Comparing Bleaching Sequence Configurations with Respect to Chemical Efficiency and Brightness Response, 1997 Pulping Conference Proceedings

In order to better understand the efficiency of a particular bleaching sequence; in terms of chemical efficiency, brightness development, and brightness ceiling; a comparison methodology has been developed. Using brightness, kappa number, and oxidizing equivalents; a response curve can be developed which is normalized for different types of bleaching sequences. This allows the relative efficiency of different sequences and equipment configurations to be compared.

This paper will utilize this methodology in order to compare the bleaching response for various configurations. This will include hardwood versus softwood kraft pulps, oxygen versus non-oxygen delignified kraft pulps, and Mill versus Laboratory bleaching response.

In addition to comparing bleaching configurations, an extensive database has been developed. This includes general information from more than 100 bleaching sequences on North American pulps. From this database, “average” or “typical” bleaching response curves have been constructed for benchmarking purposes.