Desulfurization + Ammonium Sulfate question bank

Look for desulfurization information here: Process technology operation standards for the desulfurization section in the recycling workshop. Brief description of the process: This section involves the wet oxidation desulfurization of coke oven gas, using ammonia present in the gas as a base source and cobalt phthaloate sulfonate as the main catalyst; it is also known as the combined ammonia-sulfur washing method or HPF method. The process is as follows: The gas sent from the blower section enters a direct-cooling pre-cooling tower, where it comes into counter-current contact with the circulating cooling fluid sprayed from the top of the tower, thereby being cooled to 27–28°C. The circulating cooling fluid is pumped out from the bottom of the tower and sent to a circulating water cooler, where it is cooled to 27°C using refrigeration water before being circulated and sprayed back at the top of the tower. Part of the excess ammonia water is used to update the circulating cooling water, while the remaining circulating water is returned to the condensation and blower section. The gas coming from the pre-cooling tower enters two desulfurization towers in parallel, where it comes into countercurrent contact with the desulfurization liquid sprayed from the tops of the towers, thereby absorbing H2S and HCN from the gas (while also absorbing ammonia from the gas to replenish the volatile ammonia in the desulfurization liquid). After desulfurization, the gas passes through the desulfurization liquid mist catcher at the outlet of the desulfurization tower before being sent to the ammonium sulfate production unit. The desulfurization fluid, which has absorbed H2S and HCN, flows from the storage tank at the bottom of the desulfurization tower to the reaction tank by gravity. It is then pumped by a desulfurization fluid circulation pump to the bottom of the regeneration tower, where it is fed into the regeneration tower through the premixing nozzles ； The temperature of the desulfurization solution is maintained about 3°C higher than that of the gas entering the tower; at the same time, compressed air is injected at the bottom of the regeneration tower through premixing nozzles, allowing the solution to be oxidized and regenerated within the tower. The regenerated solution then flows back to the top of the desulfurization tower via a level controller for reuse. The sulfur foam floating on the expanded section at the top of the regeneration tower flows automatically into the foam tank due to the difference in pressure ； After being heated and stirred in the foam tank, it is pumped to the sulfur melting vessel using a foam pump. After heating and dehydration, the clear liquid overflows through the clear liquid pipe at the top of the sulfur melting tank into the waste liquid tank. Most of it is pumped by the waste liquid pump to the desulfurization liquid cooler for cooling before being fed into the reaction tank, while a small portion is pumped by the waste liquid pump to the coal yard for spraying. After the sulfur paste is melted in the sulfur melting vessel, it is discharged through the discharge valve of the vessel onto the sulfur cooling tray; once cooled, it is packaged and sold externally. The catalyst consumed during the desulfurization process must be replenished in a timely manner, with an appropriate amount added based on the test results showing the catalyst concentration in the desulfurization solution. After being dosed, the catalyst is added to the dissolution tank located above the reaction tank; after mixing it thoroughly with water, it is slowly poured into the reaction tank to minimize unnecessary waste of the catalyst. With this process, the growth rate of by-product salts is very slow; thiosulfate and ammonium thiocyanate can be kept within certain concentration ranges without affecting the catalyst’s activity, allowing for the elimination of the need for by-product salt extraction ； To prevent the accumulation of by-products in the desulfurization liquid from affecting its efficiency, a small amount of this liquid can be appropriately discharged and used to spray the coal seams in the coal preparation area. 2 Principles of desulfurization processes 2.1 Wet oxidation desulfurization using ammonia as a base source is a liquid-phase catalytic oxidation reaction. The catalyst plays a catalytic role in both the desulfurization and regeneration processes; it possesses high catalytic activity. Moreover, it is easily soluble in water and has good fluidity, which helps to prevent blockages in the equipment pipelines. 2.2 The ammonia-based desulfurization process is employed; during the absorption of H2S, it is not necessary to use pure soda ash – the ammonia present in the gas itself can serve as the alkaline source. With an appropriate addition of concentrated ammonia solution, H2S and HCN in the gas can be absorbed quite completely. Meanwhile, under the catalytic action of a catalyst, the oxygen in the air is used to oxidize NH4HS in the absorption solution into elemental sulfur, thereby allowing the absorption solution to be regenerated for reuse. 2.3 Several main chemical reactions in the desulfurization process: 2.3.1 Absorption reactions: NH3 (gas) → NH3 (liquid); H2S (gas) → H2S (liquid); HCN (gas) → HCN (liquid); CO2 (gas) → CO2 (liquid). Reactions include: NH3 + H2O → NH4OH (ammonia water); NH4OH + H2S → NH4HS + H2O; 2NH4OH + H2S → (NH4)2S + 2H2O; HCN + NH4OH → NH4CN + H2O; CO2 + NH4OH → NH4HCO3; NH4OH + NH4HCO3 → (NH4)2CO3 + H2O. 2.3.2 Catalytic chemical reactions: NH4HS + NH4OH + (X-1)S → H2. P. F (NH4) 2Sx + H2O → 2NH4HS + (NH4)2CO3 + 2(X-1)S·H. P. F 2(NH4) 2Sx + CO2 + H2O → NH4HS + NH4HCO3 + (X-1)S·H2O. P. F (NH4) 2Sx + H2O + CO2 → NH4CN + (NH4) 2Sx·H2O. P. F NH4CNS + (NH4) 2SX-1 → (NH4) 2SX-1 + S H. P. F (NH4) 2Sx 2.3.3 Catalytic regeneration reaction: NH4HS + 1/2O2 → S↓ + NH4OH; (NH4)2S + 1/2O2 → 2NH4OH + S↓; (NH4)2SX + 1/2O2 → Sx↓ + 2NH4OH. NH4CNS → H2N—C(=S)—NH2; H2N —C(=HS) = NH; H2N —C(=S)—NH2 + 1/2 O2 → H2N — C(C =O) —NH2 + S; H2N—C(=O)—H2N + 2H2O; (NH4)2CO3 + H2O → 2NH4OH + CO2. 2.4 Side reactions: 2NH4HS + 2O2 → (NH4)2SO3 + H2O; 2(NH4)2SO3 + O2 → 2(NH4)2SO4 + 2S↓. 3 Process characteristics 3.1 The desulfurization unit is placed in the overall coal gas purification process before ammonium sulfate and crude benzene, resulting in a rational technical approach with a short and simple process flow. 3.2 By using ammonia in the gas as a base source, operating costs and production costs are reduced. It also replenishes the ammonia vapor resulting from the evaporation of excess ammonia water, thereby effectively controlling the ammonia content in the desulfurization solution and contributing to the stability of desulfurization efficiency. 3.3 By using cobalt phthaloate sulfonate catalysts in combination with KHSS-1 type fillers in the desulfurization tower, this process achieves good desulfurization and decyanation results, with a desulfurization efficiency of ≥99% and a decyanation efficiency of ≥75%, offering significant social and environmental benefits. 3.4 The sulfur foam formed is easily separable from the clear liquid, making the sulfur melting process convenient; the method of adding catalyst is simple. Moreover, during the desulfurization process, the growth rate of by-product salts is slow, so it is not necessary to install a device for recovering these salts. 4 Main technical parameters 4.1 Gas temperature entering the desulfurization tower: 27-28℃ ； 4.2 Temperature of the solution in the desulfurization tower: 30-35℃ ； 4.3 Maximum liquid-to-gas ratio in the desulfurization tower: 0.33 t/Nm3 ； 4.4 Air flow rate into the regeneration tower: 2000 m3/h ； 4.5 Desulfurization tower resistance: ≤1000Pa ； 4.6 Pre-cooling tower resistance: ≤1000Pa ； 4.7 Solution pH value: 8-9 ； 4.8 Catalyst concentration: 30-50ppm ； 4.9 Steam pressure: 0.4-0.6MPa ； 4.10 Compressed air pressure: 0.5-0.6 M 4.11 Foam tank heating temperature: 80-90℃ ； 4.12 Temperature in the channel of the sulfur melting tank: 130-150℃ ； 4.13 Pressure inside the sulfur melting tank: ＜0.6MPa ； 4.14 Liquid level in the reaction tank: 1/2-2/3 ； 4.15 Total content of by-products: ＜300g/L ； 4.16 Suspended sulfur content: ≤1.5g/L ； 4.17 Free ammonia content in desulfurization cycle fluid: 4–5 g/L ； 4.18 H2S content after the tower: ＜300mg/m3 ； 4.19 Desulfurization circulation pump shaft temperature: ＜75℃ 4.20 Desulfurization efficiency: ≥98% ； 4.21 Decyanation efficiency: ≥80 ； 4.22 Liquid level at the lower part of the pre-cooling tower: Maintain it at the middle position of the level gauge ； 5 Technical Operation Standards 5.1 Operating Standards for Circulation Pump Operators 5.1.1 Operation under normal conditions 5.1.1.1 Items to be checked hourly: pump outlet pressure and bearing temperature, motor operating current and casing temperature, sound of the pump, solution temperature and circulation rate, gas temperature and pressure, cooling water circulation rate in the pre-cooling tower, etc. Circulating ammonia water (cooled to 27–28 degrees Celsius by the ammonia water cooler) is sent from the drum cooling section until the liquid level in the tower level gauge reaches 3.5 m, at which point the supply is stopped. 5.1.1.2 Items to be checked every half hour: liquid levels in tanks such as accident tanks, underground tanks, and reaction tanks, as well as the amount of regeneration air and air pressure. 5.1.1.3 Items to be checked every two hours: Check whether outdoor equipment is leaking air or fluid; any abnormal conditions must be addressed promptly. If it is not possible to resolve the issue, it should be reported immediately, and regular inspections should be carried out until the abnormal condition is resolved. 5.1.1.4 Clean the gas water seal and the outlet pipe of the mist catcher regularly once a week (during the day shift). 5.1.1.5 The catalyst is added during the day shift on a daily basis. The method of adding the catalyst involves calculating the amount required based on the catalyst concentration determined through testing each day. Then, water is added and stirred in the dissolution tank above the reaction tank; once the catalyst is completely dissolved, it is added drop by drop into the reaction tank to prevent uneven catalyst concentration within the system and catalyst loss, thereby reducing catalyst consumption. 5.1.2 Startup of the desulfurization circulation pump: 5.1.2.1 Before starting, it is necessary to check that the pipeline valves are in their normal condition prior to operation, as well as to inspect the lubricating oil in the bearings and motor. The coupling should be turned by hand to verify that it rotates smoothly. 5.1.2.2 Before starting, open the inlet valve of the pump. Open the exhaust valve on the pump body to release the air inside it, then close the exhaust valve. Close the pressure gauge valve as well, and subsequently start the motor. Once the pump is rotating properly, open the pressure gauge valve and the inlet valve. After the pressure gauge shows normal pressure, gradually open the outlet valve until the desired flow rate is achieved. 5.1.2.3 Pay attention to changes in motor current, sound, motor temperature, etc. 5.1.3 Shutting down the pump: First, reduce the flow rate by closing the pump’s outlet valve; after shutting off the power supply to stop the pump, then close the inlet valve ； The liquid inside the pump should be drained during winter or during maintenance. 5.2 Operator Standards for Towers 5.2.1 Starting the Pre-cooling Tower: 5.2.1.1 Before starting the ammonia vaporization tower, supply circulating water and low-temperature water to the front of the tower; check that the manholes are properly sealed, that the water seal tank is filled with water, and that the drain pipe connecting the gas pipeline to the water seal tank is closed. Open the vent valve at the top of the tower, while keeping the inlet and outlet valves of the pre-cooling circulation pump closed. 5.2.1.2 Open the nitrogen valve connected to the inlet of the tower and the nitrogen valve on the coal gas outlet of the tower, and supply nitrogen into the tower and the coal gas pipeline to displace the air. Once a large amount of nitrogen begins to flow out from the tower’s vent pipe, reduce the valve opening of that vent pipe in order to maintain a nitrogen pressure of 50 Pa inside the tower. Then remove the blind flanges on the inlet and outlet coal gas lines as well as the blind flange for ammonia gas ； 5.2.1.3 Close the tower vent line valve ； 5.2.1.4 Slightly open the gas inlet valve to use gas to displace nitrogen in the tower; once the oxygen content of the gas at the outlet of the vent pipe is within acceptable levels, close the vent valve ； 5.2.1.5 Open the gas outlet valve of the pre-cooling tower, slowly open the gas inlet valve, and gradually close the gas connection pipe valve. Pay attention to changes in the gas resistance inside the tower, and keep the resistance of the pre-cooling tower below 1 kPa ； 5.2.1.6 Once the gas operation is stable, start the pre-cooling circulation liquid pump to ensure normal circulation of the liquid; at the same time, supply low-temperature cooling water to the cooler, and continuously feed in the cooled recycled ammonia solution. The excess circulation liquid should be sent to the drum cooling section (to determine the optimal amount), in order to maintain the liquid level at the middle position indicated by the level gauge ； 5.2.1.7 Open the ammonia vapor inlet valve of the pre-cooling tower to feed in the ammonia vapor from the ammonia vaporization unit ； 5.2.1.8 Adjust various control parameters to meet the requirements specified in the technical regulations ； 5.2.1.9 Open the drain valve of the gas pipe leading to the water seal tank, and plug the nitrogen blind flange ； 5.2.2 Shutdown of the pre-cooling tower: 5.2.2.1 Stop supplying circulating ammonia water to the drum cooling section; stop the cooling water flow to the ammonia cooler; cease feeding circulating liquid to this section. For ammonia vapor generation, stop supplying ammonia vapor and close the valve for ammonia vapor entering the tower ； 5.2.2.2 Open the gas bypass valve, close the gas inlet and outlet valves of the tower, stop the circulating liquid pump, close the inlet and outlet valves of the pump, and stop the low-temperature cooling water flow ； 5.2.2.3 In the case of a short-term shutdown of the tower, keep the gas outlet valve slightly open to maintain positive pressure inside the tower ； 5.2.2.4 When the tower is to be shut down for an extended period and maintenance work is required inside it: First, steam is introduced and the vent valve is opened until a large amount of steam emerges from the vent. With the vent valve set to maintain a positive pressure of 50 Pa inside the tower, the blind valves for gas inlet and outlet, as well as those for ammonia vapor and nitrogen, are closed. The liquid present in the tower is drained, and the vent valve at the top of the tower is opened to clean it using steam. After that, the steam supply is turned off, and the manholes on the tower are opened for ventilation. Maintenance work can only begin after samples taken show satisfactory results. 5.2.3 Starting the desulfurization tower and regeneration tower: 5.2.3.1 Fill the water seal tank of the coal gas pipeline in the desulfurization tower with water; close the valve of the drain pipe connecting the coal gas pipeline to the water seal tank. The electrostatic tar catcher is already in operation and functioning properly ； Fill the reaction tank with water, and fill the bottom of the desulfurization tower to full flow. 5.2.3.2 Open the valves on the vent pipes at the top of the regeneration tower and the desulfurization tower; close the drainage valve located at the lower part of the \"U\"-shaped pipe connecting the regeneration tower and the desulfurization tower. Set the liquid level regulator of the regeneration tower to its lowest position, and close the valve connecting the regeneration tower to the foam tank ； 5.2.3.3 Open the nitrogen valves on the desulfurization tower and the coal gas outlet pipe; use nitrogen to displace the air inside the tower and the coal gas outlet pipe. By adjusting the opening degree of the vent pipe at the top of the desulfurization tower, maintain a nitrogen pressure of 50 Pa inside the tower, and then remove the blind flanges from the inlet and outlet of the coal gas in the desulfurization tower ； 5.2.3.4 When fresh water added to the reaction tank raises its level to 2/3 of the total capacity, start the desulfurization liquid circulation pump (ensure that the flow rate at the pump outlet is not too high). As the desulfurization liquid flows from the bottom and top of the regeneration tower, back to the top and bottom of the tower again, stop the desulfurization liquid circulation pump. Once the liquid level in the reaction tank remains stable at 2/3 of its capacity during this circulation process, it is possible to cease adding fresh water, and then close the nitrogen valve ； 5.2.3.5 Slightly open the gas inlet valve of the desulfurization tower and use gas to displace nitrogen from inside the tower; once the oxygen content in the gas at the outlet of the vent pipe is found to be within acceptable levels, close the vent pipe valve ； 5.2.3.6 Open the gas outlet valve of the desulfurization tower, slowly open the gas inlet valve, and gradually close the gas bypass valve. Pay attention to changes in gas pressure, and keep the resistance in the desulfurization tower below 1 kPa ； 5.2.3.7 Once the gas operation is stable, start the desulfurization circulation liquid pump to maintain the liquid level in the reaction tank between 1/2 and 2/3 of its capacity ； 5.2.3.8 Feed compressed air into the regeneration tower, and add catalyst dropwise to the reaction tank ； 5.2.3.9 Adjust various control parameters such as flow rate, pressure, and temperature to their optimal levels ； 5.2.3.10 Open the valve of the drain pipe from the gas pipeline to the water seal tank, and plug the nitrogen blind flange ； 5.2.4 Shutting down the desulfurization tower and regeneration tower: 5.2.4.1 Complete the removal of sulfur foam from the system before shutting down the towers ； 5.2.4.2 Open the gas traffic valve of the desulfurization tower, slowly close the inlet and outlet valves of the gas in the desulfurization tower, stop supplying compressed air, and stop the circulation pump for the desulfurization liquid ； 5.2.4.3 During a short-term shutdown of the tower, a slight opening of the gas outlet valve of the desulfurization tower can be used to maintain positive pressure inside the tower. 5.2.4.4 When the tower is shut down for an extended period for maintenance work inside it: Steam should be introduced, and the vent pipe at the top of the desulfurization tower should be opened. The steam pressure inside the tower should be maintained at 50 Pa by adjusting the opening degree of this vent pipe. The gas inlets and outlets of the desulfurization tower as well as the nitrogen supply valves should be sealed, and all liquid present in the tower should be drained. Afterwards, the vent pipe at the top of the tower should be opened further to use steam to clean the tower; once the steam supply valve is closed, the manholes on the tower should be opened for ventilation. Only after gas samples taken from within the tower show satisfactory results can maintenance work proceed inside the tower. 5.3 Operating Standards for the Sulfur Foam Tank 5.3.1 Adjustment of the Regeneration Tower Overflow Volume Regularly check the overflow condition of the regeneration tower. Under normal circumstances, the overflow level of the level controller is adjusted to control the overflow volume ； In some cases, it is also possible to adjust by regulating the circulation volume of the solution or the amount of compressed air ； When the concentration of the liquid in the foam tank is high, lower the overflow height; when the concentration is low, raise the overflow height. 5.3.2 Normal operation of the foam tank: 5.3.2.1 The sulfur foam overflowing from the regeneration tower is directed to the foam tank; when the foam tank is nearly full, another sulfur foam tank is used to continue collecting the foam. 5.3.2.2 Heat the filled tank and introduce indirect steam until the temperature reaches around 80-90°C. During the heating phase, it is necessary to run the mixer to prevent large localized clumps of sulfur powder from forming and blocking the pipes ； 5.3.2.3 After heating is completed, allow the mixture to stand and separate for half an hour; the sulfur slurry obtained through sedimentation should be communicated to the sulfur melting tank crew, who will then pump it into the melting tank using a foam pump. The liquid level in the foam tank should be kept below the full-flow level indicator. 5.4 Operating Standards for the Sulfur Melting Vessel 5.4.1 Check and close the valve at the bottom of the vessel, then open the feed valve of the sulfur melting vessel to start feeding material. 5.4.2 Open the sulfur melting drain valve to discharge the liquid. It is strictly prohibited for the clear liquid to contain sulfur foam (which can be observed at the funnel opening); when sulfur slurry flows out of the funnel, close the clear liquid vent pipe and the feed valve. 5.4.3 Heat the sulfur melting tank’s jacket with steam to melt the sulfur; maintain the temperature at around 130–150°C for 4 hours. 5.4.4 Allow steam to flow into the jacket surrounding the feed valve for about 15 minutes, then open the feed valve. Once all the sulfur has been discharged, close the feed valve. Open the slag discharge valve to remove the slag; once all the slag has been removed, close the slag valve ； Open the feed valve to continue feeding. 5.4.5 Steam shutdown procedure: 5.4.5.1 When releasing sulfur, the steam should be shut off, and the discharge valve must be closed immediately ； 5.4.5.2 Stop the steam when discharging the slag liquid; drain all of the slag liquid before closing the slag discharge valve. 8 Safety Operating Procedures 8.1 Strictly abide by all safety management regulations established within the factory. 8.2 Before entering towers or tanks for work, relevant procedures must be followed, and protective measures must be put in place before work can commence. 8.3 It is strictly prohibited to dry clothes in equipment, pipelines, and operation rooms. 8.4 When working at heights on the tower, hold onto the handrails and guardrails to prevent falling from great heights. 8.5 Open flames and smoking are strictly prohibited in the production area. 8.6 Cleaning and repair are prohibited on the moving parts of the equipment. 8.7 Regularly inspect safety valves and pressure gauges to ensure that the safety valves are safe and reliable to use, and that the pressure gauges are accurate. 8.8 The sulfur melting furnace equipment must be pressure-tested regularly in accordance with relevant regulations to ensure safety. 8.9 When handling molten sulfur, be careful to avoid burns and pour it slowly. 8.10 The protective covers for the transmission components are complete and in good condition; the maintenance of fire-fighting equipment is properly carried out

Reference questions for the ammonium sulfate section: http://bbs.hcbbs.com/viewthread.php?tid=384876&highlight=%C1%F2%EF%A7

I. Fill-in-the-blank questions 1. The desulfurization of coke oven gas can generally be divided into two methods: dry desulfurization and wet desulfurization. 2. Wet desulfurization can be classified into three methods: physical absorption, chemical absorption, and oxidation. 3. The H2S content in coke oven gas is generally between 5 g/m3 and 8 g/m3, while the HCN content is between 1 g/m3 and 2.5 g/m3. 4. The desulfurization catalyst PDS refers to cobalt bipyridyl hexasulfonate; it is not a single compound, but rather a mixture containing monocyclic cobalt phthalocyanine sulfonates and polycyclic cobalt phthalocyanine sulfonates. 5. The gas-to-liquid ratio of the absorption liquid in the desulfurization tower is generally controlled at 12–30 L/m3. 6. The effective gas-liquid contact time inside the desulfurization tower is 8–12 seconds. 7. Blowing intensity of the regeneration tower: 80–120 m3/m2•h. 8. The residence time of the desulfurization solution in the reaction tank should be 8–10 minutes. 9. The air consumption of the regeneration tower can be calculated at 9~13 m3/kg (sulfur). 10. The residence time of the desulfurization liquid in the regeneration tower should be set at 25–30 minutes. 11. The volume of the desulfurization accident tank is equivalent to that of the desulfurization regeneration tower. 12. In the HPF method for gas desulfurization, since ammonia present in the gas itself is used as the base source, no additional base needs to be added when absorbing H2S from the gas. 13. The HPF gas desulfurization method using ammonia as a base source belongs to the liquid-phase catalytic oxidation method. 14. The HPF catalyst can accelerate the regeneration of the desulfurization solution and the formation of elemental sulfur. 15. In the H.P.F catalyst: H refers to hydroquinone, P refers to dinitrilotriacetic acid disulfonate, i.e., PDS, and F refers to ferrous sulfate. 16. In the desulfurization reaction, ammonia water acts as an absorbent. 17. The HPF acts as a load-starting oxygen carrier. 18. The HPF catalyst plays a catalytic role throughout the entire process of desulfurization and regeneration. 19. During the coking process, about 30% to 35% of the sulfur in coal is converted into sulfides such as H2S. 20. The main factors affecting the desulfurization absorption efficiency include the absorption temperature, the ratio of NH3 to H2S in the gas, the concentration of ammonia water, and the amount of ammonia water sprayed.

Desulfurization Test Questions – Questions for Desulfurization Workers. Class, Position, Employee ID, Name, Score. I. Fill in the blanks: 1. The desulfurization tower is a __ tower, and its resistance should be __ Pa. 2. Air pressure entering the regeneration tower, in MPa. 3. The solution flow rate in the current regeneration tower is m3/h. 4. The temperature of the gas after the pre-cooling tower is ℃, and the temperature of the solution in the reaction tank is ℃. 5 The resistance of the desulfurization tower is Pa. 6. The content of suspended sulfur in the system is maintained at g/h. 7 The technical specification requires the H2S content after the desulfurization tower to be in g/h. 8 It is now required that the air volume entering the regeneration tower be no less than m3/h. . 9. The pressure inside the sulfur melting tank is less than MPa. 10. The desulfurization efficiency is required to reach . 11. In the sulfur melting process, it is required that the medium-pressure steam pressure be no less than Mpa, and the low-pressure steam pressure be no less than MPa. 12. The four methods of extinguishing fires are , , and . 13. The equipment leakage rate is . 14. Motors with a power of over 50kw must not be started more than once. II. True or False Questions 1. The function of a pre-cooling tower is to lower the temperature of gas; the pre-cooling tower used by Hansteel is an air-jet type tower. ( ) 2. The function of the externally discharged desulfurization liquid is to reduce the salt content in the solution. ( ) 3. The function of the foam pump is to bring the pressure inside the sulfur melting tank to the level required by the process. （ ） 4. The gas flow in the desulfurization tower is from top to bottom. ( ) 5. Circulating water can be used for replenishing liquid in the desulfurization tower. ( ) III. Multiple-choice questions 1. The pH value of the desulfurization liquid in the system should be within the range of. A: 6–7 B: 8–9 C: 9–10 2. Absorbing H2S from gas using NH3 is a reaction. A: Exothermic B: Endothermic C: Neither exothermic nor endothermic 3. The gas-liquid flow direction in the desulfurization tower is . A: With the current B: Against the current 4. The pre-cooling tower belongs to the category of towers. A: Air spray B: Filler 5. The function of the level regulator is . A: Adjust air volume B: Adjust circulating fluid flow rate C: Control the liquid level in the regeneration tower. 6. The diameter of the stripping tower is mm. A: 4500 B: 50000 C: 5500 7. The volume of the reaction tank is in m3. A: 80 B: 100 C: 120 8. The diameter of the sulfur melting tank is mm. A: 800 B: 900 C: 1000 9. The temperature of the upper part of the sulfur melting tank should reach ℃. A: 70–80 B: 80–90 C: 90–100 10. The circulating fluid in the pre-cooling tower is cooled using . A: Circulating water B: Deep well water C: Cooling water IV. Short-answer questions 1. Briefly describe the desulfurization fluid process 2. What are the “four skills” required for a position? 3. Write the absorption reaction equation? What is the function of a 4-level regulator? V. Briefly describe what factors affect desulfurization efficiency? What measures can be taken? Ammonium sulfate test questions: Exam questions for workers handling ammonium sulfate. Class, Position, Employee ID, Name, Score. I. Fill in the blanks: 1. The ammonia content in the gas after the spray-type saturator should be no more than g/Nm3. 2. The temperature of the mother liquor in the saturator is generally controlled at °C. 3. The heat exchange area of the preheater is in m2. 4. When preparing the mother liquor, measure the acidity once per minute. 5 During normal production, the liquid level in the full-flow tank must be maintained above. 6. Start the centrifuge to discharge the material when the mother liquid ratio is reached. 7. The specific gravity of 90% sulfuric acid is approximately . 8. The resistance of a spray-type saturator is generally not greater than Pa. 9. Based on the conditions of gas inlets and outlets as well as the material accumulation at the full-flow openings, these areas are cleaned separately with warm water for several minutes. 10. The rated flow rate of the mother liquor circulation pump is m3/h. II. Multiple-choice Questions 1. The acidity of the mother liquor in the spray saturator should be controlled at ( ). A、3.0～3.5% ； B, 3.5～4.0% ； C, 4.0～4.5% ； 2. When adding acid to the mother liquor, the acidity is generally controlled at ( ). A、4～6% ； B, 6–8% ； C, 8–10% ； 3. The diameter of the spray saturator at Handan Iron and Steel is ( ). A、4600mm ； B、4800mm ； C、5200mm 4. When adding acid to the mixture, the time taken to add the acid until it reaches the mother liquor is generally controlled at ( ) minutes. A、 10 ； B, 20 ； C、30 5. Under normal operation, the specific gravity of the mother liquor should be controlled at ( ) t/m3. A、1.26～1.28% ； B, 1.28～1.30% ； C、1.62～1.82 6. The centrifuge should be stopped when the mother liquid crystal ratio reaches ( ). A, 20% ； B, 15% ； C、10% 7. Sulfuric acid with a concentration greater than ( ) is called concentrated sulfuric acid. A、 65% ； B, 75% ； C、85% 8. The resistance of the spray-type saturator shall not be greater than ( ). A、2000 Pa ； B, 2200 Pa ； C、 2300 Pa 9. During normal production, the tar in the crystallization chamber should be removed once every ( ) hours. A, 1 ； B, 2 ； C、 4 10. The rated current of the mother liquor circulation pump motor is ( ). A, 269A ； B, 279A ； C, 289A III. Short-answer questions 1. What are the main factors affecting the recovery rate of ammonium sulfate? 2. What are the main responsibilities of a saturator operator? 3. What is the purpose of designing a mother liquor storage tank? 4. Describe the gas flow process in the second recovery section IV. Essay Question (choose one) 1. What is the startup sequence for a spray-type saturator? 2. What are the shutdown procedures for the saturator?

Sulfamic Acid Worker Exam Questions: Employee ID, Name, Score. I. Fill in the blanks (2 points × 10). 1. Mother liquor acidity: Perform this test once, keeping the acidity within a certain range; the mother liquor is when acid is added. 2. The specific gravity of the mother liquor in the saturator shall be no less than , and the ammonia content in the gas exiting the apparatus shall be less than g/Nm3. 3. Sulfuric acid consumption shall not exceed kg/t of sulfur amine. (100% sulfuric acid) 4. The tar in the crystallization chamber is discharged once per hour. 5 Crystallization ratio during centrifuge startup, crystallization ratio during shutdown. 6. The centrifuge should be fed continuously during operation. 7. The centrifuge must not be started; it is not allowed to be started, under no circumstances. It must not operate if it has not stopped. 8 The wind temperature at the dryer inlet is . 9. The upper section of the spray saturator is , and the lower section is . 10. To maintain a certain acidity in the circulating mother liquor, concentrated sulfuric acid is continuously added from and . II. True or False Questions (3 points × 9) 1. Ammonia can easily cause the benzene washing oil to emulsify and deteriorate. ( ) 2. The upper and lower sections of the saturator are connected by a downcomer. （ ） 3. Maintain the equilibrium of the saturator using the mother liquor from the mother liquor tank. ( ) 4. The level of the full-flow tank should be at least 1/2 full. ( ) 5. The number of reciprocating feed strokes per minute by the centrifuge should not exceed 30 times. ( ) 6. The moisture content in qualified ammonium sulfate products should be no more than 1.0%. ( ) 7. The temperature of the mother liquor is mainly regulated by the amount of concentrated sulfuric acid added. ( ) 8. The main purpose of rinsing with warm water is to remove the nitrate deposits from the gas inlets and outlets, the full-flow openings, and the walls of the device. （ ） 9. The backflow valve of the crystallization chamber in the saturator is often left open in order to prevent material from accumulating at the bottom of the crystallization chamber. ( ) III. Short-answer questions (5 points × 5) 1. What are the process characteristics of producing ammonium sulfate using a spray saturator? 2. What issues should be considered when starting a centrifuge in operation? 3. What is crystal ratio? What should be the appropriate crystal-to-solvent ratio for a spray-type saturator? 4. How to handle a sudden power outage during the operation of the saturator? 5. What causes the color of ammonium sulfate to turn black? How to eliminate it? IV. Essay Question (28 points) What are the main factors affecting the quality of ammonium sulfate? Desulfurization Worker Exam Questions Class Position Employee ID Name Score I. Fill in the blanks 1. The temperature of the gas entering the desulfurization tower is ℃, and the temperature of the liquid entering the desulfurization tower is ℃. 2. The resistance of the desulfurization tower shall not exceed Pa, and the resistance of the pre-cooling tower shall not exceed Pa. 3. The gas temperature at the pre-cooling tower is ℃, and the gas temperature after the pre-cooling tower is ℃. 4. Liquid temperature in the reaction tank: °C, pH value of the desulfurization liquid. The liquid flow rate in the 5-stage regeneration tower is approximately m3/h (per tower), with an air pressure greater than Pa. 6. The dosages added to the reaction tank are , , , and . 7. Ammonia gas from Hansteel’s ammonia evaporation process enters. The air volume of Tower 8 is adjusted based on and . 9. Desulfurization pre-cooling uses . 10. The off-gas flow rate from the regeneration tower can be adjusted by , and the amount of compressed air. II. True or False: 1. The pressure of medium-pressure steam is ≥ 0.4 MPa. ( ) 2. The pressure inside the sulfur melting vessel is ≤0.6 MPa. ( ) 3. Discharging the content of the sulfur melting tank can remove all the sulfur inside it. ( ) 4. Before entering the tower or tank, relevant procedures must be completed and a successful test must be carried out. ( ) 5. It is prohibited to wipe or repair the moving parts of the machine, and it is forbidden to operate electrical equipment with wet hands. （ ） 6. The pre-cooling circulating water requires regular drainage and ammonia replenishment. （ ） 7. The accident tank is used to hold excess desulfurization liquid. ( ) 8. The function of the mist catcher is to capture the liquid droplets contained in the gas. （ ） 9. The amount of suspended sulfur in the system has no impact on the desulfurization efficiency. ( ) 10. The suspended sulfur content is ≤1.5 g/l. ( ) III. Short-answer questions 1. Briefly describe the steps for shutting down a desulfurization tower? 2. Briefly describe the startup, shutdown methods, and precautions for the desulfurization liquid circulation pump? 3. What are the methods for adjusting the overflow rate of the regeneration tower? 4. List the main equipment in the desulfurization unit and its key process parameters? IV. Essay Question: Analyze the factors affecting desulfurization efficiency?

Thank you all for your help. Brother upstairs, where are the answers to the questions? Bang also sent them; I need a large number of single-choice, multiple-choice, and true/false questions

What do you need a question bank for desulfurization and ammonium sulfate for? Is it a workshop exam, or does it require a skill assessment like mine?

To create a chemical production question bank for use in future training and examinations! ! ! Please feel free to share the test questions

Are there any questions related to coke oven production?