Enhanced Delignification and Bleaching Using TAED Activated Peroxide, 1998 Pulping Conference Proceedings

The peroxide bleach activator T.A.E.D (Tetra Acetyl Ethylene Diamine) reacts with peroxide to form a strong oxidant, which has been found to enhance the performance of peroxide alone. T.A.E.D can be used under both alkaline and near neutral conditions which demonstrates its flexibility in application.

The combination of T.A.E.D with peroxide (PA stage) under near neutral conditions (pH 6 - 8) to produce strong oxidant in situ, offers a safe, low capital alternative for delignifying chemical pulps to using preformed peracids or other strong oxidising species.

Research studies have shown that the strong oxidant generated from the reaction between T.A.E.D and peroxide under neutral pH provides significant delignification and brightness gain for various chemical pulps (kraft, sulphite; hard, soft and non-woods) with good maintenance of viscosity.

Alternatively, the use of T.A.E.D within an alkaline P stage can enhance brightening of mechanical pulps.

The combination of T.A.E.D with peroxide under near neutral conditions can also be applied towards the end of bleaching sequences to give high brightness. Results from studies have shown that the use of T.A.E.D combined with peroxide under near neutral conditions, followed by a conventional alkaline peroxide stage (i.e. PAP sequence) to bleach softwood and hardwood kraft and hardwood sulphite pulps gives rise to higher brightness than two conventional peroxide stages (PP sequence).