熔融结晶分离精制2,5-二甲酚

Separation and purification of 2,5-xylenol by melting crystallization

采用熔融结晶分离提纯2,5-二甲酚,考察结晶终温、降温速率、发汗终温对结晶的影响。优化的精制工艺参数为:将物料在熔融状态73℃恒温20 min,按温度控制曲线进行操作,降温速率以3℃/h降温10 h;结晶终温43℃,恒温20 min;然后以3℃/h升温10 h,发汗终温70℃;恒温20 min,最后快速升温至78℃,收集样品,得到含量达99.5%的2,5-二甲酚产品,收率达76.3%。

2,5-Xylenol was purified by melt crystallization,the effects of crystallization final temperature,cooling rate and sweating final temperature on crystallization were investigated,the optimized refining process parameters were as follows:the material was kept at 73℃for 20 min in the melting state,and operated according to the temperature control curve,the cooling rate was 3℃/h for 10 h;Crystallization final temperature 43℃,constant temperature 20 min;Then the samples were heated at 3℃/h for 10 h,and the final sweating temperature was 70℃;The product was collected at a constant temperature of 20 min and heated up to 78℃,the content of 2,5-xylenol can reach 99.5%,in addition the yield of 2,5-xylenol can reach 76.3%.