10 Batch Extractive Distillation

The separation of azeotropic or close boiling mixtures is often the most difficult task in many chemical industries. Under normal operating conditions high recovery of species with high purity is not possible. The separation of these mixtures using a conventional distillation column is not an economically feasible option as a very large column or a very high reflux ratio operation would be required to separate these mixtures. Pressure swing distillation is used sometimes to break the azeotropic...

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Optimum Temperature Trajectories (Feedback Strategies) Albet, J., Le Lann, J.M., Joulia, X. and Koehret, B., In Proceedings Computer Oriented Process Engineering (Elsevier Science Publishers B.V., Amsterdam, 1991), 75. Balasubramhanya, L.S. and Doyle III, F.J., J. Proc. Cont. 10 (2000), 209. Basualdo, M.S. and Ruiz, C.A., Lat. Ame. Appl. Res. 25-S (1995), 29. Barbosa, D. and Doherty, M.F Chem. Eng. Sei. 43 (1988), 529. Bernot, C., Doherty, M.F. and Malone, M.F., Chem. Eng. Sei. 46...

Batch Reactive Distillation Bread

Reactive Distillation processes combine the benefits of traditional unit operations with a substantial progress in reducing capital and operating costs and environmental impact BP Review, 1997 Taylor and Krishna, 2000 . Traditionally, as in many chemical industries, reaction and separation take place separately Figure 9.1 in a batch reactor followed by a batch distillation column Charalambides et al., 1994 . Therefore, the distillation of desired species cannot influence the conversion of the...

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Batch Distillation Picture

Representation of Design, Operations and Separations Duties 7.3.1.1. Design and Operation Decision Variables It is aimed to optimally design a batch column capable of processing M number of feed mixtures, each mixture constituted of NCm number of components Multiple Separation Duties, Figure 7.3 . The most important variables characterising a batch column design are the still capacity B0 , the number of theoretical stages N and the vapour boilup rate V . The latter can be used to obtain...

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WV 1 to Total mass balance The other equations for the reboiler are same as equations V.16-V.24 where j is replaced by N. Cuille and Reklaitis 1986 and Albet et al. 1991 used similar model to simulate batch reactive distillation process. Egly et al. 1979 , Reuter et al. 1989 , Mujtaba 1989 and Mujtaba and Macchietto 1992, 1997 used a modified version of this model based on constant molar holdup in their studies. Sorensen and Skogestad 1996c , Sorensen et al. 1996b , Balasubramhanya...

Design And Operation Optimisation

There are many papers in the literature dealing with the optimisation of the operation of batch distillation for a given column design and for a single separation duty Farhat et al. 1990 Bernot et al., 1991, 1993 Logsdon and Biegler, 1993 Mujtaba and Macchietto, 1993 . However, the design of batch columns has attracted much less attention. The main design parameters Al-Tuwaim and Luyben, 1991 are the Number of stages plates in the column Still capacity batch size Reboiler and condenser size...

Column Configurations

Conventional Column Configuration In this configuration, the available separation section tray or packed is utilised in rectifying mode, with product cuts recovered and intermediate off-cut fractions disposed of or recycled collected as condensed distillate. A final residue bottom fraction may also be a desired product. Conventional column configuration has been discussed in section 1.4 of Chapter 1. Further details are given in later chapters. 2.2. Unconventional Column Configurations...

Operation

Representation of Operational Alternatives Using State Task Network The batch distillation operation can be schematically represented as a State Task Network STN . A state denoted by a circle represents a specified material, and a task rectangular box represents the operational task distillation which transforms the input state s into the output state s Kondili et al., 1988 Mujtaba and Macchietto, 1993 . For example, Figure 3.1 shows a single distillation task producing a main-cut 1 Di and...

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Where Mw is the vapour molecular weight, pv is the vapour density lb ft3 , Vm is the maximum allowable superficial velocity ft s given by where Kv empirical constant 0.3 ft s for 24-in spacing between plates pL is the liquid density lb ft3 . c. The energy consumption ', Btu hr where, Hv' is the molal heat of vaporisation of the feed Btu lb mole d. The steam flowrate W lb hr where, Hv is the heat of vaporisation of steam 915.5 Btu lb The Energy Cost Cg, hr can be calculated using e. The reboiler...

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Quasi-steady State Off-cut Recycle Strategy in Binary Batch Distillation Mayur et al. measured the benefits of recycling in terms of a potential reduction in batch time. However the benefits may be measured Mujtaba, 1989 as follows 1. Reduction in batch time For a given fresh feed and a given separation, the column performance is measured in terms of minimum batch time required to achieve a desired separation specified top product purity x D and bottom product purity x B2 for binary...

Batch Distultiuon Introduction

In the 1950s, chemical engineers might have the impression that the ultimate mission of the engineers was to transform old-fashioned batch processes into modern continuous ones Rippin, 1983 . With such a perspective it is surprising to find that, today, fifty years later a significant proportion of the world's chemical production by volume and a much larger proportion by value is still made in batch plants and it is unlikely that this proportion will decline in the near future. Parakrama 1985...

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XB1A lt 0.0, 0.0, 0.004,0.996 gt Figure 4.20. MultiBD Column - Product Amounts and Compositions 4.4. Packed Batch Distillation and Model Extensive literature survey shows that only a few considered modelling, simulation and optimal control of such column Hitch and Rousseau, 1988 Hansen and Jorgensen, 1986 . Nad and Spiegel 1987 simulated their experimental packed column using the methods developed for tray columns by estimating the number of trays representative of the packed height. The...