A SO2 resource recovery system and method based on liquid flow battery regeneration cycle

Abstract

The present invention relates to a SO2 resource recovery system and method based on a liquid flow battery regeneration cycle. The system comprises an energy release unit I (1), an energy release unit II (10) and an energy regeneration unit (6) electrically connected to an energy storage unit (13). The method converts the chemical energy of the SO2 redox reaction into electrical energy through the energy release unit and provides it to the energy storage unit (13). The Br generated by the energy release unit is converted into electrical energy. ‑ and S x 2‑ Regenerated into Br2 and S by the energized regeneration unit (6) 2‑ The chemical energy is then returned to the energy release unit for recycling and provides the energy required for the reaction to the energy regeneration unit (6), thereby realizing energy recycling. Compared with the prior art, the present invention is suitable for industries that produce a large amount of SO2 as a by-product. The method can be used to convert the chemical energy released by the reaction into electrical energy for storage and utilization. The present invention can obtain sulfuric acid and sulfur products without consuming additional energy and reagents, and has good economic and environmental benefits and application and promotion prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of sulfur dioxide recovery and resource utilization, and relates to a SO2 resource recovery system and method based on liquid flow battery regeneration cycle. Background Art

[0002] The non-ferrous metals industry typically uses metal sulfides as its primary raw material. The smelting process produces large amounts of sulfur-laden flue gas, severely impacting the natural environment and public health. To address this high-concentration sulfur-laden flue gas, non-ferrous metallurgical companies typically employ a two-conversion, two-absorption process to convert sulfur dioxide in the flue gas into sulfur trioxide, which is then produced as sulfuric acid. However, this process carries high operating costs and energy consumption for materials such as catalysts. Traditional dry and wet desulfurization methods also continuously and significantly consume lime, which is then converted into gypsum. All of these methods suffer from high material and energy consumption and a low input-output ratio.

[0003] In the 1980s, General Atomics (GA) in the United States proposed an iodine-sulfur cycle technology. This technology includes the Bunsen reaction (I2 + SO2 + 2H2O → H2SO4 + 2HI), hydrogen iodide decomposition (2HI → H2 + I2), and sulfuric acid decomposition (H2SO4 → SO2 + 0.5O2 + H2O). These three reactions form a closed loop and can produce H2. Zhejiang University built on this and proposed an open-loop iodine-sulfur cycle technology, replacing the sulfuric acid decomposition process with a sulfuric acid concentration process, thereby achieving the coupling of SO2 resource recovery and H2 production. These technologies fully consider the material cycle in the SO2 resource recovery process, achieving product economy and low drug consumption. However, the process is still energy-intensive and does not fully consider energy recovery and utilization in SO2 resource recovery. Patent CN115159466A discloses a method for recycling SO2 flue gas. This method utilizes the catalytic capacity of sulfur-containing activated carbon to disproportionate sulfite into sulfur and bisulfate at 50°C. Patent CN115159467A discloses the use of ammonia to absorb SO2 and, under the action of a catalyst, convert sulfite into sulfur and bisulfate. While these patents provide methods for disproportionating SO2 into bisulfate and sulfur, they suffer from catalytic rate limitations, harsh reaction conditions, and difficult phase separation. There is still a need for a SO2 recycling technology with low material and energy consumption. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of high chemical consumption and high energy consumption in the above-mentioned prior art for high-value recovery and utilization of sulfur dioxide and to provide a SO2 resource recovery system and method based on liquid flow battery regeneration cycle. The present invention is based on the regeneration principle of sodium polysulfide / bromine liquid flow battery, and makes full use of the energy released during the SO2 form transformation to empower the regeneration of chemicals, thereby achieving low chemical consumption and energy consumption in the SO2 resource process; the present invention also produces by-products such as sulfuric acid and sulfur, which have good economic value and environmental benefits.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] One of the technical solutions of the present invention is to provide a SO2 resource recovery system based on a liquid flow battery regeneration cycle, which includes an energy release unit I, an energy release unit II and an energy-enabling regeneration unit electrically connected to an energy storage unit, wherein the energy release unit I includes an energy release unit I positive electrode region and an energy release unit I negative electrode region, the energy release unit II includes an energy release unit II positive electrode region and an energy release unit II negative electrode region, and the energy-enabling regeneration unit includes an energy-enabling regeneration unit anode region and an energy-enabling regeneration unit cathode region;

[0007] The positive electrode region of the energy release unit I, the regeneration buffer tank I, the anode region of the energizing regeneration unit and the regeneration storage tank I constitute a loop, the negative electrode region of the energy release unit I is connected to the material tank I, the positive electrode region of the energy release unit II is connected to the material tank II, the negative electrode region of the energy release unit II, the regeneration buffer tank II, the cathode region of the energizing regeneration unit and the regeneration storage tank II constitute a loop.

[0008] As a preferred technical solution, the energy release unit I, energy release unit II and energy regeneration unit are connected to the regeneration storage tank I, regeneration buffer tank I, regeneration storage tank II, regeneration buffer tank II, material tank I and material tank II through pumps to extract the solution.

[0009] As a preferred technical solution, the positive electrode area of ​​the energy release unit I, the anode area of ​​the energy regeneration unit, the regeneration storage tank I and the regeneration buffer tank I are kept sealed and leak-proof during operation to prevent a small amount of hydrogen bromide from volatilizing in gaseous form.

[0010] Furthermore, sulfur dioxide is introduced into the negative electrode region of the energy release unit I and the positive electrode region of the energy release unit II. The sulfur dioxide is deoxygenated sulfur dioxide gas with a purity of 5-100%, and the other component is nitrogen.

[0011] Furthermore, the substance in the positive electrode region of the energy release unit I is a Br2 / H2SO4 mixed solution, wherein the concentration of Br2 is 0.5-1.0 mol / L, and the concentration of H2SO4 is 0.5-1.0 mol / L;

[0012] The substance in the negative electrode region of the energy release unit I is H2SO4 solution, wherein the concentration of H2SO4 is 0.5-3.0 mol / L, and the ratio of SO2 flow rate to H2SO4 solution volume is 4-40h -1 , so that the molar ratio of SO2 to bromine in the positive electrode region of the energy release unit I is (2.0-3.0):1, and the SO2 concentration is maintained at 0.75-1.25 mol / L;

[0013] The substance in the positive electrode region of the energy release unit II is H2SO4 solution, wherein the concentration of H2SO4 is 0.5-1.0 mol / L, and the ratio of SO2 flow rate to H2SO4 solution volume is 2-20h -1 ;

[0014] The material in the negative electrode region of the energy release unit II is S 2- / S x 2- Mixed solution, in which S 2- The concentration is 0.5-1.0 mol / L, S x 2- The concentration is 0-0.5 mol / L, and x is 2-4;

[0015] The substance in the anode region of the energy-enabling regeneration unit is Br - / Br2 / H2SO4 mixed solution, in which Br - The concentration of is 0.5-1.0mol / L, the concentration of Br2 is 0-0.5mol / L, and the concentration of H2SO4 is 0.5-1.0mol / L;

[0016] The substance in the cathode region of the energizing regeneration unit is S 2- / S x 2- Mixed solution, in which S 2- The concentration is 0-0.5 mol / L, S x 2- The concentration is 0.5-1.0 mol / L, and x is 2-4.

[0017] Furthermore, the ratio of the amount of SO2 substance introduced into the negative electrode region of the energy release unit I and the positive electrode region of the energy release unit II is (1.5-3.0):1.

[0018] Furthermore, a separator I is provided between the positive and negative regions of the energy release unit I, a separator III is provided between the positive and negative regions of the energy release unit II, and a separator II is provided between the anode and cathode regions of the energy regeneration unit. Separators I, II, and III are proton exchange membranes (PEGM), which are perfluorosulfonic acid-based proton exchange membranes with excellent corrosion resistance, a thickness of 100-300 μm, a conductivity of 0.08-0.09 S / cm, and an exchange capacity of 0.8-1.0 meq / g. During discharge or regeneration, only positive ions are allowed to pass through to maintain charge balance.

[0019] Furthermore, the energy release unit I, energy release unit II and energy regeneration unit are provided with electrodes, the material of the electrodes is a mesh porous graphite with a pore size of 0.01-6.00 mm, a porosity of 30-80%, and a resistivity of 1.0×10 -5 -1.0×10 -2 Ω·m, thickness is 1-15mm;

[0020] The electrode is kept at a distance of 2-5 cm from the proton exchange membrane.

[0021] Furthermore, the energy release unit I, energy release unit II and energy regeneration unit are provided with a stirring device to eliminate concentration polarization during operation, and the material tank II is provided with a sulfur filtering device to obtain sulfur products.

[0022] Furthermore, in order to control the voltage of energy release unit I and energy release unit II, the energy release unit is designed as multiple discharge modules connected in series to meet the voltage requirements of power storage. The energy release unit I is connected in series with 3-6 modules, and the energy release unit II is connected in series with 10-20 modules.

[0023] One of the technical solutions of the present invention is to provide a method for SO2 resource recovery system based on liquid flow battery regeneration cycle, which comprises the following steps:

[0024] (1) The Br in the positive electrode region of the energy release unit I contains the reacted - The solution is partially pumped into the regeneration buffer tank I, and at the same time, the solution containing the regenerated Br2 in the regeneration storage tank I is transported to the positive electrode area of ​​the energy release unit I to maintain the Br2 concentration in the positive electrode area of ​​the energy release unit I;

[0025] (2) After the sulfuric acid product in the negative electrode region of the energy release unit 1 accumulates to a certain concentration, it is partially drawn into the feed tank 1 to obtain the resource-based sulfuric acid product. At the same time, SO2 is continuously introduced into the negative electrode region of the energy release unit 1 to maintain the SO2 supply to the negative electrode region of the energy release unit 1;

[0026] (3) The sulfur product in the positive electrode region of the energy release unit II is partially drawn into the feed tank II, and after filtration, the resource-recovered sulfur product is obtained. At the same time, SO2 is continuously introduced into the positive electrode region of the energy release unit II to maintain the SO2 supply to the negative electrode region of the energy release unit I;

[0027] (4) The S in the negative electrode region of the energy release unit II contains the reacted x 2- The solution is partially pumped into the regeneration buffer tank II, and the regeneration storage tank II contains the regenerated S 2- The solution is transported to the negative electrode area of ​​the energy release unit II to maintain the S 2- concentration;

[0028] (5) The solution containing Br2 after charge regeneration in the anode area of ​​the energizing regeneration unit is transported to the regeneration storage tank I, and the solution containing Br2 after discharge reaction is transported to the regeneration storage tank I. - The solution enters the anode area of ​​the energy-generating regeneration unit from the regeneration buffer tank I to maintain the Br in the positive electrode area of ​​the energy-releasing unit I. - concentration;

[0029] (6) The cathode region of the energizing regeneration unit contains S after charging and regeneration. 2- The solution is transported to the regeneration storage tank II, and contains S after the discharge reaction x 2- The solution enters the cathode area of ​​the energizing regeneration unit from the regeneration buffer tank II to maintain the S x 2- concentration;

[0030] (7) The energy storage unit absorbs the discharge reaction energy of the energy release unit I and the energy release unit II, and at the same time supplements the charging regeneration energy of the energy regeneration unit.

[0031] Furthermore, the proportion of the partial extraction is 20-50%, and the accumulated concentration of the sulfuric acid product is 2-3 mol / L.

[0032] In the 1980s, Professors Remick and Ang of Georgia Institute of Technology first proposed the concept of a sodium polysulfide / bromine flow battery. By the early 1990s, Regenesys had developed a practical sodium polysulfide / bromine flow battery. This flow battery system uses NaBr and Na2S2 as the positive and negative electrolytes, respectively, and a sodium ion exchange membrane as the separator. The following reactions occur during charge and discharge in a sodium polysulfide / bromine flow battery:

[0033] Charging reaction positive electrode process: 2Br - →2Br 0 +2e -

[0034] Charging reaction negative electrode process: S x 2- +2e - →S 2- +S x-1 2-

[0035] Discharge reaction cathode process: 2Br 0 +2e - →2Br -

[0036] Discharge reaction negative electrode process: S 2- +S x-1 2- →S x 2- +2e -

[0037] After the sodium polysulfide / bromine flow battery is charged, both the positive and negative electrolytes can react with SO2 to generate sulfuric acid and sulfur respectively, which can achieve the purpose of SO2 resource utilization; however, the byproduct Br - and S x 2- This is the product of the sodium polysulfide / bromine flow battery after discharge, and the electrical energy of the sodium polysulfide / bromine flow battery is consumed. The sulfur dioxide in flue gas is tetravalent sulfur, which has the potential to adjust its valence state. The electron gain and loss associated with the sulfur atom's valence state transition will generate some usable electrical energy. This conversion of chemical energy into electrical energy is expected to provide new ideas for the high-value utilization of sulfur dioxide. Consider the following two reactions:

[0038] 2Br2+2SO2+4H2O→4Br - +2SO4 2- +8H + ,ΔH<0,ΔG<0

[0039] SO2+4S 2- +4H + →S 0 +2S2 2- +2H2O,ΔH<0,ΔG<0

[0040] Both reactions are spontaneous reactions that release chemical energy, and the chemical energy released is higher than that of Br - and S2 2- The energy required for regeneration, so energy recovery is used for Br - and S 2- However, there is currently no technology for recycling SO2 and utilizing its chemical energy.

[0041] The following electrode reactions occur during operation of the present invention:

[0042] (1) The energy release unit I undergoes the following primary cell reaction:

[0043] Positive electrode: Br2+2e - =2Br -

[0044] Negative electrode: 2H2O+SO2-2e - =SO4 2- +4H +

[0045] (2) The following galvanic cell reaction occurs in the energy release unit II:

[0046] Positive electrode: 2H + +0.5SO2+2e - =0.5S+H2O

[0047] Negative electrode: S 2- +S x-1 2- -2e - =S x 2-

[0048] (3) The following electrolytic reaction occurs in the energized regeneration unit:

[0049] Anode: 2Br - -2e - =Br2

[0050] Cathode: S x 2- +2e - =S 2- +S x-1 2-

[0051] SO2 is introduced into the negative electrode area of ​​energy release unit I and the positive electrode area of ​​energy release unit II respectively, and sulfuric acid and sulfur are produced by electrode reaction and recycled as resources; Br produced in the positive electrode area of ​​energy release unit I and the negative electrode area of ​​energy release unit II - and S x 2- Then they enter the anode and cathode areas of the energy-generating and regenerating units respectively, and are regenerated into Br2 and S through electrolysis reaction. 2- , re-enter the positive electrode area of ​​energy release unit I and the negative electrode area of ​​energy release unit II to participate in the original battery reaction.

[0052] This technology can make full use of the high concentration of sulfur dioxide in the flue gas to achieve high-value recovery of sulfur resources, and realize low-cost and low-energy consumption of the SO2 resource process through material circulation and energy recovery.

[0053] Compared with the prior art, the present invention has the following advantages:

[0054] (1) The present invention can obtain sulfuric acid product in the feed tank I and sulfur solid product in the feed tank II, thereby achieving high-value utilization of SO2;

[0055] (2) The present invention can convert chemical energy of sulfur dioxide into electrical energy through the electrode reaction process in energy release unit I and energy release unit II, and this energy can effectively supplement the electrical energy consumption of the energy regeneration unit;

[0056] (3) The present invention uses the energized regeneration unit to - With S x 2- Empowering regeneration and achieving Br - and S x 2- Recycling of materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 Schematic diagram of the technical process of the SO2 resource recovery system and method based on the regeneration cycle of the flow battery in an embodiment of the present invention;

[0058] Figure 2 Schematic diagram of an energy release unit I with multiple modules connected in series in an embodiment of the present invention;

[0059] Figure 3 Schematic diagram of energy release unit II with multiple modules connected in series in an embodiment of the present invention.

[0060] Description of the marks in the figure:

[0061] 1—energy release unit I, 1-1—positive electrode region of energy release unit I, 1-2—negative electrode region of energy release unit I, 2—diaphragm I, 3—feeding tank I, 4—regeneration buffer tank I, 5—regeneration storage tank I, 6—energizing regeneration unit, 6-1—energizing regeneration unit anode region, 6-2—energizing regeneration unit cathode region, 7—diaphragm II, 8—regeneration buffer tank II, 9—regeneration storage tank II, 10—energy release unit II, 10-1—positive electrode region of energy release unit II, 10-2—negative electrode region of energy release unit II, 11—diaphragm III, 12—feeding tank II, 13—energy storage unit. DETAILED DESCRIPTION

[0062] The present invention is described in detail below with reference to specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0063] Unless otherwise specified, the equipment used in the following examples are all conventional equipment in the art; the reagents used are all commercially available products or prepared by conventional methods in the art unless otherwise specified. Anything not described in detail in the following examples can be achieved by conventional experimental means in the art.

[0064] Example 1:

[0065] A SO2 resource recovery system and method based on liquid flow battery regeneration cycle, the specific steps are as follows:

[0066] In this example, an electrochemical reaction device with a volume of 500 mL was first built, using a mesh porous graphite sheet as the electrode material with a pore size of 0.05 mm, a porosity of 75%, and a resistivity of 1.0×10 -3 Ω·m, with a thickness of 10mm. The positive and negative electrodes of the reaction system are separated by a Nafion 117 perfluorosulfonic acid proton exchange membrane. The membrane is 200μm thick, has a conductivity of 0.08S / cm, and an exchange capacity of 0.92meq / g. The solutions in the positive and negative electrodes are connected by the membrane, with a distance of 4cm between the positive and negative electrodes and the membrane, respectively.

[0067] 200mL of bromine water and 1.0mol / L sulfuric acid were added to the positive electrode; 200mL of 1.0mol / L sulfuric acid was added to the negative electrode, and a 20% SO2 gas was continuously introduced into the negative electrode at a flow rate of 4L / h. As SO2 neared saturation, an open-circuit voltage of 0.6-1.0V was observed at the positive and negative electrodes of the device, and a current of 20-40mA / cm3 was detected in the circuit. 2 The current density was 2.5 volts. After 30 hours of discharge, the current reading gradually dropped to 0, and the positive electrode region turned from brown to colorless. 80 mL of 2.0 mol / L sulfuric acid solution was collected from the negative electrode region. The efficiency of SO2 conversion to sulfuric acid reached 90%, and the efficiency of chemical energy conversion to electrical energy reached 93%.

[0068] After this example, an electrochemical reaction device with a volume of 500 mL was built, using a mesh porous graphite sheet as the electrode material, with a pore size of 0.05 mm, a porosity of 75%, and a resistivity of 1.0×10 -3 Ω·m, with a thickness of 10mm. The positive and negative electrodes of the reaction system are separated by a Nafion 117 perfluorosulfonic acid proton exchange membrane. The membrane is 200μm thick, has a conductivity of 0.08S / cm, and an exchange capacity of 0.92meq / g. The solutions in the positive and negative electrodes are connected by the membrane, with a distance of 4cm between the positive and negative electrodes and the membrane, respectively.

[0069] 200mL of 1.0mol / L sulfuric acid solution was added to the positive electrode, and a 20% SO2 gas was continuously introduced at a SO2 flow rate of 2L / h. 200mL of 1.0mol / L sodium sulfide solution was added to the negative electrode. As SO2 neared saturation, an open-circuit voltage of 0.2-0.4V was observed at the positive and negative electrodes of the device, and a current of 1-3mA / cm3 was detected in the circuit. 2 The current density was 1.5 liters, indicating that the galvanic reaction was proceeding spontaneously and that the chemical energy was being released as electrical energy. After 120 hours of discharge, the current reading gradually dropped to 0, and the amount of yellow solid gradually increased. At this point, 2.5 g of solid sulfur was obtained from the positive electrode, indicating an 80% efficiency in converting SO2 to sulfur and an 85% efficiency in converting chemical energy to electrical energy.

[0070] Example 2:

[0071] A SO2 resource recovery system and method based on liquid flow battery regeneration cycle, the specific steps are as follows:

[0072] In this embodiment, Figure 1 As shown in FIG, three electrochemical reaction devices with a volume of 500 mL were built, namely energy release unit I1, energy release unit II 10 and energy regeneration unit 6. For ease of understanding, Figure 1 The design of the energy discharging unit I1 and the energy discharging unit II 10 is simplified, and only the design of one discharge module is shown. In actual use, the energy discharging unit I1 and the energy discharging unit II 10 are composed of multiple discharge modules connected in series to achieve the voltage required for power storage. Figure 2 and 3 As shown, the energy release unit I1 and the energy release unit II10 are respectively shown as 4 modules connected in series, but this does not mean that only 4 modules can be connected in series. During actual operation, the number of modules in series can be increased or decreased according to voltage requirements. In this embodiment, the energy release unit I1 is 5 modules connected in series, and the energy release unit II 10 is 10 modules connected in series.

[0073] Each unit uses a mesh porous graphite sheet as the electrode material with a pore size of 0.05 mm, a porosity of 75%, and a resistivity of 1.0×10 -3 Ω·m, with a thickness of 10mm. The anode and cathode regions, as well as the positive and negative regions, of the reaction system were separated by a Nafion 117 perfluorosulfonic acid proton exchange membrane. The membrane had a thickness of 200μm, a conductivity of 0.08S / cm, and an exchange capacity of 0.92meq / g. The solutions between the two electrodes were connected via the membrane, with a spacing of 4cm between the electrodes and the membrane.

[0074] 200 mL of bromine water and a 1.0 mol / L sulfuric acid solution were added to the positive electrode region 1-1 of energy release unit I. 200 mL of a 1.0 mol / L sulfuric acid solution was added to the negative electrode region 1-2 of energy release unit I, and a 20% SO2 gas was continuously introduced into the negative electrode region 1-2 of energy release unit I at a SO2 flow rate of 4 L / h. 200 mL of a 1.0 mol / L sulfuric acid solution was added to the positive electrode region 10-1 of energy release unit II, and a 20% SO2 gas was continuously introduced into the negative electrode region 10-2 of energy release unit II at a SO2 flow rate of 2 L / h. 200 mL of a 1.0 mol / L sodium sulfide solution was added to the negative electrode region 10-2 of energy release unit II. A 1.0 mol / L sodium bromide solution was added to the anode region 6-1 of the energy regeneration unit, and a 1.0 mol / L sodium tetrasulfide (Na2S4) solution was added to the cathode region 6-2 of the energy regeneration unit. As the electrolysis reaction proceeds, the color of the solution in the anode region 6-1 of the energized regeneration unit gradually darkens, indicating that Br - After 20 hours of electrolysis, Br2 and S with a concentration of 0.9 mol / L were obtained from the anode and cathode respectively. 2- The solution in the anode region 6-1 and cathode region 6-2 of the energy-enabling regeneration unit is drawn back to the positive electrode region 1-1 of the energy-discharging unit I and the negative electrode region 10-2 of the energy-discharging unit II through the regeneration storage tank I 5 and the regeneration storage tank II 9, so that the energy-discharging unit I 1 and the energy-discharging unit II 10 can continue to operate. - 40% of the solution is pumped into the regeneration buffer tank I 4, and the S4 in the negative electrode area 10-2 of the energy release unit II is reacted. 2- 40% of the solution is pumped into the regeneration buffer tank II 8. After the sulfuric acid product in the negative electrode area 1-2 of the energy release unit I accumulates to 2 mol / L, 40% is pumped into the feed tank I (3) to obtain the sulfuric acid product, and 40% of the sulfur product in the positive electrode area 10-1 of the energy release unit II is pumped into the feed tank II (12), and the sulfur product is obtained after filtering by the sulfur filtering device. The energy release unit I1, the energy release unit II 10 and the energy-enabling regeneration unit 6 are provided with a stirring device. The energy release unit I1, the energy release unit II10 and the energy-enabling regeneration unit 6 are connected to the regeneration storage tank I 5, the regeneration buffer tank I 4, the regeneration storage tank II 9, the regeneration buffer tank II 8, the feed tank I 3 and the feed tank II 12 through a pump and extract the solution. The positive electrode area 1-1 of the energy release unit I, the anode area 6-1 of the energy-enabling regeneration unit, the regeneration storage tank I 5 and the regeneration buffer tank I 4 are kept sealed and leak-proof during operation. After 20 hours of operation, 80 mL of 2.0 mol / L sulfuric acid solution and 2.5 g of sulfur solid were obtained. The efficiency of converting SO2 into sulfuric acid and sulfur reached 90% and 80% respectively. The energy utilization efficiency of the system reached 70%, which is sufficient to maintain the operation of the empowerment regeneration unit without the need for additional energy.

[0075] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A SO2 resource recovery system based on liquid flow battery regeneration cycle, characterized in that: The system comprises an energy release unit I (1), an energy release unit II (10) and an energy regeneration unit (6) electrically connected to an energy storage unit (13), wherein the energy release unit I (1) comprises an energy release unit I positive electrode region (1-1) and an energy release unit I negative electrode region (1-2), the energy release unit II (10) comprises an energy release unit II positive electrode region (10-1) and an energy release unit II negative electrode region (10-2), and the energy regeneration unit (6) comprises an energy regeneration unit anode region (6-1) and an energy regeneration unit cathode region (6-2); The positive electrode region (1-1) of the energy release unit I, the regeneration buffer tank I (4), the anode region (6-1) of the energizing regeneration unit and the regeneration storage tank I (5) form a loop, the negative electrode region (1-2) of the energy release unit I is connected to the material taking tank I (3), the positive electrode region (10-1) of the energy release unit II is connected to the material taking tank II (12), and the negative electrode region (10-2) of the energy release unit II, the regeneration buffer tank II (8), the cathode region (6-2) of the energizing regeneration unit and the regeneration storage tank II (9) form a loop; Sulfur dioxide is introduced into the negative electrode region (1-2) of the energy release unit I and the positive electrode region (10-1) of the energy release unit II. The sulfur dioxide is deoxygenated sulfur dioxide gas with a purity of 5-100%, and the other component is nitrogen; The substance in the positive electrode region (1-1) of the energy release unit I is a Br2 / H2SO4 mixed solution, wherein the concentration of Br2 is 0.5-1.0 mol / L, and the concentration of H2SO4 is 0.5-1.0 mol / L; The substance in the negative electrode region (1-2) of the energy release unit I is H2SO4 solution, wherein the concentration of H2SO4 is 0.5-3.0 mol / L, and the ratio of SO2 flow rate to H2SO4 solution volume is 4-40 h -1 ; The substance in the positive electrode region (10-1) of the energy release unit II is H2SO4 solution, wherein the concentration of H2SO4 is 0.5-1.0 mol / L, and the ratio of SO2 flow rate to H2SO4 solution volume is 2-20 h -1 ; The substance in the negative electrode region (10-2) of the energy release unit II is S 2- / S x 2- Mixed solution, in which S 2- The concentration is 0.5-1.0 mol / L, S x 2- The concentration is 0-0.5 mol / L, x is 2-4; The substance in the anode region (6-1) of the energy-generating regeneration unit is Br - / Br2 / H2SO4 mixed solution, in which Br - The concentration of is 0.5-1.0 mol / L, the concentration of Br2 is 0-0.5 mol / L, and the concentration of H2SO4 is 0.5-1.0 mol / L; The substance in the cathode region (6-2) of the energizing regeneration unit is S 2- / S x 2- Mixed solution, in which S 2- The concentration is 0-0.5 mol / L, S x 2- The concentration is 0.5-1.0 mol / L, x is 2-4.

2. The SO2 resource recovery system based on liquid flow battery regeneration cycle according to claim 1 is characterized in that: The ratio of the amount of SO2 introduced into the negative electrode region (1-2) of the energy release unit I and the positive electrode region (10-1) of the energy release unit II is (1.5-3.0):

1.

3. The SO2 resource recovery system based on liquid flow battery regeneration cycle according to claim 1 is characterized in that: A diaphragm I (2) is provided between the positive electrode region (1-1) of the energy release unit I and the negative electrode region (1-2) of the energy release unit I, a diaphragm III (11) is provided between the positive electrode region (10-1) of the energy release unit II and the negative electrode region (10-2) of the energy release unit II, and a diaphragm II (7) is provided between the anode region (6-1) of the energy-enabling regeneration unit and the cathode region (6-2) of the energy-enabling regeneration unit. The diaphragm I (2), diaphragm II (7) and diaphragm III (11) are proton exchange membranes, which are perfluorosulfonic acid type proton exchange membranes with a thickness of 100-300 μm, a conductivity of 0.08-0.09 S / cm, and an exchange capacity of 0.8-1.0 meq / g.

4. The SO2 resource recovery system based on liquid flow battery regeneration cycle according to claim 1 is characterized in that: The energy release unit I (1), the energy release unit II (10) and the energy regeneration unit (6) are provided with electrodes, the material of which is a mesh porous graphite with a pore size of 0.01-6.00 mm, a porosity of 30-80%, and a resistivity of 1.0×10 -5 -1.0×10 -2 Ω·m, thickness 1-15 mm; The electrode is kept at a distance of 2-5 cm from the proton exchange membrane.

5. The SO2 resource recovery system based on liquid flow battery regeneration cycle according to claim 1 is characterized in that: The energy release unit I (1), the energy release unit II (10) and the energy regeneration unit (6) are provided with a stirring device, and the material taking tank II (12) is provided with a sulfur filtering device.

6. The SO2 resource recovery system based on liquid flow battery regeneration cycle according to claim 1 is characterized in that: The energy release unit I (1) is connected in series with 3-6 modules, and the energy release unit II (10) is connected in series with 10-20 modules.

7. A method for SO2 resource recovery system based on flow battery regeneration cycle according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: (1) The energy release unit I positive electrode region (1-1) contains Br after reaction - The solution is partially pumped into the regeneration buffer tank I (4), while the solution containing regenerated Br2 in the regeneration storage tank I (5) is transported to the positive electrode area (1-1) of the energy release unit I; (2) After the sulfuric acid product in the negative electrode region (1-2) of the energy release unit I accumulates to a certain concentration, it is partially drawn into the feed tank I (3) to obtain the sulfuric acid product, and at the same time, SO2 is continuously introduced into the negative electrode region (1-2) of the energy release unit I; (3) The sulfur product in the positive electrode region (10-1) of the energy release unit II is partially drawn into the feed tank II (12), and the sulfur product is obtained after filtration. At the same time, SO2 is continuously introduced into the positive electrode region (10-1) of the energy release unit II; (4) The negative electrode region (10-2) of the energy release unit II contains the reacted S x 2- The solution is partially pumped into the regeneration buffer tank II (8), while the regeneration storage tank II (9) contains the regenerated S 2- The solution is transported to the negative electrode area (10-2) of the energy release unit II; (5) The solution containing Br2 after charge regeneration in the anode area (6-1) of the energizing regeneration unit is transported to the regeneration storage tank I (5), and the solution containing Br2 after discharge reaction is - The solution enters the anode area (6-1) of the energized regeneration unit from the regeneration buffer tank I (4); (6) The cathode region (6-2) of the energized regeneration unit contains S after charge regeneration. 2- The solution is transported to the regeneration storage tank II (9), and contains S after the discharge reaction x 2- The solution enters the cathode area (6-2) of the energized regeneration unit from the regeneration buffer tank II (8); (7) The energy storage unit (13) absorbs the discharge reaction energy of the energy release unit I (1) and the energy release unit II (10), and at the same time replenishes the charging regeneration energy of the energy regeneration unit (6).

8. A method according to claim 7, characterized in that The proportion of the partial extraction is 20-50%, and the accumulated concentration of the sulfuric acid product is 2-3 mol / L.

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