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Physical characteristics and quantitative elemental composition of PM and residual ash produced from sugarcane leaves (SCL) combustion were investigated using TEM-EDS compared with forest leaves (FRL). SEM-EDS was used to analyze the microstructure and chemical composition of biomass raw leaves and PM. XRD analysis was also performed to investigate the characterization of the crystalline nanostructure, structure of PM, and residual ash compared to the TEM image processing method. The oxidation kinetics of biomass raw materials, PM, and residual ash were investigated by TGA. The morphology of fine and ultrafine agglomerate structure of SCL soot and residual ash are not significantly different from the FRL soot and residual ash. The average diameter sizes of single primary nanoparticles of SCL and FRL soot are approximately 37 nm and 35 nm, while the sizes of residual ash are about 18 nm and 22 nm, respectively. The single primary nanoparticles of soot are mainly composed of curve line crystallites of carbon fringes, while residual ash is composed of straight-line lattice fringes. The average fringe lengths of SCL and FRL soot are about 1.25 nm and 1.04 nm from the outer shell and 0.89 nm and 0.74 nm from the inner core. The interlayer spacing of curve line carbon fringes of SCL and FRL soot is approximately 0.359 nm and 0.362 nm by the TEM image analysis and it was matched with XRD analysis. The biomass PMs are mainly composed of soot, Si, Ca, and K compounds: SiO 2 , CaCO 3 , and KCl., (Copyright © 2020. Published by Elsevier B.V.)

The physical characteristics and elemental composition of particulate matters (PMs) from gasoline direct injection spark ignition (GDI-SI) engines were successfully investigated using transmission electron microscopy - energy dispersive X-ray spectroscopy (TEM-EDS). Thermogravimetric analysis (TGA) was used to analyze the PMs oxidation. The morphology of agglomerated GDI-PMs is not significantly different from the diesel direct injection compression ignition (DDI-CI) engine's PMs. The spherical single primary nanoparticles of the engine's soot composed of curve line carbon crystallites. The average diameter size of the single primary nanoparticles of GDI, DDI, and carbon black are approximately 24 nm, 26 nm, and 31 nm, while the inter-planar spacing is about 0.364 nm, 0.358 nm, and 0.356 nm, respectively. The total fringe lengths of GDI, DDI, and carbon black are approximately 154 nm, 159 nm, and 163 nm measured from the areas of 10 nm × 10 nm inner core regions of primary nanoparticles, and are 180 nm, 195 nm, and 228 nm from the outer shell regions, respectively. The total fringe lengths of inner core are shorter than the outer shell. Besides, the engine's PMs contains both crystalline and amorphous carbon structure using XRD analysis. The GDI-PMs had the least crystalline structure compared to the DDI-PMs and carbon black due to the higher percentage of amorphous fraction. TGA analysis showed that the GDI-PMs oxidation was faster than the DDI-PMs and CB-N330 oxidation because of the primary particle size, the fringe length, and the crystal size which have an impact on oxidation kinetics of particulate matters. • The physicochemical characteristics of PMs from GDI-SI and DDI-CI engines were successfully investigated using TEM, EDS, XRD and TGA. • The average diameter size of the soot single primary nanoparticles of GDI-SI, DDI-CI, and carbon black are approximately 24 nm, 26 nm, and 31 nm, while the inter-planar spacing is about 0.364 nm, 0.358 nm, and 0.356 nm, respectively. • The engine's soot contains both crystalline and amorphous carbon structure. The GDI-SI soot had the least crystalline structure compared to the DDI-CI soot and carbon black due to the higher percentage of amorphous fraction. • The GDI-SI soot oxidation was faster than the DDI-CI soot and carbon black oxidation because of the primary particle size, the fringe length, and the crystal size which have an impact on soot oxidation kinetics. [ABSTRACT FROM AUTHOR]

This study was conducted two distinct experiments, using a light-duty diesel vehicle at various engine speeds and loads as well as the new European driving cycle (NEDC) comparing commercial diesel fuel (B7) and pure biodiesel (B100). The NEDC involves a combination of urban and extra urban driving conditions. It aims to study a diesel vehicle's thermal efficiency as well as its gaseous and particulate matter (PM) emissions. This involves comparing results with and with no diesel oxidative catalyst (DOC) and a partial flow diesel particulate filter (PDPF) system. The surface morphology, micro- and nanostructure of a diesel vehicle's PM were also examined using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) to determine nanostructural and dimensional changes after mounting a DOC-PDPF system. Comparison of B7 and B100 combustion showed that B100 had around 1 % increase in brake thermal efficiency (BTE) at 1500 and 2000 rpm compared to B7 since B100 is a more oxygenated biofuel. At 2500 rpm, similar BTE values were observed. Introduction of a DOC-PDPF system resulted in an approximately 1 % BTE reduction for both fuels. This was due to greater friction losses caused by backpressure from the DOC-PDPF system. Increased exhaust backpressure was progressive, ranging from 1 kPa at idle speed to 6 kPa at high engine speeds for both tested fuels. The DOC-PDPF system respectively minimized PM emissions and particle numbers (PNs) by more than 50 % and 35 % for B7 and 71 % and 31 % for B100. These results are average values under the various phases of NEDC testing. A 30 % decrease in PM and a 44 % reduction in PNs under the overall test cycle were found when B100 was tested compared to B7. The soot primary particle size was reduced from 34.69 to 29.08 nm and the carbon fringe length diminished from 1.25 to 0.949 nm at different pre- and post-DOC-PDPF locations. This was due to partial oxidation on the surfaces of the PDPF metallic microstructure. PM undergoes simultaneous partial oxidation after passing through the DOC-PDPF system, as confirmed by TGA analysis. • The DOC-PDPF system reduces the BTE of the vehicle by approximately 0.67% and 0.52% for B7 and B100, respectively. • PM and PNs under NEDC can be reduced using the retrofitted DOC-PDPF by approximately 50% and 35% for B7 as well as 71% and 38% for B100, respectively. • Although, the mass flow rate of pure biodiesel B100 fuel consumption is higher than that of commercial diesel B7 due to the lower calorific value of the former fuel, the energy consumption and BTE are comparable. • Moreover, PM and PNs can be reduced by approximately 29% and 44%, respectively, by using pure biodiesel B100. • The remarkable average primary particle size, fringe length, interplanar spacing, and carbon atom density of B7 soot before and after the DOC-PDPF system under nanoscale analysis using TEM and XRD are 34.69 and 29.08 nm, 1.25 and 0.949 nm, 0.37 and 0.365 nm, as well as 94 and 87 atoms/nm3, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Particulate matters (PMs) must be removed from the exhaust gas emitted from engines to protect the environment and human health. The problem of particulate emissions from diesel engine can be reduced in many ways, for examples: development of modern engine, fuel additives, diesel particulate filter (DPF) and oxygenated fuel. This paper describes a part of an ongoing research project in PM reduction as emitted from combustion. The main part is study of PM nanostructure by using Transmission Electron Microscopy (TEM). The primary size distributions as well as PM structures were presented by TEM images. The average primary sizes of biodiesel and diesel fuels PMs are approximately 30-40nm and 50-60nm, respectively. The average carbon platelet sizes of both PMs are in the range of 0.1-7.0nm. Moreover, approximately 830 carbon atoms per cubic nanometer of PMs also could be estimated and presented in the present report. The results of this research would be used as basic information for design and develop removing process of PM emitted from engine combustion which using in diesel and biodiesel fuels. [Copyright &y& Elsevier]