Effect of mixed solvent on the sub- and supercritical liquefaction of agricultural waste

The sub- and supercritical liquefaction of rice straw to produce bio-oil with mixed solvent (ethanol-water and 2-propanol-water mixture) was studied in a 1000 mL autoclave at 553-573 K, 6-18 MPa. The results showed that using mixture could promote the conversion of rice straw below 50%, and inhibit the formation of low-boiling point materials. The oxygen content in the bio-oil was decreased with the the increase of the ratio of hydrogen donor solvent (ethanol and 2-propanol). The bio-oil was analyzed with gas chromatography-mass spectrometry (GC-MS), and the results indicated that the component characterization of bio-oil was largely depended on the ratio of mixture, and the liquefaction of rice straw yielded primarily ester derivatives.