Particulate Matter Oxidation Research Articles

Dielectric barrier discharge plasma catalysis for diesel particulate matter oxidation: Optimization and synergistic differences in transition metal catalysts

Dielectric barrier discharge plasma catalysis for diesel particulate matter oxidation: Optimization and synergistic differences in transition metal catalysts

Manganese-substituted strontium ferrite catalyst on honeycomb structured cordierite support for oxidation of diesel particulate matter

Perovskite-based catalysts have been explored as low-cost substitutes for platinum (Pt)- based catalysts for diesel particulate matter (DPM) oxidation. In this work, manganese (Mn)-substituted strontium ferrite (SrFeMnO3-δ) (SFM) as a catalyst was coated on the honeycomb structure of cordierite support and tested for its catalytic performance for DPM oxidation using a real-world engine. The characteristic diffraction peaks due to the presence of the perovskite structure of SFM were observed for the cordierite-supported SFM. Mn was substituted in the lattice of un-substituted strontium ferrite and no other impurities were formed upon the Mn-substitution. Highly agglomerated SFM particles were formed solely due to the perovskite phase formation temperature (900 °C). The SFM catalyst enhanced catalytic Printex-V oxidation performance compared to its oxidation without the catalyst, where Printex V was used as the model DPM. The SFM catalyst showed high CO2 selectivity upon the oxidation of DPM. These results infer that the SFM catalyst possesses promise as an alternative to commercially available DOC catalysts based on PGM for DPM oxidation. SFM-coated cordierite support performed much better in terms of particle number, mass and surface area than commercial diesel oxidation catalyst (DOC) or without DOC at no engine load. The performance is substantially higher even at moderate engine loads of up to 40% and comparable at very high engine loads of 100%. Detailed investigations on a real engine exhaust and measurement of crucial parameters like particle number, mass and surface area suggest convincing and relatively rare evidence for its potential as a catalyst for diesel exhaust emission control catalyst.

Effect of nano-graphene lubricating oil on particulate matter of a diesel engine

Nano-graphene lubricating oil with appropriate concentration shows excellent performance in reducing friction and wear under different working conditions of diesel engines, and has been widely concerned. Lubricating oil has a significant impact on particulate matter (PM) emissions. At present, there are few studies on the impact of nano-graphene lubricating oil on the physicochemical properties of PM. In order to comprehensively evaluate the impact of nano-graphene lubricating oil on diesel engines, this paper mainly focused on the effects of lubricating oil nano-graphene additives on the particle size distribution and physicochemical properties of PM. The results show that, compared with pure lubricating oil, the total number of nuclear PM and accumulated PM of nano-graphene lubricating oil is significantly increased. The fractal dimension of PM of nano-graphene lubricating oil increases and its structure becomes more compact. The average fringe separation distance of basic carbon particles decreases, the average fringe length increases. The degree of ordering and graphitization of basic carbon particles are higher. The fringe tortuosity of basic carbon particles decreases, and the fluctuation of carbon layer structure of basic carbon particles decreases. Aliphatic substances in PM are basically unchanged, aromatic components and oxygen functional groups increase. The initial PM oxidation temperature and burnout temperature increase, the maximum oxidation rate temperature and combustion characteristic index decrease, and the activation energy increases, making it more difficult to oxidize. This was mainly caused by the higher graphitization degree of PM of nano-graphene lubricating oil and the increased content of aromatic substances.

Quantitative Analysis of the Impacts of Ash from Lubricating Oil on the Nanostructure of Diesel Particulate Matter

Microscopic analyses of the effects of ash on particulate matter oxidation are rather scarce. In this study, three different lubricating oils with varying ash contents were used to investigate their effects on the nanostructure of diesel particulate matter. The nanostructure and nanostructure parameters, including fringe length, fringe separation distance, and fringe tortuosity, were studied using high-resolution transmission electron microscopy. The results show that all samples obtained from blending with different lubricant oil present typical core–shell structures. The inner cores remain relatively unchanged, whereas the thickness of the outer shells increases with the increasing ash content in the lubricant oil under the same working conditions. The fringe length increases and the fringe separation distance decreases with the rising ash content in the lubricant oil operating in the same working conditions. The fringe tortuosity decreases when the ash content in the lubricant oil increases from 0.92% to 1.21%, but shows little change when the ash content in the lubricant oil increases from 1.21% to 1.92%. Based on the effects of ash on the nanostructure parameters, it can be inferred that the oxidation activity of particles decreases with increasing ash content in the lubricant oil.

Effect of Reaction Temperature on the Degradation and Oxidation Behavior of Particulate Matter by Nonthermal Plasma

Diesel particulate matter (PM), especially small particle size PM, has been highlighted as a hazard to the environment and people. Nonthermal plasma (NTP) has shown significant low temperature (<200°C) advantage for PM degradation. In this paper, we conducted online PM degradation experiments at different reaction temperatures with a self-built NTP injection system to investigate the changes of PM particle size distribution, micro-nano structure, graphitization degree and oxidation characteristics of elemental carbon (EC) before and after NTP action. The maximum removal rate increased from 90 ℃ (25% load) to 130 ℃ (100% load) with the increase of the load, and there was a “trade-off” effect between PM decomposition and NTP pyrolysis. The average microcrystalline length, microcrystalline spacing and microcrystalline curvature of PM particles showed an overall trend of decreasing and then increasing with the increase of temperature. When the reaction temperature was 130 ℃ (75% load), the microcrystalline structure parameters of the carbon particles showed extreme values, and the newly exposed “shells” were rearranged under the action of van der Waals force, and the graphitization of PM increased and the overall oxidation activity was weakened. The reaction between NTP and carbon particles goes through the process of surface oxidation, simultaneous oxidation of surface and interior, and the fragmentation of carbon particles to complete disappearance.

Effect of Temperature-controlled conditions on the decomposition of particulate matter deposited in the diesel particulate filter channel by treatment with Non-thermal plasma

The regeneration effect of the diesel particulate filter (DPF) under steady-state and dynamically controlled reaction temperature (≤200C) was compared using a home-designed non-thermal plasma (NTP) injection system. The particle sediments and corresponding DPF channel wall were sampled as a whole, in order to analyze the evolution of the micromorphology, lattice structure and oxidation characteristics of particulate matter (PM) at the DPF regeneration interface more accurately. The results showed that after NTP treatment, the degree of aggregation of PM, the transition to a chain structure, and the diameter of primary carbon particles all decreased. The microcrystalline length La distribution converged in a short crystalline (≤1.00 nm) interval, and the proportion of small microcrystalline layer spacing Ds (≤0.45 nm) increased. With the deepening of oxidation, the characteristic temperature parameters of elemental carbon (EC), the light off temperature Ts, burnout temperature Te and maximum temperature Tmax tended to shift to a lower temperature, and lattice defects, number of active sites, and PM oxidation activity increased. Dynamic control of the reaction temperature in the range of 127 ∼ 142 ℃ can promote the oxidative decomposition of PM, which is conducive to improving the regeneration efficiency of the DPF. The process of NTP degradation of PM consists of three stages, namely the outer shell, inner shell and core oxidation, and carbon microcrystals are exhausted in the iterative process of irregular and regular structure, which is essentially a process of continuously removing carbon atoms in the form of COx.

Exploration on the emissions and catalytic reactors interactions of a non-road diesel engine through experiment and system level simulation

In this paper, the emission characteristics and catalytic reactors interactions of a non-road diesel engine are investigated under non-road transient cycle (NRTC) by experiment and system level simulation. The results showed that the overall emission conversion efficiency of hydrocarbon (HC), carbon monoxide (CO), nitrogen oxides (NOX) and particulate matter (PM) is 96.68 %, 91.45 %, 97.67 % and 93.33 %, respectively under NRTC in experiment. In addition, the interactions of each catalytic converter for emissions under NRTC have been obtained through simulation. When the diesel oxidation catalytic (DOC) temperature is higher than 600 K, CO and HC emissions basically achieve almost 0 through DOC purification. Furthermore, DOC can convert nitric oxide (NO) into nitrogen dioxide (NO2) which provides strong oxidation for the passive regeneration of diesel particulate filter (DPF). The NO reaction rate is closely related to DOC temperature. And the average conversion efficiency from NO to NO2 in DOC is 40.36 %. Moreover, the DOC inlet pressure has almost no effect on the conversion of HC and CO. When the temperature of selective catalytic reduction (SCR) is higher than 500 K, the averages NOx conversion efficiency of SCR is up to 98.74 %. And ammonia purification catalyst (ASC) can further reduce NO emissions while absorbing slip ammonia. When the inlet temperature of DPF is more than 520 K, it has almost no effect on the oxidation of PM. The PM conversion efficiency of aftertreatment system (ATS) is mainly affected by the PM collection efficiency of DPF. The average PM collection efficiency of DPF is 53.32 %, while the PM conversion efficiency of ATS is 91.54 % by simulation. Although DPF will convert PM to CO, these CO cannot be completely converted into carbon dioxide (CO2). So the CO conversion efficiency of ATS is lower than that of DOC.

Activity for Diesel Particulate Matter Oxidation of Silver Supported on Al2O3, TiO2, ZnO, and CeO2: The Effect of Oxygen Concentration

Particulate matter (PM) is a problem for human health the major producer of PM are diesel engines. The diesel particulate filters (DPFs) are used for the limitation of the PM. The DPF operation consists of two sequential functions: PM filtering and regeneration. One of the main contributing factors affecting the regeneration of DPF is the oxygen concentration in the exhaust gas. This study investigates the impact of different oxygen concentrations (99.99%, 10%, and 5%) on (PM) oxidation when using silver catalysts supported on CeO2, ZnO, TiO2, and Al2O3. The synthesized catalysts were characterized using XRD, SEM, SEMEDX, and H2-TPR techniques, and the PM oxidation activity was evaluated using TGA. The results demonstrated that different oxygen concentrations had little effect on light VOCs oxidation compared to no catalyst or the same catalyst. However, heavy VOCs and soot combustion, which require a higher oxygen concentration, significantly reduce combustion performance when the oxygen concentration decreases.

Utilization of waste-derived biodiesel in a compression ignition engine

Air pollution has been broadly concerned as a global issue in all regions. Particulate matter (PM) emission mainly originated from the combustion of diesel engine in transport sector is progressively solved for mitigation. The purpose of this study is to preliminary utilize biodiesel from different feedstock as an alternative fuel in a diesel engine. Waste-derived biodiesel was prepared from waste cooking oil (WCOME) and waste chicken oil (CKOME) by transesterification process. Palm oil-derived biodiesel (POME) was also prepared and used as a reference. Fatty acid profiles of the prepared biodiesel were characterized by a gas chromatography–mass​ spectrometer. The biodiesel was analyzed for fuel characteristics under ASTM standards. The engine test was carried out on a single-cylinder diesel engine at the engine speed of 1500 rpm with full engine load. The engine combustion and performance as well as exhaust emissions of waste-derived biodiesel were compared with palm oil biodiesel and diesel fuel. The PM oxidation temperature was indicated by a simultaneous thermal analyzer. The obtained results disclosed that main fatty acids of POME and CKOME were palmitic acid (C16:0) and oleic acid (C18:1) while that of WCOME were oleic acid (C18:1) and linoleic acid (C18:2). It was evident that kinematic viscosity, specific gravity and flash point of biodiesels were above the limit prescribed by the diesel fuel standard. Lubricity of all biodiesels was bounded by the limitation of diesel specification. CKOME possessed excellent lubricating properties among biodiesels tested. The combustion of WCOME lowered CO, HC and smoke emissions compared to POME while the combustion of CKOME produced similar CO, HC and smoke emissions with more benefit in NOx emissions compared to POME. PM emissions caused by the combustion of biodiesel derived from WCOME and CKOME tended to oxidize easier than those of diesel fuel because the lower temperature for maximum soot oxidation by thermo-gravimetric analysis was obtained. Consequently, biodiesel derived from waste cooking oil and waste chicken oil can be considered as potential candidates to replace the biodiesel derived from palm oil as main feedstock of biodiesel production in Thailand without any penalty in exhaust emissions.

Effect of temperature control conditions on DPF regeneration by nonthermal plasma.

A regeneration test of a diesel particulate filter (DPF) was conducted under different temperature conditions with air as the gas source and a nonthermal plasma (NTP) injection system. We investigated the influence of the ambient temperature on the DPF regeneration performance and the oxidative decomposition amount of particulate matter (PM) and analyzed the changes in the PM oxidation characteristics by thermogravimetric analysis (TGA). The higher the temperature, the lower the decomposition amount of PM was under constant temperature conditions. The decomposition amount of PM was the highest at 80°C (3.74g), and the PM at interface P2 was not completely removed. The volume concentrations of the DPF regeneration products (CO and CO2) were higher under variable than constant temperature conditions. In addition, the peak temperature of interface P1 occurred 10-30min earlier, complete regeneration occurred at interface P2, and DPF regeneration occurred faster than under temperature conditions. The initial temperature of the control device was 110°C, and the maximum mass of PM oxidation decomposition was 4.26g after regeneration for 15min cooling to 80°C. The main form of elemental carbon (EC) transformed into the low ignition point component and the oxidation activity was improved after NTP injection.

Evidence of long term biogeochemical interactions in carbonate weathering: The role of planktonic microorganisms and riverine bivalves in a large fluviokarst system

The infiltration of organic-rich surface waters towards groundwaters, is known to play a significant role in carbonate weathering and in contributing to the atmospheric continental carbon sink. This paper investigated biogeochemical interactions in karst critical zones, with strong surface water /groundwater interactions, and in particular the role of planktonic microorganisms and riverine bivalves through the analysis of particulate organic matter (OM) oxidation on carbonate weathering. In the large Val d'Orléans fluviokarst aquifer (France), a 20-year monthly dataset of Nitrates, Dissolved Oxygen (DO), dissolved inorganic and organic Carbon (DIC and DOC) fluxes was gathered. The surface water-groundwater comparison of geochemical trends showed that planktonic microorganisms had drastically decreased in surface waters, related to the proliferation of Corbicula bivalves spreading and a decrease in nutrients. This decrease in planktonic microorganisms was followed by a DO increase and an DIC decrease at the karst resurgence. The degradation of planktonic microorganisms consumes DO and produces NO3, dissolved inorganic carbon (DIC) and a proton that in turn, dissolves calcite and produces DIC. Without the input from planktonic microorganisms, the fluviokarst has lost 29 % of this nitrification and 12 % of the carbonate dissolution capacities. Thus, the oxidation of particulate organic matter of planktonic microorganisms, which is part of heterotrophic respiration, appears to be a significant source of the inorganic carbon flux in riverine ecosystems. This shows how weathering can remain active under waters saturated versus calcite and suggests that the oxidation of organic matter can be a more appropriate mechanism than autotrophic respiration to explain the relationship between global warming and DIC flux change in rivers. Through the consumption of plankton, the animal life in rivers thus influences the inorganic carbon in groundwaters, creating a negative feedback in the carbon cycle.

Catalytic effect of diesel PM derived ash on PM oxidation activity

With diesel particulate filter and gasoline particulate filter periodical regeneration, more and more ash accumulates on the substrate of filter. Ash gathering on the substrate of filter leads to more contact area of particulate matter and ash. Specific ingredients in ash present catalytic effects on particulate matter oxidation. However, the catalytic effect of diesel particulate matter derived ash on its oxidation, mimicking the ash accumulating on filter substrate, is still uncovered using experiments. In this paper, diesel particulate matter derived ash was put at the bottom of particulate matter samples to imitating the soot loading on filter substrate which was covered by much ash. The results indicated that the burnout temperature of diesel particulate matter was in the range of 500–600 °C; while it was 600–700 °C for Printex (U). The burnout temperature drop by ash was lower than 10 °C for diesel particulate matter. The maximum mass loss rate corresponded to approximately 450 °C for diesel particulate matter, and it was changed minorly by ash and ramp rates. However, the temperature corresponding to the maximum mass loss rate was seriously retarded by high ramp rates for Printex (U), and ash presented limited effect on it. The maximum activation energy drop by ash was approximately 60 kJ/mol at the initial stage of oxidation for diesel particulate matter. The activation energy was approximately 132.19, 114.78, 157.26, and 144.67 kJ/mol for diesel PM, diesel PM-ash, Printex (U), and Printex (U)-ash, respectively. Organic compounds dropped gradually in the oxidation process of diesel particulate matter. Nanostructure evolutions of diesel particulate matter and Printex (U) were similar, experiencing smaller sizes and void cores at the end of oxidation process.

Evolution of particulate matter deposited in the DPF channel during low-temperature regeneration by non-thermal plasma

In this paper, diesel particulate filters (DPFs) were regenerated at a low temperature (100 °C) using a non-thermal plasma (NTP) injection system. The physical and chemical characteristics of the particles deposited at different regeneration stages, such as their macromorphology, microstructure, oxidation activity, surface functional groups, and soluble organic fraction, were analyzed. The results showed that when NTP flowed through the DPF, the deposited particles were oxidized, decomposed, and then removed from the channels. The soot cake dispersed into blocks from an initially dense morphology and gradually shrank until it disappeared. The residual ash lost the initial spherical structure of the carbonaceous particulate matter (PM). The weak part of the flocculant structure of PM broke first during the oxidation of NTP active substances and decomposed into a chain structure. As DPF regeneration proceeded, O atoms were continuously bonded into the PM to form oxidation intermediate products that contained C-O, C=O, and other functional groups, which improved the PM oxidation activity. Changes in the physical and chemical properties of PM at the DPF regeneration interface were more significant than those at the most downstream sampling position. The high carbon atom fraction in the soluble organic fraction (SOF) decreased, and the DPF regeneration by NTP involved the continuous removal of carbon atoms.

Experimental investigation of particle number reduction in turbocharged GDI engines

Introduction (problem statement and relevance). Now it is difficult to imagine the automotive industry without constant improvement of the power plant. This is due to the constant tightening of environmental standards, so in environmental standards Euro 6 there is a limit of the countable concentration of particulate matters. To meet the Euro 6 environmental standard, vehicle manufacturers use catalytic converters, and gasoline particle filters (GPF). These methods of reducing the emissions of the exhaust gas are quite common, but they also have a limitation on the service life. The use of only catalytic converters and GPF may not be sufficient to meet the Euro 7 standards in the future. So, there is a need to reduce emissions with exhaust gases by improving the combustion process.The purpose of work is to investigate the combustion process of a turbocharged gasoline direct injection engine to reduce particulate matter by increasing the injection pressure and optimizing the injection timing. Methodology and research methods. The studies are of an experimental nature, the reliability of the data is confirmed by the use of modern measuring equipment and post processing of the measured data. Scientific novelty and results. The fuel injection parameters, which have a significant influence on the particulate matter formation and oxidation are defined.Practical significance. The recommendations to reduce particulate matter formation and to meet the requirements of the future Euro standards are given.

The effect of nonthermal plasma on the oxidation and removal of particulate matter under different diesel engine loads

AbstractNonthermal plasma (NTP) can oxidize and decompose particulate matter (PM) of diesel engines at low temperatures (≤200°C), exhibiting good application prospects. PM samples were collected under different diesel engine loads and were oxidized using an NTP method. The volatile fraction (VF) mass fraction of the PM samples decreases under low engine loads (&lt;70%) and increases under high engine loads (≥70%) after the NTP treatment. NTP can remove aldehyde groups in PM and weaken the volatilization of PM. A higher temperature is needed for the VF to reach its maximum volatilization rate after the NTP treatment. The relative content of the small molecules is significantly higher after the NTP treatment.

Effects of La incorporation in catalytic activity of Ag/La-CeO2 catalysts for soot oxidation

Owing to strengthened regulations toward vehicle emissions, the use of diesel particulate filter technology to reduce particulate matter emissions has attracted significant attention. To achieve low temperature oxidation of particulate matter, numerous studies on Ag/CeO2 catalysts for soot oxidation have been reported. Herein, Ag/La-CeO2 catalysts with different La contents are synthesized and compared to analyze the effect of La. Hydrogen temperature programmed reduction analysis confirms that the reducibility increases with an increase in the La content in La-CeO2. X-ray photoelectron spectroscopy and Raman analysis confirm an increase of oxygen vacancies with La doping. Accordingly, the soot oxidation performances estimated by temperature programmed oxidation experiments increase with La doping. However, the catalytic activity of Ag/La-CeO2 exhibits a volcano trend. When an appropriate amount of La is incorporated in Ag/CeO2, peroxide generation and reducibility improve, thereby enhancing the soot oxidation performance. Conversely, the catalytic activities gradually decrease with excess La-doping. Scanning transmission electron microscopy analysis and density functional theory calculations confirm that excess amounts of La induce the sintering of Ag particles, which lead to the degradation of peroxide generation and reducibility of the catalysts. Consequently, an optimal amount of La incorporation on Ag/La-CeO2 results in the best soot oxidation performance.

Impact of early injection on physicochemical characteristics of diesel soot particles

The early injection is widely employed in advanced combustion technologies, which could substantially impact the engine particulate matter (PM) emissions. The primary objective of the present study was to investigate the effect of early injection on the diesel soot particle characteristics, so as to obtain comprehensive information when using a diesel particulate filter (DPF) for PM reduction. Three operating modes were employed, including P (-50 CA), P (-30 CA) and P (-10 CA), which were marked by the early injection timing. The main injection was adjusted such that three modes have similar combustion phases. The soot particles were produced from a heavy-duty diesel engine. Transmission electron microscopy (TEM) and Raman spectroscopy were used to analyze morphology, nanostructure and graphitization degree. Thermalgravimetric analysis (TGA) was done to quantify the volatile fraction content of particles, as well as the oxidation reactivity. Results showed that with early injection advanced, primary particle size became bigger with more disordered nanostructure and lower graphitization degree. Meanwhile, the advanced early injection resulted in relatively more organic carbon (OC) and higher oxidation reactivity of the produced soot particles because incomplete combustion caused by spray-wall impingement and suppressed in-cylinder PM oxidation process.

The Effect of Pore Structure on Thermal Characteristics of a Cordierite Diesel Particulate Filter for Heavy Duty Diesel Vehicle

As emissions regulations are tightened, various engine and emission reduction improvements have been applied. The reduction of particulate matter (PM), a major diesel engine emission, relies solely on after-treatment in the diesel particulate filter (DPF). It is not possible to satisfy current exhaust regulations without a DPF installed downstream of a diesel engine. Therefore, in the design of DPF systems, thermal stability and durability at the high temperatures experienced during the regeneration process are considered critical in determining the substrate material, as any defects (cracking, damage, or melting) cause increased pollutant emissions. In this study, the regeneration characteristics of 10.5 in cordierite DPF substrates applied in large commercial vehicles were investigated according to pore structure. The pore structure was changed while maintaining the thermal expansion coefficient and thermal properties by changing the particle size of talc during fabrication. Two different substrate compositions were evaluated and applied in a 6-L diesel engine to analyze their thermal characteristics during normal and uncontrolled (drop-to-idle) regeneration according to PM loading. The improvement in pore structure was observed to increase the PM oxidation rate under normal regeneration and extended the PM loading limit under uncontrolled regeneration.

Effect of Lubricant Additives on the Oxidation Characteristics of Diesel Engine Particulate Matter

Three common lubricant additives, including an antioxidant, detergent, and an antifoamer, were added to diesel fuel to perform a diesel engine bench test. Particulate matter samples underwent thermogravimetric analysis to investigate the effect of lubricant additives on the particulate matter oxidation process, characteristic temperature, and activation energy. The results showed the following. Different lubricant additives result in different variation trends in the thermogravimetric curve of a particulate matter sample by varying the rotating speed and torque. When the rotating speed was stable, as the torque increased, the ignition temperature of the particulate matter of Fuel C declined rapidly during the initial stage and then increased rapidly. When the torque was stable, as the rotating speed increased, the ignition temperature of the particulate matter of Fuel C increased initially and then declined. The particulate matter of Fuel C had the lowest level of activation energy at approximately 57.89 J·mol−1. The particulate matter of Fuel A had the highest level of activation energy at approximately 74.10 J·mol−1. When the fuel has a higher cetane number, the combustion chemical reaction rate is faster and results in a more complete reaction. The active substance contact surface increases, which facilitates particulate matter oxidation.

Influence of alternative fuels on the particulate matter micro and nano-structures, volatility and oxidation reactivity in a compression ignition engine

The present study investigates the impact of various alternative fuels, including biodiesel, methanol, ethanol, butanol and pentanol, on the micro and nano-structures, volatility and oxidation reactivity of particulate matter (PM) from a 4-cylinder compression ignition engine under low (10%) and high (80%) engine loads at a constant engine speed of 1800 rpm. Four alcohols were mixed with diesel and biodiesel to obtain ternary fuels. The overall oxygen concentration of each ternary fuel was fixed at 6% by mass for establishing the same condition for comparing. In addition to the ternary fuels, pure biodiesel was also compared with diesel fuel. The results of the micro and nano-structures characteristics obtained from a Scanning Transmission Electron Microscope (STEM) reveal that the alternative fuels can disorder the PM micro and nano-structures, and also the particles produced by these fuels have lower primary particle diameter, particle agglomerate size and fringe length, however, higher fringe tortuosity and almost equal (insignificant rise) fringe separation distance compared to those produced by diesel fuel. The results obtained from a Thermogravimetric Analyzer/Differential Scanning Calorimeter (TGA/DSC) show that both biodiesel and alcohols have the potential to increase in PM volatile substances and oxidation reactivity rate, and decrease in PM non-volatile substances in comparison with those of diesel fuel. It is concluded that the pure biodiesel has the highest impact on the PM structure, volatility and oxidation reactivity among all the tested alternative fuels, while methanol has the highest impact on these parameters among all the tested alcohol fuels.