1 reply to this topic

[bhagat]

In distillation column what is sensitive tray.
In distillation product quality is control either by temperature or steady reboiling flow(posible by other ways also). In our system we control product quality by steady reboiling flow, even maitaining steady flow, we get off spec at top/bottom.
I would like to know the reasons.
thanks.

[Ritesh Suratwala]

Your query has very few parameters and too general in nature. This may be the reason no reply for such an interesting topic of "distillation".

Anyway, I'll give you my thumbrule on off-spec product in distillation system.

When either Top or bottom product is going off-spec, it is maily related to material balance. So, little adjustment in draw-off rate can improove product quality.

When top and bottom, both product are going off, something wrong with column performance.

Regarding performance, it depends upon efficiency (no of theratical stages) and internal vapor/liquid ratio. In your case, this vapor/liquid ratio is changed by changing reboiling rate which is measured in terms of column temperature.

I don't know anything about your problem, but hope above guideline can help you little bit in understanding real problem and finding solution.