| Solid particles, which can enhance the gas-liquid mass transfer, have attractedgreat attention from the domestic and foreign scholars and got lots of researchfindings. However, the process and mechanisms of solid particles enhancinggas-liquid mass transfer, which is one of the focuses in the gas-liquid mass transferresearch subjects, is still to be further explained. The purpose of this paper is toinvestigate and analyze the vapor-liquid equilibria of the binary systems in thepresence of micron particles and nanoparticles, so as to lay a foundation for thefurther investigation on gas-liquid mass transfer with the nanoparticles.In order to investigate and analyze the mechanism of the nanoparticles enhancinggas-liquid mass transfer, it is indispensable to study the phase equilibrium. On thebasis of determining the headspace parameters and chromatographic conditions ofethanol-water, ethanol-ethyl acetate, acetic acid-ethyl acetate and hexane-heptane, thevapor-liquid equilibrium(VLE) of ethanol-water, ethanol-ethyl acetate, aceticacid-ethyl acetate and hexane-heptane binary systems in the absence and presence ofmicron particles and nanoparticles were determined by using the headspce gaschromatography, and investigated some factors such as pore size, weight, propertiesof micron particles and solvent properties that affect the VLE of binary systems in thepresence of micron particles. The results show that the micron particles hadsignificant effect on vapor-liquid equilibria of the considered binary systems withcorresponding polarity. If a binary system is the azeotrope, the azeotrope point wouldbe shifted or broken in the presence of micron particles with corresponding polarity.However,0.01g and0.1g of nanoparticles had no effect on the vapor-liquid equilibriaof binary systems considered in this work. In addition, the alteration of thevapor-liquid equilibria of binary systems decreased with increasing the pore size ofmicron particles, and that increased with increasing the weight of micron particles andremained stable beyond the maximum amount. And the types of micron particles, theproperties of micron particles and solvents also had a certain effect on thevapor-liquid equilibria of binary systems. Finally, the mathematical model of the phase equilibrium among three-phase wasestablished initially, according to some basic assumptions. The theories of phaseequilibria and adsorption characteristics of nanoparticles were used to explain thealteration in the VLE of binary systems in the presence of solid particles with certainadsorption capacity. The vapor-liquid equilibria of binary systems in the presence ofmicron particles are altered, because the pores of micron particles can selectivelyadsorb the component which has much smaller molecular critical diameter than thepores of micron particles. The pore sizes of nanoparticles are smaller than themolecular critical diameter of any one component from the binary solutions and itspores are less than the micron particles, so the nanoparticles have no effect on thevapor-liquid equilibria of binary systems. |
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