Cashew nut shell liquid as alternate fuel for CI engine—optimization approach for performance improvement

Increased consumption of fossil fuels and growing concerns regarding environmental pollution triggered by burning fossil fuels have directed investigators to search for renewable fuels as an alternative. Among different opportunities explored to replace diesel as sole fuel, biodiesel produced from vegetable oils is ascertained as one of the strong contestants for lowering the exhaust emissions. In this work, experiments are carried out to evaluate the performance behavior of a four-stroke single-cylinder compression ignition diesel engine running on cashew nut shell liquid (CNSL) mixed with oxygenated additive diethyl ether (DEE) and diesel. The prepared blends are characterized for their kinematic viscosity, density, flash point, and calorific value. These blends’ effectiveness is optimized for brake thermal efficiency, brake power and specific fuel consumption considering fuel blend, % of additive addition, and injection pressure. Split-plot design in response surface methodology (RSM) is used for performing the experiments, and desirability analysis is used for optimization. The investigation outcomes show that brake thermal efficiency increases for B10 biodiesel blend and for lower injection pressure and for 15% addition of diethyl ether as additive. Similarly, specific fuel consumption is higher for blended fuel and for 10% addition of additive addition and 210 injection pressure. For all the outputs, the most influential parameter is injection pressure and its interaction effect with the type of fuel used. Finally, the optimized condition is obtained for both diesel and CNSL-DEE-diesel blend.