Oxygen Delignification

Intensive delignification with pure oxygen.

Delignification with oxygen reduces active chlorine requirements, environmental impact and water treatment operational costs.

Oxygen delignification enhances yield in bleached pulp production and offers relevant operating cost advantages over the use of bleaching agents. Not less important is the environmental benefits it leads to, mainly the minimisation of adsorbable organic halides (AOX). Also, oxygen application leads to lower wastewater treatment oxygen requirements and less color in effluent.

Come funziona la delignificazione con ossigeno

Il processo di rimozione della lignina utilizza l'ossigeno per ridurre il fabbisogno di cloro attivo nell'impianto di sbiancamento.

Questo processo è un passo importante verso l'assenza di cloro totale (TCF) e di cloro elementare (ECF) nella produzione della pasta di cellulosa.

Less environmental impact

Reduced or eliminated AOX production reducing environmental impact

Lower cost

Lower overall bleaching chemical costs

Lower BOD/COD

Lower BOD/COD production and less colour in the effluent

Important bleaching

Important bleaching step towards TCF or ECF pulp production and mill closure

Reduced wastewater

Reduced wastewater treatment costs (COD and colour removal)

Better yield

Better yield than extended cooking

Oxygen in delignification

We can find different types of delignification processes:

– HCOD – High Consistency Oxygen Delignification

– MCOD – Medium Consistency Oxygen Delignification
(following bullets within MCOD)
– Double Stage
– Single Stage
– Mini

– Pre – bleaching cellulose HCOD and MCOD
applications are well stablished technologies, adapted
to the concept of a modern plant

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