2 replies to this topic

[rabindra]

We have two distillation columns which are operated in series i.e the 1st Column top draw is C7 rich stream. 1st Column bottom (mixture of C8 and C9 rich stream) is again distilled in the 2nd Distillation column where two streams C8 and C9 are drawn separately. Due to feed mix change we have to operate the 1st column only. However, since there is no process line from 1st column bottom to rundown tanks, we have to pump the 1st column bottom to 2nd column and then from the 2nd column bottom pump the liquid is to be pumped to rundown tanks. There will not be any reboiling in 2nd column.

My question is can a column be used as a vessel as described above. The liquid load in the column will be less than design. DO you envisage any problem in the column?

regards
rabindra

[Pilesar]

You will be flowing over trays in the second column? You may have some stagnant areas where liquid will collect. This may result in polymerization leading to fouling. Stuck tray valves probably would not be noticed until the second column were made active again. You may want to isolate the reboiler from the column for the same reason if you intend to pass through for a long duration.

[rabindra]

Thanks for the reply.

We are planning to operate on trial basis for abt 10 days. If found successful; we will lay a new process line from 1st column bottom itself. Is there any thing else I should take care?