Evaluating the Sustainability and Efficiency of Waste Swine Oil Biodiesel in Compression Ignition Engines

Abstract

Waste swine oil biodiesel has emerged as a promising alternative fuel for compression ignition (CI) engines, offering a pathway to sustainable waste management and renewable energy production. This study provides a comprehensive evaluation of the sustainability and efficiency of biodiesel produced from waste swine oil, with a global scope and a focus on general applications. The fuel’s performance is benchmarked against conventional diesel and other biodiesels (especially those from vegetable oils) regarding environmental impacts, economic feasibility, and engine performance metrics. Key environmental findings include substantially reduced tailpipe emissions of carbon monoxide (CO), unburned hydrocarbons (HC), particulate matter (PM), and smoke opacity with waste swine oil biodiesel, alongside a slight increase in nitrogen oxides (NOx) emissions relative to diesel [1]  Lifecycle assessments indicate greenhouse gas reductions of 50–80% compared to fossil diesel when using waste animal fat feedstocks [2]. Likewise, our economic analysis indicates that using waste swine oil as a feedstock can reduce biodiesel production costs by approximately 30–50% compared to virgin vegetable oils, primarily due to its lower purchase cost and the elimination of waste disposal expenses. Engine testing under internationally accepted protocols (following ASTM and ISO standards) demonstrates that waste swine oil biodiesel can achieve comparable brake thermal efficiency to diesel with blends up to B100, although with a 3 – 10% increase in specific fuel consumption due to its slightly lower energy content [1]. Notably, the high cetane number of swine fat biodiesel (>60) contributes to reliable ignition and may mitigate NOx formation [3]. The study concludes that waste swine oil biodiesel is a viable and sustainable diesel substitute in road transport, yielding environmental benefits and acceptable engine performance. Challenges remain in optimizing cold-flow properties and emissions control, but with proper standards compliance and engine tuning, waste swine oil biodiesel can significantly contribute to cleaner and more sustainable transportation.