Effects of solvents and catalysts in liquefaction of pinewood sawdust for the production of bio-oils

• Published in: Biomass & bioenergy Vol. 59; pp. 158 - 167
• Main Authors: Wang, Yun, Wang, Hui, Lin, Hongfei, Zheng, Ying, Zhao, Jianshe, Pelletier, Andre, Li, Kecheng
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-12-2013; Elsevier
• Subjects: acetone; Alternative fuels. Production and utilization; Applied sciences; Bio-oils; biofuels; Biomass; carbon dioxide; catalysts; Catalytic conversion; Energy; ethanol; Exact sciences and technology; Fourier transform infrared spectroscopy; Fuels; gas chromatography; General treatment and storage processes; Liquefaction; mass spectrometry; Miscellaneous; nuclear magnetic resonance spectroscopy; oils; Pollution; potassium carbonate; sawdust; solvents; Supercritical carbon dioxide; Wastes; zeolites; Catalytic conversion; Supercritical carbon dioxide; Biomass; Liquefaction; Bio-oils; Solvent effect; Alkali metal Compounds; Chemical analysis; Waste treatment; Carbon dioxide; Flash pyrolysis; Biofuel; Pinus; Wood waste; Molecular sieve; Potassium Carbonates; Upgrading; Gymnospermae; Chemical composition; Sawdust; Woody plant; Zeolite; Supercritical state; Waste reuse; Coniferales; Spermatophyta; Degradation product; Catalyst
• ISSN: 0961-9534; 1873-2909
• DOI: 10.1016/j.biombioe.2013.10.022

Liquefaction of biomass with proper solvents and catalysts is a promising process to produce liquid biofuels and valuable chemicals. In this study, pinewood sawdust was liquefied in the presence of various supercritical solvents (carbon dioxide, water, acetone, and ethanol) and catalysts (alkali salts and acidic zeolites). The liquid, gas and solid products were analyzed using GC–MS, FT-IR, elemental analyzer, 1H NMR, 13C NMR. The experimental results showed that both solvent and catalyst can significantly improve the liquefaction process by increasing the yield of liquid oil and suppressing the formation of solid residue. K2CO3 showed the best performance by doubling the yield of bio oil. Meanwhile, the maximum bio-oil yield (30.8 wt%) and the minimum solid residue yield (28.9 wt%) were obtained when ethanol was employed as the solvent. Solvents can also strongly affect the distribution of liquid products. 2,4,5,7-tetramethyl-phenanthrene and bis(2-ethylhexyl) phthalate were the premier compounds in liquid product as supercritical carbon dioxide is used as solvent while 2-methyl-naphthalene became the main composition when water is used as solvent.
•The yields of bio-oil almost tripled when organic solvents were employed.•SCCO2, acetone and ethanol gave similar bio-oil yields, which are 29.3 wt%, 27.9 wt% and 30.8 wt%, respectively.•Water showed lower performance as only 17.3 wt% bio-oil was generated. 2-methyl-naphthalene is the dominant component.•2,4,5,7-tetramethyl-phenanthrene and bis(2-ethylhexyl) phthalate become the primary compounds with SCCO2 as solvent.•All the bio-oils contain phenol derivatives, naphthalene derivatives, ketones, alcohols and carboxylic acids/esters.