Resumen
The increased amount of food waste every year has become a concerned to the community. Disposal of food waste to landfills has attributed to greenhouse effect and odors. Utilizing the food waste to value-added products is preferable method to refrain food waste from going to landfills. Higher moisture content, lower carbon content and low calorific value are the properties of food waste which can be improved through the torrefaction process. Torrefaction can be defined as a thermal degradation of biomass in an inert condition (oxygen-free environment) under atmospheric pressure at the temperature between 200-300°C. This thermochemical process commonly used to produce solid char. The aim of this study is to investigate the improvement of torrefied food waste properties by integrating microwave heating pre-treatment prior to torrefaction. The experiment is conducted by collecting, drying, grinding and sieving the food waste. The dried food waste was pre-treated using microwave heating with the power of 240W for 5 minutes before being torrefied at 280, 300 and 320°C for 30, 45 and 60 minutes in a tubular reactor. In this study, the highest high heating value (HHV) of torrefied food waste was 24.21 MJ/kg with torrefaction conditions of 320°C and 45 minutes. Microwave heating was increased the HHV of torrefied food waste by 15.21% by creating porous structure in the food waste sample, thus provide bigger surface area of food waste.