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Batch Distillation (batch + distillation)
Selected AbstractsFRUIT BRANDY PRODUCTION BY BATCH COLUMN DISTILLATION WITH REFLUXJOURNAL OF FOOD PROCESS ENGINEERING, Issue 1 2005MICHAEL J. CLAUS ABSTRACT The relationship between the operating parameters of batch fruit spirits column stills with reflux and the congener (trace compounds that provide flavors and aromas) concentrations in resulting fruit spirits has not been widely studied. Congener concentrations were determined in three different collection fractions, or "cuts," during batch distillation. Acetaldehyde and ethyl acetate were found in higher concentrations in the head cut, first overhead fraction, of the distillation and have lower boiling points relative to ethanol. 1-Propanol and isoamyl alcohol (isopentanol) were present in higher concentrations in the tail cut, third or final fraction, of the distillation and have boiling points that are higher than ethanol. Methanol has a unique concentration profile as it has higher concentrations in both the head and tail cuts, but a lower concentration in the heart cut, the middle fraction which is the desired product of the distillation. Methanol was of particular interest because the distillate must adhere to governmental regulations that limit its concentration in the product. Operating-condition parameters that were studied include the number of trays used in the distillation as well as the use of a "catalytic converter," a high surface, copper-packing material thought to catalyze formation of cyanide-containing compounds allowing them to be separated from the distillate. The effect of the number of trays used in a distillation on the concentration of ethanol and the congeners, methanol, acetaldehyde, ethyl acetate, 1-propanol and isoamyl alcohol in the final distilled spirits product is presented. An additional result of acetaldehyde production at the copper surface of the catalytic converter was also discovered in the analysis of the data. [source] Optimal design of azeotropic batch distillationAICHE JOURNAL, Issue 3 2006M. C. Mussati Abstract This study explores integrating models with different degrees of detail for optimizing azeotropic batch distillation systems. A detailed dynamic model is used from outside the optimization program both to verify feasibility of the design and to update the parameters needed by the optimization model. The updated parameters are the constant relative volatilities between pseudo-components, used in a binary Fenske,Underwood,Gilliland-type model. The approach was used to optimize the design of a batch process for the recovery of spent isopropyl alcohol, which works cyclically to separate the excess water, satisfying an environmentally acceptable specification, and using cyclohexane as entrainer, which in turn is recovered in the same process and recycled. The approach permitted optimizing the batch sizes, number of separation stages, the reflux ratios of a piecewise constant multilevel reflux policy, the extent of each separation, and the size of the intermediate cuts to be recycled, with affordable computation and problem setup times. © 2005 American Institute of Chemical Engineers AIChE J, 2006 [source] Analysis and control of heteroazeotropic batch distillationAICHE JOURNAL, Issue 4 2005S. Skouras Abstract The separation of close-boiling and azeotropic mixtures by heterogeneous azeotropic distillation is addressed in batch columns. Both a common rectifier and a multivessel batch column are considered. Theoretical and graphical analyses of the process are presented for both column configurations and different separation strategies are presented. A simple control scheme is proposed for the practical operation of the columns, the implementation of different separation strategies and the realization of the final results. Dynamic simulations for mixtures classified under Serafimov's topological classes 2.0-2b and 3.1-2 verify the theoretical findings. The results show that heteroazeotropic batch distillation exhibits substantial flexibility. The column profile can be totally restored during the process and lie in regions different from those of the initial feed. The still path can cross distillation boundaries and the still product does not have to be the stable node of the feed region. Such results cannot be obtained by homogeneous azeotropic batch distillation. © 2005 American Institute of Chemical Engineers AIChE J, 2005 [source] Backstepping-based cascade control scheme for batch distillation columnsAICHE JOURNAL, Issue 9 2004Rosendo Monroy-Loperena Abstract Nonstationary dynamics, finite-time operation, large thermodynamical uncertainty and delayed composition measurements make the control of batch distillation processes a challenging and interesting problem. In this paper, a cascade control design to regulate the overhead composition of a batch distillation column is presented. The controller is designed within the framework of robust nonlinear control with modeling error compensation techniques in conjunction with a backstepping approach. The result is a cascade controller with a master loop that, driven by the composition regulation error, produces a time-varying set point for the temperature in a certain tray; and with a secondary controller that manipulates the internal reflux ratio to track the time-varying set point determined by the master composition loop. How to extend the controller design to have multiple slave temperature controllers, to improve the regulation of the overhead composition in a batch distillation column, is also presented. The proposed control approach is illustrated by numerical simulations on a full dynamical model. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2113,2129, 2004 [source] Regular and inverted batch process structures for pressure swing distillation: a case studyASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 6 2009Andreas Klein Abstract The main focus of this paper is on the comparison of the inverted and the regular pressure swing batch distillation processes for the separation of a homogenous azeotropic mixture. On the basis of a successful, experimentally validated rigorous model, a simulation study to identify the differences between the two processes and the influences of different structures on them is carried out. This identification of influences helps in finding out a heuristic base of the most suitable batch structure for a given separation problem. Especially the influence of the feed flow rate on the processes and the differences between the results on operation with different pressures will be addressed. Furthermore advantages, disadvantages and the limitations of both processes will be shown. In the end the best way of operating the pressure swing batch distillation will be presented depending on the product purity and the feed concentration for a given example. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Nichtlineare stochastische Optimierung unter UnsicherheitenCHEMIE-INGENIEUR-TECHNIK (CIT), Issue 7 2003H. Arellano-Garcia Dipl.-Ing. Abstract Das Treffen von Entscheidungen unter Berücksichtigung von Unsicherheiten wird in zahlreichen Fachrichtungen und Anwendungsgebieten als grundlegend wichtig erachtet. In dynamischen chemischen Prozessen existieren insbesondere Parameter, die üblicherweise unsicher sind und große Auswirkungen auf die Auslegung von Anlagen, die Betriebsdurchführung sowie auf die wirtschaftliche Analyse haben. Daher ist die Einbeziehung der Stochastik der unsicheren Variablen in die Formulierung eines Optimierungsproblems in Hinblick auf ein optimales Prozessdesign sowie auf eine robuste Prozessführung notwendig. Infolgedessen ist die effiziente Optimierung unter Wahrscheinlichkeitsrestriktionen zu einem wichtigen Forschungsgebiet in der Prozesssystemtechnik geworden. Ein neuer Lösungsansatz für die stochastische Optimierung dynamischer Systeme wird am Beispiel eines diskontinuierlichen Prozesses mit einem rigorosen Modell vorgestellt und angewandt. Nonlinear Stochastic Optimization under Uncertainty Robust decision making under uncertainty is considered to be of fundamental importance in numerous disciplines and application areas. In dynamic chemical processes in particular there are parameters which are usually uncertain, but may have a large impact on equipment decisions, plant operability, and economic analysis. Thus the consideration of the stochastic property of the uncertainties in the optimization approach is necessary for robust process design and operation. As a part of it, efficient chance constrained programming has become an important field of research in process systems engineering. A new approach is presented and applied for stochastic optimization problems of batch distillation with a detailed dynamic process model. [source] | ||||||||||