Sensitivity of pollutants abatement in oxidation catalysts to the use of alternative fuels

• Published in: Fuel (Guildford) Vol. 297; p. 120686
• Main Authors: Piqueras, Pedro, Ruiz, María José, Herreros, José Martín, Tsolakis, Athanasios
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.08.2021; Elsevier BV
• Subjects: Air pollution; Alkanes; Alternative fuel; Alternative fuels; Carbon content; Carbon dioxide; Carbon dioxide emissions; Catalysts; Combustion; Conversion efficiency; Diesel fuels; Efficiency; Emissions; Exhaust emissions; Exhaust gases; Exhaust pipes; Exhaust systems; Fuel combustion; Fuel technology; Fuels; Gas temperature; Incentives; Internal combustion engine; Oxidation; Oxidation catalyst; Pollutants; Pollution abatement; Pollution control; Rapeseed; Sensitivity; Speciation; Alternative fuel; Internal combustion engine; Conversion efficiency; Oxidation catalyst; Emissions
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2021.120686

[Display omitted] •Oxidation catalyst response to diesel, RME, GTL and diesel-propane combustion.•Experimental and modelled conversion efficiency sensitivity to real exhaust gas.•HC surrogate distinguishing light-heavy and low–high reactivity HCs for each fuel.•GTL and RME showed the earliest light-off, improving diesel combustions.•Light-off temperature reduction via low raw CO/HC emission with low light alkanes. The aim to reduce well to wheel CO2 emissions incentives the utilisation of alternative fuels (low to zero carbon content and/or low well to tank CO2 emissions) as well as the enhancement of engine efficiency. In parallel, the reduction of engine tailpipe CO2 emissions brings new challenges such as the decrease of the exhaust gas temperature. This trend penalises the ability of the exhaust aftertreatment system to eliminate pollutant emissions. In addition, the combustion of alternative fuels and new combustion modes induce changes in the nature and concentration of the exhaust species, which is known to affect the pollutants abatement mechanisms. This investigation provides new understanding on the sensitivity of pollutants abatement in oxidation catalysts to the use of alternative fuels. The studied fuels are conventional diesel, alternative fuels (rapeseed methyl ester and gas to liquid) as well as propane using a dual-fuel combustion strategy. The research combines experimental conversion efficiency from genuine exhaust gases with modelling work useful to explain the reasons for the change in light-off temperature as a function of the fuel. In addition to the CO and NO impact, HC surrogates are proposed distinguishing species of different reactivity for each fuel based on the experimental HC speciation. The results highlight the role of the engine-out emissions on the pollutants conversion efficiency. Their fashion with different fuels contributes to evidence the interest for low engine-out emissions along with low light alkanes content in total HC, as promoted by alternative fuels, to reduce the oxidation light-off temperature.