Extraction and characterisation of lignin from rice straws.

Abstract

Lignin makes up 10-25 percent of the lignocellulosic biomass making it the second most abundant naturally occurring polymer. Lignin comprises three substituted phenol types, sinaply, p-coumaryl and coniferyl alcohols. It is a three dimensional cross-linked macromolecules. In this paper, lignin focus was on the Lignin obtained from rice straws one of the lignocellulosic materials with high content. Rice straws have unique characteristics due to silica content in them The paper was intended to review the extraction and characterization of different methods of Lignin obtained from rice straws. The extraction methods such as ultrasound-assisted extraction, DES, hydrotropic treatment, organosolv extraction and soda-AQ were compared in yields of Lignin obtained from rice straws. The characterization methods discussed included; Fourier transformation infrared spectroscopy (FTIR), Thermo gravimetric analysis (TGA), UV spectroscopy and X-ray photo electron spectroscopy. It was discovered that the Lignin obtained by ultrasound-assisted extraction from rice straws yielded the highest percentage compared to other methods. Key words: rice straw, Lignin, extraction, biomass, yield