Biodiesel Production from Oil Waste and Animal Fat

The growing global population and rising energy demands have driven the search for sustainable alternatives to fossil fuels. Biodiesel, a renewable and eco-friendly fuel, offers lower emissions and compatibility with diesel engines. Biodiesel production from waste oil and animal fat offers a sustainable approach to waste management and renewable energy generation. While vegetable oils have traditionally been used, concerns over food security and land competition have shifted focus toward nonedible and waste-based sources. Discarded animal fats (DAFs), derived from slaughterhouse and meat processing by-products, present a cost-effective, energy-dense alternative with high cetane numbers and oxidation stability, improving combustion efficiency. Biodiesel production primarily occurs via transesterification, converting triglycerides into fatty acid methyl esters (FAME), alongside thermochemical and biochemical methods, like pyrolysis, gasification, and anaerobic digestion. Biodiesel applications include transportation, industrial machinery, and energy production, significantly reducing greenhouse gas emissions and fossil fuel dependence. Despite its benefits, biodiesel production from waste feedstocks faces challenges such as feedstock variability, high free fatty acid content, and cold flow limitations. However, advancements in processing techniques and catalysts are enhancing efficiency and yield. Environmentally, repurposing waste oils and animal fats minimizes waste accumulation, mitigates pollution, and promotes a circular bioeconomy. This chapter provides a comprehensive overview of biodiesel production from waste oils and animal fats, emphasizing their properties, production methods, applications, and challenges, ultimately highlighting their potential as a viable solution for sustainable energy.