Year: 1998
Type: article
Abstract: Delignifi cation of wheat straw with aqueous methanol, ethanol, 1-propanol, n-butanol, dioxane, and acetone in the presence of acid catalyst (0.02 N H,SO,) at low temperature (75°C) for 2 h was studied.The effect of ethanol-water ratios on the yield of dissolved lignin is also reported here.There was no significant difference in the organosolv lignin yields among the various organic solvents used, which accounted for 24-28% of the total amount of acidic chlorite lignin present in wheat straw.Increase of ethanol-water volume ratio from 40160 to 70130 resulted in raising lignin yields from 25 to 31%, while the reverse yield from 31 to 24% appeared in the increase of volume ratio from 70130 to 90110.The isolated organosolv lignin fractions contained low amounts of polysaccharide sugars (4.5-5.3%) and had low average molecular weights (1 190-1650 Da), which corresponded with the ball-milling lignin, enzyme lignin, and alkali lignin obtained from wheat straw.The predominant components of the alkali nitrobenzene oxidation products were found to be vanillin and syringaldehyde.The yield of vanillin was slightly higher than that of syringaldehyde in all the nitrobenzene oxidation products of the isolated organosolv lignin preparations.
Authors: Run‐Cang Sun, J. Mark Lawther, W. B. Banks
Language: English
Topic: Lignin and Wood Chemistry
Subfield: Process Chemistry and Technology
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2472717236