Regarding distillation column operation

What you’re saying isn’t clear. If it’s only the moisture content in the tower bottom that is high, and there are no faults with the tower itself, then increasing the steam supply could be considered.

First, check whether the temperature meets the requirements; second, consider the flow rate; third, check if there is any blockage in the tray

It can only be said that there is such a possibility – your water consists of light components. If the distillate taken from the top of the tower increases after continuous feeding and discharging, the moisture content at the bottom of the tower can be reduced. Or increasing the temperature at the bottom of the tower can also work

In a fully reflux condition, if the moisture level is not up to standard, then why not continue to remove moisture? The usual approach is to first remove the moisture once the tower is operating stably, so that the moisture content in the reactor bottom reaches the required level. After that, the reflux ratio and feed rate are controlled to maintain the moisture level at an acceptable level over an extended period of time. If the moisture level was already below standard initially, it’s possible to bring it up to standard by continuing with the operations, but this will require a long time of operation. This is a highly wasteful approach in terms of time and energy. More importantly, it will severely affect the production schedule

It’s probably because the temperature at the bottom of the tower isn’t up to standard; moreover, it’s in full reflux mode and the light components along with water aren’t being removed. So when there is continuous feeding and discharging and the temperature is within the required range, things will definitely improve

With full recirculation, it’s normal for the water quality not to meet the standards; if it did meet them, that would be abnormal

If water is the light component, the steam volume can be increased to raise the output from the tower top. If impurities are introduced from the previous section, consider whether water can be distilled off; if not, the product from the bottom of the tower can be sent to a mobile dehydrating tower for water removal.

Continuous feeding and continuous extraction should meet the requirements, but it will take a long time. Why not solve it? First, the temperature needs to reach the required level or a higher one. Second, since water is a light-component, if its amount is too high, it should be removed at the extraction point in the reflux tank

Reply to 6# madegood: This full reflux occurs during the operation phase; it is used to bring the tower into equilibrium. Currently, the moisture level in the bottom of the tower does not meet the required standards. If water is removed from the tower through intermittent distillation, then the moisture content in the bottom of the tower will definitely decrease. However, this tower operates on a continuous basis, and if water is removed, some feed must be added. Based on material balance, could the conditions then become satisfactory? Increasing the temperature at the bottom of the tower can help bring the water content there to the required level. But it is possible that the Reorganization fraction at the top of the tower is too high. At the current temperature of the tower bottom and under full reflux conditions, the heavy components at the tower top have exceeded the required level. If the above situations occur, how should they be handled, and how can we determine where the problem lies? Thank you.

I’m not sure what type of material the poster is working with; is an azeotrope formation occurring? If so, full reflux operation should be used. It’s normal for there to be heavy components at the top of the tower, and phase-separation reflux should be employed so that the water content at the bottom of the tower meets the required standards, as well as ensuring that the product coming from the top of the tower meets the required specifications.