Azeotropic distillation in a middle vessel batch column. 2: Nonlinear separation boundaries

Journal Article · Thu Apr 01 04:00:00 EST 1999 · Industrial and Engineering Chemistry Research

DOI:https://doi.org/10.1021/ie980470q· OSTI ID:345351

Cheong, W; Barton, P I ^[1]

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1. Massachusetts Inst. of Tech., Cambridge, MA (United States)

On the basis of the analytical tools developed for the middle vessel column (MVC) operated under limiting conditions, analysis of the qualitative dynamics of the MVC in separating an azeotropic mixture is extended to the more realistic case in which the separation boundaries are nonlinear. The differences between batch stripper pot composition boundaries and batch rectifier pot composition being able to cross these pot composition boundaries. On the basis of these insights, operating procedures are developed in which ternary azeotropic mixtures of acetone, benzene, and chloroform can be separated into their constituent pure components, a separation not achievable with either the batch stripper or the batch rectifier. The operating procedures suggested for separating the ternary azeotropic mixture of acetone, benzene, and chloroform in the MVC are then shown to be the time analogues of sequences of continuous distillation columns that achieve the same separation. On the basis of this space-time analogy, further analogies are developed between the MVC and a continuous column, and it is postulated that many complex separations currently achieved with sequences of continuous columns can also be achieved with a single MVC. Thus, the MVC represents the ultimate multipurpose solvent recovery technology, as it can handle, in a batch multipurpose mode. separations that will otherwise require a dedicated continuous distillation sequence. Finally, the characteristics of perfect MVC batch entrainers, which allow the complete separation of any azeotrope into its constituent pure components in a single MVC, are discussed.

• Sponsoring Organization: USDOE, Washington, DC (United States); Massachusetts Inst. of Tech., Cambridge, MA (United States)
• DOE Contract Number: FG02-94ER14447
• OSTI ID: 345351
• Journal Information: Industrial and Engineering Chemistry Research, Journal Name: Industrial and Engineering Chemistry Research Journal Issue: 4 Vol. 38; ISSN IECRED; ISSN 0888-5885
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
ACETONE
AZEOTROPE
BENZENE
BOUNDARY CONDITIONS
CHLOROFORM
DISTILLATION EQUIPMENT
ENERGY EFFICIENCY
EXTRACTION COLUMNS
FLUID MECHANICS
MATHEMATICAL MODELS