S-zorb flue gas desulfurization device and method

Abstract

The invention belongs to the technical field of petroleum refining, and specifically provides an S-zorb flue gas desulfurization device and method, comprising an alkali liquid tank and an absorption tower, wherein a quenching module, an absorption module, a filtering module, a gas-liquid separation module and a chimney are sequentially distributed in the absorption tower from bottom to top, the alkali liquid tank is respectively connected to the quenching module, the absorption module and the filtering module, and the alkali liquid tank is filled with a NaOH solution; the invention solves the problems that when the existing organic catalytic ammonia flue gas treatment process and the integrated machine salt liquid evaporation fertilizer are used, steam is directly discharged into the atmosphere, COD and ammonia nitrogen content in the steam seriously exceed the standard, the device is seriously corroded, the machine pump seal corrodes and leaks frequently, the device operation and maintenance cost is high, the workload is large, the by-product is ammonium sulfate fertilizer, and the storage and transportation cost is high; the invention makes the flue gas emission higher than the emission standard, does not pollute the environment, protects the entire device, and does not produce the by-product ammonium sulfate fertilizer at the same time, does not need to set up special storage and transportation for the by-product, can reduce the labor intensity of employees, and saves costs;

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum refining, and specifically relates to an S-zorb flue gas desulfurization device and method. Background Art

[0002] The existing flue gas desulfurization includes flue gas treatment part and fertilizer treatment part:

[0003] Flue gas treatment part: Flue gas is drawn out from the top outlet of the regeneration reactor of the S Zorb device. After decompression and cooling by the heat exchanger, the initial temperature of 205℃ and 69kPa is reduced to 120℃ and 12-15kPa. Flue gas enters the absorption tower, and the sulfur dioxide carried in the flue gas is removed by spraying under the action of the catalyst and converted into sulfuric acid. The absorption tower is injected with 10% mass concentration of dilute ammonia water to neutralize the sulfuric acid and convert it into ammonium sulfate. When the concentration of ammonium sulfate solution at the bottom of the absorption tower reaches 30%, the discharge pump is started to transport the mixed salt solution to the separator. After separation, the light phase organic catalyst returns to the absorption tower for reuse, and the heavy phase ammonium sulfate solution enters the salt liquid tank for temporary storage. The salt liquid in the salt liquid tank will be transported to the evaporation, crystallization and filtration integrated machine for treatment by the salt liquid pump within 8 hours. Purification of flue gas after desulfurization Flue gas enters the demisting tower from the top of the adsorption tower to remove the excess water carried and directly discharged at high altitude.

[0004] Fertilizer processing: The ammonium sulfate solution produced by the previous desulfurization process enters the salt liquid tank for temporary storage. The integrated machine processes a certain amount of salt liquid (ammonium sulfate solution) every day. During the processing, the salt liquid is transported to the integrated machine by a salt liquid pump, and the ammonium sulfate crystal solid is obtained after evaporation, filtration and drying in the integrated machine. During the drying and filtration process, the vacuum pump needs to be used to evacuate the integrated machine. After the filtration is completed, the ammonium sulfate with qualified moisture content is scraped out of the integrated machine, and enters the packaging machine through the fertilizer warehouse for packaging, and then sold after packaging. The steam is adjusted by the regulating valve and enters the jacket pipe of the integrated machine. The condensed water goes to the condensed water recovery unit after the steam trap.

[0005] Process principle:

[0006] The flue gas treatment unit process technology adopts an organic catalytic ammonia flue gas treatment process to remove sulfur dioxide from the S-Zorb flue gas and convert it into sulfuric acid. Ammonia water is then added as a neutralizer to obtain ammonium sulfate fertilizer, and the purified flue gas is directly discharged into the atmosphere.

[0007] Desulfurization principle:

[0008] SO2+H2O→H2SO3

[0009] H2SO3+LPC(organic catalyst)→LPC·H2SO3

[0010] LPC·H2SO3+O2→H2SO4+LPC

[0011] H2SO4+NH3·H2O→(NH4)2SO4+H2O

[0012] The complex directly generates H2SO4 under the action of oxygen, and reacts quickly with ammonia to produce high-quality ammonium sulfate fertilizer. The catalyst regains its capture ability and repeats the previous reaction.

[0013] Process operation:

[0014] Separation of part operations

[0015] (a) As SO2 in the flue gas is removed and ammonia is neutralized, ammonium sulfate is generated and the specific gravity of the mixed liquid in the absorption tower continues to increase to 1.15 g / cm 3 When the above conditions are met, the pipelines between the absorption tower, the discharge pump, the separator, the absorption tower, the separator and the salt liquid tank are connected, the discharge pump and the separator are started, the mixed liquid in the absorption tower is pumped to the separator through the discharge pump, and then the mixed liquid is separated into organic catalyst and salt liquid by the separator, the organic catalyst returns to the absorption tower, and the salt liquid enters the salt liquid tank. When the salt liquid separated by the separator contains organic catalyst, it is temporarily introduced into the underground collection tank.

[0016] (b) According to the amount of salt solution produced by the absorption tower, the discharge pump and separator can be operated intermittently to ensure that the specific gravity of the mixed liquid in the absorption tower does not exceed 1.15g / cm 3 That's it.

[0017] Fertilizer preparation part

[0018] a. When the brine reserve in the brine tank reaches 50%, check and connect the brine tank-brine pump-integrated machine-filtrate tank pipeline.

[0019] b. Start the salt solution pump to pump the salt solution into the integrated machine. When the salt solution in the integrated machine reaches the specified level, introduce steam into the integrated machine to concentrate the salt solution. When the salt solution concentration in the integrated machine reaches the specified value, stop passing steam and start the vacuum pump for filtration. After a certain period of filtration, stop filtration and introduce steam into the integrated machine to dry the filter cake. After the filter cake is dried, open the discharge valve of the integrated machine and unload the dried ammonium sulfate into the silo.

[0020] c. When a certain amount of ammonium sulfate is stored in the silo, it is bagged and packaged.

[0021] d. If the integrated machine is out of use for a long time, for example, more than 3 days, the residual crystals in the equipment should be flushed with water.

[0022] Working principle of the all-in-one machine

[0023] evaporation

[0024] After the slurry enters the tank, the equipment barrel, chassis, and rotating stirring paddle can heat the material separately or simultaneously. The material is turned and mixed while evaporating under the rotation of the stirring paddle.

[0025] filter

[0026] After evaporation, the slurry is filtered to separate the solid and liquid. When cracks appear on the surface of the filter cake, lower the stirring blade to the surface of the filter cake, stir, reverse, compact, and smooth the surface of the filter cake to avoid the phenomenon of filter channel flow and improve the filtration efficiency and quality. After filtration, it is recommended to use dry gas to press the filter cake dry. If drying is not required, open the discharge valve for unloading operation; if drying is required, proceed to the next drying operation.

[0027] dry

[0028] While the agitator is stirring the material, the equipment barrel, chassis, and rotating stirring blades can heat the material separately or simultaneously. The material is turned and mixed under the rotation of the stirring blades, and heat is obtained at the same time, thereby achieving the purpose of drying.

[0029] In order to speed up the drying process, the three-in-one vacuum cleaner is usually used during drying to quickly take away the evaporated gas, thereby speeding up the drying process.

[0030] Discharging

[0031] The dried material is pushed by the stirring blades and automatically discharged from the side discharge port.

[0032] The existing S-zorb unit of Yongping Refinery uses the regenerated flue gas of the gasoline refining unit as raw material and adopts the organic catalytic ammonia flue gas treatment process to achieve the purpose of desulfurization and demercuration. The purified flue gas is directly discharged into the atmosphere, and the by-product is ammonium sulfate fertilizer. Due to process reasons, when the integrated machine evaporates the fertilizer with salt liquid, the steam generated is directly discharged into the atmosphere, and the COD and ammonia nitrogen content in the steam seriously exceeds the standard, polluting the environment; the device is severely corroded, the machine pump seal corrodes and leaks frequently, the device operation and maintenance costs are high, and the workload is large; the by-product is ammonium sulfate fertilizer, and the storage and freight costs are high.

[0033] In order to solve the above problems, the flue gas treatment of the S-zorb device was modified. Summary of the invention

[0034] The purpose of the S-zorb flue gas desulfurization device and method provided by the present invention is to overcome the problems that in the prior art, the organic catalytic ammonia flue gas treatment process is adopted, and when the integrated machine salt liquid evaporates the fertilizer, the steam generated is directly discharged into the atmosphere, and the COD and ammonia nitrogen content in the steam seriously exceed the standard, polluting the environment; the device is severely corroded, the machine pump seal corrodes and leaks frequently, the device operation and maintenance cost is high, and the workload is large; the by-product is ammonium sulfate fertilizer, and the storage and freight costs are high.

[0035] To this end, the present invention provides an S-zorb flue gas desulfurization device, including an alkali liquid tank and an absorption tower, the absorption tower includes a quenching module, an absorption module, a filtering module, a gas-liquid separation module and a chimney, the quenching module, the absorption module, the filtering module, the gas-liquid separation module and the chimney are arranged in sequence from bottom to top, a flue gas inlet is provided in the horizontal direction of the quenching module, a flue gas outlet of the quenching module is connected to an inlet of the absorption module, an outlet of the absorption module is connected to an inlet of the filtering module, an outlet of the filtering module is connected to an inlet of the gas-liquid separation module, a gas outlet of the gas-liquid separation module is connected to an inlet of the chimney, the alkali liquid tank is respectively connected to the quenching module, the absorption module and the filtering module through pipelines, and the alkali liquid is contained in the alkali liquid tank, and the alkali liquid is a NaOH solution.

[0036] The quenching module comprises a first nozzle, which is connected to the alkali liquid tank through a pipeline and is located above the smoke inlet of the quenching module.

[0037] The absorption module comprises a second nozzle, which is connected to the alkali solution tank through a pipeline and is located above the inlet of the absorption module.

[0038] It also includes a slurry circulation pump, and the first nozzle and the second nozzle are both connected to the alkali liquid tank through the slurry circulation pump.

[0039] The filter module includes a plurality of filter channels, and the plurality of filter channels are arranged in a ring shape.

[0040] The outlet of each of the multiple filter channels is provided with a third nozzle, the third nozzle sprays downward, the inlet of the third nozzle is connected to the outlet of the slurry circulation pump, and the inlet of each filter channel is connected to the outlet of the absorption module.

[0041] The gas-liquid separation module comprises a plurality of water droplet separators, which are circumferentially evenly spaced, the inlet of each of the water droplet separators is connected to the outlet of the filter channel, and the gas outlet of each water droplet separator is connected to the chimney inlet.

[0042] The inlet of each water drop separator is provided with a fixed guide vane.

[0043] The filtration module also includes a circulating liquid collecting tank, and the liquid outlet of each water droplet separator is connected to the inlet of the circulating liquid collecting tank through a pipeline.

[0044] An S-zorb flue gas desulfurization method comprises the following steps: an alkali liquid tank supplies NaOH solution to a quenching module, an absorption module and a filtration module respectively through pipelines, the flue gas enters the flue gas inlet of the quenching module horizontally, the quenching module sprays NaOH solution on the incoming flue gas, cools and saturates the incoming flue gas and removes particulate dust in the flue gas; the cooled and saturated flue gas rises to the absorption module, the absorption module sprays NaOH solution on the incoming flue gas, washes catalyst particles in the incoming flue gas and absorbs sulfur dioxide and other acidic gases in the flue gas; the washed and absorbed flue gas rises to the filtration module, the filtration module sprays NaOH solution on the incoming flue gas again, removes particulate dust and SO3 in the incoming flue gas; the flue gas removed again by the filtration module rises to the gas-liquid separation module, the gas-liquid separation module performs gas-liquid separation on the incoming flue gas, the separated liquid enters the filtration module for collection, and the separated gas rises to the chimney.

[0045] Beneficial effects of the present invention: The S-zorb flue gas desulfurization device and method provided by the present invention respectively supplies NaOH solution to the quenching module, the absorption module and the filtration module through pipelines, and the quenching module is used to spray the NaOH solution on the incoming flue gas to cool and saturate the incoming flue gas and remove particulate dust in the flue gas. Solution is used to wash the catalyst particles entering the flue gas and absorb sulfur dioxide and other acidic gases in the flue gas. The filtration module is used to spray NaOH solution on the incoming flue gas again to remove particulate dust and SO3 entering the flue gas. The gas-liquid separation module is used to separate the flue gas into gas and liquid. The separated liquid enters the filtration module for collection, and the separated gas enters the chimney; NaOH solution is used to wash the catalyst particles in the flue gas and absorb sulfur dioxide and other acidic gases in the flue gas, so that sulfur dioxide is dissolved in water to generate sulfurous acid solution for acid-base neutralization reaction, and the pH value of the circulating slurry is adjusted by adjusting the amount of sodium hydroxide added; It is ensured that the flue gas emission is higher than the emission standard, does not pollute the environment, protects the entire device, and does not produce by-product ammonium sulfate fertilizer. There is no need to set up special storage and transportation for by-products, which can reduce the labor intensity of employees and save costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present invention will be further described in detail below with reference to the accompanying drawings.

[0047] Figure 1 It is a schematic diagram of the structure of the S-zorb flue gas desulfurization device.

[0048] Explanation of the accompanying reference numerals: 1. alkali liquid tank; 2. absorption tower; 3. quenching module; 4. absorption module; 5. filtration module; 6. gas-liquid separation module; 7. chimney; 8. flue gas inlet; 9. first nozzle; 10. second nozzle; 11. slurry circulation pump; 12. filtration channel; 13. third nozzle; 14. water droplet separator; 15. circulation collecting tank; 16. water. DETAILED DESCRIPTION

[0049] Embodiment 1:

[0050] like Figure 1 As shown, an S-zorb flue gas desulfurization device includes an alkali liquid tank 1 and an absorption tower 2. The absorption tower 2 includes a quenching module 3, an absorption module 4, a filtering module 5, a gas-liquid separation module 6 and a chimney 7. The quenching module 3, the absorption module 4, the filtering module 5, the gas-liquid separation module 6 and the chimney 7 are arranged in sequence from bottom to top. The quenching module 3 is provided with a flue gas inlet 8 in the horizontal direction. The flue gas outlet of the quenching module 3 is connected to the inlet of the absorption module 4, the outlet of the absorption module 4 is connected to the inlet of the filtering module 5, the outlet of the filtering module 5 is connected to the inlet of the gas-liquid separation module 6, and the gas outlet of the gas-liquid separation module 6 is connected to the inlet of the chimney 7. The alkali liquid tank 1 is connected to the quenching module 3, the absorption module 4 and the filtering module 5 respectively through pipelines. The alkali liquid tank 1 is filled with alkali liquid, and the alkali liquid is a NaOH solution.

[0051] The S-zorb flue gas desulfurization device provided by the present invention comprises a quenching module 3 for the incoming flue gas (the flue gas includes sulfur oxides, nitrogen oxides and hot flue gas of the catalyst (with positive pressure)). The alkali liquid tank 1 supplies NaOH solution to the quenching module 3, the absorption module 4 and the filtration module 5 through pipelines respectively. The quenching module 3 is used to spray the NaOH solution on the incoming flue gas to cool and saturate the incoming flue gas and remove particulate dust in the flue gas. The NaOH solution is sprayed on the incoming flue gas to wash the catalyst particles in the incoming flue gas and absorb sulfur dioxide and other acidic gases in the flue gas. The filtration module 5 is used to spray the NaOH solution on the incoming flue gas again to remove particulate dust and SO3 in the incoming flue gas. The gas-liquid separation module 6 is used to perform gas-liquid separation on the flue gas. The separated liquid enters the filter module 5 for collection, and the separated gas enters the chimney 7; NaOH solution is used to wash the catalyst particles in the flue gas and absorb sulfur dioxide and other acidic gases in the flue gas, so that sulfur dioxide is dissolved in water to generate a sulfurous acid solution for acid-base neutralization reaction, and the pH value of the circulating slurry is adjusted by adjusting the amount of sodium hydroxide and water 16 added; It is ensured that the flue gas emission is higher than the emission standard, does not pollute the environment, protects the entire device, and does not produce by-product ammonium sulfate fertilizer. There is no need to set up special storage and transportation for by-products, which can reduce the labor intensity of employees and save costs. The quenching module 3 has a flue gas inlet 8 in the horizontal direction to ensure that the flue gas is fully sprayed with NaOH solution, improve the cooling saturation efficiency of the incoming flue gas and the removal rate of particulate dust in the flue gas.

[0052] Embodiment 2:

[0053] Furthermore, the quenching module 3 includes a first nozzle 9, which is connected to the alkali liquid tank 1 through a pipeline, and the first nozzle 9 is located above the flue gas inlet 8 of the quenching module 3. The flue gas enters the quenching module 3 of the absorption tower 2 horizontally, and the circulating slurry is sprayed by the first nozzle 9 in this part to form a high-density water curtain perpendicular to the flue gas entry direction. The flue gas is fully in contact with the circulating slurry, and the flue gas is rapidly cooled and saturated to the set temperature; here, the atomized water droplets move in a cross-flow manner, covering the entire cross-section of the flue gas flow, greatly reducing the flue gas temperature and saturating it, removing larger particles of dust, and evenly flushing the entire inner wall.

[0054] Further, the absorption module 4 includes a second nozzle 10, which is connected to the alkali liquid tank 1 through a pipeline, and the second nozzle 10 is located above the inlet of the absorption module 4. The second nozzle 10 mainly washes catalyst particles larger than 3 microns and absorbs sulfur dioxide and other acidic gases in the flue gas. The second nozzle 10 is located above the inlet of the absorption module 4 to improve the washing and absorption rate.

[0055] Furthermore, it also includes a slurry circulation pump 11, and the first nozzle 9 and the second nozzle 10 are both connected to the alkali liquid tank 1 through the slurry circulation pump 11.

[0056] The slurry circulation pump 11 provides NaOH solution to the first nozzle 9 and the second nozzle 10. The water-gas ratio and the number of nozzles required for absorbing sulfur dioxide are selected based on the inlet concentration of sulfur dioxide, the emission requirements and the temperature of the saturated gas.

[0057] The desulfurization mechanism of NaOH solution is to carry out acid-base neutralization reaction between alkaline substances and sulfurous acid solution generated by sulfur dioxide dissolved in water, and adjust the pH value of the circulating slurry by adjusting the amount of sodium hydroxide added.

[0058] NaOH reacts with sulfide to produce sodium sulfite and sodium sulfate, which are used to absorb SO in the scrubber. X The chemical reaction is as follows: sulfur dioxide in the flue gas comes into contact with water to produce sulfurous acid:

[0059] SO2(g)+H2O←→H2SO3

[0060] Then sulfurous acid reacts with NaOH to form sodium sulfite

[0061] H2SO3+2NaOH←→Na2SO3+2H2O

[0062] Sodium sulfite further reacts with sulfurous acid to form sodium bisulfite

[0063] Na2SO3+H2SO3←→2NaHSO3

[0064] Sodium bisulfite reacts with sodium hydroxide to accelerate the formation of sodium sulfite

[0065] NaHSO3+NaOH←→2Na2SO3+2H2O

[0066] Overall reaction formula:

[0067] SO2(g)+H2O+2NaOH←→2H2O+Na2SO3

[0068] Side effects:

[0069] 2NaOH+SO3—→Na2SO4+H2O

[0070] NaOH+HC1→NaC1+H2O

[0071] At the same time, the pH value of the circulating slurry in the absorption module 4 is controlled by injecting NaOH, and the optimal value is about 7. In order to control the chloride ion and solid content in the circulating absorption liquid not to exceed the standard, part of the absorption liquid needs to be discharged to ensure the desulfurization effect.

[0072] Furthermore, a plurality of flue gas temperature measuring points are provided in the absorption module 4 ; the flue gas temperature measuring points are used to measure the operating temperature of the absorption module 4 to prevent the operating temperature from being too high, thereby causing potential safety hazards.

[0073] Furthermore, a self-quenching nozzle is provided in the absorption module 4; in actual operation, when more than half of the multiple flue gas temperature measuring points exceed the set temperature, the emergency cold water is started, and fire water is sprayed from the self-quenching nozzle to cool the absorption module 4 until it drops below the set temperature. The measurement accuracy is high, and when the flue gas load changes under the working conditions of 50% to 110%, the S-zorb flue gas desulfurization device can still adapt to the load fluctuation and maintain normal operation.

[0074] Furthermore, the filter module 5 includes a plurality of filter channels 12, and the plurality of filter channels 12 are arranged in a ring shape. The filter module 5 arranged in a ring shape can once again completely remove particulate dust and SO3 in the flue gas.

[0075] Furthermore, the outlet of each filter channel 12 of the plurality of filter channels 12 is provided with a third nozzle 13, the third nozzle 13 sprays downward, the inlet of the third nozzle 13 is connected to the outlet of the slurry circulation pump 11, and the inlet of each filter channel 12 is connected to the outlet of the absorption module 4. The flue gas is divided into multiple streams by the plurality of filter channels 12, and the flue gas rises through the plurality of filter channels 12 respectively. A third nozzle 13 is provided above each filter channel 12, and the third nozzle 13 sprays downward into the outlet of the riser, which has a simple structure and a good removal effect.

[0076] Furthermore, the gas-liquid separation module 6 includes a plurality of water droplet separators 14, which are circumferentially evenly spaced, and the inlet of each of the water droplet separators 14 is connected to the outlet of the filter channel 12, and the gas outlet of each water droplet separator 14 is connected to the inlet of the chimney 7. This ensures that the water droplets in the flue gas are fully separated and improves the separation effect.

[0077] Furthermore, a fixed guide vane is provided at the inlet of each of the plurality of water droplet separators 14. The fixed guide vane allows the flue gas to rotate, and separates the water droplets in the flue gas by centrifugal separation, which has a simple structure and good separation effect, and the separated water can evenly flush the inner wall of the pipeline for self-cleaning.

[0078] Furthermore, the filtration module 5 further includes a circulating liquid collecting tank 15, and the liquid outlet of each water bead separator 14 is connected to the inlet of the circulating liquid collecting tank 15 through a pipeline. The water outlet of the water bead separator 14 is arranged at the bottom of the water bead separator 14, so that all the separated water flows into the circulating liquid collecting tank 15 through the pipeline, and the water in the circulating liquid collecting tank 15 can be reused after being processed as needed.

[0079] Furthermore, the pipeline is located below the liquid level of the liquid separated by the water droplet separator 14 ; the liquid level forms a seal to prevent the flue gas from bypassing the rotating water droplet separator 14 .

[0080] Furthermore, a water pit is provided at the bottom of the chimney 7; the flue gas without water droplets flows into the bottom of the chimney 7 after being sorted. The flow rate of the flue gas in the chimney 7 is low so that the condensed water (from the flue gas cooling) flows downward back to the absorption module 4; there is a water pit at the bottom of the chimney 7 to collect the water droplets discharged from the flue gas flow and the condensed water vapor, and these waters are discharged to the circulating liquid collecting tank 15 of the filter module 5 through a pipeline, and the water in the circulating liquid collecting tank 15 can be reused after being treated as needed; a liquid seal is also provided on the pipeline to prevent the flue gas from bypassing the rotating water droplet separator 14. The clean flue gas after dehydration is discharged into the atmosphere through the upper chimney 7.

[0081] Embodiment 3:

[0082] On the basis of Example 2, an S-zorb flue gas desulfurization method comprises the following steps: an alkali liquid tank 1 supplies NaOH solution to a quenching module 3, an absorption module 4 and a filtering module 5 through pipelines, respectively; the flue gas enters the flue gas inlet 8 of the quenching module 3 horizontally; the quenching module 3 sprays NaOH solution on the incoming flue gas to cool and saturate the incoming flue gas and remove particulate dust in the flue gas; the cooled and saturated flue gas rises to the absorption module 4, the absorption module 4 sprays NaOH solution on the incoming flue gas to wash the catalyst particles in the incoming flue gas and absorb sulfur dioxide and other acidic gases in the flue gas; the flue gas after washing and absorption rises to the filtering module 5, the filtering module 5 sprays NaOH solution on the incoming flue gas again to remove particulate dust and SO3 in the incoming flue gas; the flue gas removed again by the filtering module 5 rises to the gas-liquid separation module 6, the gas-liquid separation module 6 performs gas-liquid separation on the incoming flue gas, the separated liquid enters the filtering module 5 for collection, and the separated gas rises to the chimney 7.

[0083] The S-zorb flue gas desulfurization method ensures that the flue gas discharged is higher than the emission standard, does not pollute the environment, and thus protects the entire device. The use of NaOH desulfurization does not produce by-product ammonium sulfate fertilizer, and does not require special storage and transportation for by-products, which can reduce the labor intensity of employees and save costs.

[0084] Embodiment 4:

[0085] An S-zorb flue gas desulfurization device includes an absorption tower 2, which includes a quenching module 3, an absorption module 4, a filtering module 5, a gas-liquid separation module 6 and a chimney 7. The quenching module 3, the absorption module 4, the filtering module 5, the gas-liquid separation module 6 and the chimney 7 are connected in sequence. The quenching module 3 includes a first nozzle 9. The absorption module 4 includes a second nozzle 10. The absorption module 4 also includes a slurry circulation pump 11, which transports circulating slurry, and the circulating slurry is a 30% NaOH solution. The outlet of the slurry circulation pump 11 is connected to the inlet of the first nozzle 9 and the inlet of the second nozzle 10 respectively. The filtering module 5 includes 17 filtering channels 12, and the 17 filtering channels 12 are annularly arranged in the upper part of the absorption tower 2; a third nozzle 13 is arranged above each filtering channel 12, and the inlet of the third nozzle 13 is connected to the outlet of the slurry circulation pump 11. The gas-liquid separation module 6 includes 12 water droplet separators 14, which are circumferentially evenly spaced in the chimney 7; a fixed guide vane is provided at the inlet of each water droplet separator 14. The filtration module 5 also includes a circulating liquid collecting tank 15, and the water outlet of each water droplet separator 14 is connected to the inlet of the circulating liquid collecting tank 15 through a pipeline.

[0086] The flue gas enters the quenching module 3 of the absorption tower 2, and the first nozzle 9 sprays 30% NaOH solution to form a high-density water curtain perpendicular to the flue gas entry direction. The flue gas is fully contacted with the 30% NaOH solution to quench the flue gas and saturate it to about 62.7°C. Here, the atomized water droplets move in a cross-flow manner to cover the entire cross-section of the flue gas flow. The flue gas temperature is greatly reduced and saturated, larger dust particles are removed, and the entire inner wall of the quenching module 3 is evenly washed; the cooled and saturated flue gas rises to the absorption module 4, and the second nozzle 10 mainly washes the catalyst particles larger than 3 microns, absorbs sulfur dioxide and other acidic gases in the flue gas, and the pH value of the NaOH solution is controlled at 7.0. The NaOH solution is sent to the second nozzle 10 for spraying through the tower slurry circulation pump 11; the flue gas after washing and absorption enters the filtration module 5, and the flue gas is divided into 17 streams, which rise through 17 filtration channels 12 respectively, and the third nozzle 13 sprays downward into the riser outlet; the flue gas removed again by the filtration module 5 enters the gas-liquid separation module 6, and each water droplet separator 14 processes a part of the flue gas, and the fixed guide vanes at the inlet allow the flue gas to rotate, and the water droplets in the flue gas are separated by centrifugal separation. The separated water evenly washes the inner wall of the pipe for self-cleaning, and gathers at the bottom of the separator and returns to the filter module 5 area; the flue gas without water droplets flows into the bottom of the chimney 7 after being sorted. The speed of the chimney 7 is relatively low so that the condensed water (from the flue gas cooling) can flow downward back to the absorption module 4. There is a puddle at the bottom of the chimney 7 to collect the water droplets discharged from the flue gas flow and condensed water vapor. The water is discharged to the circulation tank of the filter module 5 through a pipe, and the dehydrated clean flue gas is discharged into the atmosphere through the upper chimney 7 (about 80 meters high).

[0087] The present invention runs for 366 days and 8864 hours. Then:

[0088] 1. Reduce costs:

[0089] (1) Catalyst can save:

[0090] 0.5 tons / year × 170,769 yuan / ton = 85,400 yuan

[0091] (2) Ammonia saving:

[0092] 400t / a×1040 yuan / t=416,000 yuan

[0093] (3) Savings in water, electricity, steam and wind consumption:

[0094] Demineralized water: 0.12t / h×21.13 yuan / ton×8864h=22,500 yuan

[0095] 1.0MP steam: 0.57t / h×203.93 yuan / ton×8864h=1.0303 million yuan

[0096] Electricity: 20.23Kw×0.69 yuan / kW·h×8864h=123,700 yuan

[0097] Purified air: 90Nm3 / h×0.12 yuan / Nm3×8864h=95,700 yuan

[0098] Subtotal of reduced expenses: RMB 1,773,600

[0099] (ii) Additional costs:

[0100] (1) Increase the consumption of caustic soda flakes:

[0101] The main parameters of the flue gas from the S-zorb device are as follows: flow rate is 264Nm3 / h, and SOX concentration is 28465mg / m3.

[0102] The SOx concentration generated per hour is 264Nm3 / h×28465mg / m3=7.5kg / h

[0103] The chemical reactions that occur in the scrubber of the flue gas desulfurization unit to absorb SOx are as follows:

[0104] Overall reaction formula: SO2(g)+H2O+2NaOH←→2H2O+Na2SO3

[0105] Side reaction: 2NaOH+SO3—→Na2SO4+H2O

[0106] The hourly consumption of NaOH is 9.375 kg / h, equivalent to 9.57 kg / h of 98% flake caustic soda.

[0107] After technical transformation, the consumption of caustic soda flakes increased by 98%:

[0108] 9.57kg / h×4950 yuan / ton×8864h=419,900 yuan

[0109] (2) Project investment costs:

[0110] The total material cost of the 900,000 tons / year S-Zorb unit regeneration flue gas to secondary catalytic desulfurization project is 161,928 yuan, the mechanical equipment depreciation period is 15 years, and the cost is amortized, the project investment cost is 10,800 yuan / year. The total project construction cost is 34,300 yuan.

[0111] Subtotal of additional expenses: RMB 454,200

[0112] (III) Total cost savings

[0113] The project ended on May 8, 2020, with a total of 366 days and 8,864 hours, and cost savings:

[0114] 1.7736 million yuan - 454.2 thousand yuan = 1.3194 million yuan

[0115] The monitoring results of the implementation of the present invention show that the emission concentrations of sulfur dioxide, nitrogen oxides, particulate matter, etc. are in line with and higher than the emission standards. The successful implementation of the project has fully verified the feasibility and stability of the present invention in treating S-zorb flue gas, which is not only of reference significance for the technical transformation of the same type of S-zorb flue gas, but also has a strong reference value for the flue gas treatment transformation of sulfur recovery incinerators.

[0116] In the description of the present invention, it should be understood that if any term indicates an orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, 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. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on the present invention.

[0117] The above examples are merely illustrative of the present invention and do not constitute a limitation on the protection scope of the present invention. All designs that are the same or similar to the present invention fall within the protection scope of the present invention.

Claims

1. An S-zorb flue gas desulfurization device, characterized in that: The invention comprises an alkali liquid tank (1) and an absorption tower (2). The absorption tower (2) comprises a quenching module (3), an absorption module (4), a filtration module (5), a gas-liquid separation module (6) and a chimney (7). The quenching module (3), the absorption module (4), the filtration module (5), the gas-liquid separation module (6) and the chimney (7) are arranged in sequence from bottom to top. The quenching module (3) is provided with a flue gas inlet (8) in the horizontal direction. The flue gas outlet of the quenching module (3) is connected to the inlet of the absorption module (4). The outlet of the absorption module (4) is connected to the inlet of the filtration module (5). The outlet of the filtration module (5) is connected to the inlet of the gas-liquid separation module (6). The gas outlet of the gas-liquid separation module (6) is connected to the inlet of the chimney (7). The alkali liquid tank (1) is connected to the quenching module (3), the absorption module (4) and the filtration module (5) respectively through pipelines. The alkali liquid tank (1) contains alkali liquid, which is NaOH. solution; the filtration module (5) comprises a plurality of filtration channels (12), the plurality of filtration channels (12) being arranged in a ring shape; the gas-liquid separation module (6) comprises a plurality of water droplet separators (14), the plurality of water droplet separators (14) being circumferentially evenly spaced, the inlet of each of the plurality of water droplet separators (14) being connected to the outlet of the filtration channel (12), and the gas outlet of each water droplet separator (14) being connected to the inlet of the chimney (7); the filtration module (5) further comprises a circulating liquid collecting tank (15), the liquid outlet of each water droplet separator (14) being connected to the inlet of the circulating liquid collecting tank (15) via a pipeline; the pipeline being located below the liquid surface of the liquid separated by the water droplet separator (14).

2. The S-zorb flue gas desulfurization device according to claim 1, characterized in that: The quenching module (3) comprises a first nozzle (9), the first nozzle (9) being connected to the alkali liquid tank (1) via a pipeline, and the first nozzle (9) being located above the flue gas inlet (8) of the quenching module (3).

3. The S-zorb flue gas desulfurization device according to claim 2, characterized in that: The absorption module (4) comprises a second nozzle (10), the second nozzle (10) being connected to the alkali liquid tank (1) via a pipeline, and the second nozzle (10) being located above the inlet of the absorption module (4).

4. The S-zorb flue gas desulfurization device according to claim 3, characterized in that: It also includes a slurry circulation pump (11), and the first nozzle (9) and the second nozzle (10) are both connected to the alkali liquid tank (1) via the slurry circulation pump (11).

5. The S-zorb flue gas desulfurization device according to claim 4, characterized in that: The outlet of each of the plurality of filter channels (12) is provided with a third nozzle (13), the third nozzle (13) sprays downward, the inlet of the third nozzle (13) is connected to the outlet of the slurry circulation pump (11), and the inlet of each filter channel (12) is connected to the outlet of the absorption module (4).

6. The S-zorb flue gas desulfurization device according to claim 5, characterized in that: The inlet of each water drop separator (14) is provided with a fixed guide vane.

7. A desulfurization method based on the S-zorb flue gas desulfurization device according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: a alkali liquid tank (1) supplies NaOH solution to a quenching module (3), an absorption module (4) and a filtration module (5) through pipelines, and flue gas enters the flue gas inlet (8) of the quenching module (3) horizontally; the quenching module (3) sprays NaOH solution on the incoming flue gas to cool and saturate the incoming flue gas and remove particulate dust in the flue gas; the cooled and saturated flue gas rises to the absorption module (4); the absorption module (4) sprays NaOH solution on the incoming flue gas to wash the catalyst particles in the incoming flue gas and absorb sulfur dioxide and other acidic gases in the flue gas; The flue gas after washing and absorption is raised to the filter module (5), and the filter module (5) sprays NaOH solution on the incoming flue gas again to remove particulate dust and SO3 in the incoming flue gas; the flue gas removed again by the filter module (5) is raised to the gas-liquid separation module (6), and the gas-liquid separation module (6) separates the incoming flue gas into gas and liquid, and the separated liquid enters the filter module (5) for collection, and the separated gas is raised to the chimney (7).

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