Hydrothermal Liquefaction of Food Waste and Remediation of Aqueous Byproducts

Thermochemical processing via hydrothermal liquefaction (HTL) is capable of processing a broad range of feedstocks, has a favorable net energy ratio, and produces an energy-dense liquid biooil product. However, there is an obstacle with current HTL processes that has hampered the adoption of this technology—the HTL process produces a considerable amount of aqueous organic byproducts. This problem can be addressed by minimizing the formation of aqueous-phase organics or by post-processing the aqueous phase to remove the dissolved organics. Mainstream Engineering is proposing a synergistic combination of these two approaches for improving the environmental and economical aspects of food waste HTL. By addressing the aqueous waste hurdle, this project will catalyze the adoption of HTL to convert high-moisture waste biomass to renewable fuel. Prof. Timko of Worchester Polytechnic Institute will develop new hydrothermally stable catalysts to improve the yield of the oil phase and minimize aqueous byproducts. Mainstream will develop a hydrothermal gasification system to create reducing gas for the liquefaction process while also removing dissolved organics from the aqueous phase. This will result in clean water that can be recycled or safely disposed. The proposed hybrid HTL/HTG process is focused on the conversion of waste biomass material to a renewable fuel that would displace petroleum-derived fuels, thereby addressing both a waste disposal challenge and a renewable fuel challenge. The public will benefit from renewable energy and reduced environmental impacts from liquefaction processes. Key Words – Catalyst, biofuels, thermochemical Summary for Members of Congress: The yield and quality of hydrothermal liquefaction oil must be improved for commercial adoption. We are developing new processes to improve the oil yield and reduce the aqueous byproducts during hydrothermal liquefaction of wet wastes.