Comparative study of hot air drying and microwave drying for dewatered sludge

The seafood processing industries produce large amounts of wastewater sludge in Thailand. Most is dewatered and then sent directly to landfills without utilization nor resource recovery. dried sludge, having a gross calorific value (GCV) higher than 21.9 MJ/kg, might be worthwhile utilize as refuse-derived fuel. However, the critical obstacle its high moisture content 87.4 wt%. This study investigated two techniques for drying sludge: hot air microwave drying. effects temperatures (100 °C–170 °C) power levels (100–800 W) were studied their specific energy consumption (SEC), product characteristics, kinetics. results showed that times decreased with increase power. Under tested conditions this study, application microwaves reduced time by at least 37.5% compared using air. reduction led consumption. Approximately 72.5–80.3 wt% was volatile matter (VM). As component devolatilized, GCV decreased. had 20.8–21.4 while 19.4–21.8 MJ/kg. from analysis suggested technique could an alternative method when one requires shorter conventional technique.