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Multicomponent Mixtures (multicomponent + mixture)
Selected AbstractsCFD Simulation of Multicomponent Mixture of Ethanol and Glycerol in Stirred SBR with Anchor Type ImpellerCHEMIE-INGENIEUR-TECHNIK (CIT), Issue 8 2005L. Abu-Farah Dipl.-Ing. No abstract is available for this article. [source] SHELF LIFE OF FRESH NOODLES AS AFFECTED BY THE FOOD GRADE MONOLAURIN MICROEMULSION SYSTEMJOURNAL OF FOOD PROCESS ENGINEERING, Issue 5 2008XIAOWEI FU ABSTRACT Food grade monolaurin (the glycerol monoester of lauric acid) microemulsions (MMEs) based on multicomponent mixtures and the effects of MMEs on the shelf life of fresh noodles were studied. A microemulsion system consisting of monolaurin (M), surfactants (Tween 20 and Tween 80, Wenzhou Qingming Chemical Engineering Company, Wenzhou, Zhejiang, China ) and cosurfactant (pentanol and dodecanol) dispersed in distilled water was used. The influence of surfactants on the phase behavior was studied in this article. Subsequently, two MMEs with large oil in water regions have demonstrated the enhanced antimicrobial activities against Bacillus subtilis, Escherichia coli, Aspergillus niger and Penicillium digitatum, compared to monolaurin (M) alone. In addition, the shelf life of fresh noodles prepared with monolaurin (M) alone was about 4 days, whereas MMEs extended shelf life by 10 days at least when stored at 37C. PRACTICAL APPLICATIONS The effect of monolaurin microemulsion (MME) as antimicrobial agents in foods, especially those neutral foods such as noodles, is obvious, and MME has demonstrated a much longer shelf life of fresh noodles than M alone. In addition, for those neutral foods other than fresh noodles, the application of MMEs can also be studied. [source] Unified model for nonideal multicomponent molecular diffusion coefficientsAICHE JOURNAL, Issue 11 2007Alana Leahy-Dios Abstract Multicomponent diffusion is important in a variety of applications. In order to calculate diffusion flux, molecular diffusion coefficients are required, where fluid nonideality and the multicomponent nature of the mixture have a significant effect. A unified model for the calculation of diffusion coefficients of gas, liquid and supercritical states of nonpolar multicomponent mixtures is presented. A new correlation is proposed for the binary infinite dilution-diffusion coefficients. The generalized Vignes relation is used in multicomponent mixtures. Nonideality is rigorously described by the fugacity derivatives evaluated by the volume-translated Peng-Robinson equation of state. Predictions for highly nonideal gas and liquid multicomponent mixtures demonstrate the reliability of the proposed methodology. © 2007 American Institute of Chemical Engineers AIChE J, 2007 [source] A dual extremum principle in thermodynamics ,AICHE JOURNAL, Issue 8 2007Alexander Mitsos Abstract Phase equilibria of multicomponent mixtures are considered and a reinterpretation of the Gibbs tangent plane stability criterion is proposed via Lagrangian duality. The starting point is the natural primal problem of minimizing the Gibbs free energy subject to material balance. The stable phase split is the solution of the corresponding dual problem, providing a necessary and sufficient dual extremum principle. Only in the absence of duality gap is the physical phase split also the solution of the primal problem. The only requirements are continuity of the Gibbs free energy and the trivial requirement that each species is present in the overall composition. The number of phases is permitted to be infinite, and does not need to be known a priori. No assumption is made on the presence of all species in all phases. Case studies are presented based on the NRTL and UNIQUAC activity coefficient model. © 2007 American Institute of Chemical Engineers AIChE J, 2007 [source] Multicomponent thermally coupled systems of distillation columns at minimum refluxAICHE JOURNAL, Issue 12 2001Zbigniew T. Fidkowski A method for calculating the minimum vapor flow in a ternary fully thermally coupled system of distillation columns was developed earlier by Fidkowski and Krolikowski. This method was developed further for fully thermally coupled systems separating four or more components. For multicomponent mixtures having constant relative volatilities and equal latent heats, the method leads to the identification of all of the minimum vapor flow rates in each distillation column that provide the same overall minimum heat duty in the reboiler. The quaternary fully coupled system of columns requires less heat energy than conventional configurations. These savings are often on the order of 20,50%. [source] Kinetics of separating multicomponent mixtures by nondispersive solvent extraction: Ni and CdAICHE JOURNAL, Issue 4 2001Inmaculada Ortiz A model for nonsteady metals separation using nondispersive solvent extraction presented explicitly accounts for selective separation of multicomponent solutions and concentration of separated components in a back-extraction phase. The separation process comprises extraction and back-extraction steps carried out in two different hollow-fiber modules, connected through the organic phase, together with three homogenization tanks. The model is based on a set of coupled differential equations describing mass balances of metallic solutes in the fluid phases. To be applied in its simplest form, it requires the knowledge of three characteristic parameters, two parameters related to the chemical reactions, and one mass-transport parameter. The latter describes the mass-transport rate through pores of the hollow-fiber membrane filled with the organic phase. The mathematical model was checked against the kinetic results of the separation of Cd/Ni mixtures working with high-concentration solutions and obtaining the characteristic parameters of this system. [source] Molecular and macroscopic modeling of phase separationAICHE JOURNAL, Issue 10 2000Fernando A. Escobedo Recently proposed pseudoensemble Monte Carlo methods are extended in this work to map out diverse phase diagrams (projections of the phase-coexistence hypersurface) of multicomponent mixtures required to characterize fluid-phase equilibrium phenomena and to design separation processes. Within the pseudoensemble framework, the macroscopic models of different equilibrium processes can be readily integrated to the mathematical constraints that specify the thermodynamic state of the system. The proposed Monte Carlo methods allow, for example, the simulation of isopleths and cloud-point lines to compare experimental to simulation data and to test molecular force fields. Applications of this approach include the study of retrograde phenomena in a model natural-gas mixture through simulation of dewlines and coexistence lines at constant vaporization fraction. As demonstrated, pseudoensemble simulations can also be used to generate the thermodynamic data necessary to solve problems encountered in continuous and discontinuous distillation processes. [source] Solving multicomponent chiral separation challenges using a new SFC tandem column screening toolCHIRALITY, Issue 3 2007Christopher J. Welch Abstract A tool for improved tandem column chiral supercritical fluid chromatography (SFC) method development screening was prepared by modification of a commercial analytical SFC instrument with two different software-controllable, six position high-pressure column selection valves, each controlling a bank of five different columns and a pass through line. The resulting instrument, which has the ability to screen 10 different individual columns and 25 different tandem column arrangements, is a useful tool for facilitating the screening of tandem column SFC arrangements for separation of complex mixtures of stereoisomers or other multicomponent mixtures. Strategies for optimal use of the instrument are discussed, and several examples of the use of the instrument in developing tandem SFC methods for resolution of multicomponent mixtures are presented. Chirality, 2007. © 2006 Wiley-Liss, Inc. [source] | ||||||||||