Can anyone help me identify 2 causes of high liquid level in the bottom of a distillation column?

Question

Please give a brief description for each cause

Answer 1

A high reflux ratio would increase the level in the bottoms (assuming that the extraction rate isn't increased as well). With more reflux coming back, there's more liquid there.

A low boiler duty would also increase the amount of liquid in the bottom because with less energy, you'll get less boiling and thus end up with more liquid (this again assumes that the flow out of the bottoms is not increased to account for it).

Answer 2

I've seen that occur several times in industry. Usually it's because somebody screwed up or a level gauge was wrong. I've also seen it happen because the flow out of the column was restricted.

LOL - I was called in to diagnose problems with a column in a refinery one time several years ago. They had just worked on the column in a turnaround but it wouldn't work after the unit came back up. I determined through some testing it was a high bottoms level and that the flow to the reboiler was probably restricted. Turns out a scaffold board had been left in the bottom of the column after the turnaround. Man, the refinery was PISSED at the contractor that did the turnaround.

Answer 3

for ur homework??!!!!!!!!!