Assessing combustion and emission performance of direct use of SVO in a diesel engine by oxygen enrichment of intake air method

► Direct use of straight vegetable oil in diesel engines can reduce CO2 and save cost. ► Oxygen enrichment in intake air can improve combustion of straight vegetable oil. ► Particulate emissions were reduced by 60% between 21 and 22% of oxygen rate. ► NOx emissions were increased by 50% for every 1% of increase of oxygen rate. ► 22% oxygen rate was recommended to achieve lower than diesel PM emissions.