Use of Continuous Columns for Batch Distillation

In the mid Eighties, 99 batch processes within 74 UK companies were identified (Parakrama, 1985). In the last decade or more a continuous shift towards batch processes has been noticed and many small-scale companies are using their existing continuous columns for batch distillation (Willet, 1995) without much realising the implications of such practice. Also R D sections of many multi-national chemical companies do the pilot plant study in CBD columns for their continuous distillation columns which are in operation in the plant (Chen, 1995 Jenkins, 2000 Greaves, 2003). Because of confidentiality the results of such studies are not available in public. 

Mujtaba (1997) explored the potentials of using continuous columns for batch distillation in detail. 

Separation of multiple mixtures using a single column is a very common feature in CBD columns (Mujtaba and Macchietto, 1996). If a continuous column were to be used for batch distillation then it would be interesting to evaluate the performance of such column undergoing multiple separation duties. 

Mujtaba (1997) considered single separation duty where a single column is used for separating only one mixture during its total operation period in a year and compared the performances of CBD with continuous column operation. The author 

Reprinted with permission from IChemE, UK. Full reference is at the end of the chapter. 

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