Study On Vapor Liquid Equilibrium Of Pinene System

In order to provide theoretic fundament and basic data of vapor liquid equilibrium for separation and purification of turpentine system, research contents, research methods, research results and conclusions were mainly summarized as the following aspects:Firstly, an experimental facility which was composed of vapor liquid binary Rose kettle with principle of vapour-liquid alternative circulation was designed to measure the vapor liquid equilibrium data of pinene system. The vapor liquid equilibrium data of α-pinene+β-pinene, α-pinene+β-cymene, β-pinene+ρ-cymene and α-pinene+β-pinene+ρp-cymene at the pressure of 46.7kPa and 66.7kPa were determined by the facility. The experimental data were satisfied the thermodynamic consistency by means of Herington method.Secondly, In order to get an efficient optimization algorithm for obtaining the model parameters of vapor liquid equilibrium, a new adaptive cuckoo search algorithm (ACS) based on Cuckoo Search algorithm (CS) was founded. The ACS algorithm overcome the problem of weak local search ability of CS algorithm, in addition ACS algorithm have powerful ability of global optimization as the same as CS algorithm. Test results indicate that whether the unimodal function, or the multimodal functions, whether the low-dimensional function or the high-dimensional function, the global search capability and local search ability of ACS algorithm are better than CS algorithm.Thirdly, the sum of the squares of the relative deviation between experimental data and the model calculation value of Vapor liquid equilibrium data for a-pinene+β-pinene, α-pinene+ρ-cymene and β-pinene+ρ-cymene were provided to be as the the objective function. The ACS algorithm was used to obtain the binary parameters. Wilson model, NRTL model and UNIQUAC model were used to correlate and calculate the vapor liquid equilibrium data of there binary systems. The calculation results show that the average absolute deviations of vapor phase composition between experimental values and calculated values were less than 0.0022, the average absolute deviations of bobble point temperature between experimental values and calculated values were less than 0.55K. Prediction accuracy is significantly higher than simulation results by UNIFAC model. Those indicate that the three above models and ACS algorithm is efficient and reliableFinally, the binary interaction parameters extended to predict vapor liquid equilibrium data of α-pinene+β-pinene+β-cymene. The results show that the NRTL model predicted results are the best. The average absolute deviations of vapor phase composition between experimental values and calculated values were less than 0.0045. The average absolute deviations of bobble point temperature between experimental values and calculated values were less than 0.46K. Wilson model and UNIQUAC model predicted results is a bit bad than NRTL model.In conclusion, experimental method for determination of the pinene system is feasible and the experiment results are reliable. The optimization ability of ACS algorithm is strong. Prediction accuracy of Wilson model, the NRTL and UNIQUAC models to predict the vapor liquid equilibrium data of binary system of pinene is significantly higher than the group contribution of UNIFAC model predicted results. Precision accuracy of NRTL model to predict the vapor liquid equilibrium data of ternary system of pinene is better than that of Wilson model and UNIQUAC model prediction results. Experiment results and simulation results can provide reliable thermodynamic basic data for separation and purification of turpentine system.