Hydrogen Peroxide Decomposition During Pressurized Peroxide Bleaching, 1996 Pulping Conference Proceedings

Jeff A Stevens AND Dr. Jeffery S. Hsieh

Georgia Institute of Technology

Pressurized hydrogen peroxide bleaching utilizes higher temperature to achieve a faster rate of reaction and a higher brightness ceiling for kraft pulp under alkaline conditions. When the temperature is increased over l00°C, the rate of decomposition itself is increased with an activation energy of 9 kcal/mol. The base catalyzed decomposition of hydrogen peroxide follows the rate law -(rate) = k[H2 O2 k[HO2 -] over the temperature range 20° to 110°C. This law holds for hydrogen peroxide in solution with sodium hydroxide. In this work, the rate of hydrogen peroxide decomposition is developed both in solution and in pulp suspensions up to 5% consistency. Also, the rate of peroxide decomposition during pressurized peroxide bleaching is quantified and compared to a control decomposition rate. The effects of pH, temperature, and magnesium salt addition on the rate of peroxide decomposition are discussed.