Rectification of α-Terpineol from the Byproduct of Eucalyptus Oil by Batch Vacuum Distillation

The technology of rectifying α-terpineol by batch vacuum distillation from terpineol fraction,a byproduct of eucalyptus oil,was studied.The composition of the raw material terpineol fraction was analyzed by means of GC-MS.Based on the effusing curves of the target α-terpineol and those of the main impurities of γ-terpinene,terpinen-4-ol,and trans-pinocarveol by batch vacuum distillation,the effect of tower packing pretreated with water and four organic solvents on the separation of α-terpineol was investigated.In addition,the reflux ratio for fractioning α-terpineol was optimized.The optimum conditions were found as follows:tower packing pretreated with water,distillation in a varied reflux ratio,and the reflux ratio kept at 6 when α-terpineol effused,whereby α-terpineol obtained was at 129～132 ℃/5.0 kPa with a purity of more than 90% by GC and a recovery of 50%.