Simulation and Analysis of a Middle Vessel Batch Distillation Column by Weiyang Cheong Submitted to the Department of Chemical Engineering in partial fulllment of the requirements for the degree of Bachelor of Science in Chemical Engineering at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY June c Massachusetts Institute of Technology All rights reserved Author Department of Chemical Engineering May Certied by Paul I Barton Assistant Professor Department of Chemical Engineering Thesis Sup ervisor Accepted by Charles M Mohr Undergraduate Ocer Simulation and Analysis of a Middle Vessel Batch Distillation Column by Weiyang Cheong Submitted to the Department of Chemical Engineering on May in partial fulllment of the requirements for the degree of Bachelor of Science in Chemical Engineering Abstract In this thesis a batch distillation column with the holdup vessel feed in the middle of the column was mo delled and simulated This distillation conguration termed as a Middle Vessel Column MVC by various researchers was rst prop osed by Robinson and Gilliland but has only b een analyzed in detail recently It is in contrast to the traditional batch distillation congurations of batch rectiers with feed from the holdup p ot at the b ottom of the column and batch stripp ers with feed from the holdup pot at the top of the column A mathematical mo del was develop ed for the MVC and a theoretical analysis of the mo del conducted For validation purp oses simulations were conducted with the mo del using ABACUSS Advanced Batch and Continuous Unsteady State Simulator a program develop ed for simulation and optmization of dynamic mo dels The results compared favorably with the theoretical analysis A theoretical analysis was also con ducted on the exploitation of curved separatrices to separate azeotropic mixtures into the complete set of pure comp onents in a single middle vessel column Feasible sep aration schemes were formulated and simulated with the ABACUSS mo del to arm validity Finally the mo del was extended to that of a MultiVessel Column their MuVC where there are several trays in the column with substantial amounts of holdup and from which pro duct streams maybedrawn The traditional batch recti ers stripp ers and the recently suggested MVC can all b e considered as sp ecial cases of the MuVC The results of this thesis also suggests substantial environmental benets to sp e ciality chemical and pharmaceutical manufacturers due to the ability of the MVC to break azeotrop es in a single multipurp ose unit op eration thereby removing the haz ard of chemical spillage asso ciated with transfers b etween unit op erations The MVC thus represents the ultimate multipurp ose solventrecovery technology for batch pro cesses Thesis Sup ervisor Paul I Barton Title Assistant Professor Department of Chemical Engineering Acknowledgments Iwould like to thank my thesis sup ervisor Professor Paul Barton for his undying pa tience with me and his invaluable guidance Iwould also like to thank John Tolsma Santos Galan Wade Martinson and Arvind Mallik in the BartonGroup who have help ed in many ways to make my work a reality Certainly I would also like to ex tend my deep est heartfelt gratitude to my friends Pitip orn Phanaphat Wanwipa Siriwatwechakul Michael Sy and TsehHwan Yong for their enlightening moral sup port in my darkest days prior to the completion of my Bachelors Thesis Last but not least I would like to thank my b eloved family for their moral supp ort in whatever little way p ossible all the way from the other side of the earth in sunny Singap ore Contents Intro duction The Middle Vessel Column ARoadMap Background Batch Distillation The Middle Vessel Column The MultiVessel Column Basic Mo del of the Middle Vessel Column Development of Mo del A Graphical Interpretation of the Mo del Equivalence of Middle Vessel Column with Innitessimal Rectiers and Stripp ers A Contrast with Davidyan et al and Meski and Morari Theoretical Analysis of the Limiting Behavior of the MVC Mo del es and Distillation Column Proles The NonEquivalence of Residue Curv Innite Reux Innite Trays Higher Dimensionality Systems A Bifurcation Analysis of the MVC Batch Distillation Regions More on the Equivalency of the Middle Vessel Column vs a Stripp er and a Rectier A Comparison to Safrit and Westerb erg in Related Topics Insights on the Use of the Middle Vessel Column in Azeotropic Batch Distillations NonEquivalence of Pot Comp osition Boundaries for Stripp ers and Rectiers in the Presence of Curved Separtrices Op erating Pro cedures Applicable for Breaking Azeotrop es A Comparison to Wahnschat et als Continuous Column Sequences for Separating the Acetone Benzene and Chloroform Mixture A Discussion ab out the Equivalence of the Middle Vessel Column ver sus a Continuous Batch Distillation Column A Discussion on the Perfect Entrainer Simulation Analysis of the MVC Mo del The AcetoneChloroformMethanol System Op eration of the Middle Vessel Column as A Stripp er and A Rectier An Analysis of the Results From Region Y An Analysis of the Results From Region Z Op eration of the Middle Vessel Column with the Op erating Parameter at An Analysis of the Results From Region An Analysis of the Results From Region An Analysis of the Results From Region An Analysis of the Results From Region An Analysis of the Results From Region An Analysis of the Results From Region A Comparison of Results in the Presence of Holdup in Trays Azeotropic Batch Distillations with a Middle Vessel Column in the Presence of Curved Separatrices Separation of an Acetone Benzene and Chloroform Mixture in a Mid dle Vessel Column Op erating Parameters FeedMixture Comp osition and Charge Sizes Separation in the Middle Vessel Column Using Op eration Mo de B Simulation For the Separation of F az eotr ope Simulation For the Separation of F Simulation For the Separation of F A Comparison of Mo de A of Op eration vs Mo de B of Op eration Comparison of a QuasiStatic Op eration for F Versus a Non az eotr ope QuasiStatic Op eration Conclusions A Study of MultiVessel Columns Separation Possibilities at Finite Reux Ratios Optimal Control of a Middle Vessel Column Feasible Entrainers For Separations in a Middle Vessel Column A Derivation of Middle Vessel Column Mo del Equations B Residue Curve Maps for the ACM and ABC Systems B Residue Curve Maps for Ternary System of Acetone Chloroform and Methanol B Residue Curve Maps for Ternary System of Acetone Benzene and Chloroform For Middle Vessel Column in the C Derivation of Mo del Equations Presence of Entrainers D Detailed Simulation Results of the Comp onent Mixture of Ace tone Chloroform and Methanol D Pro duct Sequences Exp ected For Each Stripp er and Rectier Batch Distillation Region in the Presence of StraightLine Boundaries D Simulation Results From ABACUSS Mo del of Various Initial Still Pot Comp osition in Each of the Rectifying and Stripping Regions D Simulation Results for Region Y D Simulation Results for Region Y D Simulation Results for Region Y Simulation Results for Region Y D D Simulation Results for Region Y D Simulation Results for Region Y D Simulation Results for Region Z ulation Results for Region Z D Sim D Simulation Results for Region Z D Simulation Results for Region Z D Simulation Results for Region Z D Simulation Results for Region Z D Pro duct Sequences Exp ected For Each Middle Vessel Batch Distillation Region in the Presence of Straight Line Boundaries D Simulation Results From ABACUSS Mo del of Various Initial Still Pot Comp osition in Each of the Middle Vessel Regions D Simulation Results for Region D Simulation Results for Region D Simulation Results for Region D Simulation Results for Region D Simulation Results for Region D Simulation Results for Region D Simulation Results for Region D Simulation Results for Region D Simulation Results for Region Simulation Results for Region D D Simulation Results for Region D Simulation Results for Region D Simulation Results for Region D Simulation Results for Region D Simulation Results for Region D Simulation Results for Region D Simulation Results for Region D Simulation Results