Academic literature on the topic 'Paraffins; Liquids; Mixtures'
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Journal articles on the topic "Paraffins; Liquids; Mixtures"
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Ebrahimi, Hadi, Akbar Zamaniyan, and Khaled Forsat. "Improving Gas to Liquid production by Associated Gases." Journal of Petroleum Research and Studies 7, no. 2 (May 6, 2021): 211–25. http://dx.doi.org/10.52716/jprs.v7i2.197.
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Gas-to-Liquids (GTL) is a process for converting natural gas into synthetic oil, which can be further processed into fuels and other hydrocarbon-based products. The total GTL plant is self-sufficient. Therefore most of the required utilities provided, too. High energy cost is the main driving force behind currently increasing interest in the Fischer-Tropsch synthesis (FTS) for the conversion of GTL. The catalytic synthesis of hydrocarbons from CO and H2 Syngas mixtures leads to a large variety of products such as paraffins, olefins, alcohols, and aldehydes. The process uses mainly natural gas. However, other gases fuels could also be employed. Three-fourths of Iraq's natural gas resources are associated with oil. Meanwhile, Majnoon oil production is generating significant amounts of associated gas that was usually flared while different options to abate flaring are under review. The current article presents using a 10 MM m3 annually associated gases in the southern part of Iraq in 3000 BPD GTL plant. The simulation of the plant shows that the added associated gas which is currently flared could increase the productivity and there is no need to send it to the flares. Research Institute of Petroleum Industry has a license of the GTL process, both fixed-bed and slurry types.
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Zotov, Yu L., D. M. Zapravdina, E. V. Shishkin, and Yu V. Popov. "Synthesis of stabilizers based on glycerides of monocarboxylic acids for industrial chloroparaffins." Fine Chemical Technologies 17, no. 4 (September 30, 2022): 298–310. http://dx.doi.org/10.32362/2410-6593-2022-17-4-298-310.
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Objectives. The study aimed to develop new effective heat stabilizers based on glycerol esters of monocarboxylic acids for industrial chlorinated paraffins and to select of the optimal ratio of active ingredients in the stabilizing composition in order to provide the maximum thermostabilizing effect.Methods. The thermostabilizing effect of the studied samples on chlorinated paraffins was evaluated according to the standard method for determining the thermal stability of liquid chlorinated paraffins in terms of the mass fraction of split off hydrogen chloride. Quantitative and qualitative analysis of the obtained mixtures of monocarboxylic acid glycerides was carried out using chromato-mass spectrometry.Results. Glycerides of monocarboxylic acids (oleic, octanoic, hexanoic, and propionic acids) were obtained and identified, and the compositions of the resulting mixtures of mono-, di- and triesters were determined. The stabilizing effect of the obtained mixtures of glycerides of monocarboxylic acids in the amount of 0.5–2.0 wt parts per 100 wt parts of unstabilized industrial chlorinated paraffin CP-30 was determined. The combined use of glycerides of monocarboxylic acids with calcium-containing compounds as a complex stabilizer with a molar ratio of esters/Ca 0.93–0.86/0.07–0.14, respectively, was investigated. Chloroparaffin CP-470, stabilized by the developed complex stabilizer, was successfully used in a polyvinyl chloride composition for cable compound of the brand OM-40.Conclusions. A proposed variant of a complex stabilizer for chlorinated paraffins based on Russian raw materials for import substitution will expand the range of effective stabilizers for organochlorine substances. Glycerides of monocarboxylic acids are shown to exhibit a thermostabilizing effect on industrial chlorinated paraffins. The relationship between the length of the hydrocarbon substituent of the carboxylic acid in the ester and the thermostabilizing effect is obtained. With an increase in the number of carbon atoms in the hydrocarbon substituent of the carboxylic acid, the heat-stabilizing ability decreases. The minimum sufficient concentration of glycerides of carboxylic acids was 0.05 ± 0.005 mol/kg, above which no increase in the thermostabilizing effect on chloroparaffin was observed. A synergistic ratio of the components of the stabilizing mixture in terms of thermal stability—glycerides of monocarboxylic acids/calcium-containing compounds—was found equal to 0.85–0.9/0.15–0.1.
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Asaftei, Iuliean Vasile, Ion Sandu, Neculai Catalin Lungu, Adrian Florin Spac, and Maria Ignat. "Transformation of Gaseous Technical Mixture of the Alkanes and Alkenes Into Liquid Fraction Over Ni-HZSM-5 Obtained by Ionic Exchange." Revista de Chimie 69, no. 4 (May 15, 2018): 938–43. http://dx.doi.org/10.37358/rc.18.4.6232.
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Paraffin�s and olefins in the cracked naphtha can be transformed into aromatics and iso-paraffins to reduce the olefins content as well to improve the octane number of the gasoline commercial fraction. In this work Ni-HZSM-5 bifunctional catalyst was prepared by ion exchange with Ni(NO3)2 aqueous solution. The activity of Ni-HZSM-5 (wt.% 1.34% Ni) catalyst prepared by ion exchange method was investigated in the conversion of light hydrocarbons resulted as by-products of petroleum refining process (mixtures of butenes and (normal + iso) butanes as main components). The obtained Ni-based catalyst has been compare with HZSM-catalyst. The conversion experiments have been performed in a fixed-bed stainless-steel reactor (Twin Reactor System Naky) at 450oC, under 4 atm. (over Ni-HZSM-5) and 8 atm. pressure (over HZSM-5), respectively and at a space velocity (WHSV) of 1h-1. The catalytic activity of (Ni-HZSM-5 catalyst) monitored over 10 catalytic tests (with regeneration of catalyst after each test) using a mixtures butanes-butylenes. The catalytic activity and selectivity towards liquid products - BTX aromatic hydrocarbons and oligo(iC5-iC10, nC5-nC10, ] C10) - depends on time streaming, composition of butanes-butylenes mixture and pressure. In the first hours of each test the aromatic BTX are the main component of the liquid product (connected with butylenes consume) and after that, the oligo fraction become predominant. The initial aromatization process described as dehydrocyclodimerization of alkanes and alkenes, principally to aromatics BTX and molecular hydrogen, is accompanied by oligomerization, isomerization, cracking and alkylation processes to form finally in the liquid phase product an excessively mixture of iso- and normal - C5 -C10 and ] C10 aliphatic hydrocarbons.
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Aimbetova, I. O., U. S. Suleimenov, O. A. Kostikov, and R. A. Ristavletov. "DEVELOPMENT OF HEAT STORAGE MATERIALS BASED ON COMMODITY PARAFFINS." NEWS of National Academy of Sciences of the Republic of Kazakhstan 6, no. 444 (December 15, 2020): 6–13. http://dx.doi.org/10.32014/2020.2518-170x.124.
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Heat storage materials on the basis of liquid paraffins and their narrow fractions with the set temperature of phase transition and the increased heat capacity for enclosing the structures of buildings are received. A method of formulating compositions heat-storage materials with melting temperatures below 250C and increased heat capacity from a mixture of narrow fractions of commodity paraffins is proposed. The technique of obtaining heat-storage materials on the basis of commodity paraffin by mixing components, in obtaining HSM with specified thermal characteristics, the research of component composition, physico-chemical and thermophysical properties, in the research of their operational properties. The technical conditions for the obtained heat- storage materials on the basis of commodity paraffins are developed and the possibility of their application in the enclosing structures of buildings is substantiated. The developed heat-storage material with the set operational properties provides energy saving due to increase of heat capacity and intensity of heat exchange of enclosing designs of buildings.
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Fredi, Giulia, Matteo Favaro, Damiano Da Ros, Alessandro Pegoretti, and Andrea Dorigato. "Thermotropic Optical Response of Silicone–Paraffin Flexible Blends." Polymers 14, no. 23 (November 24, 2022): 5117. http://dx.doi.org/10.3390/polym14235117.
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Organic phase change materials, e.g., paraffins, are attracting increasing attention in thermal energy storage (TES) and thermal management applications. However, they also manifest interesting optical properties such as thermotropism, as they can switch from optically opaque to transparent reversibly and promptly at the melting temperature. This work aims at exploiting this feature to produce flexible silicone-based blends with thermotropic properties for applications in glazed windows or thermal sensors. Blends are produced by adding paraffin (Tm = 44 °C, up to 10 phr) to a silicone bicomponent mixture, and, for the first time, cetyltrimethylammonium bromide (CTAB) is also added to promote paraffin dispersion and avoid its exudation. CTAB is proven effective in preventing paraffin exudation both in the solid and in the liquid state when added in a fraction above 3 phr with respect to paraffin. Rheological results show that paraffin decreases the complex viscosity, but neither paraffin nor CTAB modifies the curing behavior of silicone, which indicates uniform processability across the investigated compositions. On the other hand, paraffin causes a decrease in the stress and strain at break at 60 °C, and this effect is amplified by CTAB, which acts as a defect and stress concentrator. Conversely, at room temperature, solid paraffin only slightly impairs the mechanical properties, while CTAB increases both the elastic modulus and tensile strength, as also highlighted with ANOVA. Finally, optical transmittance results suggest that the maximum transmittance difference below and above the melting temperature (65–70 percentage points) is reached for paraffin amounts of 3 to 5 phr and a CTAB amount of max. 0.15 phr.
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Mianowski, A., and T. Siudyga. "Thermal analysis of polyolefin and liquid paraffin mixtures." Journal of Thermal Analysis and Calorimetry 74, no. 2 (2003): 623–30. http://dx.doi.org/10.1023/b:jtan.0000005203.55828.c5.
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Moir, Michael E., Stéphanie Charbonneau, and J. Brian A. Mitchell. "SOOT REDUCTION CHEMICALS FOR IN-SITU BURNING." International Oil Spill Conference Proceedings 1993, no. 1 (March 1, 1993): 761–63. http://dx.doi.org/10.7901/2169-3358-1993-1-761.
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ABSTRACT A soot reduction additive for use in the in-situ burning of oil spills has been developed. The additive is in the form of a liquid concentrate that can be sprayed on a spill. The soot producing tendency of hydrocarbons decreases in the order: aromatics, branched paraffins, cycloalkanes, normal paraffins. Similarly, the soot reduction ability of ferrocene and derivatives decreases in the order: aromatics, cycloalkanes, branched paraffins, normal paraffins. A method of predicting soot reduction is inferred from model studies and confirmation obtained from experiments on known hydrocarbon mixtures.
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Fall, David J., Jaimie L. Fall, and Kraemer D. Luks. "Liquid-liquid-vapor immiscibility limits in carbon dioxide + n-paraffin mixtures." Journal of Chemical & Engineering Data 30, no. 1 (January 1985): 82–88. http://dx.doi.org/10.1021/je00039a028.
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Estrera, Susana S., and Kraemer D. Luks. "Liquid-liquid-vapor equilibria behavior of certain ethane + n-paraffin mixtures." Journal of Chemical & Engineering Data 32, no. 2 (April 1987): 201–4. http://dx.doi.org/10.1021/je00048a022.
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Sehabiague, Laurent, and Badie I. Morsi. "Hydrodynamic and Mass Transfer Characteristics in a Large-Scale Slurry Bubble Column Reactor for Gas Mixtures in Actual Fischer–Tropsch Cuts." International Journal of Chemical Reactor Engineering 11, no. 1 (June 18, 2013): 83–102. http://dx.doi.org/10.1515/ijcre-2012-0042.
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Abstract The hydrodynamics (gas holdup, Sauter mean bubble diameter, d 32) and the overall volumetric liquid-side mass transfer coefficients (kLa) were measured in a large-scale (0.29 m ID, 3 m high) slurry bubble column reactor (SBCR) for He/N2 gaseous mixtures, as surrogates for syngas, in three different Fisher–Tropsch (F-T) products (liquid paraffins mixture, light F-T cut and heavy F-T cut) in the presence and absence of three different solids (spent iron oxides catalyst, alumina powder and Puralox alumina). The effects of pressure (10–30 bar), temperature (up to 500 K), superficial gas velocity (0.14–0.26 m/s), solid concentration (0–20 vol.%) and gas density on these design parameters were investigated. The experimental data revealed that increasing the reactor pressure or gas density increased the gas holdup and decreased d 32, by increasing the population of the small gas bubbles, which increased the overall kLa values for all the gas mixtures used in the three F-T cuts under most of the operating conditions employed. Increasing temperature increased the gas holdup in the three F-T cuts, except for N2-light F-T cut, where the gas holdup values remained almost constant from 400 to 500 K. Increasing the slurry concentration decreased the gas holdup and increased d 32, mainly for gaseous mixtures with high He mole fractions, which decreased the overall kLa under all conditions used. Increasing the gas superficial velocities (UG ) increased the gas holdup and kLa values, even though d 32 was found to increase or decrease with increasing UG . Increasing the He mole fraction in the He/N2 gaseous mixture at constant pressure led to low gas holdup and high d 32 which decreased kLa values, and under similar operating conditions, kLa values of He as a single gas were always lower than those of N2 as a single gas. Increasing the He mole fraction in the He/N2 gaseous mixture at constant density, however, was found to have negligible effect on the gas holdup, d 32 and subsequently on the overall kLa. The gas holdup, the overall kLa and the population of the small gas bubbles for N2 in the liquid paraffins mixture were greater than those in the light F-T cut. Operating the SBCR with the heavy F-T cut resulted in the lowest gas holdup and the largest gas bubbles size which led to the lowest gas–liquid interfacial area and consequently, the lowest kLa values. Also, under the operating conditions investigated, the behavior of overall kLa for the gases used in the three F-T cuts in the presence and absence of the three solids employed was controlled by that of the gas–liquid interfacial area (a). Using the data obtained, two novel empirical correlations for predicting the gas holdup and the overall kLa for gases specifically in F-T cuts are proposed.
Dissertations / Theses on the topic "Paraffins; Liquids; Mixtures"
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Sabourin, Shaun. "Auto-Ignition of Liquid n-Paraffin Fuels Mixtures as Single Droplets Using Continuous Thermodynamics." Thèse, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/20135.
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This thesis reports a model to predict the auto-ignition time of single droplets of n-paraffin fuel mixtures using the method of continuous thermodynamics. The model uses experimental data for pure fuels to fit rate parameters for a single-step global chemical reaction equation; from this, correlations for rate parameters as a function of species molecular mass are derived, which are integrated to produce a continuous thermodynamics expression for mixture reaction rate. Experiments were carried out using the suspended droplet-moving furnace technique. The model was then tested and compared to experimental data for three continuous mixtures with known compositions: one ranging from ¬n-octane to n-hexadecane, the second ranging from n-dodecane to n-eicosane, and the third being a combination of the first two mixtures to produce a “dumbbell” mixture. Discrete and continuous mixture models of the ASTM standard distillation test were compared to design the experimental mixtures and provide the distribution parameters of the continuous mixtures intended to simulate them. The results of calculations were found to agree very well with measured ignition times for the mixtures.
Book chapters on the topic "Paraffins; Liquids; Mixtures"
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Moura, Leila, Catherine C. Santini, and Margarida F. Costa Gomes. "Gas Separations using Ionic Liquids." In Chemical Processes for a Sustainable Future, 582–602. The Royal Society of Chemistry, 2014. http://dx.doi.org/10.1039/bk9781849739757-00582.
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Cryogenic distillation is the most used separation process for mixtures of gases. Implementation of alternative processes with improved economic and environmental performance is needed, especially for low molar mass gaseous hydrocarbon separation in the petrochemical industry. Ionic liquids have been suggested as separating agents for olefin/paraffin gas separation, as absorbents, or as solvents for the chemical complexation of olefins with silver or copper salts. This chapter presents current knowledge on the solubility of ethane, ethylene, acetylene, propane, propylene and methyl acetylene in pure ionic liquids. Whenever possible, the ionic liquid absorption capacity and ideal selectivity (solubility ratio) is calculated for ethane–ethylene, ethylene–acetylene, propane–propylene and propylene–methyl acetylene mixtures, enabling an assessment of the potential of each studied ionic liquid as a separating agent.
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Kara, Ozan, and Arif Karabeyoglu. "Hybrid Propulsion System: Novel Propellant Design for Mars Ascent Vehicles." In Propulsion - New Perspectives and Applications [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.96686.
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This chapter briefly introduces hybrid rocket propulsion for general audience. Advantageous of hybrid rockets over solids and liquids are presented. This chapter also explains how to design a test setup for hybrid motor firings. Hybrid propulsion provides sustainable, safe and low cost systems for space missions. Therefore, this chapter proposes hybrid propulsion system for Mars Ascent Vehicles. Paraffin wax is the fuel of the rocket. Propulsion system uses CO2/N2O mixture as the oxidizer. The goal is to understand the ignition capability of the CO2 as an in-situ oxidizer on Mars. CO2 is known as major combustion product in the nature. However, it can only burn with metallic powders. Thus, metallic additives are added in the fuel grain. Results show that CO2 increase slows down the chemical kinetics thus reduces the adiabatic flame temperature. Maximum flammability limit is achieved at 75% CO2 by mass in the oxidizer mixture. Flame temperature is 1700 K at 75% CO2. Ignition quenches below the 1700 K.
Conference papers on the topic "Paraffins; Liquids; Mixtures"
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Molie`re, Michel, Philippe Cozzarin, Se´bastien Bouchet, and Philippe Rech. "Catalytic Detection of Fuel Leaks in Gas Turbines Units: Gaseous and Volatile Hydrocarbon Based Fuels." In ASME Turbo Expo 2005: Power for Land, Sea, and Air. ASMEDC, 2005. http://dx.doi.org/10.1115/gt2005-68875.
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Gas/vapor detection is a critical function in Gas Turbines (GT) units as it allows to take appropriate steps in case of incipient fuel leaks in the confined volume of enclosures. This important subject is being actively revisited by the GT community and safety organizations, namely under the impulse of the HSE of UK. Historically the catalytic detection technology that is of common use in stationary GT, has been applied to detect leakages of gaseous fuels — and more especially Natural Gas (NG) — since the catalytic detectors or “pellistors” are most sensitive to methane. Indeed, the response of catalytic detectors is specific to each individual hydrocarbon molecule and decrease with the size of the latter. After years this technology has been extended to the detection of rich NG (containing some amounts of C3-C4) then to hydrogen and liquefied petroleumliquids (LPG). The use of alternative gas turbine fuels such as LPG, syngas and volatile fuels is becoming increasingly popular in some world regions and requires to adapt the leak detection systems. Especially, volatile liquid fuels that comprise naphtha, “natural gas liquids”, gas condensates (and alcohols) are critical in safety terms. Indeed these fuels exhibit both low initial boiling points (IBP as low as 30°C) and Flash Points (down to-20°C); in case of leak, they generate — as liquids — large masses of flammable substances. In addition, vapors of liquid fuels have a more complex response in catalytic detection than gases due to their complex composition with tens of HC molecules of various size and structure. In this context, the behavior of commercial detectors in presence of not only gas fuels but also of synthetic vapors of naphtha has been the matter of a comprehensive evaluation at the laboratory of INERIS, a French Institute devoted to safety and environment. This work that targets the detection of hydrocarbon (CnHm) fuels is the first phase of an overall, GE-INERIS joint evaluation program covering both hydrocarbon and non-hydrocarbon GT fuels, i.e. the complete CnHm/CO/H2/N2(CO2) spectrum. The first part of this program phase addressed the lightest terms of the paraffin series (C1 to C4) and some mixtures of the same that are involved in the detection of NG and LPG vapors. The second part was dedicated to the higher paraffins terms (C5 to C8) including various mixtures of the same and 2 synthetic naphtha compositions. Particular emphasis has been placed on the capability to detect hydrocarbons at the levels (as low as 5%) that result from recent safety codes. After a record of principles, the paper summarizes the results of these tests that confirm the general capability of the catalytic technology for the detection of LPG and naphtha vapors.
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Arumugam, Sridhar, Adebola S. Kasumu, and Anil K. Mehrotra. "Modeling the Static Cooling of Wax–Solvent Mixtures in a Cylindrical Vessel." In 2012 9th International Pipeline Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/ipc2012-90691.
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Under subsea conditions, the transportation of ‘waxy’ crude oil through pipelines is accompanied by the precipitation and deposition of higher paraffinic compounds as solids (waxes) onto the cooler surfaces of the pipeline. Wax deposition is more pronounced during shut down of a pipeline since the fluid is held at static conditions. In this study, the static cooling of wax–solvent mixtures in a cylindrical vessel was modeled as a moving boundary formulation involving liquid–solid phase transformation. The deposition process during the transient cooling was treated as a partial freezing/solidification process. Also, the effect of the mixture composition and the cooling rate on the Wax Precipitation Temperature (WPT) or the solubility curve of the wax–solvent mixture was taken into consideration when the bulk liquid phase temperature was lowered below the WAT of the initial mixture composition. The predictions for the transient temperature profiles in the liquid and the deposit region, and the location of the liquid–deposit interface were validated with recently reported experimental results [19]. The predictions were also compared with the predictions for the gelling behavior of wax–solvent mixtures under static cooling reported by Bidmus [19]. The predictions for the temperature profile at seven thermocouple locations and the location of the liquid–deposit interface were in agreement with the experimental results and signified the important role of the solubility curve. The mathematical model presented was based on heat transfer considerations and regarded the deposition process to be thermally driven.
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Diaconescu, E. N., and V. F. Zegrean. "A Simple Flow Model for Amorphous Molecular Solids." In ASME 2008 9th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2008. http://dx.doi.org/10.1115/esda2008-59426.
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Theoretical and experimental investigations suggest that EHD oil films exhibit amorphous solid properties. Therefore, oil EHD traction properties may be found by the shear of corresponding molecular solids, such as amorphous paraffin. To check this possibility, the viscosity of solid paraffin under controlled pressure and temperature is measured on a computer assisted shear device. Experimental results indicate that some viscosity properties in amorphous solids do not match those found in liquids. AFM investigations show that solid paraffin structure is a mixture of clusters and simple molecules. A possible mechanism of flow in molecular amorphous solid was advanced which explains the observed discrepancies.
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Gokulakrishnan, P., M. S. Klassen, and R. J. Roby. "Ignition Characteristics of a Fischer-Tropsch Synthetic Jet Fuel." In ASME Turbo Expo 2008: Power for Land, Sea, and Air. ASMEDC, 2008. http://dx.doi.org/10.1115/gt2008-51211.
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Ignition delay times of a “real” synthetic jet fuel (S8) were measured using an atmospheric pressure flow reactor facility. Experiments were performed between 900 K and 1200 K at equivalence ratios from 0.5 to 1.5. Ignition delay time measurements were also performed with JP8 fuel for comparison. Liquid fuel was prevaporized to gaseous form in a preheated nitrogen environment before mixing with air in the premixing section, located at the entrance to the test section of the flow reactor. The experimental data show shorter ignition delay times for S8 fuel than for JP8 due to the absence of aromatic components in S8 fuel. However, the ignition delay time measurements indicate higher overall activation energy for S8 fuel than for JP8. A detailed surrogate kinetic model for S8 was developed by validating against the ignition delay times obtained in the present work. The chemical composition of S8 used in the experiments consisted of 99.7 vol% paraffins of which approximately 80 vol% was iso-paraffins and 20% n-paraffins. The detailed kinetic mechanism developed in the current work included n-decane and iso-octane as the surrogate components to model ignition characteristics of synthetic jet fuels. The detailed surrogate kinetic model has approximately 700 species and 2000 reactions. This kinetic mechanism represents a five-component surrogate mixture to model generic kerosene-type jets fuels, namely, n-decane (for n-paraffins), iso-octane (for iso-paraffins), n-propylcyclohexane (for naphthenes), n-propylbenzene (for aromatics) and decene (for olefins). The sensitivity of iso-paraffins on jet fuel ignition delay times was investigated using the detailed kinetic model. The amount of iso-paraffins present in the jet fuel has little effect on the ignition delay times in the high temperature oxidation regime. However, the presence of iso-paraffins in synthetic jet fuels can increase the ignition delay times by two orders of magnitude in the negative temperature (NTC) region between 700 K and 900 K, typical gas turbine conditions. This feature can have a favorable impact on preventing flashback caused by the premature autoignition of liquid fuels in lean premixed prevaporized (LPP) combustion systems.
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Hasegawa, Hiroya, Makoto Ono, Makoto Hishida, and Gaku Tanaka. "Flow Pattern and Friction Coefficient of Water/Nonadecane-Particle Mixture Flow in Horizontal and Vertical Pipes." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-41565.
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Cold heat storage utilizing night-time electricity is one of the relevant technologies for the electric load leveling. Latent heat storage system with a large number of small paraffin particles is one of the promising technologies for the cold heat storage system. Small paraffin particles are generated by nozzle injection of liquid paraffin into cold water. Direct heat transfer between the ascending particles and surrounding cold water enhances the storage of latent heat in a short time. Transportation of solid paraffin particles suspended in water should be the best way to transport cold heat, because the density of cold heat stored in water/paraffin-particle mixture is very high. The present paper aims at investigating flow patterns and pressure loss of water/nonadecane-particle mixture flowing in horizontal and vertical pipes. The inner diameter and the average diameter of the nonadecane particle were 20mm and 3.7mm, respectively. Reynolds number, Froude number and volumetric concentration of nonadecane particles were varied in the ranges of 5000 ≤ Re ≤ 80000, 1 ≤ Fr ≤ 260 and 0.02 ≤ Cv ≤ 0.25. We found the following main results: (1) Four flow patterns were observed in the horizontal flow, (a) flow with a stationary particle bed, (b) flow with a sliding particle layer (c) heterogeneous suspension flow and (d) homogeneous suspension flow. The flow pattern shifted from (a) to (d) with increasing Reynolds number. (2) Homogeneous suspension flow was observed in the vertical up-flow. (3) Homogeneous and heterogeneous suspension flow was observed in the vertical down-flow. (4) The pressure loss coefficients λ of the horizontal flow were correlated by a function of λ and Re (λ = 0.479 Re−0.311) for the heterogeneous and homogeneous suspension flows (Re ≥ about 25000) and by a function of the excess pressure loss coefficient Φ, Fr and Cv (φ/Cv0.58 = 72.4Fr−1.25) for the flow with a sliding particle layer (Re ≤ about 20000). (5) The pressure loss coefficients of the vertical up-flow were correlated by a function of λ and Re (λ = 4.45 Re−0.501) in a large Reynolds number range of Re ≥ about 40000 and by a function of Φ, Fr and Cv (φ/Cv0.47 = 282Fr−1.47) in a small Reynolds number range of Re ≤ about 40000. (6) The pressure loss coefficients of the vertical down-flow were correlated by a function of Φ and Fr (φ = 73.0Fr−0.765).
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McCloskey, John, Amy Fleischer, Sneha Patel, and Rashida Ng. "The Determination of Thermal Properties of Paraffin-Based Phase Change Material [PCM] Within a Daylighting Panel." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-12192.
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The addition of phase change material (PCM) to a transparent polyester panel is used to create an energy absorbing building material that can be used for daylighting. One of the key development needs of this energy efficient material is the identification of the thermal properties. Without a clear understanding of the thermal properties and thermal performance with embedded solid and liquid PCM, design optimization is not possible. This experiment analyzes the thermal conductivity of various mixtures of thermoplastic polyester and PCMs. It was determined that the addition of PCM slightly increases the thermal conductivity of panels when the PCM is solid. Once the PCM has melted, the panel conductivity is lowered.
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McGrath, Thomas, Adrian Covaci, Els Van Hoeck, Franck Limonier, Giulia Poma, Jasper Bombeke, Kevin Vanneste, Laure Joly, Mirjana Andjelkovic, and Raf Winand. "Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-high resolution mass spectrometry (LC-HRMS) approaches for analysis of chlorinated paraffins in edible fats and oils." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/wycg9726.
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Chlorinated paraffins (CPs) are high production volume chemicals composed of complex mixtures of thousands of compounds that have been applied widely as flame retardants and plasticizers. CPs have demonstrated toxic and bioaccumulative properties, while evidence suggests dietary intake to constitute a major pathway for human exposure. This study reports on the optimization and validation of an analytical method for the quantification of short- and medium-chained CPs (SCCPs and MCCPs, respectively) using gas chromatography-mass spectrometry (GC-MS) in fats and oils, and the development of liquid chromatography-high resolution mass spectrometry (LC-HRMS) methods for investigation of long chain CP (LCCP) occurrence. Extraction was performed by ultrasonication in n-hexane and dichloromethane followed by sulphuric acid and acidified silica cleanup and fractionation on neutral silica to remove potentially interfering organohalogen contaminants. Quantification of GC-MS results using a chlorine-content calibration procedure was assessed via repeated analysis (n=3) of olive oil fortified with SCCP and MCCP technical mixtures at two concentration levels and spiked lard samples from a recent European Union Reference Laboratory (EURL) interlaboratory study. The average accuracy ranged from 76 to 126% in the olive oil samples and from 57 to 150% in fortified lard, meeting the EURLs acceptability criteria for all tests, while the precision was < 15%. The applicability of the method was demonstrated by analysis of 26 fats and oil samples purchased in Belgium. SCCPs were detected in 31% of samples, ranging < LOQ to 19 ng/g, and MCCPs were present in 85%, ranging < LOQ to 190 ng/g. Each of four samples selected for homologue profiling by LC-HRMS were also found to contain LCCPs. This research demonstrates reliable methods for CP analysis in fats and oils and highlights the potential for contamination of these products by CPs. Fats and oils appear to be substantial contributors to overall human exposure to CPs.
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Jaubert, Jean-Noe¨l, Romain Privat, and Michel Molie`re. "Ethanol and Distillate Blends: A Thermodynamic Approach to Miscibility Issues." In ASME Turbo Expo 2010: Power for Land, Sea, and Air. ASMEDC, 2010. http://dx.doi.org/10.1115/gt2010-22126.
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In the recent years, the quest for an ever wider cluster of sustainable primary energies has prompted an increasing number of attempts to combine the emission sobriety of bio fuels with the energy density advantage of fossil fuels. A number of compositions incorporating hydrocarbons, ethanol and in some cases limited amounts of water have been proposed, especially in the forms of micro emulsions, with a variable success. Indeed due to markedly different physical and chemical properties, ethanol and gasoil are able to blend and form homogeneous solutions only in limited proportion ranges. Indeed, such mixtures often give rise to liquid-liquid equilibrium. A key parameter is thus the Minimum Miscibility Temperature (MMT), i.e. the temperature above which ethanol and gasoil become completely miscible. In fact, commercial gasoils do not constitute a monolithic product but display in the contrary a large span of compositions that influence the stability of these blends. In this context, the LRGP laboratory (Laboratoire Re´actions et Ge´nie des Proce´de´s) has undertaken an investigation program intended to understand the factors underlying the stability of ethanol/gasoil blends. The approach is based on the calculation of the liquid-liquid phase diagrams formed by anhydrous ethanol and a mixture of various hydrocarbons representative of the diesel oil pool using the group contribution concept. Indeed, for correlating thermodynamic properties, it is often convenient to regard a molecule as an aggregate of functional groups; as a result, some thermodynamic properties (heat of mixing, activity coefficients) can be calculated by summing group contributions. In this study, the universal quasichemical functional group activity coefficient (UNIFAC) method has been employed as it appears to be particularly useful for making reasonable estimates for the studied non ideal mixtures for which data are sparse or totally absent. In any group-contribution method, the basic idea is that whereas there are thousands of chemical compounds of interest in chemical technology, the number of functional groups that constitute these compounds is much smaller. Therefore, if we assume that a physical property of a fluid is the sum of contributions made by the molecule’s functional groups, we obtain a possible technique for correlating the properties of a very large number of fluids in terms of a much smaller number of parameters that characterize the contributions of individual groups. This paper shows the large influence exerted by the paraffinic, aromatic and naphthenic character of the gasoil but also the sulfur content of the fossil fraction on the shape of the liquid-liquid phase diagram and on the value of the minimum miscibility temperature.
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Koso, Toru. "Mixing of Matter by a Falling Spherical Particle in a Still Liquid." In ASME/JSME/KSME 2015 Joint Fluids Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/ajkfluids2015-24647.
Full textAbstract:
The mixing of liquid mass caused by a spherical solid particle falling in a still liquid in a pipe was investigated by visualization and noninvasive concentration measurement using a photochromic dye. A spherical particle with diameter of 4.76 mm was dropped in a kerosene-paraffin mixture liquid with a photochromic dye. The photochromic dye was activated by an ultraviolet light and was subjected to the mixing by the particle wake. The falling velocity of particle was changed by using 8 different densities of particle. The effect of the particle Reynolds number on the mixing was investigated for the Reynolds number range from 10 to 2490. The effect of liquid viscosity on the mixing time was also investigated using two liquids having different viscosity. The visualized dye patterns indicated the mixing process depended strongly on the particle Reynolds number. For the Reynolds numbers higher than 300, the particle shed the vortices behind the particle and the dye was mixed isotropically by large-scale vortices. For the Reynolds numbers lower than 300, the dye was drawn straightly by a laminar wake of the particle. The concentration of the mixed dye was measured using the photochromic concentration measuring (PCM) technique to discuss the mass mixing quantitatively. The turbulent diffusion coefficient (TDC) was evaluated for the cases the dye was mixed by the vortices. It was found that the evaluated TDCs showed strong time-dependency, which was attributed to the change in scale and whirling velocity of wake vortices. The maximum TDC depended on the falling velocity regardless of the fluid viscosity. The mixing time depended strongly on the liquid viscosity. The mixing time of the TDC was suggested to be governed by the viscous decay time and expanding time of vortices in the pipe. The amount of dye drift was evaluated for the cases the particle wake was laminar. It was found that the dye drift increased sharply just after the particle passing and then saturated. The final dye drift increased gradually with increasing Reynolds number.
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Privat, Romain, Jean-Noe¨l Jaubert, and Michel Molie`re. "Ethanol and Distillate Blends—A Thermodynamic Approach to Miscibility Issues: Part 2—The Influence of Water." In ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/gt2011-45896.
Full textAbstract:
In recent years, the quest for sustainable primary energies has increased the potential interest of biogenic/fossil fuels mixes. As an example, ethanol is used as a gasoline extender to both partly substitute hydrocarbons and increase octane number while improving vehicle emissions. In a previous paper (GT2010-22126), it has been shown that ethanol and gasoil are able to blend and form homogeneous solutions only in limited proportion ranges, due to their markedly different physical and chemical properties. However the incorporation of small amounts of water in ethanol dramatically decreases this already narrow miscibility domain. Indeed, in function of the temperature, such ternary mixtures often give rise to liquid-liquid equilibria i.e. to two separated phases that are respectively lipophilic and hydrophilic. A key parameter is thus the Minimum Miscibility Temperature, i.e. the temperature above which ethanol, water and gasoil become completely miscible. On another hand, commercial gasoils do not constitute a single product but display worldwide a large range of compositions that influence the stability of these ternary blends. In this context, an investigation program intended to characterize and predict the stability of ternary ethanol + water + gasoil blends has been carried out by the LRGP laboratory (Laboratoire Re´actions et Ge´nie des Proce´de´s). The approach is based on a thermodynamical, theoretical calculation of the liquid-liquid phase diagrams formed by ethanol, water and a mixture of various hydrocarbons representative of the diesel oil pool using the group-contribution concept. The basic idea is that whereas there are thousands of chemical compounds, the number of functional groups that constitute these compounds is much smaller. The work relies on the experimentally verified theory that a physical property of a fluid can be expressed as the sum of contributions made by molecule’s functional groups, which allows correlating the properties of a very large number of substances in terms of a much smaller number of parameters that represent the contributions of individual groups. This work shows the huge influence exerted by the water content of ethanol on the shape of the liquid-liquid phase diagram and on the value of the Minimum Miscibility Temperature (MMT). As seen in our previous paper, the paraffinic, aromatic or naphthenic character of the fossil fraction, also considerably influences the value of the MMT. Calculations were performed with a water content varying between 1 and 10%. This study concludes that the MMT expressed in kelvins is generally multiplied by two when the water content rises from 1 to 10%.