Introduction to Renewable Energy Resources and Sustainable Feedstocks for Biodiesel

Researchers worldwide are investigating alternative energy sources to meet the increasing energy demand due to urbanization and population growth. Renewable energy sources (RESs) like hydro, wind, solar, geothermal, and biomass offer sustainable and environmentally friendly solutions to replace fossil fuels. However, challenges related to cost, regulations, technology, and climate impacts (such as floods, droughts, and windstorms) make large-scale energy production difficult to commercialize. Biomass energy, which produces electricity from organic resources like waste or plant remnants, currently provides 70% of RESs 14% share of global energy demand. By-products like biofuel are projected to meet 14% of global transportation energy by 2050, up from 4% in 2020, highlighting the growing importance of biofuels in the energy mix. Biofuels offer numerous advantages over fossil fuels, such as including powering internal combustion engines without modification, reducing greenhouse gas emissions and pollutants like Nitrogen Oxides (NOx), Carbon Monoxide (CO), and Sulphur Oxides (SOx), being biodegradable and environmentally friendly, boosting farmers’ incomes, improving social welfare, and reducing reliance on imported oil. Feedstock typically makes up 70–95% of total biodiesel production costs. The transition from Generation 1 to Generation 4 feedstocks has brought both advantages and limitations, prompting researchers to focus on more economically viable options for biodiesel production. Challenges associated with Generation 3 and 4 feedstocks for biodiesel production include inefficient oil extraction technologies and high production costs. The rising cost of food-based products and the food vs. fuel debate have discouraged the use of Generation 1 feedstocks. Generation 2 feedstock, including non-food crops and non-edible seeds with over 30% oil content, are well-suited for cost-effective biodiesel production. Utilizing region-specific, low-cost feedstocks with higher oil content can further decrease production costs, making second-generation feedstocks a sustainable, technical, and economical option for biodiesel production.