Download or read book Impact of Oxygen Enrichment on Soot Properties and Soot Oxidative Reactivity written by Hee Je Seong and published by . This book was released on 2010 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Oxygen Enrichment on Soot Formation and Thermal Radiation in Turbulent Non Premixed Methane Flames written by and published by . This book was released on 2015 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Soot in Combustion Systems and Its Toxic Properties written by J. Lahaye and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 429 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our interest in Mulhouse for carbon black and soot began some 30 years ago when J.B. Donnet developed the concept of surface chemistry of carbon and its involvement in interactions with gas, liquid and solid phases. In the late sixties, we began to study soot formation in pyrolytic systems and later on in flames. The idea of organ1z1ng a meeting on soot formation originated some four or five years ago, through discussions among Professor J.B. Howard, Dr. A. D'Alessio and ourselves. At that time the scientific community was becoming aware of the necessity to strictly control soot formation and emission. Being involved in the study of surface properties of carbon black as well as of formation of soot, we realized that the combustion community was not always fully aware of the progress made by the physical-chemists on carbon black. Reciprocally, the carbon specialists were often ignoring the research carried out on soot in flames. One objective of this workshop was to stimulate discussions between these two scientific communities. During the preparation of the meeting, and especially during the review process by the Material Science Committee of the Scientific Affairs Division of N.A.T.O. the toxicological aspect emerged as being an important component to be addressed during the workshop. To reflect these preoccupations we invited biologists, physical chemists and engineers, all leaders in their field. The final programme is a compromise of the different aspects of the subject and was divided in five sessions.

Download or read book Measurement Characterization Identification and Control of Combustion Produced Soot written by Madhu Singh and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The negative health implications associated with combustion produced soot demand identification of contributing sources, quantification and characterization of their emissions to assess its impact, and control to minimize the imposed hazard. Distinguishing different sources of soot from engines and combustors is challenging, given the morphological and chemical similarity of the emitted soot. Leaner combustion conditions and tighter emission limits challenge traditional filter-based measurements for soot mass. Meanwhile, current after-treatment particulate control strategies are based on regeneration, i.e., soot oxidation which in turn depends upon soot nanostructure and composition (such as in a diesel particulate filter). Presently, effects on human health associated with soot exposure are largely correlative, while controlled lab studies predominantly use varied washings or extracts of soot, but rarely the actual particulate. Given the intertwined nature of these topics this dissertation addresses each in an integrated approach. Laser-induced incandescence (LII) is used to determine soot concentration while Time-resolved LII (TiRe-LII) can be used to estimate soot primary particle size largely by using available and appropriate models. The use of laser diagnostics has been used to experimentally demonstrate prevailing inconsistencies between experimentally measured and model-derived particle diameter values. Discrepancies have been attributed (a) to the empiricism associated with evaluating modeling variables and (b) to the lack of proper accountability of the changes in soot nanostructure upon heating with a pulsed laser. This work uses an experimental approach coupled with microscopy to (a) test the robustness of existing LII models and (b) inform existing models of experimental observations so that these can be accounted for in future models. Specifically, the contribution of changing soot nanostructure on laser heating is known and is shown here again with transmission electron microscopy (TEM). However, the change in soots optical properties because of an altered nanostructure remains unclear. Optical properties change when soot is laser-heated, and this alteration of optical properties upon laser heat treatment has been shown in this work experimentally, by using UV-Vis spectroscopy. Also, the effect of the degree of aggregation on the soots cooling profile is highlighted. This work demonstrates that different degrees of aggregation results in a shift of the time-temperature-history (TTH), thereby resulting in erroneous particle size predictions, which are calculated from the materials TTH. Unfortunately, most models assume point-contacting spheres and aggregation remains unaccounted for. The effect of the thermal accommodation coefficient is similar in that a small change in the value of this mathematical parameter significantly alters particle cooling as simulated here by an open-access simulator, indicating the need to exercise caution when assigning a value to this parameter in the model. While the change in soot nanostructure as a consequence of laser annealing complicates the interpretation from LII measurements, laser heating of soot can reciprocally be used to purposefully study the evolution in soot nanostructure as a function of its chemistry. Soot chemistry varies with its combustion environment, with fuel and combustion conditions specific to each source. Thus, by association, the evolution of soot nanostructure observed upon laser heat treatment can be correlated to its fuel origins and combustion origins, potentially identifying its formation source. Fundamentally, the presence of oxygen in nascent soot is identified here as a key compositional parameter. The increase in oxygen content of the fuel, as diesel is blended with increased proportions of biofuel, is correlated to increased oxygen content in the soot that is generated by the respective fuel. In other words, fuel with a higher oxygen content generates soot which also has oxygen content relatively higher than soot generated by fuel with low oxygen content. This work shows that oxygen dictates the evolution of soot nanostructure when it escapes the material upon laser heat treatment. When laser heated, the nanostructure of soot with a higher oxygen content evolves as hollow-shell like structures while nanostructure of soot with a low oxygen content evolves to show a ribbon-like interior. This divergence in soot nanostructure based on the oxygen content of nascent soot, which in turn is shown to be a function of the fuel composition, could be used to identify the source that generated the soot sample studied. Given the lack of availability of authentic soot samples, the combination of laser heat treatment and TEM of soot to identify fuel or source is powerful when sample quantities are in the range of less than a few nanograms. Being able to identify sources and their contributions using laser derivatization of soot as a diagnostic can help optimize new or existing control measures to reduce the concentration of atmospheric soot. For instance, diesel particulate filters (DPFs) are used to reduce diesel soot emissions. Effective protocols for DPF operation can be developed by understanding soot nanostructure changes as captured soot is oxidized during passive and active DPF regeneration. Typically, O2, NO2 or a combination of the two oxidants are encountered during DPF regeneration. In this work, soot nanostructure has been shown to vary with the order of oxidants to which it is exposed, a significant finding towards optimizing DPF filter regeneration protocols. The study has been performed on authentic diesel soot in a thermogravimetric analyzer under conditions mimicking active and passive regeneration in a DPF. To validate observations with diesel soot, three carbon blacks with varying nanostructure are also subjected to oxidation by O2 and NO2. The intriguing result is that order of oxidation matters, i.e., the oxidation rates are dependent upon nanostructure changes in response to oxidation by O2 alone, or O2 with NO2.Prolonged exposure to particulate matter causes unwanted ill-health, lung dysfunctions, and breathing problems. Most toxicity studies are done using a washing, or an extract of the organic fraction of soot and cells are exposed to this extract. This work tests the adverse effect of soot on human (male) lung cells when these are exposed to surrogate soot as is, i.e., structure and chemistry intact to mimic real-time exposure conditions. The impact of soot chemistry and the presence of acidic functional groups on lung epithelial cells for varying exposure times is demonstrated in our collaborative work with the College of Medicine at Penn State, Hershey, PA. Soot chemistry is shown to directly and adversely impact cell viability and mRNA expressions of the IL-1B and IL-6 cytokines as well as mRNA expression of the TLR4 protein. Specifically, cell viability was shown to reduce significantly after 6- and 24-hours of exposure to carboxylic groups on the soot, thereby demonstrating the health impact of soot surface chemistry in comparison to extracts.In summary, soot measurement, its extensive characterization to identify source contributions and develop practically applicable control strategies has a direct implication on our health and surroundings and can aid in promoting a healthy living environment.

Download or read book Reducing Green House Effect Caused by Soot Via Oxidation Using Modified LaFe1 xCuxO3 Catalysts written by Paritosh C. Kulkarni and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soot has been the cause of global warming since the dawn of diesel engines. Soot oxidation in the diesel particulate filters fixated at the exhaust of the engine has been a boon to reduce the particulate matter from entering the atmosphere. Here we have attempted to synthesize the smooth powder of supported and macro-porous perovskite LaFeO3 and its doped variant with 5, 10, 20, and 30% copper on B site. Subsequent catalysts, termed as LFO and LFCO- (5, 10, 20, 30) with formula LaFe1-xCuxO3, were investigated as catalysts for soot oxidation reaction. The structural and physical and chemical attributes of LaFe1-xCuxO3 and LaFeO3 are characterized by XRD patterns, FESEM, BET, particle size analysis measurements. Undoped LaFeO3 with desired textural structures were successfully prepared, employing the citric-acid auto combustion method, and the porous sample exhibits the best activity towards redox reactions, pointing out the enriched activity at redox sites of fabrication of porous perovskite for the responses. By correlating with the catalytic activities and the physical and chemical properties, of both doped and undoped samples, it is inferred that the best activity obtained from the porous LaFe0.9Cu0.10O3 is attributed to its extensive surface area corresponding to least particle size, precious active lattice oxygen, high oxygen storage capacity and vigorous surface activity.

Download or read book Cleaner Combustion written by Frédérique Battin-Leclerc and published by Springer Science & Business Media. This book was released on 2013-09-06 with total page 657 pages. Available in PDF, EPUB and Kindle. Book excerpt: This overview compiles the on-going research in Europe to enlarge and deepen the understanding of the reaction mechanisms and pathways associated with the combustion of an increased range of fuels. Focus is given to the formation of a large number of hazardous minor pollutants and the inability of current combustion models to predict the formation of minor products such as alkenes, dienes, aromatics, aldehydes and soot nano-particles which have a deleterious impact on both the environment and on human health. Cleaner Combustion describes, at a fundamental level, the reactive chemistry of minor pollutants within extensively validated detailed mechanisms for traditional fuels, but also innovative surrogates, describing the complex chemistry of new environmentally important bio-fuels. Divided into five sections, a broad yet detailed coverage of related research is provided. Beginning with the development of detailed kinetic mechanisms, chapters go on to explore techniques to obtain reliable experimental data, soot and polycyclic aromatic hydrocarbons, mechanism reduction and uncertainty analysis, and elementary reactions. This comprehensive coverage of current research provides a solid foundation for researchers, managers, policy makers and industry operators working in or developing this innovative and globally relevant field.

Download or read book Impact of Oxygenated Fuels on Sooting Tendency and Soot Oxidative Reactivity with Application to Biofuels written by Eduardo Jose Barrientos Betancourt and published by . This book was released on 2014 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Surface Intermediates Mechanism and Reactivity of Soot Oxidation written by Shazam Williams and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Introduction to Carbon Science written by Ian A. S. Edwards and published by Butterworth-Heinemann. This book was released on 2013-10-22 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction to Carbon Science deals with various aspects of carbon science, from polymer science and prosthetics to crystallography, carbonization, spectroscopy, and surface science. Topics covered include the mechanisms of formation of isotropic and anisotropic carbons, physical properties of pitch relevant to the fabrication of carbon materials; kinetics and catalysis of carbon gasification; and porosity in carbons and graphites. Carbon fibers, cokes and composites, and coal to coke transformations are also discussed. This book is comprised of nine chapters and begins with an overview of the basic structural features of carbon materials, along with definitions of the various carbon forms encountered in carbon science. The principal techniques for studying the structure of solid carbons are also considered. The reader is then introduced to the mechanisms underlying the formation of isotropic and anisotropic carbons; the physicochemical changes that take place when pitch is pyrolyzed to carbon; and kinetics and catalysis of carbon gasification reactions. The following chapters explore various types of porosity in carbons and graphites; manufacture, properties, structure, and applications of carbon fibers; and mechanical properties of cokes and composites. This text concludes by describing the conversion of coal to coke. This monograph will be of interest to carbon scientists, technologists, and engineers, as well as those entering the field of carbon science for the first time.

Download or read book Soot Formation and Its Impact on Flame RadiatioSoot Formation and Its Impact on Flame Radiation During Turbulent Non Premixed Oxygen Enriched Combustion of Methane written by and published by . This book was released on 2015 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Potassium doping and Oxygen Concentration on Soot Oxidation in O2 CO2 Atmosphere A Kinetics Study by Thermogravimetric Analysis written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Application of Clean Fuels in Combustion Engines written by Gabriele Di Blasio and published by Springer Nature. This book was released on 2022-01-04 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the impact of fuels characteristics and their effects on the combustion processes in internal combustion engines. It includes the analysis of a variety of biofuels (alcohol fuels and biodiesel) and biogases (natural gas, hydrogen, etc.), providing valuable information related to consequent effects on performance and emissions. The contents focus on recent results and current trends of fuel utilization in the transport sector. State-of-the-art of clean fuels application are also discussed. Thighs book will be of interest to those in academia and industry involved in fuels, IC engines, engine instrumentation, and environmental research.

Download or read book Development and Implementation of Detailed Soot Surface Oxidation Model Into Kinetic Monte Carlo Simulations of Graphene Edge Oxidation written by Ravi Ishwar Singh and published by . This book was released on 2016 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents a newly established, detailed model of elementary reactions of soot oxidation. Surface oxidation is the primary mechanism by which carbon is removed from soot. Previously, soot oxidation has been modeled using a one-step global mechanism based on chemical analogy to phenyl oxidation. The one-step model, however, is limited to simple descriptions of surface geometry. Studies of soot growth revealed that chemical analogy alone is insufficient to describe the reactions taking place at the particle surface. Steric effects, neighboring sites, and substrate size must also be considered. For soot growth, studies performed by the Frenklach group found a much richer chemistry than previously thought to exist, most notably the incorporation of five-member rings into the substrate leading to curvature of the initially planar aromatics. Recent experimental studies have found that the soot oxidation rate depends on soot particle curvature, so a one-step global mechanism is insufficient to explain the experimental observations. The purpose of developing a detailed kinetic model is to gain a qualitative and quantitative understanding of oxidation processes of soot particles, large polycyclic aromatics, and graphene edges. To build the oxidation model, the energetics and kinetics of key elementary oxidation reactions were investigated. Reaction rate coefficients and product branching ratios were calculated for the oxidation of six- and five-member ring graphene-edges by molecular oxygen at temperatures and pressures relevant to combustion. The reactions and their corresponding rates were added to an existing model of soot surface growth along with reactions for oxidation of six-member rings by OH, thermal decomposition of oxyradicals, and O, H, and OH abstraction and addition. Detailed kinetic Monte Carlo (KMC) simulations of high-temperature oxidation by molecular oxygen of a graphene sheet were performed using the newly established model of graphene-edge reactions. The KMC results revealed two principal pathways for an oxyradical site: oxidation and regeneration of an aromatic radical site. The overall oxidation rate is computed to be time-dependent, with reactivity decreasing over time as the ratio of reactive edge sites decreases relative to the number of basal-plane carbon atoms. At the same time, the oxidation rate was found to be higher for graphene with a higher initial curvature. Both results are in accord with experimental observations. Analysis showed that distinct aspects of graphene-edge morphology are responsible for curvature either raising or reducing the oxidative reactivity of the graphene edge. Oxidation pathways for graphene-edge five-member rings reacting with atomic oxygen were investigated. The rate coefficient for oxidation by atomic oxygen exceeded that of for oxidation by molecular oxygen by several orders of magnitude. The detailed surface oxidation model was augmented to include this reaction along with several more abstraction and oxidation reactions. KMC simulations were then performed in an evolving gas phase environment that was coupled to the surface chemistry for conditions analogous to those of shock tube experiments of soot oxidation at high temperatures. The KMC results showed that the oxidation rate was dependent on several factors. CO concentration profiles calculated from the KMC model were found to be in agreement with experimental measurements.

Download or read book The Impact of Carbon Dioxide and Exhaust Gas Recirculation on the Oxidative Reactivity of Soot from Ethylene Flames and Diesel Engines written by Khalid O. Al-Qurashi and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Impacts of Oxygenated Compounds Concentration on Sooting Propensities and Soot Oxidative Reactivity Application to Diesel and Biodiesel Surrogates written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Oxygen Enhanced Combustion written by Charles E. Baukal Jr. and published by CRC Press. This book was released on 2013-03-15 with total page 779 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combustion technology has traditionally been dominated by air/fuel combustion. However, two developments have increased the significance of oxygen-enhanced combustion-new technologies that produce oxygen less expensively and the increased importance of environmental regulations. Advantages of oxygen-enhanced combustion include less pollutant emissi

Download or read book Soot Reaction Properties Ground Based Study written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-19 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three major soot reaction processes are needed to predict soot properties in flame environments: soot growth, or the formation of soot on soot nuclei and soot particles; soot oxidation, or the reaction of soot with oxidizing species to yield the combustion products of soot oxidation; and soot nucleation, or the formation of soot nuclei from soot precursors having large molecular weights (generally thought to be large and particularly stable PAH molecules in flame environments, called stabilomers). These processes are addressed in the following, considering soot growth, oxidation and nucleation, in turn, by exploiting the soot and flame structure results for premixed and diffusion flames already discussed in Section 2. Dai, Z. and El-Leathy, A. M. and Lin, K.-C. and Sunderland, P. B. and Xu, F. and Faeth, G. M. and Urban, D. L. (Technical Monitor) and Yuan, Z.-G. (Technical Monitor) Glenn Research Center