为高效节能地制备燃料乙醇，采用有效能分析法对燃料乙醇萃取蒸馏工艺的4个塔进行分析．其中醪塔由塔顶常压操作、水蒸气预热进料变为塔顶压力50kPa、塔底废醪液预热进料后，有效能效率从33．3％增加到61．0％；精馏塔塔顶压力从常压变为200kPa时，有效能效率从1．6％增加到64．0％；萃取精馏塔的萃取剂乙二醇中添加醋酸钾后，有效能效率从原来的25．0％增大到29．0％；萃取剂回收塔的有效能效率为25．9％．说明利用有效能分析法可以清晰地辨别系统能耗高的位置．

In order to effectively produce fuel ethanol with low energy consumption, four columns of extractive distillation for fuel ethanol are analyzed by the exergy method. It is found that （ 1 ） the exergy efficiency of the prefractionator increases from 33.3% to 61.0% when the top pressure varies from 101. 325 kPa to 50 kPa and the feed is preheated by waste water in the bottom instead of by water vapor; （2） the exergy efficiency of the distillation column increases from 1.6% to 64. 0% when the top pressure improves from 101. 325kPa to 200kPa; （3） the exergy efficiency of the extractive distillation column increases from 25.0% to 29.0% after the addition of KAc in the extractant glycol; and （4） the exergy efficiency of the extractant recovery tower is up to 25.9%. All this demonstrates that exergy analysis is feasible in distinguishing the position of high energy consumption in an extractive distillation system.