1. Case 2B - Unit A in the south of France lost 40°C of activity in few days Evolution de la temp é rature normalis é e %S de la chage = 5000 ppm, GO d é sulfur é = 320 ppm, VVH = 1 h, PPH 2 = 25 bar, H 2 /Hc = 90 Nm 3 /m 3 300 310 320 330 340 350 360 370 380 390 0306090120150180210240270300330360390 Temp é rature normalis é e en °C Jours de cycle Case 2 – Unit Poor Performances

2. Possible causes: - Catalyst deactivation during shut-down? - Catalyst pollution by heavier feeds (metals)? - Gas/Liquid maldistribution? - … Always the same: WHAT CHANGED BEFORE THEN AND NOW? Case 2 – Unit Poor Performances

3. 250 mm Reactor diameter - 3000 mm Beam of 321 stainless steel Thermal growth of 2 mm/m/100°C (general rule for steels is 1 mm/m/100°C)

4. Case 2 – Unit Poor Performances temperature HP separator liquid level flowrate HP separator pressure Possible causes: - beam dilatation? - other?