Optimization and Kinetics Studies of Biodiesel Synthesis from Jatropha Curcas Oil Under the Application of Eco-Friendly Microwave Heating Technique: An Environmentally Benign and Sustainable Bio-Waste Management Approach

Abstract

This study attempts to synthesize biodiesel as a green liquid fuel from Jatropha curcas oil utilizing waste eggshell (WES) as an effective and excellent sustainable source of the heterogeneous catalyst under the application of environmental benign microwave heating technique. After preparing the CaO-based catalyst, diverse characterization techniques such as XRD, EDS, SEM, FITR, and BET were employed for measurements. Under different optimized conditions, a considerable high biodiesel yield of 91.7% was attained while employing the following reaction conditions; methanol to oil ratio (MTOR) of 9:1, 5 wt% catalyst loading, 165 min reaction time with a microwave power of 800 W, and a 65°C reaction temperature. The developed catalyst had significantly retained its reusability up to the 5th cycle of reuse. The catalysed transesterification process's activation energy (Ea) of 9.58 kJ/mol demonstrated that the reaction is chemically controlled. The physico-chemical properties of the Jatropha curcas oil (JCO) biodiesel were studied in accordance with international standards such as ASTM D6751 and EN14214, among others. Therefore, the waste eggshell has been utilized as a renewable base heterogeneous catalyst for novel biodiesel synthesis from JCO, which can be applied in diesel engines to lessen air pollution, specifically pollutant emissions from diesel vehicles. The results of this study are not for academic purposes only. They can also serve as models for industrial biodiesel production by exploiting bio-waste as catalysts and non-edible oils as feedstocks in microwave heating systems as environmentally friendly chemistry systems. In addition, our study uses non-consumable oil feedstock and bio-waste materials in an economical way to produce biofuel while contributing to environmental sustainability and sustainable bio-waste management. This approach extends to the existing state-of-the-art research. Therefore, the proposed value increase method contributes to integrating the circular economy concept through an efficient biorefinery model.