a novel diesel fuel additive to improve fuel properties and to reduce emissions

global air pollution is a serious threat caused by excessive use of fossil fuels for transportation. despite the fact that diesel fuel is a big environmental pollutant as it contains different hydrocarbons, sulphur and crude oil residues, it is yet regarded as a highly critical fuel due to its wide applications. nowadays, biodiesel as a renewable additive is blended with diesel fuel to achieve numerous advantages such as lowering co2, and co emissions as well as higher lubricity. however, a few key drawbacks including higher production cost, deteriorated performance and likelihood to increase nitrogen oxide emissions have also been attributed to the application of diesel-biodiesel blends. expanded polystyrene (eps), known as a polymer for packaging and insulation, is an ideal material for energy recovery as it holds high energy value (1 kg of eps is equivalent to 1.3 liters of liquid fuel). in this study, biodiesel was applied as a solvent of expanded polystyrene (eps) during a special chemical and physical treatment. various percentages of eps in biodiesel blended diesel were tested to evaluate the fuel properties, emissions and performance of ci engine. the results of the variance analysis revealed that the addition of the additive improved diesel fuel properties by increasing the flash point as well as the reduction of density and viscosity. despite a 3.6% reduction in brake power, a significant decrease in brake specific fuel consumption (7.26%) and an increase in brake thermal efficiency (7.83%) were observed at the full load and maximum speed of the engine. additionally, considerable reductions of co, co2, nox and smoke were achieved.