The document provides an overview of a fluidized catalytic cracking unit (FCCU) at an Indian oil corporation. It describes the FCCU's feedstocks as heavy vacuum gas oil and once-through hydrogen cracker unit bottom oil. The main products are dry gas, LPG, gasoline, heavy naphtha, light cycle oil, and coke. It outlines the reactor, regenerator, fractionator, and gas concentration sections of the FCCU and discusses key operating parameters like temperatures, pressures, and catalyst/oil ratio.

1. Indian oil Corporation Limited
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JUNE- JULY 2023
BY KRISHNA KUMAR-(200103040)
OVERVIEW OF
FLUIDZED CATALYTIC
CRACKING UNIT

2. CONTENTS
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• Introduction to Fluidized catalytic cracking unit
• Feed of Fluidized catalytic cracking unit
• Products of fluidized catalytic cracking unit
• Flow sheet of fluidized catalytic Cracking unit
• Reactor-Regenerator Section
• Fractionator Section
• Gas Concentration unit
• Operating parameter of fluidized catalytic cracking unit

3. What do you mean by FCCU?
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Fluidized Catalytic Cracking is a process
for converting higher molecular weight
hydrocarbons into lighter, more valuable
product through contact with a
powdered catalyst at appropriate
process conditions

4. Feed of Fluidized catalytic cracking unit
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Design capacity -1.0 million metric ton per annum
Present capacity- 1.5 million metric 10 per annum
Design feed
• Heavy vacuum gas oil {derived from Nigerian and
Bombay High crude}
• Once Through hydrogen cracker unit bottom
(UCO)

5. Composition of Feed
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Feed
Specification M3/hr Vol% Wt%
Nigerian
HVGO 140 68.29% 70.20%
OHCU Bottom 65 31.71% 29.80%

6. Products of Fluidized Catalytic Cracking Unit
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Component Wt%
Dry Gas (H2S,H2,C1) 3.16
C3 15.52
Total LPG 35.01
Gasoline 34.82
Heavy Naphtha 10.1
LCO 8.44
Coke 4.59
Above yield is based on design feed with 50KG per day ZM5 additive dosing
And 3m3/ hr Slurry recycle recycle to riser

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Reactor Section
• At riser bottom feed comes in contact with hot catalyst and
cracking start occurring.
• Flow of hot catalyst is regulated by slide valve in order to
control reactor temperature.
• The cracking reactions are endothermic.
• Coke generated in the cracking reactions get deposited on
the surface of the catalyst particle.
• The catalyst gets separated from cracked hydrocarbon
vapour and steam at two sets of direct coupled cyclones

9. Regenerator Section
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• The spent catalyst firm reactor stripper goes to
regenerative under level control.
• In Regenerator air is being supplied from MAB to burn of
the deposited Coke and thus the catalyst get
regenerated.
• Oxidation of Coke is highly endothermic reaction
• Supplies the necessary heat to reactor for reaction in
such a way that the unit remains in heat balance always.
• Flue gas leaving that dense bed of catalyst passes
through three sets of 2 stage cyclone separator

10. Fractionator Section
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• The superheated vapors from reactor enters below the bottom most tray and is cooled
down to 360 degree Celsius for fractionation.
• The superheated vapors rises up in the fractionation column, The first faction
accumulates in draw off tray is heavy cycle oil.
• LCO Drawn from the accumulator below 19 th tray is sent back to column as circulating
reflux after supplying heat to reboiler
• Heavy naphtha cut is drawn from accumulator below second packing and returned back
to column as a circulating reflux.
• A part of LCO and heavy naphtha draws are stripped and rooted to product tank after
exchanging heat and cooling as diesel component.

11. Gas Concentration Unit
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• Uncondenced vapor is compressed by wet gas compressor (wgc),cooled
and liquid is collected in hp reciever.​
• Wgc is a two stage wet gas compressor system driven by h steam turbine.​
• The partially condensed stream is seperated into net gas ,
hydrocarban condensate and sour water in wgc inter stage knockout drum
(kod).
• Uncondensed vapours from kod is compressed by second stage
of compressor.​
• The cooled stram is routed to the hp seperator , the uncondensed vaour ,
high pressure distillate and sour water are seperated out in this drum.

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• The uncondensed vapour from hp receiver are outed to the primary absorber
• c3-c4 recovery gases and h2s then passes through sponge absorber for the
recovery of gasoline and finally routed to refinery fuel gas system.
• Liquid from hp seperator is fed to stripper 20c3 where it is heated in reboiler to
strip out hydrogn sulfide , methane and ethane etc. Before sending it to de-
butanizers for stabilization.
• 20c3 bottom is fed to 20c4 an 20c205 where it seperated into lpg and gasoline.
• Lpg is routed to lpg treater unit(lpgtu) for h2s & merceptan removal.
• Gosoline is routed to shu of prime-g unit.

13. CATALYST ADDITION SYSTEM
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The unit require following types of catalyst .
• Fresh catalyst
• Zsm 5 catalyst
• Co promoter additive catalyst​

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Operating Parameter of FCCU
Operating Parameter
Riser outlet Temperature 547(celsius)
Regenerator temperature 700(Celsius)
Reactor pressure 2.81kg/cm2
Regenerator pressure 3.23kg/cm2
Fresh feed 205m3/hr(max)
Catalyst/oil ratio 7.48wt/wt

15. THANK YOU
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