Microwave-assisted pyrolysis of oil palm shell biomass using an overhead stirrer

► First time microwave pyrolysis of biomass was done using stirrer. ► Temperature of the process was controlled by means of biomass to carbon ratio. ► Optimum bio-oil yield was obtained at 1:0.5 biomass to carbon ratio and at 500 °C. ► High phenolic bio-oil was obtained in this study. ► Process time and energy could be saved via MW pyrolysis with stirrer.