Information Technology Reference
In-Depth Information
Figure 10.5
Lumping and component mapping.
equilibrium on the products of reaction. Two primary options are available for each
reaction: specification of the extent of reaction as described by equations (10.1)
through (10.4), or calculation of the equilibrium constant for the reaction
K
eq
from
the standard state change Gibbs free energy,
G
◦
, of the components of the reaction,
using the equation
K
eq
=
e
−
(g
◦
/RT )
(10.5)
where
g
◦
=
g
products
−
g
reactants
(10.6)
The effect of temperature on the reaction equilibrium constant can be calculated as
h
◦
T
2
ln
K
T
2
1
R
eq
K
T
1
eq
=
dT
(10.7)
Subsequently, the compositions of the products and reactants at equilibrium are
calculated using equation (10.7):
f
product
f
reactants
K
eq
=
(10.8)
where
f
is the fugacity of a component.
An example of REquil, the chlorination of benzene, using the approach to the equi-
librium option may be found at Examples/REquilExample1. The reaction setup and
specifications are shown in Figure 10.6. Note that the selection “temperature approach”
is 0
◦
F, which indicates equilibrium. An example of REquil using the “extent of reac-
tion” option, with the same reactions, may be found at Examples/REquilExample2.
