Boosting Oxygen Delignification of Poplar Kraft Pulp by Xylanase Pretreatment

Xingxiang Ji, Jiachuan Chen, Qiang Wang, Zhongjian Tian, Guihua Yang, Shanshan Liu

Abstract


Enhancement of oxygen delignification is critical to improve subsequent bleaching efficiency while being environmentally compatible. In the present study, xylanase was used to improve the delignification process of poplar kraft pulp. Results showed that the kappa number reduction ratio (KRR) of 14.5% was achieved for the pulp under xylanase-assisted oxygen delignification processes when compared to the control without xylanase treatment. Other pulp properties, such as intrinsic viscosity and brightness, also improved somewhat; i.e., viscosity increased by 28 mL/g units and ISO brightness increased 1.4% points. Furthermore, 31P-NMR was employed to characterize the chemical structure of the residual lignin of the pulps before and after oxygen delignification. It showed that the condensed phenolic and syringyl hydroxyl groups decreased significantly for the xylanase-assisted oxygen-delignified pulps.

Keywords


Kraft pulp; Oxygen delignification; Xylanase; Kappa number; Residual lignin

Full Text: PDF

Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022, hubbe@ncsu.edu; Lucian A. Lucia, (919) 515-7707, lucian.lucia@gmail.com URLs: bioresourcesjournal.com; http://ncsu.edu/bioresources ISSN: 1930-2126