Comparative analysis of waste vegetable oil versus transesterified waste vegetable oil in diesel blend as alternative fuels for compression ignition engine

The study presents a comparative evaluation of waste vegetable oil (WVO) versus transesterified waste vegetable oil (WVBD) in diesel blends for engine performance, emission characteristics, economics, and sustainability as an alternative fuel for a compression ignition engine. The impact of blend fraction and blend type on the fuel properties were determined. Increased WVO or WVBD fraction in the blend resulted in increased density, viscosity, flash points, and reduced calorific value. WVBD blends showed lower fuel consumption and better thermal efficiency performance, whereas other engine performance parameters were comparable to WVO blends. Emission characteristics of all the blends were comparable under all load conditions. Economic analysis showed that WVO blends are more cost-effective than WVBD blends. The sustainability analysis using the life cycle assessment methodology revealed lower environmental impacts were associated with WVO blends as compared to WVBD blends. The study pegs WVO blend as a more sustainable and economical diesel fuel alternative against the predominant and more explored WVBD blend.