ZnCl2 pretreatment of bamboo chips to produce chemi-thermomechanical pulp: Saving refining energy and improving pulp properties

The pretreatment of biomass materials is critical for improvement of the overall production process and product quality. In this work, a dilute zinc chloride (ZnCl2) solution was used to pretreat bamboo chips, followed by defiberization (mechanical pulping). Compared to the results from the traditional chemi-thermomechanical pulping process, the results from this study showed that the refining energy consumption of the modified process was lowered 27%, and the tensile and burst index of the resultant pulp increased 22% and 82%, respectively. The morphological changes on the fiber surface, functional groups, and crystallinity of resultant pulps due to the ZnCl2 treatment were also analyzed.