Synergistic and Antagonistic Interactions during Hydrothermal Liquefaction of Soybean Oil, Soy Protein, Cellulose, Xylose, and Lignin

We conducted hydrothermal liquefaction (HTL) of soybean oil, soy protein, microcrystalline cellulose, xylose, and lignin as individual compounds and binary, ternary, quaternary, and quinary mixtures at 350 °C for 30 min. The 34.5 wt % biocrude yield from HTL of the quinary mixture, which mimics the biochemical composition of swine manure, is much higher than the 21.5 wt % yield calculated from the weighted average yields from HTL of the individual components. HTL of binary mixtures of protein and cellulose, protein and xylose, cellulose and lignin, and xylose and lignin revealed synergistic effects on biocrude yield. On the other hand, HTL of soybean oil and lignin together exhibited an antagonistic effect on biocrude yield. These results from individual compounds and binary mixtures lead to a new model that can predict the yield, higher heating value, and C, H, and N content of biocrude from HTL of ternary, quaternary, and quinary mixtures of the biomolecules used in this study as well as in biocrude from HTL of different manures, algae, and lignocellulosic materials. The synergies identified in this work provide insights into strategies that could be employed in feedstock blending to improve biocrude yields and feedstock energy recovery from HTL of biomass resources.