A thermodynamic approach to assess the sustainability of third-generation sunflower waste cooking oil in DICI engine along with exergoeconomic and enviroeconomic perspective

Abstract

The present study explores incorporating biodiesel made from sunflower waste cooking oil (SWO) into petroleum diesel in varying concentrations. It examines various aspects, including energy, exergy, emissions, exergoeconomic and enviroeconomic factors, and the sustainability index (SI). Experimental findings indicate that higher biodiesel proportions in blends decrease thermal efficiency ( η th ). Notably, D90WB10 (90% diesel and 10% biodiesel) demonstrates superior η th , ranging from 14.98 to 29.37% across loads, closely resembling diesel (D100) values. Blends show significant reductions in carbon monoxide (CO) emissions (by 10.59–48.23%) and in unburned hydrocarbon (UHC) emissions (by 10.34–27.58%) compared to D100 at full engine load. D90WB10 exhibits a maximum exergy efficiency of 27.22% at full load among all blends. Better exergoeconomic efficient fuel is indicated by lower relative cost difference ( C R ). Among all tested fuels, D100 exhibits the lowest C R value of 2.21. D100 exhibits the least annual CO2 emissions cost, whereas pure biodiesel (WB100) shows the highest, ranging from 55.46 to 144.86 USD/year across loads. The SI values for all tested fuels range between 1.281 and 1.393 at full engine load. Results indicate that blends of SWO biodiesel and diesel, particularly D90WB10, offer promising performance akin to diesel without significant modification.