Abstract
In this study, the effect of a combined treatment consisting of calcium hydroxide (CH) followed by activated carbon (AC) on the purification of hemicellulose in the pre-hydrolysis liquor (PHL) from pulping process has been evaluated. The results show that lignin and furfural of PHL are efficiently removed, and the lignin removal is achieved by forming complexes onto CH particles in the CH treatment process, while acetic acid (acetate) is formed from the hydrolysis of acetyl groups present in the dissolved hemicelluloses in the PHL. The loss of xylo-oligosaccharides (XOS) is moderate, even at a high CH dosage of 0.8% while the xylose concentration is essentially unchanged. For the AC treatment, the optimal treating pH can enhance the interactions between AC and residual lignin and change the zeta potential of AC resulting in improved lignin adsorption onto AC. An increase of AC dosage has the tendency to adsorb more XOSDP>6 than XOSDP2~6. Overall, 66.9% of lignin and 70.1% of furfural removals are achieved under the optimal conditions of CH and AC treatment process, with a 5.9% total xylosugars loss. The present combination of CH and AC treatment process was more effective and selective for purification of xylosugars of PHL.
Highlights
As a significantly global strategy, the biorefinery concept gets a perfect embodiment and application in platform chemicals, biological materials, and biological energy
It is well known that hemicelluloses saccharides have wide applications in many fields
The present study introduces a purification method consisting of calcium hydroxide (CH) treatment, followed by activated carbon (AC)
Summary
As a significantly global strategy, the biorefinery concept gets a perfect embodiment and application in platform chemicals, biological materials, and biological energy. In this concept, it is imperative to make a sustainable and environmentally friendly utilization for biomass resources, especially lignocellulosic materials. As a vital aspect for the implementation of integrated forest biorefinery, separation of hemicellulose from wood chips by hot water/steam pre-extraction/hydrolysis prior to the process of kraft-based dissolving pulping can offer a potential opportunity to obtain valued-added lignocellulosic products. It is well known that hemicelluloses saccharides have wide applications in many fields. They can be transformed into fuel ethanol, levulinic acid, xylitol, etc. Xylo-oligosaccharides (XOS) are considered as important platform chemicals to produce value-added products due to their diverse physiological functions, such as lowering cholesterol, improving bowel function, Polymers 2019, 11, 1558; doi:10.3390/polym11101558 www.mdpi.com/journal/polymers
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
