PRESENTATION:
RFCC CATALYST
Group 2: Trần Kiều Mỹ
Đỗ Bảo Trâm
Nguyễn Thị Khánh Huyền
Phạm Thị Trang
Hoàng Thị Tú Uyên
Đỗ Tuấn Cương
I. INTRODUCTION
RFCC VS FCC
FCC stands for Fluid Catalytic Cracking and
RFCC stands for Residue Fluid Catalytic Cracking.
2. Essentially, both processes refer to cracking from the high-boiling, high-molecular weight hydrocarbon of petroleum crude oils to more valuable gasoline, olefinic gases, and other products. At which, RFCC center on ultra cracking bottom with the heavy gas oil and residue to form gasoline and propylene.
Objective of RFCCU:
Convert crude oil to desirable products.
II. Catalyst in RFCCU
RFCC catalyst components
ZEOLITE
Formula: Na56[(AlO2)56(SiO2)136].250H2O
Acid site:





The activity of catalyst is decided by zeolite because zeolite provides acid sites and pores.
Pore size
MECHANISM OF CATALYTIC CRACKING

FOUR STAGES:
Substances dissociate on the catalyst surface.
Adsorption
Reaction on catalyst surface
Desorption of products.


MECHANISM
CATALYST DEACTIVATION
Physical factors:
concentration of acid sites, pores obstruction, …
2. Chemical factors:
Competitive adsorption by impurities.
Metal poisoning:
Vanadium (V): reacts with H2O(vapor) in O2 to form Vanadic acid which removes Al and destroys zeolite structure.
Nickel (Ni): catalyze for dehydrogenation make heavy substances and participates in condensation reaction to form coke and H2.
Self-poisoning from desirable reactions.
3. Methods to prevent deactivation:
For Vanadium, use MgO, CaO, Re2O3… to form stable compounds with Vanadium.
For Nickel, add Pd compounds and atinomy.
Coke products can be eliminated by heating with O2 stream and increasing acid sites.

CATALYST REGENERATION
Why we have to regenerate catalyst?
The amount of waste catalyst per day is very large ( 15-20 tons/day in RFCCU of Dung Quat Refinery).
Then, regenerate catalyst increases the efficiency and productivity of the process.
2. Methods:
Decrease the coke products.
Increase the acidity.
Increase surface area.
=> Burning coke by the air in hot regenerator at the appropriate temperature ( about 540-680C).

NOTE:
The productivity of the regeneration process is not 100% ,That mean it always exist amount of non-regenerate catalyst . Then we need to supplement fresh catalyst to keep the stable productivity.

3. Reactions
C + ½ O2 → CO + Q
CO + ½ O2 → CO2 + Q
H2 + ½ O2 → H2O + Q
=>Q will supply the catalyst in reactor.
4. Process
Simple diagram:
(7)->(5)->(9)->Regenerator->(6)

CONCLUSION:
RFCC unit is the heart of refinery company. Therefore, every companies now end then is finding the way to improve the technology in these aspect.
Nowaday, Solid acid is more preferable than Liquid acid although the Liquid acid provides a higher efficiency because Solid acid can be regenerated easier, friendly with environment and supply a large porous system.
The end