Analysis of physicochemical properties of liquefaction bio-oil from food waste

Abstract

Abstract Recently, several research has been studied on the hydrothermal liquefaction (HTL) of food wastes to obtain bio-oils. However, most of studies do not fully discuss the physicochemical properties of liquefaction bio-oil from food wastes. In this study, the food waste was pretreated with K2CO3 at 100 °C for 1h, then raising to 300 °C for 1h in a semi-pilot reactor to produce the liquefaction bio-oil. To understand the characterization of the liquefaction bio-oil food waste and compare to liquefaction bio-oils from other feedstocks, the bio-oil was analyzed with thermogravimetric analysis (TGA) under nitrogen and air atmosphere was conducted to evaluate the thermal properties. Furthermore, GC/MS was conducted to discover the chemical composition of the bio-oil and compared the results with different kinds of liquefaction bio-oil. The obtained results revealed that the liquefaction bio-oil contains higher heating value (HHV) of 34.79 MJ/kg and the increment was about 53% compared to the original food waste source (22.74 MJ/kg). The maximum boiling point distribution of liquefaction bio-oil appears around 200 °C to 350 °C. Likewise, the ignition temperature and burnout temperature of the liquefaction bio-oil found lower when compare to other liquefaction bio-oils indicating that the bio-oil from the food is much easier to be ignited and burned. Two obviously groups, fatty acids and amides, can be easily distinguished from the GC/MS analysis of the liquefaction bio-oil components which believed mainly be converted by the carbohydrate and protein from the food waste.