Sample records for asphaltenes content combustion

  1. Combustion of drops of Mexican fuel oils with high asphaltenes content; Combustion de gotas de combustoleos mexicanos con alto contenido de asfaltenos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Rodriguez, Jose Francisco [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)


    In this work the combustion of fuel drops with a content of 18% of asphaltenes has been studied . The results obtained for this fuel were compared with the ones obtained for another with a content of 12% asphaltenes. The drops were suspended in a platinum filament and burned in an spherical radiant furnace. The drop size varied between 600 and 800 microns. The fuel drops with 12% asphaltenes showed shorter combustion times, a smaller diameter increment of the smaller diameter during the combustion stages and also a shorter burning time of the carbonaceous residue than the fuel drops with a content of 18% asphaltenes. [Espanol] En el presente trabajo se ha estudiado la combustion de gotas de combustible con 18% de contenido de asfaltenos. Los resultados obtenidos para este combustible se compararon con los obtenidos para otro con 12% de contenido de asfaltenos. Las gotas fueron suspendidas en un filamento de platino y quemadas en un horno radiante esferico. El tamano de las gotas vario entre 600 y 800 micras. Las gotas de combustible con 12% de asfaltenos mostraron tiempos de combustion mas cortos, un incremento del diametro menor durante las etapas de combustion y un tiempo de quemado del residuo carbonoso tambien mas corto que las gotas del combustible con 18% de contenido de asfaltenos.

  2. Monitoring of large diesel engines through asphaltene content

    Energy Technology Data Exchange (ETDEWEB)

    Declerck, R. [Texaco Technology Ghent (Belgium)


    Lubricants in large diesel engines, for marine and power plant application, are open contaminated with heavy fuel. This type of contamination results in blackening of the engines and deposit formation because of the coagulation of asphaltene particles. Monitoring of the asphaltene content presents the operator with important information on the condition of the engine and the lubricant. This technique was an important asset in developing a new range of lubricants highly capable of tackling the presence of asphaltenes. (orig.)

  3. Modélisation de la combustion de fuels lourds prenant en compte la dispersion des asphaltènes Modeling Heavy Fuel-Oil Combustion (While Considering Or Including Asphaltene Dispersion

    Directory of Open Access Journals (Sweden)

    Audibert F.


    difficultés relevant du mode d'exploration et de la non adéquation entre les structures asphalténiques et fractales. On a finalement opté pour une détermination visuelle s'appuyant sur les clichés sur lesquels les agglomérats d'asphaltènes sont clairement visualisés tels qu'ils sont dans le fuel. Ce mode d'exploration laborieux a cependant permis de déterminer un modèle construit sur une série de 25 fuels dont 10 ont été brûlés sur une chaudière de 2 MW, et 15 sur un four de 100 kW. Ce modèle fait intervenir les teneurs en carbone Conradson et en métaux, ainsi que le taux de dispersion des asphaltènes. Le perfectionnement des moyens d'exploration aidant, on peut s'attendre à ce que soient disponibles des techniques d'évaluation de la dispersion sur les clichés. Ce paramètre pourra alors être pris en considération pour une meilleure prédiction de résultats de combustion insuffisamment expliqués avec les paramètres classiques. Various models aiming to predict the amount of unburned particles (solids during heavy fuel-oil combustion have been developed. The parameters taken into consideration are generally asphaltenes precipitated by normal heptane or pentane and Conradson carbon as well as the metals content having a known catalytic effect on cenosphere combustion in the combustion chamber. The Exxon and Shell models can be mentioned, which were developed respectively in 1979 and 1981 (Chapter II. Other models also give consideration to the fuel-oil composition, the way it is atomized and diffused in the chamber and the combustion kinetics (research done by the MIT Energy Laboratory published in 1986. However, the above parameters are not the only ones involved. For some fuel oils, experience has shown that the state of dispersion of asphaltenes may also play an important role particularly for combustion installations with mechanical injection for which the dispersion of fuel-oil droplets is not very great and does not affect the structures built

  4. Effects of the asphaltene and resin contents of the bitumens on the water-bitumen interface properties

    Energy Technology Data Exchange (ETDEWEB)

    Jada, A.; Salou, M. [Institut de Chimie des Surfaces et Interfaces, 15 rue Jean Starcky, B.P. 2488, 68057 Mulhouse (France)


    The contact angles between various bitumen solid surfaces and aqueous solutions having pH values equal to 3, 6, 9 and 12 were measured. The objective of this work was to analyse the possible acid-base interactions at the water-bitumen interface for substrates having various asphaltenes and resins contents. In addition, the work of adhesion at a bitumen-water interface, W{sub A}, was calculated from the measured contact angle. This allows us to analyze the surface acidity and basicity of the bitumens. The results obtained indicate that the work of adhesion decreases when the bitumen asphaltenes content increases at any aqueous solution pH value. Further, the variation of the work of adhesion versus the pH for various bitumens shows the presence of acidic, basic and amphoteric groups in the surfaces of these components. The nature and the amount of acidic and basic functionalities present in the bulk bitumen were evaluated by a non-aqueous potentiometric titration method and by comparison with acid-base models compounds. No relationship was found between the acid and base contents of the bulk bitumens and the bitumen surface character determined from the work of adhesion. In order to find any correlation between the adhesion work and the stability of the bitumen aqueous dispersions, zeta potentials of the bitumen droplets dispersed in acidic aqueous solutions were measured. Stable bitumen dispersions having zeta potential values higher than 50 mV and work of adhesion values higher than 55 mJ/m{sup 2} were obtained with bitumens having high values of the resin/asphaltenes ratios. The determination of a surface's acidity and basicity by measuring the contact angles at a water-bitumen interface seems to be a more useful method than the non-aqueous potentiometric titration. Hence, a good correlation is found between the surface charge of the bitumen droplet as measured by zeta potential and the work of adhesion at water-bitumen interface.

  5. Thermogravimetric assessment of thermal degradation in asphaltenes

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    Barneto, Agustín García, E-mail: [Department of Chemical Engineering, Physical Chemistry and Organic Chemistry, University of Huelva, Huelva (Spain); Carmona, José Ariza [Department of Chemical Engineering, Physical Chemistry and Organic Chemistry, University of Huelva, Huelva (Spain); Garrido, María José Franco [CEPSA, RDI Centre, Madrid (Spain)


    Graphical abstract: - Highlights: • Asphaltenes content of visbreaking streams in oil refinery can be measured by using TGA. • Deconvoluting TGA curves allows the thermal-based composition of asphaltenes to be elucidated. • Asphaltenes cracking involves acceleratory stages compatible with autocatalytic kinetic. • Activation energy during asphaltenes pyrolysis increased with increasing temperature. • Activation energy remained almost constant at 200–225 kJ/mol during oxidative cracking. - Abstract: Monitoring asphaltenes is very important with a view to optimizing visbreaking units in oil refineries. Current analyses based on selective dissolution in different solvents are slow, so new, more expeditious methods for measuring asphaltenes are required to facilitate fuel-oil production. In this work, we studied the thermal degradation of asphaltenes as the potential basis for a thermogravimetric method for their monitoring in visbreaking streams. The thermal degradation of asphaltenes occurs largely from 400 to 500 °C; the process is quite smooth in an inert environment but involves several fast mass loss events in the air. Kinetic parameters for characterizing the process were determined by using two model-free methods and the modified Prout–Tompkins kinetic equation to examine asphaltene thermolysis. Both types of methods showed the activation energy to increase during pyrolysis but to remain almost constant during cracking in the presence of oxygen or even diminish during char oxidation. Deconvoluting the thermogravimetric profiles revealed that asphaltene thermolysis in the air cannot be accurately described in terms of an nth order kinetic model because it involves some acceleratory phases. Also, thermogravimetric analyses of visbreaking streams revealed that char production in them is proportional to their asphaltene content. This relationship enables the thermogravimetric measurement of asphaltenes.

  6. Separation of Asphaltenes by Polarity using Liquid-Liquid Extraction

    DEFF Research Database (Denmark)

    Andersen, Simon Ivar


    In order to investigate the nature of petroleum asphaltenes in terms of polarity a process was developed using initial liquid-liquid extraction of the oil phase followed by precipitation of the asphaltenes using n-heptane. The liquid-liquid extraction was performed using toluene-methanol mixtures...... with increasing content of toluene. Although large fractions of the crude oil (Alaska ´93) was extracted in the higher polarity solvents (high concentration of methanol), the asphaltene content of the dissolved material was low. As the toluene content increased more asphaltenes were transferred to the solvent...... of the maltene phase also increase while H/C decreases. The content of heteroatoms in the asphaltenes are relatively higher and apparently increase with the polarity of the solvent. It is concluded that these asphaltenes are indeed dominated by high molecular weight substances that cannot be extracted...

  7. The Critical Micelle Concentration of Asphaltenes as Measured by Calorimetry

    DEFF Research Database (Denmark)

    Andersen, Simon Ivar; Christensen, S. D.


    of asphaltenes obtained by solvent extraction with toluene/heptane mixtures. These subfractions get more complex in structure as the toluene content of the extraction solvent increases and at the same time the CMC of the asphaltenes in pure toluene decreases. There is an indication that the presence of "lower...

  8. Soot content in a gas turbine combustion chamber

    Energy Technology Data Exchange (ETDEWEB)

    Sudarev, A.V.; Antonovsky, V.I. (VTUS - Leningrad Metal Plant - LMZ, Leningrad (USSR))


    The measurement complex within the liner space, including the determination of concentration of soot particles, gaseous products, completeness of fuel combustion, was carried out on the gas turbine combustion model. The soot distribution lengthwise the liner for the investigated class of combustors and the distillate liquid fuel was determined by means of the pressure in the combustion chamber and the air excess ratio in the liner cross-section. The design formulae for determination of the fuel combustion completeness and the soot content by the flame length are recommended.

  9. Raman spectrum of asphaltene

    KAUST Repository

    Abdallah, Wael A.


    Asphaltenes extracted from seven different crude oils representing different geological formations from around the globe were analyzed using the Raman spectroscopic technique. Each spectrum is fitted with four main peaks using the Gaussian function. On the basis of D1 and G bands of the Raman spectrum, asphaltene indicated an ordered structure with the presence of boundary defected edges. The average aromatic sheet size of the asphaltene molecules is estimated within the range of 1.52-1.88 nm, which represents approximately seven to eight aromatic fused rings. This estimation is based on the integrated intensity of D1 and G bands, as proposed by Tunistra and Koenig. The results here are in perfect agreement with so many other used techniques and indicate the potential applicability of Raman measurements to determine the average aromatic ring size and its boundary. © 2012 American Chemical Society.

  10. Structural Study of Asphaltenes from Iranian Heavy Crude Oil

    Directory of Open Access Journals (Sweden)

    Davarpanah L.


    Full Text Available In the present study, asphaltene precipitation from Iranian heavy crude oil (Persian Gulf off-shore was performed using n-pentane (n-C5 and n-heptane (n-C7 as light alkane precipitants. Several analytical techniques, each following different principles, were then used to structurally characterize the precipitated asphaltenes. The yield of asphaltene obtained using n-pentane precipitant was higher than asphaltene precipitated with the use of n-heptane. The asphaltene removal affected the n-C5 and n-C7 maltene fractions at temperatures below 204°C, as shown by the data obtained through the simulated distillation technique. Viscosity of heavy oil is influenced by the asphaltene content and behavior. The viscosity dependence of the test heavy oil on the shear rate applied was determined and the flow was low at y. above 25 s-1 . The reconstituted heavy oil samples were prepared by adding different amounts of asphaltenes to the maltenes (deasphalted heavy oil and asphaltene effects were more pronounced at the low temperature of 25°C as compared with those at the higher temperatures. According to the power law model used in this study the flowability of the test heavy oil exhibited a pseudoplastic character. Structural results obtained from Fourier Transform InfraRed (FTIR spectroscopy showed the presence of the different functional groups in the precipitated asphaltenes. For instance, the presence of different hydrocarbons (aliphatic, aromatic and alicyclic based on their characteristics in the FTIR spectra was confirmed. Resins are effective dispersants, and removal of this fraction from the crude oil is disturbing to the colloidal nature of heavy oil; asphaltene flocculation and precipitation eventually occur. Appearance of pores in the Scanning Electron Microscopy (SEM images was used as an indicator of the resin detachment. With the use of 1H and 13C Nuclear Magnetic Resonance (NMR spectroscopy, two important structural parameters of the

  11. Asphaltene based photovoltaic devices (United States)

    Chianelli, Russell R.; Castillo, Karina; Gupta, Vipin; Qudah, Ali M.; Torres, Brenda; Abujnah, Rajib E.


    Photovoltaic devices and methods of making the same, are disclosed herein. The cell comprises a photovoltaic device that comprises a first electrically conductive layer comprising a photo-sensitized electrode; at least one photoelectrochemical layer comprising metal-oxide particles, an electrolyte solution comprising at least one asphaltene fraction, wherein the metal-oxide particles are optionally dispersed in a surfactant; and a second electrically conductive layer comprising a counter-electrode, wherein the second electrically conductive layer comprises one or more conductive elements comprising carbon, graphite, soot, carbon allotropes or any combinations thereof.

  12. Discussion of the role of asphaltene in heavy crudes and tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Yen, T.F.


    A discussion of the role of asphaltene in heavy crudes and tar sands covers a definition of heavy oil as a dark-colored, high-density, and high-viscosity oil, rich in heteroatom components, such as asphaltics (asphaltenes plus resin), and metallo complexes, such as vanadyl porphyrin; the classification of heavy oil into thermally transformed, biodegraded, and severely cracked oil; the structural parameters of various asphaltenes derived from petroleum, shale, and coal; and the relationship of asphaltene content in heavy oil to the metals and sulfur contents, to upgrading via thermal and hydrocracking processes, to reactivity, to mesophase growth, to enhanced oil recovery, and to weathering, which was shown in one study of an oilspill to increase the asphaltenes and carbene content.

  13. A study of the processes related to coagulation of asphaltenes by electronic spin resonance

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    Tagirzyanov, M.I.; Yakubov, M.R.; Romanov, G.V. [A.E. Arbuzov Inst. of Organic and Physical Chemistry, Russian Academy of Sciences (Russian Federation)


    This study examined the coagulation of asphaltenes in crude oil from the Volga-Ural region in Russia. In particular, it examined the contents of vanadyl complexes and free radicals in crude oils and asphaltenes by electron spin resonance. Asphaltenes fall into two major structural categories based on vanadium content. The interactions between vanadyl complexes and free radicals of the asphaltenes liquid phase were modelled in order to determine if they can form diamagnetic associations. Asphaltenes with low vanadium content (less than 0.1 per cent by weight), have large polyaromatic fragments in the molecules. Therefore, more than half of the free radicals recombine when the asphaltene are separated from the crude oil. Vanadium rich asphaltenes (greater than 0.3 per cent by weight) have polyaromatic fragments in the inner part of the structure. It was concluded that interaction between vanadyl complexes and asphaltene fragments containing free radicals do not result in the formation of diamagnetic associations. 23 refs., 3 tabs., 3 figs.

  14. Charge dependent asphaltene adsorption onto metal substrate : electrochemistry and AFM, STM, SAM, SEM analysis

    Energy Technology Data Exchange (ETDEWEB)

    Batina, N.; Morales-Martinez, J. [Univ. Autonoma Metropolitana-Iztapalapa (Mexico). Lab. de Nanotecnologia e Ingenieria Molecular; Ivar-Andersen, S. [Technical Univ. of Denmark (Denmark). Dept. Hem. Eng; Lira-Galeana, C. [Inst. Mexicano del Petroleo, Lazaro (Mexico). Molecular Simulation Research Program; De la Cruz-Hernandez, W.; Cota-Araiza, L.; Avalos-Borja, M. [Univ. Nacional Autonoma de Mexico (Mexico)


    Asphaltenes have been identified as the main component of pipeline molecular deposits that cause plugging of oil wells. In this study, Atomic Force Microscopy (AFM), Scanning Tunneling Microscopy (STM), Scanning Auger Microprobe Spectroscopy (SAM) and Scanning Electron Microscopy (SEM) were used to characterized molecular deposits of Mexican crude oil and asphaltenes formed at a charged metal surface. The qualitative and quantitative characterization involved determining the size and shape of adsorbed molecules and aggregates, and the elemental analysis of all components in molecular films. Samples were prepared by electrolytic deposition under galvanostatic or potentiostatic conditions directly from the crude oil or asphaltene in toluene solutions. The study showed that the formation of asphaltene deposit depends on the metal substrate charge. Asphaltenes as well as crude oil readily adsorbed at the negatively charged metal surface. Two elements were present, notably carbon and sulfur. Their content ratio varied depending on the metal substrate charge.

  15. An electron spin resonance probe method for the understanding of petroleum asphaltene macrostructure

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    Wong, G.K.; Yen, T.F. [Department of Civil and Environmental Engineering, University of Southern California, 3620 South Vermont Avenue 224A, 90089-2531 Los Angeles, CA (United States)


    Molecularly, petroleum asphaltenes are induced dipoles, which agglomerate into nanometer-sized colloids of different aggregation states. The electron spin resonance (ESR) vanadyl probe method is used to investigate the asphaltene macrostructures under different temperatures and microwave powers. Oxovanadium complexes native to an asphaltene isolated from Boscan crude oil, Venezuela, function as tracers to examine the behavior of micelle agglomerates when subjected to a microwave field. Both mobile and bounded oxovanadium compounds in colloidal asphaltene solution are in a state of equilibrium. It is noted that a greater amount of mobile vanadyl complexes can be stabilized in a dispersing medium (single-aromatic ring solvent series) with a higher-valued Hansen hydrogen bonding solubility parameter. We found that conversion of ESR vanadyl hyperfine lines occurs from anisotropic to isotropic as the temperature of a 4% Boscan asphaltene solution in o-xylene increased from 25C to 100C. Free tumbling of total vanadyl complexes in organic solvent signifies dissociation of micelles at packing imperfections prior to their release from aromatic hosts. Coupling of petroleum asphaltenes with microwave power can overcome charge transfer and charge balance interactions within micelle agglomerates. The relative content of mobile to bounded vanadyl complexes in 4% Boscan asphaltene solution of o-xylene was found to increase with microwave power at 45C. Microwave energy will enable effective dispersion of colloidal asphaltene in heavy oil refining and upgrading.

  16. Oxy-combustion of high water content fuels (United States)

    Yi, Fei

    As the issues of global warming and the energy crisis arouse extensive concern, more and more research is focused on maximizing energy efficiency and capturing CO2 in power generation. To achieve this, in this research, we propose an unconventional concept of combustion - direct combustion of high water content fuels. Due to the high water content in the fuels, they may not burn under air-fired conditions. Therefore, oxy-combustion is applied. Three applications of this concept in power generation are proposed - direct steam generation for the turbine cycle, staged oxy-combustion with zero flue gas recycle, and oxy-combustion in a low speed diesel-type engine. The proposed processes could provide alternative approaches to directly utilize fuels which intrinsically have high water content. A large amount of energy to remove the water, when the fuels are utilized in a conventional approach, is saved. The properties and difficulty in dewatering high water content fuels (e.g. bioethanol, microalgae and fine coal) are summarized. These fuels include both renewable and fossil fuels. In addition, the technique can also allow for low-cost carbon capture due to oxy-combustion. When renewable fuel is utilized, the whole process can be carbon negative. To validate and evaluate this concept, the research focused on the investigation of the flame stability and characteristics for high water content fuels. My study has demonstrated the feasibility of burning fuels that have been heavily diluted with water in a swirl-stabilized burner. Ethanol and 1-propanol were first tested as the fuels and the flame stability maps were obtained. Flame stability, as characterized by the blow-off limit -- the lowest O2 concentration when a flame could exist under a given oxidizer flow rate, was determined as a function of total oxidizer flow rate, fuel concentration and nozzle type. Furthermore, both the gas temperature contour and the overall ethanol concentration in the droplets along the

  17. Sans study of asphaltene aggregation

    Energy Technology Data Exchange (ETDEWEB)

    Overfield, R.E.; Sheu, E.Y.; Sinha, S.K.; Liang, K.S. (Esso Resources Canada Ltd., 339-50 Avenue S.E., Calgary, Alberta T2G 2B3 (CA))


    The colloidal properties of asphaltenes have long been recognized from peculiarities in their solubility and colligative properties. A layered micellar model or asphaltenes was proposed by others in which a highly condensed alkyl aromatic formed the central part, and molecules of decreasingly aromatic character (resins) clustered around them. Numerous studies, based on a variety of techniques such as ultracentrifugation and electron microscopy indicated a particulate nature for asphaltenes with size 20-40 A diameter. Others have proposed a refined model based on x-ray diffraction and small angle scattering. In this model, interactions between flat sheets of condensed aromatic rings form the central ''crystallite'' part of a spherical particle with the outer part being comprised of the aliphatic positions of the same molecules. These particles are bunched together with some degree of entanglement into ''micelles''. Concentration and solvent dependent radii of gyration, ranging from 30-50 A were reported. The aggregation creates a good deal of uncertainty as to the true molecular size or weight of asphaltenes. Neutron scattering offers novel contrast relative to light scattering (refractive index) and x-ray scattering (electron density). This is because the scattering length of proton is negative, whereas that from deuterium and other nuclei such as C, S, O, and N are positive. Thus by replacing hydrogen with deuterium in either the solvent or the scatterer the contrast can be varied, and different parts of the molecule can be highlighted.

  18. Sans study of asphaltene aggregration

    Energy Technology Data Exchange (ETDEWEB)

    Overfield, R.E.; (Esso Resources Canada Ltd., Alberta); Sheu, E.Y.; Sinha, S.K.; Liang, K.S. (Exxon Research and Engineering Co., Annandale, NJ (USA))


    The colloidal properties of asphaltenes have long been recognized from peculiarities in their solubility and colligative properties. A layered micellar model for asphaltenes was proposed by Pfeiffer and Saal in 1940, in which a highly condensed alkyl aromatic formed the central part, and molecules of decreasingly aromatic character (resins) clustered around them. Numerous studies, based on a variety of techniques such as ultracentrifugation and electron microscopy indicated a particulate nature for asphaltenes with size 20-40 {angstrom} diameter. T.F. Yen and co-workers proposed a refined model based on x-ray diffraction and small angle scattering. In this model, interactions between flat sheets of condensed aromatic rings form the central crystallite part of a spherical particle with the outer part being comprised of the aliphatic positions of the same molecules. These particles are bunched together with some degree of entanglement into micelles. Concentration and solvent dependent radii of gyration, ranging from 30-50 {angstrom} were reported. The aggregation creates a good deal of uncertainty as to the true molecular size of weight of asphaltenes. Neutron scattering offers novel contrast relative to light scattering (refractive index) and x-ray scattering (electron density). This is because the scattering length of proton is negative, whereas that from deuterium and other nuclei such as C, S, O, and N are positive. Thus by replacing hydrogen with deuterium in either the solvent or the scatterer the contrast can be varied, and different parts of the molecule can be highlighted.

  19. Ozonation of Canadian Athabasca asphaltene (United States)

    Cha, Zhixiong

    Application of ozonation in the petrochemical industry for heavy hydrocarbon upgrading has not been sufficiently explored. Among heavy hydrocarbons, asphaltenes are the heaviest and the most difficult fractions for analysis and treatment. Therefore, ozonation of asphaltenes presents an interesting application in the petrochemical industry. Commercial application of ozonation in the petrochemical industry has three obstacles: availability of an ozone-resistant and environmentally friendly solvent, the precipitation of ozonation intermediates during reaction, and recovery of the solvent and separation of the ozonation products. Preliminary ozonation of Athabasca oil sands asphaltene in nonparticipating solvents encountered serious precipitation of the ozonation intermediates. The precipitated intermediates could be polymeric ozonides and intermolecular ozonides or polymeric peroxides. Because the inhomogeneous reaction medium caused low ozone efficiency, various participating solvents such as methanol and acetic acid were added to form more soluble hydroperoxides. The mass balance results showed that on average, one asphaltene molecule reacted with 12 ozone molecules through the electrophilic reaction and the subsequent decomposition of ozonation intermediates generated acetone extractable products. GC/MS analysis of these compounds indicated that the free radical reactions could be important for generation of volatile products. The extensively ozonated asphaltene in the presence of participating solvents were refluxed with methanol to generate more volatile products. GC/MS analysis of the methanol-esterified ozonation products indicated that most volatile products were aliphatic carboxylic acid esters generated through cleavage of substituents. Reaction kinetics study showed that asphaltene ozonation was initially a diffusion rate-controlled reaction and later developed to a chemical reaction rate-controlled reaction after depletion of the reactive aromatic sites

  20. Molecular thermodynamics for prevention of asphaltene precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jianzhong; Prausnitz, J.M.


    Crude petroleum is a complex mixture of compounds with different chemical structures and molecular weights. Asphaltenes, the heaviest and most polar fraction of crude oil, are insoluble in normal alkanes such as n-heptane, but they are soluble in aromatic solvents such as toluene. The molecular nature of asphaltenes and their role in production and processing of crude oils have been the topic of numerous studies. Under some conditions, asphaltenes precipitate from a petroleum fluid, causing severe problems in production and transportation Our research objective is to develop a theoretically based, but engineering-oriented, molecular-thermodynamic model which can describe the phase behavior of asphaltene precipitation in petroleum fluids, to provide guidance for petroleum-engineering design and production. In this progress report, particular attention is given to the potential of mean force between asphaltene molecules in a medium of asphaltene-free solvent. This potential of mean force is derived using the principles of colloid science. It depends on the properties of asphaltene and those of the solvent as well as on temperature and pressure. The effect of a solvent on interactions between asphaltenes is taken into account through its density and through its molecular dispersion properties.

  1. A stochastic method for asphaltene structure formulation from experimental data: avoidance of implausible structures. (United States)

    De León, Jennifer; Velásquez, Ana M; Hoyos, Bibian A


    This work presents a stochastic procedure designed to formulate a discrete set of molecular structures that, as a whole, adjust properly to experimental asphaltene data. This algorithm incorporates the pentane effect concept and Clar's sextet rule to the formulation process. The set of viable structures was constructed based on probability distribution functions obtained from experimental information and an isomer database containing all plausible configurations for a given number of rings, avoiding high-energy structures. This procedure was applied to a collection of experimental data from the literature. Ten sets, consisting of 5000 structures each, were obtained. Each set was then optimized. For the most accurate representation, four molecules were sufficient to properly reproduce the experimental input. The asphaltene system obtained is consistent with the reported molecular weight, number of aromatic rings and heteroatom content. Molecular dynamic simulations showed that the asphaltene representation adequately reproduced asphaltene aggregation behavior in toluene and n-heptane. In toluene, a single three-molecule aggregate was observed, and the majority of asphaltene molecules remained in a monomeric state. In n-heptane, aggregates containing up to four molecules were observed; both porous and compact aggregates were found. The asphaltene molecular representation obtained, which allows researchers to avoid inappropriate torsions in the molecule, is able to reproduce interplanar distances between aromatic cores of 4 Å or less for the aggregation state, as supported by experimental results.

  2. On the Mass Balance of Asphaltene Precipitation

    DEFF Research Database (Denmark)

    Andersen, Simon Ivar; Lira-Galeana, C.; Stenby, Erling Halfdan


    In the evaluation of experimental data as well as in calculation of phase equilibria the necessity of the application of mass balances is obvious. In the case of asphaltenes the colloidal nature of these compounds may highly affect the mass balance. In the present paper several experiments...... are performed in order to check the consistency of mass balances within asphaltene precipitation. Asphaltenes are precipitated in two step processes either by changing temperature or by changes in precipitant with increasing precipitation power. This has been performed for three different oils. The data...... indicates that in temperature experiments as well as in solvent series experiments the precipitation of heavy asphaltenes affects the following precipitation of lighter asphaltenes. In both cases the mass balance using standard separation techniques cannot be closed, as less material is precipitated...

  3. Modeling of asphaltene and wax precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, F.; Sarathi, P.; Jones, R.


    This research project was designed to focus on the development of a predictive technique for organic deposition during gas injection for petroleum EOR. A thermodynamic model has been developed to describe the effects of temperature, pressure, and composition on asphaltene precipitation. The proposed model combines regular solution theory with Flory-Huggins polymer solutions theory to predict maximum volume fractions of asphaltene dissolved in oil. The model requires evaluation of vapor-liquid equilibria, first using an equation of state followed by calculations of asphaltene solubility in the liquid-phase. A state-of-the-art technique for C{sub 7+} fraction characterization was employed in developing this model. The preliminary model developed in this work was able to predict qualitatively the trends of the effects of temperature, pressure, and composition. Since the mechanism of paraffinic wax deposition is different from that of asphaltene deposition, another thermodynamic model based on the solid-liquid solution theory was developed to predict the wax formation. This model is simple and can predict the wax appearance temperature with reasonable accuracy. Accompanying the modeling work, experimental studies were conducted to investigate the solubility of asphaltene in oil land solvents and to examine the effects of oil composition, CO{sub 2}, and solvent on asphaltene precipitation and its properties. This research focused on the solubility reversibility of asphaltene in oil and the precipitation caused by CO{sub 2} injection at simulated reservoir temperature and pressure conditions. These experiments have provided many observations about the properties of asphaltenes for further improvement of the model, but more detailed information about the properties of asphaltenes in solution is needed for the development of more reliable asphaltene characterization techniques. 50 refs., 8 figs., 7 tabs.

  4. Asphaltenes as new objects for nanoelectronics (United States)

    Dolomatov, M. Yu; Petrov, A. M.; Bakhtizin, R. Z.; Dolomatova, M. M.; Khairudinov, I. R.; Shutkova, S. A.; Kovaleva, E. A.; Paymurzina, N. Kh


    Abstract. Modern carbon nanomaterials (carbon nanotubes, graphenes, fullerenes, polycyclic molecules) are products of rather complicated technologies. Therefore development of new not expensive materials on the basis of natural substances, in particular high-molecular compounds of oil - asphaltenes, is actual for nanoelectronics. Asphaltenes are complex materials that are found in crude oil, bitumen and high-boiling hydrocarbons distillates. Usually asphaltenes are composed mainly of polyaromatic carbon with a small amount of vanadium and nickel, which are in porphyrin structures. Molecules of asphaltenes may contain 5-10-member benzene and naphthenic rings in their structure and also have paramagnetic centers. A variety of techniques: electronic phenomenological spectroscopy (EPS), atomic force microscopy (AFM) and quantum chemistry calculations were used to define the structure of oil asphaltenes. It was supposed that asphaltene fraction is a strong donor (ionization potential 4.10-6.70 eV) and an acceptor (electron affinity 1.80-2.50 eV). The structures of asphaltenes fragments were calculated by RHF-6-31G** methods. AFM images of asphaltenes obtained from crude oil showed the presence of structure fragments ranged from 3 to 10 nm, disposed to strong intermolecular interactions. We used doped compounds for formation of wide band gap amorphous semiconductors from a concentrates of asphaltens. Changes of conductivity in dispersed petroleum systems (DPS) were studied during a pyrolysis at 500 K. The numerous experiments defined of conductivity testify about phase transitions dielectric - semiconductor in DPS for range of 360 - 400 K. The main conclusion is paramagnetic phase of asphaltenes is organic amorphous wide band gap semiconductor. Besides this substance can be consider as an organic spin glasses.

  5. Separation and characterization of asphaltenic subfractions

    Energy Technology Data Exchange (ETDEWEB)

    Honse, Siller O.; Ferreira, Silas R.; Mansur, Claudia R. E.; Lucas, Elizabete F. [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano; Gonzalez, Gaspar, E-mail: [Centro de Pesquisas da PETROBRAS (CENPES), Rio de Janeiro, RJ (Brazil)


    The structure of the various asphaltenic subfractions found in crude oil was evaluated. For this purpose, C5 asphaltenes were extracted from an asphaltic residue using n-pentane as the flocculant solvent. The different subfractions were isolated from the C5 asphaltenes by the difference in solubility in different solvents. These were characterized by infrared spectroscopy, nuclear magnetic resonance, X-ray fluorescence, elementary analysis and mass spectrometry. The results confirmed that the subfractions extracted with higher alkanes had greater aromaticity and molar mass. However, small solubility variations between the subfractions were attributed mainly to the variation in the concentrations of cyclical hydrocarbon compounds and metals (author)

  6. Metaphysics, science and the asphaltene phase behavior problem

    Energy Technology Data Exchange (ETDEWEB)

    Lockhart, T.P. [Eniricerche SpA, Milanese (Italy)


    Spontaneous phase separation and deposition of the asphaltenic component of crude oils is the source of costly problems in the petroleum industry. Over the past several decades so-called {open_quotes}colloid stabilization{close_quotes} model has dominated attempts to account for the phase behavior of the asphaltene fraction of the crude oil. We will argue that this model is not {open_quotes}scientific{close_quotes} in the sense that is has been applied only for the post-hoc rationalization of experimental results; absent have been serious attempts to experimentally test specific predictions deduced from the model. A critical examination of the colloid stabilization model brings to light several fundamental shortcomings. An alternative thermodynamic, or {open_quotes}solvation{close_quotes} model is shown to make predictions in far better agreement with experiment, and has been the key to developing an analytical model that accurately predicts the conditions under which crude oils become unstable to asphaltene deposition. This example will be used to argue that the defining elements of (good) scientific research - the formulation of explicit hypotheses of high predictive content and their critical evaluation, above all by experimental attempts at falsification - are also effective, indeed necessary, for analyzing the complex problems offered by the {open_quotes}real{close_quotes} world and for achieving technological advancement.

  7. Interactions between Asphaltenes and Water in Solutions in Toluene

    DEFF Research Database (Denmark)

    Khvostichenko, Daria; Andersen, Simon Ivar


    Binding of water by asphaltenes dissolved in toluene was investigated for two asphaltene samples, OMV1 and OMV2, from the same reservoir deposit. Solubility of water in asphaltene solutions in toluene was found to increase with an increasing asphaltene concentration, indicative of solubilization...... of water by asphaltenes. Fourier transform infrared (FTIR) spectroscopy of stretching modes of OH groups in the region of 3800-3100 cm(-1) was used to obtain insight into the state of water in water-unsaturated asphaltene solutions in toluene. The number of water molecules bound to one asphaltene molecule...... was determined for water-saturated solutions (OMV1 and OMV2) and for water-unsaturated solutions (OMV1 only). These numbers were found to decrease from several water molecules per asphaltene molecule to below unity upon an increase of the asphaltene concentration in toluene from 0.1 to 20 g/L, suggesting...

  8. Relationship between ecotoxicity and PAH content in coal combustion waste samples

    Energy Technology Data Exchange (ETDEWEB)

    Mastral, A.M.; Callen, M.S.; Garcia, T.; Lopez, J.M.; Maranon, E. [Inst. Carboquim, Zaragoza (Spain)


    Three different series of combustion samples (from the ash pan, samples C; from the particulate matter trapped on cyclone, samples PM; and from the finest particulate matter, samples M) have been analyzed looking for any relationship between their PAH content and their ecotoxicity. PAH content was analyzed by synchronous fluorescence spectroscopy. Ecotoxicity of the combustion samples was determined by using the Photobacterium phosphoreum test to assess their toxicity through an ecotoxicity assay. Results obtained are shown and discussed in relation to the PAH content of the samples.

  9. Effect of H2 and CO contents in syngas during combustion using Micro Gas Turbine (United States)

    Othman, N. F.; Boosroh, M. H.


    Synthetic gas or syngas is produced from the gasification process. Its main compositions are hydrogen, H2; carbon monoxide, CO; methane, CH4; carbon dioxide, CO2 and nitrogen, N2. Syngas is a substitute for the depleting natural gas (80-90%.vol. CH4). Natural gas is combusted in gas turbine in gas-fired power plant to produce electricity. However, combustion of syngas using gas turbine is expected to show different behavior compared to natural gas combustion. This is because of H2 and CO contents in syngas have higher adiabatic flame temperature than CH4. In this study, different quality of syngas with different contents of H2 (0.6-0.8 %.vol.) and CO (1-3 %.vol.) were combusted using 30kW Micro Gas Turbine (MGT). Performances of different syngas quality were studied using NOx, CO, CO2 emissions and combustion efficiency parameters. NOx and CO are the main pollutants from the combustion process. NOx emissions were the highest for syngas with H2 contents of 0.8 %.vol. and CO contents of 3 %.vol. CO emissions were in the range of 220-310 ppm for all the tested syngas. While, CO2 emissions were in the range of 0.96-1.06 % for all the tested syngas. Combustion efficiencies were reduced for syngas with CO contents of 1 %.vol. and H2 contents of 0.6-0.8 %.vol. This is most probably due to the dilution effect of N2 in syngas.

  10. Combustion

    CERN Document Server

    Glassman, Irvin


    Combustion, Second Edition focuses on the underlying principles of combustion and covers topics ranging from chemical thermodynamics and flame temperatures to chemical kinetics, detonation, ignition, and oxidation characteristics of fuels. Diffusion flames, flame phenomena in premixed combustible gases, and combustion of nonvolatile fuels are also discussed. This book consists of nine chapters and begins by introducing the reader to heats of reaction and formation, free energy and the equilibrium constants, and flame temperature calculations. The next chapter explores the rates of reactio

  11. Asphaltenes-based polymer nano-composites (United States)

    Bowen, III, Daniel E


    Inventive composite materials are provided. The composite is preferably a nano-composite, and comprises an asphaltene, or a mixture of asphaltenes, blended with a polymer. The polymer can be any polymer in need of altered properties, including those selected from the group consisting of epoxies, acrylics, urethanes, silicones, cyanoacrylates, vulcanized rubber, phenol-formaldehyde, melamine-formaldehyde, urea-formaldehyde, imides, esters, cyanate esters, allyl resins.

  12. Examining Asphaltene Solubility on Deposition in Model Porous Media


    Lin, Yu-Jiun; He, Peng; Tavakkoli, Mohammad; Mathew, Nevin Thunduvila; Yap, Yit-Fatt; Chai, John; Goharzadeh, Ashfin; Vargas, F. M.; Biswal, S.L.


    Asphaltenes are known to cause severe flow\\ud assurance problems in the near-wellbore region of oil reservoirs. Understanding the mechanism of asphaltene deposition in porous media is of great significance for the development of accurate numerical simulators and effective chemical remediation treatments. Here, we present a study of the dynamics of asphaltene deposition in porous media using microfluidic devices. A model oil containing 5 wt % dissolved asphaltenes was mixed with n-heptane, a k...

  13. Investigating Asphaltenes Composition in Crude Oil Samples using ...

    African Journals Online (AJOL)

    This research was carried out to investigate the percentage composition of asphaltenes by Iatroscan analysis using Thin Layer Chromatography-Flame Ion Detection method (Iatroscan TLC-FID) The percentage composition of asphaltenes by Iatroscan TLC-FID method was compared with the weight% of asphaltenes ...

  14. Compositional thermodynamic model of asphaltenes flocculation out of crudes; Modelisation thermodynamique compositionnelle de la floculation des bruts asphalteniques

    Energy Technology Data Exchange (ETDEWEB)

    Szewczyk, V.


    The aim of this work is to propose to the oil industry a compositional thermodynamic model able to predict the operating conditions which induce asphaltenes flocculation out of crudes. In this study, various analytical methods (calorimetry, elemental analysis, {sup 13}C nuclear magnetic resonance, neutron diffusion,...) have been used in order to get a better description of the asphaltene fraction to infer its flocculation mechanism. The proposed model describes this flocculation as a thermodynamic transition inducing the formation of a new liquid phase with a high asphaltene content and formed by all the components initially in the crude: the asphaltene deposit. Asphaltenes are represented as a pseudo-component essentially made of carbon and hydrogen. The analytical modelling of the F11-F20 light fraction is the one proposed by Jaubert (1993). The F20+ heavy fraction is represented by four pseudo-components, their physical properties are calculated using the group contribution methods of Avaullee (1995) and of Rogalski and Neau (1990). The Peng-Robinson equation of state (1976) combined with the Abdoul and Peneloux group contribution mixing rules (1989) is used in order to restitute the gas-liquid-asphaltene deposit phase equilibria. This model not being able to compute flocculation conditions on a predictive manner, the method consists in fitting some physical properties of the pseudo-components introduced in the analytical representation of the asphaltene crudes. he obtained results show results show that the proposed flocculation model is then well adapted to the description of the thermodynamic properties (saturation pressures, relative volumes, flocculation curves) of asphaltene crudes within a relatively large range of temperature (30-150 deg C) and pressure (0.1-50 MPa), covering the majority of conditions met in oil production. (author) 109 refs.

  15. Investigation of Asphaltene Precipitation at Elevated Temperature

    DEFF Research Database (Denmark)

    Andersen, Simon Ivar; Lindeloff, Niels; Stenby, Erling Halfdan


    In order to obtain quantitative data on the asphaltene precipitation induced by the addition of n-alkane (heptane) at temperatures above the normal boiling point of the precipitant, a high temperature/high pressure filtration apparatus has been constructed. Oil and alkane are mixed at the appropr......In order to obtain quantitative data on the asphaltene precipitation induced by the addition of n-alkane (heptane) at temperatures above the normal boiling point of the precipitant, a high temperature/high pressure filtration apparatus has been constructed. Oil and alkane are mixed...... in the extracted fraction, hence there is no room for stirring. The equipment as well as solutions to some of the problems are presented along with precipitation data from 40 to 200 degrees C. The asphaltenes separated are analyzed using FT-ir. The filtrate containing the maltenes was cooled to room temperature...

  16. Analysis of metals in asphaltenes of KU-46 by PIXE analysis; Analisis de metales en asfaltenos de crudo mexicano KU-46 por PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Navidad G, P.; Pina L, L.I.; Lopez M, J.; Ramirez T, J.J.; Aspiazu F, J.A.; Romero G, E.T. [Gerencia de Ciencias Basicas, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)


    The content of metals of the asphaltenes obtained from the KU-46 mexican crude with n-heptane was evaluated. The found metals in higher concentration are transition metals as well as the vanadium, nickel, copper and zinc. Moreover the sulfur in high concentrations was quantified. The metallic content of the asphaltenes revealed that the crude contains a lower quantity of metals unlike the vacuum residue previously analysed. (Author)

  17. Decrease of noxious emissions in the residual fuel oil combustion; Disminucion de emisiones nocivas en la combustion de aceite combustible residual

    Energy Technology Data Exchange (ETDEWEB)

    Mandoki W, Jorge [Econergia S. de R. L. de C. V. Mexico, D. F. (Mexico)


    The residual fuel oil combustion emits noxious substances such as carbonaceous particulate, nitrogen oxides, and sulfur trioxide at unacceptable levels. Water emulsified in the fuel substantially reduces such emissions, achieving besides, in most of the cases, a net saving in the fuel consumption. The beneficial effects are shown in burning the residual fuel oil as a water emulsion, as well as the method to produce an adequate emulsion. The emulsified fuel technology offers a low cost option to reduce air pollution. The fuel oil quality has been declining during the last decades due to: 1. Increase in the production of crude heavy oils, generally with higher content of asphaltens and sulfur. 2. Less availability of vacuum distillation residues due to its conversion into greater value products. 3. More intensive conversion processes such as catalytic cracking, visbreaking, etc. that increase the asphaltenes concentration in the bottoms, causing instability problems. 4. The increase in the vanadium and other metals content as the concentration of asphaltenes increases. The use of emulsified fuel oil provides an efficient and economical method to substantially reduce the noxious emissions to the atmosphere. The emulsion contains water particles in a diameter between 2 and 20 microns, uniformly distributed in the fuel oil, generally in a proportion generally of 5 to 10%; besides, it contains a tensioactive agent to assure a stable emulsion capable of withstanding the shearing forces of the pumping and distribution systems. When the atomized oil drops get into the combustion chamber, the emulsified water flashes into high pressure steam, originating a violent secondary atomization. The effect of this secondary atomization is the rupture of the oil drops of various hundred microns, producing drops of 5 to 15 microns in diameter. Since the necessary time for combustion is an exponential function of the drop diameter, a very substantial improvement in the combustion is

  18. Colloidal interactions between asphaltene surfaces in aqueous solutions. (United States)

    Liu, Jianjun; Zhang, Liyan; Xu, Zhenghe; Masliyah, Jacob


    Asphaltene at oil/water interfaces plays a dominant role in the recovery of crude oil. In this study, asphaltene monolayer films were deposited on hydrophobic silicon wafers and silica spheres from oil-water interfaces using a Langmuir interfacial trough. The morphology of the deposited asphaltene films was characterized with an atomic force microscope (AFM). The colloidal forces between the prepared asphaltene films in aqueous solutions were measured with AFM to shed light on the stabilization of water or oil droplets coated with asphaltene films. Factors such as solution pH, KCl concentration, calcium addition, and temperature all showed a strong impact on colloidal forces between the prepared asphaltene films. The findings provided a better understanding of asphaltene interfacial films at an oil/water interface in stabilizing bitumen-in-water and water-in-bitumen emulsions.

  19. Applied Gaussian Process in Optimizing Unburned Carbon Content in Fly Ash for Boiler Combustion

    Directory of Open Access Journals (Sweden)

    Chunlin Wang


    Full Text Available Recently, Gaussian Process (GP has attracted generous attention from industry. This article focuses on the application of coal fired boiler combustion and uses GP to design a strategy for reducing Unburned Carbon Content in Fly Ash (UCC-FA which is the most important indicator of boiler combustion efficiency. With getting rid of the complicated physical mechanisms, building a data-driven model as GP is an effective way for the proposed issue. Firstly, GP is used to model the relationship between the UCC-FA and boiler combustion operation parameters. The hyperparameters of GP model are optimized via Genetic Algorithm (GA. Then, served as the objective of another GA framework, the predicted UCC-FA from GP model is utilized in searching the optimal operation plan for the boiler combustion. Based on 670 sets of real data from a high capacity tangentially fired boiler, two GP models with 21 and 13 inputs, respectively, are developed. In the experimental results, the model with 21 inputs provides better prediction performance than that of the other. Choosing the results from 21-input model, the UCC-FA decreases from 2.7% to 1.7% via optimizing some of the operational parameters, which is a reasonable achievement for the boiler combustion.

  20. Direct Observation of Asphaltene Nanoparticles on Model Mineral Substrates. (United States)

    Raj, Gijo; Lesimple, Alain; Whelan, Jamie; Naumov, Panče


    The propensity for adherence to solid surfaces of asphaltenes, a complex solubility class of heteropolycyclic aromatic compounds from the heavy fraction of crude oil, has long been the root cause of scale deposition and remains an intractable problem in the petroleum industry. Although the adhesion is essential to understanding the process of asphaltene deposition, the relationship between the conformation of asphaltene molecules on mineral substrates and its impact on adhesion and mechanical properties of the deposits is not completely understood. To rationalize the primary processes in the process of organic scale deposition, here we use atomic force microscopy (AFM) to visualize the morphology of petroleum asphaltenes deposited on model mineral substrates. High imaging contrast was achieved by the differential adhesion of the tip between asphaltenes and the mineral substrate. While asphaltenes form smooth continuous films on all substrates at higher concentrations, they deposit as individual nanoparticles at lower concentrations. The size, shape, and spatial distribution of the nanoaggregates are strongly affected by the nature of the substrate; while uniformly distributed spherical particles are formed on highly polar and hydrophilic substrates (mica), irregular islands and thicker patches are observed with substrates of lower polarity (silica and calcite). Asphaltene nanoparticles flatten when adsorbed on highly oriented pyrolytic graphite due to π-π interactions with the polycyclic core. Force-distance profiles provide direct evidence of the conformational changes of asphaltene molecules on hydrophilic/hydrophobic substrates that result in dramatic changes in adhesion and mechanical properties of asphaltene deposits. Such an understanding of the nature of adhesion and mechanical properties tuned by surface properties, on the level of asphaltene nanoaggregates, would contribute to the design of efficient asphaltene inhibitors for preventing asphaltene

  1. Asphaltene precipitates in oil production wells

    DEFF Research Database (Denmark)

    Kleinitz, W,; Andersen, Simon Ivar


    At the beginning of production in a southern German oil field, flow blockage was observed during file initial stage of production from the oil wells. The hindrance was caused by the precipitation of asphaltenes in the proximity of the borehole and in the tubings. The precipitates were of solid...

  2. Isolation of Asphaltene-Degrading Bacteria from Sludge Oil

    Directory of Open Access Journals (Sweden)

    Pingkan Aditiawati


    Full Text Available Sludge oil contains 30%–50% hydrocarbon fractions that comprise saturated fractions, aromatics, resins, and asphaltene. Asphaltene fraction is the most persistent fraction. In this research, the indigenous bacteria that can degrade asphaltene fractions from a sludge oil sample from Balikpapan that was isolated using BHMS medium (Bushnell-Hass Mineral Salt with 0.01% (w/v yeast extract, 2% (w/v asphaltene extract, and 2% (w/v sludge oil. The ability of the four isolates to degrade asphaltene fractions was conducted by the biodegradation asphaltene fractions test using liquid cultures in a BHMS medium with 0.01% (w/v yeast extract and 2% (w/v asphaltene extract as a carbon source. The parameters measured during the process of biodegradation of asphaltene fractions include the quantification of Total Petroleum Hydrocarbon (g, log total number of bacteria (CFU/ml, and pH. There are four bacteria (isolates 1, 2, 3, and 4 that have been characterized to degrade asphaltic fraction and have been identified as Bacillus sp. Lysinibacillus fusiformes, Acinetobacter sp., and Mycobacterium sp., respectively. The results showed that the highest ability to degrade asphaltene fractions is that of Bacillus sp. (isolate 1 and Lysinibacillus fusiformes (Isolate 2, with biodegradation percentages of asphaltene fractions being 50% and 55%, respectively, and growth rate at the exponential phase is 7.17x107 CFU/mL.days and 4.21x107 CFU/mL.days, respectively.

  3. Simultaneous removal of asphaltenes and water from water-in-bitumen emulsion. II. Application feasibility

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yingxian; Wei, Feng [Ningbo Institute of Technology, Zhejiang University, Ningbo, Zhejiang 315100 (China)


    Application feasibility of the accelerated deasphaltening process for simultaneous removal of asphaltenes and water from a water-in-bitumen emulsion has been examined with a pilot plant having capacity of 1.590 m3/day. The solvent (n-pentane) was injected into the emulsion from three locations with progressively increasing temperature from 423 K. The first solvent injection precipitated the asphaltenes in bitumen, the second broke the emulsion and facilitated the phase separation, and the third extracted the oil that remained in heavy asphaltenes/water phase. The effects of operation parameters such as temperature, solvent/bitumen ratio, feed rate and feedstock composition on the quality of DAO (Deasphaltening oil) were investigated. The DAO with the yield of {proportional_to} 80 wt.% and asphaltene content of < 0.5 wt.% was produced under optimal operating conditions, and the residual product was a porous solids containing 38% sulfur, 47% nitrogen, 64% MCR, and 85% metals (nickel and vanadium) of the bitumen. For a real application in oil industry, other important aspects including energy efficiency, solvent recovery and water purification have been discussed. (author)

  4. Characterisation of crude oil components, asphaltene aggregation and emulsion stability by means of near infrared spectroscopy and multivariate analysis

    Energy Technology Data Exchange (ETDEWEB)

    Aske, Narve


    Effective separation of water-in-crude oil emulsions is a central challenge for the oil industry on the Norwegian Continental Shelf, especially with the future increase in subsea and even down-hole processing of well fluids. The mechanisms and properties governing emulsion stability are far from fully understood but the indigenous surface active crude oil components are believed to play a major role. In this work a thorough physico-chemical characterisation of a set of crude oils originating from a variety of production fields has been performed. Crude oil properties responsible for emulsion stability were identified by use of multivariate analysis techniques like partial least squares regression (PLS) and principal component analysis (PCA). Interfacial elasticity along with both asphaltene content and asphaltene aggregation state were found to be main contributors to emulsion stability. Information on a crude oils ability to form elastic crude oil-water interfaces was found to be especially crucial when discussing emulsion stability. However, measured values of interfacial elasticity were highly dependent on asphaltene aggregation state. Several experimental techniques was utilised and partly developed for the crude oil characterisation. A high-pressure liquid chromatography (HPLC) scheme was developed for SARA-fractionation of crude oils and an oscillating pendant drop tensiometer was used for characterisation of interfacial rheological properties. For emulsion stability a cell for determining the stability as a function of applied electric fields was used. In addition, near infrared spectroscopy (NIR) was used throughout the work both for chemical and physical characterisation of crude oils and model systems. High pressure NIR was used to study the aggregation of asphaltenes by pressure depletion. A new technique for detection of asphaltene aggregation onset pressures based on NIR combined with PCA was developed. It was also found that asphaltene aggregation is

  5. Examining Asphaltene Solubility on Deposition in Model Porous Media. (United States)

    Lin, Yu-Jiun; He, Peng; Tavakkoli, Mohammad; Mathew, Nevin Thunduvila; Fatt, Yap Yit; Chai, John C; Goharzadeh, Afshin; Vargas, Francisco M; Biswal, Sibani Lisa


    Asphaltenes are known to cause severe flow assurance problems in the near-wellbore region of oil reservoirs. Understanding the mechanism of asphaltene deposition in porous media is of great significance for the development of accurate numerical simulators and effective chemical remediation treatments. Here, we present a study of the dynamics of asphaltene deposition in porous media using microfluidic devices. A model oil containing 5 wt % dissolved asphaltenes was mixed with n-heptane, a known asphaltene precipitant, and flowed through a representative porous media microfluidic chip. Asphaltene deposition was recorded and analyzed as a function of solubility, which was directly correlated to particle size and Péclet number. In particular, pore-scale visualization and velocity profiles, as well as three stages of deposition, were identified and examined to determine the important convection-diffusion effects on deposition.

  6. Effect of asphaltenes on crude oil wax crystallization

    DEFF Research Database (Denmark)

    Kriz, Pavel; Andersen, Simon Ivar


    The paper summarizes the experimental work done on asphaltene influenced wax crystallization. Three different asphaltenes (from stable oil, instable oil, and deposit) were mixed at several concentrations or dispersions into the waxy crude oil. These blends were evaluated by viscometry and yield...... stress measurement and compared with the original crude oil. A complex asphaltene−wax interaction as a function of asphaltene concentration and degree of asphaltene dispersion under dynamic and static condition was observed. The crystallization and the wax network strength was strongly dependent...... influence the wax crystallization at static condition more significantly than the more flocculated....

  7. Robust, Reliable Low Emission Gas Turbine Combustion of High Hydrogen Content Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Wooldridge, Margaret Stacy [Univ. of Michigan, Ann Arbor, MI (United States); Im, Hong Geum [Univ. of Michigan, Ann Arbor, MI (United States)


    The effects of high hydrogen content fuels were studied using experimental, computational and theoretical approaches to understand the effects of mixture and state conditions on the ignition behavior of the fuels. A rapid compression facility (RCF) was used to measure the ignition delay time of hydrogen and carbon monoxide mixtures. The data were combined with results of previous studies to develop ignition regime criteria. Analytical theory and direct numerical simulation were used to validate and interpret the RCF ignition data. Based on the integrated information the ignition regime criteria were extended to non-dimensional metrics which enable application of the results to practical gas turbine combustion systems.

  8. Effect of fuel zinc content on toxicological responses of particulate matter from pellet combustion in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Uski, O., E-mail: [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); National Institute for Health and Welfare, Department of Environmental Health, P.O. Box 95, FI-70701 Kuopio (Finland); Jalava, P.I., E-mail: [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Happo, M.S., E-mail: [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Torvela, T., E-mail: [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Leskinen, J., E-mail: [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Mäki-Paakkanen, J., E-mail: [National Institute for Health and Welfare, Department of Environmental Health, P.O. Box 95, FI-70701 Kuopio (Finland); Tissari, J., E-mail: [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Sippula, O., E-mail: [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Lamberg, H., E-mail: [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Jokiniemi, J., E-mail: [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Espoo (Finland); and others


    Significant amounts of transition metals such as zinc, cadmium and copper can become enriched in the fine particle fraction during biomass combustion with Zn being one of the most abundant transition metals in wood combustion. These metals may have an important role in the toxicological properties of particulate matter (PM). Indeed, many epidemiological studies have found associations between mortality and PM Zn content. The role of Zn toxicity on combustion PM was investigated. Pellets enriched with 170, 480 and 2300 mg Zn/kg of fuel were manufactured. Emission samples were generated using a pellet boiler and the four types of PM samples; native, Zn-low, Zn-medium and Zn-high were collected with an impactor from diluted flue gas. The RAW 264.7 macrophage cell line was exposed for 24 h to different doses (15, 50,150 and 300 μg ml{sup −1}) of the emission samples to investigate their ability to cause cytotoxicity, to generate reactive oxygen species (ROS), to altering the cell cycle and to trigger genotoxicity as well as to promote inflammation. Zn enriched pellets combusted in a pellet boiler produced emission PM containing ZnO. Even the Zn-low sample caused extensive cell cycle arrest and there was massive cell death of RAW 264.7 macrophages at the two highest PM doses. Moreover, only the Zn-enriched emission samples induced a dose dependent ROS response in the exposed cells. Inflammatory responses were at a low level but macrophage inflammatory protein 2 reached a statistically significant level after exposure of RAW 264.7 macrophages to ZnO containing emission particles. ZnO content of the samples was associated with significant toxicity in almost all measured endpoints. Thus, ZnO may be a key component producing toxicological responses in the PM emissions from efficient wood combustion. Zn as well as the other transition metals, may contribute a significant amount to the ROS responses evoked by ambient PM. - Highlights: • Zinc powder was added into the

  9. Combustion characteristics of Athabasca froth treatment tailings in a simulated fluidilized bed

    Energy Technology Data Exchange (ETDEWEB)

    Esmaeili, P.; Ghosh, M.; Speirs, B. C. [Imperial Oil Resources (Canada); Leon, M. A.; Rao, S.; Dutta, A.; Basu, P. [Greenfield Research Inc. (Canada)


    In surface-mined oil sands, a stream of water, asphaltenes, solids and residual bitumen/solvent, known as PFT tailings, is created during the bitumen production process. The aim of this study was to investigate the use of this PFT tailings stream as a fuel source for combustion in a fluidized bed for energy recovery. To do so, physical and fluidization characteristics of the fuel as well as combustion kinetics were assessed through laboratory analysis. In addition, the fuel's combustion characteristics were investigated through experiments in a quartz wool matrix tubular reactor and theoretical calculations at various moisture contents. Results showed that this fuel can be burned in a fluidized bed with a reactivity comparable to that of coal samples. This research found that PFT tailings could be used to generate energy during disposal but further work will have to be undertaken in a hot CFB combustor to confirm this.

  10. Study on the polarity, solubility, and stacking characteristics of asphaltenes

    KAUST Repository

    Zhang, Long-li


    The structure and transformation of fused aromatic ring system in asphaltenes play an important role in the character of asphaltenes, and in step affect the properties of heavy oils. Polarity, solubility and structural characteristics of asphaltenes derived from Tahe atmospheric residue (THAR) and Tuo-826 heavy crude oil (Tuo-826) were analyzed for study of their internal relationship. A fractionation method was used to separate the asphaltenes into four sub-fractions, based on their solubility in the mixed solvent, for the study of different structural and physical-chemical properties, such as polarity, solubility, morphology, stacking characteristics, and mean structural parameters. Transmission electron microscope (TEM) observation can present the intuitive morphology of asphaltene molecules, and shows that the structure of asphaltenes is in local order as well as long range disorder. The analysis results showed that n-heptane asphaltenes of THAR and Tuo-826 had larger dipole moment values, larger fused aromatic ring systems, larger mean number of stacking layers, and less interlayer spacing between stacking layers than the corresponding n-pentane asphaltenes. The sub-fractions that were inclined to precipitate from the mixture of n-heptane and tetrahydrofuran had larger polarity and less solubility. From the first sub-fraction to the fourth sub-fraction, polarity, mean stacking numbers, and average layer size from the TEM images follow a gradual decrease. The structural parameters derived from TEM images could reflect the largest fused aromatic ring system in asphaltene molecule, yet the parameters derived from 1H NMR data reflected the mean message of poly-aromatic ring systems. The structural parameters derived from TEM images were more consistent with the polarity variation of sub-fractions than those derived from 1H NMR data, which indicates that the largest fused aromatic ring system will play a more important role in the stacking characteristics of

  11. An Evaluation of the Delayed-Coking Product Yield of Heavy Feedstocks Using Asphaltene Content and Carbon Residue Évaluation du rendement en produit de cokéfaction différée de pétrole lourd à l'aide de la teneur an asphaltènes et du résidu de coke

    Directory of Open Access Journals (Sweden)

    Schabron J. F.


    Full Text Available Six residua from different crude oils were evaluated for composition and carbon residue forming tendencies. The whole residua were evaluated for elemental composition, trace metals content, carbon residue, and specific gravity. Each residuum was deasphaltened in heptane, and the heptane-soluble materials were separated into saturate, aromatic, and polar fractions on activated silica gel. The asphaltenes were evaluated for elemental composition, trace metals content, molecular weight, and carbon residue. The relationship between carbon residues and features of the asphaltenes was studied, and a correlation of contributing features was developed. The asphaltenes were further separated into four fractions according to apparent molecular size by preparative size exclusion chromatography (SEC. The preparative size exclusion chromatographic fractions from the asphaltenes were evaluated for sulfur content, molecular weight, and trace metals content. Material balances showed that the data obtained on the fractions account for the data obtained on the original material. This indicates that the contributions of the properties of the fractions can be studied and related to properties of the whole material. La composition et le résidu de coke de six résidus de raffinage de différents pétroles lourds ont été évalués afin de déterminer des tendances. La composition élémentaire, la teneur en métaux-traces, le résidu de coke et la densité spécifique ont été déterminés sur le résidu complet. Chaque résidu a été désasphalténé dans l'heptane et les produits solubles dans l'heptane ont été séparés en fractions saturée, aromatique et polaire sur du gel de silice activée. La composition élémentaire, la teneur en métaux-traces, la masse moléculaire et le résidu de coke ont été déterminés sur les asphaltènes. La relation entre les résidus de coke et les caractéristiques des asphaltènes a été étudiée, ce qui a permis d

  12. Role of asphaltenes in stabilizing thin liquid emulsion films. (United States)

    Tchoukov, Plamen; Yang, Fan; Xu, Zhenghe; Dabros, Tadeusz; Czarnecki, Jan; Sjöblom, Johan


    Drainage kinetics, thickness, and stability of water-in-oil thin liquid emulsion films obtained from asphaltenes, heavy oil (bitumen), and deasphalted heavy oil (maltenes) diluted in toluene are studied. The results show that asphaltenes stabilize thin organic liquid films at much lower concentrations than maltenes and bitumen. The drainage of thin organic liquid films containing asphaltenes is significantly slower than the drainage of the films containing maltenes and bitumen. The films stabilized by asphaltenes are much thicker (40-90 nm) than those stabilized by maltenes (∼10 nm). Such significant variation in the film properties points to different stabilization mechanisms of thin organic liquid films. Apparent aging effects, including gradual increase of film thickness, rigidity of oil/water interface, and formation of submicrometer size aggregates, were observed for thin organic liquid films containing asphaltenes. No aging effects were observed for films containing maltenes and bitumen in toluene. The increasing stability and lower drainage dynamics of asphaltene-containing thin liquid films are attributed to specific ability of asphaltenes to self-assemble and form 3D network in the film. The characteristic length of stable films is well beyond the size of single asphaltene molecules, nanoaggregates, or even clusters of nanoaggregates reported in the literature. Buildup of such 3D structure modifies the rheological properties of the liquid film to be non-Newtonian with yield stress (gel like). Formation of such network structure appears to be responsible for the slower drainage of thin asphaltenes in toluene liquid films. The yield stress of liquid film as small as ∼10(-2) Pa is sufficient to stop the drainage before the film reaches the critical thickness at which film rupture occurs.

  13. A theory of phase separation in asphaltene-micellar solutions

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco Sanchez, Juan H. [Instituto Mexicano del Petroleo, Mexico D.F. (Mexico)


    A theory of phase separation in micellar solutions of asphaltene in aromatic hydrocarbons was reported in this paper, based on both the approach of the phase behavior of amphiphile/water micelles, and the self-association of asphaltene in aromatic core. Several experimental techniques have been used by different investigators showing the existence of some kind of critical micellar concentration (CMC) on asphaltenes in aromatic solutions. So, at least asphaltene-monomer and asphaltene-micellar phases are experimentally demonstrated facts. These two phases are the main purpose in this report on a theoretical model. Some results show the temperature versus asphaltene concentration phase diagram. The phase diagram is examined against the limited critical micelle concentration data for asphaltenes-in-toluene systems. Such phase diagram is also qualitatively examined against an experimental demonstration of phase separation. The asphaltene-micelle growth depends on the parameter K responsible for the shape and size of it. At the same time, parameter K depends on both the number of asphaltene-monomer associated in the asphaltene-micelle, and the chemical potentials in the interior and in the periphery of the micelle. An expression for getting the number of asphaltene-monomers self-associated in the asphaltene-micelle was obtained. [Spanish] Se reporta una teoria de separacion de fases en soluciones micelares de asfalteno en hidrocarburos aromaticos, basada tanto en la conducta de fase de micelas formadas por anififilos en agua como en la autoasociacion de asfaltenos en nucleos aromaticos. Se han usado diversas tecnicas experimentales por diferentes investigadores que demuestran la existancia de algun tipo de concentracion micelar critica (CMC) de soluciones de asfaltenos en aromaticos. Entonces, al menos las fases de asfalteno-monomerico y de asfalteno-micelar son hechos experimentalmente demostrados. Esta dos fases son el principal proposito de este reporte en un modelo

  14. Analysis of Asphaltenes Subfractionated by N-Methyl-2-pyrrolidone

    DEFF Research Database (Denmark)

    Ascanius, Birgit Elkjær; Garcia, Daniel Merino; Andersen, Simon Ivar


    When petroleum asphaltenes are analyzed using size exclusion chromatography (SEC), it is desirable to use a mobile phase that allows elevated temperatures and suppresses effects that are not related to size. Recent developments in the analysis of tars and pitch have tried to use N-methyl-2......-pyrrolidone (NMP) as a mobile phase. However, an NMP-insoluble asphaltene fraction of 9-53 wt % was observed for different petroleum n-heptane asphaltenes. Further analysis of the insoluble fraction surprisingly has shown that this fraction hardly exhibits any ultraviolet-visible light absorption...

  15. Extraction and characterization of crude oil asphaltenes sub fractions; Extracao e caracterizacao de subfracoes de asfaltenos de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Silas R.; Calado, Lucas S.; Honse, Siller O.; Mansur, Claudia R.E.; Lucas, Elizabete F., E-mail: [Universidade Federal do Rio de Janeiro, Instituto de Macromoleculas, Laboratorio de Macromoleculas e Coloides na Industria de Petroleo, Rio de Janeiro, RJ (Brazil)


    Asphaltenes from crude oil have been studied for a long time. However, until today their chemical structures and physical-chemical properties are not well established. Nowadays, it is accepted that asphaltenes are dispersed in the crude oil as macro structures, which are mainly constituted of some condensed aromatic rings (about 6-20), containing aliphatic or naphthenic groups. The asphaltenes are also defined as the crude oil fraction that is insoluble in low molar mass n-alkanes and soluble in aromatic solvents, like benzene and toluene In order to investigate the molecular structure, in this work the asphaltenes were separated by using a different procedure as that normally described in the literature and characterized by infrared spectrometry, nuclear magnetic resonance, x-ray fluorescence, elemental analyses and particle size and size distribution. The difference in subfractions polarity can be attributed not only to the aromaticity changes but also to the content of elements, such as N, O, Fe, V, Si e Ni. (author)

  16. Effects of Oxygen Content of Fuels on Combustion and Emissions of Diesel Engines

    Directory of Open Access Journals (Sweden)

    Haiwen Song


    Full Text Available Effects of oxygen content of fuels on combustion characteristics and emissions were investigated on both an optical single cylinder direct injection (DI diesel engine and a multi-cylinder engine. Three fuels were derived from conventional diesel fuel (Finnish City diesel summer grade by blending Rapeseed Methyl Ester (RME or Diglyme and Butyl-Diglyme of different quantities to make their oxygen content 3%, 3% and 9%, respectively. The experimental results with three tested fuels show that the fuel spray development was not affected apparently by the oxygenating. Compared with the base fuel, the ignition delay to pilot injection was shortened by 0%, 11% and 19% for three oxygenated fuels, respectively. The ignition delay to main injection was shortened by 10%, 19% and 38%, respectively. With regard to emissions, the smoke level was reduced by 24% to 90%, depending on fuel properties and engine running conditions. The penalties of increased NOx emissions and fuel consumption were up to 19% and 24%, respectively.

  17. Characterization of moisture and water content on ignition and combustion of hypergolic propellants (United States)

    Zarbo, Nicholas D.

    Triethylamine borane (TEAB) and white fuming nitric acid (WFNA) is a promising hypergolic propellant combination being studied as an alternative to monomethylhydrazine (MMH) and red fuming nitric acid (RFNA) or dinitrogen tetroxide (NTO). Nitric acid and MMH are both known to be hygroscopic and their performance is affected by their water content. However, the effect of water on TEAB is yet to be determined. The goal of this research is to characterize the major consequences of water presence on the ignition and combustion performance of TEAB and to compare those results to MMH. To determine the effect of hygroscopic absorption, TEAB samples were put through accelerated aging in humid and dry environments. Along with the aged TEAB, neat TEAB and neat MMH were used in drop on pool tests with WFNA. The drop tests were conducted by controlling the relative humidity in air to either below 24% or above 94% and the water concentration in WFNA to either 0% or 10% by weight. Using the Hypertester, ignition and combustion events were recorded using a photodiode, a microphone, a high speed camera, and a UV streak camera spectrometer. A drop chamber was used to determine the time of gas production onset from the liquid phase reactions. Along with the dry and humid air environments, tests were done in a nitrogen environment in the drop chamber. MMH and RFNA drop tests in a nitrogen environment were completed to replicate the results of Forness. Statistical analysis is applied to the data to determine significant parameters and trends. While relative humidity does not appear to affect the combustion of TEAB with WFNA, water concentration in the oxidizer significantly weakens it. Relative humidity improves MMH ignition delay time and water concentration shows no effect. Water concentration in the oxidizer more than doubles the liquid induction time of both TEAB and MMH with WFNA. The ambient environment does not play a significant role in the onset time of gas production. Both

  18. The distribution of polycyclic aromatic hydrocarbons in asphaltenes

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Morales, Y. [Inst. Mexicano del Petroleo, Lazaro (Mexico). Programa de Ingenieria Molecular; Ballard Andrews, A.; Mullins, O.C. [Schlumberger-Doll Research Center, Cambridge, MA (United States)


    The distribution of polycyclic aromatic hydrocarbons (PAHs) in asphaltenes is a strong determinant for asphaltene physical properties. PAHs also provide the UV and visible absorption and emission profiles of asphaltenes. All PAHs absorb light in the UV-visible spectrum and many also emit light in this spectral range. This study combined a molecular orbital theory with an experimental approach to quantitatively link the UV-visible absorption and emission profiles to the asphaltene PAH distribution. Key features of the absorption and emission spectral data were found to be reproduced with PAH distributions centered at 7 fused rings. The study also identified other highly different distributions of PAHs in terms of plausibility to account for the measured optical data. The paper also described the affect that heteroatoms had on the analysis.

  19. Round Robin Tests to Determine Fiber Content of Carbon Fiber-Reinforced Thermoplastic Composites by Combustion and Thermogravimetry

    Directory of Open Access Journals (Sweden)

    Masahiro Funabashi


    Full Text Available To propose methods to determine the fiber content of carbon fiber-reinforced plastics (CFRP for the International Organization for Standardization, the fiber contents of CFRP with polyamide-6 were measured using a combustion method based on ISO 14127 and a thermogravimetry method based on the modified ISO 9924-3 under a round robin test managed by the Polymer Subcommittee of the Industrial Technology Cooperative Promotion Committee in Japan. In the combustion method, the fiber contents of the CFRTP (~0.3 g were determined by the mass of carbon fiber remaining after burning (ISO 14127. The fiber contents in weight of the CFRTP with 8, 9, or 10 plies were determined to be 55.720%, 61.088%, or 65.326%, respectively, by 17 research institutes. In the thermogravimetry method, the fiber contents of the CFRTP (~10 mg were determined by the mass of carbon fiber remaining after heating it to 600°C in nitrogen gas using thermogravimetry apparatus (modified ISO 9924-3. The fiber contents of the CFRTP with 8, 9, or 10 plies were determined to be 56.908%, 61.579%, or 64.819%, respectively, by 8 research institutes. It was confirmed that thermogravimetry method was as accurate as the combustion method based on ISO 14127.

  20. Asphaltene laboratory assessment of a heavy onshore reservoir during pressure, temperature and composition variations to predict asphaltene onset pressure

    Energy Technology Data Exchange (ETDEWEB)

    Bahrami, Peyman; Ahmadi, Yaser [Islamic Azad University, Tehran (Iran, Islamic Republic of); Kharrat, Riyaz [Petroleum University of Technology, Tehran (Iran, Islamic Republic of); Mahdavi, Sedigheh; James, Lesley [Memorial University of Newfoundland, Saint John' s (Canada)


    An Iranian heavy oil reservoir recently encountered challenges in oil production rate, and further investigation has proven that asphaltene precipitation was the root cause of this problem. In addition, CO{sub 2} gas injection could be an appropriate remedy to enhance the production of heavy crudes. In this study, high pressure-high temperature asphaltene precipitation experiments were performed at different temperatures and pressures to investigate the asphaltene phase behavior during the natural depletion process and CO{sub 2} gas injection. Compositional modeling of experimental data predicted onset points at different temperatures which determine the zone of maximum probability of asphaltene precipitation for the studied heavy oil reservoir. Also, the effect of CO{sub 2} gas injection was investigated as a function of CO{sub 2} concentration and pressure. It was found that a CO{sub 2}-oil ratio of 40% is the optimum for limiting precipitation to have the least formation damage and surface instrument contamination.

  1. The relationship between mineral contents, particle matter and bottom ash distribution during pellet combustion: molar balance and chemometric analysis. (United States)

    Jeguirim, Mejdi; Kraiem, Nesrine; Lajili, Marzouk; Guizani, Chamseddine; Zorpas, Antonis; Leva, Yann; Michelin, Laure; Josien, Ludovic; Limousy, Lionel


    This paper aims to identify the correlation between the mineral contents in agropellets and particle matter and bottom ash characteristics during combustion in domestic boilers. Four agrifood residues with higher mineral contents, namely grape marc (GM), tomato waste (TW), exhausted olive mill solid waste (EOMSW) and olive mill wastewater (OMWW), were selected. Then, seven different pellets were produced from pure residues or their mixture and blending with sawdust. The physico-chemical properties of the produced pellets were analysed using different analytical techniques, and a particular attention was paid to their mineral contents. Combustion tests were performed in 12-kW domestic boiler. The particle matter (PM) emission was characterised through the particle number and mass quantification for different particle size. The bottom ash composition and size distribution were also characterised. Molar balance and chemometric analyses were performed to identify the correlation between the mineral contents and PM and bottom ash characteristics. The performed analyses indicate that K, Na, S and Cl are released partially or completely during combustion tests. In contrast, Ca, Mg, Si, P, Al, Fe and Mn are retained in the bottom ash. The chemometric analyses indicate that, in addition to the operating conditions and the pellet ash contents, K and Si concentrations have a significant effect on the PM emissions as well as on the agglomeration of bottom ash.

  2. Effect of Simulated High Hydrogen Content Combustion Environments on Abradable Properties of Ceramic Turbine Coatings (United States)

    Basu Majumder, Madhura

    Air plasma sprayed (APS) abradable coatings are used in the turbine hot section to reduce the stator-rotor gap, minimizing gas leakage. These coatings are designed to exhibit controlled removal of material in thin layers when the turbine blades sweep through the coating, which protects the mechanical integrity of the turbine blade. In an effort to lower CO2 emissions, high H2 content fuel is being explored. This change in chemical composition of the fuel may affect the microstructure, abradability and durability of the coatings at turbine operational temperatures. The presence of high water vapor in the combustion chamber leads to accelerated degradation of the sacrificial coating materials. In this work, zirconia based composite materials with a machinable phase and varied porosity have been used to study microstructural evolution, thermal and chemical stability of the phases and abradable characteristics of baseline coating systems in both humid and dry environments. Investigation of the mechanisms that control the removal of materials and performance of abradable coatings through thermo-mechanical tests will be discussed.

  3. Reducing the nicotine content of combusted tobacco products sold in New Zealand. (United States)

    Donny, Eric C; Walker, Natalie; Hatsukami, Dorothy; Bullen, Chris


    Large reductions in nicotine content could dramatically reduce reinforcement from and dependence on cigarettes. In this article, we summarise the potential benefits of reducing nicotine in combusted tobacco and address some of the common concerns. We focus specifically on New Zealand because it may be ideally situated to implement such a policy. The available data suggest that, in current smokers, very low nicotine content (VLNC) cigarettes decrease nicotine exposure, decrease cigarette dependence, reduce the number of cigarettes smoked per day and increase the likelihood of contemplating, making and succeeding at a quit attempt. New smokers would almost certainly be exposed to far less nicotine as a result of smoking VLNC cigarettes and, consequently, would probably be less likely to become chronic, dependent, smokers. Many of the concerns about reducing nicotine including compensatory smoking, an exacerbation of psychiatric symptoms, the perception that VLNC cigarettes are less harmful, and the potential for a black market are either not supported by the available data, likely mitigated by other factors including the availability of nicotine-containing e-cigarettes, or unlikely to offset the potential benefit to public health. Although not all concerns have been addressed or can be a priori, the magnitude of the potential benefits and the growing evidence of relatively few potential harms should make nicotine reduction one of the centrepieces for discussion of how to rapidly advance tobacco control. Policies that aim to render the most toxic tobacco products less addictive could help New Zealand attain their goal of becoming smokefree by 2025. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to

  4. Estimating the Energy Content of Wastewater Using Combustion Calorimetry and Different Drying Processes

    Directory of Open Access Journals (Sweden)

    Benjamin Korth


    Full Text Available The energy content of wastewater is routinely assessed by chemical oxygen demand (COD measurements that only provide an incomplete picture and the data fundament of other energy parameters remains scarce. The volumetric heat of combustion (ΔCH of raw wastewater from a municipal wastewater treatment plant (WWTP was assessed using oven drying method (ΔCHvol = −6.8 ± 4.3 kJ L−1, n = 20 and freeze drying method (ΔCHvol = −20.2 ± 9.7 kJ L−1, n = 6 illustrating the substantial loss during the oven drying approach. Normalizing ΔCH to COD of raw wastewater yielded −6.2 ± 3.5 kJ gCOD−1 for oven-dried samples (n = 14 and −13.0 ± 1.6 kJ gCOD−1 for freeze-dried samples (n = 3. A subsequent correlation analysis with further chemical wastewater parameters revealed a dependency of ΔCHvol on COD, total organic carbon (TOC, C:N ratio, and total sulfur content. To verify these correlations, wastewater of a second WWTP was sampled and analyzed. Only COD and TOC were in accordance with the data set from the first WWTP representing potential predictors for the chemical energy stored in wastewater for comparable WWTPs. Unfortunately, during the most practical method (oven drying, a certain loss of volatile compounds is inevitable so that the derived ΔCHvol systematically underestimates the total energetic potential of wastewater. Nevertheless, this work expands the, so far, little data fundament on the energy resource wastewater and implies the requirement for further long-term studies on different sites and different wastewater types with a highly standardized sample treatment protocol.

  5. Effects of the asphaltene structure and the tetralin/heptane solvent ratio on the size and shape of asphaltene aggregates. (United States)

    Lee, Hwankyu; Lee, Yong-Kul


    Asphaltene molecules, which consist of differently hydrogenated polyaromatic cores grafted with side alkyl chains of different sizes and grafting densities, were simulated with a solvent mixture of heptane and tetralin using coarse-grained force fields. Starting with the initial configuration of randomly distributed asphaltene molecules and solvents, the asphaltene molecules aggregate because of the attractive force between their polyaromatic cores, but their sizes and shapes differ. The average aggregate size decreases with an increase in the hydrogenated polycyclic core, side-chain length, and tetralin concentration, which agree with experimental observations in the hydrocracking process. The number of side chains also influences the aggregate size but only in the presence of tetralin. In particular, the effect of tetralin addition occurs more significantly for asphaltene molecules with more side chains because side chains sterically block the intermolecular interactions between polyaromatic cores, which makes it easier for the aromatic ring of tetralin to bind to the polyaromatic core of asphaltene. These steric effects of side chains yield different shapes of aggregates, showing parallel stacking (face-to-face) for aromatic cores with many side chains, and T-shape (edge-to-face) or offset-parallel stacking for those with fewer side chains. These findings agree with the experimental observation regarding the effect of tetralin on the solubility of asphaltene, and indicate that the extent of the tetralin effect depends on the number of side alkyl chains, implying that tetralin solvents need to be added with consideration for the structural change of asphaltene under hydrogenation or dealkylation conditions.

  6. Dioxin emissions from coal combustion in domestic stove: Formation in the chimney and coal chlorine content influence

    Directory of Open Access Journals (Sweden)

    Paradiz Bostjan


    Full Text Available Combustion experiments conducted in domestic stove burning hard coal demonstrated a predominant influence of the coal chlorine content on the PCDD/F emissions, together with a pronounced effect of the flue gas temperature. PCDD/F concentrations of over 100 ng TEQ/m3, three orders of magnitude higher than in a modern waste incinerator, were measured in the flue gases of a domestic stove when combusting high chlorine coal (0.31 %. The PCDD/F concentrations in the flue gases dropped below 0,5 ng TEQ/m3, when low chlorine coal (0.07 % was used. When low chlorine coal was impregnated with NaCl to obtain 0.38 % chlorine content, the emission of the PCDD/Fs increased by two orders of magnitude. Pronounced nonlinearity of the PCDD/F concentrations related to chlorine content in the coal was observed. The combustion of the high chlorine coal yielded PCDD/F concentrations in flue gases one order of magnitude lower in a fan cooled chimney when compared to an insulated one, thus indicating formation in the chimney. The influence of flue gas temperature on the PCDD/F emissions was less pronounced when burning low chlorine coal. The predominant pathway of the PCDD/F emissions is via flue gases, 99 % of the TEQ in the case of the high chlorine coal for insulated chimney.

  7. Waxes in asphaltenes of crude oils and wax deposits

    Directory of Open Access Journals (Sweden)

    Yulia M. Ganeeva


    Full Text Available Abstract Composition and molecular mass distribution of n-alkanes in asphaltenes of crude oils of different ages and in wax deposits formed in the borehole equipment were studied. In asphaltenes, n-alkanes from C12 to C60 were detected. The high molecular weight paraffins in asphaltenes would form a crystalline phase with a melting point of 80–90 °C. The peculiarities of the redistribution of high molecular paraffin hydrocarbons between oil and the corresponding wax deposit were detected. In the oils, the high molecular weight paraffinic hydrocarbons C50–C60 were found, which were not practically detected in the corresponding wax deposits.

  8. Methods for estimating properties of hydrocarbons comprising asphaltenes based on their solubility (United States)

    Schabron, John F.; Rovani, Jr., Joseph F.


    Disclosed herein is a method of estimating a property of a hydrocarbon comprising the steps of: preparing a liquid sample of a hydrocarbon, the hydrocarbon having asphaltene fractions therein; precipitating at least some of the asphaltenes of a hydrocarbon from the liquid sample with one or more precipitants in a chromatographic column; dissolving at least two of the different asphaltene fractions from the precipitated asphaltenes during a successive dissolution protocol; eluting the at least two different dissolved asphaltene fractions from the chromatographic column; monitoring the amount of the fractions eluted from the chromatographic column; using detected signals to calculate a percentage of a peak area for a first of the asphaltene fractions and a peak area for a second of the asphaltene fractions relative to the total peak areas, to determine a parameter that relates to the property of the hydrocarbon; and estimating the property of the hydrocarbon.

  9. Enhanced Oil Recovery (EOR by Miscible CO2 and Water Flooding of Asphaltenic and Non-Asphaltenic Oils

    Directory of Open Access Journals (Sweden)

    Edwin A. Chukwudeme


    Full Text Available An EOR study has been performed applying miscible CO2 flooding and compared with that for water flooding. Three different oils are used, reference oil (n-decane, model oil (n-C10, SA, toluene and 0.35 wt % asphaltene and crude oil (10 wt % asphaltene obtained from the Middle East. Stearic acid (SA is added representing a natural surfactant in oil. For the non-asphaltenic oil, miscible CO2 flooding is shown to be more favourable than that by water. However, it is interesting to see that for first years after the start of the injection (< 3 years it is shown that there is almost no difference between the recovered oils by water and CO2, after which (> 3 years oil recovery by gas injection showed a significant increase. This may be due to the enhanced performance at the increased reservoir pressure during the first period. Maximum oil recovery is shown by miscible CO2 flooding of asphaltenic oil at combined temperatures and pressures of 50 °C/90 bar and 70 °C/120 bar (no significant difference between the two cases, about 1% compared to 80 °C/140 bar. This may support the positive influence of the high combined temperatures and pressures for the miscible CO2 flooding; however beyond a certain limit the oil recovery declined due to increased asphaltene deposition. Another interesting finding in this work is that for single phase oil, an almost linear relationship is observed between the pressure drop and the asphaltene deposition regardless of the flowing fluid pressure.

  10. Pyrolysis of petroleum asphaltenes from different geological origins ...

    Indian Academy of Sciences (India)

    Asphaltenes separated from two different crude oils from upper Assam, India, having different geological origins, viz. DK(eocene) and JN (oligocene–miocene) were pyrolysed at 600 °C and the products were analysed by gas chromatography–mass spectrometry (GC/MS) especially for the generated alkylnaphthalenes and ...

  11. A Thermodynamic Mixed-Solid Asphaltene Precipitation Model

    DEFF Research Database (Denmark)

    Lindeloff, Niels; Heidemann, R.A.; Andersen, Simon Ivar


    A simple model for the prediction of asphaltene precipitation is proposed. The model is based on an equation of state and uses standard thermodynamics, thus assuming that the precipitation phenomenon is a reversible process. The solid phase is treated as an ideal multicomponent mixture. An activity...

  12. Permeability reduction by asphaltenes and resins deposition in porous media

    Energy Technology Data Exchange (ETDEWEB)

    R. Hamadou; M. Khodja; M. Kartout; A. Jada [Sonatrach/Division Centre de Recherche et Developpement, Boumerdes (Algeria)


    The deposition of crude oil polar fractions such as asphaltenes and resins in oil reservoir rocks reduce considerably the rock permeability and the oil production. In the present work, a crude oil and various core samples were extracted from Rhourd-Nouss (RN) reservoir rock. Afterwards, core flow experiments were carried out in the laboratory to investigate permeability reduction that causes formation damage. The core permeability damage was evaluated by flooding Soltrol, through the sample and measuring the solvent permeabilities, K{sub I} and K{sub f}, respectively, before and after injection of a given pore volume number of the crude oil. The data indicate that upon flooding the crude oil through the porous medium, considerable permeability reduction, expressed as the ratio (K{sub I} - K{sub f})/K{sub I}, and ranging from 72.4% to 98.3% were observed. The permeability reduction is found to result from irreversible retention of asphaltenes and resins in the porous core sample. However, no correlations could be established between the depth of the well, the core porosity, the core mineral compositions determined by X-ray analysis, and the permeability damage factors. In addition, effluents flowing away from RN wells were collected and analysed at various periods, after carrying out aromatic solvents squeezes. The amount of saturates, aromatics, resins, and asphaltenes (SARA analysis), of the crude oil, the deposited crude oil fraction, and the effluent's residues were measured and compared. The asphaltenes weight percent was found to increase from 1.56% for the crude oil to 11.42% for the deposited oil fraction, and was in the range 1.37-2.36% for the effluent's residues. Such results indicate that the deposited oil fraction and the effluent's residues consist mainly of asphaltenes and resins. 26 refs., 1 fig., 11 tabs.

  13. Role of resins, asphaltenes and aromatics on water-oil emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Jones, C.; Sermon, P.A.; Skidmore, P.G.; Collins, I.R. [Surrey Univ., Sunbury (United Kingdom). Dept. of Chemistry


    Following primary and secondary oil recovery, the remaining oil within the reservoir can be trapped by capillary forces within a network of rock pores. Tertiary oil recovery can then be based upon carbon dioxide flooding, alkaline flooding, steam injection and chemical flooding-with polymers or surfactants. However, surfactants can only be useful if they are soluble in the aqueous phase at reservoir temperature, salinity and pH. Surfactants are only modestly adsorbed on the reservoir rock and are responsible for oil-water emulsions, phase equilibria, surface tensions and viscosities. Maximum additional oil-phase displacement can be achieved when the correct surfactant blend is selected. This presentation included a table demonstrating the composition of middle phase emulsions formed with brine. GC-HPLC, phase equilibria, conductivity, optical microscopy and atomic force microscopy were used to determine how the asphaltene-resinous-aromatic content of crude oils affect the ease of formation of water-oil emulsions. The study showed that the ratio of water to oil in the emulsions formed depends on the proportion of asphaltenes and resins in the oil. This information can be used to ensure that the ratio reaches a plateau in production, thus optimizing oil production.

  14. Hindered diffusion of asphaltenes at elevated temperature and pressure. [Semi-annual report], September 20, 1995--March 20, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Guin, J.A.


    In this study equilibrium adsorption isotherms were determined for two petroleum asphaltenes, AAD-1 and AAK-1, and one coal asphaltene, called No. 97500. Isotherms were determined for three different temperatures, namely 20, 35 and 50{degrees}C. The experimental data for the petroleum asphaltenes were fitted with a Freundlich isotherm. For the coal asphaltene a Freundlich isotherm was used to fit the experimental data for lower concentrations; however, for higher concentrations a linear isotherm fitted the experimental data better. The coal asphaltene showed a tendency to form multilayers on the catalyst surface. Upon comparison of the adsorption isotherms for the three different temperatures, an interesting effect was observed. Although a decrease of the asphaltenes adsorption for higher temperatures was expected, the adsorption as a function of the temperature in fact showed a maximum for the petroleum asphaltenes and a minimum for the coal asphaltenes. This interesting and unexpected behavior was speculated to be due to the formation of micelles in the coal asphaltene solution and the different dependence of micelle formation and adsorption on temperature. Comparing the adsorption isotherms for the three different asphaltenes revealed that the adsorption of the coal asphaltenes was initially lower than the adsorption of the petroleum asphaltenes, but increased more rapidly, finally becoming near and even greater than the adsorption of the petroleum asphaltenes. This was suggested to be due to the tendency of coal asphaltenes for multilayer adsorption on the solid surface.

  15. Comparison between asphaltenes fractions extracted from different asphaltic residue; Comparacao de fracoes de asfaltenos obtidas a partir de residuos asfalticos distintos

    Energy Technology Data Exchange (ETDEWEB)

    Barreira, Fabio R.; Lucas, Elizabete F., E-mail: [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Ferreira, Silas R. [Clariant S/A, Rio de Janeiro, RJ (brazil)


    Asphaltenes are blamed for various problems in the petroleum industry, especially formation of solid deposits and stabilization of water-in-oil emulsions. Due to the diversity and complexity of these structures, there is still much to be investigated in terms of characterization and stability. In this study, asphaltene subfractions were extracted from an asphaltic residue (AR02), characterized by nuclear magnetic resonance (NMR), elemental analysis (CHN), X-ray fluorescence and time-of-flight mass spectrometry (MS-TOF), and compared to previous results obtained for another asphaltic residue. The precipitation onset of (sub)fractions was assessed by optical microscopy. The results obtained indicate there are more differences than similarities between the asphaltene fractions obtained from the asphaltic residues of distinct origins, with respect to aromaticity, elemental composition (CHN), presence and content of hetero elements and average molar mass. On the matter of stability, it seems that small differences in molecules polarity provoke great differences on phase behavior of every isolated asphaltenes fractions. (author)

  16. Determination of F-, Cl-, Br- and S-contents after combustion-disclosure. Fluor-, Chlor-, Brom- und Schwefel-Gehaltsbestimmung nach Verbrennungsaufschluss

    Energy Technology Data Exchange (ETDEWEB)

    Albrich, H. (GIU GmbH, Teningen (Germany)); Mueller, M. (GIU GmbH, Teningen (Germany)); Pinhack, H. (IKA-Analysentechnik, Heitersheim (Germany))


    The presentation demonstrates a method to gain efficient parallel determination of F-, Cl-, Br- and S-contents in combustible material including the determination of the calorific heat of combustion. The principle of the analysis is based on the complete oxidation of the organic sample matrix by combustion in a calorimetric container after applying with an oxygen pressure of 30 bar. Organic halides and sulfur compounds are thereby converted into the corresponding halides and/or SO[sub 3]. After all combustion products are transferred into an aqueous absorption media, the halide and sulfate contents are evaluated by ionchromatography. The procedure is to be completed within 20-30 minutes and can be reproduced easily. The detection limit of the single elements lies under 0.01 weight-%. (orig.)

  17. Modeling and Scaling of the Viscosity of Suspensions of Asphaltene Nanoaggregates

    Directory of Open Access Journals (Sweden)

    Rajinder Pal


    Full Text Available The scaling and modeling of the viscosity of suspensions of asphaltene nanoaggregates is carried out successfully taking into consideration the solvation and clustering of nanoaggragates, and the jamming of the suspension at the glass transition volume fraction of asphaltene nanoaggregates. The nanoaggregates of asphaltenes are modeled as solvated disk-shaped “core–shell” particles taking into account the most recent small-angle neutron scattering (SANS, small-angle X-ray scattering (SAXS, and solid-state 1H NMR studies available on the size and structure of asphaltene nanoaggregates. This work is an extension of our earlier studies on modeling of asphaltene suspensions where solvation of asphaltene nanoaggregates was not considered. A new mathematical model is developed for estimating the aspect ratio (ratio of thickness to diameter of particle and the corresponding intrinsic viscosity of suspension of solvated disk-shaped asphaltene nanoaggregates using the experimental relative viscosity data of suspensions at low asphaltene concentrations. The solvation of asphaltene nanoaggregates is found to be significant. The intrinsic viscosity increases with the increase in the degree of solvation of nanoaggregates. At high concentrations of asphaltenes, clustering of solvated nanoaggregates dominates resulting in large viscosities. A new scaling law is discovered to scale the viscosity data of different asphaltene suspensions. According to the new scaling law, a unique correlation is obtained, independent of the type of asphaltene system, when the data are plotted as ( η r − 1 / [ η ] S versus ϕ S where η r is the relative viscosity of suspension, [ η ] S is the intrinsic viscosity of suspension of solvated nanoaggregates, and ϕ S is the volume fraction of solvated nanoaggregates. Twenty sets of experimental viscosity data on asphaltene suspensions gathered from different sources are used to verify and confirm the scaling law and the

  18. Method for determining asphaltene stability of a hydrocarbon-containing material (United States)

    Schabron, John F; Rovani, Jr., Joseph F


    A method for determining asphaltene stability in a hydrocarbon-containing material having solvated asphaltenes therein is disclosed. In at least one embodiment, it involves the steps of: (a) precipitating an amount of the asphaltenes from a liquid sample of the hydrocarbon-containing material with an alkane mobile phase solvent in a column; (b) dissolving a first amount and a second amount of the precipitated asphaltenes by changing the alkane mobile phase solvent to a final mobile phase solvent having a solubility parameter that is higher than the alkane mobile phase solvent; (c) monitoring the concentration of eluted fractions from the column; (d) creating a solubility profile of the dissolved asphaltenes in the hydrocarbon-containing material; and (e) determining one or more asphaltene stability parameters of the hydrocarbon-containing material.

  19. Impact of fluidized bed combustion waste on metal content of crops and soil

    Energy Technology Data Exchange (ETDEWEB)

    Mays, D.A.; Giordano, P.M.; Behel, A.D. Jr. (Tennessee Valley Authority, Muscle Shoals, AL (USA). Agricultural Research Dept.)


    The fluidized bed combustion process for removing SO{sub 2} from coal-fired power plant stack gases results in generation of large tonnages of waste requiring environmentally acceptable storage or disposal. A field study was initiated in fall 1985 to determine limits of fluidized bed combustion wasted (FBCW) applications to agronomic crops without causing significant yield reduction or accumulation of heavy metals in plants or the soil. Rates of FBCW ranging from 22 to 560 t ha{sup -1} were incorporated in soil by plowing down single and split applications. Conventional agricultural lime treatments were included for comparison. Tall fescue ({ital Festuca arundinacea}), alfalfa ({ital Medicago sativa L.}), corn ({ital Zea mays L.}), and soybeans ({ital Glycine max. L.}) were grown from 1986-88. Annual applications of 22 t ha{sup -1} did not affect yield or metal uptake of any test crop. A single 112 t ha{sup -1} application had no adverse effect, but repeated applications of that rate lowered corn and soybean yields. The rate of 560 t ha{sup -1} resulted in depressed or eliminated growth of all crops. A high pH and high concentrations of Ca and S were associated with this rate but heavy metals and B concentrations in soil and plant tissue were not significantly affected. 7 refs., 12 tabs.

  20. An Experimental and Chemical Kinetics Study of the Combustion of Syngas and High Hydrogen Content Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, Robers [Pennsylvania State Univ., State College, PA (United States); Dryer, Frederick [Princeton Univ., NJ (United States); Ju, Yiguang [Princeton Univ., NJ (United States)


    An integrated and collaborative effort involving experiments and complementary chemical kinetic modeling investigated the effects of significant concentrations of water and CO2 and minor contaminant species (methane [CH4], ethane [C2H6], NOX, etc.) on the ignition and combustion of HHC fuels. The research effort specifically addressed broadening the experimental data base for ignition delay, burning rate, and oxidation kinetics at high pressures, and further refinement of chemical kinetic models so as to develop compositional specifications related to the above major and minor species. The foundation for the chemical kinetic modeling was the well validated mechanism for hydrogen and carbon monoxide developed over the last 25 years by Professor Frederick Dryer and his co-workers at Princeton University. This research furthered advance the understanding needed to develop practical guidelines for realistic composition limits and operating characteristics for HHC fuels. A suite of experiments was utilized that that involved a high-pressure laminar flow reactor, a pressure-release type high-pressure combustion chamber and a high-pressure turbulent flow reactor.

  1. Numerical and experimental studies on effects of moisture content on combustion characteristics of simulated municipal solid wastes in a fixed bed

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Rui, E-mail: [School of Energy Science and Engineering, Harbin Institute of Technology, 92, West Dazhi Street, Harbin 150001 (China); Ismail, Tamer M., E-mail: [Department of Mechanical Engineering, Suez Canal University, Ismailia (Egypt); Ren, Xiaohan [School of Energy Science and Engineering, Harbin Institute of Technology, 92, West Dazhi Street, Harbin 150001 (China); Abd El-Salam, M. [Department of Basic Science, Cairo University, Giza (Egypt)


    Highlights: • The effects of moisture content on the burning process of MSW are investigated. • A two-dimensional mathematical model was built to simulate the combustion process. • Temperature distributions, process rates, gas species were measured and simulated. • The The conversion ratio of C/CO and N/NO in MSW are inverse to moisture content. - Abstract: In order to reveal the features of the combustion process in the porous bed of a waste incinerator, a two-dimensional unsteady state model and experimental study were employed to investigate the combustion process in a fixed bed of municipal solid waste (MSW) on the combustion process in a fixed bed reactor. Conservation equations of the waste bed were implemented to describe the incineration process. The gas phase turbulence was modeled using the k–ε turbulent model and the particle phase was modeled using the kinetic theory of granular flow. The rate of moisture evaporation, devolatilization rate, and char burnout was calculated according to the waste property characters. The simulation results were then compared with experimental data for different moisture content of MSW, which shows that the incineration process of waste in the fixed bed is reasonably simulated. The simulation results of solid temperature, gas species and process rate in the bed are accordant with experimental data. Due to the high moisture content of fuel, moisture evaporation consumes a vast amount of heat, and the evaporation takes up most of the combustion time (about 2/3 of the whole combustion process). The whole bed combustion process reduces greatly as MSW moisture content increases. The experimental and simulation results provide direction for design and optimization of the fixed bed of MSW.

  2. Transportation and adhesion of asphaltenes in a heat exchanger tube through CFD simulations (United States)

    Emani, Sampath; Ramasamy, M.; Shaari, Ku Zilati Ku


    Asphaltenes are identified as the main cause of crude oil fouling in preheat trains. The understanding of individual trajectory of asphaltenes particles, transportation behavior of the fouling precursors in the domain and the effect of various attractive and/or repulsive forces acting on the asphaltenes particles, which lead to an increase/decrease in the deposition, have been impeded by a shortage of information. In the present work, an attempt has been made to understand the transportation and adhesion behavior of asphaltenes in a heat exchanger tube through Computational Fluid Dynamics approach. A Lagrangian based discrete-phase model has been implemented to understand the hydrodynamics of asphaltenes particles and the effect of various forces on the asphaltenes particles deposition on the heat transfer surfaces. The effect of wall shear stress, surface roughness, and temperature difference on asphaltenes deposition is also reported. From the CFD analysis, the net mass deposition of the asphaltenes particles is minimized with an increase in wall shear stress and surface roughness. The asphaltenes particles in the region where the temperature difference between the bulk and wall is lower at a constant wall temperature are carried forward with the flow and particles with higher temperature difference between the bulk and wall at constant wall temperature are attracted towards the heat transfer surface and deposited on the wall of the heat exchanger tube.

  3. Asphaltenes in Mexican fuel oils; Asfaltenos en combustoleos mexicanos

    Energy Technology Data Exchange (ETDEWEB)

    Longoria Ramirez, Rigoberto [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)


    In this article the main aspects in which the Instituto de Investigaciones Electricas (IIE) has worked to contribute to the solution of problems due to the presence of asphaltenes in national fuel oils, are emphasized. The increment of these compounds, that concentrate harmful elements, in the last ten years has reached 22% by weight of the fuel oil. It is demonstrated that the quantification of asphaltenes depends on the type of solvent employed. [Espanol] En este articulo se subrayan los principales aspectos en los que el Instituto de Investigaciones Electricas (IIE) ha trabajado para contribuir a la solucion de problemas debidos a la presencia de asfaltenos en combustoleos nacionales. El incremento de estos compuestos, que concentran elementos nocivos, en los ultimos diez anos ha llegado hasta un 22% del peso del combustoleo. Se demuestra que la cuantificacion de los asfaltenos depende del tipo de solvente utilizado.

  4. X-ray powder diffraction-based method for the determination of the glass content and mineralogy of coal (co)-combustion fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    O. Font; N. Moreno; X. Querol; M. Izquierdo; E. Alvarez; S. Diez; J. Elvira; D. Antenucci; H. Nugteren; F. Plana; A. Lopez; P. Coca; F.G. Pena [Institute of Environmental Assessment and Water Research (IDA-CSIC), Barcelona (Spain)


    The relevance of Al-Si glass in a number of fly ash applications, such as use as a pozzolanic material, zeolite synthesis, and geopolymer production, necessitated research towards investigation of methods for an easy and consistent determination of the glass content in this coal (co)-combustion by-products. A glass standard-addition X-ray powder diffraction (XRD)-based method is proposed in this study as an alternative to the non straightforward procedure of conventional methods for determining the amorphous components, mainly by difference of the total mass and the addition of quantified crystalline species. A >99% Al-Si glass slag sample was selected as a standard for glass. A number of glass standard/fly ash mixtures were performed on Fluidized Bed Combustion (FBC) and pulverized coal combustion (PCC) fly ashes and subsequently analyzed by XRD. The method provides results closer to quantitative proportions of the Al-Si amorphous material of this (co)-combustion by-product, with a range of values <3% when compared with those obtained by the conventional Reference Intensity Method (RIM) method, demonstrating suitability and consistence of the procedure. The mineralogy of FBC and PCC fly ash was also investigated using the RIM method. The occurrence and proportions of the crystalline components in fly ash are in line with the combustion technology and their inherent operational parameters, especially the (co)-combustion temperature. The FBC fly ash shows the highest content of relic phases from feed coal (quartz, illite, calcite, and feldspars) and lower contents of amorphous components. The PCC fly ash are characterized by the highest proportions of mullite and Al-Si glass and low contents of quartz an other relict phases. The occurrence and distribution of anhydrite and Fe-oxide species appears to be related to the content of Ca and Fe in the feed fuels, showing slightly higher contents in FBC than in PCC fly ash. 26 refs., 3 figs., 5 tabs.

  5. Combustion efficiency and altitude operational limits of three liquid hydrocarbon fuels having high volumetric energy content in a J33 single combustor (United States)

    Stricker, Edward G


    Combustion efficiency and altitude operational limits were determined in a J33 single combustor for AN-F-58 fuel and three liquid hydrocarbon fuels having high volumetric energy content (decalin, tetralin, and monomethylnaphthalene) at simulated altitude and combustor inlet-air conditions. At the conditions investigated, the combustion efficiency for the four fuels generally decreased with an increase in volumetric energy content. The altitude operational limits for decalin and tetralin fuels were higher than for AN-F-58 fuel; monomethylnaphthalene fuel gave the lowest altitude operational limit.

  6. Influence of asphaltene aggregation and pressure on crude oil emulsion stability

    Energy Technology Data Exchange (ETDEWEB)

    Auflem, Inge Harald


    Water-in-crude oil emulsions stabilised by various surface-active components are one of the major problems in relation to petroleum production. This thesis presents results from high-pressure separation experiments on ''live'' crude oil and model oil emulsions, as well as studies of Interactions between various indigenous stabilising materials in crude oil. A high-pressure separation rig was used to study the influence of gas and gas bubbles on the separation of water-in-crude oil emulsions. The results were interpreted as a flotation effect from rising gas bubbles, which led to increased separation efficiency. The separation properties of a ''live'' crude oil were compared to crude oil samples recombined with various gases. The results showed that water-in-oil emulsions produced from the ''live'' crude oil samples, generally separated faster and more complete, than emulsions based on recombined samples of the same crude oil. Adsorption of asphaltenes and resins onto a hydrophilic surface from solutions with varying aromatic/aliphatic character was investigated by a quarts crystal microbalance. The results showed that asphaltenes adsorbed to a larger degree than the resins. The resins were unable to desorb pre-adsorbed asphaltenes from the surface, and neither did they adsorb onto the asphaltene-coated surface. In solutions of both of resins and asphaltenes the two constituents associated in bulk liquid and adsorbed to the surface in the form of mixed aggregates. Near infrared spectroscopy and pulsed field gradient spin echo nuclear magnetic resonance were used to study asphaltene aggregation and the influence of various amphiphiles on the asphaltene aggregate size. The results showed Interactions between the asphaltenes and various chemicals, which were proposed to be due to acid-base interactions. Among the chemicals used were various naphthenic acids. Synthesised monodisperse acids gave a reduction of

  7. Impact of maltene and asphaltene fraction on mechanical behavior and microstructure of bitumen

    NARCIS (Netherlands)

    Hofko, B.; Eberhardsteiner, L.; Fussl, J.; Grothe, H.; Handle, F.; Hospodka, M.; Grossegger, D.; Nahar, S.N.; Schmets, A.J.M.; Scarpas, A.


    As a widely accepted concept, bitumen consists of four fractions that can be distinguished by their polarity. Highly polar asphaltene micelles are dispersed in a viscous phase of saturates, aromatics and resins (maltene phase). Different concentrations of asphaltenes in the bitumen result in a range

  8. Mixture Effect on the Dilatation Rheology of Asphaltenes-Laden Interfaces. (United States)

    Liu, Fang; Darjani, Shaghayegh; Akhmetkhanova, Nelya; Maldarelli, Charles; Banerjee, Sanjoy; Pauchard, Vincent


    Asphaltenes are a solubility class of crude oils comprising polyaromatic and heterocyclic molecules with different interfacial activities. The previously neglected effects of compositional mixture on dilatational rheology are discussed in the light of diffusional relaxation models. It is demonstrated that the reported deviations from the Lucassen-van den Tempel model for a single-component solution could largely originate from a distribution in adsorption coefficients within the asphaltenes class. This particularly applies to the peculiar gel point rheology previously ascribed to asphaltenes cross-linking at the interface. Furthermore, an extensive bibliographical review shows that asphaltenes dilatational rheology data always verify the main features of diffusional relaxation, including a decrease in modulus at high bulk concentrations and phase shift values always lower than 45°. Using diffusional relaxation concepts, the reanalysis of the most extensive dataset so far confirmed recently published studies, showing that asphaltenes exhibit a unique equation of state (EOS) irrespective of adsorption conditions. This EOS proves to be very similar for bitumen and petroleum asphaltenes. Finally, a numerical application of a binary diffusional model proved efficient to capture both dynamic interfacial tension and dilatational rheology, with the same parameters. It appears that a minority of asphaltenes (less than 10%) have a much stronger interfacial activity than the bulk of them, as previously demonstrated by fractionation. These results open up the need for a reinterpretation of the physical mechanisms of asphaltenes adsorption in terms of classical amphiphilic behavior, with a potential impact on emulsion breaking and enhanced oil recovery strategies.

  9. Diagnosis of asphaltene stability in crude oil through “two parameters” SVM model

    DEFF Research Database (Denmark)

    Chamkalani, Ali; Mohammadi, Amir H.; Eslamimanesh, Ali


    Asphaltene precipitation/deposition and its imposing difficulties are drastic issues in petroleum industry. Monitoring the asphaltene stability conditions in crude oil systems is still a challenge and has been subject of many studies. In this work, the Refractive Index (RI) of several oil samples...

  10. Comparisons Between Asphaltenes from the Dead and Live-Oil Samples of the Same Crude Oils

    DEFF Research Database (Denmark)

    Aquino-Olivos, M.A.; Andersen, Simon Ivar; Lira-Galeana, C.


    extracted and analyzed. These pressure-driven asphaltenes found on the filter were found to make up in the range between 50 and 100 ppm of the whole crude oil. Opening of the cell did not reveal asphaltenes retained due to wall adhesion. Size exclusion chromatography tests performed on both the live...

  11. Real-time monitoring of asphaltene deposition for solvent job cycle optimization

    NARCIS (Netherlands)

    Boer, J.P. de; Linden, R.J.P. van der; Renes, W.A.


    Asphaltene agglomeration and deposition is a complex process, leading to progressive production losses without mitigative actions. Injection of asphaltenes inhibitors (solvents) in the tubing is a common practice to avoid deposition in production tubing. This does however not avoid deposition in the

  12. Asphaltene self-association: Modeling and effect of fractionation with a polar solvent

    DEFF Research Database (Denmark)

    Garcia, Daniel Merino; Murgich, J; Andersen, Simon Ivar


    of DeltaH(a) obtained suggest that a fraction of asphaltenes is not active in the calorimetric experiments. Asphaltenes from Venezuela (LM1) and Mexico (KU) have been fractionated by precipitation with a mixture of acetone and toluene. It is considered that the most polar compounds are collected...

  13. Enhancing the Effectiveness of Carbon Dioxide Flooding by Managing Asphaltene Precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Deo, Milind D.


    This project was undertaken to understand fundamental aspects of carbon dioxide (CO2) induced asphaltene precipitation. Oil and asphaltene samples from the Rangely field in Colorado were used for most of the project. The project consisted of pure component and high-pressure, thermodynamic experiments, thermodynamic modeling, kinetic experiments and modeling, targeted corefloods and compositional modeling.

  14. Asphaltene adsorption on quartz sand in the presence of pre-adsorbed water. (United States)

    Gonzalez, Valeska; Taylor, Spencer E


    In the oil industry, asphaltenes are known for their tendency to aggregate in solution and to deposit on surfaces, with both properties being connected with operational problems associated with recovery, production and refining. Interactions involving asphaltenes and other crude oil components have been a major aspect of investigation in attempting to understand the full nature of these problems. Water is implicated in asphaltene behavior in solution, for example, where it has been found to delay the deposition of asphaltene aggregates. At interfaces, there is evidence that water-in-crude oil emulsion stability is enhanced through asphaltene-water interactions, and there have been a few reports that asphaltene adsorption on mineral surfaces is reduced in the presence of water. We consider the latter aspect, because the instances of reduced adsorption to date have not attempted to quantify the effect. Previous studies showed that vapor-phase adsorption of organic molecules is reduced in the presence of pre-adsorbed water and we were interested to determine whether the same is true for liquid-phase adsorption of asphaltenes. The surface of quartz sand was controlled by pre-adsorption of water from different relative humidity (RH) environments as the water adsorption isotherm is known from previous studies. These pre-conditioned sand samples were used as substrates for the adsorption from toluene solutions of n-heptane-precipitated asphaltenes (C7A) from an Athabasca oil sands bitumen. To supplement the adsorption behavior, atomic force microscopy (AFM) images were taken of the resultant sand grains at 0 and 80% RH, and low-field NMR was used to estimate the sand wettability. Asphaltene adsorption on sand is sensitive to surface-adsorbed water, with ∼4-fold reduction in adsorption when increasing the RH from 0 to 100%. This is in general agreement with previous vapor-phase adsorption of small organic molecules, and is therefore believed to be the first demonstration

  15. Effect of Simulated High Hydrogen Content Combustion Environments on Abradable Properties of Ceramic Turbine Coatings


    Basu Majumder, Madhura


    Air plasma sprayed (APS) abradable coatings are used in the turbine hot section to reduce the stator-rotor gap, minimizing gas leakage. These coatings are designed to exhibit controlled removal of material in thin layers when the turbine blades sweep through the coating, which protects the mechanical integrity of the turbine blade. In an effort to lower CO2 emissions, high H2 content fuel is being explored. This change in chemical composition of the fuel may affect the microstructure, abradab...

  16. Calorimetric Evidence about the Application of the Concept of CMC to Asphaltene Self-Association

    DEFF Research Database (Denmark)

    Garcia, Daniel Merino; Andersen, Simon Ivar


    usually found in the literature as the CMC region of asphaltenes indicates that this concept is not appropriate for asphaltene self-association. Tests were performed down to concentrations of 34ppm without any sign of a critical micellization or aggregation concentration. Based on the various techniques a......For many years, the concept of critical micellar concentration (CMC) has been projected from surfactant science into asphaltene science. There are several similarities between these two species, such as the stabilization of water-in-oil emulsions and surface activity, which suggested...... that asphaltenes may also have a concentration at which self-association occurs (CMC). This article presents evidence found by calorimetry and spectroscopic techniques, that suggest that this concept may not be adequate for asphaltene self-association in toluene solutions. Isothermal titration calorimetry has been...

  17. Chemical modification of cobalt ferrite nanoparticles with possible application as asphaltene flocculant agent

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, G.E.; Clarindo, J.E.S.; Santo, K.S.E., E-mail: [Universidade Federal do Espirito Santo (CCE/DQUI/UFES), Vitoria, ES (Brazil). Centro de Ciencias Exatas. Dept. de Quimica; Souza Junior, F.G. [Universidade Federal do Rio de Janeiro (IMA/UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Macromoleculas


    Asphaltenes can cause enormous losses in the oil industry, because they are soluble only in aromatic solvents. Therefore, they must be removed from the petroleum before it is refined, using flocculant agents. Aiming to find new materials that can work as flocculant agents to asphaltenes, cobalt ferrite nanoparticles were chemically modified through acid-base reactions using dodecylbenzene sulfonic acid (DBSA) to increase their lipophilicity. Nanoparticle synthesis was performed using the co-precipitation method followed by annealing of these nanoparticles, aiming to change the structural phase. Modified and unmodified nanoparticles were tested by FTIR-ATR, XRD and TGA/DTA. In addition, precipitation onset of the asphaltenes was performed using modified and unmodified nanoparticles. These tests showed that modified nanoparticles have a potential application as flocculant agents used to remove asphaltenes before oil refining, since the presence of nanoparticles promotes the asphaltene precipitation onset with the addition of a small amount of non-solvent (author)

  18. Cooee bitumen. II. Stability of linear asphaltene nanoaggregates

    DEFF Research Database (Denmark)

    Lemarchand, Claire; Schrøder, Thomas; Dyre, J. C.


    Asphaltene and smaller aromatic molecules tend to form linear nanoaggregates in bitumen. Over the years bitumen undergoes chemical aging and during this process, the size of the nanoaggregate increases. This increase is associated with an increase in viscosity and brittleness of the bitumen......, eventually leading to road deterioration. This paper focuses on understanding the mechanisms behind nanoaggregate size and stability. We used molecular dynamics simulations to quantify the probability of having a nanoaggregate of a given size in the stationary regime. To model this complicated behavior, we...

  19. Simultaneous removal of asphaltenes and water from water-in-bitumen emulsion. I. Fundamental development

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yingxian; Wei, Feng [Ningbo Institute of Technology, Zhejiang University, 1 Xuefu Road, Ningbo Higher Education Zone, Zhejiang, 315100 (China)


    Simultaneous removal of asphaltenes and water from a water-in-bitumen emulsion by adding light paraffinic solvents was investigated with a bench-scale unit. Asphaltene precipitation in bitumen, emulsion breaking, and phase separation were found to be largely dependent on solvency and temperature. Increasing temperature facilitated the precipitation of asphaltenes in bitumen, and accelerated the separation of the light deasphalting oil (DAO)/solvent phase and the heavy asphaltenes/water phase. The removal of 98 +% asphaltenes and 99.9 +% water from the emulsion was achieved with the n-pentane/bitumen volumetric ratio of 3.0 in temperature range of 423-453 K. The interaction between asphaltene particles and water droplets is actually beneficial to the removal process. For process design and optimization, the operation pathway including two-step solvent injections at different temperature, the supercritical recovery of solvent from DAO stream and the solidification of asphaltenes by depressurization, as well as other important issues have been addressed. (author)

  20. Mesoscale Simulation and Machine Learning of Asphaltene Aggregation Phase Behavior and Molecular Assembly Landscapes. (United States)

    Wang, Jiang; Gayatri, Mohit A; Ferguson, Andrew L


    Asphaltenes constitute the heaviest fraction of the aromatic group in crude oil. Aggregation and precipitation of asphaltenes during petroleum processing costs the petroleum industry billions of dollars each year due to downtime and production inefficiencies. Asphaltene aggregation proceeds via a hierarchical self-assembly process that is well-described by the Yen-Mullins model. Nevertheless, the microscopic details of the emergent cluster morphologies and their relative stability under different processing conditions remain poorly understood. We perform coarse-grained molecular dynamics simulations of a prototypical asphaltene molecule to establish a phase diagram mapping the self-assembled morphologies as a function of temperature, pressure, and n-heptane:toluene solvent ratio informing how to control asphaltene aggregation by regulating external processing conditions. We then combine our simulations with graph matching and nonlinear manifold learning to determine low-dimensional free energy surfaces governing asphaltene self-assembly. In doing so, we introduce a variant of diffusion maps designed to handle data sets with large local density variations, and report the first application of many-body diffusion maps to molecular self-assembly to recover a pseudo-1D free energy landscape. Increasing pressure only weakly affects the landscape, serving only to destabilize the largest aggregates. Increasing temperature and toluene solvent fraction stabilizes small cluster sizes and loose bonding arrangements. Although the underlying molecular mechanisms differ, the strikingly similar effect of these variables on the free energy landscape suggests that toluene acts upon asphaltene self-assembly as an effective temperature.

  1. Droplet Coalescence and Spontaneous Emulsification in the Presence of Asphaltene Adsorption. (United States)

    Bochner de Araujo, Simone; Merola, Maria; Vlassopoulos, Dimitris; Fuller, Gerald G


    In a refinery, undesired high levels of salt concentration in crude oils are reduced by the contact of water with crude oils, where an emulsion is formed. Later, the separation of the water from the desalted oil is essential for the quality of both wastewater discharge and refined oil. However, complex components of crude oils such as asphaltenes may stabilize these emulsions, causing difficulties in efficient separation. Here, we show the coalescence inhibition caused by asphaltene adsorption for both water-in-oil and oil-in-water emulsions, where the oil phase consists of a simple model of asphaltenes dissolved in toluene. We find that oil-in-water emulsions are less stable than water-in-oil emulsions by using a newly developed instrument where controlled experiments can be performed to measure the coalescence time of a single droplet against an oil/water interface as a function of asphaltene aging (associated with the adsorption process of asphaltene molecules onto the interfaces) and asphaltene concentration. Furthermore, we find that the coalescence time for water droplets exhibits a maximum because of a spontaneous emulsification at the oil/water interface that produces droplets consisting of asphaltene-laden water droplets.

  2. Study on the dipole moment of asphaltene molecules through dielectric measuring

    KAUST Repository

    Zhang, Long Li


    The polarity of asphaltenes influences production, transportation, and refining of heavy oils. However, the dipole moment of asphaltene molecules is difficult to measure due to their complex composition and electromagnetic opaqueness. In this work, we present a convenient and efficient way to determine the dipole moment of asphaltene in solution by dielectric measurements alone without measurement of the refractive index. The dipole moment of n-heptane asphaltenes of Middle East atmospheric residue (MEAR) and Ta-He atmospheric residue (THAR) are measured within the temperature range of -60°C to 20°C. There is one dielectric loss peak in the measured solutions of the two types of asphaltene at the temperatures of -60°C or -40°C, indicating there is one type of dipole in the solution. Furthermore, there are two dielectric loss peaks in the measured solutions of the two kinds of asphaltene when the temperature rises above -5°C, indicating there are two types of dipoles corresponding to the two peaks. This phenomenon indicates that as the temperature increases above -5°C, the asphaltene molecules aggregate and present larger dipole moment values. The dipole moments of MEAR C7-asphaltene aggregates are up to 5 times larger than those before aggregation. On the other hand, the dipole moments of the THAR C7-asphaltene aggregates are only 3 times larger than those before aggregation. It will be demonstrated that this method is capable of simultaneously measuring multi dipoles in one solution, instead of obtaining only the mean dipole moment. In addition, this method can be used with a wide range of concentrations and temperatures.

  3. Effect of hydrophobic ionic liquids on petroleum asphaltene dispersion and determination using UV-visible spectroscopy (United States)

    Rashid, Zeeshan; Wilfredand, Cecilia Devi; Murugesan, Thanabalan


    Asphaltene aggregation and flocculation is one of the main problems faced by upstream industry. The aim of this research activity is to explore the effect of synthesized imidazolium and pyridinium based ionic liquids on the prevention of asphaltene aggregation problem in crude oil. In this research, number of hydrophobic and hydrophilic ionic liquids were tested. The investigations were performed for evaluating; the dispersion yield, effect of temperature, effect of stirring time and effect of solvent to flocculant ratio. Analysis were done using UV-visible Spectroscopy. The results depicted that the investigated hydrophobic ionic liquids have the tendency to abate asphaltene aggregation and can be considered as deflocculants.

  4. Effect on molecular interactions of chemical alteration of petroleum asphaltenes. I

    DEFF Research Database (Denmark)

    Juyal, Priyanka; Garcia, Daniel Merino; Andersen, Simon Ivar


    of asphaltenes have not been fully elucidated. It is especially important to characterize the polar functionalities of these fractions, because they participate in the intermolecular aggregation by means of hydrogen bonds. The chemical derivatization of asphaltenes has been used, in combination with suitable...... these fractions. Experimental data from isothermal titration calorimetry has been used in assessing the role of polar hydrogen bonding functionalities in self-association of these complex molecules. Stability characteristics of these altered asphaltenes have further been studied by onset flocculation titration...

  5. The zeta potential and surface properties of asphaltenes obtained with different crude oil/n-heptane proportions

    Energy Technology Data Exchange (ETDEWEB)

    Hilda Parra-Barraza; Daniel Hernandez-Montiel; Jaime Lizardi; Javier Hernandez; Ronaldo Herrera Urbina; Miguel A. Valdez [Universidad de Sonora, Sonora (Mexico). Departamento de Ciencias Quimico Biologicas


    We have investigated some surface properties of asphaltenes precipitated from crude oil with different volumes of n-heptane. According to the crude oil/n-heptane proportions used, asphaltenes are identified as 1:5, 1:15 and 1:40. Zeta potential results indicate that the amount of n-heptane determines the electrokinetic behaviour of asphaltenes in aqueous suspensions. Asphaltene 1:5 exhibits an isoelectric point (IEP) at pH 4.5 whereas asphaltenes 1:15 and 1:40 show an IEP at about pH 3. Surface charge on asphaltenes arises from the dissociation of acid functionalities and the protonation of basic functional groups. The presence of resins remaining on the asphaltene molecules may be responsible for the different IEP of asphaltene 1:5. Both sodium dodecyl sulfate (an anionic surfactant) and cetylpyridinium chloride (a cationic surfactant) were found to adsorb specifically onto asphaltenes. They reverse the sign of the zeta potential under certain conditions. These surfactants may be potential candidates to aid in controlling the stability of crude oil dispersions. Critical micelle concentration, interfacial tension measurements, and Langmuir isotherms at the air water interface confirm the different nature of asphaltene 1:5, which also showed more solubility and a larger molecular size. 26 refs., 3 figs., 1 tab.

  6. Low content uranium alloys for nuclear fuels; Alliages d'uranium a faible teneur pour elements combustibles

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, H.; Laniesse, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires


    A description is given of the structure and the properties of low content alloys containing from 0.1 to 0.5 per cent by weight of Al, Fe, Cr, Si, Mo or a combination of these elements. A study of the kinetics and of the mode of transformation has made it possible to choose the most satisfactory thermal treatment. An attempt has been made to prepare alloys suitable for an economical industrial development having a small {alpha} grain structure without marked preferential orientation, with very fine and stable precipitates as well as a high creep-resistance. The physical properties and the mechanical strength of these alloys are given for temperatures of 20 to 600 deg C. These alloys proved very satisfactory when irradiated in the form of normal size fuel elements. (authors) [French] Sont decrits la structure et les proprietes d'alliages a faible teneur, contenant de 0,1 a 0,5 pour cent en poids de Al, Fe, Cr, Si, Mo ou une combinaison de ces elements. L'etude des cinetiques et du mode de transformation permet de choisir le traitement thermique le plus favorable. On a cherche a mettre, au point des alliages se pretant a une mise en oeuvre industrielle economique et presentant une structure a petits grains {alpha}, sans orientation preferentielle marquee, avec des precipites tres fins et stables ainsi qu'une bonne resistance au fluage. Les proprietes physiques et la resistance mecanique de ces alliages sont decrites entre la temperature ambiante et 600 deg C. Irradies sous forme d'elements combustibles de dimensions normales, ces alliages ont montre un bon comportement. (auteurs)

  7. Multi-scale simulation of asphaltene aggregation and deposition in capillary flow. (United States)

    Boek, Edo S; Headen, Thomas F; Padding, Johan T


    Asphaltenes are known as the 'cholesterol' of crude oil. They form nano-aggregates, precipitate, adhere to surfaces, block rock pores and may alter the wetting characteristics of mineral surfaces within the reservoir, hindering oil recovery efficiency. Despite a significant research effort, the structure, aggregation and deposition of asphaltenes under flowing conditions remain poorly understood. For this reason, we have investigated asphaltenes, their aggregation and their deposition in capillary flow using multi-scale simulations and experiments. At the colloid scale, we use a hybrid simulation approach: for the solvent, we used the stochastic rotation dynamics (also known as multi particle collision dynamics) simulation method, which provides both hydrodynamics and Brownian motion. This is coupled to a coarse-grained MD approach for the asphaltene colloids. The colloids interact through a screened Coulomb potential with varying well depth epsilon. We tune the flow rate to obtain Pe(flow) > 1 (hydrodynamic interactions dominate) and Re force (PMF) between pairs of asphaltene molecules in an explicit solvent. We obtain a reasonable fit using a -1/r2 attraction for the attractive tail of the PMF at intermediate distances. We speculate that this is due to the two-dimensional nature of the asphaltene molecules. Finally, we discuss how we can relate this interaction to the mesoscopic colloid aggregate interaction. We assume that the colloidal aggregates consist of nano-aggregates. Taking into account observed solvent entrainment effects, we deduct the presence of lubrication layers between the nano-aggregates, which leads to a significant screening of the direct asphaltene-asphaltene interactions.

  8. Extraction methods influence in asphaltenes structure; Influencia de metodos de extracao na estrutura de asfaltenos

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, C.C.V.; Moreira, L.C.; Pereira, A. [Universidade Federal, Rio de Janeiro, RJ (Brazil); Chrisman, E.C.A.N. [Universidade Federal Rural do Rio de Janeiro, RJ (Brazil)]. E-mail:; Seidl, P.R. [Universidade Federal Fluminense, Niteroi, RJ (Brazil)]. E-mail:


    The oil is a balanced mixture of different fractions (saturated hydro-carbons and insaturated, aromatical, sulphurated composites, oxygen and nitrogen, asphaltenes and resins). The majority of the components is found in the residue proceeding from the unit of distillation the vacuum. This fraction, called heavy or deep barrel possesses a low commercial value. Adding it this, its constituent are most difficult to characterize, between which if it finds the asphaltene that forms a complex subgroup still more. The asphaltenes are recognized as being a complex mixture of species of molecular weights, diversified polarity and functional classrooms. They are a soluble classroom that it precipitates for the addition of an excess of paraffinic hydro-carbons that contains condensed aromatical ring systems polynuclear, loaded of alquil chains. In the industry of the oil they are a problem of increasing importance therefore since the stage of attainment of the oil still in the reservoirs, the presence of asphaltenes in its structure already becomes a bother in the perforation process. Moreover, it causes to serious problems of clogging and corrosivity in the tubings of the refining process. Recent studies have been directed with sufficient attention to the case of the asphaltenes. Currently, the performance of a refinery can be evaluated from the capacity that the same one possesses to transform residual fractions into products of bigger commercial value. The attainment, or better, the isolation of the asphaltenes from vacuum residues would be the first step to extend possibilities in this line of research. This would collaborate in the resolution of the diverse problems that the asphaltene generates in the field of chemistry. This work had as purpose the comparison of two methods of extraction of asphaltenes (IP-143 and Method HEPT) how much the quantification of this fraction and determination of molecular characteristics of three different residues of vacuum: A, B and C

  9. Prediction of the Gas Injection Effect on the Asphaltene Phase Envelope

    Directory of Open Access Journals (Sweden)

    Bahrami Peyman


    Full Text Available Asphaltene instability may occur when pressure, temperature and compositional variations affect the reservoir oil. Permeability reduction, wettability alteration, and plugging of wells and flow lines are the consequences of this phenomenon. Therefore, it is crucial to investigate the asphaltene behavior in different thermodynamic conditions by knowing the Asphaltene Precipitation Envelope (APE in a preventive way rather than the costly clean-up procedures. The selected reservoir oil has faced a remarkable decline in production due to several years of extraction, and Enhanced Oil Recovery (EOR has been considered as a solution. Therefore, in this paper, a comprehensive study was carried out to predict the effects of different injected gases on asphaltene onset and to prevent future asphaltene precipitation based on the laboratory data. The Advanced Redlich-Kwong-Soave (RKSA equation of state was considered to develop APE using Multiflash (Infochem Co.. For the selected reservoir oil, with temperature reduction at low temperatures, asphaltene precipitation weakened and made the onset pressure decrease, so this behavior is different from the results obtained in other published reports. On the basis of this model, several sensitivity analyses were performed with different gases (i.e., methane, CO2, N2 and associated gases to compare the risk of each gas for future EOR strategies. APE tend to expand as the amount of injected gases increases, except for CO2 gas injection, that showed another unconventional behavior for this crude oil. It was observed that for CO2 gas injection below a certain temperature, asphaltene stability increased, which can be considered as a good inhibitor of asphaltene precipitation.

  10. Chemistry and structure of coal derived asphaltenes and preasphaltenes. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    Yen, T. F.


    It is the objective of this project to isolate the asphaltene and preasphaltene fractions from coal liquids from a number of liquefaction processes. These processes consist of in general: catalytic hydrogenation, staged pyrolysis and solvent refining. The asphaltene fractions may be further separated by both gradient elution through column chromatography, and molecular size distribution through gel permeation chromatography. These coal-derived asphaltene and preashpaltene fractions will then be investigated by various chemical and physical methods for characterization of their structures. After the parameters are obtained, these parameters will be correlated with the refining and conversion variables which control a given type of liquefaction process. The effects of asphaltene in catalysis, ash or metal removal, desulfurization and denitrification will also be correlated. It is anticipated that understanding the role of asphaltenes in liquefaction processes will enable engineers to both improve existing processes, and to make recommendations for operational changes in planned liquefaction units. The objective of Phase 1 was to complete the isolation and separation of coal liquid fractions and to initiate their characterization. The objective of Phase 2 is to continue the characterization of coal asphaltenes and other coal liquid fractions by use of physical and instrumental methods. The structural parameters obtained will be used to postulate hypothetical average structures for coal liquid fractions.The objective of Phase 3 is to concentrate on the characterization of the preasphaltene (benzene insoluble fraction) of coal liquid fraction by the available physical and chemical methods to obtain a number of structural parameters.

  11. Evaluating the hydrophilic-lipophilic nature of asphaltenic oils and naphthenic amphiphiles using microemulsion models. (United States)

    Kiran, Sumit K; Acosta, Edgar J; Moran, Kevin


    Asphaltenes and naphthenic acid derivatives, which are polar and surface-active species, are known to interfere with the recovery of heavy crude oil by promoting the formation of stable emulsions. In this study, previously established microemulsion phase behavior models were applied to quantify the hydrophilic-lipophilic nature of asphaltenic oils (bitumen, deasphalted bitumen, asphalt, naphthalene) and surface-active species found in heavy oils (naphthenic compounds and asphaltenes). For the test oils, the equivalent alkane carbon number (EACN) was determined by evaluating the "salinity shifts" of microemulsions formulated with a reference surfactant (sodium dihexyl sulfosuccinate--SDHS) and a reference oil (toluene) as a function of test oil volume fraction. Similarly, the characteristic curvature (C(C)) of surface-active species was determined by evaluating the salinity shifts as a function of the molar fraction of the surface-active species in mixture with SDHS. As a part of the oil phase, asphaltenes and asphaltene-like species are highly hydrophilic, which lead to low EACN values despite their large molecular weight. As a surface-active material, asphaltenes are hydrophobic species that lead to the formation of water-in-oil emulsions. Naphthenates, particularly sodium naphthenates, are highly hydrophilic compounds that lead to the formation of oil-in-water emulsions. These hydrophilic-lipophilic characterization parameters, and the methods used to determine them, can be used in the future to understand the phase behavior of complex oil-water systems.

  12. Chemistry and structure of coal derived asphaltenes and preasphaltenes. Quarterly progress report, April-June 1980

    Energy Technology Data Exchange (ETDEWEB)

    Yen, T. F.


    It is the objective of this project to isolate the asphaltene and preasphaltene fractions from coal liquids from a number of liquefaction processes. These processes consist of in general: catalytic hydrogenation, staged pyrolysis and solvent refining. These asphaltene fractions may be further separated by both gradient elution through column chromatography, and molecular size distribution through gel permeation chromatography. Those coal-derived asphaltene and preasphaltene fractions will be investigated by various chemical and physical methods for characterization of their structures. After the parameters are obtained, these parameters will be correlated with the refining and conversion variables which control a given type of liquefaction process. The effects of asphaltene in catalysis, ash or metal removal, desulfurization and denitrification will also be correlated. It is anticipated that understanding the role of asphaltenes in liquefaction processes will enable engineers to both improve existing processes, and to make recommendations for operational changes in planned liquefaction units in the United States. The objective of Phase 1 was to complete the isolation and separation of coal liquid fractions and to initiate their characterization. The objective of Phase 2 is to continue the characterization of coal asphaltenes and other coal liquid fractions by use of physical and instrumental methods. The structural parameters obtained will be used to postulate hypothetical average structures for coal liquid fractions. The objective of Phase 3 is to concentrate on the characterization of the preasphaltene (benzene insoluble fraction) of coal liquid fraction by the available physical and chemical methods to obtain a number of structural parameters.

  13. Upgrading fuzzy logic by GA-PS to determine asphaltene stability in crude oil

    Directory of Open Access Journals (Sweden)

    Saeid Ahmadi


    Full Text Available Precipitation and deposition of asphaltene are undesirable phenomena that arise during petroleum production which give rise to a pronounced rate of increase in operational cost and adversely affect production rates as well. Hence, it is imperative to develop a mathematical model for the assessment of asphaltene stability in crude oil. In the present study, delta RI which constitutes the difference between refractive index of crude oil (RI and refractive index of crude oil at the onset of asphaltene precipitation (PRI is employed as the principal factor for determining the asphaltene stability of the region. Fuzzy logic is a potent tool capable of extracting the underlying dependency between SARA fractions (saturate, aromatic, resin, and asphaltene data and delta RI for the inexpensive and rapid diagnosis of asphaltene stability. In this study a novel strategy known as hybrid genetic algorithm-pattern search (GA-PS is suggested for the development of an optimal fuzzy logic model as a reliable alternative for the widely-applied subtractive clustering (SC method. While SC solely optimizes mean of input Gaussian membership functions (GMFs, GA-PS tool optimizes both mean and variance of input GMFs. Comparison between GA-PS and SC methods confirmed the capability of GA-PS for developing an optimal fuzzy logic model.

  14. CFD modelling of shell-side asphaltenes deposition in a shell and tube heat exchanger (United States)

    Emani, Sampath; Ramasamy, M.; Shaari, Ku Zilati Ku


    Asphaltenes are identified as the main cause of crude oil fouling in the shell and tube exchangers. There are occasions where the crude oil flows through the shell side of the heat exchangers and some fouling is reported in the shell side of those heat exchangers. Understanding the fouling phenomena in the shell sides requires the knowledge on the irregular fluid flow paths and most susceptible locations of particles deposition. In the present work, an attempt has been made to investigate the effect of shear stress and surface roughness on shell-side asphaltenes deposition in a shell and tube heat exchanger through Computational Fluid Dynamics approach. The hydrodynamics of asphaltenes particles and the effect of various forces on the asphaltenes deposition on the heat transfer surfaces has been investigated through a Lagrangian based discrete-phase model. From the CFD analysis, the net mass deposition of the asphaltenes particles reduces with an increase in surface roughness from 0 to 0.04 mm and wall shear stress from 0 to 0.04 Pa for flow velocity 1 m/s, respectively. The asphaltenes mass deposition becomes constant with further increase in wall shear stress and surface roughness.

  15. Bubble Combustion (United States)

    Corrigan, Jackie


    A method of energy production that is capable of low pollutant emissions is fundamental to one of the four pillars of NASA s Aeronautics Blueprint: Revolutionary Vehicles. Bubble combustion, a new engine technology currently being developed at Glenn Research Center promises to provide low emissions combustion in support of NASA s vision under the Emissions Element because it generates power, while minimizing the production of carbon dioxide (CO2) and nitrous oxides (NOx), both known to be Greenhouse gases. and allows the use of alternative fuels such as corn oil, low-grade fuels, and even used motor oil. Bubble combustion is analogous to the inverse of spray combustion: the difference between bubble and spray combustion is that spray combustion is spraying a liquid in to a gas to form droplets, whereas bubble combustion involves injecting a gas into a liquid to form gaseous bubbles. In bubble combustion, the process for the ignition of the bubbles takes place on a time scale of less than a nanosecond and begins with acoustic waves perturbing each bubble. This perturbation causes the local pressure to drop below the vapor pressure of the liquid thus producing cavitation in which the bubble diameter grows, and upon reversal of the oscillating pressure field, the bubble then collapses rapidly with the aid of the high surface tension forces acting on the wall of the bubble. The rapid and violent collapse causes the temperatures inside the bubbles to soar as a result of adiabatic heating. As the temperatures rise, the gaseous contents of the bubble ignite with the bubble itself serving as its own combustion chamber. After ignition, this is the time in the bubble s life cycle where power is generated, and CO2, and NOx among other species, are produced. However, the pollutants CO2 and NOx are absorbed into the surrounding liquid. The importance of bubble combustion is that it generates power using a simple and compact device. We conducted a parametric study using CAVCHEM

  16. The colloidal structure of crude oils and suspensions of asphaltenes and resins

    Energy Technology Data Exchange (ETDEWEB)

    Bardon, C.; Barre, L.; Espinat, D.; Guille, V.; Li, M.H.; Lambard, J.; Ravey, J.C.; Rosenberg, E.; Zemb, T. [Institut Francais du Petrole, Rueil Malmaison (France)


    This paper presents new results that contribute to the understanding of the colloidal macrostructure of the heavy petroluem products and their complex fractions. Scattering methods (using X-rays and neutrons) are applied to study both the fractionated products (asphaltene and resin solutions in more or less good solvents) and the real systems (Safaniya vacuum residue). The lamellar structural model for asphaltenes and resins is confirmed and the molecular weight of these species determined using a polydisperse size distribution. Discussion is presented concerning he specificity of X-ray and neutron scattering: X-ray experiments are more sensitive to the aromatic-rich regions, whereas the neutron scattering data provide information about all the particle volume. Viscosimetry measurements provide information on the molecular shape of asphaltenes and confirm the disk-like model. Critical micellar concentration has been obtained using Vapour Pressure Osmometry for asphaltene suspensions in toluene and in pyridine. The resin molecules are smaller than asphaltenes, and appear to be a good solvent for asphaltenes. One of the major conclusions of this work is the wide-spread presence of density heterogeneities in diluted solutions of asphaltenes and resins as well as in the pure product (Safaniya vacuum residue). The heating effects were studied: a temperature increase leads to the decrease of molecular weight, but heterogeneities remain present. The structure of vacuum residue exhibits large density fluctuations which are thermally stable. These dense regions remain connected into a network up to 393 K and determine the yield value of the rheological behaviour. 66 refs., 19 figs., 5 tabs.

  17. Molecular Dynamics Simulation to Investigate the Interaction of Asphaltene and Oxide in Aggregate

    Directory of Open Access Journals (Sweden)

    Rui Li


    Full Text Available The asphalt-aggregate interface interaction (AAI plays a significant role in the overall performances of asphalt mixture, which is caused due to the complicated physicochemical processes and is influenced by various factors, including the acid-base property of aggregates. In order to analyze the effects of the chemical constitution of aggregate on the AAI, the average structure C65H74N2S2 is selected to represent the asphaltene in asphalt and magnesium oxide (MgO, calcium oxide (CaO, aluminium sesquioxide (Al2O3, and silicon dioxide (SiO2 are selected to represent the major oxides in aggregate. The molecular models are established for asphaltene and the four oxides, respectively, and the molecular dynamics (MD simulation was conducted for the four kinds of asphaltene-oxide system at different temperatures. The interfacial energy in MD simulation is calculated to evaluate the AAI, and higher value means better interaction. The results show that interfacial energy between asphaltene and oxide reaches the maximum value at 25°C and 80°C and the minimum value at 40°C. In addition, the interfacial energy between asphaltene and MgO was found to be the greatest, followed by CaO, Al2O3, and SiO2, which demonstrates that the AAI between asphalt and alkaline aggregates is better than acidic aggregates.

  18. Removal of asphaltene and paraffin deposits using micellar solutions and fused reactions. Final report, 1995--1997

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C.L.; Nalwaya, V.; Singh, P.; Fogler, H.S.


    Chemical treatments of paraffin and asphaltene deposition by means of cleaning fluids were carried out in this research project. Research focused on the characterization of asphaltene and paraffin materials and dissolution of asphaltene and paraffin deposits using surfactant/micellar fluids developed early in the project. The key parameters controlling the dissolution rate were identified and the process of asphaltene/paraffin dissolution were examined using microscopic apparatus. Numerical modeling was also carried out to understand the dissolution of paraffin deposits. The results show that fused chemical reaction systems are a promising way of removing paraffin deposits in subsea pipelines. The fused system may be in the form of alternate pulses, emulsions systems or encapsulated catalyst systems. Fused reaction systems, in fact, are extremely cost-effective--less than 10% of the cost of replacing entire sections of the blocked pipeline. The results presented in this report can have a real impact on the petroleum industry and the National Oil Program, if it is realized that the remediation technologies developed here can substantially delay abandonment (due to asphaltene/paraffin plugging) of domestic petroleum resources. The report also sheds new light on the nature and properties of asphaltenes and paraffin deposits which will ultimately help the scientific and research community to develop effective methods in eliminating asphaltene/paraffin deposition problems. It must also be realized that asphaltene remediation technologies developed and presented in this report are a real alternative to aromatic cleaning fluids currently used by the petroleum industry.

  19. Estimation of vanadyl porphyrin concentration in sedimentary kerogens and asphaltenes

    Energy Technology Data Exchange (ETDEWEB)

    Premovic, P.I.; Allard, T.; Nikolic, N.D.; Tonsa, I.R.; Pavlovic, M.S. [University of Nis, Nis (Yugoslavia). Dept. of Chemistry


    The authors describe a new, rapid method for determining the concentration of vanadyl prophyrins (VO{sup 2+}-P) associated with the kerogen of bituminous sedimentary rocks using electron spin resonance (ESR). The method is simple, straightforward and inexpensive. Several concentrations of a vanadyl (VO{sup 2+}) standard dissolved in glycerol-lignite-mixture were prepared. The VO{sup 2+} concentrations ranged from 100 to 1000 ppm. The anisotropic ESR spectra of both the standards and kerogen samples were recorded at room temperature and the integrated areas of the pre-selected ESR line (attributed to nuclear spin m{sub 1} = -5/2) were computed. The concentrations of VO{sup 2+} found in the kerogen samples were calculated using the relative ratio of the integrated areas for the standards and the kerogen samples. The VO{sup 2+}-P concentrations of the kerogen materials were then calculated using 450 as the mean molecular weight of these species. Quantitative determination of VO{sup 2+}-P in the kerogen fractions in the range of 800-8000 ppm and higher is feasible by the method reported. The method of analysis was also extended to the asphaltene samples (enriched with VO{sup 2+}-P) and a coal sample containing non-porphyrin VO{sup 2+} associated with its organic fraction. 20 refs., 5 figs., 1 tab.

  20. Effect of unburned carbon content in fly ash on the retention of 12 elements out of coal-combustion flue gas. (United States)

    Bartonová, Lucie; Cech, Bohumír; Ruppenthalová, Lucie; Majvelderová, Vendula; Juchelková, Dagmar; Klika, Zdenek


    The aim of this study was to evaluate whether unburned carbon particles present in fly ash can help in the retention of S, Cl, Br, As, Se, Cu, Ni, Zn, Ga, Ge, Rb, and Pb out of flue gas during the coal combustion at fluidised-bed power station where the coal was combusted along with limestone. The competitive influence of 10%-25% CaO in fly ashes on the distribution of studied elements was studied as well to be clear which factor governs behaviour of studied elements. Except of S (with significant association with CaO) and Rb and Pb (with major affinity to Al2O3) the statistically significant and positive correlation coefficients were calculated for the relations between unburned carbon content and Br (0.959), Cl (0.957), Cu (0.916), Se (0.898), Ni (0.866), As (0.861), Zn (0.742), Ge (0.717), and Ga (0.588) content. The results suggest that the unburned carbon is promising material in terms of flue gas cleaning even if contained in highly calcareous fly ashes.

  1. The vanadium isotopic constitution of petroleum asphaltenes: La Luna Formation (Venezuela). (United States)

    Premović, P I; Tonsa, I R; López, L; Pavlović, M S; Nesković, O M; LoMonaco, S; Dordević, D M; Veljković, M V


    High-resolution mass spectrometry indicates that the isotopic abundance of 50V of the Late Cretaceous La Luna petroleum asphaltenes of marine origin (highly enriched with V > 2000 ppm) is higher by about 3.5% than that of the inorganic source (VOSO4 x 5H2O, Merck). We propose that the difference in the 50V/51V values between the La Luna petroleum asphaltenes and the inorganic source can be best ascribed to the biological processing of seawater vanadium. The fact that the V isotopic compositions of petroleum asphaltenes vary over a very narrow range (2.46-2.52) suggests essentially the same (or similar) and fixed biological source of vanadium.

  2. Modeling of Asphaltene Precipitation from Crude Oil with the Cubic Plus Association Equation of State

    DEFF Research Database (Denmark)

    Arya, Alay; Liang, Xiaodong; von Solms, Nicolas


    In this study, different modeling approaches using the Cubic Plus Association (CPA) equation of state (EoS) are developed to calculate the asphaltene precipitation onset condition and asphaltene yield from degassed crude oil during the addition of n-paraffin. A single model parameter is fitted...... with the experimental data for eight different crude oils. Results were also obtained for seven crudes using the Perturbed Chain Statistical Associating Fluid Theory (PC-SAFT) EoS based approach described in the literature. The CPA EoS based approaches treat the asphaltene fraction as an associating component whereas...... the PC-SAFT EoS based approach does not. A comparison between the approaches shows that the CPA EoS based approaches, developed in this work, give more reliable results. The predictions from the PC-SAFT EoS based approach result in behavior that is unphysical: the mole fraction of n-paraffin (at...

  3. Structural modifications of petroleum asphaltenes by reductive alkylation investigated by TLC-FID

    Energy Technology Data Exchange (ETDEWEB)

    Cagniant, D.; Nosyrev, I.; Cebolla, V.; Vela, J.; Membrado, L.; Gruber, R. [Universite de Metz, Metz (France). Laboratoire de Thermodynamique et d' Analyses Chimiques


    The reductive alkylation of a French petroleum asphaltene (Lagrave) was studied with potassium in THF, in absence of an electron transfer reagent. From the number of butyl and benzyl groups added to the starting asphaltene, the difference of reactivity of the alkyl reagents, butyl iodide and benzyl bromide, was pointed out. Special attention was focused on the cleavage of C-S and C-O linkages in relation to the structural modifications. From the number of hydrogen atoms added during the reduction step, it was concluded that the sulphide linkages are mainly of aryl-S-aryl, aryl-S-alkyl or alkyl-S-alkyl types. The TLC-FID (Iatroscan) analysis was found to be very suitable to follow the 'depolymerization' process of the asphaltene, qualitatively as well as quantitatively, by the application hydrocarbon group type analysis. 23 refs., 2 figs., 5 tabs.

  4. Influence of containing of asphaltenes and naphthenic acids over organic deposition inhibitor performance

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Geiza E.; Mansur, Claudia R.E.; Pires, Renata V.; Passos, Leonardo B.; Lucas, Elizabete F. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Macromoleculas; Alvares, Dellyo R.S.; Gonzalez, Gaspar [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)


    Organic deposition is a serious problem confronted by the petroleum industry in Brazil and worldwide. Among the main petroleum components that may cause deposition problems are waxes and asphaltenes. This work aims at evaluating the influence of petroleum fractions (asphaltenes and naphthenic acids) on the organic deposition phenomenon as well as on organic deposition inhibitors performance. The influence of the organic fractions was evaluated by their ability to change wax crystals, to lower the pour point and to alter the initial wax appearance temperature. The efficiency of the additives was tested by pour point measurements. The results show that asphaltenes seem to act as organic deposition inhibitors, while naphthenic acids do not significantly change the system. Moreover, employing both of them produces no synergic effect. Among polymeric inhibitors, all of the chemically modified EVA copolymer presented better results than the non-modified commercial EVA copolymer. The best result was observed for EVA28C{sub 16}. (author)

  5. Asphaltene-laden interfaces form soft glassy layers in contraction experiments: a mechanism for coalescence blocking. (United States)

    Pauchard, Vincent; Rane, Jayant P; Banerjee, Sanjoy


    In previous studies, the adsorption kinetics of asphaltenes at the water-oil interface were interpreted utilizing a Langmuir equation of state (EOS) based on droplet expansion experiments.1-3 Long-term adsorption kinetics followed random sequential adsorption (RSA) theory predictions, asymptotically reaching ∼85% limiting surface coverage, which is similar to limiting random 2D close packing of disks. To extend this work beyond this slow adsorption process, we performed rapid contractions and contraction-expansions of asphaltene-laden interfaces using the pendant drop experiment to emulate a Langmuir trough. This simulates the rapid increase in interfacial asphaltene concentration that occurs during coalescence events. For the contraction of droplets aged in asphaltene solutions, deviation from the EOS consistently occurs at a surface pressure value ∼21 mN/m corresponding to a surface coverage ∼80%. At this point droplets lose the shape required for validity of the Laplace-Young equation, indicating solidlike surface behavior. On further contraction wrinkles appear, which disappear when the droplet is held at constant volume. Surface pressure also decreases down to an equilibrium value near that measured for slow adsorption experiments. This behavior appears to be due to a transition to a glassy interface on contraction past the packing limit, followed by relaxation toward equilibrium by desorption at constant volume. This hypothesis is supported by cycling experiments around the close-packed limit where the transition to and from a solidlike state appears to be both fast and reversible, with little hysteresis. Also, the soft glass rheology model of Sollich is shown to capture previously reported shear behavior during adsorption. The results suggest that the mechanism by which asphaltenes stabilize water-in-oil emulsions is by blocking coalescence due to rapid formation of a glassy interface, in turn caused by interfacial asphaltenes rapidly increasing in

  6. A study of some asphaltenes solutions structure and of a Safaniya vacuum residue

    Energy Technology Data Exchange (ETDEWEB)

    Guille, V.


    A lot of problems in the petroleum industry are due to the presence of asphaltenes compounds in petroleum products. A good knowledge of the chemical composition and the different properties of asphaltenes in solution are necessary to cope with these difficulties. We have then examined a Safaniya Vacuum Residue (VR) and its fractions (asphaltenes, resins, aromatics and saturates). In order to describe the macro-structure of these complex colloidal systems, we used different characterisation techniques: small angle X-ray and neutron scattering (SAXS and SANS), rheology and electron microscopy. Scattering techniques allows us to precise the model for asphaltenes and resins in solution. These macromolecules are poly-dispersed disk-like particles with thickness and diameter which are respectively close to 1 to 10 nm. The average molecular weight is equal to 106 000 for asphaltenes and 3 300 for resins. We have shown that SAXS is more sensitive to the scattering of the aromatic part of the molecule. Adding n-heptane induces first a de-solvation of the molecules and then an aggregation up to flocculation. These solutions present large heterogeneities due to concentration fluctuations. A huge difference in the chemical composition of the different asphaltenes molecules can explain these fluctuations. These heterogeneities are stable as a function of temperature; this means that exist strong molecular interactions. Ultracentrifugation gives two different fractions which contain different chemical structures, more or less aromatic. Solutions, in good solvent, of these two fractions are homogeneous but a mixture of these two fractions exhibits, heterogeneities. SAXS gives information about the structure of VR. We have observed the presence of large density fluctuations up to 300 deg. C. Rheological measurements confirm three-dimensional organisation. (author). 11 refs., 11 figs., 49 tabs.

  7. Determination of asphaltene onset conditions using the cubic plus association equation of state

    DEFF Research Database (Denmark)

    Arya, Alay; von Solms, Nicolas; Kontogeorgis, Georgios M.


    The cubic-plus-association (CPA) equation of state (EoS) has already been proven to be a successful model for phase equilibrium calculations for systems containing associating components and has already been applied for asphaltene modeling by few researchers. In the present work, we apply the CPA...... EoS to determine asphaltene precipitation onset conditions for various reservoir fluids but with a different modeling approach than literature approaches. A simple oil characterization technique, based on SARA analysis, is adopted which divides the C6+ fraction of the oil into “heavy component...

  8. Experimental Study and Mathematical Modeling of Asphaltene Deposition Mechanism in Core Samples

    Directory of Open Access Journals (Sweden)

    Jafari Behbahani T.


    Full Text Available In this work, experimental studies were conducted to determine the effect of asphaltene deposition on the permeability reduction and porosity reduction of carbonate, sandstone and dolomite rock samples using an Iranian bottom hole live oil sample which is close to reservoir conditions, whereas in the majority of previous work, a mixture of recombined oil (a mixture of dead oil and associated gas was injected into a core sample which is far from reservoir conditions. The effect of the oil injection rate on asphaltene deposition and permeability reduction was studied. The experimental results showed that an increase in the oil injection flow rate can result in an increase in asphaltene deposition and permeability reduction. Also, it can be observed that at lower injection flow rates, a monotonic decrease in permeability of the rock samples can be attained upon increasing the injection flow rate, while at higher injection rates, after a decrease in rock permeability, an increasing trend is observed before a steady-state condition can be reached. The experimental results also showed that the rock type can affect the amount of asphaltene deposition, and the asphaltene deposition has different mechanisms in sandstone and carbonate core samples. It can be seen that the adsorption and plugging mechanisms have a more important role in asphaltene deposition in carbonate core samples than sandstone core samples. From the results, it can be observed that the pore volumes of the injected crude oil are higher for sandstone cores compared with the carbonate cores. Also, it can be inferred that three depositional types may take place during the crude oil injection, i.e., continuous deposition for low-permeability cores, slow, steady plugging for high-permeability cores and steady deposition for medium-permeability cores. It can be seen from the experimental results that damage to the core samples was found to increase when the production pressures were

  9. Long term analysis of the biomass content in the feed of a waste-to-energy plant with oxygen-enriched combustion air. (United States)

    Fellner, Johann; Cencic, Oliver; Zellinger, Günter; Rechberger, Helmut


    Thermal utilization of municipal solid waste and commercial wastes has become of increasing importance in European waste management. As waste materials are generally composed of fossil and biogenic materials, a part of the energy generated can be considered as renewable and is thus subsidized in some European countries. Analogously, CO(2) emissions of waste incinerators are only partly accounted for in greenhouse gas inventories. A novel approach for determining these fractions is the so-called balance method. In the present study, the implementation of the balance method on a waste-to-energy plant using oxygen-enriched combustion air was investigated. The findings of the 4-year application indicate on the one hand the general applicability and robustness of the method, and on the other hand the importance of reliable monitoring data. In particular, measured volume flows of the flue gas and the oxygen-enriched combustion air as well as corresponding O(2) and CO(2) contents should regularly be validated. The fraction of renewable (biogenic) energy generated throughout the investigated period amounted to between 27 and 66% for weekly averages, thereby denoting the variation in waste composition over time. The average emission factor of the plant was approximately 45 g CO(2) MJ(-1) energy input or 450 g CO(2) kg(-1) waste incinerated. The maximum error of the final result was about 16% (relative error), which was well above the error (<8%) of the balance method for plants with conventional oxygen supply.

  10. Chemistry and structure of coal-derived asphaltenes, Phase III. Quarterly progress report, July--September 1978

    Energy Technology Data Exchange (ETDEWEB)

    Yen, T. F.


    Preparative scale GPC separation of Synthoil asphaltene was carried out on styrene-divinyl benzene packing (Bio-Beads S-X8). The elution took place in the order of high to low molecular weight. Analyses indicate that aromatic ring systems with large saturated substituents elute first followed by more aromatic molecules with less saturated substituents. Infrared measurements on coal-derived asphaltenes were carried out with a large path cell (1 cm) in order to measure absorbance as a function of concentration in dilute solution down to 0.3 g/l where association between asphaltenes is not significant. VPO molecular weight studies indicate that coal-derived oils and resins undergo very little association in the solvent THF in the range 4 to 30 g/l in contrast to coal-derived asphaltenes and benzene insolubles. Thermal treatment of a Synthoil Coal liquid solvent fraction (oil + resin), in tetralin (1:2 wt. ratio) at 232/sup 0/C for 20 h resulted in the transformation of 3 to 10% of the oil + resin into asphaltene. These results support the proposed reversibility of coal liquefaction steps. Pryolysis of coal-derived asphaltenes has been shown to produce residues that are characteristic of coalesced mesophase. Asphaltenes from three liquefaction processes, Catalytic Incorporatd SRC, Synthoil, and FMC-COED, were pyrolyzed under a nitrogen atmosphere at 20/sup 0/C/h to 360/sup 0/C and at 5/sup 0/C/h to 420/sup 0/C. Crossed polarized light reflection micrographs showed a coarse deformed structure for Synthoil asphaltene, a course, but not deformed structure for Catalytic Inc. asphaltne, and a fine isotropic structure for FMC-COED asphaltene.

  11. Experimental investigation of asphaltene deposition mechanism during oil flow in core samples

    Energy Technology Data Exchange (ETDEWEB)

    Papadimitriou, N.I.; Romanos, G.E.; Charalambopoulou, G.Ch.; Kainourgiakis, M.E.; Katsaros, F.K.; Stubos, A.K. [National Center for Scientific Research ' ' Demokritos' ' , Aghia Paraskevi, Attica, 15310 (Greece)


    Asphaltene deposition is an issue that has received much attention since it has been shown to be the cause of major production problems in enhanced oil recovery processes. Asphaltenes are heavy oil components which, under certain conditions, precipitate and the solid phase they form may deposit in the porous media of the oil reservoir. All proposed remediation techniques have proven costly and not highly effective, so prevention becomes the only way to counteract the problem. Revelation of the deposition mechanism and determination of the parameters they affect it are necessary in order to devise reliable prevention strategies. In this work, an experimental effort is made to investigate the deposition process in core samples, under simulant and realistic flow conditions. The main experimental tools utilized for this purpose are permeability measurements, analysis of asphaltene concentration, pore structure characterization techniques and Soxhlet extraction for the determination of the deposited asphaltenes. Both dead and reservoir oils are used as well as cores of various permeabilities and pore structure characteristics. (author)

  12. Solubility and interaction parameters as references for solution properties II: precipitation and aggregation of asphaltene in organic solvents. (United States)

    Johansson, Bjarne; Friman, Rauno; Hakanpää-Laitinen, Hannele; Rosenholm, Jarl B


    The total combinatory Gibbs free energy was successfully used to model the solubility of two purified asphaltenes in pure and mixed solvents, as well as the precipitation of asphaltenes from mixed solvents. Intrinsic viscosity and aggregate size both sensitively reflected the state of the asphaltenes in homogeneous solution and were used for determining the solubility parameters of the asphaltenes. Phase separation was clearly reflected by a dramatic increase in aggregate size. The interaction parameter was subdivided into enthalpy and entropy contributions. All parameters indicate an extensive association or phase transition when the phase boundary was followed by simultaneously varying the temperature and the solubility parameter of the solvent. However, the interaction parameter is frequently derived in two ways. We show that, depending on the definition, the enthalpy and entropy contributions lead to conflicting results. These were evaluated on thermodynamic grounds.

  13. Content

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    Aim, content and methods are fundamental categories of both theoretical and practical general didactics. A quick glance in recent pedagogical literature on higher education, however, reveals a strong preoccupation with methods, i.e. how teaching should be organized socially (Biggs & Tang, 2007...... a theoretical approach, which takes complexity as fundamental premise for modern society (Luhmann, 1985, 2002). In educational situations conditionally valuable content generally will exceed what can actually be taught within the frames of an education. In pedagogy this situation is often referred...... to as ‘abundance of material’, and in many cases it is not obvious, how the line between actually chosen and conditionally relevant content can be draw. Difficulties in drawing the line between actual educational content and conditionally relevant content can be handled in different way. One way, quite efficient...

  14. The influence of petroleum asphaltenic sub fractions on the demulsifiers performance; Influencia de subfracoes asfaltenicas de petroleo sobre a acao de desemulsificantes

    Energy Technology Data Exchange (ETDEWEB)

    Honse, Siller O.; Mansur, Claudia R.E.; Lucas, Elizabete F. [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas. Lab. de Macromoleculas e Coloides na Industria de Petroleo], e-mail:


    The aim of this work is to evaluate the influence of asphaltene fractions and subfractions on the stabilization of petroleum emulsions, as well as on the efficiency of demulsifiers based on poly(ethylene oxide-b-propylene oxide) (PEO-PPO). Asphaltenes were extracted from an asphaltic residue using n-heptane (C5 asphaltenes) and n-decane (asphaltenes C10). Intermediate subfractions were also obtained. Model emulsions, consisted of water and dispersions of the asphaltene in toluene were prepared, with and without adding demulsifier. The stability of the emulsions was higher when adding more polar fractions. However, asphaltenes presenting a broad distribution of polarity cause higher emulsion stability than that presenting very narrow distribution of intermediate polarity. The efficiency of PEO-PPO copolymer on emulsions separation is related to the original stability of the emulsions. In this work, it was confirmed that branched surfactant presents higher efficiency than the linear. (author)

  15. Adsorption of asphaltenes and resins on organic and inorganic substrates and their correlation with precipitation problems in production well tubing

    Energy Technology Data Exchange (ETDEWEB)

    Acevedo, S.; Ranaudo, M.A.; Escobar, G.; Gutierrez, L.; Ortega, P. [Universidad Central de Venezuela, Caracas (Venezuela). Centro de Quimica Organica


    The solute-solid adsorption isotherms (SSA) of asphaltenes and resins were measured using the inorganic fraction (97% SiO{sub 2}) of the deposit that plugged the tubing of a production well as an inorganic adsorbent. In other experiments, Ceuta asphaltenes and the product (HA) of heating them at 350{degree}C for 11 h were used as organic adsorbents in heptane, toluene and heptane-toluene at 26{degree}C. Ceuta and Furrial asphaltenes on the inorganic substance resulted in multilayer formation (L-3 type adsorption) whereas a Cerro Negro sample gave simple Langmuir-type adsorption. A possible correlation between these results and the tendency of the asphaltenes to precipitate from the crude oils is suggested. Saturation, multilayer formation and pore penetration were apparent in the SSA experiments for the system resins-heptane-asphaltenes. SSA results for the system resin-heptane/toluene-HA were consistent with the steric stabilization theory of colloidal dispersions. Adsorption of aggregates or micelles of asphaltenes was apparent in both the organic and the inorganic substrates. 22 refs., 6 figs., 1 tab.

  16. Molecular Dynamics Simulation: The Behavior of Asphaltene in Crude Oil and at the Oil/Water Interface

    KAUST Repository

    Gao, Fengfeng


    Carboxyl asphaltene is commonly discussed in the petroleum industry. In most conditions, electroneutral carboxyl asphaltene molecules can be deprotonated to become carboxylate asphaltenes. Both in crude oil and at the oil/water interface, the characteristics of anionic carboxylate asphaltenes are different than those of the carboxyl asphaltenes. In this paper, molecular dynamics (MD) simulations are utilized to study the structural features of different asphaltene molecules, namely, C5 Pe and anionic C5 Pe, at the molecular level. In crude oil, the electroneutral C5 Pe molecules prefer to form a steady face-to-face stacking, while the anionic C5 Pe molecules are inclined to form face-to-face stacking and T-shaped II stacking because of the repulsion of the anionic headgroups. Anionic C5 Pe has a distinct affinity to the oil/water interface during the simulation, while the C5 Pe molecules persist in the crude oil domain. A three-stage model of anionic C5 Pe molecules adsorbed at the oil/water interface is finally developed.

  17. Sulfur Chemistry in Combustion I

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Glarborg, Peter


    Most fossil fuels contain sulphur and also biofuels and household waste have a sulphur content. As a consequence sulphur species will often be present in combustion processes. In this paper the fate and influence of fuel sulphur species in combustion will be treated. First a description...... of the sulphur compounds in fossil fuels and the possibilities to remove them will be given. Then the combustion of sulphur species and their influence on the combustion chemistry and especially on the CO oxidation and the NOx formation will be described. Finally the in-situ removal of sulphur in the combustion...

  18. The vanadium isotopic constitution of petroleum asphaltenes: La Luna Formation (Venezuela

    Directory of Open Access Journals (Sweden)



    Full Text Available High resolution mass spectrometry indicates that the isotopic abundance of 50vanadium (V of the Late Cretaceous La Luna petroleum asphaltenes and related source kerogen of marine origin (both highly enriched with V >> 2000 ppm is higher by about 3,5 % than that of an inorganic vanadium source (VOSO4 > 5H2O, Merck. It is proposed that the difference in the 50V/51V values between the La Luna source kerogen/the associated petroleum asphaltenes and the inorganic source can be best ascribed to the biological processing of seawater V. The fact that the isotopic compositions of V vary over a very narrow range (2.46-2.50 suggest an essentially same (or similar and fixed bilogical source of V.

  19. Smoldering Combustion


    Rein, G


    Smoldering combustion is the slow, low temperature, flameless burning of porous fuels and is the most persistent type of combustion phenomena. It is especially common in porous fuels which form a char on heating, like cellulosic insulation, polyurethane foam or peat. Smoldering combustion is among the leading causes of residential fires, and it is a source of safety concerns in industrial premises as well as in commercial and space flights. Smoldering is also the dominant combustion phenomena...

  20. Effect of varying Ga content in ZnO:GaN solid solution synthesized by solution combustion technique for photocatalytic applications (United States)

    Menon, Sumithra Sivadas; Janani, R.; Baskar, K.; Gupta, Bhavana; Singh, Shubra


    ZnO:GaN (oxy)nitride solid solution has been established as the most efficient non-oxide photocatalyst for water splitting under visible irradiation with one step photoexcitation and also boasts a band gap tunability from 2.8 eV to 2.5 eV[1]. The solid solution of GaN in ZnO is formed by the intersubstitution of few of Zn/O ions by Ga/N ions, and this results in the introduction of new defect levels above the valence band which narrows the effective band gap enabling activity under visible region of spectra. In this work, we report the synthesis of ZnO:GaN solid solution by a solution combustion technique where metal nitrates and urea are used as precursors. The Zn/Ga ratio was varied from 16 to 1 in the precursors. The as synthesized samples were characterized as phase pure by X-ray diffraction, where the wurtzite structure was retained up to Zn/Ga ratio of 5. The Diffuse reflectance spectroscopy studies revealed that as the Ga content in the solid solution increases there is a reduction in band gap, from 2.9 eV to 2.4 eV. The reduced band gap of the samples facilitates its photocatalytic activity under visible region of the spectra as evaluated by photoelectrochemical measurements.

  1. Electron spin resonance study of the kerogen/asphaltene vanadyl porphyrins: air oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Premovic, P.I.; Tonsa, I.R.; Pajovic, M.T.; Lopez, L.; Monaco, S.L.; Dordevic, D.M.; Pavlovic, M.S. [University of Nis, Nis (Yugosalvia). Lab. for Geochemistry and Cosmochemistry, Dept. of Chemistry


    Thermal behavior of vanadyl porphyrins was studied by electron spin resonance during heating of the kerogens isolated from the La Luna (Venezuela), Maganik (Montenegro) and Serpiano (Switzerland) bituminous rocks at 150 and 250{degree}C for 1 to 20 days in the presence of air. During the thermal treatment of the kerogens the vanadyl porphyrins' resonance signals decrease monotonically and become quite small after six days of heating. Concomitantly, new vanadyl signals appear, and, at longer heating times, dominate the spectrum. It is suggested that the secondary vanadyl species must have been formed from vanadyl porphyrins. Similar conversion of vanadyl porphyrins are observed under the same experimental conditions for the asphaltenes extracted from the La Luna and Serpiano rocks, and the floating asphalt from the Dead Sea (Israel). A comparison of the spin-Hamiltonian parameters for vandyl porphyrisn and vanadyl compounds obtained during pyrolysis of the kerogens/asphaltenes suggests that these are of non-porphyrin type. For comparison, a study was conducted on the Western Kentucky No. 9 coal enriched with vanadium (up to 800 ppm) from six mines. All coal samples show only the presence of predominant vanadyl-non-porphyrin compounds similar to those generated through laboratory heating of the kerogens/asphaltenes in air. In addition, some samples also contain a minor amount of vanadyl porphyrins. 21 refs., 2 figs.

  2. Estimation of the size of asphaltene aggregates produced by shear of crude oil

    Energy Technology Data Exchange (ETDEWEB)

    Gmachowski, L.; Paczuski, M. [Warsaw Univ. of Technology, Plock (Poland). Inst. of Chemistry


    This study investigated asphaltene aggregation in Russian Export Blend Crude Oil (REBCO) using a Couette device over a range of shear rates similar to that in pipelines transporting the crude oil. After each experiment an amount of n-heptane was added to a crude oil sample. A turbidimeter was used to observe the sedimentation behaviour of the obtained suspension. The behaviour was found to be highly dependent on the concentration of the crude oil in the mixture. The fractal dimension was determined upon analyzing the sedimentation velocity of asphaltene aggregates. The mutual dependence between the sedimentation velocity and the turbidity for different concentrations was also determined. The fractal dimension was shown to be very close to that of the diffusion limited process, suggesting that aggregates were formed during a secondary process induced by the addition of n-heptane. The earlier aggregates produced by shear of crude oil were monomers for the secondary aggregates. The affect of the shear rate on the settling velocity-turbidity relation was very weak, indicating that the size of asphaltene aggregates produced by crude oil shear does not change much with the shear rate.

  3. Air oxidation of the kerogen/asphaltene vanadyl porphyrins: an electron spin resonance study

    Directory of Open Access Journals (Sweden)



    Full Text Available The thermal behavior of vanadyl porphyrins was studied by electron spin resonance during heating of kerogens, isolated from the La Luna (Venezuela and Serpiano (Switzerland bituminous rocks, at 25°C for 1 to 20 days in the presence of air. During the thermal treatment of the kerogens, the vanadyl porphyrins resonance signals decrease monotonically and become quite small after 6 days of heating. Concomitantly, new vanadyl signals appear and, at longer heating times, dominate the spectrum. It is suggested that the secondary vanadyl species must have been formed from vanadyl porphyrins. Similar conversions of vanadyl porphyrins are observed under the same experimental conditions for asphaltenes extracted from the La Luna and Serpiano rocks, and floating asphalt from the Dead Sea (Israel. A comparison of the spin-Hamiltonian parameters for vanadyl porphyrins and the vanadyl compounds obtained during pyrolysis of the kerogens/asphaltenes suggests that the latter are of a non-porphyrin type. For comparison a study was conducted on Western Kentucky No. 9 coal enriched with vanadium (>>400 ppm from six mines. All the coal samples show only the presence of predominant by non-porphyrin vanadyl compounds, similar to those generated through laboratory heating of the kerogens/asphaltenes in air. In addition, some samples also contain a minor amount of vanadyl porphyrins.

  4. Developing grey-box model to diagnose asphaltene stability in crude oils: Application of refractive index

    Directory of Open Access Journals (Sweden)

    Mahdi Zeinali Hasanvand


    Full Text Available Asphaltene precipitation can cause serious problems in petroleum industry while diagnosing the asphaltene stability conditions in crude oil system is still a challenge and has been subject of many investigations. To monitor and diagnose asphaltene stability, high performance intelligent approaches based bio-inspired science like artificial neural network which have been optimized by various optimization techniques have been carried out. The main purpose of the implemented optimization algorithms is to decide high accurate interconnected weights of proposed neural network model. The proposed intelligent approaches are examined by using extensive experimental data reported in open literature. Moreover, to highlight robustness and precision of the addressed approaches, two different regression models have been developed and results obtained from the aforementioned intelligent models and regression approaches are compared with the corresponding refractive index data measured in laboratory. Based on the results, hybrid of genetic algorithm and particle swarm optimization have high performance and average relative absolute deviation between the model outputs and the relevant experimental data was found to be less than 0.2%. Routs from this work indicate that implication of HGAPSO-ANN in monitoring refractive index can lead to more reliable estimation of addressed issue which can lead to design of more reliable phase behavior simulation and further plans of oil production.

  5. Synthesis and evaluation of copolymer based on cardanol and styrene on the stability of asphaltenes; Sintese e avaliacao de copolimero a base de cardanol e estireno sobre a estabilidade dos asfaltenos

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, Tatiana S.; Spinelli, Luciana S., E-mail: [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Macromoleculas


    The destabilization of asphaltenes in crude oil mainly happens due to variations in pressure, temperature and oil composition, causing significant losses. Polymers containing specific groups can be used as asphaltenes stabilizers and thus, avoid your precipitation, or as asphaltenes flocculants to assist the removal of suspended particles in a particular oil. The monitoring of asphaltenes precipitation is usually evaluated by tests with variation in stability of asphaltenes in function of adding a flocculant solvent. In this work, it was evaluated the influence of a synthesized copolymer based on cardanol and styrene on the stability of asphaltenes. The stability of asphaltenes was monitored by precipitation tests induced by a flocculant agent (n-heptane), using an ultraviolet-visible (UV-Vis) spectrometer. The structural characterization of copolymer was performed by FTIR and {sup 1}H NMR. The results showed that copolymer can act as asphaltene flocculant. (author)

  6. Effects of Ca Content on Formation and Photoluminescence Properties of CaAlSiN3:Eu2+ Phosphor by Combustion Synthesis

    Directory of Open Access Journals (Sweden)

    Shyan-Lung Chung


    Full Text Available Effects of Ca content (in the reactant mixture on the formation and the photoluminescence properties of CaAlSiN3:Eu2+ phosphor (CASIN were investigated by a combustion synthesis method. Ca, Al, Si, Eu2O3, NaN3, NH4Cl and Si3N4 powders were used as the starting materials and they were mixed and pressed into a compact which was then wrapped up with an igniting agent (i.e., Mg + Fe3O4. The compact was ignited by electrical heating under a N2 pressure of ≤1.0 MPa. By keeping the molar ratios of Al and Si (including the Si powder and the Si in Si3N4 powder both at 1.00 and that of Eu2O3 at 0.02, XRD (X-ray diffraction coupled with TEM-EDS (transmission electron microscope equipped with an energy-dispersive X-ray spectroscope and SAED (selected area electron diffraction measurements show that AlN:Eu2+ and Ca-α-SiAlON:Eu2+ are formed as the major phosphor products when the Ca molar ratio (denoted by Y is equal to 0.25 and AlN:Eu2+ and Ca-α-SiAlON:Eu2+ could not be detected at Y ≥ 0.75 and ≥1.00, respectively. CASIN (i.e., CaAlSiN3:Eu2+ becomes the only phosphor product as Y is increased to 1.00 and higher. The extent of formation of CASIN increases with increasing Y up to 1.50 and begins to decrease as Y is further increased to 1.68. While the excitation wavelength regions are similar at various Y, the emission wavelength regions vary significantly as Y is increased from 0.25 to 1.00 due to different combinations of phosphor phases formed at different Y. The emission intensity of CASIN was found to vary with Y in a similar trend to its extent of formation. The Ca and Eu contents (expressed as molar ratios in the synthesized products were found to increase roughly with increasing Y but were both lower than the respective Ca and Eu contents in the reactant mixtures.

  7. Computational Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, C K; Mizobuchi, Y; Poinsot, T J; Smith, P J; Warnatz, J


    Progress in the field of computational combustion over the past 50 years is reviewed. Particular attention is given to those classes of models that are common to most system modeling efforts, including fluid dynamics, chemical kinetics, liquid sprays, and turbulent flame models. The developments in combustion modeling are placed into the time-dependent context of the accompanying exponential growth in computer capabilities and Moore's Law. Superimposed on this steady growth, the occasional sudden advances in modeling capabilities are identified and their impacts are discussed. Integration of submodels into system models for spark ignition, diesel and homogeneous charge, compression ignition engines, surface and catalytic combustion, pulse combustion, and detonations are described. Finally, the current state of combustion modeling is illustrated by descriptions of a very large jet lifted 3D turbulent hydrogen flame with direct numerical simulation and 3D large eddy simulations of practical gas burner combustion devices.

  8. Combustion engineering

    CERN Document Server

    Ragland, Kenneth W


    Introduction to Combustion Engineering The Nature of Combustion Combustion Emissions Global Climate Change Sustainability World Energy Production Structure of the Book   Section I: Basic Concepts Fuels Gaseous Fuels Liquid Fuels Solid Fuels Problems Thermodynamics of Combustion Review of First Law Concepts Properties of Mixtures Combustion StoichiometryChemical EnergyChemical EquilibriumAdiabatic Flame TemperatureChemical Kinetics of CombustionElementary ReactionsChain ReactionsGlobal ReactionsNitric Oxide KineticsReactions at a Solid SurfaceProblemsReferences  Section II: Combustion of Gaseous and Vaporized FuelsFlamesLaminar Premixed FlamesLaminar Flame TheoryTurbulent Premixed FlamesExplosion LimitsDiffusion FlamesGas-Fired Furnaces and BoilersEnergy Balance and EfficiencyFuel SubstitutionResidential Gas BurnersIndustrial Gas BurnersUtility Gas BurnersLow Swirl Gas BurnersPremixed-Charge Engine CombustionIntroduction to the Spark Ignition EngineEngine EfficiencyOne-Zone Model of Combustion in a Piston-...

  9. On the application of NiO nanoparticles to mitigate in situ asphaltene deposition in carbonate porous matrix (United States)

    Hashemi, Seyed Iman; Fazelabdolabadi, Babak; Moradi, Siyamak; Rashidi, Ali Morad; Shahrabadi, Abbas; Bagherzadeh, Hadi


    Prevention of asphaltene formation in reservoir rocks can result in resolving a severe long-lasting issue in petroleum production. The present research addresses the issue in the context of exploring the potential effect of nickel oxide (NiO) nanoparticles in destabilizing asphaltene deposition in porous media, in the presence of carbon dioxide. To ensure proper distribution within the system and to retain future field-scale applicability, the NiO nanoparticles were exposed to the in situ oil via injection gas stream, in which they had been uniformly dispersed using polydimethylsiloxane (PDMS). The experimental results, established under miscible CO2 state, indicate a considerable improvement in permeability/porosity reduction of core, as well as less asphaltene accumulation in porous media and increased oil recovery factor after applying NiO nanoparticles.

  10. Prediction of Gas Injection Effect on Asphaltene Precipitation Onset Using the Cubic and Cubic-Plus-Association Equations of State

    DEFF Research Database (Denmark)

    Arya, Alay; Liang, Xiaodong; von Solms, Nicolas


    precipitation onset condition during gas injection. The modeling approach is used with the Soave Redlich Kwong, Soave Redlich Kwong-Plus-Huron Vidal mixing rule and cubic-plus-association (CPA) equations of state (EoS). Six different reservoir fluids are studied with respect to asphaltene onset precipitation...... during nitrogen, hydrocarbon gas mixture, and carbon dioxide injection. It is also shown how to extend the modeling approach when the reservoir fluid is split into multiple pseudocomponents. It is observed that the modeling approach using any of the three models can predict the gas injection effect......Gas injection is a proven enhanced oil recovery technique. The gas injection changes the reservoir oil composition, temperature, and pressure conditions, which may result in asphaltene precipitation. In this work, we have used a modeling approach from the literature in order to predict asphaltene...

  11. Contents

    Directory of Open Access Journals (Sweden)

    Editor IJRED


    Full Text Available International Journal of Renewable Energy Development Volume 1             Number 3            October 2012                ISSN 2252- 4940   CONTENTS OF ARTICLES page Design and Economic Analysis of a Photovoltaic System: A Case Study 65-73 C.O.C. Oko , E.O. Diemuodeke, N.F. Omunakwe, and E. Nnamdi     Development of Formaldehyde Adsorption using Modified Activated Carbon – A Review 75-80 W.D.P Rengga , M. Sudibandriyo and M. Nasikin     Process Optimization for Ethyl Ester Production in Fixed Bed Reactor Using Calcium Oxide Impregnated Palm Shell Activated Carbon (CaO/PSAC 81-86 A. Buasri , B. Ksapabutr, M. Panapoy and N. Chaiyut     Wind Resource Assessment in Abadan Airport in Iran 87-97 Mojtaba Nedaei       The Energy Processing by Power Electronics and its Impact on Power Quality 99-105 J. E. Rocha and B. W. D. C. Sanchez       First Aspect of Conventional Power System Assessment for High Wind Power Plants Penetration 107-113 A. Merzic , M. Music, and M. Rascic   Experimental Study on the Production of Karanja Oil Methyl Ester and Its Effect on Diesel Engine 115-122 N. Shrivastava,  , S.N. Varma and M. Pandey  

  12. Isothermal Titration Calorimetry and Fluorescence Spectroscopy Study Of Asphaltene Self-Association In Toluene And Interaction With A Model Resin

    DEFF Research Database (Denmark)

    Garcia, Daniel Merino; Andersen, Simon Ivar


    This article collects the work performed by Isothermal Titration Caloritnetry (ITC) in the study of the self-association of asphaltenes in toluene solutions. Calorimetric experiments show that asphaltenes, start self-associating at very low concentrations and that the existence of a Critical...... with the results of the titration of three model molecules: nonylphenol, which associates by means of hydrogen bond formation, and coronene and pyrene, which associates by stacking. The results obtained leave open the question about the model-stacking molecules, as it was not possible to elucidate whether they do...

  13. Substances synthesis of the asphaltenes simplifying models; Sintese de substancias modelo simplificadas de asfaltenos

    Energy Technology Data Exchange (ETDEWEB)

    Romeiro, T.F.; Pereira, A. [Universidade Federal, Rio de Janeiro, RJ (Brazil); Chrisman, E.C.A.N. [Universidade Federal Rural do Rio de Janeiro, RJ (Brazil)]. E-mail:; Seidl, P.R. [Universidade Federal Fluminense, Niteroi, RJ (Brazil)]. E-mail:


    The products derived from oil are essential in practically all the sectors of the modern life. The necessity of if using heavy fractions in efficient way in the production of nobler fractions, resulted in a great interest in the briefing of the molecular structure of asphaltenes, since its behavior, during the thermal processes and catalytic, it is function of its structure. In the refining, the asphaltenes increase the viscosity of the fractions submitted to the distillation and contribute for the coke formation and the poisoning and deactivation of catalyzers, used in processes as cracking, reform, etc. Therefore, a ampler knowledge of the structure of the asphaltenes and its action becomes very important to assist in the job of these fractions and to minimize the de current problems of its possible use made through substances model, suggested for the de current analyses of the separations and determination of some parameters of these substances that will be source of information for the molecular modeling. With this, from the information gotten with the extraction and the separation, it was decided to synthesize initially simpler molecules involving the formation of 4 the 5 aromatical rings, of different arrangements, involving only molecules with carbon, hydrogen and oxygen, in the form of derivatives of anthraquinones. The used methodology involved the job of reaction of aromatical electrofilic substitution using as substance phthalic anhydride reacting way Friedel-Crafts, with naphthalene and anthracene, initially, with specific methods for each isomer. Separation and purification of the products, followed of analysis and characterization of the same ones for infra-red ray and RMN. To the end, can be observed important characteristics, such as the gotten photosensibility of one of the isomer through the reaction with naphthalene. (author)

  14. Compact electrostatic filter at small-scale combustion of fuels with high ash content; Kompakt elektrostatiskt filter vid smaaskalig foerbraenning av askrika braenslen

    Energy Technology Data Exchange (ETDEWEB)

    Baefver, Linda; Yngvesson, Johan


    To facilitate combustion of these fuels in small combustion devices (50 kW - a few MW), there is a need of inexpensive dust cleaning devices. Electrostatic filters for dust cleaning at heat and power plants are well established. However, the cost of these filters is often expensive to bear for a small plant. A few electrostatic filters for residential applications are available, but the experience is limited. In the capacity-area in between, i.e. small district heating plants, it is of special importance to find new cheap alternatives for an improved dust cleaning. The Norwegian company Applied Plasma Physics (APP) have products for dust- and odour-cleaning. APP also has the electrostatic filter called RESP (Residential Electrostatic Precipitator) for combustion of wood close to commercially available. The purpose of this report is to evaluate the electrostatic filter RESP at combustion of biofuels rich in ash, and by this contribute to increased knowledge about electrostatic precipitation at small-scale applications. A sub-goal is to separate 85 % of the particles in the flue gas. Experimental tests were performed at SPs Energy laboratory. RESP was mounted downstream of a chimney, which was mounted on a multi-stoker/boiler. The multi-stoker has a nominal heat output of 65 kW at combustion of wood pellets. In this project pellets of bark or reed canary grass were fired. Dust separation efficiency over the RESP with respect to number concentration and size distribution was tested for several powers of the filter, during combustion of the two fuels. Combustion of bark was selected for a longer time test with respect to separation efficiency by particle mass. Number concentration and size distribution were measured in real time using an electrical low pressure impactor (ELPI) and mass concentration was measured by filter sampling. The combustion conditions were favourable, with low concentrations of hydrocarbons and carbon monoxide. The number concentration of

  15. Particles from combustion of fuel with high content of ash - Experimental study of reed canary grass and straw; Partiklar fraan foerbraenning av askrika braenslen - Experimentell studie paa roerflen och halm

    Energy Technology Data Exchange (ETDEWEB)

    Baefver, Linda; Ryde, Daniel


    Domestic combustion of solid fuels is, besides traffic and industry, a major source to particles in the air. Increased biomass combustion means a risk of contributing to high concentrations of particles with respect to the environmental goals. Particles are a health risk. The number of ultrafines and the content of the particles are considered crucial for the effects. Gradually, new solid biofuels with high ash content and different ash composition are used. This means an enhanced risk of high particle emission and a change in the formation of particles. The aim of the project is to contribute to the description of the mechanisms for formation of particles at combustion of biomass with high content of ash. The possibility to decrease the particle emission by the use of additives will be especially investigated. Thereby, problems with particle emissions, as well as formation of deposits may be minimized. The project contains two parts. The first one is about combustion of oat grain, and has already been reported. In this report the second part of the project is presented. Reed canary grass and straw were studied. To decrease the particle emission from combustion of straw, tests with straw and the additive kaolin (clay mineral) were also carried out. The fuels were pelletized and contained 4-5 % ash (dry fuel). Reed canary grass (perennial grass) was chosen because it is has potential and it has also been much studied in Sweden. Straw was chosen because it has high accessibility, and is already fired to a certain degree. Straw contained 2.6 times more chlorine than reed canary grass. Reed canary grass had Si as dominating ash element (79 %), and thereafter it contained K (6 %), Ca (6 %) and P (3 %). A good half of the straw ash contained Si and thereafter K (23 %) and Ca (15 %) were most abundant. The fuels were continuously fired in a multi-stoker from Sonnys Maskiner, connected to a boiler from Centrometal. The particles mass concentration was measured by sampling

  16. Comparative studies on compounds occluded inside asphaltenes hierarchically released by increasing amounts of H{sub 2}O{sub 2}/CH{sub 3}COOH

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Jing [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)] [Laboratoire des Fluides Complexes, UMR 5150 TOTAL-CNRS-UPPA, BP 1155, 64013 Pau Cedex (France); Liao Zewen, E-mail: [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Zhang Luehui [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Creux, Patrice [Laboratoire des Fluides Complexes, UMR 5150 TOTAL-CNRS-UPPA, BP 1155, 64013 Pau Cedex (France); Yang Chupeng [Guangzhou Marine Geological Survey, Ministry of Land and Resources, Guangzhou 510760 (China); Chrostowska, Anna [Institut Pluridisciplinaire de Recherche sur l' Environnement et les Materiaux, UMR CNRS 5254, Universite de Pau et des Pays de l' Adour, Av. de l' Universite, BP 1155, 64013 Pau Cedex (France); Zhang Haizu [Institute of Petroleum Exploration and Development, Tarim Oilfield Company, Korla 841000 (China); Graciaa, Alain [Laboratoire des Fluides Complexes, UMR 5150 TOTAL-CNRS-UPPA, BP 1155, 64013 Pau Cedex (France)


    Research highlights: {yields} Some other molecules are occluded inside asphaltenes {yields} These occluded molecules can be released from asphaltenes by H{sub 2}O{sub 2}/CH{sub 3}COOH oxidation {yields} These occluded molecules are representatives of the original oils from kerogens - Abstract: Being the heaviest fraction of crude oils, asphaltenes are liable to aggregate, and other molecules in the oils can be steadily adsorbed onto, and even occluded inside the macromolecular structures of the asphaltenes. These occluded compounds inside the asphaltenes can survive over geological time in oil reservoirs owing to effective protection by the macromolecular structures of the asphaltenes. The asphaltenes of a crude oil (ZG31) from the central Tarim Basin, NW China, were hierarchically degraded by increasing the amount of H{sub 2}O{sub 2}/CH{sub 3}COOH to release the occluded compounds. Besides the common components, series of even numbered n-alk-1-enes and 3-ethylalkanes were detected among the occluded compounds. Comparison of the biomarker distributions and the compound-specific C isotopic results between the compounds from the maltenes and those from the occluded fraction, the ZG31 reservoir was suggested to have been charged multiple times, with different charges being derived from different strata of source rocks.

  17. Study of flow properties of asphaltenic oils in a porous medium; Etude des proprietes d`ecoulement des bruts asphalteniques en milieu poreux

    Energy Technology Data Exchange (ETDEWEB)

    Petrova-Bensalem, R.


    Deposits of asphaltenes during production can adversely affect the exploitation of certain fields, that of Hassi Messaoud is a known example. The objective of this study is essentially focused on the damage aspects due to formation of this deposits. A methodology has been developed which makes it possible to determine the flow properties of asphaltenic oils in a porous medium under conditions close to those of a reservoir and to detect the formation of organic deposits in situ. Several types of rocks with different morphology were selected along with a number of asphaltenic oils having varied geographic origins. It was shown with these that it was possible to evaluate, in laboratory, the reduction in permeability to the oil resulting from an asphaltene deposit during the circulation of crude oil in the samples. It was observed that the variation in blocking the cores as a function of the volume of injected fluid is similar to the blocking kinetics ascertained for the retention of solid suspended particles in injection water. This similarity in the phenomena led to using particle damage models developed for the latter case. Several experiments involving blocking by asphaltenes could thus be satisfactory simulated, showing that this approach is worth developing despite the differences between the two types of colloidal suspension. The method using injection or `squeeze` of co- solvents was studied with the same systems (rock/crude oil) as a possible remedy for asphaltene deposition. To select suitable solvents and additives. A methodology was established based on application of Hansen`s theory for adjusting the polarity of solvent to the chemical properties of the asphaltene to be eliminated. This was combined with a series of in vitro tests with separated asphaltenes and the minerals of the reservoir rock. The efficiency of the co-solvents thus selected was verified by slug injection in to cores which has been damaged by asphaltenes. This approach may well help the

  18. Problematic stabilizing films in petroleum emulsions: shear rheological response of viscoelastic asphaltene films and the effect on drop coalescence. (United States)

    Harbottle, David; Chen, Qian; Moorthy, Krishna; Wang, Louxiang; Xu, Shengming; Liu, Qingxia; Sjoblom, Johan; Xu, Zhenghe


    Adsorption of asphaltenes at the water-oil interface contributes to the stability of petroleum emulsions by forming a networked film that can hinder drop-drop coalescence. The interfacial microstructure can either be liquid-like or solid-like, depending on (i) initial bulk concentration of asphaltenes, (ii) interfacial aging time, and (iii) solvent aromaticity. Two techniques--interfacial shear rheology and integrated thin film drainage apparatus--provided equivalent interface aging conditions, enabling direct correlation of the interfacial rheology and droplet stability. The shear rheological properties of the asphaltene film were found to be critical to the stability of contacting drops. With a viscous dominant interfacial microstructure, the coalescence time for two drops in intimate contact was rapid, on the order of seconds. However, as the elastic contribution develops and the film microstructure begins to be dominated by elasticity, the two drops in contact do not coalescence. Such step-change transition in coalescence is thought to be related to the high shear yield stress (~10(4) Pa), which is a function of the film shear yield point and the film thickness (as measured by quartz crystal microbalance), and the increased elastic stiffness of the film that prevents mobility and rupture of the asphaltene film, which when in a solid-like state provides an energy barrier against drop coalescence.

  19. Investigation of the Gas Injection Effect on Asphaltene Onset Precipitation Using the Cubic-Plus-Association Equation of State

    DEFF Research Database (Denmark)

    Arya, Alay; von Solms, Nicolas; Kontogeorgis, Georgios M.


    Miscible and immiscible gas flooding is one of the enhanced oil recovery (EOR) techniques that has been widely used to increase the oil production. One of the critical problems with gas flooding is that it generally aggravates the asphaltene precipitation, which further creates a flow assurance...

  20. Molecular mechanics and microcalorimetric investigations of the effects of molecular water on the aggregation of asphaltenes in solutions

    DEFF Research Database (Denmark)

    Murgich, J.; Lira-Galeana, C.; Garcia, Daniel Merino


    by titration calorimetry. A simple dimer dissociation model was used to derive the information about the heat and the constant of dissociation from asphaltenes of Mexico and Alaska obtained from the calorimetric data. The association enthalpies calculated were found to be in excellent agreement with those...

  1. Compositional Simulation of In-Situ Combustion EOR: A Study of Process Characteristics

    DEFF Research Database (Denmark)

    Jain, Priyanka; Stenby, Erling Halfdan; von Solms, Nicolas


    combustion simulation is used. Preceding research work primarily focused on a kinetic model that was based on six components and incorporated four chemical reactions. However, modeling of a thermal process as complex as In-situ combustion requires in-depth understanding of detailed reaction kinetics...... and multidisciplinary process data. This paper extends the understanding of previous research done in this domain by performing the process simulations to study further the impact of oxidation reactions and combustion reactions of crude oils along with their saturate, aromatic, resin, and asphaltene (SARA) fractions....... This incorporates fourteen pseudo components and fourteen reactions (distributed amongst thermal cracking, low temperature oxidation and high temperature oxidation). The paper presents a set of derivative plots indicating that reservoir process characterization in terms of thermal behavior of oil can be well...

  2. Organic sulphur in macromolecular sedimentary organic matter : I. Structure and origin of sulphur-containing moieties in kerogen, asphaltene and coal as revealed by flash pyrolysis

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Eglinton, T.I.; Leeuw, J.W. de; Schenk, P.A.


    The distributions of sulphur-containing compounds generated by flash pyrolysis of macromolecular sedimentary organic matter (kerogen, coal, asphaltenes) were studied by gas chromatography in combination with S-selective flame photometric detection or mass spectrometry. The abundance of

  3. A Practical Approach for Formation Damage Control in Both Miscible and Immiscible CO2 Gas Flooding in Asphaltenic Crude Systems Using Water Slugs and Injection Parameters (United States)

    David, Sergio Z.

    CO2 flooding has proven to be an effective technique for enhanced oil recovery. However, the application of CO2 flooding in the recovery process of asphaltenic crude systems is often avoided, as high asphaltene precipitation rates may occur. While the effects of asphaltene concetration and CO2 injection pressure on asphaltene precipitation rate have been the focus of many studies, asphaltene precipitation rate is not a reliable factor to predict the magnitude of asphaltene-induced formation damage. Wettability alteration is only caused by the immobile asphaltene deposits on the rock surface. The enternmaint of flocs may occur at high fluid velocity. Morover, the effective permeability reduction is only caused by the flocs, which have become large enough to block the pore throats. The dissociation of the flocs may occur under certain flow conditions. In this study, a compositional reservoir simulation was conducted using Eclipse 300 to investigate the injection practice, which avoids asphaltene-induced formation damage during both immiscible and miscible CO2 flooding in asphaltenic crude system. Without injection, at pressure above bubble point, slight precipitation occurred in the zone of the lowest pressure near the producing well. As pressure approached the bubble point, precipitation increased due to the change in the hydrocarbon composition, which suggested that the potential of asphaltene-induced formation damage is determined by the overall fluid composition. At very low pressure, precipitation decreased due to the increase in the density. As CO2 was injected below the minimum miscibility pressure, a slight precipitation occurred in the transition zone at the gas-oil interface due to the microscopic diffusion of the volatile hydrocarbon components caused by the local concentration gradients. The increase in CO2 injection rate did not significantly increase the precipitation rate. As CO2 was injected at pressure above the minimum miscibility pressure

  4. Combustion and regulation; Combustion et reglementation

    Energy Technology Data Exchange (ETDEWEB)



    This conference was organized after the publication of the French by-law no 2010 relative to combustion installations and to the abatement of atmospheric pollution. Five topics were discussed during the conference: the new regulations, their content, innovations and modalities of application; the means of energy suppliers to face the new provisions and their schedule; the manufacturers proposals for existing installations and the new equipments; the administration control; and the impact of the new measures on exploitation and engineering. Twenty papers and 2 journal articles are reported in these proceedings. (J.S.)

  5. Biofuels combustion. (United States)

    Westbrook, Charles K


    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly.

  6. Influence sur les imbrûlés solides de composés métalliques particuliers et du taux de dispersion des asphaltènes dans les fuels lourds Influence of Unburned Solids Made of Unusual Metal Compounds and of the Asphaltene Dispersion Rate in Heavy Fuel Oils

    Directory of Open Access Journals (Sweden)

    Audibert F.


    des asphaltes précipités au pentane dilués avec un gaz oil aromatique de raffinerie. Il a été notamment mis en évidence le rôle joué par les résines dans les dispersions des agglomérats d'asphaltènes et par voie de conséquence dans l'émission d'imbrûlés solides. L'ensemble des observations faites permet de mieux comprendre certains mécanismes intervenant en combustion de fuels lourds. Si l'on se situe sur le plan des émissions particulaires, celles-ci peuvent être largement réduites par l'utilisation de taux suffisants de vapeur auxiliaire au niveau de l'injection. The growing diversity of the origins of crude oils has led to giving consideration to the metal content in combustion models in addition of Conradson carbon or C7 asphaltenes in heavy fuel oils. Such models have been developed by Exxon (1979 and Shell (1981 in particular. Recent research done at Institut Français du Pétrole (IFP on a 2 MW package boiler has shown the influence of unusual metal compounds present in fuel oil in the form of sulfides impregnating porous carbon particles. These microparticles may be formed when severe operating conditions are applied to the visbreaking of residual fuel oils in the presence of hydrogen and a suitable catalyst. These microparticles have proved to be very active in combustion and have shown that the metal concentration is not the only factor to be taken into consideration but that the way in which it is combined may be preponderant. To widen the field of application of models, other parameters, such as the operating conditions of the boiler and the spraying of the fuel oil, have been taken into consideration together with the actual parameters of the influence of the fuel oil (research by the MIT Energy Laboratory, publications in 1986. Concerning the predicting of particulate emissions, a method in addition to tests for Conradson residue and n-heptane insolubility has been applied at IFP as part of a project to upgrade heavy oils in

  7. Turbulent combustion

    Energy Technology Data Exchange (ETDEWEB)

    Talbot, L.; Cheng, R.K. [Lawrence Berkeley Laboratory, CA (United States)


    Turbulent combustion is the dominant process in heat and power generating systems. Its most significant aspect is to enhance the burning rate and volumetric power density. Turbulent mixing, however, also influences the chemical rates and has a direct effect on the formation of pollutants, flame ignition and extinction. Therefore, research and development of modern combustion systems for power generation, waste incineration and material synthesis must rely on a fundamental understanding of the physical effect of turbulence on combustion to develop theoretical models that can be used as design tools. The overall objective of this program is to investigate, primarily experimentally, the interaction and coupling between turbulence and combustion. These processes are complex and are characterized by scalar and velocity fluctuations with time and length scales spanning several orders of magnitude. They are also influenced by the so-called {open_quotes}field{close_quotes} effects associated with the characteristics of the flow and burner geometries. The authors` approach is to gain a fundamental understanding by investigating idealized laboratory flames. Laboratory flames are amenable to detailed interrogation by laser diagnostics and their flow geometries are chosen to simplify numerical modeling and simulations and to facilitate comparison between experiments and theory.

  8. Multiple-sourced features of marine oils in the Tarim Basin, NW China - Geochemical evidence from occluded hydrocarbons inside asphaltenes (United States)

    Tian, Yankuan; Zhao, Jing; Yang, Chupeng; Liao, Zewen; Zhang, Lühui; Zhang, Haizu


    The Tarim Basin, NW China, is a large composite basin with multiple sets of petroleum source rocks. The basin has undergone numerous episodes of hydrocarbon generation, migration and accumulation, making it difficult to assess the source rocks and oil-source correlation for the widespread marine oils in this area. Protected by the molecular structure of asphaltenes, occluded hydrocarbons can provide information about the early source rocks. In this work, the occluded hydrocarbons released from the asphaltenes by a mild chemical degradation method were compared with the crude oil maltenes and the adsorbed compounds from asphaltenes. Analysis of biomarker distribution and the carbon isotope composition of individual n-alkanes suggests that the widespread marine oils in the Tazhong Uplift, Tabei Lunnan Uplift and Halahatang Depression were contributed by Cambrian-Lower Ordovician source rocks at an early stage, and later mixed with hydrocarbons derived from Middle-Upper Ordovician source rocks. The marine oils in the Tarim Basin demonstrate extensive characteristics of having been derived from multiple source rocks.

  9. Sorption and distribution of asphaltene, resin, aromatic and saturate fractions of heavy crude oil on quartz surface: molecular dynamic simulation. (United States)

    Wu, Guozhong; He, Lin; Chen, Daoyi


    The molecular scale sorption, diffusion and distribution of asphaltene, resin, aromatic and saturate fractions of heavy crude oil on quartz surface were studied using molecular dynamic simulation. Sorption of saturates on quartz decreased by 31% when temperature increased from 298 to 398K while opposite trend was observed for resins, but insignificant changes were found in asphaltenes and aromatics. Despite of this variety, the main contribution of interactions was van der Waals energy (>90%) irrespective of molecular components and temperatures. The diffusion coefficient of saturates was predicted as 10.8×10(-10)m(2)s(-1) while that of the remaining fractions was about 4×10(-10)m(2)s(-1) at 298K. The most likely oil distribution on quartz surface was that aromatics and saturates transported randomly into and out of the complex consisting of asphaltenes surrounded by resins, which was influenced by temperature. Overall, the knowledge on quartz-oil and oil-oil interactions gained in this study is essential for future risk assessment and remediation activities as previous studies on soil remediation either limited to light oil fractions with <40 carbons or treated the heavy crude oil as a single pseudo entity ignoring the interactions between oil fractions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Tubular combustion

    CERN Document Server

    Ishizuka, Satoru


    Tubular combustors are cylindrical tubes where flame ignition and propagation occur in a spatially confined, highly controlled environment, in a nearly flat, elongated geometry. This allows for some unique advantages where extremely even heat dispersion is required over a large surface while still maintaining fuel efficiency. Tubular combustors also allow for easy flexibility in type of fuel source, allowing for quick changeover to meet various needs and changing fuel pricing. This new addition to the MP sustainable energy series will provide the most up-to-date research on tubular combustion--some of it only now coming out of private proprietary protection. Plentiful examples of current applications along with a good explanation of background theory will offer readers an invaluable guide on this promising energy technology. Highlights include: * An introduction to the theory of tubular flames * The "how to" of maintaining stability of tubular flames through continuous combustion * Examples of both small-scal...

  11. Advanced Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, Gordon R. [NETL


    The activity reported in this presentation is to provide the mechanical and physical property information needed to allow rational design, development and/or choice of alloys, manufacturing approaches, and environmental exposure and component life models to enable oxy-fuel combustion boilers to operate at Ultra-Supercritical (up to 650{degrees}C & between 22-30 MPa) and/or Advanced Ultra-Supercritical conditions (760{degrees}C & 35 MPa).

  12. Asphaltenes analysis arising of non conventional oils; Analise de asfaltenos oriundos de petroleos nao convencionais

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Fernanda B. da; Fiorio, Paula G.P.; Guimaraes, Maria Jose O.C.; Seidl, Peter R. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica


    The need to use heavy fractions in an efficient way in the production of nobler fractions has motivated the search for ways of separating the asphaltenes, since these molecules increase the viscosity of the fractions submitted to distillation, contribute to the formation of coke and to poisoning and deactivation of catalysts used in process such as cracking, reform, etc, besides provoking cloggings and blockages caused by its deposition, generating losses on the productivity and increases of the operational costs. This paper evaluates the influence of solvent blends (EQ-NP) in the selective extraction of constituents of three samples from Brazilian heavy crude. For the extraction process was used two solvent blends (N1P1 and N1P2). The solvent blend composed of N1P1 showed a higher selectivity in the extraction of aggregates than N1P2. The extracted fraction was characterized by Hydrogen Nuclear Magnetic Resonance ({sup 1}H-NMR) and revealed that the chemical species extracted from different blends exhibit very small differences. (author)

  13. Hydrogen bonding in asphaltenes and coal liquids. Quarterly report, 1 February-30 April 1981

    Energy Technology Data Exchange (ETDEWEB)

    Li, N. C.; Jones, L.; Yaggi, N. F.


    The objective of this project is to investigate the nature and strength of hydrogen bonding and other molecular interactions in coal liquids and their fractions. Determinations are made of the molecular interactions involving the preasphaltene, asphaltent and oil, together with their separated fractions, obtained from coal liquids after hydroprocessing under different processing conditions and accelerated aging. NMR, IR, GC/MS, calorimetric, GPC, ESR, viscosity methods are used to determine structural changes caused by upgrading and aging of coal liquids. The upgraded coal liquids, derived from catalytic hydroprocessing of a 30 to 70 weight percent blend of solid solvent refined coal product (SRC-I) with liquid solvent-refined coal product (SRC-II) were analyzed as a function of contact time and temperature, and the observed variations of structural parameters were correlated with the physical properties of the liquid products. The oxidative degradation of a SRC-II middle distillate, which is an oil, free of asphaltenes and benzene-insolubles, was investigated to determine the molecular types of compounds responsible for the viscosity change and postulate mechanisms. Since the middle distillate is relatively stable to oxidative degradation, copper shavings were added to accelerate the process. Results and discussion are presented in detail.

  14. Investigating co-combustion characteristics of bamboo and wood. (United States)

    Liang, Fang; Wang, Ruijuan; Jiang, Changle; Yang, Xiaomeng; Zhang, Tao; Hu, Wanhe; Mi, Bingbing; Liu, Zhijia


    To investigate co-combustion characteristics of bamboo and wood, moso bamboo and masson pine were torrefied and mixed with different blend ratios. The combustion process was examined by thermogravimetric analyzer (TGA). The results showed the combustion process of samples included volatile emission and oxidation combustion as well as char combustion. The main mass loss of biomass blends occurred at volatile emission and oxidation combustion stage, while that of torrefied biomass occurred at char combustion stage. With the increase of bamboo content, characteristic temperatures decreased. Compared with untreated biomass, torrefied biomass had a higher initial and burnout temperature. With the increase of heating rates, combustion process of samples shifted to higher temperatures. Compared with non-isothermal models, activation energy obtained from isothermal model was lower. The result is helpful to promote development of co-combustion of bamboo and masson pine wastes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Combustion Research Laboratory (United States)

    Federal Laboratory Consortium — The Combustion Research Laboratory facilitates the development of new combustion systems or improves the operation of existing systems to meet the Army's mission for...

  16. Maturity trends in asphaltenes from pyrolysed source rocks and natural coals - multivariate modelling of diffuse reflectance Fourier-transform infrared spectra

    Energy Technology Data Exchange (ETDEWEB)

    Barth, T.; Seim, M.; Christy, A.A.; Kvalheim, O.M. [University of Bergen, Bergen (Norway). Dept. of Chemistry


    Drift spectra of asphaltenes have been modelled by multivariate methods to show the patterns of maturity dependent changes in chemical composition. The asphaltenes are from source rocks that have been artificially matured by hydrous pyrolysis, and cover a wide range of kerogen types and maturity levels. Asphaltenes from a set of naturally matured coal samples are modelled for comparison. The modelling results in defining a limited number of systematic trends in maturity dependent chemical changes in the spectra. The trends are comparable for similar source rocks and are interpreted as representing defunctionalisation, aromatisation and cracking reactions. However, the timing and maturity dependence of the reactions are specific for each source rock, and a general maturation model that includes all source rock types could not be established.

  17. Combustion chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N.J. [Lawrence Berkeley Laboratory, CA (United States)


    This research is concerned with the development and use of sensitivity analysis tools to probe the response of dependent variables to model input variables. Sensitivity analysis is important at all levels of combustion modeling. This group`s research continues to be focused on elucidating the interrelationship between features in the underlying potential energy surface (obtained from ab initio quantum chemistry calculations) and their responses in the quantum dynamics, e.g., reactive transition probabilities, cross sections, and thermal rate coefficients. The goals of this research are: (i) to provide feedback information to quantum chemists in their potential surface refinement efforts, and (ii) to gain a better understanding of how various regions in the potential influence the dynamics. These investigations are carried out with the methodology of quantum functional sensitivity analysis (QFSA).

  18. Characterization of asphaltene molecular structures by cracking under hydrogenation conditions and prediction of the viscosity reduction from visbreaking of heavy oils (United States)

    Rueda Velasquez, Rosa Imelda

    The chemical building blocks that comprise petroleum asphaltenes were determined by cracking samples under conditions that minimized alterations to aromatic and cycloalkyl groups. Hydrogenation conditions that used tetralin as hydrogen-donor solvent, with an iron-based catalyst, allowed asphaltenes from different geological regions to yield 50-60 wt% of distillates (catalytic activity, and preservation of the cycloalkyl structures. Quantitative recovery of cracking products and characterization of the distillates, by gas chromatography-field ionization--time of flight high resolution mass spectrometry, displayed remarkable similarity in molecular composition for the different asphaltenes. Paraffins and 1-3 ring aromatics were the most abundant building blocks. The diversity of molecules identified, and the high yield of paraffins were consistent with high heterogeneity and complexity of molecules, built up by smaller fragments attached to each other by bridges. The sum of material remaining as vacuum residue and coke was in the range of 35-45 wt%; this total represents the maximum amount of large clusters in asphaltenes that could not be converted to lighter compounds under the evaluated cracking conditions. These analytical data for Cold Lake asphaltenes were transformed into probability density functions that described the molecular weight distributions of the building blocks. These distributions were input for a Monte Carlo approach that allowed stochastic construction of asphaltenes and simulation of their cracking reactions to examine differences in the distributions of products associated to the molecular topology. The construction algorithm evidenced that a significant amount of asphaltenes would consist of 3-5 building blocks. The results did not show significant differences between linear and dendritic molecular architectures, but suggested that dendritic molecules would experience slower reaction rates as they required more breakages to reach a given

  19. Improved Economic Performance of Municipal Solid Waste Combustion Plants by Model Based Combustion Control

    NARCIS (Netherlands)

    Leskens, M.


    The combustion of municipal solid waste (MSW) is used for its inertisation, reduction of its volume and the conversion of its energy content into heat and/or electricity. Operation and control of modern large scale MSW combustion (MSWC) plants is determined by economic and environmental objectives

  20. Characterisation of wood combustion ashes

    DEFF Research Database (Denmark)

    Maresca, Alberto

    for their composition and leaching properties. Despite the relatively large variations in the contents of nutrients and trace metals, the overall levels were comparable to typical ranges reported in the literature for other wood combustion ashes, as well as with regards to leaching. In general, the composition......The combustion of wood chips and wood pellets for the production of renewable energy in Denmark increased from 5.7 PJ to 16 PJ during the period 2000-2015, and further increases are expected to occur within the coming years. In 2012, about 22,300 tonnes of wood ashes were generated in Denmark....... Currently, these ashes are mainly landfilled, despite Danish legislation allowing their application onto forest and agricultural soils for fertilising and/or liming purposes. During this PhD work, 16 wood ash samples generated at ten different Danish combustion plants were collected and characterised...

  1. Oxygen-enhanced combustion

    CERN Document Server

    Baukal, Charles E


    Combustion technology has traditionally been dominated by air/fuel combustion. However, two developments have increased the significance of oxygen-enhanced combustion-new technologies that produce oxygen less expensively and the increased importance of environmental regulations. Advantages of oxygen-enhanced combustion include less pollutant emissions as well as increased energy efficiency and productivity. Oxygen-Enhanced Combustion, Second Edition compiles information about using oxygen to enhance industrial heating and melting processes. It integrates fundamental principles, applications, a

  2. Chemical modification of a bitumen and its non-fuel uses. [Reactions of tar sand asphaltenes in synthesis of non-fuel products

    Energy Technology Data Exchange (ETDEWEB)

    Moschopedis, S.E.; Speight, J.G.


    Simple reactions are described whereby tar sand bitumen can be converted to a whole range of materials. Examples are given to illustrate the non-fuel uses of the products. The following reactions of Athabasca asphaltenes are considered: oxidation, halogenation, sulfonation and sulfomethylation, phosphorylation, hydrogenation, reactions with S and O, reactions with metal salts, and miscellaneous chemical conversions. (JGB)

  3. Combustion 2000

    Energy Technology Data Exchange (ETDEWEB)

    A. Levasseur; S. Goodstine; J. Ruby; M. Nawaz; C. Senior; F. Robson; S. Lehman; W. Blecher; W. Fugard; A. Rao; A. Sarofim; P. Smith; D. Pershing; E. Eddings; M. Cremer; J. Hurley; G. Weber; M. Jones; M. Collings; D. Hajicek; A. Henderson; P. Klevan; D. Seery; B. Knight; R. Lessard; J. Sangiovanni; A. Dennis; C. Bird; W. Sutton; N. Bornstein; F. Cogswell; C. Randino; S. Gale; Mike Heap


    . To achieve these objectives requires a change from complete reliance of coal-fired systems on steam turbines (Rankine cycles) and moving forward to a combined cycle utilizing gas turbines (Brayton cycles) which offer the possibility of significantly greater efficiency. This is because gas turbine cycles operate at temperatures well beyond current steam cycles, allowing the working fluid (air) temperature to more closely approach that of the major energy source, the combustion of coal. In fact, a good figure of merit for a HIPPS design is just how much of the enthalpy from coal combustion is used by the gas turbine. The efficiency of a power cycle varies directly with the temperature of the working fluid and for contemporary gas turbines the optimal turbine inlet temperature is in the range of 2300-2500 F (1260-1371 C). These temperatures are beyond the working range of currently available alloys and are also in the range of the ash fusion temperature of most coals. These two sets of physical properties combine to produce the major engineering challenges for a HIPPS design. The UTRC team developed a design hierarchy to impose more rigor in our approach. Once the size of the plant had been determined by the choice of gas turbine and the matching steam turbine, the design process of the High Temperature Advanced Furnace (HITAF) moved ineluctably to a down-fired, slagging configuration. This design was based on two air heaters: one a high temperature slagging Radiative Air Heater (RAH) and a lower temperature, dry ash Convective Air Heater (CAH). The specific details of the air heaters are arrived at by an iterative sequence in the following order:-Starting from the overall Cycle requirements which set the limits for the combustion and heat transfer analysis-The available enthalpy determined the range of materials, ceramics or alloys, which could tolerate the temperatures-Structural Analysis of the designs proved to be the major limitation-Finally the commercialization

  4. Rapid estimation of the organic sulphur content of kerogens, coals and asphaltenes by pyrolysis-gas chromatography

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Eglinton, T.I.; Kohnen, M.E.L.; Leeuw, J.W. de


    A pyrolysis-gas Chromatographic (py-g.c.) method for estimation of the Sorg/C ratio in kerogens and other forms of sedimentary macromolecular organic matter is described. The method is based upon flash pyrolysis at 610 °C for 10s and areal integration of the FID peaks attributed to

  5. Probing the Carbonyl Functionality of a Petroleum Resin and Asphaltene through Oximation and Schiff Base Formation in Conjunction with N-15 NMR.

    Directory of Open Access Journals (Sweden)

    Kevin A Thorn

    Full Text Available Despite recent advances in spectroscopic techniques, there is uncertainty regarding the nature of the carbonyl groups in the asphaltene and resin fractions of crude oil, information necessary for an understanding of the physical properties and environmental fate of these materials. Carbonyl and hydroxyl group functionalities are not observed in natural abundance 13C nuclear magnetic resonance (NMR spectra of asphaltenes and resins and therefore require spin labeling techniques for detection. In this study, the carbonyl functionalities of the resin and asphaltene fractions from a light aliphatic crude oil that is the source of groundwater contamination at the long term USGS study site near Bemidji, Minnesota, have been examined through reaction with 15N-labeled hydroxylamine and aniline in conjunction with analysis by solid and liquid state 15N NMR. Ketone groups were revealed through 15N NMR detection of their oxime and Schiff base derivatives, and esters through their hydroxamic acid derivatives. Anilinohydroquinone adducts provided evidence for quinones. Some possible configurations of the ketone groups in the resin and asphaltene fractions can be inferred from a consideration of the likely reactions that lead to heterocyclic condensation products with aniline and to the Beckmann reaction products from the initially formed oximes. These include aromatic ketones and ketones adjacent to quaternary carbon centers, β-hydroxyketones, β-diketones, and β-ketoesters. In a solid state cross polarization/magic angle spinning (CP/MAS 15N NMR spectrum recorded on the underivatized asphaltene as a control, carbazole and pyrrole-like nitrogens were the major naturally abundant nitrogens detected.

  6. Probing the carbonyl functionality of a petroleum resin and asphaltene through oximation and schiff base formation in conjunction with N-15 NMR (United States)

    Thorn, Kevin A.; Cox, Larry G.


    Despite recent advances in spectroscopic techniques, there is uncertainty regarding the nature of the carbonyl groups in the asphaltene and resin fractions of crude oil, information necessary for an understanding of the physical properties and environmental fate of these materials. Carbonyl and hydroxyl group functionalities are not observed in natural abundance 13C nuclear magnetic resonance (NMR) spectra of asphaltenes and resins and therefore require spin labeling techniques for detection. In this study, the carbonyl functionalities of the resin and asphaltene fractions from a light aliphatic crude oil that is the source of groundwater contamination at the long term USGS study site near Bemidji, Minnesota, have been examined through reaction with 15N-labeled hydroxylamine and aniline in conjunction with analysis by solid and liquid state 15N NMR. Ketone groups were revealed through 15N NMR detection of their oxime and Schiff base derivatives, and esters through their hydroxamic acid derivatives. Anilinohydroquinone adducts provided evidence for quinones. Some possible configurations of the ketone groups in the resin and asphaltene fractions can be inferred from a consideration of the likely reactions that lead to heterocyclic condensation products with aniline and to the Beckmann reaction products from the initially formed oximes. These include aromatic ketones and ketones adjacent to quaternary carbon centers, β-hydroxyketones, β-diketones, and β-ketoesters. In a solid state cross polarization/magic angle spinning (CP/MAS) 15N NMR spectrum recorded on the underivatized asphaltene as a control, carbazole and pyrrole-like nitrogens were the major naturally abundant nitrogens detected.

  7. Rheological properties of hydrate suspensions in asphaltenic crude oils; Proprietes rheologiques de suspensions d'hydrate dans des bruts asphalteniques

    Energy Technology Data Exchange (ETDEWEB)

    Marques de Toledo Camargo, R.


    The development of offshore oil exploitation under increasing water depths has forced oil companies to increase their understanding of gas hydrate formation and transportation in multiphase flow lines in which a liquid hydrocarbon phase is present. This work deals with the flow behaviour of hydrate suspensions in which a liquid hydrocarbon is the continuous phase. Three different liquid hydrocarbons are used: an asphaltenic crude oil, a condensate completely free of asphaltenes and a mixture between the asphaltenic oil and heptane. The rheological characterisation of hydrate suspensions is the main tool employed. Two original experimental devices are used: a PVT cell adapted to operate as a Couette type rheometer and a semi-industrial flow loop. Hydrate suspensions using the asphaltenic oil showed shear-thinning behaviour and thixotropy. This behaviour is typically found in flocculated systems, in which the particles attract each other forming flocs of aggregated particles at low shear rates. The suspensions using the condensate showed Newtonian behaviour. Their relative viscosities were high, which suggests that an aggregation process between hydrate particles takes. place during hydrate formation. Finally, hydrate suspensions using the mixture asphaltenic oil-heptane showed shear-thinning behaviour, thixotropy and high relative viscosity. From these results it can be inferred that, after the achievement of the hydrate formation process, the attractive forces between hydrate particles are weak. making unlikely pipeline obstruction by an aggregation process. Nevertheless, during the hydrate formation, these attractive forces can be sufficiently high. It seems that the hydrate surface wettability is an important parameter in this phenomena. (author)

  8. Combustion Research Facility (United States)

    Federal Laboratory Consortium — For more than 30 years The Combustion Research Facility (CRF) has served as a national and international leader in combustion science and technology. The need for a...

  9. Combustion Aerosols from Pulverised Coal Combustion and Biomass Grate Combustion. Filtration aspects

    Energy Technology Data Exchange (ETDEWEB)

    Lillieblad, Lena [Vaexjoe Univ. (Sweden). Div. of Bioenergy Technology


    Combustion processes generate particles, which are formed both from the inorganic content in the fuel and from organic compounds as a result of incomplete combustion. The particles are removed from the flue gas by cyclones, electrostatic precipitators (ESPs) or fabric filters (FFs). The particle removal capacity is strongly depending on the particle properties, operating conditions and selected particle removal technology. The particle properties are depending on fuel type, combustion technique and combustion conditions. In this study the particle properties for two different types of solid fuel combustion were investigated and compared. The two processes were pulverised coal combustion and grate boilers operating on woody biomass. Characterisation of fuels was made both with standard analyses and more sophisticated methods like computer controlled scanning electron microscopy (CCSEM) and subsequent leaching procedures. A major difference between coal and woody biomass is the occurrence of potassium. In woody biofuel potassium is a reactive components, mainly water-soluble or organically associated, whereas it in coal it is associated to minerals like illite. The particle number size and particle mass size distributions were measured with low-pressure impactors (LPI), electrical mobility analysers and electrical low-pressure impactors (ELPI). The submicrometer particle mass concentration was similar for the two combustion processes. There is a difference between different coals and also between different woody biofuels. The coarse particle fraction is considerably larger for coal combustion, due to the high content of minerals in the coal. Potassium, sulphur and chlorine dominate the submicrometer particle chemical composition from wood fired grate boilers. Coarser particles have a high content of calcium. Silicon and aluminium are the major elements in particles from pulverised coal combustion. An enrichment of calcium, sulphur and phosphorous in the submicrometer

  10. Environmental optimisation of waste combustion

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Robert [AaF Energikonsult, Stockholm (Sweden); Berge, Niclas; Stroemberg, Birgitta [TPS Termiska Processer AB, Nykoeping (Sweden)


    The regulations concerning waste combustion evolve through R and D and a strive to get better and common regulations for the European countries. This study discusses if these rules of today concerning oxygen concentration, minimum temperature and residence time in the furnace and the use of stand-by burners are needed, are possible to monitor, are the optimum from an environmental point of view or could be improved. No evidence from well controlled laboratory experiments validate that 850 deg C in 6 % oxygen content in general is the best lower limit. A lower excess air level increase the temperature, which has a significant effect on the destruction of hydrocarbons, favourably increases the residence time, increases the thermal efficiency and the efficiency of the precipitators. Low oxygen content is also necessary to achieve low NO{sub x}-emissions. The conclusion is that the demands on the accuracy of the measurement devices and methods are too high, if they are to be used inside the furnace to control the combustion process. The big problem is however to find representative locations to measure temperature, oxygen content and residence time in the furnace. Another major problem is that the monitoring of the operation conditions today do not secure a good combustion. It can lead to a false security. The reason is that it is very hard to find boilers without stratifications. These stratifications (stream lines) has each a different history of residence time, mixing time, oxygen and combustible gas levels and temperature, when they reach the convection area. The combustion result is the sum of all these different histories. The hydrocarbons emission is in general not produced at a steady level. Small clouds of unburnt hydrocarbons travels along the stream lines showing up as peaks on a THC measurement device. High amplitude peaks has a tendency to contain higher ratio of heavy hydrocarbons than lower peaks. The good correlation between some easily detected

  11. Catalytic combustion in small wood burning appliances

    Energy Technology Data Exchange (ETDEWEB)

    Oravainen, H. [VTT Energy, Jyvaeskylae (Finland)


    There is over a million hand fired small heating appliances in Finland where about 5,4 million cubic meters of wood fuel is used. Combustion in such heating appliances is a batch-type process. In early stages of combustion when volatiles are burned, the formation of carbon monoxide (CO) and other combustible gases are difficult to avoid when using fuels that have high volatile matter content. Harmful emissions are formed mostly after each fuel adding but also during char burnout period. When the CO-content in flue gases is, say over 0.5 %, also other harmful emissions will be formed. Methane (CH{sub 4}) and other hydrocarbons are released and the amount of polycyclic aromatic hydrocarbons (PAH)-compounds can be remarkable. Some PAH-compounds are very carcinogenic. It has been estimated that in Finland even more than 90 % of hydrocarbon and PAH emissions are due to small scale wood combustion. Emissions from transportation is excluded from these figures. That is why wood combustion has a net effect on greenhouse gas phenomena. For example carbon monoxide emissions from small scale wood combustion are two fold compared to that of energy production in power plants. Methane emission is of the same order as emission from transportation and seven fold compared with those of energy production. Emissions from small heating appliances can be reduced by developing the combustion techniques, but also by using other means, for example catalytic converters. In certain stages of the batch combustion, temperature is not high enough, gas mixing is not good enough and residence time is too short for complete combustion. When placed to a suitable place inside a heating appliance, a catalytic converter can oxidize unburned gases in the flue gas into compounds that are not harmful to the environment. (3 refs.)

  12. Leaching from biomass combustion ash

    DEFF Research Database (Denmark)

    Maresca, Alberto; Astrup, Thomas Fruergaard


    The use of biomass combustion ashes for fertilizing and liming purposes has been widely addressed in scientific literature. Nevertheless, the content of potentially toxic compounds raises concerns for a possible contamination of the soil. During this study five ash samples generated at four...... in water. The content of the selected heavy metals (i.e. Cr, Ni, Pb and Cd) complied with the Danish Statutory Order on the use of bio-ash for agricultural purposes; however, critical releases of Cr were detected in the leachate extracts, especially in the fly ash. High alkaline pHs were measured in all...

  13. The influence of asphaltenes of the petroleum on the rheology of O/W (Oil/Water) emulsions; Influencia de asfaltenos do petroleo sobre a reologia de emulsoes O/A (Oleo/Agua)

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Ronaldo Goncalves dos; Mohamed, Rahoma Sadeg; Loh, Watson; Bannwart, Antonio Carlos [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil)


    Heavy oils represent a large fraction of the Brazilian petroleum reserves and display a great potential for application as substitute to the conventional oils, provided a suitable technology for their transportation is available. The high viscosity of these heavy oils leads to high flow resistance and increase in the recovery and transportation costs. Methodologies employed to reduce these problems involve application of heat of addition of diluents or lighter oils, but are associated with high costs. Formation of low viscosity oil-in-water emulsions has been proposed as an alternative for the transportation of heavy oils, as investigated in this work. Preliminary results indicate significant viscosity decreases upon emulsification of heavy oils (viscosities greater than 1,000 cP) forming o/w emulsions with high oil content (between 50-65 vol. %), which display viscosities within 4-25 cP. Additionally, the effect of different surfactants, methodology of preparation and oil asphaltene content on the emulsion stability was also evaluated. These results confirm the potential of emulsification as a viable methodology for heavy oil transportation. (author)

  14. Effect of asphaltene and resin oils on the viscosity of bituminous petroleum materials to be used as asphalt primers

    Directory of Open Access Journals (Sweden)

    Bencomo, M. R.


    Full Text Available The bituminous crude from the Machete, Venezuela, area, which has such a fluid consistency that it falls outside the normal scope of the A5TM D-5 (1 penetration test exceeding the 3D-mm ceiling specified in that standard and can be used as an asphalt primer: Like other asphalt products, these materials are -chemically speaking- a mix of numerous naphthenic, paraffinic and aromatic hydrocarbons and heterocyclic compounds containing sulphur, nitrogen, oxygen and so on. They have a dense and a malthene oil phase which, along with the natural hydrocarbons additives used in these products acts as a volatile fluidizer. The former is described as a mix of asphaltenes: complex high molecular weight substances that are insoluble in paraffinic hydrocarbons and soluble in aromatic compounds such as benzene. The malthene oil phase, in turn, consists in a mix of resins and hydrocarbons and together the two constitute a colloidal system. The experiments discussed in the present paper were conducted to determine the effect of the proportion of asphaltenes and resin oils on the viscosity of such bituminous crude emulsions/ with a view to their use as primers. These experiments were run in a Parr batch reactor in a nitrogen atmosphere using n-heptane as a solvent. The resins were separated after the asphaltenes precipitated from the samples and subsequently from the malthene fraction obtained. The results showed that the asphaltenes account for the structural characteristics and consistency of the medium and the resin oils for its cohesive properties/,the malthene oils act as solvents.Los crudos extrapesados procedentes del área Machete (Venezuela son materiales de consistencia blanda o fluida, por lo que se salen del campo en el que normalmente se aplica el ensayo de penetración a productos asfálticos según el método ASTM D-5 (1, cuyo límite máximo es 30 mm, y pueden ser utilizados como pinturas asfálticas de imprimación. Al igual que otros productos

  15. Géochimie des résines et asphaltènes Geochernistry of Resins and Asphaltenes

    Directory of Open Access Journals (Sweden)

    Tissot B.


    Full Text Available Les produits lourds des huiles brutes (résines et asphaltènes jouent un rôle important dans la genèse et l'accumulation du pétrole, ainsi que dans la mise en production par des méthodes conventionnelles ou par récupération assistée. Les asphaltènes et résines sont considérés ici comme des fragments de kérogène, avec une structure d'ensemble comparable : ils peuvent constituer des intermédiaires dans la genèse de l'huile brute par dégradation thermique du kérogène. De plus, la pyrolyse des asphaltènes séparés à partir d'un pétrole biodégradé peut produire de nouveaux hydrocarbures saturés qui reproduisent la fraction saturée primitive, détruite par la dégradation ; on peut ainsi disposer d'un nouvel outil pour corréler ce type d'huiles brutes. Les produits lourds semblent défavorisés par rapport aux hydrocarbures, dans la migration de la roche-mère vers le réservoir, où les résines et asphaltènes sont proportionnellement moins abondants. La structure physique des asphaltènes et résines dans les pétroles, et en particulier l'existence d'une macrostructure du type micelles ou agrégats, est probablement responsable de la viscosité élevée des huiles lourdes. Une meilleure connaissance de cette macrostructure pourrait suggérer de nouvelles méthodes pour diminuer la viscosité et améliorer la récupération des huiles lourdes. The heavy constituents of crude oil (resins and asphaltenes play an important role in generation and accumulation of petroleum, and also in production by conventional and enhanced oil recovery processes. Asphaltenes and resins are considered here as small fragments of kerogen, with a comparable overall structure: they may act as intermediate compounds in oil generation by thermal breakdown of kerogen. Furthermore, pyrolysis of asphaltenes separated from a degraded crude oil is able to generate a new saturated hydrocarbon fraction which duplicates the original one, now degraded

  16. Brewster angle microscopy of Langmuir films of athabasca bitumens, n-C5 asphaltenes, and SAGD bitumen during pressure-area hysteresis. (United States)

    Hua, Yujuan; Angle, Chandra W


    Bitumen films formed on water surfaces have negative consequences, both environmental and economic. CanmetENERGY has placed considerable research emphasis on understanding the structures of the bitumen films on water as a necessary step before optimization of bitumen extraction. The detailed structures of the adsorbed molecules and, especially, the role of asphaltene molecules at the interfaces are still under scrutiny and debate. In the present study, we compared bitumen and asphaltene films as they were compressed and expanded under various surface pressures in order to achieve a clearer understanding of bitumen film structures. We used a customized NIMA Langmuir trough interfaced to a Brewster angle microscope (BAM) and CCD camera (Nanofilm_ep3BAM, Accurion, previously Nanofilm Gmbh) to study images of bitumen films at the air/water interface. The bitumen film appeared uniform with high reflectivity at a surface pressure of 18 mN·m(-1) and exhibited a coarse pebblelike interface with reduced reflectivity in the liquid condensed (LC) phase at higher pressures (18-35 mN·m(-1)). During the first cycle of compression asphaltene films showed well-defined phase transitions and a uniformly smooth interface in the LC phase between 9 and 35 mN·m(-1). However, folding or buckling occurred at surface pressures from 35 to 44 mN·m(-1). On expansion, asphaltene films appeared to break into islands. The hysteresis of the pressure-area isotherm was much larger for asphaltenes than for bitumen. In both compression and expansion cycles, BAM images for bitumen films appeared to be more reproducible than those of the asphaltene films at the same surface pressures. Films for low-°API SAGD bitumen were almost identical to those for surface-mined bitumen. Films formed from partially deasphalted surface-mined bitumens showed higher compressibility and lower rigidity than the original bitumen. The BAM images illustrated significant differences between the partially deasphalted and

  17. New combustion, environment regulations: the answers for natural gas; Nouvelles reglementations, combustion, environnement: les reponses pour le gaz naturel

    Energy Technology Data Exchange (ETDEWEB)

    Le Peltier-Marc, A. [Gaz de France (GDF), 75 - Paris (France)


    This paper reports on the point of view from Gaz de France (GdF) company concerning the potential consequences of the use of natural gas in combustion systems with respect to the new regulations about combustion and environment. Details concerning the measures relative to the limitation of pollutants in small combustion installations (2 - 20 MW) are given (chimney height, SO{sub x}, NO{sub x} and dusts content in exhaust gases). (J.S.)

  18. Combustion modeling in internal combustion engines (United States)

    Zeleznik, F. J.


    The fundamental assumptions of the Blizard and Keck combustion model for internal combustion engines are examined and a generalization of that model is derived. The most significant feature of the model is that it permits the occurrence of unburned hydrocarbons in the thermodynamic-kinetic modeling of exhaust gases. The general formulas are evaluated in two specific cases that are likely to be significant in the applications of the model.

  19. Boiler using combustible fluid (United States)

    Baumgartner, H.; Meier, J.G.


    A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

  20. Avaliação geoquímica de biomarcadores ocluídos em estruturas asfaltênicas Geochemical evaluation of occluded biomarkers in asphaltenic structures

    Directory of Open Access Journals (Sweden)

    Débora de Almeida Azevedo


    Full Text Available Asphaltenes from two Brazilian crude oils were submitted to mild oxidation to disrupt their structure, releasing the occluded oil. The released hydrocarbons were compared with those from the original crude oil, and used to evaluate the alteration of the oils, especially as a result of biodegradation, but also thermal maturity. The crude oils used are depleted in n-alkanes, which are usually related to biodegradation. However, the released products from the corresponding asphaltenes have n-alkane distributions from nC10 to nC40, suggesting a protection effect from biodegradation. The m/z 191 mass chromatograms showed higher relative intensities for tricyclic terpanes than the hopanes in the crude in comparison with the released ones.

  1. Combustion characteristics and air pollutant formation during oxy-fuel co-combustion of microalgae and lignite. (United States)

    Gao, Yuan; Tahmasebi, Arash; Dou, Jinxiao; Yu, Jianglong


    Oxy-fuel combustion of solid fuels is seen as one of the key technologies for carbon capture to reduce greenhouse gas emissions. The combustion characteristics of lignite coal, Chlorella vulgaris microalgae, and their blends under O2/N2 and O2/CO2 conditions were studied using a Thermogravimetric Analyzer-Mass Spectroscopy (TG-MS). During co-combustion of blends, three distinct peaks were observed and were attributed to C. vulgaris volatiles combustion, combustion of lignite, and combustion of microalgae char. Activation energy during combustion was calculated using iso-conventional method. Increasing the microalgae content in the blend resulted in an increase in activation energy for the blends combustion. The emissions of S- and N-species during blend fuel combustion were also investigated. The addition of microalgae to lignite during air combustion resulted in lower CO2, CO, and NO2 yields but enhanced NO, COS, and SO2 formation. During oxy-fuel co-combustion, the addition of microalgae to lignite enhanced the formation of gaseous species. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. The Heat of Combustion of Tobacco and Carbon Oxide Formation

    Directory of Open Access Journals (Sweden)

    Norman AB


    Full Text Available Recent studies demonstrated a relationship between mass burn rates of straight-grade cigarettes and heats of combustion of the tobacco materials. In the present work, relationships between measured heats of combustion and elemental composition of the tobacco materials were further analyzed. Heats of combustion measured in oxygen were directly correlated with the carbon and hydrogen content of the tobacco materials tested. Ash content of the materials was inversely related to the heats of combustion. The water insoluble residues from exhaustively extracted tobacco materials showed higher heats of combustion and higher carbon content than the non-extracted materials, confirming a direct relationship between carbon content and heat of combustion. A value for the heat of formation of tobacco was estimated (1175 cal/g from the heat of combustion data and elemental analysis results. The estimated value for heat of formation of tobacco appears to be constant regardless of the material type. Heat values measured in air were uniformly lower than the combustion heats in oxygen, suggesting formation of CO and other reaction products. Gases produced during bomb calorimetry experiments with five tobacco materials were analyzed for CO and CO2 content. When the materials were burned in oxygen, no CO was found in the gases produced. Measured heats of combustion matched estimates based on CO2 found in the gas and conversion of the sample hydrogen content to water. Materials burned in air produced CO2 (56% to 77% of the sample carbon content and appreciable amounts of CO (7% to 16% of the sample carbon content. Unburned residue containing carbon and hydrogen was found in the air combustion experiments. Estimated heat values based on amounts of CO and CO2 found in the gas and water formed from the hydrogen lost during combustion in air were higher than the measured values. These observations indicate formation of products containing hydrogen when the materials

  3. Lump wood combustion process (United States)

    Kubesa, Petr; Horák, Jiří; Branc, Michal; Krpec, Kamil; Hopan, František; Koloničný, Jan; Ochodek, Tadeáš; Drastichová, Vendula; Martiník, Lubomír; Malcho, Milan


    The article deals with the combustion process for lump wood in low-power fireplaces (units to dozens of kW). Such a combustion process is cyclical in its nature, and what combustion facility users are most interested in is the frequency, at which fuel needs to be stoked to the fireplace. The paper defines the basic terms such as burnout curve and burning rate curve, which are closely related to the stocking frequency. The fuel burning rate is directly dependent on the immediate thermal power of the fireplace. This is also related to the temperature achieved in the fireplace, magnitude of flue gas losses and the ability to generate conditions favouring the full burnout of the fuel's combustible component, which, at once ensures the minimum production of combustible pollutants. Another part of the paper describes experiments conducted in traditional fireplaces with a grate, at which well-dried lump wood was combusted.

  4. Study of Asphaltene Solutions by Electrical Conductivity Measurements Conductivité électrique des solutions d'asphaltènes

    Directory of Open Access Journals (Sweden)

    Behar E.


    Full Text Available The asphaltene interactions in model solutions were studied using a technique based on the electrical conductivity measurement. Interactions with n-heptane, resins, surfactants, water, phenol and NaCI were investigated. The conclusions drawn from this study confirmed previous opinions on aggregation mechanism of asphaltenes in solutions. They confirmed also the interpretation of asphaltene behaviour in terms of colloidal solution theories. Les interactions des asphaltènes avec leur environnement moléculaire dans des solutions modèles ont été étudiées par la mesure de la conductivité électrique de ces solutions. Les interactions avec le n-heptane, des résines, des tensioactifs, l'eau, le phénol et le chlorure de sodium ont été explorées. Les conclusions tirées de cette étude ont confirmé certaines hypothèses faites sur les mécanismes d'agrégation des asphaltènes en solution, en particulier dans le cadre de la théorie des solutions colloïdales.

  5. Effect of various catalysts on the chemical structure of oils and asphaltenes obtained from the hydroliquefaction of a highly volatile bituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Cebolla, V.L.; Diack, M.; Oberson, M.; Bacaud, R.; Cagniant, D.; Nickel-Pepin-Donat, B. (Universite de Metz, Metz (France))


    The catalysts studied were aerosols of SiO{sub 2}, Fe{sub 2}O{sub 3}, MoO{sub 3} and Ni-Mo/Al{sub 2}O{sub 3}. The hydroliquefaction runs at 350, 400 and 430{degree}C, in the presence of tetralin and sulfur, were evaluated by solvent extractions, hydrogen consumption and structural analysis of the isolated oil and asphaltene fractions. At 350 {degree}C, a clear influence of the catalyst on the extraction yields is observed. This effect disappears at higher temperatures. Nevertheless, hydrogen consumption from gas or solvent is affected by the nature of the catalyst at a given temperature. The influence of the catalyst is also confirmed by electron spin resonance study of the stable radicals of the tetrahydrofuran insoluble fractions. After elimination of tetralin, the structural analyses were carried out by gas chromatography (oils), size exclusion chromatography (oils and asphaltenes) and extrography (raw hydroliquefaction products). The oils obtained with sulfided Fe{sub 2}O{sub 3} or MoO{sub 3} contained significantly more two-ringed aromatic compounds than oils obtained with the other catalysts or without added catalyst. No significant influence of the catalyst at a given temperature on the oils and asphaltenes is observed by size exclusion chromatography. In contrast, a large temperature effect is evidenced for each fraction, independently of the nature of the catalyst. 38 refs., 7 figs., 6 tabs.

  6. Combustion Byproducts Recycling Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower


    Ashlines: To promote and support the commercially viable and environmentally sound recycling of coal combustion byproducts for productive uses through scientific research, development, and field testing.

  7. Combustion Properties of Briquettes Produced from Maize Cob of ...

    African Journals Online (AJOL)

    mm were densified into briquettes using starch as binder. Combustion related properties namely percentage volatile matter, percentage ash content, percentage fixed carbon and calorific or heating value of the briquettes were determined.

  8. Sulfur Release during Alternative fuels Combustion in Cement Rotary Kilns

    DEFF Research Database (Denmark)

    Cortada Mut, Maria del Mar

    to fossil fuels, due to the lack of experience in handling the different and va rying combustion characteristics caused by different chemical and physical properties, e.g. higher moisture content and larger particle sizes. When full combustion of alternative fuels in the calcin er and/or main burner......, the usage of selected waste, biomass, and by-products with recoverable calorific value, defined as alternative fuels, is increasing and their combustion is mo re challenging compared to fossil fuels, due to the lack of experience in handling the different and va rying combustion characteristics caused...... by different chemical and physical properties, e.g. higher moisture content and larger particle sizes. When full combustion of alternative fuels in the calcin er and/or main burner is not achieved, partially or unburned solid fuels may drop into the material bed in dire ct contact with the bed material...

  9. Molecular Weight and Association of Asphaltenes: a Critical Review Masse moléculaire et association des asphaltènes : une revue critique

    Directory of Open Access Journals (Sweden)

    Speight J. G.


    Full Text Available The determination of asphaltene molecular weights is complicated by the tendency of asphaltene molecules to associate with each other and with other petroleum constituents, and reported molecular weights vary from 900 to 300 000. This paper reviews the methods (vapor pressure osmometry, size exclusion chromatography, ultrafiltration, ultracentrifugation, viscosity, small angle X-ray scattering, infrared spectroscopy, solubilization, and interfacial tension that have been used to estimate asphaltene molecular weights and to probe association phenomena. It is concluded that asphaltene fractions from typical crudes have a number average molecular weight of 1 200-2 700 and a molecular weight range of 1,000-10,000 or higher. Intermolecular association phenomena are primarily responsible for observed molecular weights up to and in excess of 100,000 but detailed mechanisms of the intermolecular associations are not well understood. Certain observations suggest that asphaltene molecules are associated in reversedmicelles and that asphaltenes interact selectively with resins although the evidence on these points is subject to alternate interpretations. H-bond interactions between asphaltenes and resins have been demonstrated. La détermination de la masse moléculaire des asphaltènes est difficile à cause de la tendance qu'ont les molécules d'asphaltènes à s'associer les unes aux autres et avec d'autres constituants des pétroles. Ces masses moléculaires varient de 900 à 300 000. Cet article passe en revue les méthodes (osmométrie par tension de vapeur, chromatographie d'exclusion stérique, ultrafiltration, ultracentrifugation, viscosité, diffusion centrale des rayons X, spectroscopie infra-rouge, solubilisation et tension interfaciale qui ont été utilisées pour estimer les masses moléculaires des asphaltènes et pour étudier les phénomènes d'association. On conclut que les asphaltènes extraits de bruts types ont des masses mol

  10. Lectures on combustion theory

    Energy Technology Data Exchange (ETDEWEB)

    Burstein, S.Z.; Lax, P.D.; Sod, G.A. (eds.)


    Eleven lectures are presented on mathematical aspects of combustion: fluid dynamics, deflagrations and detonations, chemical kinetics, gas flows, combustion instability, flame spread above solids, spark ignition engines, burning rate of coal particles and hydrocarbon oxidation. Separate abstracts were prepared for three of the lectures. (DLC)

  11. Strobes: An Oscillatory Combustion

    NARCIS (Netherlands)

    Corbel, J.M.L.|info:eu-repo/dai/nl/341356034; van Lingen, J.N.J.|info:eu-repo/dai/nl/311441769; Zevenbergen, J.F.; Gijzeman, O.L.J.|info:eu-repo/dai/nl/073464708; Meijerink, A.|info:eu-repo/dai/nl/075044986


    Strobe compositions belong to the class of solid combustions. They are mixtures of powdered ingredients. When ignited, the combustion front evolves in an oscillatory fashion, and flashes of light are produced by intermittence. They have fascinated many scientists since their discovery at the

  12. Strobes: An oscillatory combustion

    NARCIS (Netherlands)

    Corbel, J.M.L.; Lingen, J.N.J. van; Zevenbergen, J.F.; Gijzeman, O.L.J.; Meijerink, A.


    Strobe compositions belong to the class of solid combustions. They are mixtures of powdered ingredients. When ignited, the combustion front evolves in an oscillatory fashion, and flashes of light are produced by intermittence. They have fascinated many scientists since their discovery at the

  13. Rocket Combustion Chamber Coating (United States)

    Holmes, Richard R. (Inventor); McKechnie, Timothy N. (Inventor)


    A coating with the ability to protect (1) the inside wall (i.e., lining) of a rocket engine combustion chamber and (2) parts of other apparatuses that utilize or are exposed to combustive or high temperature environments. The novelty of this invention lies in the manner a protective coating is embedded into the lining.

  14. PDF Modeling of Turbulent Combustion

    National Research Council Canada - National Science Library

    Pope, Stephen B


    .... The PDF approach to turbulent combustion has the advantages of fully representing the turbulent fluctuations of species and temperature, and of allowing realistic combustion chemistry to be implemented...

  15. Fuels and Combustion

    KAUST Repository

    Johansson, Bengt


    This chapter discusses the combustion processes and the link to the fuel properties that are suitable for them. It describes the basic three concepts, including spark ignition (SI) and compression ignition (CI), and homogeneous charge compression ignition (HCCI). The fuel used in a CI engine is vastly different from that in an SI engine. In an SI engine, the fuel should sustain high pressure and temperature without autoignition. Apart from the dominating SI and CI engines, it is also possible to operate with a type of combustion: autoignition. With HCCI, the fuel and air are fully premixed before combustion as in the SI engine, but combustion is started by the increased pressure and temperature during the compression stroke. Apart from the three combustion processes, there are also a few combined or intermediate concepts, such as Spark-Assisted Compression Ignition (SACI). Those concepts are discussed in terms of the requirements of fuel properties.

  16. Résines et asphaltènes : évolution en fonction des types de matière organique et de leur enfouissement Resins and Asphaltenes: Evolution As a Function of Organic-Matter Type and Burial

    Directory of Open Access Journals (Sweden)

    Castex H.


    several basins. It was shown that: (a Resins have higher mean carbon and hydrogen values as well as a lower C/H ratio than asphaltenes. Resins thus have a more aliphatic and or more alicyclic structure. On the other hand, asphaltenes contain more sulfur, oxygen end nitrogen. (b Sulfur and oxygen are not parameters enabling basins to be differentiated. (c Different types of organic matter are revealed by an H/C, O/C diagram. Their chemical evolution with burial is characterized by a decrease in hydrogen, oxygen and sulfur contents. Proton nuclear magnetic resonance (NMR and infrared spectroscopy (IRS were used to follow the structural evolution of resins and asphaltenes coming from different types of organic matter (algal, marine and terrestrial buried at increasing depths. NMR can be used to compute several structural parameters such as FA aromaticity and the degree of sigma substitution of the aromatic system. The FA factor seems to increase with burial and according to the type of organic matter, while sigma seems to decrease. These data were completed by infrared spectroscopy. The surface areas of the bands corresponding to the following functions were computed: (a OH in the 3700-2700 cm-1 range; (b carbonyl C-O around 1700 cm-1; (c aliphatic C-H at 2900, 2455 and 1380 cm-1; (d aromatic C-H at 1610 cm-1. Variations in the intensity of bands: (a decrease of aliphatic C-H and of C-O functions; (b increase of aromatic C-H and C-C are related to both the type of organic matter and its catagenesis.

  17. Combustibility Determination for Cotton Gin Dust and Almond Huller Dust. (United States)

    Hughs, Sidney E; Wakelyn, Phillip J


    It has been documented that some dusts generated while processing agricultural products, such as grain and sugar, can constitute combustible dust hazards. After a catastrophic dust explosion in a sugar refinery in 2008, the Occupational Safety and Health Administration (OSHA) initiated action to develop a mandatory standard to comprehensively address the fire and explosion hazards of combustible dusts. Cotton fiber and related materials from cotton ginning, in loose form, can support smoldering combustion if ignited by an outside source. However, dust fires and other more hazardous events, such as dust explosions, are unknown in the cotton ginning industry. Dust material that accumulates inside cotton gins and almond huller plants during normal processing was collected for testing to determine combustibility. Cotton gin dust is composed of greater than 50% inert inorganic mineral dust (ash content), while almond huller dust is composed of at least 7% inert inorganic material. Inorganic mineral dust is not a combustible dust. The collected samples of cotton gin dust and almond huller dust were sieved to a known particle size range for testing to determine combustibility potential. Combustibility testing was conducted on the cotton gin dust and almond huller dust samples using the UN test for combustibility suggested in NFPA 652.. This testing indicated that neither the cotton gin dust nor the almond huller dust should be considered combustible dusts (i.e., not a Division 4.1 flammable hazard per 49 CFR 173.124). Copyright© by the American Society of Agricultural Engineers.

  18. Influence of catalysts on pulverized coal combustion characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Xu, W.; Du, H. [Northeastern University, Shenyang (China). Dept. of Metallurgy


    The influence of various catalysts on the combustion characteristics of bituminous and anthracite coals have been investigated by examining the combustibility, SEM and XRD of combustion products in the PC combustion equipment. The results show that the catalytic effect of Fe{sup 3+}, Fe{sup 2+}, Ca{sup 2+} and CaCO{sub 3} with a little Ca{sup 2+} or Fe{sup 3+}(Fe{sup 2+}) on PC combustion is strong and better for anthracite. These catalysts increase the combustibility by 1-3% for bituminous and by 10-17% for anthracite and the optimum addition content is equal to 5-7 W%. The strengthened effect of the catalysts on PC combustion have also been confirmed by SEM morphology and X-ray diffraction patterns of char particles. The CaCO{sub 3} with a little maceration extract is a good and cheap catalyst for pulverized coal combustion and the catalytic combustion reaction is in agreement with redox and oxygen transfer mechanism. 7 refs., 6 figs., 1 tab.

  19. Sandia Combustion Research: Technical review

    Energy Technology Data Exchange (ETDEWEB)



    This report contains reports from research programs conducted at the Sandia Combustion Research Facility. Research is presented under the following topics: laser based diagnostics; combustion chemistry; reacting flow; combustion in engines and commercial burners; coal combustion; and industrial processing. Individual projects were processed separately for entry onto the DOE databases.

  20. Particle Emissions from Biomass Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Szpila, Aneta; Bohgard, Mats [Lund Inst. of Technology (Sweden). Div. of Ergonomics and Aerosol Technology; Strand, Michael; Lillieblad, Lena; Sanati, Mehri [Vaexjoe Univ. (Sweden). Div. of Bioenergy Technology; Pagels, Joakim; Rissler, Jenny; Swietlicki, Erik; Gharibi, Arash [Lund Univ. (Sweden). Div. of Nuclear Physics


    We have shown that high concentrations of fine particles of the order of 2-7x10{sup -7} particles per cm{sup 3} are being formed in all the combustion units studied. There was a higher difference between the units in terms of particle mass concentrations. While the largest differences was found for gas-phase constituents (CO and THC) and polyaromatic hydrocarbons. In 5 out of 7 studied units, multi-cyclones were the only measure for flue-gas separation. The multicyclones had negligible effect on the particle number concentration and a small effect on the mass of particles smaller than 5 {mu}m. The separation efficiency was much higher for the electrostatic precipitators. The boiler load had a dramatic influence on the coarse mode concentration during combustion of forest residue. PM0.8-6 increased from below 5 mg/m{sup 3} to above 50 mg/m{sup 3} even at a moderate change in boiler load from medium to high. A similar but less pronounced trend was found during combustion of dry wood. PM0.8-PM6 increased from 12 to 23 mg/m{sup 3} when the load was changed from low to high. When increasing the load, the primary airflow taken through the grate is increased; this itself may lead to a higher potential of the air stream to carry coarse particles away from the combustion zone. Measurements with APS-instrument with higher time-resolution showed a corresponding increase in coarse mode number concentration with load. Additional factor influencing observed higher concentration of coarse mode during combustion of forest residues, could be relatively high ash content in this type of fuel (2.2 %) in comparison to dry wood (0.3 %) and pellets (0.5 %). With increasing load we also found a decrease in PM1 during combustion of forest residue. Whether this is caused by scavenging of volatilized material by the high coarse mode concentration or a result of a different amount of volatilized material available for formation of fine particles needs to be shown in future studies. The

  1. Combustion Technology Outreach (United States)


    Lewis' High Speed Research (HSR) Propulsion Project Office initiated a targeted outreach effort to market combustion-related technologies developed at Lewis for the next generation of supersonic civil transport vehicles. These combustion-related innovations range from emissions measurement and reduction technologies, to diagnostics, spray technologies, NOx and SOx reduction of burners, noise reduction, sensors, and fuel-injection technologies. The Ohio Aerospace Institute and the Great Lakes Industrial Technology Center joined forces to assist Lewis' HSR Office in this outreach activity. From a database of thousands of nonaerospace firms considered likely to be interested in Lewis' combustion and emission-related technologies, the outreach team selected 41 companies to contact. The selected companies represent oil-gas refineries, vehicle/parts suppliers, and manufacturers of residential furnaces, power turbines, nonautomobile engines, and diesel internal combustion engines.

  2. Dioxins and polyvinylchloride in combustion and fires. (United States)

    Zhang, Mengmei; Buekens, Alfons; Jiang, Xuguang; Li, Xiaodong


    This review on polyvinylchloride (PVC) and dioxins collects, collates, and compares data from selected sources on the formation of polychlorinated dibenzofurans (PCDFs) and dibenzo-p-dioxins (PCDDs), or in brief dioxins, in combustion and fires. In professional spheres, the incineration of PVC as part of municipal solid waste is seldom seen as a problem, since deep flue gas cleaning is required anyhow. Conversely, with its high content of chlorine, PVC is frequently branded as a major chlorine donor and spitefully leads to substantial formation of dioxins during poorly controlled or uncontrolled combustion and open fires. Numerous still ill-documented and diverse factors of influence may affect the formation of dioxins during combustion: on the one hand PVC-compounds represent an array of materials with widely different formulations; on the other hand these may all be exposed to fires of different nature and consequences. Hence, attention should be paid to PVC with respect to the ignition and development of fires, as well as attenuating the emission of objectionable compounds, such as carbon monoxide, hydrogen chloride, polycyclic aromatic hydrocarbons, and dioxins. This review summarises available dioxin emissions data, gathers experimental and simulation studies of fires and combustion tests involving PVC, and identifies and analyses the effects of several local factors of influence, affecting the formation of dioxins during PVC combustion. © The Author(s) 2015.

  3. Sandia Combustion Research Program

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, S.C.; Palmer, R.E.; Montana, C.A. (eds.)


    During the late 1970s, in response to a national energy crisis, Sandia proposed to the US Department of Energy (DOE) a new, ambitious program in combustion research. Shortly thereafter, the Combustion Research Facility (CRF) was established at Sandia's Livermore location. Designated a ''user facility,'' the charter of the CRF was to develop and maintain special-purpose resources to support a nationwide initiative-involving US inventories, industry, and national laboratories--to improve our understanding and control of combustion. This report includes descriptions several research projects which have been simulated by working groups and involve the on-site participation of industry scientists. DOE's Industry Technology Fellowship program, supported through the Office of Energy Research, has been instrumental in the success of some of these joint efforts. The remainder of this report presents results of calendar year 1988, separated thematically into eleven categories. Referred journal articles appearing in print during 1988 and selected other publications are included at the end of Section 11. Our traditional'' research activities--combustion chemistry, reacting flows, diagnostics, engine and coal combustion--have been supplemented by a new effort aimed at understanding combustion-related issues in the management of toxic and hazardous materials.

  4. Carbon Shale Combustion in the Fluidized Bed Reactor

    Directory of Open Access Journals (Sweden)

    Olek Małgorzata


    Full Text Available The purpose of this article is to present the possibilities of coal shale combustion in furnaces with bubbling fluidized bed. Coal shale can be autothermally combusted in the fluidized bed, despite the low calorie value and high ash content of fuel. Established concentrations of CO (500 ppm and VOC (30 mg/m3 have indicated a high conversion degree of combustible material during combustion process. Average concentrations of SO2 and NOx in the flue gas were higher than this received from the combustion of high quality hard coal, 600 ppm and 500 ppm, respectively. Optional reduction of SO2 and NOx emission may require the installation of flue gas desulphurization and de-NOx systems.

  5. Burning characteristics of microcellular combustible objects

    Directory of Open Access Journals (Sweden)

    Wei-tao Yang


    Full Text Available Microcellular combustible objects for application of combustible case, caseless ammunition or combustible detonator-holding tubes are fabricated through one-step foaming process, in which supercritical CO2 is used as foaming agent. The formulations consist of inert polymer binder and ultra fine RDX. For the inner porous structures of microcellular combustible objects, the cell sizes present a unimodal or bimodal distribution by adjusting the foaming conditions. Closed bomb test is to investigate the influence of both porous structure style and RDX content on burning behavior. The sample with bimodal distribution of cell sizes burns faster than that with unimodal distribution, and the concentration of RDX can influence the burning characteristics in a positive manner. In addition, the translation of laminar burning to convective burning is determined by burning rate versus pressure curves of samples at two different loading densities, and the resulting transition pressure is 30 MPa. Moreover, the samples with bigger sample size present higher burning rate, resulting in providing deeper convective depth. Dynamic vivacity of samples is also studied. The results show that the vivacity increases with RDX content and varies with inner structure.

  6. Experimental study on combustion of biomass micron fuel (BMF) in cyclone furnace

    Energy Technology Data Exchange (ETDEWEB)

    Luo Siyi, E-mail: [School of Environmental Science and Engineering, Huanzhong University of Science and Technology, Wuhan 430074 (China); Xiao Bo; Hu Zhiquan; Liu Shiming; He Maoyun [School of Environmental Science and Engineering, Huanzhong University of Science and Technology, Wuhan 430074 (China)


    Based on biomass micron fuel (BMF) with particle size less than 250 {mu}m, a cyclone combustion concept was presented and a lab-scale cyclone furnace was designed to evaluate the feasibility. The influences of equivalence ration (ER) and particle size of BMF on combustion performance were studied, as well as temperature distribution in the combustion chamber. The results show that BMF combustion in the cyclone furnace is reliable, with rational temperature distribution inside furnace hearth, lower CO emission, soot concentration and C content in ashes. As ER being 1.2, the temperature in the chamber is maximized up to 1200 deg. C. Smaller particles results in better combustion performances.

  7. Experimental study on combustion of biomass micron fuel (BMF) in cyclone furnace

    Energy Technology Data Exchange (ETDEWEB)

    Siyi Luo; Bo Xiao; Zhiquan Hu; Shiming Liu; Maoyun He [School of Environmental Science and Engineering, Huanzhong University of Science and Technology, Wuhan 430074 (China)


    Based on biomass micron fuel (BMF) with particle size less than 250 {mu}m, a cyclone combustion concept was presented and a lab-scale cyclone furnace was designed to evaluate the feasibility. The influences of equivalence ration (ER) and particle size of BMF on combustion performance were studied, as well as temperature distribution in the combustion chamber. The results show that BMF combustion in the cyclone furnace is reliable, with rational temperature distribution inside furnace hearth, lower CO emission, soot concentration and C content in ashes. As ER being 1.2, the temperature in the chamber is maximized up to 1200 C. Smaller particles results in better combustion performances. (author)

  8. A Review on Suspended Wood Dust Combustion. Efficiency and Fuel Quality (United States)

    Silins, Kaspars


    The paper is dedicated to review the combustion efficiency in low capacity wood dust suspension burners. Fuel quality is reviewed as the main contributor to the combustion efficiency. Wood dust moisture content, particle size and shape, amount of volatiles are discussed as the main contributors. Some additional aspects like burner ignition, fuel and combustion air feeding are reviewed to increase the efficiency. A brief overview of particle combustion process is provided followed by an identification and discussion of combustion efficiency influencing parameters. The significance of fuel feeding and air supply is discussed at the end of the paper.

  9. Combustion Engines Development Mixture Formation, Combustion, Emissions and Simulation

    CERN Document Server

    Schwarz, Christian; Teichmann, Rüdiger


    In the development of engines and vehicles it is nowadays standard practice to use commercially available computing programmes for simulation, not only of the transient reaction of vehicles or of the complete driveshaft, but also of the highly unsteady processes in the combustion chamber of an engine. Normally the source code is not available for these computing programmes and it takes too much time to study the respective specifications, so the users often do not have sufficient knowledge about the physical and chemical contents of the approaches that the programmes are based on. We have often been faced with this fact in talks to employees or in discussions during the presentation of results of simulation. Therefore it is our aim to point out different physical and chemical approaches and to show the possibilities and limits of the models used.

  10. Environmentally conscious coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Hickmott, D.D.; Brown, L.F.; Currier, R.P. [and others


    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project was to evaluate the environmental impacts of home-scale coal combustion on the Navajo Reservation and develop strategies to reduce adverse health effects associated with home-scale coal combustion. Principal accomplishments of this project were: (1) determination of the metal and gaseous emissions of a representative stove on the Navajo Reservation; (2) recognition of cyclic gaseous emissions in combustion in home-scale combustors; (3) `back of the envelope` calculation that home-scale coal combustion may impact Navajo health; and (4) identification that improved coal stoves require the ability to burn diverse feedstocks (coal, wood, biomass). Ultimately the results of Navajo home-scale coal combustion studies will be extended to the Developing World, particularly China, where a significant number (> 150 million) of households continue to heat their homes with low-grade coal.

  11. Fast Reacting Nano Composite Energetic Materials: Synthesis and Combustion Characterization (United States)


    Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 aluminum combustion; energetic materials; fluorine ; reaction kinetics; fluoropolymers; self...techniques will be examined to quantify combustion performance. All of this information will provide a basis for future research and applications involving... fluorine content in the acids and their structural differences contribute to difference in burn velocity. The mechanisms controlling reactivity will be

  12. Combustible structural composites and methods of forming combustible structural composites (United States)

    Daniels, Michael A.; Heaps, Ronald J.; Steffler, Eric D.; Swank, W. David


    Combustible structural composites and methods of forming same are disclosed. In an embodiment, a combustible structural composite includes combustible material comprising a fuel metal and a metal oxide. The fuel metal is present in the combustible material at a weight ratio from 1:9 to 1:1 of the fuel metal to the metal oxide. The fuel metal and the metal oxide are capable of exothermically reacting upon application of energy at or above a threshold value to support self-sustaining combustion of the combustible material within the combustible structural composite. Structural-reinforcing fibers are present in the composite at a weight ratio from 1:20 to 10:1 of the structural-reinforcing fibers to the combustible material. Other embodiments and aspects are disclosed.

  13. 3D-RISM-KH molecular theory of solvation and density functional theory investigation of the role of water in the aggregation of model asphaltenes. (United States)

    da Costa, L M; Hayaki, S; Stoyanov, S R; Gusarov, S; Tan, X; Gray, M R; Stryker, J M; Tykwinski, R; Carneiro, J Walkimar de M; Sato, H; Seidl, P R; Kovalenko, A


    We applied a multiscale modeling approach that involves the statistical-mechanical three-dimensional reference interaction site model with the Kovalenko-Hirata closure approximation (3D-RISM-KH molecular theory of solvation) as well as density functional theory (DFT) of electronic structure to study the role of water in aggregation of the asphaltene model compound 4,4'-bis(2-pyren-1-yl-ethyl)-2,2'-bipyridine (PBP) [X. Tan, H. Fenniri and M. R. Gray, Energy Fuels, 2008, 22, 715]. The solvation free energy and potential of mean force predicted by 3D-RISM-KH reveal favorable pathways for disaggregation of PBP dimers in pure versus water-saturated chloroform solvent. The water density distribution functions elucidate hydrogen bonding preferences and water bridge formation between PBP monomers. The ΔG(298) values of -5 to -7 kcal mol(-1) for transfer of water molecules in chloroform to a state interacting with PBP molecules are in agreement with experimental results. Geometry optimization and thermochemistry analysis of PBP dimers with and without water bridges using WB97Xd/6-31G(d,p) predict that both PBP dimerization and dimer stabilization by water bridges are spontaneous (ΔG(298) experiment. The ΔG(298) results show that hydrogen bonding to water and water-promoted polynuclear assembly bridging is as important as π-π interactions for asphaltene aggregation.

  14. Internal combustion engine (United States)

    Baker, Quentin A.; Mecredy, Henry E.; O'Neal, Glenn B.


    An improved engine is provided that more efficiently consumes difficult fuels such as coal slurries or powdered coal. The engine includes a precombustion chamber having a portion thereof formed by an ignition plug. The precombustion chamber is arranged so that when the piston is proximate the head, the precombustion chamber is sealed from the main cylinder or the main combustion chamber and when the piston is remote from the head, the precombustion chamber and main combustion chamber are in communication. The time for burning of fuel in the precombustion chamber can be regulated by the distance required to move the piston from the top dead center position to the position wherein the precombustion chamber and main combustion chamber are in communication.

  15. Fluidised Bed Combustion: A Novel Technology for the Combustion ...

    African Journals Online (AJOL)

    A firing technology, which is increasingly becoming popular for the combustion of fuels with difficult combustion properties, is fluidised bed combustion (FBC). In the current paper, the special features of FBC have been reviewed and their advantages as compared to conventional firing systems highlighted. This has been ...

  16. Alcohol combustion chemistry

    KAUST Repository

    Sarathy, Mani


    Alternative transportation fuels, preferably from renewable sources, include alcohols with up to five or even more carbon atoms. They are considered promising because they can be derived from biological matter via established and new processes. In addition, many of their physical-chemical properties are compatible with the requirements of modern engines, which make them attractive either as replacements for fossil fuels or as fuel additives. Indeed, alcohol fuels have been used since the early years of automobile production, particularly in Brazil, where ethanol has a long history of use as an automobile fuel. Recently, increasing attention has been paid to the use of non-petroleum-based fuels made from biological sources, including alcohols (predominantly ethanol), as important liquid biofuels. Today, the ethanol fuel that is offered in the market is mainly made from sugar cane or corn. Its production as a first-generation biofuel, especially in North America, has been associated with publicly discussed drawbacks, such as reduction in the food supply, need for fertilization, extensive water usage, and other ecological concerns. More environmentally friendly processes are being considered to produce alcohols from inedible plants or plant parts on wasteland. While biofuel production and its use (especially ethanol and biodiesel) in internal combustion engines have been the focus of several recent reviews, a dedicated overview and summary of research on alcohol combustion chemistry is still lacking. Besides ethanol, many linear and branched members of the alcohol family, from methanol to hexanols, have been studied, with a particular emphasis on butanols. These fuels and their combustion properties, including their ignition, flame propagation, and extinction characteristics, their pyrolysis and oxidation reactions, and their potential to produce pollutant emissions have been intensively investigated in dedicated experiments on the laboratory and the engine scale

  17. Scramjet Combustion Processes (United States)


    Propulsion a vitesse elevee : Conception du moteur - integration et gestion thermique ) 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF...entrance to the combustion duct, where the production of the chemical radicals, which are a first stage in Scramjet Combustion Processes RTO-EN-AVT-185...314KM) Nosecone Eject (47SEC,73KM,M7.7) Orion Burnout (39SEC,56KM,M7.1) Orion Ignition (12SEC,9.4KM,M3.2) Terrier Ignition (0SEC,0KM,M0) Stage

  18. Radiative Augmented Combustion. (United States)


    86-0085 In 00I to RADIATIVE AUGMENTED COMBUSTION MOSHE LAVID M.L. ENERGIA , INC. P.O. BOX 1468 1 PRINCETON, NEW JERSEY 08542 AUGUST 1985 *.. plo...Combustion conducted at M.L. ENERGIA . It is funded by the Air Force Office of Scientific Research under Contract No. F49620-83-C-0133, with Dr. J.M...reported. It covers the second year of the contract, from July 15, 1984 through July 14, 1985. The work was performed at ENERGIA , Princeton, New Jersey

  19. Studies in combustion dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Koszykowski, M.L. [Sandia National Laboratories, Livermore, CA (United States)


    The goal of this program is to develop a fundamental understanding and a quantitative predictive capability in combustion modeling. A large part of the understanding of the chemistry of combustion processes comes from {open_quotes}chemical kinetic modeling.{close_quotes} However, successful modeling is not an isolated activity. It necessarily involves the integration of methods and results from several diverse disciplines and activities including theoretical chemistry, elementary reaction kinetics, fluid mechanics and computational science. Recently the authors have developed and utilized new tools for parallel processing to implement the first numerical model of a turbulent diffusion flame including a {open_quotes}full{close_quotes} chemical mechanism.

  20. Toxicology of Biodiesel Combustion products (United States)

    1. Introduction The toxicology of combusted biodiesel is an emerging field. Much of the current knowledge about biological responses and health effects stems from studies of exposures to other fuel sources (typically petroleum diesel, gasoline, and wood) incompletely combusted. ...

  1. Fuel-Rich Catalytic Combustion (United States)

    Brabbs, Theodore A.; Olson, Sandra L.


    Two-stage combustion system reduces particulate emissions. Program on catalytic oxidation of iso-octane demonstrates feasibility of two-stage combustion system for reducing particulate emissions. With fuel-rich (fuel/air equivalence ratios of 4.8 to 7.8) catalytic-combustion preburner as first stage, combustion process free of soot at reactor-outlet temperatures of 1,200 K or less.

  2. Adsorption Isotherms of Phenol and 4-Chlorophenol on Petroleum Asphaltenes Adsorption du phénol et du 4-chlorophénol sur les asphaltènes pétroliers

    Directory of Open Access Journals (Sweden)

    Jaoui M.


    Full Text Available The adsorption isotherms for phenol and 4-chlorophenol from water onto asphaltenes flocculated in bulk and asphaltenes deposited on silica were established by frontal analysis chromatography at 293, 298, 303, and 308 K. The adsorption was more important with asphaltenes flocculated in bulk and corresponded to a Freundlich isotherm mechanism. The high adsorbed amount of phenols suggests possible migration of phenols through the loose asphaltene structure. Isotherms observed with the silica coated by asphaltenes showed that adsorption occurs in two stages corresponding probably to two different organizations of solute molecules at the surface. Les isothermes d'adsorption du phénol et du 4-chlorophénol en solution dans l'eau sur des asphaltènes floculés en masse et sur des asphaltènes déposés sur de la silice ont été déterminés par analyse chromatographique frontale à 293, 298, 303 et 308 K. L'adsorption sur des asphaltènes floculés en masse était la plus importante avec des isothermes correspondant à un mécanisme de Freundlich. La quantité élevée de phénols adsorbés suggère une migration possible des molécules du phénol à travers la structure peu compacte des asphaltènes. Les isothermes observés dans le cas de silice tapissée d'asphaltènes ont montré que l'adsorption se produit en deux étapes correspondant probablement à deux organisations différentes des molécules de soluté à la surface.

  3. Coal combustion research

    Energy Technology Data Exchange (ETDEWEB)

    Daw, C.S.


    This section describes research and development related to coal combustion being performed for the Fossil Energy Program under the direction of the Morgantown Energy Technology Center. The key activity involves the application of chaos theory for the diagnosis and control of fossil energy processes.

  4. Nonlinear Combustion Instability Prediction (United States)

    Flandro, Gary


    The liquid rocket engine stability prediction software (LCI) predicts combustion stability of systems using LOX-LH2 propellants. Both longitudinal and transverse mode stability characteristics are calculated. This software has the unique feature of being able to predict system limit amplitude.

  5. Supersonic Combustion Ramjet Research (United States)


    engine). As noted above in USAF scramjet flight scenarios , high vehicle heat loads will ensure that the fuel (initially a liquid hydrocarbon such as a... cinema stereoscopic PIV system for the measurement of micro- and meso-scale turbulent premixed flame dynamics,” Paper B13, 5th US Combustion

  6. Low emission internal combustion engine (United States)

    Karaba, Albert M.


    A low emission, internal combustion compression ignition engine having a cylinder, a piston movable in the cylinder and a pre-combustion chamber communicating with the cylinder near the top thereof and in which low emissions of NO.sub.x are achieved by constructing the pre-combustion chamber to have a volume of between 70% and 85% of the combined pre-chamber and main combustion chamber volume when the piston is at top dead center and by variably controlling the initiation of fuel injection into the pre-combustion chamber.

  7. Solution combustion synthesis of α-Al2O3 using urea


    Zhuravlev, V. D.; Bamburov, V. G.; Beketov, A. R.; Perelyaeva, L. A.; BAKLANOVA I.V.; Sivtsova, O. V.; Vasil'ev, V. G.; Vladimirova, E. V.; Shevchenko, V.G.; Grigorov, I. G.


    The processes involved in the solution combustion synthesis of α-Al2O3 using urea as an organic fuel were investigated. The data describing the influence of the relative urea content on the characteristic features of the combustion process, the crystalline structure and the morphology of the aluminium oxide are presented herein. Our data demonstrate that the combustion of stable aluminium nitrate and urea complexes leads to the formation of α-alumina at temperatures of approximately 600-800 °...

  8. Constant-Pressure Combustion Charts Including Effects of Diluent Addition (United States)

    Turner, L Richard; Bogart, Donald


    Charts are presented for the calculation of (a) the final temperatures and the temperature changes involved in constant-pressure combustion processes of air and in products of combustion of air and hydrocarbon fuels, and (b) the quantity of hydrocarbon fuels required in order to attain a specified combustion temperature when water, alcohol, water-alcohol mixtures, liquid ammonia, liquid carbon dioxide, liquid nitrogen, liquid oxygen, or their mixtures are added to air as diluents or refrigerants. The ideal combustion process and combustion with incomplete heat release from the primary fuel and from combustible diluents are considered. The effect of preheating the mixture of air and diluents and the effect of an initial water-vapor content in the combustion air on the required fuel quantity are also included. The charts are applicable only to processes in which the final mixture is leaner than stoichiometric and at temperatures where dissociation is unimportant. A chart is also included to permit the calculation of the stoichiometric ratio of hydrocarbon fuel to air with diluent addition. The use of the charts is illustrated by numerical examples.

  9. Combustion characteristics of biodried sewage sludge. (United States)

    Hao, Zongdi; Yang, Benqin; Jahng, Deokjin


    In this study, effects of biodrying on the characteristics of sewage sludge and the subsequent combustion behavior were investigated. 7-Day of biodrying removed 49.78% of water and 23.17% of VS initially contained in the sewage sludge and increased lower heating value (LHV) by 37.87%. Meanwhile, mass contents of C and N decreased from 36.25% and 6.12% to 32.06% and 4.82%, respectively. Surface of the biodried sewage sludge (BDSS) appeared granulated and multi-porous, which was thought to facilitate air transfer during combustion. According to thermogravimetric (TG) analysis coupled with mass spectrometer (MS) with a heating rate of 10 °C/min from 35 °C to 1000 °C, thermally-dried sewage sludge (TDSS) and BDSS lost 74.39% and 67.04% of the initial mass, respectively. In addition, combustibility index (S) of BDSS (8.67 × 10 -8  min -2  K -3 ) was higher than TDSS. TG-MS analyses also showed that less nitrogenous gases were generated from BDSS than TDSS. It was again showed that the average CO and NO concentrations in exit gas from isothermal combustion of BDSS were lower than those from TDSS, especially at low temperatures (≤800 °C). Based on these results, it was concluded that biodrying of sewage sludge was an energy-efficient water-removal method with less emission of air pollutants when BDSS was combusted. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Slagging and fouling risk of Mediterranean biomasses for combustion

    Energy Technology Data Exchange (ETDEWEB)

    Vega-Nieva, Daniel J.; Dopazo, Raquel; Ortiz, Luis (Univ. of Vigo (Spain), Forestry School, A Xunqueira Campus, Pontevedra)


    The interest in biomass combustion has grown exponentially in the last years, as a means for renewable heat and energy promoting local development and mitigating climate change. Various Mediterranean agricultural and forest resources such as olive stone, almond shell or pinecone chips remain large unutilized, despite their potential for being utilized in biomass combustion. New energy crops such as Cardoon, Brassica or Sorghum, are being introduced in Mediterranean countries for Bioenergy production; however, the slagging and fouling risk of many of these potential feedstocks are currently limiting their application in combustion processes given their high alkali, silica or chlorine contents. In this publication, various methods for biomass slagging and fouling hazard monitoring and prediction are presented based on recent studies with Mediterranean biomasses combustion in Spain

  11. Aerosols from biomass combustion

    Energy Technology Data Exchange (ETDEWEB)

    Nussbaumer, T.


    This report is the proceedings of a seminar on biomass combustion and aerosol production organised jointly by the International Energy Agency's (IEA) Task 32 on bio energy and the Swiss Federal Office of Energy (SFOE). This collection of 16 papers discusses the production of aerosols and fine particles by the burning of biomass and their effects. Expert knowledge on the environmental impact of aerosols, formation mechanisms, measurement technologies, methods of analysis and measures to be taken to reduce such emissions is presented. The seminar, visited by 50 participants from 11 countries, shows, according to the authors, that the reduction of aerosol emissions resulting from biomass combustion will remain a challenge for the future.

  12. Fluid-bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, G.; Schoebotham, N.


    In Energy Equipment Company's two-stage fluidized bed system, partial combustion in a fluidized bed is followed by burn-off of the generated gases above the bed. The system can be retrofitted to existing boilers, and can burn small, high ash coal efficiently. It has advantages when used as a hot gas generator for process drying. Tests on a boiler at a Cadbury Schweppes plant are reported.

  13. Premixed Supersonic Combustion (Rev) (United States)


    lean and low temperature flameout points). Figure 11. Chemiluminescence image (0.6 ms capture) at global φ = 0.41 (cavity-side = 0.27...mixing can still be rate-controlling if the flow temperature is high or if a flame holder is present and there is an adequate source of combustion... temperature associated with kinetic energy and ΔTc is the change in temperature associated with the chemistry [3]. If the rise in temperature

  14. Theory of Combustion Noise (United States)


    The overall sound generation processes have been classi- fied in terms of the sound due to an isolated turbulent flame and that due to the...of the fluid mechanics of the reacting gas. The overall sound generation processes have been classified in terms of the sound due to an isolated ...steady intercoupling between various aerothermochemical modes excited in the combustion zone. To be specific, the non-steady exo- thermic and

  15. Combustion science and engineering

    CERN Document Server

    Annamalai, Kalyan


    Introduction and Review of Thermodynamics Introduction Combustion Terminology Matter and Its Properties Microscopic Overview of Thermodynamics Conservation of Mass and Energy and the First Law of Thermodynamics The Second Law of Thermodynamics Summary Stoichiometry and Thermochemistry of Reacting Systems Introduction Overall Reactions Gas Analyses Global Conservation Equations for Reacting Systems Thermochemistry Summary Appendix Reaction Direction and Equilibrium Introduction Reaction Direction and Chemical Equilibrium Chemical Equilibrium Relations Vant Hoff Equation Adi

  16. Combustion Characteristics of Sprays (United States)


    regarded by implication or otherwise, or in any way licensing the holder or any other person or corporation, or conveying any rights or permission to...00 _’N 1. TI TLE inctuat Security CZaaafication5 Combustion Characteristics of Sprays 12. PERSONAL AUTHOR(S) Sohrab, Siavash H. 13& TYPE OF ?!HF of rich butane/air 3unsen flames. .lso, the rotacion speed and :he oerodic temDeracure fluc:uations of rotacfng ?HF are examined. :’!naily

  17. Evaluation of nano emulsion containing asphaltenes dispersant additive in dehydration of oil; Avaliacao de nanoemulsoes contendo aditivo dispersante de asfaltenos na desidratacao de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Priscila F. de; Rodrigues, Jessica S.; Mansur, Claudia R.E. [Universidade Federal do Rio de Janeiro/ Instituto de Macromoleculas/ Laboratorio de Macromoleculas e Coloides na Industria de Petroleo, Rio de Janeiro, RJ (Brazil)], e-mail:


    Due to the problem of the formation of emulsions type water-oil during oil production, new alternatives of the breakdown of these emulsions have been proposed over the years. Several polymers have been used to destabilize these emulsions and among them are those based on polyphenylene ether. The aim of this study was to develop nanoemulsions type oil / water, where an asphaltenes dispersant additive was dissolved in dispersed phase in order to evaluate them as a new alternative in the breakdown of oil emulsions. The nanoemulsions were prepared in the presence of surfactant based on polyoxide using a high pressure homogenizer (HPH). We obtained stable nanoemulsions for more than 30 days in the presence or absence of additive. These nanoemulsions were effective in water /oil phase separation, and the nanoemulsion containing the dispersant additive provided a faster separation of these phases. (author)

  18. Optical fiber extrinsic refractometer to measure RI of samples in a high pressure and temperature systems: Application to wax and asphaltene precipitation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Jimmy Castillo; Carlos Canelon; Socrates Acevedo; Herve Carrier; Jean-Luc Daridon [Universidad Central de Venezuela, Caracas (Venezuela). Facultad de Ciencias, Escuela de Quimica


    An optical fiber extrinsic sensor for measurement of changes in the refractive index of liquids confined in chambers for high pressure and temperature experiments is described. One head sensor composed by two fibers is fixed in front of a high pressure and temperature cell filled with the sample. The operation principle is based in the reflectivity dependence in the refractive index of the glass-liquid interface. Excellent results and a sensitivity of 10{sup -5} RI were obtained for pure liquids. The applicability of the sensor is demonstrated following the changes in the refractive index for pure liquids at different pressure and temperatures and by measuring the asphaltenes and wax precipitation in crude oils under pressure. The extrinsic probe designed for refractive index measurement proves to be a reliable tool for measuring heavy organics deposition in crude oils under high pressures and temperatures where the sample to be measured is not very accessible. 25 refs., 11 figs., 2 tabs.

  19. Strobes: an oscillatory combustion. (United States)

    Corbel, Justine M L; Lingen, Joost N J; Zevenbergen, John F; Gijzeman, Onno L J; Meijerink, Andries


    Strobe compositions belong to the class of solid combustions. They are mixtures of powdered ingredients. When ignited, the combustion front evolves in an oscillatory fashion, and flashes of light are produced by intermittence. They have fascinated many scientists since their discovery at the beginning of the 20th century. However, the chemical and physical processes involved in this curious oscillatory combustion remain unknown. Several theories have been proposed: One claims that two different reactions occur: one during the slow dark phase and another during the fast flash phase. The alternation between the phases is ascribed to heat variations. Other theories suggest that the formation of intermediate species during the dark phase and the change of phase are caused by variations in their concentration. A ternary strobe composition with ammonium perchlorate, magnalium, and barium sulfate is analyzed. The role of barium sulfate is studied by replacing it by other metal sulfates that have different physical properties (melting points), and the burning of the compositions is recorded with a high-speed camera and a spectrometer coupled with a charge-coupled device (CCD) camera. Experimental results show noticeable differences in the physical and chemical processes involved in the strobe reactions.

  20. Internal combustion piston engines

    Energy Technology Data Exchange (ETDEWEB)

    Segaser, C.L.


    Current worldwide production of internal combustion piston engines includes many diversified types of designs and a very broad range of sizes. Engine sizes range from a few horsepower in small mobile units to over 40,000 brake horsepower in large stationary and marine units. The key characteristics of internal combustion piston engines considered appropriate for use as prime movers in Integrated Community Energy Systems (ICES) are evaluated. The categories of engines considered include spark-ignition gas engines, compression-ignition oil (diesel) engines, and dual-fuel engines. The engines are evaluated with respect to full-load and part-load performance characteristics, reliability, environmental concerns, estimated 1976 cost data, and current and future status of development. The largest internal combustion piston engines manufactured in the United States range up to 13,540 rated brake horsepower. Future development efforts are anticipated to result in a 20 to 25% increase in brake horsepower without increase in or loss of weight, economy, reliability, or life expectancy, predicated on a simple extension of current development trends.

  1. Issues in waste combustion

    Energy Technology Data Exchange (ETDEWEB)

    Gustavsson, Lennart; Robertson, Kerstin; Tullin, Claes [Swedish National Testing and Research Inst., Boraas (Sweden); Sundquist, Lena; Wrangensten, Lars [AaF-Energikonsult AB, Stockholm (Sweden); Blom, Elisabet [AaF-Processdesign AB, Stockholm (Sweden)


    The main purpose of this review is to provide an overview of the state-of-the-art on research and development issues related to waste combustion with relevance for Swedish conditions. The review focuses on co-combustion in grate and fluidised bed furnaces. It is primarily literature searches in relevant databases of scientific publications with to material published after 1995. As a complement, findings published in different report series, have also been included. Since the area covered by this report is very wide, we do not claim to cover the issues included completely and it has not been possitile to evaluate the referred studies in depth. Basic knowledge about combustion issues is not included since such information can be found elsewhere in the literature. Rather, this review should be viewed as an overview of research and development in the waste-to-energy area and as such we hope that it will inspire scientists and others to further work in relevant areas.

  2. Spray combustion stability (United States)

    Liang, Pak-Yan; Jeng, S. M.; Litchford, Ronald


    The central purpose of this project is the improvement of liquid-fueled rocket motor design technology in order to assist the establishment of economical commercial access to space through the development of engines with enhanced performance and reliability. Specific research effort in the project is focused on spray physics and associated combustion instability phenomena. Results garnered from this work will contribute to the development of new computational tools for design of stable liquid propellant rocket engines. The specific objectives of the research effort include identifying and evaluating physical submodels which pertain to spray combustion stability with the idea of enhancing or refining existing submodels with a more comprehensive approach. In particular, any refinements to the spray combustion physical submodels which are achieved during the project will be channeled back to Rocketdyne for incorporation in their ARICC liquid rocket combustor code as second generation improvements. Also, as the ARICC code forms the basis or future CFD development, some effort is devoted to an evaluation of the code's capability for modeling oscillating pressure waves within the combustor.

  3. The Diesel Combustion Collaboratory: Combustion Researchers Collaborating over the Internet

    Energy Technology Data Exchange (ETDEWEB)

    C. M. Pancerella; L. A. Rahn; C. Yang


    The Diesel Combustion Collaborator (DCC) is a pilot project to develop and deploy collaborative technologies to combustion researchers distributed throughout the DOE national laboratories, academia, and industry. The result is a problem-solving environment for combustion research. Researchers collaborate over the Internet using DCC tools, which include: a distributed execution management system for running combustion models on widely distributed computers, including supercomputers; web-accessible data archiving capabilities for sharing graphical experimental or modeling data; electronic notebooks and shared workspaces for facilitating collaboration; visualization of combustion data; and video-conferencing and data-conferencing among researchers at remote sites. Security is a key aspect of the collaborative tools. In many cases, the authors have integrated these tools to allow data, including large combustion data sets, to flow seamlessly, for example, from modeling tools to data archives. In this paper the authors describe the work of a larger collaborative effort to design, implement and deploy the DCC.

  4. Internal combustion engine using premixed combustion of stratified charges (United States)

    Marriott, Craig D [Rochester Hills, MI; Reitz, Rolf D [Madison, WI


    During a combustion cycle, a first stoichiometrically lean fuel charge is injected well prior to top dead center, preferably during the intake stroke. This first fuel charge is substantially mixed with the combustion chamber air during subsequent motion of the piston towards top dead center. A subsequent fuel charge is then injected prior to top dead center to create a stratified, locally richer mixture (but still leaner than stoichiometric) within the combustion chamber. The locally rich region within the combustion chamber has sufficient fuel density to autoignite, and its self-ignition serves to activate ignition for the lean mixture existing within the remainder of the combustion chamber. Because the mixture within the combustion chamber is overall premixed and relatively lean, NO.sub.x and soot production are significantly diminished.

  5. Oxy combustion with CO{sub 2} capture

    Energy Technology Data Exchange (ETDEWEB)



    An update for oxyfuel-combustion carbon capture in the power industry is provided. The report was developed by the Electric Power Research Institute (EPRI) on behalf of the Global CCS Institute. In the oxyfuel-combustion processes, the bulk nitrogen is removed from the air before combustion. The resulting combustion products will have CO2 content up to about 90 per cent (dry basis). The flue gas impurities (predominantly O2, N2, and Ar) may be removed by reducing the flue gas (at moderate pressure) to a temperature at which the CO2 condenses and the impurities do not. Oxyfuel-combustion may be employed with solid fuels such as coal, petroleum coke, and biomass, as well as liquid and gaseous fuels. Some key points raised in the oxyfuel-combustion carbon capture report are: The oxyfuel-combustion/CO2 capture power plant designs being developed and deployed for service in the next four or five years are based on individual component technologies and arrangements which have demonstrated sufficient maturity, with the greatest remaining technical challenge being integrating the systems into a complete steam-electric power plant; By its nature, an oxyfuel-coal power plant is likely to be a 'near zero' emitter of all criteria pollutants; Existing air-fired power plants might be retrofitted with an air separation unit, oxyfuel-fired burners, flue gas recycle, and a CO2 processing unit, with the large fleet of air-fired power plants in service calling for more study of this option; and, Future efficiency improvements to the oxyfuel-combustion process for power generation point toward an oxyfuel-combustion plant with near zero emissions of conventional pollutants, up to 98 per cent CO2 capture, and efficiency comparable to the best power plants currently being built.

  6. Effects of intake air temperature on homogenous charge compression ignition combustion and emissions with gasoline and n-heptane

    Directory of Open Access Journals (Sweden)

    Zhang Jianyong


    Full Text Available In a port fuel injection engine, Optimized kinetic process (OKP technology is implemented to realize HCCI combustion with dual-fuel injection. The effects of intake air temperature on HCCI combustion and emissions are investigated. The results show that dual-fuel control prolongs HCCI combustion duration and improves combustion stability. Dual-fuel HCCI combustion needs lower intake air temperature than gasoline HCCI combustion, which reduces the requirements on heat management system. As intake air temperature decreases, air charge increases and maximum pressure rising rate decreases. When intake air temperature is about 55ºC, HCCI combustion becomes worse and misfire happens. In fixed dual fuel content condition, HC and CO emission decreases as intake air temperature increases. The combination of dual-fuel injection and intake air temperature control can expand operation range of HCCI combustion.

  7. Computational study of the effect of dispersion interactions on the thermochemistry of aggregation of fused polycyclic aromatic hydrocarbons as model asphaltene compounds in solution. (United States)

    Moreira da Costa, Leonardo; Stoyanov, Stanislav R; Gusarov, Sergey; Seidl, Peter R; Walkimar de M Carneiro, José; Kovalenko, Andriy


    Density functional theory (DFT), Møller-Plesset second-order perturbation theory (MP2), and semiempirical methods are employed for the geometry optimization and thermochemistry analysis of π-π stacked di-, tri-, tetra-, and pentamer aggregates of the fused polycyclic aromatic hydrocarbons (PAHs) naphthalene, anthracene, phenanthrene, tetracene, pyrene, and coronene as well as benzene. These aggregates (stabilized by dispersion interactions) are highly relevant to the intermolecular aggregation of asphaltenes, major components of heavy petroleum. The strength of π-π stacking interaction is evaluated with respect to the π-stacking distance and thermochemistry results, such as aggregation enthalpies, entropies, and Gibbs free energies (ΔG(298)). For both π-stacking interplanar distances and thermochemistry, the ωB97X-D functional with an augmented damped R(-6) dispersion correction term and MP2 are in the closest agreement with the highly accurate spin-component scaled MP2 (SCS-MP2) method that we selected as a reference. The ΔG(298) values indicate that the aggregation of coronene is spontaneous at 298 K and the formation of pyrene dimers occurs spontaneously at temperature lower than 250 K. Aggregates of smaller PAHs would be stable at even lower temperature. These findings are supported by X-ray crystallographic determination results showing that among the PAHs studied only coronene forms continuous stacked aggregates in single crystals, pyrene forms dimers, and smaller PAHs do not form π-π stacked aggregates. Thermochemistry analysis results show that PAHs containing more than four fused benzene rings would spontaneously form aggregates at 298 K. Also, round-shaped PAHs, such as phenanthrene and pyrene, form more stable aggregates than linear PAHs, such as anthracene and tetracene, due to decreased entropic penalty. These results are intended to help guide the synthesis of model asphaltene compounds for spectroscopic studies so as to help understand

  8. Soil moisture dynamics and smoldering combustion limits of pocosin soils in North Carolina, USA (United States)

    James Reardon; Gary Curcio; Roberta Bartlette


    Smoldering combustion of wetland organic soils in the south-eastern USA is a serious management concern. Previous studies have reported smoldering was sensitive to a wide range of moisture contents, but studies of soil moisture dynamics and changing smoldering combustion potential in wetland communities are limited. Linking soil moisture measurements with estimates of...

  9. Development of flameless combustion; Desarrollo de la combustion sin flama

    Energy Technology Data Exchange (ETDEWEB)

    Flores Sauceda, M. Leonardo; Cervantes de Gortari, Jaime Gonzalo [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail:;


    The paper intends contribute to global warming mitigation joint effort that develops technologies to capture the CO{sub 2} produced by fossil fuels combustion and to reduce emission of other greenhouse gases like the NO{sub x}. After reviewing existing combustion bibliography is pointed out that (a) touches only partial aspects of the collective system composed by Combustion-Heat transfer process-Environment, whose interactions are our primary interest and (b) most specialists think there is not yet a clearly winning technology for CO{sub 2} capture and storage. In this paper the study of combustion is focused as integrated in the aforementioned collective system where application of flameless combustion, using oxidant preheated in heat regenerators and fluent gas recirculation into combustion chamber plus appropriated heat and mass balances, simultaneously results in energy saving and environmental impact reduction. [Spanish] El trabajo pretende contribuir al esfuerzo conjunto de mitigacion del calentamiento global que aporta tecnologias para capturar el CO{sub 2} producido por la combustion de combustibles fosiles y para disminuir la emision de otros gases invernadero como NOx. De revision bibliografica sobre combustion se concluye que (a) trata aspectos parciales del sistema compuesto por combustion-proceso de trasferencia de calor-ambiente, cuyas interacciones son nuestro principal interes (b) la mayoria de especialistas considera no hay todavia una tecnologia claramente superior a las demas para captura y almacenaje de CO{sub 2}. Se estudia la combustion como parte integrante del mencionado sistema conjunto, donde la aplicacion de combustion sin flama, empleando oxidante precalentado mediante regeneradores de calor y recirculacion de gases efluentes ademas de los balances de masa y energia adecuados, permite tener simultaneamente ahorros energeticos e impacto ambiental reducido.

  10. Pyrolysis and combustion behaviour of coal-MBM blends. (United States)

    Skodras, G; Grammelis, P; Basinas, P


    In the present work, thermogravimetric analysis was employed in order to investigate the behaviour of MBM and their blends with Greek brown coal, under pyrolysis and combustion conditions. MBM presented enhanced pyrolysis rates reflecting its high volatile and low ash contents compared to Greek brown coal. Increased conversion rates were observed when MBM was added in the brown coal sample. Significant interactions were detected between the two fuel blend components leading to significant deviations from the expected behaviour. The catalytic effect of mineral matter on the pyrolysis of MBM resulted in reaction rate decrease and DTG curve shift to lower temperatures for the demineralised MBM. Alterations in the combustion process due to the mineral matter were minimal when testing the blends. Interactions maintained during combustion and lower reactivity of MBM was achieved due to the reduced oxygen content.

  11. Pulsating combustion - Combustion characteristics and reduction of emissions

    Energy Technology Data Exchange (ETDEWEB)

    Lindholm, Annika


    In the search for high efficiency combustion systems pulsating combustion has been identified as one of the technologies that potentially can meet the objectives of clean combustion and good fuel economy. Pulsating combustion offers low emissions of pollutants, high heat transfer and efficient combustion. Although it is an old technology, the interest in pulsating combustion has been renewed in recent years, due to its unique features. Various applications of pulsating combustion can be found, mainly as drying and heating devices, of which the latter also have had commercial success. It is, however, in the design process of a pulse combustor, difficult to predict the operating frequency, the heat release etc., due to the lack of a well founded theory of the phenomenon. Research concerning control over the combustion process is essential for developing high efficiency pulse combustors with low emissions. Natural gas fired Helmholtz type pulse combustors have been the experimental objects of this study. In order to investigate the interaction between the fluid dynamics and the chemistry in pulse combustors, laser based measuring techniques as well as other conventional measuring techniques have been used. The experimental results shows the possibilities to control the combustion characteristics of pulsating combustion. It is shown that the time scales in the large vortices created at the inlet to the combustion chamber are very important for the operation of the pulse combustor. By increasing/decreasing the time scale for the large scale mixing the timing of the heat release is changed and the operating characteristics of the pulse combustor changes. Three different means for NO{sub x} reduction in Helmholtz type pulse combustors have been investigated. These include exhaust gas recirculation, alteration of air/fuel ratio and changed inlet geometry in the combustion chamber. All used methods achieved less than 10 ppm NO{sub x} emitted (referred to stoichiometric

  12. Combustion from basics to applications

    CERN Document Server

    Lackner, Maximilian; Winter, Franz


    Combustion, the process of burning, is defined as a chemical reaction between a combustible reactant (the fuel) and an oxidizing agent (such as air) in order to produce heat and in most cases light while new chemical species (e.g., flue gas components) are formed. This book covers a gap on the market by providing a concise introduction to combustion. Most of the other books currently available are targeted towards the experienced users and contain too many details and/or contain knowledge at a fairly high level. This book provides a brief and clear overview of the combustion basics, suitable f

  13. The modes of gaseous combustion

    CERN Document Server

    Rubtsov, Nickolai M


    This book provides an analysis of contemporary problems in combustion science, namely flame propagation, detonation and heterophaseous combustion based on the works of the author. The current problems in the area of gas combustion, as well as the methods allowing to calculate and estimate limiting conditions of ignition, and flame propagation on the basis of experimental results are considered. The book focuses on the virtually inaccessible works of Russian authors and will be useful for experienced students and qualified scientists in the area of experimental studies of combustion processes.

  14. Active Combustion Control Valve Project (United States)

    National Aeronautics and Space Administration — Over the past decade, research into active combustion control has yielded impressive results in suppressing thermoacoustic instabilities and widening the operational...

  15. Light Duty Efficient, Clean Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Stanton, Donald W. [Cummins Inc., Columbus, IN (United States)


    Cummins has successfully completed the Light Duty Efficient Clean Combustion (LDECC) cooperative program with DoE. This program was established in 2007 in support of the Department of Energy’s Vehicles Technologies Advanced Combustion and Emissions Control initiative to remove critical barriers to the commercialization of advanced, high efficiency, emissions compliant internal combustion (IC) engines for light duty vehicles. Work in this area expanded the fundamental knowledge of engine combustion to new regimes and advanced the knowledge of fuel requirements for these diesel engines to realize their full potential. All of our objectives were met with fuel efficiency improvement targets exceeded.

  16. Mathematical Modeling in Combustion Science

    CERN Document Server

    Takeno, Tadao


    An important new area of current research in combustion science is reviewed in the contributions to this volume. The complicated phenomena of combustion, such as chemical reactions, heat and mass transfer, and gaseous flows, have so far been studied predominantly by experiment and by phenomenological approaches. But asymptotic analysis and other recent developments are rapidly changing this situation. The contributions in this volume are devoted to mathematical modeling in three areas: high Mach number combustion, complex chemistry and physics, and flame modeling in small scale turbulent flow combustion.

  17. Microgravity Smoldering Combustion Takes Flight (United States)


    The Microgravity Smoldering Combustion (MSC) experiment lifted off aboard the Space Shuttle Endeavour in September 1995 on the STS-69 mission. This experiment is part of series of studies focused on the smolder characteristics of porous, combustible materials in a microgravity environment. Smoldering is a nonflaming form of combustion that takes place in the interior of combustible materials. Common examples of smoldering are nonflaming embers, charcoal briquettes, and cigarettes. The objective of the study is to provide a better understanding of the controlling mechanisms of smoldering, both in microgravity and Earth gravity. As with other forms of combustion, gravity affects the availability of air and the transport of heat, and therefore, the rate of combustion. Results of the microgravity experiments will be compared with identical experiments carried out in Earth's gravity. They also will be used to verify present theories of smoldering combustion and will provide new insights into the process of smoldering combustion, enhancing our fundamental understanding of this frequently encountered combustion process and guiding improvement in fire safety practices.

  18. Fuel properties to enable lifted-flame combustion

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Eric [Ford Motor Company, Dearborn, MI (United States)


    The Fuel Properties to Enable Lifted-Flame Combustion project responded directly to solicitation DE-FOA-0000239 AOI 1A, Fuels and Lubricants for Advanced Combustion Regimes. This subtopic was intended to encompass clean and highly-efficient, liquid-fueled combustion engines to achieve extremely low engine-out nitrogen oxides (NOx) and particulate matter (PM) as a target and similar efficiency as state-of-the-art direct injection diesel engines. The intent of this project was to identify how fuel properties can be used to achieve controllable Leaner Lifted Flame Combustion (LLFC) with low NOx and PM emissions. Specifically, this project was expected to identify and test key fuel properties to enable LLFC and their compatibility with current fuel systems and to enhance combustion models to capture the effect of fuel properties on advanced combustion. Successful demonstration of LLFC may reduce the need for after treatment devices, thereby reducing costs and improving thermal efficiency. The project team consisted of key technical personnel from Ford Motor Company (FMC), the University of Wisconsin-Madison (UW), Sandia National Laboratories (SNL) and Lawrence Livermore National Laboratories (LLNL). Each partner had key roles in achieving project objectives. FMC investigated fuel properties relating to LLFC and sooting tendency. Together, FMC and UW developed and integrated 3D combustion models to capture fuel property combustion effects. FMC used these modeling results to develop a combustion system and define fuel properties to support a single-cylinder demonstration of fuel-enabled LLFC. UW investigated modeling the flame characteristics and emissions behavior of different fuels, including those with different cetane number and oxygen content. SNL led spray combustion experiments to quantify the effect of key fuel properties on combustion characteristics critical for LLFC, as well as single cylinder optical engine experiments to improve fundamental

  19. Volumetric Combustion Diagnostics (United States)


    i.e., the central plane of the burner and the plane where the PLIF measurement was taken) was extracted and plotted in Fig. 7b. Fig. 7c directly...Hsu, Particle Image Velocimetry in a Nonreacting and Reacting High-Speed Cavity, Journal of Propulsion and Power, 30(3) (2014) 576-591. [7] Y.W...quantitative laser sensors to kinetics, propulsion and practical energy systems, Proceedings of the Combustion Institute, 33(1) (2011) 1-40. [13] A.W

  20. Alternate fuels; Combustibles alternos

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes R, Hernando; Ambriz G, Juan Jose [Universidad Autonoma Metropolitana. Iztapalapa (Mexico)


    In the definition and description of alternate fuels we must center ourselves in those technological alternatives that allow to obtain compounds that differ from the traditional ones, in their forms to be obtained. In this article it is tried to give an overview of alternate fuels to the conventional derivatives of petroleum and that allow to have a clear idea on the tendencies of modern investigation and the technological developments that can be implemented in the short term. It is not pretended to include all the tendencies and developments of the present world, but those that can hit in a relatively short term, in accordance with agreed with the average life of conventional fuels. Nevertheless, most of the conversion principles are applicable to the spectrum of carbonaceous or cellulosic materials which are in nature, are cultivated or wastes of organic origin. Thus one will approach them in a successive way, the physical, chemical and biological conversions that can take place in a production process of an alternate fuel or the same direct use of the fuel such as burning the sweepings derived from the forests. [Spanish] En la definicion y descripcion de combustibles alternos nos debemos centrar en aquellas alternativas tecnologicas que permitan obtener compuestos que difieren de los tradicionales, al menos en sus formas de ser obtenidos. En este articulo se pretende dar un panorama de los combustibles alternos a los convencionales derivados del petroleo y que permita tener una idea clara sobre las tendencias de la investigacion moderna y los desarrollos tecnologicos que puedan ser implementados en el corto plazo. No se pretende abarcar todas las tendencias y desarrollos del mundo actual, sino aquellas que pueden impactar en un plazo relativamente corto, acordes con la vida media de los combustibles convencionales. Sin embargo, la mayor parte de los principios de conversion son aplicables al espectro de materiales carbonaceos o celulosicos los cuales se

  1. Combustion, pyrolysis, gasification, and liquefaction of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Reed, T.B.


    All the products now obtained from oil can be provided by thermal conversion of the solid fuels biomass and coal. As a feedstock, biomass has many advantages over coal and has the potential to supply up to 20% of US energy by the year 2000 and significant amounts of energy for other countries. However, it is imperative that in producing biomass for energy we practice careful land use. Combustion is the simplest method of producing heat from biomass, using either the traditional fixed-bed combustion on a grate or the fluidized-bed and suspended combustion techniques now being developed. Pyrolysis of biomass is a particularly attractive process if all three products - gas, wood tars, and charcoal - can be used. Gasification of biomass with air is perhaps the most flexible and best-developed process for conversion of biomass to fuel today, yielding a low energy gas that can be burned in existing gas/oil boilers or in engines. Oxygen gasification yields a gas with higher energy content that can be used in pipelines or to fire turbines. In addition, this gas can be used for producing methanol, ammonia, or gasoline by indirect liquefaction. Fast pyrolysis of biomass produces a gas rich in ethylene that can be used to make alcohols or gasoline. Finally, treatment of biomass with high pressure hydrogen can yield liquid fuels through direct liquefaction.

  2. Characterization of combustion synthesized zirconia powder by UV ...

    Indian Academy of Sciences (India)

    Fine powders of zirconia were prepared by employing combustion method with varying fuel to precursor molar ratios. The zirconia powders contained more amount of monoclinic phase as the fuel content was increased. This aspect was studied using XRD, IR and UV-vis diffuse reflectance techniques. The surface acidbase ...

  3. Combustion Stratification for Naphtha from CI Combustion to PPC

    KAUST Repository

    Vallinayagam, R.


    This study demonstrates the combustion stratification from conventional compression ignition (CI) combustion to partially premixed combustion (PPC). Experiments are performed in an optical CI engine at a speed of 1200 rpm for diesel and naphtha (RON = 46). The motored pressure at TDC is maintained at 35 bar and fuelMEP is kept constant at 5.1 bar to account for the difference in fuel properties between naphtha and diesel. Single injection strategy is employed and the fuel is injected at a pressure of 800 bar. Photron FASTCAM SA4 that captures in-cylinder combustion at the rate of 10000 frames per second is employed. The captured high speed video is processed to study the combustion homogeneity based on an algorithm reported in previous studies. Starting from late fuel injection timings, combustion stratification is investigated by advancing the fuel injection timings. For late start of injection (SOI), a direct link between SOI and combustion phasing is noticed. At early SOI, combustion phasing depends on both intake air temperature and SOI. In order to match the combustion phasing (CA50) of diesel, the intake air temperature is increased to 90°C for naphtha. The combustion stratification from CI to PPC is also investigated for various level of dilution by displacing oxygen with nitrogen in the intake. The start of combustion (SOC) was delayed with the increase in dilution and to compensate for this, the intake air temperature is increased. The mixture homogeneity is enhanced for higher dilution due to longer ignition delay. The results show that high speed image is initially blue and then turned yellow, indicating soot formation and oxidation. The luminosity of combustion images decreases with early SOI and increased dilution. The images are processed to generate the level of stratification based on the image intensity. The level of stratification is same for diesel and naphtha at various SOI. When O concentration in the intake is decreased to 17.7% and 14

  4. Some Factors Affecting Combustion in an Internal-Combustion Engine (United States)

    Rothrock, A M; Cohn, Mildred


    An investigation of the combustion of gasoline, safety, and diesel fuels was made in the NACA combustion apparatus under conditions of temperature that permitted ignition by spark with direct fuel injection, in spite of the compression ratio of 12.7 employed. The influence of such variables as injection advance angle, jacket temperature, engine speed, and spark position was studied. The most pronounced effect was that an increase in the injection advance angle (beyond a certain minimum value) caused a decrease in the extent and rate of combustion. In almost all cases combustion improved with increased temperature. The results show that at low air temperatures the rates of combustion vary with the volatility of the fuel, but that at high temperatures this relationship does not exist and the rates depend to a greater extent on the chemical nature of the fuel.


    The report discusses air emissions from two types of scrap tire combustion: uncontrolled and controlled. Uncontrolled sources are open tire fires, which produce many unhealthful products of incomplete combustion and release them directly into the atmosphere. Controlled combustion...

  6. Plasma igniter for internal-combustion engines (United States)

    Breshears, R. R.; Fitzgerald, D. J.


    Hot ionized gas (plasma) ignites air/fuel mixture in internal combustion engines more effectively than spark. Electromagnetic forces propel plasma into combustion zone. Combustion rate is not limited by flame-front speed.

  7. Characterisation of wood combustion particles using electron probe microanalysis (United States)

    Osán, János; Alföldy, Bálint; Török, Szabina; Van Grieken, René

    Biomass combustion for energy production has increased in recent years, mostly in domestic households and for the space heating of some public and agricultural buildings. Small wood combustion boilers are not equipped with any flue gas filtering system, and they release most of the small particles generated on combustion to the air. Particulate emissions from a 400 kW wood-fired heating plant were measured during standard winter operation. Cyclone fly ash and bottom ash, as well as ambient aerosol samples, were collected on site. The samples were analysed using conventional single-particle electron probe microanalysis (EPMA) including use of a thin-window detector allowing the determination of low- Z major elements such as C and O. The particles were classified based on the analyses obtained and using hierarchical cluster analysis. The majority of stack-gas particles were found to be in the respirable size range. Using EPMA, the wood combustion particles could be traced in the neighbouring air because of their characteristic potassium content. The cyclone- and bottom-ash particles have lower potassium contents due to alkali release during the combustion process.

  8. Combustion of Methane Hydrate (United States)

    Roshandell, Melika

    A significant methane storehouse is in the form of methane hydrates on the sea floor and in the arctic permafrost. Methane hydrates are ice-like structures composed of water cages housing a guest methane molecule. This caged methane represents a resource of energy and a potential source of strong greenhouse gas. Most research related to methane hydrates has been focused on their formation and dissociation because they can form solid plugs that complicate transport of oil and gas in pipelines. This dissertation explores the direct burning of these methane hydrates where heat from the combustion process dissociates the hydrate into water and methane, and the released methane fuels the methane/air diffusion flame heat source. In contrast to the pipeline applications, very little research has been done on the combustion and burning characteristics of methane hydrates. This is the first dissertation on this subject. In this study, energy release and combustion characteristics of methane hydrates were investigated both theoretically and experimentally. The experimental study involved collaboration with another research group, particularly in the creation of methane hydrate samples. The experiments were difficult because hydrates form at high pressure within a narrow temperature range. The process can be slow and the resulting hydrate can have somewhat variable properties (e.g., extent of clathration, shape, compactness). The experimental study examined broad characteristics of hydrate combustion, including flame appearance, burning time, conditions leading to flame extinguishment, the amount of hydrate water melted versus evaporated, and flame temperature. These properties were observed for samples of different physical size. Hydrate formation is a very slow process with pure water and methane. The addition of small amounts of surfactant increased substantially the hydrate formation rate. The effects of surfactant on burning characteristics were also studied. One finding

  9. Optimization of asphaltenes decantation equipment used in deasphalting process using computational fluid dynamics; Otimizacao de um equipamento para a decantacao de asfaltenos no processo de desasfaltacao usando fluidodinamica computacional

    Energy Technology Data Exchange (ETDEWEB)

    Arenales, Carlos Gregorio Dallos [Cooperativa de Trabajadores Profesionales Ltda (CTP), Santander (Colombia); Pimiento, Carlos Eduardo Lizcano; Quintero, Lina Constanza Navarro; Bueno, Jhon Ivan Penaloza [Empresa Colombiana de Petroleos S.A. (ICP/ECOPETROL), Santander (Colombia). Instituto Colombiano del Petroleo


    Heavy crude oil is a complex mixture of compounds that include saturates, aromatics, resins and asphaltenes. In this mixture, the asphaltenes are the heaviest components and can be unstable and precipitate. This kind of components causes troubles in transportation and processing. One way to reduce this problem is through technologies that use solvents, which under adequate operating conditions, separate the heavy fraction, improving the properties and conditions for transporting and refining of heavy crude oil. One of the processes used in the petroleum industry to improve the properties of heavy and residue oil is the solvent deasphalting. These processes have the disadvantage of work at elevated pressure and temperature. The Colombian Petroleum Company, ECOPETROL S.A. has developed its own process of upgrading heavy oils, ECODESF, a process that is designed to work at moderate conditions of pressure and temperature and that by using a paraffinic solvent, significantly improves the quality of heavy oil, reducing its viscosity and increasing API gravity. The present work develops a model of computational fluid dynamics (CFD) for asphaltene settler, using microscopic balance. The response of this model allowed determine: the solids flow pattern distribution and accumulation points of heavy phase. This information is useful for understanding the fluid-dynamic behavior of the system. The model was validated using data from a pilot plant with capacity for treatment 1.25 BPD of heavy crude oil. This pilot plant is located in the Colombian Petroleum Institute of ECOPETROL (ICP), Piedecuesta city, Santander, Colombia. (author)

  10. Estudo da interatividade entre macromoléculas asfaltênicas e compostos estabilizantes: LCC e Cardanol Study of the interactivity between asphaltenic macromolecules and stabilizing compounds: cashew-nut Shell liquid and Cardanol

    Directory of Open Access Journals (Sweden)

    Luiz Fernando B. Moreira


    Full Text Available O asfalteno contido no petróleo pode se depositar gerando inúmeros problemas que podem afetar não só a produção, mas também todas as etapas que envolvem o transporte, armazenamento e processamento do óleo cru. Este trabalho apresenta uma adaptação matemática de modelos de interatividade para o sistema asfalteno/estabilizante capaz de prever o desempenho do estabilizante em evitar a precipitação de asfalteno. A capacidade do líquido da casca da castanha de caju (LCC e de um dos seus derivados, o cardanol, foi estudada empregando-se o teste de peptização. Tanto o LCC quanto o cardanol apresentaram propriedades estabilizadoras de asfaltenos e exibiram interatividade positiva em ambos os casos.Asphaltenes deposition may cause serious problems for crude oil production, treatment and refining. Additives that disperse or peptisize asphaltenes particles may prevent this deposition process, avoiding serious technological problems. The results presented in this paper show that the oil extracted from cashew nut shell and cardanol, one of its components, may be used as peptizing agent for asphaltenes. Furthermore, it is shown that dispersants display binding isotherms presenting typical co-operative association.

  11. Experimental investigation of wood combustion in a fixed bed with hot air

    Energy Technology Data Exchange (ETDEWEB)

    Markovic, Miladin, E-mail:; Bramer, Eddy A.; Brem, Gerrit


    Highlights: • Upward combustion is a new combustion concept with ignition by hot primary air. • Upward combustion has three stages: short drying, rapid devolatilization and char combustion. • Variation of fuel moisture and inert content have little influence on the combustion. • Experimental comparison between conventional and upward combustion is presented. - Abstract: Waste combustion on a grate with energy recovery is an important pillar of municipal solid waste (MSW) management in the Netherlands. In MSW incinerators fresh waste stacked on a grate enters the combustion chamber, heats up by radiation from the flame above the layer and ignition occurs. Typically, the reaction zone starts at the top of the waste layer and propagates downwards, producing heat for drying and devolatilization of the fresh waste below it until the ignition front reaches the grate. The control of this process is mainly based on empiricism. MSW is a highly inhomogeneous fuel with continuous fluctuating moisture content, heating value and chemical composition. The resulting process fluctuations may cause process control difficulties, fouling and corrosion issues, extra maintenance, and unplanned stops. In the new concept the fuel layer is ignited by means of preheated air (T > 220 °C) from below without any external ignition source. As a result a combustion front will be formed close to the grate and will propagate upwards. That is why this approach is denoted by upward combustion. Experimental research has been carried out in a batch reactor with height of 4.55 m, an inner diameter of 200 mm and a fuel layer height up to 1 m. Due to a high quality two-layer insulation adiabatic conditions can be assumed. The primary air can be preheated up to 350 °C, and the secondary air is distributed via nozzles above the waste layer. During the experiments, temperatures along the height of the reactor, gas composition and total weight decrease are continuously monitored. The influence of

  12. Manifold methods for methane combustion

    Energy Technology Data Exchange (ETDEWEB)

    Yang, B.; Pope, S.B. [Cornell Univ., Ithaca, NY (United States)


    Great progresses have been made in combustion research, especially, the computation of laminar flames and the probability density function (PDF) method in turbulent combustion. For one-dimensional laminar flames, by considering the transport mechanism, the detailed chemical kinetic mechanism and the interactions between these two basic processes, today it is a routine matter to calculate flame velocities, extinction, ignition, temperature, and species distributions from the governing equations. Results are in good agreement with those obtained for experiments. However, for turbulent combustion, because of the complexities of turbulent flow, chemical reactions, and the interaction between them, in the foreseeable future, it is impossible to calculate the combustion flow field by directly integrating the basic governing equations. So averaging and modeling are necessary in turbulent combustion studies. Averaging, on one hand, simplifies turbulent combustion calculations, on the other hand, it introduces the infamous closure problems, especially the closure problem with chemical reaction terms. Since in PDF calculations of turbulent combustion, the averages of the chemical reaction terms can be calculated, PDF methods overcome the closure problem with the reaction terms. It has been shown that the PDF method is a most promising method to calculate turbulent combustion. PDF methods have been successfully employed to calculate laboratory turbulent flames: they can predict phenomena such as super equilibrium radical levels, and local extinction. Because of these advantages, PDF methods are becoming used increasingly in industry combustor codes.

  13. Liquid propellant rocket combustion instability (United States)

    Harrje, D. T.


    The solution of problems of combustion instability for more effective communication between the various workers in this field is considered. The extent of combustion instability problems in liquid propellant rocket engines and recommendations for their solution are discussed. The most significant developments, both theoretical and experimental, are presented, with emphasis on fundamental principles and relationships between alternative approaches.

  14. Evaluation of the urea content in the synthesis by combustion reaction of the NiAl{sub 2}O{sub 4} catalysts; Avaliacao do teor de ureia na sintese por reacao de combustao do catalisador NiAl{sub 2}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Leal, E.; Sousa, J.-P.L.M.L.; Costa, A.C.F.M.; Gama, L. [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais; Argolo, F. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica; Sasaki, J.M. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Fisica


    The aim of this work is to evaluate the influence of the urea fuel in the structure and morphology of the NiAl{sub 2}O{sub 4} prepared by combustion reaction. The powders were prepared according to the propellants and explosives theory, using urea in the stoichiometric composition, with 10% of excess and deficiency of this fuel. The samples were characterized by XRD, FTIR, particle size distribution and textural analysis by nitrogen adsorption (BET/BJH). The DRX results showed the presence of NiAl{sub 2}O{sub 4} as major phase and traces of NiO for all the samples. Also show crystallites size between 13 and 21 nm. All the samples showed large agglomerates size distribution, with D{sub 50%} between 18.6 and 20.4 {mu}m, and morphology with irregular plates shape. The increase of the urea content caused an increase in the particle size and a reduction in the surface area, from 270 to 52 m{sup 2}/g. (author)

  15. Co-occurrence of arseniasis and fluorosis due to indoor combustion of high fluorine and arsenic content coal in a rural township in northwest China: epidemiological and toxicological aspects

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Guo-fang; Shen, Jian-hua [Chinese Academy of Sciences, Shanghai Institutes for Biological Sciences, Institute of Plant Physiology and Ecology, Shanghai (China); Gong, Shi-you [County Center for Disease Control and Prevention of Ziyang, Ziyang, Shaanxi (China); Wei, Cheng [Township Clinics of Haoping, Ziyang, Shaanxi (China); Chen, Ji-gang [Municipal Center for Disease Prevention and Control of Shanghai, Shanghai (China); Golka, Klaus [Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund (Germany)


    A large number of fluorosis and arseniasis cases appeared in a mountainous area in northwest China. The residents relied on local inferior coal (''bone coal'') of high fluorine and arsenic content for domestic heating and cooking. For deep-inside information about this rare case of co-endemia of fluorosis and arseniasis in the population in this special exposure scenario, a field investigation in one of the hyperendemic townships was conducted. The resident population registered (n = 27,713) was enrolled in the investigation. All cases were diagnosed and assigned to three symptom severity groups, that is severe, medium, and mild according to Chinese National Standard Criteria GB 16396-96 and to the technical guideline WS/T208-01 or WS/T211-01 issued by the Chinese Ministry of Health. Gender difference was analyzed by standardized incidence ratio. Age trend and severity trend were tested by {chi}{sup 2} analysis. Fluorosis was diagnosed in 56.7% of the residents. Over 95% of the diagnosed arseniasis cases were simultaneously diagnosed with fluorosis symptoms. Combined fluorosis-arseniasis represented 11.9% of the total fluorosis cases and 6.7% of the local population. No gender-related differences in the prevalence of skeletal, dental, or dermal symptoms inside all severity groups were detected. Symptom severity increased with age. The high frequency of superposition of arseniasis with fluorosis might be due to the fact that the local resident population has been exposed to very high levels of fluorine and arsenic via the same exposure route. (orig.)

  16. Combustion & Laser Diagnostics Research Complex (CLDRC) (United States)

    Federal Laboratory Consortium — Description: The Combustion and Laser Diagnostics Research Complex (CLRDC) supports the experimental and computational study of fundamental combustion phenomena to...

  17. Ignition and combustion characteristics of molded amorphous boron under different oxygen pressures (United States)

    Liang, Daolun; Liu, Jianzhong; Zhou, Yunan; Zhou, Junhu; Cen, Kefa


    Ignition and combustion characteristics of amorphous boron (B) have received much attention from researchers in recent decades. A pressurized concentrated ignition experimental system was designed to evaluate the ignition and combustion characteristics of molded B samples. The ignition experiments were carried out under different oxygen pressures (1-9 atm). The condensed combustion products were then analyzed using a scanning electron microscope, an X-ray energy dispersive spectrometer, and an X-ray diffractometer. Furthermore, the complete oxidation rates of the samples were detected by inductively coupled plasma chromatography. As the oxygen pressure increased, the combustion intensity of the samples steadily increased, and the ignition delay time and combustion time both decreased. Under the oxygen pressure of 9 atm, the average ignition delay time and combustion time were 2640 ms and 2596 ms, respectively, and the highest combustion temperature reached 1561.5 °C. The initial diffusion flame on the sample surface was green and the brightest, which was produced by an intermediate combustion product, BO2 (corresponding molecular emission spectrum wavelength, 547.3 nm). Emission spectra of another intermediate product, BO (431.9 nm) was also detected. Two different types of structures were found in the condensed combustion products of the samples. The first type was the flaky B2O3 structure, and the second type was the flocculent structure of incomplete combustion products. The B2O3 content in the condensed combustion products increased with the oxygen pressure during combustion. The complete oxidation ratio of the samples also increased with the oxygen pressure, and reached the maximum value of 68.71% under 9 atm. Overall, the samples showed better ignition and combustion characteristics under higher oxygen pressure.

  18. Evaluation of catalytic combustion of actual coal-derived gas (United States)

    Blanton, J. C.; Shisler, R. A.


    The combustion characteristics of a Pt-Pl catalytic reactor burning coal-derived, low-Btu gas were investigated. A large matrix of test conditions was explored involving variations in fuel/air inlet temperature and velocity, reactor pressure, and combustor exit temperature. Other data recorded included fuel gas composition, reactor temperatures, and exhaust emissions. Operating experience with the reactor was satisfactory. Combustion efficiencies were quite high (over 95 percent) over most of the operating range. Emissions of NOx were quite high (up to 500 ppm V and greater), owing to the high ammonia content of the fuel gas.

  19. Spying on spontaneous combustion

    Energy Technology Data Exchange (ETDEWEB)


    The British Coal Technical Services and Research Executive (TSRE) has carried out a project to investigate potential applications of fibre optic based distributed temperature sensing (DTS) technology within a mining environment. The objective was to determine whether DTS could identify and locate spontaneous combustion earlier than conventional systems. The trials took place in a British mine from April to September 1992 and from August to November 1993 using a commercially available system from York Sensors Ltd. Results indicate that DTS is capable of very sensitive temperature monitoring, revealing sub-degree thermal trends resulting from various activities and local heatings. DTS has several prospective mining applications, e.g. monitoring known hot spots, investigating ventilation and heat flow through mine workings. The trials show that the system can be installed, calibrated, operated and maintained by relatively inexperienced personnel. 1 photo.

  20. Forced cocurrent smoldering combustion (United States)

    Dosanjh, Sudip S.; Pagni, Patrick J.; Fernandez-Pello, A. Carlos


    An analytical model of cocurrent smoldering combustion through a very porous solid fuel is developed. Smoldering is initiated at the top of a long radially insulated uniform fuel cylinder, so that the smolder wave propagates downward, opposing an upward-forced flow of oxidizer, with the solid fuel and the gaseous oxidizer entering the reaction zone from the same direction (hence, cocurrent). Radiative heat transfer was incorporated using a diffusion approximation, and smoldering was modeled using a one-step reaction mechanism. The results indicate that, for a given fuel, the final temperature depends only on the initial oxygen mass flux, increasing logarithmically with the mass flux. The smolder velocity is linearly dependent on the initial oxygen mass flux, and, at a fixed value of the flux, increases with initial oxygen mass fraction. The mathematical relationship determining the conditions for steady smolder propagation is presented.

  1. Filtration combustion: Smoldering and SHS (United States)

    Matkowsky, Bernard J.


    Smolder waves and SHS (self-propagating high-temperature synthesis) waves are both examples of combustion waves propagating in porous media. When delivery of reactants through the pores to the reaction site is an important aspect of the process, it is referred to as filtration combustion. The two types of filtration combustion have a similar mathematical formulation, describing the ignition, propagation and extinction of combustion waves in porous media. The goal in each case, however, is different. In smoldering the desired goal is to prevent propagation, whereas in SHS the goal is to insure propagation of the combustion wave, leading to the synthesis of desired products. In addition, the scales in the two areas of application may well differ. For example, smoldering generally occurs at a relatively low temperature and with a smaller propagation velocity than SHS filtration combustion waves. Nevertheless, the two areas of application have much in common, so that mechanisms learned about in one application can be used to advantage in the other. In this paper we discuss recent results in the areas of filtration combustion.

  2. Co-combustion of pulverized coal and solid recovered fuel in an entrained flow reactor- General combustion and ash behavior

    DEFF Research Database (Denmark)

    Wu, Hao; Glarborg, Peter; Frandsen, Flemming


    of the additives increased the S-retention in ash. Analysis of the bulk composition of fly ash from different experiments indicated that the majority of S and Cl in the fuels were released to gas phase during combustion, whereas the K and Na in the fuels were mainly retained in ash. When co-firing coal and SRF...... propensity in co-combustion was decreased with increasing share of SRF. The addition of NaCl and PVC significantly increased the ash deposition propensity, whereas the addition of ammonium sulphate or kaolinite showed a slight reducing effect. The chlorine content in the deposits generally implied a low...

  3. Catalytic Combustion of Gasified Waste

    Energy Technology Data Exchange (ETDEWEB)

    Kusar, Henrik


    This thesis concerns catalytic combustion for gas turbine application using a low heating-value (LHV) gas, derived from gasified waste. The main research in catalytic combustion focuses on methane as fuel, but an increasing interest is directed towards catalytic combustion of LHV fuels. This thesis shows that it is possible to catalytically combust a LHV gas and to oxidize fuel-bound nitrogen (NH{sub 3}) directly into N{sub 2} without forming NO{sub x} The first part of the thesis gives a background to the system. It defines waste, shortly describes gasification and more thoroughly catalytic combustion. The second part of the present thesis, paper I, concerns the development and testing of potential catalysts for catalytic combustion of LHV gases. The objective of this work was to investigate the possibility to use a stable metal oxide instead of noble metals as ignition catalyst and at the same time reduce the formation of NO{sub x} In paper II pilot-scale tests were carried out to prove the potential of catalytic combustion using real gasified waste and to compare with the results obtained in laboratory scale using a synthetic gas simulating gasified waste. In paper III, selective catalytic oxidation for decreasing the NO{sub x} formation from fuel-bound nitrogen was examined using two different approaches: fuel-lean and fuel-rich conditions. Finally, the last part of the thesis deals with deactivation of catalysts. The various deactivation processes which may affect high-temperature catalytic combustion are reviewed in paper IV. In paper V the poisoning effect of low amounts of sulfur was studied; various metal oxides as well as supported palladium and platinum catalysts were used as catalysts for combustion of a synthetic gas. In conclusion, with the results obtained in this thesis it would be possible to compose a working catalytic system for gas turbine application using a LHV gas.

  4. On Lean Turbulent Combustion Modeling

    Directory of Open Access Journals (Sweden)

    Constantin LEVENTIU


    Full Text Available This paper investigates a lean methane-air flame with different chemical reaction mechanisms, for laminar and turbulent combustion, approached as one and bi-dimensional problem. The numerical results obtained with Cantera and Ansys Fluent software are compared with experimental data obtained at CORIA Institute, France. First, for laminar combustion, the burn temperature is very well approximated for all chemical mechanisms, however major differences appear in the evaluation of the flame front thickness. Next, the analysis of turbulence-combustion interaction shows that the numerical predictions are suficiently accurate for small and moderate turbulence intensity.

  5. Combustion of Solid Propellants (La Combustion des Propergols Solides) (United States)


    poudres modificateurs balistiques, des noirs de A mouler de caract~ristiques volontairement carbone sont souvent incorpor~s car ils ont diffdrontes antilueurs (suppresseurs de la post noir de carbone eat souvent utilisd combustion). Ceux-ci, g~ndralement des sels industriellemont comae param...devient compressible at is vitesse de combustion Pour 6tablir un bilan sur le risque eat modifide. La figure 7 illustre cet d’appariticn d’instabilit~s

  6. Numerical Analysis of the Factors about Combustion Stability on Boiler

    Directory of Open Access Journals (Sweden)

    Gao Yang


    Full Text Available Through the research of the coal pulverized catches fire and steadily combustion mechanism and the numerical Simulation of the 300MW Tangentially Pulverized Coal Fired Boiler by Coal-fire software?combine the operating data of the boiler, establish the corresponding relation between the result of numerical simulation and combustion stability. The result indicates that the higher volatile matter, lower content of ash and moisture of the coal, it helps the coal pulverized air current to catch fire . More fineness coal pulverized is favorable to catch fire. When boiler load reduced, it will influence the characteristic" lighted by itself " of the tangentially pulverized coal fired boiler, and it will cause combustion unstably.

  7. Pulsating combustion: Theoretical and empirical substantiation of ecological effect (United States)

    Berg, I. A.; Porshnev, S. V.; Oshchepkova, V. Y.


    There are two primary parameters that characterize operation of modern energy generation units that burn fuel, namely - unit efficiency and the amount of noxious emissions. Usually units that operate at the maximum efficiency produce maximum potential emissions of noxious substances (as NOx) into the atmosphere. This work provides theoretical substantiation for control of the combustion process by superimposing controlled irregularities to the fuel supply rate in order to suppress NOx generation while retaining the unit's technical parameters and cost efficiency. The substantiation uses known empirically obtained NOx generation dependency from the air excess ratio. Evaluation of the generated NOx content was performed using numerical integration of the composed time sequences describing changes in the NOx concentration in the combustion products for various types of control actions. Evaluation of bands of operating frequencies for the proposed method of combustion control are presented. The proposed theoretical substantiation made it possible to determine conditions and technics for experimental work.

  8. Measures for a quality combustion (combustion chamber exit and downstream); Mesures pour une combustion de qualite (sortie de chambre de combustion et en aval)

    Energy Technology Data Exchange (ETDEWEB)

    Epinat, G. [APAVE Lyonnaise, 69 (France)


    After a review of the different pollutants related to the various types of stationary and mobile combustion processes (stoichiometric, reducing and oxidizing combustion), measures and analyses than may be used to ensure the quality and efficiency of combustion processes are reviewed: opacimeters, UV analyzers, etc. The regulation and control equipment for combustion systems are then listed, according to the generator capacity level

  9. Computational Modeling of Turbulent Spray Combustion

    NARCIS (Netherlands)

    Ma, L.


    The objective of the research presented in this thesis is development and validation of predictive models or modeling approaches of liquid fuel combustion (spray combustion) in hot-diluted environments, known as flameless combustion or MILD combustion. The goal is to combine good physical insight,

  10. Fifth International Microgravity Combustion Workshop (United States)

    Sacksteder, Kurt (Compiler)


    This conference proceedings document is a compilation of 120 papers presented orally or as poster displays to the Fifth International Microgravity Combustion Workshop held in Cleveland, Ohio on May 18-20, 1999. The purpose of the workshop is to present and exchange research results from theoretical and experimental work in combustion science using the reduced-gravity environment as a research tool. The results are contributed by researchers funded by NASA throughout the United States at universities, industry and government research agencies, and by researchers from at least eight international partner countries that are also participating in the microgravity combustion science research discipline. These research results are intended for use by public and private sector organizations for academic purposes, for the development of technologies needed for the Human Exploration and Development of Space, and to improve Earth-bound combustion and fire-safety related technologies.

  11. Sixth International Microgravity Combustion Workshop (United States)

    Sacksteder, Kurt (Compiler)


    This conference proceedings document is a compilation of papers presented orally or as poster displays to the Sixth International Microgravity Combustion Workshop held in Cleveland, Ohio on May 22-24, 2001. The purpose of the workshop is to present and exchange research results from theoretical and experimental work in combustion science using the reduced-gravity environment as a research tool. The results are contributed by researchers funded by NASA throughout the United States at universities, industry and government research agencies, and by researchers from international partner countries that are also participating in the microgravity combustion science research discipline. These research results are intended for use by public and private sector organizations for academic purposes, for the development of technologies needed for Human Exploration and Development of Space, and to improve Earth-bound combustion and fire-safety related technologies.

  12. Scalable, chromatography-free synthesis of alkyl-tethered pyrene-based materials. Application to first-generation "archipelago model" asphaltene compounds. (United States)

    Diner, Colin; Scott, David E; Tykwinski, Rik R; Gray, Murray R; Stryker, Jeffrey M


    In this paper, we report a highly efficient, scalable approach to the total synthesis of conformationally unrestricted, electronically isolated arrays of alkyl-tethered polycyclic aromatic chromophores. This new class of modular molecules consists of polycyclic aromatic "islands" comprising significant structural fragments present in unrefined heavy petroleum, tethered together by short saturated alkyl chains, as represented in the "archipelago model" of asphaltene structure. The most highly branched archipelago compounds reported here share an architecture with first-generation dendrimeric constructs, making the convergent, chromatography-free synthesis described herein particularly attractive for further extensions in scope and applications to materials chemistry. The syntheses are efficient, selective, and readily adaptable to a multigram scale, requiring only inexpensive, "earth-abundant" transition-metal catalysts for cross-coupling reactions and extraction and fractional crystallization for purification. This approach avoids typical limitations in cost, scale, and operational practicality. All of the archipelago compounds and synthetic intermediates have been fully characterized spectroscopically and analytically. The solid-state structure of one archipelago model compound has been determined by X-ray crystallography.

  13. Combustion characteristics and kinetics of anthracite with added chlorine (United States)

    Wang, Cui; Zhang, Jian-liang; Wang, Guang-wei; Jiao, Ke-xin; Liu, Zheng-jian; Chou, Kuo-chih


    The combustion process of Yangquan anthracite (YQ) with the addition of 0.045wt%, 0.211wt%, 1.026wt%, and 2.982wt% chlorine was investigated using a thermogravimetric method from an ambient temperature to 1173 K in an air atmosphere. Results show that the YQ combustion characteristics are not significantly affected by an increase in chlorine content. Data acquired for combustion conversion are then further processed for kinetic analysis. Average apparent activation energies determined using the model-free method (specifically the KAS method) are 103.025, 110.250, 99.906, and 110.641 kJ/mol, respectively, and the optimal kinetic model for describing the combustion process of chlorine-containing YQ is the nucleation kinetic model, as determined by the z( α) master plot method. The mechanism function of the nucleation kinetic model is then employed to estimate the pre-exponential factor, by making use of the compensation effect. The kinetic models to describe chlorine-containing YQ combustion are thus obtained through advanced determination of the optimal mechanism function, average apparent activation energy, and the pre-exponential factor.

  14. Residential Electrostatic Precipitator - Performance at efficient and poor combustion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Baefver, Linda; Yngvesson, Johan; Niklasson, Fredrik


    The performance of a pilot residential electrostatic precipitator R{sub E}SP (Applied Plasma Physics AS), was investigated at laboratory. Measurements of TSP (Total Suspended Particles), content of organic and elemental carbon, and mass size distribution of particles upstream and downstream of ESP were performed. Values for PM1 (particles < 1 {mu}m) were calculated from the particle size distributions. Concentrations and size distributions with respect to particle numbers were measured in separate tests. Gas concentrations, temperatures and boiler parameters were also measured. The TSP concentrations upstream of the R{sub E}SP were varied in range of 15-390 mg/m{sub N}{sup 3}. Up to concentrations of about 300 mg/m{sub N}{sup 3}, the TSP-concentrations out from the ESP were less than 20 mg/m{sub N}{sup 3}, which is well below the German emission limit for wood stoves. The removal efficiencies with respect to mass were about 87% at efficient combustion and 93% at poor combustion. Corresponding values with respect to number concentrations were about 97% at efficient combustion and almost 99% at poor combustion. The better performance at poor combustion may be explained by lower flue gas temperature, leading to longer residence time in the ESP. High removal efficiencies were also found with respect to particulate organic and elemental carbon.

  15. Smoldering Combustion Experiments in Microgravity (United States)

    Walther, David C.; Fernandez-Pello, A. Carlos; Urban, David L.


    The Microgravity Smoldering Combustion (MSC) experiment is part of a study of the smolder characteristics of porous combustible materials in a microgravity environment. Smoldering is a non-flaming form of combustion that takes place in the interior of porous materials and takes place in a number of processes ranging from smoldering of porous insulation materials to high temperature synthesis of metals. The objective of the study is to provide a better understanding of the controlling mechanisms of smolder, both in microgravity and normal-gravity. As with many forms of combustion, gravity affects the availability of oxidizer and transport of heat, and therefore the rate of combustion. Microgravity smolder experiments, in both a quiescent oxidizing environment, and in a forced oxidizing flow have been conducted aboard the NASA Space Shuttle (STS-69 and STS-77 missions) to determine the effect of the ambient oxygen concentration and oxidizer forced flow velocity on smolder combustion in microgravity. The experimental apparatus is contained within the NASA Get Away Special Canister (GAS-CAN) Payload. These two sets of experiments investigate the propagation of smolder along the polyurethane foam sample under both diffusion driven and forced flow driven smoldering. The results of the microgravity experiments are compared with identical ones carried out in normal gravity, and are used to verify present theories of smolder combustion. The results of this study will provide new insights into the smoldering combustion process. Thermocouple histories show that the microgravity smolder reaction temperatures (Ts) and propagation velocities (Us) lie between those of identical normal-gravity upward and downward tests. These observations indicate the effect of buoyancy on the transport of oxidizer to the reaction front.

  16. The combustion of biomass - the impact of its types and combustion technologies on the emission of nitrogen oxide

    Directory of Open Access Journals (Sweden)

    Mladenović Milica R.


    Full Text Available Harmonization of environmental protection and the growing energy needs of modern society promote the biomass application as a replacement for fossil fuels and a viable option to mitigate the green house gas emissions. For domestic conditions this is particularly important as more than 60% of renewables belongs to biomass. Beside numerous benefits of using biomass for energy purposes, there are certain drawbacks, one of which is a possible high emission of NOx during the combustion of these fuels. The paper presents the results of the experiments with multiple biomass types (soybean straw, cornstalk, grain biomass, sunflower oil, glycerin and paper sludge, using different combustion technologies (fluidized bed and cigarette combustion, with emphasis on the emission of NOx in the exhaust gas. A presentation of the experimental installations is given, as well as an evaluation of the effects of the fuel composition, combustion regimes and technology on the NOx emissions. As the biomass combustion took place at temperatures low enough that thermal and prompt NOx can be neglected, the conclusion is the emissions of nitrogen oxides primarily depend on the biomass composition- it is increasing with the increase of the nitrogen content, and decreases with the increase of the char content which provides catalytic surface for NOx reduction by CO. [Projekat Ministarstva nauke Republike Srbije, br. TR33042: Improvement of the industrial fluidized bed facility, in scope of technology for energy efficient and environmentally feasible combustion of various waste materials in fluidized bed i br. III42011: Development and improvement of technologies for efficient use of energy of several forms of agricultural and forest biomass in an environmentally friendly manner, with the possibility of cogeneration

  17. Co-combustion of tyre granulate. Tests in grate fired biomass boiler; Samfoerbraenning av klippta gummidaeck. Foersoek i biobraenslepelletseldad rosterpanna

    Energy Technology Data Exchange (ETDEWEB)

    Goldschmidt, Barbara


    In this report results from co-combustion tests with tyres in a biomass fired boiler are reported. Operational experiences from other plants with co-combustion with tyres are also reported. The test results are summarised below: Co-combustion, because of the higher energy content in the tyres as compared to the biomass, made it possible to increase boiler load. Superheater temperatures were not changed significantly during co-combustion. The combustion on the grate was more intense during co-combustion. SO{sub 2} emissions were increased from a few mg/MJ to 170 mg/MJ when 20% weight tyres were co-combusted, as the boiler is not equipped with sulphur removal. The SO{sub 2} corresponded to half of the fuel's sulphur content. The remainder of the sulphur was found in the fly ash. Desulphurisation tests with sodium bicarbonate showed that the SO{sub 2} content could be lowered by 50%, with a stoichiometry of 1. CO and NO{sub x} emissions increased somewhat during co-combustion. No other significant changes in flue gas parameters were observed. Ash amounts, both bottom ash and fly ash, increased during co-combustion. The ash amounts showed large variations, due to varying ash content in the tyres and varying carbon content in the ash. About half of the fuel's sulphur content and almost all of the zinc content was found in the ash during co-combustion. Almost all of this sulphur and zinc was found in the fly ash. Tests with deposition probes in the superheater area showed that the deposition rate was increased during co-combustion. The rate was 1-5, 2-7 and 3-10 g/m{sup 2}/h respectively with 0, 10 and 20% co-combustion. Analysis of the deposits showed that the alkali chlorides in the deposits were exchanged for less corrosive alkali sulphates, due to the sulphur content in the tyres. The deposits from co-combustion also had high zinc content.

  18. Physicochemical properties and combustion behavior of duckweed during wet torrefaction. (United States)

    Zhang, Shuping; Chen, Tao; Li, Wan; Dong, Qing; Xiong, Yuanquan


    Wet torrefaction of duckweed was carried out in the temperature range of 130-250°C to evaluate the effects on physicochemical properties and combustion behavior. The physicochemical properties of duckweed samples were investigated by ultimate analysis, proximate analysis, FTIR, XRD and SEM techniques. It was found that wet torrefaction improved the fuel characteristics of duckweed samples resulting from the increase in fixed carbon content, HHVs and the decrease in nitrogen and sulfur content and atomic ratios of O/C and H/C. It can be seen from the results of FTIR, XRD and SEM analyses that the dehydration, decarboxylation, solid-solid conversion, and condensation polymerization reactions were underwent during wet torrefaction. In addition, the results of thermogravimetric analysis (TGA) in air indicated that wet torrefaction resulted in significant changes on combustion behavior and combustion kinetics parameters. Duckweed samples after wet torrefaction behaved more char-like and gave better combustion characteristics than raw sample. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Synthetic fuel aromaticity and staged combustion

    Energy Technology Data Exchange (ETDEWEB)

    Longanbach, J. R.; Chan, L. K.; Levy, A.


    Samples of middle and heavy SRC-II distillates were distilled into 50 C boiling point range fractions. These were characterized by measurements of their molecular weight, elemental analysis and basic nitrogen content and calculation of average molecular structures. The structures typically consisted of 1 to 3 aromatic rings fused to alicyclic rings with short, 1 to 3 carbon aliphatic side chains. The lower boiling fractions contained significant amounts (1 atom/molecule) of oxygen while the heavier fractions contained so few heteroatoms that they were essentially hydrocarbons. Laboratory scale oxidative-pyrolysis experiments were carried out at pyrolysis temperatures of 500 to 1100 C and oxygen concentrations from 0 to 100 percent of stoichiometry. Analysis of liquid products, collected in condensers cooled with liquid nitrogen showed that aromatization is a major reaction in the absence of oxygen. The oxygen-containing materials (phenolics) seem to be more resistant to thermal pyrolysis than unsubstituted aromatics. Nitrogen converts from basic to nonbasic forms at about 500 C. The nonbasic nitrogen is more stable and survives up to 700 C after which it is slowly removed. A recently constructed 50,000 Btu/hr staged combustor was used to study the chemistry of the nitrogen and aromatics. SRC II combustion was studied under fuel-rich, first-stage conditions at air/fuel ratios from 0.6 to 1.0 times stoichiometric. The chemistry of the fuel during combustion calls for further investigation in order to examine the mechanism by which HCN is evolved as a common intermediate for the formation of the nitrogen-containing gaseous combustion products. 25 references, 45 figures, 25 tables.

  20. Techniques de combustion Combustin Techniques

    Directory of Open Access Journals (Sweden)

    Perthuis E.


    Full Text Available L'efficacité d'un processus de chauffage par flamme est étroitement liée à la maîtrise des techniques de combustion. Le brûleur, organe essentiel de l'équipement de chauffe, doit d'une part assurer une combustion complète pour utiliser au mieux l'énergie potentielle du combustible et, d'autre part, provoquer dans le foyer les conditions aérodynamiques les plus propices oux transferts de chaleur. En s'appuyant sur les études expérimentales effectuées à la Fondation de Recherches Internationales sur les Flammes (FRIF, au Groupe d'Étude des Flammes de Gaz Naturel (GEFGN et à l'Institut Français du Pétrole (IFP et sur des réalisations industrielles, on présente les propriétés essentielles des flammes de diffusion aux combustibles liquides et gazeux obtenues avec ou sans mise en rotation des fluides, et leurs répercussions sur les transferts thermiques. La recherche des températures de combustion élevées conduit à envisager la marche à excès d'air réduit, le réchauffage de l'air ou son enrichissement à l'oxygène. Par quelques exemples, on évoque l'influence de ces paramètres d'exploitation sur l'économie possible en combustible. The efficiency of a flame heating process is closely linked ta the mastery of, combustion techniques. The burner, an essential element in any heating equipment, must provide complete combustion sa as to make optimum use of the potential energy in the fuel while, at the same time, creating the most suitable conditions for heat transfers in the combustion chamber. On the basis of experimental research performed by FRIF, GEFGN and IFP and of industrial achievements, this article describesthe essential properties of diffusion flames fed by liquid and gaseous fuels and produced with or without fluid swirling, and the effects of such flames on heat transfers. The search for high combustion temperatures means that consideration must be given to operating with reduced excess air, heating the air or

  1. Jet plume injection and combustion system for internal combustion engines (United States)

    Oppenheim, Antoni K.; Maxson, James A.; Hensinger, David M.


    An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure.

  2. Combustion Byproducts Recycling Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower


    The Combustion Byproducts Recycling Consortium (CBRC) program was developed as a focused program to remove and/or minimize the barriers for effective management of over 123 million tons of coal combustion byproducts (CCBs) annually generated in the USA. At the time of launching the CBRC in 1998, about 25% of CCBs were beneficially utilized while the remaining was disposed in on-site or off-site landfills. During the ten (10) year tenure of CBRC (1998-2008), after a critical review, 52 projects were funded nationwide. By region, the East, Midwest, and West had 21, 18, and 13 projects funded, respectively. Almost all projects were cooperative projects involving industry, government, and academia. The CBRC projects, to a large extent, successfully addressed the problems of large-scale utilization of CCBs. A few projects, such as the two Eastern Region projects that addressed the use of fly ash in foundry applications, might be thought of as a somewhat smaller application in comparison to construction and agricultural uses, but as a novel niche use, they set the stage to draw interest that fly ash substitution for Portland cement might not attract. With consideration of the large increase in flue gas desulfurization (FGD) gypsum in response to EPA regulations, agricultural uses of FGD gypsum hold promise for large-scale uses of a product currently directed to the (currently stagnant) home construction market. Outstanding achievements of the program are: (1) The CBRC successfully enhanced professional expertise in the area of CCBs throughout the nation. The enhanced capacity continues to provide technology and information transfer expertise to industry and regulatory agencies. (2) Several technologies were developed that can be used immediately. These include: (a) Use of CCBs for road base and sub-base applications; (b) full-depth, in situ stabilization of gravel roads or highway/pavement construction recycled materials; and (c) fired bricks containing up to 30%-40% F

  3. Challenges in Propellants and Combustion: 100 Years after Nobel

    National Research Council Canada - National Science Library

    Kuo, Kenneth


    .... The Topics covered include: chemical kinetics of propellant combustion, environmental considerations in combustion of solid and liquid propellants, commercial application in the combustion of energetic materials, effective...

  4. Combustion of char from plastic wastes pyrolysis (United States)

    Saptoadi, Harwin; Rohmat, Tri Agung; Sutoyo


    A popular method to recycle plastic wastes is pyrolysis, where oil, gas and char can be produced. These products can be utilized as fuels because they are basically hydrocarbons. The research investigates char properties, including their performance as fuel briquettes. There are 13 char samples from PE (Polyethylene) pyrolyzed at temperatures of around 450 °C, with and without a catalyst. Some of the samples were obtained from PE mixed with other types, such as Polystyrene (PS), Polypropylene (PP), Polyethylene Terephthalate (PET), and Others. Char properties, such as moisture, ash, volatile matter, and fixed carbon contents, are revealed from the proximate analysis, whereas calorific values were measured with a bomb calorimeter. Briquettes are made by mixing 4 g of char with 0.5 - 1 g binder. Briquettes are hollow cylinders with an outer and inner diameter of around 1.75 cm and 0.25 cm, respectively. Combustion is carried out in a furnace with wall temperatures of about 230°C and a constant air velocity of 0.7 m/s. Five out of 13 char briquettes are not feasible because they melt during combustion. Briquettes made from 100% PE wastes burn in substantially shorter duration than those from mixed plastic wastes. Char #1 and #5 are excellent due to their highest energy release, whereas #10 show the worst performance.

  5. Numerical study on the combustion process of a biogas spark-ignition engine

    Directory of Open Access Journals (Sweden)

    Carrera José L.


    Full Text Available The fuel called biogas is obtained through anaerobic digestion of different types of organic waste, providing a way to tap the energy stored in organic matter. The use of this fuel is also attractive from the standpoint of global warming because its application does not register a net emission of carbon dioxide into the atmosphere. One possible use for this fuel is to feed the spark-ignition internal combustion engines. In the present, there is little information available about the process of combustion in internal combustion engines fueled by biogas. The combustion process of an internal combustion engine ignition powered by biogas is characterized in terms of the duration of combustion, i.e., depending on the time elapsed while the reactants (methane and oxygen are transformed into products (mainly carbon dioxide and water. This study numerically evaluates the way in which the geometrical parameters such as the compression ratio and operating parameters like engine speed, the excess air, the time of spark timing and carbon dioxide content of biogas affect the evolution of the combustion process. To carry out this study, a five factors and two levels experiment was designed and conducted, based on which, the most influential parameters were identified. Equations expressing the combustion characteristic parameters, as a function of the geometric and operation parameters of a spark ignited engines, are delivered as a result.

  6. The use of maize stalks for energy purposes and emissions measurement during their combustion

    Directory of Open Access Journals (Sweden)

    Marek Angelovič


    Full Text Available The objective of the work was a monitoring of possibilities of maize cortical harvesting by combine harvesters and its subsequent use for energy purposes during combustion. We monitored the combustion of packages with the moisture of 18% and 38% and the effect of moisture on the content of gas emissions of CO2, NO, NO2 as well as the percentage of residual O2 in the flue gas after combustion. All values of monitored emission limits were in current normative limits defined in Collection of Laws no. 356/2010.

  7. Laser Desorption/Ionization-Time of Flight (LDI-TOF and Matrix-Assisted Laser Desorption/Ionization - Time of Flight (MALDI – TOF mass spectrometry of an Algerian asphaltene

    Directory of Open Access Journals (Sweden)

    T. Fergoug


    Full Text Available Both LDI-TOF and MALDI-TOF Mass spectroscopy experiments of an Algerian asphaltene derived from a deposit were performed. LDI mass experiments were conducted for both linear and reflectron modes under laser wavelength/attenuation variation. The different LDI-Mass spectra show that mass distribution depends on experimental condition for masses below 1000 amu and that the average molecular weight is around 650 for the polar fraction and beyond 1000 amu for non-polar ones. The use of different matrices as CHCA, HABA and Dithranol changes slightly the aspect of the spectra.

  8. Journal of Nire, Vol. 4, No. 6, November 1995. Special issue: Novel development of combustion and heat-use technologies

    Energy Technology Data Exchange (ETDEWEB)



    ;Table of Contents: Special Issue: Novel Development of Combustion and Heat-use Technologies: Review: Chemical Reactions Kinetics and Modeling; Original Papers: Fluidized Bed Catalytic Combustion-Measurement of Temperature Variations in a Bed; Effect of Char Particles on N2O Formation and Destruction in a Small Quartz CFBC; Combustion Characteristics of Biomass Waste (Superficial combustion characteristics of wood saw dust and tangerine peels); Direct Injection of Absorbents into a Pulverized Coal Combustion Furnace; A Method of Measuring Total Radiance Emmitted from High-Temperature Flames using a Thermopile Detector; Enhancement of Evaporative Heat Transfer in a Horizontal Tube Using Screen Mesh Wicks with Unique Configurations; Experimental Study of Heat pipe with Heat driven Pump; Calculation on Spectral Absorption Characteristics of High-Temperature Combustion Gasses; Study on the Resistance Wire Methods for Detonation Velocity and Observation of the Explosion for Explosive; Abstracts of Published Papers; Editorial.

  9. Catalytic combustion over high temperature stable metal oxides

    Energy Technology Data Exchange (ETDEWEB)

    Berg, M. [TPS Termiska Processer AB, Nykoeping (Sweden)


    This thesis presents a study of the catalytic effects of two interesting high temperature stable metal oxides - magnesium oxide and manganese substituted barium hexa-aluminate (BMA) - both of which can be used in the development of new monolithic catalysts for such applications. In the first part of the thesis, the development of catalytic combustion for gas turbine applications is reviewed, with special attention to alternative fuels such as low-BTU gas, e.g. produced in an air blown gasifier. When catalytic combustion is applied for such a fuel, the primary advantage is the possibility of decreasing the conversion of fuel nitrogen to NO{sub x}, and achieving flame stability. In the experimental work, MgO was shown to have a significant activity for the catalytic combustion of methane, lowering the temperature needed to achieve 10 percent conversion by 270 deg C compared with homogeneous combustion.The reaction kinetics for methane combustion over MgO was also studied. It was shown that the heterogeneous catalytic reactions were dominant but that the catalytically initiated homogeneous gas phase reactions were also important, specially at high temperatures. MgO and BMA were compared. The latter showed a higher catalytic activity, even when the differences in activity decreased with increasing calcination temperature. For BMA, CO{sub 2} was the only product detected, but for MgO significant amounts of CO and C{sub 2}-hydrocarbons were formed. BMA needed a much lower temperature to achieve total conversion of other fuels, e.g. CO and hydrogen, compared to the temperature for total conversion of methane. This shows that BMA-like catalysts are interesting for combustion of fuel mixtures with high CO and H{sub 2} content, e.g. gas produced from gasification of biomass. 74 refs

  10. Studying the specific features pertinent to combustion of chars obtained from coals having different degrees of metamorphism and biomass chars (United States)

    Bestsennyi, I. V.; Shchudlo, T. S.; Dunaevskaya, N. I.; Topal, A. I.


    Better conditions for igniting low-reaction coal (anthracite) can be obtained, higher fuel burnout ratio can be achieved, and the problem of shortage of a certain grade of coal can be solved by firing coal mixtures and by combusting coal jointly with solid biomass in coal-fired boilers. Results from studying the synergetic effect that had been revealed previously during the combustion of coal mixtures in flames are presented. A similar effect was also obtained during joint combustion of coal and wood in a flame. The kinetics pertinent to combustion of char mixtures obtained from coals characterized by different degrees of metamorphism and the kinetics pertinent to combustion of wood chars were studied on the RSK-1D laboratory setup. It was found from the experiments that the combustion rate of char mixtures obtained from coals having close degrees of metamorphism is equal to the value determined as a weighted mean rate with respect to the content of carbon. The combustion rate of char mixtures obtained from coals having essentially different degrees of metamorphism is close to the combustion rate of more reactive coal initially in the process and to the combustion rate of less reactive coal at the end of the process. A dependence of the specific burnout rate of carbon contained in the char of two wood fractions on reciprocal temperature in the range 663—833 K is obtained. The combustion mode of an experimental sample is determined together with the reaction rate constant and activation energy.

  11. Combustion of droplets and sprays (United States)

    Eigenbrod, Christian; Sattelmayer, Thomas; Bäßler, Stefan; Mauss, Fabian; Meisl, Jürgen; Oomens, Bas; Rackwitz, Leif; Tait, Nigel; Angelberger, Christian; Eilts, Peter; Magnusson, Ingemar; Lauvergne, Romain; Tatschl, Reinhard


    The combustion of liquid hydrocarbon fuels in internal combustion engines and gas turbines for energy production and aircraft propulsion is intrinsically tied to the formation of pollutants. Apart from aiming for the highest combustion efficiencies in order to lower the operational costs and the emission of CO2, the reduction of poisonous and environmentally harmful exhaust constituents is a challenging task for scientists and engineers. The most prominent pollutants are soot, identified to trigger respiratory diseases and cancer, and nitric oxides such as NO and NO2, which promote the formation of ozone affecting the cardiovascular system when released in the lower atmosphere. Soot and nitric oxides are greenhouse pollutants in the upper atmosphere. Even though only 2-3% of the anthropogenic emission of nitric oxides are contributed by aircraft, it is the only emission at high altitudes. Unfortunately, it has the greatest impact on climate there and it does not matter whether the fuels are fossil or, in the future, biomass.

  12. Novel Active Combustion Control Valve (United States)

    Caspermeyer, Matt


    This project presents an innovative solution for active combustion control. Relative to the state of the art, this concept provides frequency modulation (greater than 1,000 Hz) in combination with high-amplitude modulation (in excess of 30 percent flow) and can be adapted to a large range of fuel injector sizes. Existing valves often have low flow modulation strength. To achieve higher flow modulation requires excessively large valves or too much electrical power to be practical. This active combustion control valve (ACCV) has high-frequency and -amplitude modulation, consumes low electrical power, is closely coupled with the fuel injector for modulation strength, and is practical in size and weight. By mitigating combustion instabilities at higher frequencies than have been previously achieved (approximately 1,000 Hz), this new technology enables gas turbines to run at operating points that produce lower emissions and higher performance.

  13. Thermal effects on arsenic emissions during coal combustion process. (United States)

    Zhang, Weiqiang; Sun, Qiang; Yang, Xiuyuan


    In this study, the rate of emission of arsenic during the burning process of different kinds of coal is examined in order to study the volatile characteristics of arsenic during coal combustion which have negative effects on the ecological environment and human health. The results show that the emission rate of arsenic gradually increases with increased burning temperature, with a threshold of approximately 700°C to 800°C in the process of temperature increase. Then, the relationships among the arsenic emission rate and combustion environment, original arsenic content, combustion time, burning temperature, air flow and amount of arsenic fixing agent are discussed, and it is found that except for the original arsenic content, the rest of the factors have a nonlinear relationship with the emission rate of arsenic. That is, up to a certain level, they all contribute to the release of arsenic, and then their impact is minimal. The original arsenic content in coal is proportional to the arsenic emission rate. Therefore, taking into consideration the nonlinear relationships between factors that affect the arsenic emission rate can reduce contamination from arsenic. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Co-combustion of fossil fuels and waste

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hao


    The Ph.D. thesis deals with the alternative and high efficiency methods of using waste-derived fuels in heat and power production. The focus is on the following subjects: 1) co-combustion of coal and solid recovered fuel (SRF) under pulverized fuel combustion conditions; 2) dust-firing of straw and the utilization of a waste-derived material as an additive; 3) the combustion of a biomass residue rich in phosphorus. Co-combustion of coal and SRF was conducted in an entrained flow reactor (EFR). The work revealed that when coal was co-fired with up to 25 wt% SRF, the burnout and the emissions of SO{sub 2} and NO were decreased with increasing share of SRF. The Cl content in the fly ash was very low (<0.07 wt%) when coal was co-fired up to 25 wt% SRF, indicating that the majority of the Cl in the SRF were released to gas phase during cocombustion. The formation of fouling deposits on a probe was reduced with increasing share of SRF and the resulting deposits had a very small Cl content (<0.01 wt%). On the other hand, when NaCl or PVC was added to the mixture of coal and SRF, the formation of alkali chlorides was significantly promoted. The partitioning of trace elements (As, Cd, Cr, Pb, Sb and Zn) during co-combustion of coal and SRF was investigated through the experiments in the EFR. They revealed that As, Cd, Pb, Sb and Zn were highly volatile during combustion, while the volatility of Cr was relatively low. The volatility of Cd, Pb and Zn increased significantly with the injection of Cl based additives such as PVC and NaCl, while the addition of ammonium sulphate generally decreased the volatility of trace elements. The addition of kaolinite reduced the volatility of Pb, while the effect on other trace elements was insignificant. Full-scale tests on co-combustion of coal and SRF were carried out in a pulverized coal-fired power plant, and the formation of fine particles was evaluated by applying a low-pressure cascade impactor. Compared to dedicated coal

  15. Autodesk Combustion 4 fundamentals courseware

    CERN Document Server



    Whether this is your first experience with Combustion software or you're upgrading to take advantage of the many new features and tools, this guide will serve as your ultimate resource to this all-in-one professional compositing application. Much more than a point-and-click manual, this guide explains the principles behind the software, serving as an overview of the package and associated techniques. Written by certified Autodesk training specialists for motion graphic designers, animators, and visual effects artists, Combustion 4 Fundamentals Courseware provides expert advice for all skill le

  16. Chemical kinetics and combustion modeling

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.A. [Sandia National Laboratories, Livermore, CA (United States)


    The goal of this program is to gain qualitative insight into how pollutants are formed in combustion systems and to develop quantitative mathematical models to predict their formation rates. The approach is an integrated one, combining low-pressure flame experiments, chemical kinetics modeling, theory, and kinetics experiments to gain as clear a picture as possible of the process in question. These efforts are focused on problems involved with the nitrogen chemistry of combustion systems and on the formation of soot and PAH in flames.

  17. Catalytic Combustion of Ethyl Acetate


    ÖZÇELİK, Tuğba GÜRMEN; ATALAY, Süheyda; ALPAY, Erden


    The catalytic combustion of ethyl acetate over prepared metal oxide catalysts was investigated. CeO, Co2O3, Mn2O3, Cr2O3, and CeO-Co2O3 catalysts were prepared on monolith supports and they were tested. Before conducting the catalyst experiments, we searched for the homogeneous gas phase combustion reaction of ethyl acetate. According to the homogeneous phase experimental results, 45% of ethyl acetate was converted at the maximum reactor temperature tested (350 °C). All the prepare...

  18. Application of the FIRST Combustion model to Spray Combustion

    NARCIS (Netherlands)

    de Jager, B.; Kok, Jacobus B.W.


    Liquid fuel is of interest to apply to gas turbines. The large advantage is that liquids are easily storable as compared to gaseous fuels. Disadvantage is that liquid fuel has to be sprayed, vaporized and mixed with air. Combustion occurs at some stage of mixing and ignition. Depending on the

  19. Local Content

    CSIR Research Space (South Africa)

    Gibberd, Jeremy


    Full Text Available is also delineated in order to demonstrate the implications of local content on building design, construction and operation. The advantages and disadvantages of local content approaches are discussed and illustrated through examples. Finally, broad...

  20. Scramjet Combustion Stability Behavior Modeling Project (United States)

    National Aeronautics and Space Administration — A recent breakthrough in combustion stability analysis (UCDS) offers the means to accurately predict the combustion stability of a scramjet. This capability is very...

  1. Scramjet Combustion Stability Behavior Modeling Project (United States)

    National Aeronautics and Space Administration — A recent breakthrough in combustion stability analysis (UCDS) offers the potential to predict the combustion stability of a scramjet. This capability is very...

  2. Free Energy and Internal Combustion Engine Cycles


    Harris, William D.


    The performance of one type (Carnot) of Internal Combustion Engine (ICE) cycle is analyzed within the framework of thermodynamic free energies. ICE performance is different from that of an External Combustion Engine (ECE) which is dictated by Carnot's rule.

  3. Cytotoxic and genotoxic responses of human lung cells to combustion smoke particles of Miscanthus straw, softwood and beech wood chips (United States)

    Arif, Ali Talib; Maschowski, Christoph; Garra, Patxi; Garcia-Käufer, Manuel; Petithory, Tatiana; Trouvé, Gwenaëlle; Dieterlen, Alain; Mersch-Sundermann, Volker; Khanaqa, Polla; Nazarenko, Irina; Gminski, Richard; Gieré, Reto


    Inhalation of particulate matter (PM) from residential biomass combustion is epidemiologically associated with cardiovascular and pulmonary diseases. This study investigates PM0.4-1 emissions from combustion of commercial Miscanthus straw (MS), softwood chips (SWC) and beech wood chips (BWC) in a domestic-scale boiler (40 kW). The PM0.4-1 emitted during combustion of the MS, SWC and BWC were characterized by ICP-MS/OES, XRD, SEM, TEM, and DLS. Cytotoxicity and genotoxicity in human alveolar epithelial A549 and human bronchial epithelial BEAS-2B cells were assessed by the WST-1 assay and the DNA-Alkaline Unwinding Assay (DAUA). PM0.4-1 uptake/translocation in cells was investigated with a new method developed using a confocal reflection microscope. SWC and BWC had a inherently higher residual water content than MS. The PM0.4-1 emitted during combustion of SWC and BWC exhibited higher levels of Polycyclic Aromatic Hydrocarbons (PAHs), a greater variety of mineral species and a higher heavy metal content than PM0.4-1 from MS combustion. Exposure to PM0.4-1 from combustion of SWC and BWC induced cytotoxic and genotoxic effects in human alveolar and bronchial cells, whereby the strongest effect was observed for BWC and was comparable to that caused by diesel PM (SRM 2 975), In contrast, PM0.4-1 from MS combustion did not induce cellular responses in the studied lung cells. A high PAH content in PM emissions seems to be a reliable chemical marker of both combustion efficiency and particle toxicity. Residual biomass water content strongly affects particulate emissions and their toxic potential. Therefore, to minimize the harmful effects of fine PM on health, improvement of combustion efficiency (aiming to reduce the presence of incomplete combustion products bound to PM) and application of fly ash capture technology, as well as use of novel biomass fuels like Miscanthus straw is recommended.

  4. High Frequency Combustion Instabilities of LOx/CH4 Spray Flames in Rocket Engine Combustion Chambers

    NARCIS (Netherlands)

    Sliphorst, M.


    Ever since the early stages of space transportation in the 1940’s, and the related liquid propellant rocket engine development, combustion instability has been a major issue. High frequency combustion instability (HFCI) is the interaction between combustion and the acoustic field in the combustion

  5. Method and device for diagnosing and controlling combustion instabilities in internal combustion engines operating in or transitioning to homogeneous charge combustion ignition mode (United States)

    Wagner, Robert M [Knoxville, TN; Daw, Charles S [Knoxville, TN; Green, Johney B [Knoxville, TN; Edwards, Kevin D [Knoxville, TN


    This invention is a method of achieving stable, optimal mixtures of HCCI and SI in practical gasoline internal combustion engines comprising the steps of: characterizing the combustion process based on combustion process measurements, determining the ratio of conventional and HCCI combustion, determining the trajectory (sequence) of states for consecutive combustion processes, and determining subsequent combustion process modifications using said information to steer the engine combustion toward desired behavior.

  6. Straw combustion on slow-moving grates

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen


    Combustion of straw in grate-based boilers is often associated with high emission levels and relatively poor fuel burnout. A numerical grate combustion model was developed to assist in improving the combustion performance of these boilers. The model is based on a one-dimensional ‘‘walking...

  7. 30 CFR 56.4104 - Combustible waste. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Combustible waste. 56.4104 Section 56.4104... Control Prohibitions/precautions/housekeeping § 56.4104 Combustible waste. (a) Waste materials, including... properly, waste or rags containing flammable or combustible liquids that could create a fire hazard shall...

  8. Laboratory Test of Reciprocating Internal Combustion Engines (United States)


    700, Laboratory Tests of Reciprocating Internal Combustion Engines , dated 24 January 1985. Marginal notations are not used in this revision to...performance and endurance of reciprocating internal combustion engines . Test equipment includes engine dynamometers, precision fuel flow meters, oil...D-1 *This TOP supersedes TOP 02-2-700, Laboratory Tests of Reciprocating Internal Combustion Engines , dated 24

  9. Furnaces with multiple ?ameless combustion burners

    NARCIS (Netherlands)

    Danon, B.


    In this thesis three different combustion systems, equipped with either a single or multiple ?ameless combustion burner(s), are discussed. All these setups were investigated both experimentally and numerically, i.e., using Computational Fluid Dynamics (CFD) simulations. Flameless combustion is a

  10. C60 fullerenes from combustion of common fuels. (United States)

    Tiwari, Andrea J; Ashraf-Khorassani, Mehdi; Marr, Linsey C


    Releases of C60 fullerenes to the environment will increase with the growth of nanotechnology. Assessing the potential risks of manufactured C60 requires an understanding of how its prevalence in the environment compares to that of natural and incidental C60. This work describes the characterization of incidental C60 present in aerosols generated by combustion of five common fuels: coal, firewood, diesel, gasoline, and propane. C60 was found in exhaust generated by all five fuels; the highest concentrations in terms of mass of C60 per mass of particulate matter were associated with diesel and coal. Individual aerosols from these combustion processes were examined by transmission electron microscopy. No relationship was found between C60 content and either the separation of graphitic layers (lamellae) within the particles, nor the curvature of those lamellae. Estimated global emissions of incidental C60 to the atmosphere from coal and diesel combustion range from 1.6 to 6.3 t yr(-1), depending upon combustion conditions. These emissions may be similar in magnitude to the total amount of manufactured C60 produced on an annual basis. Consequent loading of incidental C60 to the environment may be several orders of magnitude higher than has previously been modeled for manufactured C60. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Modelling combustion reactions for gas flaring and its resulting emissions

    Directory of Open Access Journals (Sweden)

    O. Saheed Ismail


    Full Text Available Flaring of associated petroleum gas is an age long environmental concern which remains unabated. Flaring of gas maybe a very efficient combustion process especially steam/air assisted flare and more economical than utilization in some oil fields. However, it has serious implications for the environment. This study considered different reaction types and operating conditions for gas flaring. Six combustion equations were generated using the mass balance concept with varying air and combustion efficiency. These equations were coded with a computer program using 12 natural gas samples of different chemical composition and origin to predict the pattern of emission species from gas flaring. The effect of key parameters on the emission output is also shown. CO2, CO, NO, NO2 and SO2 are the anticipated non-hydrocarbon emissions of environmental concern. Results show that the quantity and pattern of these chemical species depended on percentage excess/deficiency of stoichiometric air, natural gas type, reaction type, carbon mass content, impurities, combustion efficiency of the flare system etc. These emissions degrade the environment and human life, so knowing the emission types, pattern and flaring conditions that this study predicts is of paramount importance to governments, environmental agencies and the oil and gas industry.

  12. Sulfur Chemistry in Combustion II

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Kiil, Søren


    Several options are available to control the emission of SO2 from combustion processes. One possibility is to use a cleaner technology, i.e. fuel switching from oil and coal to natural gas or biomass, or to desulphurize coal and oil. Another possibility is to change to a different technology...

  13. Structural Analysis of Combustion Models

    CERN Document Server

    Tóth, J; Zsély, I


    Using ReactionKinetics, a Mathematica based package a few dozen detailed models for combustion of hydrogen, carbon monoxide and methanol are investigated. Essential structural characteristics are pulled out, and similarities and differences of the mechanisms are highlighted. These investigations can be used before or parallel with usual numerical investigations, such as pathway analysis, sensitivity analysis, parameter estimation, or simulation.

  14. 75 FR 3881 - Combustible Dust (United States)


    ... may form combustible dust include, but are not limited to, wood, coal, plastics, biosolids, candy..., pharmaceutical manufacturing, tire manufacturing, production of rubber and plastics, plastics and rubber products manufacturing, recycling, wastewater treatment, and coal handling. OSHA is developing a standard that will...

  15. Gaseous emissions from waste combustion. (United States)

    Werther, Joachim


    An overview is given on methods and technologies for limiting the gaseous emissions from waste combustion. With the guideline 2000/76/EC recent European legislation has set stringent limits not only for the mono-combustion of waste in specialized incineration plants but also for co-combustion in coal-fired power plants. With increased awareness of environmental issues and stepwise decrease of emission limits and inclusion of more and more substances into the network of regulations a multitude of emission abatement methods and technologies have been developed over the last decades. The result is the state-of-the-art waste incinerator with a number of specialized process steps for the individual components in the flue gas. The present work highlights some new developments which can be summarized under the common goal of reducing the costs of flue gas treatment by applying systems which combine the treatment of several noxious substances in one reactor or by taking new, simpler routes instead of the previously used complicated ones or - in the case of flue gas desulphurisation - by reducing the amount of limestone consumption. Cost reduction is also the driving force for new processes of conditioning of nonhomogenous waste before combustion. Pyrolysis or gasification is used for chemical conditioning whereas physical conditioning means comminution, classification and sorting processes. Conditioning yields a fuel which can be used in power plants either as a co-fuel or a mono-fuel and which will burn there under much better controlled conditions and therefore with less emissions than the nonhomogeneous waste in a conventional waste incinerator. Also for cost reasons, co-combustion of wastes in coal-fired power stations is strongly pressing into the market. Recent investigations reveal that the co-firing of waste can also have beneficial effects on the operating behavior of the boiler and on the gaseous emissions.

  16. Influence of Zn{sup 2+} content on morphological and magnetic properties of Mn{sub 1-x}Zn{sub x}Fe{sub 2}O{sub 4} ferrites synthesized on a large scale by combustion reaction; Influencia do teor de Zn{sup 2+} nas caracteristicas morfologicas e magneticas de ferritas Mn{sub 1-x}Zn{sub x}Fe{sub 2}O{sub 4} sintetizados em grande escala por reacao de combustao

    Energy Technology Data Exchange (ETDEWEB)

    Diniz, V.C.S.; Silveira Junior, J.E.R.; Costa, A.C.F.M., E-mail:, E-mail:, E-mail: [Universidade Federal de Campina Grande (UFCG), Campina Grande, PB (Brazil). Departamento de Engenharia de Materiais; Cornejo, D.R., E-mail: [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Fisica; Kiminami, R.H.G.A., E-mail: [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Engenharia de Materiais


    This study aimed to evaluate the influence of Zn{sup 2+} in the morphological and magnetic characteristics of ferrites Mn{sub 1-x}Zn{sub x} Fe{sub 2} O{sub 4} (where x= 0.0, 0.35, 0.5 and 0.65 mol of Zn) synthesized by combustion reaction in a pilot scale with batches of 200 g/reaction. The samples were characterized by X-ray diffraction, scanning/transmission electron microscopy, and magnetic measurements. The results indicated that all compositions were single phase of ferrite; morphologically the addition of Zn to MnFe{sub 2} O{sub 4} system caused a slight reduction in size of the agglomerates, and reduced the particle size, but this behavior was not linear with the Zn{sup 2+} content. The samples had characteristic magnetic behavior of soft magnetic materials, maximum saturation magnetization of 62 emu/g for the sample with lower zinc content in its composition. (author)

  17. The determination of maturity levels in source rocks of the La Luna Formation, Maracaibo Basin, Venezuela, based on convention geochemical parameters and asphaltenes; Determinacao do grau de maturacao em rochas geradoras de petroleo, formacao La Luna, Bacia de Maracaibo, Venezuela: parametros geoquimicos convencionais e asfaltenos

    Energy Technology Data Exchange (ETDEWEB)

    Castro, L.P. de [Pontificia Universidade Catolica (PUC-RS), Porto Alegre, RS (Brazil). Centro de Excelencia em Pesquisas sobre o Armazenamento de Carbono; Franco, N. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Dept. de Geologia; Lopez, L.; Lo Monaco, S.; Escobar, G. [Universidad Central de Venezuela (UCV), Caracas (Venezuela); Kalkreuth, W. [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Centro de Excelencia em Analises de Carvao e Rochas Geradoras de Petroleo


    The La Luna Formation, main source rock of the Maracaibo Basin was studied by conventional geochemical parameters, used to determine the maturity, and they were compared with the physic-chemical and molecular properties of the asphaltenes present in the bitumen of the rocks. Three wells were studied (A, B and C) with a total of 13 samples. Based on Rock-Eval results the organic matter in well A (455 deg C Tmax) shows a relatively high level of maturation (top of the oil window), whereas the organic matter in well B (435 - 436 deg C Tmax) is in the beginning of the oil window. Tmax values in well C (438 - 446 deg C) and well C suggest an intermediate maturity level. The biomarkers identified in well B and C show ratios indicating an equilibrium state in the maturity level. A good correlation was found comparing the conventional analytical data with the determination of maturity level obtained from the asphaltenes precipitated from the bitumen of the samples. With increased maturity levels the H1 NMR analysis showed enrichment in aromatic molecules in relation to aliphatic, due to the bitumen aromatization process. Similarly, the asphaltenes molecular weight has higher values in samples characterized by elevated maturity levels. This confirms earlier studies that showed that asphaltenes may be utilized as maturity parameter of organic matter. (author)

  18. Light Duty Efficient, Clean Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Donald Stanton


    Cummins has successfully completed the Light Duty Efficient Clean Combustion (LDECC) cooperative program with DoE. This program was established in 2007 in support of the Department of Energy's Vehicles Technologies Advanced Combustion and Emissions Control initiative to remove critical barriers to the commercialization of advanced, high efficiency, emissions compliant internal combustion (IC) engines for light duty vehicles. Work in this area expanded the fundamental knowledge of engine combustion to new regimes and advanced the knowledge of fuel requirements for these diesel engines to realize their full potential. All of the following objectives were met with fuel efficiency improvement targets exceeded: (1) Improve light duty vehicle (5000 lb. test weight) fuel efficiency by 10.5% over today's state-of-the-art diesel engine on the FTP city drive cycle; (2) Develop and design an advanced combustion system plus aftertreatment system that synergistically meets Tier 2 Bin 5 NOx and PM emissions standards while demonstrating the efficiency improvements; (3) Maintain power density comparable to that of current conventional engines for the applicable vehicle class; and (4) Evaluate different fuel components and ensure combustion system compatibility with commercially available biofuels. Key accomplishments include: (1) A 25% improvement in fuel efficiency was achieved with the advanced LDECC engine equipped with a novel SCR aftertreatment system compared to the 10.5% target; (2) An 11% improvement in fuel efficiency was achieved with the advanced LDECC engine and no NOx aftertreamtent system; (3) Tier 2 Bin 5 and SFTP II emissions regulations were met with the advanced LDECC engine equipped with a novel SCR aftertreatment system; (4) Tier 2 Bin 5 emissions regulations were met with the advanced LDECC engine and no NOx aftertreatment, but SFTP II emissions regulations were not met for the US06 test cycle - Additional technical barriers exist for the no NOx


    Energy Technology Data Exchange (ETDEWEB)

    J.Y. Hwang; X. Huang; M.G. McKimpson; R.E. Tieder; A.M. Hein; J.M. Gillis; D.C. Popko; K.L. Paxton; Z. Li; X. Liu; X. Song; R.I. Kramer


    Low NO{sub x} combustion practices are critical for reducing NO{sub x} emissions from power plants. These low NO{sub x} combustion practices, however, generate high residual carbon contents in the fly ash produced. These high carbon contents threaten utilization of this combustion by-product. This research has successfully developed a separation technology to render fly ash into useful, quality-controlled materials. This technology offers great flexibility and has been shown to be applicable to all of the fly ashes tested (more than 10). The separated materials can be utilized in traditional fly ash applications, such as cement and concrete, as well as in nontraditional applications such as plastic fillers, metal matrix composites, refractories, and carbon adsorbents. Technologies to use beneficiated fly ash in these applications are being successfully developed. In the future, we will continue to refine the separation and utilization technologies to expand the utilization of fly ash. The disposal of more than 31 million tons of fly ash per year is an important environmental issue. With continued development, it will be possible to increase economic, energy and environmental benefits by re-directing more of this fly ash into useful materials.

  20. Electrochemical treatment of wood combustion fly ash for the removal of cadmium

    DEFF Research Database (Denmark)

    Damø, Anne Juul


    Due to a high content of macronutrients and a potential liming capacity, recycling of ashes from biomass combustion to agricultural fields as fertilisers and/or for soil improvement is considered in Denmark and other countries utilising biomass as an energy source. However, especially the fly ash...... fractions contain amounts of the toxic heavy metal Cd that may exceed the limiting values for agricultural utilisation given by the Danish EPA. In this work the advances of using an electrochemical remediation method to reduce the Cd content in wood combustion fly ash - for the aim of recycling...

  1. Fuel oil-water emulsions combustion and application perspectives in Mexico; Combustion de emulsiones de agua en combustoleo y perspectivas de aplicacion en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ocampo Barrera, Rene [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)


    Fuel drops with a content of 16% by weight were burned in three emulsions prepared with 5%, 15% and 25% water. The combustion of the drops was carried out in an spherical furnace utilizing the technique of a drop suspended in a filament. The combustion process was registered by a high velocity video system. It was found that the surface of the particles produced by the combustion of the emulsions, had larger holes than the ones of the fuel, therefore it is expected that emulsifying the fuel can help in reducing the unburned particles emission. [Espanol] Se quemaron gotas de un combustoleo, con un contenido de asfaltenos del 16% en peso, y de tres emulsiones preparadas con 5%, 15% y 25% de agua. La combustion de las gotas se llevo a cabo en un horno esferico empleando la tecnica de gota suspendida en un filamento. El proceso de combustion se registro mediante un sistema de video de alta velocidad. Se encontro que la superficie de las particulas de coque, producidas por la combustion de emulsiones, tuvo hoyos mas grandes que la del combustoleo, por lo que es de esperarse que emulsionar el combustoleo puede ayudar a reducir las emisiones de particulas inquemadas.

  2. Effects of moisture release and radiation properties in pulverized fuel combustion

    DEFF Research Database (Denmark)

    Yin, Chungen


    to improve the plant efficiency and is also expected to affect the combustion process. Thermal radiation is the principal mode of heat transfer in combustion. In PF furnaces, radiation consists of contribution from both participating gases and solid particles, in which gas and particle radiation properties...... play an important role. There are different methods or models in the literature to address fuel moisture release and radiation properties, some of which may be inappropriate and can produce misleading results. This paper compares the different methods and models and demonstrates their implementation...... for fuel moisture release may not induce distinct difference in combustion of PF with relatively low moisture content. For radiation, it has to be emphasized that particle radiation largely overwhelms gas radiation in PF combustion. The current tide of radiation research that over-focuses on gas radiation...

  3. Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ojeda, William de


    The project which extended from November 2005 to May of 2010 demonstrated the application of Low Temperature Combustion (LTC) with engine out NOx levels of 0.2 g/bhp-hr throughout the program target load of 12.6bar BMEP. The project showed that the range of loads could be extended to 16.5bar BMEP, therefore matching the reference lug line of the base 2007 MY Navistar 6.4L V8 engine. Results showed that the application of LTC provided a dramatic improvement over engine out emissions when compared to the base engine. Furthermore LTC improved thermal efficiency by over 5% from the base production engine when using the steady state 13 mode composite test as a benchmark. The key enablers included improvements in the air, fuel injection, and cooling systems made in Phases I and II. The outcome was the product of a careful integration of each component under an intelligent control system. The engine hardware provided the conditions to support LTC and the controller provided the necessary robustness for a stable combustion. Phase III provided a detailed account on the injection strategy used to meet the high load requirements. During this phase, the control strategy was implemented in a production automotive grade ECU to perform cycle-by-cycle combustion feedback on each of the engine cylinders. The control interacted on a cycle base with the injection system and with the Turbo-EGR systems according to their respective time constants. The result was a unique system that could, first, help optimize the combustion system and maintain high efficiency, and secondly, extend the steady state results to the transient mode of operation. The engine was upgraded in Phase IV with a Variable Valve Actuation system and a hybrid EGR loop. The impact of the more versatile EGR loop did not provide significant advantages, however the application of VVA proved to be an enabler to further extend the operation of LTC and gain considerable benefits in fuel economy and soot reduction. Finally

  4. Microscale combustion and power generation

    CERN Document Server

    Cadou, Christopher; Ju, Yiguang


    Recent advances in microfabrication technologies have enabled the development of entirely new classes of small-scale devices with applications in fields ranging from biomedicine, to wireless communication and computing, to reconnaissance, and to augmentation of human function. In many cases, however, what these devices can actually accomplish is limited by the low energy density of their energy storage and conversion systems. This breakthrough book brings together in one place the information necessary to develop the high energy density combustion-based power sources that will enable many of these devices to realize their full potential. Engineers and scientists working in energy-related fields will find: An overview of the fundamental physics and phenomena of microscale combustion; Presentations of the latest modeling and simulation techniques for gasphase and catalytic micro-reactors; The latest results from experiments in small-scale liquid film, microtube, and porous combustors, micro-thrusters, a...

  5. Fundamental studies of spray combustion

    Energy Technology Data Exchange (ETDEWEB)

    Li, S.C.; Libby, P.A.; Williams, F.A. [Univ. of California, San Diego, CA (United States)


    Our research on spray combustion involves both experiment and theory and addresses the characteristics of individual droplets and of sprays in a variety of flows: laminar and turbulent, opposed and impinging. Currently our focus concerns water and fuel sprays in two stage laminar flames, i.e., flames arising, for example from a stream of fuel and oxidizer flowing opposite to an air stream carrying a water spray. Our interest in these flames is motivated by the goals of reducing pollutant emissions and extending the range of stable spray combustion. There remains considerable research to be carried out in order to achieve these goals. Thus far our research on the characteristics of sprays in turbulent flows has been limited to nonreacting jets impinging on a plate but this work will be extended to opposed flows with and without a flame. In the following we discuss details of these studies and our plans for future work.

  6. Oxy-coal Combustion Studies

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, J. [Univ. of Utah, Salt Lake City, UT (United States); Eddings, E. [Univ. of Utah, Salt Lake City, UT (United States); Lighty, J. [Univ. of Utah, Salt Lake City, UT (United States); Ring, T. [Univ. of Utah, Salt Lake City, UT (United States); Smith, P. [Univ. of Utah, Salt Lake City, UT (United States); Thornock, J. [Univ. of Utah, Salt Lake City, UT (United States); Y Jia, W. Morris [Univ. of Utah, Salt Lake City, UT (United States); Pedel, J. [Univ. of Utah, Salt Lake City, UT (United States); Rezeai, D. [Univ. of Utah, Salt Lake City, UT (United States); Wang, L. [Univ. of Utah, Salt Lake City, UT (United States); Zhang, J. [Univ. of Utah, Salt Lake City, UT (United States); Kelly, K. [Univ. of Utah, Salt Lake City, UT (United States)


    The objective of this project is to move toward the development of a predictive capability with quantified uncertainty bounds for pilot-scale, single-burner, oxy-coal operation. This validation research brings together multi-scale experimental measurements and computer simulations. The combination of simulation development and validation experiments is designed to lead to predictive tools for the performance of existing air fired pulverized coal boilers that have been retrofitted to various oxy-firing configurations. In addition, this report also describes novel research results related to oxy-combustion in circulating fluidized beds. For pulverized coal combustion configurations, particular attention is focused on the effect of oxy-firing on ignition and coal-flame stability, and on the subsequent partitioning mechanisms of the ash aerosol.

  7. Combustion synthesis continuous flow reactor

    Energy Technology Data Exchange (ETDEWEB)

    Maupin, G.D.; Chick, L.A.; Kurosky, R.P.


    The present invention is a reactor for combustion synthesis of inorganic powders. The reactor includes a reaction vessel having a length and a first end and a second end. The reaction vessel further has a solution inlet and a carrier gas inlet. The reactor further has a heater for heating both the solution and the carrier gas. In a preferred embodiment, the reaction vessel is heated and the solution is in contact with the heated reaction vessel. It is further preferred that the reaction vessel be cylindrical and that the carrier gas is introduced tangentially into the reaction vessel so that the solution flows helically along the interior wall of the reaction vessel. As the solution evaporates and combustion produces inorganic material powder, the carrier gas entrains the powder and carries it out of the reactor. 10 figs.

  8. Combustion synthesis continuous flow reactor

    Energy Technology Data Exchange (ETDEWEB)

    Maupin, Gary D. (Richland, WA); Chick, Lawrence A. (West Richland, WA); Kurosky, Randal P. (Maple Valley, WA)


    The present invention is a reactor for combustion synthesis of inorganic powders. The reactor includes a reaction vessel having a length and a first end and a second end. The reaction vessel further has a solution inlet and a carrier gas inlet. The reactor further has a heater for heating both the solution and the carrier gas. In a preferred embodiment, the reaction vessel is heated and the solution is in contact with the heated reaction vessel. It is further preferred that the reaction vessel be cylindrical and that the carrier gas is introduced tangentially into the reaction vessel so that the solution flows helically along the interior wall of the reaction vessel. As the solution evaporates and combustion produces inorganic material powder, the carrier gas entrains the powder and carries it out of the reactor.

  9. Steady Nuclear Combustion in Rockets (United States)

    Saenger, E.


    The astrophysical theory of stationary nuclear reactions in stars is applied to the conditions that would be met in the practical engineering cases that would differ from the former, particularly with respect to the much lower combustion pressures, dimensions of the reacting volume, and burnup times. This application yields maximum rates of hear production per unit volume of reacting gas occurring at about 10(exp 8) K in the cases of reactions between the hydrogen isotopes, but yields higher rates for heavier atoms. For the former, with chamber pressures of the order of 100 atmospheres, the energy production for nuclear combustion reaches values of about 10(exp 4) kilocalories per cubic meter per second, which approaches the magnitude for the familiar chemical fuels. The values are substantially lower for heavier atoms, and increase with the square of the combustion pressure. The half-life of the burnup in the fastest reactions may drop to values as low as those for chemical fuels so that, despite the high temperature, the radiated energy can remain smaller than the energy produced, particularly if an inefficiently radiating (i.e., easily completely ionized reacting material like hydrogen), is used. On the other hand, the fraction of completely ionized particles in the gases undergoing nuclear combustion must not exceed a certain upper limit because the densities (approximately 10(exp -10) grams per cubic centimeter)) lie in the range of high vacua and only for the previously mentioned fraction of nonionized particles can mean free paths be retained small enough so that the chamber diameters of several dozen meters will suffice. Under these conditions it appears that continuously maintained stable nuclear reactions at practical pressures and dimensions are fundamentally possible and their application can be visualized as energy sources for power plants and propulsion units.

  10. Coal combustion by wet oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Bettinger, J.A.; Lamparter, R.A.; McDowell, D.C.


    The combustion of coal by wet oxidation was studied by the Center for Waste Management Programs, of Michigan Technological University. In wet oxidation a combustible material, such as coal, is reacted with oxygen in the presence of liquid water. The reaction is typically carried out in the range of 204/sup 0/C (400/sup 0/F) to 353/sup 0/C (650/sup 0/F) with sufficient pressure to maintain the water present in the liquid state, and provide the partial pressure of oxygen in the gas phase necessary to carry out the reaction. Experimental studies to explore the key reaction parameters of temperature, time, oxidant, catalyst, coal type, and mesh size were conducted by running batch tests in a one-gallon stirred autoclave. The factors exhibiting the greatest effect on the extent of reaction were temperature and residence time. The effect of temperature was studied from 204/sup 0/C (400/sup 0/F) to 260/sup 0/C (500/sup 0/F) with a residence time from 600 to 3600 seconds. From this data, the reaction activation energy of 2.7 x 10/sup 4/ calories per mole was determined for a high-volatile-A-Bituminous type coal. The reaction rate constant may be determined at any temperature from the activation energy using the Arrhenius equation. Additional data were generated on the effect of mesh size and different coal types. A sample of peat was also tested. Two catalysts were evaluated, and their effects on reaction rate presented in the report. In addition to the high temperature combustion, low temperature desulfurization is discussed. Desulfurization can improve low grade coal to be used in conventional combustion methods. It was found that 90% of the sulfur can be removed from the coal by wet oxidation with the carbon untouched. Further desulfurization studies are indicated.

  11. Status of Boron Combustion Research (United States)


    Chemical M. K. King, ARC L. Cook, NBS C. E. Kolb, Aerodyne *T. Curran, AFWAL/PO C. K. Law, U. Cal.-Davi3 P. Davidovits , Boston College *C. R. Martel...Homogeneous Combustion Kinetics of Boron Compounds. A. Fontijn, RPI. 1030 Simple Boron Atom Reactions. P. Davidovits , Boston College. 1050 Ultra-Fast Energy... DAVIDOVITS . J. Chem. Phys. 74, 3287 (1981). DED - T. G. DIGIUSEPPI. Rt. ESTES, and P. DAVIDOVITS . J. Phys. Chem.. 6, 260 (1982). ERF -A. J. ENGLISH

  12. An experimental investigation of the combustion performance of human faeces. (United States)

    Onabanjo, Tosin; Kolios, Athanasios J; Patchigolla, Kumar; Wagland, Stuart T; Fidalgo, Beatriz; Jurado, Nelia; Hanak, Dawid P; Manovic, Vasilije; Parker, Alison; McAdam, Ewan; Williams, Leon; Tyrrel, Sean; Cartmell, Elise


    Poor sanitation is one of the major hindrances to the global sustainable development goals. The Reinvent the Toilet Challenge of the Bill and Melinda Gates Foundation is set to develop affordable, next-generation sanitary systems that can ensure safe treatment and wide accessibility without compromise on sustainable use of natural resources and the environment. Energy recovery from human excreta is likely to be a cornerstone of future sustainable sanitary systems. Faeces combustion was investigated using a bench-scale downdraft combustor test rig, alongside with wood biomass and simulant faeces. Parameters such as air flow rate, fuel pellet size, bed height, and fuel ignition mode were varied to establish the combustion operating range of the test rig and the optimum conditions for converting the faecal biomass to energy. The experimental results show that the dry human faeces had a higher energy content (∼25 MJ/kg) than wood biomass. At equivalence ratio between 0.86 and 1.12, the combustion temperature and fuel burn rate ranged from 431 to 558 °C and 1.53 to 2.30 g/min respectively. Preliminary results for the simulant faeces show that a minimum combustion bed temperature of 600 ± 10 °C can handle faeces up to 60 wt.% moisture at optimum air-to-fuel ratio. Further investigation is required to establish the appropriate trade-off limits for drying and energy recovery, considering different stool types, moisture content and drying characteristics. This is important for the design and further development of a self-sustained energy conversion and recovery systems for the NMT and similar sanitary solutions.

  13. Perspective -- Aerodynamic control of combustion

    Energy Technology Data Exchange (ETDEWEB)

    Oppenheim, A.K. [Univ. of California, Berkeley, CA (United States). Mechanical Engineering


    To do useful work, the exothermic process of combustion should be carried out in an enclosure, as is typically the case with i.c. engines -- the subject of this paper`s particular concern. To meet the requirements of high efficiency and low pollutant production, this process should be executed at a relatively low temperature -- a condition attainable by the use of lean air-fuel mixtures. For this purpose it has to be distributed in space upon multipoint initiation and kept away from the walls to minimize their detrimental effects. In principle, all this can be accomplished by a system referred to as fireball combustion that takes advantage of entrainment and spiral mixing associated with large scale vortex structures of jet plumes. As demonstrated in this paper, the success in such an endeavor depends crucially upon the utilization of the essential elements of classical aerodynamics: the properly distributed sources, expressed in terms of velocity divergences prescribed by the thermodynamic process of combustion and of the vorticity field generated by shear between the jets and the fluid into which they are injected.

  14. Combustion instability modeling and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, R.J.; Yang, V.; Santavicca, D.A. [Pennsylvania State Univ., University Park, PA (United States)] [and others


    It is well known that the two key elements for achieving low emissions and high performance in a gas turbine combustor are to simultaneously establish (1) a lean combustion zone for maintaining low NO{sub x} emissions and (2) rapid mixing for good ignition and flame stability. However, these requirements, when coupled with the short combustor lengths used to limit the residence time for NO formation typical of advanced gas turbine combustors, can lead to problems regarding unburned hydrocarbons (UHC) and carbon monoxide (CO) emissions, as well as the occurrence of combustion instabilities. Clearly, the key to successful gas turbine development is based on understanding the effects of geometry and operating conditions on combustion instability, emissions (including UHC, CO and NO{sub x}) and performance. The concurrent development of suitable analytical and numerical models that are validated with experimental studies is important for achieving this objective. A major benefit of the present research will be to provide for the first time an experimentally verified model of emissions and performance of gas turbine combustors.

  15. Demonstration of Active Combustion Control (United States)

    Lovett, Jeffrey A.; Teerlinck, Karen A.; Cohen, Jeffrey M.


    The primary objective of this effort was to demonstrate active control of combustion instabilities in a direct-injection gas turbine combustor that accurately simulates engine operating conditions and reproduces an engine-type instability. This report documents the second phase of a two-phase effort. The first phase involved the analysis of an instability observed in a developmental aeroengine and the design of a single-nozzle test rig to replicate that phenomenon. This was successfully completed in 2001 and is documented in the Phase I report. This second phase was directed toward demonstration of active control strategies to mitigate this instability and thereby demonstrate the viability of active control for aircraft engine combustors. This involved development of high-speed actuator technology, testing and analysis of how the actuation system was integrated with the combustion system, control algorithm development, and demonstration testing in the single-nozzle test rig. A 30 percent reduction in the amplitude of the high-frequency (570 Hz) instability was achieved using actuation systems and control algorithms developed within this effort. Even larger reductions were shown with a low-frequency (270 Hz) instability. This represents a unique achievement in the development and practical demonstration of active combustion control systems for gas turbine applications.

  16. Modeling the internal combustion engine (United States)

    Zeleznik, F. J.; Mcbride, B. J.


    A flexible and computationally economical model of the internal combustion engine was developed for use on large digital computer systems. It is based on a system of ordinary differential equations for cylinder-averaged properties. The computer program is capable of multicycle calculations, with some parameters varying from cycle to cycle, and has restart capabilities. It can accommodate a broad spectrum of reactants, permits changes in physical properties, and offers a wide selection of alternative modeling functions without any reprogramming. It readily adapts to the amount of information available in a particular case because the model is in fact a hierarchy of five models. The models range from a simple model requiring only thermodynamic properties to a complex model demanding full combustion kinetics, transport properties, and poppet valve flow characteristics. Among its many features the model includes heat transfer, valve timing, supercharging, motoring, finite burning rates, cycle-to-cycle variations in air-fuel ratio, humid air, residual and recirculated exhaust gas, and full combustion kinetics.

  17. Method and apparatus for active control of combustion rate through modulation of heat transfer from the combustion chamber wall (United States)

    Roberts, Jr., Charles E.; Chadwell, Christopher J.


    The flame propagation rate resulting from a combustion event in the combustion chamber of an internal combustion engine is controlled by modulation of the heat transfer from the combustion flame to the combustion chamber walls. In one embodiment, heat transfer from the combustion flame to the combustion chamber walls is mechanically modulated by a movable member that is inserted into, or withdrawn from, the combustion chamber thereby changing the shape of the combustion chamber and the combustion chamber wall surface area. In another embodiment, heat transfer from the combustion flame to the combustion chamber walls is modulated by cooling the surface of a portion of the combustion chamber wall that is in close proximity to the area of the combustion chamber where flame speed control is desired.



    Nureddin Dinler; Nuri Yucel


    Combustion is an important subject of internal combustion engine studies. To reduce the air pollution from internal combustion engines and to increase the engine performance, it is required to increase combustion efficiency. In this study, effects of air/fuel ratio were investigated numerically. An axisymmetrical internal combustion engine was modeled in order to simulate in-cylinder engine flow and combustion. Two dimensional transient continuity, momentum, turbulence, energy, and combustion...


    Energy Technology Data Exchange (ETDEWEB)



    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, the Lignite Research Council, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (UU) and the University of North Dakota Energy and Environmental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NO combustion systems, and new power generation x plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). This report covers the reporting period from 1 July 1998 through 30 September 1998. During this period distribution of all three Phase II coals was completed. Standard analyses for the whole coal samples were also completed. Mössbauer analysis of all project coals and fractions received to date has been completed in order to obtain details of the iron mineralogy. The analyses of arsenic XAFS data for two of the project coals and for some high arsenic coals have been completed. Duplicate splits of the Ohio 5,6,7 and North Dakota lignite samples were taken through all four steps of the selective leaching procedure. Leaching analysis of the Wyodak coal has recently commenced. Preparation of polished coal/epoxy pellets for probe/SEM studies is underway. Some exploratory mercury LIII XAFS work was

  20. Oxy-fuel combustion of solid fuels

    DEFF Research Database (Denmark)

    Toftegaard, Maja Bøg; Brix, Jacob; Jensen, Peter Arendt


    Oxy-fuel combustion is suggested as one of the possible, promising technologies for capturing CO2 from power plants. The concept of oxy-fuel combustion is removal of nitrogen from the oxidizer to carry out the combustion process in oxygen and, in most concepts, recycled flue gas to lower the flame...... provide additional options for improvement of process economics are however likewise investigated. Of particular interest is the change of the combustion process induced by the exchange of carbon dioxide and water vapor for nitrogen as diluent. This paper reviews the published knowledge on the oxy......-fuel process and focuses particularly on the combustion fundamentals, i.e. flame temperatures and heat transfer, ignition and burnout, emissions, and fly ash characteristics. Knowledge is currently available regarding both an entire oxy-fuel power plant and the combustion fundamentals. However, several...

  1. Pollutant Formation in Monodisperse Fuel Spray Combustion (United States)

    Cernansky, N. P.; Sarv, H.


    The combustion of liquid sprays represents an extremely important class of combustion processes. In the transition region, encompassing droplet sizes in the range of 25-80 micron diameter, the mixing and evaporation processes are both incomplete at the flame front and burning occurs in a combined diffusive and premixed fashion. Under these conditions, the relative importance of heterogeneous and homogeneous effects in dominating the combustion process is switched and gives rise to a number of interesting phenomena. NO (sub x) formation in monodisperse spray combustion was investigated with the following specific objectives: (1) to quantitatively determine the effect of droplet size, number density, etc. on NO sub x formation in monodisperse fuel spray combustion; and (2) to isolate the important physical and chemical phenomena in NO sub x formation in these combustion systems.

  2. Sandia Combustion Research Program: Annual report, 1986

    Energy Technology Data Exchange (ETDEWEB)


    This report presents research results of the past year, divided thematically into some ten categories. Publications and presentations arising from this work are included in the appendix. Our highlighted accomplishment of the year is the announcement of the discovery and demonstration of the RAPRENOx process. This new mechanism for the elimination of nitrogen oxides from essentially all kinds of combustion exhausts shows promise for commercialization, and may eventually make a significant contribution to our nation's ability to control smog and acid rain. The sections of this volume describe the facility's laser and computer system, laser diagnostics of flames, combustion chemistry, reacting flows, liquid and solid propellant combustion, mathematical models of combustion, high-temperature material interfaces, studies of engine/furnace combustion, coal combustion, and the means of encouraging technology transfer. 182 refs., 170 figs., 12 tabs.

  3. Combustion and Heat Transfer Studies Utilizing Advanced Diagnostics: Combustion Studies (United States)


    Also, m ass conservation balance in the plane of th 1.0 . ./Id -005 0- bluff body base provided an additional cross-check against (W/Uei U/a...jet than asa thick jet spreading into adump combustor. Ass a . NAlI 2’A.. , 2.0 L K consequence, in Fig. 5b. streamlines around die recirculatiofi zone...Combustio of 23. Rawe., It, and Kremer, H.: EWmtwa Spwsposm IfWhucabon Fucks wih Air NACA Rept. 1300,29M. (nternational) on Combustion, p.667, The

  4. Experimental research on combustion fluorine retention using calcium-based sorbets during coal combustion (I)

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Qing-jie; Lin, Zhi-yan; Liu, Jian-zhong; Wu, Xian; Zhou, Jun-hu; Cen, Ke-fa [Liaoning Technical University, Fuxin (China). College of Resource and Environment Engineering


    In order to provide experimental guide to commercial use of fluorine pollution control during coal combustion, with fluorine pollution control during coal combustion in mind, this paper proposed the theory of combustion fluorine retention technology. Feasibility of fluorine retention reaction with calcium-based fluorine retention agent was analyzed through thermodynamic calculation during coal combustion. By simulating the restraining and retention effects and influential factors of calcium-based sorbets on vaporized fluoride during experimental combustion using fixed bed tube furnace, the paper systematically explored the influential law of such factors as combustion temperature, retention time, and added quantities of calcium-based sorbets on effects of fluorine retention. The research result shows that adding calcium-based fluorine retention agent in coal combustion has double effects of fluorine retention and sulfur retention, it lays an experimental foundation for commercial test of combustion fluorine retention. 7 refs., 2 figs., 4 tabs.


    The Environmental Technology Verification report discusses the technology and performance of the Xonon Cool Combustion System manufactured by Catalytica Energy Systems, Inc., formerly Catalytica Combustion Systems, Inc., to control NOx emissions from gas turbines that operate wit...

  6. The combustion of solid fuels and wastes

    CERN Document Server

    Tillman, David


    Careful organization and empirical correlations help clarify the prodigious technical information presented in this useful reference.Key Features* Written for practicing engineers, this comprehensive book supplies an overall framework of the combustion process; It connects information on specific reactions and reaction sequences with current applications and hardware; Each major group of combustion solids is evaluated; Among the many topics covered are:* Various biomass forms* The coalification process* Grate, kiln, and suspension firing* Fluidized bed combustion

  7. Materials for High-Temperature Catalytic Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ersson, Anders


    Catalytic combustion is an environmentally friendly technique to combust fuels in e.g. gas turbines. Introducing a catalyst into the combustion chamber of a gas turbine allows combustion outside the normal flammability limits. Hence, the adiabatic flame temperature may be lowered below the threshold temperature for thermal NO{sub X} formation while maintaining a stable combustion. However, several challenges are connected to the application of catalytic combustion in gas turbines. The first part of this thesis reviews the use of catalytic combustion in gas turbines. The influence of the fuel has been studied and compared over different catalyst materials. The material section is divided into two parts. The first concerns bimetallic palladium catalysts. These catalysts showed a more stable activity compared to their pure palladium counterparts for methane combustion. This was verified both by using an annular reactor at ambient pressure and a pilot-scale reactor at elevated pressures and flows closely resembling the ones found in a gas turbine combustor. The second part concerns high-temperature materials, which may be used either as active or washcoat materials. A novel group of materials for catalysis, i.e. garnets, has been synthesised and tested in combustion of methane, a low-heating value gas and diesel fuel. The garnets showed some interesting abilities especially for combustion of low-heating value, LHV, gas. Two other materials were also studied, i.e. spinels and hexa aluminates, both showed very promising thermal stability and the substituted hexa aluminates also showed a good catalytic activity. Finally, deactivation of the catalyst materials was studied. In this part the sulphur poisoning of palladium, platinum and the above-mentioned complex metal oxides has been studied for combustion of a LHV gas. Platinum and surprisingly the garnet were least deactivated. Palladium was severely affected for methane combustion while the other washcoat materials were

  8. Biofuel Combustion Fly Ash Influence on the Properties of Concrete

    Directory of Open Access Journals (Sweden)

    Aurelijus Daugėla


    Full Text Available Cement as the binding agent in the production of concrete can be replaced with active mineral admixtures. Biofuel combustion fly ash is one of such admixtures. Materials used for the study: Portland cement CEM I 42.5 R, sand of 0/4 fraction, gravel of 4/16 fraction, biofuel fly ash, superplasticizer, water. Six compositions of concrete were designed by replacing 0%, 5%, 10%, 15% 20%, and 25% of cement with biofuel fly ash. The article analyses the effect of biofuel fly ash content on the properties of concrete. The tests revealed that the increase of biofuel fly ash content up to 20% increases concrete density and compressive strength after 7 and 28 days of curing and decreases water absorption, with corrected water content by using plasticizing admixture. It was found that concrete where 20% of cement is replaced by biofuel ash has higher frost resistance.

  9. Strategy for intelligent internal combustion engine with homogenous combustion in cylinder


    Weclas, Miroslaw


    In this report the author proposes strategy for development of intelligent combustion systems with a goal to approach a near-zero emission internal combustion engine operating in a wide range of speeds and loads. Main requirement for future I.C. engine is to develop a system permitting homogeneous combustion process (minimum of engine emissions) under all operational conditions. The author suggests, that none existing individual combustion system may satisfy these conditions. However, combina...

  10. Selection of technology for the low calorific synthetic gas combustion in the gas turbine combustion chamber (United States)

    Filippov, Prokopy; Levin, Evgeny; Ryzhkov, Alexander


    The leading gas turbines manufacturers are developing the technologies of the environmental friendly combustion of industrial and synthetic gases of low calorific values. In this case they are faced with critical problems concerning combustion stability assurance and the necessity of the gas turbines significant modernization due to the differences between the low calorific and natural gases. The numerical simulation results of the low calorific value synthetic gas combustion in the combustion chamber by means of different technologies are considered in the paper.

  11. Supercritical Combustion of Liquid Oxygen and Hydrocarbon for Staged-Combustion Cycle Engine Technology Development (United States)


    Mixtures," by G. Ribert, N. Zong, V. Yang, L. Pons , N. Darabiha, and S. Candel, Combustion and Flame, Vol. 154, 2008, pp. 319-330. 3. "Mass Transfer...and Combustion in Transcritical Non-Premixed Counterflows," by L. Pons , N. Darabiha, S. Candel, G. Ribert, and V. Yang, Combustion Theory and...supercritical environment," Combust. Sci. Tech. 178, 193 (2006). T. Poinsot and S. Lele , "Boundary conditions for direct simulation of compressible viscous

  12. Pyrolysis reactor and fluidized bed combustion chamber (United States)

    Green, Norman W.


    A solid carbonaceous material is pyrolyzed in a descending flow pyrolysis reactor in the presence of a particulate source of heat to yield a particulate carbon containing solid residue. The particulate source of heat is obtained by educting with a gaseous source of oxygen the particulate carbon containing solid residue from a fluidized bed into a first combustion zone coupled to a second combustion zone. A source of oxygen is introduced into the second combustion zone to oxidize carbon monoxide formed in the first combustion zone to heat the solid residue to the temperature of the particulate source of heat.

  13. Fuel gas combustion research at METC

    Energy Technology Data Exchange (ETDEWEB)

    Norton, T.S.


    The in-house combustion research program at METC is an integral part of many METC activities, providing support to METC product teams, project managers, and external industrial and university partners. While the majority of in-house combustion research in recent years has been focussed on the lean premixed combustion of natural gas fuel for Advanced Turbine Systems (ATS) applications, increasing emphasis is being placed on issues of syngas combustion, as the time approaches when the ATS and coal-fired power systems programs will reach convergence. When the METC syngas generator is built in 1996, METC will have the unique combination of mid-scale pressurized experimental facilities, a continuous syngas supply with variable ammonia loading, and a team of people with expertise in low-emissions combustion, chemical kinetics, combustion modeling, combustion diagnostics, and the control of combustion instabilities. These will enable us to investigate such issues as the effects of pressure, temperature, and fuel gas composition on the rate of conversion of fuel nitrogen to NOx, and on combustion instabilities in a variety of combustor designs.

  14. Study of the interface solid/solutions containing PEO-PPO block copolymers and asphaltenes by FTIR/ATR; Estudo de solucoes de copolimeros em bloco de PEO-PPO contendo asfaltenos por FTIR/DTA

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Janaina I.S.; Neto, Jessica S.G.; Mansur, Claudia R.E. [Universidade Federal do Rio de Janeiro, Instituto de Macromoleculas, Laboratorio de Macromoleculas e Coloides na Industria de Petroleo, Rio de Janeiro, RJ (Brazil)], E-mails:,;


    The formation of water/oil emulsions can cause problems in various stages of production, processing and refining of petroleum. In this study, the technique of Fourier transform infrared spectroscopy (FTIR) using the method of attenuated total reflectance (ATR) was applied to study the solid-solutions of block copolymers based on poly(ethylene oxide)-poly(propylene oxide) (PEO-PPO) interface and its interaction in this interface with asphaltenic fractions of petroleum. The solid is the crystal of the ATR. Initially, we determined the critical micelle concentration values of the copolymers, which were consistent those obtained by a tensiometer. Bottle Test was also performed to correlate the efficiency of PEO-PPO copolymers in the breaking of water/oil emulsions with its adsorption at the interfaces solutions. (author)

  15. Pulsed atmospheric fluidized bed combustion

    Energy Technology Data Exchange (ETDEWEB)


    In order to verify the technical feasibility of the MTCI Pulsed Atmospheric Fluidized Bed Combustor technology, a laboratory-scale system was designed, built and tested. Important aspects of the operational and performance parameters of the system were established experimentally. A considerable amount of the effort was invested in the initial task of constructing an AFBC that would represent a reasonable baseline against which the performance of the PAFBC could be compared. A summary comparison of the performance and emissions data from the MTCI 2 ft {times} 2 ft facility (AFBC and PAFBC modes) with those from conventional BFBC (taller freeboard and recycle operation) and circulating fluidized bed combustion (CFBC) units is given in Table ES-1. The comparison is for typical high-volatile bituminous coals and sorbents of average reactivity. The values indicated for BFBC and CFBC were based on published information. The AFBC unit that was designed to act as a baseline for the comparison was indeed representative of the larger units even at the smaller scale for which it was designed. The PAFBC mode exhibited superior performance in relation to the AFBC mode. The higher combustion efficiency translates into reduced coal consumption and lower system operating cost; the improvement in sulfur capture implies less sorbent requirement and waste generation and in turn lower operating cost; lower NO{sub x} and CO emissions mean ease of site permitting; and greater steam-generation rate translates into less heat exchange surface area and reduced capital cost. Also, the PAFBC performance generally surpasses those of conventional BFBC, is comparable to CFBC in combustion and NO{sub x} emissions, and is better than CFBC in sulfur capture and CO emissions even at the scaled-down size used for the experimental feasibility tests.

  16. High pressure optical combustion probe

    Energy Technology Data Exchange (ETDEWEB)

    Woodruff, S.D.; Richards, G.A.


    The Department of Energy`s Morgantown Energy Technology Center has developed a combustion probe for monitoring flame presence and heat release. The technology involved is a compact optical detector of the OH radical`s UV fluorescence. The OH Monitor/Probe is designed to determine the flame presence and provide a qualitative signal proportional to the flame intensity. The probe can be adjusted to monitor a specific volume in the combustion zone to track spatial fluctuations in the flame. The probe is capable of nanosecond time response and is usually slowed electronically to fit the flame characteristics. The probe is a sapphire rod in a stainless steel tube which may be inserted into the combustion chamber and pointed at the flame zone. The end of the sapphire rod is retracted into the SS tube to define a narrow optical collection cone. The collection cone may be adjusted to fit the experiment. The fluorescence signal is collected by the sapphire rod and transmitted through a UV transmitting, fused silica, fiber optic to the detector assembly. The detector is a side window photomultiplier (PMT) with a 310 run line filter. A Hamamatsu photomultiplier base combined with a integral high voltage power supply permits this to be a low voltage device. Electronic connections include: a power lead from a modular DC power supply for 15 VDC; a control lead for 0-1 volts to control the high voltage level (and therefore gain); and a lead out for the actual signal. All low voltage connections make this a safe and easy to use device while still delivering the sensitivity required.

  17. Combustion and environmental performance of clean coal end products

    Energy Technology Data Exchange (ETDEWEB)

    Skodras, G.; Sakellaropoulos, G. [Centre for Research and Technology, Hellas, Ptolemaidas-Kozanis, Ptolemaida (Greece). Inst. for Solid Fuel Technolgy and Applications]|[Aristotle Univ. of Thessaloniki, Thessaloniki (Greece). Dept. of Chemical Engineering, Chemical Process Engineering Lab]|[Chemical Process Engineering Research Inst., Thessaloniki (Greece). Lab. of Solid Fuels and Environment; Someus, E. [Thermal Desorption Technology Group (Greece); Grammelis, P.; Amarantos, P.S. [Centre for Research and Technology, Hellas, Ptolemaidas-Kozanis, Ptolemaida (Greece). Inst. for Solid Fuel Technolgy and Applications; Palladas, A.; Basinas, P.; Natas, P.; Prokopidou, M.; Diamantopoulou, I.; Sakellaropoulos, G. [Aristotle Univ. of Thessaloniki, Thessaloniki (Greece). Dept. of Chemical Engineering, Chemical Process Engineering Lab


    Clean and affordable power production is needed in order to achieve sustainable economic development. This paper focused on clean coal technologies in which coal-fired power plants are used in conjunction with large amounts of renewable energy sources to offer a high level of process safety and long term management of all residual operation streams. Thermal Desorption Recycle-Reduce-Reuse Technology (TDT-3R) was described as being a promising solid fuel pretreatment process for clean energy production up to 300 MWe capacities. TDT-3R is based on low temperature carbonisation fuel pre-treatment principles, which produce cleansed anthracite type fuels from coal and other carbonaceous material such as biomass and organic wastes. The combustion efficiency of such clean coals and the environmental performance of the TDT-3R process were investigated in this study via pilot scale tests of clean fuel production. Tests included flue gas emissions monitoring, raw fuel and product characterisation and thermogravimetric tests, polychlorinated dibenzo-p-dioxins and dibenzo-furans, and heavy metals analyses, and toxicity tests. Raw material included coal and biomass, such as willow, straw and demolition wood. The fuels were heated in a rotary kiln operating at 550 degrees C under slightly vacuum conditions. Clean coals were tested either alone or in conjunction with biomass fuels in a pilot scale combustion facility at Dresden, Germany. The clean coal samples were shown to have higher fixed carbon and ash content and lower volatiles compared to the respective raw coal samples. The major advantage of the TDT-3R process is the production of fuels with much lower pollutants content. Low nitrogen, sulphur, chlorine and heavy metal contents result in produced fuels that have excellent environmental performance, allow boiler operation in higher temperatures and overall better efficiency. Moreover, the use of clean fuels reduces deposition problems in the combustion chamber due to the

  18. Combustion characterization of rape seed meal and suggestions for optimal use in combustion appliances; Foerbraenningskarakterisering av rapsmjoel och foerslag till optimalt nyttjande i olika foerbraenningsanlaeggningar

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Gunnar; Hedman, Henry; Oehman, Marcus; Bostroem, Dan; Pettersson, Esbjoern; Pommer, Linda; Lindstroem, Erica; Backman, Rainer; Oehman, Rikard


    When rape oil is chemically extracted, rape seed meal, a solid residue remains. Currently, it is used as animal feed. Several plants for the production of rape methyl ester (RME, biodiesel) are in operation or under construction. Combustion properties have been studied for rape seed meal produced as a by product to rape-methyl esther (RME, biodiesel). Composition of the material has been measured, using proximate and ultimate analysis. The lower heating value was 18.2 +- 0.3 MJ/kg d.w. and the ash content was 7-8 percent d.w. The material is rich in nitrogen and sulphur. Concentrations of K, P, Ca and Mg are high in the fuel. Rape seed meal was mixed with bark and pelletised. Bark pellets were also used as a reference fuel. Pellets with 10 and 30 percent rape seed meal were produced. Material with 80 percent rape seed meal and 20 percent planer shavings was also pelletised. Wood had to be added to provide enough friction in the pelletising process, with adapted equipment rape seed meal could probably be easily pelletised). The material was studied using Thermo-Gravimetric Analysis (TGA), and compared with data from tests with wood powder. The pyrolysis of the rape seed meal has a characteristic temperature of 320 deg C. Devolatilisation starts at 150 deg C (at a lower temperature than for wood powder), and proceeds within a rather wide temperature range. The probable cause is the difference in organic content, in particular protein content. The result does not suggest that the material will be difficult to ignite. Experiments in a bench-scale fluidised bed (5 kW) showed that pellets containing only bark, and the mixture rape seed meal/wood had a bed agglomeration temperature well over the normal operational bed temperature. For the fuel mixtures rape seed meal and bark, the agglomeration temperature was slightly over the operational temperature. Particle emissions from fluidised bed combustion and grate combustion were, the latter simulated using a commercial

  19. Effect of the Reburning Zone Stoichiometry on the Nox Concentration at the Three-Stage Combustion of Pulverized Coal

    Directory of Open Access Journals (Sweden)

    Chernetskaya Nelya


    Full Text Available Numerical study of heat and mass transfer taking into account the combustion of coal particles in the furnace at the three-stage combustion of pulverized coal was performed. Analysis of the reburning zone stoichiometry on the concentration of nitrogen oxides at the furnace outlet was made. The values of excess air in the primary and reburning combustion zones, providing for the concentration of nitrogen oxides at the furnace outlet is not more than 350 mg/m3 and unburned carbon not more than 1 % when burning coal with a high content of nitrogen were established.

  20. Theoretical studies of combustion dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, J.M. [Emory Univ., Atlanta, GA (United States)


    The basic objectives of this research program are to develop and apply theoretical techniques to fundamental dynamical processes of importance in gas-phase combustion. There are two major areas currently supported by this grant. One is reactive scattering of diatom-diatom systems, and the other is the dynamics of complex formation and decay based on L{sup 2} methods. In all of these studies, the authors focus on systems that are of interest experimentally, and for which potential energy surfaces based, at least in part, on ab initio calculations are available.

  1. Transient combustion in hybrid rockets (United States)

    Karabeyoglu, Mustafa Arif


    Hybrid rockets regained interest recently as an alternative chemical propulsion system due to their advantages over the solid and liquid systems that are currently in use. Development efforts on hybrids revealed two important problem areas: (1) low frequency instabilities and (2) slow transient response. Both of these are closely related to the transient behavior which is a poorly understood aspect of hybrid operation. This thesis is mainly involved with a theoretical study of transient combustion in hybrid rockets. We follow the methodology of identifying and modeling the subsystems of the motor such as the thermal lags in the solid, boundary layer combustion and chamber gasdynamics from a dynamic point of view. We begin with the thermal lag in the solid which yield the regression rate for any given wall heat flux variation. Interesting phenomena such as overshooting during throttling and the amplification and phase lead regions in the frequency domain are discovered. Later we develop a quasi-steady transient hybrid combustion model supported with time delays for the boundary layer processes. This is integrated with the thermal lag system to obtain the thermal combustion (TC) coupled response. The TC coupled system with positive delays generated low frequency instabilities. The scaling of the instabilities are in good agreement with actual motor test data. Finally, we formulate a gasdynamic model for the hybrid chamber which successfully resolves the filling/emptying and longitudinal acoustic behavior of the motor. The TC coupled system is later integrated to the gasdynamic model to obtain the overall response (TCG coupled system) of gaseous oxidizer motors with stiff feed systems. Low frequency instabilities were also encountered for the TCG coupled system. Apart from the transient investigations, the regression rate behavior of liquefying hybrid propellants such as solid cryogenic materials are also studied. The theory is based on the possibility of enhancement

  2. Buoyancy effects on smoldering combustion (United States)

    Dosanjh, S.; Peterson, J.; Fernandez-Pello, A. C.; Pagni, P. J.


    The effect of buoyancy on the rate of spread of a concurrent smolder reaction through a porous combustible material is investigated theoretically and experimentally. In the experiments, buoyant forces are controlled by varying the density difference, and the smolder rate spread through porous alpha cellulose (0.83 void fraction) is measured as a function of the ambient air pressure. The smolder velocity is found to increase with the ambient pressure; extinction occurs when the buoyancy forces cannot overcome the drag forces, indicating that diffusion by itself cannot support the spread of a smolder reaction. Theoretical predictions are found to be in good qualitative agreement with the experimental results.


    Directory of Open Access Journals (Sweden)

    Yalçın ÖRS


    Full Text Available In this study, the combustion properties of some impregnation materials (abiotic and biotic factors used for eucalyptus wood in interior or exterior environments were investigated. The experimental samples were prepared from Eucalyptus wood based on ASTM-D-1413-76 Tanalith-CBC, boric acid, borax, vacsol-WR, immersol-WR, polyethylen glycole-400 and ammonium sulphate were used as an impregnation material. The results indicated that, vacuum treatment on Eucalyptus gave the lowest retention value of salts. Compounds containing boron+salt increased fire resistance however water repellents decreased the wood flammability.

  4. Determination of Critical Conditions of Spontaneous Combustion of Coal in Longwall Gob Areas / Wyznaczanie Warunków Krytycznych Samozapalania Węgla W Zrobach Ścian

    National Research Council Canada - National Science Library

    Janusz Cygankiewicz


    ..., such as: susceptibility of coals to spontaneous combustion, oxygen content in the air incoming to the self-heating coal, conditions of heat exchange between the self-heating coal mass and the environment...

  5. Low-NO{sub x}, wood chip combustion

    Energy Technology Data Exchange (ETDEWEB)

    Saastamoinen, J.; Oravainen, H.; Haemaelaeinen, J.; Paakkinen, K. [VTT Energy, Jyvaeskylae (Finland)


    The regulations for nitrogen oxide emissions vary in different countries, but the general trend in the future will probably be that the emissions limits will be lowered also for wood combustion plants, which are small or medium size units. Thus, the development of wood chip burning furnaces (grate furnaces, fluidized bed combustors, stoker furnaces) with lower nitrogen oxide emissions, is important. The wood used in the combustor, its particle size, moisture and fuel properties (nitrogen content) affect the nitrogen emissions. The nitrogen oxide release is also much affected by the design and operation of the combustor (air staging, fuel air preheat, flue gas circulation, air to fuel mass ratio). The fate of nitrogen compounds originally in the virgin wood depends much on the design of the combustor system and by proper planning it is possible to reduce the emission of nitrogen oxides. Basic knowledge of the release of nitrogen compounds from single wood particles is attained. The release of gaseous nitrogen compounds from wood particles during pyrolysis and combustion is studied experimentally and by modelling. Nitrogen release is studied experimentally by two ways, by analysing the gas and by quenching the particle and analysing the char residue. Formation of nitrogen oxide emissions in a fuel bed is studied by modelling and by combustion experiments with a pot furnace. This research gives general information of nitrogen oxide formation in wood bunting especially in fixed beds. The development of a horizontal stoker burner for wood chips with low emissions is the practical aim of the research. (orig.)

  6. Modelling of turbulent combustion in the blast furnace raceway

    Energy Technology Data Exchange (ETDEWEB)

    Karvinen, R.; Maekiranta, R. [Tampere Univ. (Finland). Energy and Process Engineering


    The phenomena concerning coke-gas -suspension and simultaneous combustion of solid coke particles and residual fuel oil in a blast furnace raceway are modelled. The flow field of suspension is predicted by using the two fluid model, which is based on the Eulerian method, in the Phoenics code. The standard k-e -model of turbulence is used. Pyrolysis of oil droplets is calculated with the own coded subroutine, which is based on the Lagrangian approach. Gas phase reaction rate is assumed to be controlled by chemical kinetics. Radiative heat transfer is calculated by using the six-flux method. Heterogenous surface reactions are used for the coke particles. Calculations without coke combustion show that due to a poor mixing in the hot blast, pyrolysis gases of residual fuel oil have not time enough to react with oxygen. It is obvious that if combustion of coke particles is taken into account, the oxygen content in the blast decreases to such a level, that unburnt pyrolysis gases can flow out of the raceway causing problems. The distribution of coke void fraction has been succeeded to predict in the raceway domain. Coke particles fall from the upper part of the raceway to the hot blast forming locally high concentrations, which affect very strongly the oxygen distribution of the hot blast. (orig.) SULA 2 Research Programme; 10 refs.

  7. Design principles and fabrication method for a miniaturized fuel gas combustion reactor

    NARCIS (Netherlands)

    Zhao, Yiyuan; Veltkamp, Henk-Willem; de Boer, Meint J.; Zeng, Yaxiang; Groenesteijn, Jarno; Wiegerink, Remco J.; Lötters, Joost Conrad


    Wobbe Index meter is widely used to reflect the energy content and gas quality of a fuel gas mixture. It is highly in demand to downscale from the conventionally large Wobbe Index facility to a miniaturized Wobbe Index meter. Therefore spontaneously combustion of the fuel gas/air mixtures on a

  8. Incineration and co-combustion of waste: accounting of greenhouse gases and global warming contributions

    DEFF Research Database (Denmark)

    Astrup, Thomas; Møller, Jacob; Fruergaard, Thilde


    Important greenhouse gas (GHG) emissions related to waste incineration and co-combustion of waste were identified and considered relative to critical aspects such as: the contents of biogenic and fossil carbon, N2O emissions, fuel and material consumptions at the plants, energy recovery, and soli...

  9. Experimental Investigation of NO Formation from Combustion of Wood and Straw in a Batch Combustor

    DEFF Research Database (Denmark)

    Christensen, Esben; Jensen, Lars Skaarup; Jensen, Anker


    The formation of NOx from combustion of biomass fuels has been investigated. Samples of wood and straw with an average nitrogen content of 0.04 and 0.4 % mass respectively were burned in a laboratory scale batch fixed bed reactor at 570 °C and 832 °C. The flue gas was analyzed for O2, NO, CO and ...

  10. Use of domestic low-grade fuels by combustion in fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Vuletic, V.; Ristic, M.


    The use of low-grade of coals with high sulphur and ash contents and low ash fusibility is difficult in conventional plant. The advantages of fluidized bed combustion for the utilization of such coals are described, and the possible application of this technology in Yugoslavia is examined.

  11. Effects of biomass on dynamics of combustion in circulating fluidized beds

    Directory of Open Access Journals (Sweden)

    Tourunen Antti


    Full Text Available Fluidized bed technology is very suitable for the combustion of biomass Nevertheless substitution of coal with biomass affects boiler operation and especially dynamics and controllability. Non-homogeneity of biomass and fuel feeding disturbances cause process instability, such as variations in temperatures and pressures, which reduce lifetime of equipment and structures. Because of process instability higher air coefficient must be used in order to avoid CO emissions, which is not economical. Combustion profiles for coal, wood and peat, measured at the VTT Processes Pilot circulating fluidized bed reactor, have been compared. Process stability and char inventories have been studied by the measurements and the model. Biofuel are usually very reactive and their combustion profiles are quite different compared to coals. Because of high reactivity and low char content combustion process with biofuel is very sensitive for fuel feeding. Also low char inventory effect on load changes combined with combustion profile that differs from coals. Because of different combustion profile heat transfer can be a limiting factor in load changes despite the high reactivity and fast oxygen response.


    Directory of Open Access Journals (Sweden)

    Daniele Dell'Antonia


    Full Text Available The importance of emission control has increased sharply due to the increased need of energy from combustion. However, biomass utilization in energy production is not free from problems because of physical and chemical characteristics which are substantially different from conventional energy sources. In this situation, the quantity and quality of emissions as well as used renewable sources as wood or corn grain are often unknown. To assess this problem the paper addresses the objectives to quantify the amount of greenhouse gases during the combustion of corn as compared to the emissions in fossil combustion (natural gas, LPG and diesel boiler. The test was carried out in Friuli Venezia Giulia in 2006-2008 to determine the air pollution (CO, NO, NO2, NOx, SO2 and CO2 from fuel combustion in family boilers with a power between 20-30 kWt. The flue gas emission was measured with a professional semi-continuous multi-gas analyzer, (Vario plus industrial, MRU air Neckarsulm-Obereisesheim. Data showed a lower emission of fossil fuel compared to corn in family boilers in reference to pollutants in the flue gas (NOx, SO2 and CO. In a particular way the biomass combustion makes a higher concentration of carbon monoxide (for an incomplete combustion because there is not a good mixing between fuel and air and nitrogen oxides (in relation at a higher content of nitrogen in herbaceous biomass in comparison to another fuel.

  13. Combustion heat of wood in the course of white and brown rots

    Energy Technology Data Exchange (ETDEWEB)

    Rypacek, V.; Coufalikova, J.


    Beech wood samples (4 by 2 by 0.5 cm) decayed by Pleurotus ostreatus and Lentinus tignius (white rot) and spruce wood samples decayed by Fomitopsis pinicola and Serpula lacrymans (brown rot) were investigated. Decomposition was expressed by the decrease of mass in percent. The pulverized samples were extracted with benzene and dried. Heat of combustion extractives in 0.1 NaOH were determined. Heat of combustion was different according to whether the wood was attacked by white or brown rot fungi. Heat of combustion decreased proportionally to the degree of decomposition with white rot, while the decrease got slower during decomposition by brown rot after reaching the loss in weight of approximately 25%. The amount of holocellulose and lignin in the wood decreased with advancing decomposition. The heat of combustion due to the holocellulose and lignin content was practically equal regardless of whether white or brown rot were active. Heat of combustion of wood decomposed by brown rot was at the given degree of decomposition equal to the sum of the heat of combustion of the high-molecular humid acid + hymatomelanic acid (HU+HY) fractions contained in it and that of the wood decomposed by the white rot. It can be assumed that the loss in weight of 20-30% represents an important stage in decomposition by brown rot. 36 references.

  14. On the potential for BECCS efficiency improvement through heat recovery from both post-combustion and oxy-combustion facilities. (United States)

    Dowell, N Mac; Fajardy, M


    In order to mitigate climate change to no more than 2 °C, it is well understood that it will be necessary to directly remove significant quantities of CO 2 , with bioenergy CCS (BECCS) regarded as a promising technology. However, BECCS will likely be more costly and less efficient at power generation than conventional CCS. Thus, approaches to improve BECCS performance and reduce costs are of importance to facilitate the deployment of this key technology. In this study, the impact of biomass co-firing rate and biomass moisture content on BECCS efficiency with both post- and oxy-combustion CO 2 capture technologies was evaluated. It was found that post-combustion capture BECCS (PCC-BECCS) facilities will be appreciably less efficient than oxy-combustion capture BECCS (OCC-BECCS) facilities. Consequently, PCC-BECCS have the potential to be more carbon negative than OCC-BECCS per unit electricity generated. It was further observed that the biomass moisture content plays an important role in determining the BECCS facilities' efficiency. This will in turn affect the enthalpic content of the BECCS plant exhaust and implies that exhaust gas heat recovery may be an attractive option at higher rates of co-firing. It was found that there is the potential for the recovery of approximately 2.5 GJ heat per t CO 2 at a temperature of 100 °C from both PCC-BECCS and OCC-BECCS. On- and off-site applications for this recovered heat are discussed, considering boiler feedwater pre-heating, solvent regeneration and district heating cases.

  15. Combustion

    National Research Council Canada - National Science Library

    Glassman, Irvin


    ... permission in writing from the publisher. Permissions may be sought directly from Elsevier's Science and Technology Rights Department in Oxford, UK. Phone (44) 1865 843830, Fax: (44) 1865 853333, e-mail: You may also complete your request on-line via the Elsevier homepage: by selecting "...

  16. Formation and combustion characteristics of elephantgrass and energycane wafers (United States)

    Mofleh, Mohamad I.

    Elephantgrass (Pennisetum purpureum Schum.) and energycane (Saccharum Spp.) are two cane type grasses. These are tall-growing perennial bunchgrasses that produce long hardened stems and grow in the tropics and subtropics. Traditionally, they have been used for forage and, in some regions, have been randomly burned on fields or disposed of uselessly. However, these plants have high dry matter yield and, thus, are excellent candidates as energy crops. Elephantgrass and energycane have been used for direct combustion in their loose form in large-scale applications. Several problems, many of which were attributed to their low bulk density, were encountered with using the materials. Consequently, this project was initiated to investigate the formation and combustion characteristics of the two materials in the form of small compact units called wafers. A hydraulic press that applied axial stresses on the material in four different dies was used. A load cell and a displacement transducer were utilized to measure the stresses and material detection. Wafer quality was evaluated using a tumbler built according to the American Society of Agricultural Engineers standards. In addition, a small stove was built to test wafer combustion. Thermocouples were used to measure temperatures during combustion. All the data gathered was transferred to a computer using a data acquisition system. It was found that the stress-deformation and stress-density relationships of elephantgrass and energycane were of exponential nature. Compaction energy required, which was calculated from the area under the force-deformation curves, ranged from 0.1 to 0.3% of their energy content. It was also found that wafer quality (durability) was mainly a function of wafer size and its final (relaxed) density in addition to material stem-to-leaf ratio and its crude protein content. Wafers possessed poor ignition quality but once ignited, they burned satisfactorily. The results indicated that sufficient and

  17. Measurement and analysis of combustion response to transverse combustion instability (United States)

    Pomeroy, Brian R.

    This research aimed to gain a better understanding of the response of a gas-centered swirl coaxial injector to transverse combustion instability. The goals of the research were to develop a combustion chamber that would be able to spontaneously produce transverse combustion instability at elevated pressures and temperatures. Methods were also developed to analyze high-speed video images to understand the response of the injector. A combustion chamber was designed that produced high levels of instabilities. The chamber was capable of pressures as high as 1034 kPa (150 psi) and operated using decomposed 90% hydrogen peroxide and JP-8. The chamber used an array of seven gas-centered swirl coaxial injectors that exhibited linear instability to drive the transverse oscillations. The injector elements would operate in a monopropellant configuration flowing only decomposed hydrogen peroxide or in a bipropellant configuration. The location of the bipropellant injectors could be varied to change the level of the instability in the chamber from 10% of the chamber pressure up to 70% of the chamber pressure. A study element was placed in the center of the chamber where it was observed simultaneously by two high-speed video cameras which recorded a backlit video to show the location of the fuel spray and the location of the emitted CH* chemiluminescence. The videos were synchronized with high frequency pressure measurements to gain a full understanding of the physics in the combustion chamber. Results showed that the study element was coupled with the first mode velocity wave. This was expected due to the first mode velocity anti-node being located in the center of the chamber. The velocity is an absolute maximum twice during each cycle so the coupling with the second mode pressure was also investigated showing a possible coupling with both the velocity and pressure. The results of the first mode velocity showed that, as the velocity wave traveled through the chamber, the fuel

  18. Combustion of hythane diluted with CO2

    Directory of Open Access Journals (Sweden)

    Hraiech Ibtissem


    Full Text Available With increasing concern about energy shortage and environmental protection, improving engine fuel economy and reducing exhaust emissions have become major research topics in combustion and engine development. Hythane (a blend of hydrogen H2 and natural gas NG has generated a significant interest as an alternative fuel for the future. This paper describes an experimental study of the effects of CO2 addition on the stability of a turbulent jet diffusion NG-H2 flame. The mole fraction of hydrogen (% H2 in NG-H2 mixture was varied from 0% to 50%. The equivalence ratio of the hythane/CO2/air mixture was kept at stoichiometry. The results show that the lift-off height increases with the addition of CO2 at various % H2 content in hythane. However, we observe that with 20% H2, we can obtain a stable flame diluted with 40% CO2, while for 0% H2, the flame is blown out above 20% CO2. This means that the limits of flame blowing out are pushed with the additions of H2. Moreover, the results show that for %H2 content in NG-H2 fuel up to 10%, the addition of CO2 could produce lifted flame if the % CO2 is low. At higher % CO2 dilution, flame would remain attached until blow-out. This is mainly due to the fact that the dilution leads to ejection velocities very high but reactivity of the mixture does not change so the flame tends to stretch.

  19. Combustion chemistry and formation of pollutants; Chimie de la combustion et formation des polluants

    Energy Technology Data Exchange (ETDEWEB)



    This book of proceedings reports on 7 papers on combustion chemistry and formation of pollutants presented during the workshop organized by the `Combustion and Flames` section of the French society of thermal engineers. The chemistry of combustion is analyzed in various situations such as: turbojet engines, spark ignition engines, industrial burners, gas turbines etc... Numerical simulation is used to understand the physico-chemical processes involved in combustion, to describe the kinetics of oxidation, combustion and flame propagation, and to predict the formation of pollutants. (J.S.)

  20. Variable stroke internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Roseby, B.; Hallman, E.P.


    An internal combustion engine is described in which the longitudinal center line of the cylinders are parallel to and equally spaced around the longitudinal center line of the engine. The pistons, working within said cylinders, are mounted on a swash plate mechanism, by means of which the reciprocating motion the pistons is translated into the rotary motion of a carrier plate to which the said swash plate is mounted and, from which, is taken the drive into the vehicle transmission. Said swash plate is mounted on a post at the circumference of the carrier plate and pivots around said post when moved, on a longitudinal axis, by a mechanism. As each piston, in turn, passes the point on the swashplate adjacent to the mounting post, it is at the top-dead-center position in its cylinder. As said piston passes the diametrically opposite point on the swash plate it is at the bottom-dead-center position. When the swash plate angle is changed, by moving said mechanism, the bottom dead center position is changed thus causing the stroke of the piston to be changed. A circular form cylinder head contains a combustion chamber for each cylinder and a disc, driven by a forward projecting shaft mounted on the carrier plate, through gearing, and having cam forms on the face actuates the valve mechanism to cause the inlet and exhaust gases to flow to and from the cylinders as required for operation of the running cycle.

  1. Investigation of pressurized combustion and characterization of solid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Aho, M.; Haemaelaeinen, J.; Paakkinen, K. [VTT Energy, Espoo (Finland); Joutsenoja, T. [Tampere Univ. of Technology (Finland)


    The objective of the research of Technical Research Centre of Finland (VTT) was to produce results of the effects of pressure and other important parameters on the combustion of pulverized coals using both experimental and theoretical methods. The results can be utilized to model pressurized combustion and to plan pilot-scale reactors. The studied coals were Polish hvb coal, French lignite (Gardanne), German anthracite (Niederberg) and German (Goettelborn) hvb coal. In was originally planned to study also a char of one of these coals. However, anthracite was selected instead of char, because the theoretical studies predicted maximum pressure effect to be found for antracite-type coals (with low reactivity and low content of volatiles). The pulverized coal samples were combusted in an electrically heated, pressurized entrained flow reactor (PEFR), where the experimental conditions were controlled with a high precision. The studied particle size fractions were 100-125 Em and 140-180 Am for anthracite and 140-180 {mu}m for the other coals. The studied things were combustion rates and temperatures of burning particles. Two types of sets of experiments were carried out. In the first case, experimental planning was done and the results were handled with multivariable partial least squares (PLS) method. Gas temperature varied from 1073K to 1473K and pressure from 0.2 MPa to 0.8 MPa. The other variables were PO2 and PCO{sub 2}. Some of the experiments were carried out at conditions prevailing during flue gas recirculation (CO{sub 2} concentration was > 20 vol%). In the second case, oxygen concentration was kept constant ( 10 vol%) and pressure was varied from 0.2 MPa to 0.8 MPa with an interval of 0.1 MPa

  2. C60 fullerenes from combustion of common fuels

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, Andrea J., E-mail: [Department of Civil & Environmental Engineering, Virginia Tech, 200 Patton Hall, 750 Drillfield Drive, Blacksburg, VA 24061 (United States); Ashraf-Khorassani, Mehdi, E-mail: [Department of Chemistry, Virginia Tech, 480 Davidson Hall, 900 West Campus Drive, Virginia Tech, Blacksburg, VA 24061 (United States); Marr, Linsey C., E-mail: [Department of Civil & Environmental Engineering, Virginia Tech, 200 Patton Hall, 750 Drillfield Drive, Blacksburg, VA 24061 (United States)


    Releases of C{sub 60} fullerenes to the environment will increase with the growth of nanotechnology. Assessing the potential risks of manufactured C{sub 60} requires an understanding of how its prevalence in the environment compares to that of natural and incidental C{sub 60}. This work describes the characterization of incidental C{sub 60} present in aerosols generated by combustion of five common fuels: coal, firewood, diesel, gasoline, and propane. C{sub 60} was found in exhaust generated by all five fuels; the highest concentrations in terms of mass of C{sub 60} per mass of particulate matter were associated with diesel and coal. Individual aerosols from these combustion processes were examined by transmission electron microscopy. No relationship was found between C{sub 60} content and either the separation of graphitic layers (lamellae) within the particles, nor the curvature of those lamellae. Estimated global emissions of incidental C{sub 60} to the atmosphere from coal and diesel combustion range from 1.6 to 6.3 t yr{sup −1}, depending upon combustion conditions. These emissions may be similar in magnitude to the total amount of manufactured C{sub 60} produced on an annual basis. Consequent loading of incidental C{sub 60} to the environment may be several orders of magnitude higher than has previously been modeled for manufactured C{sub 60}. - Highlights: • Exhaust of common fuels (coal, diesel, etc.) analyzed via chromatography for C{sub 60.} • All five fuels tested produced C{sub 60} in aerosols in mass fractions up to several ppm. • Emissions of incidental C{sub 60} may be comparable to the total amount manufactured.

  3. Thermally stimulated luminescence studies in combustion ...

    Indian Academy of Sciences (India)

    Synthesis of materials by combustion technique results in homogeneous and fine crystalline product. Further, the technique became more popular since it not only saved time and energy but also was easy to process. Aluminum oxide phosphor was synthesized by using urea as fuel in combustion reaction.

  4. 30 CFR 57.4104 - Combustible waste. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Combustible waste. 57.4104 Section 57.4104... Control Prohibitions/precautions/housekeeping § 57.4104 Combustible waste. (a) Waste materials, including liquids, shall not accumulate in quantities that could create a fire hazard. (b) Waste or rags containing...

  5. Sandia combustion research program: Annual report, 1987

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, R.E.; Sanders, B.R.; Ivanetich, C.A. (eds.)


    More than a decade ago, in response to a national energy crisis, Sandia proposed to the US Department of Energy a new, ambitious program in combustion research. Our strategy was to apply the rapidly increasing capabilities in lasers and computers to combustion science and technology. Shortly thereafter, the Combustion Research Facility (CRF) was established at Sandia's Livermore location. Designated a ''User Facility,'' the charter of the CRF was to develop and maintain special-purpose resources to support a nationwide initiative--involving US universities, industry, and national laboratories--to improve our understanding and control of combustion. This report includes descriptions of several research projects which have been stimulated by Working Groups and involve the on-site participation of industry scientists. DOE's Industry Technology Fellowship Program has been instrumental in the success of some of the joint efforts. The remainder of this report presents research results of calendar year 1987, separated thematically into nine categories. Refereed journal articles appearing in print during 1987, along with selected other publications, are included at the end of Section 10. In addition to our ''traditional'' research--chemistry, reacting flow, diagnostics, engine combustion, and coal combustion--you will note continued progress in somewhat recent themes: pulse combustion, high temperature materials, and energetic materials, for example. Moreover, we have just started a small, new effort to understand combustion-related issues in the management of toxic and hazardous materials.

  6. Internal combustion engines in hybrid vehicles

    NARCIS (Netherlands)

    Mourad, S.; Weijer, C.J.T. van de; Beckman, D.E.


    In this paper the use of internal combustion engines in hybrid powertrains is investigated. The substantial difference between the use of internal combustion engines in conventional and in hybrid vehicles mean that engines for hybrid vehicles should be designed specifically for the purpose. At the

  7. Injector tip for an internal combustion engine (United States)

    Shyu, Tsu Pin; Ye, Wen


    This invention relates to a the tip structure of a fuel injector as used in a internal combustion engine. Internal combustion engines using Homogeneous Charge Compression Ignition (HCCI) technology require a tip structure that directs fuel spray in a downward direction. This requirement necessitates a tip design that is capable of withstanding mechanical stresses associated with the design.

  8. Coal slurry combustion and technology. Volume 2

    Energy Technology Data Exchange (ETDEWEB)


    Volume II contains papers presented at the following sessions of the Coal Slurry Combustion and Technology Symposium: (1) bench-scale testing; (2) pilot testing; (3) combustion; and (4) rheology and characterization. Thirty-three papers have been processed for inclusion in the Energy Data Base. (ATT)

  9. A model for premixed combustion oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Janus, M.C.; Richards, G.A.


    This paper describes a simulation based on a time dependent, nonlinear control volume analysis. The combustion is modeled as a well-stirred reactor having finite kinetics. Flow properties and species in the nozzle, combustion, and tailpipe regions are determined using a control volume formulation of the conservation equation.

  10. Combustion synthesis and photoluminescence study of silicate ...

    Indian Academy of Sciences (India)

    Silicate based bioceramics are promising candidates as biomaterials for tissue engineering. The combustion synthesis method provides control on the morphology and particle size of the synthesized material. This paper discusses the combustion synthesis of akermanite (Ca2MgSi2O7 and Sr2MgSi2O7), which has been ...

  11. A predictive model of natural gas mixture combustion in internal combustion engines

    Directory of Open Access Journals (Sweden)

    Henry Espinoza


    Full Text Available This study shows the development of a predictive natural gas mixture combustion model for conventional com-bustion (ignition engines. The model was based on resolving two areas; one having unburned combustion mixture and another having combustion products. Energy and matter conservation equations were solved for each crankshaft turn angle for each area. Nonlinear differential equations for each phase’s energy (considering compression, combustion and expansion were solved by applying the fourth-order Runge-Kutta method. The model also enabled studying different natural gas components’ composition and evaluating combustion in the presence of dry and humid air. Validation results are shown with experimental data, demonstrating the software’s precision and accuracy in the results so produced. The results showed cylinder pressure, unburned and burned mixture temperature, burned mass fraction and combustion reaction heat for the engine being modelled using a natural gas mixture.

  12. A predictive model of natural gas mixture combustion in internal combustion engines

    Directory of Open Access Journals (Sweden)

    Henry Espinoza


    Full Text Available This study shows the development of a predictive natural gas mixture combustion model for conventional com-bustion (ignition engines. The model was based on resolving two areas; one having unburned combustion mixture and another having combustion products. Energy and matter conservation equations were solved for each crankshaft turn angle for each area. Nonlinear differential equations for each phase’s energy (considering compression, combustion and expansion were solved by applying the fourth-order Runge-Kutta method. The model also enabled studying different natural gas components’ composition and evaluating combustion in the presence of dry and humid air. Validation results are shown with experimental data, demonstrating the software’s precision and accuracy in the results so produced. The results showed cylinder pressure, unburned and burned mixture temperature, burned mass fraction and combustion reaction heat for the engine being modelled using a natural gas mixture.

  13. Internal and surface phenomena in metal combustion (United States)

    Dreizin, Edward L.; Molodetsky, Irina E.; Law, Chung K.


    Combustion of metals has been widely studied in the past, primarily because of their high oxidation enthalpies. A general understanding of metal combustion has been developed based on the recognition of the existence of both vapor-phase and surface reactions and involvement of the reaction products in the ensuing heterogeneous combustion. However, distinct features often observed in metal particle combustion, such as brightness oscillations and jumps (spearpoints), disruptive burning, and non-symmetric flames are not currently understood. Recent metal combustion experiments using uniform high-temperature metal droplets produced by a novel micro-arc technique have indicated that oxygen dissolves in the interior of burning particles of certain metals and that the subsequent transformations of the metal-oxygen solutions into stoichiometric oxides are accompanied with sufficient heat release to cause observed brightness and temperature jumps. Similar oxygen dissolution has been observed in recent experiments on bulk iron combustion but has not been associated with such dramatic effects. This research addresses heterogeneous metal droplet combustion, specifically focusing on oxygen penetration into the burning metal droplets, and its influence on the metal combustion rate, temperature history, and disruptive burning. A unique feature of the experimental approach is the combination of the microgravity environment with a novel micro-arc Generator of Monodispersed Metal Droplets (GEMMED), ensuring repeatable formation and ignition of uniform metal droplets with controllable initial temperature and velocity. The droplet initial temperatures can be adjusted within a wide range from just above the metal melting point, which provides means to ignite droplets instantly upon entering an oxygen containing environment. Initial droplet velocity will be set equal to zero allowing one to organize metal combustion microgravity experiments in a fashion similar to usual microgravity

  14. Time Resolved Measurements and Reactive Pathways of Hypergolic Bipropellant Combustion

    National Research Council Canada - National Science Library

    Smith, Jr, James E


    This research has improved the fundamental understanding of the physical mechanisms leading to the ignition and combustion of hypergolic propellants from high-speed visualization and combustion diagnostics...

  15. Calidad de los combustibles en Colombia

    Directory of Open Access Journals (Sweden)

    Jorge Humberto Arango


    Full Text Available Para conocer el estado actual de los combustibles usados en Colombia y para conocer las necesidades en el marco de los biocombustibles, el Ingeniero Jorge Humberto Arango, gerente de refinados de Ecopetrol, presenta un resumen de la calidad de la gasolina, diesel, biodiesel, y el gas natural, tomando en cuenta aspectos tales como el contenido de azufre, la presencia de aromáticos y la emisión de material particulado. En resumen, se muestra el interesante e importante trabajo de Ecopetrol desde los años 90, relacionado con el cumplimento de los estándares nacionales e internacionales. Por ejemplo, para el caso de diesel, Colombia muestra uno de los contenidos más bajos en azufre con respecto a Latinoamérica, llegando a niveles de 500 ppm para la ciudad de Bogotá. Para el caso de aromáticos en gasolina, Colombia presenta una de las mejores en el mundo en términos de aromáticos, con contenidos de gasolina regular en 20% y en gasolina Premium en 22 %. Por otro lado, la emisión de compuestos azufrados y material particulado no se está reduciendo en la misma proporción que la calidad de los combustibles colombianos, que están siendo mejorados especialmente en parque automotor de trasporte pesado antiguo (mayor de 25 años. / In order to acquire a brief understanding of the state o the fuels in Colombia and then frame the necessities for biofuels, the engineer Jorge Humberto Arango, fuels refining manager at Ecopetrol, displayed a summary regarding the work carried out by Ecopetrol during the last decade to improve the quality of gas, diesel, biodiesel, and natural gas by analyzing aspects such as sulfur and aromatics presence, and particle matter emissions when fueling motors. For example, sulfur concentration for Diesel reaches one of the lowest reported in Latinamerica (500 ppm moreover, the aromatics content in Colombian gasoline projects it as one of the best in world (regular gasoline, 20 % and Premium 22 %. On the other hand, even

  16. Some characteristics of fine beryllium particle combustion (United States)

    Davydov, D. A.; Kholopova, O. V.; Kolbasov, B. N.


    Beryllium dust will be produced under plasma interaction with beryllium armor of the first wall in ITER. Exothermal reaction of this dust with water steam or air, which can leak into the reactor vacuum chamber in some accidents, gives concern in respect to reactor safety. Results of studies devoted to combustion of fine beryllium particles are reviewed in the paper. A chemically active medium and elevated temperature are prerequisite to the combustion of beryllium particles. Their ignition is hampered by oxide films, which form a diffusion barrier on the particle surface as a result of pre-flame oxidation. The temperature to initiate combustion of particles depends on flame temperature, particle size, composition of combustible mixture, heating rate and other factors. In mixtures enriched with combustible, the flame temperature necessary to ignite individual particles approaches the beryllium boiling temperature.

  17. 2003 Laser Diagnostic in Combustion Conference

    Energy Technology Data Exchange (ETDEWEB)

    Mark G. Allen


    The GRC Laser Diagnostics in Combustion aims at bringing together scientists and engineers working in the front edge of research and development to discuss and find new ways to solve problems connected to combustion diagnostics. Laser-based techniques have proven to be very efficient tools for studying combustion processes thanks to features as non-intrusiveness in combination with high spatial and temporal resolution. Major tasks for the community are to develop and apply techniques for quantitative measurements with high precision e.g of species concentrations, temperatures, velocities and particles characteristics (size and concentration). These issues are of global interest, considering that the major part of the World's energy conversion comes from combustion sources and the influence combustion processes have on the environment and society.

  18. Interactive wood combustion for botanical tree models

    KAUST Repository

    Pirk, Sören


    We present a novel method for the combustion of botanical tree models. Tree models are represented as connected particles for the branching structure and a polygonal surface mesh for the combustion. Each particle stores biological and physical attributes that drive the kinetic behavior of a plant and the exothermic reaction of the combustion. Coupled with realistic physics for rods, the particles enable dynamic branch motions. We model material properties, such as moisture and charring behavior, and associate them with individual particles. The combustion is efficiently processed in the surface domain of the tree model on a polygonal mesh. A user can dynamically interact with the model by initiating fires and by inducing stress on branches. The flames realistically propagate through the tree model by consuming the available resources. Our method runs at interactive rates and supports multiple tree instances in parallel. We demonstrate the effectiveness of our approach through numerous examples and evaluate its plausibility against the combustion of real wood samples.

  19. Distributed combustion in a cyclonic burner (United States)

    Sorrentino, Giancarlo; Sabia, Pino; de Joannon, Mara; Cavaliere, Antonio; Ragucci, Raffaele


    Distributed combustion regime occurs in several combustion technologies were efficient and environmentally cleaner energy conversion are primary tasks. For such technologies (MILD, LTC, etc…), working temperatures are enough low to boost the formation of several classes of pollutants, such as NOx and soot. To access this temperature range, a significant dilution as well as preheating of reactants is required. Such conditions are usually achieved by a strong recirculation of exhaust gases that simultaneously dilute and pre-heat the fresh reactants. However, the intersection of low combustion temperatures and highly diluted mixtures with intense pre-heating alters the evolution of the combustion process with respect to traditional flames, leading to significant features such as uniformity and distributed ignition. The present study numerically characterized the turbulence-chemistry and combustion regimes of propane/oxygen mixtures, highly diluted in nitrogen, at atmospheric pressure, in a cyclonic combustor under MILD Combustion operating conditions. The velocity and mixing fields were obtained using CFD with focus on mean and fluctuating quantities. The flow-field information helped differentiate between the impact of turbulence levels and dilution ones. The integral length scale along with the fluctuating velocity is critical to determine Damköhler and Karlovitz numbers. Together these numbers identify the combustion regime at which the combustor is operating. This information clearly distinguishes between conventional flames and distributed combustion. The results revealed that major controllers of the reaction regime are dilution and mixing levels; both are significantly impacted by lowering oxygen concentration through entrainment of hot reactive species from within the combustor, which is important in distributed combustion. Understanding the controlling factors of distributed regime is critical for the development and deployment of these novel combustion

  20. Indirect combustion noise of auxiliary power units (United States)

    Tam, Christopher K. W.; Parrish, Sarah A.; Xu, Jun; Schuster, Bill


    Recent advances in noise suppression technology have significantly reduced jet and fan noise from commercial jet engines. This leads many investigators in the aeroacoustics community to suggest that core noise could well be the next aircraft noise barrier. Core noise consists of turbine noise and combustion noise. There is direct combustion noise generated by the combustion processes, and there is indirect combustion noise generated by the passage of combustion hot spots, or entropy waves, through constrictions in an engine. The present work focuses on indirect combustion noise. Indirect combustion noise has now been found in laboratory experiments. The primary objective of this work is to investigate whether indirect combustion noise is also generated in jet and other engines. In a jet engine, there are numerous noise sources. This makes the identification of indirect combustion noise a formidable task. Here, our effort concentrates exclusively on auxiliary power units (APUs). This choice is motivated by the fact that APUs are relatively simple engines with only a few noise sources. It is, therefore, expected that the chance of success is higher. Accordingly, a theoretical model study of the generation of indirect combustion noise in an Auxiliary Power Unit (APU) is carried out. The cross-sectional areas of an APU from the combustor to the turbine exit are scaled off to form an equivalent nozzle. A principal function of a turbine in an APU is to extract mechanical energy from the flow stream through the exertion of a resistive force. Therefore, the turbine is modeled by adding a negative body force to the momentum equation. This model is used to predict the ranges of frequencies over which there is a high probability for indirect combustion noise generation. Experimental spectra of internal pressure fluctuations and far-field noise of an RE220 APU are examined to identify anomalous peaks. These peaks are possible indirection combustion noise. In the case of the

  1. Filtration Combustion in Smoldering and SHS (United States)

    Matkowsky, Bernard J.


    Smolder waves and SHS (self-propagating high-temperature synthesis) waves are both examples of filtration combustion waves propagating in porous media. Smoldering combustion is important for the study of fire safety. Smoldering itself can cause damage, its products are toxic and it can also lead to the more dangerous gas phase combustion which corresponds to faster propagation at higher temperatures. In SHS , a porous solid sample, consisting of a finely ground powder mixture of reactants, is ignited at one end. A high temperature thermal wave, having a frontal structure, then propagates through the sample converting reactants to products. The SHS technology appears to enjoy a number of advantages over the conventional technology, in which the sample is placed in a furnace and "baked" until it is "well done". The advantages include shorter synthesis times, greater economy, in that the internal energy of the reactions is employed rather than the costly external energy of the furnace, purer products, simpler equipment and no intrinsic limitation on the size of the sample to be synthesized as exists in the conventional technology. When delivery of reactants through the pores to the reaction site is an important aspect of the combustion process, it is referred to as filtration combustion. The two types of filtration combustion have a similar mathematical formulation, describing the ignition, propagation and extinction of combustion waves in porous media. The goal in each case, however, is different. In smoldering the desired goal is to prevent propagation, whereas in SHS the goal is to ensure propagation of the combustion wave, leading to the synthesis of desired products. In addition, the scales in the two areas of application differ. Smoldering generally occurs at lower temperatures and propagation velocities than in SHS nevertheless, the two applications have much in common so that what is learned fit make application can be used to advantage in the other. In porous

  2. Basic Aerodynamics of Combustion Chambers, (United States)


    n layer, an- its rhti re ai ei ar td . te II- to vortical wraXes which are also cplled "vo-tical rolls." r, and r,~=the er-temal 142 GaI M6.12 *%AAtM...8217-2XCC, UMn Th-~ t tr’.~t in ain~zttfror tecit vr’ 0 7 fij74,it ~r ~ h-t >2 h’’tof the jeb ,;p ~ ’ - ~~ *~~~k -. A--w.- - -- Chaptler 8 Tur~l.flftece Jet...G, is very small (the straight line AD), then, it is only possible to have combustion when one has temperature TD ; no other condition will do. If one

  3. Nanoparticle emissions from combustion engines

    CERN Document Server

    Merkisz, Jerzy


     This book focuses on particulate matter emissions produced by vehicles with combustion engines. It describes the physicochemical properties of the particulate matter, the mechanisms of its formation and its environmental impacts (including those on human beings). It discusses methods for measuring particulate mass and number, including the state-of-the-art in Portable Emission Measurement System (PEMS) equipment for measuring the exhaust emissions of both light and heavy-duty vehicles and buses under actual operating conditions. The book presents the authors’ latest investigations into the relations between particulate emission (mass and number) and engine operating parameters, as well as their new findings obtained through road tests performed on various types of vehicles, including those using diesel particulate filter regeneration. The book, which addresses the needs of academics and professionals alike, also discusses relevant European regulations on particulate emissions and highlights selected metho...

  4. Catalytic combustion of residual fuels (United States)

    Bulzan, D. L.; Tacina, R. R.


    A noble metal catalytic reactor was tested using two grades of petroleum derived residual fuels at specified inlet air temperatures, pressures, and reference velocities. Combustion efficiencies greater than 99.5 percent were obtained. Steady state operation of the catalytic reactor required inlet air temperatures of at least 800 K. At lower inlet air temperatures, upstream burning in the premixing zone occurred which was probably caused by fuel deposition and accumulation on the premixing zone walls. Increasing the inlet air temperature prevented this occurrence. Both residual fuels contained about 0.5 percent nitrogen by weight. NO sub x emissions ranged from 50 to 110 ppm by volume at 15 percent excess O2. Conversion of fuel-bound nitrogen to NO sub x ranged from 25 to 50 percent.

  5. Extended lattice Boltzmann scheme for droplet combustion. (United States)

    Ashna, Mostafa; Rahimian, Mohammad Hassan; Fakhari, Abbas


    The available lattice Boltzmann (LB) models for combustion or phase change are focused on either single-phase flow combustion or two-phase flow with evaporation assuming a constant density for both liquid and gas phases. To pave the way towards simulation of spray combustion, we propose a two-phase LB method for modeling combustion of liquid fuel droplets. We develop an LB scheme to model phase change and combustion by taking into account the density variation in the gas phase and accounting for the chemical reaction based on the Cahn-Hilliard free-energy approach. Evaporation of liquid fuel is modeled by adding a source term, which is due to the divergence of the velocity field being nontrivial, in the continuity equation. The low-Mach-number approximation in the governing Navier-Stokes and energy equations is used to incorporate source terms due to heat release from chemical reactions, density variation, and nonluminous radiative heat loss. Additionally, the conservation equation for chemical species is formulated by including a source term due to chemical reaction. To validate the model, we consider the combustion of n-heptane and n-butanol droplets in stagnant air using overall single-step reactions. The diameter history and flame standoff ratio obtained from the proposed LB method are found to be in good agreement with available numerical and experimental data. The present LB scheme is believed to be a promising approach for modeling spray combustion.

  6. Technologies for the treatment of the sulfur dioxide and nitrogen oxides generated by the combustion in open chamber; Tecnologias para el tratamiento de dioxido de azufre y oxidos de nitrogeno generados por la combustion en camara abierta

    Energy Technology Data Exchange (ETDEWEB)

    Salazar Villalpando, Maria Dolores [Instituto Mexicano del Petroleo, Mexico, D. F. (Mexico)


    In general terms, there are only three ways of avoiding the sulfur dioxide and the nitrogen oxides, generated by the combustion in open chamber, from contaminating the air; the first one is utilizing low sulfur and nitrogen content fuels, the second one is by controlling the parameters that affect the combustion and the third one to treat and/or clean the gases before exhausting them to the air. In this document, some of the treatments for diminishing the pollutant emissions generated by the combustion in open chamber, are presented. [Espanol] En terminos generales, solo existen 3 maneras de evitar que el dioxido de azufre y oxidos de nitrogeno generados por la combustion en camara abierta sigan contaminando el aire, la primera es utilizar un combustible de bajo contenido de azufre y nitrogeno, la segunda es controlar los parametros que afectan la combustion, y la tercera es tratar y/o limpiar los gases antes de emitirlos a la atmosfera. En este documento se presentan algunos tratamientos para disminuir las emisiones de contaminantes generados por la combustion en camara abierta.

  7. List of Article Contents

    Directory of Open Access Journals (Sweden)

    Editorial Section


    Full Text Available CONTENTS OF ARTICLES Premixed combustion of coconut oil in a hele-shaw cell DOI: 10.14710/ijred.3.3.155-160 155-160 Hadi Saroso, I.N.G. Wardana, Rudy Soenoko, Nurkholis Hamidi   Analysing the potential of retrofitting ultra-low heat loss triple vacuum glazed windows to an existing UK solid wall dwelling DOI: 10.14710/ijred.3.3.161-174 161-174 Saim Memon   Study of Gasohol as Alternative Fuel for Gasoline Substitution: Characteristics and Performances DOI: 10.14710/ijred.3.3.175-183 175-183 Bardi Murachman, Dicky Pranantyo, Eddie Sandjaya Putra   Thermal effects investigation on electrical properties of silicon solar cells treated by laser irradiation DOI: 10.14710/ijred.3.3.184-187 184-187 Ali Pourakbar Saffar, Bahman Deldadeh Barani   Synthesis of Trimethylolpropane Esters of Calophyllum Methyl Esters : Effect of Temperatur and Molar Ratio DOI: 10.14710/ijred.3.3.188-192 188-192 Yeti Widyawati, Ani Suryani, Muhammad Romli, Sukardi Sukardi   Incorporating Root Crops under Agro-Forestry as the Newly Potential Source of Food, Feed and Renewable Energy DOI: 10.14710/ijred.3.3.193-206 193-206 Yudi Widodo, St. A. Rahayuningsih, Nasir Saleh, Sri Wahyuningsih   Solmap: Project In India's Solar Resource Assessment DOI: 10.14710/ijred.3.3.207-216 207-216 Indradip Mitra, Kaushal Chhatbar, Ashvini Kumar, Godugunur Giridhar, Ramdhan Vashistha, Richard Meyer, Marko Schwandt   Thermo-economic Optimization of Solar Assisted Heating and Cooling (SAHC System DOI: 10.14710/ijred.3.3.217-227 217-227 A. Ghafoor, A. Munir   Combustion characteristics of diesel engine using producer gas and blends of Jatropha methyl ester with diesel in mixed fuel mode DOI: 10.14710/ijred.3.3.228-235 228-235 Hifjur Raheman, Debasish Padhee    

  8. List of Content

    Directory of Open Access Journals (Sweden)

    Editor IJRED


    Full Text Available CONTENTS OF ARTICLES page Tin (II Chloride Catalyzed Esterification of High FFA Jatropha Oil: Experimental and Kinetics Study DOI: 10.14710/ijred.3.2.75-81 75-81 Ratna Dewi Kusumaningtyas, Prima Astuti Handayani, Rochmadi Rochmadi, Suryo Purwono, Arief Budiman   Utilization of Iles-Iles and Sorghum Starch for Bioethanol Production DOI: 10.14710/ijred.3.2.83-89 83-89 Kusmiyati Kusmiyati, Agus Sulistiyono   Premixed Combustion of Kapok (ceiba pentandra seed oil on Perforated Burner DOI: 10.14710/ijred.3.2.91-97 91-97 I.K.G. Wirawan, I.N.G. Wardana,        Rudy Soenoko, Slamet Wahyudi   Castor Seed from Melkasa Agricultural Research Centre, East Showa, Ethiopia and it’s biodiesel performance in Four Stroke Diesel Engine DOI: 10.14710/ijred.3. 3.2.99-105 99-105 Tesfahun Tegegne Akanawa, Haimanot Gebrehiwot Moges, Ramesh Babu, Daniel Bisrat   Economic feasibility of large scale PV water pumping applications utilizing real field data for a case study in Jordan DOI: 10.14710/ijred.3.2.107-117 107-117 Ibrahim Odeh   Development of Briquette from Coir Dust and Rice Husk Blend: An Alternative Energy Source DOI: 10.14710/ijred.3.2.119-123 119-123 Md. Hamidul Islam, Md. Mosharraf Hossain,Md. Abdul Momin   Performance, Emissions and Combustion Characteristics of a Single Cylinder Diesel Engine Fuelled with Blends of Jatropha Methyl Ester and Diesel DOI: 10.14710/ijred.3.2.125-131 125-131 Debasish Padhee, Hifjur Raheman   The characteristic changes of betung bamboo (Dendrocalamus asper pretreated by fungal pretreatment DOI: 10.14710/ijred.3.2.133-143 133-143 Widya Fatriasari, Wasrin Syafii, Nyoman J Wistara, Khaswar Syamsu, Bambang Prasetya   Influence of the Determination Methods of K and C Parameters on the Ability of Weibull Distribution to Suitably Estimate Wind Potential and Electric Energy DOI: 10.14710/ijred.3.2.145-154 145-154 Ruben M. Mouangue, Myrin Y. Kazet, Alexis Kuitche, Jean-Marie Ndjaka    

  9. Production of Indigenous and Enriched Khyber Pakhtunkhwa Coal Briquettes: Combustion and Disintegration Strength Analysis

    Directory of Open Access Journals (Sweden)

    Unsia Habib


    Full Text Available Khyber Pakhtun Khwa province of Pakistan has considerable amounts of low ranked coal. However, due to the absence of any centrally administered power generation system there is a need to explore indigenous methods for effectively using this valuable energy resource. In the present study an indigenous coal briquetting technology has been developed and evaluated in terms of combustion characteristics such as moisture content, volatile matter, ash, fixed carbon and calorific value of the resulting coal briquette and disintegration strength using polyvinyl acetate (PVA in combination with calcium carbonate (sample no 3 with highest disintegration strength value of 2059N. Comparison of test samples with the commercially available coal briquettes revealed improved combustion characteristics for the PVA bonded (sample no 1 and 5 coal briquettes having higher fixed carbon content and calorific value, lower ash contents as well as lower initial ignition time.

  10. Characterization and electrodialytic treatment of wood combustion fly ash for removal of cadmium

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul


    -for the aim of recycling-was described. Initial characterisation of the experimental ash showed that the Cd content exceeded the limiting values for agricultural use and therefore needed treatment before being recycled. The pH in the ash was very high (13.3), and the Cd was not soluble at these alkaline......Due to a high content of macronutrients and a potential liming capacity, recycling of ashes from biomass combustion to agricultural fields as fertilisers and/or for soil improvement is considered in Denmark and other countries utilising biomass as an energy source. However, the fly ash fractions...... especially contain amounts of the toxic heavy metal cadmium that may exceed the limiting values for agricultural utilisation given by the Danish Environmental Protection Agency.In this work the advances of using an electrodialytic remediation method to reduce the Cd content in wood combustion fly ash...

  11. Flammability characteristics of combustible gases and vapors

    Energy Technology Data Exchange (ETDEWEB)

    Zabetakis, M. G. [Bureau of Mines, Pittsburgh, PA (United States)


    This is a summary of the available limit of flammability, autoignition and burning-rate data for more than 200 combustible gases and vapors in air and other oxidants, as well as of empirical rules and graphs that can be used to predict similar data for thousands of other combustibles under a variety of environmental conditions. Spec$c data are presented on the paraffinic, unsaturated, aromatic, and alicyclic hydrocarbons, alcohols, ethers, aldehydes, ketones, and sulfur compounds, and an assortment of fuels, fuel blends, hydraulic fluids, engine oils, and miscellaneous combustible gases and vapors.

  12. Combustion temperature charts for industrial gaseous fuels

    Energy Technology Data Exchange (ETDEWEB)

    Matouskova, V.; Gerak, A.; Hlavacka, V.


    Researchers at Czechoslovakia's State Research Institute of Mechanical Engineering offer a method for calculating the theoretical flame temperature that includes the effect of endothermic reactions, especially the dissociation of combustion products. Charts presented for eight types of fuel gases can be used to determine the flame temperature relative to the temperature of the combustion air and to the excess-air ratio. Also considered is the relationship between these parameters and the characteristic temperature relationships for equipment using heat recovered from the flue gases to preheat incoming combustion air.

  13. Novel combustion concepts for sustainable energy development

    CERN Document Server

    Agarwal, Avinash K; Gupta, Ashwani K; Aggarwal, Suresh K; Kushari, Abhijit


    This book comprises research studies of novel work on combustion for sustainable energy development. It offers an insight into a few viable novel technologies for improved, efficient and sustainable utilization of combustion-based energy production using both fossil and bio fuels. Special emphasis is placed on micro-scale combustion systems that offer new challenges and opportunities. The book is divided into five sections, with chapters from 3-4 leading experts forming the core of each section. The book should prove useful to a variety of readers, including students, researchers, and professionals.

  14. 3rd International Conference on Numerical Combustion

    CERN Document Server

    Larrouturou, Bernard; Numerical Combustion


    Interest in numerical combustion is growing among applied mathematicians, physicists, chemists, engine manufacturers and many industrialists. This proceedings volume contains nine invited lectures and twenty seven contributions carefully selected by the editors. The major themes are numerical simulation of transsonic and supersonic combustion phenomena, the study of supersonic reacting mixing layers, and turbulent combustion. Emphasis is laid on hyperbolic models and on numerical simulations of hydrocarbon planes with a complete set of chemical reactions carried out in two-dimensional geometries as well as on complex reactive flow simulations.

  15. The John Zink Hamworthy combustion handbook

    CERN Document Server

    Baukal, Charles E


    Despite the length of time it has been around, its importance, and vast amounts of research, combustion is still far from being completely understood. Issues regarding the environment, cost, and fuel consumption add further complexity, particularly in the process and power generation industries. Dedicated to advancing the art and science of industrial combustion, The John Zink Hamworthy Combustion Handbook, Second Edition: Volume 3 - Applications offers comprehensive, up-to-date coverage of equipment used in the process and power generation industries. Under the leadership of Charles E. Baukal

  16. Annual Report: Advanced Combustion (30 September 2012)

    Energy Technology Data Exchange (ETDEWEB)

    Hawk, Jeffrey [NETL; Richards, George


    The Advanced Combustion Project addresses fundamental issues of fire-side and steam-side corrosion and materials performance in oxy-fuel combustion environments and provides an integrated approach into understanding the environmental and mechanical behavior such that environmental degradation can be ameliorated and long-term microstructural stability, and thus, mechanical performance can lead to longer lasting components and extended power plant life. The technical tasks of this effort are Oxy-combustion Environment Characterization, Alloy Modeling and Life Prediction, and Alloy Manufacturing and Process Development.


    Directory of Open Access Journals (Sweden)



    Full Text Available Differences in the chemical nature between petroleum diesel fuels and vegetable oils-based fuels lead to differences in their physical properties affecting the combustion process inside the engine. In this work a detailed combustion diagnosis was applied to a turbocharged automotive diesel engine operating with neat palm oil biodiesel (POB, No. 2 diesel fuel and their blends at 20 and 50% POB by volume (B20 and B50 respectively. To isolate the fuel effect, tests were executed at constant power output without carrying out any modification of the engine or its fuel injection system. As the POB content in the blend increased, there was a slight reduction in the fuel/air equivalence ratio from 0.39 (B0 to 0.37 (B100, an advance of injection timing and of start of combustion. Additionally, brake thermal efficiency, combustion duration, maximum mean temperature, temperature at exhaust valve opening and exhaust gas efficiency decreased; while the peak pressure, exergy destruction rate and specific fuel consumption increased. With diesel fuel and the blends B20 and B50 the same combustion stages were noticed. However, as a consequence of the differences pointed out, the thermal history of the process was affected. The diffusion combustion stage became larger with POB content. For B100 no premixed stage was observed.

  18. Coal Combustion Science quarterly progress report, April--June 1990

    Energy Technology Data Exchange (ETDEWEB)

    Hardesty, D.R. (ed.); Baxter, L.L.; Fletcher, T.H.; Mitchell, R.E.


    This document provides a quarterly status report of the Coal Combustion Science Program that is being conducted at the Combustion, Research Facility, Sandia National Laboratories, Livermore, California. Coal devolatilization, coal char combustion, and fate of mineral matter during coal combustion. 56 refs., 25 figs., 13 tabs.

  19. Numerical modeling of straw combustion in a fixed bed

    DEFF Research Database (Denmark)

    Zhou, Haosheng; Jensen, Anker; Glarborg, Peter


    . The straw combustion processes include moisture evaporation, straw pyrolysis, gas combustion, and char combustion. The model provides detailed information of the structure of the ignition flame front. Simulated gas species concentrations at the bed surface, ignition flame front rate, and bed temperature...... packing condition, and heat capacity of the straw have considerable effects on the model predictions of straw combustion in the fixed bed....

  20. Key factors of combustion from kinetics to gas dynamics

    CERN Document Server

    Rubtsov, Nikolai M


    This book summarizes the main advances in the mechanisms of combustion processes. It focuses on the analysis of kinetic mechanisms of gas combustion processes and experimental investigation into the interrelation of kinetics and gas dynamics in gas combustion. The book is complimentary to the one previously published, The Modes of Gaseous Combustion.

  1. Evaluation and Improvement of Liquid Propellant Rocket Chugging Analysis Techniques. Part 2: a Study of Low Frequency Combustion Instability in Rocket Engine Preburners Using a Heterogeneous Stirred Tank Reactor Model. Final Report M.S. Thesis - Aug. 1987 (United States)

    Bartrand, Timothy A.


    During the shutdown of the space shuttle main engine, oxygen flow is shut off from the fuel preburner and helium is used to push the residual oxygen into the combustion chamber. During this process a low frequency combustion instability, or chug, occurs. This chug has resulted in damage to the engine's augmented spark igniter due to backflow of the contents of the preburner combustion chamber into the oxidizer feed system. To determine possible causes and fixes for the chug, the fuel preburner was modeled as a heterogeneous stirred tank combustion chamber, a variable mass flow rate oxidizer feed system, a constant mass flow rate fuel feed system and an exit turbine. Within the combustion chamber gases were assumed perfectly mixed. To account for liquid in the combustion chamber, a uniform droplet distribution was assumed to exist in the chamber, with mean droplet diameter determined from an empirical relation. A computer program was written to integrate the resulting differential equations. Because chamber contents were assumed perfectly mixed, the fuel preburner model erroneously predicted that combustion would not take place during shutdown. The combustion rate model was modified to assume that all liquid oxygen that vaporized instantaneously combusted with fuel. Using this combustion model, the effect of engine parameters on chamber pressure oscillations during the SSME shutdown was calculated.

  2. The solution combustion synthesis of nanophosphors

    Energy Technology Data Exchange (ETDEWEB)

    Tornga, Stephanie C [Los Alamos National Laboratory


    Nanophosphors are defined as nano-sized (1-100mn), insulating, inorganic materials that emit light under particle or electromagnetic excitation. Their unique luminescence properties provide an excellent potential for applications in radiation detection and imaging. Herein, solution combustion synthesis (SCS) is presented as a method to prepare nanophosphor powders, while X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence (PL), photoluminescence excitation (PLE), and other techniques were used to characterize their structural and optical properties. The goal of this work is to synthesize bright, high-quality powders of nanophosphors, consolidate them into bulk materials and study their structural and optical properties using XRD, TEM, PL, and PLE. SCS is of interest because it is a robust, inexpensive, and facile technique, which yields a significant amount of a wide variety of oxide materials, in a short amount of time. Several practical nanophosphors were synthesized and investigated in this work, including simple oxides such as Y{sub 2}O{sub 3}:Bi, Y{sub 2}O{sub 3}:Tb, Y{sub 2}O{sub 3}:Eu and Gd{sub 2}O{sub 3}:Eu, complex oxides such as Gd{sub 2}SiO{sub 5}:Ce, Y{sub 2}SiO{sub 5}:Ce, Lu{sub 2}SiO{sub 5}:Ce, Zn{sub 2}SiO{sub 4}:Mn, and Y{sub 3}Al{sub 5}O{sub 12}:Ce. Results demonstrate that altering the processing parameters such as water content of the precursor solution, ignition temperature, fuel type and amount, and post-synthesis annealing can significantly improve light output, and that it is possible to optimize the luminescence output of oxyorthosilicates by reducing the amount of silica in the precursor mixture.

  3. Characterization of gaseous emissions and ashes from the combustion of furniture waste. (United States)

    Moreno, Ana Isabel; Font, Rafael; Conesa, Juan A


    Gaseous emissions and ash obtained in the combustion of furniture waste have been studied, with particular emphasis on the emissions of hazardous pollutants, such as PCDD/Fs and dl-PCBS. Two different combustion procedures were carried out, one of them in a conventional residential stove (without an automatic control of combustion air and bad mixing of combustion gases with air), and the other in a laboratory-scale reactor (operating under substoichiometric conditions). Three different experiments were carried out in the residential stove, in which the gaseous emissions and ashes obtained were analysed. The fuel burnt out in two of the experiments was furniture wood waste and in one of the experiments, the fuel burnt out was briquettes composed of a mixture of furniture wood with 10wt.% of polyurethane foam. One of the purposes of these experiments was the evaluation of the possible inhibition effect of the higher nitrogen content on the formation of PCDD/Fs. Slight inhibition of the PCDD/F formation was found although, it is noteworthy that the lowest yield of PAHs, volatile and semi-volatile compounds were obtained in the combustion of these briquettes. In all experiments, the emission factors of polychlorinated dibenzo-p-dioxins and dibenzofurans and dioxin-like polychlorinated biphenyls (PCDD/Fs and dl-PCBs) were between 29 and 74ng WHO-TEQ/kg sample burnt, lower than that obtained by other authors in the burning of pine needles and cones. PCDD/Fs and dl-PCBs emissions from furniture wood waste combustion were also analysed in the laboratory scale reactor at 850°C and the results were compared with the values obtained from the combustion of solid wood (untreated wood). The total equivalent toxicity obtained was 21.1ng WHO-TEQ/kg sample for combustion of furniture wood waste, which is low in comparison with those obtained for other waste combustion in similar conditions. In the laboratory scale reactor, PCDFs were the dominant compounds in the profiles of PCDD

  4. Fine particle emissions in three different combustion conditions of a wood chip-fired appliance - Particulate physico-chemical properties and induced cell death (United States)

    Leskinen, J.; Tissari, J.; Uski, O.; Virén, A.; Torvela, T.; Kaivosoja, T.; Lamberg, H.; Nuutinen, I.; Kettunen, T.; Joutsensaari, J.; Jalava, P. I.; Sippula, O.; Hirvonen, M.-R.; Jokiniemi, J.


    A biomass combustion reactor with a moving grate was utilised as a model system to produce three different combustion conditions corresponding to efficient, intermediate, and smouldering combustion. The efficient conditions (based on a CO level of approximately 7 mg MJ-1) corresponded to a modern pellet boiler. The intermediate conditions (CO level of approximately 300 mg MJ-1) corresponded to non-optimal settings in a continuously fired biomass combustion appliance. The smouldering conditions (CO level of approximately 2200 mg MJ-1) approached a batch combustion situation. The gaseous and particle emissions were characterised under each condition. Moreover, the ability of fine particles to cause cell death was determined using the particle emissions samples. The physico-chemical properties of the emitted particles and their toxicity were considerably different between the studied combustion conditions. In the efficient combustion, the emitted particles were small in size and large in number. The PM1 emission was low, and it was composed of ash species. In the intermediate and smouldering combustion, the PM1 emission was higher, and the particles were larger in size and smaller in number. In both of these conditions, there were high-emission peaks that produced a significant fraction of the emissions. The PAH emissions were the lowest in the efficient combustion. The smouldering combustion conditions produced the largest PAH emissions. In efficient combustion conditions, the emitted fine particles had the highest potential to cause cell death. This finding was most likely observed because these fine particles were mainly composed of inorganic ash species, and their relative contents of Zn were high. Thus, even the PM1 from optimal biomass combustion might cause health effects, but in these conditions, the particle emissions per energy unit produced were considerably lower.

  5. A study of the current group evaporation/combustion theories (United States)

    Shen, Hayley H.


    Liquid fuel combustion can be greatly enhanced by disintegrating the liquid fuel into droplets, an effect achieved by various configurations. A number of experiments carried out in the seventies showed that combustion of droplet arrays and sprays do not form individual flames. Moreover, the rate of burning in spray combustion greatly deviates from that of the single combustion rate. Such observations naturally challenge its applicability to spray combustion. A number of mathematical models were developed to evaluate 'group combustion' and the related 'group evaporation' phenomena. This study investigates the similarity and difference of these models and their applicability to spray combustion. Future work that should be carried out in this area is indicated.

  6. Kinetics of coal combustion: Part 2, Mechanisms and kinetics of coal volatiles combustion

    Energy Technology Data Exchange (ETDEWEB)

    Gat, N.; Wolff, M. F.; Petach, M. B. [TRW Space and Technology Group, Redondo Beach, CA (USA)


    Presently very little is known about the combustion characteristics of mixtures of hydrocarbon fuels. Even less is known about the combustion of coal volatiles which are complex mixtures of light and high molecular weight hydrocarbons. This issue pertains not only to coal volatiles but also to the combustion of synthetic fuels, liquefaction and coal gasification products. The subject in general has been given very little attention in the literature. As a consequence, current modeling methods are based on assumptions which are not thoroughly validated and verified. The current investigation addressed this very problem of the combustion of mixtures of hydrocarbon fuels. 29 refs., 35 figs., 5 tabs.


    Directory of Open Access Journals (Sweden)

    S. V. Vorobiev


    Full Text Available The use of thermovision technology to diagnose failure of the combustion flame test tube of the main combustion chamber gas turbine engine is deal with in the article. Join the thermal radiation of the jet of combustion products and the internal elements was carried out using short-wave thermovision system AGA-782 with spectral spectral filters in several ranges from 3.2 to 5.6 microns. Thermovision is mounted on the axis of the flame tube. The output signal was recorded and processed on a computer in real time, allowing monitor the combustion process and the thermal state of the object during the experiment.

  8. Coal Combustion Products Extension Program

    Energy Technology Data Exchange (ETDEWEB)

    Tarunjit S. Butalia; William E. Wolfe


    This final project report presents the activities and accomplishments of the ''Coal Combustion Products Extension Program'' conducted at The Ohio State University from August 1, 2000 to June 30, 2005 to advance the beneficial uses of coal combustion products (CCPs) in highway and construction, mine reclamation, agricultural, and manufacturing sectors. The objective of this technology transfer/research program at The Ohio State University was to promote the increased use of Ohio CCPs (fly ash, FGD material, bottom ash, and boiler slag) in applications that are technically sound, environmentally benign, and commercially competitive. The project objective was accomplished by housing the CCP Extension Program within The Ohio State University College of Engineering with support from the university Extension Service and The Ohio State University Research Foundation. Dr. Tarunjit S. Butalia, an internationally reputed CCP expert and registered professional engineer, was the program coordinator. The program coordinator acted as liaison among CCP stakeholders in the state, produced information sheets, provided expertise in the field to those who desired it, sponsored and co-sponsored seminars, meetings, and speaking at these events, and generally worked to promote knowledge about the productive and proper application of CCPs as useful raw materials. The major accomplishments of the program were: (1) Increase in FGD material utilization rate from 8% in 1997 to more than 20% in 2005, and an increase in overall CCP utilization rate of 21% in 1997 to just under 30% in 2005 for the State of Ohio. (2) Recognition as a ''voice of trust'' among Ohio and national CCP stakeholders (particularly regulatory agencies). (3) Establishment of a national and international reputation, especially for the use of FGD materials and fly ash in construction applications. It is recommended that to increase Ohio's CCP utilization rate from 30% in 2005 to

  9. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, Malene; Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt

    Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO2, NOx, NMVOC, CH4, CO, CO2, N2O, particulate matter, heavy metals, dioxins, HCB and PAH. The CO2 emission in 2007 was 10...... incineration plants. The combustion of wood in residential plants has increased considerably in recent years resulting in increased emission of PAH, particulate matter and CO. The emission of NMVOC has increased since 1990 as a result of both the increased combustion of wood in residential plants...... and the increased emission from lean-burn gas engines. The dioxin emission decreased since 1990 due to flue gas cleaning on waste incineration plants. However in recent years the emission has increased as a result of the increased combustion of wood in residential plants....

  10. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, Malene; Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt

    Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO2, NOx, NMVOC, CH4, CO, CO2, N2O, NH3, particulate matter, heavy metals, dioxins, HCB and PAH. The CO2 emission in 2008...... incineration plants. The combustion of wood in residential plants has increased considerably in recent years resulting in increased emission of PAH, particulate matter and CO. The emission of NMVOC has increased since 1990 as a result of both the increased combustion of wood in residential plants...... and the increased emission from lean-burn gas engines. The dioxin emission decreased since 1990 due to flue gas cleaning on waste incineration plants. However in recent years the emission has increased as a result of the increased combustion of wood in residential plants....

  11. Fuels Combustion Research: Supercritical Fuel Pyrolysis

    National Research Council Canada - National Science Library

    Glassman, Irvin


    .... The focus during the subject period was directed to understanding the pyrolysis and combustion of endothermic fuels under subcritical conditions and the pyrolysis of these fuels under supercritical conditions...

  12. Fuels Combustion Research: Supercritical Fuel Pyrolysis

    National Research Council Canada - National Science Library

    Glassman, Irvin


    .... The focus during the subject period was directed to understanding the pyrolysis and combustion of endothermic fuels under subcritical conditions and the pyrolysis of these fuels under supercritical conditions...

  13. Combustion properties of Kraft Black Liquors

    Energy Technology Data Exchange (ETDEWEB)

    Frederick, W.J. Jr.; Hupa, M. (Aabo Akademi, Turku (Finland))


    In a previous study of the phenomena involved in the combustion of black liquor droplets a numerical model was developed. The model required certain black liquor specific combustion information which was then not currently available, and additional data were needed for evaluating the model. The overall objectives of the project reported here was to provide experimental data on key aspects of black liquor combustion, to interpret the data, and to put it into a form which would be useful for computational models for recovery boilers. The specific topics to be investigated were the volatiles and char carbon yields from pyrolysis of single black liquor droplets; a criterion for the onset of devolatilization and the accompanying rapid swelling; and the surface temperature of black liquor droplets during pyrolysis, combustion, and gasification. Additional information on the swelling characteristics of black liquor droplets was also obtained as part of the experiments conducted.

  14. Petroleum recovery by in situ combustion

    Energy Technology Data Exchange (ETDEWEB)

    Orkiszewski, J.


    In an in situ combustion process for the recovery of oil, the available fuel is changed to more nearly equal the minimum fuel requirement for the process. The API gravity of the reservoir oil and the temperature of the reservoir are used to determine the total available fuel. The available fuel in the reservoir is changed to more nearly equal the minimum fuel requirement for the in situ combustion process by injecting a fluid capable of changing either the API gravity of the reservoir oil, the reservoir temperature, or both. An oxygen containing gas is then injected into the reservoir to initiate combustion. Oil is recovered from the reservoir as a result of the in situ combustion process. (10 claims)

  15. Plume Diagnostics for Combustion Stability Project (United States)

    National Aeronautics and Space Administration — Sierra Engineering Inc. and Purdue University propose to develop a non-intrusive plume instrument capable of detecting and diagnosing combustion instability. This...

  16. Two phase exhaust for internal combustion engine (United States)

    Vuk, Carl T [Denver, IA


    An internal combustion engine having a reciprocating multi cylinder internal combustion engine with multiple valves. At least a pair of exhaust valves are provided and each supply a separate power extraction device. The first exhaust valves connect to a power turbine used to provide additional power to the engine either mechanically or electrically. The flow path from these exhaust valves is smaller in area and volume than a second flow path which is used to deliver products of combustion to a turbocharger turbine. The timing of the exhaust valve events is controlled to produce a higher grade of energy to the power turbine and enhance the ability to extract power from the combustion process.

  17. Plume Diagnostics for Combustion Stability Project (United States)

    National Aeronautics and Space Administration — Sierra Engineering and Purdue University propose to leverage combustion stability testing, already funded and planned for the second and third quarters of next year...

  18. CFD analysis of combustion of natural gas and syngas from biomass pyrolysis in the combustion chamber of a micro gas turbine

    Energy Technology Data Exchange (ETDEWEB)

    Fantozzi, Francesco; Laranci, Paolo; D' Alessandro, Bruno [University of Perugia (DII/UNIPG) (Italy). Dept. of Industrial Engineering], Emails:,,


    Micro gas turbines (MGT) can be profitably used for the production of distributed energy (DE), with the possibility to use gaseous fuels with low BTU derived from biomass or waste through the pyrolysis or gasification processes. These synthesis gases (SG) show significant differences with respect to natural gas (NG), in terms of composition, calorific value, content of hydrogen, tar and particulate matter content; such differences can be turn into problems of ignition, instability burning, difficulties in controlling the emissions and fouling. CFD analysis of the combustion process is an essential tool for identifying the main critical arising in using these gases, in order to modify existing geometries and to develop new generation of combustor for use with low BTU gases. This paper describes the activities of experimental and numerical analysis carried out to study the combustion process occurring inside an existing annular Rich-Quench-Lean (RQL) Combustion Chamber (CC) of a 80 kW MGT. In the paper some results of a CFD study of the combustion process performed with an original developed chemical models are reported in terms of temperature and velocity distributions inside the CC and in terms of compositions of turbine inlet gas and of its thermodynamic parameters (mass flow, temperature, pressure). An evaluation of pollutant emissions of CO, CO{sub 2} and NOx and a comparison with the available experimental data relating to the case of combustion of NG is also provided in the paper. Moreover, the carried out investigation concerns the case of operation with a SG fuel derived from biomass in an Integrated Pyrolysis Regenerated Plant (IPRP). (author)

  19. Experimental Investigation of the Asphaltene Deposition Process during Different Production Schemes Étude expérimentale du processus de dépôt d’asphaltènes au cours de différents modes de production

    Directory of Open Access Journals (Sweden)

    Bagheri M.B.


    Full Text Available This paper presents the results of asphaltene precipitation and deposition during lean gas injection, CO2 injection and natural depletion in reservoir conditions. In addition, the effect of variations in operating pressure, injection gas concentration and production rate on asphaltene precipitation and deposition were investigated. The severity of asphaltene deposition was found to be more pronounced in lean gas injection in comparison with CO2 injection and natural depletion. Increasing the flow rate in natural depletion experiments showed a considerable increase in asphaltene deposition, and consequently permeability reduction in the core matrix. Moreover, more asphaltene deposition was observed along the porous media in the gas injection experiments when the gas mol percent of the mixture was increased. Cet article présente les résultats d’une étude de la précipitation et du dépôt d’asphaltènes qui peuvent se produire lors d’une injection de gaz pauvre, d’une injection de CO2 ou d’une déplétion naturelle en conditions de réservoir. En outre, les effets de la pression de fonctionnement, de la concentration en gaz injecté et du débit de production sur la précipitation et le dépôt d’asphaltènes ont été étudiés. Il a été constaté que l’importance du dépôt d’asphaltènes est plus prononcée dans le cas d’une injection de gaz pauvre comparativement à une injection de CO2 ou à une déplétion naturelle. Une augmentation du débit au cours d’expériences de déplétion naturelle a montré un accroissement considérable du dépôt d’asphaltènes et, en conséquence, une réduction de perméabilité au sein de la matrice poreuse. Par ailleurs, un dépôt d’asphaltènes plus important a été observé au cours des expériences d’injection de gaz lorsque la concentration molaire gazeuse dans le mélange était augmentée.

  20. Emission studies from combustion of empty fruit bunch pellets in a fluidized bed combustor (United States)

    Fazli Othaman, Muhamad; Sabudin, Sulastri; Faizal Mohideen Batcha, Mohd


    Malaysia is producing a very large amount of biomass annually from milling activities of oil palm. This biomass is currently being used efficiently in many ways including as fuel for boilers together with fossil fuels. This paper reports the emission characteristics from biomass combustion in a swirling fluidized bed combustor (SFBC). Pelletized empty fruit bunch (PEFB), one of largest biomass produced from oil palm industries were used as fuel in the present study. Combustion experiments were conducted with several quantitiesof excess air: 20%, 40%, 60% and 80% for a constant fuel feedrate of 30kg/hr. The effect of excess air was investigated for three major emissions gaseous namely CO, CO2 and NOx. Fly ash produced from the combustion was also analysed to find the contents of unburnt carbon and other impurities. From the results, it was found that the emission of CO decreased from 64 ppm to 40 ppm while the amount of CO2 increased slightly with the increasing of excess air from 20% to 80%. The NOx emission also increased from 290 ppm to 350 ppm because of N2 in the EA reacts with O2 due to high combustion temperature. The combustion efficiencies of about 99% obtained in the present study, showing the prospects of using SFBC in commercial scale.

  1. Thermal analysis and kinetics of coal during oxy-fuel combustion (United States)

    Kosowska-Golachowska, Monika


    The pyrolysis and oxy-fuel combustion characteristics of Polish bituminous coal were studied using non-isothermal thermogravimetric analysis. Pyrolysis tests showed that the mass loss profiles were almost similar up to 870°C in both N2 and CO2 atmospheres, while further mass loss occurred in CO2 atmosphere at higher temperatures due to char-CO2 gasification. Replacement of N2 in the combustion environment by CO2 delayed the combustion of bituminous coal. At elevated oxygen levels, TG/DTG profiles shifted through lower temperature zone, ignition and burnout temperatures decreased and mass loss rate significantly increased and complete combustion was achieved at lower temperatures and shorter times. Kinetic analysis for the tested coal was performed using Kissinger-Akahira-Sunose (KAS) method. The activation energies of bituminous coal combustion at the similar oxygen content in oxy-fuel with that of air were higher than that in air atmosphere. The results indicated that, with O2 concentration increasing, the activation energies decreased.

  2. Characterization and integration of oxidation catalysts at small-scale biomass combustion furnaces

    Directory of Open Access Journals (Sweden)

    Matthes Mirjam


    Full Text Available Small-scale biomass combustion is a major part in heat supply from renewable resources. Drawbacks to the environmental background are the pollutant emissions, which are formed as a result of maloperation, suboptimal furnace construction or the biomass fuel composition. The named primary factors can be influenced by several measures, but the achievable emission results are limited. To provide real clean combustion technology with nearly zero pollutant emissions, secondary emission reduction measures are necessary. One of these measures is the application of catalytic flue gas cleaning as integrated or downstream solution. Catalysis is already a state of the art element in many processes and following this, some studies reveal already its potential to reduce CO, VOC as well as particle emissions in small-scale biomass combustion systems. However, a wide application of catalysts in wood combustion units didn’t take place so far, because the challenging process conditions demand a proper integration and highly stable and active catalytic materials. For the achievement of well-functioning combustion systems with catalyst solutions a procedure for application-oriented characterization is presented. Initial investigations with commercially available catalysts have shown that the gas hourly space velocity and the oxygen content have the most significant influence on the conversion rate of carbon monoxide and nitrogen oxide. Two samples with different active phases have been compared, one with solely metal oxides and one with metal oxides and noble metals. The one with noble metals showed as expected a higher activity, but also a higher stability.

  3. Characterization and integration of oxidation catalysts at small-scale biomass combustion furnaces (United States)

    Matthes, Mirjam; Hartmann, Ingo; Schenk, Joachim; Enke, Dirk


    Small-scale biomass combustion is a major part in heat supply from renewable resources. Drawbacks to the environmental background are the pollutant emissions, which are formed as a result of maloperation, suboptimal furnace construction or the biomass fuel composition. The named primary factors can be influenced by several measures, but the achievable emission results are limited. To provide real clean combustion technology with nearly zero pollutant emissions, secondary emission reduction measures are necessary. One of these measures is the application of catalytic flue gas cleaning as integrated or downstream solution. Catalysis is already a state of the art element in many processes and following this, some studies reveal already its potential to reduce CO, VOC as well as particle emissions in small-scale biomass combustion systems. However, a wide application of catalysts in wood combustion units didn't take place so far, because the challenging process conditions demand a proper integration and highly stable and active catalytic materials. For the achievement of well-functioning combustion systems with catalyst solutions a procedure for application-oriented characterization is presented. Initial investigations with commercially available catalysts have shown that the gas hourly space velocity and the oxygen content have the most significant influence on the conversion rate of carbon monoxide and nitrogen oxide. Two samples with different active phases have been compared, one with solely metal oxides and one with metal oxides and noble metals. The one with noble metals showed as expected a higher activity, but also a higher stability.

  4. 76 FR 16646 - Circadian, Inc., Clean Energy Combustion, Inc. (n/k/a Clean Energy Combustion Systems, Inc... (United States)


    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION Circadian, Inc., Clean Energy Combustion, Inc. (n/k/a Clean Energy Combustion Systems, Inc... concerning the securities of Clean Energy Combustion, Inc. (n/k/a Clean Energy Combustion Systems, Inc...

  5. Self-oscillations of an unstable fuel combustion in the combustion chamber of a liquid-propellant rocket engine (United States)

    Gotsulenko, V. V.; Gotsulenko, V. N.


    The form of the self-oscillations of a vibrating combustion of a fuel in the combustion chamber of a liquidpropellant rocket engine, caused by the fuel-combustion lag and the heat release, was determined. The character of change in these self-oscillations with increase in the time of the fuel-combustion lag was investigated.

  6. Household fuels, direct combustion, public perception, fuel

    African Journals Online (AJOL)


    Jul 10, 2005 ... w ere smo k e, fl y - ash and high b urning rate . A ma j or c ause o f the p ro b lems w as the ... Key words: Household fuels, direct combustion, public perception, fuel-switching, food-switching, health impacts. 1 IN TR ..... levels from wood combustion typically exceed the recommended limit by 13 - 50 times ...

  7. Secondary combustion system for woodburning stove

    Energy Technology Data Exchange (ETDEWEB)

    von Conta, P. E. W.


    A secondary combustion system for a woodburning stove employs a concave shaped screen for dispersing exhaust gases. A mixing chamber is formed in an insulated conduit between the concave screen and a second planar screen. The planar screen is perforated to form a random array of flaps which increase the turbulence of the exhaust stream so that a secondary combustion of the exhaust gases is produced.

  8. L'Hidrogen com a combustible


    Díaz i Pérez, Germán


    L’objectiu del projecte, és estudiar la viabilitat de l’hidrogen com a combustible net. Dissenyant un planta de producció d’hidrogen que utilitzi energia neta per a realitzar el seu procés (energia elèctrica obtinguda a partir de fonts renovables), i utilitzant l’hidrogen obtingut per a accionar un autobús amb pila de combustible.

  9. Internal combustion engine and method for control (United States)

    Brennan, Daniel G


    In one exemplary embodiment of the invention an internal combustion engine includes a piston disposed in a cylinder, a valve configured to control flow of air into the cylinder and an actuator coupled to the valve to control a position of the valve. The internal combustion engine also includes a controller coupled to the actuator, wherein the controller is configured to close the valve when an uncontrolled condition for the internal engine is determined.

  10. Building America Expert Meeting. Combustion Safety

    Energy Technology Data Exchange (ETDEWEB)

    Brand, Larry [Partnership for Advanced Residential Retrofit (PARR), Des Plaines, IL (United States)


    This is an overview of "The Best Approach to Combustion Safety in a Direct Vent World," held June 28, 2012, in San Antonio, TX. The objective of this Expert Meeting was to identify gaps and barriers that need to be addressed by future research, and to develop data-driven technical recommendations for code updates so that a common approach for combustion safety can be adopted by all members of the building energy efficiency and code communities.

  11. Building America Expert Meeting: Combustion Safety

    Energy Technology Data Exchange (ETDEWEB)

    Brand, L.


    This is a meeting overview of 'The Best Approach to Combustion Safety in a Direct Vent World', held June 28, 2012, in San Antonio, Texas. The objective of this Expert Meeting was to identify gaps and barriers that need to be addressed by future research, and to develop data-driven technical recommendations for code updates so that a common approach for combustion safety can be adopted by all members of the building energy efficiency and code communities.

  12. Fluidized bed combustion: mixing and pollutant limitation

    Energy Technology Data Exchange (ETDEWEB)

    Leckner, B. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Energy Conversion


    Fluidized bed combustion (FBC) has been applied commercially during a few decades, and sufficient knowledge is gained to design boilers with sizes of up to several hundreds of megawatt thermal power (MW{sub th}). The knowledge of what goes on inside a large combustion chamber is still limited, however, and this impedes further optimization and efficient solution of problems that might occur. Despite this lack of knowledge the present survey deals with combustion chamber processes and discusses mixing and distribution of fuel and air in the combustion chamber and its importance for sulphur capture and reduction of emissions of nitrogen oxides. It is desirable to present the material in a general way and to cover the entire field of FBC. However, the scarce openly published information deals mostly with coal combustion in atmospheric circulating fluidized bed (CFB) combustors, and therefore this application will receive most attention, but reference is also made to pressurized combustion and to other fuels than coal. In this context the important work made in the LIEKKI project on the analysis of different fuels and on the influence of pressure should be especially pointed out. (orig.)

  13. Rapid Deployment of Rich Catalytic Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Richard S. Tuthill


    The overall objective of this research under the Turbines Program is the deployment of fuel flexible rich catalytic combustion technology into high-pressure ratio industrial gas turbines. The resulting combustion systems will provide fuel flexibility for gas turbines to burn coal derived synthesis gas or natural gas and achieve NO{sub x} emissions of 2 ppmvd or less (at 15 percent O{sub 2}), cost effectively. This advance will signify a major step towards environmentally friendly electric power generation and coal-based energy independence for the United States. Under Phase 1 of the Program, Pratt & Whitney (P&W) performed a system integration study of rich catalytic combustion in a small high-pressure ratio industrial gas turbine with a silo combustion system that is easily scalable to a larger multi-chamber gas turbine system. An implementation plan for this technology also was studied. The principal achievement of the Phase 1 effort was the sizing of the catalytic module in a manner which allowed a single reactor (rather than multiple reactors) to be used by the combustion system, a conclusion regarding the amount of air that should be allocated to the reaction zone to achieve low emissions, definition of a combustion staging strategy to achieve low emissions, and mechanical integration of a Ceramic Matrix Composite (CMC) combustor liner with the catalytic module.

  14. Combustion kinetics and reaction pathways

    Energy Technology Data Exchange (ETDEWEB)

    Klemm, R.B.; Sutherland, J.W. [Brookhaven National Laboratory, Upton, NY (United States)


    This project is focused on the fundamental chemistry of combustion. The overall objectives are to determine rate constants for elementary reactions and to elucidate the pathways of multichannel reactions. A multitechnique approach that features three independent experiments provides unique capabilities in performing reliable kinetic measurements over an exceptionally wide range in temperature, 300 to 2500 K. Recent kinetic work has focused on experimental studies and theoretical calculations of the methane dissociation system (CH{sub 4} + Ar {yields} CH{sub 3} + H + Ar and H + CH{sub 4} {yields} CH{sub 3} + H{sub 2}). Additionally, a discharge flow-photoionization mass spectrometer (DF-PIMS) experiment is used to determine branching fractions for multichannel reactions and to measure ionization thresholds of free radicals. Thus, these photoionization experiments generate data that are relevant to both reaction pathways studies (reaction dynamics) and fundamental thermochemical research. Two distinct advantages of performing PIMS with high intensity, tunable vacuum ultraviolet light at the National Synchrotron Light Source are high detection sensitivity and exceptional selectivity in monitoring radical species.

  15. Carburetor for internal combustion engines (United States)

    Csonka, John J.; Csonka, Albert B.


    A carburetor for internal combustion engines having a housing including a generally discoidal wall and a hub extending axially from the central portion thereof, an air valve having a relatively flat radially extending surface directed toward and concentric with said discoidal wall and with a central conoidal portion having its apex directed toward the interior of said hub portion. The housing wall and the radially extending surface of the valve define an air passage converging radially inwardly to form an annular valving construction and thence diverge into the interior of said hub. The hub includes an annular fuel passage terminating at its upper end in a circumferential series of micro-passages for directing liquid fuel uniformly distributed into said air passage substantially at said valving constriction at right angles to the direction of air flow. The air valve is adjustable axially toward and away from the discoidal wall of the carburetor housing to regulate the volume of air drawn into the engine with which said carburetor is associated. Fuel is delivered under pressure to the fuel metering valve and from there through said micro-passages and controlled cams simultaneously regulate the axial adjustment of said air valve and the rate of delivery of fuel through said micro-passages according to a predetermined ratio pattern. A third jointly controlled cam simultaneously regulates the ignition timing in accordance with various air and fuel supply settings. The air valve, fuel supply and ignition timing settings are all independent of the existing degree of engine vacuum.

  16. Analysis of Content of Selected Critical Elements in Fly Ash

    Directory of Open Access Journals (Sweden)

    Makowska Dorota


    Full Text Available Pursuant to the new mineral policy of the European Union, searching for new sources of raw materials is required. Coal fly ash has long been considered as a potential source of a number of critical elements. Therefore, it is important to monitor the contents of the critical elements in fly ash from coal combustion. The paper presents the results of examinations of the contents of selected elements, i.e. beryllium, cobalt, chromium and germanium in fly ash from Polish power plants. The results of the conducted investigations indicate that the examined ash samples from bituminous coal combustion cannot be treated as a potential source of the analysed critical elements. The content of these elements in ash, though slightly higher than their average content in the sedimentary rocks, is, however, not high enough to make their recovery technologically and economically justified at this moment.

  17. Insulating and sheathing materials of electric and optical cables: common test methods part 4-1: methods specific to polyethylene and polypropylene compounds – resistance to environmental stress cracking – measurement of the melt flow index – carbon black and/or mineral filler content measurement in polyethylene by direct combustion – measurement of carbon black content by thermogravimetric analysis (TGA) – assessment of carbon black dispersion in polyethylene using a microscope

    CERN Document Server

    International Electrotechnical Commission. Geneva


    Specifies the test methods to be used for testing polymeric insulating and sheathing materials of electric cables for power distribution and telecommunications including cables used on ships. Gives the methods for measurements of the resistance to environmental stress cracking, for wrapping test after thermal ageing in air, for measurement of melt flow index and for measurement of carbon black and/or mineral filler content, which apply to PE and PP coumpounds, including cellular compounds and foam skin for insulation.

  18. Experimental and numerical studies on two-stage combustion of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Houshfar, Eshan


    In this thesis, two-stage combustion of biomass was experimentally/numerically investigated in a multifuel reactor. The following emissions issues have been the main focus of the work: 1- NOx and N2O 2- Unburnt species (CO and CxHy) 3- Corrosion related emissions.The study had a focus on two-stage combustion in order to reduce pollutant emissions (primarily NOx emissions). It is well known that pollutant emissions are very dependent on the process conditions such as temperature, reactant concentrations and residence times. On the other hand, emissions are also dependent on the fuel properties (moisture content, volatiles, alkali content, etc.). A detailed study of the important parameters with suitable biomass fuels in order to optimize the various process conditions was performed. Different experimental studies were carried out on biomass fuels in order to study the effect of fuel properties and combustion parameters on pollutant emissions. Process conditions typical for biomass combustion processes were studied. Advanced experimental equipment was used in these studies. The experiments showed the effects of staged air combustion, compared to non-staged combustion, on the emission levels clearly. A NOx reduction of up to 85% was reached with staged air combustion using demolition wood as fuel. An optimum primary excess air ratio of 0.8-0.95 was found as a minimizing parameter for the NOx emissions for staged air combustion. Air staging had, however, a negative effect on N2O emissions. Even though the trends showed a very small reduction in the NOx level as temperature increased for non-staged combustion, the effect of temperature was not significant for NOx and CxHy, neither in staged air combustion or non-staged combustion, while it had a great influence on the N2O and CO emissions, with decreasing levels with increasing temperature. Furthermore, flue gas recirculation (FGR) was used in combination with staged combustion to obtain an enhanced NOx reduction. The

  19. Real time identification of the internal combustion engine combustion parameters based on the vibration velocity signal (United States)

    Zhao, Xiuliang; Cheng, Yong; Wang, Limei; Ji, Shaobo


    Accurate combustion parameters are the foundations of effective closed-loop control of engine combustion process. Some combustion parameters, including the start of combustion, the location of peak pressure, the maximum pressure rise rate and its location, can be identified from the engine block vibration signals. These signals often include non-combustion related contributions, which limit the prompt acquisition of the combustion parameters computationally. The main component in these non-combustion related contributions is considered to be caused by the reciprocating inertia force excitation (RIFE) of engine crank train. A mathematical model is established to describe the response of the RIFE. The parameters of the model are recognized with a pattern recognition algorithm, and the response of the RIFE is predicted and then the related contributions are removed from the measured vibration velocity signals. The combustion parameters are extracted from the feature points of the renovated vibration velocity signals. There are angle deviations between the feature points in the vibration velocity signals and those in the cylinder pressure signals. For the start of combustion, a system bias is adopted to correct the deviation and the error bound of the predicted parameters is within 1.1°. To predict the location of the maximum pressure rise rate and the location of the peak pressure, algorithms based on the proportion of high frequency components in the vibration velocity signals are introduced. Tests results show that the two parameters are able to be predicted within 0.7° and 0.8° error bound respectively. The increase from the knee point preceding the peak value point to the peak value in the vibration velocity signals is used to predict the value of the maximum pressure rise rate. Finally, a monitoring frame work is inferred to realize the combustion parameters prediction. Satisfactory prediction for combustion parameters in successive cycles is achieved, which

  20. Physicochemical characterisation of combustion particles from vehicle exhaust and residential wood smoke

    Directory of Open Access Journals (Sweden)

    Schwarze Per E


    Full Text Available Abstract Background Exposure to ambient particulate matter has been associated with a number of adverse health effects. Particle characteristics such as size, surface area and chemistry seem to influence the negative effects of particles. In this study, combustion particles from vehicle exhaust and wood smoke, currently used in biological experiments, were analysed with respect to microstructure and chemistry. Methods Vehicle exhaust particles were collected in a road tunnel during two seasons, with and without use of studded tires, whereas wood smoke was collected from a stove with single-stage combustion. Additionally, a reference diesel sample (SRM 2975 was analysed. The samples were characterised using transmission electron microscopy techniques (TEM/HRTEM, EELS and SAED. Furthermore, the elemental and organic carbon fractions were quantified using thermal optical transmission analysis and the content of selected PAHs was determined by gas chromatography-mass spectrometry. Results Carbon aggregates, consisting of tens to thousands of spherical primary particles, were the only combustion particles identified in all samples using TEM. The tunnel samples also contained mineral particles originating from road abrasion. The geometric diameters of primary carbon particles from vehicle exhaust were found to be significantly smaller (24 ± 6 nm than for wood smoke (31 ± 7 nm. Furthermore, HRTEM showed that primary particles from both sources exhibited a turbostratic microstructure, consisting of concentric carbon layers surrounding several nuclei in vehicle exhaust or a single nucleus in wood smoke. However, no differences were detected in the graphitic character of primary particles from the two sources using SAED and EELS. The total PAH content was higher for combustion particles from wood smoke as compared to vehicle exhaust, whereas no source difference was found for the ratio of organic to total carbon. Conclusion Combustion particles from