Fractionation and characterization of lignin from waste rice straw: Biomass surface chemical composition analysis.

Waste rice straw (RS) was fractionated to extract the lignin using alkaline (sodium hydroxide) treatment (SHT) and organic acid (Formic acid/Acetic acid) treatment (OAT) process. Rice straw fractionation by the acetic OAT and alkaline SHT methods resulted in the recovery of OAT-lignin and SHT-lignin respectively. The structural characterization of the extracted lignin fractions was done by UV-vis spectroscopy, FTIR and H NMR technique.