Kinetics of static crystallization of durene

The boiling points of tetra-methyl benzene are very close,which is difficult to separate by distillation.But the differences of melting points in-between isomers are quite distinctive.Therefore,the static melt crystallization is feasible to separate and purify durene from its isomers.Considering the change of surface temperature between solid and liquid phase with the coolant temperature,the dynamics of static crystallization is studied by analytic iteration method and verified by experiments.The nonlinear least square method is applied to estimate the combined dynamic parameter by fitting the experimental data of isothermal crystallization and the relationship between dynamic parameter and coolant temperature is obtained by fitting of a polynomial.The results were used to simulate the crystal growing during nonisothermal crystallization process and the calculated results fitted well with experimental results,which indicated that the model can predict the growing of the crystalline layer very well.