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Continuous distillation at total reflux

  • Start the model Continuous distillation column with default parameters (propanol-isopropanol mixture, isopropanol mass fraction 65%, 9 trays+boiler, feed tray n°6)
  • Feed the column with 2000 kg.h-1 until boiler reach a 100% level, then stop the feed
  • Heat the bottom product and, when it start to boil, set the heating controller TIC in manual with an output at 30%
  • When the reflux drum level reach 25%, start the reflux pump and put the reflux controller in automatic with a setpoint of ~3000 kg.h-1.
  • Feed the column with some product if necessary to keep the boiler level at ~50%, then stop feed
  • Set the reflux flow controller in cascade mode to put the column at total reflux
  • Look at Mac Cabe and Thiele graphic construction at total reflux
  • Stop the heat input, empty the column and determine its product inventory

Continous distillation, and column feed limit

Start the model Continuous distillation column with default data (propanol-isopropanol mixture, isopropanol mass fraction 65%, 9 trays+boiler, feed tray n°6). Distillation objectives are to run the column at distillate specification of 90%, residue specification of 15%, feed 1000 kg.h-1, and when at steady state, increase the feed up to the maximum to determine what equipment is limiting.

  • Start the column at total reflux
  • When one of the bottom or overhead product is on specification, you can start the draw off by starting the pump and setting level control
  • Set the reflux ratio at R=3, by setting the reflux flow controller in cascade mode
  • Start the feed to the column and set temperature control at feed boiling temperature
  • Feed the column as necessary, up to 1000 kg.h-1, while trying to keep distillate and residue on spec
  • When the column is at 1000 kg.h-1 and at steady state, try to increase the feed up to the maximum allowable, keeping on spec products
  • If the limit is on heat input, increase steam network pressure, or reboiler heating area
  • If the limit in on column flooding, try to decrease reflux ratio, or increase tray numbers