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Physical and chemical properties of aerosol, filter media properties, aerosol composition, dust cake properties, construction of filter unit, dew point and temperature are the parameters that affect the filtration performance during the control of industrial air pollution. No comprehensive experimental study has been reported on the effect of varying cleaning cycle times on the filtration performances, and no emission study at the clean side was conducted using PTFE-coated membrane on polyester needle punched filter media. In this experimental work, we are studying the filtration performances and characterization of emitted particles with varying cleaning cycle times in a pulse jet filtration system with membrane-coated media. The particulate emissions in terms of PM2.5 and PM10 are substantially lower, when using a coated membrane on filter media. Mass concentration and number concentration in downstream emission is also lower for filter media using PTFE membrane on needle felt nonwovens fabric media. Filtration efficiency is higher for filter media with PTFE coated than without PTFE membrane coating. PTFE membrane-coated media fabric exhibits lower residual pressure drop (∆P), which ultimately enhances the filter media life, more energy saving and better control on emissions. The downstream D10, D50, and D90 particles values are much higher in non-PTFE membrane-coated filter media. Overall, it is observed that fabric filter media with PTFE membrane, arrests a higher proportion of the fine particles, which causes lesser impacts on human health by industrial air pollution. Hence, the membrane-coated filter media (i.e. membrane separation) effectively controls the fine particles emission at downstream side/clean side. [ABSTRACT FROM AUTHOR]

Brake discs for the rear axle of a high-performance sports car have been manufactured in three different lightweight materials; AA6082, AA7075 and AA2024 aluminium alloys. These were subsequently coated with a Keronite plasma electrolytic oxidation (PEO) ceramic layer. Full-scale dynamometer tests have been conducted against a standard low-met brake pad using a modified AK master test at increasing levels of braking temperature until a physical limit is reached. Microstructural characterisation of coating and brake pad wear and tribo-layer have been studied using SEM and EDX. In addition, post-dynamometer-test friction discs have been exposed to salt fog testing. Dynamometer tests give confidence that PEO-coated aluminium brake discs are a viable technical solution for vehicle lightweighting. In particular, compelling performance with respect to good coefficient-of-friction (CoF), extremely high coating adhesion, minimal disc and pad wear, low disc run-out, good heat dissipation, and good corrosion resistance has been demonstrated for Mat A (AA6082) alloy discs. Despite higher room temperature strength, the resulting performances of Mat B (AA7075) and Mat C (AA2024) are poor at higher braking temperatures, resulting in excessive coating spallation and subsequent grain boundary attack followed by severe intergranular corrosion. [ABSTRACT FROM AUTHOR]

In this work, we evaluated the impact of disc rotors of gray cast iron (GCI), nitrocarburized (NC), and superhard ceramic-coated (SCC) GCI on the brake wear PM emissions of passenger vehicles using dynamometric measurements. The brake emission factor (BEF) of the SCC was greatly reduced by more than a factor of 1/5 compared with those for the GCI and NC for both low-steel and non-steel friction materials. Surface topological and microstructural analyses confirmed that more severe wear was pronounced for the NC rotor compared with the SCC, as evidenced by large concave pits in the wear tracks. Analysis of the size-classified airborne PM suggests that reduced micron-sized particles, which originated from the GCI disc, were responsible for the lower BEF due to the increased hardness of the SCC. [ABSTRACT FROM AUTHOR]

The effect of progressive pulse cleaning pressure (2 bar to 3.5 bar) on filtration behaviour of two different polyester needle-punched nonwoven filter materials, viz. PTFE finished and without finished media has been studied at varying dust densities using flyash aerosol. The filter materials have been investigated on a flatbed filtration test rig based on cleaning at a fixed peak pressure drop of 1000 Pascal for an equal number of test cycles during the first three phases (conditioning, ageing and stabilizing phase) and further for the final measuring phase of four hours. The particulate emission and residual pressure drop behaviour are found to be significantly less in the case of PTFE-coated material under all the operating conditions. However, a significant difference among all levels of progressive pulse pressure has been found for both the examined materials. [ABSTRACT FROM AUTHOR]

Present study embodies filtration characterization of two nonwoven needle-felt polyester filter materials, viz. PTFE coated and without coated media. The materials have been assessed using flyash aerosol under varying time intervals (6, 9 and 12 min) at different inlet dust densities (50, 90 and 150 g/m3). The flyash particles are charged prior to their deposition over the filter media using a three phase parallel plate box pre-charger at two different levels of pre-charge, viz. 4 kV and 8 kV along with 0 kV. Results reveal that the filtration performance for PTFE coated material is better under all conditions. However, an enhanced filtration performance in terms of particle emission and pressure drop is noted at increased pre-charge level and higher cyclic interval. It may also be noted that the level of improvement in filtration behavior for both the materials has been better at initial level of pre-charge from 0 kV to 4 kV. However, the cumulative behavior of all the factors is also found significant. [ABSTRACT FROM AUTHOR]

Smouldering combustion can emit a large amount of CO2, CO and particulate matter (PM). Moisture content is an important factor of the emission characteristics. As the hot spot of forest smouldering combustion, the gas and particulate emissions of the Huzhong National Nature Reserve with different moisture contents are discussed herein. The emission factors (EF) of CO2 and CO were 100.71 ± 39.14 g/kg and 11.76 ± 3.89 g/kg, respectively. The EF of PM2.5, PM4 and PM10 were 87.11 ± 19.47 g/kg, 353.37 ±159.25 g/kg and 602.59 ± 276.80 g/kg, respectively. PM2.5 accounted for 16.59 ± 5.25% of the PM, and PM4 and PM10 were 54.03 ± 13.46% and 91.00 ± 10.81%, respectively. There was no significant difference in the EF of CO2 and CO with different moisture contents, nor in the EF of PM2.5, but there was a significant difference in the EF of PM4 and PM10 with different moisture contents. In addition, the peak of CO2 and CO appeared at 2~3 h; the peak of PM2.5 lagged behind that of PM4 and PM10. According to the regression analysis, experimental expressions were obtained for the modified combustion efficiency (MCE) and the EF of PM. [ABSTRACT FROM AUTHOR]

In this work, we evaluated the impact of disc rotors of gray cast iron (GCI), nitrocarburized (NC), and superhard ceramic-coated (SCC) GCI on the brake wear PM emissions of passenger vehicles using dynamometric measurements. The brake emission factor (BEF) of the SCC was greatly reduced by more than a factor of 1/5 compared with those for the GCI and NC for both low-steel and non-steel friction materials. Surface topological and microstructural analyses confirmed that more severe wear was pronounced for the NC rotor compared with the SCC, as evidenced by large concave pits in the wear tracks. Analysis of the size-classified airborne PM suggests that reduced micron-sized particles, which originated from the GCI disc, were responsible for the lower BEF due to the increased hardness of the SCC.

Both the EU and China are evaluating the feasibility of lowering the detection limit of particle number (PN) measurement to 10 nm in future legislations, making it necessary to better understand the sub-23 nm particle emission characteristics from state-of-the-art vehicles. In this study, solid PN emissions with a diameter larger than 10 nm and 23 nm (known as SPN10 and SPN23) were compared over the WLTC, RTS95, and a so-called "worst-case" real driving emission (RDE) cycle (highly dynamic/0 °C) using two certification-level particle number counters (PNCs) employing evaporation tube (ET) and catalytic stripper (CS) as volatile particle remover (VPR). The results show that SPN10 emissions were 31.7%, 27.8%, and 15.2% higher than SPN23 over the WLTC, RTS95, and laboratory RDE cycles. Sub-23 nm particles were almost not identified within the engine cold-start phase and tended to be a hot-running pollutant favored by aggressive driving styles (frequent accelerations and high engine loads), fuel-cut during decelerations, and long idles. Lower testing temperature delayed the light-off of catalyst and, therefore, significantly reduced the formation of sub-23 nm particles within the engine warm-up stage. Lowering the detection limit to 10 nm is deemed to provide more public health protection since it will guide manufacturers to pay more attention to vehicle hot-running emissions. [ABSTRACT FROM AUTHOR]

Abstract In this article, in order to optimize diesel aftertreatment system with periodically reciprocating flow (PRF), an experimental study is conducted to investigate its characteristics such as pollution emissions, regeneration of diesel particulate filter (DPF), concentration, and size distribution of particulate matter (PM) escaped as well as temperature distribution under unidirectional flow and PRF operating conditions. The effects of reciprocating flow cycle and exhaust gas flow on the performance of aftertreatment system are investigated in detail. The energy efficiency analysis of the aftertreatment system is also carried out. Experimental results show that (a) as the temperature is lower than the light‐off threshold of combustible gas, the aftertreatment system cannot restrain the formation of second particles under the low‐temperature condition of unidirectional flow; and (b) the aftertreatment system demonstrates excellent performance of trapping particles and filter regeneration as the symmetrical temperature distribution is formed. The PM filter efficiency αPM is 92%, and the specific energy consumption β is 124% for symmetrical temperature distribution; (c) the increase in reciprocating flow cycle could lead to the shifting of the temperature profiles, and this would affect the particle size distribution; (d) a certain increase in exhaust gas flow from engine would have insignificant change for the temperature distribution; and (e) the critical energy efficiency ηc of the system could reach 96.61%.

Using straw and herbaceous crops to replace or augment fossil fuels is becoming popular as access to forest biomass becomes environmentally stricter and more expensive. The low bulk density raw biomass is pre-processed and densified into pellets to facilitate handling and use. Dust is generated during collection, baling and debaling, grinding, drying, and densifying processed herbaceous biomass. Abundant literature deals with dust generated during the industrial handling of woody biomass, grains, and other crops like cotton. But the information on handling herbaceous biomass in the open literature is scarce. This paper reviews the available literature on dust generation from handling and processing of herbaceous biomass. Limited available data shows that herbaceous biomass species have a lower ignition temperature than woody biomass. The paper identifies several crucial pieces of information needed to ensure safety in the handling and pelleting of herbaceous crops. [ABSTRACT FROM AUTHOR]

The emission of particulate matter (PM) from agricultural activities, such as concentrated animal feeding, straw combustion, and mechanized harvest, is a hot issue in the sustainable development of agriculture, which has attracted more and more attention from government departments and researchers. However, the research on the transport of particulate matter in the agri-environment still lacks flexible and efficient measurement methods to obtain real-time and accurate spatial distribution data. The objective of our study is to produce a new intelligent platform for agri-environment atmospheric monitoring with high mobility, temporal and spatial resolution, and remote data transmission function to overcome the shortcomings of traditional atmospheric particulate matter monitoring stations, such as small particle size range, immovability, and high cost. Through the light scattering sensor, microcontroller, and wireless data transmission device assembled on the high-mobility drone, the platform could measure the mass concentration of PM2.5, PM10, and TSP at different spatial points in the agri-environment and transmit the measurement data to the receiving device on the ground through three modes: CLOUD, TCP, and UDP. We also developed monitoring software based on the Android platform, which could complete the connection of device and real-time monitoring of measurement data on the ground. Compared with stationary measurement devices, the biggest advantage of our mobile monitoring system is that it has the ability to measure the concentration of TSP and the vertical distribution of PM, which is very important for the research of agricultural environmental particulate matter emission characteristics. After the sensor and communication performance experiments, the sensors had high consistency in the overall change trend, and the communication accuracy rate was high. We carried out a flight measurement comparison experiment at the Wenhua Road Campus of Henan Agricultural University, and the measurement data were highly consistent with the data from the national monitoring stations. We also conducted an agri-environmental atmospheric measurement experiment in Muzhai Village and obtained the vertical distribution data of PM concentration at the nearby measuring point when the harvester was working. The results showed that after the harvester worked for a period of time, the PM2.5, PM10, and TSP concentrations reached the maximum at the altitude of 20 m at the measurement point, which were 80, 198, and 384 μg/m3, respectively, 2.64~3.10 times the particle concentration in the environment before the harvester began to work. Our new platform had high mobility, sensitive reading, and stable communication during the experiment, and had high application value in agricultural environmental monitoring.

External cost or negative externality is a cost that a transaction or activity imposes on a party that is not part of the transaction or activity. In the present work, an attempt is made to calculate the external cost per unit of electricity generation from coal-based power plants in India due to the emissions of SO2, CO2, NOx and Particulate Matter. Purchasing Power Parity and population density correction factor are considered for the estimation of external cost to suit Indian economic and demographic conditions. Total external cost due to release of emissions from nine states having more coal-based power plants in India during the year 2018 is estimated to be INR 19.5 trillion and unit external cost of coal-based electricity generation is estimated to be INR 2.92. The cost of power generation from coal-based power plants in India with and without considering the external cost is estimated till the year 2030. Comparison is also made between the cost of solar power generation and coal-based thermal power generation. It is predicted that the cost of solar power generation without energy storage is cheaper than the power generation from coal-based power plants if the external cost of power generation is included in the cost. [ABSTRACT FROM AUTHOR]

Both the EU and China are evaluating the feasibility of lowering the detection limit of particle number (PN) measurement to 10 nm in future legislations, making it necessary to better understand the sub-23 nm particle emission characteristics from state-of-the-art vehicles. In this study, solid PN emissions with a diameter larger than 10 nm and 23 nm (known as SPN10 and SPN23) were compared over the WLTC, RTS95, and a so-called “worst-case” real driving emission (RDE) cycle (highly dynamic/0 °C) using two certification-level particle number counters (PNCs) employing evaporation tube (ET) and catalytic stripper (CS) as volatile particle remover (VPR). The results show that SPN10 emissions were 31.7%, 27.8%, and 15.2% higher than SPN23 over the WLTC, RTS95, and laboratory RDE cycles. Sub-23 nm particles were almost not identified within the engine cold-start phase and tended to be a hot-running pollutant favored by aggressive driving styles (frequent accelerations and high engine loads), fuel-cut during decelerations, and long idles. Lower testing temperature delayed the light-off of catalyst and, therefore, significantly reduced the formation of sub-23 nm particles within the engine warm-up stage. Lowering the detection limit to 10 nm is deemed to provide more public health protection since it will guide manufacturers to pay more attention to vehicle hot-running emissions.

This study investigates effects of a novel GDI injector outer tip design on the airflow behavior, spray formation, injector deposits and engine particulate emissions. The novel design has turbine-like blades that are located on the tip of the injector. The effects of turbine-like blades on the airflow behavior below the injector tip is initially investigated by means of numerical simulations with three simulation parameters: airflow velocity, air wall shear stress and prehole wetting. Simulations show that turbine-like blades increase the airflow velocity within the boundary layer. Consequently, wall shear stress increase over the injector tip. Therefore, the average prehole wetting decreases. Spray measurements show that the air entrainment increases and spray penetration reduces due to blades, which also confirm the increased airflow velocity. According to engine experiments, particulate emissions reduce slightly at high engine loads. Turbine-like blades do not cause a decrease on particulate emissions from low-to-mid engine loads. The deposit formation reduces around preholes and at the outer side of the injector tip. However, deposits cannot be avoided over the dome of the injector tip. [ABSTRACT FROM AUTHOR]

In this article, in order to optimize diesel aftertreatment system with periodically reciprocating flow (PRF), an experimental study is conducted to investigate its characteristics such as pollution emissions, regeneration of diesel particulate filter (DPF), concentration, and size distribution of particulate matter (PM) escaped as well as temperature distribution under unidirectional flow and PRF operating conditions. The effects of reciprocating flow cycle and exhaust gas flow on the performance of aftertreatment system are investigated in detail. The energy efficiency analysis of the aftertreatment system is also carried out. Experimental results show that (a) as the temperature is lower than the light‐off threshold of combustible gas, the aftertreatment system cannot restrain the formation of second particles under the low‐temperature condition of unidirectional flow; and (b) the aftertreatment system demonstrates excellent performance of trapping particles and filter regeneration as the symmetrical temperature distribution is formed. The PM filter efficiency αPM is 92%, and the specific energy consumption β is 124% for symmetrical temperature distribution; (c) the increase in reciprocating flow cycle could lead to the shifting of the temperature profiles, and this would affect the particle size distribution; (d) a certain increase in exhaust gas flow from engine would have insignificant change for the temperature distribution; and (e) the critical energy efficiency ηc of the system could reach 96.61%. [ABSTRACT FROM AUTHOR]

Using straw and herbaceous crops to replace or augment fossil fuels is becoming popular as access to forest biomass becomes environmentally stricter and more expensive. The low bulk density raw biomass is pre-processed and densified into pellets to facilitate handling and use. Dust is generated during collection, baling and debaling, grinding, drying, and densifying processed herbaceous biomass. Abundant literature deals with dust generated during the industrial handling of woody biomass, grains, and other crops like cotton. But the information on handling herbaceous biomass in the open literature is scarce. This paper reviews the available literature on dust generation from handling and processing of herbaceous biomass. Limited available data shows that herbaceous biomass species have a lower ignition temperature than woody biomass. The paper identifies several crucial pieces of information needed to ensure safety in the handling and pelleting of herbaceous crops.

The use of Fischer–Tropsch (F–T) diesel synthesised from coal in automobiles can alleviate petroleum shortages and promote clean utilisation of coal. Because F–T diesel does not contain oxygen, in this study, we added TiO 2 nanoparticles and n-octanol to the F–T diesel to serve as oxygenated enhancers to increase the oxygen content and reduce the particulate matter emission of F–T diesel. To achieve better combustion characteristics and emission performance, TiO 2 nanoparticles with different concentrations (20, 50, and 100 ppm) were dispersed to the fuel blends of F–T diesel and n-octanol to determine the optimum amount of TiO 2 nanoparticles. The brake thermal efficiency (BTE), combustion stability, number concentration, and size distribution of the ultrafine particulate (UFP) emission of the three nano-emulsion fuels were investigated on a turbocharged heavy-duty diesel engine. The experimental results indicated that the BTE of the F–T diesel and that of the nano-emulsion fuel T50 increased by 0.75 % and 2.26 %, respectively, compared with petro-diesel. The nano-emulsion fuels had higher peak cylinder pressure and peak heat release rate owing to the faster combustion rate caused by the micro-explosion of fuel droplets and higher thermal conductivity caused by the high surface-to-volume ratio of TiO 2 nanoparticles. Moreover, the nano-emulsion fuels exhibited higher cyclic variations of peak cylinder pressures and more dispersed corresponding crank angles with the increase in the concentration of TiO 2 nanoparticles. Compared with petro-diesel, the soot emission of the F–T diesel was reduced by an average of 27.32 % at various loads, whereas that of the optimal T50 decreased by an average of 43.61 %. Additionally, the number concentration of UFPs of T50 was reduced by an average of 21.2 % compared to the F–T diesel. At low loads, the three nano-emulsion fuels exhibited greater geometric mean diameters (GMDs) of UFPs and lower ratios of nucleation mode particulates (NMPs) owing to the higher fuel viscosity in the pre-injection stage at a lower in-cylinder temperature. At medium and high loads, the nano-emulsion fuels exhibited smaller GMDs of UFPs and higher ratios of NMPs owing to micro-explosion and secondary atomisation at higher temperatures. [ABSTRACT FROM AUTHOR]

Abstract Accurate estimation of particulate emissions is fundamental to assessing the air quality risks posed by existing and proposed open cut black coal mines. The currently available emission estimation techniques are based on a limited range of empirical studies, and the need for additional research and development of activity and region specific particulate emission estimation methods has been recognised. This paper presents the results of empirical testing of particulate emission rates for open area surfaces in open cut black coal mines in three Australian regions. The emission rates are provided for specific wind speeds, thus allowing adjustment of emission rates for prevailing meteorology in these regions. The influence of surface watering as a control technique is also considered. Particulate emission rates are presented for a range of coal mining sources, and for specific wind speeds. Comparison of the emission rates with the existing published research confirms the emission rates are consistent with current approaches. This research significantly expands our current understanding by presenting emission rates for a range of open area sources, for specific wind speeds and surface watering controls. This more detailed emission estimation dataset provides for adjustments to default particulate emission rates to allow site specific data to be integrated into emissions estimation. This will result in more accurate emissions estimates for existing and future projects and reduce the potential for significant over- or under-estimation of particulate emissions from surface sources in open cut coal mines. Graphical abstract Image Highlights • Particulate emission rates from open cut coal mines were experimentally challenged. • Results enable regional adjustments of emission rates for prevailing meteorology. • The influence of surface watering as emission control technique was also considered. • More accurate emission estimates for existing and future projects will be possible. [ABSTRACT FROM AUTHOR]

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 1207 μg/m3 and 30 μg/m3, respectively. On average, the oxidized fragment families (CxHyO1+, and CxHyOz+) account for ~13% of the three family sum, while ~87% comes from the CxHy+ family. The two peaks of C2H3O2 (m/z 59.01) and C3H7O (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.

Abstract The present study investigated the effect of coolant temperature, injection pressure, and injection timing on emissions in a gasoline direct injection (GDI) engine. Two coolant temperatures of 40 °C and 80 °C, and wide range of injection timings from before top dead center (BTDC) 360° to BTDC 210° were tested under injection pressures in the range of 5 MPa–50 MPa. Particle number (PN), soot, total hydrocarbon (THC), and nitrogen oxides (NOx) were measured under the various experimental conditions. In addition, the spray and flame images were used to observe the spray-wall interaction and to identify the existence of a fuel film. Experimental results showed that the increase in injection pressure significantly reduced the particulate emissions, especially for the wall wetting condition (BTDC 330°). The PN emissions from the wall wetting condition was reduced by about 90% by increasing injection pressure from 10 MPa to 50 MPa. Furthermore, increasing the coolant temperature was an effective way to reduce the PN, soot, and THC. In particular, the THC was reduced by about 30%, while the change in injection pressure and injection timing varied by only 10%. Highlights • Effects of high injection pressure (up to 50 MPa) and coolant temperature on PN emissions were analyzed. • We achieved 90% reduction in PN emissions by applying 50 MPa injection pressure from 10 MPa. • Increased coolant temperature contributed to decrease PN, soot, and THC emissions. [ABSTRACT FROM AUTHOR]

Commercial vehicle brake pads play an important role in the environmental impact caused by road transport. Their complex raw material requirements and increasingly prevalent contribution to traffic pollution is forcing the industry to look for alternative solutions. Natural lignocellulosic fibers have already been investigated as sustainable brake pad ingredients, and while braking performance results appear promising, important characteristics such as wear and particulate matter emission are either deteriorated or outright neglected. In this study, rice husk, a byproduct of the agricultural industry, is investigated as possible environmentally friendly natural ingredient. Friction material samples based on a commercial formulation were modified by adding different percentages of both rice husk and rice husk ash, the product of a thermal treatment of the former, and then tested with a modified pin-on-disc tribometer. The experimental setup included collecting instruments for emitted wear particles. 6 to 12 wt% of rice husk showed preservation of the braking performance whilst possibly improving wear and emission characteristics of the friction material. Higher amounts of modifications led to deterioration of tribological properties. Overall, this investigation suggest that limited yet substantial amounts of rice husk could successfully substitute conventional filler ingredients in brake pad formulations, as an effective approach in lowering their environmental impact. [Display omitted] • Rice husk shows no detrimental effects on the friction material braking performance. • Quantity of added ingredient affects tribological and emission properties. • Rice husk and rice husk ash support the formation of secondary plateaus. • Friction layer and emission composition is similar for all material compositions. • Friction layer characteristics related to tribological and emission properties. [ABSTRACT FROM AUTHOR]

In this paper, five particulate emission points from a sinter plant in China, including anthracite crusher, raw material blender, sinter strand, screener, and circular cooler, were selected for particle sampling. The particle size distribution, the toxic element content (As, Cd, Co, Cr, Cu, Ni, Pb, Ti, and Zn), and the morphology of the samples were determined by the gravimetric method, the ICP-OES, and the SEM-EDS, respectively. In addition, the gray relational analysis method was used to evaluate the rank of the particulate emission points in the sinter plant. The results show that the emission factor of PM, PM, and PM of the whole sintering process is 0.121, 0.075, and 0.039 kg/t-sinter, respectively. Furthermore, the total toxic element emission factor is 5282.49 mg/t-sinter. The sinter strand is the most important emitter and contributes 43.8% of PM, 53.3% of PM, 56.4% of PM, and 81.1% of total toxic element in the sinter plant. Nevertheless, particles emitted from the post-sintering process are non-negligible and contribute 48.8% of PM, 41.3% of PM, 38.5% of PM, and 15.5% of total toxic element in the sinter plant. [ABSTRACT FROM AUTHOR]

Two new formulations of non-noble metal based diesel oxidation catalysts based on Co Ce based mixed oxide (DOC 2 ) and perovskite catalysts (DOC 3 ) were prepared and retrofitted in a 4-cylinder diesel engine fueled by diesel and Karanja biodiesel blend (KB20). In this study, their effectiveness in reducing raw exhaust particulate emissions vis-à-vis a commercial diesel oxidation catalyst (DOC 1 ) was evaluated. Emission characteristics such as particle number-size distribution, mass-size distribution, and surface area-size distribution, total particle number concentration and count mean diameter as a function of engine load at constant engine speed were evaluated. Variations in total particle number concentration as a function of engine speed were also determined. The prepared DOCs and the commercial DOC showed varying degrees of performance as a function of engine operating conditions. Overall, effectiveness of the prepared DOC's appeared to be more fuel specific. For diesel exhaust, overall performance of DOC 1 was more effective compared to both prepared DOCs, with DOC 2 being superior to DOC 3 . In case of KB20 exhaust, the overall performance of DOC 2 was either more effective or nearly comparable to DOC 1, while DOC 3 being not so effective. This showed that the DOCs based on Co Ce based mixed oxide catalysts have potential to replace commercial noble metal based DOC's, especially in engines fueled by biodiesel. [ABSTRACT FROM AUTHOR]

Selective catalytic reduction catalyst coated on filter (SDPF) is one of the important technical routes to meet the future Euro-Ⅶ emission regulations for engines. To efficiently control and optimize the SDPF, it is necessary to have a comprehensive understanding of its regeneration characteristics. Therefore, the temperature, particulate emission characteristics and reduction emission performance of SDPF under the drop to idle (DTI) regeneration with different soot loads were investigated. The results show that, during DTI regeneration, the SDPF inlet outer-ring temperature was the highest and the outlet outer-ring temperature was the lowest, the radial temperature gradient of the outer-ring was larger than that of the inner-ring, and the axial temperature gradient of the rear section was larger than that of the front section. As the soot load increased, the start of regeneration was delayed, the regeneration duration extended, and both the peak temperature and the maximum temperature gradient of the substrate increased. A rapid increase in the proportion of nucleation-mode particle at the SDPF outlet was a signal of the end of DTI regeneration. The higher the soot load, the higher the regeneration efficiency and the lower the particle filtration efficiency and NOx conversion efficiency of the SDPF after DTI regeneration. • The higher the soot load, the longer the DTI regeneration duration. • DTI regeneration was divided into three stages. • High proportion of NM particle (>70%) was a signal of the end of DTI regeneration. • Reduction emission performance of SDPF would decease after DTI regeneration. [ABSTRACT FROM AUTHOR]

The use of coal as fuel in coal-fired power plant (CFPP) for electricity generation results in emission of particulate which contains trace quantities of naturally occurring radionuclides, namely Uranium-238 ( 238 U), Thorium-232 ( 232 Th) including their decay series and Potassium-40 ( 40 K). These naturally occurring radionuclides may increase their natural radioactivity level in the ambient particulate matter vicinity of the plant resulting from the combustion processes. This paper presents an investigation of radioactivity level of particulate emission and maximum deposition due to natural radioactive emissions from a typical CFPP using standard Gaussian dispersion model approach. The predicted maximum ground level particulate concentration (C max ) and downwind distance were 55 μg m −3 and 1600 m away from the source, respectively. The results recorded that the C max released from the CFPP was significantly lower than the national and international ambient air quality limits, which means that radiological hazards from inhalation due to particulate emission released from the stack is insignificant. The air dispersion modelling results suggested that this activity does not impose any significant effect to the human population at large and potential contamination at vicinity of CFPP is remote. [ABSTRACT FROM AUTHOR]

Internal combustion engines were the technology of choice for propulsion and decentral power supply in the last century. Due to the high energy density of hydrocarbon based fuels that could so far not be reached by alternative technologies they will keep their leading role in most applications for the next decades. Although, its general functionality seems to be unchanged since its invention, the internal combustion engine has gone through substantial developments driven by various challenges. Within these, the pollution control has to be named first due to its role as the main driver for engine and aftertreatment development since the discussions on air quality which started 70 years ago. Meanwhile, all industrialized countries and most of the emerging countries have more or less stringent regulations for the main harmful exhaust components (HC, CO, NO, Particulates). The second main challenge to be named is the reduction of CO emissions. Various engine technologies that are currently used to tackle these global trends lead to major impact on the exhaust aftertreatment components. To tackle these challenges the exhaust aftertreatment development has to be understood as integrated, multi-disciplinary and multi-scale design process considering engine design and operation, on board diagnosis and aftertreatment design and operation likewise. [ABSTRACT FROM AUTHOR]

An experimental study of particulate matter emissions was conducted on a Direct Injection Gasoline (DIG) engine produced by a Chinese Original Equipment Manufacturer (OEM) to investigate the impacts of fuel properties from China market on particulate emissions of modern gasoline vehicles. The emissions include both the primary emissions and the secondary ones in the atmosphere. The objective of this work is to provide some experimental data and analysis on the impacts of fuel properties and vehicle technologies on Particulate Matter 2.5 (PM2.5) in China. On the basis of better understanding of those impacts, it is desired to provide some suggestions and guidelines on how to improve fuel quality and vehicle technology to help effectively reduce air pollution in China. In this paper, six test fuels with different aromatics, olefin, sulfur, Methyl-cyclopentadienyl Manganese Tricarbonyl (MMT), ethanol content were blended and tested to research on the influences on primary particulate emission including mass, number, size distribution and compounds including Polycyclic Aromatic Hydrocarbons (PAHs) and the toxicity of PAHs emissions. The test results demonstrated that the fuel compositions impacted significantly on particulate emissions of DIG engine. Higher aromatics in gasoline resulted in much higher Particle Mass (PM), Particle Number (PN) and PAHs emission and much higher toxicity to human health. Reducing olefin content in gasoline showed benefits to a certain degree on reducing PM and PN emission especially under high load engine operation conditions, and did not show obvious improvement of PAHs emission factor, but reduced the toxicity of PAHs. 10% of Ethanol in gasoline showed limited improvement on particulate emissions comparing with the effect of reducing aromatics and olefin content in gasoline, moreover E10 increased PN emission under low load conditions. The test results also demonstrated that the typical China Phase V gasoline did not show benefits of reducing vehicle emissions the typical Phase IV gasoline with higher sulfur (<=50 ppm) and manganese (<=8 mg Mn/l) in China market. The particulate compounds of DIG engine mainly consisted Elemental Carbon (EC), Organic Matter (OM) and small amount of inorganic ions. The mass percentage of EC in total PM increased as the load of engine rose. Three-way Catalyst (TWC) is more effective in reducing OM than EC, with the overall OM reduction rate of 67–85%. [ABSTRACT FROM AUTHOR]

Experimental investigations were conducted on a diesel engine to evaluate the effects of hydrogen addition on engine combustion, unregulated gaseous emissions and particulate emissions based on the Japanese 13-mode testing cycle. A diesel–hydrogen co-operated combustion strategy is proposed in which hydrogen is naturally aspirated into the diesel engine to substitute 10, 20 and 30% of the total fuel energy at 10 selected modes and diesel is used as the sole fuel for the other 3 modes. Gradual increase of peak in-cylinder pressure and heat release rate is observed at medium and high engine loads. Pre-ignition might occur at high engine load and speed. Cyclic variation of the indicated mean effective pressure and maximum pressure derivative increased with hydrogen addition. The brake specific emissions of acetaldehyde (CH 3 CHO), alkenes (C 2 H 4 , C 3 H 6 and C 4 H 6 ), arenes (C 6 H 6 , C 7 H 8 and C 8 H 10 ) and particulate mass can be evidently reduced. However, with H30 operation, the weighted total HC and formaldehyde (HCHO) increased by around 27% and 8%, respectively, while NO x increased by around 17%. The simultaneous decrease of particle size and number are believed to be associated with the inhibition effect of hydrogen on soot particle formation based on the HACA (H 2 abstraction and C 2 H 2 addition) mechanism. [ABSTRACT FROM AUTHOR]

In this study the on-road particle number (PN) performance of a Euro-5 direct-injection (DI) gasoline passenger car was investigated. PN emissions were measured using the prototype of a portable emission measurement system (PEMS). PN PEMS correlations with chassis dynamometer tests show a good agreement with a chassis dynamometer set-up down to emissions in the range of 1·10 10 #/km. Parallel on-line soot measurements by a photo acoustic soot sensor (PASS) were applied as independent measurement technique and indicate a good on-road performance for the PN-PEMS. PN-to-soot ratios were 1.3·10 12 #/mg, which was comparable for both test cell and on-road measurements. During on-road trips different driving styles as well as different road types were investigated. Comparisons to the world harmonized light-duty test cycle (WLTC) 5.3 and to European field operational test (euroFOT) data indicate the PEMS trips to be representative for normal driving. Driving situations in varying traffic seem to be a major contributor to a high test-to-test variability of PN emissions. However, there is a trend to increasing PN emissions with more severe driving styles. A cold start effect is clearly visible for PN, especially at low ambient temperatures down to 8 °C. [ABSTRACT FROM AUTHOR]

Ethanol has the potential to improve engine efficiency and reduce harmful emissions when used as fuel in a spark-ignited engine. Ethanol is mostly supplied in a splash-blended form with gasoline or in a pure form; however, this is not an optimal way of using ethanol because the use of ethanol leads to increased brake specific fuel consumption. To fully utilize the merits of ethanol, on-demand control of ethanol and gasoline is required so that the fuel-blending ratio can be altered according to the engine operating conditions. This study investigated the effect of ethanol port fuel injection and gasoline direct injection systems on engine combustion and emission characteristics under full load conditions. The experiment was conducted using two different compression ratios and various ethanol injection timings. Knock occurrence decreased as the ethanol injection timing was held while intake valves were open. Minor reductions in carbon monoxide, total hydrocarbon, and particulate emissions were observed under a compression ratio of 9.5, while the reduction in emissions became significant under a compression ratio of 13.3 as the amount of ethanol injection increased. [ABSTRACT FROM AUTHOR]