Diffusion and convective flow in the pores of pellets formed by compressing mixtures of calcined limestone and CaSO 4 /CaCl 2 powders have been studied experimentally by using the single pellet moment technique. The experiments were conducted in a diffusion cell by flowing nitrogen gas (carrier) thr
Effective diffusivities for catalyst pellets under reactive conditions
β Scribed by D. Ryan; R.G. Carbonell; S. Whitaker
- Publisher
- Elsevier Science
- Year
- 1980
- Tongue
- English
- Weight
- 482 KB
- Volume
- 35
- Category
- Article
- ISSN
- 0009-2509
No coin nor oath required. For personal study only.
β¦ Synopsis
A theory is developed that allows the calculatron of the components of the effective diffusivity tensor under reaction conditions In spatially periodic porous media. Under normal conditions, it can be shown that the effective diffusivity should be independent of the rate of the chemical reaction. Preliminary calculations are provided illustratlng the effect of the particle void fraction on the effective diffusivlty.
π SIMILAR VOLUMES
The transient behavior of exothermic, irreversible, first-order catalytic reaction inside a spherical, porous pellet is analyzed using mixed type boundary conditions to represent extetial resistances. Calculations are performed for Lewis number, pC,DJeh,, equal to unity and a pellet initially at uni
In tlus connectlon It IS a strmghtforward matter to show that EC (7) IS an exact representation for Enhancement at the limits of slow and fast reaction This LS because It can be denved by assummg that the species k 1s constant and equal to the concentration of k at the Interface, at least up to the