Application of Hydrogen Peroxide in the Pulp and Paper Industry

Hydrogen peroxide is a very versatile pulp bleaching agent. Under alkaline conditions it is applied to bleach chemical pulp, mechanical pulp and recycled fibres.This paper summarizes the reaction mechanism, typical process conditions of hydrogen peroxide bleaching.Typically the same reaction mechanism applies in all applications. The versatility of hydrogen peroxide allows its application in different positions within a bleaching sequence of chemical pulps. In kraft pulp bleaching, typical sequences of the ECF technology are ODoEopD1EpD2 or ODoEopD1P, and that of TCF are OOQZP or OOZPZP. Hydrogen peroxide is specially suitable for mechanical pulp bleaching , can brighten the high yield pulps, such as CTMP and APMP pulps,to a high brightness level. And hydrogen peroxide bleaching plays a more and more importment role in waste paper recycling. The suitable temperature range for the application is between 60 ℃ and 80 ℃. With the advent of strenghtening chelation treatments with EDTA or DTPA and improving mixing of bleaching chemicals and fiber material, it becomes a trend that hydrogen peroxide bleaching be used at a higher temperature.