Activated Rice Husk as a Heterogenous Catalyst Over Optimised Waste Cooking Oil Biodiesel Production

Biodiesel is a globally accepted biofuel as an alternative to fossil fuel based petro-diesel. Production of biodiesel through transesterification reaction involves the use of vegetable oils or animal fats and alcohol in the presence of catalysts. In this present work, activated sodium silicate rice husks was used as a heterogenous catalyst for the production of biodiesel using methanol through transesterification process. The process was optimized using central composite design-based Response Surface Methodology to investigate the interaction of five factor five level process parameters for biodiesel production of methanol oil ration of 3:1-15:1, catalyst dosage 1-5 wt%, reaction temperature 45-65 oC, reaction time of 1-5 hrs and agitation rate of 100- 500 rpm for the multi-response parameters of biodiesel yield, viscosity, flashpoint, cetane number and cloud point. Under the optimal reaction conditions of 9:1 methanol to oil ratio, 3 wt% catalyst dosage at 3hrs and reaction temperature of 55 oC with the agitation rate of 300 rpm, the optimal biodiesel yield obtained was 86.3%. The produced biodiesel was confirmed to comply with the ASTM standards and rice husk ash (RHA) developed can serve as a low-cost catalyst support to produce biodiesel in industrial scale.