Non-road Diesel Research Articles

Effects of a Diesel Particulate Filter on Emission Characteristics of a China II Non-road Diesel Engine

The emission standard of China’s non-road diesel engines is experiencing the transition period from China II to China III, and the relative non-road diesel engine emission issues need to be urgently solved. As a kind of effective after-treatment technology, a diesel particulate filter (DPF) has become increasingly important in non-road diesel engine emission research. To evaluate the emission characteristics of a non-road diesel engine retrofitted with a DPF, particulate matter (PM) and gaseous emissions emitted from a China II non-road diesel engine loaded with a DPF were investigated on the engine bench. The mass (specific emissions) and number concentrations of PM emissions were obtained by a DLS7200 mass collection system and matter CU-2 number instrument with and without a DPF, respectively. Additionally, gaseous emissions [NOx, CO, and hydrocarbon (HC)] were quantitatively analyzed with and without a DPF by a MEXA-7100EGR emission analysis chamber. Results showed that a DPF could lower the mass and ...

Monitoring particle emission for non-road diesel machineries equipped with particulate filters

Diesel particulate filters (DPF) are a very effective means to reduce emissions of soot particles contained in the exhaust gases of diesel engines for non-road mobile machineries. However, DPF can be damaged, leading to particle emission levels exceeding the regulatory limits. Verification of the particle number PN should normally be performed in line with the Particle Measuring Program (PMP) protocol for the measurement of the “solid” particles ≥ 23nm. The current method used on-site to monitor particle emissions is based on measurement of the light-attenuation using opacimeters. But opacimeters are not sufficiently sensitive and not able to detect small DPF leakages. Therefore a new test procedure requiring practical and not too expensive instruments is needed. In this study, various methods to measure particulate emission in terms of PN and particle mass PM were investigated in different configurations: with and without removal of volatile compounds by thermo-dilution, with and without DPF. The use of a diffusion charge classifier (DISCmini) for PN determination and an aethalometer for the black carbon mass concentration was studied. These techniques used in combination appear promising for the verification of DPF functioning.

Polycyclic aromatic hydrocarbon emissions of non-road diesel engine treated with non-thermal plasma technology

Non-road diesel engines are important polycyclic aromatic hydrocarbon (PAH) sources in the environment due to their high emission concentration compared to on-road diesel engines. Particle- and gas-phase PAH concentrations of a non-road diesel engine were investigated. Non-thermal plasma (NTP) as an effective after-treatment technology was used to reduce PAH emissions. The results showed that particle-phase PAH concentrations were 329.7 µg/m3, 3,206.7 µg/m3, and 1,185.7 µg/m3 without the action of NTP at three different engine loads respectively. Relatively low concentrations were measured for gas-phase PAHs. Excellent linearity was shown for particle-phase with total PAH concentrations both with, and without, NTP. The gas-phase PAH concentrations linearly increased with engine load without NTP. The five most abundant compounds of PAHs were among low molecular weight (LMW) and medium molecular weight (MMW) compounds. Total PAH cleaning efficiency was beyond 50% when treated with NTP at the three different engine loads. We hypothesized that naphthalene (Nap) concentrations increased greatly at 60% and 80% engine loads because it was produced within the plasma zone by decomposition of high molecular weight (HMW) PAHs. The PAHs content of particulate matter (PM) aggregation at 60% load was approximately three times higher than at 40% and 80% loads. High correlation values were observed for MMW PAHs with total PAH concentrations. Correlations of PAH concentration reduction could be important to clarify the PAH reduction mechanism with NTP technology.

Design of combustion bowl geometry to meet final Tier 4 of 11 L non-road heavy-duty diesel engine with multi-dimensional combustion simulation

To comply with the new non-road emission standards, final Tier 4, two big strategies have been applied to the 11 L heavy-duty diesel engine. The first strategy is to apply Exhaust gas recirculation and selectivity catalytic reduction system to meet the NOx limitation. The other one is to apply low swirl ratio (for higher volumetric efficiency) and multi-hole nozzle, a high pressure direct injection, and an optimized combustion system in order to reduce PM emission. Both strategies put a focus on the optimization of combustion system. In this study, a ULPC bowl concept applied in the previous works has been successfully verified in 11 L heavy-duty diesel engine with wellvalidated 3D combustion simulation, and the ULPC bowl shape has been geometrically optimized. A rough 0D calculation is used to calculate the fuel split ratio of the various ULPC bowl shapes. In the rated-power operating condition of the final Tier 4 engine which is deduced by 1D cyclic simulation, the optimal fuel split ratio of the injected fuel has been verified. Also, additional geometric optimization has been achieved without changing the optimal fuel split ratio. From these results, soot has been reduced by about 30% with ULPC optimum bowl shape against the Tier 3 re-entrant bowl shape.

Simulation study on improving the selective catalytic reduction efficiency by using the temperature rise in a non-road transient cycle

In this study, the transient nitrogen oxide reduction performance of a urea selective catalytic reduction system installed on a non-road diesel engine was tested on an engine dynamometer bench over a scheduled non-road transient cycle mode. Based on the measurement results, the characteristics of the transient selective catalytic reduction behaviours of nitrogen oxide reduction were evaluated. Also, in this study, the effects of several thermal management strategies for improving the selective catalytic reduction efficiency was investigated by transient selective catalytic reduction simulations. The kinetic parameters of the current simulation code for selective catalytic reduction were calibrated and validated by comparison with the measurement data. As a result of this study, it was found that a thermal management strategy utilizing a partial temperature rise in the transient time domain can be an efficient approach for improving the transient selective catalytic reduction efficiency, in comparison with the temperature rise over the entire cycle period. Furthermore, this study can provide some guideline data for the magnitude and the duration of the temperature rise required to obtain the target selective catalytic reduction efficiency over the non-road transient cycle mode. In the last part of this study, the impact of the variation in the space velocity on the transient selective catalytic reduction efficiency was assessed using transient selective catalytic reduction simulations.

Effects of wood-based renewable diesel fuel blends on the performance and emissions of a non-road diesel engine

Renewable fuels form an essential means to reduce greenhouse gas (GHG) emissions emitted by vehicles and non-road machines. Due to the limited production so far, different blends of renewable fuels in fossil fuels are a realistic way to implement the increasing use of renewable fuels. In addition to significant GHG emissions reduction, further benefits can be achieved when high quality renewable fuels are utilized as blending components since the pollutant exhaust emissions, such as unburned hydrocarbons (HC), carbon monoxide (CO), particulate matter mass (PM) and particle number (PN), may also decrease. A global Finnish forestry company has developed an innovative production process from crude tall oil (CTO), a wood-based residue of pulp making process, to renewable diesel. The fuel properties correspond to those of the traditional fossil fuels but the GHG emissions are reduced significantly.

Particle- and gas-phase PAHs toxicity equivalency quantity emitted by a non-road diesel engine with non-thermal plasma technology.

Polycyclic aromatic hydrocarbon (PAH) toxicity equivalency quantity (TEQ, denoted by benzo(a)pyrene equivalent (BaPeq) concentration) is more meaningful when evaluating the influence of non-road diesel engines PAH toxicity on environment. Particle- and gas-phase PAH BaPeq concentrations were calculated based on gas chromatography-mass spectrometer (GC-MS) results and toxic equivalency factors. A non-thermal plasma (NTP) reactor was applied to a non-road diesel engine to decrease PAH TEQ content. Only the gas-phase Nap BaPeq concentration increased slightly with the action of NTP at three different generator power outputs. BaP dominated the BaPeq concentration for 15 samples with, and without NTP except in the gas-phase at 4kW. Almost all medium molecular weight (MMW) and high molecular weight (HMW) PAH TEQs increased for particle- and gas-phases at 3kW power output compared to 2kW without the use of NTP. Particle-phase Nap, Acp, and AcPy (low molecular weight, LMW) TEQ were under detection at 3 and 4kW, while gas-phase BkF, IND, DBA, and BghiP (HMW) concentrations were below the limits of detection. The most abundant PAH TEQ compounds were MMW and HMW PAHs for gas- and particle-phase while they were BaA, CHR, BbF, BaP, and IND for PM aggregation. The total BaPeq emission factors were 15.1, 141.4, and 46.5μgm(-3) at three engine loads, respectively. Significant BaPeq concentration percentage reduction was obtained (more than 80 and 60%) with the use of NTP for particle- and gas-phases. A high TEQ content was observed for PM aggregation (38.8, 98.4, and 50.0μgkg(-1)) which may have caused secondary PAH toxicity emissions. With the action of NTP, the breakup of MMW and HMW into LMW PAHs led to reduction of some PAH concentrations.

Impacts of biodiesel blends on PM2.5, particle number and size distribution, and elemental/organic carbon from nonroad diesel generators

As an important alternative to diesel fuel, biodiesel is considered sustainable and environmentally friendly and has attracted increased interest over the last few decades. For the evaluation of biodiesel’s impact on engine performance and emissions, most studies have focused on diesel vehicles and on-road diesel engines. There is also limited data available to assess the effect of biodiesels on emissions of unregulated pollutants, such as ultrafine particulate (UFP), particle number (PN) and size distributions. For developing successful emission control strategies, an understanding of biodiesel impact on emissions from both on-road and nonroad diesel engines is necessary. In this study, two nonroad diesel generators were tested with diesel and two biodiesel blends with 5% (v/v) (B5) and 20% (v/v) (B20) biodiesel under varied engine load conditions. The effects of engine load and biodiesel blends on emissions (g/min) and emission factor (g/kWh) of PM2.5, PN, elemental and organic carbon (EC/OC), as well as particle size distribution were investigated. A method for the determination of EC/OC in overloaded filter samples was also developed and evaluated. While emissions (except OC) were found to increase with increasing load, emission factors of PN and OC decreased with increasing load while lowest emission factors for PM2.5 and EC were recorded under medium load. Although limited, the impacts on PM2.5, PN, EC/OC, as well as particle size distribution from biodiesel blends were more noticeable under the lowest and/or the highest engine load conditions and depended strongly on engine type.

Atmospheric impacts of black carbon emission reductions through the strategic use of biodiesel in California

The use of biodiesel as a replacement for petroleum-based diesel fuel has gained interest as a strategy for greenhouse gas emission reductions, energy security, and economic advantage. Biodiesel adoption may also reduce particulate elemental carbon (EC) emissions from conventional diesel engines that are not equipped with after-treatment devices. This study examines the impact of biodiesel blends on EC emissions from a commercial off-road diesel engine and simulates the potential public health benefits and climate benefits.EC emissions from the commercial off-road engine decreased by 76% when ultra-low sulfur commercial diesel (ULSD) fuel was replaced by biodiesel. Model calculations predict that reduced EC emissions translate directly into reduced EC concentrations in the atmosphere, but the concentration of secondary particulate matter was not directly affected by this fuel change. Redistribution of secondary particulate matter components to particles emitted from other sources did change the size distribution and therefore deposition rates of those components. Modification of meteorological variables such as water content and temperature influenced secondary particulate matter formation.Simulations with a source-oriented WRF/Chem model (SOWC) for a severe air pollution episode in California that adopted 75% biodiesel blended with ULSD in all non-road diesel engines reduced surface EC concentrations by up to 50% but changed nitrate and total PM2.5 mass concentrations by less than ±5%. These changes in concentrations will have public health benefits but did not significantly affect radiative forcing at the top of the atmosphere. The removal of EC due to the adoption of biodiesel produced larger coatings of secondary particulate matter on other atmospheric particles containing residual EC leading to enhanced absorption associated with those particles. The net effect was a minor change in atmospheric optical properties despite a large change in atmospheric EC concentrations. These results emphasize the importance of considering EC mixing state in climate research.

Characterization of Particulate Emissions from Biodiesel using High Resolution Time of Flight Aerosol Mass Spectrometer

In the past several decades, biofuels have emerged as candidates to help mitigate the issues of global warming, fossil fuel depletion and, in some cases, atmospheric pollution. To date, the only biofuels that have achieved any significant penetration in the global transportation sector are ethanol and biodiesel. The global consumption of biodiesel was rapidly increased from 2005. The goal of this study was to examine the chemical composition on particulate pollutant emissions from a diesel engine operating on several different biodiesels. Tests were performed on non-road diesel engine. Experiments were performed on 5 different fuel blends at 2 different engine loading conditions (50% and 75%). 5 different fuel blends were ultra-low sulfur diesel (ULSD, 100%), soy biodiesel (Blend 20% and Blend 100%) and canola biodiesel (Blend 20% and Blend 100%). The chemical properties of particulate pollutants were characterized using an Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS). Organic matter and nitrate were generally the most abundant aerosol components and exhibited maximum concentration of <TEX>$1207{\mu}g/m^3$</TEX> and <TEX>$30{\mu}g/m^3$</TEX>, respectively. On average, the oxidized fragment families (<TEX>$C_xH_yO_1{^+}$</TEX>, and <TEX>$C_xH_yO_z{^+}$</TEX>) account for ~13% of the three family sum, while ~87% comes from the <TEX>$C_xH_y{^+}$</TEX> family. The two peaks of <TEX>$C_2H_3O_2$</TEX> (m/z 59.01) and <TEX>$C_3H_7O$</TEX> (m/z 59.04) located at approximately m/z 59 could be used to identify atmospheric particulate matter directly to biodiesel exhaust, as distinguished from that created by petroleum diesel in the AMS data.

Sources of ultrafine particles in the Eastern United States

Source contributions to ultrafine particle number concentrations for a summertime period in the Eastern U.S. are investigated using the chemical transport model PMCAMx-UF. New source-resolved number emissions inventories are developed for biomass burning, dust, gasoline automobiles, industrial sources, non-road and on-road diesel. According to the inventory for this summertime period in the Eastern U.S., gasoline automobiles are responsible for 40% of the ultrafine particle number emissions, followed by industrial sources (33%), non-road diesel (16%), on-road diesel (10%), and 1% from biomass burning and dust. With these emissions as input, the chemical transport model PMCAMx-UF reproduces observed ultrafine particle number concentrations (N3-100) in Pittsburgh with an error of 12%. For this summertime period in the Eastern U.S., nucleation is predicted to be the source of more than 90% of the total particle number concentrations. The source contributions to primary particle number concentrations are on average similar to those of their source emissions contributions: gasoline is predicted to contribute 36% of the total particle number concentrations, followed by industrial sources (31%), non-road diesel (18%), on-road diesel (10%), biomass burning (1%), and long-range transport (4%). For this summertime period in Pittsburgh, number source apportionment predictions for particles larger than 3 nm in diameter (traffic 65%, other combustion sources 35%) are consistent with measurement-based source apportionment (traffic 60%, combustion sources 40%).

Mitigation of PAH and nitro-PAH emissions from nonroad diesel engines.

More stringent emission requirements for nonroad diesel engines introduced with U.S. Tier 4 Final and Euro Stage IV and V regulations have spurred the development of exhaust aftertreatment technologies. In this study, several aftertreatment configurations consisting of diesel oxidation catalysts (DOC), diesel particulate filters (DPF), Cu zeolite-, and vanadium-based selective catalytic reduction (SCR) catalysts, and ammonia oxidation (AMOX) catalysts are evaluated using both Nonroad Transient (NRTC) and Steady (8-mode NRSC) Cycles in order to understand both component and system-level effects of diesel aftertreatment on emissions of polycyclic aromatic hydrocarbons (PAH) and their nitrated derivatives (nitro-PAH). Emissions are reported for four configurations including engine-out, DOC+CuZ-SCR+AMOX, V-SCR+AMOX, and DOC+DPF+CuZ-SCR+AMOX. Mechanisms responsible for the reduction, and, in some cases, the formation of PAH and nitro-PAH compounds are discussed in detail, and suggestions are provided to minimize the formation of nitro-PAH compounds through aftertreatment design optimizations. Potency equivalency factors (PEFs) developed by the California Environmental Protection Agency are then applied to determine the impact of aftertreatment on PAH-derived exhaust toxicity. Finally, a comprehensive set of exhaust emissions including criteria pollutants, NO2, total hydrocarbons (THC), n-alkanes, branched alkanes, saturated cycloalkanes, aromatics, aldehydes, hopanes and steranes, and metals is provided, and the overall efficacy of the aftertreatment configurations is described. This detailed summary of emissions from a current nonroad diesel engine equipped with advanced aftertreatment can be used to more accurately model the impact of anthropogenic emissions on the atmosphere.

Fuel quality management versus vehicle emission control in China, status quo and future perspectives

China’s fuel quality standards and fuel supply management have long been an impediment to improved air quality by hindering the progress of vehicle emission control. This paper summarizes the status of China’s fuel quality standards, fuel supply and vehicle emission standards focusing on the major problems of fuel quality management. The mechanism that China uses to establish its fuel quality standards is outlined. The gaming of stakeholders such as regulatory authorities, vehicle and engine manufacturers and the gigantic state-owned oil companies in the development of fuel quality standard formulation and fuel supply is illustrated. Results are presented from testing 59 gasoline samples for sulphur, olefins, aromatics, benzene, and manganese content and from testing 59 diesel samples for sulphur and polyaromatic hydrocarbons collected across the country from 2010 to 2011. This paper also provides key policy suggestions to improve future fuel quality in China. China should improve fuel quality through the application of policy measures such as adjusting the fuel quality standard formulation process, introducing competition and enforcing the transition period for improved fuel introduction, unifying on-road diesel and non-road diesel fuel quality standards, and pay attention to issues like fuel detergent, methanol addition and evaporative emissions.

Particle and NOx emissions of a non-road diesel engine with an SCR unit: The effect of fuel

Diesel engines are challenged to reduce their emissions. Nitrogen oxides (NOx), hydrocarbons, particulate matter and carbon dioxide are most important regulated diesel emissions. The legislation is driving for the use of renewable fuels in vehicles but all the impacts of those on emission control technology are not clear yet. In this study the number and chemical composition of particles emitted from a non-road diesel engine with and without a selective catalytic reduction (SCR) unit were investigated. Common diesel fuel oil (DFO) and untreated rape seed oil (RSO) were used as fuels. The NOx reduction activity of the fresh SCR catalyst was also investigated. The results indicated that the fuel had a great impact on the particles emitted from the engine. The particle number was 10–100 times higher when RSO was used as fuel compared to DFO. The DFO particles contained carbon in significantly higher proportions compared to the RSO particles. Metals, such as Fe and Cu, were also found in the DFO particles. For both fuels the NOx reduction activity was 79% with a SCR converter. As a conclusion, the use of the SCR converter decreased the number of particles in general but increased the number of the nanoparticles.

Diesel Engine performance improvement in a 1-D engine model using Particle Swarm Optimization

AbstractA particle swarm optimization (PSO) technique was implemented to improve the engine development and optimization process to simultaneously reduce emissions and improve the fuel efficiency. The optimization was performed on a 4-stroke 4-cylinder GT-Power based 1-D diesel engine model. To achieve the multi-objective optimization, a merit function was defined which included the parameters to be optimized: Nitrogen Oxides (NOx), Nonmethyl hydro carbons (NMHC), Carbon Monoxide (CO), Brake Specific Fuel Consumption (BSFC). EPA Tier 3 emissions standards for non-road diesel engines between 37 and 75 kW of output were chosen as targets for the optimization. The combustion parameters analyzed in this study include: Start of main Injection, Start of Pilot Injection, Pilot fuel quantity, Swirl, and Tumble. The PSO was found to be very effective in quickly arriving at a solution that met the target criteria as defined in the merit function. The optimization took around 40-50 runs to find the most favourable engine operating condition under the constraints specified in the optimization. In a favourable case with a high merit function values, the NOx+NMHC and CO values were reduced to as low as 2.9 and 0.014 g/kWh, respectively. The operating conditions at this point were: 10 ATDC Main SOI, -25 ATDC Pilot SOI, 0.25 mg of pilot fuel, 0.45 Swirl and 0.85 tumble. These results indicate that late main injections preceded by a close, small pilot injection are most favourable conditions at the operating condition tested.

Sustainability Planning Framework for Reducing Ground-level Ozone Formation in Construction Activities

Many metropolitan areas struggle to meet the EPA standard for ozone. These areas need to realistically assess all potential pollutant emitting sources to comply. One pollution source that needs close examination is construction activities that employ nonroad diesel equipment that emit ozone-forming pollutants, including nitrogen oxides and volatile organic compounds. Furthermore, days exceeding the ozone standard typically occur between May and September, the same time of year when construction activity is at its peak; thus, a sustainable construction planning framework is needed to minimize conflicts between high pollutant emissions activities and forecasted high ozone days. This paper presents a framework for leveraging schedule float and allocating equipment resources for activities that may have the greatest impact on the formation of ground-level ozone. This scheduling approach will sustain good air quality by reducing ozone-forming emissions from construction activities.

Effect of oxygenated fuels on physicochemical and toxicological characteristics of diesel particulate emissions.

A systematic study was conducted to make a comparative evaluation of the effects of blending five different oxygenates (diglyme (DGM), palm oil methyl ester (PME), dimethyl carbonate (DMC), diethyl adipate (DEA), and butanol (Bu)) with ultralow sulfur diesel (ULSD) at 2% and 4% oxygen levels on physicochemical and toxicological characteristics of particulate emissions from a nonroad diesel engine. All blended fuels led to an overall decrease in the particulate mass concentration and elemental carbon (EC) emissions, which was strongly associated with the oxygen content in fuels and the specific type of fuels used. In general, the proportion of particulate-bound organic carbon (OC) and water-soluble organic carbon (WSOC) increased while using oxygenated fuel blends. Compared to ULSD, all fuel blends showed different emission factors of particle-phase PAHs and n-alkanes, slight alterations in soot nanostructure, lower soot ignition temperature, and lower activation energy. The total counts of particles (≤ 560 nm diameter) emitted decreased gradually for ULSD blended with DMC, DEA, and Bu, while they increased significantly for other fuel blends. The in vitro toxicity of particulates significantly increased with ULSD blended with DMC and DEA, while it decreased when ULSD was blended with PME, DGM, and Bu.

Predicting the effects of nanoscale cerium additives in diesel fuel on regional-scale air quality.

Diesel vehicles are a major source of air pollutant emissions. Fuel additives containing nanoparticulate cerium (nCe) are currently being used in some diesel vehicles to improve fuel efficiency. These fuel additives also reduce fine particulate matter (PM2.5) emissions and alter the emissions of carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbon (HC) species, including several hazardous air pollutants (HAPs). To predict their net effect on regional air quality, we review the emissions literature and develop a multipollutant inventory for a hypothetical scenario in which nCe additives are used in all on-road and nonroad diesel vehicles. We apply the Community Multiscale Air Quality (CMAQ) model to a domain covering the eastern U.S. for a summer and a winter period. Model calculations suggest modest decreases of average PM2.5 concentrations and relatively larger decreases in particulate elemental carbon. The nCe additives also have an effect on 8 h maximum ozone in summer. Variable effects on HAPs are predicted. The total U.S. emissions of fine-particulate cerium are estimated to increase 25-fold and result in elevated levels of airborne cerium (up to 22 ng/m3), which might adversely impact human health and the environment.

Major Challenges to the Sustainable Operations of Construction Equipment in Malaysia

The growing considerations of people, profit and planet have emphasized the integration of sustainable concepts in the construction processes. The previous research in sustainable construction has underlined the issues pertaining to raw material and its manufacturing; design aspects along with the occupancy phase of a building life cycle. However, concerned over GHG emissions from the operation of non-road diesel equipment are still being ignored in the established literature. These non-road construction equipment consume fossil fuel and a serious threat for green environment. In addition to this, health and safety issues are also important concerns for the human well-being. Thus, mitigating these impacts are the important aspects of sustainable planning for onsite construction activities. A questionnaire survey was carried out to explore the contractors views towards potential challenges that are relevant with the growing attention of sustainability in construction sector. A group of large civil contractors of Malaysian construction industry were solicited through online survey to prioritize the potential barriers. The research findings presents a broader view and a number of challenges that inhibits the contractors for acquiring, adopting and implementing sustainable practices for onsite mechanized construction activities.

Physicochemical and toxicological characteristics of particulate matter emitted from a non-road diesel engine: Comparative evaluation of biodiesel-diesel and butanol-diesel blends

Combustion experiments were conducted to evaluate the effects of using blends of ultralow sulfur diesel (ULSD) with biodiesel or n-butanol on physicochemical and toxicological characteristics of particulate emissions from a non-road diesel engine. The results indicated that compared to ULSD, both the blended fuels could effectively reduce the particulate mass and elemental carbon emissions, with butanol being more effective than biodiesel. The proportion of organic carbon and volatile organic compounds in particles increased for both blended fuels. However, biodiesel blended fuels showed lower total particle-phase polycyclic aromatic hydrocarbons (PAHs) emissions. The total number emissions of particles ≤560nm in diameter decreased gradually for the butanol blended fuels, but increased significantly for the biodiesel blended fuels. Both the blended fuels indicated lower soot ignition temperature and activation energy. All the particle extracts showed a decline in cell viability with the increased dose. However, the change in cell viability among test fuels is not statistically significant different with the exception of DB-4 (biodiesel–diesel blend containing 4% oxygen) used at 75% engine load.