Microsoft Word master thesis report fina doc

4.4.4. Influents / effluents scheme 
The following schemes represent simply what enters and what goes out the battery limit 
during normal operations.

---

48
Figure B-4-5: Influents/effluents scheme for C
3
 selective hydrogenation during normal 
operations 
Figure B-4-6: Influents/effluents scheme for C
4
 selective hydrogenation during normal 
operations 
Figure B-4-7: Influents/effluents scheme for gasoline hydrogenation during normal 
operations 
Gasoline 
hydrogenation 
H
2
Gasoline product 
Fugitive emissions 
Gas relieves 
Off-gas 
C
4
selective 
hydrogenation 
H
2
Hydrogenated C
4
cut 
Fugitive emissions 
Gas relieves 
C
3
selective 
hydrogenation 
H
2
Hydrogenated C
3
cut 
Fugitive emissions 
Gas relieves 
Raw C
3
cut 
Raw C
4
cut 
Recycle C
4
cut 
Reflux drum purge gas 
Reflux drum water draw-off 
Raw pyrolysis 
gasoline 

---

49
4.5. Intermittent operations 
4.5.1. Catalyst reduction / reactivation / hot hydrogen stripping 
Catalyst reduction 
Before the first use of the catalyst, and after regenerations, the catalyst is in the oxide form, 
which is inactive. It has to be reduced with hydrogen to recover its active form. The reduction 
reaction is the following: 
MeO + H
2
→ Me + H
2
O 
(Me corresponds here to the metal used as catalyst, for instance palladium Pd) 
The flow of dry reduction gas through the catalyst allows the elimination of the water 
contained in the catalyst. 
 
Catalyst reactivation / hot hydrogen stripping 
Reactivation is hot hydrogen stripping used when the catalyst is deactivated by free water 
carry-over. These two operations are similar to reduction except the operating temperature.
Figure B-4-8: Influents/effluents scheme for C
3
 selective hydrogenation during catalyst 
reduction or reactivation 
 
Figure B-4-9 Influents/effluents scheme for C
4
 selective hydrogenation during catalyst 
reduction, reactivation or stripping 
 
C
4
selective 
hydrogenation 
Catalyst reduction 
/ reactivation / 
stripping 
Gas (H
2
(25%) 
+ N
2
(75%)) 
Gas with presence 
of HC and H
2
O 
C
3
selective 
hydrogenation 
Catalyst reduction 
/ reactivation 
Reduction / 
reactivation 
gas 
Reduction / 
reactivation gas 
with presence of 
HC and H
2
O 

---

50