Elevating the flexibility and operability of dividing-wall distillation columns via feed thermal condition adjustment  

作　　者：Yang Yuan Kejin Huang Liang Zhang Haisheng Chen Shaofeng Wang Yingjie Jiao 

机构地区：[1]College of Information Science and Technology,Beijing University of Chemical Technology,Beijing 100029,China

出　　处：《Chinese Journal of Chemical Engineering》2017年第7期947-954,共8页中国化学工程学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(21076015,21376018,21576014,21676011)

摘　　要：Because of the complicated interplay between the prefractionator and main distillation column involved,the black-hole problem might occur and prohibit the assignment of four specifications to dividing-wall distillation columns(DWDCs)(e.g., the three main product compositions plus an impurity ratio in the intermediate product), which lowers terribly process flexibility and operability. In this paper, a feed thermal condition adjustment strategy, achieved by the installation of a pre-heater in feed pipeline, is employed to eliminate the black-hole problem and serve to enhance process flexibility and operability. Through the strong influence to the overall mass and energy balance of the DWDC, the feed thermal condition adjustment can alter the interlinking flows between the thermally coupled prefractionator and main distillation column and work effectively to coordinate their relationship. A DWDC separating a benzene, toluene, and o-xylene mixture is chosen to ascertain the feasibility of the philosophy proposed. The static and dynamic studies demonstrate that the feed thermal condition adjustment is an effective way to refine process design and can completely eliminate the black-hole problem and elevate consequently process flexibility and operability.Because of the complicated interplay between the prefractionator and main distillation column involved,the black-hole problem might occur and prohibit the assignment of four specifications to dividing-wall distillation columns（DWDCs）（e.g., the three main product compositions plus an impurity ratio in the intermediate product）, which lowers terribly process flexibility and operability. In this paper, a feed thermal condition adjustment strategy, achieved by the installation of a pre-heater in feed pipeline, is employed to eliminate the black-hole problem and serve to enhance process flexibility and operability. Through the strong influence to the overall mass and energy balance of the DWDC, the feed thermal condition adjustment can alter the interlinking flows between the thermally coupled prefractionator and main distillation column and work effectively to coordinate their relationship. A DWDC separating a benzene, toluene, and o-xylene mixture is chosen to ascertain the feasibility of the philosophy proposed. The static and dynamic studies demonstrate that the feed thermal condition adjustment is an effective way to refine process design and can completely eliminate the black-hole problem and elevate consequently process flexibility and operability.

关 键 词：DWDC Process flexibility Process operability Black-hole problem Feed thermal condition 

分 类 号：TQ053.5[化学工程]