A process for purifying xylosugars of pre-hydrolysis liquor from kraft-based dissolving pulp production process

Biotechnology for Biofuels

Guihua Yang¹  Jiachuan Chen¹  Jiran Dong¹  Pedram Fatehi¹  Ming He¹  Feng Xu¹ 

[1] State Key Laboratory of Bio-based Materials and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences);

关键词: Pre-hydrolysis liquor;    Ca(OH)2;    Lignin removal;    Activated carbon;    Laccase;    Xylosugars;   

DOI  :  10.1186/s13068-018-1336-0

来源: DOAJ

【 摘 要 】

Abstract Background In the kraft-based dissolving pulp production process, pre-hydrolysis liquor (PHL) is produced, which contains hemicelluloses, lignin, furfural and acetic acid. PHL is currently burned in the recovery boiler of the kraft pulping process, but it can be utilized for the generation of high-valued products, such as xylitol and xylanase, via fermentation processes. However, some PHL constituents, e.g., furfural and lignin, are contaminants for fermentation processes and they must be eliminated for production of value-added products. Results In this work, a process is introduced for removing contaminants of PHL. Ca(OH)2 treatment is the first step of this process, which removed 41.2% of lignin and negligible amount of sugars. In this step, a notable increase in the concentration of acetic acid was achieved (ranging from 6.2 to 11.7 g/L). In the second step, the implementation of adsorption using activated carbon (AC) at 1 wt% dosage led to additional 32% lignin and 5.9% xylosugar removals. In addition, laccase assisted activated carbon treatment led to further removal of lignin via accelerating lignin polymerization and adsorption on AC (i.e., removal from PHL). Overall, 90.7% of lignin, 100% of furfural, 5.7% of xylose, and 12% of xylan were removed from PHL, while the concentration of acetic acid became twofolds in the PHL. Conclusions This study reports an attractive process for purifying sugars and acetic acid of PHL. This process may be implemented for producing sugar-based value-added products from PHL. It also discusses the mechanism of Ca(OH)2 treatment, AC adsorption and laccase assisted activated carbon treatment for lignin removal.

【 授权许可】

Unknown