Application of waste cocoa pod husks as a heterogeneous catalyst in homogenizer-intensified biodiesel production at room temperature

Waste agricultural biomass available abundantly with limited utilization. The cocoa pod husks comprise of inorganic compounds particularly potassium oxide which can be used as a catalyst for biodiesel production. The waste cocoa pod husks were successfully transformed into a heterogeneous catalyst under calcination at 750 °C for 4 hours. The calcined cocoa pod (CCP) was characterized using thermogravimetric analysis (TGA), x-ray diffraction (XRD), x-ray fluorescence (XRF), and scanning electron microscope – energy dispersive x-ray (SEM EDX) while the catalytic activity was evaluated using parameters of reaction time, catalyst weight, molar ratio of palm oil to methanol and rotational speed of a homogenizer. The biodiesel conversion of 96.2 ± 0.3 % was achieved under reaction conditions of a reaction time of 20 minutes, and a catalyst weight of 7 wt% (based on oil weight), molar ratio of 1:15 and rotational speed of 6000 rpm. The homogenizer-intensified biodiesel production using waste CCP as a heterogeneous catalyst could save reaction time by 87–65 % compared with other studies.