Cellulose Fiber Isolation and Characterization from Sweet Blue Lupin Hull and Canola Straw
In this study, cellulose fibers were removed from crop by-products using a combination of sodium hydroxide treatment followed by acidified sodium chlorite treatment. The objective was to obtain high recovery of cellulose by optimizing treatment conditions with sodium hydroxide (5–20%, 25–75 °C and 2–10 h) followed by acidified sodium chlorite (1.7%, 75 °C for 2–6 h) to remove maximum lignin and hemicellulose, as well as to investigate the effect of lignin content of the starting materials on the treatment efficiency. Samples were characterized for their chemical composition, crystallinity, thermal behavior and morphology to evaluate the effects of treatments on the fibers’ structure. The optimum sodium hydroxide treatment conditions for maximum cellulose recovery was at 15% NaOH concentration, 99 °C and 6 h. Subsequent acidified sodium chlorite treatment at 75 °C was found to be effective in removing both hemicellulose and lignin, resulting in higher recovery of cellulose in lupin hull (~ 95%) and canola straw (~ 93%). The resultant cellulose fibers of both crop by-products had increased crystallinity without changing cellulose I structure (~ 68–73%). Improved thermal stabilities were observed with increased onset of degradation temperatures up to 307–318 °C. Morphological investigations validated the effectiveness of treatments, revealing disrupted cell wall matrix and increased surface area due to the removal of non-cellulosics. The results suggest that the optimized combination of sodium hydroxide and acidified sodium chlorite treatments could be effectively used for the isolation of cellulose fibers from sweet blue lupin hull and canola straw, which find a great number of uses in a wide range of industrial applications.
KeywordsAcidified sodium chlorite Canola straw Cellulose Lignocellulosic biomass Lupin hull Sodium hydroxide
We are grateful to Natural Sciences and Engineering Research Council of Canada (NSERC, #05356-2014) and the Food Processing Center of University of Nebraska-Lincoln for the financial support to carry out this research.
- 3.Kadla JF, Gilbert RD (2000) Cell Chem Technol 34:197–216Google Scholar
- 6.Osong SH, Norgren S, Engstrand P (2015) Cellulose 23:1–31Google Scholar
- 7.Modenbach A (2013) Ph.D. dissertation at the University of Kentucky, pp 147–191Google Scholar
- 10.Pan X, Xie D, Kang KY (2007) Appl Biochem Biotechnol 140:367–377Google Scholar
- 12.Carvalheiro F, Duarte LC, Gírio FM (2008) J Sci Ind Res 67:849–864Google Scholar
- 14.Kim TH, Lee YY (2007) Appl Biochem Biotechnol 137:81–92Google Scholar
- 21.Sluiter A, Hames B, Ruiz R, Scarlata C, Sluiter J, Templeton D, Crocker D (2008) NREL/TP-510-42618. National Renewable Laboratory, GoldenGoogle Scholar
- 36.Brebu M, Vasile C (2010) Cell Chem Technol 44(9):353–363Google Scholar