Comparison of EGR strategies of between waste cooking oil biodiesel and diesel fuel in a diesel engine

Increasing energy demand around the world and the damages caused during meeting theseincreasing energy demands are now growned to a very important sizes. For the meetings ofthese demands, to offer a new alternative energy sources and reducing the exhaust gasemissions during the usage of these sources are the main ideas of this experimental study.Waste frying oil biodiesel was chosen for this research due to being a cheap raw material andby recycling of these waste frying oils it is possible to minimize the environmental damagesthat will be caused. EGR application was chosed as NOx emission reduction method due tothe possibility of application on a standart diessel engine without much modifications. Viacross-analyse of the fuels by power, fuel consumption, emissions and soot to determine theoptimum EGR ratio for the biodiesel fuel is the main purpose of this study.During the analyses, %0, %5, %10, %15, %20 EGR ratios were applied on a diesel enginewith full gas pedal position at 6 different engine speed, and torque, power, cooling watertemperature, volumetric values of NOx, CO, HC, ?, CO2, O2 emissions in exhaust gas, kabsorption values, fuel flow parameters were measured at each of these conditions.On the result of the study, while using the waste frying oil biodiesel with %20 EGR ratio,NOx emissions were reduced by %65,7, while using a standart diesel fuel emissions reducedby %54,4. It was understood that with the same EGR ratio it is possible to reduce more NOxby using waste frying oil biodiesel as a fuel and because of the other emissions getting worse%10 EGR ratio was set as an upper limit.At this limit EGR ratio it was concluded that, without optimizing the diessel engine for theusage of waste frying oil biodiesel as a fuel, by applying %10 EGR ratio, it is possible toreduce NOx emissions as an amount of average %27,08, and amount of maximum %36,1without increasing the other emissions too high and without reducing performance of theengine too low.Keywords: EGR, waste frying oil, biodiesel, emissions, soot, NOx