Investigation of Catalytic Properties of Immobilized Enzymes and Cells by Flow Microcalorimetry - Advances in Biochemical Engineering Biotechnology - page 72

Fig. 3. The reactor model describing the column packed with particles of immobilized bio-
catalyst

When no heat losses cross the reactor wall are present, the local temperature
change depends directly on the reaction rate. Then, material and heat balances
can be defined as

dc Sb

-w = eh v kin (1)

8

dz

dc Pb

w = eh v kin (2)

8

dz

dT

w Ç C P = eh v kin (- D H r ) (3)

6

dz

where c Sb and c Pb are the local bulk-phase concentrations of substrate and pro-
duct,respectively,T is the absolute temperature,z is the axial coordinate, is the

effectiveness factor expressing the effect of the particle mass transfer on the
reaction rate.V kin is the intrinsic reaction rate considered as the reaction rate per
unit of void volume of the packed bed.The superficial flow rate,w,bed void frac-
tion,

h

H r ,and fluid specific heat capa-
city,C p ,will be considered constant for the specific experimental system.
The above differential equation system is coupled with one of boundary
conditions according to the notation used in Fig. 3:

e ,fluid density, r ,molar reaction enthalpy, D

z = 0: T =T 1 c Sb = c Sb1 c Pb = c Pb1 (4)

z = Z: T = T 2 c Sb = c Sb2 c Pb = c Pb2 . (5)