Sustainable production of biodiesel from non-edible kernel-derived feedstocks: A comprehensive review of production processes, properties, and optimization

With the evolving global demand of energy, depleting resources of fossil fuel reserves and rising concern over CO 2 emissions, biodiesel from non-edible feedstocks as viable options have come up as an alternative for sustainable biodiesel production. This review paper rigorously analyzes contemporary breakthroughs and optimization processes in the extraction, transesterification, and catalytic conversion of oils derived from non-edible seeds, including Jatropha, Pongamia, Neem, and Jojoba. Key findings underscore the efficacy of innovative catalysts, process intensification strategies, and feedstock pretreatment approaches in improving biodiesel yield and quality. Analyses of physiochemical properties demonstrate that biodiesel derived from these non-edible oils can meet international fuel standards, including those established by ASTM, EN, and ISO, when optimal processing conditions are employed. Research on engine performance and emissions indicates significant decreases in greenhouse gas emissions and similar engine efficiency compared to traditional diesel. Techno-economic evaluations demonstrate the increasing competitiveness of non-edible biodiesel, especially when combined with waste recycling and biorefinery principles. Life cycle assessments reinforce the environmental and economic feasibility of these feedstocks for widespread implementation. Despite these advancements, challenges remain in feedstock supply chain logistics, economic catalyst recovery, and process scalability. Future research should prioritize genetic crop improvement, advanced catalyst development, and innovative biorefinery integration to address these challenges. Biodiesel derived from non-edible kernels represents a viable avenue for sustainable energy transition, with significant potential to impact future biofuel policy and industrial practices. • Increasing demand for renewable fuels substitutes fossil fuels • Biodiesel from non-edible seeds avoids food-vs-fuel concerns • Physicochemical properties of non-edible seed biodiesel meet reference standards • Process intensification reduces time and energy use for biodiesel production • Optimization enhances transesterification yield from non-edible seed oils