Page 460 - Elements of Chemical Reaction Engineering Ebook
P. 460
Sec. 8.2 The Energy Balance 431
(8-12)
We first express the molar flow rates in terms of .conversion.
In general, the molar flow rate of species i for the case of no accunnula-
tion and a stoichiometric coefficient vi is
Fi = FAo (Oi + viX)
Specifically, for Reaction (2-2) we have
/ \
/ \
Steady-state
operation
(8-13)
The term in parentheses that is multiplied by FAOX is called the heat of
reaction at temperature T and is designated AH,,.
Heat of reaction at d b
temperature T ara,, (TI = - H, ( T) + f H, ( T) - a H, ( T) - H, (T) (8-14)
a
All of the enthalpies (e.g., HA, HB) are evaluated at the temperature at the out-
let of the system volume, and consequently, [AHRx(T)] is the heat of reaction
at the specific temperature ip: The heat of reaction is always given per mole of
