Integrating microwave heating pre-treatment to improve torrefaction of food waste

Abstract

Abstract The food waste (FW) disposal is one of the main issues of concern, as it affects environmental and sustainable development in Malaysia. FW should be utilized to produce more valuable products such as energy. However, FW is characterized by its low high heating value (HHV) and high moisture content and which lower the energy efficiency during energy production process. To overcome this problem, torrefaction assisted by microwave heating pretreatment is used to upgrade FW properties to produce solid biofuel which is called as biochar. The objective of this study is to investigate the feasibility of microwave (MW) heating power at 240 W for 5 min to enhance the quality of torrefied FW. The pre-treated FW is then torrefied at three different temperatures (280, 300 and 320 °C) for 30, 45 and 60 min. The torrefied FW was then characterized in terms of ultimate and proximate analysis, HHV, mass and energy yield as well as its functional groups. The optimum condition of torrefaction in this study was 320°C and 30 min with HHV of 23.82 MJ/kg, 95.54% of energy yield and 84.28% of mass yield. This suggests that torrefied FW with MW heating pre-treatment has the potential to be used as an energy source.