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1
Downard, Jared Matthew. "Particulate emissions of tire combustion." Thesis, University of Iowa, 2014. https://ir.uiowa.edu/etd/4615.
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The disposal of used tires represents an environmental and health hazard, especially when large stockpiles of tires start on fire. This study focuses on ambient particulate matter samples collected during the Iowa City landfill tire fire and laboratory emissions of tire combustion. Levels of elemental (EC) and organic carbon (OC), metals, polycyclic aromatic hydrocarbons (PAH), azaarenes and oxygenated PAH (oxy-PAH) were determined by thermo-optical analysis, high precision mass, inductively-coupled plasma mass spectrometry and gas chromatography mass spectrometry. Results demonstrate that tire combustion emissions are enriched in elemental carbon and PAH. Levels of hazardous metals, such as lead and zinc, are not enhanced in particulate emissions 4.2 km from the fire. In addition, fresh tire combustion emissions have increased amounts of lower molecular weight PAH in the particle phase when compared to diluted real world emissions. This is due to gas phase partitioning of lower molecular weight PAH in plume transport. To build on the prior, qualitative understanding of organic compounds in tire emissions, 15 total azaarenes and oxy-PAH were identified, including four azaarenes and three oxy-PAH that were identified in tire combustion emission for the first time. The combustion of tires has significant health implications, particularly when open burning occurs near populations. This study serves to characterize the major chemical components of tire smoke and to quantify emissions of select chemicals with known carcinogenic, mutagenic, and toxic effects.
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Price, Philip Daniel. "Direct injection gasoline engine particulate emissions." Thesis, University of Oxford, 2009. http://ora.ox.ac.uk/objects/uuid:35c0d6bf-bde3-4ef0-a87e-4af89a94b16f.
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Direct fuel injection technology is increasingly being applied to the spark ignition internal combustion engine as one of the many actions required to reduce the CO2 emissions from road transport. Whilst the potential for CO2 reductions is compelling, the technology is not without disadvantages. Early examples typically emitted over an order of magnitude more Particulate Matter (PM) than vehicles with conventional spark ignition engines. Consequently, future revisions to European and North American exhaust emissions legislation are likely to regulate the particulate emissions from vehicles with direct injection gasoline engines. This thesis undertakes to investigate a) instrumentation capable of simultaneously resolving the number concentration and size distribution of particles in the 5-1000 nm size range and b) the factors affecting the PM emissions from spark ignition engines with direct fuel injection. The first objective is achieved by evaluation and comparison of a differential mobility spectrometer; photo-acoustic soot sensor; condensation particle counter and electrical low pressure impactor. To address the second question, a differential mobility spectrometer is applied to quantify the PM emissions from a number of direct injection gasoline engines, together with investigation of their dependence on various calibratable parameters, operating temperature and fuel composition. The differential mobility spectrometer showed good agreement with the other more established instruments tested. Moreover, it exhibited a faster time response and finer resolution in particle size. The number weighted size distribution of the PM emitted was typically lognormal with either one or two modes located between 20 and 100 nm. Chemical analysis of PM samples showed the presence of elemental carbon, volatile organic material and sulphates. Transient PM measurements enabled short time-scale events such as mode switching between homogeneous and stratified mixture preparation to be identified. PM number concentrations in stratified mode exceeded those in homogeneous mode by a factor of 10-100. Dynamometer based experiments showed that PM emissions increase for rich air fuel ratios, retarded fuel injection and advanced ignition events. They also demonstrated a strong dependence on fuel composition: the highest PM emissions were measured with an aromatic fuel, whereas blending alcohols such as methanol or ethanol tended to suppress PM emissions, particularly in the accumulation mode size range. These measurements are amongst the first of their kind and demonstrate the applicability of the differential mobility spectrometer to the measurement of ultra-fine particulate emissions from engines with direct fuel injection systems. Numerous explanations are put forward to describe the data obtained, together with suggestions for future work on PM control and abatement.
3
Martin, Rebecca. "Particulate Emissions in Selected Maine Saw Mills." Fogler Library, University of Maine, 2008. http://www.library.umaine.edu/theses/pdf/MartinR2008.pdf.
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Megaritis, Athanasios. "Particulate emissions in direct-injection diesel engines." Thesis, Imperial College London, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.344010.
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Abdullahi, Lami Karimatu. "Characterisation of particulate matter emissions from cooking." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7397/.
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Cooking fume have been found to be a significant component of ambient particulate matter and also to contribute to high concentrations of aerosol indoors. A linkage of individual exposure to cooking emissions with adverse health effects has been found and thus has led to the need for further understand the composition of this source of particulate matter. This study was concerned with gaining further insights into the chemical composition of aerosol generated from typical styles of cooking and the understanding of trends of the formation of particles among different culinary methods. Cooking source profile for African, Chinese, Western and Indian styles was obtained in a specially designed laboratory based kitchen. These profiles were used as input in a Chemical Mass Balance model where ambient data collected in Birmingham, UK were analysed in order to apportion the quantity of organic matter from cooking sources in the location sampled. It was found that cooking generated a significant mass of aerosol with the particle sizes largely within the respirable size range. The Chinese style of cooking was found to generate the highest concentration of particles with PM mass of 21.61µg/m3. The source profile from cooking obtained from the study were found to correlate well with each other with Indian and Western profiles exhibiting the highest correlation. When used for the CMB model runs, these two profiles provided the best output with the model runs apportioning 16% of the Organic Carbon to be from cooking, with traffic, wood smoke and soil debris contributing 44%, 18% and 24% respectively.
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Leach, Felix Charles Penrice. "Particulate emissions from gasoline direct injection engines." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:ea9c349e-5ade-4878-b758-c9a050c8f069.
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Direct injection spark ignition (DISI) engines are the next generation of gasoline fuelled engines. Their greater fuel economy and reduced CO2 emissions compared with port fuel injection (PFI) engines has led to their popularity. However, DISI engines produce a greater number of particulate matter (PM) emissions than PFI engines. Concern over the health effects of PM emissions, and forthcoming European legislation to regulate them from gasoline powered vehicles has led to an increased interest in the study of PM formation, measurement, and characterisation. A model was developed by Aikawa et al, the PM index, correlating PM emissions with fuel composition. PM emissions are thought to be linked both to the vapour pressure (VP) and the double bond equivalent (DBE) of the components of the fuel. However, there was no independent control of these parameters and the study was undertaken on a PFI engine. In this thesis, experiments have been conducted to validate this model and extend it, as the PN index, to DISI engines. Fuels have been designed using Raoult’s law and UNIFAC (with careful consideration of octane number) such that the DBE and VP of the fuel mix could be varied independently. The design of the fuels was such that the component parts would co-evaporate upon injection into the cylinder, ensuring a homogeneous mixture of the components at the point of ignition. The PN index has been tested on a single cylinder engine, at a matrix of test points, using these model fuels, and their PM emissions have been analysed using a Cambustion DMS500. The results show that the PN index is followed closely using model fuels, provided that these model fuels contain a ‘light-end’ (in this case 5 % v/v n-pentane). Imaging of in-cylinder evaporation and in-cylinder measurement of hydrocarbons shows how the composition of model fuels affects their PM emissions. The PN index has also been tested using commercial fuels on a single cylinder engine and a Jaguar V8 engine; the results again show that the PN index is also an excellent predictor of PN emissions for market fuels from both of these engines. PN emissions have been evaluated from two fuels representing the EU5 reference fuel specification, developed using the PN index to give a difference in PM emissions. Testing these fuels on both a single cylinder engine and a Jaguar V8 engine has shown up to a factor of three variation in observed PN emissions. This has important implications for forthcoming European emissions legislation. The results of these tests were fed into the recommendations for the EU6 reference fuel specification. The PN index has also been investigated in a Jaguar V6 engine with five different fuels with a spread of calculated PN indices over a simulated NEDC. Here the PN emissions have been measured using two PN, and one PM instrument and the results compared. The results show that the trends of the PN index are followed, but not as closely as predicted. Detailed analysis shows that this discrepancy is due to other effects, for example cold start, dominating the PN emissions in certain phases. PN emissions have been measured from a highly boosted engine at a variety of operating points using 14 different fuels. It has been shown that for a large variety of engine operating parameters PN emissions from highly boosted engines behave as expected. When changing the fuels, the results show that a variation of over three orders of magnitude can be observed. The predictions of the PN index are inconclusive however, with further work suggested to fully evaluate the PN index on highly boosted engines.
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Tornehed, Petter. "Particulate Emissions Associated with Diesel Engine Oil Consumption." Doctoral thesis, KTH, Maskinelement, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-25880.
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Particulate emissions from diesel engines have been a key issue for diesel engine developers in recent decades. Their work has succeeded in reducing the exhaust particles from the combustion of fuel, which has led to increasing interest in the contribution of particulates from lubrication oil. When discussing oil-related particulate emissions, hydrocarbon particles are customarily referred to. This thesis uses a broader definition, in which oil-related particulate emissions are modelled not only by the hydrocarbons, but also include the ash, carbons, and sulphate oil particulate emissions. The model developed in the project uses input data as oil consumption and oil ash content combined with tuning parameters, such as the oil ash transfer rate (ash emissions divided by oil consumption and oil ash content). Controlled engine tests have been performed to verify assumptions and fill knowledge gaps. The model can be applied to a variety of diesel engines, although the tuning factors might have to be reset. For example, introducing diesel particulate filters would dramatically reduce the oil ash emissions, since oil ash would accumulate in the filter. Oil consumption has played a central role in the present research. The modelling results indicate that special attention should be paid to oil consumption under running conditions with a low in-cylinder temperature, since the oil survival rate is high there. Under low-load and motoring conditions, hydrocarbons proved to be the main contributor to oil-related particulate emissions. At high engine load, oil ash emissions were the largest contributor to oil-related particulate emissions.QC 20101103
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Boman, Christoffer. "Particulate and gaseous emissions from residential biomass combustion." Doctoral thesis, Umeå : Univ, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-501.
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Guo, Li. "Measurement and control of particulate emissions from cattle feedlots in Kansas." Diss., Kansas State University, 2011. http://hdl.handle.net/2097/8549.
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Doctor of PhilosophyDepartment of Biological & Agricultural Engineering
Ronaldo G. Maghirang
Emissions of particulate matter (PM) are an increasing concern for large open beef cattle feedlots. Research is needed to develop science-based information on PM emissions and abatement measures for mitigating those emissions. This research was conducted to (1) measure PM concentrations emitted from large cattle feedlots, (2) compare different samplers for measuring concentrations of PM with equivalent aerodynamic diameter of 10 µm or less (PM10), (3) evaluate the relative effectiveness of pen surface treatments in reducing PM10 emissions, and (4) predict PM control efficiency of vegetative barriers. Concentrations of PM with equivalent aerodynamic diameter of 2.5 µm or less (PM2.5), PM10, and total suspended particulates (TSP) upwind and downwind of two large cattle feedlots (KS1, KS2) in Kansas were measured with gravimetric samplers. The downwind and net concentrations generally decreased with increasing water content (WC) of the pen surface; for effective control of PM emissions from feedlots, it appears that pen surface WC should be at least 20% (wet basis). Three types of samplers for measuring PM10 concentrations in feedlots KS1 and KS2 were compared: Tapered Element Oscillating Microbalance™ (TEOM), high-volume (HV), and low-volume (LV) PM10 samplers. Measured PM10 concentration was generally largest with the TEOM PM10 sampler and smallest with the LV PM10 sampler. A laboratory apparatus was developed for measuring the PM10 emission potential of pen surfaces as affected by surface treatments. The apparatus was equipped with a simulated pen surface, mock cattle hooves that moved horizontally across the pen surface, and PM10 samplers that collected emitted PM10. Of the surface treatments evaluated, application of water (6.4 mm) and hay (723 g/m2) exhibited the greatest percentage reduction in PM10 emission potential (69% and 77%, respectively) compared with the untreated manure layer. Computational fluid dynamics (CFD) was applied to predict airflow and particle collection by a row of trees (2.2 m high × 1.6 m wide). Predicted particle collection efficiencies generally agreed with published data and ranged from less than 1% for 0.875-µm particles to approximately 32% for 15-µm particles.
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Chen, Longfei. "Measurement of particulate emissions from gasoline direct injection engines." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:19e8dc75-9873-4b76-831d-3878fd048169.
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Gasoline Direct Injection (GDI) engines have been considered to be the key enabler for reducing the CO2 emission from gasoline-powered vehicles. Compared to Port Fuel Injection (PFI) engines, GDI engines realize a higher compression ratio, a lower intake temperature and the absence of throttling which will deliver higher volumetric efficiency and lower fuel consumption. However, due to the reduced time for fuel atomization and the possibility of fuel impingement, GDI engines will inherently generate more Particulate Matter (PM) emissions than PFI engines. Previous research demonstrated that GDI engines typically emit one order of magnitude more PM than PFIs. Therefore, the number-based measurement of PM emissions from GDI engines is essential, for engine researchers and manufacturers to meet the number-based PM regulations in the near future. This thesis undertakes to investigate: a) the effects of the after-treatment (Three-Way Catalyst) and various engine operational parameters, such as injection and ignition timing, injection strategy and valve timing on the PM emissions; b) the characteristics of GDI PM emissions using a range of gasoline/ethanol blends; c) The compositional information for GDI-generated PM emissions, i.e. the PM mass fractions in different volatility ranges. The first objective was achieved by using a Cambustion Ltd Differential Mobility Spectrometer 500 (DMS500) to simultaneously derive the PM size-resolved number concentrations and mass concentrations in the range of 5-1000 nm. The second objective was addressed by using the DMS500 together with other instruments such as a Photron high-speed camera, a Cambustion Ltd fast Flame Ionization Detector (FID). The third objective was realized by using Thermo-Gravimetric Analysis (TGA). These experiments are amongst the first of their kind and may well provide vehicle manufacturers and the fuel industry with useful data for PM control and abatement. Data acquisition (DAQ) systems for two test engines, namely, a V8 GDI engine and a single-cylinder optical access engine, have been developed in LabVIEW to facilitate recording various experimental data at different sampling rates (1Hz to 300 kHz). The DAQ system in the single-cylinder engine is also capable for communicating with the engine controlling system to enable automatic data logging. A controlled automatic dilution system has been developed for taking filter samples in a way that is consistent with emissions legislation.
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Capper, Anthony John. "The control of particulate emissions during production of coke." Thesis, University of South Wales, 1986. https://pure.southwales.ac.uk/en/studentthesis/the-control-of-participate-emissions-during-production-of-coke(128b8ced-637d-4464-a509-af04f67665a5).html.
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This work is divided into two main parts, investigational and theoretical. The first part deals with the investigation of deposition values around integrated iron and steel works, and coke works, in South Wales, and with the changes in such values which arise as a result of modifications to process control or to arrestment equipment. A method of evaluation of such changes, based on the cumulative sum technique, is developed, which m1n1m1ses the effect of seasonal variations in the deposition values. It is demonstrated that there are two significant sources of particulate emission, from coke oven discharges, and from coke quenching. These are shown to have different spatial distributions, emissions from quench towers being very widespread, whereas emissions from oven discharges deposit relatively closer to the source. Methods to reduce both of these sources are described: It is shown that the use of arrestors in quench towers leads to enhanced emission of dissolved solids, but that the increase can be controlled by the use of additional sprays above the arrestors. The second part considers some theoretical aspects of quench tower operation. It is shown that the installation of arrestors leads to changes in gas temperature and gas composition in a quench tower, which cause increases in terminal settling velocity. The same changes lead to reduced condensation within the quench tower, and hence greater emission of steam, which gives a more buoyant emission, with more widespread dispersion than from open quench towers, as well as enhanced emissions of dissolved solids. Calculations are included which confirm the extent of the dispersion from towers fitted with arrestment devices.
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Gander, Nathan. "Assessing Particulate and Chemical Emissions from Additive Manufacturing Processes." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1595848332301779.
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Bonifacio, Henry F. "Particulate matter emissions from commercial beef cattle feedlots in Kansas." Thesis, Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/2325.
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Hamm, Lee Bradford. "Engineering analysis of fugitive particulate matter emissions from cattle feedyards." Texas A&M University, 2005. http://hdl.handle.net/1969.1/3240.
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An engineering analysis of the fugitive particulate matter emissions from a
feedyard is not simple. The presence of an evening dust peak in concentration
measurements downwind of a feedyard complicates the calculation of an average 24-h
emission flux for the feedyard. The evening dust peak is a recurring event that occurs
during evening hours when particulate matter concentration measurements increase and
decrease dramatically during a short period of time. The concentrations measured during
the evening can be up to 8 times the concentrations measured throughout the rest of the
day. There is a perception that these concentration increases are due to increases in cattle
activity as the temperature decreases during the evening. The purpose of Objective 1 of
this research was to quantify the changes in concentrations based on changes in
meteorological conditions and/or cattle activity. Using ISCST3, a Gaussian-based EPAapproved
dispersion model used to predict concentrations downwind of the feedyard , the
results of this work indicate that up to 80% of the increase in concentrations can be
attributed to changes in meteorological conditions (wind speed, stability class, and
mixing height.)The total fugitive particulate matter emissions on a cattle feedyard are due to two
sources: unpaved roads (vehicle traffic) and pen surfaces (cattle activity). Objective 2 of
this research was to quantify the mass fraction of the concentration measurements that
was due to unpaved road emissions (vehicle traffic). A recent finding by Wanjura et al.
(2004) reported that as much as 80% of the concentrations measured after a rain event
were due to unpaved road emissions. An engineering analysis of the potential of the
unpaved road emissions versus the total feedyard emissions using ISCST3 suggests that it
is possible for 70 to 80% of the concentration measurements to be attributed to unpaved
road emissions.
The purpose of Objective 3 was to demonstrate the science used by ISCST3 to
predict concentrations downwind of an area source. Results from this study indicate that
the ISCST3 model utilizes a form of the Gaussian line source algorithm to predict
concentrations downwind of an area source.
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Henshaw, Geoffrey Stephen. "Surface analysis of particulate emissions before and after atmospheric aging." Thesis, University of Auckland, 1992. http://hdl.handle.net/2292/2453.
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The reactions and transformations of atmospheric primary particles have been studied using the surface analysis techniques of X-ray Photoelectron Spectroscopy (XPS), Auger Electron Spectroscopy (AES), Scanning Electron Microscopy (SEM) and Secondary Ion Mass Spectrometry (SIMS). Particles emitted from a steel mill were studied at their point of emission, during transport through the atmosphere and after deposition. The mill was located in a coastal region removed from other major industrial particle sources which made the identification of the mill particulate emissions possible in ambient samples. The mill utilizes indigenous titanomagnetite ironsand and coal as the raw materials. There is evidence of the surface enrichment of volatile trace elements such as Zn, S, Na, K and P from the raw materials in the particulate emissions. Particle samples were collected from sites within the mill which represented different stages in the iron-making process, including the rotary kilns, electric melting furnaces and the vanadium recovery plant. This established an inventory of particulate emissions. Mill sourced particles were then identified and studied in air samples collected downwind of the mill on silver-coated nucleopore filters. AES and SIMS depth profiling studies indicated the mill particles became surface enriched in sea salt components such as S, predominately as sulfate, Cl- and Na+ after atmospheric aging. This was attributed to their coagulation with the marine derived ambient aerosol. SIMS ion imaging and mass spectral analysis suggested a characteristic "fingerprint" of the mill emissions could be distinguished in the ambient aerosol up to 8 km downwind of the mill. An experimental rig was constructed to model the interaction between the mill particles and the natural marine aerosol. A bubble nebuliser was developed to produce an artificial sea salt aerosol which was reacted with a metal powder in the fluidised bed of the rig. The metal powder was then aged under controlled relative humidity (RH) conditions. It was shown that an iron powder, after reaction and aging at 75% RH, developed an aqueous surface layer which quickly led to electrochemical corrosion, dissolution and oxidation of the particle surface. Evidence of this corrosion of metal particles occurring in the environment was found in a SEM-EDX study of the mill particles deposited on pine needles downwind of the mill. It was argued that these reactions would increase the bio-availability of the particle components. A model which incorporated these observations was developed to describe the morphogenesis of atmospheric primary particles during aging in the New Zealand environment. XPS was used to study ambient aerosols deposited on both botanical and artificial passive sampling surfaces. Plant leaves were shown to be excellent collectors of particulate material and were suited to analysis by XPS. Site differences in the atmospheric aerosol load and composition were detected on vine leaves located on a hill side (high NaCl) and at a roadside (high sulfate and silicates) in a rural area. Zn and Fe species were detected by XPS on pine needles up to 2 km downwind of the steel mill.
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Pritchard, Joseph James. "The effects of secondary air injection on particulate matter emissions." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/87963.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 69-71).
An experimental study was performed to investigate the effects of secondary air injection (SAI) on particulate matter (PM) emissions. SAI was developed to reduce hydrocarbon (HC) emissions and has been shown to be effective as a strategy to reduce HC emissions at cold-start. In general, cold-start emissions have become an increasingly important problem due to new, more stringent vehicle emissions regulations. Direct-injection, spark-ignition (DISI) engines, which emit high levels of PM, are growing in popularity because of their fuel efficiency improvements. Meeting PM emissions becomes a more difficult task due to more stringent standards and the greater adoption of DISI engines. This study seeks to investigate the potential use of SAI to reduce PM emissions in the exhaust system. Engine based experiments were conducted using a 2.0 L, turbocharged, DISI General Motors LNF engine. The engine was outfitted with a secondary air injection system and several thermocouples to measure exhaust stream temperature. A TSI Model 3934 Scanning Mobility Particle Sizer (SMPS) was used to measure particle emissions at various engine operating conditions and secondary air rates. PM reductions were observed for the engine conditions and SAI flow rates that were tested. The maximum particle number reduction achieved was 80%. Particle number and particle volume reduction were observed to correlate well with exhaust enthalpy release.
by Joseph James Pritchard.
S.M.
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Zhao, Huayong. "Optical diagnostics and particulate emissions analysis of hydrogen-hydrocarbon combustion." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:e835a67a-88d6-44aa-95ee-485d032b82b2.
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With the depletion of hydrocarbon fuels, the hydrogen-hydrocarbon combustion system provides a good solution for the transition period from a hydrocarbon-based energy sys- tem to a hydrogen-based energy system because of its desirable combustion characteristics and the low level of modification to current combustion systems. Though extensive re- search has been carried out to investigate the combustion process of hydrogen-hydrocarbon fuels, no experiments have been reported to study the Particulate Matter (PM) formations in hydrogen-hydrocarbon combustion systems. To measure the PM concentrations in a laminar diffusion flame, a new optical diagnostic technique, called Cone-Beam Tomographic Three Colour Spectrometry (CBT-TCS) has been developed to measure the spatially distributed temperature, soot diameter and soot volume fraction. This technique is based on the principle of three colour pyrometry, but uses a more rigorous light scattering model to calculate the soot diameter and soot volume fraction. The cone beam tomography technique has also been used to reconstruct the 3D property fields from the 2D flame images. The detailed theoretical principles, the exper- imental setup, the optical considerations, the reconstruction algorithm and the sensitivity analysis are all introduced. The CBT-TCS technique has been successfully applied to several laminar diffusion flames to study the PM formation. The temperature and soot volume fracction profiles measured by CBT-TCS for a ethylene laminar diffusion flame are consistent with the data reported by Snelling et al. [77]. The helium-ethylene-air flame tests show that adding helium reduces the PM formation (due to the dilution effect). The hydrogen-ethylene-air flame tests show that adding hydrogen is more effective in reducing the PM formation due to the combined effect of dilution and direct chemical reaction. A PM sampling system has also been de- veloped to verify the PM size distributions measured by CBT-TCS. The comparison results show that the CBT-TCS tends to overestimate the particle size. Several optical engine experiments have also been undertaken to investigate the effect of adding hydrogen on the PM emissions from a Gasoline Direct Injection (GDI) engine. The hydrogen-ethylene engine tests show that adding hydrogen can reduce the PM emissions without sacrificing the power output. The hydrogen-base fuel (65% isooctane and 35% toluene) tests show that adding hydrogen can improve the combustion stability and reduce the PM emissions, especially at low load. Adding 5% stoichiometric of hydrogen can reduce the total PM number concentration by 90% for a stoichiometric mixture and 97% for richer mixture at low load. At high load, adding 10% stoichiometric of hydrogen can also reduce the total PM number concentration by 85% for richer mixture but has little effect upon the stoichiometric mixture.
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Cambra, López María. "Control of particulate matter emissions from poultry and pig houses." Doctoral thesis, Universitat Politècnica de València, 2010. http://hdl.handle.net/10251/8501.
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Los alojamientos ganaderos, especialmente avícolas y porcinos, son una fuente importante de material particulado ("particulate matter", PM). Las concentraciones elevadas de PM en el ambiente pueden afectar a la salud de las personas y animales, así como al medio ambiente. La mejor manera de reducir las emisiones de PM de los alojamientos ganaderos es evitar que éste se genere y así, controlando el PM en origen, no sólo se pueden reducir las emisiones, sino también mejorar la calidad del aire en el interior de los alojamientos ganaderos. Por otra parte, para evaluar la posible exposición al PM por un lado, y para desarrollar medidas para reducirlo, por otro, es necesario conocer la morfología y composición de las partículas. En consecuencia, el objetivo de esta tesis fue identificar y caracterizar el origen del PM en diferentes sistemas de alojamientos ganaderos y evaluar técnicas de reducción de dicho PM en relación con otros contaminantes.
La tesis está compuesta por cuatro trabajos de investigación y una revisión previa, sobre el estado de la cuestión del PM en los sistemas de producción ganaderos, que establece el marco del trabajo experimental. En primer lugar, se muestrearon fuentes conocidas de PM en alojamientos ganaderos que fueron aerosolizadas experimentalmente en un generador de polvo de laboratorio para recoger muestras de PM fino y grueso. Estas muestras fueron analizadas posteriormente mediante: i) microscopía electrónica de barrido con un espectrómetro de rayos X para obtener una caracterización morfológica y química detallada de las fuentes; ii) mediante un contador óptico de partículas para obtener la distribución por tamaños de cada fuente. En segundo lugar, se investigaron las características más adecuadas de las partículas para distinguir entre las distintas fuentes en base a la caracterización de las mismas anteriormente obtenida y a las características morfológicas obtenidas con análisis digital de imagen.
En su conjunto, se puede concluir de manera genérica que los
resultados presentados en esta tesis contribuyen a proporcionar unas herramientas
básicas que permitirán diseñar unas medidas de reducción de PM en origen mejores y
más eficientes y, paralelamente, a predecir su funcionamiento.Cambra López, M. (2010). Control of particulate matter emissions from poultry and pig houses [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8501
Palancia
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Gerazounis, Stylianos. "Design and development of a particulate emission monitor." Thesis, University College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326226.
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Goodrich, Lee Barry. "A PM10 emission factor for free stall dairies." Texas A&M University, 2002. http://hdl.handle.net/1969.1/3858.
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Ambient concentration measurements of total suspended particulate (TSP) were made at
a commercial dairy in central Texas during the summers of 2002 and 2003. The facility
consisted of both open pen housing and free-stall structures to accommodate
approximately 1840 head of milking cattle. The field sampling results were used in the
EPA approved dispersion model Industrial Source Complex Short Term version 3
(ISCST-v3) to estimate emission fluxes and ultimately a seasonally corrected emission
factor for a free-stall dairy.
Ambient measurements of TSP concentrations for sampling periods ranging from 2 to 6
hours were recorded during the summer of 2002. The mean upwind concentration was
115µg/m3 with a maximum of 231µg/m3 and a minimum of 41.4µg/m3. The mean net
downwind TSP concentration was 134µg/m3 with a maximum of 491µg/m3 and a
minimum of 14µg/m3. Field sampling at this same dairy in the summer of 2003 yielded
significantly more 2 to 6 hour TSP concentration measurements. The mean upwind TSP
concentration was 76µg/m3 with a maximum concentration of 154µg/m3. The mean net downwind TSP concentration was 118µg/m3 with a maximum of 392µg/m3 and a
minimum of 30µg/m3.
The particle size distributions (PSD) of the PM on the downwind TSP filters was
determined using the Coulter Counter Multisizer. The results of this process was a
representative dairy PM PSD with 28% of TSP emissions being PM10.
The reported PM10 24-hour emission factors were 4.7 kg/1000hd/day for the free-stall
areas of the facility and 11.7 kg/1000hd/day for the open pen areas of the dairy. These
emission factors were uncorrected for rainfall events. Corrections for seasonal dust
suppression events were made for the San Joaquin Valley of California and the
panhandle region of Texas. Using historical rainfall and ET data for central California,
the seasonally corrected PM10 emission factor is 3.6kg/1000hd/day for the free-stalls,
and 8.7kg/1000hd/day for the open pens. For Texas, the seasonally corrected emission
factor is 3.7kg/1000hd/day for the free-stall areas and 9.2kg/1000hd/day for the open lot
areas.
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Xu, Fan. "Experimental research on particulate matter emissions from gasoline direct injection engines." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:308fc929-a747-4793-8d90-1d5bf81fae5d.
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As the legislation on vehicle emissions is becoming more and more stringent, increasing attention has been paid to the fine particles emitted by diesel and gasoline vehicles. The high number emission of fine particles has been shown to have a large impact on the atmospheric environment and human health. Researchers have shown that gasoline engines, especially Gasoline Direct Injection (GDI) engines, tend to emit large amounts of small size particles compared to Port Fuel Injection (PFI) gasoline engines and diesel engines fitted with Diesel Particulate Filters (DPFs). As a result, the particle number emissions of GDI engines will be restricted by the EU6 legislation. The particulate emission level of GDI engines means that they would face some challenges in meeting the EU6 requirement. This thesis undertakes research in the following area. Firstly, the filtration efficiencies of glass fibre filters were quantified using a Cambustion Differential Mobility Spectrometer 500 (DMS500) to see if all of the particles from the sampled gas can be collected by the filters. Secondly, various valve timings and different injection modes such as double injection with a second injection after compression, single early injection and split early injection were implemented to measure the Particulate Matter (PM) emissions and combustion characteristics of a GDI engine under warm-up operating conditions. Thirdly, the techniques for removing volatile particles were investigated using a catalytic Volatile Particle Remover (VPR) and an Evaporation Tube (ET) with hot air dilution under various test conditions. The results show that for the glass fibre filters tested here, the transmission efficiencies of the particles are very low, indicating that PM sampling using fibre filters is an effective method of studying the particulate emissions from the engine. Particle number emissions using double injection with injection after compression were much higher than those with single injection during the intake stroke. Under 1200 rpm, 110 Nm cold engine operation, no reduction effect on PM emissions was shown by using split intake injection to further facilitate homogeneous mixture formation compared with single intake injection. Valve timings showed moderate effects on particulate emissions. Properly adjusted timing for exhaust valve closure led to reduced particulate emissions by a factor of about 2 and the combustion characteristics were not adversely affected much. The VPR temperature and exhaust residence time did not show much effect on the catalytic VPR performance once the mass flow rate of exhaust was above 0.09 g/s. Generally, the transmission efficiencies of the VPR follow the trends of the scaled PMP counting efficiency specification. Hot air dilution is effective in reducing the small size particles. At 23 nm, the transmission efficiencies are within the error range of the PMP specification. The catalytic VPR and the Evaporation Tube were all found to be effective in reducing the particle number of small size (nucleation mode) particles. Both systems have some particle loss mainly due to the physical effects of diffusion and thermophoresis. Until now, GDI engines have not been optimised for reducing particulate emissions as the focus has been on gaseous emissions and fuel economy. With careful re-optimisation of the catalyst light-off and engine calibration (especially for transients) then there is scope for GDI engines to meet forthcoming emissions legislation.
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Lagally, Christie D. "A morphological survey of particulate matter emissions from spark-ignited engines." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/33754.
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Spark-ignited engines are known to produce PM composed of solid, volatile or semi-volatile particles including spheres of carbon soot formed into agglomerates, other forms of carbonaceous particles, metal particles and charred droplets of engine oil. In this thesis, detailed observation has revealed that SI PM is partly composed of fully-formed carbon nanotubes and fullerenes in addition to known particle types previously presented in the literature.
The purpose of this work is to ascertain the shape and size of particulate matter being emitted by SI engines. In this thesis, PM thermophoretic sampling and transmission electron microscopy were used to collect and analyze engine soot samples, respectively. Furthermore, the operation of the thermophoretic sampling device used in engine PM sample collection was characterized to identify the sampling efficiency based on particle deposition and sampling biases based on differences in particle thermoconductivity for various forms of carbon such as turbostratic soot, crystalline carbon nanotubes and calcium. In general, the efficiency of the TPS method was roughly estimated to be 30-80% efficient based on experimental results.
In this thesis, carbon nanotubes and fullerenes have been identified as being emitted from in-use, spark-ignited natural gas and gasoline burning auto-rickshaw engines tested in New Delhi, India. Emission of fullerenes and CNTs was on the order of 10% +/- 7% of the non-volatile particulate matter. Agglomerates, dense spherical particles believed to be charred engine oil, and unidentified or compound particles were also cataloged.
Confirmation that nanotubes are being produced by SI engines was achieved using PM samples collected from the Ricardo Hydra laboratory test engine at the University of British Columbia, Clean Energy Research Centre. Under more controlled conditions than can be achieved sampling in-use vehicles, SI engine PM is found to be a complex collection of dense, dark (possibly charred oil) spheres, small primary particle agglomerates, small particle deposits, volatile droplets, carbon nanotubes and fullerenes and large ‘other’ particles. High resolution TEM confirmed tube-shaped particles to be fully formed multi-walled carbon nanotubes.
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Rubino, Lauretta. "After-treatment of particulate emissions from simulated and gasoline engine exhausts." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.406858.
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Micallef, Alfred. "Concentrations and vertical profiles of airborne particulate matter." Thesis, University of Nottingham, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285453.
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Johansson, Petter. "Oil-related Particle Emissions from Diesel Engines." Licentiate thesis, Stockholm : Maskinkonstruktion, Kungliga Tekniska högskolan, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9287.
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Akbar, Sameer. "Particulate air pollution and respiratory morbidity in Delhi, India." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268012.
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Singh, Rakesh Bhushan. "Modelling and measurement of particulate pollution from motor vehicles." Thesis, University of Nottingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389355.
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Karani, George N. "The chemical nature of particulate air pollution in Leeds." Thesis, University of Leeds, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303467.
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Win, Kaung Myat. "Emissions from realistic operation of residential wood pellets heating systems." Doctoral thesis, Mälardalens högskola, Framtidens energi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-29582.
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Emissions from residential combustion appliances vary significantly depending on the firing behaviours and combustion conditions, in addition to combustion technologies and fuel quality. Although wood pellet combustion in residential heating boilers is efficient, the combustion conditions during start-up and stop phases are not optimal and produce significantly high emissions such as carbon monoxide and hydrocarbon from incomplete combustion. The emissions from the start-up and stop phases of the pellet boilers are not fully taken into account in test methods for ecolabels which primarily focus on emissions during operation on full load and part load. The objective of the thesis is to investigate the emission characteristics during realistic operation of residential wood pellet boilers in order to identify when the major part of the annual emissions occur. Emissions from four residential wood pellet boilers were measured and characterized for three operating phases (start-up, steady and stop). Emissions from realistic operation of combined solar and wood pellet heating systems was continuously measured to investigate the influence of start-up and stop phases on total annual emissions. Measured emission data from the pellet devices were used to build an emission model to predict the annual emission factors from the dynamic operation of the heating system using the simulation software TRNSYS. Start-up emissions are found to vary with ignition type, supply of air and fuel, and time to complete the phase. Stop emissions are influenced by fan operation characteristics and the cleaning routine. Start-up and stop phases under realistic operation conditions contribute 80 – 95% of annual carbon monoxide (CO) emission, 60 – 90% total hydrocarbon (TOC), 10 – 20% of nitrogen oxides (NO), and 30 – 40% particles emissions. Annual emission factors from realistic operation of tested residential heating system with a top fed wood pelt boiler can be between 190 and 400 mg/MJ for the CO emissions, between 60 and 95 mg/MJ for the NO, between 6 and 25 mg/MJ for the TOC, between 30 and 116 mg/MJ for the particulate matter and between 2x1013 and 4x1013 /MJ for the number of particles. If the boiler has the cleaning sequence with compressed air such as in boiler B2, annual CO emission factor can be up to 550 mg/MJ. Average CO, TOC and particles emissions under realistic annual condition were greater than the limits values of two eco labels. These results highlight the importance of start-up and stop phases in annual emission factors (especially CO and TOC). Since a large or dominating part of the annual emissions in real operation arise from the start-up and stop sequences, test methods required by the ecolabels should take these emissions into account. In this way it will encourage the boiler manufacturers to minimize annual emissions. The annual emissions of residential pellet heating system can be reduced by optimizing the number of start-ups of the pellet boiler. It is possible to reduce up to 85% of the number of start-ups by optimizing the system design and its controller such as switching of the boiler pump after it stops, using two temperature sensors for boiler ON/OFF control, optimizing of the positions of the connections to the storage tank, increasing the mixing valve temperature in the boiler circuit and decreasing the pump flow rate. For 85 % reduction of start-ups, 75 % of CO and TOC emission factors were reduced while 13% increase in NO and 15 % increase in particle emissions was observed.
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Tippayawong, Nakorn. "Simulation of particulate emissions from gasoline engines and their interaction with autocatalysts." Thesis, Imperial College London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394468.
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George, Sam. "Investigation of lubricant oil consumption and its contribution to particulate matter emissions." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=6004.
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Thesis (Ph. D.)--West Virginia University, 2008.Title from document title page. Document formatted into pages; contains xii, 152 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 111-119).
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Hardin, John Wesley. "Quantification of soluble organic fraction measurement variation in diesel particulate matter emissions." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=6007.
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Thesis (M.S.)--West Virginia University, 2008.Title from document title page. Document formatted into pages; contains ix, 135 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 52-53).
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Rojas, Néstor Y. "Diesel exhaust system influences on transient particulate emissions and particle size distribution." Thesis, University of Leeds, 2001. http://etheses.whiterose.ac.uk/2292/.
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The behaviour of particulate matter emissions from a Ford XLD 4T, passengercar diesel engine through a practical exhaust system in place was investigated during transient conditions, namely cold start and fast acceleration. Particulate emissions were measured at four sampling points through the exhaust system and the changes in particulate total mass concentration, total number concentration, particle size distribution and Carbon/SOF fractions were determined for various engine operating conditions. Each cold start test consisted of a step-change cold-start with fast acceleration, reaching one of the following target operation conditions: Idle, 1500rpm - 15kW, 2250rpm - 15kW, 2250rpm-35kW and 3500rpm - 15kW. Two preconditioning procedures were designed to provide repeatable cold start tests. These consisted of a) Idle operation for 4 hours the day before the test, followed by overnight soak; and b)10 minutes at high engine speed operation. Fast acceleration tests consisted of idle preconditioning followed by a step change to the target operation conditions. The particulate matter changes through the exhaust system were shown to be dependent on the previous operational history of the engine, idle conditions being effective at forming particle deposits. The amount of particulate deposited or blown out from the exhaust system constituted a significant fraction of the total engine exhaust emissions in a significant number of cold start and acceleration tests. The changes in particle concentration did not occur throughout the system in the same fashion. The catalyst produced predominantly particle number and mass reduction and the second silencer was a more efficient particle collector than the first silencer. From the first silencer, particles were resuspended more easily and in many more cases. Regarding the chemical composition, high-load conditions produced lower Solvent Organic Fraction (SOF) than their low load counterpart. However, the SOF did not change significantly through the exhaust system. Part of this work consisted of examining the use of the Electrical Low Pressure Impactor (ELP1) to estimate particulate mass emissions. It was observed that the ELP1 tended to overestimate the number of particles in the large (>0.1 (im) size range. This greatly affected the conversion from total particle number concentration to particle mass concentration. A correction based on comparison between the electrical and gravimetric methods (ELPI vs. Andersen Impactors) in the common size range for both techniques was proposed. Transient and steady-state tailpipe emission factors, expressed as grams of particulate per unit of engine work in kWh, were calculated from the test results and used to estimate the effect of transients on total cycle emissions in cycles with a different design from those followed in this work. The ELPI proved to be useful, yet limited for particle collection on Transmission Electron Microscope (TEM) grids in several size ranges. TEM images of particles were analysed and their fractal dimension determined.
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Whitcombe, Joshua Matthew, and n/a. "Study of Catalyst Particle Emissions From a Fluidized Catalytic Cracker Unit." Griffith University. School of Environmental Engineering, 2003. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20031003.152200.
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The control of particle emissions from an oil refinery is often difficult, due to changing operational conditions and the limited range of available treatment options. Excessive particle emissions have often been attributed start up problems with Fluidized Catalytic Cracker Units (FCCU) and little information is available regarding the exact composition and nature of these excessive emissions. Due to the complex nature of a FCCU, it has in the past been difficult to identify and control emissions, without the use of expensive end of pipe technologies. An Australian Oil Refinery, concerned with their catalyst emissions, sponsored this study of FCCU particle emissions. Due to the industrial nature of the project, a holistic approach to the management of emissions was taken, instead of a detailed investigation of a single issue. By looking at the broader range of issues, practical and useful outcomes can be achieved for the refinery. Initially, detailed emissions samplings were conducted to investigate the degree of particle emissions under start up conditions. Stack emissions were collected during a standard start up, and analysed to determine the particle size distribution and metal concentration of the emitted material. Three distinct stages of emissions were discovered, initially a high concentration of larger particles, followed by a peak in the very fine particles and finally a reduction of particle emissions to a more steady or normal operational state. The variation in particle emissions was caused by operational conditions, hardware design and catalyst characteristics. Fluctuations in the gas velocity through the system altered the ability of the cyclones to collect catalyst material. Also, the low bed level allowed air bypass to occur more readily, contributing to the increased emissions levels seen during the initial stage of the start up. Reduced fluidity characteristics of the circulating catalyst also affected the diplegs operations, altering the collection efficiency of the cyclone. During the loading of catalyst into the system, abraded material was quickly lost due to its particle size, contributing to fine particle emissions levels. More importantly, thermal fracturing of catalyst particles occurred when the cold catalyst was fed into the hot regenerator. Catalyst particles split causing the generation of large amounts of fine particle material, which is easily lost from the system. This loading of catalyst directly linked to the period of high concentration of fine particles in the emissions stream. It was found that metals, and in particular iron, calcium and silicon form a thick layer on the outside of the catalyst, with large irregular shaped metal ridges, forming along the surface of the particle. These ridges reduce the fluidity of the catalyst, leading to potential disruptions in the regenerator. In addition to this, the metal rich ridges are preferentially removed via attrition, causing metal rich material to be emitted into the atmosphere. To overcome these high particle emissions rates from the FCCU the refinery should only use calcinated catalyst to reduce the influence of thermal process and particle fracture and generation. Although the calcinated catalyst can fracture when added to the system, it is far less than that obtained with uncalicinated catalyst. To further reduce the risk of particle fracture due to thermal stresses the refinery should consider reducing the temperature gradients between the hot and cold catalyst. Due to the economics involved with the regenerator, possible pre-warming of catalyst before addition into system is the preferred option. This pre-heating of catalyst should also incorporate a controlled attrition stage to help remove the build up of metals on the surface of the particles whilst allowing this material to be collected before it can be released into the atmosphere. The remove of the metal crust will also improve the fluidity of the system and reduce the chance of catalyst blockages occurring. Finally, modelling of the system has shown that control of key parameters such as particle size and gas velocity are essential to the management of air emissions. The refinery should look at adjusting start up procedures to remove fluctuations in these key parameters. Also the refinery should be careful in using correlation found in the literature to predicted operational conditions in the system as these correlations are misleading when used under industrial situations.
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Vawda, Yasmin. "Factors influencing the dry deposition of atmospheric trace particulate species." Thesis, University of Essex, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280467.
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MANUZON, RODERICK BEROIN. "Electrostatic Precipitation Technologies for the Mitigation of Particulate Matter Emissions from Poultry Facilities." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1345562603.
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Faghani, Ehsan. "Effect of injection strategies on particulate matter emissions from HPDI natural-gas engine." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/55606.
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Internal combustion engines produce emissions of NOx and particulate matter (PM). Westport Innovations Inc. has developed the pilot-ignited high-pressure direct-injection (HPDI) natural gas (NG) engine system. To ignite the natural gas, HPDI uses a small diesel pilot injection (~5% of total fuel energy), which is normally injected before the NG. Although HPDI engines produce less PM than diesel engines, further reductions of engine-out PM emissions are desired in order to meet future regulations. The goal of this project is to reduce PM from HPDI engines and study the drawbacks of the injection strategies in terms of engine performance or other emissions. This thesis proposes mechanisms for two injection strategies useful in PM reduction: Late Post Injection (LPI) and Slightly Premixed Combustion (SPC). Tests on LPI and SPC were performed in the UBC Single Cylinder Research Engine (SCRE). In LPI, a second natural gas injection (10-25% of total fuel mass) is injected into the cylinder later in the cycle. In SPC, more premixing of NG is achieved by injecting NG before the diesel injection and engine operating parameters are adjusted to minimize the effect on other emissions. Both of the injection strategies show significant PM reduction (over 75% on the SCRE) with small effects on other emissions and engine performance. Westport’s computational fluid dynamics package, “GOLD”, was used to help to understand the mechanisms of the new injection strategies. The PM reductions from LPI and SPC were captured by GOLD.
A phenomenological model (Transient Slice Model, TSM) has been developed in this study to provide better insight into the PM reduction process, using the Hiroyasu model with a transport equation for soot. TSM results show good agreement in the prediction of pressure trace and heat release rates in most cases. Engine-out PM trends with changing engine parameters are well-captured in the TSM for exhaust gas recirculation (EGR), equivalence ratio (EQR), load and natural gas (NG) flow. TSM cannot predict the effect of NG injection pressure. For the new injection strategies, TSM can predict the PM trends for LPI, relative gas-diesel timing and the SPC injection strategy.Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate
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Heinrich, Victoria. "Assessment of techniques to detect particulate emissions from the Olympic Dam Copper smelter /." Title page, abstract and contents only, 2000. http://web4.library.adelaide.edu.au/theses/09SB/09sbh469.pdf.
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Zhang, Yihao S. M. Massachusetts Institute of Technology. "Assessing the effects of ethanol addition on particulate matter emissions in GDI engines." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/118678.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2018.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 75-78).
Previous research on the effects of ethanol addition on particulate matter (PM) emissions in GDI engines show diverse results. In this thesis, an overview on three major aspects, PM formation, effects of engine operating conditions, and ethanol effects, unveils the large number of factors that can simultaneously affect PM emissions from gasoline-ethanol blends in GDI engines, partially explaining the reasons for the diverse results from previous research. A further experimental work was conducted to assess three potential ethanol effects, displacement effect, evaporative cooling effect, and oxygen content effect. The displacement effect is based on PM Index (PMI) in the literature. Ethanol has very low PMI and thus very low propensity to form PM. Therefore, the addition of ethanol replaces the high-PMI components in the gasoline, lowering PM emissions. Although the PMI value incorporates species reactivity and volatility, it does not take latent heat of vaporization (HOV) into account. The high HOV of ethanol suppresses the fuel evaporation and potentially causes more liquid fuel films, which serve as sources for PM emissions. This evaporative cooling effect was assessed along with the oxygen content effect, a widely used effect in the literature to explain why ethanol lowers PM emissions. Through the method of control variables, the displacement effect and oxygen content effect were separated out and could be assessed individually. The existence of the displacement effect was confirmed. It was also found that the oxygen content effect was negligible, while the evaporative cooling effect changed PN emission significantly. The extent of the evaporative cooling effect depended on operating conditions, such as fuel injection timing, engine coolant temperature, and load.
by Yihao Zhang.
S.M.
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Predicala, Bernardo Z. "Characterization and modeling of concentrations and emissions of particulate matter in swine buildings /." Search for this dissertation online, 2003. http://wwwlib.umi.com/cr/ksu/main.
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Parker, Gavin James. "Analysis of metals in airborne particulate matter in eastern Iowa." Thesis, University of Iowa, 2019. https://ir.uiowa.edu/etd/7010.
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Airborne particulate matter (PM) consists of solid and liquid particles suspended in air. PM causes many negative health effects when inhaled like exacerbations of asthma, chronic obstructive pulmonary disease (COPD), and premature death. The health impacts of PM depend on the physical size and chemical composition of the inhaled particles. Particles less than 2.5 micrometers can penetrate the deep lung and enter the bloodstream. Understanding the composition of PM helps study human exposures and evaluate PM sources to support control and mitigation strategies. This thesis examines PM in power plant emissions, in ambient air, and in homes, with an emphasis on characterizing hazardous metals.
PM emissions from the University of Iowa power plant were examined during a transition away from coal. Biomass is a renewable fuel and when used in place of or co-fired alongside coal it directly reduces emissions of fossil CO2 and PM to the atmosphere. PM emissions were examined under two scenarios: the first was a stoker boiler that fired 100% renewable energy pellets. PM and metal emissions reduced by 59 and 80% respectively despite increases to polycyclic aromatic hydrocarbons (PAHs) that was attributed to emission of unburned carbon fuel. The second test was done in a circulating fluidized bed boiler firing 78% oat hulls, 17% coal, and 5% energy pellets. Decreases in PM, PAHs, and metal emissions were 32, 33, and 50%, respectively. Reductions in PM, PAHs, and metals when firing renewable fuels provide environmental advantages to local air quality while trying to eliminate the use of coal.
Ambient air quality was examined downwind of the power plant. The levels of PM2.5 in Iowa City in 2016 ranged from 1.4-32.1 µg m-3 with an annual mean of 7.5 µg m-3. These levels are below the National Ambient Air Quality Standards (NAAQS) for 24-hours (35 µg m-3) and the annual average (12 µg m-3). On average, the analyzed metals accounted for 10.7 ± 5.3% of PM2.5. Potassium, calcium, and zinc were the most abundant metals (averaging 250 ± 10, 170 ± 40, and 11.2 ± 0.5 ng m-3, respectively) and are associated with geological sources and biomass burning. Metals associated with fossil fuel combustion such as arsenic, lead, or vanadium were observed at low levels (averaging 0.58 ± 0.01, 1.32 ± 0.03, and 0.19 ± 0.01 ng m 3, respectively). Harmful metals were at least an order of magnitude lower than the World Health Organization’s guideline concentrations in Iowa City PM2.5. Overall, the hazardous metals in ambient PM2.5 observed in Iowa City were not at concerning levels. The work in this chapter helps provide a metal speciation profile for future studies and these measurements can be used to assess future changes in PM2.5 metal concentrations.
Indoor PM collected in homes of Eastern Iowa COPD patients was characterized for its metal content. COPD patients are at higher risk of developing respiratory infections, which cause acute exacerbations of COPD—the leading cause of mortality in COPD patients—and airborne PM increases risk of infection. From the 21 homes studied 6-87 mg of indoor PM was collected over 30 days in winter. Crustal metals such as magnesium, iron, and aluminum were the most concentrated in indoor PM, having mass fractions from 3000-25,000 ng mg-1. Toxic metals like vanadium and arsenic were at lower levels from 3-65 ng mg-1. Between homes the relative abundance of metals was similar, but the absolute abundance was highly variable. Analyzing indoor PM is essential since Americans on average spend 80% of their day indoors making it a significant environment for PM exposure. This chapter provides a chemical profile for different homes when studying the impact PM has on respiratory health.
This thesis also provides new measurements of the chemical composition of PM at the point of emission, in ambient air, and within homes. Advancing knowledge of PM composition in different environments is vital in understanding its impacts on human health. Improvements to local air quality with reductions to PM and metal emissions were observed when firing alternative fuels. Ambient PM2.5 concentrations in Iowa City were lower than NAAQS levels and the composition of both ambient and indoor PM was evaluated. With greater understanding of PM composition, better control strategies can be studied and employed to improve local air quality.
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Bonifacio, Henry F. "Estimating particulate emission rates from large beef cattle feedlots." Diss., Kansas State University, 2013. http://hdl.handle.net/2097/15530.
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Doctor of PhilosophyDepartment of Biological and Agricultural Engineering
Ronaldo G. Maghirang
Emission of particulate matter (PM) and various gases from open-lot beef cattle feedlots is becoming a concern because of the adverse effects on human health and the environment; however, scientific information on feedlot emissions is limited. This research was conducted to estimate emission rates of PM[subscript]10 from large cattle feedlots. Specific objectives were to: (1) determine feedlot PM[subscript]10 emission rates by reverse dispersion modeling using AERMOD; (2) compare AERMOD and WindTrax in terms of their predicted concentrations and back-calculated PM[subscript]10 emission rates; (3) examine the sensitivity of both AERMOD and WindTrax to changes in meteorological parameters, source location, and receptor location; (4) determine feedlot PM[subscript]10 emission rates using the flux-gradient technique; and (5) compare AERMOD and computational fluid dynamics (CFD) in simulating particulate dispersion from an area source. PM[subscript]10 emission rates from two cattle feedlots in Kansas were determined by reverse dispersion modeling with AERMOD using PM[subscript]10 concentration and meteorological measurements over a 2-yr period. PM[subscript]10 emission rates for these feedlots varied seasonally, with overall medians of 1.60 and 1.10 g /m[superscript]2 -day. Warm and prolonged dry periods had significantly higher PM emissions compared to cold periods. Results also showed that the PM[subscript]10 emissions had a diurnal trend; highest PM[subscript]10 emission rates were observed during the afternoon and early evening periods. Using particulate concentration and meteorological measurements from a third cattle feedlot, PM[subscript]10 emission rates were back-calculated with AERMOD and WindTrax. Higher PM[subscript]10 emission rates were calculated by AERMOD, but their resulting PM[subscript]10 emission rates were highly linear (R[superscript]2 > 0.88). As such, development of conversion factors between these two models is feasible. AERMOD and WindTrax were also compared based on their sensitivity to changes in meteorological parameters and source locations. In general, AERMOD calculated lower concentrations than WindTrax; however, the two models responded similarly to changes in wind speed, surface roughness, atmospheric stability, and source and receptor locations. The flux-gradient technique also estimated PM[subscript]10 emission rates at the third cattle feedlot. Analyses of PM[subscript]10 emission rates and meteorological parameters indicated that PM[subscript]10 emissions at the feedlot were influenced by friction velocity, sensible heat flux, temperature, and surface roughness. Based on pen surface water content measurements, a water content of at least 20% (wet basis) significantly lowered PM[subscript]10 emissions at the feedlot. The dispersion of particulate from a simulated feedlot pen was predicted using CFD turbulence model ([kappa]-[epsilon] model) and AERMOD. Compared to CFD, AERMOD responded differently to wind speed setting, and was not able to provide detailed vertical concentration profiles such that the vertical concentration gradients at the first few meters from the ground were negligible. This demonstrates some limitations of AERMOD in simulating dispersion for area sources such as cattle feedlots and suggests the need to further evaluate its performance for area source modeling.
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Mediavilla-Sahagun, Antonio. "Integrated assessment modelling applied to particulate concentrations and urban air quality management." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271718.
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Boswell, Colin R. "Atlanta automotive particulate matter exposure and evaluation." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34679.
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The following thesis titled, Atlanta Automotive Particulate Matter Exposure and Evaluation, presents data obtained as a part of a joint project with Emory University, Rollin's School of Public Health. The Atlanta Commuters Exposure (ACE) Study uses both real-time and time-integrated sampling techniques for ambient aerosol concentrations. The ACE study is unique in that it will correlate the ambient aerosol concentrations with the concurrent health measurements. The primary objective of this thesis is to measure the concentration, size distribution and the chemical composition of PM2.5 inside the vehicle cabin for several commuters. The vehicles followed a scripted route along roadways in the Atlanta metropolitan region during periods of peak traffic volume, while the compact air sampling package of both real-time and time-integrated instruments recorded data. Real-time measurements for Particulate Matter (PM) were made using compact Optical Particle Counters (OPC), a Condensation Particle Counter, and a MicroAethalometer. The time-integrated measurements for Elemental Carbon (EC), Organic Carbon (OC), Water Soluble Organic Carbon (WSOC), particulate elemental concentrations, and speciated organics required filter collection methods. Thus a compact air-sampling package was created to combine both sets of real-time and time-integrated instruments. The following results are presented for the first four commutes. The framework for analyzing and presenting results is developed, and will be used for future commutes.
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Cerit, Ersen Recep. "Investigation Of The Effect Of Oxidation Filters On The Particulate Emissions Of Diesel Engines." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607561/index.pdf.
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Oxidation filters are used to decrease particulate emissions commonly. In this study, design of a particulate trap to produce an alternative, low cost filter has been aimed. An experimental setup has been installed according to standards to carry out tests of these designed filters. Electronic measurement and control systems have been attached to this setup to increase efficiency of experiments.
Two filter designs have been used in the experiments. First design consists of aluminum wire cloth. Second design is sheet metal structure, which includes three longitudinal cells. Metal chip is used as filter material. Empty filter tests have been performed firstly, and then experiments have been repeated with aluminum, iron, and copper chip addition in filter.
Copper chip test results are better than other metal chip for first experiments. Afterwards, experiments have been repeated with varying copper chip amount. Suitable copper chip amount was determined based on fuel consumption rate of the engine.
As a result, designed filter reduce the particulate emissions with high efficiency. Although, carbon monoxide, and carbon dioxide gaseous emissions increase with designed filter, hydro carbon emissions decrease.
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Galvis, Remolina Boris. "Characterizing the emissions of fine particulate matter in the vicinity of a rail yard." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/52927.
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Aerosol emissions from diesel combustion and other activities in rail yards can affect the health of urban populations. Fine particulate (PM[subscript 2.5]) concentrations near the Inman and Tilford rail yards in Atlanta, Georgia, are the highest measured in the state. The rail yard complex is surrounded by homes, schools, businesses and other industries. The impact of the aerosol emissions from these rail yards on local concentrations of PM[subscript 2.5] was quantified. Specifically, black carbon and PM[subscript 2.5] fuel-based emission factors from the rail yards were estimated by carbon balance using high time-resolution monitoring, a BC and PM[subscript 2.5] emissions inventory was estimated and dispersion modeling was applied to assess the impact of the rail yard activities on local air quality and the cost and benefits of upgrading locomotive engines with cleaner technologies was assessed. Further, baseline information that will allow a later evaluation of the improvement of local air quality as locomotives operating in the rail yards are upgraded was generated, and a composition profile of the rail yard aerosols was developed using chemical speciation techniques. These results found that activities from locomotives in the Inman and Tilford Rail yards lead to and an average emission factor of 6.0 ± 0.5 g of PM[subscript 2.5] per gallon of fuel and are responsible for increases in annual average concentrations of approximately 1.3 µg/m³ of PM[subscript 2.5] as far as 1 km from the perimeter of the rail yard complex. Approximately 11.7 tons of BC and 26 tons of PM[subscript 2.5] per year were emitted from the rail yards in 2011. The rail yards were found to be important sources of hydrocarbon-like organic aerosols (HOA) and black carbon from fuel (BCf). Upgrading the engines at the rail yards would decrease PM[subscript 2.5] emissions by about 9 t/year, reducing PM[subscript 2.5] concentrations around 0.5±0.1 µg/m³ as far as 1 km from the perimeter of the rail yard complex and producing monetized health benefits of approximately 24 million dollars per year.
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Korontzi, Stefania. "Modeling of seasonal trace gas and particulate emissions from vegetation fires in southern africa." College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/1415.
Full textAbstract:
Thesis (Ph. D.) -- University of Maryland, College Park, 2004.Thesis research directed by: Geography. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Bugarski, Aleksandar D. "Characterization of particulate matter and hydrocarbon emissions from in-use heavy-duty diesel engines." Morgantown, W. Va. : [West Virginia University Libraries], 1999. http://etd.wvu.edu/templates/showETD.cfm?recnum=1174.
Full textAbstract:
Thesis (Ph. D.)--West Virginia University, 1999.Title from document title page. Document formatted into pages; contains xxviii, 254 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 218-232).
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Xu, Zhuyun. "Analysis of particulate matter concentration and size distribution in heavy-duty vehicle exhaust emissions." Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=2012.
Full textAbstract:
Thesis (M.S.)--West Virginia University, 2001.Title from document title page. Document formatted into pages; contains xi, 133 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 129-133).
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Keshtkar, Haleh. "Characterization of polycyclic aromatic hydrocarbons (PAH) in particulate and gaseous emissions from agricultural burning /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.
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