Abstract
Distillation is the process in which the separation of components in a mixture is achieved due to differences in volatility, that is differences in vapour pressure, of the components in the mixture to be separated. The simplest kind of batch distillation process results in only a limited increase in the concentration of the more volatile component (MVC) in the distillate; a greater degree of separation can be obtained by using a fractionating column. In the food industry, distillation is used in the purification of raw alcohol and the production of beverage alcohol from wheat; the separation of flavour components, for example from the condensed vapour resulting from evaporation of fruit juices; as an important step in the production of bioethanol from sugar beet; and in the production of food grade white oils which are used as binders or coating materials. Other applications of distillation are the recovery, concentration and fractionation of aromas; the recovery of solvents from miscella; and the concentration and recovery of solvents used in extraction process such as the recovery of isopropanol used in the extraction of pectin from fruit peel.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Abbreviations
- a :
-
Coefficient
- b :
-
Constant
- D :
-
Molar flow rate (molar mass) of distillate
- F :
-
Molar flow rate (molar mass) of feed
- h f :
-
Enthalpy per kmol of feed at its boiling point
- h fg :
-
Molar latent heat of vaporisation
- h L :
-
Molar specific enthalpy of liquid stream
- h V :
-
Molar specific enthalpy of vapour stream
- hʹ :
-
Enthalpy per kmol of feed
- H :
-
Mass flow rate of ‘difference’ stream
- K :
-
Mass of solution per unit mass of inert solids in the underflow
- L :
-
Molar flow rate of liquid
- LVC:
-
Less volatile component
- MVC:
-
More volatile component
- p :
-
Partial pressure
- pʹ :
-
Pure component vapour pressure
- P :
-
System pressure
- q :
-
Heat to vaporise 1 kmol of feed entering the column per unit molar latent heat of feed
- R :
-
Reflux ratio
- \({R_{\min }}\) :
-
Minimum reflux ratio
- S :
-
Molar flow rate of steam
- V :
-
Molar flow rate of vapour
- w :
-
Mass flow rate of overflow stream
- W :
-
Molar flow rate (molar mass) of residue; mass flow rate of the underflow stream
- x :
-
Mole fraction of MVC in liquid phase; mass fraction of solute in underflow
- x D :
-
Mole fraction of MVC in distillate
- x F :
-
Mole fraction of MVC in feed
- x q :
-
Co-ordinate of point of intersection of operating lines
- x W :
-
Mole fraction of MVC in residue
- y :
-
Mole fraction of MVC in vapour phase; mass fraction of solute in overflow
- y q :
-
Co-ordinate of point of intersection of operating lines
- A:
-
Component A; solute
- B:
-
Component B; inert solids
- S:
-
Solvent
- n :
-
Plate in rectifying section; leaching stage
- m :
-
Plate in stripping section
- L:
-
Liquid
- V:
-
Vapour
- α :
-
Relative volatility
Further Reading
Grandison, A. S. and Lewis, M. J. 1996. Separation processes in the food and biotechnology industries. Cambridge: Woodhead.
Treybal, R. E. 1980. Mass transfer operations. New York, NY: McGraw-Hill.
Author information
Authors and Affiliations
Rights and permissions
Copyright information
© 2011 Springer Science+Business Media, LLC
About this chapter
Cite this chapter
Smith, P. (2011). Mass Transfer Operations. In: Introduction to Food Process Engineering. Food Science Text Series. Springer, Boston, MA. https://doi.org/10.1007/978-1-4419-7662-8_15
Download citation
DOI: https://doi.org/10.1007/978-1-4419-7662-8_15
Published:
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4419-7661-1
Online ISBN: 978-1-4419-7662-8
eBook Packages: Chemistry and Materials ScienceChemistry and Material Science (R0)