半连续精馏操作的研究

Study on operation mode of semi-continuous distillation

以甲醇-水、氯仿-甲醇-水为物系,采用半连续操与连续、间歇操作方式进行二元、三元组分的分离纯化的对比。实验结果表明,半连续操作甲醇分离的质量分数要高于连续操作的甲醇分离的质量分数;半连续操作塔顶甲醇质量分数的最大值小于间歇操作,但其平均值高于间歇操作;在回流比为4,加料温度为74.6℃,处理量为6 kg,操作时间为60 min的条件下,半连、连续、间歇方式操作,分离后甲醇的质量分数分别为99.92%、98.68%、99.93%,甲醇的回收率分别为97.55%、96.21%、94.93%,半连续相对于连续、间歇分别节能25%、36%;回流比为4,进料温度为25℃,加热功率为3 600 W,处理量为6 kg的条件下,当采出温度≤56.5℃时,在该三元体系中,氯仿的产量为4.82 kg/h,回收率为100%;当采出温度≤65℃时,甲醇的产量为0.59 kg/h,回收率为49.20%。

The comparison of purified components between binary and ternary through semi-continuous,continuous and batch operation is performed with methanol-water,chloroform-methanol-water as the material system.The results show that the mass fraction of methanol separation by semi-continuous operation is higher than the mass fraction of methanol separation by continuous operation.The maximum value of methanol at the top of tower by semi-continuous operation is less than batch operation＇s.But the average is higher than the average of batch operation.The concentrations after the methanol separation by semi-continuous,continuous and batch operation are 99.92％,98.68％,99.93％,respectively,under the following conditions：4 of the reflux ratio,74.6℃ of feed temperature,6 kg of capacity,60 minutes of operation time.Methanol recoveries are 97.55％,96.21％ and 94.93 ％,respectively.Compared to continuous operation and batch operation,energy saving of semi-continuous is 25 ％ and 36％,respectively.Under the conditions of the reflux ratio as 4,the feed temperature as 25℃,heating power as 3600w,handling capacity as 6 kg,and taken out temperature greater than or equal to 56.5℃,the recovery rate is 100％.When taken out temperature is greater than or equal to 65℃,the methanol production is 0.59 kg / h,and the recovery rate is 49.20％.