The Experts below are selected from a list of 87 Experts worldwide ranked by ideXlab platform
Zaharaddeen S Gano - One of the best experts on this subject based on the ideXlab platform.
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new tetrapropylammonium bromide based deep eutectic solvents synthesis and characterizations
Journal of Molecular Liquids, 2014Co-Authors: Baba Y. Jibril, Jamil Naser, Farouq S. Mjalli, Zaharaddeen S GanoAbstract:Abstract Deep eutectic solvents are analogues of ionic liquids that are environmentally benign, have a range of desirable liquid properties and are easy to prepare. In this study, new tetrapropylammonium bromide (TPAB)-based deep eutectic solvents (DESs) are introduced. Different hydrogen bond donors (HBDs) — ethylene glycol, triethylene glycol and glycerol were used at different molar ratios of TPAB:HBD (1:2.5–1:5). Effects of temperature and the TPAB:HBD ratios on the DESs were investigated. Solvents of different physicochemical properties and wide liquid ranges with minimum melting point temperatures of 249.75, 253.95 and 257.05 K were obtained for TPAB:ethylene glycol (1:4), TPAB:triethylene glycol (1:3) and TPAB/glycerol (1:3) respectively. The samples were further characterized in the temperature range of 293.15 to 353.15 K and the property ranges measured were density (1.096–1.218 g/cm 3 ), viscosity (6.02–1510.0 cP), surface tension (41.9–53.2 mN m − 1 ), conductivity (167.2–11,500.0 μS cm − 1 ), refractive index (1.4466–1.4908) and pH (4.837–7.290). These demonstrate that the samples have excellent potentials for different applications. Relationships between these properties and temperature were explored. Depending on the property, the effect of temperature was modeled using either simple linear or Arrhenius-based models. The properties of these new DESs could be predicted at different temperatures for potential applications. The potential of tunable properties makes it possible to employ DESs as a reaction Medium, electrochemical Process Medium, solvent and absorbent. Therefore, these properties must be measured and modeled for possible use in Process simulation package databases.
Dongshun Deng - One of the best experts on this subject based on the ideXlab platform.
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new levulinic acid based deep eutectic solvents synthesis and physicochemical property determination
Journal of Molecular Liquids, 2016Co-Authors: Guobing Li, Yaotai Jiang, Dongshun DengAbstract:Abstract Recently, deep eutectic solvents (DESs) have emerged as new and inexpensive ionic liquids (ILs) analogues. They possess attractive and similar solvent properties with traditional ILs. In present work a serials of DESs were prepared by pairing renewable levulinic acid (LA) as hydrogen donor with seven quarternary ammonium salts as hydrogen acceptor. The samples were further characterized in the temperature ranging from 293.15 to 333.15 K at atmospheric pressure with the results of density (0.99891–1.17735 g cm− 3), dynamic viscosity (12.70–376.50 mPa s), electrical conductivity (0.35–8.27 mS cm− 1), and refractive index data (1.44384–1.47273). The temperature dependence of these properties was explored and correlated with simple linear or Vogel-Fulcher-Tamman (VFT) models. The volume expansivities (β), molar volumes (Vm), molar refractions (Rm), and free volumes (fm) values have been calculated on the basis of density and refractive index data. The active energy of viscosity (Eη), molar electric conductivity (Λ), and ionicity were also determined. Partial structure-property relationship for DESs was also investigated. The tunable properties make DESs as a potential reaction Medium, electrochemical Process Medium, solvent and absorbent. Therefore, the determination and correlation can provide relevant information for the engineering and industrial applications of DESs.
Andrew Vince - One of the best experts on this subject based on the ideXlab platform.
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particle scale modelling of the multiphase flow in a dense Medium cyclone effect of Medium to coal ratio
POWDERS AND GRAINS 2013: Proceedings of the 7th International Conference on Micromechanics of Granular Media, 2013Co-Authors: Kaiwei Chu, Jiang Chen, Andrew VinceAbstract:The effect of solids loading ratio or the Medium-to-coal (M:C) ratio is the most important operational parameter of the Dense Medium Cyclones (DMC) that are widely used in the coal industry to upgrade the run-of-mine coal by separating gangue from product coal. However, its effect is still not well understood so far, since the flow pattern within a DMC is complicated due to the size and density distributions of the feed and Process Medium solids, and the turbulent vortex formed. Recently, it is shown that the particle-laden flow in a DMC can be modelled by the so-called combined Computational Fluid Dynamics (CFD) and Discrete Element Method (DEM) (CFD-DEM) in which the flow of coal particles is modelled by DEM which applies Newton’s laws of motion to individual particles and that of Medium flow by the conventional CFD which solves the local-averaged Navier-Stokes equations, allowing consideration of particle-fluid mutual interaction and particle-particle collisions. In this work, the effect of Medium-to-coal (M:C) ratio is studied by a two-way coupling CFD-DEM approach for a large diameter DMC. The flow structure, and particle-particle and particle-fluid forces are analysed to understand the fundamentals governing this effect. The results suggest that the solids volume fraction of 20% (or M:C ratio of 4 by volume) is a critical point for the DMC performance under the conditions considered.
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cfd dem modelling of multiphase flow in dense Medium cyclones
Powder Technology, 2009Co-Authors: Kaiwei Chu, Bo Wang, Aibing Yu, Andrew VinceAbstract:Abstract Dense Medium cyclone (DMC) is a high-tonnage device that is widely used to upgrade run-of-mine coal in coal preparation. It is simple in design but the flow pattern within it is complex due to the size and density distributions of the feed and Process Medium solids, and the turbulent vortex formed. This paper presents a mathematical model to describe this flow system by means of combining Discrete Element Method (DEM) with Computational Fluid Dynamics (CFD). The DEM is used to model the motion of discrete particles by applying Newton's laws of motion. The CFD is used to model the motion of slurry Medium by numerically solving the local-averaged Navier–Stokes equations facilitated with the Volume of Fluid (VOF) and Mixture multiphase flow models. The approach is shown to be able to reproduce typical flow phenomena in DMCs. The effect of Medium-to-coal ratio and the so-called “surging” phenomenon are analyzed. An attempt is made to explain the observed phenomena in terms of particle–particle, particle–fluid and particle–wall interaction forces. The approach offers a convenient way to examine the flow and performance of DMC in relation to geometric, material and operational conditions.
Baba Y. Jibril - One of the best experts on this subject based on the ideXlab platform.
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new tetrapropylammonium bromide based deep eutectic solvents synthesis and characterizations
Journal of Molecular Liquids, 2014Co-Authors: Baba Y. Jibril, Jamil Naser, Farouq S. Mjalli, Zaharaddeen S GanoAbstract:Abstract Deep eutectic solvents are analogues of ionic liquids that are environmentally benign, have a range of desirable liquid properties and are easy to prepare. In this study, new tetrapropylammonium bromide (TPAB)-based deep eutectic solvents (DESs) are introduced. Different hydrogen bond donors (HBDs) — ethylene glycol, triethylene glycol and glycerol were used at different molar ratios of TPAB:HBD (1:2.5–1:5). Effects of temperature and the TPAB:HBD ratios on the DESs were investigated. Solvents of different physicochemical properties and wide liquid ranges with minimum melting point temperatures of 249.75, 253.95 and 257.05 K were obtained for TPAB:ethylene glycol (1:4), TPAB:triethylene glycol (1:3) and TPAB/glycerol (1:3) respectively. The samples were further characterized in the temperature range of 293.15 to 353.15 K and the property ranges measured were density (1.096–1.218 g/cm 3 ), viscosity (6.02–1510.0 cP), surface tension (41.9–53.2 mN m − 1 ), conductivity (167.2–11,500.0 μS cm − 1 ), refractive index (1.4466–1.4908) and pH (4.837–7.290). These demonstrate that the samples have excellent potentials for different applications. Relationships between these properties and temperature were explored. Depending on the property, the effect of temperature was modeled using either simple linear or Arrhenius-based models. The properties of these new DESs could be predicted at different temperatures for potential applications. The potential of tunable properties makes it possible to employ DESs as a reaction Medium, electrochemical Process Medium, solvent and absorbent. Therefore, these properties must be measured and modeled for possible use in Process simulation package databases.
Guobing Li - One of the best experts on this subject based on the ideXlab platform.
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new levulinic acid based deep eutectic solvents synthesis and physicochemical property determination
Journal of Molecular Liquids, 2016Co-Authors: Guobing Li, Yaotai Jiang, Dongshun DengAbstract:Abstract Recently, deep eutectic solvents (DESs) have emerged as new and inexpensive ionic liquids (ILs) analogues. They possess attractive and similar solvent properties with traditional ILs. In present work a serials of DESs were prepared by pairing renewable levulinic acid (LA) as hydrogen donor with seven quarternary ammonium salts as hydrogen acceptor. The samples were further characterized in the temperature ranging from 293.15 to 333.15 K at atmospheric pressure with the results of density (0.99891–1.17735 g cm− 3), dynamic viscosity (12.70–376.50 mPa s), electrical conductivity (0.35–8.27 mS cm− 1), and refractive index data (1.44384–1.47273). The temperature dependence of these properties was explored and correlated with simple linear or Vogel-Fulcher-Tamman (VFT) models. The volume expansivities (β), molar volumes (Vm), molar refractions (Rm), and free volumes (fm) values have been calculated on the basis of density and refractive index data. The active energy of viscosity (Eη), molar electric conductivity (Λ), and ionicity were also determined. Partial structure-property relationship for DESs was also investigated. The tunable properties make DESs as a potential reaction Medium, electrochemical Process Medium, solvent and absorbent. Therefore, the determination and correlation can provide relevant information for the engineering and industrial applications of DESs.