A H2S desulfurizer regeneration combined desulfurization and denitrification system

Abstract

The invention discloses a H2S desulfurizer regeneration combined desulfurization and denitration system, comprising a caustic solution storage tank, a wet regeneration device, a dry regeneration device, a flue gas mixing tank, a desulfurization and denitration liquid temporary storage tank and a desulfurization and denitration tower; wherein the caustic solution storage tank, the wet regeneration device, the desulfurization and denitration liquid temporary storage tank and the desulfurization and denitration tower are connected in sequence, and the dry regeneration device, the flue gas mixing tank and the desulfurization and denitration tower are connected in sequence. The system of the invention can not only realize the complete regeneration of the H2S desulfurizer, but also can make resource utilization of the regeneration waste liquid, purify the flue gas containing NO / SO2, and has both economic and environmental benefits.

Description

Technical Field

[0001] The invention relates to the technical field of environmental engineering, and more specifically to a H2S desulfurizer regeneration combined desulfurization and denitrification system. Background Art

[0002] Hydrogen sulfide (chemical formula: H2S) is a common toxic gas that is widely produced in industries such as steel, gas, coal chemical industry, synthetic ammonia, sewage treatment and papermaking.

[0003] H2S desulfurizer usually refers to an adsorption or catalytic material prepared by using activated carbon or molecular sieve as carrier and loading active components. Its characteristic is that the surface has a certain oxidation ability, which can adsorb and oxidize H2S into S element and attach it to the surface of the desulfurizer, so that the exhaust gas is purified.

[0004] Due to the complexity of exhaust gas conditions, H2S removal is often carried out in a high temperature and high humidity environment, which causes some H2S and active metals to easily combine to form sulfides, causing the function of active components to decline. The accumulation of sulfur on the surface of the desulfurizer and the formation of sulfides are the main causes of desulfurization. Due to the huge amount of H2S exhaust gas generated by various industries, if the deactivated desulfurizer is directly discarded without regeneration and reuse, it will cause a huge waste of resources and a mountain of hazardous waste.

[0005] The current mainstream H2S desulfurizer regeneration methods are mainly wet and dry. However, wet regeneration will produce a large amount of wastewater, and the S resources cannot be reused; while dry regeneration requires high-temperature purge of inert gas, and to realize the resource utilization of S, the high-temperature regeneration gas must be condensed, which consumes a lot of energy. In addition, neither the dry method nor the wet method can achieve 100% regeneration, because the existing regeneration method can only achieve the removal of elemental S on the surface of the desulfurizer, but cannot achieve the regeneration of active components, which causes the desulfurization capacity of the desulfurizer to decrease after regeneration. Enterprises have to frequently replace the desulfurizer, resulting in complicated operations and waste of labor costs. At the same time, in industries such as electricity, steel, coal chemical industry, and electronics, due to the combustion of coal and the use of acidic gases, a large amount of flue gas containing NO / SO2 will be generated. The treatment of these flue gases will also cause huge resource and energy consumption, adding burden to enterprises. It can be seen that in many industries, H2S waste gas and NO / SO2 flue gas exist at the same time. If a process method can be developed that can simultaneously achieve complete regeneration of H2S desulfurizer and removal of NO / SO2 in flue gas, it will not only greatly alleviate the above-mentioned waste of resources and energy, but also achieve standard emission of flue gas and reduce the economic and environmental pressure of enterprises.

[0006] The invention patent application publication number is CN 106147885 A, "Regeneration method of regenerable composite metal oxide high temperature coal gas desulfurization agent", the bed temperature is 600-750℃, the air velocity is 1000-3000h-1 , the regeneration gas composition is 1-3% SO2, N2 balance, when the outlet elemental sulfur concentration is less than 1ppm, the regeneration is stopped; during the desulfurizer regeneration process, the reactor outlet gas is cooled to below 70°C, the elemental sulfur in the gas is separated and recovered, and the remaining regeneration gas is recycled for the next step; the regeneration process is ended, the regenerated desulfurizer is subjected to the next round of desulfurization, and the regeneration product is all elemental sulfur. Although the invention recovers the S on the surface of the desulfurizer, it cannot restore the sulfided active metals, and the treatment method of SO2 in the regeneration gas is not mentioned.

[0007] The invention patent "A method for regenerating a hydrogen sulfide desulfurizer" with the authorization announcement number CN 102489278 B adopts a leaching or soaking-leaching method, and the reagent is acetone, cyclohexane or tetrachloromethane. The eluent can be collected and recycled until the sulfur concentration in the eluent is stable. The invention uses a wet method to recover the S on the surface of the desulfurizer, but it also cannot restore the sulfided active metals, and the desulfurizer adsorbed with organic matter needs further treatment. In addition, the invention will produce desulfurization waste liquid.

[0008] The invention with application publication number CN 112138525 A, "Method for simultaneous desulfurization and denitrification by ozone graded oxidation combined with wet absorption", adds ozone to flue gas to remove NO x Oxidation treatment is carried out, and then the gas products after the oxidation reaction are absorbed by a wet scrubbing absorption system; during the ozone oxidation treatment process, the amount of ozone added is graded and controlled according to the emission standards for flue gas desulfurization and denitrification treatment. Although this invention oxidizes NO to NO2, it does not realize the resource utilization of waste, and does not mention the regeneration of H2S desulfurizer, and the wet absorption adopts the traditional CaCO3 / CaO slurry.

[0009] Therefore, how to develop a H2S desulfurizer regeneration combined desulfurization and denitrification system is a problem that technical personnel in this field need to solve urgently. Summary of the invention

[0010] In view of this, the purpose of the present invention is to provide a H2S desulfurizer regeneration combined desulfurization and denitrification system to solve the deficiencies in the prior art. The system can not only achieve complete regeneration of the H2S desulfurizer, but also recycle the regeneration waste liquid to purify the flue gas containing NO / SO2, with both economic and environmental benefits.

[0011] In order to achieve the above object, the present invention adopts the following technical solution:

[0012] A H2S desulfurizer regeneration combined desulfurization and denitrification system comprises a caustic solution storage tank, a wet regeneration device, a dry regeneration device, a flue gas mixing tank, a desulfurization and denitrification liquid temporary storage tank and a desulfurization and denitrification tower; wherein the caustic solution storage tank, the wet regeneration device, the desulfurization and denitrification liquid temporary storage tank and the desulfurization and denitrification tower are connected in sequence, and the dry regeneration device, the flue gas mixing tank and the desulfurization and denitrification tower are connected in sequence.

[0013] In the present invention,

[0014] The H2S desulfurizer is a supported desulfurizer, comprising a carrier and an active component or an auxiliary agent; wherein the carrier is activated carbon, activated carbon fiber, molecular sieve or zeolite, and the active component or auxiliary agent is a metal oxide, and the metal oxide includes but is not limited to oxides of Cu, Fe, Zn, Mn, Al, Co, Ce, Mo, La, Zr, V, and Cr.

[0015] The caustic solution storage tank is used to store caustic solution. Specifically, the caustic is NaOH or KOH; the mass concentration of the caustic in the caustic solution is 1% to 30%; the liquid-to-solid ratio of the caustic solution to the saturated H2S desulfurizer is 5 to 50L / kg. Specifically, when preparing the caustic solution, NaOH or KOH solid is added to a certain volume of tap water for dissolution to obtain a regeneration solution. Then, the saturated H2S desulfurizer is soaked in a container, or the saturated H2S desulfurizer is rinsed with a leaching device, so that the S element on the surface of the saturated H2S desulfurizer fully reacts with the caustic to generate an alkaline solution of Na2S or K2S. The reaction formula is as follows: 3S+6NaOH=2Na2S+Na2SO3+3H2O(1); 3S+6KOH=2K2S+Na2SO3+3H2O(2).

[0016] The wet regeneration device is used to soak or rinse the saturated H2S desulfurizer with a caustic solution, and then wash the H2S desulfurizer with water after filtering to obtain the wet regenerated H2S desulfurizer; at the same time, the soaking liquid or the rinsing liquid and the washing liquid are mixed to obtain a desulfurization and denitrification liquid. Specifically, the soaking or rinsing temperature is 20-100°C, and the time is more than 30 minutes. Furthermore, the H2S desulfurizer is soaked or rinsed according to the type of the H2S desulfurizer carrier. Specifically: for the H2S desulfurizer with activated carbon or activated carbon fiber as the carrier, soaking is selected as the wet regeneration method; for the H2S desulfurizer with molecular sieve or zeolite as the carrier, rinsing is selected as the wet regeneration method. Wash until the pH of the washing liquid is ≤9.

[0017] The dry regeneration device is used to transfer the H2S desulfurizer after wet regeneration to the dry regeneration device, and use a gas containing excess oxidant to purge the H2S desulfurizer after wet regeneration, so that the H2S desulfurizer is regenerated; at the same time, the purged gas is collected to obtain a purge gas. Specifically, the oxidant is at least one of O3, O2, hydroxyl radicals and ClO2. The dry regeneration process of the H2S desulfurizer is carried out in specific equipment, which includes but is not limited to a desulfurization tower, a tubular furnace, a fixed bed, a moving bed, and a fluidized bed. The purpose of the dry regeneration of the H2S desulfurizer is to restore the sulfided metal to an oxidized state to achieve complete regeneration of the desulfurizer (regeneration efficiency ≥ 99%). Taking the active component as CuO and the oxidant as O2 as an example, the reaction formula is as follows: 2CuS+3O2=2CuO+2SO2(3). The gas is air, containing NO x / SO x At least one of flue gas, clean flue gas, N2 and other inert gases except N2. The temperature of the purge gas is 20-150℃; the purge space velocity is 2000-20000h -1 , time ≥ 30min; purge until the SO2 concentration in the purge gas is reduced to below 1ppm. Preferably, the specific temperature of the purge gas needs to be determined according to the type of oxidant and the type of gas. For example, when using a weaker oxidant such as O2, it needs to be heated to a higher temperature; when using a stronger oxidant O3 or hydroxyl radical, no heating is required or only appropriate heating is required; when using a moderate oxidant such as ClO2, appropriate heating is sufficient. The gas used is NO x / SO x When the flue gas is heated, it needs to be properly heated to ensure NO x / SO x It is not physically adsorbed on the surface of the H2S desulfurizer, and the purge gas must be kept dry to avoid nitration or sulfation of active metals; when air, clean flue gas, N2, or other inert gases except N2 are used as the purge gas, heating and drying are not required.

[0018] The flue gas mixing tank is used to mix and react the purge gas and the flue gas containing NO / SO2 to obtain a mixed flue gas containing NO2 / SO3. Specifically, the reaction device is a flue gas mixing tank or a flue, and the time is greater than 2s. Preferably, the flue gas mixing tank is spherical or ellipsoidal, and there should be no dead corners in the flue gas mixing tank to ensure that the gas is completely mixed and uniform. By reacting the purge gas and the flue gas containing NO / SO2 in the flue gas mixing tank or the flue, the remaining oxidant in the purge gas can be used to oxidize NO and SO2 into NO2 and SO3, respectively.

[0019] The desulfurization and denitrification liquid temporary storage tank is used to temporarily store the desulfurization and denitrification liquid.

[0020] The desulfurization and denitrification tower is used to spray and wash the mixed flue gas containing NO2 / SO3 with desulfurization and denitrification liquid, so that the flue gas meets the emission standards. Specifically, the spray washing device (desulfurization and denitrification tower) is a vertical packed spray tower or a horizontal packed spray tower. Furthermore, the packing in the spray tower includes but is not limited to ball rings, Raschig rings, hollow balls, and the packing material includes but is not limited to PP, PE, PVC, and Teflon. In order to ensure that the equipment and pipelines are not corroded, the flue gas mixing tank, flue and spray tower should be made of anti-corrosion materials, or the inner layer of the flue gas mixing tank, flue and spray tower should be coated with anti-corrosion materials. The desulfurization and denitrification liquid is used to remove the NO2 and SO3 obtained by oxidation. Taking the regeneration liquid as an aqueous solution of NaOH, that is, the desulfurization and denitrification liquid is a NaOH solution of Na2S as an example, the reaction formula is as follows: 2Na2S+8NO2+6NaOH=8NaNO2+Na2S2O3+3H2O(4); 2NaOH+SO3=Na2SO4+H2O(5). In addition, the desulfurization and denitrification liquid is recycled to remove NO2 / SO3 and other acidic substances in the flue gas, and the flue gas meets the direct discharge standards. x 、SO x The concentration monitoring determines whether it needs to be replaced, that is, when its conductivity is ≥50ms / cm 2 Or NO in the flue gas at the outlet of the desulfurization and denitrification device x 、SO x When the standard is exceeded, the desulfurization and denitrification liquid is judged to be ineffective. At this time, the ineffective desulfurization and denitrification liquid is discharged and fresh desulfurization and denitrification liquid is replenished. The ineffective desulfurization and denitrification liquid is treated as sewage and can be discharged into the factory's sewage treatment system, or mixed salt is obtained through evaporation and concentration and treated as solid waste.

[0021] Furthermore, the above-mentioned H2S desulfurizer regeneration combined desulfurization and denitrification system also includes a caustic solution dosing pump; further, the caustic solution dosing pump is arranged between the caustic solution storage tank and the wet regeneration device.

[0022] The beneficial effect of adopting the above further technical solution is that the caustic solution dosing pump is used to pump the caustic solution in the caustic solution storage tank to the wet regeneration device for wet regeneration of the H2S desulfurizer.

[0023] Furthermore, the above-mentioned H2S desulfurizer regeneration combined desulfurization and denitrification system also includes an electric heater; further, the electric heater is connected to the dry regeneration device.

[0024] The beneficial effect of adopting the above further technical solution is that in the dry regeneration process of H2S desulfurizer, when the gas is NO x / SO x When the flue gas is heated, an electric heater should be used to heat it appropriately to ensure that NO x / SO xNot physically adsorbed on the surface of H2S desulfurizer.

[0025] Furthermore, the above-mentioned H2S desulfurizer regeneration combined desulfurization and denitrification system also includes a thermometer; further, the thermometer is connected to the dry regeneration device.

[0026] The beneficial effect of adopting the above further technical solution is that during the dry regeneration process of the H2S desulfurizer, the thermometer is used to detect and control the temperature of the purge gas to be 20-150°C.

[0027] Furthermore, the above-mentioned H2S desulfurizer regeneration combined desulfurization and denitrification system also includes a desulfurization and denitrification liquid circulation pump; further, the inlet of the desulfurization and denitrification liquid circulation pump is connected to the bottom of the desulfurization and denitrification tower, and the outlet of the desulfurization and denitrification liquid circulation pump is connected to the top of the desulfurization and denitrification tower.

[0028] The beneficial effect of adopting the above-mentioned further technical scheme is that in the process of mixed flue gas desulfurization and denitrification, the desulfurization and denitrification liquid is circulated by a desulfurization and denitrification liquid circulation pump, and after removing NO2 / SO3 and other acidic substances in the flue gas, the flue gas meets the direct discharge standards.

[0029] Furthermore, the above-mentioned H2S desulfurizer regeneration combined desulfurization and denitrification system also includes a flue gas online monitor; further, the flue gas online monitor is connected to the top of the desulfurization and denitrification tower.

[0030] Furthermore, the above-mentioned H2S desulfurizer regeneration combined desulfurization and denitrification system also includes a conductivity meter; further, the conductivity meter is connected to the bottom of the desulfurization and denitrification tower.

[0031] The beneficial effect of adopting the above further technical solution is that in the mixed flue gas desulfurization and denitrification process, the desulfurization and denitrification liquid is measured according to the conductivity measured by the conductivity meter and the outlet NO measured by the flue gas online monitoring instrument. x 、SO x The concentration determines whether it needs to be replaced, that is, when its conductivity is ≥50ms / cm 2 Or NO in the flue gas at the outlet of the desulfurization and denitrification device x 、SO x When the standard is exceeded, the desulfurization and denitrification liquid is judged to be ineffective. At this time, the ineffective desulfurization and denitrification liquid is discharged and fresh desulfurization and denitrification liquid is added.

[0032] Furthermore, the above-mentioned H2S desulfurizer regeneration combined desulfurization and denitrification system also includes a flue gas fan; further, the flue gas fan is arranged downstream of the desulfurization and denitrification tower.

[0033] The beneficial effect of adopting the above further technical solution is that the flue gas fan is used to ensure that the flue gas meets the emission standards.

[0034] It can be seen from the above technical solution that compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] (1) The present invention can achieve complete regeneration of failed H2S desulfurizer, greatly reducing the number of replacement times of H2S desulfurizer, extending the use time of H2S desulfurizer, and reducing enterprise costs;

[0036] (2) The present invention utilizes the waste liquid from the regeneration of the H2S desulfurizer as a resource, and uses it for simultaneous desulfurization and denitrification in the factory, thereby realizing waste resource utilization while reducing emissions, and having both economic and environmental benefits;

[0037] (3) The H2S desulfurizer regeneration waste liquid (desulfurization and denitrification liquid) in the present invention has strong alkalinity. While achieving flue gas desulfurization and denitrification, it can also remove other acidic substances in the flue gas, thereby achieving ultra-low emissions;

[0038] (4) The system process of the present invention is simple and easy to operate, and the operating temperature of each link is lower than 150°C, with low safety risks.

[0039] (5) The present invention has both economic and environmental benefits. It can achieve complete regeneration of H2S desulfurizer at low temperature and realize waste utilization. The regenerated waste liquid (desulfurization and denitrification liquid) is reused for flue gas desulfurization and denitrification. At the same time, it achieves the purpose of energy conservation and emission reduction. It is suitable for market and industrial promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0041] Figure 1 Schematic diagram of the device and process flow of the H2S desulfurizer regeneration combined desulfurization and denitrification system (immersion) in Example 1-2 of the present invention;

[0042] Figure 2 This is a schematic diagram of the apparatus and process flow of the H2S desulfurizer regeneration combined desulfurization and denitrification system (elution) in Example 3 of the present invention.

[0043] Figure 1 and Figure 2 Among them, 1- caustic soda solution storage tank, 2- caustic soda solution dosing pump, 3- wet regeneration device, 4- electric heater, 5- dry regeneration device, 6- thermometer, 7- flue gas mixing tank, 8- desulfurization and denitrification liquid temporary storage tank, 9- desulfurization and denitrification tower, 10- desulfurization and denitrification liquid circulation pump, 11- flue gas online monitor, 12- conductivity meter, 13- flue gas fan. DETAILED DESCRIPTION

[0044] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0045] In the description of the present invention, it is necessary to understand that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0046] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0047] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0049] The embodiment of the present invention discloses a H2S desulfurization agent regeneration combined desulfurization and denitrification device, such as Figure 1 or Figure 2 As shown, it includes a caustic solution storage tank 1, a wet regeneration device 3, a dry regeneration device 5, a flue gas mixing tank 7, a desulfurization and denitration liquid temporary storage tank 8 and a desulfurization and denitration tower 9; wherein, the caustic solution storage tank 1, the wet regeneration device 3, the desulfurization and denitration liquid temporary storage tank 8 and the desulfurization and denitration tower 9 are connected in sequence, and the dry regeneration device 5, the flue gas mixing tank 7 and the desulfurization and denitration tower 9 are connected in sequence. In the present invention, the caustic solution storage tank 1 is used to store caustic solution. The wet regeneration device 3 is used to soak or rinse the saturated H2S desulfurizer with a caustic solution, and then wash the H2S desulfurizer with water after filtering to obtain the H2S desulfurizer after wet regeneration; at the same time, the soaking liquid or rinsing liquid and the washing liquid are mixed to obtain a desulfurization and denitration liquid. The dry regeneration device 5 is used to transfer the H2S desulfurizer after wet regeneration to the dry regeneration device 5, and use the gas containing excess oxidant to purge the H2S desulfurizer after wet regeneration, so that the H2S desulfurizer is regenerated; at the same time, the gas after purge is collected to obtain purge gas. The flue gas mixing tank 7 is used to mix the purge gas and the flue gas containing NO / SO2, and react to obtain a mixed flue gas containing NO2 / SO3. The desulfurization and denitrification liquid temporary storage tank 8 is used to temporarily store the desulfurization and denitrification liquid. The desulfurization and denitrification tower is used to spray and wash the mixed flue gas containing NO2 / SO3 with the desulfurization and denitrification liquid, so that the flue gas meets the emission standards.

[0050] In one embodiment, a caustic solution dosing pump 2 is further included; the caustic solution dosing pump 2 is disposed between the caustic solution storage tank 1 and the wet regeneration device 3. The caustic solution dosing pump 2 is used to pump the caustic solution in the caustic solution storage tank 1 to the wet regeneration device 3 for wet regeneration of the H2S desulfurizer.

[0051] In one embodiment, an electric heater 4 is further included; the electric heater 4 is connected to the dry regeneration device 5. In the dry regeneration process of the H2S desulfurizer, when the gas is NO x / SO x When the flue gas is heated, an electric heater 4 is required to ensure that NO x / SO x Not physically adsorbed on the surface of H2S desulfurizer.

[0052] In one embodiment, a thermometer 6 is further included; the thermometer 6 is connected to the dry regeneration device 5. During the dry regeneration process of the H2S desulfurizer, the thermometer 6 is used to detect and control the temperature of the purge gas to be 20-150°C.

[0053] In one embodiment, a desulfurization and denitration liquid circulation pump 10 is further included; the inlet of the desulfurization and denitration liquid circulation pump 10 is connected to the bottom of the desulfurization and denitration tower 9, and the outlet of the desulfurization and denitration liquid circulation pump 10 is connected to the top of the desulfurization and denitration tower 9. In the mixed flue gas desulfurization and denitration treatment process, the desulfurization and denitration liquid is circulated by the desulfurization and denitration liquid circulation pump, and after removing NO2 / SO3 and other acidic substances in the flue gas, the flue gas is directly discharged when it meets the standards.

[0054] In one embodiment, an online flue gas monitor 11 is also included; the online flue gas monitor 11 is connected to the top of the desulfurization and denitrification tower 9 .

[0055] In one embodiment, a conductivity meter 12 is further included; the conductivity meter 12 is connected to the bottom of the desulfurization and denitrification tower 9. During the desulfurization and denitrification treatment of the mixed flue gas, the desulfurization and denitrification liquid is calibrated according to the conductivity measured by the conductivity meter 12 and the outlet NO measured by the flue gas online monitor 11. x 、SO x The concentration determines whether it needs to be replaced, that is, when its conductivity is ≥50ms / cm 2 Or NO in the flue gas at the outlet of the desulfurization and denitrification device x 、SO x When the standard is exceeded, the desulfurization and denitrification liquid is judged to be ineffective. At this time, the ineffective desulfurization and denitrification liquid is discharged and fresh desulfurization and denitrification liquid is added.

[0056] In one embodiment, a flue gas fan 13 is further included; the flue gas fan 13 is arranged downstream of the desulfurization and denitration tower 9. The flue gas fan 13 is used to ensure that the flue gas meets the emission standards.

[0057] Example 1

[0058] The H2S desulfurizer for blast furnace gas of a steel enterprise is prepared by using activated carbon loaded with 5% MnO2. 1000 kg of saturated H2S desulfurizer is taken for regeneration.

[0059] Method of using H2S desulfurizer regeneration combined desulfurization and denitrification system, such as Figure 1 As shown, the specific steps include:

[0060] (1) Wet regeneration of H2S desulfurizer

[0061] A NaOH solution with a mass concentration of 10% is prepared in the caustic solution storage tank 1, 1000 kg of saturated H2S desulfurizer is placed in the wet regeneration device 3, and 10 m3 of saturated H2S desulfurizer is added to the wet regeneration device 3 using the caustic solution dosing pump 2. 3The H2S desulfurizer is soaked in NaOH solution at room temperature for 5 hours until the NaOH solution gradually changes from colorless and transparent to yellow, filtered, and the soaking liquid is passed into the desulfurization and denitrification liquid temporary storage tank 8 for temporary storage; then the tap water valve is opened, and the soaked H2S desulfurizer is washed 4 times in the wet regeneration device 3, and 10m of tap water is flowed in each time. 3 , until the pH value of the washing liquid is 8, and the H2S desulfurizer after wet regeneration is obtained; finally, the washing liquid is passed into the desulfurization and denitration liquid temporary storage tank 8 to be mixed with the soaking liquid to obtain the desulfurization and denitration liquid;

[0062] (2) H2S desulfurizer dry regeneration

[0063] The H2S desulfurizer after wet regeneration is transferred to the dry regeneration device 5, and 5000m 3 / h containing 1000ppm O 3 The air is heated by an electric heater 4 to 50°C as measured by a thermometer 6 to purge the H2S desulfurizer after wet regeneration. A handheld SO2 detector is used to detect the purge gas at the outlet of the dry regeneration device 5. The purge is stopped when the SO2 concentration is less than 1ppm. The purge time is 2 hours, and the regeneration of the H2S desulfurizer is completed.

[0064] At the same time, the purged gas is collected to obtain the purge gas;

[0065] (3) Preparation of mixed flue gas

[0066] The purge gas in step (2) and the flue gas containing NO / SO2 are mixed in a flue gas mixing tank 7 to react, and NO is oxidized to NO2 and SO2 is oxidized to SO3 under the action of O3, thereby obtaining a mixed flue gas containing NO2 / SO3;

[0067] (4) Mixed flue gas desulfurization and denitrification

[0068] The desulfurization and denitration liquid in step (1) is introduced from the desulfurization and denitration liquid temporary storage tank 8 into the desulfurization and denitration tower 9, and the desulfurization and denitration liquid circulation pump 10 is used to circulate and spray the mixed flue gas containing NO2 / SO3 in step (3), and the following reaction occurs:

[0069] 2Na2S+8NO2+6NaOH=8NaNO2+Na2S2O3+3H2O;

[0070] 2NaOH+SO3=Na2SO4+H2O;

[0071] HCN+NaOH=NaCN+H2O;

[0072] After desulfurization and denitrification, the flue gas is drawn out from the flue gas fan 13 and discharged into the air through the chimney;

[0073] At the same time, the NO in the outlet flue gas is monitored by the flue gas online monitor 11. x 、SO x Concentration, use conductivity meter 12 to monitor the conductivity of desulfurization and denitrification liquid, when the conductivity is ≥50ms / cm 2 or NO in the outlet flue gas x 、SO x When the concentration exceeds the standard, open the sewage drain valve to discharge the failed desulfurization and denitrification liquid into the sewage station, and at the same time add fresh desulfurization and denitrification liquid.

[0074] Example 2

[0075] The H2S desulfurizer used in the waste gas treatment of a semiconductor enterprise sewage station is prepared by using activated carbon fiber loaded with 6% CuO. 500 kg of saturated H2S desulfurizer is taken for regeneration.

[0076] Method of using H2S desulfurizer regeneration combined desulfurization and denitrification system, such as Figure 1 As shown, the specific steps include:

[0077] (1) Wet regeneration of H2S desulfurizer

[0078] A KOH solution with a mass concentration of 5% is prepared in the caustic solution storage tank 1, 500 kg of saturated H2S desulfurizer is placed in the wet regeneration device 3, and 500 kg of saturated H2S desulfurizer is added to the wet regeneration device 3 using the caustic solution dosing pump 2. 3 The H2S desulfurizer is soaked in KOH solution at room temperature for 10 hours until the KOH solution gradually changes from colorless and transparent to yellow, filtered, and the soaking liquid is passed into the desulfurization and denitrification liquid temporary storage tank 8 for temporary storage; then the tap water valve is opened, and the soaked H2S desulfurizer is washed 4 times in the wet regeneration device 3, and 5m of tap water is flowed in each time. 3 , until the pH value of the washing liquid is 7.5, and the H2S desulfurizer after wet regeneration is obtained; finally, the washing liquid is passed into the desulfurization and denitration liquid temporary storage tank 8 to be mixed with the soaking liquid to obtain the desulfurization and denitration liquid;

[0079] (2) H2S desulfurizer dry regeneration

[0080] The H2S desulfurizer after wet regeneration is transferred to the dry regeneration device 5, and 2000m 3 / h air containing 1000ppm ClO2 is heated by electric heater 4 to 80℃ measured by thermometer 6 to purge the H2S desulfurizer after wet regeneration. A handheld SO2 detector is used to detect the purge gas at the outlet of the dry regeneration device 5. The purge is stopped when the SO2 concentration is less than 1ppm. The purge time is 5h, and the regeneration of the H2S desulfurizer is completed;

[0081] At the same time, the purged gas is collected to obtain the purge gas;

[0082] (3) Preparation of mixed flue gas

[0083] The purge gas in step (2) and the flue gas containing NO / SO2 are mixed in a flue gas mixing tank 7 to react, and NO is oxidized to NO2 and SO2 is oxidized to SO3 under the action of ClO2, thereby obtaining a mixed flue gas containing NO2 / SO3;

[0084] (4) Mixed flue gas desulfurization and denitrification

[0085] The desulfurization and denitration liquid in step (1) is introduced from the desulfurization and denitration liquid temporary storage tank 8 into the desulfurization and denitration tower 9, and the desulfurization and denitration liquid circulation pump 10 is used to circulate and spray the mixed flue gas containing NO2 / SO3 in step (3) and the following reaction occurs:

[0086] 2K2S+8NO2+6KOH=8KNO2+K2S2O3+3H2O;

[0087] 2KOH+SO3=K2SO4+H2O;

[0088] KOH+HCl=KCl+H2O;

[0089] After desulfurization and denitrification, the flue gas is drawn out from the flue gas fan 13 and discharged into the air through the chimney;

[0090] At the same time, the NO in the outlet flue gas is monitored by the flue gas online monitor 11. x 、SO x Concentration, use conductivity meter 12 to monitor the conductivity of desulfurization and denitrification liquid, when the conductivity is ≥50ms / cm 2 or NO in the outlet flue gas x 、SO x When the concentration exceeds the standard, open the sewage drain valve to discharge the failed desulfurization and denitrification liquid into the sewage station, and at the same time add fresh desulfurization and denitrification liquid.

[0091] Example 3

[0092] The H2S desulfurizer used for tail gas treatment at the outlet of the H2S concentration tower of the low-temperature methanol washing system of a coking enterprise is prepared by using 13X molecular sieve loaded with 10% Fe2O3. 2000kg of saturated H2S desulfurizer is taken for regeneration.

[0093] Method of using H2S desulfurizer regeneration combined desulfurization and denitrification system, such as Figure 2 As shown, the specific steps include:

[0094] (1) Wet regeneration of H2S desulfurizer

[0095] A KOH solution with a mass concentration of 20% is prepared in the caustic solution storage tank 1, 2000 kg of saturated H2S desulfurizer is placed in the wet regeneration device 3, and a caustic solution dosing pump 2 is used to slowly spray 25 m3 of H2S in the wet regeneration device 3. 3 The KOH solution is used to elute the H2S desulfurizer at 50°C for 1 hour until the eluent gradually changes from colorless and transparent to yellow, and the eluent is passed into the desulfurization and denitrification liquid temporary storage tank 8 for temporary storage; then the tap water valve is opened, and the eluted H2S desulfurizer is washed 3 times in the wet regeneration device 3, and 10m of tap water is flowed in each time. 3 , until the pH value of the washing liquid is 8.5, and the H2S desulfurizer after wet regeneration is obtained; finally, the washing liquid is passed into the desulfurization and denitration liquid temporary storage tank 8 to be mixed with the eluent to obtain the desulfurization and denitration liquid;

[0096] (2) H2S desulfurizer dry regeneration

[0097] The H2S desulfurizer after wet regeneration is transferred to the dry regeneration device 5, and 6000m 3 / h air containing 40% O2 is heated to 120°C measured by thermometer 6 by electric heater 4 to purge the H2S desulfurizer after wet regeneration, and a handheld SO2 detector is used to detect the purge gas at the outlet of the dry regeneration device 5. The purge is stopped when the SO2 concentration is less than 1ppm. The purge time is 10h, and the regeneration of the H2S desulfurizer is completed;

[0098] At the same time, the purged gas is collected to obtain the purge gas;

[0099] (3) Preparation of mixed flue gas

[0100] The purge gas in step (2) and the flue gas containing NO / SO2 are mixed in a flue gas mixing tank 7 to react, and NO is oxidized to NO2 and SO2 is oxidized to SO3 under the action of O2, thereby obtaining a mixed flue gas containing NO2 / SO3;

[0101] (4) Mixed flue gas desulfurization and denitrification

[0102] The desulfurization and denitration liquid in step (1) is introduced from the desulfurization and denitration liquid temporary storage tank 8 into the desulfurization and denitration tower 9, and the desulfurization and denitration liquid circulation pump 10 is used to circulate and spray the mixed flue gas containing NO2 / SO3 in step (3), and the following reaction occurs:

[0103] 2K2S+8NO2+6KOH=8KNO2+K2S2O3+3H2O;

[0104] 2KOH+SO3=K2SO4+H2O;

[0105] After desulfurization and denitrification, the flue gas is drawn out from the flue gas fan 13 and discharged into the air through the chimney;

[0106] At the same time, the NO in the outlet flue gas is monitored by the flue gas online monitor 11. x 、SO x Concentration, use conductivity meter 12 to monitor the conductivity of desulfurization and denitrification liquid, when the conductivity is ≥50ms / cm 2 or NO in the outlet flue gas x 、SO x When the concentration exceeds the standard, the sewage drain valve is opened to pass the failed desulfurization and denitrification liquid into the factory's three-effect evaporation system. After evaporation and concentration, a mixed salt of KOH, K2S, K2SO3, KNO3, K2S2O3, and K2SO4 is obtained. Due to the small amount of mixed salt, it is sold as solid waste for disposal. At the same time, fresh desulfurization and denitrification liquid is added to the desulfurization and denitrification tower 9.

[0107] Performance Testing

[0108] 1. Regeneration test of H2S desulfurizer

[0109] The H2S desulfurizers after regeneration in step (2) of Examples 1-3 were taken respectively, and their regeneration efficiencies were counted and calculated respectively, and their activity was tested respectively to see whether they were restored.

[0110] The calculation formula of regeneration efficiency is as follows:

[0111]

[0112] in,

[0113] η R Indicates the regeneration efficiency of H2S desulfurizer, %;

[0114] M RS It indicates the sulfur capacity of H2S desulfurizer after regeneration to remove H2S, mg / g;

[0115] M S It indicates the sulfur capacity of fresh H2S removal agent for removing H2S, mg / g.

[0116] The results are shown in Table 1.

[0117] Table 1 H2S desulfurizer regeneration test results

[0118]

[0119]

[0120] As can be seen from Table 1, the inactivated H2S desulfurizers in Examples 1-3 were regenerated by the system and method of the present invention, and after regeneration, it was found that the regeneration efficiency of the H2S desulfurizers was ≥99.0%.

[0121] The regenerated H2S desulfurizer is reused for H2S removal. The usage time of the H2S desulfurizer before deactivation is equivalent to that of the fresh H2S desulfurizer. It can be considered that the activity of the H2S desulfurizer has recovered well.

[0122] 2. Desulfurization and denitrification test of mixed flue gas

[0123] Take the flue gas containing NO / SO2 after dust removal and cooling in step (3) of each enterprise in Examples 1-3, and the flue gas after desulfurization and denitrification treatment in step (4), and perform component analysis respectively.

[0124] The results are shown in Table 2.

[0125] Table 2 Desulfurization and denitrification test results of mixed flue gas

[0126]

[0127] As shown in Table 2, the NO content of the original flue gas in Examples 1-3 is x Concentration 550~2000mg / Nm 3 In the range of SO2 concentration, the concentration is between 50 and 2200 mg / Nm 3 Within the range, after being treated by the methods of Examples 1-3 of the present invention, NO x Concentration ≤20mg / Nm 3 , SO2 concentration ≤ 20mg / Nm 3 , and a small amount of acidic pollutants such as HCN and HCl in the flue gas are also purified simultaneously.

[0128] The mixed flue gases treated in Examples 1-3 all meet the "Integrated Emission Standards for Air Pollutants" (GB16297-1996), and Example 1 meets the sulfur dioxide (35 mg / Nm 3 ) and nitrogen oxides (50mg / Nm 3 ) Minimum emission control indicators.

[0129] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0130] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A H2S desulfurizer regeneration combined desulfurization and denitrification system, characterized in that: It includes caustic solution storage tank, wet regeneration device, dry regeneration device, flue gas mixing tank, desulfurization and denitrification liquid temporary storage tank and desulfurization and denitrification tower; The caustic solution storage tank, the wet regeneration device, the desulfurization and denitration liquid temporary storage tank and the desulfurization and denitration tower are connected in sequence; The dry regeneration device, the flue gas mixing tank and the desulfurization and denitrification tower are connected in sequence; The wet regeneration device is used to soak or rinse the saturated H2S desulfurizer with a caustic solution, and then wash the H2S desulfurizer with water after filtering to obtain the wet regenerated H2S desulfurizer; at the same time, the soaking liquid or the rinsing liquid and the washing liquid are mixed to obtain a desulfurization and denitrification liquid; The dry regeneration device is used to transfer the H2S desulfurizer after wet regeneration to the dry regeneration device, and use the gas containing excess oxidant to purge the H2S desulfurizer after wet regeneration, so that the H2S desulfurizer is regenerated; at the same time, the purge gas is collected to obtain the purge gas; The flue gas mixing tank is used to mix and react the purge gas and the flue gas containing NO / SO2 to obtain a mixed flue gas containing NO2 / SO3.

2. The H2S desulfurizer regeneration combined desulfurization and denitrification system according to claim 1, characterized in that: Also included is a caustic solution dosing pump; The caustic solution dosing pump is arranged between the caustic solution storage tank and the wet regeneration device.

3. The H2S desulfurizer regeneration combined desulfurization and denitrification system according to claim 1, characterized in that: Also included is an electric heater; The electric heater is connected to the dry regeneration device.

4. The H2S desulfurizer regeneration combined desulfurization and denitrification system according to claim 1, characterized in that: Also included is a thermometer; The thermometer is connected to the dry regeneration device.

5. The H2S desulfurizer regeneration combined desulfurization and denitrification system according to claim 1, characterized in that: It also includes a desulfurization and denitrification liquid circulation pump; The inlet of the desulfurization and denitration liquid circulation pump is connected to the bottom of the desulfurization and denitration tower, and the outlet of the desulfurization and denitration liquid circulation pump is connected to the top of the desulfurization and denitration tower.

6. The H2S desulfurizer regeneration combined desulfurization and denitrification system according to claim 1, characterized in that: It also includes an online flue gas monitor; The flue gas online monitor is connected to the top of the desulfurization and denitrification tower.

7. The H2S desulfurizer regeneration combined desulfurization and denitrification system according to claim 1, characterized in that: Also included is a conductivity meter; The conductivity meter is connected to the bottom of the desulfurization and denitrification tower.

8. The H2S desulfurizer regeneration combined desulfurization and denitrification system according to claim 1, characterized in that: Also includes a flue gas fan; The flue gas fan is arranged downstream of the desulfurization and denitrification tower.

Images