Separation of binary mixtures by pervaporation and reverse osmosis / Separação de misturas binarias por pervaporação e osmose inversa

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

In this work, the modelling and simulation of pervaporation and reverse osmosis processes for binary mixtures were carried out. The development of prediction methodologies for process variables of pervaporation and reverse osmosis without the necessity of experimental data was the general guideline followed; the experimental data used in these methodologies were the fundamental properties of pure components of feed. Based on the literature review for available models for pervaporation process, a prediction methodology according to the solution-difusion model was choosen and developed. The inicial step for the methodology elaboration was the development of a software for sorption composition determination in the membrane, based on the UNIQUAC model and UNIFAC group contribution method, both suitable for polymer applications. The software was validated applying it forideal and non-ideal systems on thermodynamic viewpoint. The results obtained according to the UNIQUAC model agreed well with experimental data; in the case of the results obtained by the UNIFAC method when applied for organic solvents, it was obtained a good agreement with experimental data, but, on the other hand, for the water, the results showed that the model must be improved. In the second step of methodology development, the study of the prediction of the diffusion coefficient in the membrane according Fick and Maxwell-Stefan approaches, the determination of models parameters, the validation of the prediction method with experimental data and a parametric sensitivity analysis were carried out. The results agreed well with experimental data. So, using the sorption compositions and diffusion coeficients calculated, it was developed a software for pervaporation prediction; the software was applied for some cases of literature. It was also studied the application of pervaporation to phenol-water system using poly(dimethylsiloxane) as selective barrier. The results agreed well with available experimental data and showed that a best selectivity and separation performance were achieved for phenol concentration lesser than 0.2% molar in the feed side. The final step of this work was the development of a software for simulation of reverse osmosis process based on a mecanical-statistical model. By using the model parameters, the rejection and permeate flux of ethanol-water mixture were predicted in a poliamide membrane. The diffusion coefficient of Maxwell-Stefan in high pressure was predicted and used in the reverse osmosis simulation

ASSUNTO(S)

separação (tecnologia) simulation mathematical models reverse osmosis simulação (computadores) separação de membrana pervaporation modeling modelos matematicos osmose solution-diffusion model misturas

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