I’m seeking advice from everyone: in a low-temperature methanol washing unit’s methanol-water tower, the water content at the top of the tower often exceeds the allowable level. What should be done?
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The design specification is less than 1%, but it often exceeds this value recently; the top temperature is controlled at 95.5 degrees, while the pressure remains between 0.2 and 0.21 MPA
We have a naphtha recovery system, with the ratio of methanol to water designed to be 1:1. I would like to ask how a low methanol concentration can lead to an excessive level of methanol at the top of the tower. Will the situation improve if I increase the amount of methanol used? Thank you
If the methanol-water content in the reflux at the top of the tower is high and the feed inlet is located near the top outlet, then the water content at the top of the tower will definitely be above the acceptable level. A high temperature of the refluxing methanol or a low reflux rate can also lead to an excessive water content at the top of the tower. Alternatively, the high heat load at the top of the tower causes the temperature to rise.
Noting that the original poster used the word “recently,” the recent warming of the climate may also have an impact on the heat load and return temperature; if there have been no significant changes in previous operations, external factors should be taken into consideration.
Currently, the temperature at the top of the tower is not high, and the temperature of the sensitive plate is also not high
We are operating at atmospheric pressure; the vent of the reflux tank is kept open. The feed temperature is 56 degrees, and the temperature at the top of the tower is 67 degrees. With a pressure of two kilograms, the temperature at the top of the tower should be much higher. Try reducing the temperature, lowering the pressure, increasing the reflux ratio, and reducing the feed temperature – these are the only solutions. In my case, it’s about separating methanol from water, and the purity is very high. Additionally, there’s too much moisture in your methanol; in that case, use a high reflux ratio to gradually purify it
The water content of the entire system is also high; it’s currently 1.06
Sure, a high temperature at the top of your water-alcohol separation tower will definitely lead to an increase in the water content within the system over time.
In the methanol-water separation tower, if more of the heavier component, namely water, is carried away from the top of the tower, the best solution is to lower the temperature of the sensitivity plate and the top of the tower; there is no other way. The temperatures designed for the sensor plate and tower top temperature may be on the high side.