The world relies heavily on oil for its energy needs, leading to problems like energy dependence and climate change. To find a better solution, researchers are exploring alternative fuels like biodiesel. However, the catalysts used in biodiesel production can affect how well it is made. Some catalysts work well but have drawbacks like saponification and higher costs. So, scientists are working on developing better catalysts. This study used a commercial calcium carbonate-derived catalyst to turn used cooking oil into biodiesel at 60°C. The commercial calcium carbonate was calcined at temperatures ranging from 800° to 1000°C. The synthesized catalysts were taken through SEM, XRF, EDS, and XRD analysis. According to the XRF and XRD data, the significant component CaO was identified at a calcination temperature of 1000°C. We tested different ratios of methanol/oil and found that the calcined CaO catalyst achieved the highest yields. The yields obtained were 93.7%, 91.4%, 89.8%, and 95.48% for molar ratios of 15:1, 12:1, 6:1, and commercial CaO catalyst (15:1), respectively, under constant conditions of 1.5% catalyst, 1-hour time taken by the reaction, and temperature of the reaction 60 degree Celsius. The results showed that calcined CaO could be used again as a catalyst, significantly impacting the amount of biodiesel produced and its quality. The heterogeneous (alkaline) catalyst used in this study to support biodiesel production from WCO is derived from the commercial Ca(CO)3 as a good substitution for diesel fuel in engines that use compression ignition engines without any modification.
Kumar et al. (2025) studied this question.