Sharif Digital Repository

Oil contamination can affect the mechanical and physical properties of soil, making its reuse a challenge. In the present study, the effect of kerosene contamination on two types of poorly graded sand (S1 and S2) was investigated. Geotechnical tests for compaction, direct shear and constant head permeability were conducted. The compaction test revealed that dry density increased at a 3% and 6% kerosene content for S1 and S2 soil, respectively. A further increase in kerosene content caused the dry density to decrease for both S1 and S2. The optimum moisture content of kerosene-contaminated soil samples decreased. The direct shear test showed that kerosene contamination increased cohesion and... 

Rhenium distribution between Tri-n-butyl phosphate (TBP) dissolved in kerosene and sulfuric aqueous media is investigated under different temperatures, acidities, and TBP concentrations. Results show an exothermic extraction reaction with a distribution factor that decreases with the increase of the temperature and increases with the increase of the acidity and the TBP concentration. The stoichiometry of the reaction indicates neutralization of 1 mole of H+ with 1 mole of ReO4- and solvating of a neutral molecule with four molecules of TBP. The structure of the complexes formed is, therefore, 4TBP · HReO4. The apparent Gibbs free energy of the formation of 4TBP · HReO4 from TBP, ReO4-, and... 

An experimental study was conducted on the desulfurization of non-hydrotreated kerosene with oxidation followed by liquid-liquid extraction. Various types of solvents including acetonitrile, methanol, and ethanol have been examined in the extraction of oxidized sulfur-containing compounds of kerosene. The performance of these solvents has been carefully examined and compared. It was found that their performance follows the order: acetonitrile > methanol > ethanol. The effects of number of extraction stages and solvent to kerosene ratio on the desulfurization and recovery of kerosene have been investigated. The experimental results show that for all three solvents, solvent/kerosene ratio and... 

This study examines different soot sub-models to simulate the soot nano-aerosol formation in turbulent kerosene-surrogate flames. The examinations are carried out at three different elevated pressures. We use a two-equation soot model considering the aerosol dynamics and chemistry of soot nano-particles, i.e. nucleation, coagulation, surface growth, and oxidation. Four different soot sub-models are used to predict the structures of pressurized flames. These structures are then compared with each other as well as the data collected by experiment. Our findings indicate that the acetylene soot-inception sub-model performs poorly in prediction of the flames’ structures at different elevated... 

In this article, droplet size and its distribution along a pulsed liquid-liquid extraction column, is studied where SiO2 nanoparticles with concentrations of 0.01, 0.05 and 0.1vol.% and different hydrophobicities are applied to the dispersed phase. Using ultrasonication, nanoparticles were dispersed in kerosene as the base fluid. Nanofluids' stability was ensured using a UV-vis spectrophotometer. Some 22,000 droplets were measured by photographic technique and results were compared with systems containing no-nanoparticles (Water-Acetic acid-Kerosene). Addition of nanoparticles changed the droplet shape from ellipsoidal to spherical. Also, there was a marked influence on droplet breakage and... 

Three-dimensional thermo-hydrodynamic analysis of gas turbine combustion chambers is of great importance in the power generation industry to achieve higher efficiency and reduced emissions. However, it is prohibitive to use a comprehensive full-detailed mechanism in their simulation algorithms because of the huge CPU time and memory space requirements. Many reduction approaches are available in the literature to remedy this problem. Here a new approach is presented to reduce large detailed or skeletal mechanisms of oxidation of hydrocarbon fuels to a low-cost skeletal mechanism. The method involves an integrated procedure including a Sensitivity Analysis (SA) and a procedure of Gradual... 

In this study, we simulate the thermal behavior of a kerosene-fired oxy-fuel burner. To do this, the velocity of pure oxygen is suitably changed to achieve variable-mixing of fuel and oxidizer. Before the simulation procedure, a number of primitive steps are taken to evaluate the selected numerical approaches and methods. In other words, we simulate the turbulent non-premixed kerosene–air flame confined in a combustor and compare the achieved numerical solutions with the available measurements to appraise the validity of achieved solutions. The comparisons are mainly provided for the predicted flame structure. The comparison indicates that the achieved numerical solutions are accurate enough... 

A simple chemisorption method was used to graft on the surface of MWCNTs and Graphene nanoparticles to prepare stable kerosene-based MWCNTs and Graphene nanofluids. The prepared nanofluids remained stable for more than five months and no sedimentation was observed. Regarding the effect of temperature on thermo-physical properties, it was observed that although increasing nanoparticle concentration led to an increase in the fluid viscosity, it was negligible enough at lower nanoparticle loading. Moreover, adding nanoparticles to the base fluid did not have any noticeable impact on the fluid density which was negligible even at high concentrations. The thermal conductivity improvement was... 

In this study, solvent extraction method has been utilized for separation of molybdenum and vanadium from nitrate solution by utilizing coupling of acid and solvating extractants (D2EHPA and TBP extractants). The outcomes demonstrated that synergistic solvent extraction improves stability of formatted complexes for transfer to the organic phase. The main parameters such as pH value, concentration of extractants, NH4OH concentration as the stripping agent and contact time were optimized at 0.4, 15% (v/v) D2EHPA, 10% (v/v) TBP, 2 M and 30 min, respectively. The maximum separation factor of 24.84 was obtained with a new synergistic mixture of D2EHPA and TBP diluted with kerosene. According to... 

The combustion of kerosene spray under hot-diluted conditions and conventional conditions was experimentally investigated. By examining flame photographs, chemiluminescence images, and in-field temperature measurements, the separate effect of different variables including oxygen concentration, temperature and velocity of the co-flowing air, fuel flow rate and injection pressure, and eventually the type of spray nozzle on multiple parameters such as flame stability, structure, luminosity, temperature field, and qualitative CH radical distribution, as well as HCO and NO2 with lower precision, in the reaction region, have been studied. It was observed that an increment in injection pressure and... 

This work numerically studies the effects of inlet air and fuel turbulators on the thermal behavior of a combustor burning the jet propulsion (JP) (kerosene-surrogate) fuel and its resulting pollutants emission including the nanoparticulate soot aerosols and aromatic compounds. To model the soot formation, the method employs a semi-empirical two-equation model, in which the transport equations for soot mass fraction and soot number density are solved considering soot nanoparticles evolutionary process. The soot nucleation is described using the phenyl route in which the soot is formed from the polycyclic aromatic hydrocarbons. Incorporating a detailed chemical mechanism described by 200... 

A gaseous-kerosene/air turbulent nonpremixed flame in a combustion chamber is simulated to investigate the effects of fuel-injector cone-angle on the pollutions of soot nano-particles, carbon monoxide, and carbon dioxide. We use a two-equation soot model in our studying, consider a detailed chemical scheme consisting of 121 species and 2613 elementary reactions, use the flamelet model, employ the presumed-shape probability density functions PDFs, apply the two-equation κ-ε turbulence model with round-jet corrections, and take into account the radiation effects assuming optically-thin flame in our numerical modeling. This research concentrates on investigating the impacts of kerosene injector... 

A novel type of four-impinging-jets reactor (FIJR) has been proposed and tested successfully for the oxidative desulfurization of kerosene as a typical light fuel oil. The FIJR is characterized by a high-intensity mixing chamber located at the bottom of the reactor and equipped with four impinging jets. The influences of various operating and design parameters such as feed flow rate, internozzle distance, jet diameter, and jet Reynolds number on the performance of the FIJR have been carefully investigated. As a result of both the impinging process and shear forces exerted on the phases, the rate of desulfurization in FIJR increased significantly compared to that obtained by a conventional... 

Feeding a laboratory furnace with the gaseous kerosene, the resulting two-phase turbulent flame is simulated to study the effects of injecting soot nano-particles into the inflow air on the emissions of smoke aerosol, CO, and CO2species pollutants, and the resulting radiation heat transfer. We use our past experiences in aerosol modeling of soot nano/micro particles in turbulent nonpremixed flames burning simple hydrocarbon fuels and extend them to study the effects of injecting gaseous kerosene on the aforementioned parameters. To model the evolutionary process of soot nanoparticle formation, i.e., the nucleation, coagulation, surface growth, and oxidation, we employ a two-equation soot... 

Application of the colloidal gas aphrons (CGAs) in minimizing formation damage by plugging pore mechanism is now wildly accepted due to numerous successful field experience. One of the pivotal factors which affects the pore blockage ability of micro-bubbles is their stability. This experimental study tries to investigate the possible synergistic effect of nanoparticles on improving the stability and other properties of non-aqueous CGA drilling fluids, in both bulk and porous media. In particular, two types of hydrophobic nanoparticles including silicon dioxide nanopowder coated with 2 wt% Silane and nanoclay, in presence of a treated version of bentonite (Bentone 34) as a stabilizer and... 

Hybrid nanofluids are new and most fascinating types of fluids that involve superior thermal characteristics. These fluids exhibit better heat-transfer performance as equated to conventional fluids. Our concern, in this paper, is to numerically interpret the kerosene oil-based hybrid nanofluids comprising dissimilar nanoparticles like silver (Ag) and manganese zinc ferrite (MnZnFe2O4). A numerical algorithm, which is mainly based on finite difference discretization, is developed to find the numerical solution of the problem. A numerical comparison appraises the efficiency of this algorithm. The effects of physical parameters are examined via the graphical representations in either case of... 

The combustion of kerosene spray under hot-diluted conditions and conventional conditions was experimentally investigated. By examining flame photographs, chemiluminescence images, and in-field temperature measurements, the separate effect of different variables including oxygen concentration, temperature and velocity of the co-flowing air, fuel flow rate and injection pressure, and eventually the type of spray nozzle on multiple parameters such as flame stability, structure, luminosity, temperature field, and qualitative CH radical distribution, as well as HCO and NO2 with lower precision, in the reaction region, have been studied. It was observed that an increment in injection pressure and... 

Comprehensive two-dimensional gas chromatography and flame ionization detection combined with unfolded-partial least squares is proposed as a simple, fast and reliable method to assess the quality of gasoline and to detect its potential adulterants. The data for the calibration set are first baseline corrected using a two-dimensional asymmetric least squares algorithm. The number of significant partial least squares components to build the model is determined using the minimum value of root-mean square error of leave-one out cross validation, which was 4. In this regard, blends of gasoline with kerosene, white spirit and paint thinner as frequently used adulterants are used to make...