Catalyst Reusability and Kinetic Modeling of Biodiesel Produced from Rubber Seed Oil

Determination of stability and reusability of catalyst in biodiesel production will help in producing commercially, a cost-effective final product. Reusability of calcined eggshells, a solid waste material as heterogeneous catalyst, in the production of biodiesel from rubber seed oil (RSO) has been studied in this work. After transesterification process at the optimum operating conditions of 12:1 methanol: oil (molar ratio), 4 wt% catalyst, 3 hours of reaction time, reusability of catalyst for subsequent transesterification runs is studied at the same operating conditions. 99.6% conversion of RSO to biodiesel was observed initially before catalyst regeneration and it dropped to 86.4% after the 7th regeneration run. Kinetic modeling of the biodiesel production process was also made to establish the order of the reaction and estimate the reaction rate constant. The data fits well with pseudo first order reaction kinetics with a rate constant,k, of value 0.0128 min(-1).