Hybrids of C. citriodora and C. torelliana for kraft pulp production

摘要

The objective of this work was to characterize the wood from hybrids of C. citriodora and C. torelliana for pulp production. Wood chips from four hybrids of C. citriodora and C. torelliana (two C. citriodora x C. torelliana and two C. torelliana x C. citriodora) plantations with 7 years-old were used. Wood fibers morphology and chemical composition were analyzed. After that, a modified kraft pulping was carried out to achieve kappa 18 on brownstock pulps. The results show that all Corymbia woods presented higher basic density and lower lignin content than Eucalyptus wood. Moreover, Corymbia wood has fibers with higher length, lower width, lower lumen width, higher wall thickness and higher wall fraction. On pulping, all the Corymbia genetic materials demanded higher alkali and temperature to achieve the target delignification degree in comparison to Eucalyptus reference material. One of the C. citriodora x C. torelliana hybrids had very low specific wood consumption. Among the genetic materials analyzed, the maternal influence on C. citriodora and C. torelliana hybridization was very clear: hybrids having C. citriodora as maternal genitor (C. citriodora x C. torelliana) have better quality to pulping than those who have C. torelliana as maternal genitor (C. torelliana x C. citriodora).