Michael R. Resetarits Forum Moderator 23 Posts
Re: Why is the bottom distillation column temperature too high?10 June 2014 at 10:27am Last edited: 10 June 2014 at 10:28am
This column needs an internal inspection.
There are several possible reasons why the bottom temperature might be too high:
1. An excessive pressure drop across the column
- Fouled/plugged rings
- Deteriorated rings sticking together
- Fouling at the feed pipe
2. The bottom's composition is heavier than it used to be.
3. The column top pressure is higher than it used to be.
4. The steam is overly superheated.
A gamma scan might also expose the source of the problem.
It is "unusual" to control column temperature with reflux. Column pressure, column compositions and steam temperature usually determine column temperature.
I work in at a chemical plant which produces dimethyl ether (DME). In our DME distillation column where DME and water and methanol are separated we our having trouble keeping the bottom temperature below the normal temperature of max 250 F, which has caused us to cut feed rate of methanol to reactor. The column has a packing consisting of Ballast rings. We have raised the reflux to a point where it doesn't cool anymore. This column also has not been opened up for repair since original 1981. Any ideas on how we can get the bottom distillation column temp down to normal range of 235-250 F.
Have an insight or suggestion?
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