The illustration depicts a standard installation flowsheet of an atmospheric extraction stage type EOP.
Extraction stages are intermediate stages in the bleaching aimed to dissolute all lignin fragments liberated in previous oxidizing bleaching stages. Many benefits can be gained from using a pressurized extraction stage.
Benefits of pressurized extraction compared to atmospheric:
• Possibility to integrate extraction action with bleaching action
• Possibility to significantly increase the brightness due to the possibility of large consumptions of hydrogen peroxide in beneficial bleaching reactions