Compression ignition (CI) engines are highly efficient and are therefore often the first choice in application of heavy machinery and heavy duty vehicles. However, diesel engines are known to emit soot and oxides of nitrogen (NOx) emission. Replacing fossil diesel fuel with renewable fuel is one possibility to reduce emissions and to meet legislative requirements. In this experimental work, an oxygenated fuel blend was investigated for soot morphology and results were compared with fossil diesel fuel without oxygenates. Soot was sampled at a medium load case in a light duty single cylinder research engine and samples were analyzed with a transmission electron microscope (TEM). Furthermore, combustion characteristics and particle number (PN) emissions were compared for both fuels. The primary particle diameter (Dp), fringe length (L), fringe separation (S), and tortuosity (T) were also discussed in terms of soot nanostructure. The particle size distribution (PSD) showed a reduction in PN over for the renewable fuel blend compared to diesel. This PN reduction was from 107 to 106 (one order magnitude lower). The maximum Dp from morphological analysis of diesel fuel and renewable fuel was 69.93 and 66.36 nm respectively. Size range of fringe separation (S) was nearly identical for both fuels. Diesel fuel has marginally higher fringe separation, fringe length, and tortuosity. This investigation is valuable for fuel industries which are continuously upgrading renewable and oxygenated fuels to meet stringent emission norms.
SunZ-YLiG-X. On reliability and flexibility of sustainable energy application route for vehicles in China. Renew Sustain Energy Rev2015; 51: 830–846.
2.
RajashekaraK. Present status and future trends in electric vehicle propulsion technologies. IEEE J Emerg Sel Top Power Electron2013; 1: 3–10.
3.
SharmaNAgarwalAK. Effect of the fuel injection pressure on particulate emissions from a gasohol (E15 and M15)-fueled gasoline direct injection engine. Energy Fuels2017; 31: 4155–4164.
4.
GrenLMalmborgVBFalkJ, et al. Effects of renewable fuel and exhaust aftertreatment on primary and secondary emissions from a modern heavy-duty diesel engine. J Aerosol Sci2021; 156: 105781.
5.
HuaYLiuFWuHLeeC-FLiY. Effects of alcohol addition to traditional fuels on soot formation: a review. Int J Eng Res2021; 22: 1395–1420.
6.
ArmasOYehliuKBoehmanAL. Effect of alternative fuels on exhaust emissions during diesel engine operation with matched combustion phasing. Fuel2010; 89: 438–456.
7.
KittlesonDKraftM. Particle formation and models in internal combustion engines. Technical Report 142. Cambridge Centre for Computational Chemical Engineering University of Cambridge (England) preprint, 2014.
8.
NovakovicMShamunSMalmborgVB, et al. Regulated emissions and detailed particle characterisation for diesel and RME biodiesel fuel combustion with varying EGR in a heavy-duty engine. SAE technical paper 2019-01-2291, 2019.
9.
YehliuKBoehmanALArmasO. Emissions from different alternative diesel fuels operating with single and split fuel injection. Fuel2010; 89: 423–437.
10.
PreussJMunchKDenbrattI. Effect of injection strategy and EGR on particle emissions from a CI engine fueled with an oxygenated fuel blend and HVO. SAE technical paper 2021-01-0560, 2021.
11.
WeiJZengYPanM, et al. Morphology analysis of soot particles from a modern diesel engine fueled with different types of oxygenated fuels. Fuel2020; 267: 117248.
12.
VermaPPickeringEJafariM, et al. Influence of fuel-oxygen content on morphology and nanostructure of soot particles. Combust Flame2019; 205: 206–219.
13.
OkyayGHéripréEReissTHaghi-AshtianiPAugerTEnguehardF. Soot aggregate complex morphology: 3D geometry reconstruction by SEM tomography applied on soot issued from propane combustion. J Aerosol Sci2016; 93: 63–79.
14.
BeatriceCCostagliolaMAGuidoCNapolitanoPPratiMV. How much regeneration events influence particle emissions of DPF-equipped vehicles? SAE technical paper 2017-24-0144, 2017.
15.
Rodríguez-FernándezJLapuertaMSánchez-ValdepeñasJ. Regeneration of diesel particulate filters: effect of renewable fuels. Renew Energy2017; 104: 30–39.
16.
LapuertaMOlivaFAgudeloJRBoehmanAL. Effect of fuel on the soot nanostructure and consequences on loading and regeneration of diesel particulate filters. Combust Flame2012; 159: 844–853.
17.
WangDWangYWangXGuoFBaiY. Impact of n-hexanol blending on morphology, nanostructure, graphitization, and oxidation characteristics of diesel particles. Energy Fuels2020; 34: 12940–12950.
18.
WangXWangYBaiY. Oxidation behaviors and nanostructure of particulate matter produced from a diesel engine fueled with n-pentanol and 2-ethylhexyl nitrate additives. Fuel2021; 288: 119844.
19.
TseHLeungCCheungC. Performances, emissions and soot properties from a diesel-biodiesel ethanol blend fuelled engine. Adv Automob Eng. 2016; S1: 005.
20.
ZhangZ-HBalasubramanianR. Effect of oxygenated fuels on physicochemical and toxicological characteristics of diesel particulate emissions. Environ Sci Technol2014; 48: 14805–14813.
21.
ZöllnerCHaralampousOBrüggemannD. Effect of engine operating conditions on soot layer permeability and density in diesel particulate filters. Int J Engine Res2021; 22: 50–63.
22.
NithyanandanKLinYDonahueRMengXZhangJChia-fonFL. Characterization of soot from diesel-CNG dual-fuel combustion in a CI engine. Fuel2016; 184: 145–152.
23.
JungYHwangJBaeC. Assessment of particulate matter in exhaust gas for biodiesel and diesel under conventional and low temperature combustion in a compression ignition engine. Fuel2016; 165: 413–424.
24.
VermaPJafariMRahmanSA, et al. The impact of chemical composition of oxygenated fuels on morphology and nanostructure of soot particles. Fuel. 2020; 259: 116167.
25.
WangQSunWGuoL, et al. Particle number size distribution from direct-injection premixed combustion engine fueled with gasoline/diesel blends. Proc IMechE, Part D: J Automobile Engineering2020; 234: 258–269.
26.
HwangJJungYBaeC. Spray and combustion of waste cooking oil biodiesel in a compression-ignition engine. Int J Engine Res2015; 16: 664–679.
27.
BrodayDMRosenzweigR. Deposition of fractal-like soot aggregates in the human respiratory tract. J Aerosol Sci2011; 42: 372–386.
28.
PreußJMunchKDenbrattI. Performance and emissions of long-chain alcohols as drop-in fuels for heavy duty compression ignition engines. Fuel2018; 216: 890–897.
29.
DastanpourRRogakSN. Observations of a correlation between primary particle and aggregate size for soot particles. Aerosol Science and Technology2014; 48(10): 1043–1049. DOI: 10.1080/02786826.2014.955565
30.
Vander WalRLBrygVMHaysMD. Fingerprinting soot (towards source identification): physical structure and chemical composition. J Aerosol Sci2010; 41: 108–117.
31.
BurtscherH. Physical characterization of particulate emissions from diesel engines: a review. J Aerosol Sci2005; 36: 896–932.
32.
FayadMAHerrerosJMMartosFJTsolakisA. Role of alternative fuels on particulate matter (PM) characteristics and influence of the diesel oxidation catalyst. Environ Sci Technol2015; 49: 11967–11973.
33.
FayadMTsolakisAFernández-RodríguezDHerrerosJMMartosFLapuertaM. Manipulating modern diesel engine particulate emission characteristics through butanol fuel blending and fuel injection strategies for efficient diesel oxidation catalysts. Appl Energy2017; 190: 490–500.
34.
KittelsonDB. Engines and nanoparticles: a review. J Aerosol Sci1998; 29: 575–588.
35.
MaricqMM. Chemical characterization of particulate emissions from diesel engines: a review. J Aerosol Sci2007; 38: 1079–1118.
36.
EastwoodP. Particulate emissions from vehicles. Chichester: John Wiley & Sons, 2008.
37.
LipkeaWHJohnsonJHVukCT. The physical and chemical character of diesel particulate emissions—measurement techniques and fundamental considerations. SAE Trans1978; 87: 405–461.
38.
SuDSJentoftREMüllerJ-O, et al. Microstructure and oxidation behaviour of Euro IV diesel engine soot: a comparative study with synthetic model soot substances. Catal Today2004; 90: 127–132.
39.
La RoccaABonatestaFFayMCampanellaF. Characterisation of soot in oil from a gasoline direct injection engine using transmission electron microscopy. Tribol Int2015; 86: 77–84.
40.
YanFSongJZhuangYQiuLLiZMengZ. Three-dimension soft X-ray tomographic reconstruction of particulates emitted from a diesel engine. J Aerosol Sci2021; 156: 105784.
41.
Van GulijkCMarijnissenJMakkeeMMoulijnJSchmidt-OttA. Measuring diesel soot with a scanning mobility particle sizer and an electrical low-pressure impactor: performance assessment with a model for fractal-like agglomerates. J Aerosol Sci2004; 35: 633–655.
42.
ShortMWalkerP. Measurement of interlayer spacings and crystal sizes in turbostratic carbons. Carbon1963; 1: 3–9.
43.
ApicellaBAlfèMCiajoloAGargiuloVPréPRouzaudJ. Soot structure by high resolution electron transmission microscopy (HR-TEM) image analysis: current potentialities and perspectives. In: XXXVI meeting of the Italian section of the combustion institute, 2013, pp.13–15. Italy Combustion Institute Procida (NA).
44.
ApicellaBPréPAlfèM, et al. Soot nanostructure evolution in premixed flames by high resolution electron transmission microscopy (HRTEM). Proc Combust Inst2015; 35: 1895–902.
45.
Al-QurashiKBoehmanAL. Impact of exhaust gas recirculation (EGR) on the oxidative reactivity of diesel engine soot. Combust Flame2008; 155: 675–695.
46.
Al-QurashiKO. The impact of carbon dioxide and exhaust gas recirculation on the oxidative reactivity of soot from ethylene flames and diesel engines. Thesis, The Pennsylvania State University, 2007.
47.
LapuertaMMartosFJHerrerosJM. Effect of engine operating conditions on the size of primary particles composing diesel soot agglomerates. J Aerosol Sci2007; 38: 455–466.
48.
FayadMAAl-SalihiHADhahadHAMohammedFMAl-OgidiBR. Effect of post-injection and alternative fuels on combustion, emissions and soot nanoparticles characteristics in a common-rail direct injection diesel engine. Energy Sources A Recovery Util Environ Eff. Epub ahead of print 24 August 2021. DOI: 10.1080/15567036.2021.1970292.
49.
SakaiMIgumaHKondoKAizawaT. Nanostructure analysis of primary soot particles directly sampled in diesel spray flame via HRTEM. SAE technical paper 2012-01-1722, 2012.
50.
QianWHuangHPanMHuangRWeiJLiuJ. Analysis of morphology, nanostructure, and oxidation reaction of soot particulates from CI engines with dimethoxymethane–diesel blends under different loads and speeds. Fuel2020; 278: 118263.
