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Cresol is important fine chemical intermediates, an extremely wide range of applications in the field of synthetic fibers, engineering plastics, rubber additives and antioxidants. Its main source of the natural resources of coal chemical synthesis process. From coal tar extract in the mixed cresol, o-cresol, m-cresol and p-cresol three kinds of isomers, wherein orthocresol lower boiling point by distillation can be easily and m-cresol or p-cresol separation, and the m-cresol and p-cresol minimal boiling point differences are difficult to separate and therefore studied the separation of the mixed cresol significance. The paper mainly studied the separation of mixed cresol, using the alkylation reaction, the alkylation product using the generated under certain conditions the difference between the boiling point of the distillation separation. The paper examines the impact of the alkylation reaction factors, optimizing the alkylation process parameters; studied the vacuum distillation of the alkylation liquid separation, designing a distillation scheme. In the quality of 55% of the amount of mixed cresol by acidification of a strongly acidic cation exchange resin catalyst, 75 ° C, the molar ratio of MTBE and mixed cresol 3.5:1 under conditions of mixed cresols alkylated 150min, obtained 2,6 - di-tert-butyl-p-cresol (referred to as BHT), and 4,6 - di-tert-butyl-m-cresol, alkylated liquid; through 70 ° C atmospheric distillation and steam distillation to obtain a pale yellow transparent liquid; and then through in system pressure 14mmHg, the tower kettle temperature 152 ° C and the tower kettle temperature 178 ° C the operating condition, for vacuum distillation separation BHT crude and 4,6 - di-tert-butyl-p-cresol crude. This paper also examines the process parameters as the main raw material preparation to separate the product of 4,6 - di-tert-butyl-m-cresol Antioxidant 300. 4,6 - di-tert-butyl-m-cresol as the main raw material, petroleum ether as solvent, and 4,6 - di-tert-butyl-m-cresol volume than 2.2:1,4,6 - di-tert-butyl-A phenol with sulfur dichloride The molar ratio of 1.0:1.11, sulfur dichloride dissolved therein, after the 75 ° C reaction 60min, a mixed solvent was added dropwise at 5 ℃ 150min thio condensation reaction, obtained The conversion was 77% Antioxidant 300. With the help of analytical tools such as gas chromatography, UV - visible spectroscopy, infrared spectroscopy and melting point determination, were used to characterize the structure of the experimental products, consistent with the theoretical values ??or literature values, the successful acquisition of the target product BHT and antioxidants 300, which showed that using separate mixed cresol alkylation, and cogeneration the BHT and antioxidants 300 technically feasible.
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