Page 253 - Principles of Catalyst Development

APPENDIX 3

Units and Nomenclature

Conversion
Quantity Symbol Common units SI Units factor

I. DIFFUSION
Bulk diffusivity D8 cm 2 js m 1 S-I 1.000E - 4
Knudsen diffusivity DI< cm 2 js m 2 S--I 1.000E - 4
Pellet effective Dell cm 2 js m 2 s- I 1.000E - 4
diffusivity
Heat transfer h caljs cm' °C J S -I m-' K- 1 4.187E+4
coefficient
Heat transfer factor jH
Mass transfer k, cmjs ms- I 1.000E - 2
coefficient kg moles/s em' atm mole m- 2 s 1 Pa-I 9.871E-8
Mass transfer factor jn
Thiele modulus <P
Effective factor 17, EF
2. ADSORPTION
Volume adsorbed V cm 3 /g m 3 kg 1 1.000E - 3
Monolayer volume Vm cm'/g m 3 kg-I 1.000E - 3
Surface area S,' m'/cm' (cat) m'(m' cat) -, 1.000E + 6
S, m'jg m 2 kg 1 1.000E + 3
Surface coverage Ii
Adsorption KA atm' 1 Pa'" 9.869E - 6
coefticient
Enthalpy of H" kcal/mole J mole-I 4.187E+3
adsorption
Activation energy of E" kcal/mole J mole-I 4.187£ + 3
adsorption
3. KINETICS
Total pressure P, atm Pa 1.013£+5
Partial pressure P, atm Pa 1.0UE + 5
Concentration C,' mole/liter mole m- 3 1.000E + 3
(continued)
243