Characterization of Fuel from the Pyrolysis of Post-Consumption Food Waste in an Auger Reactor

Food waste produced in the household, public restaurants, and hospitality sectors is causing serious concerns due to its negative environmental impact if disposed of by landfill. This paper presents an experimental investigation of food waste pyrolysis in a continuous auger reactor. Analysis of the food waste samples revealed highly desirable characteristics (e.g., volatile=75.2%, lipid=15.4%, and HHV=20.1 MJ kg-1). The overall pyrolysis yield was 37.2% bio-oil, 14.2% aqueous phase, 27.6% biochar, and 21.0% non-condensable gas. The bio-oil showed attractive fuel characteristics (HHV=28.2 MJ kg-1, water content=4.6%, and pH=6), however, the viscosity was high (136 cSt). The most abundant compounds in the bio-oil were major fatty acids commonly found in dairy fats, meat, and hydrogenated vegetable oils. The aqueous phase was equally produced by drying of the feedstock and the gas dehydration reactions. The non-condensable gas was of moderate heating value (11.6 MJ kg-1) and consisted of high CO2 (60%). Analysis of the reactor performance indicates that the biomass conversion efficiency is 95.76%, however, the overall thermal efficiency of the system was low due to heat losses. The outcome of this study is hoped to pave the way for the development of bioenergy technology in regions where conventional biomass resources are limited.