Problems with the propane removal column in the gas section.
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In the propane removal section of the distillation column, when there are no changes in the feed and the vapor at the bottom of the column, it is common for the top temperature to rise, while the bottom temperature remains unchanged and the temperatures in the middle and upper sections drop. What is the reason for this? How to adjust? Feed: 14T Top temperature: 48 Recycle: 22.5T Bottom temperature: 108 Feed temperature: 66
Personally, I think the reflux is too low
The reflux ratio is also quite high; personally, I think the feed inlet should be moved downward
You can try changing the position of the feed inlet........ I have three feed inlets here
Unstable feed composition leads to heat imbalance in the tower. This situation is likely due to the lighter composition of the feed, which results in an excess of light components in the distillation section and consequently an increase in the tower top temperature.
:I’m so familiar with this problem; I keep running into it as well, and I don’t know how to solve it ?
I think the feed inlet can be adjusted or the feed temperature can be controlled.
First, you need to analyze whether the feed composition and feed rate of this tower are within a reasonable range! You need to analyze the changes in reflux temperature and reflux volume, as well as the changes in pressure in the deethanizer, to determine whether your reflux ratio is normal! I can’t see the pressure of your tower; if it’s around 17 KG, it seems that the top temperature is a bit high!
What is the pressure? If the composition changes and there are more light components, the pressure will increase. This tower generally has three feed inlets, which are designed to accommodate such compositional changes; material can be fed from below to increase the number of plates in the distillation section
The feed is wet, right? It shouldn’t cause the back pressure to rise, should it? Furthermore, if the temperature rises after cooling, it is also due to water entering the top of the tower’s condenser; this water is then removed from the top of the tower in the reflux tank
The bottom temperature is very high; if there isn’t much C5, it indicates that the pressure is high. It’s normal for the top temperature to be high when the pressure is high, and a high top temperature can also be caused by a high proportion of propane in the components at the top of the tower