Valmet Oxygen Delignification system removes lignin with excellent efficiency. It is the ideal oxygen delignification stage and a great asset for pulp mills. Up to 65-70% of the remaining lignin after cooking is removed. This result remains unchallenged. The secret lies in the carefully optimized conditions.
Delignification with Valmet Oxygen Delignification results in a low kappa number of the pulp entering the bleach plant. This enables a substantial reduction of the consumption of chemicals.
Other objectives of extending the delignification are to reach a higher brightness of bleached pulp and to facilitate bleach plant closure. A higher yield of bleached pulp is obtained if an extended delignification by oxygen replaces a part of the residual delignification by cooking.