What’s the reason why the water content in the low-methane system cannot be reduced?
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Routine inspections revealed no issues; the water cooler, reboiler, shift gas, and the moisture level at the top of the water separation tower was 1.8. The moisture level in the lean methanol tank was between 2 and 3. Could anyone tell me if there are any other problems?
Is there a leak somewhere or is there an issue with the pre-washing?
“The water content at the top of the water separation tower is 1.8, while the water content in the methanol-depleted tank is between 2 and 3 – this situation is not correct
What is the temperature distribution in the tower? Is there a direct steam pipeline? Is it directly compensating for the steam leak?
We also encounter such a situation: we check whether there are leaks in the cooler at the top of the regeneration tower and the reboiler of the regeneration tower, and take samples to examine them
Be careful not to overload the water separation tower; if it exceeds the tower’s designed capacity, the efficiency of the tray system decreases, and it becomes impossible to reduce the water content.
So, the purity of that gas isn’t above the standard? Is it inaccurate without analysis, or is it driving in its original state?
The moisture content in the methanol vapor at the top of the methanol-water separation tower has exceeded the allowable level
Let’s clarify a few points first: which is the methanol-depleted tank – the one used to replenish low-methanol levels, or a storage tank within the purification system? The moisture level at the top of the water separation tower is above the specified limit, but this is not the main cause. 1.8% is indeed above the design value, but it’s not that high; as long as the moisture content in the water returning to the system is lower than that in the water leaving the system, dehydration should occur theoretically. What is the operating condition of your water separation tower? Have any changes been made to the feed or the reflux stream? Is there an abnormality in the temperature gradient inside the tower?
Although the moisture content at the top of the water separation tower is only 1.8, this methanol vapor enters the thermal regeneration tower; in the stripping section of this distillation column, moisture gets concentrated again, resulting in a slight increase in the water content
Is the moisture content in the lean methanol tank between 2 and 3? This has already exceeded the limit; there is a leak in the reboiler, and there are issues with the control of the water separation tower. The heat load has increased, resulting in higher moisture levels at the top of the tower; the temperature is likely high as well. Try to reduce the heat load, and it’s okay if the wastewater level at the bottom of the tower is a bit high – focus first on reducing the moisture content.