重质松节油中间馏分对长叶烯单离的影响

Effect of Heavy Turpentine's Middle Distillate on the Rectification of Longifolene

为了降低实际生产时中间馏分对高纯度长叶烯单离的影响,对重质松节油单离长叶烯过程中的中间馏分质量分数进行监测,并测定产品的相对密度和折光指数,实验结果表明:长叶蒎烯、长叶环烯存在于整个长叶烯单离过程,长叶蒎烯的影响显著高于长叶环烯。在操作压力-0.1 MPa、塔釜温度150℃、回流比1∶7条件下对重质松节油进行精馏,在精馏过程中可通过调整回流比或降低塔釜温度的方式最大程度降低中间馏分对长叶烯质量分数的影响。当塔顶馏出液的d_(20)位于0.9260~0.9263时,调整回流比为1∶10或当塔顶馏出液中长叶烯质量分数超过30%后,塔釜温度降低至140~145℃之间,当塔顶馏出液d_(20)>0.9335时,塔釜温度再升至150℃。这两种方式均可获得90%以上长叶烯,并且长叶蒎烯、长叶环烯质量分数总和低于1.5%。

In order to reduce the influence of middle distillate on the rectification of high-purity longifolene in real production,the mass fraction of middle distillate in the process of isolating longifolene from heavy turpentine was monitored,and the relative density and refractive index of the product were measured.The experimental results showed that longipinene and(+)-longicyclene existed in the whole process of longifolene rectification,and the effect of longipinene was significantly higher than that of(+)-longicyclene.Under the operating pressure of-0.1 MPa,the tower kettle temperature of 150℃,and the reflux ratio of 1∶7,the distillation of heavy turpentine was carried out.In this process,the influence of the middle distillate on the longifolene rectification could be minimized by adjusting the reflux ratio or lowering the temperature of the column kettle.When the d_(20) of the top distillate was between 0.9260 and 0.9263 and the reflux ratio was adjusted to 10∶1(or the temperature of the tower reduced to 140-150℃when the mass fraction of longifolene in the overhead distillate exceeded 30%),or the temperature of the tower increased to 150℃when the d_(20) of overhead distillate was greater than 0.9335,more than 90%longifolene could be obtained,and the total mass fractions of longipinene and(+)-longicyclene was less than 1.5%.