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Research On Solid-Liquid Phase Equilibrium Of Vanilla Organic Compounds

Posted on:2016-07-20Degree:MasterType:Thesis
Country:ChinaCandidate:J H LiFull Text:PDF
GTID:2191330473461870Subject:Chemical Engineering and Technology
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Vanilla compounds is a kind of important chemical products in our daily life, widely used in food, medicine, cosmetics and other industries. Therefore, this research is mainly aiming at the solubility of ethyl vanillin and vanilla ethanone which are not yet reported in the literature. The research can also provide a theoretical basis and basic data for industrial production.This study takes the ethyl vanillin and vanilla ethanone as the research objects. First of all, building the device of gravimetric method. The solubility of ethyl vanillin in ethyl acetate, water, benzene, methyl acetate, isobutanol, n-butanol, isopropanol, ethanol, propanol, acetone and binary mixtures of water+ethanol about nine concentration gradients in the range from 293.15K to 308.15K, the solubility of vanilla ethanone in water, methanol, benzene, methyl acetate, isobutanol, n-butanol, isopropanol, ethanol, propanol, acetone and binary mixtures of water+ ethanol about nine concentration gradients in the range from 293.15K to 323.15K, are determined. Draw the solubility curve of solutes in pure and mixture solvents, and analyse the trend of solubility curves. The solubility data are correlated with the thermodynamic model Apelblat, Van’t Hoff,λh, Wilson, NRTL, and Uniquac, finding the optimal relevance model.Secondly, physical characterization of the two vanilla compounds are determined. The melting point and melting enthalpy are measured by differential scanning calorimeter. Using X ray diffraction, the solute before and after dissolution are same, confirming that the solute structure do not change.Finally, by using the improved Jouyban-Acree model, optimizing the associated parameter, it is applied to correlate the two vanilla compounds in mixed solvents.In pure solvents, ethyl vanillin is correlated with Van’t Hoff model with average relative deviation of 0.260%, to fit the minimum, the maximum is Wilson equation,1.878%; vanilla ethanone is correlated with Van’t Hoff model with average relative deviation of 1.253%, to fit the minimum, the maximum is Uniquac equation,3.488%. In mixed solvents, ethyl vanillin is correlated with Van’t Hoff model with average relative deviation of 0.505%, to fit the minimum, the maximum is NRTL equation,8.751%; vanilla ethanone is correlated with Van’t Hoff model with average relative deviation of 1.212%, to fit the minimum, the maximum is Wilson equation,8.053%.The innovation of this paper, is made Jouyban-Acree model connect with Van’t Hoff and Apelblat equation, obtaining Jouyban-Van’t Hoff and Jouyban-Apelblat model.The two kinds of improved Jouyban-Acree models are used to correlate the solubility of ethyl vanillin and vanilla ethanone in mixed solvents. The results show that:the correlation of Jouyban-Van’t Hoff model is better than the Jouyban-Apelblat model, illustrating that the more correlation parameters are associated with, the effects are not necessarily better, depending on the model theory.
Keywords/Search Tags:ethyl vanillin, vanilla ethanone, gravimetric method, solubility, correlation model, modified Jouyban-Acree model
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