Polpação soda de eucalipto com adição de tetraidroantraquinona
Keywords:
polpação soda, tetraidroantraquinona THA, aceleração deslignificação, rendimento da polpa, processo kraftAbstract
The effect of tetrahydroanthraquinone (THA) on soda pulping of Eucalyptus grandis wood was analyzed using 0.02, 0.05 and 0.10 percent of THA (based on Wwood) and 10, 12, and 14 percent of active alkali. Soda, kraft, and soda-anthraqui- none (soda-AQ) cooks were also performed for reference. THA showed and effici- ent delignifying action mainly at lower alkalinity and when added in extremely low concentrations (less than 0.05 Dpercent). For a given kappa number level, addi- tion of THA resulted in higher yield, savings in active alkali consumed, higher pulp viscosity, and higher 8 and y — cellulose content. Addition of 0.10 percent of THA resulted in pulps with strenght properties 5 - 7 percent higher than the refe- rence kraft pulp. THA showed a slightly higher effectiveness as a delignifying agent than AQ.
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