Effect of renewable fuels and intake O2 concentration on diesel engine emission characteristics and reactive oxygen species (ROS) formation
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Renewable diesel fuels have the potential to reduce net CO2 emissions, and simultaneously decrease particulate matter (PM) emissions. This study characterized engine-out PM emissions and PM-induced reactive oxygen species (ROS) formation potential. Emissions from a modern heavy-duty diesel engine without external aftertreatment devices, and fueled with petroleum diesel, hydrotreated vegetable oil (HVO) or rapeseed methyl ester (RME) biodiesel were studied. Exhaust gas recirculation (EGR) allowed us to probe the effect of air intake O2 concentration, and thereby combustion temperature, on emissions and ROS formation potential. An increasing level of EGR (decreasing O2 concentration) resulted in a general increase of equivalent black carbon (eBC) emissions and decrease of NOx emissions. At a medium level of EGR (13% intake O2), eBC emissions were reduced for HVO and RME by 30 and 54% respectively compared to petroleum diesel. In general, substantially lower emissions of polycyclic aromatic hydrocarbons (PAHs), including nitro and oxy-PAHs, were observed for RME compared to both HVO and diesel. At low-temperature combustion (LTC, O2 < 10%), CO and hydrocarbon gas emissions increased and an increased fraction of refractory organic carbon and PAHs were found in the particle phase. These altered soot properties have implications for the design of aftertreatment systems and diesel PM measurements with optical techniques. The ROS formation potential per mass of particles increased with increasing engine O2 concentration intake. We hypothesize that this is because soot surface properties evolve with the combustion temperature and become more active as the soot matures into refractory BC, and secondly as the soot surface becomes altered by surface oxidation. At 13% intake O2, the ROS-producing ability was high and of similar magnitude per mass for all fuels. When normalizing by energy output, the lowered emissions for the renewable fuels led to a reduced ROS formation potential.
| Originalsprog | Engelsk |
|---|---|
| Artikelnummer | 641 |
| Tidsskrift | ATMOSPHERE |
| Vol/bind | 11 |
| Udgave nummer | 6 |
| DOI | |
| Status | Udgivet - 2020 |
| Eksternt udgivet | Ja |
Bibliografisk note
Funding Information:
Author Contributions: Overall idea and design of experiments: J.P., U.V., L.G., M.T., V.B.M. Design of aerosol characterization experiments and data interpretation: L.G., J.P., V.B.M., A.C.E. Aerosol data collection and analysis: L.G., V.B.M. TEM analysis and particle extraction: L.G. Selection/design of engine operation and set points: M.T., P.C.S. Engine operation and collection of engine data: P.C.S., S.S. Analysis of engine data: S.S. Design, Atmosphere 2020, 11, × FOR PEER REVIEW 21 of 34 data collection and analysis of ROS measurements N.R.J. Interpretation of ROS data based on physicochemical properties: L.G., V.B.M., N.R.J., J.P., K.M.B., U.V. Development of method for PAH derivatives: B.S., A.M.K. Design, data collection and analysis of ROS measurements N.R.J. Interpretation of ROS data based on Collection of PAH data and analysis: Y.J.E., A.M.K. Design of metal analysis, data collection and data analysis: physicochemical properties: L.G., V.B.M., N.R.J., J.P., K.M.B., U.V. Development of method for PAH derivatives: K.L. L.G. drafted the original manuscript with major input from V.B.M. and J.P. All co-authors contributed to B.S., A.M.K.. Collection of PAH data and analysis: Y.J.E., A.M.K. Design of metal analysis, data collection and data analysis:K.L.L.G. drafted the original manuscript with major input from V.B.M. and J.P. All co-authors contributed to writing and/or critical revisions. All co-authors accepted the final manuscript before submission. (2018-04200) and AFA Insurance (160323). Funding: This research was financed by the Swedish Research Councils FORMAS (2016-00697), Vetenskapsrådet Acknowledgments: Flemming Cassee, Dan Leseman, Aneta Wierzbicka and Christina Isaxon are acknowledged (2018-04200) and AFA Insurance (160323). for contributing to selecting the particle extraction and weighing methods and valuable discussions. Karin Lovén is ackAnockwnloedwgleeddgfmorentt:hsFelemOCm/iEnCg Caansasleyes, iDs.aLne Kseamtriann, LAoneeastc Whnieerrzbthikcaan aknsd AChgriliestnitnaf oIsraoxpnr aorvei daicnkgnwothleedgAegdi lent 8900 ICfoPr- cQoQntQribinusttirgnutmo seenlet.ctingthe particle extraction and weighing methods and valuable discussions. Karin Lovén is acknowledged for the OC/EC analysis. Katrin Loeschner thanks Agilent for providing the Agilent 8900 ICP- Conflicts of Interest: The authors declare no conflict of interest. QQQ instrument.
Funding Information:
This research was financed by the Swedish Research Councils FORMAS (2016-00697), Vetenskapsr?det (2018-04200) and AFA Insurance (160323). Flemming Cassee, Dan Leseman, Aneta Wierzbicka and Christina Isaxon are acknowledged for contributing to selecting the particle extraction and weighing methods and valuable discussions. Karin Lov?n is acknowledged for the OC/EC analysis. Katrin Loeschner thanks Agilent for providing the Agilent 8900 ICP-QQQ instrument.
Publisher Copyright:
© 2020 by the authors.
ID: 319469741