Evaporators for BCTMP Liquor

The liquor from a BCTMP plant has a high COD (Chemical Oxygen Demand) value of 15 to 22 kg/t of water and the specific water consumption of around 10 m³/t of pulp.

It is economically  and environmentally justified to replace the conventional biological effluent water treatment plant with an evaporation system and concentrate combustion in a recovery boiler.


  • Condensate from evaporation can be used as washing water in the BCTMP process
  • Recovery of chemicals
  • COD is converted into steam in the recovery boiler

Key features

  • Up to 8-effect trains with falling film evaporators
  • High DS possible with up-flow falling film concentrator
  • Low steam consumption due to flashing of the liquor and condensate from effect to effect
  • Excellent condensate segregation


  • On-stream washing system for each effect
  • MVR falling film evaporators as pre-evaporator