Operation of the alcohol-water separation tower in low-temperature methanol washing
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After the system is washed with water, the water content remains high inside the system due to incomplete drying before methanol is introduced. What should be done? Increasing the reflux for the separation of alcohol from water results in the tower top temperature not dropping – how should this be addressed?
I hope everyone can provide valuable suggestions; the Linde 6-tower process is being used
Is the amount of lean methanol at the top of the tower high, resulting in a high temperature at the tower top? You can try adding a little more methanol as a spray to lower the temperature of the methanol-poor stream at the top of the tower, and see if that improves the situation
The top temperature cannot be reduced because the water content in the methanol-water tower is too high； Reduce the amount of washing water coming from the exhaust gas scrubber tower, and increase the discharge volume of wastewater at the bottom of the tower. It is important to communicate with the utility water treatment department to reduce the usage of heating steam; otherwise, the water content in the system will keep increasing, which will affect the absorption efficiency. Increase the frequency of analysis to provide a basis for operations.
High temperature means there is too much moisture; discharge more water from the 6 towers to the wastewater system, and reduce the amount of steam used in those towers slightly
It is recommended that the original poster check the analysis data: the water content in methanol vapor, the water content in lean methanol, as well as these trends. Most importantly, it is necessary to determine how much water is discharged from the bottom of the tower, and then calculate how much water enters the absorption tower from the feed gas. By performing a simple water balance and comparing the amounts of water entering and leaving, it will be possible to determine whether the amount of water in the system is increasing, decreasing, or remaining constant.
Try lowering the liquid level at the bottom of the tower and increasing the steam supply to the reboiler