A desire to survey the effects of fuel composition and additives on the make-up and evolution of the deposits in a working EGR system required development of rapid procedures to both generate and characterise them. Thermogravimetric analysis (TGA) is here shown to be a very useful characterisation technique. It is most readily used on end-of-test samples yet is also capable of studying deposit evolution. Samples from the deposits, or fractions of these samples, after separation using Organic Geochemistry extraction techniques, may be examined. Deposit evolution was shown to be consistent with mechanisms proposed in the literature. Critically, comparison of test to ‘real-world’ deposits showed those generated rapidly in the laboratory to be representative of those generated over longer periods in vehicles on the road.
PrabhakarBBoehmanAL.Effect of engine operating conditions and coolant temperature on the physical and chemical properties of deposits from an automotive exhaust gas recirculation cooler. J Eng Gas Turbine Power2013; 135(2): 22801–22809.
2.
LanceMJStoreyJLewisSSluderCS.Analysis of lacquer deposits and plugging found in field-tested EGR coolers. SAE technical paper, 2014 (2014-01-0629).
3.
WilliamsRCookSWoodallK, et al. Development of an engine test to rate the EGR deposit formation propensity of fuels in light-duty diesel engines. SAE technical paper, 2020 (2020-01-2096).
4.
HugheyCAHendricksonCLRodgersRPMarshallAG.Elemental composition analysis of processed and unprocessed diesel fuel by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. Energy Fuels2001; 15(5): 1186–1193.
5.
BarkerJLangleyGJRichardsP.Insights into deposit formation in high pressure diesel fuel injection equipment. SAE technical papers (2010-01-2243), 2010.
6.
EdneyMKLambJSSpanuM, et al. Spatially Resolved Molecular Compositions of Insoluble Multilayer Deposits Responsible for Increased Pollution from Internal Combustion Engines. ACS Applied Materials & Interfaces2020; 12(45): 51026–51035.
7.
SlavchovRISalamancaMRussoD, et al. The role of NO2 and NO in the mechanism of hydrocarbon degradation leading to carbonaceous deposits in engines. Fuel2020; 267: 117218.
8.
MeredithWRussellCACooperM, et al. Trapping hydropyrolysates on silica and their subsequent thermal desorption to facilitate rapid fingerprinting by GC–MS. Org Geochem2004; 35(1): 73–89.
9.
AscoughPLBirdMIBrockF, et al. Hydropyrolysis as a new tool for radiocarbon pre-treatment and the quantification of black carbon. Quat Geochronol2009; 4(2): 140–147.
10.
HanTBoothASongS, et al. Review and a conceptual model of exhaust gas recirculation (EGR) cooler fouling deposition and removal mechanism. In: Proceedings of the int. conf. on heat exchanger fouling and cleaning2015: 154–165. https://heatexchanger-fouling.com/wp-content/uploads/2021/09/20_Han_F.pdf
11.
StoreyJMESluderCSLanceMJStylesDJSimkoSJ.Exhaust gas recirculation cooler fouling in diesel applications: fundamental studies of deposit properties and microstructure. Heat Transf Eng2013; 34(8-9): 655–664.
12.
TanakaKSakaiTFujinoT, et al. Evaluation of mechanism for EGR deposit Formation based on spatially- and time-resolved scanning-electron-microscope observation. SAE Int J Adv Curr Pract Mob2020; 3: 150–158.
13.
FurukawaNGotoSSunaokaM.On the mechanism of exhaust gas recirculation valve sticking in diesel engines. Int J Engine Res2014; 15(1): 78–86.
14.
SakaidaSKimiyamaSSakaiT, et al. Effect of exhaust gas composition on EGR deposit formation. SAE technical paper 2019. SAE 2019-01-2358.
15.
StratakisG.Thermogravimetric analysis of soot emitted by a modern diesel engine run on catalyst-doped fuel. Combust Flame2003; 132(1-2): 157–169.
16.
GilotPBrillardAStanmoreBR.Geometric effects on mass transfer during thermogravimetric analysis: application to reactivity of diesel soot. Combust Flame1995; 102(4): 471–480.
17.
Rodríguez-FernándezJOlivaFVázquezRA.Characterization of the diesel soot oxidation process through an optimized thermogravimetric method. Energy Fuels2011; 25(5): 2039–2048.
18.
SharmaHNPahalagedaraLJoshiASuibSLMhadeshwarAB.Experimental study of carbon black and diesel engine soot oxidation kinetics using thermogravimetric analysis. Energy Fuels2012; 26(9): 5613–5625.
19.
ColluraSChaouiNAzambreB, et al. Influence of the soluble organic fraction on the thermal behaviour, texture and surface chemistry of diesel exhaust soot. Carbon N Y2005; 43(3): 605–613.
20.
Al-QurashiKZhangYBoehmanAL.Impact of intake CO2 addition and exhaust gas recirculation on NOx emissions and soot reactivity in a common rail diesel engine. Energy Fuels2012; 26(10): 6098–6105.
21.
Al-QurashiKBoehmanAL.Impact of exhaust gas recirculation (EGR) on the oxidative reactivity of diesel engine soot. Combust Flame2008; 155(4): 675–695.
22.
MeredithWAscoughPLBirdMI, et al. Assessment of hydropyrolysis as a method for the quantification of black carbon using standard reference materials. Geochim Cosmochim Acta2012; 97: 131–147.
23.
DalyHMHornAB.Heterogeneous chemistry of toluene, kerosene and diesel soots. Phys Chem Chem Phys2009; 11(7): 1069–1076.
24.
Al-QurashiKLuekingADBoehmanAL.The deconvolution of the thermal, dilution, and chemical effects of exhaust gas recirculation (EGR) on the reactivity of engine and flame soot. Combust Flame2011; 158(9): 1696–1704.
