Hydrothermal liquefaction of cornstalk: 7-lump distribution and characterization of products

Hydrothermal liquefaction of cornstalk at 180-300 °C at ratios of water to cornstalk of 6-14 was conducted, and the reaction products were lumped into gas, water-soluble organics (ethanol-insoluble and ethanol-soluble organics), heavy oil, volatile organic compounds, and acid-soluble and acid-insoluble solid residues. Low temperature, high ratio of water to cornstalk, and short reaction time favored the formation of bio-oil (ethanol-insoluble organics, ethanol-soluble organics, and heavy oil) but inhibited the formation of acid-insoluble solid residue. Increasing temperature and reaction time increased the yields of gas and volatile organic compounds, whereas decreased the yield of acid-soluble solid residue. Bio-oil yields increased first and then decreased at a ratio of water to cornstalk higher than 10. Overall, the studied reaction parameters influenced the conversion among the lumps and product properties. This study suggests that lump analysis provides a promising approach to describe the product distributions in biomass liquefaction.