Simulate Of Crystallization Process Of HMX

Crystallization as a solid-liquid separation process, is widely used in the chemical industry. The transfer of the solute molecules from the continuous phase to the solid phase is governed by nucleation and growth rate, which are important basis for the design and performance of the industrial crystallizers. In order to obtain the data, the appropriate crystallization model is expected to develop. However, the various fundamental mechanisms involved in crystallization are so complex and unpredictable that the mathematic description of crystallization process is relatively difficult, which slows the further application of the crystallization separation craft. The progress basis on the study of crystallization and then the research of kinetic models for batch crystallizers was carried out in this thesis. The dilution crystallization of HMX was studied systematically both in experiment and theory, including crystallization thermodynamics, crystallization kinetics and crystallization process simulation.The solubility of HMX a in acetone-water binary solvent mixtures was determined by a synthetic method from 293.15K to 313.15K employing a laser monitoring observation technique. It is a function of temperature and the concentration of water in the solvent mixture. Results of these measurements were correlated with an Apelblat empirical equation and a (CNIBS)/Redlich-Kister equation. The simulated solubility of HMX shows good agreement with the experimental value,and the experimental solubility and correlation equation in this work can be used as essential data and models in the crystallization process of HMX.The surface tension and surface entropy factors of the dilution crystallization process of HMX were estimated, which indicated a screw dislocation growth model. The dilution crystallization kinetics of HMX was studied by the classes method. By using the least square method for the multivariate linear regression, the kinetic parameters under the considered experimental conditions were obtained. The experimental kinetic data is useful for process simulation and scale-up.On the basis of population balance, crystallization kinetics and mass balance equations, the mathematical model for dilution crystallization of HMX was established. Process simulation was developed by Ronge-Kutta-Gill algorithm and MATLAB language. The mathematical model of crystallization process has been verified by the consistent results of crystallization from simulation and experiment. The effect of temperature, agitation intensity, seed amount and addition rate of diluent on the crystal size distribution and supersaturation were analyzed by simulation.The paper supplied basic data and important foundation for scale up and further research on crystallization of HMX.