned above the liquid surface inside the dust collection tower, and horizontally positioned between the sixth and seventh enhanced mass transfer reactors. This scheme delivers the dust collection liquid into the dust collection tower via the sprayer. This method can increase dust collection efficiency, and by positioning the sprayer horizontally between the sixth and seventh enhanced mass transfer reactors, the sprayed dust collection liquid is more concentrated between the six and seven enhanced mass transfer reactors, thereby further improving dust collection efficiency.

[0028] Preferably, an auxiliary dust collector is also provided inside the dust removal tower. This auxiliary dust collector is vertically located between the sprayer and the sixth enhanced mass transfer reactor. The auxiliary dust collector is a cone shape that gradually decreases in size from top to bottom vertically, and its bottom opening is horizontally located between the sixth and seventh enhanced mass transfer reactors. This design, by providing an auxiliary dust collector, restricts the upward movement of gas from a position relative to the sixth and seventh enhanced mass transfer reactors. Furthermore, since the sprayer is horizontally positioned between the sixth and seventh enhanced mass transfer reactors, the newly added spray liquid is concentrated between them. In this case, the gas rises along the area where the spray liquid is concentrated, thereby further improving dust removal efficiency.

[0029] Preferably, a rotary motor is installed on the outside of the dust removal tower, and the rotary motor is connected to a rotating shaft. The rotating shaft passes through the tower wall and extends into the interior of the dust removal tower, with a rotating fan blade connected to the end of the rotating shaft away from the rotary motor. The rotating fan blade is located vertically below the sixth enhanced mass transfer reactor and horizontally between the sixth and seventh enhanced mass transfer reactors. This design, by incorporating a rotating fan blade, helps to improve the uniformity of microbubble distribution, thereby further increasing the mass transfer area at the phase boundary between the gas and liquid phases, which helps to further improve the dust removal effect.

[0030] Preferably, the oxidation reaction tower is equipped with an eighth enhanced mass transfer reactor and a ninth enhanced mass transfer reactor. Both the eighth and ninth enhanced mass transfer reactors are vertically located below the liquid surface within the oxidation reaction tower. The eighth enhanced mass transfer reactor is vertically located above the ninth enhanced mass transfer reactor, and their outlets are opposite each other. Both the eighth and ninth enhanced mass transfer reactors are connected to oxidizing gas pipelines. Preferably, the outlet of the eighth enhanced mass transfer reactor is connected to the outlet of the ninth enhanced mass transfer reactor via a second connecting pipe. The second connecting pipe has multiple through holes on its wall. In this design, the eighth and ninth enhanced mass transfer reactors can disperse and break the oxidizing gas (which can be oxygen or air) into micron-sized microbubbles, increasing the phase boundary mass transfer area between the gas and the industrial wastewater, thereby improving the wet oxidation efficiency. Furthermore, by positioning the outlets of the two enhanced mass transfer reactors opposite each other, the two microbubble streams can be counteracted, achieving further dispersion and breakage. In a further embodiment, by setting a second connecting pipe, a space can be provided for the two microbubble streams to collide. The collided microbubbles can then diffuse evenly into the liquid phase material in the oxidation reaction tower along the through holes on the second connecting pipe, which helps to further improve the wet oxidation efficiency.

[0031] Preferably, the heat exchanger includes an inner tube and an outer shell, with the inner tube disposed inside the outer shell, forming a heat exchange chamber between the inner tube and the outer shell. The waste liquid pipeline is connected to the oxidation reaction tower via the inner tube, and the waste gas pipeline is connected to the dust removal tower via the heat exchange chamber. Multiple baffles are arranged inside the inner tube along the material flow direction, with adjacent baffles staggered. In this design, by setting baffles, the flow path of the industrial waste brine can be extended, thereby extending the heat exchange time between the industrial waste brine and the industrial waste gas. This allows the high temperature carried by the industrial waste gas to heat the industrial waste brine, facilitating the subsequent wet oxidation reaction. It is understood that the reaction temperature of the wet oxidation reaction is generally around 250℃, while the temperature of industrial waste gas dust removal is usually below 100℃. This design, by thermally coupling the industrial waste brine and industrial waste gas, helps to significantly reduce energy consumption and further save production costs.

[0032] Preferably, the baffle plate is inclined towards the outlet end of the inner tube, and the angle between the baffle plate and the inner tube wall is within the range of [30°, 50°]. This design, by setting the inclination angle of the baffle plate, can further extend the flow path of industrial waste brine, thereby helping to further improve heat exchange performance.

[0033] Preferably, a heat exchange chamber is provided with a heat insulation plate, which divides the heat exchange chamber into a first heat exchange chamber and a second heat exchange chamber along the material flow direction; the exhaust gas pipeline is connected to the dust removal tower via the first heat exchange chamber; the first conveying pipeline is connected to the preliminary carbonization reaction tower via the second heat exchange chamber. In this scheme, the heat carried by the industrial waste gas and oxidation products can be fully utilized to heat the industrial waste brine, which can further reduce the energy required for subsequent heating of the industrial waste brine. Simultaneously, in this scheme, the industrial waste brine is first thermally coupled with the industrial waste gas, and then thermally coupled with the oxidation products. This is because the temperature of the industrial waste gas itself is usually high (above 300℃), while the initial temperature of the industrial waste brine is low, resulting in a large temperature difference and high heat exchange efficiency, which can quickly raise the temperature of the industrial waste brine and lower the temperature of the industrial waste gas. Then, through heat exchange between the oxidation products and the industrial waste brine, the industrial waste brine can be reheated, bringing its temperature closer to the temperature requirements of the wet oxidation reaction, thus ensuring efficient subsequent reactions. In summary, this staged heating method can further improve heat exchange efficiency and reduce energy consumption.

[0034] In the above-described scheme of the present invention, industrial waste gas and industrial waste brine undergo heat exchange before entering the dust removal process section (i.e., dust removal tower) and the wet oxidation process section (i.e., oxidation reaction tower), respectively. This thermal coupling method helps reduce energy consumption and save production costs. Simultaneously, in the dust removal process section, by combining enhanced mass transfer technology with spray dust removal technology and specifically positioning the enhanced mass transfer reactor, sprayer, and auxiliary dust collector, the industrial dust removal efficiency is improved, thereby increasing the CO2 concentration in the dust removal products and ensuring the orderly progress of the subsequent alkali production process. In the wet oxidation process section, by combining enhanced mass transfer technology with wet oxidation reaction, the wet oxidation efficiency can be improved, thereby increasing the purification efficiency of the industrial waste brine, reducing the COD value in the industrial waste brine, and enabling it to participate in the subsequent alkali production process. In the alkali production process section, by setting up a two-stage carbonization reaction tower, the conversion rate of the reaction raw materials can be improved. By combining enhanced mass transfer technology, the interphase contact area between gaseous and liquid feedstocks can be increased, thus ensuring good alkali production efficiency even at low CO2 concentrations. This means that CO2 from industrial waste gas can be used for alkali production, achieving a carbon-negative alkali production method. This production method has the advantages of being green, environmentally friendly, and energy-efficient. In summary, the present invention utilizes CO2 from industrial waste gas and NaCl from industrial waste brine to achieve a green synthesis process for soda ash, which helps reduce production costs. This method not only does not cause environmental pollution itself but also consumes waste gas and waste brine from other industries, which helps reduce waste gas and waste brine treatment costs and achieves a carbon-negative production method. The present invention reuses industrial waste and further transforms it into valuable industrial chemicals, realizing the circular transformation of industrial production. It not only does not consume pure CO2 gas but also further purifies and utilizes industrial waste, forming a carbon-negative industrial chain, perfectly matching the concept of green and sustainable development.

[0035] It will be understood by those skilled in the art that the enhanced mass transfer reactor used in this invention has been reflected in the inventors' prior patents, such as patents with application numbers CN201610641119.6, CN201610641251.7, CN201710766435.0, CN106187660A, CN105903425A, CN205833127U and CN207581700U. The prior patent CN201610641119.6 details the specific product structure and working principle of a micron-sized bubble generator (i.e., a bubble breaker). This application document states that "the micron-sized bubble generator includes a main body and a secondary breaking component. The main body has a cavity, and an inlet communicating with the cavity is provided on the main body. The first and second ends of the cavity are both open, and the cross-sectional area of ​​the cavity decreases from the middle of the cavity towards the first and second ends. The secondary breaking component is located at at least one of the first and second ends of the cavity, with a portion of the secondary breaking component located within the cavity. A ring-shaped channel is formed between the secondary breaking component and the open through-holes at both ends of the cavity. The micron-sized bubble generator also includes an air inlet pipe and a liquid inlet pipe." From the specific structure disclosed in this application document, its specific working principle can be understood as follows: liquid enters the micron-sized bubble generator tangentially through the liquid inlet pipe, rotates at ultra-high speed, and cuts the gas, causing the gas bubbles to break into micron-sized microbubbles, thereby increasing the mass transfer area between the liquid and gas phases. Moreover, the micron-sized bubble generator in this patent is a pneumatic bubble breaker.

[0036] Furthermore, prior patent 201610641251.7 describes a primary bubble breaker with a circulating liquid inlet, a circulating gas inlet, and a gas-liquid mixture outlet, while a secondary bubble breaker connects the feed inlet to the gas-liquid mixture outlet. This indicates that both bubble breakers require a gas-liquid mixture to enter. Additionally, as shown in the accompanying drawings, the primary bubble breaker primarily utilizes the circulating liquid as its power source, thus classifying it as a hydraulically driven enhanced mass transfer reactor. The secondary bubble breaker simultaneously introduces the gas-liquid mixture into an elliptical rotating sphere for rotation, thereby achieving bubble breakage during rotation. Therefore, the secondary bubble breaker is actually a gas-liquid linkage bubble breaker. In fact, both hydraulically driven and gas-liquid linkage bubble breakers are specific forms of bubble breakers. However, the enhanced mass transfer reactor used in this invention is not limited to these forms; the specific structure of the bubble breaker described in the prior patent is merely one possible form for this invention.

[0037] Furthermore, prior patent 201710766435.0 states that "the principle of the bubble breaker is to achieve mutual collision of gases by high-speed jetting"; and prior patent CN106187660 also describes the specific structure of the bubble breaker, as detailed in paragraphs

[0031] -

[0041] of the specification and the attached drawings. It elaborates on the specific working principle of the bubble breaker S-2. The top of the bubble breaker is the liquid phase inlet, and the side is the gas phase inlet. The liquid phase entering from the top provides the entrainment force, thereby achieving the effect of crushing into ultrafine bubbles. The attached drawings also show that the bubble breaker has a conical structure, with the upper diameter being larger than the lower diameter, which is also to allow the liquid phase to provide better entrainment force.

[0038] Because bubble breakers were newly developed in the early stages of the prior patent application, they were initially named micron bubble generators (CN201610641119.6), etc. With continuous technological improvements, they were later renamed bubble breakers. The enhanced mass transfer reactor in this invention is equivalent to the previous micron bubble generators, micro-interface generators, etc., only with different names. In summary, the enhanced mass transfer reactor of this invention belongs to the prior art.

[0039] The present invention also provides a method for producing alkali using industrial waste gas and industrial waste brine, wherein the method applies the system for alkali production in any of the above-mentioned schemes.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] 1. This invention utilizes CO2 from industrial waste gas and NaCl from industrial waste brine to achieve a green synthesis process for soda ash, reducing production costs. It not only does not cause environmental pollution itself, but also consumes waste gas and waste brine from other industries, reducing the cost of waste gas and waste brine treatment and achieving a carbon-negative production method.

[0042] 2. This invention enables the preparation of soda ash using low-concentration CO2 under low-pressure conditions with high production efficiency. This reaction system integrates enhanced mass transfer technology into the soda ash preparation process, effectively improving the reaction efficiency of raw materials and the utilization rate of carbon dioxide, while simultaneously reducing the input pressure of carbon dioxide and lowering energy consumption.

[0043] 3. The reaction raw materials of this invention are low-carbon and environmentally friendly. The ammonia raw material can be green ammonia or blue ammonia, and the CO2 can be low-concentration CO2 of 70% or less. Alternatively, recovered CO2 with a concentration of 75-80% from the calcining furnace can be mixed with low-concentration CO2 from the flue gas to form 50-75% CO2 as a carbon source. Thus, the production process of this invention becomes a negative-carbon production process, reducing production costs. Attached Figure Description

[0044] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0045] Figure 1 A schematic diagram of an alkali production system according to an embodiment of this application is shown;

[0046] Figure 2 This diagram shows a structural schematic of a heat exchanger according to one embodiment of the present application;

[0047] Figure 3 A schematic diagram of the structure of an oxidation reaction tower according to an embodiment of this application is shown;

[0048] Figure 4 A schematic diagram of the structure of a dust removal tower according to an embodiment of this application is shown;

[0049] Figure 5 This diagram shows a structural schematic of an auxiliary dust collector according to an embodiment of the present application;

[0050] Figure 6 A schematic diagram of the structure of a preliminary carbonization reaction tower according to an embodiment of this application is shown;

[0051] Figure 7 A schematic diagram of the structure of a deep carbonization reaction tower according to an embodiment of this application is shown;

[0052] Figure 8 A flow chart of an alkali production process according to an embodiment of the present invention is shown.

[0053] In the picture:

[0054] 1. Waste liquid pipeline; 2. Heat exchanger; 201. Inner tube; 202. Outer shell; 203. Insulation plate; 204. Baffle plate; 3. Waste gas pipeline; 4. Heater; 5. Oxidation reaction tower; 501. Eighth enhanced mass transfer reactor; 502. Second connecting pipe; 503. Ninth enhanced mass transfer reactor; 504. Exhaust port; 6. Oxidizing gas pipeline; 7. First conveying pipeline; 8. Dust removal tower; 801. Rotary motor; 802. Rotating shaft; 803. Rotating fan blade; 804. Sixth enhanced mass transfer reactor; 805. Seventh enhanced mass transfer reactor; 806. Auxiliary dust collector; 807. Sprayer; 9. Dust removal liquid pipeline; 10. Second conveying pipeline; 11. Fourth conveying pipeline; 12. Preliminary carbonization reaction tower; 1201. Fourth enhanced mass transfer reactor; 1202. 1. First connecting pipe; 1203. Fifth enhanced mass transfer reactor; 1204. Gas collecting pipe; 1205. Suction pump; 1206. Back mixing pipe; 1207. Baffle plate; 13. Deep carbonization reaction tower; 1301. Stirring motor; 1302. Stirring shaft; 1303. Third enhanced mass transfer reactor; 1304. Extension pipe; 1305. Stirring blade; 1306. First enhanced mass transfer reactor; 1307. Distribution pipe; 1308. Second enhanced mass transfer reactor; 1309. Transfer pump; 1310. Circulation pipe; 14. Third transfer pipe; 15. Filter tower; 16. Calcination tower; 17. Mother liquor storage tank; 18. Product conveyor; 19. Calcination gas pipe; 20. Product transfer pipe; 21. Fifth transfer pipe; 22. Ammonia pipe; 23. Gas-liquid separator. Detailed Implementation

[0055] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0056] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0057] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0058] See Figure 1-7 The present invention provides a system for producing alkali using industrial waste gas and industrial waste brine, comprising: waste liquid pipeline 1, waste gas pipeline 3, ammonia pipeline 22, heat exchanger 2, oxidation reaction tower 5, dust removal tower 8, preliminary carbonization reaction tower 12 and deep carbonization reaction tower 13.

[0059] The outlet of waste liquid pipeline 1 is connected to oxidation reaction tower 5, and heat exchanger 2 is installed on waste liquid pipeline 1; the industrial waste brine in waste liquid pipeline 1 undergoes wet oxidation reaction in oxidation reaction tower 5, and the generated oxidation products are transported to the preliminary carbonization reaction tower 12 via the first conveying pipeline 7.

[0060] The exhaust gas pipeline 3 is connected to the dust removal tower 8 via the heat exchanger 2. After the industrial exhaust gas in the exhaust gas pipeline 3 is dusted in the dust removal tower 8, the dust removal product is transported to the preliminary carbonization reaction tower 12 via the second conveying pipeline 10.

[0061] Ammonia pipeline 22 is connected to the preliminary carbonization reaction tower 12. The bottom outlet of the preliminary carbonization reaction tower 12 is connected to the third conveying pipeline 14. The outlet of the third conveying pipeline 14 is connected to the deep carbonization reaction tower 13.

[0062] The deep carbonization reaction tower 13 is equipped with a first enhanced mass transfer reactor 1306 and a second enhanced mass transfer reactor 1308. The first enhanced mass transfer reactor 1306 and the second enhanced mass transfer reactor 1308 are respectively located on opposite side walls inside the deep carbonization reaction tower 13, and the outlets of the first enhanced mass transfer reactor 1306 and the second enhanced mass transfer reactor 1308 are opposite to each other. Both the first enhanced mass transfer reactor 1306 and the second enhanced mass transfer reactor 1308 are connected to the second conveying pipeline 10. After the dust removal product is dispersed and broken into micron-sized microbubbles by the first enhanced mass transfer reactor 1306 and the second enhanced mass transfer reactor 1308, it reacts with the material conveyed by the third conveying pipeline 14 to realize the production of alkali using the negative carbon production process.

[0063] In this embodiment, the main component of the industrial waste gas should be CO2, which mainly comes from industries such as petroleum cracking, coal-to-methanol, coal-to-ethanol, thermal power plants, and new energy battery production. The waste gas passes through a dust removal process section (i.e., dust removal tower 8), which can remove excess gaseous impurities (such as SO2, H2S, NO2, etc.) and separate CO2 gas with high purity. The mixed gas may contain inert gases such as N2 and He. Due to the adoption of enhanced mass transfer technology, the low concentration of CO2 does not affect the soda ash production efficiency of the alkali production process.

[0064] In this embodiment, the industrial waste gas can enter the waste gas pipeline 3 after pretreatment. This pretreatment can employ any existing or future dust removal process, which will not be elaborated upon. In this embodiment, the industrial waste gas sequentially undergoes pretreatment and dust removal in the dust collection tower 8, which can further improve the purity of CO2 in the gas.

[0065] In this embodiment, the main component of the industrial waste brine is NaCl, which can mainly come from wastewater from any industrial production such as petrochemicals, natural gas extraction, papermaking, and pharmaceuticals.

[0066] In some embodiments, industrial waste brine can be pretreated before entering waste liquid pipeline 1. Specifically, the industrial waste brine can be pretreated to reduce its COD value, and then passed through oxidation reaction tower 5 to remove trace amounts of difficult-to-oxidize organic waste, reducing the COD value to below 10 mg / L, thereby obtaining a raw material liquid (i.e., oxidation product) mainly containing inorganic salt NaCl.

[0067] Continue reading Figure 1 A heater 4 can also be installed on the waste liquid pipeline 1. The heater 4 is located behind the heat exchanger 2 along the material flow direction to further heat the industrial waste brine after heat exchange, so that it can meet the reaction temperature requirements of the wet oxidation reaction.

[0068] In some embodiments, the oxidation products can be separated and filtered. For example... Figure 1In the illustrated embodiment, the system further includes a gas-liquid separator 23. The oxidation products in the first conveying pipeline 7, after exchanging heat with industrial waste brine in the heat exchanger 2, enter the gas-liquid separator 23. The liquid phase (mainly containing inorganic salt NaCl) is conveyed to the preliminary carbonization reaction tower 12, while the gas phase (mainly including unreacted oxygen) can be directly discharged into the air or conveyed to the oxidation reaction tower 5 via an air compressor to continue participating in the wet oxidation of the industrial waste brine. It can be understood that in this embodiment, the first conveying pipeline 7 can be considered to include three pipeline sections: a first pipeline section located between the outlet of the oxidation reaction tower 5 and the heat exchanger 2, a second pipeline section located between the heat exchanger 2 and the gas-liquid separator 23, and a third pipeline section located between the liquid phase outlet of the gas-liquid separator and the preliminary carbonization reaction tower 12.

[0069] like Figure 2 As shown, the heat exchanger 2 includes an inner tube 201 and an outer shell 202. The inner tube 201 is disposed inside the outer shell 202, and a heat exchange chamber is formed between the inner tube 201 and the outer shell 202. The waste liquid pipeline 1 is connected to the oxidation reaction tower 5 through the inner tube 201, and the waste gas pipeline 3 is connected to the dust removal tower 8 through the heat exchange chamber. Multiple baffles 204 are arranged inside the inner tube 201 along the material flow direction, and adjacent baffles 204 are staggered.

[0070] Continue reading Figure 2 The baffle 204 is inclined toward the outlet end of the inner tube 201, and the angle between the baffle 204 and the wall of the inner tube 201 is within the range of [30°, 50°].

[0071] Continue reading Figure 2 The heat exchange chamber is equipped with a heat insulation plate 203, which divides the heat exchange chamber into a first heat exchange chamber and a second heat exchange chamber along the material flow direction. The exhaust gas pipeline 3 is connected to the dust removal tower 8 through the first heat exchange chamber. The first conveying pipeline 7 is connected to the preliminary carbonization reaction tower 12 through the second heat exchange chamber.

[0072] like Figure 3 As shown, the oxidation reaction tower 5 is equipped with an eighth enhanced mass transfer reactor 501 and a ninth enhanced mass transfer reactor 503. Both the eighth enhanced mass transfer reactor 501 and the ninth enhanced mass transfer reactor 503 are located vertically below the liquid surface in the oxidation reaction tower 5. The eighth enhanced mass transfer reactor 501 is located vertically above the ninth enhanced mass transfer reactor 503, and the outlets of the eighth enhanced mass transfer reactor 501 and the ninth enhanced mass transfer reactor 503 are opposite each other. Both the eighth enhanced mass transfer reactor 501 and the ninth enhanced mass transfer reactor 503 are connected to an oxidizing gas pipeline 6.

[0073] Continue reading Figure 3The outlet of the eighth enhanced mass transfer reactor 501 is connected to the outlet of the ninth enhanced mass transfer reactor 503 through the second connecting pipe 502; the second connecting pipe 502 has multiple through holes on its wall.

[0074] Continue reading Figure 3 An vent 504 can be installed at the bottom of the oxidation reaction tower 5.

[0075] The above-mentioned method of using oxidation reaction tower 5 to treat industrial waste brine can be called micro-interface wet oxidation process.

[0076] like Figure 4 As shown, a sixth enhanced mass transfer reactor 804 and a seventh enhanced mass transfer reactor 805 are installed inside the dust removal tower 8. Both the sixth enhanced mass transfer reactor 804 and the seventh enhanced mass transfer reactor 805 are located below the liquid level inside the dust removal tower 8, and are respectively located on opposite side walls inside the dust removal tower 8. Both the sixth enhanced mass transfer reactor 804 and the seventh enhanced mass transfer reactor 805 are connected to the exhaust gas pipeline 3.

[0077] Continue reading Figure 4 The dust removal tower 8 is equipped with a sprayer 807, which is connected to a dust removal liquid pipeline 9. The sprayer 807 is located vertically above the liquid surface inside the dust removal tower 8, and horizontally positioned between the sixth enhanced mass transfer reactor 804 and the seventh enhanced mass transfer reactor 805. The dust removal liquid in the dust removal liquid pipeline 9 can be water.

[0078] See also Figure 4-5 The dust removal tower 8 is also equipped with an auxiliary dust collector 806, which is located vertically between the sprayer 807 and the sixth enhanced mass transfer reactor 804. The auxiliary dust collector 806 is a cone shape that gradually decreases in size from top to bottom in the vertical direction, and the bottom opening of the auxiliary dust collector 806 is located horizontally between the sixth enhanced mass transfer reactor 804 and the seventh enhanced mass transfer reactor 805.

[0079] like Figure 4 As shown, a rotary motor 801 is installed on the outside of the dust removal tower 8. The rotary motor 801 is connected to a rotary shaft 802. The rotary shaft 802 passes through the tower wall of the dust removal tower 8 and extends into the interior of the dust removal tower 8. A rotary fan blade 803 is connected to the end of the rotary shaft 802 away from the rotary motor 801. The rotary fan blade 803 is located vertically below the sixth enhanced mass transfer reactor 804 and horizontally between the sixth enhanced mass transfer reactor 804 and the seventh enhanced mass transfer reactor 805.

[0080] The dust removal process in the above embodiments can be called a micro-interface purification and separation process.

[0081] like Figure 6 As shown, a fourth enhanced mass transfer reactor 1201 and a fifth enhanced mass transfer reactor 1203 are installed inside the preliminary carbonization reaction tower 12. The fourth enhanced mass transfer reactor 1201 is located below the liquid level inside the preliminary carbonization reaction tower 12, and the fifth enhanced mass transfer reactor 1203 is located above the liquid level inside the preliminary carbonization reaction tower 12. The outlet of the fifth enhanced mass transfer reactor 1203 is connected to a first connecting pipe 1202, and the outlet of the first connecting pipe 1202 is connected to the fourth enhanced mass transfer reactor 1201. The first conveying pipeline 7 is connected to the fifth enhanced mass transfer reactor 1203. The ammonia pipeline 22 and the second conveying pipeline 10 are both connected to the fourth enhanced mass transfer reactor 1201.

[0082] Continue reading Figure 6 A gas collecting pipe 1204 can be installed on the fifth enhanced mass transfer reactor 1203 to facilitate the entrainment of the gas from the top of the tower into the fifth enhanced mass transfer reactor 1203.

[0083] Continue reading Figure 6 A backmixing pipe 1206 is provided on one side of the preliminary carbonization reaction tower 12. The inlet of the backmixing pipe 1206 is connected to the side wall of the preliminary carbonization reaction tower 12, and the outlet is connected to the fifth enhanced mass transfer reactor 1203. The inlet of the backmixing pipe 1206 is located vertically between the liquid surface of the fourth enhanced mass transfer reactor 1201 and the preliminary carbonization reaction tower 12. Figure 6 In the middle, a suction pump 1205 can be installed on the back mixing pipeline 1206 to provide power for the material flow in the back mixing pipeline 1206.

[0084] It should be understood that each pipeline in this scheme can be equipped with a pump to facilitate material flow and meet the corresponding material conveying pressure requirements. The specific setup method can be selected according to actual needs, and will not be elaborated here.

[0085] Continue reading Figure 6 The preliminary carbonization reaction tower 12 is equipped with multiple layers of baffles 1207 arranged in an alternating manner, and the baffles 1207 are located below the fourth enhanced mass transfer reactor 1201.

[0086] like Figure 7As shown, the system also includes a stirrer, which includes a stirring motor 1301, a stirring shaft 1302, and a stirring blade 1305. The stirring motor 1301 is connected to the stirring shaft 1302, and the stirring blade 1305 is located at the end of the stirring shaft 1302 away from the stirring motor 1301. The end of the stirring shaft 1302 away from the stirring motor 1301 passes through the deep carbonization reaction tower 13 and extends into the interior of the deep carbonization reaction tower 13. The stirring blade 1305 is located vertically above the first enhanced mass transfer reactor 1306 and the second enhanced mass transfer reactor 1308, and horizontally between the first enhanced mass transfer reactor 1306 and the second enhanced mass transfer reactor 1308.

[0087] Continue reading Figure 7 A distribution pipe 1307 is provided between the outlet of the first enhanced mass transfer reactor 1306 and the outlet of the second enhanced mass transfer reactor 1308; multiple distribution holes are provided on the pipe wall of the distribution pipe 1307 on the side near the stirring blade 1305.

[0088] Continue reading Figure 7 The deep carbonization reaction tower 13 is also equipped with a third enhanced mass transfer reactor 1303, which is located above the liquid surface of the deep carbonization reaction tower 13. The outlet of the third enhanced mass transfer reactor 1303 is connected to an extension pipe 1304, which extends into the liquid surface of the deep carbonization reaction tower 13, and the outlet of the extension pipe 1304 is located above the first enhanced mass transfer reactor 1306 and the second enhanced mass transfer reactor 1308. The outlet of the third conveying pipeline 14 is connected to the third enhanced mass transfer reactor 1303.

[0089] Continue reading Figure 7 A circulation pipeline 1310 is provided on one side of the deep carbonization reaction tower 13. The inlet of the circulation pipeline 1310 is connected to the side wall of the deep carbonization reaction tower 13, and the outlet is connected to the third enhanced mass transfer reactor 1303. The inlet of the circulation pipeline 1310 is located vertically between the liquid surface of the first enhanced mass transfer reactor 1306 and the deep carbonization reaction tower 13.

[0090] In this embodiment, a delivery pump 1309 is installed on the circulation pipeline 1310, and a tail gas outlet can be provided at the top of the deep carbonization reaction tower 13.

[0091] The method of preparing soda ash using the initial carbonization reaction tower and the deep carbonization reaction tower 13 in this embodiment can be called the "Hou's 2.0" soda ash production process.

[0092] like Figure 1As shown, the system may also include a fourth conveying pipeline 11 for conveying high-concentration CO2. In this scheme, high-concentration CO2 can be used to purify low-concentration CO2 obtained from industrial waste gas, and then mixed into the subsequent alkali production process, which helps to further improve alkali production efficiency.

[0093] In this embodiment, the CO2 delivery pressure can be 0.03-0.18 MPa. In related technologies, the CO2 delivery pressure in the "Hou's Alkali Production Process 1.0" is usually 0.45 MPa, while this embodiment only requires a delivery pressure of 0.03-0.18 MPa, thereby helping to reduce the energy consumption of alkali production.

[0094] like Figure 1 As shown, the system also includes a filter tower 15, a calcination tower 16, a mother liquor storage tank 17, and a product conveyor 18. A fifth conveying pipeline 21 is connected to the lower part of the deep carbonization reaction tower 13. The outlet of the fifth conveying pipeline 21 is connected to the filter tower 15. The solid product outlet of the filter tower 15 is connected to the calcination tower 16, and the liquid product outlet is connected to the mother liquor storage tank 17. The product from the deep carbonization reaction tower 13 enters the filter tower 15 for filtration, and the liquid enters the mother liquor storage tank 17. Then, through conventional separation, ammonium chloride is obtained (specifically, by adding sodium chloride to the mother liquor to precipitate ammonium chloride; the remaining sodium chloride solution can be reused as a reaction raw material). The filter residue enters the calcination tower 16, where the sodium bicarbonate is thermally decomposed to obtain soda ash, which is then output from the product conveying pipeline 20 under the drive of the product conveyor 18 installed on the product conveying pipeline 20. The calcination tower 16 can be connected to a calcination gas pipeline 19, which can be used to supply high-temperature gas to the calcination tower 16.

[0095] This embodiment also provides a method for producing alkali using industrial waste gas and industrial waste brine, which can be implemented using the system of any of the above embodiments.

[0096] Figure 8 A flow chart of an alkali production process according to an embodiment of the present invention is shown. Figure 8 As shown, industrial wastewater, after pretreatment, undergoes further COD removal via a micro-interface wet oxidation process. The resulting NaCl, after separation and filtration, is fed into the "Hou's 2.0" alkali production process. Industrial waste gas, after pretreatment, undergoes a micro-interface purification and separation process to obtain a gas with high CO2 purity, which is then fed into the "Hou's 2.0" alkali production process. Simultaneously, ammonia and CO2 from the synthetic ammonia plant can also be fed into the "Hou's 2.0" alkali production process. All the above raw materials are processed through the "Hou's 2.0" alkali production process to obtain soda ash (Na2CO3).

[0097] To more clearly illustrate the technical solutions in this invention, specific embodiments are described below.

[0098] Example 1

[0099] In this embodiment, the following is adopted: Figure 1 The system shown is used to prepare soda ash.

[0100] Example 2

[0101] The difference between this embodiment and Embodiment 1 is that the stirring blade 1305 in the deep carbonization reaction tower is located below the first enhanced mass transfer reactor 1306.

[0102] Example 3

[0103] The difference between this embodiment and Embodiment 1 is that the distribution holes on the distribution pipe 1307 are located on the pipe wall on the side away from the stirring blade 1305.

[0104] Example 4

[0105] The difference between this embodiment and Embodiment 1 is that the outlet of the extension tube 1304 is located below the first enhanced mass transfer reactor.

[0106] Example 5

[0107] The difference between this embodiment and Embodiment 1 is that the partition 1207 is located above the fourth enhanced mass transfer reactor 1201.

[0108] Experimental Example 1

[0109] The same industrial waste gas, industrial waste brine and ammonia were respectively introduced into the systems of Examples 1-5, and soda ash was produced using the systems of Examples 1-5 respectively.

[0110] The yield and purity of soda ash in the product output from the product conveying pipeline, as well as the CO2 concentration in the tail gas discharged from the top of the deep carbonization reaction tower, were tested. The test results are shown in the table below.

[0111] Table 1 Test Results

[0112]

[0113] As shown in the table above, it can be seen that the system of the present invention can ensure high soda ash yield and purity when using industrial waste gas and industrial waste brine to prepare soda ash, and the CO2 conversion rate is also high.

[0114] Comparing Example 1 and Example 2, it can be observed that Example 2 has a lower soda ash yield and a higher CO2 concentration in the tail gas. This may be due to the different position of the stirring blades. Specifically, it may be because the stirring blades are positioned too low, causing back-mixing of the product during stirring, which affects the stable output of the product.

[0115] Comparing Example 1 and Example 3, it can be observed that Example 3 has a lower soda ash yield and a higher CO2 concentration in the tail gas. This may be due to the different positions of the distribution holes. Specifically, the scheme in Example 1, by placing the distribution holes on the pipe wall near the stirring blades, allows the output microbubbles to be directly dispersed into the liquid phase material inside the tower via stirring, resulting in a higher degree of uniform distribution. Therefore, it has a higher soda ash yield and CO2 conversion rate.

[0116] Comparing Example 1 with Example 4, it can be observed that the soda ash yield is lower and the CO2 concentration in the tail gas is higher in Example 4. This may be because the material in the extension tube is directly fed to the bottom of the first enhanced mass transfer reactor, which on the one hand impacts the bottom product and causes some product backmixing. On the other hand, the microbubbles directly fed to the bottom may have aggregated, reducing the phase boundary mass transfer area.

[0117] Comparing Example 1 with Example 5, it can be observed that Example 5 exhibits lower soda ash yield and higher CO2 concentration in the tail gas. This may be because the upper baffle plate affects the feedstock reaction between the two enhanced mass transfer reactors, leading to a decrease in feedstock conversion rate and soda ash yield.

[0118] In summary, it can be seen that the scheme in Example 1 improves the raw material conversion rate and soda ash production by specifically setting the positions of the first enhanced mass transfer reactor, the second enhanced mass transfer reactor, the extension pipe, the stirring blade, and the distribution pipe. Therefore, Example 1 is a preferred embodiment of the present invention.

[0119] Experimental Example 2

[0120] Oxidation products and dust removal products from Example 1 were collected, and the COD content in the oxidation products and the CO2 content in the dust removal products were measured. The results are shown in the table below:

[0121] Table 2 Detection Results

[0122]

[0123] As shown in the table above, it can be seen that the present invention can effectively reduce the COD concentration in industrial wastewater and effectively increase the CO2 content in industrial waste gas.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A system for producing alkali using industrial waste gas and industrial waste brine, characterized in that, include: Waste liquid pipelines, waste gas pipelines, ammonia pipelines, heat exchangers, oxidation reaction towers, dust removal towers, preliminary carbonization reaction towers, and deep carbonization reaction towers; The outlet of the waste liquid pipeline is connected to the oxidation reaction tower, and the heat exchanger is installed on the waste liquid pipeline; the industrial waste brine in the waste liquid pipeline undergoes a wet oxidation reaction in the oxidation reaction tower, and the generated oxidation products are transported to the preliminary carbonization reaction tower via the first conveying pipeline. The exhaust gas pipeline is connected to the dust removal tower via the heat exchanger. After the industrial exhaust gas in the exhaust gas pipeline is dusted in the dust removal tower, the dust removal product is transported to the preliminary carbonization reaction tower via the second conveying pipeline. The ammonia pipeline is connected to the preliminary carbonization reaction tower, and the bottom outlet of the preliminary carbonization reaction tower is connected to a third conveying pipeline, the outlet of which is connected to the deep carbonization reaction tower. The deep carbonization reaction tower is equipped with a first enhanced mass transfer reactor and a second enhanced mass transfer reactor. The first enhanced mass transfer reactor and the second enhanced mass transfer reactor are respectively located on opposite side walls of the deep carbonization reaction tower, and their outlets are opposite to each other. Both the first enhanced mass transfer reactor and the second enhanced mass transfer reactor are connected to the second conveying pipeline. The dust removal product is dispersed and broken into micron-sized microbubbles by the first enhanced mass transfer reactor and the second enhanced mass transfer reactor, and then reacts with the material conveyed by the third conveying pipeline to realize the production of alkali using the negative carbon production process. It also includes a stirrer, which includes a stirring motor, a stirring shaft, and stirring blades. The stirring motor is connected to the stirring shaft, and the stirring blades are disposed at the end of the stirring shaft away from the stirring motor. The end of the stirring shaft away from the stirring motor passes through the deep carbonization reaction tower and extends into the interior of the deep carbonization reaction tower. The stirring blades are located vertically above the first enhanced mass transfer reactor and the second enhanced mass transfer reactor, and horizontally between the first enhanced mass transfer reactor and the second enhanced mass transfer reactor. A distribution pipe is provided between the outlet of the first enhanced mass transfer reactor and the outlet of the second enhanced mass transfer reactor; the distribution pipe has multiple distribution holes on the pipe wall near the stirring blade. The dust removal tower is equipped with a sixth enhanced mass transfer reactor and a seventh enhanced mass transfer reactor. Both the sixth and seventh enhanced mass transfer reactors are located below the liquid level in the dust removal tower and are respectively located on opposite side walls of the dust removal tower. Both the sixth and seventh enhanced mass transfer reactors are connected to the exhaust gas pipeline.

2. The system according to claim 1, characterized in that, The deep carbonization reaction tower is further equipped with a third enhanced mass transfer reactor, which is located above the liquid surface of the deep carbonization reaction tower. The outlet of the third enhanced mass transfer reactor is connected to an extension pipe that extends into the liquid surface of the deep carbonization reaction tower, and the outlet of the extension pipe is located above the first enhanced mass transfer reactor and the second enhanced mass transfer reactor. The outlet of the third conveying pipeline is connected to the third enhanced mass transfer reactor. A circulation pipeline is provided on one side of the deep carbonization reaction tower. The inlet of the circulation pipeline is connected to the side wall of the deep carbonization reaction tower, and the outlet is connected to the third enhanced mass transfer reactor. The inlet of the circulation pipeline is located vertically between the liquid surface of the first enhanced mass transfer reactor and the deep carbonization reaction tower.

3. The system according to claim 1, characterized in that, The primary carbonization reaction tower is equipped with a fourth enhanced mass transfer reactor and a fifth enhanced mass transfer reactor. The fourth enhanced mass transfer reactor is located below the liquid level in the primary carbonization reaction tower, and the fifth enhanced mass transfer reactor is located above the liquid level in the primary carbonization reaction tower. The outlet of the fifth enhanced mass transfer reactor is connected to a first connecting pipe, and the outlet of the first connecting pipe is connected to the fourth enhanced mass transfer reactor. A first conveying pipeline is connected to the fifth enhanced mass transfer reactor. The ammonia pipeline and the second conveying pipeline are both connected to the fourth enhanced mass transfer reactor. A backmixing pipeline is provided on one side of the preliminary carbonization reaction tower. The inlet of the backmixing pipeline is connected to the side wall of the preliminary carbonization reaction tower, and the outlet is connected to the fifth enhanced mass transfer reactor. The inlet of the backmixing pipeline is located vertically between the liquid surface of the fourth enhanced mass transfer reactor and the preliminary carbonization reaction tower. The preliminary carbonization reaction tower is equipped with multiple layers of baffles arranged in an alternating manner, and the baffles are located below the fourth enhanced mass transfer reactor.

4. The system according to claim 1, characterized in that, The dust removal tower is equipped with a sprayer, which is connected to a dust removal liquid pipeline. The sprayer is located vertically above the liquid surface inside the dust removal tower and horizontally between the sixth enhanced mass transfer reactor and the seventh enhanced mass transfer reactor.

5. The system according to claim 4, characterized in that, An auxiliary dust collector is also installed inside the dust removal tower. The auxiliary dust collector is located vertically between the sprayer and the sixth enhanced mass transfer reactor. The auxiliary dust collector is a cone shape that gradually decreases in size from top to bottom in the vertical direction. The bottom opening of the auxiliary dust collector is located horizontally between the sixth enhanced mass transfer reactor and the seventh enhanced mass transfer reactor. A rotary motor is installed on the outside of the dust removal tower. The rotary motor is connected to a rotating shaft. The rotating shaft passes through the tower wall and extends into the interior of the dust removal tower. A rotating fan blade is connected to the end of the rotating shaft away from the rotary motor. The rotating fan blade is located vertically below the sixth enhanced mass transfer reactor and horizontally between the sixth enhanced mass transfer reactor and the seventh enhanced mass transfer reactor.

6. The system according to claim 1, characterized in that, The oxidation reaction tower is equipped with an eighth enhanced mass transfer reactor and a ninth enhanced mass transfer reactor. The eighth enhanced mass transfer reactor and the ninth enhanced mass transfer reactor are both located below the liquid surface in the oxidation reaction tower in the vertical direction. The eighth enhanced mass transfer reactor is located above the ninth enhanced mass transfer reactor in the vertical direction, and the outlets of the eighth enhanced mass transfer reactor and the ninth enhanced mass transfer reactor are opposite to each other. Both the eighth enhanced mass transfer reactor and the ninth enhanced mass transfer reactor are connected to an oxidizing gas pipeline. The outlet of the eighth enhanced mass transfer reactor is connected to the outlet of the ninth enhanced mass transfer reactor via a second connecting pipe; the second connecting pipe has multiple through holes on its wall.

7. The system according to any one of claims 1-6, characterized in that, The heat exchanger includes an inner tube and an outer shell. The inner tube is disposed inside the outer shell, and a heat exchange cavity is formed between the inner tube and the outer shell. The waste liquid pipeline is connected to the oxidation reaction tower via the inner tube, and the waste gas pipeline is connected to the dust removal tower via the heat exchange cavity. Multiple baffles are arranged inside the inner tube along the material flow direction, and adjacent baffles are staggered. The baffle plate is inclined toward the outlet end of the inner tube, and the angle between the baffle plate and the inner tube wall is within the range of [30°, 50°]. The heat exchange chamber is equipped with a heat insulation plate, which divides the heat exchange chamber into a first heat exchange chamber and a second heat exchange chamber along the material flow direction; the exhaust gas pipeline is connected to the dust removal tower via the first heat exchange chamber; the first conveying pipeline is connected to the preliminary carbonization reaction tower via the second heat exchange chamber.

8. A method for producing alkali using industrial waste gas and industrial waste brine, characterized in that, The system described in any one of claims 1-7 is used for alkali production.

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