EFFECTS OF BIODIESEL DISTILLATION PROCESS OF WASTE COOKING OIL BLENDS ON PARTICLE NUMBER AND MASS EMISSIONS

The use of biodiesel has been widely accepted as an effective solution to reduce greenhouse emissions. The high potential of biodiesel in terms of PM emission reduction may represent an additional motivation for its wide diffusion. This potential is related to the oxygenated nature of biodiesel, leading to a different PM-NOx trade-off. Wide diffusion is also under debate as it may represent a solution to the highly disputed issue of the development of alternative biofuels sources not competing with the food chain. In fact, besides second generation biofuels (e.g. from algae), the transesterification of Waste Cooking Oil (WCO) is another option, that however needs additional insight. In fact, in this case, the effects on particle emissions are still not well assessed, as well as the impact of fuel distillation on engine performance and emissions. In this paper an experimental study on particle emissions of a DEUTZ 4L off-road Diesel engine coupled to a DOC-DPF system is proposed. Experimental data have been gathered at the engine test bench of the University of Rome Tor Vergata, by using baseline fossil fuel (B06) and blends (30 % vol) with both distilled and non distilled WCO biodiesel. Data have been acquired with respect to the three most probable engine points referring to the NRTC (Non-Road-Transient-Cycle), upstream and downstream of the AfterTreatment System. Results show that B30 fuels have always lower emission on a mass and number basis, and that distillation process may have an impact especially at high power and torque operation. A slightly better behavior in terms of mass emissions has been observed for the blend with distilled fuel, while a slightly better behavior in terms of particle number has been observed for the blend with non-distilled fuel.