Pilot scale production of biodiesel from Madhuca indica and comparative techno-economic analysis.

The increasing global energy demand and the depletion of conventional fossil fuel supplies, coupled with greenhouse gas emissions from excessive fossil fuel use, open the door for consideration of renewable energy sources. Among these, biodiesel has arisen as a sustainable and feasible alternative, providing environmental and economic advantages by reducing dependence on finite fossil fuel resources. This study focuses on biodiesel production from Madhuca indica seed oil using three catalysts: HCl, KOH, and dolomite. The optimum reaction parameters were methanol:oil molar ratio 20:1, catalyst weight percentage 5% and reaction temperature 60 °C. The reaction duration for each catalyst was 20 h for acid-catalyzed (HCl) process, 2 h for alkali-catalyzed (KOH) process, and 10 h for dolomite-based reaction. The biodiesel yields for acid, alkali, and dolomite catalysts are 94%, 96%, and 93%, respectively. According to the techno-economic study conducted with Aspen Plus, the payback periods for transesterification based on acid, alkali, and dolomite would be 3.66, 5.42, and 2.96 years, respectively. These results demonstrate the economic viability of dolomite as a green catalyst with competitive biodiesel yields and the shortest payback period.