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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)

    1998-09-01

    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)

    1997-12-31

    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. The Asphaltenes

    Science.gov (United States)

    Mullins, Oliver C.

    2011-07-01

    Asphaltenes, the most aromatic of the heaviest components of crude oil, are critical to all aspects of petroleum utilization, including reservoir characterization, production, transportation, refining, upgrading, paving, and coating materials. The asphaltenes, which are solid, have or impart crucial and often deleterious attributes in fluids such as high viscosity, emulsion stability, low distillate yields, and inopportune phase separation. Nevertheless, fundamental uncertainties had precluded a first-principles approach to asphaltenes until now. Recently, asphaltene science has undergone a renaissance; many basic molecular and nanocolloidal properties have been resolved and codified in the modified Yen model (also known as the Yen-Mullins model), thereby enabling predictive asphaltene science. Advances in analytical chemistry, especially mass spectrometry, enable the identification of tens of thousands of distinct chemical species in crude oils and asphaltenes. These and other powerful advances in asphaltene science fall under the banner of petroleomics, which incorporates predictive petroleum science and provides a framework for future developments.

  4. Electrodeposition of Asphaltenes. 2. Effect of Resins and Additives

    DEFF Research Database (Denmark)

    Khvostichenko, Daria S; Andersen, Simon Ivar

    2010-01-01

    Electrodeposition of asphaltenes from oil/heptane, asphaltene/heptane, and asphaltene/heptane/additive mixtures has been investigated. Toluene, native petroleum resins, and a synthetic asphaltene dispersant, p-nonylphenol, were used as additives. The addition of these components led to partial...... preparation of the mixture and the toluene content. Introduction of petroleum resins into asphaltene/heptane mixtures resulted in neutralization of the asphaltene particle charge. The addition of p-nonylphenol to asphaltene suspensions in heptane did not alter the charge of asphaltene particles. Current...

  5. 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.

    2006-11-01

    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

  6. Athabasca asphaltene structures

    Energy Technology Data Exchange (ETDEWEB)

    Dettman, H.; Salmon, S.; Zinz, D. [National Centre for Upgrading Technology, Devon, AB (Canada)

    2009-07-01

    In order to model petroleum behaviour during production and refining processes, it is important to understand the molecular character of oil components. Gas chromatography can be used to separate components with boiling points less than 524 degrees C. However, since asphaltenes have a higher boiling point, gel permeation chromatography (GPC) must be used to separate species before analysis. Analysis of Athabasca asphaltene GPC fractions has shown that asphaltenes consist of 2 types of species, notably crunchy species that are graphitic in appearance, and oily species. The molecular weights range from 400 to 2000 g/mole as measured by low resolution mass spectrometry. This poster described the ongoing effort to separate the asphaltenes by polarity. Athabasca asphaltenes were subfractioned into 4 parts according to differential solubility in pentane and centrifugation. Acidic species were isolated from the asphaltenes using adsorption chromatography. The 4 polarity fractions and acid species have been characterized with particular reference to elemental and metals content. Analyses were performed by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) carbon type analyses. This poster provided comparisons of their elution profiles by GPC. tabs., figs.

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

    DEFF Research Database (Denmark)

    Andersen, Simon Ivar

    1997-01-01

    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...... extracted in the high polarity solvents....

  8. Asphaltene Aggregation and Fouling Behavior

    Science.gov (United States)

    Derakhshesh, Marzie

    This thesis explored the properties of asphaltene nano-aggregates in crude oil and toluene based solutions and fouling at process furnace temperatures, and the links between these two phenomena. The link between stability of asphaltenes at ambient conditions and fouling at the conditions of a delayed coker furnace, at over 450 °C, was examined by blending crude oil with an aliphatic diluent in different ratios. The stability of the blends were measured using a S-value analyzer, then fouling rates were measured on electrically heated stainless steel 316 wires in an autoclave reactor. The less stable the blend, the greater the rate and extent of fouling. The most severe fouling occurred with the unstable asphaltenes. SEM imaging of the foulant illustrates very different textures, with the structure becoming more porous with lower stability. Under cross-polarized light, the coke shows the presence of mesophase in the foulant layer. These data suggest a correlation between the fouling rate at high temperature furnace conditions and the stability index of the crude oil. Three organic polysulfides were introduced to the crude oil to examine their effect on fouling. The polysulfides are able to reduce coking and carbon monoxide generation in steam crackers. The fouling results demonstrated that polysulfide with more sulfur content increased the amount of corrosion-fouling of the wire. Various additives, solvents, ultrasound, and heat were employed to attempt to completely disaggregate the asphaltene nano-aggregates in solution at room temperature. The primary analytical technique used to monitor the nano-aggregation state of the asphaltenes in solution was the UV-visible spectroscopy. The results indicate that stronger solvents, such as pyridine and quinoline, combined with ionic liquids yield a slight reduction in the apparent absorbance at longer wavelengths, indicative of a decrease in the nano-aggregate size although the magnitude of the decrease is not significant

  9. Interfacial behavior of asphaltenes.

    Science.gov (United States)

    Langevin, Dominique; Argillier, Jean-François

    2016-07-01

    We review the existing literature on asphaltenes at various types of interfaces: oil-water, air-water, gas-oil and solid-liquid, with more emphasis on the oil-water interfaces. We address the role of asphaltene aggregation, recently clarified for asphaltenes in bulk by the Yen-Mullins model. We discuss the questions of adsorption reversibility and interfacial rheology, especially in connection with emulsion stability. PMID:26498501

  10. Non-isothermal kinetics of styrene—butadiene—styrene asphalt combustion

    International Nuclear Information System (INIS)

    The combustion characteristics of styrene—butadiene—styrene (SBS) asphalt are studied by thermogravimetric analysis (TG/DTG) at four different heating rates. According to the saturates/aromatics/resins/asphaltenes (SARA) fractionation method, the combustion process of SBS asphalt can be divided by Gaussian peak fitting into three main stages: oil content release, resin pyrolysis, and asphaltene and char combustion. When the heating rate increases, the mass losses of the oil content and resin pyrolysis increase, and less asphaltenes are formed at a higher temperature. The activation energy values are calculated by the Coats—Redfern method to be in the range 61.6 kJ/mol–142.9 kJ/mol. The Popescu method is used for the kinetic analysis, and the result shows that the three stages of asphalt combustion can be explained by the sphere phase boundary reaction model, the second order chemical reaction model, nucleation, and its subsequent growth model, respectively

  11. The fractal aggregation of asphaltenes.

    Science.gov (United States)

    Hoepfner, Michael P; Fávero, Cláudio Vilas Bôas; Haji-Akbari, Nasim; Fogler, H Scott

    2013-07-16

    This paper discusses time-resolved small-angle neutron scattering results that were used to investigate asphaltene structure and stability with and without a precipitant added in both crude oil and model oil. A novel approach was used to isolate the scattering from asphaltenes that are insoluble and in the process of aggregating from those that are soluble. It was found that both soluble and insoluble asphaltenes form fractal clusters in crude oil and the fractal dimension of the insoluble asphaltene clusters is higher than that of the soluble clusters. Adding heptane also increases the size of soluble asphaltene clusters without modifying the fractal dimension. Understanding the process of insoluble asphaltenes forming fractals with higher fractal dimensions will potentially reveal the microscopic asphaltene destabilization mechanism (i.e., how a precipitant modifies asphaltene-asphaltene interactions). It was concluded that because of the polydisperse nature of asphaltenes, no well-defined asphaltene phase stability envelope exists and small amounts of asphaltenes precipitated even at dilute precipitant concentrations. Asphaltenes that are stable in a crude oil-precipitant mixture are dispersed on the nanometer length scale. An asphaltene precipitation mechanism is proposed that is consistent with the experimental findings. Additionally, it was found that the heptane-insoluble asphaltene fraction is the dominant source of small-angle scattering in crude oil and the previously unobtainable asphaltene solubility at low heptane concentrations was measured. PMID:23808932

  12. Raman spectrum of asphaltene

    KAUST Repository

    Abdallah, Wael A.

    2012-11-05

    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.

  13. Polymeric stabilization of colloidal asphaltenes

    Science.gov (United States)

    Hashmi, Sara; Firoozabadi, Abbas

    2010-03-01

    Asphaltenes, the heaviest component of crude oil, cause many problems in petroleum extraction and recovery. Operationally defined as insoluble in long chain alkanes but soluble in toluene, asphaltenes have been described by bulk thermodynamic models such as the Flory-Huggins theory. However, bulk models work well only for asphaltenes in good solvents. Characterization of asphaltenes in poor solvents remains elusive: molecular scale asphaltenes readily aggregate to the colloidal scale and become highly unstable in solution. We investigate the ability of polymers to stabilize colloidal asphaltene suspensions in heptane. In the absence of added polymer, sedimentation measurements reveal dynamics reminiscent of collapsing gels. Adding polymers to colloidal asphaltene suspensions can delay the characteristic sedimentation time by orders of magnitude. Light scattering results suggest that the mechanism of stabilization may be related to a decrease in both particle size and polydispersity as a function of added polymer.

  14. Syngas obtainment from the gasification of asphaltenes of the San Fernando crude oil

    International Nuclear Information System (INIS)

    In this work, we developed the first study in Colombia to obtain and evaluate syngas compositions derived from asphaltenes gasification. These asphaltenes came from the implementation of a Deasphalting process to San Fernando crude oil, with the purpose of looking for technological options for their utilization. We performed the design, installation and commissioning of facilities for the gasification of asphaltenes at laboratory scale, it following an experimental methodology, performing nine tests and considering temperature and agent gasification quantity (oxygen) as independent variables. The syngas derived from gasification was analyzed by two chromatographic techniques, which reported the presence of refinery gases and sulfur. We evidenced a growth tendency of CO, H2 and sulfur composition and a decrease in CH4 and CO2 composition with temperature. The composition of the syngas was evaluated with different quantities of gasification agent (33%, 40% and 47% the amount of oxygen theoretically required for complete combustion) at each temperature levels operated. It was established that when using a 40% of gasification agent, you get greater average content of CO and H2, which are the interest gases in the gasification process.

  15. Structural Study of Asphaltenes from Iranian Heavy Crude Oil

    Directory of Open Access Journals (Sweden)

    Davarpanah L.

    2015-11-01

    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

  16. Oxy-combustion of high water content fuels

    Science.gov (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. Investigation of Asphaltene Precipitation at Elevated Temperature

    DEFF Research Database (Denmark)

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

    1998-01-01

    appropriate temperature and the pressure in closed vessels keeping the mixture at the liquid state. The filtration is performed with a small differential pressure over the filter so as to avoid flashing the mixture. The technique requires a low dead volume in the system to minimize the content of maltenes 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 and the asphaltenes separating upon cooling was collected and analyzed. The oil and selected maltene fractions and extraction/cleaning solvents were analyzed using GC....

  18. COMPARISON BETWEEN ASPHALTENES (SUBFRACTIONS EXTRACTED FROM TWO DIFFERENT ASPHALTIC RESIDUES: CHEMICAL CHARACTERIZATION AND PHASE BEHAVIOR

    Directory of Open Access Journals (Sweden)

    Silas R. Ferreira

    2016-01-01

    Full Text Available Asphaltenes are blamed for various problems in the petroleum industry, especially formation of solid deposits and stabilization of water-in-oil emulsions. Many studies have been conducted to characterize chemical structures of asphaltenes and assess their phase behavior in crude oil or in model-systems of asphaltenes extracted from oil or asphaltic residues from refineries. However, due to the diversity and complexity of these structures, there is still much to be investigated. In this study, asphaltene (subfractions were extracted from an asphaltic residue (AR02, characterized by NMR, elemental analysis, X-ray fluorescence and MS-TOF, and compared to asphaltene subfractions obtained from another asphaltic residue (AR01 described in a previous article. The (subfractions obtained from the two residues were used to prepare model-systems containing 1 wt% of asphaltenes in toluene and their phase behavior was evaluated by measuring asphaltene precipitation onset using optical microscopy. The results obtained indicated minor differences between the asphaltene fractions obtained from the asphaltic residues of distinct origins, with respect to aromaticity, elemental composition (CHN, presence and content of heteroelements and average molar mass. Regarding stability, minor differences in molecule polarity appear to promote major differences in the phase behavior of each of the asphaltene fractions isolated.

  19. Asphaltene based photovoltaic devices

    Science.gov (United States)

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

    2016-03-22

    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.

  20. Effect of ash content on the combustion process of simulated MSW in the fixed bed.

    Science.gov (United States)

    Sun, Rui; Ismail, Tamer M; Ren, Xiaohan; Abd El-Salam, M

    2016-02-01

    This paper experimentally and numerically investigates the effects of ash content on the combustion process of simulated Municipal Solid Waste (MSW). A fixed-bed experimental reactor was utilized to reveal the combustion characteristics. Temperature distributions, ignition front velocity, and the characteristics of gas species' release were measured and simulated during the combustion process. In the present work, the two-dimensional unsteady mathematical heterogeneous model was developed to simulate the combustion process in the bed, including the process rate model as well as NOx production model. The simulation results in the bed are accordant with the experimental results. The results show that as ash content increases, the lower burning rate of fuel results in char particles leaving the grate without being fully burned, causing a loss of combustible material in the MSW in a fixed bed and therefore reducing the combustion efficiency and increasing the burning time of the MSW. PMID:26476592

  1. 40 CFR 60.4360 - How do I determine the total sulfur content of the turbine's combustion fuel?

    Science.gov (United States)

    2010-07-01

    ... content of the turbine's combustion fuel? 60.4360 Section 60.4360 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4360 How do I determine the total sulfur content of the turbine's combustion fuel? You must monitor the total sulfur content of...

  2. Analysis of metals in asphaltenes of KU-46 by PIXE analysis

    International Nuclear Information System (INIS)

    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)

  3. Non-combustible nuclear radiation shields with high hydrogen content

    International Nuclear Information System (INIS)

    The invention relates to compositions, methods of production, and uses of non-combustible nuclear radiation shields, with particular emphasis on those containing a high concentration of hydrogen atoms, especially effective for moderating neutron energy by elastic scatter, dispersed as a discontinuous phase in a continuous phase of a fire resistant matrix

  4. Experimental study on the influence of oxygen content in the combustion air on the combustion characteristics

    International Nuclear Information System (INIS)

    This study was focused on the experimental investigation of the very promising combustion technology called as the oxygen-enhanced combustion (OEC), which uses the oxidant containing higher proportion of oxygen than in the atmospheric air, i.e. more than 21%. The work investigated and compared the characteristics of two OEC methods, namely the premix enrichment and air-oxy/fuel combustion, when the overall oxygen concentration was varied from 21% to 46%. The combustion tests were performed with the experimental two-gas-staged burner of low-NOx type at the burner thermal input of 750 kW for two combustion regimes – one-staged and two-staged combustion. The oxygen concentration in the flue gas was maintained in the neighborhood of 3% vol. (on dry basis). The aim of tests was to assess the impact of the oxidant composition, type of OEC method and fuel-staging on the characteristic combustion parameters in detail. The investigated parameters included the concentration of nitrogen oxides (NOx) in the flue gas, flue gas temperature, heat flux to the combustion chamber wall, and lastly the stability, shape and dimensions of flame. It was observed that NOx emission is significantly lower when the air-oxy/fuel method is used compared to the premix enrichment method. Moreover, when the fuel was staged, NOx emission was below 120 mg/Nm3 at all investigated oxygen flow rates. Increasing oxygen concentration resulted in higher heating intensity due to higher concentrations of CO2 and H2O. The available heat at 46% O2 was higher by 20% compared with that at 21% O2. - Highlights: • Premix-enrichment and air-oxy/fuel combustion methods were experimentally studied. • NOx increased sharply as oxygen concentration increased during PE tests. • NOx was below 120 mg/Nm3 for all investigated oxygen flow rates in AO tests. • Radiative heat transfer was enhanced ca. 20% as O2 concentration was increased. • OEC flames were observed stable, more luminous and longer than air

  5. A study of asphaltene solubility and precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Hong E.; Paul Watkinson [University of British Columbia, Vancouver, BC (Canada). Department of Chemical and Biological Engineering

    2004-10-01

    The effects of diluent composition on asphaltene precipitation from Cold Lake vacuum residue and Athabasca atmospheric tower bottoms were determined using the hot filtration method at 60-85{sup o}C. For selected mixtures the temperature range was extended to 300{sup o}C. The diluents include pure n-alkanes, a lube oil base-stock, a heavy vacuum gas oil and a resin-enriched fraction recovered from Cold Lake vacuum residue by supercritical fluid extraction and fractionation. The latter three complex diluents were tested alone and in blends, in order to cover a range of saturates from 56 to 99.4 wt%, aromatics from 0.6 to 25 wt%, and resins from 0 to 19 wt%. The scaling equation proposed by Rassamdana et al. in which the weight percent of asphaltenes precipitated is expressed as a function of alkane to feed ratio, and the alkane molecular mass, gave good agreement with the data for the pure alkane diluents. For the more complex diluents, an extension to the scaling equation was developed with two additional variables (the density and saturate content of the diluents). This equation provided good agreement with the data over a wide range of diluent to feed ratios. By the addition of the colloidal instability index of the feed oil into the variables of the scaling equation, the precipitation data from the two different feed oils could be correlated. 13 refs., 8 figs., 3 tabs.

  6. Distribution of metals in vacuum residuums, asphaltenes and maltenes by PIXE

    International Nuclear Information System (INIS)

    The PIXE technique for determining directly the distribution and abundance of trace metals in vacuum residuum, asphaltenes and maltenes separated with n-alkanes (C5-C8) is used. The metal content of petroleum derivatives revealed that the vacuum residuum contains iron, aluminium, vanadium and nickel mainly, while that the asphaltenes and maltenes maintain inside of their composition only preferably the vanadium and nickel as majority elements. (Author)

  7. Effect of H2 and CO contents in syngas during combustion using Micro Gas Turbine

    Science.gov (United States)

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

    2016-03-01

    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.

  8. Heavy Oil Process Monitor: Automated On-Column Asphaltene Precipitation and Re-Dissolution

    Energy Technology Data Exchange (ETDEWEB)

    John F. Schabron; Joseph F. Rovani; Mark Sanderson

    2007-03-31

    An automated separation technique was developed that provides a new approach to measuring the distribution profiles of the most polar, or asphaltenic components of an oil, using a continuous flow system to precipitate and re-dissolve asphaltenes from the oil. Methods of analysis based on this new technique were explored. One method based on the new technique involves precipitation of a portion of residua sample in heptane on a polytetrafluoroethylene-packed (PTFE) column. The precipitated material is re-dissolved in three steps using solvents of increasing polarity: cyclohexane, toluene, and methylene chloride. The amount of asphaltenes that dissolve in cyclohexane is a useful diagnostic of the thermal history of oil, and its proximity to coke formation. For example, about 40 % (w/w) of the heptane asphaltenes from unpyrolyzed residua dissolves in cyclohexane. As pyrolysis progresses, this number decrease to below 15% as coke and toluene insoluble pre-coke materials appear. Currently, the procedure for the isolation of heptane asphaltenes and the determination of the amount of asphaltenes soluble in cyclohexane spans three days. The automated procedure takes one hour. Another method uses a single solvent, methylene chloride, to re-dissolve the material that precipitates on heptane on the PTFE-packed column. The area of this second peak can be used to calculate a value which correlates with gravimetric asphaltene content. Currently the gravimetric procedure to determine asphaltenes takes about 24 hours. The automated procedure takes 30 minutes. Results for four series of original and pyrolyzed residua were compared with data from the gravimetric methods. Methods based on the new on-column precipitation and re-dissolution technique provide significantly more detail about the polar constituent's oils than the gravimetric determination of asphaltenes.

  9. The effect of lime addition on the combustion properties and sulfur contents of three different coals

    Energy Technology Data Exchange (ETDEWEB)

    Ozbas, K.E.; Hicyilmaz, C.; Kok, M.V. [Middle East Technical University, Ankara (Turkey)

    2002-07-01

    In this research, combustion characterization of 3 different coals of Turkey, from the Soma, Tuncbilek, and Afsin Elbistan regions, were investigated with thermal analysis techniques such as differential scanning calorimetry (DSC) and thermogravimetry (TG/DTG). Lime was added to these coals in concentrations of 3, 7, and 10% by weight to investigate the change in combustible sulfur content and sulfur in ash. It was observed that lime has a positive effect on sulfur emission. Kinetic analysis was also performed to see the effect of lime addition on combustion properties and reaction parameters of the coal samples studied.

  10. Modelling asphaltene precipitation equilibrium : influence of the experimental contact time and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Dufour, J.; Marugan, J.; Calles, J.A.; Gimenez-Aguirre, R. [Rey Juan Carlos Univ., Madrid (Spain). Dept. of Chemical and Environmental Technology, Repsol-YPF Flow Assurance Laboratory; Pena, J.L. [Rey Juan Carlos Univ., Madrid (Spain). Dept. of Chemical and Environmental Technology, Repsol-YPF Flow Assurance Laboratory; Centro Tecnologico Repsol-YPF, Madrid (Spain); Merino-Garcia, D. [Centro Tecnologico Repsol-YPF, Madrid (Spain)

    2008-07-01

    Asphaltene deposition creates flow assurance problems and economic losses for petroleum companies. Predictive models are therefore needed to prevent these problems. Most models found in the literature are based on equilibrium calculations and must be checked against experimental data of both onset and amount of asphaltenes separated. However, the samples must be equilibrated for a long time since the kinetics of asphaltene aggregation and precipitation are slow. This paper discussed the kinetics of asphaltene precipitation, based on results obtained from a problematic South American crude and its residue. The influence of temperature, chain length of the n-alkane solvent and n-alkane/oil mass ratio was evaluated. The solids were characterized by 1H NMR, elemental analysis and Fourier transform infrared (FTIR) spectroscopy to determine their chemical structure. Metal contents (mainly Fe, V and Ni) have been measured by atomic emission spectroscopy. The true equilibrium data will be used to validate equilibrium models from the literature.

  11. Asphaltenes and Asphaltene model compounds: Adsorption, Desorption and Interfacial Rheology.

    OpenAIRE

    Pradilla, Diego

    2016-01-01

    There are numerous problems encountered during extraction, production, transportation and refining of crude oil. Most of these problems are typically oil-specific, meaning that they depend upon the source of the oil, and sometimes they are reservoir-specific, meaning that they depend on the stage of extraction (primary, secondary or enhanced recovery). Nevertheless, a great part of the problems are related to the indigenous surface-active species such as asphaltenes, naphthenat...

  12. Characterization of the onset asphaltenes by focused-beam laser reflectance : a tool for chemical additives screening

    Energy Technology Data Exchange (ETDEWEB)

    Marugan, J.; Calles, J.A.; Dufour, J.; Gimenez-Aguirre, R. [Univ. Rey Juan Carlos, Madrid (Spain). URJC-Repsol-YPF Flow Assurance Laboratory, Dept. of Chemical and Environmental Technology; Pena, J.L. [Univ. Rey Juan Carlos, Madrid (Spain). URJC-Repsol-YPF Flow Assurance Laboratory, Dept. of Chemical and Environmental Technology; Centro Tecnologico Repsol-YPF, Madrid (Spain); Merino-Garcia, D. [Centro Tecnologico Repsol-YPF, Madrid (Spain)

    2008-07-01

    The deposition of asphaltenes in crude oil can cause flow assurance problems. In this study, a laser reflectance technique known as Focused-Beam Reflectance Measurement (FBRM) was used to study the kinetics of asphaltenes aggregation near onset. The FBRM tool provides a very sensitive way of determining the onset n-alkane/oil mass ratio. The influence of the n-alkane solvent and temperature on the solvent/oil threshold ratio of 2 South American crude oils with 21 and 27 API were investigated. The FBRM technique provided kinetic information about the evolution with time of the size distribution of asphaltenes flocs. Additional FBRM experiments of asphaltene redissolution and reprecipitation were also performed for a comparative evaluation, beginning with the solids recovered following the IP- 143 standard, which were fractionated into 4 different polarity groups using n-pentane - chloroform mixtures. The objective was to find correlations between polarity of the asphaltenes and its instability near the onset. Metal content was determined through atomic emission spectroscopy. The solids were characterized by 1H NMR, FT-IR spectroscopy, and vapour-pressure osmometry in order to determine the chemical and structural features of the most unstable asphaltenes. The FBRM probe was used to screen commercial chemical additives to prevent asphaltenes deposits. This technique was shown to be a very powerful tool for examining the influence of additives on the aggregation kinetics and the particle size distribution of the first asphaltene solids.

  13. Combustion

    CERN Document Server

    Glassman, Irvin

    1987-01-01

    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

  14. Combustion studies of high moisture content waste in a fluidised bed.

    Science.gov (United States)

    Suksankraisorn, K; Patumsawad, S; Fungtammasan, B

    2003-01-01

    The combustion of three high moisture content waste materials in a fluidised bed combustor has been investigated and a comparison with co-firing of these materials with coal in the same combustor has been made. Waste materials burnt were olive oil waste, municipal solid waste and potato, which is representative of vegetable waste. Mixtures of up to 20% mass concentration water in the waste were fed to the combustor. Above that value the moisture content was too high to sustain combustion without addition of coal. Measurements of CO, NOx, SO2 temperatures were made and the carbon combustion efficiency evaluated. Co-firing with coal resulted in markedly higher combustion efficiencies with an increase of approximately 10-80% when burning the simulated MSW. However, this was much lower than the value of 93% when coal was burnt on its own. It was also much lower than the value obtained, average 90%, when co-firing potato and olive oil waste with coal and there was little difference in the combustion efficiency between the two types of waste and with increasing moisture content. It was concluded that the high ash content of the simulated MSW 26%, compared with 5% in the other two waste materials resulted in slower burning and consequently the char particles were elutriated from the bed without being fully burnt. In term of gaseous emissions during co-combustion, CO emission is relatively insensitive to change in waste fraction. While emission of SO2 can be reduced as the waste fraction increases as a result of fuel-S dilution. But in terms of percent fuel-S converted, it is actually increased by increasing waste fraction. Emissions of NO and N2O increase slightly with MSW fraction. PMID:12893016

  15. Variability of total and mobile element contents in ash derived from biomass combustion

    Czech Academy of Sciences Publication Activity Database

    Száková, J.; Ochecová, P.; Hanzlíček, Tomáš; Perná, Ivana; Tlustoš, P.

    2013-01-01

    Roč. 67, č. 11 (2013), s. 1376-1385. ISSN 0366-6352 R&D Projects: GA MZe QI102A207 Institutional support: RVO:67985891 Keywords : biomass combustion * fly ash * bottom ash * element contents Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.193, year: 2013

  16. Molecular thermodynamics for prevention of asphaltene precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jianzhong; Prausnitz, J.M.

    1996-06-01

    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.

  17. Behavior of asphaltene model compounds at w/o interfaces.

    Science.gov (United States)

    Nordgård, Erland L; Sørland, Geir; Sjöblom, Johan

    2010-02-16

    Asphaltenes, present in significant amounts in heavy crude oil, contains subfractions capable of stabilizing water-in-oil emulsions. Still, the composition of these subfractions is not known in detail, and the actual mechanism behind emulsion stability is dependent on perceived interfacial concentrations and compositions. This study aims at utilizing polyaromatic surfactants which contains an acidic moiety as model compounds for the surface-active subfraction of asphaltenes. A modified pulse-field gradient (PFG) NMR method has been used to study droplet sizes and stability of emulsions prepared with asphaltene model compounds. The method has been compared to the standard microscopy droplet counting method. Arithmetic and volumetric mean droplet sizes as a function of surfactant concentration and water content clearly showed that the interfacial area was dependent on the available surfactant at the emulsion interface. Adsorption of the model compounds onto hydrophilic silica has been investigated by UV depletion, and minor differences in the chemical structure of the model compounds caused significant differences in the affinity toward this highly polar surface. The cross-sectional areas obtained have been compared to areas from the surface-to-volume ratio found by NMR and gave similar results for one of the two model compounds. The mean molecular area for this compound suggested a tilted geometry of the aromatic core with respect to the interface, which has also been proposed for real asphaltenic samples. The film behavior was further investigated using a liquid-liquid Langmuir trough supporting the ability to form stable interfacial films. This study supports that acidic, or strong hydrogen-bonding fractions, can promote stable water-in-oil emulsion. The use of model compounds opens up for studying emulsion behavior and demulsifier efficiency based on true interfacial concentrations rather than perceived interfaces. PMID:19852481

  18. Quantification of asphaltene precipitation by scaling equation

    Science.gov (United States)

    Janier, Josefina Barnachea; Jalil, Mohamad Afzal B. Abd.; Samin, Mohamad Izhar B. Mohd; Karim, Samsul Ariffin B. A.

    2015-02-01

    Asphaltene precipitation from crude oil is one of the issues for the oil industry. The deposition of asphaltene occurs during production, transportation and separating process. The injection of carbon dioxide (CO2) during enhance oil recovery (EOR) is believed to contribute much to the precipitation of asphaltene. Precipitation can be affected by the changes in temperature and pressure on the crude oil however, reduction in pressure contribute much to the instability of asphaltene as compared to temperature. This paper discussed the quantification of precipitated asphaltene in crude oil at different high pressures and at constant temperature. The derived scaling equation was based on the reservoir condition with variation in the amount of carbon dioxide (CO2) mixed with Dulang a light crude oil sample used in the experiment towards the stability of asphaltene. A FluidEval PVT cell with Solid Detection System (SDS) was the instrument used to gain experimental knowledge on the behavior of fluid at reservoir conditions. Two conditions were followed in the conduct of the experiment. Firstly, a 45cc light crude oil was mixed with 18cc (40%) of CO2 and secondly, the same amount of crude oil sample was mixed with 27cc (60%) of CO2. Results showed that for a 45cc crude oil sample combined with 18cc (40%) of CO2 gas indicated a saturation pressure of 1498.37psi and asphaltene onset point was 1620psi. Then for the same amount of crude oil combined with 27cc (60%) of CO2, the saturation pressure was 2046.502psi and asphaltene onset point was 2230psi. The derivation of the scaling equation considered reservoir temperature, pressure, bubble point pressure, mole percent of the precipitant the injected gas CO2, and the gas molecular weight. The scaled equation resulted to a third order polynomial that can be used to quantify the amount of asphaltene in crude oil.

  19. 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: elucas@ima.ufrj.br [Centro de Pesquisas da PETROBRAS (CENPES), Rio de Janeiro, RJ (Brazil)

    2012-07-01

    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)

  20. Combustive approach for measuring total volatile phosphorus content in landfill gas

    OpenAIRE

    Roels, Joris; Vanhaecke, Frank; Verstraete, Willy

    2005-01-01

    A technique was developed to measure the total gaseous phosphorus content in biogas. The amount of air needed for a neutral to oxidising flame was mixed with the biogas. The gas mixture was burnt in a closed quartz burner and the combustion gasses were bubbled through a nitric acid solution. The phosphate content in the bubbling liquid was determined with sector field ICP-MS. The technique was validated in the lab with phosphine. Afterwards the set-up was installed on a landfill. The total ga...

  1. Determination of the molecular weight of asphaltenes

    International Nuclear Information System (INIS)

    Average molecular weights of asphaltenes from Colombian Barrancabermeja asphalts were determined using freezing point depression and MALDI TOF methods. Asphaltenes from different sources were used: fresh Barrancabermeja asphalt and recovered asphalt of the same origin that had been used as paving during five years. The results obtained using both techniques ate consistent and show that average molecular weight of asphaltenes from fresh asphalt is lower than the weight of asphaltenes from recovered asphalts. The freezing point depression method using benzene as solvent proved to be reliable and accurate when the temperature changes are measured with an uncertainty of +/- 0.00 1 K. The matrix preparation for the MALDI TOF method was modified using silver trifluoroacetate as ionisation promoter

  2. Asphaltenes-based polymer nano-composites

    Science.gov (United States)

    Bowen, III, Daniel E

    2013-12-17

    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.

  3. Rheology of asphaltene-toluene/water interfaces.

    Science.gov (United States)

    Sztukowski, Danuta M; Yarranton, Harvey W

    2005-12-01

    The stability of water-in-crude oil emulsions is frequently attributed to a rigid asphaltene film at the water/oil interface. The rheological properties of these films and their relationship to emulsion stability are ill defined. In this study, the interfacial tension, elastic modulus, and viscous modulus were measured using a drop shape analyzer for model oils consisting of asphaltenes dissolved in toluene for concentrations varying from 0.002 to 20 kg/m(3). The effects of oscillation frequency, asphaltene concentration, and interface aging time were examined. The films exhibited viscoelastic behavior. The total modulus increased as the interface aged at all asphaltene concentrations. An attempt was made to model the rheology for the full range of asphaltene concentration. The instantaneous elasticity was modeled with a surface equation of state (SEOS), and the elastic and viscous moduli, with the Lucassen-van den Tempel (LVDT) model. It was found that only the early-time data could be modeled using the SEOS-LVDT approach; that is, the instantaneous, elastic, and viscous moduli of interfaces aged for at most 10 minutes. At longer interface aging times, the SEOS-LVDT approach was invalid, likely because of irreversible adsorption of asphaltenes on the interface and the formation of a network structure. PMID:16316096

  4. Determination of trace elements in GPC fractions of oil-sand asphaltenes by INAA

    International Nuclear Information System (INIS)

    Asphaltene samples precipitated from Athabasca and Cold Lake oil-sand bitumens were separated into 12 fractions of varying molecular weight by preparative gel permeation chromatography (GPC). Each fraction was then analyzed by analytical GPC and visible spectrometry. Concentrations of As, Ce, Co, Cr, Eu, Ga, Hf, Hg, La, Ni, Sb, Sc, Se, Sm, Tb, Th, U, V, Zn, and Zr in the fractions were determined by neutron activation analysis. Molecular weights of the Athabasca fractions are generally higher than the corresponding Cold Lake fractions. Between 58% and 90% of the metal contents occur in the high molecular weight fractions of both asphaltenes. Except for V and Cr, which show biomodel distributions, all the elements have decreasing concentrations as the molecular weight of the fraction decreases. High molecular weight fractions, constituting about 55% of the whole asphaltenes, contain nonporphyrin bound vanadium compounds. It is estimated that 27% and 31% of V present in Athabasca and Cold Lake asphaltenes respectively occur as porphyrin type compounds, including vanadyl prophyrins released from the asphaltene micelle during the separation and vanadyl porphyrins bearing high-molecular-weight substituents

  5. 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)

    1994-12-31

    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

  6. 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: oskari.uski@uef.fi [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: pasi.jalava@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Happo, M.S., E-mail: mikko.happo@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Torvela, T., E-mail: tiina.torvela@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Leskinen, J., E-mail: jani.leskinen@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Mäki-Paakkanen, J., E-mail: jorma.maki-paakkanen@thl.fi [National Institute for Health and Welfare, Department of Environmental Health, P.O. Box 95, FI-70701 Kuopio (Finland); Tissari, J., E-mail: jarkko.tissari@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Sippula, O., E-mail: olli.sippula@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Lamberg, H., E-mail: heikki.lamberg@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Jokiniemi, J., E-mail: jorma.jokiniemi@uef.fi [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

    2015-04-01

    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

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

    International Nuclear Information System (INIS)

    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−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 pure

  8. 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.

    1997-12-02

    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.

  9. 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)

    2002-07-01

    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)

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

    DEFF Research Database (Denmark)

    Andersen, Simon Ivar; Christensen, S. D.

    2000-01-01

    solvent mixture) is titrated with a solution of asphaltene in the same solvent. The asphaltene concentration of the injected solution is at a level above the critical micelle concentration (CMC). In the present paper the procedure is applied in investigation of asphaltenes as well as subfractions...

  11. Determination of asphaltenes in heavy oils using an on-column method

    Energy Technology Data Exchange (ETDEWEB)

    Rogel, E.; Ovalles, C.; Moir, M. [Chevron Energy Technology Co., Richmond, CA (United States); Schabron, J.F. [Western Research Inst., Laramie, WY (United States)

    2009-07-01

    An improved analytical method for determining the asphaltene content in crude oil and petroleum samples was presented. The method used an on-column precipitation technique coupled with an evaporative light scattering detector (ELSD). The column has an inert packing material where the asphaltene was precipitated and re-dissolved using a solvent. Heavy crude oils with asphaltene contents ranging from 5 to 25 per cent w/w were tested. A blend of 90:10 dichloromethane and methanol was used to decrease the influence of hydrocarbon adsorption mechanisms from the polymeric liquid chromatographic phases. A series of laboratory experiments were conducted to compare results obtained using the method with results obtained using traditional gravimetric methods. Regression analysis was used to determine the calibration constants. The study showed that the method can be used as replacement for conventional gravimetric methods when faster results are needed or when sample sizes are small. It was concluded that the method was able to accurately quantify asphaltene contents as low as 120 ppm. 8 refs., 1 tab., 3 figs.

  12. 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)

    1994-12-31

    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

  13. A kinetic study on pyrolysis and combustion characteristics of oil cakes:Effect of cellulose and lignin content

    Institute of Scientific and Technical Information of China (English)

    Ramakrishna Gottipati; Susmita Mishra

    2011-01-01

    Pyrolysis and combustion characteristics of three different oil cakes such as Pongamia ( Pongamia Pinnata), Madhuca (Madhuca Indica), and Jatropha (Jatropha curcas) were investigated in this study.The cellulose and lignin contents of oil cakes play very important role in pyrolysis and combustion processes.A kinetic investigation of three oil cakes was carried out and major part of the samples decomposed between 210 ℃ and 500 ℃.Pyrolysis and combustion were carried out with the mixtures of cellulose and lignin chemicals in different ratios and compared with the oil cakes.The biomass with higher cellulose content showed faster rate of pyrolysis than the biomass with higher lignin content.However at higher temperatures ( >600 ℃ ) all the oil cakes exhibited similar conversion at low heating rate in N2 atmosphere.Apparent activation energies increased for Madhuca and Pongamia oil cakes indicating the presence of more cellulose whereas, low activation energy of Jatropha confirms more lignin content.

  14. Trends in the Rare Earth Element Content of U.S.-Based Coal Combustion Fly Ashes.

    Science.gov (United States)

    Taggart, Ross K; Hower, James C; Dwyer, Gary S; Hsu-Kim, Heileen

    2016-06-01

    Rare earth elements (REEs) are critical and strategic materials in the defense, energy, electronics, and automotive industries. The reclamation of REEs from coal combustion fly ash has been proposed as a way to supplement REE mining. However, the typical REE contents in coal fly ash, particularly in the United States, have not been comprehensively documented or compared among the major types of coal feedstocks that determine fly ash composition. The objective of this study was to characterize a broad selection of U.S. fly ashes of varied geological origin in order to rank their potential for REE recovery. The total and nitric acid-extractable REE content for more than 100 ash samples were correlated with characteristics such as the major element content and coal basin to elucidate trends in REE enrichment. Average total REE content (defined as the sum of the lanthanides, yttrium, and scandium) for ashes derived from Appalachian sources was 591 mg kg(-1) and significantly greater than in ashes from Illinois and Powder River basin coals (403 and 337 mg kg(-1), respectively). The fraction of critical REEs (Nd, Eu, Tb, Dy, Y, and Er) in the fly ashes was 34-38% of the total and considerably higher than in conventional ores (typically less than 15%). Powder River Basin ashes had the highest extractable REE content, with 70% of the total REE recovered by heated nitric acid digestion. This is likely due to the higher calcium content of Powder River Basin ashes, which enhances their solubility in nitric acid. Sc, Nd, and Dy were the major contributors to the total REE value in fly ash, based on their contents and recent market prices. Overall, this study shows that coal fly ash production could provide a substantial domestic supply of REEs, but the feasibility of recovery depends on the development of extraction technologies that could be tailored to the major mineral content and origins of the feed coal for the ash. PMID:27228215

  15. Investigation of Asphaltene Precipitation at Elevated Temperature

    DEFF Research Database (Denmark)

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

    1998-01-01

    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...... 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...

  16. Colloidal structural evolution of asphaltene studied by confocal microscopy

    Science.gov (United States)

    Hung, Jannett; Castillo, Jimmy A.; Reyes, A.

    2004-10-01

    In this work, a detail analysis of the flocculation kinetic of asphaltenes colloidal particles has been carried out usng confocal microscopy. The colloidal structural evolution of the asphaltene flocculated has had varies postulated; however, the aggregation process of asphaltene is still not fully understood. In a recent paper, using Confocal microscope (homemade), we reported high-resolution micrographic images of asphaltenes flocculated and the correlation between crude oil stability and flocculation process. This technique permitted visualizes directly the physical nature of asphaltene flocculated. In this work, a detail analysis of the flocculation kinetic of asphaltene colloidal particles has been carried out using confocal microscopy. The physical nature of asphaltene flocculated from different crude oils is showed through of high-resolution image micrographies and its colloidal structural evolution.

  17. An experimental study of the effect of water content on combustion of coal tar/water emulsion droplets

    International Nuclear Information System (INIS)

    Isolated high asphaltene droplets of coal tar/water emulsion were studied to investigate the non-steady behavior of the burning droplets. Data on size and temperature histories were obtained. Coke residues were analyzed by scanning electron microscope. Lower and upper limits for ignition time delay were established. The error, defined as the time lag between these two limits, was less than 8 ms. Ignition time delays of emulsions were longer than for ordinary coal tar (CT) droplets of the same size but the peak temperature of emulsions occurred much earlier. A steeper temperature rise observed in the emulsions during portions of their combustion history is evidence not only of soot reduction but also the extent of burnout of the cenospheres. The latter is an important aspect in the reduction of pollutant emissions. The emulsion droplets indicated swelling of considerable magnitude compared with that of CT. Coke particles formed from emulsions were more porous, with thinner and fragile shells. The CT residues were harder and more resistant to burning. Excess burnout time or the ratio of burnout time of the emulsions depended on the water concentration, indicating that longer oxidation time was required for coke particles from coal tar than from emulsions. -- Highlights: → The droplet was subject to disruptive behavior in the pre-ignition and visible flame period. → The coke particle from the emulsion presented more fragile and thinner shells than that of the CT. The steeper temperature rise was observed in the emulsions. → Swelling of the emulsions occurred earlier than for CT-A droplet. → The morphology of the CT carbonaceous residue was denser than that of the emulsion carbonaceous residue.

  18. Asphaltene precipitates in oil production wells

    DEFF Research Database (Denmark)

    Kleinitz, W,; Andersen, Simon Ivar

    1998-01-01

    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...

  19. Asphaltenes : interfacial aggregates characterization and film structure

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, G.; Argillier, J.F. [Inst. Francais du Petrole, Rueil-Malmaison Cedex (France); Langevin, D. [Univ. Paris-Sud, Orsay Cedex (France). Laboratoire de Physique des Solides

    2008-07-01

    An understanding of stability mechanisms of crude oil emulsions is necessary for controlling and improving heavy oil production. The properties of the amphiphilic film that surrounds the droplets influence the behaviour of emulsions. This study examined the complex composition of asphaltenes, resins and naphtenic acids found in crude oil using a combination of techniques, such as measurement of dynamic interfacial tension and rheology of water; and modelling the oil interface where asphaltenes or naphthenic acids are dissolved. The study revealed the properties of the films. The amount of adsorbed asphaltene at the interface was determined through small-angle neutrons scattering (SANS) measurements, in which the structure of the interfacial layer and aggregates characteristics were obtained, along with UV-VIS experiments. The study showed that different parameters have a significant influence on interfacial structure and film properties, and therefore on emulsions behaviour. The parameters include naphthenic acid/asphaltene ratio, molecular weight of the naphtenic acid, pH and ionic strength of the aqueous phase. Some correlation between microscopic properties and macroscopic behaviour were obtained using stability tests on emulsions.

  20. On the Mass Balance of Asphaltene Precipitation

    DEFF Research Database (Denmark)

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

    2001-01-01

    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 pe...

  1. 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

    2002-06-01

    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

  2. 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)

    2011-07-01

    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.

  3. Characterization of moisture and water content on ignition and combustion of hypergolic propellants

    Science.gov (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

  4. Separation and characterization of resins and asphaltenes coming from Castilla crude Evaluation of their molecular interaction

    International Nuclear Information System (INIS)

    The study of resins and asphaltenes, the heaviest fractions of oil, has become an area of interest due to the abundance of heavy crude oils in Colombia and Latin America. We studied the chemical composition of the heavy fractions of Castilla crude oil, evaluated some of its molecular parameters and found evidence of the interaction between the resins extracted from the crude with the asphaltenes of the original crude. With this objective, we carried out at the pilot plant level precipitation of the resin-asphaltene (R-A) aggregate by adding and mixing under controlled conditions, a paraffin solvent, from the Apiay refinery, called Apiasol. By extracting Soxhlet with the same solvent, resin 1 of aggregate R-A was separated. Resin ll defined as the soluble fraction that is part of the maltenes, was separated from the deasphalted crude by open column chromatography, using alumina as support, according to the SAR method (Saturated, Aromatics, Resins). The fractions of resins and the asphaltenes obtained, were characterized by: Nuclear Magnetic Resonance (NMR), FT-lR, DRX, elementary analysis (C, H, N, S), metal content (Ni and V), distribution of molecular weight by GPC, and average molecular weight by VPO. The results obtained show evidence that resin l which is part of the aggregate has less average molecular weight than resin ll which is present in the fraction of maltenes. In addition, some changes were found in the elementary analysis of among the resins. On the one hand, and taking into account the existing theories of molecular interactions among these fractions, it was found that the resins l separated from the R-A aggregate, when added to the crude, they stabilize their asphaltenes. This evaluation was carried out by analyzing the flocculation point of the crude and its mixtures with 1,9% and 3,8% of resin l, when they are titrated with a precipitating agent in an NIR cell that works with high pressure and temperature

  5. DETERMINATION OF THE KINETIC PARAMETERS OF OXY-FUEL COMBUSTION OF COAL WITH A HIGH ASH CONTENT

    OpenAIRE

    K. G. P. Nunes; N. R. Marcílio

    2015-01-01

    Abstract The aim of this study was to determine the kinetic parameters of the oxy-fuel combustion of char from a Brazilian bituminous coal with a high ash content. The char, with a particle diameter of 715 μm, was prepared in a N2 atmosphere at 1173 K. The oxy-fuel combustion assays were performed using a thermobalance at different temperatures and O2/CO2 gas mixtures of different concentrations. According to the unreacted core model, the process is determined by chemical reaction at low temp...

  6. Pyrolysis of petroleum asphaltenes from different geological origins and use of methylnaphthalenes and methylphenanthrenes as maturity indicators for asphaltenes

    Indian Academy of Sciences (India)

    Manoj Kumar Sarmah; Arun Borthakur; Aradhana Dutta

    2010-08-01

    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 alkylphenanthrenes. Both the asphaltenes produced aliphatic as well as aromatic compound classes. Alkylnaphthalenes and alkylphenanthrenes were identified by using reference chromatograms and literature data and the distributions were used to assess thermal maturity of the asphaltenes. The ratios of -substituted to α-substituted isomers of both alkylnaphthalenes and alkylphenanthrenes revealed higher maturity of the JN asphaltenes than the DK asphaltenes. For both the asphaltenes the abundance of 1-methylphenanthrene dominated over that of 9-methylphenanthrene showing the terrestrial nature of the organic matter.

  7. Pyrolysis of petroleum asphaltenes from different geological origins and use of methylnaphthalenes and methylphenanthrenes as maturity indicators for asphaltenes

    Indian Academy of Sciences (India)

    Manoj Kumar Sarmah; Arun Borthakur; Aradhana Dutta

    2013-04-01

    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 alkylphenanthrenes. Both the asphaltenes produce aliphatic as well as aromatic compound classes. Alkylnaphthalenes and alkylphenanthrenes were identified by using reference chromatograms and literature data and the distributions used to assess thermalmaturity of the asphaltenes. The ratios of -substituted to -substituted isomers of both alkylnaphthalenes and alkylphenanthrenes revealed higher maturity of the JN asphaltenes than the DK asphaltenes. For both the asphaltenes, the abundance of 1-methylphenanthrene dominates over that of 9-methylphenanthrene showing the terrestrial nature of the organic matter.

  8. Effect of asphaltenes on crude oil wax crystallization

    DEFF Research Database (Denmark)

    Kriz, Pavel; Andersen, Simon Ivar

    2005-01-01

    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...

  9. Quantitative Determination of Asphaltenes and Resins in Solution by Means of Near-Infrared Spectroscopy. Correlations to Emulsion Stability.

    Science.gov (United States)

    Kallevik, Harald; Kvalheim, Olav M.; Sjöblom, Johan

    2000-05-15

    Near-infrared (NIR) spectroscopy in the range 1100-2250 nm together with a latent-variable regression technique is used to analyze the content of asphaltene and resins in solution. It is shown that this technique is capable of determining the amount of these components individually. w/o emulsions were prepared from the separated components of asphaltenes and resins from crude oils. The stability was directly determined with the critical voltage in a dielectric instrumentation. The emulsion stability decreased linearly with an increase in the resin/asphaltene ratio. A final linear model correlating the critical voltage and the analytical concentrations (from the NIR spectra) could be established for this model system. Copyright 2000 Academic Press. PMID:11254289

  10. Study of asphaltene precipitation by Calorimetry

    DEFF Research Database (Denmark)

    Verdier, Sylvain Charles Roland; Plantier, Frédéric; Bessières, David; Andersen, Simon Ivar; Stenby, Erling Halfdan; Carrier, Hervé

    2007-01-01

    Can calorimetry bring new input to the Current understanding of asphaltene precipitation? In this work, two types of precipitation were studied by means of calorimetry: addition of n-heptane into asphaltene solutions and temperature/pressure variations on a recombined live oil. The first series of...... experiments showed that weak forces determine precipitation. Indeed, isothermal titration calorimetry could not detect any clear signal although this technique can detect low-energy transitions such as liquid-liquid equilibrium and rnicellization. The second series of tests proved that precipitation caused by...... T and P variations is exothermic for this system. Furthermore, the temperature-induced precipitation is accompanied by an increase in the apparent thermal expansivity. Therefore, it seems that these two phase transitions exhibit different calorimetric behaviours and they may not be as similar as...

  11. Asphaltene analysis using size exclusion chromatogrphy

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, A.W.; Thomas, M.G.

    1983-09-01

    A common technique used in coal liquefaction investigations is the asphaltene analysis, whereby products are separated into four major fractions (insolubles, preasphaltenes, asphaltenes and oils) by solvent extraction techniques. The fractions are defined by their solubility in organic solvents such as tetrahydrofuran, toluene and pentane. An instrumental method of analysis, using gel permeation liquid chromatography, was developed to reduce the problems with the conventional solvent separation. The technique relies upon the fact that the fractions differ in molecular size as well as solubility. The method uses one solvent (THF) and a single 100A microstyragel column to separate the three soluble fractions. The trends in the data obtained with the molecular size separation agree with the trends obtained by conventional solvent separation on the same samples. (5 refs.)

  12. HINDERED DIFFUSION OF ASPHALTENES AT ELEVATED TEMPERATURE AND PRESSURE

    Energy Technology Data Exchange (ETDEWEB)

    James A. Guin; Ganesh Ramakrishnan; Keiji Asada

    2000-04-07

    During this past six months we continued our ongoing studies of the diffusion controlled uptake of coal and petroleum asphaltenes into a porous carbon catalyst. Toluene was used as the solvent for experiments at 20 C and 75 C while 1-methylnaphthalene was the solvent for the higher temperature experiments at 100 C, 150 C and 250 C. All runs were made at a pressure of 250 psi (inert He gas). Experiments were performed at 20 C and 75 C, for the petroleum asphaltene/toluene system. For the coal asphaltene/toluene system, experiments were performed at 75 C. Experiments were performed at 100 C, 150 C and 250 C for the coal asphaltene/1-methylnaphthalene system. A comparison between the experimental data and model simulated data showed that the mathematical model satisfactorily fitted the adsorptive diffusion of both the coal and petroleum asphaltenes onto a porous activated carbon. The adsorption constant decreases with an increase in temperature for both, the coal asphaltene/1-methylnaphthalene system as well as the petroleum asphaltene/toluene system. It was found that the adsorption constant for the coal asphaltene/toluene system at 75 C was much higher than that of the petroleum asphaltene/toluene system at the same temperature providing evidence of the greater affinity of the coal asphaltenes for the carbon surface. This could be due to the presence of more functional heteroatomic groups in the coal asphaltenes compared to their petroleum counterparts. Also during this time period, a new carbon catalyst support was prepared in our laboratory which will be used in adsorption experiments during the next phase of work.

  13. 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.

    2006-11-01

    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

  14. 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

    2015-01-01

    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.

  15. Asphaltene and solids-stabilized water-in-oil emulsions

    Science.gov (United States)

    Sztukowski, Danuta M.

    Water-in-crude oil emulsions are a problem in crude oil production, transportation, and processing. Many of these emulsions are stabilized by asphaltenes and native oilfield solids adsorbed at the oil-water interface. Design of effective emulsion treatments is hampered because there is a lack of understanding of the role asphaltenes and solids play in stabilizing these emulsions. In this work, the structural, compositional and rheological properties of water/hydrocarbon interfaces were determined for model emulsions consisting of water, toluene, heptane, asphaltenes and native oilfield solids. The characteristics of the interface were related to the properties of asphaltenes and native solids. Emulsion stability was correlated to interfacial rheology. A combination of vapour pressure osmometry, interfacial tension and emulsion gravimetric studies indicated that asphaltenes initially adsorb at the interface as a monolayer of self-associated molecular aggregates. It was demonstrated why it is necessary to account for asphaltene self-association when interpreting interfacial measurements. The interfacial area of Athabasca asphaltenes was found to be approximately 1.5 nm2 and did not vary with concentration or asphaltene self-association. Hence, more self-associated asphaltenes simply formed a thicker monolayer. The interfacial monolayer observed in this work varied from 2 to 9 nm in thickness. The asphaltene monolayer was shown to adsorb reversibly only at short interface aging times. The film gradually reorganizes at the interface to form a rigid, irreversibly adsorbed network. The elastic and viscous moduli can be modeled using the Lucassen-van den Tempel (LVDT) model when the aging time is less than 10 minutes. An increase in film rigidity can be detected with an increase in the total elastic modulus. Increased film rigidity was shown to reduce the rate of coalescence in an emulsion and increase overall emulsion stability (reduce free water resolution). The rate of

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

    KAUST Repository

    Zhang, Long-li

    2014-07-01

    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

  17. Interfacial tension change due to asphaltene flocculation in recombined oils

    Energy Technology Data Exchange (ETDEWEB)

    Carrier, H.; Pauly, J.; Daridon, J.L. [Univ. de Pau, Pau Cedex (France). Laboratoire des Fluides Complexes; Mejia, A. [Univ. de Pau, Pau Cedex (France). Laboratoire des Fluides Complexes; Univ. Central de Venezuela, Caracas (Venezuela, Bolivarian Republic of). Facultad de Ciencias; Castillo, J. [Univ. Central de Venezuela, Caracas (Venezuela, Bolivarian Republic of). Facultad de Ciencias

    2008-07-01

    Asphaltenes found in reservoirs fluids may dissolve as colloidal aggregates in crude oils. The aggregates might destabilize as a result of changes in both temperature and pressure, resulting in flocculation of asphaltenes. The insolubility of asphaltenes can cause major problems at different stages of oil production, such as deposition and flow blockage. In order to evaluate the risk of asphaltene formation and to design techniques to prevent asphaltene deposits, it is necessary to measure and predict the conditions of flocculation throughout the pressures encountered from reservoir to surface conditions. To date, most asphaltene stability studies have been conducted at atmospheric pressure for dead oils by adding precipitating solvents. However the relationship of these stability tests with asphaltene flocculation due to the decompression of live oil in reservoir or production conditions is not fully established. Accurate measurements on both atmospheric and field conditions are needed. In order to address this problem, a high-pressure device using refractive index measurements and a filtration technique was designed to measure onset of asphaltene flocculation in live oils. The capacity of the device was also extended to investigate the evolution of the interfacial tension between crude oil and gases or immiscible liquids such as water, at pressures up to 70 MPa. Interfacial tension was measured by axisymmetric drop shape analysis of a pendant oil drop. The study found that a relationship exists between the discontinuity in the trend of the superficial tension as a function of the pressure and the threshold of asphaltenes aggregation due to decompression. The study provided evidence of the effect of asphaltenes flocculation on the interfacial tension. 2 refs.

  18. Influence of the ash content of a solid fuel on the formation of charged particles on its combustion in a current of air

    Energy Technology Data Exchange (ETDEWEB)

    Zakharov, A.G.; Fialkov, B.S.; Khvan, L.A.; Mel' nichuk, A.Yu.

    1982-01-01

    An increase in the ash content of a fuel leads to a linear decrease in the amount of charges generated on its combustion. In the combustion of a fuel in a current of air, charged particles are generated in processes taking place on the interaction of the carbon with oxygen.

  19. Asphaltene precipitates in oil production wells

    DEFF Research Database (Denmark)

    Kleinitz, W,; Andersen, Simon Ivar

    1998-01-01

    compounds in the organic scales from operations definitely differed from the data published in the literature. In order to dissolve the precipitates and thus eliminate the damage, various organic solvents and industrial solvent mixtures were examined. The kinetics of the dissolution process in operational...... subsequently resumed in these wells. The production from the wells was adjusted in such a way that the conditions for asphaltene deposition are effectively suppressed for several years. The long-term success of the treatment tons also supported by modifying the production strategy. The process of optimising...

  20. Role of asphaltenes in stabilizing thin liquid emulsion films.

    Science.gov (United States)

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

    2014-03-25

    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. PMID:24564447

  1. Energy exploitation of acid gas with high H2S content by means of a chemical looping combustion system

    International Nuclear Information System (INIS)

    Highlights: • CLC can exploit the energy potential of acid gas by burning H2S. • New combustion process demonstration in a continuous CLC unit. • Highest H2S concentrations (20 vol.%) ever used in a CLC process. • Fe20γAl oxygen carrier is a suitable material for acid gas combustion. • H2S content above 20 vol.% turns the acid gas CLC into an auto-thermal process. - Abstract: In gas and petroleum industry, the waste gas stream from the sweetening process of a sour natural gas stream is commonly referred as acid gas. Chemical Looping Combustion (CLC) technology has the potential to exploit the combustible fraction of acid gas, H2S, to produce energy obtaining a flue gas highly concentrated on CO2 and SO2, which can be cost-effectively separated for subsequent applications, such as sulfuric acid production. At the same time, a concentrated CO2 stream ready for storage is obtained. The resistance of oxygen carriers to sulfur becomes crucial when an acid gas is subjected to a CLC process since the H2S content can be very high. In this work, a total of 41 h of continuous operation with acid gas and H2S concentrations up to 20 vol.% has been carried out in a 500 Wth CLC unit with two oxygen carriers based on Cu (Cu14γAl) and Fe (Fe20γAl). The formation of copper sulfides and the SO2 emissions in the air reactor made the Cu14γAl material not adequate for the process. In contrast, excellent results were obtained during acid gas combustion with the Fe20γAl oxygen carrier. H2S was fully burnt to SO2 in the fuel reactor at all operating conditions, SO2 was never detected in the gas outlet stream of the air reactor, and iron sulfides were never formed even at H2S concentrations as high as 20 vol.%. Furthermore, it was found that a H2S content of 20 vol.% in the acid gas was high enough to turn the CLC process into an auto-thermal process. Based on these results, it can be concluded that the Fe-based materials prepared by impregnation are very adequate to exploit

  2. 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: silas@ima.ufrj.br [Universidade Federal do Rio de Janeiro, Instituto de Macromoleculas, Laboratorio de Macromoleculas e Coloides na Industria de Petroleo, Rio de Janeiro, RJ (Brazil)

    2011-07-01

    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)

  3. Chemical composition of asphaltenes from thermal dissociation of brown coal

    Energy Technology Data Exchange (ETDEWEB)

    Evstaf' ev, S.N.; Denisova, T.I.; Tuturina, V.V.

    1987-07-01

    Investigates chemical composition of asphaltenes and preasphaltenes separated from liquid products of thermal dissociation of Azeisk deposit brown coal in tetralin. Asphaltenes and preasphaltenes represent a mixture of mainly aromatic compounds containing bi- and tri-cyclic aromatic fractions differing by length of aliphatic substituents and by distribution of oxygen-containing functional groups. Describes tests carried out at 300-420 C in autoclaves using 0.1-0.3 mm coal particles and tetralin containing decalin (2.8%) and naphthalene (5.2%). Establishes that asphaltenes soluble in acetone are represented by low-molecular saturated compounds; about 60% of oxygen in asphaltenes and preasphaltenes is attached to ethereal and heterocyclic structure groups. 10 refs.

  4. A chemical process of asphaltenes dispersion : anticor DSA 700

    International Nuclear Information System (INIS)

    This work deals with asphalts dispersion chemical process. Asphaltenes are constituents of petroleum which under chemical, physical or mechanical variations effect precipitate and create deposits. In order to cope with this problem, a product : Anticor DSA 700 has been adjusted and allow to stabilize asphaltenes. This method has already been used in France and in Algeria and will be extended to others west countries. (O.L.). 2 figs

  5. Effect of Carbon Ash Content on the Thermal and Combustion Properties of Waste Wood Particle / Recycled Polypropylene Composites

    Directory of Open Access Journals (Sweden)

    Chen Kuo-Wei

    2016-01-01

    Full Text Available This study effect of carbon ash content on the thermal stability and combustion behavior of waste wood particle / recycled polypropylene composites was investigated using TGA, DTG, LOI and cone calorimeter. The TGA shows that, as carbon ash content increases, the thermal stability of composites increases, while the residual weight significantly increases, with the residual weight rate of waste wood particle / recycled polypropylene composites increases from 13.97% to 41.02% at 800 ℃ According to cone calorimeter results, in the 50 kW/M2 thermal flow, when carbon ash adding to 70%, peak heat release rate and total heat release quantity, decreases by 68% and 52%, respectively. The LOI of waste wood particle / recycled polypropylene composites improves by about 34%, Conforming UL-94 flammability standard, V-0 rating. The residual weight rate increases by 202.8%, which the significant role of carbon ash in flame retardant.

  6. Simulating Combustion

    Science.gov (United States)

    Merker, G.; Schwarz, C.; Stiesch, G.; Otto, F.

    The content spans from simple thermodynamics of the combustion engine to complex models for the description of the air/fuel mixture, ignition, combustion and pollutant formation considering the engine periphery of petrol and diesel engines. Thus the emphasis of the book is on the simulation models and how they are applicable for the development of modern combustion engines. Computers can be used as the engineers testbench following the rules and recommendations described here.

  7. HINDERED DIFFUSION OF ASPHALTENES AT ELEVATED TEMPERATURE AND PRESSURE

    Energy Technology Data Exchange (ETDEWEB)

    James A. Guin; Ganesh Ramakrishnan

    1999-10-07

    During this time period, experiments were performed to study the diffusion controlled uptake of quinoline and a coal asphaltene into porous carbon catalyst pellets. Cyclohexane and toluene were used as solvents for quinoline and the coal asphaltene respectively. The experiments were performed at 27 C and 75 C, at a pressure of 250 psi (inert gas) for the quinoline/cyclohexane system. For the coal asphaltene/toluene system, experiments were performed at 27 C, also at a pressure of 250 psi. These experiments were performed in a 20 cm{sup 3} microautoclave, the use of which is advantageous since it is economical from both a chemical procurement and waste disposal standpoint due to the small quantities of solvents and catalysts used. A C++ program was written to simulate data using a mathematical model which incorporated both diffusional and adsorption mechanisms. The simulation results showed that the mathematical model satisfactorily fitted the adsorptive diffusion of quinoline and the coal asphaltene onto a porous activated carbon. For the quinoline/cyclohexane system, the adsorption constant decreased with an increase in temperature. The adsorption constant for the coal asphaltene/toluene system at 27 C was found to be much higher than that of the quinoline/cyclohexane system at the same temperature. Apparently the coal asphaltenes have a much greater affinity for the surface of the carbon catalyst than is evidenced by the quinoline molecule.

  8. Novel stationary phases based on asphaltenes for gas chromatography.

    Science.gov (United States)

    Boczkaj, Grzegorz; Momotko, Malwina; Chruszczyk, Dorota; Przyjazny, Andrzej; Kamiński, Marian

    2016-07-01

    We present the results of investigations on the possibility of the application of the asphaltene fraction isolated from the oxidized residue from vacuum distillation of crude oil as a stationary phase for gas chromatography. The results of the investigation revealed that the asphaltene stationary phases can find use for the separation of a wide range of volatile organic compounds. The experimental values of Rohrschneider/McReynolds constants characterize the asphaltenes as stationary phases of medium polarity and selectivity similar to commercially available phases based on alkyl phthalates. Isolation of asphaltenes from the material obtained under controlled process conditions allows the production of a stationary phase having reproducible sorption properties and chromatographic columns having the same selectivity. Unique selectivity and high thermal stability make asphaltenes attractive as a material for stationary phases for gas chromatography. A low production cost from a readily available raw material (oxidized petroleum bitumens) is an important economic factor in case of application of the asphaltene stationary phases for preparative and process separations. PMID:27144876

  9. Modelling the effect of gas injections on the stability of asphaltene-containing crude oils

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.; Moorwood, T. [Infochem, Munich (Germany); Merino Garcia, D.; Pena Diez, J.L. [Repsol YPF, Madrid (Spain)

    2008-07-01

    In oil fields where asphaltene deposits occur, they present major remediation problems and can halt production due to flow blockage. Crude oils which precipitate asphaltenes generally contain both asphaltene molecules and lighter resin molecules. Resins are thought to solvate the asphaltene molecules, thus stabilizing the solution, while light gases have the opposite effect. In order to model asphaltene phase behaviour, it is important to understand the impact of adding gas to asphaltene-containing crudes. This study presented several experimental investigations of gas injection into asphaltene-containing crudes. The trends of asphaltene destabilization were discussed. The injection gases ranged from pure gases to a gas condensate. The data were modelled using a conventional equation of state together with an extra term that considered the association between asphaltene molecules and their solvation by resins. Since the model could simultaneously described the gas, oil and asphaltene phases, it was possible to calculate phase stability and phase equilibria. However, a different model had to be used to obtain the gas-oil equilibrium because the use of solubility parameters only allows the stability of the asphaltene phase to be calculated. The model correctly predicted that the gases will promote asphaltene precipitation. In its original form, the model tended to over-predict the trend. The optimal parameter values needed to represent all the available experimental data were determined. The extent to which the effect of gas injection on asphaltenes can be predicted was then discussed.

  10. 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)

    2013-09-30

    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.

  11. 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: Sunsr@hit.edu.cn [School of Energy Science and Engineering, Harbin Institute of Technology, 92, West Dazhi Street, Harbin 150001 (China); Ismail, Tamer M., E-mail: temoil@aucegypt.edu [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)

    2015-05-15

    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.

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

    International Nuclear Information System (INIS)

    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

  13. 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.

    2003-01-01

    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-oil......-derived asphaltenes and the standard asphaltenes as precipitated by atmospheric titration on the same crude oil, revealed that the live-oil asphaltenes had apparent smaller hydrodynamic volume and narrower distributions than the standard asphaltenes for two oils. Further FTIR tests also showed large differences......Asphaltenes precipitated from pressure-preserve bottomhole oil samples have been obtained for three oils at different pressures, using a bulk high-pressure filtration apparatus. The precipitates captured on the filter were recovered, the asphaltenes defined by the n-heptane insolubility were...

  14. 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.

    2003-01-01

    Asphaltenes precipitated from pressure-preserve bottomhole oil samples have been obtained for three oils at different pressures, using a bulk high-pressure filtration apparatus. The precipitates captured on the filter were recovered, the asphaltenes defined by the n-heptane insolubility were...... 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-oil......-derived asphaltenes and the standard asphaltenes as precipitated by atmospheric titration on the same crude oil, revealed that the live-oil asphaltenes had apparent smaller hydrodynamic volume and narrower distributions than the standard asphaltenes for two oils. Further FTIR tests also showed large differences...

  15. New method for the onset point determination of the petroleum asphaltene aggregation

    International Nuclear Information System (INIS)

    Work has been devoted to investigation of the process of asphaltenes aggregation in a model system asphaltene-toluene-heptane. The procedure of the onset point determination of the petroleum asphaltenes which is based on the method of photon correlation spectroscopy has been described. Two ways have been developed to determine the onset of asphaltenes aggregation by means of method of photon correlation spectroscopy. The first method allows defining the onset of asphaltenes aggregation of light scattering intensity depending on the quantity of n-alkane in the model system. The second method allows determining the onset point of asphaltenes aggregation parameter k depending on the quantity of n-alkane. A comparative evaluation of onset points, obtained in different ways has been given. The influence of the model system composition on the process of asphaltenes aggregation has been studied. The characteristic diffusion time of asphaltenes has been calculated

  16. Partitioning behavior of trace elements during pilot-scale fluidized bed combustion of high ash content lignite

    International Nuclear Information System (INIS)

    This study describes the partitioning of 20 trace elements (As, B, Ba, Cd, Co, Cr, Cu, Hg, Li, Mn, Mo, Ni, P, Pb, Sb, Se, Sn, Tl, V, Zn) and eight major and minor elements (Al, Ca, Fe, K, Mg, Na, Si, Ti) during the combustion of high ash content lignite. The experiments were carried out in the 0.3 MWt Middle East Technical University (METU) atmospheric bubbling fluidized bed combustor (ABFBC) test rig with and without limestone addition. Inert bed material utilized in the experiments was bed ash obtained previously from the combustion of the same lignite without limestone addition in the same test rig. Concentrations of trace elements in coal, limestone, bottom ash, cyclone ash and filter ash were determined by inductively coupled plasma optical emission spectroscopy (ICP-OES). Partitioning of major and minor elements are influenced by the ash split between the bottom ash and fly ash and that the major proportion of most of the trace elements (As, Ba, Cr, Hg, Li, Mo, Ni, Sn, V, Zn) are recovered in fly ash. Limestone addition shifts the partitioning of Ba, Cr, Mo, Ni, Sn, V, Zn from bottom ash to fly ash

  17. DETERMINATION OF THE KINETIC PARAMETERS OF OXY-FUEL COMBUSTION OF COAL WITH A HIGH ASH CONTENT

    Directory of Open Access Journals (Sweden)

    K. G. P. Nunes

    2015-03-01

    Full Text Available Abstract The aim of this study was to determine the kinetic parameters of the oxy-fuel combustion of char from a Brazilian bituminous coal with a high ash content. The char, with a particle diameter of 715 μm, was prepared in a N2 atmosphere at 1173 K. The oxy-fuel combustion assays were performed using a thermobalance at different temperatures and O2/CO2 gas mixtures of different concentrations. According to the unreacted core model, the process is determined by chemical reaction at low temperatures, with an activation energy of 56.7 kJ.kmol-1, a reaction order of 0.5 at 973 K and a reaction order of 0.7 overall. The use of the continuous reaction model did not provide a good fit for the experimental data because the consumption of the particles during the reaction was not constant, as predicted by the model. According to the Langmuir-Hinshelwood model, the activation energy for the first step was 37.3 kJ.kmol-1.

  18. An experimental study of asphaltene particle sizes in n-heptane-toluene mixtures by light scattering

    OpenAIRE

    Rajagopal K.; Silva S. M. C.

    2004-01-01

    The particle size of asphaltene flocculates has been the subject of many recent studies because of its importance in the control of deposition in petroleum production and processing. We measured the size of asphaltene flocculates in toluene and toluene - n-heptane mixtures, using the light-scattering technique. The asphaltenes had been extracted from Brazilian oil from the Campos Basin, according to British Standards Method IP-143/82. The asphaltene concentration in solution ranged between 10...

  19. Correlations between SARA Fractions, Density, and RI to Investigate the Stability of Asphaltene

    OpenAIRE

    Ali Chamkalani

    2012-01-01

    Asphaltene precipitation is one of the most common problems in both oil recovery and refinery processes. Its deposition causes many problems mainly because of the fuzzy nature of asphaltene and the large number of parameters affecting precipitation. Unfortunately there is not a predictive technique for screening it. Refractive index (RI) was used as a stability test for asphaltene which makes a quantitative judgment for asphaltene stability. In our study, we first represent a novel correlatio...

  20. Combustion efficiency and altitude operational limits of three liquid hydrocarbon fuels having high volumetric energy content in a J33 single combustor

    Science.gov (United States)

    Stricker, Edward G

    1950-01-01

    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.

  1. Asphaltene flocculation and collapse from petroleum fluids

    Energy Technology Data Exchange (ETDEWEB)

    Branco, Valter Antonio M.; De Almeida Xavier, Luiza Cristina [Petroleo Brasilerio S.A., Petrobras/CENPES/DIGER, Cidade Universitaria, Quadra 7, Ilma Fundao, RJ, 21910 Rio de Janeiro (Brazil); Mansoori, G. Ali; Park, Sang J.; Manafi, Hussain [Thermodynamics Research Laboratory, Department of Chemical Engineering, University of Illinois at Chicago, 810 S. Clinton Street, 60607-7000 Chicago, IL (United States)

    2001-12-29

    Deposition of complex and heavy organic compounds, which exist in petroleum crude and heavy oil, can cause a number of severe problems. To prevent deposition inside the reservoir, in the well head and inside the transmission lines, it is necessary to be able to predict the onset and amount of deposition due to various factors. In the present paper, the mechanism of asphaltene deposition, which is the major cause of most organic deposition cases, is modeled based on statistical mechanics of polydisperse polymer solutions joined with the kinetic theory of aggregation and its predictive capability is discussed. Utilization of statistical mechanics of polydisperse polymer solutions joined with kinetic theory of aggregation enables us to develop a realistic model which is able to predict both reversible and irreversible heavy organic depositions. The present model is capable of describing several reversible and irreversible situations, such as the phenomena of organic deposition, growing mechanism of heavy organic aggregates, the size distributions of precipitated organics and the solubility of heavy organics in a crude oil due to variations in oil pressure, temperature and composition. As an example, the present model is applied for heavy organics deposition prediction of two different Brazilian crude oils for which experimental data are available. It is shown that the prediction results of the present model are in good agreement with the experimental data.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    chose first to consider the simple case where only asphaltene molecules are counted in a nanoaggregate. We used a master equation approach and a related statistical mechanics model. The linear asphaltene nanoaggregates behave as a rigid linear chain. The most complicated case where all aromatic......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...... molecules are counted in a nanoaggregate is then discussed. The linear aggregates where all aromatic molecules are counted seem to behave as a flexible linear chain...

  3. Hindered Diffusion of Asphaltenes at Evaluated Temperature and Pressure

    Energy Technology Data Exchange (ETDEWEB)

    James A. Guin; Surya Vadlamani; Xiafeng Yang

    1998-12-04

    During this time period, uptake experiments were performed at elevated temperatures up to 280 o C for the adsorptive diffusion of a coal asphaltene in 1- methylnaphthalene onto alumina catalyst pellets. Model simulation results showed that a mathematical model incorporating diffusion and adsorption mechanisms satisfactorily fitted the adsorptive diffusion of coal asphaltenes onto the alumina catalyst in a fairly wide temperature range of 55 o C to 280 o C. The logarithm of the adsorption constant, obtained by simulating the experimental data with the model solution, was found to be linearly dependent on temperature. As temperature increased, the value of the adsorption constant decreased. On the other hand, the effective diffusivity of the asphaltene increased with temperature. These off-setting temperature dependencies resulting from the adsorption constant and the effective diffusivity compensated at least to some extent in the uptake process.

  4. Thin film pyrolysis of oil sands asphaltenes for structural analysis

    Energy Technology Data Exchange (ETDEWEB)

    Karimi, Arash; Gray, Murray R [Department of Chemical and Materials Engineering, University of Alberta (Canada); Qian, Kuangnan; Olmstead, William N.; Freund, Howard [ExxonMobil Research and Engineering (United States)], email: murray.gray@ualberta.ca

    2010-07-01

    Current methods to extract asphaltene building blocks only produce small sample quantities per batch for analysis. To reach sample quantities sufficient for several analytical methods on each batch, the following method was investigated in a preliminary study. Asphaltenes from Alberta bitumen were spray coated as thin films on alloy plates to be used in controlled pyrolysis. Each batch of six plates reacted around 1 g of asphaltenes in the furnace. Reaction products were purged from the reaction chamber with cold nitrogen, then cooled in a cold trap. Gases were collected and analysed using gas chromatography. Liquid products were condensed in a cold trap, rinsed with solvent, and evaporated overnight. The coke was also recovered from the plates and analysed. The method yielded mass balances greater than 90%. Products analysis revealed molecular fragment sizes ranging from C10 to C100. Lighter components (C5-C10) were not detected, having probably evaporated during solvent removal.

  5. Polymeric dispersants delay sedimentation in colloidal asphaltene suspensions.

    Science.gov (United States)

    Hashmi, Sara M; Quintiliano, Leah A; Firoozabadi, Abbas

    2010-06-01

    Asphaltenes, among the heaviest components of crude oil, can become unstable under a variety of conditions and precipitate and sediment out of solution. In this report, we present sedimentation measurements for a system of colloidal scale asphaltene particles suspended in heptane. Adding dispersants to the suspension can improve the stability of the system and can mediate the transition from a power-law collapse in the sedimentation front to a rising front. Additional dispersant beyond a crossover concentration can cause a significant delay in the dynamics. Dynamic light scattering measurements suggest that the stabilization provided by the dispersants may occur through a reduction of both the size and polydispersity of the asphaltene particles in suspension. PMID:20334407

  6. Cooee bitumen II: Stability of linear asphaltene nanoaggregates

    CERN Document Server

    Lemarchand, Claire A; Dyre, Jeppe C; Hansen, Jesper S

    2014-01-01

    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 chose first to consider the simple case where only asphaltene molecules are counted in a nanoaggregate. We used a master equation approach and a related statistical mechanics model. The linear asphaltene nanoaggregates behave as a rigid linear chain. The most complicated case where all aromatic molecules are counted in a nanoaggregate is then discussed. The linear aggregates where all aromatic molecules are counted seem ...

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

    Science.gov (United States)

    Lemarchand, Claire A.; Schrøder, Thomas B.; Dyre, Jeppe C.; Hansen, Jesper S.

    2014-10-01

    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 chose first to consider the simple case where only asphaltene molecules are counted in a nanoaggregate. We used a master equation approach and a related statistical mechanics model. The linear asphaltene nanoaggregates behave as a rigid linear chain. The most complicated case where all aromatic molecules are counted in a nanoaggregate is then discussed. The linear aggregates where all aromatic molecules are counted seem to behave as a flexible linear chain.

  8. Stability and demulsification of emulsions stabilized by asphaltenes or resins.

    Science.gov (United States)

    Xia, Lixin; Lu, Shiwei; Cao, Guoying

    2004-03-15

    Experimental data are presented to show the influence of asphaltenes and resins on the stability and demulsification of emulsions. It was found that emulsion stability was related to the concentrations of the asphaltene and resin in the crude oil, and the state of dispersion of the asphaltenes and resins (molecular vs colloidal) was critical to the strength or rigidity of interfacial films and hence to the stability of the emulsions. Based on this research, a possible emulsion minimization approach in refineries, which can be implemented utilizing microwave radiation, is also suggested. Comparing with conventional heating, microwave radiation can enhance the demulsification rate by an order of magnitude. The demulsification efficiency reaches 100% in a very short time under microwave radiation. PMID:14972628

  9. Computational fluid dynamics (CFD) analysis of the combustion process of a leather residuals gasification fuel gas: influence of fuel moisture content

    Energy Technology Data Exchange (ETDEWEB)

    Antonietti, Anderson Jose; Beskow, Arthur Bortolin; Silva, Cristiano Vitorino da [Universidade Regional Integrada do Alto Uruguai e das Missoes (URI), Erechim, RS (Brazil)], E-mails: arthur@uricer.edu.br, mlsperb@unisinos.br; Indrusiak, Maria Luiza Sperb [Universidade do Vale do Rio dos Sinos (UNISINOS), Sao Leopoldo, RS (Brazil)], E-mail: cristiano@uricer.edu.br

    2010-07-01

    This work presents a numerical study of the combustion process of leather residuals gasification gas, aiming the improvement of the process efficiency, considering different concentrations of water on the gas. The heating produced in this combustion process can be used to generation of thermal and/or electrical energy, for use at the leather industrial plant. However, the direct burning of this leather-residual-gas into the chambers is not straightforward. The alternative in development consists in processing this leather residuals by gasification or pyrolysis, separating the volatiles and products of incomplete combustion, for after use as fuel in a boiler. At these processes, different quantities of water can be used, resulting at different levels of moisture content in this fuel gas. This humidity can affect significantly the burning of this fuel, producing unburnt gases, as the carbon monoxide, or toxic gases as NOx, which must have their production minimized on the process, with the purpose of reducing the emission of pollutants to the atmosphere. Other environment-harmful-gases, remaining of the chemical treatment employed at leather manufacture, as cyanide, and hydrocarbons as toluene, must burn too, and the moisture content has influence on it. At this way, to increase understanding of the influence of moisture in the combustion process, it was made a numerical investigation study of reacting flow in the furnace, evaluating the temperature field, the chemical species concentration fields, flow mechanics and heat transfer at the process. The commercial CFD code CFX Ansys Inc. was used. Considering different moisture contents in the fuel used on the combustion process, with this study was possible to achieve the most efficient burning operation parameters, with improvement of combustion efficiency, and reduction of environmental harmful gases emissions. It was verified that the different moisture contents in the fuel gas demand different operation conditions

  10. Degradation of Asphaltenic Fraction by Locally Isolated Halotolerant Bacterial Strains

    OpenAIRE

    Ali, Hager R.; Nour Sh. El-Gendy; Moustafa, Yasser M.; Roushdy, Mohamed I.; Hashem, Ahmed I.

    2012-01-01

    Three halotolerant bacterial species were isolated from locally oil-polluted water sample for their ability to utilize asphaltene (Asph) fraction as sole carbon and energy source. These bacteria degrade 83–96% of 2500 mg/L asphaltene within 21 d at 30°C and pH7. They were identified as Bacillus sp. Asph1, Pseudomonas aeruginosa Asph2, and Micrococcus sp. Asph3. A statistically significant difference at 95% confidence level for cell growth and percentage biodegradation (%BD) was observed in al...

  11. The effect of asphaltene particle size and distribution on the temporal advancement of the asphaltene deposition profile in the well column

    Science.gov (United States)

    Zeinali Hasanvand, Mahdi; Mosayebi Behbahani, Reza; Feyzi, Farzaneh; Ali Mousavi Dehghani, Seyed

    2016-05-01

    Asphaltene deposition in oil wells is an inconvenient production problem. Generating a precise deposition model for the well column is essential for optimal well design and prevention/reduction of deposition-associated difficulties. The goal of this study is to determine the effects of various parameters on the deposition process. These parameters include oil viscosity, temperature, flow velocity, well diameter and asphaltene particle size and particle size distribution. The first five parameters are analyzed using Escobedo and Mansoori (2010), Cleaver and Yates (1975) and Friedlander and Johnstone (1957) asphaltene deposition models. The last parameter (asphaltene particle size distribution) is not directly included in the asphaltene deposition models. Therefore, a dynamic well column model is generated by combining transport phenomena (mass, heat and momentum transfer) equations with thermodynamic models. The model is fine-tuned and verified based on field data from an Iranian producing oil well with frequent asphaltene deposition problem and subsequently used for predicting the time-dependent development of the asphaltene deposition profile in the well column for a series of asphaltene particle size distributions. The results show the effect of the said parameters depends on how the buffer layer and Brownian motion are defined. The Escobedo and Mansoori (2010) model is found to make better predictions of deposited asphaltene in the studied well.

  12. 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

    2009-09-01

    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.

  13. Asphaltene detection using surface enhanced Raman scattering (SERS).

    Science.gov (United States)

    Alabi, O O; Edilbi, A N F; Brolly, C; Muirhead, D; Parnell, J; Stacey, R; Bowden, S A

    2015-04-28

    Surface enhanced Raman spectroscopy using a gold substrate and excitation at 514 nm can detect sub parts per million quantities of asphaltene and thereby petroleum. This simple format and sensitivity make it transformative for applications including sample triage, flow assurance, environmental protection and analysis of unique one of a kind materials. PMID:25812164

  14. Langmuir films of asphaltene model compounds and their fluorescent properties.

    Science.gov (United States)

    Nordgård, Erland L; Landsem, Eva; Sjöblom, Johan

    2008-08-19

    The relationship between the physicochemical properties of asphaltenes and asphaltene structure is an issue of increasing focus. Surface pressure-area isotherms of asphaltene model compounds have been investigated to gain more knowledge of their arrangement at an aqueous surface. Variations in interfacial activity have been correlated to proposed arrangements. The presence of a carboxylic acid has shown to be crucial for their interfacial activity and film properties. The acid group directs the molecules normal to the surface, forming a stable monolayer film. The high stability was absent when no acidic groups were present. Fluorescence spectra of deposited Langmuir-Blodgett films showed only the presence of the excimer emission for thin films of acidic model compounds, indicating a close face-to-face arrangement of the molecules. Time-correlated single photon counting (TCSPC) of the model compounds in toluene indicated the presence of aggregates for two of four compounds at low concentrations. However, a sudden drop of interfacial tension observed could not be correlated to the aggregation. Instead, aggregation induced by addition of a "poor" solvent showed decreased interfacial activity when aggregated due to decrease of monomers in bulk. The findings regarding these asphaltene model compounds and their structural differences show the great effect an acidic group has on their physicochemical properties. PMID:18652499

  15. A Thermodynamic Mixed-Solid Asphaltene Precipitation Model

    DEFF Research Database (Denmark)

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

    1998-01-01

    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 activi...

  16. Aggregation of model asphaltenes: a molecular dynamics study.

    Science.gov (United States)

    Costa, J L L F S; Simionesie, D; Zhang, Z J; Mulheran, P A

    2016-10-01

    Natural asphaltenes are defined as polyaromatic compounds whose chemical composition and structure are dependent on their geological origin and production history, hence are regarded as complex molecules with aromatic cores and aliphatic tails that occur in the heaviest fraction of crude oil. The aggregation of asphaltenes presents a range of technical challenges to the production and processing of oil. In this work we study the behaviour of the model asphaltene-like molecule hexa-tert-butylhexa-peri-hexabenzocoronene (HTBHBC) using molecular dynamics simulation. It was found that the regular arrangement of the tert-butyl side chains prevents the formation of strongly-bound dimers by severely restricting the configurational space of the aggregation pathway. In contrast, a modified molecule with only 3 side chains is readily able to form dimers. This work therefore confirms the influence of the molecular structure of polyaromatic compounds on their aggregation mechanism, and reveals the unexpected design rules required for model systems that can mimic the behavior of asphaltenes. PMID:27465036

  17. Microfluidic investigation of the deposition of asphaltenes in porous media.

    Science.gov (United States)

    Hu, Chuntian; Morris, James E; Hartman, Ryan L

    2014-06-21

    The deposition of asphaltenes in porous media, an important problem in science and macromolecular engineering, was for the first time investigated in a transparent packed-bed microreactor (μPBR) with online analytics to generate high-throughput information. Residence time distributions of the μPBR before and after loading with ~29 μm quartz particles were measured using inline UV-Vis spectroscopy. Stable packings of quartz particles with porosity of ~40% and permeability of ~500 mD were obtained. The presence of the packing materials reduced dispersion under the same velocity via estimation of dispersion coefficients and the Bodenstein number. Reynolds number was observed to influence the asphaltene deposition mechanism. For larger Reynolds numbers, mechanical entrapment likely resulted in significant pressure drops for less pore volumes injected and less mass of asphaltenes being retained under the same maximum dimensionless pressure drop. The innovation of packed-bed microfluidics for investigations on asphaltene deposition mechanisms could contribute to society by bridging macromolecular science with microsystems. PMID:24777527

  18. A Thermodynamic Mixed-Solid Asphaltene Precipitation Model

    DEFF Research Database (Denmark)

    Lindeloff, Niels; Heidemann, R.A.; Andersen, Simon Ivar; Stenby, Erling Halfdan

    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...

  19. Water-in-Hydrocarbon Emulsions Stabilized by Asphaltenes at Low Concentrations.

    Science.gov (United States)

    Yarranton; Hussein; Masliyah

    2000-08-01

    The role of Athabasca asphaltene particles and molecules in stabilizing emulsions was examined by measuring the surface area of water-in-toluene/hexane emulsions stabilized by various asphaltene fractions, each with a different proportion of soluble and insoluble asphaltenes. The stabilized interfacial area was found to depend only on the amount of soluble asphaltenes. Furthermore, the amount of asphaltenes on the interface was consistent with molecular monolayer coverage. Hence, at low concentrations, asphaltenes appear to both act as a molecular surfactant and stabilize emulsions. The effect of the hexane : toluene ratio on emulsion stability was examined as well. At lower hexane : toluene ratios, more asphaltenes were soluble but the surface activity of a given asphaltene molecule was reduced. The two effects oppose each other but, in general, a smaller fraction of asphaltenes appeared to stabilize emulsions at lower hexane : toluene ratios. The results imply that the emulsifying capacity of asphaltenes is reduced but not eliminated in better solvents. Copyright 2000 Academic Press. PMID:10882493

  20. 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)

    2008-08-15

    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.

  1. The importance of asphaltene origin on its behaviour in production systems

    Energy Technology Data Exchange (ETDEWEB)

    Grutters, M.; Stankiewicz, A.; Cornelisse, P.; Utech, N. [Shell Global Solutions, The Hague (Netherlands)

    2008-07-01

    Despite much progress in characterizing asphaltenes, little is known about the relation between the size and shape of asphaltenes and their impact on flow assurance. This lack of understanding is related primarily to the fact that the asphaltenes structure found in crudes depends on many geochemical processes that are generally not included as input for flow assurance studies. The geochemical processes that are important to asphaltenes are type of source rock and deposited organic matter, maturity, migration history, and processes in the reservoir as hybridization and biodegradation. A careful examination of geochemical processes can reveal the relationship between asphaltene behaviour in fields that are seemingly very different or distant. This paper provided some examples of these relationships. Understanding the structure of asphaltenes is critical and warrants the further development of methods for more accurate characterization.

  2. Method for determining asphaltene stability of a hydrocarbon-containing material

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-02-05

    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.

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

    OpenAIRE

    Bahrami Peyman; Kharrat Riyaz; Mahdavi Sedigheh; Firoozinia Hamed

    2015-01-01

    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 face...

  4. Bayesian Belief Network Method for Predicting Asphaltene Precipitation in Light Oil Reservoirs

    OpenAIRE

    Jeffrey O. Oseh (M.Sc.); Olugbenga A. Falode (Ph.D)

    2015-01-01

    Asphaltene precipitation is caused by a number of factors including changes in pressure, temperature, and composition. The two most prevalent causes of asphaltene precipitation in light oil reservoirs are decreasing pressure and mixing oil with injected solvent in improved oil recovery processes. This study focused on predicting the amount of asphaltene precipitation with increasing Gas-Oil Ratio in a light oil reservoir using Bayesian Belief Network Method. These Artificial Intelligence-Baye...

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

    OpenAIRE

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

    2015-01-01

    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 of mechanical response properties. In an interdisciplinary study the impact of the maltene phase and asphaltenes on the linear viscoelastic behavior and the microstructure of bitumen were analyzed...

  6. The acoustic spectroscopy of asphaltene aggregation in petroleum

    International Nuclear Information System (INIS)

    A sphaltenes are well known to be important in causing blockages during production, transportation and refining. They are also responsible for the formation of tar mats in petroleum reservoirs, which can impede crude oil recovery. Acoustic spectroscopy in the frequency range 2 – 120 MHz was used to detect the aggregation of asphaltenes in a North Sea crude oil (UK continental shelf). In the absence of aggregation, both the toluene solvent and the maltenes isolated from the oil exhibit a power law dependence which is a function of the continuous phase. In contrast the crude oil itself showed clear signs of a changing size of the scattering entities. With sufficient information, it may in future be possible to determine the size of the scattering particles from the acoustic spectrum including the changing size of the asphaltene particles during aggregation.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

    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.

  8. Cooee bitumen II: Stability of linear asphaltene nanoaggregates

    OpenAIRE

    Lemarchand, Claire,; Schrøder, Thomas; Dyre, J.C.; Hansen, Jesper Schmidt

    2014-01-01

    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 ...

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

    Energy Technology Data Exchange (ETDEWEB)

    Auflem, Inge Harald

    2002-07-01

    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

  10. Combustion apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, S.; Mitsudomi, H.

    1984-04-17

    A new burner provides the high temperatures required in the manufacture of high-grade china and artificial jewels by using air enriched with oxygen through an oxygen permselective membrane. Operators can vary the combustion air quantity and oxygen content as needed. Three flow paths arranged coaxially from a radially inner position to outside the burner supply it with the fuel, oxygen-enriched air, and combustion air. Each line is equipped with a control valve to allow variation in the furnace's heating power.

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

    Energy Technology Data Exchange (ETDEWEB)

    Deo, Milind D.

    2002-02-21

    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.

  12. Molecular dynamic simulation of asphaltene co-aggregation with humic acid during oil spill.

    Science.gov (United States)

    Zhu, Xinzhe; Chen, Daoyi; Wu, Guozhong

    2015-11-01

    Humic acid in water and sediment plays a key role in the fate and transport of the spilled oil, but little is known about its influence on the aggregation of heavy oil asphaltenes which is adverse for remediation. Molecular dynamic simulation was performed to characterize the co-aggregation of asphaltenes (continental model and Violanthrone-79 model) with Leonardite humic acid (LHA) at the toluene-water interface and in bulk water, respectively, to simulate the transport of asphaltenes from oil to water. At the toluene-water interface, a LHA layer tended to form and bind to the water by hydrogen bonding which provided a surface for the accumulation of asphaltenes by parallel or T-shape stacking. After entering the bulk water, asphaltene aggregates stacked in parallel were tightly sequestrated inside the inner cavity of LHA aggregates following surface adsorption and structure deformation. Asphaltene aggregation in water was 2-fold higher than at the toluene-water interface. The presence of LHA increased the intensity of asphaltene aggregation by up to 83% in bulk water while relatively less influence was observed at the toluene-water interface. Overall results suggested that the co-aggregation of asphaltene with humic acid should be incorporated to the current oil spill models for better interpreting the overall environmental risks of oil spill. PMID:26149857

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

    International Nuclear Information System (INIS)

    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)

  14. An experimental study of asphaltene particle sizes in n-heptane-toluene mixtures by light scattering

    Directory of Open Access Journals (Sweden)

    Rajagopal K.

    2004-01-01

    Full Text Available The particle size of asphaltene flocculates has been the subject of many recent studies because of its importance in the control of deposition in petroleum production and processing. We measured the size of asphaltene flocculates in toluene and toluene - n-heptane mixtures, using the light-scattering technique. The asphaltenes had been extracted from Brazilian oil from the Campos Basin, according to British Standards Method IP-143/82. The asphaltene concentration in solution ranged between 10-6 g/ml and 10-7 g/ml. Sizes was measured for a period of about 10000 minutes at a constant temperature of 20°C. We found that the average size of the particles remained constant with time and increase with an increase in amount of n-heptane. The correlation obtained for size with concentration will be useful in asphaltene precipitation models.

  15. The formation of rag layers and the role of interfacial partition of naphthenates and asphaltenes

    Energy Technology Data Exchange (ETDEWEB)

    Moran, K. [Syncrude, Edmonton, AB (Canada); Kiran, S.; Acosta, E.J. [Toronto Univ., ON (Canada). Dept. of Chemical Engineering and Applied Chemistry

    2008-07-01

    Stable emulsions of oil and water are known as rag layers and have been associated with the precipitation of asphaltenes and the formation of liquid crystal phases. This paper presented optical microscopy studies of rag layers produced under different conditions. Liquid crystal formation was observed only under specific conditions, such as in the presence of un-dissociated naphthenic acids. Liquid crystal phases were not observed in the absence of naphthenic acids or in the presence of sodium naphthenates. The formation of rag layer was associated to the fraction of asphaltene where the oil was reduced. Optical micrographs showed that the droplets of oil and/or water in the rag layer were not stabilized by the particles of asphaltene precipitated. These observations were explained using a hypothesis of asphaltene interfacial partition, whereby the asphaltene molecules accumulate near the oil/water interface to form skins that inhibit their coalescence and separation.

  16. 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: geiza.oliveira@ufes.br [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

    2013-11-01

    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)

  17. Evaluation of the asphaltenes macromolecules stabilization by alkylbenzenes compounds; Avaliacao da estabilizacao de macromoleculas asfaltenicas por compostos alquilbenzenicos

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, G.E.; Mansur, C.R.E.; Lucas, E.F. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Macromoleculas]. E-mail: elucas@ima.ufrj.br; geiza@ima.ufrj.br; Gonzalez, G. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas]. E-mail: gaspar@cenpes.petrobras.com.br

    2003-07-01

    The asphaltene deposition is a problem that affects oil production, transportation and storage. Some researches about asphaltene stabilization have been made in order to avoid its flocculation and deposition. In this work, the performance of four alkylbenzene compounds as asphaltene stabilizer was evaluated. The additive were tested in two different concentrations: 5000 and 10000 mg/L. Cardanol, polycardanol, polystyrene and polystyrene sulfonade were used as additive. The study was carried out by asphaltene precipitation in a solvent mixture (toluene and heptane), since that the asphaltene solubility in these solvents are different. The best results were obtained by using cardanol, at 5000 mg/L. (author)

  18. Geochemistry of raw Asphaltenes of the Oriental Plains

    International Nuclear Information System (INIS)

    Were studied samples of asphaltenes previously separate from 44 raw (p.eb ≥ 200 Celsius degrades) of the three regions of the Oriental Plains: Meta, Casanare and Arauca. The elementary analysis of asphaltenes samples of was carried out in a Carlo Erba CHNS analyzing, with a Coulometric auxiliary of Sulfur (Western Atlas, Core Laboratories). Starting from this analysis the atomic relationships were calculated (H/C), (O/C), (N/S), (C/S) and (C/N) which were used to discriminate or to separate the samples in groups. The pyrolysis Rock-eval was carried out on 20 mg, of each sample diluted with 80 mg of fine quartz, in order to avoiding the problems that are presented when it works with samples that contain more than 20% of Total Organic Carbon (COT). The results of this pyrolysis allowed establishing the presence of six groups or families in the samples of asphaltenes. It was also proven that the raw of the Arauca Field is of terrestrial origin while those of Cano Limon are originated of marine kerogens. With Nuclear Magnetic Resonance of proton (RMN of H) the percentages of Ha, Hβ, Ha, Hox y HAR+F, were calculated as well as the percentage of carbon aromatic insubstituted (% CAR (US)). Also, it was calculated the Aromatic Factor, FA and the substitution degree a, they were also calculated starting from these data the relationships FA/s, Hα/Hox+F y Hα/Hβ. When correlating the diverse data obtained starting from the elementary analysis to each other, the pyrolysis rock-eval and the RMN of H was possible to find two families or groups of raw in each one of the three areas of the Oriental Plains, giving a total of six families or groups of raw in the 44 studied samples. The correlations were: S2/S3 versus (N/S)AT, (C/S)AT versus FA/a, % Car (US) versus FA/d, FA versus, Ha /Ha r+d versus F A/d. Keeping in mind that Behar et al (1984) they concluded in their investigation of asphalts Geochemistry that the gases chromatography (PY -GC) of asphalts it could be used for

  19. Bubble Combustion

    Science.gov (United States)

    Corrigan, Jackie

    2004-01-01

    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

  20. Characterization of Physically and Chemically Separated Athabasca Asphaltenes Using Small-Angle X-ray Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Amundaraín Hurtado, Jesús Leonardo; Chodakowski, Martin; Long, Bingwen; Shaw, John M. (Alberta)

    2012-02-07

    Athabasca asphaltenes were characterized using small-angle X-ray scattering (SAXS). Two methods were used to separate asphaltenes from the Athabasca bitumen: namely, chemical separation by precipitation with n-pentane and physical separation by nanofiltration using a zirconia membrane with a 20 nm average pore size. The permeate and chemically separated samples were diluted in 1-methylnaphtalene and n-dodecane prior to SAXS measurements. The temperature and asphaltene concentration ranges were 50-310 C and 1-10.4 wt %, respectively. Model-independent analysis of SAXS data provided the radius of gyration and the scattering coefficients. Model-dependent fits provided size distributions for asphaltenes assuming that they are dense and spherical. Model-independent analysis for physically and chemically separated asphaltenes showed significant differences in nominal size and structure, and the temperature dependence of structural properties. The results challenge the merits of using chemically separated asphaltene properties as a basis for asphaltene property prediction in hydrocarbon resources. While the residuals for model-dependent fits are small, the results are inconsistent with the structural parameters obtained from model-independent analysis.

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

    KAUST Repository

    Zhang, Long Li

    2015-01-01

    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.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    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...... is determined using the existing SARA fractions experimental data for this purpose. The powerful Least-Square modification of Support Vector Machine (LSSVM) strategy is applied to develop a computer program, by which the asphaltene stability region can be determined for various crudes. The developed two...

  3. Investigating molecular interactions and surface morphology of wax-doped asphaltenes.

    Science.gov (United States)

    Pahlavan, Farideh; Mousavi, Masoumeh; Hung, Albert; Fini, Ellie H

    2016-04-01

    The nature and origin of bee-like microstructures (bees) in asphalt binders and their impact on asphalt oxidation have been the subject of extensive discussions in recent years. While several studies refer to the bees as solely surface features, some others consider them to be bulk microcrystalline components that are formed due to co-precipitation of wax and asphaltene molecules. In this study, we use a rigorous theoretical and experimental approach to investigate the interplay of asphalt components (mainly asphaltene and wax) and their impact on bee formation. In the theoretical section, quantum-mechanical calculations using density functional theory (DFT) are used to evaluate the strength of interactions between asphaltene unit sheets in the presence and absence of a wax component, as well as the mutual interactions between asphaltene molecules (monomers and dimers) and paraffin wax. The results of this section reveal that paraffin waxes not only do not reinforce the interaction between the asphaltene unit sheets, they destabilize asphaltene assembly and dimerization. AIM (Atom in Molecules) analysis shows the destabilizing effect of wax on asphaltene assembly as a reduction in the number of cage and bond critical points between asphaltenes. This destabilization effect among interacting systems (asphaltene-asphaltene and wax-asphaltene) does not support the hypothesis that interaction between paraffin waxes and non-wax components, such as asphaltene, is responsible for their co-precipitation and bee formation. To further examine the effect of wax component on asphalt microstructure experimentally, we used atomic force microscopy (AFM) to study the surface morphology of an asphalt sample doped with 1% to 25% paraffin wax. In agreement with the conclusions drawn from the DFT approach, our experiments indicate that paraffin wax tends to crystallize separately and form lamellar paraffin wax crystal inclusions with 10 nm thickness. Moreover, the addition of 3% wax

  4. Exposure to coal combustion residues during metamorphosis elevates corticosterone content and adversely affects oral morphology, growth, and development in Rana sphenocephala

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, J.D.; Peterson, V.A.; Mendonca, M.T. [Auburn University, Auburn, AL (USA). Dept. of Biological Science

    2009-01-15

    Coal combustion residues (CCRs) are documented to negatively impact oral morphology, growth, and development in larval amphibians. It is currently unclear what physiological mechanisms may mediate these effects. Corticosterone, a glucocorticoid hormone, is a likely mediator because when administered exogenously it, like CCRs, also negatively influences oral morphology, growth, and development in larval amphibians. In an attempt to identify if corticosterone mediates these effects, we raised larval Southern Leopard Frogs, Rana sphenocephala, on either sand or CCR substrate and documented effects of sediment type on whole body corticosterone, oral morphology, and time to and mass at key metamorphic stages. Coal combustion residue treated tadpoles contained significantly more corticosterone than controls throughout metamorphosis. However, significantly more oral abnormalities occurred early in metamorphosis when differences in corticosterone levels between treatments were minimal. Overall, CCR-treated tadpoles took significantly more time to transition between key stages and gained less mass between stages than controls, but these differences between treatments decreased during later stages when corticosterone differences between treatments were greatest. Our results suggest endogenous increase in corticosterone content and its influence on oral morphology, growth and development is more complex than previously thought.

  5. Performance, emission and combustion characteristic of a multicylinder DI diesel engine running on diesel-ethanol-biodiesel blends of high ethanol content

    International Nuclear Information System (INIS)

    Highlights: → Diesel-ethanol-biodiesel blends of high ethanol content are tested for a Multicylinder DI diesel engine. → Brake specific fuel consumption is increased but the brake thermal efficiency is improved for high ethanol content blends. → Combustion process of high ethanol content blend is delayed at low loads but approached to the diesel fuel at high loads. → Smoke reduced remarkably at high loads for steady state but no benefit is observed on peak smoke during free acceleration. → NO emission variation depends on operating conditions while CO emissions drastically increased at low loads. -- Abstract: Feasibility of using high percentage of ethanol in diesel-ethanol blends, with biodiesel as a co-solvent and properties enhancer has been investigated. The blends tested are D70/E20/B10 (blend A), D50/E30/B20 (blend B) D50/E40/B10 (blend C), and Diesel (D100). The blends are prepared to get maximum percentage of oxygen content but keeping important properties such as density, viscosity and Cetane index within acceptable limits. Experiments are conducted on a multicylinder, DI diesel engine, whose original injection timing was 13o CA BTDC. The engine did not run on blends B and C at this injection timing and it was required to advance timing to 18o and 21o CA BTDC to enable the use of blends B and C respectively. However advancing injection timing almost doubled the NO emissions and increased peak firing pressure. The P-θ and net heat release diagrams shows that the combustion process of these blends delayed at low loads but approaches to the diesel fuel at high loads. The comparison of blend results with baseline diesel showed that brake specific fuel consumption increased considerably, thermal efficiency improved slightly, smoke opacity reduced remarkably at high loads. NO variation depends on operating conditions while CO emissions drastically increased at low loads. Blend B which replaced 50% diesel and having oxygen content up to 12.21% by

  6. Process of spontaneous combustion of solid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Postrzednik, S.; Bialecki, R.; Nowak, A. (Politechnika Slaska, Gliwice (Poland))

    1988-01-01

    Reviews literature on coal spontaneous combustion and oxidation. The following aspects are discussed: low-temperature oxidation, medium and high-temperature oxidation, theories of spontaneous coal combustion (bacteria theory, phenol theory, water-coal system theory, water adsorption theory), factors that influence spontaneous combustion (coal rank, petrology, porosity, moisture content, storage method, storage temperature, air circulation, macrostructure and geometry of the system for storage of coal), effects of mineral content on coal hazards of spontaneous combustion, physicochemical phenomena that influence spontaneous combustion, laboratory investigations into spontaneous combustion, experimental methods used in laboratory investigations, forecasting energy effects of spontaneous combustion, mathematical models of coal spontaneous combustion. 94 refs.

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

    Energy Technology Data Exchange (ETDEWEB)

    Deo, Milind D.

    2002-02-21

    Objectives of this project was to understand asphaltene precipitation in General and carbon dioxide induced precipitation in particular. To this effect, thermodynamic and kinetic experiments with the Rangely crude oil were conducted and thermodynamic and reservoir models were developed.

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

    DEFF Research Database (Denmark)

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

    2004-01-01

    The self-association of asphaltenes in toluene is believed to occur step-wise, rather than by the formation of micelles. A number of step-wise models have been used to fit the calorimetric titration of asphaltenes in dried toluene solutions, with excellent results. All the models are based on...... chemical reactions equivalent to the ones found in polymerization. The study shows that the choice of the average properties of asphaltenes, such as the molecular weight, is critical in the final value of the parameter of interest, namely the average heat of self-association DeltaH(a). The low values of...... because it does not self-associate or because the dilution effect is not strong enough to break the aggregates. Fluorescence and IR spectroscopy experiments confirm there is self-association in INS fraction, leading to the conclusion that asphaltene aggregates are formed by bonds of different strengths...

  9. Bayesian Belief Network Method for Predicting Asphaltene Precipitation in Light Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Jeffrey O. Oseh (M.Sc.

    2015-04-01

    Full Text Available Asphaltene precipitation is caused by a number of factors including changes in pressure, temperature, and composition. The two most prevalent causes of asphaltene precipitation in light oil reservoirs are decreasing pressure and mixing oil with injected solvent in improved oil recovery processes. This study focused on predicting the amount of asphaltene precipitation with increasing Gas-Oil Ratio in a light oil reservoir using Bayesian Belief Network Method. These Artificial Intelligence-Bayesian Belief Network Method employed were validated and tested by unseen data to determine their accuracy and trend stability and were also compared with the findings obtained from Scaling equations. The obtained Bayesian Belief Network results indicated that the method showed an improved performance of predicting the amount of asphaltene precipitated in light oil reservoirs thus reducing the number of experiments required.

  10. Studies of water-in-oil emulsions: the role of asphaltenes and resins

    International Nuclear Information System (INIS)

    Experiments were conducted to study the role of asphaltenes in water-in-oil emulsions. Asphaltenes are the agents that act like surfactants and are responsible for the formation and stability of these emulsions. Experiments were conducted on an emulsion that had been standing for three months, and on a salt water-oil emulsion. A series of tests were performed to study how asphaltenes would migrate in the absence of a strong gravity effect. All the experiments showed that asphaltenes migrate to the oil-water interface from the oil. This explains why an emulsion which sits for a long time can become more viscous and more stable as time progresses. Future work will determine whether resins will behave in the same manner. 36 refs., 2 tabs

  11. Investigation of asphaltene precipitation in miscible gas injection processes: experimental study and modeling

    Directory of Open Access Journals (Sweden)

    S. Moradi

    2012-09-01

    Full Text Available Asphaltene precipitation during natural depletion and miscible gas injection is a common problem in oilfields throughout the world. In this work, static precipitation tests are conducted to investigate the effects of pressure, temperature and gas type and concentration on asphaltene instability. Three different oil samples have been studied under reservoir conditions with/without nitrogen and methane injection. Besides applying common thermodynamic models, a new scaling equation is presented to predict asphaltene precipitation under HPHT gas injection. Extensive published data from the literature are also used in model development. The scaling approach is attractive because it is simple and complex asphaltene properties are not involved in the calculations. Moreover, the proposed model provides universal parameters for different fluid samples over a wide range of pressure and temperature that makes it novel for evaluation of future gas injection projects when simple PVT data are available.

  12. Evaluation of bromine and iodine content of milk whey proteins combining digestion by microwave-induced combustion and ICP-MS determination.

    Science.gov (United States)

    da Silva, Sabrina Vieira; Picoloto, Rochele Sogari; Flores, Erico Marlon Moraes; Wagner, Roger; dos Santos Richards, Neila Silvia Pereira; Barin, Juliano Smanioto

    2016-01-01

    The bromine and iodine content of whey protein concentrate (WPC), hydrolysate (WPH), and isolate (WPI) was evaluated combining microwave-induced combustion (MIC) digestion with inductively coupled plasma mass spectrometry (ICP-MS) determination. MIC digestion allowed the decomposition of up to 500 mg of samples using diluted NH4OH solution (25 mmol L(-1)) for absorption of analytes, assuring the compatibility with ICP-MS determination. Accuracy was evaluated using milk powder certified reference material (NIST 8435) with good agreements for Br and I (102% and 105%, respectively). For Br and I, the limit of quantification obtained by ICP-MS was 7 and 281 times lower in comparison with ion chromatography determination, respectively. Iodine could be enriched in whey protein production and up to 70% of the tolerable upper intake level was found, thus revealing the need to monitor it in whey proteins. On the other hand, the concentration of Br was below its acceptable daily intake. PMID:26212983

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

    Directory of Open Access Journals (Sweden)

    Bahrami Peyman

    2015-11-01

    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.

  14. Effect of CO Combustion Promoters on Combustion Air Partition in FCC under Nearly Complete Combustion

    Institute of Scientific and Technical Information of China (English)

    王锐; 罗雄麟; 许锋

    2014-01-01

    With CO combustion promoters, the role of combustion air flow rate for concerns of economics and control is important. The combustion air is conceptually divided to three parts:the air consumed by coke burning, the air consumed by CO combustion and the air unreacted. A mathematical model of a fluid catalytic cracking (FCC) unit, which includes a quantitative correlation of CO heterogeneous combustion and the amount of CO combustion promoters, is introduced to investigate the effects of promoters on the three parts of combustion air. The results show that the air consumed by coke burning is almost linear to combustion air flow rate, while the air consumed by CO combustion promoters tends to saturate as combustion air flow rate increases, indicating that higher air flow rate can only be used as a manipulated variable to control the oxygen content for an economic concern.

  15. Kinetic studies on the pyrolysis of asphaltenes from differenttypes of kerogens

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The pyrolysis kinetics of a series of asphaltenes, from different types of kerogens, are studied in this work. The results indicate that the distributions of activation energy are over a wide range for the asphaltenes from type I kerogens. There is still a large potential of hydrocarbon generation in case the activation energy is above 350 kJ·mol-1. While the distributions of activation energy are comparatively over a narrow range for the asphaltenes from type II and II kerogens,there is a little or almost no potential of hydrocarbon generation with the activation energy above 350 kJ·mol-1 respectively. For the asphaltenes from some specific type of kerogens, the pyrolysis kinetics can be applied to marking their maturity. Furthermore, based on detailed discussions of the kinetics parameter frequency factor, the asphaltenes from type I kerogens are considered to be of great potential to regenerate oils, while the asphaltenes' potential for oil-to-gas conversion tends to go down in order of primitive kerogen types of Ⅲ II and I.

  16. Structural Characterisation of Asphaltenes during Residue Hydrotreatment with Light Cycle Oil as an Additive

    Directory of Open Access Journals (Sweden)

    Yong-Jun Liu

    2015-01-01

    Full Text Available Several atmospheric residues (AR of Kuwaiti crude, in the absence, or in the presence, of light cycle oil (LCO as an aromatic additive, were hydrotreated in an experimental plant. Asphaltenes (precipitated from Kuwaiti AR, a hydrotreated AR, and a hydrotreated blend of AR and LCO were characterised by chemical structure and changes during residue hydrotreatment. The average structural parameters of these asphaltenes, obtained from a combined method of element analysis, average molecular weight, X-ray diffraction, and NMR, demonstrate that, after hydrotreatment, the aromatic cores of the asphaltenes become more compact and smaller whereas the peripheral alkyl branches are decreased in number and shortened. The influence of LCO on residue hydrotreating is also studied in terms of structural changes in the asphaltenes. The findings imply that LCO added to AR during hydrotreating improves the degree of aromatic substitution, the total hydrogen/carbon atomic ratio per average molecule, the distance between aromatic sheets and aliphatic chains, and so forth, by modifying the colloidal nature and microstructure of asphaltene: this is beneficial for the further hydroprocessing of AR. Three hypothetical average molecules are proposed to represent the changes undergone by such asphaltenes during hydrotreatment as well as the effects of additive LCO.

  17. Asphaltene macrostructure of petroleum crude investigated by small angle neutron scattering

    International Nuclear Information System (INIS)

    Complete text of publication follows. The amount and the phase stability of the asphaltene fraction in petroleum and crude oils are important during the production, the processing and the transportation of these crude fluids. Small angle neutron scattering SANS technique was used to investigate the colloidal properties of an Algerian petroleum crude. Dilute samples with various concentrations up to 11% vol. were studied. The macrostructure of the present asphaltene fraction as well as its size distributions and volume fraction were extracted by modeling the experimental scattering data using a non linear least squares fitting program. The analysis results suggest that into the studied conditions, the petroleum crude asphaltene fraction seems to form stable micellar systems with a polydisperse globular like shape structures. It was found that the micelles mean size radius was about 2 nm and did not vary with the petroleum fluid medium concentration. The volume fraction of asphaltenes did not also increase with petroleum fluid medium concentration. These results suggest that the forming micelles were stable and there was no aggregation. In order to probe the internal structure of the asphaltene micelles the contrast variation technique was also performed on the isolated asphaltene fraction and from these results a form factor shape model was proposed. (author)

  18. Formation of asphaltene deposits from crude oil destabilized by addition of propane

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.; Creek, J. [Chevron Energy Technology Co., Houston, TX (United States); Fan, T.; Buckley, J. [New Mexico Inst. of Mining and Technology, NM (United States)

    2008-07-01

    As oil development moves into deeper water and deeper wells, it is increasingly important to predict the formation of asphaltene deposits. The first step toward predicting deposition is knowing the asphaltene stability as a function of temperature, pressure, and composition. Flocculated asphaltenes can segregate under the influence of gravity in low energy environments. The challenge lies in understanding the deposits that form on pipe walls in producing wells. This paper reported on a continuing study of arterial deposition from destabilized crude oils in stainless steel capillary tubing as a function of several variables, including the molecular size of the paraffinic precipitating agent. The initial studies revealed that destabilization of asphaltenes from a given crude oil with higher molecular weight precipitants produced a larger volume of asphaltene enriched deposit compared to a lower molecular weight precipitant with the same crude oil. Liquid n-paraffins precipitants from n-pentane to n-pentadecane were used in the initial studies. The data was then used to forecast precipitation with solution gas at different pressures and temperatures. In this present study, the range of paraffinic precipitants was extended to include propane for a comparative evaluation to determine the driving force for asphaltene precipitation in reservoir fluids.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yen, T. F.

    1979-01-01

    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.

  20. 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; R...... strategy is theoretically based on systems theory as formulated by Niklas Luhmann (Luhmann, 1995; 2002) and on own work, where. Luhmann’s general ideas and concepts of the educational system are transposed into a didactical framework (Keiding, 2005,2007,2008).......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......, is subordinating content to methods as seen in modern didactics, hereby transforming content to a medium for achievement of learning-to-learn skills rather than something valuable in its own right. At the level of general didactics quite few attempts have been made to formulate criteria and...

  1. COMPARISON BETWEEN ASPHALTENES (SUB)FRACTIONS EXTRACTED FROM TWO DIFFERENT ASPHALTIC RESIDUES: CHEMICAL CHARACTERIZATION AND PHASE BEHAVIOR

    OpenAIRE

    Silas R. Ferreira; Fabio R. Barreira; Luciana S. Spinelli; Katia Z. Leal; Peter Seidl; Elizabete F. Lucas

    2016-01-01

    Asphaltenes are blamed for various problems in the petroleum industry, especially formation of solid deposits and stabilization of water-in-oil emulsions. Many studies have been conducted to characterize chemical structures of asphaltenes and assess their phase behavior in crude oil or in model-systems of asphaltenes extracted from oil or asphaltic residues from refineries. However, due to the diversity and complexity of these structures, there is still much to be investigated. In this study,...

  2. Study on the interaction of asphaltenes macromolecules and stabilizer compounds: LCC and cardanol; Estudo da interatividade entre macromoleculas asfaltenicas e compostos estabilizantes: LCC e cardanol

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Luiz Fernando Bandeira; Lucas, Elizabete Fernandes [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Macromoleculas; Gonzalez, Gaspar [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    1998-09-01

    Petroleum contains asphaltene which can be precipitated, generating various problems affecting the crude oil production and transport, storage and processing. This work presents a mathematical adaptation of interaction models for the asphaltene-stabilizer system allowing prediction of stabilizer performance for avoiding asphaltene precipitation. The ashew liquid and particularly the cardanol have been studied by using the peptising test. The ashew and cardanol present the asphaltene stabilizer properties and positive properties in both cases. (author)

  3. CONTENTS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The Development and Evolution of the Idea of the Mandate of Heaven in the Zhou Dynasty The changes in the idea of Mandate of Heaven during the Shang and Zhou dynasties are of great significance in the course of the development of traditional Chinese culture. The quickening and awakening of the humanistic spirit was not the entire content of the Zhou idea of Mandate of Heaven. In the process of annihilating the Shang dynasty and setting up their state, the Zhou propagated the idea of the Mandate of Heaven out of practical needs. Their idea of the Mandate of Heaven was not very different from that of the Shang. From the Western Zhou on, the Zhou idea of Mandate of Heaven by no means developed in a linear way along a rational track. The intermingling of rationality and irrationality and of awakening and non-awakening remained the overall state of the Zhou intellectual superstructure after their "spiritual awakening".

  4. STUDY ON THE CHANGING OF COMPOSITION AND STRUCTURE OF ASPHALTENE DURING RESIDUE HYDROTREATING%渣油加氢处理中沥青质组成和结构的变化研究

    Institute of Scientific and Technical Information of China (English)

    王跃; 张会成; 凌凤香; 马波

    2012-01-01

    Residue oil hydrotreating experiments were carried out on a pilot plant unit to investigate the effect of reaction temperature and hydrotreating severity on the composition and the molecular structure of asphaltenes in the treated residue samples. Results showed that with the increase of reaction temperature or the depth of hydrogenation, the asphaltene content in the treated residue sample decreased; the sulfur, nickel and vanadium contents of asphaltene dropped, but the nitrogen content gave an increase trend. The average molecular structural parameters of asphaltene in the obtained samples were calculated from the spectrum of 1H-NMR and 13C-NMR. Results showed that with the increase of reaction temperature, the fraction of paraffins decreased and the fraction of aromatics increased; however, with the increase of hydrogenation depth, the fraction of paraffins increased and the fraction of aromatics decreased.%利用渣油加氢处理中试装置考察反应温度和加氢深度对加氢产物渣油中沥青质组成、结构的影响,结果表明:随温度或加氢深度增加,加氢产物渣油中沥青质含量降低,沥青质中硫、镍、钒含量降低,氮含量呈增加趋势.采用13C-NMR谱和1H-NMR谱,计算了沥青质的平均分子结构参数,结果表明:随着温度的升高,饱和碳分率逐渐下降,芳香碳分率逐渐升高;随着加氢深度增大,饱和碳分率逐渐升高,而芳香碳分率逐渐下降.

  5. The aggregation and diffusion of asphaltenes studied by GPU-accelerated dissipative particle dynamics

    Science.gov (United States)

    Wang, Sibo; Xu, Junbo; Wen, Hao

    2014-12-01

    The heavy crude oil consists of thousands of compounds and much of them have large molecular weights and complex structures. Studying the aggregation and diffusion behavior of asphaltenes can facilitate the understanding of the heavy crude oil. In previous studies, the fused aromatic rings were treated as rigid bodies so that dissipative particle dynamics (DPD) integrated with the quaternion method can be used to study asphaltene systems. In this work, DPD integrated with the quaternion method is implemented on graphics processing units (GPUs). Compared with the serial program, tens of times speedup can be achieved when simulations performed on a single GPU. Using multiple GPUs can provide faster computation speed and more storage space for simulations of significant large systems. By using large systems, simulations of the asphaltene-toluene system at extremely dilute concentrations can be performed. The determined diffusion coefficients of asphaltenes are similar to that in experimental studies. At last, the aggregation behavior of asphaltenes in heptane was investigated, and the simulation results agreed with the modified Yen model. Monomers, nanoaggregates and clusters were observed from the simulations at different concentrations.

  6. HEAVY OIL PROCESS MONITOR: AUTOMATED ON-COLUMN ASPHALTENE PRECIPITATION AND RE-DISSOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    John F. Schabron; Joseph F. Rovani Jr; Mark Sanderson

    2006-06-01

    About 37-50% (w/w) of the heptane asphaltenes from unpyrolyzed residua dissolve in cyclohexane. As pyrolysis progresses, this number decrease to below 15% as coke and toluene insoluble pre-coke materials appear. This solubility measurement can be used after coke begins to form, unlike the flocculation titration, which cannot be applied to multi-phase systems. Currently, the procedure for the isolation of heptane asphaltenes and the determination of the amount of asphaltenes soluble in cyclohexane spans three days. A more rapid method to measure asphaltene solubility was explored using a novel on-column asphaltene precipitation and re-dissolution technique. This was automated using high performance liquid chromatography (HPLC) equipment with a step gradient sequence using the solvents: heptane, cyclohexane, toluene:methanol (98:2). Results for four series of original and pyrolyzed residua were compared with data from the gravimetric method. The measurement time was reduced from three days to forty minutes. The separation was expanded further with the use of four solvents: heptane, cyclohexane, toluene, and cyclohexanone or methylene chloride. This provides a fourth peak which represents the most polar components, in the oil.

  7. Asphaltene precipitation and its effects on the vapour extraction (VAPEX) heavy oil recovery process

    Energy Technology Data Exchange (ETDEWEB)

    Luo, P.; Wang, X.; Gu, Y. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[Regina Univ., SK (Canada). Petroleum Technology Research Centre; Zhang, H. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[Core Laboratories Canada Ltd., Calgary, AB (Canada); Moghadam, L. [Fekete Associates Inc., Calgary, AB (Canada)

    2008-10-15

    One of the most important physical phenomena during the solvent vapour extraction (VAPEX) of heavy oil recovery is asphaltene precipitation. After the asphaltene precipitation occurs, the produced heavy oil is deasphalted in-situ, resulting in a lower viscosity and better quality. However, precipitated asphaltenes may plug some small pores of the reservoir formation, thus reducing its permeability. This paper examined the effects of three operating factors on the asphaltene precipitation during the VAPEX process, notably solvent type; operating pressure; and sand-pack permeability. Eight VAPEX tests were conducted to recover two different Lloydminster heavy oil samples from a rectangular sand-packed physical model with a butane mixture and propane as the respective solvents. The accumulative heavy oil and solvent production from the physical model were measured in the entire VAPEX process. The paper described the materials, experimental set-up, and experimental preparation. The VAPEX test was also explained. Results were presented for sand consolidation; solvent effect; pressure effect; and permeability effect. It was concluded that when the extracting solvent is in a liquid-gas state, asphaltene precipitation occurs and leads to in-situ deasphalting. 15 refs., 3 tabs., 6 figs.

  8. Contents

    Directory of Open Access Journals (Sweden)

    Editor IJRED

    2012-11-01

    Full Text Available International Journal of Renewable Energy Development www.ijred.com 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  

  9. 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; Andersen, Simon Ivar; del Rio-Garcia, J.M.

    2002-01-01

    The interaction of two model asphaltene molecules from the Athabasca sand oil with a water molecule in a toluene solution was studied by means of molecular mechanics calculations. It was found that water forms bridging H bonds between the heteroatoms of asphaltenes with a considerable span in ene...

  10. 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

    2002-01-01

    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 Mice...

  11. 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.

    1998-05-01

    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.

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

    DEFF Research Database (Denmark)

    Garcia, Daniel Merino; Andersen, Simon Ivar

    2005-01-01

    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...... widely used in surfactant science to determine both the CMC and the enthalpy of micellation of many surfactants. The concentration interval could be divided into three regions: monomer region, micellation region, and micelle region. The absence of the first region (monomer) in the concentration range...

  13. 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

    2001-01-01

    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.

  14. Sulfur K-edge X-ray absorption spectroscopy of petroleum asphaltenes and model compounds

    International Nuclear Information System (INIS)

    The utility of sulfur K-edge X-ray absorption spectroscopy for the determination and quantification of sulfur forms in petroleum asphaltenes has been investigated. Both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectra were obtained for a selected group of model compounds and for several petroleum asphaltene samples. For the model compounds the sulfur XANES was found to vary widely from compound to compound and to provide a fingerprint for the form of sulfur involved. The use of third derivatives of the spectra enabled discrimination of mixtures of sulfidic and thiophenic model compounds and allowed approximate quantification of the amount of each component in the mixtures and in the asphaltene samples. These results represent the first demonstration that nonvolatile sulfur forms can be distinguished and approximately quantified by direct measurement

  15. Sulfur Chemistry in Combustion I

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Glarborg, Peter

    2000-01-01

    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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Guille, V.

    1996-05-20

    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.

  17. 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

    2016-03-01

    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.

  18. Combustion of coffee husks

    Energy Technology Data Exchange (ETDEWEB)

    Saenger, M.; Hartge, E.-U.; Werther, J. [Technical Univ. Hamburg-Harburg, Chemical Engineering 1, Hamburg (Germany); Ogada, T.; Siagi, Z. [Moi Univ., Dept. of Production Engineering, Eldoret (Kenya)

    2001-05-01

    Combustion mechanisms of two types of coffee husks have been studied using single particle combustion techniques as well as combustion in a pilot-scale fluidized bed facility (FBC), 150 mm in diameter and 9 m high. Through measurements of weight-loss and particle temperatures, the processes of drying, devolatilization and combustion of coffee husks were studied. Axial temperature profiles in the FBC were also measured during stationary combustion conditions to analyse the location of volatile release and combustion as a function of fuel feeding mode. Finally the problems of ash sintering were analysed. The results showed that devolatilization of coffee husks (65-72% volatile matter, raw mass) starts at a low temperature range of 170-200degC and takes place rapidly. During fuel feeding using a non water-cooled system, pyrolysis of the husks took place in the feeder tube leading to blockage and non-uniform fuel flow. Measurements of axial temperature profiles showed that during under-bed feeding, the bed and freeboard temperatures were more or less the same, whereas for over-bed feeding, freeboard temperatures were much higher, indicating significant combustion of the volatiles in the freeboard. A major problem observed during the combustion of coffee husks was ash sintering and bed agglomeration. This is due to the low melting temperature of the ash, which is attributed to the high contents of K{sub 2}O (36-38%) of the coffee husks. (Author)

  19. Effects of Asphaltene Aggregation in Model Heptane-Toluene Mixtures on Stability of Water-in-Oil Emulsions

    Science.gov (United States)

    McLean; Kilpatrick

    1997-12-01

    As part of an ongoing investigation into the stability of water-in-crude oil emulsions, model oils have been utilized to further probe the effects of crude solvency as well as specific resin-asphaltene interactions on emulsion stability. These model oils were constructed by dissolving varying amounts of resins and/or asphaltenes in a mixture of heptane and toluene. The resins and asphaltenes used in this study were isolated from four different crude types-Arab Berri (AB), Arab Heavy (AH), Alaska North Slope (ANS), and San Joaquin Valley (SJV)-and characterized in a previous study using heptane precipitation of the asphaltenes followed by an extrographic separation of the resins from silica gel. Asphaltenes dissolved in heptol at concentrations of just 0.5% were shown to generate emulsions which were even more stable than those generated from their respective whole crude oils. Some types of resins (e.g., from AH and SJV) also demonstrated an ability to stabilize emulsions although these resin-stabilized emulsions were considerably less stable than those prepared with asphaltenes. The primary factors governing the stability of these model emulsions were the aromaticity of the crude medium (as controlled by the heptane:toluene ratio), the concentration of asphaltenes, and the availability of solvating resins in the oil (i.e., the resin/asphaltene or R/A ratio). The model emulsions were the most stable when the crude medium was 30-40% toluene and in many cases at small R/A ratios (i.e., R/A asphaltenes are the most effective in stabilizing emulsions when they are near the point of incipient precipitation. The types of resins and asphaltenes used to construct these model oils also played a role in determining the resultant emulsion stability which indicates the importance of specific resin-asphaltene interactions. The interfacially active components that stabilized these model systems were the most polar and/or condensed portions of the resin and asphaltene fractions as

  20. Fractal characteristics of an asphaltene deposited heterogeneous surface

    International Nuclear Information System (INIS)

    Several methods have been employed in recent years to investigate homogeneous surface topography based on image analysis, such as AFM (atomic force microscopy) and SEM (scanning electron microscopy). Fractal analysis of the images provides fractal dimension of the surface which is used as one of the most common surface indices. Surface topography has generally been considered to be mono-fractal. On the other hand, precipitation of organic materials on a rough surface and its irregular growth result in morphology alteration and converts a homogeneous surface to a heterogeneous one. In this case a mono-fractal description of the surface does not completely describe the nature of the altered surface. This work aims to investigate the topography alteration of a glass surface as a result of asphaltene precipitation and its growth at various pressures using a bi-fractal approach. The experimental results of the deposited surfaces were clearly indicating two regions of micro- and macro-asperities namely, surface types I and II, respectively. The fractal plots were indicative of bi-fractal behavior and for each surface type one fractal dimension was calculated. The topography information of the surfaces was obtained by two image analyses, AFM and SEM imaging techniques. Results of the bi-fractal analysis demonstrated that topography alteration in surface type II (macro-asperities) is more evident than that in surface type I (micro-asperities). Compared to surface type II, a better correlation was observed between the fractal dimensions inferred from the AFM images (DA) and those of the SEM images (DS) in surface type I.

  1. Monitoring the formation of asphaltene and pre-asphaltene through solvent soaking during liquefaction of Mukah Malingian Malaysian coal via semi-continuous solvent flow high-pressure reactor system

    Energy Technology Data Exchange (ETDEWEB)

    Khudzir Ismail; Nur Nasulhah Kasim; Mohd Azlan Mohd Ishak; Mohd Fauzi Abdullah [University Technology MARA Perlis, Perlis (Malaysia). Fuel Combustion Research Laboratory

    2007-07-01

    One of the problems that could affect the production of high percentage of oil + gas yield during liquefaction of low-rank coal is the production of high amount of asphaltene, pre-asphaltene and coke through de-polymerisation and re-polymerisation of the radical species within the coal carbon matrix at high temperature regime. Hence, one solution is to suppress the re-polymerisation reaction by supplying sufficient amount of fresh donor solvent at the appropriate liquefaction temperature to instantaneously cap the reactive radical species. In this work, the effect of solvent flow rates and solvent soaking time at selective isothermal temperatures on the formation of asphaltene and preasphaltene during liquefaction of Mukah Balingian low-rank Malaysian coal via semi-continuous solvent flow high-pressure reactor system were studied. The liquefaction processes were carried out at 4 MPa with three different solvent flow rates i.e. at 2, 7, and 10 ml/min, and at temperature ranging from 300 to 450{sup o}C by using tetralin as hydrogen donor solvent. Initial findings showed that asphaltene and pre-asphaltene begin to form at liquefaction temperature range of 300-350{sup o}C, with the percent yields tend to increase with increasing in the solvent flow rate and solvent soaking time. At above 400{sup o}C, the percent of asphaltene and pre-asphaltene seem to decrease slightly probably due to conversion of these components to oil + gas. The slight reduction in the percentage of asphaltene and pre-asphaltene suggest that sufficient amount of hydrogen donors were present during the soaking condition to cap the small radical species, thus preventing the re-polymerisation reaction and promoting the formation of oil+gas. Apparently, the percentages of coal conversion and oil + gas yield were almost similar regardless whether the solvent soaking was applied at 400 or 420{sup o}C. 18 refs., 4 figs., 4 tabs.

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

    DEFF Research Database (Denmark)

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

    2005-01-01

    Asphaltenes are naturally occurring components of crude oil and have been the subject of many studies that have involved a variety of methods to determine their complex structure, their association in crude oil with resins, and their agglomeration phenomena. Yet, the molecular structures of aspha...

  3. 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.

    2015-01-01

    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...

  4. Investigating the factors influencing recovery of asphaltenic oil by water and miscible CO{sub 2} flooding

    Energy Technology Data Exchange (ETDEWEB)

    Chukwudeme, Edwin Andrew

    2009-09-15

    Conclusions that may be drawn from this work on the influence of CO{sub 2}, temperature, pressure and water composition on the recovery of asphaltenic oil by water and CO{sub 2} flooding are as follows: Asphaltene is found to alter outcrop chalk wettability from water-wet to more oil wet, which influence oil recovery by miscible CO{sub 2} and water flooding. Modification of Hirschberg solubility model for predicting asphaltene deposition has been done to account for the effect of CO{sub 2} fraction in the liquid phase during miscible flooding. This is done based on data from this work and literature. This model made it possible to isolate the effect of CO{sub 2} fraction in liquid phase on asphaltene deposition during miscible flooding. Hence, determine the critical fraction of CO{sub 2} that initiate the asphaltene deposition. The critical fraction of CO{sub 2} is estimated to be between 17 to 42 mol percent (mol%), with 33 mol% as average value. A ternary diagram is developed and is based on solubility parameter ratio (S.P.R) and molar volume ratio (V{sub CO2}/V{sub L}) and their relation to asphaltene deposition using data from this work and literature. From this data, it may be suggested that S.P.R is a determining factor for asphaltene deposition during CO{sub 2} flooding, which is not unreasonable since it is influenced by the molar volume ratio, hence temperature, pressure and composition. It is interesting to see a linear relationship between asphaltene precipitation and pressure drop regardless of the flowing pressure at isothermal condition. This is tested for under-saturated fluids. Oil recovery by miscible CO{sub 2} flooding shows low ultimate oil recovery with increasing temperature and pressure for asphaltenic oil compared to non-asphaltenic. CO{sub 2} flooding is found to be plausible for asphaltenic reservoir at lower temperature (< 70 C). From simulation studies, EOR by CO{sub 2} initiated after at least three years of water injection show the

  5. Dynamic Surface Properties of Asphaltenes and Resins at the Oil-Air Interface.

    Science.gov (United States)

    Bauget, Fabrice; Langevin, Dominique; Lenormand, Roland

    2001-07-15

    Because of the existence of large reserves, the production of heavy oils is presently the object of much interest. Some heavy oil reservoirs show anomalous behavior in primary production, with rates of production better than predicted. In Canada and Venezuela some heavy oils are produced in the form of "bubbly" oil, which is stable for several hours in open vessels. These crude oils are therefore commonly called "foamy oils". Since the presence of bubbles could be responsible for an enhanced rate of production, a better knowledge of the properties of the gas-oil interface is desirable. We have experimentally studied the effect of concentration of asphaltenes and resins on static and dynamic properties of oil-air interfaces and also on bulk viscosity. The experiments include surface tension measurements using the pendant-drop method, surface viscosity by the oscillating-drop method, foamability by continuous gas injection, and film lifetime. All the experiments were performed using resins and asphaltenes in toluene solutions at 20 degrees C. At first asphaltenes enhance foamability and film lifetime. All the experiments performed showed a change in regime for asphaltene concentrations around 10% by weight, possibly due to clustering. At the studied concentrations, the adsorption process at the air-oil interface is not diffusion controlled but rather involves a reorganization of asphaltene molecules in a network structure. The formation of a solid skin is well identified by the increase of the elastic modulus. This elastic modulus is also an important property for foam stability, since a rigid interface limits bubble rupture. The interface rigidity at long times decreases with increases in resin fraction, which could decrease foam stability as well as emulsion stability. Copyright 2001 Academic Press. PMID:11427016

  6. 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

    2010-07-01

    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

  7. Problematic stabilizing films in petroleum emulsions: shear rheological response of viscoelastic asphaltene films and the effect on drop coalescence.

    OpenAIRE

    Harbottle, D; Q. Chen; Moorthy, K.; Wang, L.; Xu, S; Liu, Q.; Sjoblom, J; Z. Xu

    2014-01-01

    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 condition...

  8. Computational Combustion

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-08-26

    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.

  9. 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: celias@ima.ufrj.br

    2011-07-01

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

    Yen, T. F.

    1978-01-01

    The solubility limits of Synthoil and PAMCO asphaltenes have been measured as a function of Hildebrand solubility parameters and hydrogen bonding. Solvents with moderate hydrogen bonding capacity such as dioxane, ethyl benzoate and dibutyl phthalate were found to be most effective in dissolving asphaltenes over the widest range of solubility parameters. VPO molecular weight studies of coal liquid derived carbenes, as a function of concentration in the solvent THF, indicate that these fractions are more strongly self-associated than the corresponding asphaltenes, and generally afford high infinite dilution number average molecular weights: Synthoil, 861; HRI H-Coal, 1156; Cat. Inc. SRC, 1228; PAMCO SRC, 1054. The variable ESR temperature dependence of the spin intensity for a Synthoil asphaltene-I/sub 2/ charge transfer followed a 1/T (Curie--Weiss) dependence over the temperature range from 25/sup 0/ to -114/sup 0/C suggesting that independent, non-interacting donor and acceptor doublets were formed. Weight percent OH values, determined from 'H NMR analysis of silylated asphaltenes, were found to provide a reasonably linear correlation with the absorbance of the monomeric OH infrared stretching bands of the asphaltenes.

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

    KAUST Repository

    Gao, Fengfeng

    2014-12-18

    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.

  12. Application of the PC-SAFT EoS in the definition of a universal plot for asphaltene stability

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, F.; Hirasaki, G.; Chapman, W. [Rice Univ., Houston, TX (United States). Dept. of Chemical and Biomolecular Engineering; Gonzalez, D. [Rice Univ., Houston, TX (United States). Dept. of Chemical and Biomolecular Engineering; Schlumberger, Houston, TX (United States); Wang, J.; Creek, J. [Chevron Energy Technology Co., Houston, TX (United States); Buckley, J. [New Mexico Tech, Socorro, NM (United States). PRRC

    2008-07-01

    This paper presented a new tool to model asphaltene stability under reservoir conditions. Asphaltene poses a problem in deep water production because of it has the tendency to precipitate, and the mechanisms of aggregation and deposition are not completely understood. A universal model is needed to predict the stability of these species, under different conditions. This paper presented advances in developing a general method to model asphaltene stability in oil, using the PC-SAFT Equation of State (EoS), regardless of the oil components and their compositions. The PC-SAFT EoS is an alternative to the Flory-Huggins theory (FHT) and has been successfully used to model asphaltene stability. By defining dimensionless parameters, the equilibrium curves of different multicomponent mixtures collapse onto one single curve. The obtained universal plots for the bubble point and the onset of asphaltene precipitation were found to be in excellent agreement with results obtained from simulations. This paper also presented an extension of this model to mixtures containing dissolved gases, such as methane, carbon dioxide and ethane. The study also addressed the issue regarding the validity of the current mixing rule for solubility parameters of mixtures containing dissolved gases. A new mixing rule was derived for solubility parameters of mixtures containing liquids and dissolved gases. There was good agreement between simulation results and refractive index measurements. In addition, the universal curves for asphaltene stability and the corresponding dimensionless numbers proposed in this study can be obtained using this new mixing rule.

  13. Polymer solution and lattice theory applications for modeling of asphaltene precipitation in petroleum mixtures

    Directory of Open Access Journals (Sweden)

    S. A. Mousavi-Dehghani

    2008-09-01

    Full Text Available Here asphaltene precipitation in petroleum reservoirs during natural depletion and miscible gas injection is modeled via two distinct and new methods (polymer solution and lattice theories. The first model is based on the polymer solution theory, which is a combination of Miller's combinatorial term with a modified residual term of the original Flory-Huggins theory. The second one is the application of the well-known Sanchez-Lacombe equation of state (SL EOS to describe the phase behavior of asphaltene compounds in crude oil. The results of both models show an acceptable and good agreement between the real data (field and experimental and these two models. As it can be seen from the obtained results of these two models, it seems application of the lattice or polymer solution theories (based on The Miller's combinatorial term could give the better and more close to real data.

  14. Fullerenes in asphaltenes and other carbonaceous materials: natural constituents or laser artifacts.

    Science.gov (United States)

    Santos, Vanessa G; Fasciotti, Maíra; Pudenzi, Marcos A; Klitzke, Clécio F; Nascimento, Heliara L; Pereira, Rosana C L; Bastos, Wagner L; Eberlin, Marcos N

    2016-04-25

    The presence of fullerenes as natural constituents of carbonaceous materials or their formation as laser artifacts during laser desorption ionization (LDI) mass spectrometry (MS) analysis is reinvestigated and reviewed. The results using asphaltene samples with varying composition as well as standard polycyclic aromatic hydrocarbons (PAH) and fullerene samples as models have demonstrated that indeed Cn ring fullerenes are not natural constituents but they are formed as common and often as predominant artifacts upon laser radiation, and a series of incorrect assignments based on LDI-MS data of several carbonaceous materials seems unfortunately to have been made. When the present results are evaluated also in the light of the vast literature on LDI-MS of carbonaceous materials, the formation of fullerene artifacts seems particularly common for LDI-MS analysis of asphaltenes and other carbonaceous samples with considerably high levels of PAH and varies according to the type of laser used, and the intensity of the laser beam. PMID:26805430

  15. Reduction of Water/Oil Interfacial Tension by Model Asphaltenes: The Governing Role of Surface Concentration.

    Science.gov (United States)

    Jian, Cuiying; Poopari, Mohammad Reza; Liu, Qingxia; Zerpa, Nestor; Zeng, Hongbo; Tang, Tian

    2016-06-30

    In this work, pendant drop techniques and molecular dynamics (MD) simulations were employed to investigate the effect of asphaltene concentrations on the interfacial tension (IFT) of the oil/water interface. Here, oil and asphaltene were represented by, respectively, common organic solvents and Violanthrone-79, and two types of concentration, i.e., bulk concentration and surface concentration, were examined. Correlations between the IFTs from experiments and MD simulations revealed that surface concentration, rather than the commonly used bulk concentration, determines the reduction of oil/water IFTs. Through analyzing the hydrogen bonding, the underlying mechanism for the IFT reduction was proposed. Our discussions here not only enable the direct comparison between experiments and MD simulations on the IFTs but also help with future interfacial studies using combined experimental and simulation approaches. The methodologies used in this work can be extended to many other oil/water interfaces in the presence of interfacially active compounds. PMID:27268710

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

    OpenAIRE

    Jafari Behbahani T.; Ghotbi C.; Taghikhani V.; Shahrabadi A.

    2015-01-01

    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 inj...

  17. Polymer solution and lattice theory applications for modeling of asphaltene precipitation in petroleum mixtures

    OpenAIRE

    S. A. Mousavi-Dehghani; Mirzayi, B.; M. Vafaie-Sefti

    2008-01-01

    Here asphaltene precipitation in petroleum reservoirs during natural depletion and miscible gas injection is modeled via two distinct and new methods (polymer solution and lattice theories). The first model is based on the polymer solution theory, which is a combination of Miller's combinatorial term with a modified residual term of the original Flory-Huggins theory. The second one is the application of the well-known Sanchez-Lacombe equation of state (SL EOS) to describe the phase behavior o...

  18. Organic flow assurance: Asphaltene dispersant/inhibitor formulation development through experimental design

    OpenAIRE

    Abrahamsen, Eirin L.

    2012-01-01

    The exploitation of hydrocarbon has forced the petroleum production to move closer to extreme climate areas and deep waters such as the Barents Sea. These challenges require effective and safe production, transport and processing of the petroleum sources. Chemical and physical changes in the reservoir may cause different types of unpredicted problems such as organic deposits which are mainly asphaltene and wax precipitation. Wax precipitation is very common in subsea pipelines....

  19. Correlations between diamagnetic properties and structural characters of asphaltenes and other heavy petroleum products

    Energy Technology Data Exchange (ETDEWEB)

    El-Mohamed, S.; Achard, M.-F.; Hardouin, F.; Gasparoux, H.

    1986-11-01

    Magnetic susceptibility measurements are made at room temperature on heavy petroleum products. They provide characteristic values of the diamagnetism of such organic compounds with high molecular masses. By the use of the Pascal's rules the average number of condensed aromatic rings, in asphaltenes and other heavy petroleum fractions, must be small and undoubtedly less than in the well-known Yen's model. 10 refs., 4 figs., 4 tabs.

  20. DEGRADATION OF ASPHALTENES BY INDIVIDUAL OIL-UTILIZING AEROBIC BACTERIAL STRAINS

    OpenAIRE

    Shkidchenko, Alexander; Akhmetov, Lenar; Gafarov, Arslan

    2013-01-01

    The possibility of biodegradation of asphaltenes at a room temperature by single aerobic strains Microbacterium liquefaciens Ash-10, Pseudomonas putida Ash-4, Rhodococcus erythropolis Sh-3 and Bacillus sp. 2, isolated from soil with chronic petroleum pollution has been shown. All strains possess high oil-utilizing activity and the ability to grow on agar media containing polycondensed hydrocarbons, black oil, alcohol-benzene resins, benzene resins as sole sources of carbon and energy. The str...

  1. Rheological, dielectric and structural characterization of asphaltene suspensions under DC electric fields

    Energy Technology Data Exchange (ETDEWEB)

    L. Rejon; O. Manero; C. Lira-Galeana [Instituto de Investigaciones Electricas, Morelos (Mexico)

    2004-03-01

    The rheological, dielectric and structural behavior of suspensions composed of silicon oil and asphaltene particles under DC electric fields are investigated experimentally. In the absence of an electric field, the suspensions show a near Newtonian behavior. When the electric field (E) is applied, the suspensions behave as Bingham plastics with a yield stress that varies as a power of the electric field. The increase in the viscosity of the suspensions (electrorheological phenomenon, ER) is more accentuated at low shear rates and depends on the electric field intensity. The resulting rheological behavior can be attributed to the formation of structures induced by the electric field, and they break when the shear rate is increased. The relation between the structural arrangements of the suspension under an electric field and the rheological behavior is analyzed in this study. Results show that the ER response of asphaltene suspensions is not as large as that observed in conventional ER fluids, but nevertheless they throw light on the contribution of electrorheological mechanisms upon asphaltene particle aggregation observed in the transport of the crude oil in the petroleum industry. 17 refs., 10 figs., 1 tab.

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

    Directory of Open Access Journals (Sweden)

    MIRJANA S. PAVLOVIC

    2000-02-01

    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.

  3. Colloidal asphaltene deposition in laminar pipe flow: Flow rate and parametric effects

    Science.gov (United States)

    Hashmi, S. M.; Loewenberg, M.; Firoozabadi, A.

    2015-08-01

    Deposition from a suspended phase onto a surface can aversely affect everyday transport processes on a variety of scales, from mineral scale corrosion of household plumbing systems to asphaltene deposition in large-scale pipelines in the petroleum industry. While petroleum may be a single fluid phase under reservoir conditions, depressurization upon production often induces a phase transition in the fluid, resulting in the precipitation of asphaltene material which readily aggregates to the colloidal scale and deposits on metallic surfaces. Colloidal asphaltene deposition in wellbores and pipelines can be especially problematic for industrial purposes, where cleanup processes necessitate costly operational shutdowns. In order to better understand the parametric dependence of deposition which leads to flow blockages, we carry out lab-scale experiments under a variety of material and flow conditions. We develop a parametric scaling model to understand the fluid dynamics and transport considerations governing deposition. The lab-scale experiments are performed by injecting precipitating petroleum fluid mixtures into a small metal pipe, which results in deposition and clogging, assessed by measuring the pressure drop across the pipe. Parametric scaling arguments suggest that the clogging behavior is determined by a combination of the Peclet number, volume fraction of depositing material, and the volume of the injection itself.

  4. Combustion detector

    Science.gov (United States)

    Trimpi, R. L.; Nealy, J. E.; Grose, W. L. (Inventor)

    1973-01-01

    A device has been developed for generating a rapid response signal upon the radiation-emitting combustion reaction of certain gases in order to provide a means for the detection and identification of such reaction and concurrently discriminate against spurious signals. This combustion might be the first stage of a coal mine explosion process, and thereby this device could provide a warning of the impending explosion in time to initiate quenching action. This device has the capability of distinguishing between the light emitted from a combustion reaction and the light emitted by miners' lamps, electric lamps, welding sparks or other spurious events so that the quenching mechanism is triggered only when an explosion-initiating combustion occurs.

  5. Probing Molecular Interactions of Asphaltenes in Heptol Using a Surface Forces Apparatus: Implications on Stability of Water-in-Oil Emulsions.

    Science.gov (United States)

    Zhang, Ling; Shi, Chen; Lu, Qingye; Liu, Qingxia; Zeng, Hongbo

    2016-05-17

    The behaviors and molecular interactions of asphaltenes are related to many challenging issues in oil production. In this study, the molecular interaction mechanism of asphaltenes in Heptol solvents of varying toluene/n-heptane ratio were directly measured using a surface forces apparatus (SFA). The results showed that the interactions between asphaltene surfaces gradually changed from pure repulsion to weak adhesion as the weight ratio of toluene (ω) in Heptol decreased from ω = 1 to 0. The measured repulsion was mainly due to the steric interactions between swelling asphaltene molecules and/aggregates. The micropipet technique was applied to test the stability of two water-in-oil emulsion droplets attached to glass pipettes. A computer-controlled 4-roll mill fluidic device was also built in-house to investigate the interaction of free-suspending water-in-oil emulsions under dynamic flow conditions. Both micropipet and 4-roll mill fluidic tests demonstrate that asphaltenes adsorbed at oil/water interfaces play a critical role in stabilizing the emulsion drops, in agreement with the repulsion measured between asphaltene surfaces in toluene using SFA, and that interfacial sliding or shearing is generally required to destabilize the protective interfacial apshaltene layers which facilitates the coalescence of emulsion drops. Our results provide insights into the fundamental understanding of molecular interaction mechanisms of asphaltenes in organic solvents and stabilization/destabilization behaviors of water-in-oil emulsions with asphaltenes. PMID:27128395

  6. Colloidal analysis of the asphaltene and their fractions with p-nitrophenol (PNP) of the Furrial crude oil for effect of the hydrotreating to different pressures

    Energy Technology Data Exchange (ETDEWEB)

    Labrador-Sanchez, H. [Univ. de Carabobo, Estado Carabobo (Venezuela, Bolivarian Republic of). Dept. de Quimica, Grupo de Petroleo, Hidrocarburo y Derivados; Lindarte, L. [Univ. de Carabobo, Estado Carabobo (Venezuela, Bolivarian Republic of). Dept. de Quimica, Grupo de Petroleo, Hidrocarburo y Derivados; Univ. de Carabobo, Estado Carabobo (Venezuela, Bolivarian Republic of). Dept. de Quimica, Laboratorio de Catalisis y Metales de Transicion; Luis, M.A. [Univ. de Carabobo, Estado Carabobo (Venezuela, Bolivarian Republic of). Dept. de Quimica, Laboratorio de Catalisis y Metales de Transicion

    2008-07-01

    A study was conducted to investigate the effect of hydrotreating Furrial crude oil on asphaltene and its fractions (A1 and A2) obtained by the p-Nitrophenol (PNP) method. A batch reactor was used at different pressures of hydrogen to perform 8 hydrotreating reactions on the Furrial crude oil. Asphaltenes were separated from the oil and fractioned with PNP to obtain A1 and A2. The asphaltene and their fractions were characterized for flocculation threshold, percentage of total sulfur, nuclear magnetic resonance of 13C and elemental composition. The study showed that hydrotreating influenced the colloidal behaviour of the asphaltene and that the catalyst promoted the conversion of asphaltene, its stability, and its desulfurization. Hydrotreating had a greater affect on the A2 fraction than the A1 fraction. 2 refs.

  7. Combustion and regulation; Combustion et reglementation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    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.)

  8. Thermogravimetric analysis of petroleum asphaltenes along with estimation of average chemical structure by nuclear magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Combining with the 1H and 13C nuclear magnetic resonance (NMR) determinations, elemental analysis and molecular weight measurement, average molecular formula of the chemical unit for the asphaltenes from Chinese Daqing crude oil were calculated. Thermal pyrolysis kinetics of the asphaltenes had been studied using thermogravimetric analysis (TGA). The distributed activation energy model (DAEM) was used to analyze these complex systems. The results show that the peak activation energy for pyrolysis of the asphaltenes is 245 kJ mol-1 and the pre-exponential factor is 5.88 x 1014 s-1. The DAEM method presented reasonably good results of the prediction of the weight loss curves. A linear relationship can be found from the plots of logarithm of the pre-exponential factor against the activation energy at selected conversion values. This phenomenon known as the compensation effect was explained and it was in agreement with the estimated chemical structure determined by NMR

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

    Science.gov (United States)

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

    2016-01-01

    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. Determination of (BTEX) of the gasoline's combustion in Ecuador

    International Nuclear Information System (INIS)

    The contents of benzene, toluene, ethyl benzene and xylenes (BTEX) were determined and quantified in the gasoline's combustion on an internal combustion engine. Gas chromatography with flame ionization detector were used for chemical determinations

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    In order to facilitate the study of the influence of reservoir process characteristics in In-Situ combustion modeling and advance the work of Kristensen et al. in this domain; a fully compositional In-situ combustion (ISC) model of Virtual Kinetic Cell (VKC; single-cell model) for laboratory scale...... 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...

  12. Study of the degradation of power generation combustion components at elevated temperature

    International Nuclear Information System (INIS)

    Elevated temperature combustion of fuel oil that contains large amounts of vanadium, asphaltenes and mostly sulfur, presents a major challenge for materials selection and design of combustion components for the electric power generation. The combustion system, which consists of air nozzles and air swirlers, plays a key role in the performance of electric power plants. Air nozzles and air swirlers, which were operated for one year in a 350 MW boiler, were analyzed, presenting accelerated degradation. The particular features of corrosion behavior of these components made by stainless steels: 304, 446 and HH, are presented. The results obtained after optical, metallographic, and microprobe analysis revealed that the components flame contact at very high operating temperature promoted all materials degradation mechanisms. Under this scenario, it is very difficult to find a material resistant to such accelerated wastage conditions. So, the solution of the problem must be oriented to re-design and improve the efficiency of the flame contact with these components

  13. Study of the degradation of power generation combustion components at elevated temperature

    Energy Technology Data Exchange (ETDEWEB)

    Castrejon, J. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas-UAEM, Av. Universidad 1001, C.P. 62209, Cuernavaca, Mor., Mexico (Mexico); Serna, S. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas-UAEM, Av. Universidad 1001, C.P. 62209, Cuernavaca, Mor., Mexico (Mexico)]. E-mail: aserna@uaem.mx; Wong-Moreno, A. [Instituto Mexicano del Petroleo, Eje Central No. 152, Col. San. Bartolo Atepehuacan, C.P. 07730, Mexico, DF (Mexico); Fragiel, A. [Centro de Ciencias de la Materia Condensada-UNAM, Km 7 Carretera Tijuana-Ensenada, C.P. 22800, Ensenada, Baja California (Mexico); Lopez-Lopez, D. [Instituto Mexicano del Petroleo, Eje Central No. 152, Col. San. Bartolo Atepehuacan, C.P. 07730, Mexico, DF (Mexico)

    2006-01-15

    Elevated temperature combustion of fuel oil that contains large amounts of vanadium, asphaltenes and mostly sulfur, presents a major challenge for materials selection and design of combustion components for the electric power generation. The combustion system, which consists of air nozzles and air swirlers, plays a key role in the performance of electric power plants. Air nozzles and air swirlers, which were operated for one year in a 350 MW boiler, were analyzed, presenting accelerated degradation. The particular features of corrosion behavior of these components made by stainless steels: 304, 446 and HH, are presented. The results obtained after optical, metallographic, and microprobe analysis revealed that the components flame contact at very high operating temperature promoted all materials degradation mechanisms. Under this scenario, it is very difficult to find a material resistant to such accelerated wastage conditions. So, the solution of the problem must be oriented to re-design and improve the efficiency of the flame contact with these components.

  14. Turbulent combustion

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-01

    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.

  15. 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.

    1998-06-30

    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

  16. Re-Os dating of maltenes and asphaltenes within single samples of crude oil

    Science.gov (United States)

    Georgiev, Svetoslav V.; Stein, Holly J.; Hannah, Judith L.; Galimberti, Roberto; Nali, Micaela; Yang, Gang; Zimmerman, Aaron

    2016-04-01

    Re-Os geochronology of oil may constrain the timing of oil formation and improve oil-source and oil-oil correlations. Typically, asphaltene (ASPH), the heaviest and most Re-Os rich oil fraction, from multiple oils within an oil field or a larger petroleum system are analyzed to obtain sufficient spread in Re-Os isotopic ratios, a mathematical necessity for precise Re-Os isochrons. Here we offer a new approach for Re-Os geochronology of oil based on isotopic analyses of different fractions within a single sample of crude oil. We studied three oils from the Gela oil field, southern Sicily, Italy, recovered from Triassic-Jurassic stratigraphic intervals (Streppenosa, Noto, and Sciacca Formations) within the Gela-1 well. ASPH (insoluble in n-alkane) and maltene (MALT, soluble in n-alkane) fractions of oil were separated using n-pentane, n-hexane, n-heptane and n-decane solvents. The ASPH contents of the Sciacca and Noto oils (26-33 wt%) are notably higher compared to the Streppenosa oil (7-12 wt% ASPH). We present an optimized Re-Os procedure with sample digestion in a high-pressure asher, followed by isotopic measurements using negative thermal ionization mass spectrometry. Very high metal contents of Gela oils allowed acquisition of precise Re-Os data. Systematic variations between the type of solvent used for ASPH precipitation and the ASPH content of the oil (also known from the literature) and the Re-Os contents of the ASPH and MALT fractions (first observed in this study) provide important practical applications for Re-Os analyses of oil. Most Re and Os (∼96-98%) in the Noto oil are hosted in the ASPH fraction. In contrast, a significant portion of Re and Os (∼33-34%) is stored in the MALT fraction of the lighter, but heavily biodegraded Streppenosa oil. Collectively, our new data on alkane distribution, hopane and sterane biomarkers, major and trace element contents, and Re-Os concentrations and isotopic ratios of the oils and their fractions support the

  17. Effect of demulsifiers on interfacial films and stability of water-in-oil emulsions stabilized by asphaltenes

    Energy Technology Data Exchange (ETDEWEB)

    Baydak, E.N.; Yarranton, H.W.; Ortiz, D. [Calgary Univ., AB (Canada). Dept. of Chemical and Petroleum Engineering; Moran, K. [Syncrude Research Centre, Edmonton, AB (Canada)

    2008-07-01

    In water-in-toluene/heptane emulsions stabilized by asphaltenes, there is a correlation between emulsion stability and the compressibility of interfacial asphaltene films. In order to determine if this correlation for emulsion stability is more generally applicable, a study was conducted in which the effect of commercial demulsifiers on the film properties and emulsion stability was measured. A naphthenic acid (NA) and a branched dodecylbenzene sulfonic acid (DDBS) were examined. Surface pressure isotherms were measured in a drop shape analyzer for droplets of asphaltenes, toluene, and heptane surrounded by a solution of water and surfactant. The experimental variables included heptane, asphaltene and surfactant concentration along with aging time. The compressibilities of the interfacial films were determined from the slope of the surface pressure isotherms. Water-in-oil emulsions were prepared from the same solutions. Emulsion stability was evaluated in terms of the free water evolved after a treatment of centrifugation and heating. Initial results suggest that the demulsifiers increase the compressibility of the interfacial films. In most cases, the addition of the demulsifier increased emulsion stability. The timing of the addition of the demulsifier or the phase to which it was added did not appear to have an influence on the results. It was concluded that the reduction in interfacial tension from the added surfactant may inhibit coalescence more than the weakening of the interfacial film promotes coalescence. 1 ref.

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

    Science.gov (United States)

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

    2014-06-17

    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. PMID:24845467

  19. Advanced Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, Gordon R. [NETL

    2013-03-11

    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).

  20. Certification of trace element contents (As, Cd, Co, Cu, Fe, Mn, Hg, Na, Pb and Zn) in a fly ash obtained from the combustion of pulverised coal

    International Nuclear Information System (INIS)

    The element contents of As, Cd, Co, Cu, Fe, Mn, Hg, Na, Pb and Zn of a fly ash from pulverised coal are certified. The procedures and their results for the homogenisation, the contamination and homogeneity checks and the analytical campaign are reported. The certified mass fractions and indicative values for Cr, Ni, Th, V and water soluble sulphate are given. The work was carried out within the framework of the activities of the Community Bureau of Reference (BCR) of the Commission of the European Communities. (orig.)

  1. 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.

    2006-11-01

    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

  2. 沥青质裂解反应选择性分析%Analysis for the Selectivity of Asphaltene Cracking Reactions

    Institute of Scientific and Technical Information of China (English)

    赵迎宪; 危凤; 李达

    2011-01-01

    A pentane-insoluble asphaltene was processed by thermal cracking, thermal hydrocracking and catalytic hydrocracking over NiMo/γ-Al2O3 at 703 K, respectively. Analysis of selectivity showed that at the same level of asphaltene conversion and according to the selectivity of liquid products from high to low the three cracking reactions were in the order of catalytic hydrocracking, thermal hydrocracking, thermal cracking, while according to the selectivity of coke from high to low, the three cracking reactions were in the opposite order. In thermal cracking, a large amount of sulfur converted from the feed into coke, and in thermal hydrocracking, molecular hydrogen played a certain degree role in inhibiting formation of coke with high sulfur content, and in catalytic hydrocracking the catalyst effectively activated hydrogen molecules to hydrogenate the reactant and middle products, leading to a significant reduction of coke formation and remarkable improvement of liquid stability, selectivity and quality (lower average relative molecular mass and sulfur content).%在703K下,考察了1种正戊烷不溶的沥青质的热裂解、临氢热裂解和NiMo/y-Al2O3存在时的临氢催化裂解反应.结果表明,在相同的反应物转化率水平下,3种裂解反应按液体产物选择性从大到小的排列顺序为临氢催化裂解、临氢热裂解、热裂解反应,而按焦炭的选择性的排列顺序则相反.在热裂解反应中,沥青质中大量的硫被转化生成高硫焦炭;在临氢热裂解反应中,氢气分子对高硫焦炭的生成只起到有限的抑制作用;在临氢催化裂解反应中,催化剂充分激活氢气分子,使其有效地对沥青质及中间产物发生“加氢”(氢化)作用,显著地抑制了焦炭的生成,提高了液体产物的稳定性、选择性和品质(低相对分子质量和低硫含量).

  3. Low-Temperature Combustion Technology

    OpenAIRE

    Osintsev, Konstantin

    2012-01-01

    Any coal-fired boiler is always designed on a certain kind of coal. In the EU and Russia in the old coal mines can be mined coal with a high content of moisture and ash. In order to use coal with different characteristics in the same steam generator, it is necessary to create a new coal combustion technology.

  4. Effect of inlet and outlet configurations on blow-off and flashback with premixed combustion for methane and a high hydrogen content fuel in a generic swirl burner

    International Nuclear Information System (INIS)

    Highlights: • Correlation of blowoff and flashback using the tangential inlet velocity. • The correlation appears to arise from the exhaust shear flow. • Reynolds Number effects can be important with methane and flashback. • For flashback the correlation was effective for 0.8 ⩽ swirl number ⩽ 2.2. • For blowoff the correlation was effective for 0.8 ⩽ swirl number ⩽ 4. - Abstract: The paper analyses new data for three fuels, natural gas, methane and Coke Oven Gas (COG) in two swirl burners. Flashback and blowoff can be correlated with the inlet tangential velocity, not the inlet mass flow, over a range of swirl numbers from 0.8 to more than 4. Geometry and fuel type are important. The correlation gives best fit for a particular outlet geometry and with higher hydrogen content fuels. The correlation still holds with methane and natural gas, especially with confinement. Analysis of the correlation infers that both blowoff and flashback occurrences are governed by the shear layer surrounding the Central Recirculation Zone (CRZ). The CRZ acts to control the width and strength of the shear flow region. Blowoff was found to occur when the CRZ was extensive and well develop and could be modeled by a well stirred reactor system. Two modes of flashback were found, both of which could be characterized by the same correlation of inlet tangential velocity. The first flashback case occurred at lower swirl numbers when the flame attached to the burner rim and flashed back through the outer boundary layer. At higher swirl numbers the CRZ and associated flame located next to its boundary extended back over the fuel nozzle inside the swirl chamber. Flashback occurred when the flame suddenly moved radially outwards towards the inlets. A clear trend was established for COG; as the swirl number was increased from 0.8 to 1.5 blowoff slightly worsened, whilst flashback improved. Thus higher swirl numbers are tentatively favored for flashback protection for higher

  5. New technologies reducing emissions from combustion of biofuels

    International Nuclear Information System (INIS)

    In reducing CO2 emissions, bioenergy will be the most important source of renewable energy in the next few decades. In principle, combustion of biomass is friendly to the environment because CO2 released during combustion is recycled back into natural circulation. Biofuels normally contain little nitrogen and sulphur. However, depending on the combustion technology used, emissions may be quite high. This is true of combustion of biomass fuels in small appliances like wood stoves, fireplaces, small boilers etc. When fuels having high content of volatile matter are burnt in appliances using batch type combustion, the process is rather an unsteady-state combustion. Emissions of carbon monoxide, other combustible gases and particulates are quite difficult to avoid. With continuous combustion processes this is not normally a problem. This conference paper presents some means of reducing emissions from combustion of biofuels. 5 refs., 4 figs

  6. Prediction of Volumetric Properties and (Multi- Phase Behaviour of Asphaltenic Crudes Prédiction des propriétés volumétriques et des équilibres de phases des bruts asphalténiques

    Directory of Open Access Journals (Sweden)

    Szewczyk V.

    2006-11-01

    Full Text Available Asphaltenes flocculation is described as a thermodynamic transition inducing the formation of a new liquid phase with a high asphaltenic content; this phase being the asphaltenic deposit. The thermodynamic model selected is the Peng-Robinson Equation of State associated with the Abdoul and Péneloux group contribution mixing rules. The oil is modeled by 33 pseudocomponents. Mainly, the heavy F(11+ residue is represented as one pseudocomponent for the F11 - F20 cut and as 4 pseudocomponents for the F(20+ cut : Sat F(20+ , Aro F(20+ , Resinsand Asphaltenes . The physical properties of the Sat F(20+ , Aro F(20+and Resinspseudocomponents are calculated using the group contribution methods of Avaullée, and of Rogalski and Neau, based on the knowledge of their molecular structure. The physical properties of the F11 - F20and Asphaltenespseudocomponents are fitted in order to reproduce correctly the bubble pressure, the relative volumes and the flocculated quantities at 303 K. The model gives the proportion and the composition of asphaltene deposits in the oil at different temperatures (303 - 403 K within a relatively large pressure range (0. 1 - 50 MPa including the bubble pressure of the considered crude. La floculation des asphaltènes est décrite comme une transition thermodynamique conduisant à la formation d'une nouvelle phase liquide riche en asphaltènes : le dépôt asphalténique. Le modèle thermodynamique choisi est l'équation d'état de Peng-Robinson associée aux règles de mélange d'Abdoul et Péneloux fondées sur les contributions de groupes. Le brut est représenté par 33 pseudo-constituants. La fraction lourde F(11+ est représentée par un pseudo-constituant pour la coupe F11 - F20 et 4 pseudo-constituants pour la coupe F(20+ : Sat F(20+ , Aro F(20+ , Résines , Asphaltènes . Les propriétés physiques des pseudo-constituants Sat F(20+, Aro F(20+et Résinessont calculées à l'aide des méthodes de contribution de groupes

  7. High Combustion Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — At NETL's High-Pressure Combustion Research Facility in Morgantown, WV, researchers can investigate new high-pressure, high-temperature hydrogen turbine combustion...

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

    NARCIS (Netherlands)

    Leskens, M.

    2013-01-01

    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 a

  9. Combustion chemistry

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-01

    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).

  10. Effect of Asphaltene Dispersants on Asphaltene Dispersibility in Heavy Fuel Oil%沥青质分散剂对重质燃料油沥青质分散稳定作用研究

    Institute of Scientific and Technical Information of China (English)

    刘新亮; 张菅; 尹海亮

    2014-01-01

    以总潜在沉淀物为指标,考察了沥青质分散剂对船用燃料油沥青质分散性的影响,并对其分散机理进行了讨论,结果表明,十二烷基苯磺酸、十二烷基苯酚、十二烷基醇和十二烷基胺均对燃料油中的沥青质有一定的分散作用,其中,十二烷基苯磺酸分散性能最好,99%以上的以总潜在沉淀物形式检测到的沥青质可以被其重新分散到燃料油中,其良好的分散性可能与十二烷基苯磺酸分子中的酸性官能团和苯环有关。%The dispersibilities of four different dispersants (dodecylbenzenesulfonic acid,dodecanol,dodecylamine and dodecyl phenol) to asphaltene in heavy fuel oil were evaluated by using the potential total sediment as the index, and the possible dispersing mechanism was discussed. The results show that, dodecylbenzenesulfonic acid has the highest disperability to asphaltene in heavy fuel oil, and more than 99 % asphaltene aggregation can be redispersed when dodecylbenzenesulfonic acid dosage is 4%(wt).

  11. 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.

    2016-01-01

    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...... modeling approach from the previous work and provide the conceptual base for it. Five different reservoir fluids are studied to validate whether the model is able to calculate the effect of different types (e.g., N2, CO2, and methane) and amounts (e.g., 10, 20, and 30 mol %) of gas injections in agreement...... amounts of gas injections and also remains the same at upper and lower onset pressure boundaries. On the basis of this unique characteristic, a simple procedure to predict asphaltene phase envelope (APE) for the reservoir oil with relatively simple and few experimental data, performed on STO with n...

  12. Modeling of asphaltene precipitation due to steam and n-alkane co-injection in the ES-SAGD process

    Energy Technology Data Exchange (ETDEWEB)

    Badamchizadeh, A.; Kohse, Bruce F.; Kumar, A. [Computer Modelling Group Ltd (Canada)

    2011-07-01

    This paper provides an insight into the SAGD process in general, and the formation of asphaltene participates in the hybrid ES-SAGD process in particular. The objective of this work was to build an EoS model able to calculate the physical and chemical properties of the bitumen and n-alkane mixture, develop a model to quantify asphaltene participates in bitumen due to n-alkane injection, and investigate their effect on the ES-SAGD process. Athabasca bitumen properties identified under various test conditions and from the results of previous efforts, mainly the SimDist experimental data, were illustrated. These data were used to develop the EoS model, which in turn was used to generate the STARS thermal simulator. Overall, the EoS model was successfully developed and hence was able to predict bitumen and n-heptane properties. Moreover, asphaltene deposition in the ES-SAGD process was modeled in the thermal simulator its effect in causing oil blockage and restrictions in the steam chamber over a long run of the process was demonstrated.

  13. Effect of surfactants on interfacial films and stability of water-in-oil emulsions stabilized by asphaltenes.

    Science.gov (United States)

    Ortiz, D P; Baydak, E N; Yarranton, H W

    2010-11-15

    The effect of additives on asphaltene interfacial films and emulsion stability was analyzed through the change in film properties. Surface pressure isotherms were measured at 23°C for model interfaces between aqueous surfactant solutions and asphaltenes dissolved in toluene and heptane-toluene mixtures. Compressibility, crumpling film ratio and surface pressure were determined from the surface pressure isotherms. The stability of water-in-oil emulsions was determined for the same systems based on the proportion of unresolved emulsified water after repeated treatment involving heating at 60°C and centrifugation. Experimental variables included concentration of asphaltenes (5 and 10 kg/m(3)), concentration and type of surfactant (Aerosol OT, nonylphenol ethoxylates, polypropylene oxide block-copolymer, dodecylbenzene sulfonic acids, dodecylbenzene sulfonic acid-polymer blend, diisopropyl naphthalene sulfonic acid, and sodium naphthenate) and aging time (from 10 min to 4 h). Additives were found to have two opposing effects on film properties and emulsion stability: (1) decreasing or eliminating the crumpling ratio which destabilized emulsions and (2) decreasing interfacial tension which enhanced emulsion stability. A stability parameter was defined to include both the crumpling ratio and interfacial tension and provided a consistent correlation for the percent residual emulsified water. PMID:20804982

  14. Characterization of asphaltene molecular structures by cracking under hydrogenation conditions and prediction of the viscosity reduction from visbreaking of heavy oils

    Science.gov (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 (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 yield of distillates. Thermal cracking of asphaltenes in heavy oils and bitumens can dramatically reduce viscosity, enabling pipeline transportation with less solvent addition. The viscosities of the products from visbreaking reactions of two different heavy oils were modeled with lumped kinetics based on boiling point pseudo

  15. Oxygen-enhanced combustion

    CERN Document Server

    Baukal, Charles E

    2013-01-01

    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

  16. Reactivity studies of rice husk combustion using TGA

    International Nuclear Information System (INIS)

    The reactivity of rice husks combustion is systematically studied the thermogravimetric analyzer (TGA). The kinetic parameters are determined from the Arrhenius plots based on the data of weight loss over temperature at different combustion heating rates. The results of proximate analysis (the moisture, volatile matters, fixed carbon, and ash contents) are also presented in this paper. The effects of process conditions on the self-ignition phenomenon of rice husk combustion are quantified. Finally, these results and compared with results for coal combustion. This research is part of the work to determine the optimal process conditions of rice husk combustion for energy production. (Author)

  17. Mise en évidence de la polydispersité physico-chimique des asphaltènes Evidence of the Physicochemical Polydispersity of Asphaltenes

    Directory of Open Access Journals (Sweden)

    Szewczyk V.

    2006-11-01

    Full Text Available Afin d'élaborer un modèle thermodynamique capable de décrire la floculation des asphaltènes en s'appuyant au maximum sur la réalité physicochimique, nous nous sommes efforc In order to develop a thermodynamic model able to describe the flocculation of asphaltenes according to their physicochemical properties, we have tried to give a better definition of the asphaltenes chemical structure and to show its influence on the mechanism of aggregation in solution. This work consisted in :- putting in evidence the physical and chemical polydispersity of asphaltenes;- studying simultaneously the nature and the localization of the chemical functions in the asphaltene oligomers (elemental analysis, analysis of the pyrolysed products, etc. and their capacity to aggregate in solution (X-ray diffusion to better understand the aggregation mechanims and to identify the functions responsible of this aggregation;- establishing a relation between the proportion of these functions and the size of the aggregates in order to take it in account in the thermodynamic model.The fractionation of a sample of asphaltenes with increasing quantities of n-heptane has allowed to separate different classes of aggregates. For each added quantity of n-heptane, the sample of asphaltenes has been separated in an insoluble fraction and a soluble one. The insoluble fraction contains the aggregates which firstly floculate. The elemental composition of each fraction has been determined by elemetal analysis. The pyrolysis in an open medium has allowed to break the aggregates in elementary patterns, the nature of the different patterns has been determined by liquid and gazeous chromatography. The size of the aggregates has been observed by X-ray diffusion.The results of this chemical characterization have shown that the initial sample of asphaltenes is formed by a group of oligomers having different elemental compositions and different chemical structures. The aggregates which

  18. 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

    2001-06-30

    . 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

  19. 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

    2001-06-30

    . 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

  20. Stereoscopic pyrometer for char combustion characterization.

    Science.gov (United States)

    Schiemann, M; Vorobiev, N; Scherer, V

    2015-02-10

    For many pulverized fuels, especially coal and biomass, char combustion is the time determining step. Based on intensified ICCD cameras, a novel setup has been developed to study pulverized fuel combustion, mainly in a laminar flow reactor. For char burning characterization, the typical measurement parameters are particle temperature, size, and velocity. The working principle of the camera setup is introduced and its capabilities are discussed by examination of coal particle combustion under CO(2)-enriched, so-called oxy-fuel atmospheres with varying O(2) content. PMID:25968027

  1. 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

    2012-07-01

    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)

  2. Particulate emissions from combustion of biomass in conventional combustion (air) and oxy-combustion conditions

    Science.gov (United States)

    Ruscio, Amanda Deanne

    Oxy-fuel combustion is a viable technology for new and existing coal-fired power plants, as it facilitates carbon capture and thereby, can reduce carbon dioxide emissions. The use of biomass as an energy source is another popular strategy to reduce carbon dioxide emissions as they are considered nearly carbon dioxide neutral. If the use of biomass is combined with oxy-fuel combustion, negative net emissions of carbon dioxide are possible. This work examined the particulate emissions from combustion of pulverized biomass residues burning in either conventional or oxy-fuel environments. Combustion of three biomasses (olive residue, corn residue, and torrefied pine sawdust) occurred in a laboratory-scale laminar-flow drop tube furnace (DTF) heated to 1400 K. The O2 mole fraction was increased from 20% to 60% in N2 environments while a range of 30% to 60% O2 mole fractions were used in CO2 environments to represent plausible dry oxy-fuel combustion conditions. Submicron particulate matter (PM1) emission yields of all three fuels were typically lower in O2/CO2 environments than in O2/N2 environments. When the oxygen mole fraction was increased, the PM1 yields typically increased. The mass fractions of submicron particulate matter (PM1/PM18) collected from biomass combustion were higher than those of coal combustion. PM 1 constituted approximately 50 wt% of the collected ash particles in PM18 in each environment, whereas the corresponding submicron emissions from coal constituted approximately 20 wt%. Changing the background gas had little effect on the chemical composition of the PM1 particles. Unlike the submicron particles collected from coal which contained high amounts of silicon and aluminum, high amounts of alkalis (potassium, calcium, and sodium) and chlorine were the major elements observed in PM1 from the biomasses. In addition, phosphorous and sulfur also existed in high amounts in PM1 of corn residue. Super-micron particles (PM1-18) yields exhibited no clear

  3. Combustion 2000

    Energy Technology Data Exchange (ETDEWEB)

    None

    1999-12-31

    This report presents work carried out under contract DE-AC22-95PC95144 ''Combustion 2000 - Phase II.'' The goals of the program are to develop a coal-fired high performance power generation system (HIPPS) that is capable of: {lg_bullet} thermal efficiency (HHV) {ge} 47% {lg_bullet} NOx, SOx, and particulates {le} 10% NSPS (New Source Performance Standard) {lg_bullet} coal providing {ge} 65% of heat input {lg_bullet} all solid wastes benign {lg_bullet} cost of electricity {le} 90% of present plants Phase I, which began in 1992, focused on the analysis of various configurations of indirectly fired cycles and on technical assessments of alternative plant subsystems and components, including performance requirements, developmental status, design options, complexity and reliability, and capital and operating costs. Phase I also included preliminary R&D and the preparation of designs for HIPPS commercial plants approximately 300 MWe in size. Phase II, had as its initial objective the development of a complete design base for the construction and operation of a HIPPS prototype plant to be constructed in Phase III. As part of a descoping initiative, the Phase III program has been eliminated and work related to the commercial plant design has been ended. The rescoped program retained a program of engineering research and development focusing on high temperature heat exchangers, e.g. HITAF development (Task 2); a rescoped Task 6 that is pertinent to Vision 21 objectives and focuses on advanced cycle analysis and optimization, integration of gas turbines into complex cycles, and repowering designs; and preparation of the Phase II Technical Report (Task 8). This rescoped program deleted all subsystem testing (Tasks 3, 4, and 5) and the development of a site-specific engineering design and test plan for the HIPPS prototype plant (Task 7). Work reported herein is from: {lg_bullet} Task 2.2.4 Pilot Scale Testing {lg_bullet} Task 2.2.5.2 Laboratory and Bench

  4. Combustion 2000

    Energy Technology Data Exchange (ETDEWEB)

    None

    2000-06-30

    This report presents work carried out under contract DE-AC22-95PC95144 ''Combustion 2000 - Phase II.'' The goals of the program are to develop a coal-fired high performance power generation system (HIPPS) that is capable of: {lg_bullet} thermal efficiency (HHV) {ge} 47% {lg_bullet} NOx, SOx, and particulates {le} 10% NSPS (New Source Performance Standard) {lg_bullet} coal providing {ge} 65% of heat input {lg_bullet} all solid wastes benign {lg_bullet} cost of electricity {le} 90% of present plants Phase I, which began in 1992, focused on the analysis of various configurations of indirectly fired cycles and on technical assessments of alternative plant subsystems and components, including performance requirements, developmental status, design options, complexity and reliability, and capital and operating costs. Phase I also included preliminary R&D and the preparation of designs for HIPPS commercial plants approximately 300 MWe in size. Phase II, had as its initial objective the development of a complete design base for the construction and operation of a HIPPS prototype plant to be constructed in Phase III. As part of a descoping initiative, the Phase III program has been eliminated and work related to the commercial plant design has been ended. The rescoped program retained a program of engineering research and development focusing on high temperature heat exchangers, e.g. HITAF development (Task 2); a rescoped Task 6 that is pertinent to Vision 21 objectives and focuses on advanced cycle analysis and optimization, integration of gas turbines into complex cycles, and repowering designs; and preparation of the Phase II Technical Report (Task 8). This rescoped program deleted all subsystem testing (Tasks 3, 4, and 5) and the development of a site specific engineering design and test plan for the HIPPS prototype plant (Task 7). Work reported herein is from: {lg_bullet} Task 2.2.4 Pilot Scale Testing {lg_bullet} Task 2.2.5.2 Laboratory and Bench

  5. 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)

    2000-12-01

    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

  6. Catalytic combustion in small wood burning appliances

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

    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.)

  7. Properties of Combustion Gases

    Science.gov (United States)

    Wear, J. D.; Jones, R. E.; Trout, A. M.; Mcbride, B. J.

    1986-01-01

    New series of reports: First report lists data from combustion of ASTM Jet A fuel and dry air; second report presents tables and figures for combustion-gas properties of natural-gas fuel and dry air, and equivalent ratios.

  8. Combustion of Fractal Distributions

    OpenAIRE

    Sotolongo, Oscar; Lopez, Enrique

    1994-01-01

    The advantages of introducing a fractal viewpoint in the field of combustion is emphasized. It is shown that the condition for perfect combustion of a collection of drops is the self-similarity of the distribution.

  9. Combustion Research Facility

    Data.gov (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...

  10. Steroid-Derived Naphthoquinoline Asphaltene Model Compounds: Hydriodic Acid Is the Active Catalyst in I2-Promoted Multicomponent Cyclocondensation Reactions.

    Science.gov (United States)

    Schulze, Matthias; Scott, David E; Scherer, Alexander; Hampel, Frank; Hamilton, Robin J; Gray, Murray R; Tykwinski, Rik R; Stryker, Jeffrey M

    2015-12-01

    A multicomponent cyclocondensation reaction between 2-aminoanthracene, aromatic aldehydes, and 5-α-cholestan-3-one has been used to synthesize model asphaltene compounds. The active catalyst for this reaction has been identified as hydriodic acid, which is formed in situ from the reaction of iodine with water, while iodine is not a catalyst under anhydrous conditions. The products, which contain a tetrahydro[4]helicene moiety, are optically active, and the stereochemical characteristics have been examined by VT-NMR and VT-CD spectroscopies, as well as X-ray crystallography. PMID:26584791

  11. 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)

    1997-12-31

    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.)

  12. Fluidized bed combustion research in Turkey

    International Nuclear Information System (INIS)

    At present 20% of the total energy consumption in Turkey is met by combustion of lignites. The amount of lignite utilization in the total energy consumption in the year 2000 is expected to double compared to the present. The prevalent characteristics of Turkish lignites are high volatile matter, moisture, ash, and sulfur contents and low calorific value. Also, there are combustion difficulties in conventional combustors associated with the low ash sintering temperatures. For these reasons, there is a major air pollution problem in the main cities of Turkey during winter months. In this paper, the authors review the fluidized bed combustion research work undertaken in Turkey in the last decade and discuss the relevant problem of volatile matter combustion, stability and design

  13. Opportunities in pulse combustion

    Science.gov (United States)

    Brenchley, D. L.; Bomelburg, H. J.

    1985-10-01

    In most pulse combustors, the combustion occurs near the closed end of a tube where inlet valves operate in phase with the pressure amplitude variations. Thus, within the combustion zone, both the temperature and the pressure oscillate around a mean value. However, the development of practical applications of pulse combustion has been hampered because effective design requires the right combination of the combustor's dimensions, valve characteristics, fuel/oxidizer combination, and flow pattern. Pulse combustion has several additional advantages for energy conversion efficiency, including high combustion and thermal efficiency, high combustion intensity, and high convective heat transfer rates. Also, pulse combustion can be self-aspirating, generating a pressure boost without using a blower. This allows the use of a compact heat exchanger that may include a condensing section and may obviate the need for a chimney. In the last decade, these features have revived interest in pulse combustion research and development, which has resulted in the development of a pulse combustion air heater by Lennox, and a pulse combustion hydronic unit by Hydrotherm, Inc. To appraise this potential for energy savings, a systematic study was conducted of the many past and present attempts to use pulse combustion for practical purposes. The authors recommended areas where pulse combustion technology could possibly be applied in the future and identified areas in which additional R and D would be necessary. Many of the results of the study project derived from a special workshop on pulse combustion. This document highlights the main points of the study report, with particular emphasis on pulse combustion application in chemical engineering.

  14. Far- and mid-infrared spectroscopy of complex organic matter of astrochemical interest: coal, heavy petroleum fractions, and asphaltenes

    CERN Document Server

    Cataldo, F; Manchado, A

    2012-01-01

    The coexistence of a large variety of molecular species (i.e., aromatic, cycloaliphatic and aliphatic) in several astrophysical environments suggests that unidentified IR emission (UIE) occurs from small solid particles containing a mix of aromatic and aliphatic structures (e.g., coal, petroleum, etc.), renewing the astronomical interest on this type of materials. A series of heavy petroleum fractions namely DAE, RAE, BQ-1, and asphaltenes derived from BQ-1 were used together with anthracite coal and bitumen as model compounds in matching the band pattern of the emission features of proto-planetary nebulae (PPNe). All the model materials were examined in the mid-infrared (2.5-16.7 um) and for the first time in the far-infrared (16.7-200 um), and the IR bands were compared with the UIE from PPNe. The best match of the PPNe band pattern is offered by the BQ-1 heavy aromatic oil fraction and by its asphaltenes fraction. Particularly interesting is the ability of BQ-1 to match the band pattern of the aromatic-ali...

  15. Combustion characteristics and air pollutant formation during oxy-fuel co-combustion of microalgae and lignite.

    Science.gov (United States)

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

    2016-05-01

    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. PMID:26894568

  16. Combustion modeling in internal combustion engines

    Science.gov (United States)

    Zeleznik, F. J.

    1976-01-01

    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.

  17. Boiler using combustible fluid

    Science.gov (United States)

    Baumgartner, H.; Meier, J.G.

    1974-07-03

    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.

  18. 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.

    1974-01-01

    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)

  19. A small angle neutron scattering study of the adsorbed asphaltene layer in water-in-hydrocarbon emulsions: structural description related to stability.

    Science.gov (United States)

    Jestin, Jacques; Simon, Sébastien; Zupancic, Lina; Barré, Loïc

    2007-10-01

    We have developed a specific protocol to study with SANS measurements, the structure of the interfacial film layer in water-in-oil emulsions stabilized by asphaltene. Using the contrast matching technique available for neutron scattering, we have access to both the composition and the quantity of interface. The results obtained give us a view of the asphaltene aggregates in the interfacial film, which are structured as a monolayer and show a direct correlation between the size of asphaltene aggregates in solution and the thickness of the film layer. The organization of the interface has been studied as a function of several parameters such as the quantity of resins, i.e., the size of aggregates, the pH of the aqueous phase, and the aging time of the emulsions and the consequences of these variations on the macroscopic stability of these emulsions. We show that the key parameter for the stability is the inter-asphaltene aggregate interaction inside the film layer. Changing the attractive/repulsive balance between the aggregates in the film at the microscopic scale, by changing the aggregate's size or the aggregate's ionization, has a direct incidence on the quantity of water recovered after centrifugation: the stronger the attraction between aggregates in the film, the more stable the emulsion is. PMID:17867712

  20. Carbon Shale Combustion in the Fluidized Bed Reactor

    OpenAIRE

    Olek Małgorzata; Kandefer Stanisław; Kaniowski Wiesław; Żukowski Witold; Baron Jerzy

    2014-01-01

    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 ...

  1. Comparative sinterability of combustion synthesized and commercial titanium carbides

    International Nuclear Information System (INIS)

    The influence of various parameters on the sinterability of combustion synthesized titanium carbide was investigaged. Titanium carbide powders, prepared by the combustion synthesis process, were sintered in the temperature range 1150 to 16000C. Incomplete combustion and high oxygen contents were found to be the cause of reduced shrinkage during sintering of the combustion syntheized powders when compared to the shrinkage of commercial TiC. Free carbon was shown to inhibit shrinkage. The activation energy for sintering was found to depend on stoichiometry (C/Ti). With decreasing C/Ti, the rate of sintering increased. 29 references, 16 figures, 13 tables

  2. Numerical modeling of straw combustion in a fixed bed

    DEFF Research Database (Denmark)

    Zhou, Haosheng; Jensen, Anker; Glarborg, Peter;

    2005-01-01

    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 are...... in good agreement with measurements at different operating conditions such as primary air-flow rate, pre-heating of the primary air, oxygen concentration, moisture content in straw, and bulk density of the straw in the fixed bed. A parametric study indicates that the effective heat conductivity......, straw packing condition, and heat capacity of the straw have considerable effects on the model predictions of straw combustion in the fixed bed....

  3. INVESTIGATION OF COMBUSTION IN TITANIUM-FERROSILICON SYSTEM

    OpenAIRE

    Shatokhin, Igor; Bigeev, Vahit; Shaymardanov, Kamil; Manashev, Ildar

    2013-01-01

    Results of self-sustaining combustion process in the titanium-ferrosilicon system investigations are presented. These data were used for experimental-industrial technology developing of production ferro silico titanium with high titanium content for steel alloying.

  4. 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.

  5. 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.

    2001-03-01

    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)

  6. Sewage sludge drying and combustion

    OpenAIRE

    Salgado, Mario Alejandro Heredia

    2014-01-01

    A brief review of the paper pulp production process in order to understand the origin of the sewage sludge was performed. Then a general revision of the current treatment options for this type of waste was addressed. The thermal treatment by combustion was focused and a review of the state of the art of this process was performed. The high moisture content of sludge was identified as a major concern. Thus a revision of the state of the art regarding thermal drying of sewage sludge was perform...

  7. Combustion Byproducts Recycling Consortium

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-08-31

    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.

  8. Performance of PAHs emission from bituminous coal combustion

    Institute of Scientific and Technical Information of China (English)

    严建华; 尤孝方; 李晓东; 倪明江; 尹雪峰; 岑可法

    2004-01-01

    Carcinogenic and mutagenic polycyclic aromatic hydrocarbons (PAHs) generated in coal combustion have caused great environmental health concern. Seventeen PAHs (16 high priority PAHs recommended by USEPA plus Benzo[e]pyrene) present in five raw bituminous coals and released during bituminous coal combustion were studied. The effects of combustion temperature, gas atmosphere, and chlorine content of raw coal on PAHs formation were investigated. Two additives (copper and cupric oxide) were added when the coal was burned. The results indicated that significant quantities of PAHs were produced from incomplete combustion of coal pyrolysis products at high temperature, and that temperature is an important causative factor of PAHs formation. PAHs concentrations decrease with the increase of chlorine content in oxygen or in nitrogen atmosphere. Copper and cupric oxide additives can promote PAHs formation (especially the multi-ring PAHs) during coal combustion.

  9. Combustion and utilization of low calorific value gases (LCVG)

    Energy Technology Data Exchange (ETDEWEB)

    Kishore, Puneet; Ray, Anjan

    2010-09-15

    Combustion becomes increasingly difficult / inefficient / impossible with decrease in hydrocarbon content / calorific value of gas with available technologies. Through analysis it was postulated that Low Calorific Value Gas would be combustible with Oxygen in existing burner equipment with minor changes, and experimentally tested in the laboratory. The broad conclusion is that LCVG (with 8% or more Hydrocarbon content) could be combusted as efficiently as a normal High CV natural gas. This creates opportunity to translate significant promise and potential of LCVG from a variety of un-conventional sources globally into reliable long term energy resources.

  10. Municipal waste combustion

    International Nuclear Information System (INIS)

    This book covers the proceedings of the second annual International Specialty Conference on Municipal Waste Combustion. Topics covered include: combustion; refuse derived fuel plants; ash characterization; flue gas cleaning; ash disposal; environmental effects; risk and quality assurance; mercury control; sampling; regulations

  11. Coal Combustion Science

    Energy Technology Data Exchange (ETDEWEB)

    Hardesty, D.R. (ed.); Fletcher, T.H.; Hurt, R.H.; Baxter, L.L. (Sandia National Labs., Livermore, CA (United States))

    1991-08-01

    The objective of this activity is to support the Office of Fossil Energy in executing research on coal combustion science. This activity consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency Coal Combustion Science Project. Specific tasks for this activity include: (1) coal devolatilization - the objective of this risk is to characterize the physical and chemical processes that constitute the early devolatilization phase of coal combustion as a function of coal type, heating rate, particle size and temperature, and gas phase temperature and oxidizer concentration; (2) coal char combustion -the objective of this task is to characterize the physical and chemical processes involved during coal char combustion as a function of coal type, particle size and temperature, and gas phase temperature and oxygen concentration; (3) fate of mineral matter during coal combustion - the objective of this task is to establish a quantitative understanding of the mechanisms and rates of transformation, fragmentation, and deposition of mineral matter in coal combustion environments as a function of coal type, particle size and temperature, the initial forms and distribution of mineral species in the unreacted coal, and the local gas temperature and composition.

  12. Fifteenth combustion research conference

    International Nuclear Information System (INIS)

    The BES research efforts cover chemical reaction theory, experimental dynamics and spectroscopy, thermodynamics of combustion intermediates, chemical kinetics, reaction mechanisms, combustion diagnostics, and fluid dynamics and chemically reacting flows. 98 papers and abstracts are included. Separate abstracts were prepared for the papers

  13. Lectures on combustion theory

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-09-01

    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)

  14. Heterogeneous solid mixtures combustion: influence of microstructure

    International Nuclear Information System (INIS)

    A model of solid composite microstructure is developed to predict concentration limits of heterogeneous solid mixture combustion of gasless and small-gas-content systems. The prediction is based on the percolation theory combined with the fractal concept and the Scher-Zallen criterion that postulates that the volume fraction necessary for the onset of percolation is about 16% of the total volume. The validity of the criterion is supported by a set of literature data on concentration limits of combustion for binary mixtures of transition metals and p-block elements such as Zr, Hf, Nb, Ta, Mo, B, C, Si, Al, Ge

  15. Fine particle emissions from residential wood combustion

    Energy Technology Data Exchange (ETDEWEB)

    Tissari, J.

    2008-07-01

    Residential wood combustion (RWC) appliances have the high probability of incomplete combustion, producing e.g. fine particles and hazardous organic compounds. In this thesis, the fine particle number and mass emissions, particle composition and morphology, and gas emissions were investigated from the modern (MMH) and conventional masonry heaters (CMH), sauna stoves (SS) and pellet burner. The investigation was based on laboratory and field experiments applying extensive and unique particle sampling methods. The appliance type, fuel and operational practices were found to affect clearly the fine particle emissions. In good combustion conditions (e.g. in pellet combustion), the fine particle mass (PM{sub 1}) emission factors were low, typically below 0.3 g kg-1, and over 90% of the PM{sub 1} consisted of inorganic compounds (i.e fine ash). From the CMH the typical PM{sub 1} values were 1.6-1.8 g kg-1, and from the SS 2.7-5.0 g kg-1, but were strongly dependent on operational practices. The smouldering combustion in CMH increased PM{sub 1} emission up to 10 g kg-1. The good secondary combustion in the MMH reduced the particle organic matter (POM) and gaseous emissions, but not substantially the elemental carbon (EC, i.e. soot) emission, and the typical PM{sub 1} values were 0.7-0.8 g kg-1. The particle number emissions were high, and did not correspond with the completition of combustion. The particle number distributions were mainly dominated by ultrafine (<100 nm) particles, but varied dependent on combustion conditions. The electronmicroscopy analyses showed that ultrafine particles were composed mainly of K, S and Zn. From the smouldering combustion, particles were composed mainly of carbon compounds and they had a closed sinteredlike structure, due to organic matter on the particles. Controlling the gasification rate via the primary air supply, log and batch size, as well as fuel moisture content, is important for the reduction of emissions in batch combustion

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

    Directory of Open Access Journals (Sweden)

    Tissot B.

    2006-11-01

    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

  17. 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.

    2006-03-01

    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

  18. ATOMISTIC MODELING OF OIL SHALE KEROGENS AND ASPHALTENES ALONG WITH THEIR INTERACTIONS WITH THE INORGANIC MINERAL MATRIX

    Energy Technology Data Exchange (ETDEWEB)

    Facelli, Julio; Pugmire, Ronald; Pimienta, Ian

    2011-03-31

    The goal of this project is to obtain and validate three dimensional atomistic models for the organic matter in both oil shales and oil sands. In the case of oil shales the modeling was completed for kerogen, the insoluble portion of the organic matter; for oil sands it was for asphaltenes, a class of molecules found in crude oil. The three dimensional models discussed in this report were developed starting from existing literature two dimensional models. The models developed included one kerogen, based on experimental data on a kerogen isolated from a Green River oil shale, and a set of six representative asphaltenes. Subsequently, the interactions between these organic models and an inorganic matrix was explored in order to gain insight into the chemical nature of this interaction, which could provide vital information in developing efficient methods to remove the organic material from inorganic mineral substrate. The inorganic substrate used to model the interaction was illite, an aluminum silicate oxide clay. In order to obtain the feedback necessary to validate the models, it is necessary to be able to calculate different observable quantities and to show that these observables both reproduce the results of experimental measurements on actual samples as well as that the observables are sensitive to structural differences between models. The observables that were calculated using the models include 13C NMR spectra, the IR vibrational spectra, and the atomic pair wise distribution function; these were chosen as they are among the methods for which both experimental and calculated values can be readily obtained. Where available, comparison was made to experiment results. Finally, molecular dynamic simulations of pyrolysis were completed on the models to gain an understanding into the nature of the decomposition of these materials when heated.

  19. Brewster angle microscopy of Langmuir films of athabasca bitumens, n-C5 asphaltenes, and SAGD bitumen during pressure-area hysteresis.

    Science.gov (United States)

    Hua, Yujuan; Angle, Chandra W

    2013-01-01

    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

  20. Femtosecond laser induced breakdown for combustion diagnostics

    International Nuclear Information System (INIS)

    The focused beam of a 100 fs, 800 nm laser is used to induce a spark in some laminar premixed air-methane flames operating with variable fuel content (equivalence ratio). The analysis of the light escaping from the plasma revealed that the Balmer hydrogen lines, Hα and Hβ, and some molecular origin emissions were the most prominent spectral features, while the CN (Β2Σ+-Χ2Σ+) band intensity was found to depend linearly with methane content, suggesting that femtosecond laser induced breakdown spectroscopy can be a useful tool for the in-situ determination and local mapping of fuel content in hydrocarbon-air combustible mixtures.

  1. Internal Heterogeneous Processes in Aluminum Combustion

    Science.gov (United States)

    Dreizin, E. L.

    1999-01-01

    This paper discusses the aluminum particle combustion mechanism which has been expanded by inclusion of gas dissolution processes and ensuing internal phase transformations. This mechanism is proposed based on recent normal and microgravity experiments with particles formed and ignited in a pulsed micro-arc. Recent experimental findings on the three stages observed in Al particle combustion in air and shows the burning particle radiation, trajectory (streak), smoke cloud shapes, and quenched particle interiors are summarized. During stage I, the radiation trace is smooth and the particle flame is spherically symmetric. The temperature measured using a three-color pyrometer is close to 3000 K. Because it exceeds the aluminum boiling point (2730 K), this temperature most likely characterizes the vapor phase flame zone rather than the aluminum surface. The dissolved oxygen content within particles quenched during stage I was below the detection sensitivity (about 1 atomic %) for Wavelength Dispersive Spectroscopy (WDS). After an increase in the radiation intensity (and simultaneous decrease in the measured color temperature from about 3000 to 2800 K) indicative of the transition to stage II combustion, the internal compositions of the quenched particles change. Both oxygen-rich (approx. 10 atomic %) and oxygen-lean (aluminum particle combustion behavior and the evolution of its internal composition, the change from the spherically symmetric to asymmetric flame shape occurring upon the transition from stage I to stage II combustion could not be understood based only on the fact that dissolved oxygen is detected in the particles. The connection between the two phenomena appeared even less significant because in earlier aluminum combustion studies carried in O2/Ar mixtures, flame asymmetry was not observed as opposed to experiments in air or O2/CO mixtures. It has been proposed that the presence of other gases, i.e., hydrogen, or nitrogen causes the change in the

  2. 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

    2003-05-01

    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

  3. 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

    2009-01-01

    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.

  4. Sandia Combustion Research: Technical review

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    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.

  5. Ruthenium-ion-catalyzed oxidation of asphaltenes and oil-source correlation of heavy oils from the Lunnan and Tahe oilfields in the Tarim Basin, NW China

    Institute of Scientific and Technical Information of China (English)

    MA Anlai; ZHANG Shuichang; ZHANG Dajiang; JIN Zhijun; MA Xiaojuan; CHEN Qingtang

    2005-01-01

    The identification of marine source rocks in the Tarim Basin is debated vigorously. The intention of this paper is to investigate the asphaltenes in heavy oils from the Lunnan and Tahe oilfields and Well TD2 with ruthenium-ions-catalyzed oxidation technique (RICO), in order to explore its role in oil-oil and oil-source correlations. The RICO products included n-alkanoic acids, α, ω-di-n-alkanoic acids, branched alkanoic acids, tricyclic terpanoic acids, hopanoic acids, gammacerane carboxylic acid , regular sterane carboxylic acids and 4-methylsterane carboxylic acids. The n-alkyl chains and biomarkers bounded on the asphaltenes were of unsusceptibility to biodegradation. The distribution and absolute concentrations of n-alkanoic acids in the RICO products of heavy oils from the Lunnan and Tahe oilfields are different from those of Well TD2. The biomarkers bounded on the asphaltenes, especially steranes, have a distribution trend similar to that of the counterparts in saturates. The sterane carboxylic acids and 4-methylsterane carboxylic acids in the RICO products of heavy oils from the Lunnan and Tahe oilfields, dominated by C30 sterane and C31 4-methylsterane carboxylic acids, respectively, are significantly different from those of the heavy oils of Well TD2, whose dominating sterane and 4-methylsterane carboxylic acids are C2s sterane and C29 4-methylsterane acids, respectively. The RICO products of the asphaltenes further indicate that the Middle-Upper Ordovician may be the main source rocks for heavy oils from the Lunnan and Tahe oilfields.

  6. Shale oil combustion

    International Nuclear Information System (INIS)

    A 'coutant' carbon steel combustion chamber cooled by water jacket was conslructed to burn diesel fuel and mixlure of shale oil and diesel fuels. During experimental work nir fuel ratio was determined, temperaturces were measured using Chromel/ Almel thermocouple, finally the gasous combustion product analysis was carricd out using gas chromatograph technique. The constructed combustion chamber was operating salisfactory for several hours of continous work. According to the measurements it was found that: the flame temperature of a mixture of diesel and shale oil fuels was greater than the flame temperature of diesel fuel. and the sulfer emissious of a mixture of diesel and shale oil fuels was higher than that of diesel fuel. Calculation indicated that the dry gas energy loss was very high and the incomplete combustion energy loss very small. (author). 23 refs., 35 figs

  7. Combustion Technology Outreach

    Science.gov (United States)

    1995-01-01

    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.

  8. Burning characteristics of microcellular combustible objects

    Directory of Open Access Journals (Sweden)

    Wei-tao Yang

    2014-06-01

    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.

  9. Burning characteristics of microcellular combustible objects

    Institute of Scientific and Technical Information of China (English)

    Wei-tao YANG; Yu-xiang LI; San-jiu YING

    2014-01-01

    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.

  10. Combustion gas scrubbing system

    Energy Technology Data Exchange (ETDEWEB)

    Dahlstrom, D.A.; Ellison, W.; Wilhelm, J.H.

    1979-04-03

    In a cooperative combination of two scrubbing systems, the first scrubbing system operates upon combustion gases with an aqueous solution to remove hydrogen chloride gas and other chlorine components. The second scrubbing system subsequently operates upon the combustion gases with a sodium-base solution to absorb sulfur oxides. The products of the two scrubbing systems are treated in combination to form a material for disposal and to generate the aqueous scrubbing solution for the chloride scrubbing system.

  11. Combustion theory and modeling

    OpenAIRE

    Buckmaster, J; Clavin, Paul; Liñán Martínez, Amable; Matalon, M.; Peters, N; Sivashinsky, G.; Williams, F. A.

    2005-01-01

    In honor of the fiftieth anniversary of the Combustion Institute, we are asked to assess accomplishments of theory in combustion over the past fifty years and prospects for the future. The title of our article is chosen to emphasize that development of theory necessarily goes hand-in-hand with specification of a model. Good conceptual models underlie successful mathematical theories. Models and theories are discussed here for deflagrations, detonations, diffusion flames, ignition, propellant ...

  12. Combustion within Porous Waste

    OpenAIRE

    Pfahl, Ulrich; Shepherd, Joseph E.; Unal, Cetin

    1998-01-01

    Flammable gases (primarily hydrogen and nitrous oxide but also ammonia and methane) are continuously being generated within the waste contained in the tank farms at Hanford Site. Some portions of the waste are porous and conceivably, a combustion event could occur within the waste due to accidental ignition. This has been postulated as a potential hazard since deflagrations and detonations are observed in laboratory experiments to propagate through combustible gases in porous materials, or ...

  13. Carbon Shale Combustion in the Fluidized Bed Reactor

    Directory of Open Access Journals (Sweden)

    Olek Małgorzata

    2014-06-01

    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.

  14. 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))

    1991-07-01

    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.

  15. Effect of salts on the interfacial tension of asphaltene-toluene/water interface : prediction by Poisson-Boltzmann modified model and experimental validation

    Energy Technology Data Exchange (ETDEWEB)

    Se, R.A.G.; Lima, E.R.A.; Nele, M.; Tavares, F.W. [Federal Univ. of Rio de Janeiro (Brazil). School of Chemistry; Bostrom, M. [Linkoping Univ., Linkoping (Sweden). Dept. of Physics, Chemistry and Biology

    2008-07-01

    This study presented new experimental data of interfacial tension of toluene-asphaltene/water systems in the presence of different salts. In order to study the stability of emulsions caused by the presence of salts in produced water, it is important to understand the interaction of ions at the interface. It was simpler to use model systems consisting of asphaltenes dissolved in toluene because of the complexity of the interfacially active components in oil. The study involved a Brazilian crude oil in which asphaltene was precipitated with a 1:15 ratio of n-heptane and solutions of water with salts LiCl, KCl, NaCl, NaI, NaBr and KBr in concentrations of 0.10, 0.25, 0.50, 0.75 and 1.0 M. The study investigated salt mixtures NaCl/NaBr and NaCl/NaI in the proportions 0.8:0.2, 0.6:0.4, 0.4:0.6, 0.2:0.8 molar. The experimental data was modeled using a modified Poisson-Boltzmann equation that considered dispersion in order to take into account the influence of ions at the interface.

  16. Sandia Combustion Research Program

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-01-01

    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.

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

    CERN Document Server

    Schwarz, Christian; Teichmann, Rüdiger

    2012-01-01

    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.

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

    OpenAIRE

    Yan Weiping; Gao Yang; Li Jun

    2012-01-01

    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 ca...

  19. 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.

    2006-11-01

    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

  20. COAL COMBUSTION EFFICIENCY IN CFB BOILER

    Institute of Scientific and Technical Information of China (English)

    Hairui Yang; Guangxi Yue

    2005-01-01

    The carbon content in the fly ash from most Chinese circulating fluidized bed (CFB) boilers is much higher than expected, thus directly influencing the combustion efficiency. In the present paper, carbon burnout was investigated both in field tests and laboratory experiments. The effect of coal property, operation condition, gas-solid mixing, char deactivation,residence time and cyclone performance are analyzed seriatim based on large amount of experimental results.A coal index is proposed to describe the coal rank, defined by the ratio of the volatile content to the coal heat value, is a useful parameter to analyze the char burnout. The carbon content in the fly ash depends on the coal rank strongly. CFB boilers burning anthracite, which has low coal index, usually have high carbon content in the fly ash. On the contrary, the CFB boilers burning brown coal, which has high coal index, normally have low carbon content.Poor gas-solid mixing in the furnace is another important reason of the higher carbon content in the fly ash. Increasing the velocity and rigidity of the secondary air could extend the penetration depth and induce more oxygen into the furnace center. Better gas solid mixing will decrease the lean oxygen core area and increase char combustion efficiency.The fine char particles could be divided into two groups according to their reactivity. One group is "fresh" char particles with high reactivity and certain amount of volatile content. The other group of char particles has experienced sufficient combustion time both in the furnace and in the cyclone, with nearly no volatile. These "old" chars in the fly ash will be deactivated during combustion of large coal particles and have very low carbon reactivity. The generated fine inert char particles by attrition of large coal particles could not easily burn out even with the fly ash recirculation. The fraction of large coal particles in coal feed should be reduced during fuel preparation process.The cyclone

  1. Desulfurization kinetics of coal combustion gases

    OpenAIRE

    Bragança S.R.; Jablonski A.; Castellan J.L.

    2003-01-01

    Desulfurization of the gases from coal combustion was studied, using limestone (marble) as the sorbent in a fluidized-bed reactor. The kinetic parameter, k, was measured by analyzing the reduction in SO2 emissions in relation to time when a batch of limestone was introduced directly into the combustor chamber. The influence of sorbent composition and particle size was also studied. The CaO content in the limestone was more important than the MgO content. Sorbent particle size showed a strong ...

  2. Combustible structural composites and methods of forming combustible structural composites

    Science.gov (United States)

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

    2013-04-02

    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.

  3. Combustible structural composites and methods of forming combustible structural composites

    Science.gov (United States)

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

    2011-08-30

    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.

  4. Combustion characteristics and arsenic retention during co-combustion of agricultural biomass and bituminous coal.

    Science.gov (United States)

    Zhou, Chuncai; Liu, Guijian; Wang, Xudong; Qi, Cuicui; Hu, Yunhu

    2016-08-01

    A combination of thermogravimetric analysis (TG) and laboratory-scale circulated fluidized bed combustion experiment was conducted to investigate the thermochemical, kinetic and arsenic retention behavior during co-combustion bituminous coal with typical agricultural biomass. Results shown that ignition performance and thermal reactivity of coal could be enhanced by adding biomass in suitable proportion. Arsenic was enriched in fly ash and associated with fine particles during combustion of coal/biomass blends. The emission of arsenic decreased with increasing proportion of biomass in blends. The retention of arsenic may be attributed to the interaction between arsenic and fly ash components. The positive correlation between calcium content and arsenic concentration in ash suggesting that the arsenic-calcium interaction may be regarded as the primary mechanism for arsenic retention. PMID:27136608

  5. Alcohol combustion chemistry

    KAUST Repository

    Sarathy, Mani

    2014-10-01

    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

  6. Studies in combustion dynamics

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-01

    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.

  7. Toxicology of Biodiesel Combustion products

    Science.gov (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. ...

  8. Combuster. [low nitrogen oxide formation

    Science.gov (United States)

    Mckay, R. A. (Inventor)

    1978-01-01

    A combuster is provided for utilizing a combustible mixture containing fuel and air, to heat a load fluid such as water or air, in a manner that minimizes the formation of nitrogen oxide. The combustible mixture passes through a small diameter tube where the mixture is heated to its combustion temperature, while the load fluid flows past the outside of the tube to receive heat. The tube is of a diameter small enough that the combustible mixture cannot form a flame, and yet is not subject to wall quench, so that combustion occurs, but at a temperature less than under free flame conditions. Most of the heat required for heating the combustible mixture to its combustion temperature, is obtained from heat flow through the walls of the pipe to the mixture.

  9. 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.

    2006-11-01

    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.

  10. Combustion Engine Identification and Control

    OpenAIRE

    Blasco Serrano, Daniel

    2013-01-01

    The topic of this thesis is system identification and control of two different internal combustion engines, Partially Premixed Combustion (PPC) engine and a more conventional Combustion Ignited (CI) diesel engine. The control of both engines is aimed to emission reduction and to increase the eficiency. There is an introduction to the internal combustion engine, as well as theory used about system identification and Model Predictive Control (MPC). A physical model of a PPC en...

  11. Coal combustion research

    Energy Technology Data Exchange (ETDEWEB)

    Daw, C.S.

    1996-06-01

    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.

  12. Experimental Investigation of Oxygen Enriched air intake on Combustion Parameters of a Single Cylinder Diesel Engine

    OpenAIRE

    Rajkumar, K; Govindarajan, P

    2010-01-01

    In the present experimental work a computerized Single cylinder Diesel engine with data acquisition system was used to study the effects of oxygen enriched air intake on combustion parameters. Increasing the oxygen content with the air leads to faster burn rates and the ability to burn more fuel at the same stoichiometery. Addedoxygen in the combustion air leads to shorter ignition delays and offers more potential for burning diesel. Oxy-fuel combustion reduces the volume of flue gases and re...

  13. Effect of secondary air injection on the combustion efficiency of sawdust in a fluidized bed combustor

    OpenAIRE

    K. V. N. Srinivasa Rao; G. Venkat Reddy

    2008-01-01

    Agricultural wastes like bagasse, paddy husks, sawdust and groundnut shells can be effectively used as fuels for fluidized bed combustion; otherwise these biomass fuels are difficult to handle due to high moisture and fines content. In the present work the possibility of using sawdust in the fluidized bed combustor, related combustion efficiencies and problems encountered in the combustion process are discussed. The temperature profiles for sawdust with an increase in fluidizing velocity alon...

  14. Combustion calorimetry experimental chemical thermodynamics

    CERN Document Server

    Sunner, Stig

    1979-01-01

    Combustion Calorimetry deals with expertise knowledge concerning the calorimetry of combustion reactions of an element or compound. After defining the use of units and physical constants, the book discusses the basic principles of combustion calorimetry and the various instruments and calorimeters used in the experiments to measure operations concerning temperatures and its time variations. One paper discusses the theory and design criteria of combustion calorimeter calibration. Another paper discusses the results obtained from a combustion calorimeter after it has measured the energy or entha

  15. Heat regenerative external combustion engine

    Science.gov (United States)

    Duva, Anthony W.

    1993-10-01

    A heat regenerative external combustion engine is disclosed. The engine includes fuel inlet means which extends along the exhaust passage and/or combustion chamber in order to preheat the fuel, To provide for preheating by gases in both the combustion chamber and the exhaust passage, the combustion chamber is arranged annularly around the drive shaft and between the cylinders. This configuration also is advantageous in that it reduces the noise of combustion. The engine of the invention is particularly well-suited for use in a torpedo.

  16. Gaussian process regression based optimal design of combustion systems using flame images

    International Nuclear Information System (INIS)

    Highlights: • The digital color images of flames are applied to combustion design. • The combustion with modeling stochastic nature is developed using GP. • GP based uncertainty design is made and evaluated through a real combustion system. - Abstract: With the advanced methods of digital image processing and optical sensing, it is possible to have continuous imaging carried out on-line in combustion processes. In this paper, a method that extracts characteristics from the flame images is presented to immediately predict the outlet content of the flue gas. First, from the large number of flame image data, principal component analysis is used to discover the principal components or combinational variables, which describe the important trends and variations in the operation data. Then stochastic modeling of the combustion process is done by a Gaussian process with the aim to capture the stochastic nature of the flame associated with the oxygen content. The designed oxygen combustion content considers the uncertainty presented in the combustion. A reference image can be designed for the actual combustion process to provide an easy and straightforward maintenance of the combustion process

  17. SYNTHESIS AND CHARACTERIZATION OF THE POLYSTYRENE - ASPHALTENE GRAFT COPOLYMER BY FT-IR SPECTROSCOPY SÍNTESIS Y CARACTERIZACIÓN DEL COPOLIMERO ASFALTENO - POLIESTIRENO POR ESPECTROSCOPIA INFRAROJA

    Directory of Open Access Journals (Sweden)

    Adan-Yovani León-Bermúdez

    2008-12-01

    Full Text Available The creation of new polymer compounds to be added to asphalt has drawn considerable attention because these substances have succeeded in modifying the asphalt rheologic characteristics and physical properties for the enhancement of its behavior during the time of use. This work explains the synthesis of a new graft copolymer based on an asphalt fraction called asphaltene, modified with maleic anhydride. Polystyrene functionalization is conducted in a parallel fashion in order to obtain polybenzylamine resin with an amine - NH2 free group, that reacts with the anhydride graft groups in the asphaltene, thus obtaining the new Polystyrene/Asphaltene graft copolymer.La creación de nuevos compuestos poliméricos para ser adicionados al asfalto, ha llamado la atención de manera considerable debido a que estas sustancias han logrado modificar las características reológicas y propiedades físicas del asfalto, con la finalidad de mejorar su comportamiento en el tiempo de uso. El presente trabajo explica, la síntesis de un nuevo copolímero de injerto a partir de una fracción del asfalto llamada asfalteno, la cual es modificada con anhídrido maleico. Paralelamente se realiza la funcionalización del poliestireno, resina polibencilamina, esta posee un grupo amina - NH2 libre que reacciona con los grupos anhídro, injertados en el asfalteno, y así obtener el nuevo copolímero de injerto Poliestireno/Asfalteno.

  18. Colloidal Structure of Heavy Crudes and Asphaltene Soltutions Structure colloïdale des bruts lourds et des suspensions d'asphaltènes

    Directory of Open Access Journals (Sweden)

    Barre L.

    2006-12-01

    Full Text Available Many industrial problems that arise during petroleum processing are related to the high concentration of asphaltenes. A good knowledge of the chemical composition of these macromolecules and a detailed understanding of the evolution of the colloïdal structures present in oil and its derivatives can play a decisive role in improving processing facilities. Asphaltenes are defined by their insolubility in n-heptane. Soluble molecules are called maltenes which can be fractionated by liquid chromatography in so-called resins, aromatic and saturated fractions. The major part of the research carried out on these complex molecules concerned the chemical composition determination from powerful techniques measurements as for instance IR or NMR methods. Nevertheless, very little information on the colloïdal structure of asphaltenes or resins in pure solvent or in real systems is accessible.The molecular weight determination was the first objective; several techniques, as vapour pressure osmometry (VPO, were used. The main conclusion of these determinations was the huge variation of the molecular weight measured by different methods. We used X-ray and neutron small angle scattering techniques in order to deduce the size polydispersity and the weight average molecular weight. Different systems as (i asphaltenes or resins in solution with different solvents, or (ii asphaltene and resin mixtures in suspension with good or bad solvents were investigated as a function of temperature increase. We have exhibited that the aggregation number, i.e. the number of smaller entities , can strongly vary with solvent composition and temperature. Resins appear as very good solvent for asphaltene molecules. Scattering measurements often exhibit strong scattered intensity at small scattering vector, showing the presence in the suspension of large heterogeneities in diluted solutions of asphaltenes and resins. We can suggest that these heterogeneities are due to

  19. GRANULOMETRIC INFLUENCE ON THE COMBUSTION OF CHARCOAL FOR BARBECUE1

    Directory of Open Access Journals (Sweden)

    Ananias Francisco Dias Júnior

    2015-12-01

    Full Text Available The present work analyzed characteristics of charcoal used for barbecue and mainly took interest in the influence of the granulometry in the combustion process. The material have been tested for four different grain size (8, 16, 32 and 50 mm following a combustion test called combustion index (ICOMcv, which takes in consideration time processing, temperature generated and the mass consumed. The characterization of charcoal was done according to the following parameters, moisture, apparent density, grain density, volatile materials content, ash content, fixed carbon content and calorific value. The proofed charcoal presented standard indicators for use in barbecue and was noticed the relationship between granulometric analysis and the ICOMcv. The 16 mm grain size charcoal sample showed the best results for combustion. By contrast, the largest grain size sample presented lower results compared to the other samples. Thus, establishing unprecedented quantitative indicators in relation to those observed in practice, regarding the influence of grain size on the efficiency of combustion of the charcoal when used for barbecue.

  20. 40 CFR 60.107a - Monitoring of emissions and operations for fuel gas combustion devices.

    Science.gov (United States)

    2010-07-01

    ... heating capacity of less than 100 MMBtu and is equipped with low-NOX burners (LNB) or ultra low-NOX... streams combusted in a process heater or other fuel gas combustion device that are inherently low in... this section will be considered inherently low in sulfur content. (i) Pilot gas for heaters and...

  1. Aerosols from biomass combustion

    Energy Technology Data Exchange (ETDEWEB)

    Nussbaumer, T.

    2001-07-01

    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.

  2. 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

    2015-01-01

    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.

  3. Combustion science and engineering

    CERN Document Server

    Annamalai, Kalyan

    2006-01-01

    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

  4. Combustion powered linear actuator

    Science.gov (United States)

    Fischer, Gary J.

    2007-09-04

    The present invention provides robotic vehicles having wheeled and hopping mobilities that are capable of traversing (e.g. by hopping over) obstacles that are large in size relative to the robot and, are capable of operation in unpredictable terrain over long range. The present invention further provides combustion powered linear actuators, which can include latching mechanisms to facilitate pressurized fueling of the actuators, as can be used to provide wheeled vehicles with a hopping mobility.

  5. Catalytic Coanda combustion

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, J.D.; Smith, A.G.; Kopmels, M.

    1992-09-16

    A catalytic reaction is enhanced by the use of the Coanda effect to maximise contact between reactant and catalyst. A device utilising this principle comprises a Coanda surface which directs the flow of fuel from a slot to form a primary jet which entrains the surrounding ambient air and forms a combustible mixture for reaction on a catalytic surface. The Coanda surface may have an internal or external nozzle which may be axi-symmetric or two-dimensional. (author)

  6. 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)

    2012-06-15

    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.)

  7. Emissions from RDF combustion

    International Nuclear Information System (INIS)

    The paper deals with the emissions from refuse derived fuel (RDF) combustion. The disposal of refuse has during the last years been a matter of increasing concern for many municipalities. The environment options for waste disposal has not been focusing much. This means that first the waste generation must be reduced. Then recycling of a portion of the waste must be considered before a solution with combustion of waste is chosen. Two methods are currently in use for the combustion of municipal solid waste (MSW) which are the mass burning of unprocessed MSW and RDF. The RDF product consists of the burnable organic fraction of raw MSW. In contrast to mass burning systems, the RDF-system is pre-processing the raw MSW to make a more homogeneous fuel product. By processing the MSW, it is possible to recover RDF and other materials. The RDF process is a low cost approach to resource recovery. RDF is a merchant fuel, and can be used in existing boilers alone or as a supplement to conventional fuels as oil and coal. It is important that the RDF processing technology and RDF quality matches the energy user requirements. The RDF-processing-systems is of great importance to the RDF quality. The paper shows the different steps in the RDF process. 4 refs., 15 figs

  8. 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)

    2003-05-01

    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.

  9. Internal combustion piston engines

    Energy Technology Data Exchange (ETDEWEB)

    Segaser, C.L.

    1977-07-01

    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.

  10. Preparation of porous silicon carbide by combustion synthesis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu-min; ZHANG Jian-han; HAN Jie-cai

    2005-01-01

    Porous silicon carbide ceramics were prepared by combustion synthesis technique. SiC/TiC composite was gained by combustion reaction of Si, C and Ti. Thermodynamics analysis of Si-C-Ti system indicates that the content of TiC in products should be larger than 30%. The experimental results show that the content of Ti+C should be larger than 25% to achieve a complete combustion reaction. The X-ray diffractometry results show that the final products with a relative density of 45%-64% are composed of α-SiC, β-SiC, TiC and a small quantity of Si. The images of scanning electron microscopy show that the structures of grain in SiC based porous ceramics consist of particles with a few microns in size.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-02-01

    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.

  12. 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

    2009-07-01

    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)

  13. 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: 8344afc@prodigy.net.mx; jgonzalo@servidor.unam.mx

    2010-11-15

    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.

  14. Influence of traces of impurities on the combustion kinetics of graphites

    International Nuclear Information System (INIS)

    This research thesis reports the study of the influence of the presence of impurities on the combustion kinetics of graphite. The author first discusses the benefits and drawbacks of the different methods which can be used to make the graphite impurity content vary. These methods belong to three groups: addition of impurities, purification of raw graphite, and surface accumulation of impurities during combustion. After a presentation of the adopted experimental technique, the author reports the indirect study of the influence of impurities on graphite combustion, and then its direct study. In the next part, he discusses the relationships between various kinetic values. He finally discusses the combustion mechanism

  15. Far infrared (terahertz) spectroscopy of a series of polycyclic aromatic hydrocarbons and application to structure interpretation of asphaltenes and related compounds

    Science.gov (United States)

    Cataldo, Franco; Angelini, Giancarlo; García-Hernández, D. A.; Manchado, Arturo

    2013-07-01

    A series of 33 different polycyclic aromatic hydrocarbons (PAHs) were studied by far infrared spectroscopy (terahertz spectroscopy) in the spectral range comprised between 600 and 50 cm-1. In addition to common PAHs like naphthalene, anthracene, phenanthrene, fluoranthene, picene, pyrene, benzo[α]pyrene, and perylene, also quite unusual PAHs were studied like tetracene, pentacene, acenaphtene, acenaphtylene, triphenylene, and decacyclene. A series of alkylated naphthalenes and anthracenes were studied as well as methypyrene. Partially or totally hydrogenated PAHs were also object of the present investigation, ranging from tetrahydronaphthalene (tetralin) to decahydronaphthalene (decalin), 9,10-dihydroanthracene, 9,10-dihydrophenanthrene, hexahydropyrene, and dodecahydrotriphenylene. Finally, the large and quite rare PAHs coronene, quaterrylene, hexabenzocoronene, and dicoronylene were studied by far infrared spectroscopy. The resulting reference spectra were used in the interpretation of the chemical structure of asphaltenes (as extracted from a heavy petroleum fraction and from bitumen), the chemical structures of other petroleum fractions known as DAE (distillate aromatic extract) and RAE (residual aromatic extract), and a possible interpretation of components of the chemical structure of anthracite coal. Asphaltenes, heavy petroleum fractions, and coal were proposed as model compounds for the interpretation of the emission spectra of certain proto-planetary nebulae (PPNe) with a good matching in the mid infrared between the band pattern of the PPNe emission spectra and the spectra of these oil fractions or coal. Although this study was finalized in an astrochemical context, it may find application also in the petroleum and coal chemistry.

  16. Post combustion in converter steelmaking

    Energy Technology Data Exchange (ETDEWEB)

    Oghbasilasie, H.; Holappa, L.

    1997-12-31

    The purpose of this work is to study the fundamentals of post combustion and the effect of different process parameters on the post combustion ratio (PCR) and heat transfer efficiency (HTE) in converter steelmaking process. The PCR and HTE have been determined under normal operating conditions. Trials assessed the effect of lance height, vessel volume, foaming slag and pellet additions on PCR and HTE. Based on enthalpy considerations, post combustion of CO gas is regarded as one of the most effective means of increasing the heat supply to the BOP. The thermodynamic study of gas-metal-slag reactions gives the limiting conditions for post combustion inside the converter reactor. Different process parameters influencing both thermodynamic equilibria and kinetic conditions can greatly affect the post combustion ratio. Different features of converter processes as well smelting reduction processes utilizing post combustion have been reviewed. (orig.) SULA 2 Research Programme; 26 refs.

  17. Effects of nano-TiO2 on combustion and desulfurization

    International Nuclear Information System (INIS)

    Nanosized titanium oxide powder was prepared via the sol–gel process and characterized by transmission electron microscope. The effects of nano-TiO2 on combustion characteristics of lignite, desulfurization in combustion and the properties of ashes were investigated. The calorific value of coals and the fusion point of the coal ashes were measured by calorimeter and ash fusion point determination meter; the components of coal ashes and the contents of combustible matters in ash were determined by chemical methods; the pore-size distribution and specific surface area of the coal ash were analyzed by surface area analyzer. A thermogravimetric analyzer was used to investigate the effect of nano-TiO2 on combustion. The results showed that the calorific value of the coal and the fusion temperature of the coal ash were lowered by adding CaO, while on the other hand adding nano-TiO2 to coal increased the calorific value and the melting temperature effectively. Meanwhile, the coal combustion efficiency and desulfurization in combustion could be effectively improved by the co-action of TiO2. - Highlights: • The burn-off rate of coals was raised and the combustible contents were reduced by adding nano-TiO2. • The desulfurization in combustion can be achieved by adding CaO, but the combustion efficiency was inhibited. • Nano-TiO2 can promote the transfer rate of oxygen from gas phase to the surface of char

  18. Fuel properties to enable lifted-flame combustion

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-15

    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. Pulsating combustion - Combustion characteristics and reduction of emissions

    Energy Technology Data Exchange (ETDEWEB)

    Lindholm, Annika

    1999-11-01

    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

  20. The modes of gaseous combustion

    CERN Document Server

    Rubtsov, Nickolai M

    2016-01-01

    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.

  1. Active Combustion Control Valve Project

    Data.gov (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...

  2. Mathematical Modeling in Combustion Science

    CERN Document Server

    Takeno, Tadao

    1988-01-01

    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.

  3. Combustion irreversibilities: Numerical simulation and analysis

    Science.gov (United States)

    Silva, Valter; Rouboa, Abel

    2012-08-01

    An exergy analysis was performed considering the combustion of methane and agro-industrial residues produced in Portugal (forest residues and vines pruning). Regarding that the irreversibilities of a thermodynamic process are path dependent, the combustion process was considering as resulting from different hypothetical paths each one characterized by four main sub-processes: reactant mixing, fuel oxidation, internal thermal energy exchange (heat transfer), and product mixing. The exergetic efficiency was computed using a zero dimensional model developed by using a Visual Basic home code. It was concluded that the exergy losses were mainly due to the internal thermal energy exchange sub-process. The exergy losses from this sub-process are higher when the reactants are preheated up to the ignition temperature without previous fuel oxidation. On the other hand, the global exergy destruction can be minored increasing the pressure, the reactants temperature and the oxygen content on the oxidant stream. This methodology allows the identification of the phenomena and processes that have larger exergy losses, the understanding of why these losses occur and how the exergy changes with the parameters associated to each system which is crucial to implement the syngas combustion from biomass products as a competitive technology.

  4. Combustible dusts: A serious industrial hazard

    International Nuclear Information System (INIS)

    After investigating three fatal explosions in manufacturing plants, the U.S. Chemical Safety and Hazard Investigation Board (CSB) has concluded: The explosive hazard of combustible dust is not well known, and helping industry to understand this hazard is a priority. Prompted by these three incidents in North Carolina, Kentucky and Indiana and the need to increase the hazard awareness, CSB is conducting a study to examine the nature and scope of dust explosion risks in industry and to identify initiatives that may be necessary to more effectively prevent combustible dust fires and explosions. Such initiatives may include regulatory action, voluntary consensus standards, or other measures that could be taken by industry, labor, government, and other parties. A critical task of the dust study is analyzing past incidents to determine the severity of the problem within industry. The analysis is focusing on the number of incidents, injuries and fatalities, industrial sectors affected, and regulatory oversight. This paper presents the preliminary findings from CSBs analysis of combustible dust incidents over the past 25 years. This paper has not been approved by the Board and is published for general informational purposes only. Every effort has been made to accurately present the contents of any Board-approved report mentioned in this paper. Any material in the paper that did not originate in a Board-approved report is solely the responsibility of the authors and does not represent an official finding, conclusion, or position of the Board

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

    Energy Technology Data Exchange (ETDEWEB)

    Reed, T.B.

    1980-09-01

    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.

  6. Combustion, pyrolysis, gasification, and liquefaction of biomas

    Science.gov (United States)

    Reed, T. B.

    1980-09-01

    The advantages of biomass as a feedstock are examined and biomass conversion techniques are described. 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, 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.

  7. Analysis of the fluidized bed combustion behavior of Quercus ilex char

    International Nuclear Information System (INIS)

    Because of the high content of alkaline metals, biomass has very reactive ashes and these have a strong impact upon pyrolysis and combustion phenomena. From the study of the evolution with the combustion temperature, of the kinetic and diffusive data of several wood chars, it was found that the Quercus ilex (holm oak) char had an unexpected evolution of the heterogeneous phase reaction rate constant. Scanning electronic microscopy analysis of the ashes and thermogravimetric analysis of the char where performed, and the results shown that close to 750 °C there is a loss of mass associated with the release of inorganic matter, especially potassium and phosphorus, which have a known influence on the combustion process and the subsequent kinetic data collection. - Highlights: • Fluidized bed combustion of biomass. • Combustion behavior of holm oak char. • Influence of alkaline components on char combustion kinetic data

  8. Investigation on thermal and trace element characteristics during co-combustion biomass with coal gangue.

    Science.gov (United States)

    Zhou, Chuncai; Liu, Guijian; Fang, Ting; Lam, Paul Kwan Sing

    2014-11-01

    The thermochemical behaviors during co-combustion of coal gangue (CG), soybean stalk (SS), sawdust (SD) and their blends prepared at different ratios have been determined via thermogravimetric analysis. The simulate experiments in a fixed bed reactor were performed to investigate the partition behaviors of trace elements during co-combustion. The combustion profiles of biomass was more complicated than that of coal gangue. Ignition property and thermal reactivity of coal gangue could be enhanced by the addition of biomass. No interactions were observed between coal gangue and biomass during co-combustion. The volatilization ratios of trace elements decrease with the increasing proportions of biomass in the blends during co-combustion. Based on the results of heating value, activation energy, base/acid ratio and gaseous pollutant emissions, the blending ratio of 20-30% biomass content is regarded as optimum composition for blending and could be applied directly at current combustion application with few modifications. PMID:25459855

  9. Combustion Branch Website Development

    Science.gov (United States)

    Bishop, Eric

    2004-01-01

    The NASA combustion branch is a leader in developing and applying combustion science to focused aerospace propulsion systems concepts. It is widely recognized for unique facilities, analytical tools, and personnel. In order to better communicate the outstanding research being done in this Branch to the public and other research organization, a more substantial website was desired. The objective of this project was to build an up-to-date site that reflects current research in a usable and attractive manner. In order to accomplish this, information was requested from all researchers in the Combustion branch, on their professional skills and on the current projects. This information was used to fill in the Personnel and Research sections of the website. A digital camera was used to photograph all personnel and these photographs were included in the personnel section as well. The design of the site was implemented using the latest web standards: xhtml and external css stylesheets. This implementation conforms to the guidelines recommended by the w3c. It also helps to ensure that the web site is accessible by disabled users, and complies with Section 508 Federal legislation (which mandates that all Federal websites be accessible). Graphics for the new site were generated using the gimp (www.gimp.org) an open-source graphics program similar to Adobe Photoshop. Also, all graphics on the site were of a reasonable size (less than 20k, most less than 2k) so that the page would load quickly. Technologies such as Macromedia Flash and Javascript were avoided, as these only function on some clients which have the proper software installed or enabled. The website was tested on different platforms with many different browsers to ensure there were no compatibility issues. The website was tested on windows with MS IE 6, MSIE 5 , Netscape 7, Mozilla and Opera. On a Mac, the site was tested with MS IE 5 , Netscape 7 and Safari.

  10. Experimental study on explosive mechanism of spontaneous combustion gangue dump

    Institute of Scientific and Technical Information of China (English)

    PAN Rong-kun; YU Ming-gao; LU Lai-xiang

    2009-01-01

    In order to explore the reason for the frequency explosion of spontaneous combustion coal gangue dump and get to know their explosion mechanism, established the experiment platform about spontaneous combustion coal gangue dump interoperable water. The gangue dump was heated using the external heat source, and rainy weather through water mist was simulated. Simulated experiment about explosion of spontaneous combustion coal gangue dump was carried out on the different conditions of the rainfall or not. The unusual gases produced in the course of gangue combustion and the changes in temperature were observed, and their impacts on the explosion of gangue dump were analyzed. The experimental results show that overall warming phenomenon of the gangue dump after watering occurred, the amount of H2 iS three times than that before watering,and the amount of CO is far greater than that on the conditions of no-watering, at the same time combining with local observation and tests. It is found that the content of the oxygen reduce with the temperature increasing; however, gangue dump internal hydrogen content increase unusually on the rainfall conditions at 90 ℃, but the local measuring points reach the explosion limit. The existence of the CO and H2 iS the main reason for inducing the explosion of spontaneous combustion coal gangue dump.

  11. Experimental study on explosive mechanism of spontaneous combustion gangue dump

    Energy Technology Data Exchange (ETDEWEB)

    Rong-kun Pan; Ming-gao Yu; Lai-xiang Lu [Henan Polytechnic University, Jiaozuo (China). School of Safety & Science Engineering

    2009-12-15

    In order to explore the reason for the frequency explosion of spontaneous combustion coal gangue dump and get to know their explosion mechanism, established the experiment platform about spontaneous combustion coal gangue dump interoperable water. The gangue dump was heated using the external heat source, and rainy weather through water mist was simulated. Simulated experiment about explosion of spontaneous combustion coal gangue dump was carried out on the different conditions of the rainfall or not. The unusual gases produced in the course of gangue combustion and the changes in temperature were observed, and their impacts on the explosion of gangue dump were analyzed. The experimental results show that overall warming phenomenon of the gangue dump after watering occurred, the amount of H{sub 2} is three times than that before watering, and the amount of CO is far greater than that on the conditions of no-watering, at the same time combining with local observation and tests. It is found that the content of the oxygen reduce with the temperature increasing; however, gangue dump internal hydrogen content increase unusually on the rainfall conditions at 90{sup o}C, but the local measuring points reach the explosion limit. The existence of the CO and H{sub 2} is the main reason for inducing the explosion of spontaneous combustion coal gangue dump. 9 refs., 6 figs., 1 tab.

  12. Alternate fuels; Combustibles alternos

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-01

    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

  13. Experimental research on mercury emission from one-dimensional combustion test facility

    Institute of Scientific and Technical Information of China (English)

    WANG Quan-hai(王泉海); QIU Jian-rong(邱建荣); LIU Jing(刘晶); ZHANG Jun-ying(张军营)

    2004-01-01

    The research of mercury release from coal combustion and mercury speciation in flue gas was conducted in a one-dimensional combustion test facility. The experimental results indicated that combustion temperature was the primary factor in affecting mercury vaporization and release. Experimental measurements showed high mercury levels in the particulate phase. Hg(S) is enriched in fly ash and dispersed in bottom ash. Hg(B) content decreases and the Hg(F) content increases with higher furnace temperature. At 1 100℃, the levels of Hg2+(g) are 17%~48% for limited chemical kinetics .The mercury equilibrium in the flue-gas is frozen below some temperature.

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

    Energy Technology Data Exchange (ETDEWEB)

    Markovic, Miladin, E-mail: m.markovic@utwente.nl; Bramer, Eddy A.; Brem, Gerrit

    2014-01-15

    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

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

    International Nuclear Information System (INIS)

    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

  16. A kinetic model of carbon burnout in pulverized coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Hurt, R.; Jian-Kuan Sun; Lunden, M. [Brown University, Providence, RI (United States). Division of Engineering

    1998-04-01

    The degree of carbon burnout is an important operating characteristic of full-scale suspension-fired coal combustion systems affecting boiler efficiency, electrostatic precipitator operation and the value of fly ash as a saleable product. Prediction of carbon loss requires special char combustion kinetics valid through the very high conversions targeted in industry (typically {gt} 99.5%), and valid for a wide-range of particle temperature histories occurring in full-scale furnaces. The paper presents high-temperature kinetic data for five coal chars in the form of time-resolved burning profiles that include the late stages of combustion. It then describes the development and validation of the Carbon Burnout Kinetic Model (CBK), a coal-general kinetics package that is specifically designed to predict the total extent of carbon burnout and ultimate fly ash carbon content for prescribed temperature/oxygen histories typical of pulverized coal combustion systems. The model combines the single-film treatment of cha oxidation with quantitative descriptions of thermal annealing, statistical kinetics, statistical densities, and ash inhibition in the late stages of combustion. In agreement with experimental observations, the CBK model predicts (1) low reactivities for unburned carbon residues extracted from commercial ash samples, (2) reactivity loss in the late stages of laboratory combustion, (3) the observed sensitivity of char reactivity to high-temperature heat treatment on second and subsecond time scales, and (4) the global reaction inhibition by mineral matter in the late stages of combustion observed in single-particle imaging studies. The model ascribes these various char deactivation phenomena to the combined effects of thermal annealing, ash inhibition, and the preferential consumption of more reactive particles (statistical kinetics), the relative contributions of which vary greatly with combustion conditions. 39 refs., 4 figs., 4 tabs., 1 app.

  17. Some Factors Affecting Combustion in an Internal-Combustion Engine

    Science.gov (United States)

    Rothrock, A M; Cohn, Mildred

    1936-01-01

    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.

  18. Path planning during combustion mode switch

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Li; Ravi, Nikhil

    2015-12-29

    Systems and methods are provided for transitioning between a first combustion mode and a second combustion mode in an internal combustion engine. A current operating point of the engine is identified and a target operating point for the internal combustion engine in the second combustion mode is also determined. A predefined optimized transition operating point is selected from memory. While operating in the first combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion engine to approach the selected optimized transition operating point. When the engine is operating at the selected optimized transition operating point, the combustion mode is switched from the first combustion mode to the second combustion mode. While operating in the second combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion to approach the target operating point.

  19. AIR EMISSIONS FROM SCRAP TIRE COMBUSTION

    Science.gov (United States)

    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...

  20. Plasma igniter for internal-combustion engines

    Science.gov (United States)

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

    1978-01-01

    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.

  1. 75 FR 32142 - Combustible Dust

    Science.gov (United States)

    2010-06-07

    ... combustible dust in the workplace. (74 FR 54334, Oct. 21, 2009). OSHA plans to use the information received in... Secretary's Order 5-2007 (72 FR 31160). Signed at Washington, DC, on June 1, 2010. David Michaels, Assistant... Occupational Safety and Health Administration 29 CFR Part 1910 RIN 1218-AC41 Combustible Dust...

  2. 75 FR 10739 - Combustible Dust

    Science.gov (United States)

    2010-03-09

    ... for combustible dust. (74 FR 54334, Oct. 21, 2009) II. Stakeholder Meetings OSHA conducted two... (72 FR 31160). Signed at Washington, DC, on March 2, 2010. David Michaels, Assistant Secretary of... Occupational Safety and Health Administration 29 CFR Part 1910 RIN 1218-AC41 Combustible Dust...

  3. Manifold methods for methane combustion

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-10-01

    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.

  4. Desulfurization kinetics of coal combustion gases

    Directory of Open Access Journals (Sweden)

    S.R. Bragança

    2003-06-01

    Full Text Available Desulfurization of the gases from coal combustion was studied, using limestone (marble as the sorbent in a fluidized-bed reactor. The kinetic parameter, k, was measured by analyzing the reduction in SO2 emissions in relation to time when a batch of limestone was introduced directly into the combustor chamber. The influence of sorbent composition and particle size was also studied. The CaO content in the limestone was more important than the MgO content. Sorbent particle size showed a strong influence on the reaction time and efficiency of desulfurization. The results of this work prove that marble type is very important in the choice of sorbent for a desulfurization process. A magnesian limestone showed a better performance than a dolomite. Therefore, the magnesian limestone is more efficient for a shorter particle residence time, which is characteristic of the bubbling fluidized bed.

  5. Combustion & Laser Diagnostics Research Complex (CLDRC)

    Data.gov (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...

  6. Water vapor release from biomass combustion

    Directory of Open Access Journals (Sweden)

    R. S. Parmar

    2008-10-01

    Full Text Available We report on the emission of water vapor from biomass combustion. Concurrent measurements of carbon monoxide and carbon dioxide are used to scale the concentrations of water vapor found, and are referenced to carbon in the biomass. The investigated fuel types include hardwood (oak and African musasa, softwood (pine and spruce, partly with green needles, and African savanna grass. The session-averaged ratio of H2O to the sum of CO and CO2 in the emissions from 16 combustion experiments ranged from 1.2 to 3.7, indicating the presence of water that is not chemically bound. This non-bound biomass moisture content ranged from 33% in the dry African hardwood, musasa, to 220% in fresh pine branches with needles. The moisture content from fresh biomass contributes significantly to the water vapor in biomass burning emissions, and its influence on the behavior of fire plumes and pyro-cumulus clouds needs to be evaluated.

  7. System automation for measuring coal combustion efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Ouazzane, K.; Benhadj, R. [London Metropolitan University, London (United Kingdom)

    2006-02-15

    Monitoring the combustion process for electricity generation using coal as a primary resource is of a major concern power generation companies. The carbon content of fly ash is indicative of the combustion efficiency. The determination of this parameter is useful to characterize the efficiency of coal burning furnaces. The main aim of this work is to introduce a new automated system, which can be bolted onto a furnace and work online. The system consists of three main components, namely, a laser instrument for signal acquisition, a neural network tool for training, learning and simulation, and a database system for storage and retrieval. The components have been designed, adapted and tuned for knowledge acquisition of this multi-dimensional problem. When the particles are dispersed across the test space, the instrument observed single particle counts simultaneously on the two photomultipliers. The output voltages displayed represent the intensity of horizontally and vertically polarized light, and the polarization ratio is calculated from the ratio of these voltages. It was found that the carbon-in-ash is related to the polarization ratio and the carbon mass fraction could be determined to within 1 per cent of the carbon content. However, if a proximate analysis is performed on the coal, the prediction could be improved to within 0.05 per cent using neural network simulation. The system has been tested for a range of coal ashes and proved to be efficient.

  8. Optical Tomography in Combustion

    DEFF Research Database (Denmark)

    Evseev, Vadim

    The new methodology of optical infrared tomography of flames and hot gas flows was developed in the PhD project with a view to future industrial applications. In particular, the methodology for the tomographic reconstruction of an axisymmetric lab flame temperature profile was developed and tested...... in the lab using Fourier transform infrared spectroscopy techniques, including a new tomographic measurement scheme, sweeping scanning, having great potential for industrial applications with limited optical access. The results were compared to the reference point measurements on the same flame and...... infrared spectral measurements at several line-of-sights with a view to applications for tomographic measurements on full-scale industrial combustion systems. The system was successfully applied on industrial scale for simultaneous fast exhaust gas temperature measurements in the three optical ports of the...

  9. Influence of pressure on the synthesis of cadmium sulfide by combustion of complex compound of cadmium nitrate with thiosemicarbazide

    International Nuclear Information System (INIS)

    A method of cadmium sulfide synthesis based on combustion of high-energy content complex of cadmium nitrate and thiosemicarbazide has been suggested. The combustion has been carried out in nitrogen under gas pressure varying from 0.1 to 2.0 MPa. It is shown that the complex may serve as a precursor for obtaining sulfide materials with regulated morphology and dispersivity under combustion conditions

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

    Directory of Open Access Journals (Sweden)

    Yan Weiping

    2012-06-01

    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.

  11. Social Combustion Theory: Dynamics of Social System Deterioration

    Science.gov (United States)

    Niu, Wen-Yuan

    Social Harmony Equation (SHE) leads the social system to the evolution direction of social by accumulation of “social combustion substances”, i.e., the accumulation of microcosmic entropy increase “basic particles” (individual) in social system from assimilated “basic social energy” to dissimilated one; meanwhile, the catalysis of “social combustion promoter” (social excitation energy) has enhanced the “social temperature” of disordering process of social system and completed the energy accumulation of social entropy increase that can generate the transition. Finally, ignited by the “social trigger threshold”, the social system has completed the abrupt change from orderliness to disorderliness. The continuous variation of the above-mentioned three basic non-linear processes has jointly composed the whole contents of social combustion theory. Under the restriction of such conditions of different time (t), different space (α) and different scale (β), it is finally explained as a comprehensive dynamics of social system deterioration.

  12. Combustion Properties of Straw Briquettes

    Directory of Open Access Journals (Sweden)

    Zhao Qing-ling

    2013-05-01

    Full Text Available The low bulk density of straw is one of the major barriers, which blocks the collection, handling, transportation and storage. Densification of biomass into briquettes/pellets is a suitable method of increasing the bulk density of biomass. Yet in the process, a tremendous amount of air is ejected from biomass grind, which brings substantial specific variation including combustion property. Among them, combustion property is critical for proper design and operation of burning facilities. Therefore, a series of tests about combustion properties of 75mm diameter corn briquettes were done. First, the combustion process (ignition, full flaming and glowing phases., precipitation of tar were investigated by a heating stove, then, Some ash sample from the muffle burner was subjected to an ash melting characteristic test. The results show the combustion of briquettes takes more time than that of raw straw from ignition to complete combustion; in order to meet complete combustion in a short time, the raw straw needs more supply air volume than briquettes under the same α value; the temperature of furnace chamber should been controlled under 900°C, which help to reduce the dark smoke, tar and slag.

  13. 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: prisfrias@hotmail.com

    2011-07-01

    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)

  14. Routine method for quantitative /sup 13/C NMR spectra editing and providing structural patterns. Application to every kind of petroleum fractions including residues and asphaltenes

    Energy Technology Data Exchange (ETDEWEB)

    Bouquet, M.; Bailleul, A.

    1986-09-01

    In order to derive structural hydrocarbon patterns of petroleum cuts, including high molecular fractions and heavy cuts, in both quantitative and routine procedure, the authors have built up a method based on inverse gated decoupling and gated spin-echo /sup 13/C experiments. Multiplet selection methods allow identification of CH/sub n/ groups (n is 0-3) and quantitativeness is obtained with the use of relaxation reagent, two conventional spin echo and three gated spin echo experiments, and a correction factor applied to aliphatic carbons basic spectra. Different steps of the method are discussed theoretically and examples dealing with vacuum distillates, residues and fractions (resins, asphaltenes) are given. Emphasis has been put on the experimental and practical running of the described method, convenient with routine industrial research experiments. 14 references.

  15. Catalytic Combustion of Gasified Waste

    Energy Technology Data Exchange (ETDEWEB)

    Kusar, Henrik

    2003-09-01

    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.

  16. On Lean Turbulent Combustion Modeling

    Directory of Open Access Journals (Sweden)

    Constantin LEVENTIU

    2014-06-01

    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.

  17. Techniques de combustion Combustin Techniques

    OpenAIRE

    Perthuis E.

    2006-01-01

    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 Internationale...

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

    Energy Technology Data Exchange (ETDEWEB)

    Baefver, Linda; Yngvesson, Johan; Niklasson, Fredrik

    2012-07-01

    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.

  19. Simulation of transport phenomena in coke oven with staging combustion

    International Nuclear Information System (INIS)

    A three-dimensional transient mathematical model was developed for coupled coking chamber and staging combustion chamber in large-capacity coke ovens, to describe the flow–combustion–thermo behavior. The model was solved numerically using CFX CFD package and was validated by the central temperature evolution of coke bed. The fields of temperature, fluid flow and combustible gas concentration were analyzed, with special reference to the temperature difference of coke bed and NO concentration of exhaust. The results show that staging combustion plays an important role in improving temperature uniformity of the coke bed and reducing NO concentration of exhaust, especially for the large-capacity coke oven. It is beneficial for production optimization to decrease the gas mass flow rate at the bottom inlet while increase the rate at the upper inlet in the combustion chamber. In addition, it turns out that some measures such as coal preheating, adjustment of moisture content or/and coal densification may be used to improve the coke production efficiency. It is expected the developed model and relevant data in the present research will be beneficial to realize large-scale coke oven with a higher energy efficiency and lower emission. -- Highlights: • The application of staging combustion in coke ovens and its effects are analyzed. • A 3D model is proposed to describe flow–combustion–thermo behaviors in coke oven. • Optimizing operation parameters in full-scale coke oven are studied

  20. 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)

    1996-12-31

    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

  1. 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

    2005-05-01

    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.

  2. Review of CWF combustion technology

    Energy Technology Data Exchange (ETDEWEB)

    McHale, E.T.

    1985-03-01

    A review of progress on combustion research of coal-water fuel (CWF) is presented. The technology is on the threshold of commercialization; a number of large-scale combustion trials have been and are being conducted; and definitive fundamental data are emerging from combustion studies at industrial laboratories and universities. This review addresses more fundamental combustion studies that have been reported on CWF, as opposed to demonstration trials. If such a review were attempted much earlier than the present, there would have been few reported studies to cover, and those available would have been of a very preliminary nature. There are by now a large number of studies published, most of the important ones in 1984, which makes a review of the subject justified.

  3. Combustion modeling in waste tanks

    International Nuclear Information System (INIS)

    This paper has two objectives. The first one is to repeat previous simulations of release and combustion of flammable gases in tank SY-101 at the Hanford reservation with the recently developed code GASFLOW-II. The GASFLOW-II results are compared with the results obtained with the HMS/TRAC code and show good agreement, especially for non-combustion cases. For combustion GASFLOW-II predicts a steeper pressure rise than HMS/TRAC. The second objective is to describe a so-called induction parameter model which was developed and implemented into GASFLOW-II and reassess previous calculations of Bureau of Mines experiments for hydrogen-air combustion. The pressure time history improves compared with the one-step model, and the time rate of pressure change is much closer to the experimental data

  4. Spontaneous combustion in coal massif

    International Nuclear Information System (INIS)

    The spontaneous combustion of coal seams is one of the main causes of economic and human losses associated to the operation of the mines at the Amaga basin. Several factors intervening in the spontaneous combustion of coal are analysed in this article, namely: The physico-chemical processes. The specific circumstances of the exploitations. The generation and composition of fire gasses. The explosive power of the gases. The susceptibility of coal to spontaneous combustion is determined by thermo gravimetric and petrographic analysis. The results of this study show that in the Amaga basin, the mining and geological parameters have a more influential function in the spontaneous combustion process than the intrinsic properties of coal

  5. Controlling pollution by controlling combustion

    Energy Technology Data Exchange (ETDEWEB)

    Orrin, John (South Bank Univ., London (United Kingdom))

    1994-05-04

    Modern control theory is now being used to reduce pollution from fossil fuel combustion. Powerful microprocessors using digital control algorithms are now used to make combustion systems, such as industrial furnaces and car engines, operate with optimal performance. These systems operate to achieve a balance between lean fuel burning with the reduced pollution produced, but more engine noise and vibration, and an air/fuel mixture that produces good engine performance but worse pollution. (UK)

  6. Combustion Properties of Straw Briquettes

    OpenAIRE

    Zhao Qing-ling; Chen Fu-jin; Wang Yang-yang; Zhang Bai-liang

    2013-01-01

    The low bulk density of straw is one of the major barriers, which blocks the collection, handling, transportation and storage. Densification of biomass into briquettes/pellets is a suitable method of increasing the bulk density of biomass. Yet in the process, a tremendous amount of air is ejected from biomass grind, which brings substantial specific variation including combustion property. Among them, combustion property is critical for proper design and operation of burning facilities. There...

  7. Radial Combustion Dynamics in Fe2O3/Al Thermite: Variability of the Flame Propagation Profiles

    Science.gov (United States)

    Durães, L.; Plaksin, I.; Antunes, J.; Campos, J.; Portugal, A.

    2009-12-01

    In this work, the radial combustion in thin circular samples of stoichiometric and over aluminized Fe2O3/Al mixtures is studied. Two confinement materials are tested: stainless steel and PVC. The combustion front profiles are registered by digital video-crono-photography. The radial geometry allows an easy detection of sample heterogeneities, via the circularity distortions of the combustion front profiles. The influence of the Al content in the mixtures and the type of confinement on the combustion propagation dynamics is analyzed. Additionally, an asymmetry parameter of the combustion front profiles is defined and statistically treated via ANOVA. Although the type of confinement contributes more than the mixture composition to the variability of the asymmetry parameter, they both have a weak influence. The main source of variability is the intrinsic variations of the samples, which are due to their heterogeneous character.

  8. Experimental Investigation of Oxygen Enriched air intake on Combustion Parameters of a Single Cylinder Diesel Engine

    Directory of Open Access Journals (Sweden)

    K.RAJKUMAR

    2010-08-01

    Full Text Available In the present experimental work a computerized Single cylinder Diesel engine with data acquisition system was used to study the effects of oxygen enriched air intake on combustion parameters. Increasing the oxygen content with the air leads to faster burn rates and the ability to burn more fuel at the same stoichiometery. Addedoxygen in the combustion air leads to shorter ignition delays and offers more potential for burning diesel. Oxy-fuel combustion reduces the volume of flue gases and reduces the effects of green house effect also. Engine test has been carried out in the above said engine for different loads and the following combustion parameters like Ignition delay, Combustion duration, Heat release and Cylinder pressure was discussed.

  9. Thermogravimetric investigation of the co-combustion between the pyrolysis oil distillation residue and lignite.

    Science.gov (United States)

    Li, Hao; Xia, Shuqian; Ma, Peisheng

    2016-10-01

    Co-combustion of lignite with distillation residue derived from rice straw pyrolysis oil was investigated by non-isothermal thermogravimetric analysis (TGA). The addition of distillation residue improved the reactivity and combustion efficiency of lignite, such as increasing the weight loss rate at peak temperature and decreasing the burnout temperature and the total burnout. With increasing distillation residue content in the blended fuels, the synergistic interactions between distillation residue and lignite firstly increased and then decreased during co-combustion stage. Results of XRF, FTIR, (13)C NMR and SEM analysis indicated that chemical structure, mineral components and morphology of samples have great influence on the synergistic interactions. The combustion mechanisms and kinetic parameters were calculated by the Coats Redfern model, suggesting that the lowest apparent activation energy (120.19kJ/mol) for the blended fuels was obtained by blending 60wt.% distillation residue during main co-combustion stage. PMID:27416511

  10. Materials for High-Temperature Catalytic Combustion

    OpenAIRE

    Ersson, Anders

    2003-01-01

    Catalytic combustion is an environmentally friendlytechnique to combust fuels in e.g. gas turbines. Introducing acatalyst into the combustion chamber of a gas turbine allowscombustion outside the normal flammability limits. Hence, theadiabatic flame temperature may be lowered below the thresholdtemperature for thermal NOXformation while maintaining a stable combustion.However, several challenges are connected to the application ofcatalytic combustion in gas turbines. The first part of thisthe...

  11. Effect of Auxiliary Gases on Combustion Synthesis of Si3N4

    Institute of Scientific and Technical Information of China (English)

    Weiping SHEN; Fei WANG; Zhuohui WU; Changchun GE

    2005-01-01

    This paper presents results of combustion synthesis (Self-Propagating High Temperature Synt hesis, SHS) of Si3N4under nitrogen with argon, hydrogen or ammonia. Higher percentages of α-Si3N4 content were obtained in large size cakes in SHS with hydrogen and ammonia than those with argon. Effect of the auxiliary gases for combustion synthesis of Si3N4 on α phase content, on phase transformation of α-Si3N4 toβ-Si3N4 in SHS Si3N4 and on oxygen content in SHS Si3N4 were investigated.

  12. Increase in efficiency and reduction of generation cost at hard coal-fired power plants. Post-combustion of combustion residues from co-firing of RDF and biomass during dry ash removal

    Energy Technology Data Exchange (ETDEWEB)

    Baur, Guenter [Magaldi Power GmbH, Esslingen (Germany); Spindeldreher, Olaf [RWE Generation SE, Werne (Germany); RWE Generation SE, Essen (Germany)

    2013-09-01

    Secondary as well as substitute fuels are being used in hard coal-fired power plants to improve efficiency and to enlarge fuel flexibility. However, grinding and firing systems of the existing coal-fired plants are not designed for those co-fuels. Any deterioration of the combustion performance would reduce the power output and increase ash disposal costs by increased content of combustion residues. The application of air-cooled ash removal, with simultaneous and controlled post-combustion of unburned residues on the conveyor belt, enlarges the furnace and maintains combustion efficiency even with different fuel qualities. Plant efficiency can also be increased through heat recovery. (orig.)

  13. Synthetic fuel aromaticity and staged combustion

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-11-15

    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.

  14. Content Marketing

    OpenAIRE

    Le, Duc

    2013-01-01

    The purpose of this thesis was to introduce the new trend in today’s marketing world: content marketing. It has been employed by many companies and organizations in the world and has been proven success even when it is still a fairly new topic. Five carefully selected theories of content marketing proposed by experts in the field has been collected, compared and displayed as originally and scientifically as possible in this thesis. The chosen theories provide a diversified perspectives of...

  15. Techniques de combustion Combustin Techniques

    Directory of Open Access Journals (Sweden)

    Perthuis E.

    2006-11-01

    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

  16. Spherical combustion clouds in explosions

    Science.gov (United States)

    Kuhl, A. L.; Bell, J. B.; Beckner, V. E.; Balakrishnan, K.; Aspden, A. J.

    2013-05-01

    This study explores the properties of spherical combustion clouds in explosions. Two cases are investigated: (1) detonation of a TNT charge and combustion of its detonation products with air, and (2) shock dispersion of aluminum powder and its combustion with air. The evolution of the blast wave and ensuing combustion cloud dynamics are studied via numerical simulations with our adaptive mesh refinement combustion code. The code solves the multi-phase conservation laws for a dilute heterogeneous continuum as formulated by Nigmatulin. Single-phase combustion (e.g., TNT with air) is modeled in the fast-chemistry limit. Two-phase combustion (e.g., Al powder with air) uses an induction time model based on Arrhenius fits to Boiko's shock tube data, along with an ignition temperature criterion based on fits to Gurevich's data, and an ignition probability model that accounts for multi-particle effects on cloud ignition. Equations of state are based on polynomial fits to thermodynamic calculations with the Cheetah code, assuming frozen reactants and equilibrium products. Adaptive mesh refinement is used to resolve thin reaction zones and capture the energy-bearing scales of turbulence on the computational mesh (ILES approach). Taking advantage of the symmetry of the problem, azimuthal averaging was used to extract the mean and rms fluctuations from the numerical solution, including: thermodynamic profiles, kinematic profiles, and reaction-zone profiles across the combustion cloud. Fuel consumption was limited to ˜ 60-70 %, due to the limited amount of air a spherical combustion cloud can entrain before the turbulent velocity field decays away. Turbulent kinetic energy spectra of the solution were found to have both rotational and dilatational components, due to compressibility effects. The dilatational component was typically about 1 % of the rotational component; both seemed to preserve their spectra as they decayed. Kinetic energy of the blast wave decayed due to the

  17. Combustion of char from plastic wastes pyrolysis

    Science.gov (United States)

    Saptoadi, Harwin; Rohmat, Tri Agung; Sutoyo

    2016-06-01

    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.

  18. Combustion Byproducts Recycling Consortium

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-08-31

    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

  19. Combustion Instabilities Modeled

    Science.gov (United States)

    Paxson, Daniel E.

    1999-01-01

    NASA Lewis Research Center's Advanced Controls and Dynamics Technology Branch is investigating active control strategies to mitigate or eliminate the combustion instabilities prevalent in lean-burning, low-emission combustors. These instabilities result from coupling between the heat-release mechanisms of the burning process and the acoustic flow field of the combustor. Control design and implementation require a simulation capability that is both fast and accurate. It must capture the essential physics of the system, yet be as simple as possible. A quasi-one-dimensional, computational fluid dynamics (CFD) based simulation has been developed which may meet these requirements. The Euler equations of mass, momentum, and energy have been used, along with a single reactive species transport equation to simulate coupled thermoacoustic oscillations. A very simple numerical integration scheme was chosen to reduce computing time. Robust boundary condition procedures were incorporated to simulate various flow conditions (e.g., valves, open ends, and choked inflow) as well as to accommodate flow reversals that may arise during large flow-field oscillations. The accompanying figure shows a sample simulation result. A combustor with an open inlet, a choked outlet, and a large constriction approximately two thirds of the way down the length is shown. The middle plot shows normalized, time-averaged distributions of the relevant flow quantities, and the bottom plot illustrates the acoustic mode shape of the resulting thermoacoustic oscillation. For this simulation, the limit cycle peak-to-peak pressure fluctuations were 13 percent of the mean. The simulation used 100 numerical cells. The total normalized simulation time was 50 units (approximately 15 oscillations), which took 26 sec on a Sun Ultra2.

  20. 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

    1998-01-01

    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.

  1. 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

    2012-07-01

    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)

  2. Porous medium burners for the combustion of gases from landfills. The direct simulation approach

    OpenAIRE

    Malico, Isabel

    2013-01-01

    Landfill methane recovery associated to its conversion to carbon dioxide through combustion is a common greenhouse gas mitigation strategy in developed countries. The typically low and fluctuating energy content of landfill gas makes combustion challenging. Among the several possible energy conversion technologies, innovative porous burners are a potential option. These burners offer a set of advantages when compared to free flame burners, but are still under investigation. The development...

  3. The optimisation of combustion systems for the burning of cereal straw as a fuel

    OpenAIRE

    Washbourne, John Fryer

    1986-01-01

    International interest in fluidised bed combustion (F.B.C.) derives from the fact that it involves new technology and it is the only combustion system that can use low grade fuels (including those of high or variable ash content) efficiently. This thesis presents a study of the combustion of straw in a fully fluidised and systematically interrupted flow test rig. In the interrupted flow mode, it was found that during the period in the cycle when the bed was slumped, due to the reduction...

  4. Combined gas-steam power stations with pressurized fluidized bed combustion (PFBC) of coal

    Energy Technology Data Exchange (ETDEWEB)

    Grzegorczyk, W. (Energoprojekt, Warsaw (Poland))

    1990-11-01

    Presents pressurized fluidized bed combustion (PFBC) of coal that combines fluidized bed combustion with two-agent gas-steam circulation. PFBC permits clean combustion of coal with low calorific value and high ash and sulfur content. The ABB company offered a block for the Pruszkow power plant in Poland. Specifications of the block are given as: thermal power in fuel 430 MW and electrical power 175 MW. The boiler, gas turbine and turbine set are described. Technical and economic indices are given. The supplier attests that the emission values of 70 mg sulfur dioxide per MJ and 120 mg of nitrogen dioxide will not be exceeded under normal conditions.

  5. Twenty-fifth symposium (international) on combustion

    International Nuclear Information System (INIS)

    Approximately two-thirds of the papers presented at this conference are contained in this volume. The other one-third appear in special issues of ''Combustion and Flame'', Vol. 99, 1994 and Vol. 100, 1995. Papers are divided into the following sections: Supersonic combustion; Detonations and explosions; Internal combustion engines; Practical aspects of combustion; Incineration and wastes; Sprays and droplet combustion; Coal and organic solids combustion; Soot and polycyclic aromatic hydrocarbons; Reaction kinetics; NOx; Turbulent flames; Turbulent combustion; Laminar flames; Flame spread, fire and halogenated fire suppressants; Global environmental effects; Ignition; Two-phase combustion; Solid propellant combustion; Materials synthesis; Microgravity; and Experimental diagnostics. Papers have been processed separately for inclusion on the data base

  6. Gaseous emissions during concurrent combustion of biomass and non-recyclable municipal solid waste

    Directory of Open Access Journals (Sweden)

    Oakey John

    2011-02-01

    Full Text Available Abstract Background Biomass and municipal solid waste offer sustainable sources of energy; for example to meet heat and electricity demand in the form of combined cooling, heat and power. Combustion of biomass has a lesser impact than solid fossil fuels (e.g. coal upon gas pollutant emissions, whilst energy recovery from municipal solid waste is a beneficial component of an integrated, sustainable waste management programme. Concurrent combustion of these fuels using a fluidised bed combustor may be a successful method of overcoming some of the disadvantages of biomass (high fuel supply and distribution costs, combustion characteristics and characteristics of municipal solid waste (heterogeneous content, conflict with materials recycling. It should be considered that combustion of municipal solid waste may be a financially attractive disposal route if a 'gate fee' value exists for accepting waste for combustion, which will reduce the net cost of utilising relatively more expensive biomass fuels. Results Emissions of nitrogen monoxide and sulphur dioxide for combustion of biomass are suppressed after substitution of biomass for municipal solid waste materials as the input fuel mixture. Interactions between these and other pollutants such as hydrogen chloride, nitrous oxide and carbon monoxide indicate complex, competing reactions occur between intermediates of these compounds to determine final resultant emissions. Conclusions Fluidised bed concurrent combustion is an appropriate technique to exploit biomass and municipal solid waste resources, without the use of fossil fuels. The addition of municipal solid waste to biomass combustion has the effect of reducing emissions of some gaseous pollutants.

  7. Modeling of heat release and emissions from droplet combustion of multi component fuels in compression ignition engines

    DEFF Research Database (Denmark)

    Ivarsson, Anders

    three separate combustion phases; a pre-mixed homogeneous combustion phase, a non-homogeneous pre-mixed combustion phase and a diffusion controlled combustion phase. This PhD thesis comprises a study of the non-homogeneous pre-mixed combustion process. Experimental work was performed with a pre...... it is well suited for optical line of sight diagnostics in both pre and post combustion regions. The work also includes some preliminary studies of radiant emissions from helium stabilized ethylene/air and methane/oxygen flames. It is demonstrated that nano particles below the sooting threshold...... optical method was also used to measure the soot content in terms of soot volume fraction. The measurement was based on absorption of light with wavelength between 500 and 520 nm. The third main topic of the project was to develop a CFD model of a pre-mixed flat flame. The commercial CFD software CFX 11...

  8. Effect of organic calcium compounds on combustion characteristics of rice husk, sewage sludge, and bituminous coal: thermogravimetric investigation.

    Science.gov (United States)

    Zhang, Lihui; Duan, Feng; Huang, Yaji

    2015-04-01

    Experiments were conducted in a thermogravimetric analyzer to assess the enhancement of combustion characteristics of different solid fuels blended with organic calcium compounds (OCCs). Rice husk, sewage sludge, and bituminous coal, and two OCC were used in this study. Effect of different mole ratios of calcium to sulfur (Ca/S ratio) on the combustion characteristics were also investigated. Results indicated that combustion performance indexes for bituminous coal impregnated by OCC were improved, however, an inverse trend was found for sewage sludge because sewage sludge has lower ignition temperature and higher volatile matter content compared to those of OCC. For rice husk, effect of added OCC on the combustion characteristics is not obvious. Different solid fuels show different combustion characteristics with increases of Ca/S ratio. The maximum combustion performance indexes appear at Ca/S ratios of 1:1, 2:1, and 3:1 for OCC blended with Shenhua coal, rice husk, and sewage sludge, respectively. PMID:25638405

  9. SCR at bio fuel combustion

    International Nuclear Information System (INIS)

    In this project the cause for and the extent of catalyst deactivation has been investigated when using 100 % wood as fuel. The trend of deactivation has been studied as a function of the flue gas temperature, the type of catalyst and the type of combustion technique used. The field tests have been performed in the CFB boiler in Norrkoeping, firing forest residues, and in the boiler in Jordbro, firing pulverized wood (PC). Samples of four different commercial catalyst types have been exposed to flue gas in a test rig connected to the convection section of the boiler. The samples have been analysed at even time intervals. The results after 2 100 hours show a large difference in deactivation trend between the two plants; when using a conventional honeycomb catalyst 80 % of the original activity remains in the CFB boiler but only 20 % remains in the PC boiler. The deactivation in the CFB boiler is about 3 - 4 times faster than what is expected for a conservative design for a coal fired boiler. The results show that the general deactivation trend is similar for the plate and the honeycomb catalyst types. With a catalyst optimised for bio fuels the deactivation rate was about 2/3 compared with a conventional catalyst. At an operating temperature of 315 deg C the deactivation was not as rapid as at 370 deg C. The amount of easily dissolved potassium increases on the surface of the catalyst, especially in the PC boiler, and this is probably the reason for the deactivation. The total amount of potassium in the flue gas is about 5 times higher in the CFB boiler compared with the PC boiler. This indicates that only a certain form of potassium attacks the catalyst and that the total alkali content of the fuel is not a good indicator of the deactivation tendency. The potassium on the catalyst dissolves easily in both water and sulphuric acid. A wash of deactivated catalyst samples with water resulted in higher activity than for the fresh samples if the washing was supplemented

  10. Catalytic combustion over high temperature stable metal oxides

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

    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

  11. HCCI Combustion: Analysis and Experiments

    International Nuclear Information System (INIS)

    Homogeneous charge compression ignition (HCCI) is a new combustion technology that may develop as an alternative to diesel engines with high efficiency and low NOx and particulate matter emissions. This paper describes the HCCI research activities being currently pursued at Lawrence Livermore National Laboratory and at the University of California Berkeley. Current activities include analysis as well as experimental work. On analysis, we have developed two powerful tools: a single zone model and a multi-zone model. The single zone model has proven very successful in predicting start of combustion and providing reasonable estimates for peak cylinder pressure, indicated efficiency and NOX emissions. This model is being applied to develop detailed engine performance maps and control strategies, and to analyze the problem of engine startability. The multi-zone model is capable of very accurate predictions of the combustion process, including HC and CO emissions. The multi-zone model h as applicability to the optimization of combustion chamber geometry and operating conditions to achieve controlled combustion at high efficiency and low emissions. On experimental work, we have done a thorough evaluation of operating conditions in a 4-cylinder Volkswagen TDI engine. The engine has been operated over a wide range of conditions by adjusting the intake temperature and the fuel flow rate. Satisfactory operation has been obtained over a wide range of operating conditions. Cylinder-to-cylinder variations play an important role in limiting maximum power, and should be controlled to achieve satisfactory performance

  12. Explosion limits for combustible gases

    Institute of Scientific and Technical Information of China (English)

    TONG Min-ming; WU Guo-qing; HAO Ji-fei; DAI Xin-lian

    2009-01-01

    Combustible gases in coal mines are composed of methane, hydrogen, some multi-carbon alkane gases and other gases. Based on a numerical calculation, the explosion limits of combustible gases were studied, showing that these limits are related to the concentrations of different components in the mixture. With an increase of C4H10 and C6H14, the Lower ExplosionLimit (LEL) and Upper Explosion-Limit (UEL) of a combustible gas mixture will decrease clearly. For every 0.1% increase in C4H10 and C6H14, the LEL decreases by about 0.19% and the UEL by about 0.3%. The results also prove that, by increasing the amount of H2, the UEL of a combustible gas mixture will increase considerably. If the level of H2 increases by 0.1%, the UEL will increase by about 0.3%. However, H2 has only a small effect on the LEL of the combustible gas mixture. Our study provides a theoretical foundation for judging the explosion risk of an explosive gas mixture in mines.

  13. Turbulent Combustion in SDF Explosions

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, A L; Bell, J B; Beckner, V E

    2009-11-12

    A heterogeneous continuum model is proposed to describe the dispersion and combustion of an aluminum particle cloud in an explosion. It combines the gas-dynamic conservation laws for the gas phase with a continuum model for the dispersed phase, as formulated by Nigmatulin. Inter-phase mass, momentum and energy exchange are prescribed by phenomenological models. It incorporates a combustion model based on the mass conservation laws for fuel, air and products; source/sink terms are treated in the fast-chemistry limit appropriate for such gasdynamic fields, along with a model for mass transfer from the particle phase to the gas. The model takes into account both the afterburning of the detonation products of the C-4 booster with air, and the combustion of the Al particles with air. The model equations were integrated by high-order Godunov schemes for both the gas and particle phases. Numerical simulations of the explosion fields from 1.5-g Shock-Dispersed-Fuel (SDF) charge in a 6.6 liter calorimeter were used to validate the combustion model. Then the model was applied to 10-kg Al-SDF explosions in a an unconfined height-of-burst explosion. Computed pressure histories are compared with measured waveforms. Differences are caused by physical-chemical kinetic effects of particle combustion which induce ignition delays in the initial reactive blast wave and quenching of reactions at late times. Current simulations give initial insights into such modeling issues.

  14. 渣油加氢处理前后沥青质的微观结构研究%Microstructure characterization of asphaltenes from atmospheric residue before and after hydroprocessing

    Institute of Scientific and Technical Information of China (English)

    刘勇军

    2012-01-01

    采用元素分析、扫描电镜和透射电镜等分析方法对渣油原料中的沥青质、加氢处理后的沥青质及添加高芳香性轻循环油(LCO)反应后的沥青质进行对比研究.结果发现,渣油加氢处理前后沥青质的表面呈现出光滑表面和多孔的球形颗粒表面两种完全不同的形貌.渣油加氢前后沥青质的芳核堆砌表现出明显的长程无序局部有序的特征;加氢处理后的沥青质芳核片层易于堆砌,出现了多层堆砌、长程有序的类石墨结构.渣油中高芳香性LCO的添加有利于促进沥青质的加氢反应、改善沥青质芳核系统在渣油加氢处理过程中的聚集行为.%A comparative study on microstructure of asphaltenes obtained from an atmospheric residue (AR),a hydroprocessed oil of AR and a blending of AR with high aromatic light cycle oil (LCO) was carried out by element analysis,scanning and transmission electron microscopy ( SEM and TEM). Different asphaltene morphologies,smooth surface and porous surface with spherical particles,were observed by SEM before and after hydroprocessing. The results of TEM micrographs show that the aromatic ring stacking of original asphaltene is characterized of long range disorder and short range order,and multi-stacking graphite-like carbon with long range order is observed for hydroprocessed asphaltene. The addition of high aromatic LCO into AR enhances the hydrogenation reactions of asphaltene and inhibits the aggregation of aromatic ring systems under AR hydrotreating.

  15. Novel Active Combustion Control Valve

    Science.gov (United States)

    Caspermeyer, Matt

    2014-01-01

    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.

  16. SPONTANEOUS COMBUSTION RELATED FIRE RATIOS

    Directory of Open Access Journals (Sweden)

    Cem ŞENSÖĞÜT

    1999-01-01

    Full Text Available For explaining the situation arising from spontaneous combustion, there is a necessity for quick and accurate analysis of the gaseous products of combustion. It is also very important to interpret these data correctly. This interpretation provides information prominence to mine rescue crew and the mine management concerning the withdrawal or continuity of rescue team in a rescue and recovery operation before an explosion takes place. Additionally, it is also of utmost importance to see whether the fire combating techniques are effective or the fire is under control ensuring the security of workers and equipment during and after the sealing works. Therefore, the indices related with spontaneous combustion which are still commonly in use are summarised in this work.

  17. Catalytic Combustion of Ethyl Acetate

    OpenAIRE

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

    2007-01-01

    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. Fundamentals of premixed turbulent combustion

    CERN Document Server

    Lipatnikov, Andrei

    2012-01-01

    Lean burning of premixed gases is considered to be a promising combustion technology for future clean and highly efficient gas turbine engines. This book highlights the phenomenology of premixed turbulent flames. The text provides experimental data on the general appearance of premixed turbulent flames, physical mechanisms that could affect flame behavior, and physical and numerical models aimed at predicting the key features of premixed turbulent combustion. The author aims to provide a simple introduction to the field for advanced graduate and postgraduate students. Topics covered include La

  19. Chemical kinetics and combustion modeling

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-01

    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.

  20. Autodesk Combustion 4 fundamentals courseware

    CERN Document Server

    Autodesk,

    2005-01-01

    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

  1. Development of a Premixed Combustion Capability for Scramjet Combustion Experiments

    Science.gov (United States)

    Rockwell, Robert D.; Goyne, Christopher P.; Rice, Brian E.; Chelliah, Harsha; McDaniel, James C.; Edwards, Jack R.; Cantu, Luca M. L.; Gallo, Emanuela C. A.; Cutler, Andrew D.; Danehy, Paul M.

    2015-01-01

    Hypersonic air-breathing engines rely on scramjet combustion processes, which involve high speed, compressible, and highly turbulent flows. The combustion environment and the turbulent flames at the heart of these engines are difficult to simulate and study in the laboratory under well controlled conditions. Typically, wind-tunnel testing is performed that more closely approximates engine testing rather than a careful investigation of the underlying physics that drives the combustion process. The experiments described in this paper, along with companion data sets being developed separately, aim to isolate the chemical kinetic effects from the fuel-air mixing process in a dual-mode scramjet combustion environment. A unique fuel injection approach is taken that produces a nearly uniform fuel-air mixture at the entrance to the combustor. This approach relies on the precombustion shock train upstream of the dual-mode scramjet combustor. A stable ethylene flame anchored on a cavity flameholder with a uniformly mixed combustor inflow has been achieved in these experiments allowing numerous companion studies involving coherent anti-Stokes Raman scattering (CARS), particle image velocimetry (PIV), and planar laser induced fluorescence (PLIF) to be performed.

  2. Combustion, cofiring and emissions characteristics of torrefied biomass in a drop tube reactor

    International Nuclear Information System (INIS)

    The study investigates cofiring characteristics of torrefied biomass fuels at 50% thermal shares with coals and 100% combustion cases. Experiments were carried out in a 20 kW, electrically heated, drop-tube reactor. Fuels used include a range of torrefied biomass fuels, non-thermally treated white wood pellets, a high volatile bituminous coal and a lignite coal. The reactor was maintained at 1200 °C while the overall stoichiometric ratio was kept constant at 1.15 for all combustion cases. Measurements were performed to evaluate combustion reactivity, emissions and burn-out. Torrefied biomass fuels in comparison to non-thermally treated wood contain a lower amount of volatiles. For the tests performed at a similar particle size distribution, the reduced volatile content did not impact combustion reactivity significantly. Delay in combustion was only observed for test fuel with a lower amount of fine particles. The particle size distribution of the pulverised grinds therefore impacts combustion reactivity more. Sulphur and nitrogen contents of woody biomass fuels are low. Blending woody biomass with coal lowers the emissions of SO2 mainly as a result of dilution. NOX emissions have a more complex dependency on the nitrogen content. Factors such as volatile content of the fuels, fuel type, furnace and burner configurations also impact the final NOX emissions. In comparison to unstaged combustion, the nitrogen conversion to NOX declined from 34% to 9% for air-staged co-combustion of torrefied biomass and hard coal. For the air-staged mono-combustion cases, nitrogen conversion to NOX declined from between 42% and 48% to about 10%–14%. - Highlights: • Impact of torrefaction on cofiring was studied at high heating rates in a drop tube. • Cofiring of torrefied biomasses at high thermal shares (50% and higher) is feasible. • Particle size impacts biomass combustion reactivity more than torrefaction. • In a drop tube reactor, torrefaction has no negative impact

  3. Dilute Oxygen Combustion Phase 2 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, H.M.; Riley, M.F.; Kobayashi, H.

    2005-09-30

    A novel burner, in which fuel (natural gas) and oxidant (oxygen or air) are separately injected into a furnace, shows promise for achieving very low nitrogen oxide(s) (NOx) emissions for commercial furnace applications. The dilute oxygen combustion (DOC) burner achieves very low NOx through in-furnace dilution of the oxidant stream prior to combustion, resulting in low flame temperatures, thus inhibiting thermal NOx production. The results of a fundamental and applied research effort on the development of the DOC burner are presented. In addition, the results of a market survey detailing the potential commercial impact of the DOC system are disclosed. The fundamental aspects of the burner development project involved examining the flame characteristics of a natural gas turbulent jet in a high-temperature (~1366 K) oxidant (7-27% O2 vol. wet). Specifically, the mass entrainment rate, the flame lift-off height, the velocity field and major species field of the jet were evaluated as a function of surrounding-gas temperature and composition. The measured entrainment rate of the fuel jet decreased with increasing oxygen content in the surrounding high-temperature oxidant, and was well represented by the d+ scaling correlation found in the literature. The measured flame lift-off height decreased with increasing oxygen content and increasing temperature of the surrounding gas. An increase in surrounding-gas oxygen content and/or temperature inhibited the velocity decay within the jet periphery as a function of axial distance as compared to isothermal turbulent jets. However, the velocity measurements were only broadly represented by the d+ scaling correlation. Several DOC burner configurations were tested in a laboratory-scale furnace at a nominal firing rate of 185 kW (~0.63 MMBtu/h). The flue gas composition was recorded as a function of furnace nitrogen content, furnace temperature, burner geometric arrangement, firing rate, and fuel injection velocity. NOx emissions

  4. Scramjet Combustion Stability Behavior Modeling Project

    Data.gov (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...

  5. Scramjet Combustion Stability Behavior Modeling Project

    Data.gov (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...

  6. Combustion and extinction of magnesium fires

    International Nuclear Information System (INIS)

    The studies made in France on magnesium combustion and extinguishing means are associated at the nuclear fuel of the graphite-gas reactor. Safety studies are made for ameliorate our knowledge on: - magnesium combustion - magnesium fire propagation - magnesium fire extinguishing

  7. Free Energy and Internal Combustion Engine Cycles

    CERN Document Server

    Harris, William D

    2012-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    O. Saheed Ismail

    2016-07-01

    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.

  9. Combustion Characteristics of Coated Nano Aluminum in Composite Propellants

    Directory of Open Access Journals (Sweden)

    Yunlan Sun

    2006-10-01

    Full Text Available The effects of coated nano-sized aluminum (Al powder (n-Al and micron-sized Al powder(g-Al in propellants on the burning rate and pressure exponent have been investigated. Theresults show that the burning rates of propellants increase as the n-Al content increases, butthe burning rate pressure exponents tend to decrease. Compared with propellant containing-Al, the increments of burning rates of propellants containing n-Al powder reduce graduallywith increase in the pressure because of the differences of the combustion characteristics andignition performances of n-Al powder and g-Al powder. Single short distance photograph, scanningelectron microscopy, x-ray fluorescence analysis were used to characterise the flame image,combustion phenomena, the quenched surface image, and surface elements. A substantialdifference in combustion characteristics of n-Al powder has been found in comparison with-Al powder. In addition, oxygen-bomb combustion heat, ignition temperature, and recoveryratio of residues were measured.

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

    NARCIS (Netherlands)

    Sliphorst, M.

    2011-01-01

    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 c

  11. Smouldering Combustion Phenomena in Science and Technology

    OpenAIRE

    Rein, Guillermo

    2009-01-01

    Smouldering is the slow, low-temperature, flameless form of combustion of a condensed fuel. It poses safety and environmental hazards and allows novel technological application but its fundamentals remain mostly unknown to the scientific community. The terms filtering combustion, smoking problem, deep seated fires, hidden fires, peat or peatlands fires, lagging fires, low oxygen combustion, in-situ combustion, fireflood and underground gasification, all refer to smouldering com...

  12. Combustion Chemistry Diagnostics for Cleaner Processes.

    Science.gov (United States)

    Kohse-Höinghaus, Katharina

    2016-09-12

    Climate change, environmental problems, urban pollution, and the dependence on fossil fuels demand cleaner, renewable energy strategies. However, they also ask for urgent advances in combustion science to reduce emissions. For alternative fuels and new combustion regimes, crucial information about the chemical reactions from fuel to exhaust remains lacking. Understanding such relations between combustion process, fuel, and emissions needs reliable experimental data from a wide range of conditions to provide a firm basis for predictive modeling of practical combustion processes. PMID:27440049

  13. Liquid rocket combustion chamber acoustic characterization

    OpenAIRE

    Cândido Magno de Souza; Luiz Carlos Sandoval Góes; Dimas Donizeti da Silveira; Rogério Pirk; Carlos d’Andrade Souto

    2010-01-01

    Over the last 40 years, many solid and liquid rocket motors have experienced combustion instabilities. Among other causes, there is the interaction of acoustic modes with the combustion and/or fluid dynamic processes inside the combustion chamber. Studies have been showing that, even if less than 1% of the available energy is diverted to an acoustic mode, combustion instability can be generated. On one hand, this instability can lead to ballistic pressure changes, couple with other propulsion...

  14. Potential of methanol in dual fuel combustion

    OpenAIRE

    Tuominen, Tino

    2016-01-01

    Depleting oil resources together with the climate change due to the use of fossil fuels are motivating to investigate alternative fuels and new combustion strategies used with them. At the moment, dual fuel combustion is one of the most promising new combustion strategies. Combining it to the use of renewable methanol as a primary fuel, it offers an interesting option for the conventional combustion engine. This thesis focuses on investigating the theoretical potential of methanol in dua...

  15. Numerical investigation of heat transfer characteristics in utility boilers of oxy-coal combustion

    International Nuclear Information System (INIS)

    Highlights: • Air-coal and oxy-coal combustion in an industrial scale PF boiler were simulated in ANSYS FLUENT. • The O2 concentration of 33 vol% in the oxy-coal combustion case matches the air-coal combustion case most closely. • The moisture in the flue gas has little impact on flame temperature, but positive impact on surface incident radiation. - Abstract: Oxy-coal combustion has different flue gas composition from the conventional air-coal combustion. The different composition further results in different properties, such as the absorption coefficient, emissivity, and density, which can directly affect the heat transfer in both radiation and convection zones of utility boilers. This paper numerically studied a utility boiler of oxy-coal combustion and compares with air-coal combustion in terms of flame profile and heat transferred through boiler side walls in order to understand the effects of different operating conditions on oxy-coal boiler retrofitting and design. Based on the results, it was found that around 33 vol% of effective O2 concentration ([O2]effective) the highest flame temperature and total heat transferred through boiler side walls in the oxy-coal combustion case match to those in the air-coal combustion case most; therefore, the 33 vol% of [O2]effective could result in the minimal change for the oxy-coal combustion retrofitting of the existing boiler. In addition, the increase of the moisture content in the flue gas has little impact on the flame temperature, but results in a higher surface incident radiation on boiler side walls. The area of heat exchangers in the boiler was also investigated regarding retrofitting. If boiler operates under a higher [O2]effective, to rebalance the load of each heat exchanger in the boiler, the feed water temperature after economizer can be reduced or part of superheating surfaces can be moved into the radiation zone to replace part of the evaporators

  16. Formation of fine particles in co-combustion of coal and solid recovered fuel in a pulverized coal-fired power station

    DEFF Research Database (Denmark)

    Wu, Hao; Pedersen, Anne Juul; Glarborg, Peter;

    2011-01-01

    Fine particles formed from combustion of a bituminous coal and co-combustion of coal with 7 th% (thermal percentage) solid recovered fuel (SRF) in a pulverized coal-fired power plant were sampled and characterized in this study. The particles from dedicated coal combustion and co-combustion both...... showed an ultrafine mode centered at approximately 0.1 μm. Compared with coal combustion, co-combustion of coal and SRF increased the formation of submicron particles, especially ultrafine particles below 0.2 μm. The morphology of the particles indicated that supermicron particles were primarily formed...... appear to be an important formation mechanism. The elemental composition of the particles from coal combustion showed that S and Ca were significantly enriched in ultrafine particles and P was also enriched considerably. However, compared with supermicron particles, the contents of Al, Si and K were...

  17. 30 CFR 56.4104 - Combustible waste.

    Science.gov (United States)

    2010-07-01

    ... 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...

  18. Straw combustion on slow-moving grates

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen

    2005-01-01

    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...

  19. 75 FR 3881 - Combustible Dust

    Science.gov (United States)

    2010-01-25

    ... Notice of Proposed Rulemaking (ANPR) (74 FR 54334) requesting comments, including data and other...), 29 CFR part 1911, and Secretary's Order 5-2007 (72 FR 31160). Signed at Washington, DC, on January 19... Occupational Safety and Health Administration 29 CFR Part 1910 RIN 1218-AC41 Combustible Dust...

  20. Sulfur Chemistry in Combustion II

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Kiil, Søren

    2000-01-01

    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 for ...

  1. Fluidized bed combustion in praxis

    International Nuclear Information System (INIS)

    Operation at deregulated energy markets emphasize utilities competitiveness in power generation. This means power plant investment cost as well as operation and maintenance costs must be competitive to ensure economical performance. Improvements in competitiveness can also be achieved investing to modem combustion technology and this way improve power generation efficiency (lower fuel consumption). Other means to improve cost effectiveness are optimisation of daily operation and process control system but also improving fuel flexibility if feasible (fuel price). The other need for utilities in the future is of course environmental issues like reduction of CO2 emissions in particular. As known fluidized bed combustion offers many advantages that might be needed at future energy markets. These are superior fuel and operation flexibility, multi-fuel capability, environmental performance with inherently low NOx emissions due favourable combustion conditions and cost effective sulphur reduction applying in-furnace SO2 capture. These advantages makes fluidized bed combustion attractive alternative power generation in the future. The current trends for development of the technology are discussed in this paper. (authors)

  2. Distribution of polycyclic aromatic hydrocarbons in fly ash during coal and residual char combustion in a pressurized fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Hongcang Zhou; Baosheng Jin; Rui Xiao; Zhaoping Zhong; Yaji Huang [Nanjing University of Information Science and Technology, Nanjing (China)

    2009-04-15

    To investigate the distribution of polycyclic aromatic hydrocarbons (PAHs) in fly ash, the combustion of coal and residual char was performed in a pressurized spouted fluidized bed. After Soxhlet extraction and Kuderna-Danish (K-D) concentration, the contents of 16 PAHs recommended by the United States Environmental Protection Agency (U.S. EPA) in coal, residual char, and fly ash were analyzed by a high-performance liquid chromatography (HPLC) coupled with fluorescence and diode array detection. The experimental results show that the combustion efficiency is lower and the carbon content in fly ash is higher during coal pressurized combustion, compared to the residual char pressurized combustion at the pressure of 0.3 MPa. Under the same pressure, the PAH amounts in fly ash produced from residual char combustion are lower than that in fly ash produced from coal combustion. The total PAHs in fly ash produced from coal and residual char combustion are dominated by three- and four-ring PAHs. The amounts of PAHs in fly ash produced from residual char combustion increase and then decrease with the increase of pressure in a fluidized bed. 21 refs., 1 fig., 4 tabs.

  3. Coal combustion waste management study

    International Nuclear Information System (INIS)

    Coal-fired generation accounted for almost 55 percent of the production of electricity in the United States in 1990. Coal combustion generates high volumes of ash and flue gas desulfurization (FGD) wastes, estimated at almost 90 million tons. The amount of ash and flue gas desulfurization wastes generated by coal-fired power plants is expected to increase as a result of future demand growth, and as more plants comply with Title IV of the 1990 Clean Air Act Amendments. Nationwide, on average, over 30 percent of coal combustion wastes is currently recycled for use in various applications; the remaining percentage is ultimately disposed in waste management units. There are a significant number of on-site and off-site waste management units that are utilized by the electric utility industry to store or dispose of coal combustion waste. Table ES-1 summarizes the number of disposal units and estimates of waste contained at these unites by disposal unit operating status (i.e, operating or retired). Further, ICF Resources estimates that up to 120 new or replacement units may need to be constructed to service existing and new coal capacity by the year 2000. The two primary types of waste management units used by the industry are landfills and surface impoundments. Utility wastes have been exempted by Congress from RCRA Subtitle C hazardous waste regulation since 1980. As a result of this exemption, coal combustion wastes are currently being regulated under Subtitle D of RCRA. As provided under Subtitle D, wastes not classified as hazardous under Subtitle C are subject to State regulation. At the same time Congress developed this exemption, also known as the ''Bevill Exclusion,'' it directed EPA to prepare a report on coal combustion wastes and make recommendations on how they should be managed

  4. Combustive management of oil spills

    International Nuclear Information System (INIS)

    Extensive experiments with in situ incineration were performed on a desert site at the University of Arizona with very striking results. The largest incinerator, 6 feet in diameter with a 30 foot chimney, developed combustion temperatures of 3000, F, and attendant soot production approximately 1000 times less than that produced by conventional in situ burning. This soot production, in fact, is approximately 30 times less than current allowable EPA standards for incinerators and internal combustion engines. Furthermore, as a consequence of the high temperature combustion, the bum rate was established at a very high 3400 gallons per hour for this particular 6 foot diameter structure. The rudimentary design studies we have carried out relative to a seagoing 8 foot diameter incinerator have predicted that a continuous burn rate of 7000 gallons per hour is realistic. This structure was taken as a basis for operational design because it is compatible with C130 flyability, and will be inexpensive enough ($120,000 per copy) to be stored at those seaside depots throughout the US coast line in which the requisite ancillary equipments (booms, service tugs, etc.) are already deployed. The LOX experiments verified our expectations with respect to combustion of debris and various highly weathered or emulsified oils. We have concluded, however, that the use of liquid oxygen in actual beach clean up is not promising because the very high temperatures associated with this combustion are almost certain to produce environmentally deleterious effects on the beach surface and its immediately sublying structures. However, the use of liquid oxygen augmentation for shore based and flyable incinerators may still play an important role in handing the problem of accumulated debris

  5. Gaseous emissions from waste combustion

    International Nuclear Information System (INIS)

    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

  6. Gaseous emissions from waste combustion

    Energy Technology Data Exchange (ETDEWEB)

    Werther, Joachim [Hamburg University of Technology, Institute of Solids Process Engineering and Particle Technology, D 21071 Hamburg (Germany)]. E-mail: Werther@tuhh.de

    2007-06-18

    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.

  7. Gaseous emissions from waste combustion.

    Science.gov (United States)

    Werther, Joachim

    2007-06-18

    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. PMID:17339077

  8. UTILIZATION OF LOW NOx COAL COMBUSTION BY-PRODUCTS

    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

    1998-12-01

    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.

  9. Sensitivity study of fluid dynamic effects on nitric oxide formation in CFB combustion of wood

    Energy Technology Data Exchange (ETDEWEB)

    Kallio, S.; Kilpinen, P.; Konttinen, J. [Abo Akademi Univ., Turku (Finland); Leckner, B.; Armand, L.E. [Chalmers Univ. of Technology, Goteborg (Sweden)

    2002-07-01

    The type of fuel and operating conditions in circulating fluidized bed combustion (CFBC) can vary widely. Potential fuels include coals, biofuels and wastes. The use of biofuels as an energy source has stimulated much interest around the world, but the nitric oxide (NO) emissions from CFB combustion of wood is of the same order of magnitude as from combustion of coal with high N content. This paper presents a newly developed 1.5D numerical model that examines the formation of NO and nitrous oxide (N{sub 2}O) emissions in a CFBC under varying operating conditions and different fuel types. A comprehensive kinetic scheme was used for the homogeneous chemistry and a single particle model for char combustion. Gas mixing and release of volatiles were the fluid dynamic factors that were examined for wood combustion under normal air staging conditions. The formation of high NO emissions from wood burning was found to depend greatly on the pattern of volatile releases as well as the mixing of secondary air and gas. Nitric oxide was found to form higher in the riser during wood combustion compared to coal combustion. The large amount of char at the bottom of the bed is an important source of nitric oxide. 14 refs., 1 tab., 8 figs.

  10. Combustion stability assessment for utility pulverized coal-fired boilers under low loads

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, H.-C.; Huang, Y.-L.; Li, J.; Liu, Z.-H.; Zheng, C.-G. [Huazhong University of Science and Technology, Wuhan (China). National Lab. of Coal Combustion, Dept. of Power Engineering

    2000-08-01

    Based on the influence of chemical equivalence ratio on the combustion stability of utility pulverized coal-fired boilers and the control theory about system stability, a combustion stability index, CSI, which refers to the maximum reduction ratio of the fuel mass flow rate that can be overcome by the stable combustion process under a constant air mass flow rate, was proposed to assess quantitatively the combustion stability in the boilers. MLO, the Minimum Load of Operation with stable combustion not supported by firing oil, and MCQ, the Minimum Coal Quality, which gives the lowest heat values of coals with different volatile matter contents for stable operation of boilers, are defined on the basis of CSI. In order to predict MLO and MCQ, a simple chemical reaction system model has been modified by means of the concept of lean flammability of gaseous fuels. A three-dimensional combustion simulation code integrated with the modified model was used to study the stability of combustion process in a 200 MWe pulverized coal fired utility boiler. The predictions of MLO and MCQ agreed confidently with operational experiences. 16 refs., 7 figs.

  11. A method for aircraft afterburner combustion without flameholders

    Science.gov (United States)

    Birmaher, Shai

    2009-12-01

    State of the art aircraft afterburners employ spray bars to inject fuel and flameholders to stabilize the combustion process. Such afterburner designs significantly increase the length (and thus weight), pressure losses, and observability of the engine. This thesis presents a feasibility study of a compact 'prime and trigger' (PAT) afterburner concept that eliminates the fuel spray bars and flameholders and, thus, eliminates the above-mentioned problems. In this concept, afterburner fuel is injected just upstream or in between the turbine stages. As the fuel travels through the turbine stages, it evaporates, mixes with the bulk flow, and undergoes some chemical reactions without any significant heat release, a process referred to as 'priming'. Downstream of the turbine stages, combustion could take place through autoignition. However, if fuel autoignition does not occur or if autoignition does not produce a combustion zone that is stable and highly efficient, then a low power pilot, or 'trigger', can be used to control the combustion process. The envisioned trigger for the PAT concept is a jet of product gas from ultra-rich hydrocarbon/air combustion that is injected through the afterburner liner. This 'partial oxidation' (POx) gas, which consists mostly of H2, CO, and diluents, rapidly produces radicals and heat that accelerate the autoignition of the primed mixture and, thus, provide an anchor point for the afterburner combustion process. The objective of this research was to demonstrate the feasibility of the PAT concept by showing that (1) combustion of fuel injected within or upstream of turbine stages can occur only downstream of the turbine stages, and (2) the combustion zone is compact, stable and efficient. This was accomplished using two experimental facilities, a developed theoretical model, and Chemkin simulations. The first facility, termed the Afterburner Facility (AF), simulated the bulk flow temperature, velocity and O2 content through a turbojet

  12. The moisture effect on wood combustion in an Updraft Gasifier

    International Nuclear Information System (INIS)

    Full text: This paper studies the fuel moisture content effect on the wood combustion behavior in the gasifier. The combustion process is evaluated with the variation of fuels moisture content, i.e. set at 17 %, 31 %, and 40 % respectively. The ignition front rate decreased with increasing fuel moisture content which resulted in slower gasification process in the chamber. The temperature and oxide of nitrogen (NO) concentration are decreased with the increase of the moisture in the fuel. Furthermore, the concentration of carbon monoxide (CO) increases while the change for carbon dioxide (CO2) and oxygen (O2) concentrations are only around 1% with the variation of this operating parameter. At highest gasification efficiency of 92.7 %, the moisture content of the fuel is best set at 16.1-17 % giving outlet operating temperature of 500 degree Celsius and exhaust gas concentrations with 1500 ppm of CO, 2.8 % of CO2, 30 ppm of NO and 17.6 % of O2 respectively. (author)

  13. MAIN CONTENTS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Discussion on the Modern Agriculture Management Mode and its Innovation in China Mode of agricultural management is organic unify between form of agriculture management and way of agriculture management. Changes of agricultural management form are the content of system innovation;Transformation of agricultural management way belongs to the category of technical progress. We found that, precision agriculture with the moderate scale by professional farmers is the dominant mode of agricultural management. Coexisting of multiple modes is the pattern and evolution trend of modern agriculture management mode. The precision agriculture based on household business of moderate scale mode, we needs of rural economd socialization of

  14. 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)

    1998-09-01

    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.

  15. Effects of moisture release and radiation properties in pulverized fuel combustion: A CFD modelling study

    DEFF Research Database (Denmark)

    Yin, Chungen

    2016-01-01

    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...... methods 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...

  16. Effluents of toxic and corrosion-active components at coke-oven gas combustion

    International Nuclear Information System (INIS)

    Various modes of coke-coal gas combustion are studied and dependence of concentration of nitrogen sulfur oxides and carbon monoxides originating in smoke gases on the air excess delivered to the combustion chamber is determined. The lowest summary releases of hazardous substances are achieved by the excess air coefficients α > 1.2 relative to modes of coke-coal gas combustion with smoke gases recirculation. The quantity of sulfur does not depend on the mode of fuel combustion and is determined by the total sulfur content in the fuel. To prevent the corrosion of low-temperature heat exchange surfaces it is necessary to heat up the feed-water up to the temperature exceeding the temperature of the coal gases dew point by 10-15 deg C. 10 refs

  17. Numerical modelling of coal spontaneous combustion with moisture included

    Energy Technology Data Exchange (ETDEWEB)

    Arisoy, A. [Istanbul Technical University, Istanbul (Turkey). Mechanical Engineering Faculty

    2005-07-01

    A mathematical model for spontaneous combustion of coal with moisture included is presented. The one-dimensional unsteady state model consists of conservation equations for oxygen, water vapour and inherent moisture of coal and energy for both gaseous and solid phases. A first order Arrhenius reaction rate for oxidation under both pore diffusion and chemically controlled reaction regime is considered. The rate of evaporation or condensation is also considered as a function of temperature of coal, water content of coal and gas streams. The equation of the model is solved numerically by the finite difference technique. Influences of different parameters on the process of spontaneous combustion can be examined by using this model. Also the model can be used to simulate full-scale storage conditions. 4 refs., 5 figs., 1 tab.

  18. A non-destructive determination of uranium in combustible waste

    International Nuclear Information System (INIS)

    The result of non-destructive determination of uranium content in combustible waste by using Gamma Scanner is presented. The lower detection limit is settled on 0.053 g 235U for each package of waste through a series of tests on scale, background, γ-point source and reference samples. The error of this method is +-36% (with a 95% confidence level) where 235U in waste of each package is up to 1 g and +- 20% (with a 95% confidence level) up to 5 g. This method is proven to be very stable for a long term experience for 3 months with a relative error of 4.9%. The varies-enriched combustible wastes of 235U derived from the production of Qinshan, Daya Bay fuel have been detected by this method

  19. Influence of combustion temperature conditions on nitrogen oxides emission

    International Nuclear Information System (INIS)

    In the paper presented are the results of the computation of chemical thermodynamic equilibrium for system formed by compounds and elements contained in coal and combusted air. The results are obtained at temperatures from 775 to 1700 K, pressure 1 bar, excess air α = 1.0 and 1.25, and for several different types of coal (lignite, brown and bituminous). The developed mathematical model takes into account only the thermal NOx oxides formation mechanism which is, for coals having low nitrogen content, the dominant NOx formation mechanism. The obtained results can serve, as thermodynamic indicators, for lowering NOx emission by adequately organizing and conducting the combustion processes, i.e. by preventing formation of temperature zones with NOx emission above the allowed values. 10 refs.; 5 figs.; 2 tabs

  20. Inhibiting the combustion of air-acetylene mixtures

    Science.gov (United States)

    Kopylov, S. N.; Gubina, T. V.

    2016-01-01

    The effect propane, methane, and a mixture of 18 vol % C3H6-40 vol % C3H8-42 vol % C4H10 have on the combustion of air-acetylene mixtures is investigated experimentally. The upper concentration limit of flame propagation, maximum explosion pressure, and maximum rate of rise of explosion pressure are determined. It is found that propane and a mixture of 18 vol % C3H6-40 vol % C3H8-42 vol % C4H10 are strong inhibitors of combustion of acetylene in its concentration ranges of 2-8 vol %. The inhibition effect becomes weaker as the acetylene content in the mixture increases. It disappears completely at C2H2 concentrations exceeding 15 vol %. The above experimental findings are explained using the proposed scheme of acetylene oxidation.

  1. Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ojeda, William de

    2010-07-31

    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

  2. Numerical simulation of hydrogen combustion

    International Nuclear Information System (INIS)

    The aim of this paper is to present a combustion model of hydrogen developed using the Star-cd fluid mechanics code. The model involves a detailed reaction process (11 elementary reactions and 4 intermediate elements) and a procedure is developed to solve the set of fully coupled reactions. Then, a preliminary study allowed to determine ignition conditions needed to numerically trigger a detonation phenomenon. The detonation phenomenon is computed on a first test case and the comparison with literature and another code shows a good agreement (temperature, pressure and velocity of the reaction front). The validation process is still in progress by comparison with other available results. Furthermore, combustion calculations including the prior hydrogen diffusion process can be foreseen. (author)

  3. Cellular ceramics in combustion environments

    Energy Technology Data Exchange (ETDEWEB)

    Fuessel, Alexander; Boettge, Daniela; Adler, Joerg; Marschallek, Felix; Michaelis, Alexander [Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Dresden (Germany)

    2011-11-15

    Cellular materials have become increasingly interesting for applications in combustion environments. Improvements like high power efficiency and low emissions are the main targets of technological development in combustion processes. However, despite scientific and technical success in developing new or improved burner concepts over recent years, a lot of problems remain to be solved in the field of materials science: due to the high power density of the burners the materials are subjected to high loads in terms of thermal shock, temperature and corrosion, especially in so-called porous burner technology. This article shows some examples of research and development strategies and results in developing improved cellular ceramics. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. 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)

    2012-01-06

    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.

  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)

    1997-12-31

    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. Dynamical issues in combustion theory

    International Nuclear Information System (INIS)

    This book looks at the world of combustion phenomena covering the following topics: modeling, which involves the elucidation of the essential features of a given phenomenon through physical insight and knowledge of experimental results, devising appropriate asymptotic and computational methods, and developing sound mathematical theories. Papers in this book describe how all of these challenges have been met for particular examples within a number of common combustion scenarios: reactive shocks, low Mach number premixed reactive flow, nonpremixed phenomena, and solid propellants. The types of phenomena examined are also diverse: the stability and other properties of steady structures, the long time dynamics of evolving solutions, properties of interfaces and shocks, including curvature effects, and spatio-temporal patterns

  7. Combustion generated fine carbonaceous particles

    OpenAIRE

    Bockhorn, Henning; D'Anna, Andrea; Sarofim, Adel F.; Wang, Hai

    2009-01-01

    Soot is of importance for its contribution to atmospheric particles with their adverse health impacts and for its contributions to heat transfer in furnaces and combustors, to luminosity from candles, and to smoke that hinders escape from buildings during fires and that impacts global warming or cooling. The different chapters of the book adress comprehensively the different aspects from fundamental approaches to applications in technical combustion devices.

  8. CSIR helps prevent spontaneous combustion

    Energy Technology Data Exchange (ETDEWEB)

    Vuuren, M. van (CSIR Energy Technology (South Africa))

    1992-03-01

    Heaps of stockpiled coal could present a fire hazard due to the risk of spontaneous combustion. Regular monitoring of stockpiles and bunker testing of coals help to prevent stockpile fires. This brief article describes the recent upgrading of the CSIR's bunker test facility that enables coal producers, users and exporters to test their products under simulated conditions that duplicate the actual conditions under which coal is stored. 2 photos.

  9. An intriguing oscillating combustion phenomenon

    OpenAIRE

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

    2012-01-01

    Strobes are pyrotechnic compositions that emit bright flashes of white or colored light at regular time intervals. The strobe effect has applications in various fields, most notably in the fireworks industry and in the military area (signaling – missile decoys – crowd control). However, the chemical and physical mechanisms involved in this curious combustion phenomenon remain unknown. This study investigates parameters that influence the strobe effect (frequency, sharpness of flashes). Variat...

  10. Coal combustion by wet oxidation

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-11-15

    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. ABB Combustion Engineering nuclear technology

    Energy Technology Data Exchange (ETDEWEB)

    Matzie, R.A.

    1994-12-31

    The activities of ABB Combustion Engineering in the design and construction of nuclear systems and components are briefly reviewed. ABB Construction Engineering continues to improve the design and design process for nuclear generating stations. Potential improvements are evaluated to meet new requirements both of the public and the regulator, so that the designs meet the highest standards worldwide. Advancements necessary to meet market needs and to ensure the highest level of performance in the future will be made.

  12. Effect of air-staging on anthracite combustion and NOx formation

    Energy Technology Data Exchange (ETDEWEB)

    Weidong Fan; Zhengchun Lin; Youyi Li; Jinguo Kuang; Mingchuan Zhang [Shanghai Jiao Tong University, Shanghai (China). School of Mechanical & Power Engineering

    2009-01-15

    Experiments were carried out in a multipath air inlet one-dimensional furnace to assess NOx emission characteristics of the staged combustion of anthracite coal. These experiments allowed us to study the impact of pulverized coal fineness and burnout air position on emission under both deep and shallow air-staged combustion conditions. We also studied the impact of char-nitrogen release on both the burning-out process of the pulverized coal and the corresponding carbon content in fly ash. We found that air-staged combustion affects a pronounced reduction in NOx emissions from the combustion of anthracite coal. The more the air is staged, the more NOx emission is reduced. In shallow air-staged combustion (f{sub M} = 0.85), the fineness of the pulverized coal strongly influences emissions, and finer coals result in lower emissions. Meanwhile, the burnout air position has only a weak effect. In the deep air-staged combustion (f{sub M} = 0.6), the effect of coal fineness is smaller, and the burnout air position has a stronger effect. When the primary combustion air is stable, NOx emissions increase with increasing burnout air. This proves that, in the burnout zone, coal char is responsible for the discharge of fuel-nitrogen that is oxidized to NOx. The measurement of secondary air staging in a burnout zone can help inhibit the oxidization of NO caused by nitrogen release. Air-staged combustion has little effect on the burnout of anthracite coal, which proves to be suitable for air-staged combustion. 31 refs., 11 figs., 1 tab.

  13. List of Content

    Directory of Open Access Journals (Sweden)

    Editor IJRED

    2014-05-01

    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    

  14. List of Article Contents

    Directory of Open Access Journals (Sweden)

    Editorial Section

    2014-12-01

    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    

  15. TOXIC SUBSTANCES FROM COAL COMBUSTION

    Energy Technology Data Exchange (ETDEWEB)

    Kolker, A.; Sarofim, A.F.; Palmer, C.A.; Huggins, F.E.; Huffman, G.P.; Lighty, J.; Veranth, J.; Helble, J.J.; Wendt, J.O.L.; Ames, M.R.; Finkelman, R.; Mamani-Paco, M.; Sterling, R.; Mroczkowsky, S.J.; Panagiotou, T.; Seames, W.

    1999-05-10

    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, 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 Environ-mental 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-NOx combustion systems, and new power generation 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 January 1999 to 31 March 1999. During this period, a full Program Review Meeting was held at the University of Arizona. At this meeting, the progress of each group was reviewed, plans for the following 9 month period were discussed, and action items (principally associated with the transfer of samples and reports among the various investigators) were identified.

  16. 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

    1995-10-01

    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.

  17. Modeling the internal combustion engine

    Science.gov (United States)

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

    1985-01-01

    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.

  18. Radial Combustion Dynamics in Fe2O3/Al Thermite Mixtures: Variability of the Flame Propagation Profiles

    Science.gov (United States)

    Duraes, Luisa; Plaksin, Igor; Antunes, Jose; Campos, Jose; Portugal, Antonio

    2009-06-01

    Radial combustion in thin circular samples of stoichiometric and over aluminized Fe2O3/Al mixtures is studied. Two confinement materials are tested: stainless steel and PVC. The combustion front profiles are registered by digital video-crono-photography. The radial geometry allows an easy detection of sample heterogeneities, since they cause distortions on the combustion front profiles circularity. The influence of the mixtures Al content and type of confinement on the combustion propagation dynamics is analyzed. In addition, an asymmetry analysis of the combustion front profiles is performed, defining an asymmetry parameter and using ANOVA. Although the type of confinement contributes more than the mixture composition to the variability of the asymmetry parameter, they both have a weak influence. The main source of variability is the intrinsic variations of the samples, which are due to their heterogeneous character.

  19. Physical aspects and modelling of turbulent MILD combustion

    OpenAIRE

    Minamoto, Yuki

    2014-01-01

    Moderate or Intense Low-oxygen Dilution (MILD) combustion is one of combustion technologies which can improve efficiency and reduce emissions simultaneously. This combustion type is characterised by the highly preheated reactant temperature and the relatively small temperature rise during combustion due to the intense dilution of the reactant mixture. These unique combustion conditions give MILD combustion very attractive features such as high combustion efficiency, reduction of pollutant emi...

  20. Experimental research on mercury emission from one-dimensional combustion test facility

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Q.; Qiu, J.; Liu, J.; Zhang, J. [Huazhong University of Science and Technology, Quhan (China). National Lab. of Coal Combustion

    2004-06-01

    The research of mercury release from coal combustion and mercury speciation in flue gas was conducted in a one-dimensional combustion test facility. The experimental results indicated that combustion temperature was the primary factor in affecting mercury vaporization and release. Experimental measurements showed high mercury levels in the particulate phase. Hg(S) is enriched in fly ash and dispersed in bottom ash. Hg(B) content decreases and the Hg(F) content increases with higher furnace temperature. At 1,100{sup o}C, the levels of Hg{sup 2+}(g) are 17-48% for limited chemical kinetics. The mercury equilibrium in the flue gas is frozen below some temperature. 5 refs., 4 figs., 1 tab.

  1. CFD simulation of pulse combustion's performance

    Science.gov (United States)

    Rahmatika, Annie Mufyda; Widiyastuti, W.; Winardi, Sugeng; Nurtono, Tantular; Machmudah, Siti; Kusdianto, Joni, I. Made

    2016-02-01

    This study aims to show changes in the performance of combustion using pulse combustion at specified intervals using simulation. Simulations is performed using Computational Fluid Dynamics analysis (CFD) software Ansys Fluent 15.0. Analysis used 2D illustration axisymmetric with k-ɛ turbulence models. Propane was selected as fuel at a flow rate of 15 L/min. Air with flow rate of 375 L/min is used as oxidizer. To investigate the advantages of using pulse combustion, the simulated pulse combustion is compared to normal combustion without a pulse. This is done by displaying descriptions of the phenomenon, mechanisms and results output gas combustor. From the analysis of simulation results showed that in 1 minute burning time, burning fuel without requiring pulse as much as 15 L while the pulse combustion requires half of the fuel which is 12.5 L. However, the higher average of temperature was generated by pulse combustion and the amounts of unburned fuel that comes out of the combustor less than without the use of pulse combustion. So, it can be concluded that the pulse combustion is more efficient than combustion without a pulse.

  2. Polycyclic aromatic hydrocarbons and organic matter associated to particulate matter emitted from atmospheric fluidized bed coal combustion

    International Nuclear Information System (INIS)

    The polycyclic aromatic hydrocarbons (PAH) and the organic matter (OM) content associated with particulate matter (PM) emissions from atmospheric fluidized bed coal combustion have been studied. The two main aims of the work have been (a) to study OM and PAH emissions as a function of the coal fluidized bed combustion (FBC) variables in solid phase and (b) to check if there is any correlation between OM and PAH contained in the PM. The combustion was carried out in a laboratory scale plant at different combustion conditions: temperature, percentage of oxygen excess, and total air flow. PAH associated on the particulate matter have been analyzed by fluorescence spectroscopy in the synchronous mode (FS) after PM extraction by sonication with dimethylformamide (DMF). It can be concluded that there is not a direct relationship between the OM content and the PAH supported in the PM emitted. In addition, neither PM or OM show dependence between themselves

  3. TOXIC SUBSTANCES FROM COAL COMBUSTION

    Energy Technology Data Exchange (ETDEWEB)

    A KOLKER; AF SAROFIM; CL SENIOR; FE HUGGINS; GP HUFFMAN; I OLMEZ; J LIGHTY; JOL WENDT; JOSEPH J HELBLE; MR AMES; N YAP; R FINKELMAN; T PANAGIOTOU; W SEAMES

    1998-12-08

    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

  4. COMBUSTION SIMULATION IN A SPARK IGNITION ENGINE CYLINDER: EFFECTS OF AIR-FUEL RATIO ON THE COMBUSTION DURATION

    OpenAIRE

    Nureddin Dinler; Nuri Yucel

    2010-01-01

    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...

  5. Moisture effect on the combustion of a single copper concentrate particle in a flash smelting furnace

    Science.gov (United States)

    Hassan Zaim, E.; Mansouri, S. H.; Arab Solghar, A.

    2014-03-01

    A mathematical model has been presented to study the combustion of a single copper concentrate particle with high moisture content. By using the presented model, the effect of particle moisture content on particle temperature, sulfur oxidation, and combustion heat generation has been evaluated. The mineralogical composition of the commonly used concentrate at Khatoonabad flash smelting furnace has been used in this study. It was found that the particle moisture content is removed in the sub-second time range and thus the moisture has marginal impact on the variation of particle temperature and on the reaction rate when the gas temperature is assumed to be constant in the reaction shaft. When a concentrate with high moisture content is charged, the particle size enlargement due to the agglomeration of concentrate particles causes an abrupt fall in the particle reaction rate.

  6. Application of PGNAA to preincineration assay of combustible waste for chlorine

    Energy Technology Data Exchange (ETDEWEB)

    Gehrke, R.J.; Pawelko, R.J.; Greenwood, R.C. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1995-12-31

    A prompt gamma neutron activation analysis method is being developed for on-stream pre-incineration assay of low level radioactive combustible waste for it`s chlorine content. The assay system consists of three californium 252 sources and a germanium or scintillation gamma-ray spectrometer.

  7. Incineration and co-combustion of waste: accounting of greenhouse gases and global warming contributions

    DEFF Research Database (Denmark)

    Astrup, Thomas; Møller, Jacob; Fruergaard, Thilde

    2009-01-01

    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...

  8. 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; Dam-Johansen, Kim

    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 CO...

  9. Sandia Combustion Research Program: Annual report, 1986

    Energy Technology Data Exchange (ETDEWEB)

    1986-01-01

    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.

  10. NO formation during agricultural straw combustion.

    Science.gov (United States)

    Ren, Qiangqiang; Zhao, Changsui; Duan, Lunbo; Chen, Xiaoping

    2011-07-01

    NO formation during combustion of four typical kinds of straw (wheat straw, rice straw, cotton stalk and corn stalk) which belong to soft straw and hard straw was studied in a tubular quartz fixed bed reactor under conditions relevant to grate boiler combustion. Regarding the real situation in biomass fired power plants in China, NO formation from blended straw combustion was also investigated. Nitrogen transfer during blended straw pyrolysis was performed using a thermogravimetric analyzer (TGA) coupled with a Fourier transform infrared (FTIR) spectrometer. The results show that NO conversion for the four straws during combustion is distinctive. Over 70% fuel-N converts into NO for cotton stalk, while only 37% for wheat straw under the same condition. When wheat straw and cotton stalk were mixed, N-NO conversion increases. The limestone addition promotes NO emission during cotton stalk combustion. The presence of SO(2) in atmosphere suppresses NO formation from straw combustion. PMID:21592786

  11. 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

    2016-01-01

    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.

  12. ENVIRONMENTAL ASSESSMENT OF COMBUSTION MODIFICATION CONTROLS FOR STATIONARY INTERNAL COMBUSTION ENGINES

    Science.gov (United States)

    The report gives results of an environmental assessment of combustion modification techniques for stationary internal combustion engines, with respect to NOx control reduction effectiveness, operational impact, thermal efficiency impact, capital and annualized operating costs, an...

  13. Experimental research on combustion fluorine retention using calcium-based sorbets during coal combustion (Ⅰ)

    Institute of Scientific and Technical Information of China (English)

    QI Qing-jie; LIN Zhi-yan; LIU Jian-zhong; WU Xian; ZHOU Jun-hu; CEN Ke-fa

    2008-01-01

    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 thermo-dynamic 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.

  14. Industrial Combustion Vision: A Vision by and for the Industrial Combustion Community

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1998-05-01

    The Industrial Combustion Vision is the result of a collaborative effort by manufacturers and users of burners, boilers, furnaces, and other process heating equipment. The vision sets bold targets for tomorrow's combustion systems.

  15. Basic theory research of coal spontaneous combustion

    Institute of Scientific and Technical Information of China (English)

    WANG Ji-ren; SUN Yan-qiu; ZHAO Qing-fu; DENG Cun-bao; DENG Han-zhong

    2008-01-01

    Discussed latest research results of basic theory research of coal spontaneous combustion in detail, with quantum chemical theory and method and experiment systematically studied chemical structure of coal molecule, adsorption mechanism of coal surface to oxygen molecule and chemical reaction mechanism and process of spontaneous combustion of organic macromolecule and low molecular weight compound in coal from microcosmic view, and established complete theoretical system of the mechanism of coal spontaneous combustion.

  16. Diagnostics of combustion engines` fuel system

    OpenAIRE

    Kuchař, Jan

    2011-01-01

    Thesis " Diagnostics of combustion engines` fuel system " deals with diagnostics of fuel systems for internal combustion engines. In the chapter "Fuel system for internal combustion engines” are described injection devices of modern gasoline and diesel engines. The chapter "Diagnostic equipment for fuel systems" describes the equipment used in the service to diagnose the fuel system. It further describes diagnostic methods and procedures. Chapter "Analysis of the current condition of...

  17. Materials for High-Temperature Catalytic Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ersson, Anders

    2003-04-01

    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

  18. Numerical investigation of biogas flameless combustion

    International Nuclear Information System (INIS)

    Highlights: • Fuel consumption decreases from 3.24 g/s in biogas conventional combustion to 1.07 g/s in flameless mode. • The differences between reactants and products temperature intensifies irreversibility in traditional combustion. • The temperature inside the chamber is uniform in biogas flameless mode and exergy loss decreases in this technique. • Low O2 concentration in the flameless mode confirms a complete and quick combustion process in flameless regime. - Abstract: The purpose of this investigation is to analyze combustion characteristics of biogas flameless mode based on clean technology development strategies. A three dimensional (3D) computational fluid dynamic (CFD) study has been performed to illustrate various priorities of biogas flameless combustion compared to the conventional mode. The effects of preheated temperature and wall temperature, reaction zone and pollutant formation are observed and the impacts of combustion and turbulence models on numerical results are discussed. Although preheated conventional combustion could be effective in terms of fuel consumption reduction, NOx formation increases. It has been found that biogas is not eligible to be applied in furnace heat up due to its low calorific value (LCV) and it is necessary to utilize a high calorific value fuel to preheat the furnace. The required enthalpy for biogas auto-ignition temperature is supplied by enthalpy of preheated oxidizer. In biogas flameless combustion, the mean temperature of the furnace is lower than traditional combustion throughout the chamber. Compared to the biogas flameless combustion with uniform temperature, very high and fluctuated temperatures are recorded in conventional combustion. Since high entropy generation intensifies irreversibility, exergy loss is higher in biogas conventional combustion compared to the biogas flameless regime. Entropy generation minimization in flameless mode is attributed to the uniform temperature inside the chamber

  19. The combustion of solid fuels and wastes

    CERN Document Server

    Tillman, David

    1991-01-01

    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

  20. Study of coke oven combustion control

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, F.; Ono, H.; Ariyoshi, K.; Kasaoka, H.; Ichinomiya, M.

    1986-01-01

    Gas flow and combustion in the flues of a Carl Still-type coke oven battery (employing natural draft) can be controlled by focussing on combustion control for a single oven and applying an equation for steady gas flow to all the gas passages in the combustion chambers. This effectively corrects the oven temperature distribution. The usefulness of this control technique has been confirmed, and a large reduction in coking heat consumption has been achieved. 1 ref., 3 figs.