Extraction of hemicellulose by hot water to reduce adsorbable organic halogen formation in chlorine dioxide bleaching of bagasse pulp

• Published in: Industrial crops and products 2017-02, Vol.96, p.178-185
• Main Authors: Yao, Shuangquan, Nie, Shuangxi, Zhu, Huixia, Wang, Shuangfei, Song, Xueping, Qin, Chengrong
• Format: Article
• Language: English
• Subjects: AOX formation; Hemicellulose; Hemicellulose structure; Hot water extraction; pH pre-corrected
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2016.11.046

•The relationship between hemicellulose and adsorbable organic halides (AOX) formation was confirmed.•AOX formation was decreased by 33.27% when 43.75% hemicellulose was extracted.•The formation of chlorobenzene and chlorophenol was inhibited by hemicellulose extraction.•There are differences in structure between the bagasse hemicelluloses and the solid residual hemicelluloses by ATR-FTIR and NMR analysis, AOX formation was affected by the structure of hemicellulose. To study the influence of the content of hemicellulose on the absorbable organic halogen (AOX) formation in chlorine dioxide bleaching, a pH pre-corrected hot water pretreatment was developed. The influence of lignin on AOX formation was eliminated by the control of hot water extraction time, AOX formation was decreased by 33.27% under optimal hot water extraction conditions. The chemical composition of bleaching effluent was analyzed by GC–MS, and the formation of chlorobenzene and chlorophenol was inhibited by removal of hemicellulose, the ring structures of which were degraded into chain macromolecules and small molecules. The hemicellulose structure of raw material and bleached pulp was characterized by ATR-FTIR and NMR. This finding revealed differences in the structures of the bagasse hemicelluloses and the solid residual hemicelluloses. AOX formation was affected by the structure of hemicellulose. A new process combining biorefinery and clean pulp and paper was developed through these experiments.