The assessment of the engine performance and emissions of a diesel engine fueled by biodiesel produced using different types of catalyst

In the present study, the biodiesel was produced from waste cooking oil using two types of catalyst (homogeneous (Hom. Cat.) and heterogeneous (Het. Cat.)). The produced biodiesels were characterized to obtain their physicochemical properties and fatty acid methyl esters (FAMEs) profile. Then, they were blended with net diesel fuel at volume ratios of 10:90 (B10), 25:75 (B25), and 40:60 (B40) for using in the injection system of a 6-cylinder diesel engine operated at a constant speed of 1500 rpm to compare changes in the combustion (engine performance) and exhaust emissions of engine. The results showed that the catalyst type had an insignificant effect on the physical properties of produced biodiesel such as density, viscosity, flash, cloud and pour point, higher heating value, etc., whereas the compositions of FAME contents slightly changed. On the other hand, the total production duration was lower for the biodiesel produced by heterogeneous catalyst (21 h against 26 h), while the higher amount of energy consumed (2165 against 1650 Wh/L). Blending net diesel fuel with biodiesels slightly improved the engine performance and combustion behavior. The exhaust gas emissions were also showed an appropriate decrease in carbon monoxide (5-40%), unreacted hydrocarbon (40-75%), and smoke opacity (8-25%) emissions using biodiesel produced heterogeneous catalyst. The statistical analysis of results showed that blending the net diesel fuel with 34 vol% of biodiesel and operating the diesel engine at 40% of fuel load can lead to an appropriate engine performance along with a considerably reduction in the exhaust gas emissions.