Separation and Characteristic Analysis of Enzymatic Hydrolysis Lignin from Cornstalks Residue

摘要

Enzymatic hydrolysis lignin (EHL) from the cornstalks residue was separated by two methods, the alkali solution and the organic solvent. In first method, sodium hydroxide or ammonia aqueous solution were selected to react with EHL in cornstalks residue, which was obtained from the raw material to make bio-alcohol by transforming the saccharide components through enzymatic hydrolysis. The 1,4-butdiol or the glycol was selected to dissolve the EHL in the organic solvent method, filtrated the residues to obtain EHL.The yield of EHL, reacted with alkali solution was higher than with organic solvents. The EHL were analyzed with respect to the elementary composition, molecular weights, IR spectra and 13C-NMR spectroscopy. The C9-formula of EHL was calculated by the experiment data. The results indicated that EHL contained many active chemical groups. There were different absorbance peaks at 1700cm-1 and 1328cm-1 on the IR spectra of EHL. It was showed that the non-conjugated carbonyls were existed in the EHL. According to the 13C-NMR, EHL could be classified to "GSH" type of lignin, and it was composed mainly of β-O-4 ether bonds together with β-5 and β-1 carbon-carbon linkages between the lignin structural units.