Particle Emission Characteristics Research Articles

Investigation on gas and particle emission characterization of carbon black oxidation process promoted by catalyst/ash

The study of the gas and particle emission characteristics during the oxidation of carbon black particles is the basis for exploring the particle emission characteristics during diesel particulate filter (DPF/CDPF) regeneration process. The gas and particle emission of Printex U (PU) particles oxidation under different oxidation temperatures and sample masses are investigated based on fixed bed and thermogravimetric analysis, and the oxidation processes are conducted under the cooperative effect of catalyst (CeO2)/ash (ZnO). The experimental results show that, with the increase of oxidation temperature, the CO/CO2 concentration, the extent of oxidation (η) and the total emitted solid particulate number (PN) increase, but the average particulate diameter (Da) range reduces from 60 to 100 nm to 20–40 nm. On the other hand, with the increase of PU mass, the CO/CO2 concentration and the total PN increase together, and the Da rises from about 30 nm to 40–160 nm, while the η decreases markedly. Both the CeO2 and ZnO nanoparticles can promote the PU oxidation process, and then reduce CO emissions, which lead to the rise the CO2 emissions. Beneficially, the η and the Da increase under the effect of CeO2 and ZnO, and the total PN decreases sharply. Adding catalyst (CeO2) and ash (ZnO) can effectively reduce the emission of small particle size (<23 nm) during oxidation process, which provides a research basis for controlling the emission of particles below 23 nm during DPF regeneration process.

Study of gas and particulate emission characteristics during the fast regeneration period of DPF

Based on the diesel particulate filter (DPF) regeneration test bench and the particulate loading device, the effects of regeneration temperature and flow rate on the gas and particulate emissions during the fast regeneration period of the DPF are explored. The results show that the fast regeneration period is usually easy to occur during the DPF active regeneration process, which leads to the fast increase of the internal temperature of the DPF substrate. During the fast regeneration process, the gas and particulate emissions in the regeneration process are mainly concentrated in this period, accounting for 45.8%–83.2% and 61%–84% of the total emissions respectively. With the increase of the regeneration temperature, the proportion of gas emissions during the fast regeneration period decreases, while the proportion of particulate emissions remains essentially unchanged. Increasing the regeneration temperature does not significantly improve the regeneration efficiency in the fast regeneration period. With the increase of the flow rate, both the proportion of gas and particulate emissions decrease, and the DPF regeneration is inhabited. On the other hand, after the fast regeneration period, DPF regeneration enters the slow regeneration stage, the economy of input energy for the DPF regeneration gradually decreases. Controlling active DPF regeneration needs to take into account the impact of fast regeneration period on emission and input energy, together with the effect of regeneration temperature and flow rate.

Investigation of the combustion and particle emission characteristics of a GDI engine with a 50 MPa injection system

The effects of injection pressure and injection timing are investigated in a gasoline direct injection engine with a 50 MPa injection system at part-load operating condition by experimental methods. The engine was invariably operated in stoichiometric air/fuel ratio, 1500 r/min engine speed and 5–15 bar break mean effective pressure (BMEP). The characteristics of combustion, particle size distribution (PSD) and particle number (PN) concentration of the emission are analyzed. The results indicate that delaying the injection timing can suppress the knocking tendency at higher engine loads, and significantly reduce fuel consumption, but the delayed injection increases particle emission. With the fuel injection pressure increased from 35 MPa to 50 MPa, the PN of all particle size segments are significantly reduced. High injection pressure has a significant effect on reducing the accumulation particles, and the PN concentration is reduced by more than 20%. The particles with a diameter of 5–23 nm (sub-23 nm) are a problem that cannot be ignored, which accounts for more than 50% of the total PN emission. A high fuel injection pressure can effectively reduce particulate matter emissions caused by late injection, thereby achieving both fuel consumption and particle emission reduction.

A review on morphology, nanostructure, chemical composition, and number concentration of diesel particulate emissions.

Particulate matter (PM) emitted from compression ignition (CI) engines (diesel engines) has a detrimental effect on human health and the environment. The physical and chemical characteristics of PM emitted from CI-engines are influenced by engine operating conditions and fuel properties. The morphology, nanostructure, and chemical composition of PM affect its toxicity and interaction with the environment. From automotive industry perspective, these parameters influence the design of diesel particulate filters. This study presents a review of the physical and chemical characteristics of particulate emissions from the CI-engine. The present study commences with a brief description about the composition of PM emitted from CI-engine and the PMformation mechanism in CI-engine. Later on, the detailed review of PM's physical and chemical characteristics and the effect of engine operating parameters and alternative fuels on the particle number concentration, morphology, nano-structure, and oxidative reactivity of PM is presented. Online and offline methods of diesel particulate characterization and emerging chemical characterization techniques such as X-ray photoelectron spectroscopy and X-ray absorption fine structure (EXAFS) are also discussed briefly. Correlation between physical and chemical properties, and oxidative reactivityof PM is also discussed. It was found that engine operating parameters affect the physical and chemical properties of PM. Use of alternative fuels changes the diesel particulate morphology, nanostructure, and chemical composition which enhances the oxidative reactivity of PM.

Comparative study on combustion and particulate emissions for diesel-biodiesel and diesel-diglyme blends

Experiments were conducted on a 4-cylinder direct-injection diesel engine using ultralow sulfur diesel blended with biodiesel or diglyme to investigate the influence on combustion and particulate emission characteristics. Five biodiesel blends and five diglyme blends with oxygen concentrations of 2%, 4%, 6%, 8% and 10% were prepared respectively and tested separately at five engine loads of maximum torque speed of 2400 rpm with same boundary condition. With the increase of oxygen content, in-cylinder pressure and heat release curve advanced for both blends but the peak values were lower than of diesel, the trend was more obvious for diglyme blends. Besides combustion centre was slightly varied for biodiesel fuels but postponed significantly for diglyme blends. Meanwhile, smoke opacity, brake specific particulate emissions and the geometric mean diameter of particle decreased accompanying with the increase in soluble organic fraction proportion, and biodiesel blends had more obvious variations. In addition, the total particle number concentration and the particle smaller than 100 nm in diameter increased gradually and unidirectionally for biodiesel blended fuels, but for diglyme blends, the peak value of the total particle was found from the blend containing 2% oxygen and the particles from all diglyme blends were higher than that from diesel. Compared with biodiesel, diglyme fuels had more particulate and particles emissions on the same oxygen base.

IVOC/SVOC and size distribution characteristics of particulate matter emissions from a modern aero-engine combustor in different operational modes

The particulate matter (PM) of Intermediate-Volatile Organic Compounds (IVOC) / Semi-Volatile Organic Compound (SVOC) from aircraft engine emissions, despite being significant precursors of secondary organic aerosols deteriorating air quality in the vicinity of airports, have not been fully investigated at molecular level. In this study, the particulate IVOC/SVOC emissions from a rig test on a Technology of Low Emission Stirred Swirl aero-engine combustor, being operated with dual diffusion and premixed-dominant combustion modes, have been characterized via a two-dimensional gas chromatography-time of flight mass spectrometer (GC × GC-ToFMS). The IVOC/SVOC compounds, including 25n-alkanes, 15 cyclic alkanes and 13 polycyclic aromatic hydrocarbons were analyzed in this study. We found that including the premixed-dominant combustion mode at climb/takeoff conditions reduced the particulate IVOC/SVOC emissions significantly by nearly 80%, compared to using the diffusion combustion mode alone at idle/approach condition. Meanwhile, the measurements on organic PM obtained from a scanning mobility particle sizer spectrometer with a catalytic stripper demonstrated a consistent trend with the the IVOC/SVOC emissions, which were also suppressed by over 85% at climb/takeoff compared to idle/approach. The inter-relationship between the size-resolved organic PM and the speciated IVOC/SVOC emissions has been further explored, showing that the nucleation mode PM is dominated in organic PM by over 50%, in which IVOCs/SVOCs may be a significant contributor. This study expands the understanding of aviation-emitted organic particles, and suggests a path for future aero-engine development to mitigate the IVOC/SVOC emissions particularly at low power conditions. However, compared to the real aero-engine emissions, the results from rig combustor tests should be interpreted with great care, since there are still some work to be done to establish the quantitative relationship between emissions from rig combustors andthose from real engines.

Emission characteristic of non-road mobile machinery using a catalysed diesel particle filter with different catalyst loadings under actual operating conditions

The real-world gaseous and particulate emission characteristics of an agricultural tractor retrofitted with a catalysed diesel particulate filter (CDPF) with different catalyst loadings were investigated. The tests were carried out using a portable emission measurement system (PEMS) under idling, running and working conditions. The results showed that the emissions of the tractor strongly depended on the operating conditions. From idling to running then to working condition, the emission rates increased but emission factors based on fuel consumption decreased, and the proportion of nucleation particles and geometric mean diameter presented a slight downward trend. The reduction effect of CDPF on the CO and total hydrocarbon (THC) improved from idling to running then to working condition, and it was enhanced by increasing catalyst loading. The particle number (PN) and particle mass (PM) reduction performance of CDPF was less affected by operating condition but enhanced with the increase of the catalyst loading. After the tractor was equipped with the CDPF, the particle size distribution maintained a bimodal shape, but the decrease of nucleation particles was significantly higher than that of accumulation particles, causing a decrease in the nucleation particles proportion and a shift of the peak towards smaller particle size. With the increase of the CDPF catalyst loading, the proportion of the accumulation particles increased, and the geometric mean particle size also increased. The findings of this paper can provide scientific references to design and optimize CDPF for non-road mobile machinery to achieve clean emissions.

Characteristics of particulate emissions from coal char combustion: Char fragmentation and ash coalescence behaviors

Air pollution from fossil fuel combustion motivated the extensive and in-depth investigation on particulate matter (PM) to meet the stringent emission norms. The relationship between char fragmentation/mineral coalescence and PM formation is elucidated in this paper. To separately investigate their contributions to PM formation, the effects of particle bursting during devolatilization and fragmentation of excluded minerals have been stripped off. We prepared size-graded and density-fractionated chars with varying ash content levels and conducted combustion experiments in a drop-tube furnace at 1300/1600/1800 K. The mass particle size distributions (PSDs) of collected ash were measured by an Electrical Low Pressure Impactor (for PM10) and a laser particle-size analyzer (for PM10+). The micro- morphologies and elemental compositions analyses were also shown for particles of different sizes. The results indicate that char fragmentation significantly increases the number of ash particles in fine-fragmentation mode (FFM), and the ash peak in the coarse mode comes from the char particles that show fewer fragmentation behaviors. Dense char structure disadvantages char fragmentation but enhances coalescence of included minerals. The distribution of fly ash at 1600/1800 K exhibits bi-modal with two peaks around 10 and 105 μm, while the distribution at 1300 K/50%O2 exhibits uni-modal with one peak. This can be well explained by the percolation theory that the char combustion in the kinetically-limited regime is dominated by uniform fragmentation, while particles at 1600/1800 K mainly undergo perimeter fragmentation. The effect of ash content is more related to the mineral grains distributions within the char particles.

Di-ethyl ether-diesel blends fuelled off-road tractor engine: Part-II: Unregulated and particulate emission characteristics

The use of oxygenated fuels, including ethanol, methanol, diethyl ether (DEE), and dimethyl ether (DME) in CI engines has emerged as an effective way to reduce CO, HC, and PM emissions. DEE, in particular, has significant potential to be used in CI engines. Unlike DME, it exists as a liquid state at room temperature and pressure, making its handling very smooth. In this experimental study, DEE-diesel blends were used to power an off-road tractor engine. Previous studies investigated the performance and regulated emission characteristics of DEE-fueled vehicles/ engines; unregulated emissions and particulate characteristics were not studied thoroughly. This study, therefore, investigates the effect of DEE-diesel blends on unregulated and particulate emissions from the engine. Unregulated pollutants investigated in this study include individual oxides of nitrogen (NO, NOx, NO2), saturated and unsaturated hydrocarbons (n-pentane (n-C5H12), n-octane (n-C8H18), iso-butene (iso-C4H8)), and organic and inorganic species (Sulphur dioxide (SO2), formic acid (HCOOH) and formaldehyde (HCHO)). Particulate emission characteristics include total particle mass (TPM), total particle number (TPN), particulate mass-size distributions, and count mean diameter (CMD). Four test fuels were used in this study namely: DEE0, DEE15, DEE30 and DEE45 (0%, 15%, 30% and 45% DEE (v/v) blended with mineral diesel). The results from DEE-diesel blends were compared with baseline mineral diesel (DEE0). The experiments were conducted at a constant engine speed of 1500 rpm at varying engine loads. At all engine operating conditions, DEE-diesel blends resulted in significantly lower TPN compared to baseline mineral diesel. A similar trend was observed for TPM; however, DEE15 showed slightly higher TPM than baseline mineral diesel. Emissions of individual oxides of nitrogen were also relatively lower than baseline mineral diesel. The addition of DEE in mineral diesel exhibited a slight increase in unregulated emission species concentrations such as formaldehyde, formic acid, sulfur dioxide, n-pentane, n-octane, iso-butene. However, the absolute concentration levels were still quite low. This study concluded that DEE could potentially displace mineral diesel partially, without any changes in fuel injection equipment, and achieve an improvement in PM-NOx trade-off in off-road transport diesel engines.

Regeneration performance and particulate emission characteristics during active regeneration process of GPF with ash loading

The deposited ash has an important effect on the regeneration of GPF, this paper aims to study the effects of ash particle size and loading on particle emission characteristics. The results indicates that the deposited carbon black particles are easy to be blown out during heating stage and local high temperature leads to 3 orders of magnitude of emitted particles during regeneration stage. The pure Al2O3 ash#1 (2 μm) inhibit the release of particles during heating stage and also promotes regeneration efficiency, resuliting in high total emitted particle mass concentration during regeneration stage. While the impacts of the pure Al2O3 ash#2 (15 μm) is opposite to ash#1. As the loading of mixed particle Al2O3 + SiO2 ash#3 (low thermal conductivity) increases from 5 g/L to 15 g/L, particles are more likely to be blown out because of the coupling of the ash layer and filter wall, and the exhaust particles at GPF outlet also decrease, mainly distributing in large-size aggregated particles (50–100 nm) during the regeneration stage.

Experimental Investigation on the DPF High-Temperature Filtration Performance under Different Particle Loadings and Particle Deposition Distributions

Based on DPF filtration and regeneration bench, the solid particle emission and high-temperature filtration characteristics of different carbon black particle loadings and particle deposition distributions are studied. The aerosol generator (PAlAS RGB 1000) is used to introduce carbon black particles into the inlet of a DPF, and the NanoMet3 particle meter is used to measure the solid particle concentration at the inlet and outlet of a DPF to obtain the filtration characteristics. Previous studies found that without inlet carbon black particles, there was an obvious solid particle emission peak at the outlet of the deposited DPF during the heating, and the concentration increased by 1–2 orders of magnitude. In this paper, the high-temperature filtration characteristics under steady-state temperature conditions are studied. It is found that a DPF can reduce the range of inlet fluctuating particles, and with the increase of temperature, the proportion of large solid particles in the outlet particles increases, and the size distribution range decreases. Particle loading has positive and negative effects on the DPF filtration, and the DPF has the optimal particle loading, which makes the comprehensive filtration efficiency improve the highest. The deposition transition section can make the deposition particles in the DPF uniform, but the filtration efficiency is reduced.

Characteristics of particle emissions from light duty diesel vehicle fueled with ultralow sulphur diesel and biodiesel blend

This study investigates the particle emissions from a diesel vehicle fueled with ultralow sulphur diesel (B0, ULSD) and 5 % biodiesel blend (B5) by a chassis dynamometer test under three driving conditions. Elemental carbon (EC), organic carbon (OC), 30 species of polycyclic aromatic hydrocarbon (PAH) and 10 species of oxygenated PAH (oxy-PAH) were analyzed to quantify the chemical compositions of the collected particulate matter (PM). The emission factors (EFs) of OC were increased with B5 by a range between 39.5 % and 113.7 %, compared with B0. Both fuel blends recorded a trace amount of EC (0.25 mg/kg or less). It was found that the B5 EFs of total PAHs were decreased by a range between 15.2 % and 50.2 % relative to B0. 2- to 3-ring species, the dominant PAHs and oxy-PAHs, were decreased substantially when using B5. However, the results showed that biodiesel blend promoted the emission of 4- and 5-ring oxy-PAHs and 5- to 7-ring PAHs. The application of B5 shifted the composition towards a higher proportion of PAHs with higher molecular weight and more oxy-PAHs. Due to the increased emissions in PAHs with higher toxic equivalent factors (TEFs), the application of B5 resulted in an increase in toxicity expressed in BAPeq range from 11.3 % to 117.0 %.

Thermogravimetric analysis of solid biomass fuels and corresponding emission of fine particles

A significant problem of biofuel combustion is the emerging emissions of particulate matter. This paper deals with the experimental determination of the particulate matter emission characteristics of 27 different types of conventional and less traditional solid biofuels. Thermogravimetric analysis is used for the controlled heating of all tested samples from 25 °C to 650 °C with a 10 °C·min−1 heating rate. The analysis is performed for two atmosphere compositions, namely 21 % O2 and 0 % O2. The resulting flue gas is fed to an instrument allowing fine particles' detection ranging from 18 to 545 nm in diameter. The relation between the temperature of fuel samples and the number and mass of the generated particles is investigated. The percentage of the original sample mass converted to particles is determined. Subsequently, particulate matter emission is expressed as a relation to sample ash content and sample volatile matter content. The specific particulate matter emissions range of all tested samples are expressed per megajoule of higher heating value (HHV): 1.02–2.67·1015 #·MJ−1 and 694–2844 mg MJ−1 in the atmosphere with 21 % of O2 and 1.11–3.29·1015 #·MJ−1 and 898–6823 mg MJ−1 in the atmosphere without oxygen (pyrolysis).

Characterization of Particle Emissions from a DGEN 380 Small Turbofan Fueled with ATJ Blends

The fine particulate matter (PM) emitted from jet aircraft poses a serious threat to the environment and human health which can be mitigated by using biofuels. This paper aims to quantify PM emissions from a small turbofan fueled with the alcohol to jet (ATJ) synthetic kerosene and its various blends (5%, 20%, and 30% of ATJ) with Jet A-1 fuel. Emissions from a turbofan engine (DGEN 380) with a high bypass ratio, applicable in small private jets, were studied. Among the four fuels tested, the PM-number emission index (EIN) was the lowest for the ATJ 30% blend. EIN for ATJ 30% dropped from 1.1 × 1017 to 4.7 × 1016 particles/kg of fuel. Burning alternative fuel blends reduced the particle mass emissions over the entire range of fuel flow by at least 117 mg/kg of fuel. The particles formed in the nucleation mechanism dominate PM emission, which is characteristic of jet engines. Thus, number-based particle size distributions (PSDs) exhibit a single mode log-normal distribution. The highest values of EIN were found for Jet A-1 neat compared to other fuels. The use of the ATJ additive did not cause significant changes in the size of the particles from nucleation mode. However, a magnitude reduction of nucleation mode was found with the increase in the ATJ ratio.

Characteristics of Particulate Emissions from Co-Firing in An Industrial Boiler

Characteristics of Particulate Emissions from Co-Firing in An Industrial Boiler. PT. X is a textile industry that consumes a massive amount of coal for its boiler operation. It requires substantial costs to obtain coal from Sumatra and Kalimantan. An alternative solid biofuel (briquette) was developed to combine bottom ash and biomass made from municipal solid waste called Biomass Coal Fuel (BCF) briquette. The purpose of this study is to measure the total concentration of particulate matter and emission factor (PM) emitted from two burning experiments: only coal (100%) and mixed coal fuel with 10% of BCF (co-firing). Mixed coal and BCF burning are carried out in the fire-tube boiler where the PM emission is released through the stack. The Center for Pulp and Paper measured particulate emission with methodology referring to SNI 7117.17-2009. Particulate matter concentration emitted from only coal-burning was 12,1 mg/Nm3,but when mixed BCF and coal were used, the higher concentration was emitted 70,9 mg/Nm3. The addition of BCF briquettes affects the particulate matter emission, even though the emission does not exceed the regulated quality standard. The increase of particulate concentration is due to the BCF briquette characteristics, which have a low heating value and high ash content. The boiler has already been equipped with cyclone and wet scrubber; therefore, PM emissions presented here are treated emissions. The controlled PM emission factor of BCF was 4,46 g/kg, which is higher than only coal which was 0,51 g/kg. BCF briquette can still be used as co-fuel for the boiler, but further effort is still required to reduce the ash content of the BCF and increase the calorific value of the BCF.

Characteristics of Particulate Emissions from Co-Firing in An Industrial Boiler

Characteristics of Particulate Emissions from Co-Firing in An Industrial Boiler. PT. X is a textile industry that consumes a massive amount of coal for its boiler operation. It requires substantial costs to obtain coal from Sumatra and Kalimantan. An alternative solid biofuel (briquette) was developed to combine bottom ash and biomass made from municipal solid waste called Biomass Coal Fuel (BCF) briquette. The purpose of this study is to measure the total concentration of particulate matter and emission factor (PM) emitted from two burning experiments: only coal (100%) and mixed coal fuel with 10% of BCF (co-firing). Mixed coal and BCF burning are carried out in the fire-tube boiler where the PM emission is released through the stack. The Center for Pulp and Paper measured particulate emission with methodology referring to SNI 7117.17-2009. Particulate matter concentration emitted from only coal-burning was 12,1 mg/Nm3,but when mixed BCF and coal were used, the higher concentration was emitted 70,9 mg/Nm3. The addition of BCF briquettes affects the particulate matter emission, even though the emission does not exceed the regulated quality standard. The increase of particulate concentration is due to the BCF briquette characteristics, which have a low heating value and high ash content. The boiler has already been equipped with cyclone and wet scrubber; therefore, PM emissions presented here are treated emissions. The controlled PM emission factor of BCF was 4,46 g/kg, which is higher than only coal which was 0,51 g/kg. BCF briquette can still be used as co-fuel for the boiler, but further effort is still required to reduce the ash content of the BCF and increase the calorific value of the BCF.

Fuel Effects on Engine-out Emissions Part 2 - Fuel Properties Correlations

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;Particulate matter emissions from internal combustion engines have become an increasingly important area of focus for development teams in recent years. This is due to greater regulatory scrutiny on vehicles globally, and especially on particulate emissions. The chemical composition and bulk physical properties of the fuel have been shown to influence the particulate number emissions characteristics. Although some predictive models have been proposed, the causality of specific properties or constituents has not been demonstrated due to the co-linearity of the variables considered in previous studies.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;In this work, fuels were formulated to capture the expected variation in three key properties of United States (US) market gasoline fuels. Specifically, total aromatics, volatility, and particulate matter index (PMI) were varied across market extremes within regulatory limits--while holding other properties constant. Engine dyno tests were performed with the formulated fuels on a 4-cylinder 2.3 L turbocharged direct injection spark-ignited engine, operated between 2 and 16 bar BMEP.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;ANOVA analysis was used to demonstrate that both low volatility and high PMI independently increased particle number (PN) emissions at high load at a statistically significant level, whereas total aromatics was only significant at low-load. However, neither low-volatility nor high PMI was universally bad for PN emissions, and other properties also played an important role. For example, at &amp;lt;12 bar BMEP the lowest PN formulated fuel was a low-volatility, high PMI, low aromatics fuel.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;The nine formulated fuels from this work along with ten fuels tested in Part 1 of this work were used to correlate PN and THC emissions with various fuel properties, within the repeatability of the test. For PN emissions, most of the fuel-to-fuel differences could be explained across the entire load range using a combination of 5 parameters: FBP, T90, A9&lt;sup&gt;+&lt;/sup&gt;, IP9&lt;sup&gt;+&lt;/sup&gt;, and C11. A9&lt;sup&gt;+&lt;/sup&gt; and FBP were always positively correlated with emissions, whereas IP9&lt;sup&gt;+&lt;/sup&gt; was negatively correlated, and T90 and C11 switched from negative to positive depending on load. For THC, only three parameters were required, and T70 was by far the best predictor of emissions—accounting for 50-70% of the difference between fuels.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;The work highlights the critical properties that determine engine out emissions characteristics of different fuels, and shows a path to formulating fuels that can simultaneously reduce PN and THC from vehicles.&lt;/div&gt;&lt;/div&gt;

Effects of engine restart strategy on particle number emissions from a hybrid electric vehicle equipped with a gasoline direct injection engine

Hybrid electric vehicle (HEV) tend to emit large amount of gaseous and particle emissions right after engine restart (ER). In this study, on-board particulate number (PN) measurement test and chassis dynamometer tests were conducted to analyze the effects of the ER combustion strategy on the gaseous and particle emission characteristics of a gasoline direct injection (GDI) HEV. The on-board PN measurement tests were conducted to examine the effect of a parameter sweep such as injection pressure, end of injection (EOI), spark timing of ER. It was measured by the pegasor particle sensor (PPS)-M, a device that measures the number of particles with a size from 23 nm to 25 μm, and the ES-582.1 module that can acquire electronic control unit (ECU) data. In the chassis dynamometer test, particle emissions, gaseous emissions and fuel economy of the reference case and the Combination Case 2 were compared and analyzed in the worldwide harmonized light vehicles test cycles (WLTC) mode test using Horiba, MEXA-ONE and MEXA-2000 solid particle counting system (SPCS). Reference case refers to a control strategy that does not touch anything in the vehicle's basic control strategy, and Combination Case 2 is the largest PN reduction case combined by calibrating the parameters. On-board PN measurement tests show that in reference case, ER PN accounted for about 70% of the total PN. Compared to the reference case, the sum of ER PN averages tended to decrease with higher injection pressure, advanced EOI, and retarded spark timing. The results of Combination Case 2 indicate that the sum of ER PN averages decreased by 88.7% compared to the reference case. In the WLTC mode test, THC, CO emissions and fuel economy were almost the same, and NOx was reduced by 85.6%. In both PPS and SPCS, the sum of ER PN average ratios decreased by 20%.

Studies on characteristics of fine particulate matter emissions from agricultural residue combustion

Biomass burning is largely divided into six types: open burning, agricultural waste burning, meat and fish roasts, wood stoves and boilers, furnaces, and charcoal burners. Biomass burning is largely characterized by incomplete combustion due to the difficulty of appropriate control, which results in the emission of a large amount of air pollutants and the generation of harmful substances such as volatile organic compounds (National Institute of Environmental Research, 2014). Burning agricultural residue releases a large amount of fine particulate matter (PM). Open burning of agricultural residue, burning agricultural residues without incineration facility, in the rural areas are frequently observed Therefore, management based on accurate analysis of emission characteristics is needed. In Korea, most agricultural residues except for rice straw are incinerated in the field. Agricultural residues with a high incineration ratio are Chili and Perilla. The characteristics of PM emission by agricultural residues combustion were analyzed for Chili and Perilla. PM measuring equipment are Stack sampling system and Cascade Impactor (PM10, PM2.5 Impactor, Johnas, Paul Gothe GmBH). This study, the emission characteristics of PM-10, PM-2.5 generated in the combustion of agricultural residues were examined in consideration of moisture content.

Size distribution and chemical characteristics of particles from crop residue open burning in North China

Crop residue open burning is an important emission source of ambient particles in China. This study analyzed the particle emission characteristics of crop residue open burning through combustion experiments with a novel open combustion simulation device using three typical crop straws in north China (corn, wheat, and rice). Particle samples size ranging from 0.006–9.890 µm were collected by an Electrical Low Pressure Impactor plus, a high size-resolution instrument capable of dividing particles into 14 size stages. The size distributions of organic carbon (OC), elemental carbon (EC), water-soluble ions, and elements were analyzed, and source chemical profiles were constructed for PM0.1, PM1, PM2.5, and PM10. The number concentration of particles was concentrated in the Aiken nuclei mode (0.006–0.054 µm), accounting for 75% of the total number, whereas the mass concentration was concentrated in the accumulation mode (0.054–0.949 µm), accounting for 85.43% of the mass loading. OC, EC, Cl−, and K(include total K and water-soluble K) were the major chemical components of the particles, whose mass percentage distributions differed from those of other components. These five main components exhibited a bell-shaped size distribution in the 0.006–9.890 µm range, whereas the other components exhibited a U-shaped distribution. Among the chemical profiles for PM0.1–PM10, OC was the most important component at 10–30%, followed by EC at 2%–8%. The proportions of K+, Cl−, and K varied substantially in different experimental groups, ranging from 0–15%, and K+ and Cl− were significantly correlated (r = 0.878, α = 0.000).