Stripping column can efficiently treat kraft pulp mill foul condensates for odorous total reduced sulphur (TRS) and biological oxygen demand (BOD) compounds.

The purpose of the foul condensate stripping column is:

  • To remove odorous TRS and BOD contaminants from selected foul condensate streams from the digester and evaporator areas.  This is important to off-load the effluent treatment system and to keep the mill in compliance with the environmental permit.

  • To recover the valuable heat used for stripping in a manner that meets the mill integrated energy recovery objectives.  This heat is recovered in the reflux condenser by producing steam, heating boiler feed water, or heating black liquor.

  • To produce stripper off gas (SOG) and subsequent crude methanol of a consistent quality for feed to a methanol purification system or for disposal by incineration.

  • To produce stripped condensate of a consistent quality for re-use in the mill.  Typical uses include brown stock washing and lime mud washing.

Condensate Stripping Column

The A. H. Lundberg’s foul condensate stripping system includes the following:

  • Feed tank

  • Fibre filter

  • Condensate preheater

  • Stripping column with rectification section

  • Reflux condenser

The foul condensate stripping system may be designed to use structured packing, random packing, tray systems or a combination of these steam to liquid stripping technologies. Optional enhancements to the foul condensate stripping system can include the selective condensation and storage of crude liquid methanol from the stripper off-gas for use as an auxiliary fuel.