Determination of a diesel engine operating parameters powered with canola, safflower and waste vegetable oil based biodiesel combination using response surface methodology (RSM)

•RSM based optimization of was applied using desirability approach.•Engine load, biodiesel ratio and injection pressure were the input parameters.•The optimum fuel blends were determined based on optimum diesel engine operating parameters.•The optimum operating parameters showed great promise in the maximizing of BTE and reducing of emissions and EGT.•Proposed RSM model are capable for mapping engine performance-emission paradigms with high accuracy. The primary objective of this study is to determine the optimum engine running parameters regarding the performance and emissions of diesel engine using response surface methodology (RSM). The optimization is utilized to maximize the brake thermal efficiency (BTE) and minimize the exhaust gas temperature (EGT), smoke emission, nitrogen oxide (NOx) emission and carbon dioxides (CO2) emission. The effects of different rates of biodiesel/diesel fuel blends were experimentally investigated on engine performance and exhaust emissions in a four-stroke, single cylinder, air cooled, direct injection diesel engine. A biodiesel combination involving of canola, safflower and waste vegetable oil mixtures made by transesterification was used. RSM was used to evaluate the usability of biodiesel in diesel engine. RSM model was formed by using experimental study data. Corresponding to the results taken from the optimization, best operating parameters of the engine were found to be 1484.85-watt engine load, 215.56 bar injection pressure with 25.79% biodiesel ratio. The optimum responses obtained under these operating conditions were found as 20.54%, 199.88 °C, 0.26%, 558.44 ppm and 4.52% for BTE, EGT, smoke, NOx and CO2, respectively. At the same time, R2 (correlation coefficient) values were found as 99.81%, 99.36%, 98.84%, 98.31% and 99.00% for BTE, EGT, smoke, NOx and CO2, respectively. The results of this study showed that the RSM is a useful technique for estimating and optimizing the performance and emission values of a diesel engine powered with biodiesel.