1 reply to this topic

[Amol M]

Dear All,

 

I have multi-component mixture and key component say 'A' (Boiling Point= -70⁰ C), in 1st distillation column as per the simulation result I got mass fraction 0.995 and at bottom 15000 ppm. but as per we required bottom mass fraction should be less than 5 ppm, so after several changes we found that only distillate rate change can give desired mass fraction.

 So we increased small amount of distillate rate (by 1%) with keeping reflux rate and  pressure constant, as per the simulation result mass fraction of A at top 0.992 and bottom is 3 ppm, overall temperature at top of the column and bottom of column is slightly increased, but reboiler and condenser duty bit decreased. 

 

  As practically if we increase distillate rate by keeping reflux rate constant, reboiler and condenser duty should increased, per simulation result is exactly opposite to this.

 

Please suggest me any reason for this behavior..?

[Bobby Strain]

This is what I expect with feed with much vapor. You should also include much more information next time you want help. Otherwise you won't get much useful information.

 

Bobby