Engine Exhaust Particle Sizer Spectrometer Research Articles

Unlocking the nanoparticle emission potential: a study of varied filaments in 3D printing.

This study investigates nanoparticle emission during 3D printing processes, assessing various filament materials' impact on air quality. Commonly used 3D printers, including both filament and resin-based types, were examined. The study's scope encompasses diverse filament materials like ABS (acrylonitrile butadiene styrene), PLA (polylactic acid), PETG (polyethylene terephthalate glycol), ASA (acrylonitrile styrene acrylate), TPU (thermoplastic polyurethane), PP (polypropylene), nylon, and wood-based variants, alongside three types of resins. The research delves into the relationship between the type of material and nanoparticle emissions, emphasizing temperature's pivotal role. Measurement instruments were employed for nanoparticle quantification, including an engine exhaust particle sizer spectrometer, condensation particle counter, and nanozen dust counters. Notably, results reveal substantial variations in nanoparticle emissions among different filament materials, with ASA, TPU, PP, and ABS showing considerably elevated emission levels and characteristic particle size distribution patterns. The findings prompt practical recommendations for reducing nanoparticle exposure, emphasizing printer confinement, material selection, and adequate ventilation. This study offers insights into potential health risks associated with 3D printing emissions and provides a basis for adopting preventive measures.

Diesel exhaust particulate emissions and in vitro toxicity from Euro 3 and Euro 6 vehicles

Incomplete combustion processes in diesel engines produce particulate matter (PM) that significantly contributes to air pollution. Currently, there remains a knowledge gap in relation to the physical and chemical characteristics and also the biological reactivity of the PM emitted from old- and new-generation diesel vehicles. In this study, the emissions from a Euro 3 diesel vehicle were compared to those from a Euro 6 car during the regeneration of a diesel particulate filter (DPF). Different driving cycles were used to collect two types of diesel exhaust particles (DEPs). The particle size distribution was monitored using an engine exhaust particle sizer spectrometer and an electrical low-pressure impactor. Although the Euro 6 vehicle emitted particulates only during DPF regeneration that primarily occurs for a few minutes at high speeds, such emissions are characterized by a higher number of ultrafine particles (<0.1 μm) compared to those from the Euro 3 diesel vehicle. The emitted particles possess different characteristics. For example, Euro 6 DEPs exhibit a lower PAH content than do Euro 3 samples; however, they are enriched in metals that were poorly detected or undetected in Euro 3 emissions. The biological effects of the two DEPs were investigated in human bronchial BEAS-2B cells exposed to 50 μg/mL of PM (corresponding to 5.2 μg/cm2), and the results revealed that Euro 3 DEPs activated the typical inflammatory and pro-carcinogenic pathways induced by combustion-derived particles, while Euro 6 DEPs were less effective in regard to activating such biological responses. Although further investigations are required, it is evident that the different in vitro effects elicited by Euro 3 and Euro 6 DEPs can be correlated with the variable chemical compositions (metals and PAHs) of the emitted particles that play a pivotal role in the inflammatory and carcinogenic potential of airborne PM.

Emission of particulate matter during aircraft landing operation

The article presents the results of studies conducted in the area adjacent to the airport located in Poznan, to determine the impact of aircraft landing operation on the concentration of particulate matter. Measurements were carried out using Engine Exhaust Particle Sizer Spectrometer 3090, enabling the measurement of the particle size distribution. The research allowed to determine the nature of the emitted particles and adds to the evaluation of impact on air quality. The tests were carried out during four aircraft landing operations. In each of the four cases total concentration of particulates number before landing (reference level) and during the landing of the aircraft was measured. In addition, the size distribution of reference level particles and its change after the landing operation was measured. Based on the conducted research, it was found that landing aircrafts have a significant impact on the concentration of particulate matter in the area adjacent to the airport. A single landing operation causes an substantially increase of the value of particle number concentration.

Improvement of Engine Exhaust Particle Sizer (EEPS) size distribution measurement – I. Algorithm and applications to compact-shape particles

Comparisons between the Engine Exhaust Particle Sizer Spectrometer (EEPS) and scanning mobility particle sizers (SMPS) have shown that the EEPS underestimates size and concentration of particles >~75nm and that the discrepancies vary by particle type. This paper describes the development of a new EEPS instrument matrix to improve size distribution measurements for compact-shape particles. Both the operating principle and the mathematical model of the EEPS data inversion are described. Monodisperse and polydisperse sucrose, poly-α-olefin oil (PAO), and sodium chloride (NaCl) particles were used for calibration. A new instrument matrix was developed and implemented for data inversion. This study confirms the literature findings that the geometric mean diameter, geometric standard deviation, and total number concentration by EEPS with the default instrument matrix (referred to as IM-2004) agrees with SMPS within ±20% for compact-shape particles <~75nm. However, EEPS with IM-2004 underestimates geometric mean diameters by 20–40% for larger particles. The revised instrument matrix improves the size agreement with the SMPS to within ±14% across the entire size range.

Improvement of Engine Exhaust Particle Sizer (EEPS) size distribution measurement – II. Engine exhaust particles

Particle size distributions measured by the Engine Exhaust Particle Sizer Spectrometer (EEPS) have been reported to disagree with those by scanning mobility particle sizers (SMPS). The discrepancies are larger for the accumulation mode engine exhaust particles than for compact-shape particles. Engine exhaust particles, specifically carbonaceous aggregates, have different charging characteristics compared to nearly spherical particles because aggregates acquire more charges at a given mobility diameter in a unipolar charging environment. Therefore, different instrument matrices, that represent the relationship between particle size and EEPS electrometer current distributions, are needed for compact-shape particles and aggregates. This paper reports on a study to improve the EEPS performance for engine exhaust measurements. The EEPS was calibrated with monodisperse particles from the exhaust of a diesel engine. The geometric mean diameters measured by the EEPS using the original instrument matrix agreed with SMPS within 15% for particles <50nm (that were mostly spherical), but underestimated by 20–50% for larger particles (that were mostly aggregates). A new EEPS instrument matrix was developed for fresh engine exhaust, and its performance was evaluated using a diesel engine, two passenger cars with gasoline direct injection (GDI) engines, one vehicle with a turbo direct injection (TDI) diesel engine, and a diesel generator. The geometric mean diameters by the EEPS new matrix agreed with SMPS within 14% for monodisperse engine exhaust particles<50nm while larger particles agreed within −19% to 1%. The new matrix also improved the agreement between EEPS and SMPS for polydisperse exhaust particles from different engines under different operating conditions. Diesel engine tests showed that the total concentration, geometric mean diameter, and geometric standard deviation by the SMPS and EEPS with the new matrix differed less than 16%, 33%, and 9%, respectively, with the greatest differences found for particles <15nm.

Effect of Ethanol–Diesel Fuel Blend on Diesel Engine Emissions Produced by Different Bus Fleets

AbstractThe major regulated pollutants emitted by a diesel urban bus are nitrogen oxides (NOx) and particulate matter (PM). These emissions depend on the engine and its strategies (injection, exhaust-gas recirculation, after-treatment devices, etc.), altitude, weather conditions, route, and driver. This work studies the effect of two fuels, one of them oxygenated, on both NOx emissions and particle-size distributions in comparison with a diesel fuel used as reference. The study was carried out with buses operating in two different cities, one of them located at around 650 m above sea level and the other near sea level. The test fuels were a binary blend of ethanol and diesel fuel (denoted as ED) and a diesel fuel without biodiesel (denoted as D). Emissions were measured using a Horiba OBS-1300 gas analyzer and a TSI engine exhaust particle sizer spectrometer. Results showed a reduction in both NOx emissions and total particle number concentrations with altitude, independently of fuel tested, and an increa...

The Effect of Nanoparticle Morphology on the Measurement Accuracy of Mobility Particle Sizers

The influence of particle morphology on the accuracy of nanoparticle size distributions measured by the engine exhaust particle sizer spectrometer (EEPS, TSI Model 3090) was studied using the scanning mobility particle sizer (SMPS, TSI Model 3936) as a reference. The EEPS shows higher total number concentrations with the maximum relative difference up to 67 % and smaller number median mobility diameters for polydisperse silver nanoparticles generated in the laboratory. To provide a quantitative explanation of the difference, generated polydisperse nanoparticles were classified as monodisperse particles with the initial equivalent mobility diameter (d m1) and sintered in the second furnace at different temperatures (room temperature to 600 °C), to change their morphologies for the comparison tests. Without sintering (room temperature), results show that the measured mobility diameter (d m2) of the EEPS is smaller than that measured by the SMPS when d m1 is larger than 30 nm and the difference increases as d m1 is increased from 30 to 300 nm. But the difference decreases as the morphology of particles is changed from branched chain agglomerates to spheres for d m1 less than 80 nm and the sintering temperature higher than 200 °C. Theoretical analysis shows that the mean charge per agglomerates is more than that of spheres resulting in overestimation of the electrical mobility and underestimation of the d m2 by the EEPS.

Particle size distributions from a city bus fuelled with ethanol–biodiesel–diesel fuel blends

The use of oxygenated fuels has potential to reduce the greenhouse gases and the regulated pollutant emissions from diesel engines. Apart from particulate matter and NOx emissions, the study of particle concentration and its size distribution emitted by diesel engines is gaining attention due to the harmful effects on the environment and human health. In this work, particle size distributions (PSDs) from the exhaust gas of a city bus working in real driving conditions have been measured using three different fuel blends: petroleum diesel used as reference fuel, a binary fuel blend of 7.7%v/v ethanol on diesel fuel (denoted as ED) and a ternary fuel blend (denoted as EBD) of ethanol, biodiesel and diesel fuels with 10%v/v of ethanol on a binary B30 fuel blend (30%v/v of soybean biodiesel on pure diesel fuel). For measuring the PSD, a city bus was equipped with a rotating disk diluter coupled to a dilution air thermal conditioner. The diluted gas was driven to a TSI Engine Exhaust Particle Sizer spectrometer. The main objective of this work was to evaluate the effect of the fuel on the main statistical parameters of PSD (geometric mean diameter and total concentration) during acceleration transitions in real vehicle driving operation. Compared to diesel fuel, the results showed a great reduction of particle concentration when both fuel blends were used, although the relative differences depended on the transition studied.

Onboard Measurements of Nanoparticles from a SCR-Equipped Marine Diesel Engine

In this study nanoparticle emissions have been characterized onboard a ship with focus on number, size, and volatility. Measurements were conducted on one of the ship's four main 12,600 kW medium-speed diesel engines which use low sulfur marine residual fuel and have a Selective Catalytic Reduction (SCR) system for NO(X) abatement. The particles were measured after the SCR with an engine exhaust particle sizer spectrometer (EEPS), giving particle number and mass distributions in the size range of 5.6-560 nm. The thermal characteristics of the particles were analyzed using a volatility tandem DMA system (VTDMA). A dilution ratio of 450-520 was used which is similar to the initial real-world dilution. At a stable engine load of 75% of the maximum rated power, and after dilution and cooling of the exhaust gas, there was a bimodal number size distribution, with a major peak at ∼10 nm and a smaller peak at around 30-40 nm. The mass distribution peaked around 20 nm and at 50-60 nm. The emission factor for particle number, EF(PN), for an engine load of 75% in the open-sea was found to be 10.4 ± 1.6 × 10(16) (kg fuel)(-1) and about 50% of the particles by number were found to have a nonvolatile core at 250 °C. Additionally, 20 nm particles consist of ∼40% of nonvolatile material by volume (evaporative temperature 250 °C), while the particles with a particle diameter <10 nm evaporate completely at a temperature of 130-150 °C. Emission factors for NO(X), CO, and CO(2) for an engine load of 75% in the open-sea were determined to 4.06 ± 0.3 g (kg fuel)(-1), 2.15 ± 0.06 g (kg fuel)(-1), and 3.23 ± 0.08 kg (kg fuel)(-1), respectively. This work contributes to an improved understanding of particle emissions from shipping using modern pollution reduction measures such as SCR and fuel with low sulfur content.

Particles emitted during the stops of an urban bus fuelled with ethanol–biodiesel–diesel blends

Urban buses with diesel engines produce NOx and particulate matter emissions thus affecting local city pollution. During stops, due to traffic lights, programmed stops, etc., pollutants are emitted close to people, being damaging to their health. This paper studies the effects on particle size distributions caused by the use of oxygenated fuels during stops of an urban bus. Fuels used are a blend of ethanol and diesel (denoted as ED) and a blend of ethanol, biodiesel and diesel (denoted as EBD), which are compared to a diesel fuel used as reference. Tests were carried out on a vehicle under real working conditions in the Spanish city of Seville. A Horiba 1300 on-board system (OBS) was used to measure operating conditions, and an Engine Exhaust Particle Sizer Spectrometer was used to determine particle size distributions. Results showed a reduction in the number concentration of accumulation mode when oxygenated fuels were used. However, they produced a slight increase in the nuclei mode, as well as a reduction in particle diameters from both modes when using EBD blends, being more significant when referring to accumulation mode. These findings may be considered negative for the oxygenated blends under these operating conditions.

Methodology for measurement of diesel particle size distributions from a city bus working in real traffic conditions

The study of particulate matter (PM) and nitrogen oxides emissions of diesel engines is nowadays a necessary step towards pollutant emission reduction. For a complete evaluation of PM emissions and its size characterization, one of the most challenging goals is to adapt the available techniques and the data acquisition procedures to the measurement and to propose a methodology for the interpretation of instantaneous particle size distributions (PSD) of combustion-derived particles produced by a vehicle during real driving conditions. In this work, PSD from the exhaust gas of a city bus operated in real driving conditions with passengers have been measured. For the study, the bus was equipped with a rotating disk diluter coupled to an air supply thermal conditioner (with an evaporating tube), the latter being connected to a TSI Engine Exhaust Particle Sizer spectrometer. The main objective of this work has been to propose an alternative procedure for evaluating the influence of several transient sequences on PSD emitted by a city bus used in real driving conditions with passengers. The transitions studied were those derived from the combination of four possible sequences or categories during real driving conditions: idle, acceleration, deceleration with fuel consumption and deceleration without fuel consumption. The analysis methodology used in this work proved to be a useful tool for a better understanding of the phenomena related to the determination of PSD emitted by a city bus during real driving conditions with passengers.