A comprehensive analysis of food waste derived liquefaction bio-oil properties for industrial application

Hydrothermal liquefaction is a promising technology to convert wet biomass into bio-oil with high calorific value and without drying process. To evaluate the potential application of liquefaction bio-oil in industry, the present study aims to provide a comprehensive analysis on the properties of liquefaction bio-oil derived from food waste. The food waste is pretreated with K2CO3 at 100 degrees C for 1 h, followed by liquefaction in a semi-pilot reactor at 320 degrees C for 30 min. The higher heating value of produced bio-oil is 34.79 MJ kg(-1), accounting for 53% increase when compared to the feedstock (22.74 MJ kg(-1)). The ignition and burnout temperatures of the bio-oil are lower than other liquefaction bio-oils, reflecting its higher reactivity and combustibility. Meanwhile, the bio-oil has a higher oxidation onset temperature than pyrolysis bio-oils, showing its higher thermal stability. The independent parallel reaction model in association with the particle swarm optimization indicates that the pyrolysis kinetics of the bio-oil can be approximated by four groups. The component analysis further reveals two important groups of fatty acids and amides in the bio-oil, stemming from the conversion of carbohydrate and protein in the food waste. The comprehensive analysis shows that the liquefaction bio-oil from food waste, characterized by higher energy density and better combustibility, is a potential substitute to the fossil fuels.