Oxygen Induced Bleaching in Pulp and Paper Industry: a Review

Oxygen induced bleaching (ODL) in pulp and paper industry is a predominant process in modern fibre lines of pulp and paper industry because of its environmental and economic benefits. The significances of oxygen delignification include lower chemical requirements in subsequent bleaching sequence, higher brightness of the pulp with equivalent amount of chemicals, lower rejects and reduced water consumption. The process involves the partial replacement of chlorine or chlorine dioxide delignification stages with oxygen delignification. The removal of lignin from the pulp can be done in single stage and double stage of oxygen delignification. Regulatory and economic pressures have driven the pulp and paper industry to implement such new delignification and bleaching practices. In the present paper, an attempt has been made to discuss the theory, mechanism and significances of oxygen delignification in pulp and paper industry