11.2 Daily Question: How to Speed Up Gas Flow in Cases of Hypothyroidism
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11.2 One question per day – please participate actively and indicate whether it is for methanol synthesis or ammonia synthesis. According to the rules: the bonus for replies to “One Question per Day” cannot exceed 5 wealth points, and the maximum number of such bonuses per reply is 50! But I’ll do my best to give everyone extra points!
Downstream of our plant is methanol synthesis. When introducing gas, hydrogen sulfide is easier to deal with – just increase the amount of methanol in circulation. However, the downstream process requires a certain level of CO2 content, and it is difficult to maintain a stable CO2 level. Time is wasted here every time. The low-methane systems used in methanol synthesis are equipped with CO2 control valves; I think it’s better to open such valves before introducing gas, rather than adjusting the CO2 level after gas has been introduced and then controlling the valve accordingly. Another unauthorized idea is to adjust the bypass of this automatic valve (to a slightly open position). I’m curious to hear everyone’s thoughts; I hope we can have an active discussion on this!
Ruchi’s process seems to work in this way; our Linde process should be a good match for it. We can go straight to automatic mode and then connect things together, with the DCS handling the calculations based on formulas
In the low-temperature methanol washing process, some of the process gas (shift gas) is fed first; at the beginning of the cycle, the amount of methanol used can be slightly higher. After that, the gas composition is analyzed at regular intervals, and once it meets the required standards, the gas can be sent to subsequent processes.
The key is to adjust the gas to the required standard as quickly as possible and send it to the methanol section.
Reply to 5# z880347730: Increase the flow rate of methanol in the circulation; as long as the hydrogen sulfide level is within the specified range, methanol can be supplied
Reply to 6# Yi Long Peng Fei: A certain level of CO2 content must be maintained; otherwise, the synthesis temperature will become too high to be tolerated!
This post was last edited and replied to by 654262293 on 2010-11-8 at 14:56. Reply 7# z880347730: If it is for methanol production, as long as the total sulfur content in the purified gas is below 0.1 ppm, it is feasible to supply gas for methanol synthesis; moreover, the CO2 level in the purified gas should be relatively high at the beginning! In the case of producing synthetic ammonia, it is required that, on the condition that the total sulfur content in the purified gas is within acceptable limits, CO2 levels must also be within the specified process parameters; otherwise, the load on the liquid nitrogen washing process will be too high!
Reply to 8# 654262293: For the synthesis of methanol, a low CO2 content can cause overheating in the reactor bed; therefore, the CO2 content in the gas stream is generally kept at around 2.5%.
Reply to 9# z880347730: The heat of reaction when CO2 reacts with H2 is much lower than that when CO reacts with H2. CO2 is kept at a level of 2.5%-3.0% because its presence helps to suppress side reactions, improves the quality of crude methanol, and facilitates distillation processes. Additionally, the peak temperature in the methanol synthesis tower is controlled by regulating the pressure in the drum of this tower; by adjusting the circulation rate and maintaining proper drum pressure, the peak temperature of the catalyst in the synthesis tower remains within acceptable limits.
Reply to 10# 654262293: The use of 2.5–3% CO2 in the synthesis serves four purposes – it not only suppresses side reactions but also reduces the temperature of the bed layer, prevents excessive reactions of the catalyst, and protects it; moreover, the H2O generated can also help to prevent side reactions. We also know that controlling the pressure in the drum can effectively regulate the temperature of the catalyst bed in the synthesis tower, but the management requires us to maintain a certain level of CO2 content.