Rotary bio-drying is the process to reduce moisture from Municipal Solid Waste (MSW) by using the heat from aerobic bio-degradation. This study aimed to investigate the effects of air recirculation on moisture removal efficiency in combined hydrolytic–aerobic rotary bio-drying process for drying high initial moisture content MSW, allowing satisfied moisture content to convert a waste into biofuel energy. The results from the laboratory scale experiments were indicated that increasing the exhaust air recirculation ratio, more moisture increased in the end product. However, while the air recirculation ratio was equals or greater than 50 %, the moisture content of the end product was not significant different.