关键词: 结晶, 晶种, 1,8-桉叶油素, 速率

Abstract: A crystallization process purifying the crude Eucalyptus oil [w(cineole) = 63.24%] was studied in this paper. Without any crystal seed,the concentration of 1,8-cineole would be improved from 63.24% to 77.52% under conditions:The cooling rate was 4℃/h,the cooling final temperature was -30℃,the sweating rate was 5℃/h,the sweating final temperature was -19℃. After crystal seeds were added,the operation temperature was obviously increased,the range of crystallization temperature was effectively reduced,and the purity of the product was greatly increased. The best operating value were determined:the cooling rate was 4℃/h,the crystallization temperature was -25℃,the sweating rate was 4℃/h,the sweating final temperature was -6℃,the amount of crystal seed was 0.2%,the diameter of crystal seed was 3mm with no broken,the temperature of seed added was -17℃. Under these conditions,the purity of crude oil was increased from 63.24% to 89.63%. The suitable process and its operating parameters for separating and purifying cineole under low temperature with a little crystal seed were obtained. Compared to other separation methods,this method has obvious advantages.

Key words: crystallization, crystal seed, 1,8-cineole, rate