Biodiesel production from microalgae oils: A critical review

The global energy demand is expected to rise due to improved living standards, population growth, and urbanization. It underscores the need to explore alternative energy sources. Biodiesel, derived from renewable feedstock, is considered a promising solution to meet future energy needs while addressing concerns about dwindling fossil fuel reserves and environmental issues. Microalgal oils are identified as third-generation feedstock for biofuels production due to their advantages over conventional edible crops and non-edible oils, which face limitations in availability and yield. Microalgal oils are particularly significant because edible oils serve as food sources, and non-edible oil resources have slow growth rate as well as less oil yields. For biodiesel derived from any feedstock, meeting specific physical and chemical properties to comply with biodiesel standards. Therefore, thoroughly examining the conversion process from microalgal oil to biodiesel is necessary. This study explores various aspects of microalgal oils as biodiesel feedstock, including different microalgal species and their oil content, technologies used for biodiesel production from microalgal oils and biomass, and biodiesel standards and characterization across other countries. Techno-economics and Life Cycle Assessment are applied in this study to evaluate the economic viability and environmental impact of microalgae-based processes, addressing challenges such as data availability, uncertainty, and stakeholder engagement. This review highlights a significant opportunity to produce biodiesel from microalgal feedstock, which could contribute to future biodiesel production and provide a sustainable alternative to conventional diesel fuels.