Who has questions on low-temperature methanol washing?

1. What is solubility? At a certain temperature, it is the number of grams of solute that can be dissolved in 100 grams of solvent at equilibrium. 2. What is equilibrium solubility? At a certain temperature and pressure, when equilibrium is reached, the concentration of the absorbed substance in both the vapor and liquid phases no longer changes; this represents the limit to which the absorption process can proceed. The concentration of the absorbed substance in the liquid phase at equilibrium is known as the equilibrium solubility. 3. What is the specific content of Henry’s law? At a certain temperature, when the gas and liquid phases are in equilibrium, the molar fraction XA of the soluble gas in the liquid phase is proportional to its equilibrium partial pressure PA in the gas phase; this is Henry’s law. That is, PA = E × XA. Here, XA refers to the molar fraction of the solute in the liquid phase, PA refers to the equilibrium partial pressure of the solute in the gas phase, and E is a proportionality constant known as the Henry coefficient. 4. What are the factors that affect absorption operations? ①Air flow velocity. ②Gas/liquid ratio. ③Temperature. ④Pressure. ⑤Absorbent purity. 5. What is flooding? How to avoid flooding? The phenomenon of liquid flowing back inside the tower is called flooding, and when flooding occurs, the pressure difference in the tower increases significantly. To avoid flooding, it is first necessary to control an appropriate liquid/gas ratio and space velocity. At the same time, it is necessary to prevent the liquid from foaming, improve the purity of the absorbent, and ensure that the tower plates are clean and free of contaminants. 6. How to improve tray efficiency? ①Control the appropriate liquid-to-gas ratio. ②The levelness of the tray plates must meet the requirements. ③There is no leakage from the tray. ④The absorbent has high purity and does not foam. ⑤There is no dirt or scale on the trays, ensuring an appropriate liquid layer thickness. 7. What is the rectification section and what is the stripping section? The tray where the feed material enters is called the feed tray. The section of the column above the feed tray is referred to as the distillation section, while the section of the column below the feed tray, including the feed tray itself, is known as the stripping section. 8. What are the methods for extracting gases from a solution? ①Reduce pressure. ②Heat. ③Stirring. ④Distillation. 9. What is the working principle of a centrifugal pump? What are cavitation and gas entrapment in centrifugal pumps? The working principle of a centrifugal pump is as follows: when the motor drives the impeller to rotate at high speed, the liquid is pushed by the blades and rotates as well. Due to centrifugal force, the liquid is flung from the center of the impeller toward its edges, and moves at very high speeds toward the pump casing. As the flow channel within the pump casing gradually widens, the velocity of the fluid decreases, and some of its kinetic energy is converted into static pressure energy, thereby increasing the pressure of the liquid at the pump outlet, allowing it to be discharged from there. When the liquid at the center of the impeller is thrown out, a low-pressure area is created at the pump casing’s suction inlet; under the effect of this pressure difference, liquid enters the pump through the suction inlet to fill the space left by the liquid that has been discharged. In this way, the impeller keeps rotating, allowing liquid to be continuously drawn in and pushed out, thereby achieving the purpose of transporting the liquid. Air entrapment occurs when, during the startup of a centrifugal pump, the pump casing and suction pipe are not filled with liquid, or if air leaks into the pump while it is in operation; this can result in air accumulating inside the pump. Since the density of air is lower than that of liquids, the centrifugal force generated is small; as a result, the low pressure formed at the center of the impeller is not sufficient to draw the liquid from the inlet pipe into the pump. In such a situation, although the centrifugal pump is running, it is unable to transport liquid, and this condition is known as gas locking. Cavitation occurs when the inlet pressure of a pump drops to the saturated vapor pressure corresponding to the temperature of the liquid being transported; this causes the gas at the inlet of the impeller to vaporize and form bubbles, which then move along with the liquid from the low-pressure area to the high-pressure area. As the bubbles move to high-pressure areas, they condense or burst rapidly under the pressure. The liquid surrounding them then rushes into the space formerly occupied by those bubbles at extremely high speeds, resulting in very high pressures. The frequency of these impacts is also very high; in severe cases, the pump cannot function properly. This phenomenon is called cavitation. 10. Why do most centrifugal pumps have a minimum flow line? Assume that the minimum flow pipeline ensures that a certain amount of fluid flows through the pump at all times after it is started, in order to prevent cavitation. Furthermore, when centrifugal pumps with high power operate with the outlet valve closed, the fluid becomes increasingly hot, and in severe cases this can damage the bearings. By using a pipeline with the minimum flow rate, this phenomenon can be prevented. 11. Why is the methanol washing tower divided into an upper tower and a lower tower, and what is the theoretical basis for this? The main basis is the selectivity of solvent absorption, as hydrogen sulfide has a higher solubility in methanol than carbon dioxide; this allows hydrogen sulfide to be absorbed in the lower column. The heat of dissolution released during the absorption of hydrogen sulfide and thiocarbonic acid in that column is compensated by the desorption heat of carbon dioxide in methanol, thereby preventing an increase in temperature in the desulfurization section. It facilitates the absorption of hydrogen sulfide and thiocarbon. 12. Why is it necessary to draw the methanol liquid out for cooling in the upper section of the methanol scrubber tower? When methanol absorbs carbon dioxide, heat of solution is released. As the temperature rises, the solubility of carbon dioxide in methanol decreases; when the temperature reaches a certain level, this results in an excess of carbon dioxide in the gas coming out of the top of the tower. Therefore, it is necessary to draw out the methanol liquid for cooling. 13. Why is methanol sprayed before the transformed gas enters the feed gas cooler? Since the feed gas cooler operates at low temperatures, if the shift gas enters the feed gas cooler directly and is cooled, the saturated water vapor it contains will condense and form water. The freezing of this water can cause blockages in the equipment and pipelines. Spraying methanol can capture the moisture and lower its freezing point, thereby preventing the water from freezing and causing blockages. 14. Why is LCV-20221 set after E20216? The methanol-water mixture coming out of V20201 contains a certain amount of carbon dioxide gas dissolved in it. Upon depressurization through LCV-20221, this carbon dioxide gas is released from the liquid, resulting in gas blockages in the piping system. To minimize this phenomenon, LCV-20221 is placed after E20216, so that the liquid is throttled and depressurized immediately followed by gas-liquid separation. 15. What are the reasons that can cause an excess level of carbon dioxide in the purified gas coming out of the methanol scrubber tower? ①The circulation volume of lean methanol is too low. ②The temperature of the lean methanol is too high. ③The regeneration effect is poor. ④Methanol has a low absorption capacity. ⑤The process gas flow rate fluctuates sharply. 16. What could be the reasons for an increase in the pressure difference in the methanol scrubber? ①The circulation rate of lean methanol is too high. ②The low temperature of the lean methanol increases the specific gravity of the liquid, resulting in an increased pressure difference across the tower. ③The gas flow rate is too high. ④FCV-20221 has excessive flow. ⑤E20205, E20206 blockage or poor flow causes flooding in the tower. 17. Why can the temperature be continuously reduced only after purifying the gas? Since methanol that has absorbed carbon dioxide is desorbed after being cooled with ammonia, the temperature can be reduced significantly. The flow rate during gas release is at its minimum, and as the saturation of carbon dioxide in the methanol increases after gas release, more carbon dioxide is desorbed per unit volume of methanol, causing the temperature to continue dropping. After heat exchange, this results in a decrease in the temperature at the top of the methanol scrubber. 18. What is the purpose of introducing nitrogen via stripping at the bottom of the hydrogen sulfide concentration tower? Why is it designed as an inverted “U”-shaped tube? Introducing nitrogen into the hydrogen sulfide concentration tower reduced the partial pressure of the carbon dioxide gas in the vapor phase, thereby increasing the driving force for the desorption process. It is necessary to desorb carbon dioxide from methanol at low temperatures as much as possible; the amount of nitrogen removed by gas stripping should be as high as feasible within certain limits. However, too high a level will increase nitrogen consumption, while too low a level will increase the load on the regeneration tower. The inlet pipe is designed in an inverted “U” shape to prevent methanol liquid from flowing back into the nitrogen stripping line. 19. Why cannot the liquid level at the bottom of the hydrogen sulfide concentration tower be too high? Otherwise, it will lead to a cascade shutdown of the nitrogen stripping process. If the liquid level at the bottom of the hydrogen sulfide concentration tower is higher than that in the nitrogen stripping pipeline, liquid slugging will occur; this not only can damage the equipment but also causes the nitrogen stream carrying liquid to impact the tray plates, potentially leading to their deformation or even displacement. Additionally, when parked, the liquid level at the bottom of the hydrogen sulfide concentration tower is too high, allowing methanol to easily flow back through the stripping nitrogen pipeline. Therefore, the liquid level at the bottom of the hydrogen sulfide concentration tower should not be too high; otherwise, it will trigger a sequential shutdown of the gas stripping and nitrogen production processes. The liquid level should be kept as low as possible during shutdown. 20. Why does the nitrogen stripping continue without interruption even after the purification shutdown and while the methanol cycle is still running? Because the methanol in the cold zone still contains a large amount of carbon dioxide after the gas supply is stopped, if nitrogen is removed under these conditions, a large amount of carbon dioxide will be carried into the regeneration tower, causing overpressure in it. This will result in a significant drop in the flow rate of the feed pump for the regeneration tower, as well as a sharp rise in the liquid level at the bottom of the hydrogen sulfide concentration tower. 21. What preparations should be made before starting the pump, and what should be noted after it starts running and during normal operation? Before starting the pump, the following preparatory work should be carried out: ① Conduct a thorough inspection of the pump. ②Fill the bearing housing with oil or activate the lubrication system. ③Turn the crank. ④Open the inlet valve to vent the system. ⑤Contact an electrician to test the motor’s insulation and restore power. ⑥Make sure to fully close the outlet valve before starting the pump. The following points should be noted after starting the pump and during normal operation: ① Check whether the pressure at the pump’s inlet and outlet is normal. ②Check whether the oil level in the bearing housing or the lubricating oil tank is normal. ③Monitor whether the bearing temperature and the motor stator temperature are within normal ranges, and feel the bearing housing by hand during inspections to check if it is hot. ④Monitor whether the vibration is normal and check whether the sound is normal. ⑤Check for leaks in the mechanical seal. 22. What precautions should be taken regarding exhaust gas before starting P20201, P20202, and P20203? Be sure to close the cold machine valve before venting, especially P20203, as the outlet pressure of the pump is higher than the inlet pressure. If the cold machine valve is open, the fluid at the pump’s outlet will flow back through this valve, preventing the gas inside the pump from being expelled due to the low pressure. This results in an apparent venting process that affects the proper operation of the pump. 23. What is the purpose of the V20204 nitrogen displacement pipeline? ①Ensure that P20204 has sufficient stable static head pressure. ②To keep methanol separated from air. 24. What is the role of the methanol sent from the methanol regeneration tower, via P20205, to the methanol-water separation tower? ①It serves to create a backflow of liquid. ②The water in the circulating methanol is sent to a methanol-water separation tower for treatment. 25. The lower the methanol content in the wastewater at the bottom of the methanol-water separation tower, the better, right? Why? No, because the lower the methanol content, the higher the temperature at the bottom; this increases the thermal load on the tower, resulting in an increase in the water content in the gas phase at the top. This water is then reintroduced into the circulating methanol, reducing the dehydration capacity of the methanol-water separation tower. 26. What is the basis for temperature control in the methanol-water separation tower? The temperature at the bottom of the methanol-water separation tower is controlled at the boiling point of water under the operating pressure, ensuring that the components at the tower bottom contain 99.5% water. 27. After normal driving, where is methanol primarily consumed? It is mainly consumed at the top of the regeneration tower and at the bottom of the methanol-water separation tower. The design consumption is 60 kilograms per hour. 28. What should be done if a high water content in methanol is detected before driving? A circulation system is established across the entire system; methanol containing a high amount of water at the bottom of large containers is gradually transferred to underground tanks, where it is then pumped into a methanol-water separation tower for separation. 29. Why can the reboiler, located outside the methanol-water separation tower and the regeneration tower, effectively transfer heat into the towers? Due to the use of natural circulation heating, the tubes inside the heat exchanger are usually above the liquid level, and the temperature of the heat source is higher than the boiling point of methanol. When methanol in these tubes is heated, it continuously vaporizes and rises. Since the density of methanol vapor is much lower than that of liquid methanol, this density difference creates a driving force that causes the methanol to keep vaporizing and rising into the tower. The liquid methanol at the bottom of the tower then continuously enters the heat exchanger where it is heated by the steam, thus establishing a natural circulation that ensures continuous heating of the methanol inside the tower. 30. How many methods are there to dry the system after water intermodal transport? ①Nitrogen drying method. ②The methanol cycle removes moisture. 31. How can the re-pressurization time be significantly reduced after short-term parking? By purifying the off-gas, the circulation in the cold zone is stopped immediately, while that in the hot zone continues. As a result, the temperature of methanol in the system remains low; moreover, the methanol contains a large amount of carbon dioxide, which stores a significant amount of cold energy. Once the conversion gas meets the required standards, the purification system resumes its circulation. When the methanol at the top of the tower reaches the bottom of the tower, gas flow is initiated. This approach ensures that the temperature at the top of the washing tower remains very low, facilitating rapid absorption and quick replenishment of cold energy. It allows the system to reach normal operating capacity quickly, while also preventing the carbon dioxide level at the top of the tower from exceeding acceptable limits, thereby significantly reducing the time required for gas flow to be established. 32. Why is the temperature at the top of the scrubber lower as the methanol circulation rate decreases? When the system load remains constant, the amount of cooling capacity available to the system is essentially fixed. If the volume of methanol in circulation is large, less cooling capacity is available per unit volume of methanol, resulting in a higher temperature. Furthermore, with a large methanol circulation volume, the temperature difference in the heat exchanger leads to increased cooling loss. Therefore, by using a smaller methanol circulation volume, more cooling can be obtained per unit volume of methanol, and the cooling loss is reduced as well; as a result, the temperature of the methanol flowing to the top of the wash tower is lowered. 33. Why are methanol spraying and nitrogen stripping operated for more than half an hour before purifying the gas stream? By introducing methanol via spraying first, it is possible to establish a certain layer of methanol liquid within the pipes and the raw gas cooler E20201 as well as the water separator V20201. This also ensures that the equipment and pipe walls are thoroughly wetted, so that condensate water and methanol can mix thoroughly everywhere after gas is introduced. The stripping nitrogen is introduced first to pre-cool the feed gas cooler E20201, ensuring that the temperature of the water separator V20201 does not rise significantly during gas introduction, thereby reducing the amount of saturated water carried into the methanol scrubber. 34. What conditions must be met before purifying the gas flow? ①The minimum system methanol circulation rate remains stable during operation. ②The temperature of methanol entering the washing tower is around -35°C. ③The regeneration system is now functioning properly. ④The methanol/water separation system is operating normally. ⑤Methanol spraying and nitrogen stripping have been in operation for over half an hour. 35. Which liquid levels change after purifying the gas, and why? How to ensure system stability? After gas introduction, the plate resistance increases, resulting in the formation of a certain liquid layer within the plates and downcomers. This leads to a decrease in the amount of methanol exiting the tower, causing the level in V20204 to drop. To prevent the P20204 pump from shutting down, it is necessary to reduce the liquid levels in each tank at the appropriate time during gas introduction, so as to avoid a situation where the level in V20204 becomes too low and triggers an interlock that shuts down the P20204 pump. Inside the scrubber tower, methanol absorbs carbon dioxide; as a result, its volume increases significantly after leaving the tower. This in turn causes the level of V20204 to rise sharply. Therefore, it is necessary to adjust the liquid level promptly to maintain system stability. 36. What are the main hazards of sulfides in methanol production? ①Poison the catalyst, causing it to become poisoned and deactivated. In methanol production, hydrogen sulfide can permanently poison the methanol catalyst, reducing its activity and leading to a decrease in methanol production. This is because hydrogen sulfide reacts with copper in the copper-based catalyst to form cuprous sulfide, thereby rendering the catalyst inactive. ②Corrode equipment. In the presence of moisture, gases containing hydrogen sulfide dissolve in water to form hydrosulfuric acid, which can react with metal equipment and pipes to produce corresponding metal sulfides, thereby causing corrosion. The degree of corrosion increases as the partial pressure of hydrogen sulfide in the gas rises. ③Pollute the environment. Hydrogen sulfide is a highly toxic substance; even small amounts inhaled by the human body can cause symptoms such as headaches and dizziness, while larger inhalations can lead to sudden death. In the air released from vents or gases leaking from equipment and pipelines, hydrogen sulfide settles on the ground, causing varying degrees of environmental pollution. **The industrial hygiene standard is <10mg/m3. 37. What is the main task of the purification section? The main task of the purification unit is to remove gases harmful to methanol synthesis, such as H2S, COS, and CO2, from the shifted gas, so that the purified gas meets the requirements of the methanol synthesis unit. 38. What are the characteristics of low-temperature methanol washing? The characteristics of low-temperature methanol washing include: ① It is possible to remove H2S, COS, and CO2 in a single tower, achieving a high level of purification ； ②The solvent methanol is inexpensive and readily available ； ③The solvent has a high absorption capacity and low circulation volume, resulting in low energy consumption ； ④Acidic gas containing H2S can be concentrated to over 30% and sent to the desulfurization recovery unit.

The last edit to this post was made by dongjiang1001 on 2011-4-29 at 10:29. Here are several basic questions on low-temperature methanol washing that I created back in 2009: I. Fill-in-the-blank questions 1. The purpose of insulating the pipelines in a low-temperature methanol washing unit is to (reduce heat loss) and to improve the working conditions. 2. Ways to increase the heat transfer rate include: increasing the heat transfer area, raising the average temperature difference between the hot and cold fluids, and (increasing the heat transfer coefficient). 3. The main factors affecting the quality of methanol used for washing are: (the water content in methanol), H2S concentration, CO2 concentration, NH3 concentration, as well as solid impurities. 4. In the low-temperature methanol washing process, (temperature) and (pressure) are important factors that affect the efficiency of methanol washing for purification. 5. The designed normal flow rate of the feed gas to the low-temperature methanol washing unit in the Shuifu coal-to-gas retrofit project (at 100% load) is ( ) NM3/h. II. True or False Questions 1. The process of using the difference in volatility of various components in a liquid mixture when heated under certain pressure to achieve separation is called distillation. (Incorrect) 2. The main factors affecting absorption are gas flow velocity, gas-liquid ratio, temperature, pressure, and the purity of the absorbent. (Yes) 3. The methods for removing gases from a solution include: reducing pressure, heating, stripping, and distillation. (Incorrect) 4. The process of concentrating a solution by heating it to vaporize one of its components is called evaporation. (Yes) 5. A high ammonia content in the reformate gas or poor washing efficiency of the wash tower can result in a higher total sulfur content in the purified gas. (Yes) III. Short-answer questions 1. What are the advantages of the low-temperature methanol washing process technology? Answer: a) Strong absorption capacity for acidic gases ； b) The purity of the gas is very high ； c) It has a relatively high selectivity for absorption ； d) Methanol is regenerated using methods such as vacuum flashing, N2 stripping, and heating; the process is simple ； e) Facilitates the recovery and reuse of H2S, reducing environmental pollution ； f) Methanol has good thermal and chemical stability, and it is easily available. 2. What are the sources of cooling capacity for the low-temperature methanol washing system? Answer: a) The ammonia cooler utilizes the latent heat absorbed during ammonia evaporation to cool the system through refrigeration ； b) The water cooler removes heat using circulating cooling water to provide cooling for the system ； c) During the regeneration and desorption of the methanol solution, a cooling effect is generated, providing cooling capacity for the system; CO2 desorption cooling is the main source of cooling in methanol washing. 3. What is flashing? Answer: Flash evaporation involves breaking the original gas-liquid equilibrium by reducing pressure in order to establish a new gas-liquid equilibrium, thereby achieving the separation of substances. 4. What is air lift? Answer: Stripping is a physical process that uses a gas medium to disrupt the original gas-liquid equilibrium and establish a new one, allowing a certain component in the solution to be desorbed due to the decrease in partial pressure, thereby achieving the separation of substances.

1. Fill in the blanks: In the purified syngas produced by 1T1601, the total sulfur content is less than (0.1 PPm); the CO2 level is (<4%); the methanol content in the exhaust gases is less than (150 PPm), and the total sulfur content is less than (20 ppm).
2. Write down the substances represented by the following codes: RW (raw water), DW (deionized water), BW (boiler feedwater), CWS (circulating cooling water inlet), CWR (circulating cooling water outlet), SC (steam condensate). The H2S content in the 3-sulfur recovery inlet gas is higher than (25%), while the CO2 content is lower than (74%). The sulfur produced in the sulfur recovery unit contains approximately (300 ppm) of H2S. Combined with sulfur stripping, the H2S content is reduced to below (10 ppm). In the 5-propylene compressor, the oil temperature at the compressor oil return port is (54°C); the oil temperature at the oil returner’s oil return port is also (54°C). The oil temperature at the inlet of the thin oil station is (50°C), while the oil temperature at the outlet of the thin oil station is (40°C). 6 Pressure indication control and alarm interlock for the feed gas in membrane separation: normal value (4.2), low alarm value (3.8), high alarm value (4.8), and high interlock value (5.2). II. Term Explanations 1. Cascade control system: In a control system, there are two regulators, each receiving measurement signals from different parts of the process. The output of one regulator (the primary regulator) serves as the setpoint for another regulator (the secondary regulator), and the output of this latter regulator is used to control the control valve in order to adjust the process parameters. Structurally, the two regulators operate in series; therefore, such a system is called a cascade control system. 2. Liquid flooding: The phenomenon of liquid flowing back inside the tower due to an excessive gas-liquid ratio is called liquid flooding. 3. Throttling: When a fluid flows through a pipe, the sudden reduction in the pipe’s cross-sectional area causes the flow velocity of the fluid to increase abruptly, resulting in a decrease in pressure; this phenomenon is known as throttling. 4. Distillation: To obtain products of high purity, a distillation method that involves multiple partial vaporizations and multiple partial condensations is used, which is called distillation. 5. DCS, PLC, ESD DCS: Centralized management of distributed control systems. PLC: Programmable Logic Controller. ESD: Emergency Shutdown System. 6. Henry’s Law: At a constant temperature and under equilibrium conditions, the solubility of a gas in a liquid is directly proportional to its equilibrium partial pressure; this is Henry’s Law. Three short-answer questions: 1. How to start the P1603 pump? a. Close the cooling valve of the P1603 pump. b. Check and ensure that the oil level in the bearing lubrication system is normal. c. Confirm that both the inlet pipe drain and the pump body drain are closed. d Open the root valves of the pressure gauges at the pump’s inlet and outlet. e Open the valves at the pump’s inlet and outlet. f Open the exhaust valve at the pump’s outlet as well as the bottom valve of the liquid collection funnel to allow exhaust. g Rotate the pump shaft to check for any signs of jamming; once no air is coming out of the exhaust port, close the exhaust valve. h Open the valve for minimum flow. i Contact the control room for confirmation. j Press the pump start button; after ensuring that the pump operates smoothly, in the correct direction, and that the bearing temperatures are normal, work with the control room to gradually open the outlet valve. 2. How to switch from the main line to the bypass line of a self-regulating valve: When a problem occurs with the self-regulating valve, it is usually necessary to use the bypass line for adjustment. Contact the control room; following their instructions, first open the secondary line valve, then slowly close the main line isolation valve, and subsequently open the secondary line valve simultaneously while closing the main line valve at the same time. And keep in constant contact with the control center to ensure stable traffic flow. 3. Contents and precautions for on-site inspections: When conducting inspections, bring necessary tools such as a sound detection rod, notebook, temperature gun, walkie-talkie, and gas detector, and follow the designated route. When inspecting rotating equipment, it is necessary to check whether the vibration of such equipment is normal. Use a listening stick to listen to the sounds emitted by the motors, pumps, and compressors, and use a temperature gun to measure the temperatures of the motor stator and rotor, as well as the temperatures of the bearings at the front and back of the pump. Record the pump’s current. Check whether the machine is leaking. When inspecting static equipment, pay attention to the liquid levels in various towers and tanks, and promptly verify them with the control room using a walkie-talkie. Adhere to conducting inspections on schedule, and carry out thorough inspections when more frequent checks are required under special operating conditions. 4. How to put T1605 into operation: (1) Open the feed valve FV16027 for the deionized water supply to tower 1606, raise the liquid level in T1606 to 50%, and start the P1607 pump with minimal reflux after venting it. Set FV16027 to the desired flow rate and switch to automatic mode. (2) Open the upper stop valves from T1605 to T1604. (3) Open LV16082, set the level for T1605 to 50%, and then close FV16027. (4) Open the leading drain of the E1617 reboiler to drain condensate and warm the tubes. When no liquid is more discharged from the drain, close the drain and slowly open FV16025. Heat T1605. (5) When the bottom temperature of T1605 reaches 130°C, exhaust the P1605 pump, start the P1605 pump, and set FV16023 and FV16024 to automatic flow before switching to automatic mode. (6) After methanol spraying is started, the levels of V1621 and V1601 are controlled to the set levels via the level control valves LV16007 and LV16028, after which automatic operation is initiated. (7) Pay attention to monitoring the temperature at the top of T1605; it must not exceed 100°C, while the temperature at the bottom of the tower must not be lower than 143°C. 5. Original startup steps for the flash compressor: a. Trial operation of the circulating oil system; b. Trial operation of the cylinder packing lubrication system; c. Water flow test for the cooling water system; d. Individual trial operation of the motor; e. Another individual trial operation of the motor; f. No-load trial operation; g. Purging of the compressor’s pipelines; h. Operation under load; i. Process operation test. 6. How to clean the sulfur condenser: a. Prepare some Na3PO4 and NaOH, with concentrations of 0.3 wt.% and 0.025 wt.% respectively in the boiler water. b Supply boiler feed water until the normal level is reached. Keep the ventilation holes open. Add the aforementioned chemicals to the water through the manhole and close the manhole. Keep the ventilation holes open. c Supplies steam to the boiler. Keep the water boiling at atmospheric pressure for 24 hours. The water level is maintained by draining some boiler water every 1-2 hours. d Stop the steam supply and remove all contents from the condenser. . Repeat this multiple times until the water is clear and the pH is 9.