English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In order to clalify the effects of agitation rate on the oxygen delignification of white birch Asplund pulp, the relationship between the change of oxygen content in a cooking liquor during the course of cooking under a constant oxygen pressure and Kappa number of the pulp was investigated.The rapid consumption of oxygen dissolved in cooking liquor resulted from the significant increase in the delignification rate during the early stage by the addition of Co-salen [Cobalt (II) Bis-(salicylidene)-ethylenediamine] as a oxidizing catalyst.(Table I and Fig. 3). Thus, the dissolved oxygen content decreased, and the pulp was under oxygen shortage temporarily in the case of the agitation rate below 300rpm.(Fig. 2). But the delignification rate was slowed down during the late stage of cooking, compared with the early stage, and the consumption of oxygen was decreased simultaneously.(Fig. 3). The oxygen content in cooking liquor was increased cosequently and kept constant at various levels during the late stage.(Fig. 2).Therefore, it needed a high agitation rate to compensate for the rapid consumption of oxygen during the early stage of delignification. But the agitation rate could be decreased considerably on the late stage.(Fig. 4).This phenomenon was confirmed by investigating the correlation of the oxygen pressure, instead of the agitation rate, to the delignification.(Fig. 5).

Oxygen-alkali cooking in presence of cobalt complex. Effects of agitation rate on the delignification of white birch asplund pulp.