Non-Chlorine Bleaching Alternatives: A Comparison Between Ozone and Sodium Hypochlorie Bleaching of Dyed Paper, 1996 International Pulp Bleaching Conference Proceedings

The objective of this study was to determine the effectiveness of ozone as a bleaching agent for dyed paper. The paper industry has typically used sodium or calcium hypochlorite to bleach dyed paper. However, due to increasingly stringent environmental regulations, the paper industry has investigated and established the commercial viability of non-chlorine bleaching alternatives such as ozone. Therefore, Bayer Corporation, in conjunction with Quantum Technologies, Inc., conducted a medium consistency ozone bleaching study to compare the effectiveness of ozone versus sodium hypochlorite as a paper decolorizing agent. Internally dyed paper, produced under alkaline dyeing conditions, was treated with 1.5% ozone in a Quantum Technologies Mark IV laboratory mixer/reactor at medium consistency. Our study found that ozone exhibits similar bleaching characteristics to that of sodium hypochlorite when applied to a wide spectrum of colorants used to dye paper.