Dissertations / Theses on the topic 'Alternative combustion'
To see the other types of publications on this topic, follow the link: Alternative combustion.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Alternative combustion.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Chong, Cheng Tung. "Combustion characteristics of alternative liquid fuels." Thesis, University of Cambridge, 2011. https://www.repository.cam.ac.uk/handle/1810/244379.
Full textAbstract:
Envisaged application of biodiesel in gas turbine engines or furnaces requires extensive tests on the deflagration properties of biodiesel. The laminar flame speeds of Palm Methyl Esters (PME) and blends of PME with conventional fuels are determined using the jet-wall stagnation flame configuration. The same technique is also used to measure the laminar flame speed of diesel, Jet-A1, n-heptane, acetone, methane and methane/acetone. The spray atomization characteristics of a plain-jet airblast atomizer are investigated using a phase Doppler anemometry (PDA) under non-reacting conditions. The droplet size and velocity distribution of biodiesels are compared to conventional fuels. For spray combustion investigations, a generic gas turbine-type combustor is developed to compare the spray flame established from PME, rapeseed methyl esters (RME), diesel, Jet-A1 and biodiesel blends. The spray droplet characteristics in the flame and the flow field in the combustor are investigated. Chemiluminescence imaging of OH* and CH* are applied to capture the global flame structure and heat release region. Flame spectroscopy and long bandpass filtered imaging at > 550 nm are performed to evaluate the tendency of soot formation. In general, biodiesels exhibit flame shapes and spray droplet characteristics that are comparable to conventional fuels. In spite of the higher fuel specific consumption, the emission of NOx is found to be lower for biodiesels compared to conventional fuels. The results show that biodiesels can potentially be used as alternative fuels for gas turbine operation.
2
Giles, Anthony Peter. "Alternative fuels and technology for internal combustion engines." Thesis, Cardiff University, 2006. http://orca.cf.ac.uk/56090/.
Full textAbstract:
Within this thesis is an investigation and appraisal of alternative automotive fuels, internal combustion engine technology and emission reduction techniques. A review of the developments in engine technology, with specific focus on improvements in engine efficiency and emission reductions was undertaken. Tighter emission legislation imposed after the Kyoto agreement has resulted in technological advances in the field of internal combustion engines improving the economy of modern motor vehicles while reducing their emissions of C02 and particulate matter. As part of an EU funded project entitled "Magnetic Movement Valve for Miller Cycle operation of engines", the application of a novel secondary valve apparatus to an internal combustion engine was investigated through the use of computer modelling. It was shown that the secondary valve concept is capable of controlling the output of an internal combustion engine, while increasing the operating efficiency and reducing the emission of NOx through the use of Miller cycle operation and throttle free load control. A development programme of the engine and the secondary valve apparatus, carried out in conjunction with EU project partners, resulted in a marketable engine incorporating the new technology which is now in production within Europe and the Far East. An engine test-bed facility was commissioned to investigate the emissions and performance of a diesel engine fuelled by a variety of biodiesel / diesel fuel blends. It was found that incremental addition of biodiesel to a low sulphur diesel fuel resulted in a decrease in engine power and an increase in fuel consumption, CO2 and NOx emissions. The particulates levels of pure biodiesel emissions were found to be much lower (by mass and number concentration) than that of the low sulphur diesel fuel. From analysis of the exhaust gases it was found that the average size of the particulates is larger for biodiesel fuel than for the low sulphur diesel fuel.
3
IEMMOLO, DANIELE. "Alternative fuels and combustion modes to lower pollutant emissions from conventional internal combustion engines." Doctoral thesis, Politecnico di Torino, 2017. http://hdl.handle.net/11583/2724575.
Full text
4
Altaher, Mohamed Alalim. "Combustion and emissions of alternative fuels in gas turbines." Thesis, University of Leeds, 2013. http://etheses.whiterose.ac.uk/4954/.
Full textAbstract:
Renewable biomass derived fuels are of increasing interest for many applications including industrial and aero gas turbines due to the reduction in fossil fuel CO2 and the improvement in energy supply security. The first part of this work investigated the performance of biodiesel as a fuel in low NOx combustors of the type used in industrial gas turbines. This work included comparison with kerosene and co-firing with natural gas and blends of kerosene/biodiesel. In the second phase of this work an aircraft gas turbine APU with diffusion combustion. This investigated the gaseous and particulate emissions using kerosene as a base fuel for comparison with several second generation biofuels, which covered a range of H/C and showed that emissions were correlated with the H/C. The third phase of the work was concerned with renewable or clean coal derived hydrogen combustion using a low NOx flame stabilizer for industrial power generation applications. For the industrial low NOx combustor work a radial swirler flame stabiliser was used. However, the high boiling point of B100 made operation in a premixed vane passage fuel injection mode impossible as ignition could not be achieved. The pilot fuel injector in the centre was the only fuel injection location that B100 would stabilise a flame, due to the central recirculation of burnt gases. A central 8 hole radially outward fuel injector was used as WME (B100) would not operate with radial vane passage fuel injection that is conventionally used for low NOx radial swirlers with natural gas. In the aero engine phase of the research, nine alternative fuels were tested and compared to conventional JetA1 fuel at idle and full power. The results showed that all fuels produced similar level of NOx compared to JetA1 and a slight reduction in CO. A remarkable reduction in UHC was observed at all conditions for higher H/C fuels. The results also show that there was a good correlation between fuels H/C ratio and particle concentrations, particle size and distributions characteristics. The hot idle produced ~20% less particles compare to the cold idle. The alternative fuel blends produced fewer particles than JetA1 fuel. The alternative source of renewable fuels for industrial power generation gas turbines is that of hydrogen derived from renewable or nuclear electricity or from coal or biomass gasification using the water gas shift reaction and CO2 solvent extraction to leave a pure hydrogen fuel. The key problem are in burning hydrogen in gas turbines is that of the increased NOx formation and the increased risk of flashback into the conventional premixing passages used in natural gas low NOx combustors. This work investigated a novel impinging jet configuration that had previously been used successfully with propane and kerosene fuels. It had no premixing so that there could be no flashback. However, the high reactivity of hydrogen did cause a problem with flame stabilization too close to the jet outlets. This was controlled by reducing the proportion of air added to the initial hydrogen jets. NOx emissions lower than alternative designs were demonstrated at simulated high power conditions. This was a practical combustion technique for high hydrogen content fuels with low NOx emissions and no flashback problems.
5
Tongroon, Manida. "Combustion characteristics and in-cylinder process of CAI combustion with alcohol fuels." Thesis, Brunel University, 2010. http://bura.brunel.ac.uk/handle/2438/4501.
Full textAbstract:
Controlled auto-ignition (CAI) combustion in the gasoline engine has been extensively studied in the last several years due to its potential for simultaneous improvement in fuel consumption and exhaust emissions. At the same time, there has been increasing interest in the use of alternative fuels in order to reduce reliance on conventional fossil fuels. Therefore, this study has been carried out to investigate the effect of alcohol fuels on the combustion characteristics and in-cylinder processes of CAI combustion in a single cylinder gasoline engine. In order to study the effect of alcohol fuels, combustion characteristics were investigated by heat releases analysis in the first part. The combustion process was studied through flame structure and excited molecule by chemiluminescence imaging. Furthermore, in-cylinder gas composition was analysis by GC-MS to identify the auto-ignition reactions involved in the CAI combustion. In addition, the influence of spark-assisted ignition and injection timings were also studied. Alcohol fuels, in particular methanol, resulted in advanced auto-ignition and faster combustion than that of gasoline. In addition, their use could lead to substantially lower HC, NOX and CO exhaust emissions. Spark-assisted ignition assisted gasoline combustion by advancing ignition timing and initiating flame kernel at the centre of combustion chamber but it had marginal effect on alcohol fuels. Auto-ignition always took place at the perimeter of the chamber and occurred earlier with alcohol fuels. Fuel reforming reactions during the NVO period were observed and they had significant effect on alcohol combustion.
6
Little, A. Tyler. "Analysis of alternative fuel combustion in a perfectly stirred reactor." Connect to resource, 2007. http://hdl.handle.net/1811/24514.
Full textAbstract:
Thesis (Honors)--Ohio State University, 2007.Title from first page of PDF file. Document formatted into pages: contains xii, 63 p.; also includes graphics. Includes bibliographical references (p. 62-63). Available online via Ohio State University's Knowledge Bank.
7
Bagdanavicius, Audrius. "Premixed combustion of alternative fuels under varying conditions of temperature and pressure." Thesis, Cardiff University, 2010. http://orca.cf.ac.uk/54231/.
Full textAbstract:
Temperature, pressure and CO2 and H2 addition to CH4 effects on turbulent and laminar burning velocity have been found and discussed. Novel turbulent burning velocity determination methods are presented and uncertainties have been discussed. Turbulent burning velocity correlation with nondimensional numbers have been found and flames structures have been analysed.
8
Park, Sammy Ace. "Combustion instability and active control| Alternative fuels, augmentors, and modeling heat release." Thesis, University of Maryland, College Park, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10129882.
Full textAbstract:
Experimental and analytical studies were conducted to explore thermo-acoustic coupling during the onset of combustion instability in various air-breathing combustor configurations. These include a laboratory-scale 200-kW dump combustor and a 100-kW augmentor featuring a v-gutter flame holder. They were used to simulate main combustion chambers and afterburners in aero engines, respectively. The three primary themes of this work includes: 1) modeling heat release fluctuations for stability analysis, 2) conducting active combustion control with alternative fuels, and 3) demonstrating practical active control for augmentor instability suppression.
The phenomenon of combustion instabilities remains an unsolved problem in propulsion engines, mainly because of the difficulty in predicting the fluctuating component of heat release without extensive testing. A hybrid model was developed to describe both the temporal and spatial variations in dynamic heat release, using a separation of variables approach that requires only a limited amount of experimental data. The use of sinusoidal basis functions further reduced the amount of data required. When the mean heat release behavior is known, the only experimental data needed for detailed stability analysis is one instantaneous picture of heat release at the peak pressure phase. This model was successfully tested in the dump combustor experiments, reproducing the correct sign of the overall Rayleigh index as well as the remarkably accurate spatial distribution pattern of fluctuating heat release.
Active combustion control was explored for fuel-flexible combustor operation using twelve different jet fuels including bio-synthetic and Fischer-Tropsch types. Analysis done using an actuated spray combustion model revealed that the combustion response times of these fuels were similar. Combined with experimental spray characterizations, this suggested that controller performance should remain effective with various alternative fuels. Active control experiments validated this analysis while demonstrating 50-70\% reduction in the peak spectral amplitude. A new model augmentor was built and tested for combustion dynamics using schlieren and chemiluminescence techniques. Novel active control techniques including pulsed air injection were implemented and the results were compared with the pulsed fuel injection approach. The pulsed injection of secondary air worked just as effectively for suppressing the augmentor instability, setting up the possibility of more efficient actuation strategy.
9
Zuks, Lincoln. "An evaluation of an alternative glycerol gasification, combustion and power generation system." Thesis, Zuks, Lincoln (2014) An evaluation of an alternative glycerol gasification, combustion and power generation system. Other thesis, Murdoch University, 2014. https://researchrepository.murdoch.edu.au/id/eprint/23529/.
Full textAbstract:
While great inroads have been made into finding alternate uses for the biodiesel waste glycerol, the projected growth in biodiesel production is likely to make it difficult for some producers to offload. This thesis report set out to evaluate the viability of a system which could go some way to solving this problem, while at the same time offsetting the cost of the primary production process. Aspen Plus was used to evaluate the thermodynamic feasibility of the proposed system. This modelling found, that after a couple of modifications, the system was viable from a thermodynamic standpoint. But, after systematically evaluating gasification, pyrolysis and steam reformation as possible means for converting glycerol into syngas, it was found that none of these systems, in their current form, would be suitable for making the system a reality. While it is true that these technologies are proven methods at a bench scale, an in depth literature review found a number of complicating factors which makes the conversion of glycerol into syngas an incredibly difficult task, one which is much more difficult than this investigation first anticipated. These findings cast doubt on such an idea becoming a reality in its current form. Fortunately, during the literature review process, a handful of recent studies where uncovered which looked at the co-gasification of crude glycerol with biomass. From the limited information available on the subject, it would seem that the co-gasification of glycerol and biomass has a promising future. The prospect of a simple system based on a proven technology which is able to deal with wastes from multiple sources along the biodiesel production process is an exciting prospect.
10
Kashif, Muhammad. "Measurement of sooting tendencies of alternative fuels : application to primary reference fuels." Paris 6, 2013. http://www.theses.fr/2013PA066258.
Full textAbstract:
Un dispositif a été conçu et validé pour mesurer la fraction volumique de suie dans de flammes non-prémélangées méthane/air dopées en vapeurs d’hydrocarbures liquides. La quantification en fraction volumique de suie est obtenue en inversant les données d’extinction d’un faisceau laser à travers une flamme axisymétrique par l’algorithme nommé Onion- Peeling stabilisé par une régularisation de type Tikhonov. La mesure est ensuite convertie en un indice appelé Yield Sooting Index (YSI). La méthode a été appliquée pour comparer les tendances des de mélanges de n-heptane et d’iso-octane (Primary Reference Fuels (PRFs)) à produire de suie dans une flamme non-prémélangée axisymmétrique dopée en vapeur de PRF, en maintenant constante soit la concentration en vapeur, soit de l’énergie des vapeurs injectés. Une corrélation de second ordre a été établie pour prédire la variation d’YSI avec la teneur en iso-octane dans le PRF et la concentration en dioxyde de carbone dans l’écoulement oxydant annulaire. Les études réalisées sur cette flamme de laboratoire et les résultats obtenus ont une portée pratique et doivent permettre de prédire le comportement des combustibles considérés à former de suie en condition réellesAn optical diagnostics layout is designed and validated to measure soot volume fraction in methane/air diffusion flames doped with vapors of liquid hydrocarbons. Soot volume fraction is inferred from the inversion of integrated light extinction data using an Onion-peeling algorithm stabilized by a Tikhonov regularization method. This measurement is then converted into apparatus-independent Yield Sooting Index (YSI). The method has been applied to compare the sooting tendencies of PRFs in doped axisymmetric diffusion flames when keeping the concentration or energy of injected vapors constant. A second-order correlation modeling the variation of YSI with the mole fraction of iso-octane in PRF mixture and the proportion of carbon dioxide in the co-flowing oxidizer has been established using least-squares non-linear data-fitting to experimental data. These studies performed on laboratory flames and the results obtained are of practical importance and can be used to predict the sooting behavior of fuels under practical combustion environment
11
Depman, Albert J. III. "Stoker boiler CFD modeling improvements through alternative heat exchanger modeling." Thesis, University of Iowa, 2014. https://ir.uiowa.edu/etd/4609.
Full textAbstract:
Accurate models and realistic simulations are essential in developing cleaner and more efficient coal- and biomass-fired boilers. Using the CFD simulation software Fluent The University of Iowa created a model of an industrial boiler that adequately compares the practice of co-firing biomass and coal against firing only coal. The simulations used in this comparison, show significant circulation zones and an unrealistic temperature profile inside the boiler heat exchanger region. This model is effective for comparing the relative decrease in emissions when co-firing with biomass versus exclusively coal combustion, but it does not present a realistic simulation of biomass or coal combustion.
The purpose of the current work is to develop a more realistic baseline coal combustion model. Calculations for the proximate and ultimate analysis of coal, as well as properties necessary for energy and mass flux computations, have been updated in the current model. The fuel bed model - a simple two-dimensional distribution of energy and mass fluxes from the grate - was kept the same due to the complexities of fuel bed modeling. Simulation boundary conditions and flow models were tested and modified to determine the most realistic model settings. The geometry and mesh grid of the boiler model were also varied in an attempt to fix problematic areas.
Several approaches were implemented in an effort to reduce the circulation zones and generate a realistic temperature profile. The negative energy source term in the boiler representing the energy removed by the water pipes in the heat exchanger was analyzed, and different configurations of this sink were tested. Finally, the heat exchanger models built in to Fluent were studied and implemented. These models proved to be the most effective in reducing recirculation zones and decreasing high temperature gradients. While the current model of the coal-fired boiler has a higher overall temperature than the previous one, circulation zones are almost completely eliminated, the flow path has been improved, and the temperature profile in the boiler is more realistic.
12
Filho, Fernando Luiz Sacomano. "Simulações de chamas turbulentas de etanol com modelo de turbulência k-E." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/3/3150/tde-04112011-145536/.
Full textAbstract:
Diversos equipamentos industriais utilizam processos de combustão com sprays. As principais vantagens deste processo estão relacionadas ao aumento do controle da chama e à maior segurança na logística do combustível líquido. Atualmente, o interesse na utilização de bio-combustíveis como alternativa para a redução na emissão de dióxido de carbono é crescente. Entre os tipos de bio-combustíveis o etanol se destaca por ser utilizado em vários países misturado à gasolina no setor de transportes. Partindo deste panorama, o presente trabalho apresenta a modelagem e simulação de uma chama turbulenta de spray de etanol. Os resultados das simulações realizadas são comparados com dados experimentais da literatura. O modelo resultante baseia-se no método dos volumes finitos para escoamentos com baixo número de Mach e em regime permanente. O spray foi calculado com a aproximação de escoamentos separados com uma formulação Euler-Lagrange, em que a fase dispersante é modelada com a abordagem Euleriana, enquanto que a fase dispersa é modelada com a abordagem Lagrangeana. As duas fases foram completamente acopladas nos dois sentidos. O modelo de turbulência k- Padrão foi utilizado na fase dispersante. A evaporação de gotículas foi considerada, em que o modelo de condutividade infinita foi utilizado para a fase líquida. Dessa forma, a distribuição de temperaturas no interior da gotícula é uniforme, porém varia conforme ela se move no spray. Para reproduzir os efeitos do resfriamento evaporativo, a combustão foi modelada com um modelo de folha de chama modificado que considerou uma função joint -PDF de fração de mistura e entalpia. Transferências de calor por radiação foram negligenciadas neste trabalho. Aproximações razoáveis foram obtidas entre os perfis medidos e calculados de temperatura média da fase gasosa e de distribuições de tamanhos de gotículas. Algumas discrepâncias foram observadas nas comparações entre os perfis do componente axial de velocidade média da fase gasosa, que foram atribuídas à difusão superestimada das quantidades médias transportadas pela fase gasosa nas simulações.Several industrial equipments use combustion processes with sprays. The main advantages of this process are related to the increase in the flame control and in the safety of liquid fuel logistics. Currently, the interest on the utilization of biofuels as an alternative to the reduction of carbon dioxide emissions is increasing. Among the types of biofuels the ethanol stands out by being used blended with gasoline in the transport sector of several countries. From this overview, this work presents the modeling and simulation of an ethanol turbulent spray flame. The results of the simulations were compared with experimental data from the literature. The resulting model was based on the finite volume method for low Mach number and steady state flows. The spray was calculated using the Separated Flow method (SF) with an Euler-Lagrange model, where the gaseous phase was described by an Eulerian model and the liquid phase by a Lagrangian particle method. Both phases were fully coupled in order to account for shared effects. The turbulence model k- Standard was used to determine the dispersant phase. Evaporation of droplets was calculated with the assumption of the infinite-liquid-conductivity model, where the droplet inner temperature is uniform, but varies with the mass and heat transfer within the dispersant phase. To reproduce the effects of the evaporative cooling the combustion was modeled with a modified flamesheet model which regarded a jointed mixture fraction-enthalpy -PDF. Radiactive heat transfer was not accounted for in this work. Reasonable agreement between measured and computed mean profiles of temperature of the gas phase and droplet size distributions was achieved. Some deviations were observed in the mean velocity profiles comparisons between experimental data and simulations, which were assigned to the over predicted diffusion of the mean quantities transported by the gas phase.
13
Imran, Shahid. "Experimental and numerical investigation of performance and emissions in compression ignition engines with alternative fuels." Thesis, Queen Mary, University of London, 2013. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8505.
Full textAbstract:
The experimental investigation in this work concerns the compression-ignition (CI) engine combustion process both in normal operation and dual-fuel operation. There is a bulk of literature reporting thermal efficiencies, brake specific fuel consumption (BSFC) and emissions under single and dual fueling conditions in CI engines. Most of the studies lack the full implications of changing load (power output) and speed on these performance indicators. The studies are either restricted to various loads/powers at one engine speed (neglecting the effect of engine speed) or one or two load/power conditions at various speeds (neglecting load variations). There is a scarcity of full engine maps in the open literature (these are the full contours of thermal efficiency or BSFC plotted throughout the power versus speed range of the engine, or the torque versus speed range of the engine). This thesis provides performance and emissions maps for a CI engine using two different fuels (diesel and rapeseed methyl ester used as single fuels) and two gaseous fuels (natural gas and hydrogen) used with two different pilot fuels (diesel and rapeseed methyl ester ) under what is termed dual fueling mode. A novel approach is used to present the performance and emissions over the entire engines operational range. The results are presented as iso- contours of thermal efficiency, volumetric efficiency and brake specific NOX, specific HC and specific CO2 on a power-speed graph throughout the operating range of the engine. Many studies conclude that the emissions, particularly NOX during dual fueling are expected to form in the spatial region around the pilot spray. This region is expected to be subjected to high localised temperatures as the equivalence ratio is close to stoichiometric, thus maximising heat release from combustion. The effect of changing the pilot fuel quantity on performance and emissions is rarely reported. This study addresses this scarcity in the literature and investigates the effect of changing the pilot fuel quantity and type on various combustion and emission parameters. Diesel and rapeseed methyl ester (RME) have been used as pilot fuels for both the natural gas as well as hydrogen and three different pilot fuel settings have been employed for each of the gaseous fuels. The effect of using a different pilot fuel quantity to achieve the same brake mean effective pressure (BMEP) for the two gaseous fuels has been analysed and compared. This thesis also includes a chapter on the computational modeling of the engine esmissions. This study uses combinations of different spray and combustion models to predict in-cylinder pressure, rate of heat release and emissions. The approach employs two combustion models: Unsteady Flamelet Model (UFM) with PDF method and Finite Rate Chemistry (FRC) with stiff chemistry solver implemented through In-Situ Adaptive Tabulation (ISAT) algorithm. Two spray models used includeWAVE and Kelvin Helmohltz Rayleigh Taylor (KHRT) spray models. The UFM coupled with KHRT spray model has been used to predict NOX, CO and CO2 emissions. The model captures the emissions trends well. In-cylinder contours of O2, NO and mass average temperature have also been presented. A chemical mechanism of n-heptane with 29 species and 52 reactions has been used.
14
Mosckem, Sergio Luis [UNESP]. "Análise do emprego de materiais alternativos no alto forno da Arcelormital Tubarão." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/99326.
Full textAbstract:
Made available in DSpace on 2014-06-11T19:30:10Z (GMT). No. of bitstreams: 0
Previous issue date: 2010-07-02Bitstream added on 2014-06-13T20:39:47Z : No. of bitstreams: 1
mosckem_sl_me_guara.pdf: 1245042 bytes, checksum: 8a691aa6f65edd8f060ed9355bc9c3bd (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O trabalho de análise do uso de materiais alternativos no Alto Forno 1 da ArcelorMittal Tubarão estabelece uma taxa de substituição de cada material alternativo, plástico e pneu, em relação ao uso exclusivo do carvão mineral injetado no Alto Forno através das ventaneiras. A taxa de utilização de plástico e pneu é avaliada considerando o aporte de energia e dos agentes necessários para a reação química de redução do minério de ferro em ferro metálico. No presente trabalho são elaborados os balanços de massa e de energia de acordo com a configuração operacional vigente no segundo semestre de 2009 para o Alto Forno 1 e com os dados de produção do mês de julho de 2009. O resultado mostra a viabilidade técnica do uso de plástico ou pneu e estabelece as condições de uso de cada um em relação à quantidade, tipo e granulometria. A substituição energética decorrente do uso de plástico e pneu estabelece uma forma de aplicação segura e controlada deste resíduo, além de agregar valor a estes materiais normalmente descartados pela sociedade. Contribui também para amenizar os impactos ambientais decorrentes da falta de uma destinação regulamentada e eficaz para plásticos descartados e pneus inservíveis
The study of alternative fuel materials in the Blast Furnace 1 of ArcelorMittal Tubarão, establishes a rate of each material analyzed, waste plastics packaging and waste tires, in order to replace part of the pulverized coal that is usually injected in to the Blast Furnace through the tuyeres. The injection rate of waste plastic packaging and waste tires is analyzed considering the energy input and the necessary elements for the iron ore reduction chemical reaction. The mass and energy balance is done according to the operational configuration of the Blast Furnace 1 in the second semester of 2009 and operation data from July of 2009. The result of the study shows technical viability to use waste plastics packaging and waste tires and establish requirements for the injection, such as flow rate and particles size. The alternative energy provided from these waste materials builds a safety and controlled way to reach the best utilization for each one. Moreover, the environmental impact can be reduced due to its disposal is normally done in outdoor areas
15
Stauber, Alfredsson Malin. "Effects of Different Fuels on Combustion Boiler Processes : The analysis of alternative fuel mixtures." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-231565.
Full textAbstract:
The objective of this study is to investigate the eect of dierent fuels on two uidized bed boiler systemsat the energy company Soderenergi's site in Igelsta, called IKV and IGV P3. Today, recovered wastewood (RWW) is the major fuel share fed into the boilers. However, with an insecure fuel supply in thefuture, other fuel types must be considered. Based on knowledge from previous fuel usage in the boilers,an evaluation of how other potential fuel mixtures may eect the operation is conducted. The additionalfuels considered in the fuel blends are; stem wood chips, cutter shavings, solid recycled fuel (SRF) andrubber.With elemental analysis of the fuels and established key numbers, the previous fuel mixtures are evaluated.The indications by the guiding parameters are compared with experienced problems and the formercondition of the boilers, and the risk limits for the key numbers are adjusted to a suitable level. Thepotential mixtures are evaluated with the key numbers and the updated limits. In addition to the keynumbers, the heavy metal concentration, the heating value, the moisture content and the ash content ofthe fuel blends are included in the evaluation. The considered damages in the boilers caused by the fuelblends are corrosion, sintering and fouling.The damage level from the current fuel usage for IKV and IGV P3 is fairly low. The results from theanalyzed fuel mixtures show an increased damage risk in the boilers. Additionally, adjustments of theboiler systems are required by some of the analyzed fuel mixtures. In general, the corrosion risk andthe heavy metal content will increase in comparison with today's fuel. The fouling and slagging are aswell expected to increase for the assessed fuel mixtures. Moreover, the result illustrates an increased ashgeneration, which demands a reconstruction of the ash cooling system for IKV. Furthermore, the increaseof LHV in the assessed fuel mixtures to IGV P3, is likely to require an increased capacity of the ue gasrecirculation pump.In the analysis of the potential fuel mixtures it is found that the corrosion risk expressed by the keynumbers is reduced with a higher share of rubber. The heavy metal content is, however, increased,leading to e.g. an enhanced risk for formation of eutectic salts, which as well are corrosive. On thecontrary, the fuel mixtures with a high risk expressed by the key numbers, have the lowest concentrationsof heavy metals. Due to the results are con icting, a balance between the risk indicated by the keynumbers and the heavy metal concentration must be considered in the evaluation. The fuel mixturesconsidered causing least damage to IKV are a mixture of 42% RWW, 48% wood fuel and 15% SRF, and amixture of 70% wood fuel, 20% SRF and 10% rubber. The fuel mixtures considered causing least damageto IGV P3 are a mixture of 85% RWW and 15% rubber and a mixture of 70% RWW and 30% SRF.Syftet med studien var att undersoka branslets paverkan pa tva uidbaddpannor, IKV och IGV P3, hos energiforetaget Soderenergi. Idag ar det huvudsakliga branslet i dessa pannor returtra (RT). Med en standigtrorlig branslemarknad kravs kunskap av alternativa branslen. Baserat pa tidigare bransleanvandning,har paverkan fran potentiella bransleblandningar pa pannan undersokts. Utover returtra ar stamveds is,span, papper-plast-tra (SRF) och gummi med i de analyserade blandningarna.Med elementaranalyser pa branslen och etablerade nyckeltal utvarderades de tidigare anvanda branslena.Indikationen fran nyckeltalen ar jamford med upplevda problem och risknivaerna for nyckeltalen arandrade till passande nivaer. De framtida bransleblandningarna analyserades med hjalp av nyckeltalenoch de uppdaterade risknivaerna. Utover nyckeltalen analyserades tungmetallhalten, varmevardet, fukthaltenoch askhalten i bransleblandningarna. De pannskador orsakade av bransleblandningarna somundersokts ar korrosion, sintring och paslag.Det nuvarande branslet till IKV och IGV P3 ger en relativt lag skadeniva. Resultaten fran de analyseradebransleblandningarna visar att skaderisken i pannorna kommer att oka och forandringar av pannan kankomma att kravas. Generellt kommer korrosionsrisken och tungmetallinnehallet att oka i jamforelse meddagens bransle. Okat paslag och slaggning ar ocksa forvantat. Vidare visar resultatet att askproduktionenkommer att oka, vilket gor att IKVs kylsystem for bottenaskan kommer behovas byggas ut. LHV for deanalyserade bransleblandningarna for IGV P3 okar, vilket innebar att kapaciteten for returgas aktarnatroligen maste okas.I jamforelsen av de olika bransleblandningarna visas att korrosionsrisken, forutspadd av nyckeltalen,minskar med en hogre andel gummi. Daremot okar tungmetallinnehallet, vilket leder till en okad riskfor bildning av eutektiska salter, vilka ocksa ar korrosiva. Bransleblandningarna med en indikerad hogrisk av nyckeltalen, har tvartemot den lagsta koncentrationen av tungmetaller. Eftersom resultatenar motsagande, kravs en avvagning mellan riskerna indikerade av nyckeltalen och tungmetallshalten.De bransleblandningar som ar ansedda att vara minst skadliga for IKV ar en blandning av 42% RT,48% tradbransle och 15% SRF, och en blandning av 70% tradbransle, 20% SRF och 10% gummi. Debransleblandning som ar ansedda att vara minst skadliga for IGV P3 ar en blandning av 85% RT och15% gummi, och en blandning av 70% RT och 30% SRF.
16
Carra, Filippo <1990>. "Analysis, modeling and control of standard and alternative combustion strategies in a diesel engine." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amsdottorato.unibo.it/8938/1/Filippo_Carra_PhD_Thesis.pdf.
Full textAbstract:
Research on compression ignited engines from combustion control point of view assumes an important role since this technology is being demonstrated lacks in the accomplishment of the evolving emissions standards to more stringent targets. The nature of combustion, in particular, seems not to be able to overcome some crucial trade-offs in emission and efficiency management. This work is aimed at investigating some key points on the way a diesel engine is conventionally run, such as noise control, nitrogen oxides modeling and closed loop methodologies to handle combustion. At the same time a great effort is spent in understanding the most important aspects of reactivity-controlled compression ignition (RCCI) combustion, which in the scenario of low temperature combustions is the one, theoretically speaking, to provide the most extended applicability throughout the engine operating field. Investigation on RCCI combustion has the main objective to offer a work-around to the previously cited trade-offs. Since literature provides several examples of how this kind of injection strategy is advantageous to the predetermined goals, this work tries to focus on how it can be controlled, because combustion stability remains the most critical issue.
17
Flora, Giacomo. "Fuel Structure Effects on Surrogate Alternative Jet Fuel Emission." University of Dayton / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1450286398.
Full text
18
Tira, Hendry Sakke. "Impact of alternative fuels and hydrogen-enriched gaseous fuel on combustion and emissions in diesel engines." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4376/.
Full textAbstract:
The utilisation of alternative fuels, specifically gaseous fuel, in diesel engines has some disadvantages such as reduced engine thermal efficiency and increased exhaust gas emissions, although showing good results in reducing soot and NOX, simultaneously. Therefore, the effect of the hydrogen – enriched gaseous fuel in the dual fuelled combustion process was studied as a mean of improving further the combustion process and control emissions. The hydrogen addition was very effective in overcoming the penalty of the biogas or LPG-diesel dual fuelled engine operation. With the presence of hydrogen the oxidation rate of combustion product was improved thus reducing emissions (HC, CO and PM except NOX) whilst the engine thermal efficiency was also improved. The implementation of exhaust gas recirculation (EGR) and advanced injection timing showed great potential for dual fuelled engine. The utilisation of EGR at high LPG concentration further improved soot – NOX trade-off through low in-cylinder temperatures and reduced amount of liquid fuel used for combustion. Moreover, the properties of the injected diesel fuels as a pilot fuel have been shown to significantly affect the combustion process, rate of heat release, and emissions formation and oxidation. Oxygenated fuel like RME contributed to the reduction of emissions, except NOX, while a high cetane number fuel like GTL showed better tolerance to EGR addition and soot – NOX trade-off.
19
Stratton, Russell William. "Life cycle assessment of greenhouse gas emissions and non-CO₂ combustion effects from alternative jet fuels." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/59694.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 135-144).
The long-term viability and success of a transportation fuel depends on both economic and environmental sustainability. This thesis focuses specifically on assessing the life cycle greenhouse gas (GHG) emissions and non-CO 2 combustion effects from conventional jet fuel and synthetic paraffinic kerosene (SPK). The research expands upon the work of Wong (2008) by examining Fischer-Tropsch jet fuel from coal and biomass, and hydroprocessed renewable jet (HRJ) fuel from rapeseed, jatropha, algae and salicornia. Each fuel option is a "drop-in" alternative in that they are compatible with existing aviation infrastructure. Using a modified version of the APMT climate impacts module, the additional climate forcing from non-CO 2 combustion effects is combined with the fuel life cycle GHG inventories. Life cycle GHG emissions are only one of many aspects that must be considered when evaluating the feasibility and sustainability of an alternative fuel option. While cost and fresh water availability are important constraints, fuel yield and land requirements for select biomass-based fuel pathways are quantified. This is most important for feedstocks requiring cropland for cultivation. For example, current global production of soy, palm and rapeseed oil translate to only 34%, 43% and 18% of US jet fuel demand, respectively; hence, even small fractions of the petroleum industry translate to massive production scales in absolute terms. By comparison, HRJ from algal oil can yield more than an order of magnitude higher fuel production per hectare of land. Few biofuels were identified with zero life cycle GHG emissions. This contradicts previous studies and likely results from avoiding the displacement method to allocate emissions. Considerable inter and intra fuel option variability was found in life cycle GHG emissions; land use change contributed much to the variability of many pathways. The range in life cycle GHG emissions of all fuel options examined ranged from 0 to 9.1 times those of conventional jet fuel. The uncertainty in treating non-CO 2 combustion effects was found to have a larger influence on the life cycle emissions of each fuel option than the variability of the life cycle GHG inventories; however, including non-CO 2 combustion effects reduced the overall range in emissions of all fuel options considered to only 0 to 4.7 times those of conventional jet fuel. Hence, the inclusion of non-CO 2 effects in the fuel life cycle increases the absolute uncertainty of each fuel option but reduces the overall variability in the life cycle emissions of alternative fuels relative to conventional jet fuel.
by Russell William Stratton.
S.M.
20
Omidvarborna, Hamid. "Combustion Chemistry of Biodiesel for the Use in Urban Transport Buses: Experiment and Modeling." University of Toledo / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1464863574.
Full text
21
Hui, Xin. "Flame Studies on Conventional, Alternative, and Surrogate Jet Fuels, and Their Reference Hydrocarbons." Case Western Reserve University School of Graduate Studies / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1354909906.
Full text
22
Mosckem, Sergio Luis. "Análise do emprego de materiais alternativos no alto forno da Arcelormital Tubarão /." Guaratinguetá : [s.n.], 2010. http://hdl.handle.net/11449/99326.
Full textAbstract:
Resumo: O trabalho de análise do uso de materiais alternativos no Alto Forno 1 da ArcelorMittal Tubarão estabelece uma taxa de substituição de cada material alternativo, plástico e pneu, em relação ao uso exclusivo do carvão mineral injetado no Alto Forno através das ventaneiras. A taxa de utilização de plástico e pneu é avaliada considerando o aporte de energia e dos agentes necessários para a reação química de redução do minério de ferro em ferro metálico. No presente trabalho são elaborados os balanços de massa e de energia de acordo com a configuração operacional vigente no segundo semestre de 2009 para o Alto Forno 1 e com os dados de produção do mês de julho de 2009. O resultado mostra a viabilidade técnica do uso de plástico ou pneu e estabelece as condições de uso de cada um em relação à quantidade, tipo e granulometria. A substituição energética decorrente do uso de plástico e pneu estabelece uma forma de aplicação segura e controlada deste resíduo, além de agregar valor a estes materiais normalmente descartados pela sociedade. Contribui também para amenizar os impactos ambientais decorrentes da falta de uma destinação regulamentada e eficaz para plásticos descartados e pneus inservíveisAbstract: The study of alternative fuel materials in the Blast Furnace 1 of ArcelorMittal Tubarão, establishes a rate of each material analyzed, waste plastics packaging and waste tires, in order to replace part of the pulverized coal that is usually injected in to the Blast Furnace through the tuyeres. The injection rate of waste plastic packaging and waste tires is analyzed considering the energy input and the necessary elements for the iron ore reduction chemical reaction. The mass and energy balance is done according to the operational configuration of the Blast Furnace 1 in the second semester of 2009 and operation data from July of 2009. The result of the study shows technical viability to use waste plastics packaging and waste tires and establish requirements for the injection, such as flow rate and particles size. The alternative energy provided from these waste materials builds a safety and controlled way to reach the best utilization for each one. Moreover, the environmental impact can be reduced due to its disposal is normally done in outdoor areas
Orientador: José Antonio Perrella Balestieri
Coorientador: João Andrade de Carvalho Junior
Banca: Luiz Roberto Carrocci
Banca: Ricardo Dias Martins de Carvalho
Mestre
23
Mathews, Lopez Francisco. "A Multi-Criteria Decision-Making Model for Evaluation of Waste-to-Energy Technologies from Municipal Solid Waste| Combustion or Gasification for Puerto Rico?" Thesis, The George Washington University, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10845962.
Full textAbstract:
The island of Puerto Rico, a commonwealth of the United States of America, has a population of 3,725,789 according to the 2010 census, and generates 11,100 tons daily of waste. In the Island, landfilling is the dominant form of waste disposal. Most municipal solid waste landfills (MSWLF) in Puerto Rico are a principal source of land, water, and air pollution. In addition, the scarcity of appropriate land to open new landfill facilities make this type of waste disposal an unsustainable form of waste management for the Island.
This study evaluated the current situation of the MSWLFs in Puerto Rico and the geographic limitations of continuing with this type of waste disposal on the Island. As alternatives to this problem, the principal waste-to-energy (WTE) technologies, combustion and gasification, are evaluated as environmentally responsible forms for disposal of non-recycled waste.
The evaluation methodology used is based on a multi-criteria decision-making model that uses a subjective rank-order weighting method. Evaluation of WTE technologies is performed by comparing dissimilar indicators in five interest areas: technical, economic, environmental, socio-political, and risk. The methodology is composed of two-components: an expert survey and data analysis.
An evaluation of the environmental interest area was performed to assess which of the WTE technologies studied herein, combustion or gasification, is more environmentally responsible. In addition, using the relevant scores in different interest areas, they were evaluated to determine the economic benefits of these WTE technologies as viable waste management alternatives for Puerto Rico.
24
Nerva, Jean-Guillaume. "An Assessment of fuel physical and chemical properties in the combustion of a Diesel spray." Doctoral thesis, Universitat Politècnica de València, 2013. http://hdl.handle.net/10251/29767.
Full textAbstract:
With the slow but ineluctable depletion of fossil fuels, several avenues are currently being explored in order to define the strategic boundaries for a clean and sustainable energetic future, while accounting for the specificities of each sectors involved. In regard to transport applications, alternative fuels may represent a promising solution, at least at short or middle term, such as the International Energy Agency foresees that their share could account for 9% of the road transport fuel needs by 2030 and 27 % by 2050, with the potential resources to reach 48% beyond. If they have already been included in significant blending proportions with conventional fossil fuel in most of the occidental countries, their introduction also coincides with a long-time established program of continuously more drastic standards for engine emissions of NOX and PM, now even further demanding by the seek for combustion efficiency aiming at reducing CO2 emissions.
While several works discuss the alternative fuels effect on exhaust emissions when used directly in production Diesel engines, results and analysis are sometimes contradictory, depending sometimes on the conditions in which they were obtained, and the causes of these results remain unclear. Therefore, in order to better understand their effect on the combustion processes, and thus extract the maximum benefits from these fuels in the optimization of engine design and calibration, a detailed comprehension of their spray and combustion characteristics is essential.
The approach of this study is mostly experimental and based on an incremental methodology of tests aiming at isolating injection and combustion processes with the objective to identify and quantify the role of both fuel physical and chemical properties at some key stages of the Diesel combustion process. After obtaining a detailed characterization of their properties, five fuels have been injected in an optical engine enabling a sharp control of the thermodynamic eNerva, J. (2013). An Assessment of fuel physical and chemical properties in the combustion of a Diesel spray [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/29767
Palancia
25
Agbro, Edirin Bruno. "Experimental and chemical kinetic modelling study on the combustion of alternative fuels in fundamental systems and practical engines." Thesis, University of Leeds, 2017. http://etheses.whiterose.ac.uk/17980/.
Full textAbstract:
In this work, experimental data of ignition delay times of n-butanol, gasoline, toluene reference fuel (TRF), a gasoline/n-butanol blend and a TRF/n-butanol blend were obtained using the Leeds University Rapid Compression Machine (RCM) while autoignition (knock) onsets and knock intensities of gasoline, TRF, gasoline/n-butanol and TRF/n-butanol blends were measured using the Leeds University Optical Engine (LUPOE). The work showed that within the RCM, the 3-component TRF surrogate captures the trend of gasoline data well across the temperature range. However, based on results obtained in the engine, it appears that the chosen TRF may not be an excellent representation of gasoline under engine conditions as the knock boundary of TRF as well as the measured knock onsets are significantly lower than those of gasoline. The ignition delay times measured in the RCM for the blend, lay between those of gasoline and n-butanol under stoichiometric conditions across the temperature range studied and at lower temperatures, n-butanol acts as an octane enhancer over and above what might be expected from a simple linear blending law. In the engine, the measured knock onsets for the blend were higher than those of gasoline at the more retarded spark timing of 6 CA bTDC but the effect disappears at higher spark advances. Future studies exploring the blending effect of n-butanol across a range of blending ratios is required since it is difficult to conclude on the overall effect of n-butanol blending on gasoline based on the single blend that has been considered in this study. The chemical kinetic modelling of the fuels investigated has also been evaluated by comparing results from simulations employing the relevant reaction mechanisms with the experimental data sourced from either the open literature or measured in-house. Local as well as global uncertainty/sensitivity methods accounting for the impact of uncertainties in the input parameters, were also employed within the framework of ignition delay time modelling in an RCM and species concentration prediction in a JSR, for analysis of the chemical kinetic modelling of DME, n-butanol, TRF and TRF/n-butanol oxidation in order to advance the understanding of the key reactions rates that are crucial for the accurate prediction of the combustion of alternative fuels in internal combustion engines. The results showed that uncertainties in predicting key target quantities for the various fuels studied are currently large but driven by few reactions. Further studies of the key reaction channels identified in this work at the P-T conditions of relevance to combustion applications could help to improve current mechanisms. Moreover, the chemical kinetic modelling of the autoignition and species concentration of TRF, TRF/n-butanol and n-butanol fuels was carried out using the adopted TRF/n-butanol mechanism as input in the engine simulations of a recently developed commercial engine software known as LOGEengine. Similar to the results obtained in the RCM modelling work, the knock onsets predicted for TRF and TRF/n-butanol blend under engine conditions were consistently higher than the measured data. Overall, the work demonstrated that accurate representation of the low temperature chemistry in current chemical kinetic models of alternative fuels is very crucial for the accurate description of the chemical processes and autoignition of the end gas in the engine.
26
Bernardes, Pedrozo Vinícius. "An experimental study of ethanol-diesel dual-fuel combustion for high efficiency and clean heavy-duty engines." Thesis, Brunel University, 2017. http://bura.brunel.ac.uk/handle/2438/15850.
Full textAbstract:
Higher atmospheric concentration of greenhouse gases (GHG) such as carbon dioxide and methane has contributed to an increase in Earth's mean surface air temperature and caused climate changes. This largely reflects the increase in global energy consumption, which is heavily dependent on oil, natural gas, and coal. If not controlled, the combustion of these fossil fuels can also produce high levels of nitrogen oxides (NOx) and soot emissions, which adversely affect the air quality. New and extremely challenging fuel efficiency and exhaust emissions regulations are driving the development and optimisation of powertrain technologies as well as the use of low carbon fuels to cost-effectively meet stringent requirements and minimise the transport sector's GHG emissions. In this framework, the dual-fuel combustion has been shown as an effective means to maximise the utilisation of renewable liquid fuels such as ethanol in conventional diesel engines while reducing the levels of NOx and soot emissions. This research has developed strategies to optimise the use of ethanol as a substitute for diesel fuel and improve the effectiveness of dual-fuel combustion in terms of emissions, efficiency, and engine operational cost. Experimental investigations were performed on a single cylinder heavy-duty diesel engine equipped with a high pressure common rail injection system, cooled external exhaust gas recirculation, and a variable valve actuation system. A port fuel injection system was designed and installed, enabling dual-fuel operation with ethanol energy fractions up to 0.83. At low engine loads, in-cylinder control strategies such as the use of a higher residual gas fraction via an intake valve re-opening increased the combustion efficiency (from 87.7% to 95.9%) and the exhaust gas temperature (from 468 K to 531 K). A trade-off between operational cost and NOx reduction capability was assessed at medium loads, where the dual-fuel engine performance was less likely to be affected by combustion inefficiencies and in-cylinder pressure limitations. At high load conditions, a Miller cycle strategy via late intake valve closing decreased the in-cylinder gas temperature during the compression stroke, delaying the autoignition of the ethanol fuel and reducing the levels of in-cylinder pressure rise rate. This allowed for the use of high ethanol energy fractions of up to 0.79. Finally, the overall benefits and limitations of optimised ethanol-diesel dual-fuel combustion were compared against those of conventional diesel combustion. Higher net indicated efficiency (by up to 4.4%) combined with reductions in NOx (by up to 90%) and GHG (by up to 57%) emissions can help generate a viable business case of dual-fuel combustion as a technology for future high efficiency and clean heavy-duty engines.
27
Vittori, Ruggero Maria. "Experimental study on the effect of stoichiometric air/fuel ratio of three binary oxygenated fuel blends on combustion and emissions of a heavy duty Diesel engine." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18203/.
Full textAbstract:
Low Temperature Combustion (LTC) is believed to be the best solution to the Diesel NOx and soot emissions trade-off: the latest development in LTC methods is PPC (Partially Premixed Combustion) which can be considered as a combination of Homogeneous Charge Compression Ignition (HCCI) and conventional Diesel combustion.
The increasing interest in high-octane alternative fuels, such as alcohols and aromatic compounds, leads to investigate their combustion behaviour, in order to develop cleaner fuels, making another small step towards new cleaner engines.
In this thesis, three binary oxygenated fuel blends are selected, with the aim of studying how their molecular structures and stoichiometric air-fuel ratio influenced the combustion performances and emissions of a truck heavy-duty Diesel engine.
The first part describes the fundamental elements of LTC and gives a background on the typical Diesel combustion emissions, with the description of the alternative test fuels of this research.
The second part is about the engine setup, with particular attention towards the emission measurement and data acquisition systems.
The third part gives a background on the important parameters of this research, mostly combustion control parameters: it is fundamental to understand the test results, which are presented in the final part of the thesis.
This master thesis project has been developed in collaboration with the “Multiphase and reactive flows” research group at TU/e, Eindhoven University of Technology, in the Netherlands.
28
Jain, Deeksha. "Development of Alternative Materials to Replace Precious Metals in Sustainable Catalytic Technologies." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1566176607919202.
Full text
29
Chien, Jui-Yu. "The future and outlook of alternative fuel bus industry and its marketing strategy." CSUSB ScholarWorks, 2002. https://scholarworks.lib.csusb.edu/etd-project/2332.
Full textAbstract:
According to the current governmental regulations, all diesel buses will be replaced in the United States and the European market within the next ten years. There are over 60,000 buses in the United States and each year over 3,000 new buses of approximately 40 feet in length are purchased. The bus market has a growth rate of four to five percent per year over the last two years. The improvements in technology offered by United States companies prove unsatisfactory in terms of bus performance and the emissions of new buses. The energy crisis in the United States and concern over the health hazards of the diesel fuel exhaust gases and particulates, alternative fuel vehicles are in great demand in the transit market world wide.
30
Surawski, Nicholas C. "An investigation of gaseous and particulate emissions from compression ignition engines operated with alternative fuels, injection technologies, and combustion strategies." Thesis, Queensland University of Technology, 2012. https://eprints.qut.edu.au/54194/1/Surawski_Thesis_2011.pdf.
Full textAbstract:
Whilst the compression ignition (CI) engine exhibits many design advantages relative to its spark ignition engine counterpart; such as: high thermal efficiency, fuel economy and low carbon monoxide and hydrocarbon emissions, the issue of Diesel Particulate Matter (DPM) emissions continues to be an unresolved problem for the CI engine. Primarily, this thesis investigates a range of DPM mitigation strategies such as alternative fuels, injection technologies and combustion strategies conducted with a view to determine their impact on the physico-chemical properties of DPM emissions, and consequently to shed light on their likely human health impacts. Regulated gaseous emissions, Nitric oxide (NO), Carbon monoxide (CO), and Hydrocarbons (HCs), were measured in all experimental campaigns, although the major focus in this research program was on particulate emissions...
31
MANELLI, ANDREA. "Engine Technologies for Reduction of Fuel Consumption and Pollutant Emissions in Light-Duty Diesel Engines." Doctoral thesis, Politecnico di Torino, 2022. http://hdl.handle.net/11583/2971996.
Full text
32
Kapadia, Zarashpe Zarir. "Quantifying the climate and air quality impacts of non-CO2 species from the combustion of standard and alternative fuels in aviation." Thesis, University of Leeds, 2015. http://etheses.whiterose.ac.uk/12978/.
Full textAbstract:
Aviation has the capacity to drive changes in atmospheric composition, and therefore climate and air quality, increasing human mortality through increases in cases in cardiopulmonary disease. Non-CO2 aviation emissions are estimated to have a considerable effect on the climate, and with rapid growth in the aviation sector their associated impacts could increase. There is much uncertainty surrounding the climatic impact of aviation-induced ozone and aerosols, in part due to broad range of emissions species emitted, which are not always reported in aviation emissions inventories. This thesis assesses the impact of aviation on atmospheric trace gas and aerosol concentrations, climate, air quality and human health effects for year 2000 civil aviation. These impacts are estimated through: (i) the development of an extended aviation emissions inventory, inclusive of speciated hydrocarbons; (ii) assessing the atmospheric and climatic impact from aviation based on an extend aviation emissions inventory, a comparison of these impacts with a reduced emissions aviation emissions inventory, along with a sensitivity study for emissions species included; (iii) assessing the impact of aviation on human health effects when variations in fuel sulfur content (FSC) are applied along with resulting impacts on radiative effects, and; (iv) the atmospheric, climatic, air quality and human health impacts of the use of alternative fuels in aviation. An aviation emissions inventory was developed to represent aviation-borne non-CO2 emissions: nitrogen oxides, carbon oxide, speciated hydrocarbons, sulfur dioxide, black carbon and organic carbon emissions while taking in to account the geometric mean diameter of carbonaceous particles released. Aviation non-CO2 emissions are assessed to result in a radiative effect of –13.29 mW m-2 [assessed from the ozone (O3DRE) and aerosol (aDRE) direct radiative effects, and aerosol cloud albedo effect (aCAE)], primarily driven by a cooling aCAE. In comparison an emissions inventory which only considers aviation nitrogen dioxide and black carbon emissions results in a radiative effect of –8.19 mW m-2 primarily driven by reductions in the cooling aCAE assessed. It is found that air pollution from aviation reaches ground level, as such modifying surface PM2.5 (particulate matter within the 2.5 μm size range) which results in increased human exposure. Standard aviation is estimated to result in 3597 mortalities a-1. Variations in FSC from 0–6000 ppm aviation’s human health effects range from 2950–9057 mortalities a-1. These variations in FSC result in an aviation non-CO2 radiative effect ranging from –6.08 mW m-2 to –75.48 mW m-2. It is found that variations in aviation FSC elicit a near-linear relationship between aviation-induced mortality and non-CO2 radiative effect. Additional investigations in the vertical release of aviation-borne sulfur dioxide emissions show that it possible to reduce aviation-induced mortality and increase aviation-induced cooling by adjusting the FSC of fuel used at different altitudes. An investigation of the use of Fischer-Tropsch (FT) and fatty acid methyl ester (FAME) fuels (FT50, FT100, FAME20 and FAME40 fuel blends) within aviation found that aviation-induced nitrogen dioxide and ozone concentrations were reduced in tandem with associated ozone radiative effects. Additionally due relative reductions between sulfur dioxide and carbonaceous aerosol emissions FT fuel blends were estimated to produce negative aDREs, while FAME fuel blends gave a positive aDRE. In all cases FT and FAME fuel blends decreased the aCAE induced cooling effect from aviation. FT50 is the only fuel blend currently specified for use in today’s civil aviation fleet. This fuel blend is simulated to reduce aviation’s non-CO2 emissions cooling radiative effect to –10.89 mW m-2 and reduce aviation-induced mortality by 460 mortalities a-1. Through the sustainable development of FT fuels from bio-sourced feedstocks this fuel blend has the potential to reduce aviation’s climatic impact and human health effects (when reductions in aviation’s net CO2 emissions are considered in tandem).
33
Everett, Ryan Vincent. "An Improved Model-Based Methodology for Calibration of an Alternative Fueled Engine." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1321285633.
Full text
34
Jansa, Oldřich. "Porovnání vlastností alternativních pelet." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229503.
Full textAbstract:
This thesis deals with the alternative pellets and the means of production from raw material to final customer. The theoretical part deals with different techniques and manufacturing technologies used. Furthermore, the work deals with Czech and European legislation in the field of fuel pellets. The practical part deals with measuring and comparing the properties of selected standard pellets.
35
Lezzar, Balahouane. "Contribution à l'étude de la combustion et des limites de fonctionnement dans un monocylindre à taux de compression variable alimenté au méthane, au gaz de groningue et avec un mélange méthane-éthane." Valenciennes, 1987. https://ged.uphf.fr/nuxeo/site/esupversions/0d1a9c0a-0df4-4fab-8206-316c90031798.
Full text
36
Ngo, Thi Linh Dan. "Characterization of soot particles and their precursors produced during the combustion of conventional and alternative fuels : an in-situ laser diagnostics and ex-situ mass spectrometry investigation." Thesis, Lille 1, 2019. http://www.theses.fr/2019LIL1R040/document.
Full textAbstract:
L'intérêt pour les biocarburants s’est considérablement accru ces dernières années car ceux-ci pourraient permettre de diminuer la dépendance aux combustibles fossiles et contribuer à une croissance neutre en carbone. L’influence de l’utilisation de biocarburants sur les émissions de polluants (CO,CO_2,NO_x,HC, etc.) a fait l’objet de nombreux travaux, cependant les effets de la nature de ces carburants alternatifs sur les propriétés physico-chimiques des particules et des espèces aromatiques produites sont encore peu étudiés. Dans le cadre de ce travail de thèse, nous visons à caractériser les émissions de particules de suie et d'hydrocarbures aromatiques polycycliques (HAP) lors de la combustion de carburants conventionnels et alternatifs (biocarburants) pertinents pour les secteurs de l'automobile et de l'aéronautique, tout en essayant de mettre en lumière leurs influence sur les mécanismes de formation de ces polluants. Pour atteindre cet objectif, deux réacteurs de laboratoire, un bruleur turbulent swirlé et un Combustion Aerosol STandard (CAST), ont été utilisés comme générateurs de suie. De plus, nous avons combiné différentes techniques laser complémentaires in situ, les incandescence et fluorescence induites par laser (LII/LIF), et ex situ, la spectrométrie de masse après désorption et ionisation laser (L2MS) et la spectrométrie de masse des ions secondaires (SIMS). Dans une flamme turbulente swirlée pour cinq carburants (Diesel, n-butanol, mélange 50/50 Diesel/n-butanol, Jet A1 et Synthetic Paraffinic Kerosene SPK), les profils LII et LIF et les propriétés des particules de suie et de leurs précurseurs en fonction de la hauteur dans la flamme ainsi que leur composition chimique ont été étudiés. De fortes corrélations entre les résultats obtenus avec les techniques in situ et ex situ ont été mises en évidence permettant de caractériser spectralement et chimiquement ces espèces. En outre, une nouvelle méthode d'étalonnage a été développée pour déduire directement la fraction volumique de suie à partir du signal LII en utilisant la luminance énergétique absolue émise par une source ayant un rayonnement de corps noir. En parallèle, les expériences utilisant le dispositif CAST ont été menées avec les carburants aéronautiques (Jet A1 et SPK). Outre l'influence du carburant de substitution, les effets d’un stripper catalytique (CS) sur les particules de suie et les espèces volatiles ont été examinésInterest in biofuels has increased significantly in recent years as they could reduce dependence on fossil fuels and contribute to carbon-neutral growth. The influence of using biofuels on their exhaust emissions (CO,CO_2,NO_x,HC, etc.) has been studied widely. However, the effects of the nature of these alternative fuels on the physical and chemical properties of the particles and aromatic species produced are not fully understood. As part of this thesis work, we aim to study the emissions of soot particles and polycyclic aromatic hydrocarbons (PAHs) during the combustion of conventional and alternative fuels (biofuels) relevant to the automotive and aerospace sectors, while trying to highlight their influence on the formation of such pollutants. To achieve this goal, two laboratory combustors, a swirled turbulent jet burner and a Combustion Aerosol STandard (CAST), were used as soot generators. In addition, we have combined various complementary in-situ laser techniques, laser-induced incandescence and fluorescence (LII/LIF), and ex-situ two-step laser mass spectrometry (L2MS) and secondary ion mass spectrometry (SIMS). In a swirled turbulent jet flame for five fuels (Diesel, n-butanol, 50/50 Diesel/n-butanol mixture, Jet A1 and Synthetic Paraffinic Kerosene SPK), the LII and LIF profiles and properties of soot particles and their precursors with the height in the flame as well as their chemical composition were studied. Strong correlations between the results obtained with in-situ and ex-situ techniques have been demonstrated which allowed us to characterize these species spectrally and chemically. In addition, a new calibration method has been developed to directly deduce the soot volume fraction from the LII signal using the absolute radiance emitted from a light source having black body behavior. In parallel, experiments using the CAST device were conducted with aeronautical fuels (Jet A1 and SPK). In addition to the influence of the alternative fuel, the effects of a catalytic stripper (CS) on soot particles and volatile species were examined
37
Tai, Chia-Hui. "Trace Elemental Analysis of Ashes in the Combustion of the Binder Enhanced d-RDF by Inductively Coupled Plasma Atomic Emission Spectroscopy." Thesis, University of North Texas, 1988. https://digital.library.unt.edu/ark:/67531/metadc501168/.
Full textAbstract:
Incineration is an attractive solution to the problems of disposing of municipal solid wastes and supplying energy. Because up to 25 percent of the waste in refuse-derived-fuel systems is ash, the physical and chemical characteristics of ash become more and more important for its potential impacts and methods suitable for their disposal. Trace elements concentration in ash is of great interest because of its relationship to regulatory criteria under the Resource Conservation and Recovery Act (RCRA) regarding toxicity and hazards. The applications of a microwave oven sample dissolution method has been tested on a variety of standard reference materials, with reproducible and accurate results. Fourteen trace elements, As, Ba, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se, Tl, V, and Zn, from the dissolved ash samples were determined by inductively coupled plasma atomic emission spectrometry.
38
Bodisco, Timothy Alexis. "In-cylinder pressure and inter-cycle variability analysis for a compression ignition engine : Bayesian approaches." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/62064/11/Timothy_Bodisco_Thesis.pdf.
Full textAbstract:
This thesis introduced Bayesian statistics as an analysis technique to isolate resonant frequency information in in-cylinder pressure signals taken from internal combustion engines. Applications of these techniques are relevant to engine design (performance and noise), energy conservation (fuel consumption) and alternative fuel evaluation. The use of Bayesian statistics, over traditional techniques, allowed for a more in-depth investigation into previously difficult to isolate engine parameters on a cycle-by-cycle basis. Specifically, these techniques facilitated the determination of the start of pre-mixed and diffusion combustion and for the in-cylinder temperature profile to be resolved on individual consecutive engine cycles. Dr Bodisco further showed the utility of the Bayesian analysis techniques by applying them to in-cylinder pressure signals taken from a compression ignition engine run with fumigated ethanol.
39
Hudák, Igor. "Vliv inertních plynů na charakteristické parametry spalování." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-295650.
Full textAbstract:
The dissertation thesis is focused on the investigation of the influence of inert gases on characteristic parameters of the combustion process. Inert gases are usually standard components of alternative gaseous fuels such as the producer gas, coal gas or biogas. For a long period some of the fuels were considered as waste gases and their potential was not sufficiently utilised. Compared with noble fuels such as natural gas, alternative fuels have different physical-chemical properties. For example, their lower heating value (LHV) can be lower even than 10 MJ/mN3. The composition of the alternative gaseous fuels can be various during their production process. Lower LHV is a result of the occurrence of inert gases that does not take a part in the combustion reactions. Inert gases have the ability to accumulate the heat. Under certain conditions it is possible to combust alternative fuels on conventional burners, but due to their different properties, problems can occur during the combustion. E.g. to achieve the same heat output as with the noble fuel, it is necessary to burn bigger volume of the alternative fuel. However, the limiting factor could be the burner's head geometry. Theoretical introduction of the thesis summarizes research results in the field of low calorific gaseous fuels combustion and the addition of inert gases into the noble fuels. The thesis also describes the mechanisms of the NOx formation and summarizes techniques which can be used to reduce NOx formation. Furthermore, fuels from alternative sources are categorized and described, including their composition and characteristics. Their physical-chemical properties were obtained by means of the combustion simulation carried out in the simulation software. Two devices had to be designed and manufactured to fulfil goals of the dissertation thesis. The first is a gas mixing station capable of mixing 4 different components. The second device is a burner utilized for the combustion of low calorific fuels. The key section of this thesis is a chapter describing the experimental plan, the performance and the evaluation of the experiments. The goal of the experiments was to dilute the natural gas by two inert gases, namely carbon dioxide and nitrogen. The lowest LHV value achieved during the experiment was 10,7 MJ/mN3. The influence of the inert gases on the NOx emissions, the flame stability and characteristics, the flue gas temperature, the in-flame temperatures, the heat flux and the thermal efficiency was investigated and evaluated. Each parameter was measured and evaluated for three different burners: the burner with the staged gas, the burner with the staged air and the burner for low calorific fuels. Generally, after the addition of the inert gas into the noble fuel, the in-flame temperatures decreased. As a consequence, the NOx emissions decreased as well. The effects of carbon dioxide on the investigated combustion parameters were more substantial than the effects of nitrogen. Each measured parameter is strongly dependent on the burner geometry. The experiments revealed that in most cases the addition of the inert gas into the fuel influenced the flame length (flame shortened) and also more heat was transfered into the chamber's walls closer to the burner tile.
40
Nabti, Brahim. "Contribution à l'étude du comportement d'un moteur diesel à préchambre alimentée à l'huile de colza." Valenciennes, 1987. https://ged.uphf.fr/nuxeo/site/esupversions/95663265-c958-4285-8c93-1f4e25558999.
Full textAbstract:
Etude de la combustion dans un moteur diesel à préchambre utilisant de l'huile de colza. Calcul de la quantité de chaleur dégagée. Comparaison des délais d'inflammation. Modélisation et optimisation du cycle moteur.
41
Nendel, Klaus, Brit Clauß, Uwe Böttger, Peter Käferstein, Matthias Gohla, Hendrik Reimer, Helmar Tepper, and Werner Neidel. "Kopplung von energetischer Verwertung und Aufbereitung von Biomassen - Erhöhung der Wirtschaftlichkeit." Universitätsbibliothek Chemnitz, 2002. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-200201220.
Full textAbstract:
Zielstellung des Forschungsprojekts ist es, halm- und stengelförmige biogene Brennstoffe so zu einer handlings- und verkaufsfähigen Form mit hoher Energiedichte aufzubereiten, die für Verbrennungsanlagen kleinerer Leistung geeignet ist und gegenüber bisher verwendeten Brennstofformen, z.B. Häcksel, eine wesentliche Verbesserung des Abbrand-, Emissions- und Ascheverhaltens erreicht wird. Ein Funktionsmuster zur kontinuierlichen Aufbereitung von hochverdichteten, abriebfesten und formstabilen Briketts ist zu erstellen. In Kopplung mit Verbrennungsuntersuchungen werden die spezifischen Anforderungen an die Briketts abgeleitet und der Verfahrensablauf für die Aufbereitung optimiert. Bei der Erstellung eines Konzeptes für ein Demonstrationsobjekt für die zukünftige Verwertung von Biomassebriketts bildet die Wirtschaftlichkeit einen besonderen Schwerpunkt.
Die Arbeiten zur Entwicklung des Brikettierverfahrens zeigen, daß eine Herstellung von stabilen Briketts aus Stroh oder Heu ohne zusätzliche Bindemittel möglich ist. Mit Hilfe experimenteller Untersuchungen konnten die erforderlichen Verfahrensparameter ermittelt werden. Um dauerhaft haltbare Briketts gleichbleibender Qualität herzustellen, muß das zu verarbeitende Halmgut unzerkleinert und mit einem Feuchtegehalt von 12 bis 15 % vorliegen. In der Verformung der unzerkleinerten Halme sowohl in Längsrichtung als auch in der Ebene des Stengelquerschnitts ist die Ursache für den Bindemechanismus
in den Briketts zu finden. Unter Einwirkung von Preßdrücken von 100 bis 160 MPa liegt die Dichte der hergestellten Briketts je nach Gutart, bei 0,8 bis 1,2 g/cm3. Der Abriebanteil der Briketts, ermittelt nach ASAE S.269.4, liegt bei max. 5%. Ein Funktionsmuster zur Brikettierung (Brikettpresse mit vorgeschalteter Strangformungsstufe) für 25-mm - Briketts wurde konstruiert, gebaut und getestet.
Mittels Elementar-, Immediat-, Chlor- und Schwermetallanalyse wurden die Eigenschaften für zehn verschiedene biogene Brennstoffe, vorwiegend Halmgüter (Getreide- und Rapsstroh, Wiesenheu, Miscanthus)
charakterisiert. Die Abbranduntersuchungen der Briketts im Vergleich zum Häcksel zeigen, daß die Reaktionsphasen der Flüchtigenverbrennung und des Restkoksabbrandes gleichzeitig ablaufen. Eine wesentliche Verlängerung der Abbrandzeit ist zu verzeichnen, die mit zunehmender Brikettgröße und -dichte noch steigt. Während der gesamten Brennzeit werden die Schadstoffe gleichmäßig freigesetzt.
Durch längere Verweilzeiten der Briketts im Reaktor wird der Kohlenstoffanteil des Brennstoffs vollständiger oxidiert, was sich in den wesentlich geringeren CO-Emissionen im Vergleich zum Häcksel widerspiegelt.
Im Vergleich mit der TA Luft liegen die CO- und SO2-Emissionen der Biomassebriketts durchgängig unter den Grenzwerten. Durch eine luftgestufte Verfahrensführung (60% Primärluft, 40% Sekundärluft) ist
es möglich, die NOx-Werte ebenfalls unter den Grenzwert der TA Luft abzusenken. Fallstudien zu möglichen Demonstrationsvorhaben belegen, daß eine wirtschaftliche Lösung für das Brikettieren in Verbindung mit einer energetischen Nutzung in kleinen Anlagen erreichbar ist. Die Leistung der Brikettieranlage bestimmt deutlich deren Wirtschaftlichkeit. Dabei muß eine Tagesproduktion von 8 bis 10 t erreicht werden (250 Betriebstage im Jahr). Gegenüber dem Funktionsmuster muß jedoch eine Vergrößerung des Brikettdurchmessers erfolgen.
42
Keinz, Jan. "Optimization of a Dry Low NOx Micromix Combustor for an Industrial Gas Turbine Using Hydrogen-Rich Syngas Fuel." Doctoral thesis, Universite Libre de Bruxelles, 2018. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/277234.
Full textAbstract:
Environmentally friendly and efficiently produced energy from sustainable and renewable resources is of great importance. Carbon dioxide (CO2) and nitric oxides (NOx) are the main emissions of air-breathing gas turbines in power plants. Gas turbines of the power generation industry are normally fueled with liquid fuels, natural gas or syngas in changing qualities. Syngas can be produced by gasification processes in IGCC power plants and consist of varying percentages of the main fractions hydrogen (H2) and carbon monoxide (CO). CO2 emissions can be reduced by a decrease of the CO-share and an increase of the hydrogen-share in the syngas fuel, and by using pre-combustion carbon capture and sequestration (CCS) technology. For low NOx, current gas turbine combustion chamber technologies require diluents, a rather low H2 content and modifications of the combustor hardware. A feasible solution for low NOx hydrogen and syngas combustion in gas turbines is the Micromix principle developed at Aachen University of Applied Sciences. The goal of this doctoral thesis is the research on a Micromix combustor with increased power densities fueled with hydrogen-rich syngas with about 90% by volume hydrogen, and going up to 100% hydrogen in the fuel. Test burner experiments are used to characterize the combustion and emission properties of a multitude of key drivers. Based on this optimization with a variety of scaled model test burners, a prototype dual-fuel hydrogen/syngas Micromix combustor is designed and integrated into the annular combustion chamber of an industrial gas turbine. In the gas turbine, the performance characteristics of the prototype-combustor are investigated under real operational conditions with hydrogen-rich syngas and pure hydrogen.Doctorat en Sciences de l'ingénieur et technologie
info:eu-repo/semantics/nonPublished
43
Feitosa, Marcelo Valente. "Desenvolvimento do motor de ignição por compressão alimentado por injeção direta de óleo diesel e por etanol pós-vaporizado no coletor de admissão." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/18/18135/tde-15032016-135844/.
Full textAbstract:
Desenvolveu-se um sistema de alimentação misto para motores de ignição por compressão turboalimentados, o qual utiliza diesel injetado normalmente na câmara de combustão e etanol pós-vaporizado, injetado líquido no coletor de admissão e vaporizado pela grande disponibilidade de energia contida no ar comprimido. Foram possíveis substituições de até 55% da massa de diesel por etanol; funcionamento regular e repetitivo foi verificado, resultado da admissão de álcool na forma de vapor. Constatou-se que o rendimento térmico e as emissões de gases poluentes eram bastante influenciados pelo sistema de alimentação desenvolvido: ganhos de até 25,6% no rendimento térmico foram possíveis com reduções máximas de 81% na emissão de material particulado e 80% em NOx, pela queima mais eficiente do diesel na presença do vapor de etanol. Reduções notáveis na temperatura do ar comprimido foram atingidas, possibilitando a substituição dos \"intercoolers\". A análise teórica da implantação do sistema desenvolvido, numa frota de veículos de transporte coletivo da região metropolitana de São Paulo, indicou viabilidade econômica e ambiental.It was developed a supplementary fueling system for turbocharged compression ignition, which uses diesel injected usually in the combustion chamber and post-vaporized ethanol, that is injected in the liquid state inside the intake manifold and vaporized by the energy in the compressed air. It was possible to replace up to 55% of the diesel mass by ethanol; regular and repetitive operation was verified, result of the alcohol induction in the vapor state. It was verified that engine\'s efficiency and pollutant gases emissions were quite influenced by the fueling system developed: improvements of up to 25,6% in the efficiency were possible, with maximum reductions of 81% in particulate matter and 80% in NOx, as a result of a more efficient diesel oxidation in presence of ethanol vapor. Notable reductions in the compressed air temperature were reached, making possible the substitution of the \"intercoolers\". The theoretical analysis to implantation of the developed system, on vehicles of public transportation in the metropolitan area of São Paulo, indicated economical and environmental viability.
44
Souza, Sandro Guimarães. "Um estudo sobre a evolução das câmaras de combustão dos motores do ciclo Otto à gasolina e sua aplicação ao etanol hidratado como combustível alternativo." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/18/18135/tde-16112004-103714/.
Full textAbstract:
Apresenta o estado da arte das câmaras de combustão dos motores de combustão interna ciclo Otto à gasolina e a etanol, onde observa de forma qualitativa aspectos evolutivos e específicos ao uso do etanol como combustível alternativo. Propõe sugestões para trabalhos futuros, visando a otimização de uma câmara mais apropriada ao uso deste importante combustível renovável.It presents the state of the art of combustion chambers of gasoline and ethanol Otto cycle internal combustion engines, where it observes qualitatively evolutive and specific aspects to the use of the ethanol as an alternative fuel. It proposes suggestions for future works, seeking the optimization of a more appropriate combustion chamber for the use of that important renewable fuel.
45
Cambridge, Shevonn Nathaniel. "The effect of compression ratio on emissions from an alcohol-fueled engine." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-09122009-040220/.
Full text
46
Batistella, Luciane. "Avaliação das emissões gasosas geradas na combustão de lodo de esgoto sanitário em combustor de leito móvel." reponame:Repositório Institucional da UFSC, 2015. https://repositorio.ufsc.br/xmlui/handle/123456789/159400.
Full textAbstract:
Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Química, Florianópolis, 2015.Made available in DSpace on 2016-02-23T04:00:51Z (GMT). No. of bitstreams: 1 337595.pdf: 6226604 bytes, checksum: 9b486ca8476925f2f0d3a410363192bc (MD5) Previous issue date: 2015
O lodo de esgoto, gerado em grande volume em estações de tratamento de águas residuais, pode ser uma matéria-prima alternativa valiosa de energia. Neste trabalho foram avaliadas as emissões gasosas da combustão de lodos de esgoto sanitário aeróbio e anaeróbio utilizando um combustor de leito móvel. Visando o aproveitamento da energia gerada na combustão, o gás de exaustão foi encaminhado para a secagem de lodo bruto e as emissões do processo global foram analisadas. De acordo com a caracterização, os lodos apresentaram poder calorífico inferior de 14,55 MJ·Kg-1 (lodo aeróbio) e 10,52 MJ·Kg-1 (lodo anaeróbio), indicando o potencial energético destes resíduos. O lodo aeróbio apresentou os maiores valores de matéria volátil, carbono fixo e poder calorífico. Na amostra sólida do lodo aeróbio foram detectadas concentrações de metais pesados e poluentes orgânicos persistentes como hidrocarbonetos policíclicos aromáticos, dibenzo-p-dioxinas policloradas e dibenzofuranos policlorados menores do que o limite estabelecido pela legislação pertinente (European Commission). A amostra sólida de lodo anaeróbio apresentou conteúdo de metais pesados menor do que o limite e concentração de hidrocarbonetos policíclicos aromáticos superior ao limite permitido pela legislação pertinente. As emissões de CO, NOx e BTEX resultantes dos testes de combustão dos lodos aeróbio e anaeróbio apresentaram concentrações menores do que o limite estabelecido pelas legislações pertinentes (CONAMA 316/02 e SEMA 16/2014). Devido ao alto conteúdo de enxofre nos lodos, as emissões provenientes do processo de combustão apresentaram elevadas concentrações de SO2. No processo global de combustão e secagem do lodo aeróbio, as emissões de BTEX e dibenzo-p-dioxinas policloradas e dibenzofuranos policlorados. foram inferiores aos limites permitidos pela legislação pertinente, enquanto que para o lodo anaeróbio foram superiores. Os hidrocarbonetos policíclicos aromáticos não foram detectados no processo global de combustão e secagem dos lodos aeróbio e anaeróbio. Como etapa complementar foi estudada a carbonização hidrotérmica de lodos de esgoto aeróbio e anaeróbio. O processo de carbonização hidrotérmica promoveu aumento do poder calorífico e carbono fixo do lodo aeróbio tornando este lodo uma matéria-prima com grande potencial para a geração de energia.
Abstract : The sewage sludge generated in large amounts in wastewater treatment plants can be a valuable alternative feedstock for power generation. In this work, the gas emissions of aerobic and anaerobic sewage sludge combustion process in a moving bed reactor was evaluated. In order to use the heat generated during combustion, the exhaust gas was applied in the raw sludge drying process and gas emissions after drying were also analyzed. Sewage sludge characterization results showed the energy potential of this residue (low calorific value of 14.55 MJ·Kg-1 to aerobic and 10.52 MJ·Kg-1 to anaerobic). The aerobic sludge presented the highest values of volatile matter, fixed carbon and calorific value. In the solid sample sludge aerobic were detected low concentrations of the heavy metals and persistent organic pollutants as polycyclic aromatic hydrocarbons and polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans. The solid sample anaerobic sludge showed low content of heavy metals and polycyclic aromatic hydrocarbons concentration above the limit established by legislation (European Commission). The concentration of CO, NOx, benzene, toluene, ethylbenzene and xylene emitted from the aerobic and anaeróbic sludge combustion processes were lower than the limits established by legislation (CONAMA 316/02 and SEMA 16/2014). The high emissions of SO2 from the combustion process are due to the high sulfur content in the sludge. The aerobic sludge emissions of benzene, toluene, ethylbenzene and xylene, polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in the overall combustion and drying process were lower than established limits by legislation, while for anaerobic sludge they were higher. The polycyclic aromatic hydrocarbons were not detected in overall combustion and drying process the sludge aerobic and anaerobic. As a complementary step, was studied the hydrothermal carbonization of the sewage sludge. The process of hydrothermal carbonization promoted increased calorific value and fixed carbon of the aerobic sludge making this sludge a raw materials of great energy potential.
47
Ferreira, Sérgio Lucas. "Análise por cromatografia gasosa das emissões de compostos orgânicos voláteis provenientes de motores de combustão interna." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/18/18135/tde-10022017-120021/.
Full textAbstract:
O problema da poluição do ar se constitui em uma das mais graves ameaças à qualidade de vida de homens, animais, vegetais e a todo ambiente. O aumento da concentração de poluentes atmosféricos é gerado devido à crescente urbanização e ao aumento da frota de veículos automotores, principalmente. As emissões causadas por veículos carregam diversas substâncias tóxicas como: monóxido de carbono (CO), óxidos de nitrogênio (NOx), compostos orgânicos voláteis (COV), hidrocarbonetos policíclicos aromáticos (HPA) e outros que produzem vários efeitos negativos sobre a saúde. Tendo em vista essa situação, o objetivo deste trabalho foi a análise de gases poluentes emitidos por motores por Cromatografia Gasosa de Alta Resolução (CGAR). Foram analisados compostos orgânicos voláteis (benzeno, tolueno, etilbenzeno, o-xileno, m-xileno e p-xileno) nas emissões de motores empregando diesel de petróleo como combustível, B10 e etanol. Para estes combustíveis, compararam-se os teores dessas emissões (substâncias poluentes) variando-se alguns parâmetros dos motores. Também, foram feitas determinações dessas substâncias tóxicas nas emissões de motores empregando etanol como combustível. Nas emissões deste tipo de motor variando-se os parâmetros qualidade da mistura e rotação detectou-se benzeno na concentração 0,129 ± 0,021, 0,124 ± 0,020 e 0,132 ± 0,007 μg/mL (mistura rica, estequiométrica e pobre, respectivamente); 0,134 ± 0,017, 0,129 ± 0,007 e 0,133 ± 0,044 μg/mL (1700 rpm, 2200 rpm e 2700 rpm, respectivamente) que podem ser provenientes do óleo lubrificante. Em geral, para o motor de ignição por compressão, comparando-se as emissões tanto por diesel de petróleo como com mistura B10 observou-se uma redução significativa nas emissões dos poluentes aromáticos quando se emprega a mistura B10. Principalmente, para o benzeno, notou-se diminuição nas concentrações de até 24,5%. Apesar de ter obtido um valor de concentração abaixo de 1 μg/mL tanto na utilização do diesel quanto na de B10, esta redução é extremamente significante, por ser o benzeno, um composto carcinogênico. Além disso, a adição de biodiesel ao diesel mostrou-se eficiente na redução das emissões de poluentes.Air pollution\'s is one of the most serious environment problems concerning human animals and vegetables life. The increase of concentration of atmospheric pollutants is generated mainly due to increasing urbanization and the increase on the number of motor vehicles. The emissions caused by vehicles contain several toxic substances as: carbon monoxide (CO), nitrogen oxides (NOx), volatile organic compounds (VOC), polycyclic aromatic hydrocarbons (PAH) and others substances ending quite negative effect on health. Considering this situation, this study described the procedures of analysis of pollutant gases emitted by engines, such as volatile organic compounds (benzene, toluene, ethilbenzene, o-xylene, m-xylene and p-xylene) by using High Resolution Gas Chromatography (HRGC) applied to diesel, B10 mixture, and ethanol emissions analysis. Considering the use of diesel and B10 as fuel, a comparative studies has been performed for fossil fuel (diesel) and biodiesel by varying some parameters of the engines. Also, determination of these toxic substances in the emissions of engines had been made using ethanol as fuel. In the emissions of this type of engine varying the parameters as mixture quality and rotation had been detected benzene at concentration values 0,129 ± 0,021, 0,124 ± 0,020 e 0,132 ± 0,007 μg/mL (rich, stoichiometry and lean mixture); 0,134 ± 0,017, 0,129 ± 0,007 e 0,133 ± 0,044 μg/mL (1700 rpm, 2200 rpm and 2700 rpm, respectively) that can be proceeding from the lubricant oil. In general, for CI engine burning diesel or B10 mixture it has been observed drastically reduction in the emissions of the aromatic compounds by using B10. Especially for benzene the reduction of concentrations occurs on the level of about 24.5%. Although, it has obtained a concentration value below 1 μg/mL as much as in the using diesel and B10, this reduction is, extremely significant, to being benzene a carcinogenic compound. Moreover, the addition of biodiesel to the diesel has been showed efficient in the reduction of the pollutants emissions.
48
Zancanaro, Junior Flavio Vanderlei. "Análise numérica e experimental da combustão de metano em motores de combustão interna alternativos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/109158.
Full textAbstract:
Desde o seu surgimento o motor de combustão interna é a alternativa de fornecimento de potência mais utilizada no mundo em veículos de passeio e transporte de cargas. De fato, observa-se no dia-a-dia uma forte dependência da utilização de motores e, atualmente, os estudos visando o seu aumento de eficiência e a diminuição de emissões poluentes estão cada vez mais intensos. Com os grandes avanços ocorridos na disponibilização de computadores, existe uma tendência contínua para a utilização de técnicas computacionais auxiliando no projeto de motores. No entanto, o maior desafio é simular o escoamento altamente tridimensional, turbulento e transiente, com o uso de modelos de turbulência e combustão, que tenham bom compromisso com a física envolvida. Neste âmbito, o presente trabalho tem o objetivo de desenvolver uma validação de metodologias numérica e experimental, para avaliar o comportamento dinâmico e reativo do escoamento em motores de combustão interna. A simulação é aplicada a um motor Honda GX35, que possui vasto uso comercial em roçadeiras, motocicletas de baixo custo e, atualmente, em Veículos Autônomos Não Tripulados (VANT), dentre outros. A análise tem como base soluções numéricas pelo método dos volumes finitos, usando o programa comercial Star-cd/es-ice. Para resolver o escoamento turbulento o modelo adotado foi o k-ω SST, com aproximação para baixo Reynolds e tratamento de parede híbrido. O modelo de combustão ECFM-3Z foi empregado para resolver o escoamento reativo. O combustível utilizado foi metano em mistura estequiométrica. Os resultados numéricos são confrontados com resultados experimentais, com o objetivo de examinar o estado da arte dessas metodologias. Valores transientes de pressão no interior do cilindro, vazão mássica de ar, fração mássica queimada, em relação ao eixo de manivelas e os produtos da combustão são confrontados A presença de recirculações na admissão e no cilindro foram detectadas e discutidas. As evoluções da pressão interna no cilindro e da vazão mássica de ar resultantes da simulação numérica apresentaram um bom comportamento, quando confrontado com dados experimentais. Os resultados da fração mássica de combustível queimado revelam características importantes de funcionamento do motor.Since its inception, the internal combustion engine is the alternative of delivering power most used worldwide in passenger vehicles and transportation. Indeed, it is observed in day-to-day a strong dependency on the use of engines, and currently studies aiming at its increased efficiency and reduced emissions are becoming more intense. With the great advances in the availability of computers, there is a continuing trend towards the use of computational techniques aiding in the engine designs. However, the main challenge is to simulate the highly three-dimensional, transient and turbulent flows with the turbulence and combustion models, which have good compromise with the involved physics. In this context, this work aims to develop a validation of numerical and experimental methods for evaluating the dynamic and reactive behavior of the flow in internal combustion engines. The simulation is applied to a Honda GX35 engine, which has commercial application in brushcutters, motorcycles of low cost, Unmanned Autonomous Vehicles (UAV), among others. The analysis is based on numerical solutions by the finite volume method, using the commercial software Star-CD / esice. To solve the turbulent flow the model adopted was the k-ω SST, in its Low Reynolds approach with hybrid treatment near the walls The ECFM-3Z combustion model was employed to solve the reactive flow. The fuel used was methane in the stoichiometric mixture. The numerical results are compared with experimental ones, in order to examine the state of art of these methodologies. Transient values of cylinder inside pressure, mass air flow, mass fraction of the fuel burned, in relation to the crankshaft angle and the combustion products are confronted The presence of recirculation in the intake duct and cylinder were detected and discussed. The evolutions of the internal cylinder pressure and mass flow rate of air showed a good behavior, when confronted with experimental data. The results of the burned mass fraction reveal important characteristics of engine operation.
49
Souza, Sandro Guimarães. "Desenvolvimento de uma câmara de combustão para um motor diesel ottorizado auxiliado por simulação 1D/3D." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/18/18147/tde-25062015-150938/.
Full textAbstract:
Este trabalho apresenta uma análise comparativa entre diferentes geometrias de câmaras de combustão, no intuito de eleger a que proporcione queima mais adequada de etanol a um motor originalmente projetado para operar no ciclo Diesel que foi transformado para operar no ciclo Otto. O processo de formação de mistura é analisado desde a injeção de combustível no pórtico de admissão até o momento da ignição na câmara de combustão. Esta análise se baseia em simulações 1D e 3D, cujos modelos foram previamente validados em bancada experimental.This work presents a comparative analysis between different combustion chambers, in order to elect one to provide a more suitable burning ethanol in engine originally designed to operate on diesel cycle which has been converted to operate on Otto cycle. The mixture formation process is analyzed since the port fuel injection until ignition timing in combustion chamber. This analysis is based on 1D and 3D simulations, of which models were previously validated in experimental bench.
50
Baranton, Stève. "Catalyseurs alternatifs pour cathodes de micropiles à combustion directe de méthanol." Poitiers, 2004. http://www.theses.fr/2004POIT2302.
Full textAbstract:
Les micro-DMFCs pour lesquelles la membrane est de faible épaisseur sont très sensibles au phénomène de crossover. Ce travail est orienté vers une solution qui consiste à utiliser un catalyseur pour la réduction de l'oxygène totalement insensible à la présence de méthanol : la phtalocyanine de fer. L'étude électrochimique de ce catalyseur a permis de mesurer son activité catalytique, de démontrer sa totale insensibilité à la présence de méthanol et sa sélectivité vis-à-vis des produits de la réduction de l'oxygène. Cependant, l'activité catalytique de la phtalocyanine de fer se dégrade lors de la réduction de l'oxygène en milieu acide. Une étude par spectroscopie infrarouge in situ a permis de démontrer que le mécanisme de dégradation du catalyseur est une substitution de l'ion central par deux protons. La connaissance précise de ce mécanisme a rendu possible l'intégration de la phtalocyanine de fer dans une DMFC et un comportement catalytique stable a alors pu être observéThe crossover is a major problem for the development of micro-DMFCs for which the membrane is thinner than for traditional systems. The solution studied in this work consists in using a catalyst for the oxygen reduction reaction tolerant to methanol: the iron phthalocyanine. The electrochemical study of this catalyst enabled to measure its catalytic activity, to demonstrate its total insensitivity to methanol and its selectivity with respect to the products of the oxygen reduction. However, the catalytic activity of the iron phthalocyanine decreases during the oxygen reduction in acid medium. It was possible to show by an in situ infrared spectroscopy study that the degradation mechanism is a substitution of the central ion by two protons. The precise knowledge of this mechanism enabled the integration of the iron phthalocyanine in a DMFC and a stable catalytic behavior could be observed