CHEMISTRY AND DELIGNIFICATION KINETICS OF CANADIAN INDUSTRIAL HEMP

Abstract

Strategies to diversify the Canadian fibre supply have provided an impetus for investigating a wide variety of alternative fibres including industrial hemp (Cannabis sativa L.) in Canada. The alkaline delignification kinetics of Canadian hemp (bast, core and whole stem fractions), using micro pulping units was investigated. The nature of hemp (macromolecule proportions) was a major contributor to the chemical pulping behaviour shown in the results. The initial lignin and holocellulose content of the bast were 10% and 85%, respectively, and the core lignin and holocellulose contents were 21% and 72%, respectively. The bast fibre had a comparative pulping advantage over the core fibre region due to its chemical constitution. The activation energies for lignin removal from hemp are 41 kJ/mol, 76 kJ/mol and 76 kJ/mol for the bast, core and whole stem respectively. These are considerably lower than the reported values for traditional wood pulp species.

ACKNOWLEDGMENTS

The authors thank Hempline Inc., Ontario for supplying the raw material used in this study. Sincere gratitude is extended to Dr. D.A.I Goring and Dr. H. Pande for their thoughtful insight and review of this work. The authors also gratefully acknowledge Domtar Management and NSERC-IPS for their financial support.