Increased Degradability of Cellulose by Dissolution in Cold Alkali

• Main Authors: Yan Wang, Mikael E. Lindström, Gunnar Henriksson
• Format: Article
• Language: English
• Published: North Carolina State University 2014-10-01
• Series: BioResources
• Subjects: Cellulose degradation; Cold alkali pretreatment; DP; Crystallinity; Acidic hydrolysis; Enzymatic hydrolysis
• Online Access: http://ojs.cnr.ncsu.edu/index.php/BioRes/article/view/BioRes_09_4_7566_Wang_Increased_Degradability_Cellulose

To enhance the degradability of cellulosic materials for further industrial purposes, different qualities of cellulose were dissolved in cold sodium hydroxide solution and precipitated by lowering the pH with sulfuric acid. The precipitated cellulose was subjected to acidic and enzymatic hydrolysis. The results showed that the precipitated cellulose degraded considerably faster both with enzymes and acid relative to the untreated controls. Important pretreatment parameters that can influence the degradability of the pretreated cellulosic materials were found to include temperature and concentration of the cellulose in NaOH solution. Increasing amounts of cellulose were hydrolysed with decreasing pretreatment temperature; the degradability of the pretreated cellulose increased with decreasing cellulose concentration. The degree of polymerization (DP) also can influence the pretreatment efficiency. Diluted sulfuric acid was able to decrease the DP and enhance the effect of dissolution and precipitation. The results showed that the lower DP of cellulosic materials caused an increase of degradability for the NaOH pretreated samples compared to untreated samples. The NaOH pretreatment was more effective for shorter chain cellulose.