A Comparative Study of Biofuels and Fischer–Tropsch Diesel Blends on the Engine Combustion Performance for Reducing Exhaust Gaseous and Particulate Emissions

Abstract

The worldwide consumption of fossil hydrocarbons in the road transport sector in 2020 corresponded to roughly half of the overall consumption. However, biofuels have been discreetly contributing to mitigate gaseous emissions and participating in sustainable development, and thus leading to the extending of the commercial utilization of internal combustion engines. In this scenario, the present work aims at exploring the effects of alternative fuels containing a blend of 15% ethanol and 35% biodiesel with a 50% fossil diesel (E15D50B35) or 50% Fischer–Tropsch (F-T) diesel (E15FTD50B35) on the engine combustion, exhaust emissions (CO, HC, and NOx), particulate emissions characteristics as well as the performance of an aftertreatment system of a common rail diesel engine. It was found that one of the blends (E15FTD50B35) showed more than 30% reduction in PM concentration number, more than 25% reduction in mean particle size, and more than 85% reduction in total PM mass with respect to conventional diesel fuel. Additionally, it was found that the E15FTD50B35 blend reduces gaseous emissions of total hydrocarbons (THC) by more than 25% and NO by 3.8%. The oxidation catalyst was effective in carbonaceous emissions reduction, despite the catalyst light-off being slightly delayed in comparison to diesel fuel blends.

Fischer-Tropsch Diesel and Biofuels Exergy and Energy Analysis for Low Emissions Vehicles

“…This could be a reflection of incomplete combustion occurring during the combustion process. In-cylinder pressure and detailed analysis of E15B35FTD50 and E15B35D50 fuel blends combustion process was reported in a previous work [50]. The lower combustion temperature due to the higher heat of vaporization of the ethanol is among the factors that might have influenced the higher CO results.…”

“…A recent study has reported that blends of F-T diesel and biodiesel resulted in slightly higher CO emission and the researchers attributed this to the insufficient evaporation and short mixing time of the blend during premixed combustion [13]. The application of a diesel oxidation catalyst could effectively reduce these CO levels from the combustion of these alternative fuels [50]. A slight decrease in CO2 emissions was observed when the engine was fueled with E15B35D50, while CO2 emissions for E15B35FTD50 are slightly higher than in the case of diesel fuel.…”

Numerical modelling and non-dimensional analysis of a diesel oxidation catalyst with focus on NO2 reduction

“…However, it is reported that, at low exhaust gas temperatures, engine-out NO 2 /NOx is higher than the DOC-out NO 2 /NOx. [5][6][7][8]11 . This is due to the reduction of NO 2 to NO by THC and CO. [5][6][7][8]11 Fayad et al 5 reported that the NO 2 /NOx downstream of the DOC started increasing when the DOC inlet temperature was greater than 220°C.…”

“…[5][6][7][8]11 . This is due to the reduction of NO 2 to NO by THC and CO. [5][6][7][8]11 Fayad et al 5 reported that the NO 2 /NOx downstream of the DOC started increasing when the DOC inlet temperature was greater than 220°C. NO 2 reduction in the DOC at low exhaust gas temperatures, for diesel, alternative fuels and dual fuel combustion mode, was also reported by Lefort et al.…”

“…In the washcoat, interdependent diffusion and heterogenous chemical reactions occur. It is worth mentioning that, generally, in the numerical models, both for actual exhaust and flow reactor artificial exhaust conditions, only the external mass transfer limitations of the exhaust gas species from open channel to the flow-channel interface was considered [6][7][8][9][10][11][12][13][14][15][16][17] and the internal diffusion phenomenon was ignored. In some other numerical models, the internal mass transfer phenomenon for CO and THC oxidation reactions were only considered.…”