PM Mass Emissions Research Articles

Analysis of Particle Emissions from a Jet Engine Including Conditions of Afterburner Use

Particle emissions from aircraft engines are mainly related to the emission of particles with very small diameters. The phenomena of the formation of particles in various operating conditions of turbine engines are known. However, it is difficult to find the results of research on the use of the afterburner in the literature. Increased aviation activity within military airports and situations such as air shows are associated with a very intense emission of particles, and pose a direct threat to human health. This article presents an analysis of particulate matter emissions from a military aircraft engine, with particular emphasis on operation with an afterburner. The parameters of the emission of particles determined were: PM Number Emissions Index (EIN), Particle Number Emissions Intensity (EN), PM Mass Emission Index (EIM), PM Mass Emission Intensity (EM), Differential Particle Number Emission Index, Differential Particle Volume Emission Index, and Differential Particle Mass Emission Index. The value of EIN for the afterburner use was the lowest among the whole operation range of the engine and was equal to 1.3 × 1015 particles per kilogram. The use of an afterburner resulted in a sharp increase in the EIM coefficient, which reached 670 mg/kg. Despite a very large increase in fuel consumption, the EIM coefficient turned out to be over 60 times greater than in the case of 100% engine thrust.

Combustion and emission characteristics of a diesel-powered generator running with N-butanol/coffee ground pyrolysis oil/diesel blended fuel

Abstract Demand for alternative energy is steadily increasing due to the depletion of fossil fuels. Converting biomass into alternative fuels has been proposed as a potential solution. Biofuel obtained from biomass through a pyrolysis process is called pyrolysis oil (PO). Because PO is difficult to use directly in conventional engines due to its inadequate fuel properties, various methods have been proposed to improve the fuel properties. Among them, using an alcohol fuel as an organic solvent has been proposed to mix PO with diesel to significantly improve fuel properties. In this study, a blend of diesel, n-butanol, and coffee ground pyrolysis oil (CGO) was applied to a diesel-powered generator. The experimental results showed that stable combustion was possible regardless of fuel type. Although, the fuel consumption rate of the blended fuels was about 20% higher than that of diesel, the efficiencies of all of the test fuels were comparable. NOx emissions decreased about 15–30% for the blended fuels than diesel due to high evaporating latent heat of n-butanol and water content of CGO. The blended fuels showed 70–90% lower PM mass emissions than diesel owing to the oxygen in n-butanol and CGO.

Very low particle matter mass measurements from light-duty vehicles

Recently, there are discussions about whether current sampling and measurement practices for the regulated gravimetric PM measurement are sufficiently accurate in quantifying PM at the proposed 3 and 1mg/mi emission standards for light-duty vehicles. In this study, a series of modifications were made to the existing gravimetric PM measurement method, aiming to preserve the integrity of the method while increasing the robustness and decreasing the testing variability. The experiments were conducted with a Higher (~2mg/mile) and a Lower (0.1–0.2mg/mile) PM Source Vehicle over the Federal Test Procedure (FTP) and US06 cycles, providing PM emissions with various solid/semi-volatile compositions and size distributions. The results showed the suggested modifications, i.e., increased filter face velocities (from 100 to 150cm/s) and combined filters (single filter vs. 3/4 filters), could increase the collected filter mass without introducing statistically significant differences in the measured PM mass emission rates. No statistically significant improvements were seen in the measurement variability with the Higher PM Source Vehicle. For the Lower PM Source Vehicle; however, the 4-phase cumulative filter showed a statistically significant reduction in PM mass measurement variability, while not impacting the measured PM mass emissions, but these improvements must be weighed against the increased testing costs/time required for the longer test time.

Using partial flow dilution to measure PM mass emissions from light-duty vehicles

Partial flow dilution (PFD) offers a number of benefits relative to conventional full flow dilution tunnels for motor vehicle PM emissions measurement in terms of measurement variability, footprint, and cost. Its implementation into automotive emissions test cells depends on its ability to record PM mass emissions equivalent to the current constant volume sampling (CVS) dilution tunnel approach. The present work examines factors critical to successful application of PFD sampling and compares vehicle PM emissions measured simultaneously by PFD and CVS tunnel. The combination of a current technology commercial PFD system and ultrasonic flow meter fulfill the two principal requirements of accurate exhaust flow measurement and fast time response for proportional sampling. PM mass emissions measured by PFD versus CVS systems satisfy a 1.03 ± 0.03 regression for the regulatory FTP test cycle, and comparably good agreement for the supplemental US06 drive cycle. Both dilution approaches are amenable to th...

Exhaust PM Emissions Analysis of Alcohol Fueled Heavy-Duty Engine Utilizing PPC

The focus has recently been directed towards the engine out soot from Diesel engines. Running an engine in PPC (Partially Premixed Combustion) mode has a proven tendency of reducing these emissions significantly. In addition to combustion strategy, several studies have suggested that using alcohol fuels aid in reducing soot emissions to ultra-low levels. This study analyzes and compares the characteristics of PM emissions from naphtha gasoline PPC, ethanol PPC, methanol PPC and methanol diffusion combustion in terms of soot mass concentration, number concentration and particle size distribution in a single cylinder Scania D13 engine, while varying the intake O2. Intake temperature and injection pressure sweeps were also conducted. The fuels emitting the highest mass concentration of particles (Micro Soot Sensor) were gasoline and methanol followed by ethanol. The two alcohols tested emitted nucleation mode particles only, whereas gasoline emitted accumulation mode particles as well. Regarding soot mass concentration measurements; methanol never exceeded 1.6 mg/m3 while when operating on gasoline this value never descended below 1.6 mg/m3. From this result it can be concluded that the main contributor to PM mass emissions is mainly increasing CMD (Count Mean Diameter) in the accumulation mode size range, but can in diffusion combustion also be caused by a high amount of nucleation mode particles. A probable cause of higher particle number emissions, when running the engine on methanol compared to ethanol, is the corrosiveness of the fuel itself. Except for the ultra-low PM mass emitted from alcohol combustion, it is also possible to alter the EGR concentration with a higher level of freedom without having to consider the NOX - soot tradeoff.

Wood Smoke Impact on Particulate Matter (PM)

The emission factors and emission profiles of wood combustion tracers of different wood types were assessed. Emission profiles are additionally assessed for two advanced oven/boiler types. The emission profiles and emission ratios of wood smoke tracers to the PM emission of wood fires for the major tree species were established. From this a wood smoke profile will be derived which will be used to assess the impact of wood smoke to selected PM10 and PM2.5 sampling sites. Furthermore, using the energy-normalised PM mass emission data from different types of wood combustion appliances PM reduction scenarios will be assessed with the goal of a sustainable use of wood or wood-based fuels.

Toxicological properties of emission particles from heavy duty engines powered by conventional and bio-based diesel fuels and compressed natural gas

BackgroundOne of the major areas for increasing the use of renewable energy is in traffic fuels e.g. bio-based fuels in diesel engines especially in commuter traffic. Exhaust emissions from fossil diesel fuelled engines are known to cause adverse effects on human health, but there is very limited information available on how the new renewable fuels may change the harmfulness of the emissions, especially particles (PM). We evaluated the PM emissions from a heavy-duty EURO IV diesel engine powered by three different fuels; the toxicological properties of the emitted PM were investigated. Conventional diesel fuel (EN590) and two biodiesels were used − rapeseed methyl ester (RME, EN14214) and hydrotreated vegetable oil (HVO) either as such or as 30% blends with EN590. EN590 and 100% HVO were also operated with or without an oxidative catalyst (DOC + POC). A bus powered by compressed natural gas (CNG) was included for comparison with the liquid fuels. However, the results from CNG powered bus cannot be directly compared to the other situations in this study.ResultsHigh volume PM samples were collected on PTFE filters from a constant volume dilution tunnel. The PM mass emission with HVO was smaller and with RME larger than that with EN590, but both biofuels produced lower PAH contents in emission PM. The DOC + POC catalyst greatly reduced the PM emission and PAH content in PM with both HVO and EN590. Dose-dependent TNFα and MIP-2 responses to all PM samples were mostly at the low or moderate level after 24-hour exposure in a mouse macrophage cell line RAW 264.7. Emission PM from situations with the smallest mass emissions (HVO + cat and CNG) displayed the strongest potency in MIP-2 production. The catalyst slightly decreased the PM-induced TNFα responses and somewhat increased the MIP-2 responses with HVO fuel. Emission PM with EN590 and with 30% HVO blended in EN590 induced the strongest genotoxic responses, which were significantly greater than those with EN590 + cat or 100% HVO. The emission PM sample from the CNG bus possessed the weakest genotoxic potency but had the strongest oxidative potency of all the fuel and catalyst combinations. The use of 100% HVO fuel had slightly weaker and 100% RME somewhat stronger emission PM induced ROS production, when compared to EN590.ConclusionsThe harmfulness of the exhaust emissions from vehicle engines cannot be determined merely on basis of the emitted PM mass. The study conditions and the engine type significantly affect the toxicity of the emitted particles. The selected fuels and DOC + POC catalyst affected the PM emission from the heavy EURO IV engine both qualitative and quantitative ways, which influenced their toxicological characteristics. The plain HVO fuel performed very well in emission reduction and in lowering the overall toxicity of emitted PM, but the 30% blend of HVO in EN590 was no better in this respect than the plain EN590. The HVO with a DOC + POC catalyst in the EURO IV engine, performed best with regard to changes in exhaust emissions. However some of the toxicological parameters were significantly increased even with these low emissions.

Operation of Marine Diesel Engines on Biogenic Fuels: Modification of Emissions and Resulting Climate Effects

The modification of emissions of climate-sensitive exhaust compounds such as CO(2), NO(x), hydrocarbons, and particulate matter from medium-speed marine diesel engines was studied for a set of fossil and biogenic fuels. Applied fossil fuels were the reference heavy fuel oil (HFO) and the low-sulfur marine gas oil (MGO); biogenic fuels were palm oil, soybean oil, sunflower oil, and animal fat. Greenhouse gas (GHG) emissions related to the production of biogenic fuels were treated by means of a fuel life cycle analysis which included land use changes associated with the growth of energy plants. Emissions of CO(2) and NO(x) per kWh were found to be similar for fossil fuels and biogenic fuels. PM mass emission was reduced to 10-15% of HFO emissions for all low-sulfur fuels including MGO as a fossil fuel. Black carbon emissions were reduced significantly to 13-30% of HFO. Changes in emissions were predominantly related to particulate sulfate, while differences between low-sulfur fossil fuels and low-sulfur biogenic fuels were of minor significance. GHG emissions from the biogenic fuel life cycle (FLC) depend crucially on energy plant production conditions and have the potential of shifting the overall GHG budget from positive to negative compared to fossil fuels.

Aerodynamic and Mobility Size Distribution Measurements to Reveal Biodiesel Effects on Diesel Exhaust Aerosol

This article examines the effect of biodiesel blends on the exhaust aerosol from a Euro 3 passenger car. Five different feedstock oils (soybean, palm, sunflower, rapeseed, and used frying oil) were used to produce fuels with 10% vol. content in biodiesel (B10). Use of the B10 blends led to a systematic reduction of PM mass emissions in the range of ∼9% (rapeseed) to 23% (used frying oil) on average. The combination of particle size distributions based on the aerodynamic and the mobility diameters led to the estimation of the fractal dimension (DF) for non-volatile particles. This was found to range from 2.52 for the baseline (fossil) fuel to 2.62 for the palm oil blend, suggesting that biodiesel can affect the particle morphology, even at this low blending ratio. The differences were statistically significant. The increase of the DF is translated to more compact particle structure, which in turn denotes lower specific surface area. The volatile fraction of PM lies within a range of 1–9% when fossil diesel...

Effect of alternative fuels on exhaust emissions during diesel engine operation with matched combustion phasing

The present work focuses on an experimental comparison of diesel emissions produced by three fuels: an ultra low sulfur diesel fuel (BP15), a pure soybean methyl-ester biodiesel fuel (B100), and a synthetic Fischer–Tropsch fuel (FT), practically free of sulfur and aromatic compounds, and produced in a gas-to-liquid process. The study was carried out using a 2.5 L direct injection common-rail turbodiesel engine operated at 2400 rpm and 64 N m torque (19% of maximum torque). The engine was tested with single and split (pilot and main) injections and without exhaust gas recirculation (EGR). The study has two objectives. The first objective is to investigate the impact of the start of injection (SOI) on performance and emissions of each fuel. The second objective is to study the isolated impacts of the test fuels on pollutant emissions by adjusting the injection parameters (SOI and fuel rail pressure) for each fuel, while producing practically the same combustion phasing. When the combustion phasing occurs similarly, this study has confirmed that the FT fuel can reduce all regulated diesel emissions under both single and split injection strategies. Finally, it has been confirmed that biodiesel can reduce particle mean diameter in comparison with BP15. However, higher PM mass emission for B100 has been observed under the condition of matched combustion phasing. The increase of the PM mass emission is probably due to the unburned or partially burned hydrocarbon (HC) emissions.

Emissions from different alternative diesel fuels operating with single and split fuel injection

Few factors affect diesel combustion and emissions more significantly than the composition of the fuel and the fuel injection process. In this paper, both of these factors are considered by comparing conventional, synthetic and vegetable oil-derived diesel fuels and by comparing a single pulse injection and a split (pilot and main) injection process. This paper focuses on characterization of the combustion process and emissions produced by three substantially different diesel fuels: an ultra low sulfur diesel fuel (BP15), a pure soybean methyl ester (B100), and a synthetic, practically free of sulfur and aromatic compounds, Fischer–Tropsch fuel (FT) produced in a gas-to-liquid process. The study was carried out in a direct injection (DI) 2.5 L common-rail turbodiesel engine working at four engine operation modes, spanning conditions of most interest in the engine map. In all modes the engine was tested with single and split injection (pilot and main), with constant start of injection (SOI), and without exhaust gas recirculation (EGR). Using the results from thermodynamic analysis, this study confirms that the ignition character of the fuel affects the start of the combustion process, notably for the whole combustion process when the single injection is used, and during the combustion process after the pilot injection when the split injection is used. In general, the FT fuel can reduce both NOx and PM specific emissions in all modes under both single and split injection modes, bypassing the nitrogen oxides-particulate matter (NOx–PM) trade-off. Finally, this work confirms that biodiesel can reduce the particle concentration. However, in some cases an increase of PM mass emission has been observed and this increase of the PM mass emission is due to unburned or partially burned hydrocarbon (HC) emissions.

Emission Measurements from a Crude Oil Tanker at Sea

This work presents an all-inclusive set of regulated and nonregulated emission factors for the main propulsion engine (ME), auxiliary engine (AE) and an auxiliary boiler on a Suezmax class tanker while operating at sea. The data include criteria pollutants (carbon monoxide, nitrogen oxides, sulfur oxides, and particulate matter), a greenhouse gas (carbon dioxide), the principal speciated hydrocarbons needed for human health risk assessments, and a detailed analysis of the PM into its primary constituents (ions, elements, organic, and elemental carbon). Measurements followed ISO 8178-1 methods with modifications described in the paper. The vessel burned two fuels: a heavy fuel oil in the ME and boiler and a distillate fuel in the AE. The weighted NO(x) emissions for the ME and AE are 19.87 +/- 0.95 and 13.57 +/- 0.31 g/kWh, respectively. The weighted PM mass emissions factor is 1.60 +/- 0.08 g/kWh for the ME and 0.141 +/- 0.005 g/kWh for the AE, with the sulfate content of the PM being the root cause for the difference. For the ME, sulfate with associated water is about 75% of total PM mass, and the organic carbon ranges from 15 to 25% of the PM mass. A deeper analysis showed that the conversion of fuel sulfur to sulfate in the ME ranged from 1.4to 5%. This article also provides emission factors for selected polycyclic aromatic hydrocarbons, heavy alkanes, carbonyls, light hydrocarbon species, metals, and ions for the ME, AE, and the boiler.

Nuclei-Mode Particulate Emissions and Their Response to Fuel Sulfur Content and Primary Dilution during Transient Operations of Old and Modern Diesel Engines

The effects of fuel sulfur content and primary dilution on PM number emissions were investigated during transient operations of an old and a modern diesel engine. Emissions were also studied during steady-state operations in order to confirm consistency with previous findings. Testing methods were concurrent with those implemented by the EPA to regulate PM mass emissions, including the use of the Federal Transient Testing Procedure-Heavy Duty cycle to simulate transient conditions and the use of a Critical Flow Venturi-Constant Volume System to provide primary dilution. Steady-state results were found to be consistent with previous studies in that nuclei-mode particulate emissions were largely reduced when lower-sulfur content fuel was used in the newer engine, while the nuclei-mode PM emissions from the older engine were much less affected by fuel sulfur content. The transient results, however, show that the total number of nuclei-mode PM emissions from both engines increases with fuel sulfur content, although this effect is only seen under the higher primary dilution ratios with the older engine. Transient results further show that higher primary dilution ratios increase total nuclei-mode PM number emissions in both engines.

Open burning of agricultural biomass: Physical and chemical properties of particle-phase emissions

We present the physical and chemical characterization of particulate matter (PM 2.5) emissions from simulated agricultural fires (AFs) of surface residuals of two major grain crops, rice ( Oryza sativa) and wheat ( Triticum aestivum L.). The O 2 levels and CO/CO 2 ratios of the open burn simulations are typical of the field fires of agricultural residues. In the AF plumes, we observe predominantly accumulation mode (100–1000 nm) aerosols. The mean PM 2.5 mass emission factors from replicate burns of the wheat and rice residuals are 4.7±0.04 and 13.0±0.3 g kg −1 of dry biomass, respectively. The combustion-derived PM emissions from wheat are enriched in K (31% weight/weight, w/w) and Cl (36% w/w), whereas the PM emissions from rice are largely carbonaceous (84% w/w). Molecular level gas chromatography/mass spectrometry analysis of PM 2.5 solvent extracts identifies organic matter that accounts for as much as 18% of the PM mass emissions. A scarcity of detailed PM-phase chemical emissions data from AFs required that comparisons among other biomass combustion groups (wildfire, woodstove, and fireplace) be made. Statistical tests for equal variance among these groups indicate that the degree to which molecular emissions vary is compound dependent. Analysis of variance testing shows significant differences in the mean values of certain n-alkane, polycyclic aromatic hydrocarbon (PAH), oxy-PAH, and sugar marker compounds common to the biomass combustion types. Individual pairwise comparisons of means at the combustion group level confirm this result but suggest that apportioning airborne PM to these sources may require a more comprehensive use of the chemical emissions fingerprints. Hierarchical clustering of source test observations using molecular markers indicates agricultural fuels as distinct from other types of biomass combustion or biomass species. Rough approximations of the total potential PM 2.5 emissions outputs from the combustion of the wheat and rice surface residues are given. This agricultural activity could significantly contribute to emissions inventories at regional, national, and global geographic levels.

A SIMULATED APPROACH TO ESTIMATING PM10 AND PM2.5 CONCENTRATIONS DOWNWIND FROM COTTON GINS

Cotton gins are required to obtain operating permits from state air pollution regulatory agencies (SAPRA), whichregulate the amount of particulate matter that can be emitted. Industrial Source Complex Short Term version 3 (ISCST3) isthe Gaussian dispersion model currently used by some SAPRAs to predict downwind concentrations used in the regulatoryprocess in the absence of field sampling data. The maximum ambient concentrations for PM10 and PM2.5 are set by theNational Ambient Air Quality Standard (NAAQS) at 150 .g/m3 and 65 .g/m3 (24 h average), respectively. Some SAPRAs usethe NAAQS concentrations as property line concentrations for regulatory purposes. This article reports the results of a uniqueapproach to estimating downwind PM10 and PM2.5 concentrations using Monte Carlo simulation, the Gaussian dispersionequation, the Hino power law, and a particle size distribution that characterizes the dust typically emitted from cotton ginexhausts. These results were then compared to a 10 min concentration (C10) and the concentrations that would be measuredby an FRM PM10 and PM2.5 sampler. The total suspended particulate (TSP) emission rate, particle size distributions, andsampler performance characteristics were assigned to triangular distributions to simulate the real-world operation of the ginand sampling systems. The TSP emission factor given in AP-42 for cotton gins was used to derive the PM mass emission ratefrom a 40 bale/h plant. The Gaussian equation was used to model the ambient TSP concentration downwind from the gin.The performance characteristics for the PM10 and PM2.5 samplers were then used to predict what the measured concentrationwould be for two PSD conditions. The first PSD assumption was that the mass median diameter (MMD) and geometricstandard deviation (GSD) were constant at 12 .m and 2, respectively, and the second scenario assigned a triangulardistribution to the MMD and GSD of {15, 20, 25} .m and {1.8, 2.0, 2.2}, respectively. The results show that the PM2.5 fractionof the dust emitted under either PSD condition was negligible when compared to the NAAQS for PM2.5 of 65 .g/m3. The resultsalso demonstrate that correcting for wind direction changes within the hour using the power law reduces the ambientconcentration by a factor of 2.45.