A
Chemical species
Ac
Cross-sectional area (m2)
Ap
Total external surface area of particle (m2)
ap
External surface area of catalyst per unit bed volume (m2/m3)
a
Area of heat exchange per unit volume of reactor (m-1)
ac
External surface area per volume of catalyst pellets (m2/m3)
B
Chemical species
BA
Flux of A resulting from bulk flow (mol/m2 · s)
Bo
Bodenstein number
C
Chemical species
Ci
Concentration of species i (mol/dm3)
Cpi
Heat capacity of species i at temperature T (cal/gmol · K)
Mean heat capacity of species i between temperature T0 and temperature T (cal/mol · K)
Mean heat capacity of species i between temperature TR and temperature T (cal/mol · K)
c
Total concentration (mol/dm3) (Chapter 14)
D
Chemical species
Da
Damköhler number (dimensionless)
DAB
Binary diffusion coefficient of A in B (dm2/s)
Da
Dispersion coefficient (cm2/s)
De
Effective diffusivity (dm2/s)
DK
Knudsen diffusivity (dm2/s)
D*
Taylor dispersion coefficient
E
Activation energy (cal/gmol)
(E)
Concentration of free (unbound) enzyme (mol/dm3)
Fi
Molar flow rate of species i (mol/s)
Fi0
Entering molar flow rate of species i (mol/s)
G
Superficial mass velocity (g/dm2 · s)
Rate of generation of species i (mol/s)
Gibbs free energy of species i at temperature T (cal/gmol · K)
Hi (T)
Enthalpy of species i at temperature T (cal/mol i)
Hi0 (T)
Enthalpy of species i at temperature T0 (cal/mol i)
Enthalpy of formation of species i at temperature TR (cal/gmol i)
h
Heat transfer coefficient (cal/m2 · s · K)
JA
Molecular diffusive flux of species A (mol/m2 · s)
KA
Adsorption equilibrium constant
Kc
Concentration equilibrium constant
Ke
Equilibrium constant (dimensionless)
KP
Partial pressure equilibrium constant
k
Specific reaction rate (constant)
kc
Mass transfer coefficient (m/s)
Mi
Molecular weight of species i (g/mol)
mi
Mass of species i (g)
Ni
Number of moles of species i (mol)
n
Overall reaction order
Nu
Nusselt number (dimensionless)
Pe
Peclet number (Chapter 17)
Pi
Partial pressure of species i (atm)
Pr
Prandtl number (dimensionless)
Q
Heat flow from the surroundings to the system (cal/s)
R
Ideal gas constant
Re
Reynolds number
r
Radial distance (m)
rA
Rate of generation of species A per unit volume (gmol A/s·dm3)
–rA
Rate of disappearance of species A per unit volume (mol A/s·dm3)
Rate of disappearance of species A per mass of catalyst (mol A/g·s)
Rate of disappearance of A per unit area of catalytic surface (mol A/m2·s)
S
An active site (Chapter 10)
(S)
Substrate concentration (gmol/dm3) (Chapter 7)
Sa
Surface area per unit mass of catalyst (m2/g)
SD/U
Instantaneous selectivity (Chapter 8)
Overall selectivity of D to U
Sc
Schmidt number (dimensionless) (Chapter 10)
Sh
Sherwood number (dimensionless) (Chapter 10)
SV
Space velocity (s-1)
T
Temperature (K)
t
Time (s)
U
Overall heat transfer coefficient (cal/m2·s·K)
V
Volume of reactor (dm3)
V0
Initial reactor volume (dm3)
υ
Volumetric flow rate (dm3/s)
Entering volumetric flow rate (dm3/s)
W
Weight of catalyst (kg)
WA
Molar flux of species A (mol/m2·s)
X
Conversion of key reactant, A
Yi
Instantaneous yield of species i
Overall yield of species i
y
Pressure ratio P/P0
yi
Mole fraction of species i
yi0
Initial mole fraction of species i
Z
Compressibility factor
z
Linear distance (cm)
0
Entering or initial condition
b
Bed (bulk)
c
Catalyst
e
Equilibrium
p
Pellet
α
Reaction order (Chapter 3)
α
Pressure drop parameter (Chapter 5)
αi
Parameter in heat capacity (Chapter 12)
βi
Parameter in heat capacity
β
Reaction order
γi
Parameter in heat capacity
δ
Change in the total number of moles per mole of A reacted
ε
Fraction change in volume per mole of A reacted resulting from the change in total number of moles
η
Internal effectiveness factor
Θi
Ratio of the number of moles of species i initially (entering) to the number of moles of A initially (entering)
λ
Dimensionless distance (z/L) (Chapter 15)
λ
Life expectancy (s) (Chapter 17)
μ
Viscosity (g/cm·s)
ρ
Density (g/cm3)
ρc
Density of catalyst pellet (g/cm3 of pellet)
ρb
Bulk density of catalyst (g/cm3 of reactor bed)
τ
Space time (s)
ϕ
Void fraction (Porosity)
ϕn
Thiele modulus
ψ
Dimensionless concentration (CA/CAs)
Ω
35.175.212.5