Abstract
Miscanthus × giganteus bark was subjected to mild fractionation with peroxyformic acid by a two stage process. A factorial experimental design was used to study and quantify the effect of the variables (formic acid concentration (80–90%), hydrogen peroxide concentration (0.2–0.4%), temperature of the first stage (60–80 °C), and treatment time of the second stage (60–120 min)) on the main parameters of fractionation: pulp yield, remaining lignin and total polysaccharides in pulp. The dependence of lignin precipitation rate on hydrogen peroxide concentration in liquor was also studied. Hydrogen peroxide concentrations inferior to 0.5% seems to be suitable to recover high percentages of lignin. The isolated lignin was analysed by 2D-HSQC, 13C- and 31P NMR spectroscopy, FTIR spectroscopy, size-exclusion chromatography and chemical analysis. The most important chemical modifications taken place in the lignin during the fractionation were identified: β -O-4′ cleavage and hydrolysis of LC-bond structures. The C9-formula was also determined: C 9H 6.81O 2.90(OCH 3) 0.68(COOH) 0.07(OH Ph) 0.38(OH Al) 0.33.
Sign-in/Register to access full text options 
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.
