Bleaching of Rice Straw Pulp with Various Options for Oxygen Reinforcement in Plant Practice

摘要

Oxygen delignification is now increasingly used as a favorable method of reducing the requirement of elemental chlorine during bleaching. Though some information is available for oxygen pulping for rice straw, there is no information for oxygen delignification in bleaching of rice straw pulp and its effluent quality. It is not also known to us that attempts to go up to 50% delignification by oxygen treatment of pulps is valid for rice straw pulp or not. Therefore, it is of urgent importance to examine the effect of all the parameters on oxygenated bleaching of rice straw pulp in multi stage sequences The present investigation has been carried out with an aim to achieve a brightness level of at least above 80 - 82% PV for a typical rice straw pulp. The bleaching sequences considered in this investigation were: CE_(OP)HP, OCE_(OP)HP and then the result were compared with the results of CEH and CE_pHP sequences. The results shows that the sequence OCE_(OP)HP is the best in terms of chemical consumption and TOCl formation per unit of brightness increased, whereas the sequence CE_(op)HP is good for getting higher degree of brightness with increase in TOCl generation.