Development of Complex Batch Distilllation System for Energy Conservation

提出了一种新型的“复杂间歇精馏塔”分离系统，并对该塔的特点进行了研究。从能源消耗的角度来看，间歇蒸馏与连续蒸馏相比是一种无效的分离方法。然而，这里提出的复杂塔可以看作是一个多热集成系统，其中一个塔的冷凝器与下一个塔的再沸器热集成。因此，分离多个组分所需的能量明显小于普通间歇蒸馏系统。由于杂质可以从顶部和底部同时取出，因此复合塔方便从原料中去除轻杂质和重杂质。通过分析普通间歇精馏塔与汽提间歇精馏塔的区别，明确了复合精馏塔与普通间歇精馏塔相比有效工作的条件。从节能的角度对间歇精馏塔的优化结构进行了探讨。本研究除考虑普通馏分塔和汽提间歇馏分塔外，还考虑了多种类型的复杂馏分塔。首先，通过分析普通馏分塔、汽提馏分塔和全回流间歇馏分塔分离二元组分的差异，推导出两种启发式规则。很明显，通过使用这些启发式规则，最优结构的候选可以被限制在几个结构中。在不同的分离条件下，对复合塔的能耗与普通连续蒸馏系统的能耗进行了比较。通过详尽的仿真工作，发现在许多情况下，当两种系统的塔板总数相同时，复合塔的能耗等于或小于最优连续蒸馏系统的能耗。少

A new type of separation system called "complex batch distilllation column" is proposed, and the characteristics of this column are examined.From the view point of energy consumption, batch distilllation has been considered to be an ineffective separation method compared with continuous distilllation. However, the complex column proposed here can be regarded as a multiple-heat-integrated system in which a condenser of one column is heat-integrated with the reboiler of the next column. Therefore, the energy required for separating multiple components is markedly less than that of an ordinary batch distilllation system.The complex column is convenient for removing light and heavy impurities from the raw materials since the impurities could be withdrawn simultaneously from the top and the bottom. By analyzing the differences between ordinary and stripping batch distilllation columns, the conditions at which the complex column works effectively compared with ordinary batch distilllation co … More lumn are clarified.The optimal structure of the batch distilllation column is discussed from the viewpoint of energy conservation. In this research, in addition to ordinary and stripping batch distilllation columns, many types of complex columns are taken into account. At first, by analyzing the differences among ordinary, stripping, and total reflux batch distilllation columns separating binary components, two heuristic rules with regard to the separation performance of those columns are derived. It becomes clear that, by using these heuristic rules, the candidates of the optimal structure can be limited to a few structures.The energy consumption of the complex column is compared with that of an ordinary continuous distilllation system for various separation conditions. Through exhaustive simulation work, it is found that in many cases the energy consumption of the complex column is the same or smaller than that of optimal continuous distilllation systems when the total number of trays is the same for both systems. Less