Environmental Engineering Reference
In-Depth Information
Figure 6.13: Initial cumulative yields of CO
2
from stepwise isothermal burn-off of spent catalyst in
air [From ref.
374
. Reprinted with permission].
this manner are much more accurate than those determined by the other techniques, e.g.,
measuring weight loss during regeneration.
Table 6.3 [387]
compares kinetic parameters determined from the weight loss during thermal
gravimetric analysis (TGA) and those obtained from the cumulative yields of products
determined in the chemically controlled burn-off region. The TGA results were affected by the
O
2
chemisorption that had an opposite effect on the weight loss. This resulted in the
Table 6.3: Rate constants from TGA and from yield of products [From ref.
387
. Reprinted with
permission].
Temperature (
◦
C)
Rate constant (1/min atm)
TGA
Yields
Oxidic
Sulfided
Oxidic
Sulfided
300
-
-
0
.
094
0
.
97
350
0
.
095
1
.
64
-
-
400
0
.
37
2
.
00
1
.
08
3
.
01
450
0
.
65
2
.
46
-
-
500
1
.
52
2
.
60
10
.
30
18
.
90
