Environmental Engineering Reference
In-Depth Information
Figure 6.15: Model for simultaneous carbon and hydrogen oxidation [From ref.
13
. Reprinted
with permission].
size of FCC catalysts is much smaller than that of the spent hydroprocessing catalysts. It was
observed that for the latter catalyst containing 7 wt.% of coke, even at 350
◦
C, the skin of coke
had to be combusted before O
2
could diffuse into particle interior
[322]
. This is evident from
Fig. 6.16
, showing the evolution of CO
2
, CO, HCN, and NH
3
during regeneration of the
Figure 6.16: Cumulative formation of CO
2
, CO, HCN, and NH
3
during oxidation of spent catalyst
in 2% O
2
at 350
C [From ref.
422
. Reprinted with permission].
