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Study On Liquid-liquid Equilibrium And Engineering Application

Posted on:2013-02-24Degree:MasterType:Thesis
Country:ChinaCandidate:W T LiFull Text:PDF
GTID:2211330371954388Subject:Chemical Engineering
Abstract/Summary:PDF Full Text Request
In this paper, several liquid-liquid equilibrium(LLE) data were measured by background of CPL process. According to the conditions of phase equilibrium, the thermodynamic model was established to correlate LLE data and the parameters of model were obtained by optimization method. Based on the parameters, prediction data of LLE were calculated in ternary extraction system. According to the compare with experimental result, it was found that the NRTL used for LLE could provide good predictions. The extraction process of CPL was simulated with Aspen plus. Research on the method of scale-up continuous countercurrent extraction column of CPL process.At first, the LLE data were measured for the ternary systems of oximation extraction column, ammonium sulfate extraction column and crude product extraction column in different temperatures. The data of density, viscosity and interfacial tension were also measured for these extraction columns. Based on phase equilibrium conditions, the objective function was established to correlate the LLE data. Because the solution of the global optimization is difficult to obtain for the non-linear equations, several measurements had been employed, such as the minimization of Gibbs free energy of multi-component systems, several initial guesses for objective function and Quasi-Newton algorithm. The parameters of the thermodynamics model were guaranteed to be near the solution of global optimization. The results showed that NRTL used for LLE could provide a good prediction.Then, extraction process were simulated with thermodynamic model. The extraction process of CPL was simulated with Aspen plus, and the data obtained before were used as the property parameters of process simulation software. The results of simulation showed that the parameters of NRTL were suitable for the ternary system of industrial extraction column.Last, the method for scale-up of extraction column were studied. Based on the original industrial extraction column, calculated the structural parameters of packed extraction column and rotating disc column in the new operating conditions by the axial diffusion model and a series of empirical formula. Industrial operation data show, these designed columns were correct.
Keywords/Search Tags:Caprolactam, Liquid-liquid equilibrium, Simulation, NRTL, Aspen plus
PDF Full Text Request
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