A Study On The Melt Crystallization Process Of6-tert-buty-3-methylphenol

6-tert-Butyl-3-methylphenol （3M6TB）,is the main materials to produce antioxidant.During the production processes of3M6TB, there are two different isomers wereobtained, which is3M6TB and2-tert-buty-4-methylphenol （4M2TB）. Usually,Separating of the isomer always conducted by distillation, which is high energyconsumption and lower purity than what we are pursuit. We tried to separate3M6TB and4M2TB by melting crystallization.Firstly, we measured the solid-liquid equilibrium phase diagram of3M6TB+4M2TB by DSC, and found that this is a eutectic system. And then we predicted thephase diagram by the software of Integrated Computer Aided System （ICAS）. We correlatedthe data by Margules, Wilson and NRTL models.Then we studied the kinetic behaviour of the static melt crystallization of3M6TBwas investigated by DSC at different cooling rates (1K·min^-1,2K·min^-1,5K·min^-1,10K·min^-1,15K·min^-1). We obtained the relationship between relative crystalinity andtemperature at different cooling rates by the equipped software of the DSC. We dealtthe experimental data by Avrami-Ozawa Model and obtained some kinetic parameterssuch as FTand θ which revealed the mechanism of static melt crystallization of3M6TB.,The results showed that the cooling rate had signature effect on crystallizationof3M6TB.Based on the above fundamental researches, the melt crystallization process formanufacturing3M6TB was systemically investigated. The effects of the initial conditionof crystallization, the cooling rate, the final crystallization temperature, the sweatingtemperature, the sweating rate and the time of the melt crystallization process on the yieldand the purity of3M6TB were studied. Finally, an optimal melt crystallizationtechnology for manufacturing3M6TB was developed. By using of the new developedtechnology, the3M6TB product with purity more than99.9%can be obtained from theraw material without adding any solvent. Summarily, this new melt crystallizationtechnology for producing3M6TB has a good foreground of industrial application.