要求在常压下分离环己烷a.(沸点80.8℃)和苯b.(沸点80.2℃),它们的恒沸组成为苯0.502(摩尔分数),共沸点77.4℃,现以丙酮为恒沸剂进行恒沸精馏,丙酮与环己烷形成恒沸物,共沸组成为0.60(环己烷摩尔分数),若希望得到几乎纯净的苯,试计算:①所需恒沸剂量。②塔顶、塔釜馏出物量各为多少。(以100kmol/h进料计)

解:以100kmol/h进料为基准,设丙酮恒沸剂的用量为Skg,恰好与料液中的环己烷组成恒沸物,进料量和塔顶恒沸物的量和组成分别为<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/150908759004048c5eb98188347ddb7889e0356d1816eimage1.png">。<br>对环己烷作物料平衡&nbsp;<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1509087590117cf615bd0ca31441aac450952e87e47b0image2.png">;<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/150908759019351f2b5b0deaf43c09244a9cb0bd40887image3.png"><br>恒沸剂S的用量为<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1509087590265ced37e6e9f8f41b88a3bfe293a90ce18image4.png"><br>由于塔釜希望得到几乎纯净的苯,<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/15090875903417a9996c660c041eb84e6f5b1507dd1e5image5.png">
解:以100kmol/h进料为基准,设丙酮恒沸剂的用量为Skg,恰好与料液中的环己烷组成恒沸物,进料量和塔顶恒沸物的量和组成分别为。对环己烷作物料平衡 ;恒沸剂S的用量为由于塔釜希望得到几乎纯净的苯,