Emission characteristics of particulate matter and particle-bound metals from a diesel engine generator fueled with waste cooking oil-based biodiesel blended with n-butanol and acetone

This study examines the emission properties of particulate matter and particle-bound metals from a diesel engine generator fueled by traditional fossil diesel (D100) with the addition of n-butanol (B), hydrous n-butanol (B′), acetone (A), hydrous acetone (A′), isopropyl alcohol (I) or waste cooking oil-based biodiesel (W). The fuel blends were B30W20D50 (abbr. B30), B′30W20D50 (abbr. B′30), A3I1W20D76 (abbr. A3), A′3I1W20D76 (abbr.A′3), B30A3I1W20D46 (abbr. B30A3) and B′30A′3I1W20D46 (abbr. B′30A′3) tested at loads of 1.5 kW and 3.0 kW for the diesel engine generator. Experimental results indicate that adding B30, A3 or B30A3 reduces the PM mass concentration in the exhaust at both engine loads compared to using only W20. Additionally, the PM emission concentrations are lower when using B′30, A′3 and B′30A′3 than when using B30, A3 and B30A3, respectively; in other words, replacing pure n-butanol/acetone with hydrated n-butanol/acetone in the blends further reduces the PM emission concentrations. However, B30 or B30A3 is more effective than A3 in reducing the PM emissions, irrespective of the water content in the fuel blends. Conversely, using B30, B′30, A3, A′3, B30A3 or B′30A′3 instead of W20 reduces the metal content in the PM emissions at both engine loads. The major metal components in PM are Na, Mg, Al, K, Ca, Fe and Zn, accounting for about 97 wt.% of 21 overall metals. The remaining analyzed metals were dominated by Mn, Ni, Cu, Mo and Ba. Accordingly, adding biodiesel from waste cooking oil and hydrous acetone/n-butanol to diesel fuel for diesel engine generators reduces the levels of PM and particle-bound metals. The waste hydrous acetone/n-butanol can be used for recycling purposes during this process.