Comparison of plausibility of equilibrium model and mass transfer model to modeling a extractive distillation column with simulations based on ASPEN
Because of the high relative volatility and azeotropical point, it is not efficient to regain butene from the mixture of butene and n-butane by using simple distillation column. To overcome the difficulties, extractive distillation column was engaged in industry. However, the operating of an existing extractive dustillation columm indicated that the HETP value of real plant was more than twice as much as ideal test system. One essential information source to estimate HETP-value and thereof the overall height of column is measured value by manufacturer using ideal material system. Thereby, there existed a information gap between theoretical stage number, which was calculated on the base of equilibrium concept, and the overall height of real column. It raises now a question, if there is a methodological error in the designing of the extractive distillation column and if the mass transfer models in the position this gap to close. With the help of ASPEN program, RateSep, RateFrac and RadFrac, three different extractive distillation columns were implemented on the base of mass transfer model and equilibrium model to study the plausibility of the results, which were provided by mass transfer model and equilibrium model. The study shows that mass transfer model provides a more realistic and more plausible result than equilibrium concept, whereas, there are some improvement should be made for ASPEN program, such as, with the increasing of viscosity of fluid reduces the interface area, this should be taken into account by the designing of column.
extractive distillation column mass transfer model equilibrium model Simulation HETP value RateSep RadFrac RateFrac
Yiming Song Xiaoxun Ma
School of Chemical Engineering, Northwest University, Xian 710069, China
国际会议
The 5th International Conference on Separation Science and Technology(第五届国际分离科学与技术会议)
北京
英文
2007-10-14（万方平台首次上网日期，不代表论文的发表时间）