Page 4 - Academic Press Encyclopedia of Physical Science and Technology 3rd Chemical Engineering

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Encyclopedia of Physical Science and Technology EN001H-01 May 31, 2001 11:5

Absorption (Chemical

Engineering)

James R. Fair

University of Texas at Austin

Henry Z. Kister
Fluor-Daniel Corp.

I. Absorption in Practice
II. Principles of Absorption
III. Models for Absorption Equipment
IV. Absorber Design

GLOSSARY period of time so that equilibrium is obtained, and are
then separated.
Absorption factor Ratio of liquid to gas flow rate divided Inerts Gas components that are not absorbed by the
by the slope of the equilibrium curve. liquid.
Films Regions on the liquid and gas sides of the interface Interface Surface separating the liquid from the gas.
in which fluid motion is considered slow and through Equilibrium is assumed to exist at this surface.
which material is transported by molecular diffusion LPG Liquified petroleum gas.
alone. Lean gas Gas leaving the absorber, containing the inerts
Gas solubility Quantity of gas dissolved in a given quan- and little or no solute.
tity of solvent at equilibrium conditions. Lean solvent Solvent entering the absorber, containing
Hatta number Ratio of the maximum conversion of re- little or no solute.
acting components into products in the liquid film to the Mass transfer coefficient Quantity describing the rate of
maximum diffusion transport through the liquid film. mass transfer per unit interfacial area per unit concen-
Height of a transfer unit Vertical height of a contactor tration difference across the interface.
required to give a concentration change equivalent to Number of transfer units Parameter that relates the
one transfer unit. change in concentration to the average driving force.
Ideal stage Hypothetical device in which gas and liquid It is a measure of the ease of separation by ab-
areperfectlymixed,arecontactedforasufficientlylong sorption.

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