Fractionation and Characterization of Bio-Oils Produced From Microwave-Assisted Pyrolysis of Rice Straw

Bio-oil from biomass pyrolysis is a complex mixture of polar and non-polar compounds, and cannot be used directly as a liquid engine fuel due to its low heating value, high viscosity, chemical instability, and incomplete volatility.  The aims of this work are to develop an analytical approach and separation process to determine the chemical composition of bio-oils produced from microwave-assisted pyrolysis of rice straw. The bio-oils are supposed to be firstly separated to different fractions which still mixtures using solvent extraction, and then each fraction is analyzed using GC-MS, Gel Permeation Chromatography (GPC) and thermogravimetric (TG) techniques. The bio-oil composition can be described as a mixture of water, volatile acids, aldehydes and ketones, pyrans and furans, sugars, phenyl derivatives, lignin extractives and solids. This method can be used to monitor the main differences in composition of various biomass derived pyrolysis liquids.