Fluid Catalytic Cracking Unit

FCC OPERATIONS & SALIENT DESIGN ASPECTS

17TH MARCH 2011

V.SRIKANTH SENIOR MANAGER(NHT/ISOM)

CONTENTS
GENERAL FCCU SCENARIO CRACKING REACTIONS FLUIDISATION CATALYST PROCESS DESCRIPTION PROCESS VARIABLES CRACKER EQUIPMENT

GENERAL

GENERAL
PRODUCTS OF PETROLEUM CRUDE OIL
Gas (Methane & Ethane) LPG (Propane & Butane) Naphtha Kerosene / ATF Diesel Industrial fuel Household fuel Industrial feed / Motor Spirit (MS) Household fuel / Aviation Fuel Automobile fuel

Vacuum Gas Oil

No direct end use

Lube oil Lubricating oil Paraffin Wax Candle, Matches, Water proof coating Vacuum residue (Bottom) Industrial fuel, Asphalt

GENERAL
Price $/ton
H WW BS PP

Yield vs Price

Base Case GRM = 4.75 $/bbl

800 700 600 500 400

MW C3 LUB ATF MS Loc HSD KERO LPG Exp HSD Loc Naph Exp Naph
CRU Feed FCC Feed HCU Feed

Average Crude Price = 377 $/t 300 200 100

SULP LO Byp Loc FO BIT Stocks Exp FO F&L
VBU Feed PDU Feed

0 0% 10% 20% 30% 40% 50% Cum yield %wt 60% 70% 80% 90% 100%

GENERAL
PRIMARY PROCESSING UNIT SECONDARY PROCESSING UNIT Secondary units are installed to:
Upgrade lower grade products Increase value added products Maximise production of products in demand Production of specialty products Minimise production of undesired products To meet Product / Environmental specifications

GENERAL
MEANS OF VALUE ADDITION
Thermal Cracking Catalytic Cracking Hydro Cracking Extraction / Filtration Iso-Dewaxing High value light products - do - do Lube base oil / Wax Lube base oil

GENERAL
CATALYTIC CRACKING
Cracking VGO into low molecular weight products of high value, by application of heat and in the presence of catalyst Good selectivity for producing desired products Good quality products (Mainly mono-olefins) Specialty products (Propylene, Butylenes) High initial investment Low fuel and loss

WHY FCCU?
Benefits of FCCU:
Converts heavy ends into desired lighter products Reaction involves regrouping of molecules to provide the quality product Flexibility in product pattern Production of lower molecular weight special products like Propylene, Butylenes Reduces the Sulphur content in liquid streams by converting into H2S Minimise production of undesired products

FLEXIBILITY IN FCC
Easy Catalyst / Additive Loading & Withdrawal No Hot Spot Automatic Balancing of Heat / Pressure Feed Quality Variations Low pressure , Moderate temp.

FCC is Flexible and Thus Growing

Flexibility of Operating FCC Unit

Operating Conditions Reactor Temp. C Residence Time Catalyst/ Oil Ratio Recycle, CFR Middle Dist. Mode 449 510 < Base < Base 1.4 (HCO) Gasoline Mode 527 538 Base Base Optional (HDT LCO) Light Olefin Mode 538 560 > Base > Base Optional (Heavy Naphtha)

Flexibility of Operating FCC Unit

Product Yield H2S, wt.% C2, wt.% C3, LV% C4, LV% C5+ gasoline, LV % LCO, LV% HCO, LV% Middle Dist. Mode 0.7 2.6 6.9 9.8 43.4 37.5 9.2 Gasoline Mode 1.0 3.2 10.7 15.4 60.0 13.9 7.2 Light Olefin Mode 1.0 4.7 16.1 20.5 55.2 10.1 7.0

FCC BALANCES
Mass Balance Heat Balance

Coke Balance
Pressure Balance FCC is floating on balances

FCCU SCENARIO

FLUIDISED CATALYTIC CRAKING

400 FCC Units in World Major Secondary Process since 1942 Major source of high value lighter hydrocarbon Complex, Interlinked but Flexible Flexible operation modes: LPG, MS & Diesel Continuous developments in Design Development of Catalyst & Additives

FCC is Workhorse of Refinery

FCC/RFCC UNITS IN INDIA

S. NO 1 2 3 4 5 6 7 8 9 10 11 12 13 REFINERY HPCL(BOMBAY) BPCL( BOMBAY) HPCL(VISAKH) IOCL(GUJARAT) IOCL(MATHURA) CPCL (MADRAS) BPCL(BOMBAY) KRL(COCHIN) HPCL(VISAKH) IOCL(PANIPAT) Reliance (Jamnagar) IOCL(HR) RFCC IOCL(BR) RFCC CAPACITY MMTPA 0.40 1.20(0.60) 0.95(0.40) 1.4 1.00 0.78(0.60) 0.85 1.75(1.00) 0.60 0.70 8.0 1.0 1.4 LICENSOR ESSO SHELL(MODEL IV) EXXON(ESSO) UOP UOP UOP SWEC(UOP) UOP UOP S&W UOP S&W S&W YEAR OF COMMISSIONING 1954 1995(1955) 2000(1957) 1982 1983 2004(1985) 2002(1985) 2005(1985) 1985 1997 1998 2001 2002

BLOCK FLOW DIAGRAM OF MODERN REFINERY

CRACKING REACTIONS

Principal Reaction Paths

Thermal Cracking Catalytic Cracking

Primary Reactions Secondary Reactions

Process Variables

19

Primary Reactions

Paraffin Alkyl naphthene Alkyl aromatic Multi-ring naphthene

Smaller paraffin + olefin Naphthene + olefin Aromatic + olefin Alkylated naphthene with fewer rings
Process Variables 20

Secondary Reactions

Olefin + paraffin Olefin + naphthene Olefin + olefin Olefin + olefin

Paraffin + olefin Paraffin + aromatic Paraffin + diolefin (or coke) Paraffin + aromatic

Process Variables

21

FLUIDISATION

FLUIDIZATION REGIMES IN FCC

Name Packed Bed Min Fluidization Bubbling bed Dense Bed Turbulent Bed Fast Fluid Bed Pneumatic Flow FCC Section -Standpipe Stripper Regenerator -Combustor Riser Gas Velocity M/Sec < 0.05 .01 - .05 .05 - .30 .30 - .70 .70 - 1.1 1.1 - 3.0 2.0 - 20.0 Bed Density, KG/M3 700 - 850 700 - 800 600 - 750 400 - 600 300 - 500 100 - 300 30 - 100

FLUIDIZATION REGIME IN FCCU

TC

LC

V=0.05-0.30
Stripper

=700-800
Air

V=0.3-0.7 = 400-600

V=2-20 = 30-100
V=0 = 7.01-0.0 00-8 5 00
Riser

CATALYST

FCC CATALYST
CLAY

Re-EARTHS

ZEOLITE

MATRIX

PERFORMANCE FEATURES OF FCC CATALSYTS

Zeolite type and level of rare earth Particle size Distribution, density Activity and stability Fluidization Selectivity

Zeolite type matrix type and amount

Unit retention

Metal tolerance

Density, Attrition resistance

Zeolite type, matrix type, traps

FCC CATALYST ADDITIVES

Olefin maximisation additives Octane enhancement additives Bottom Cracking Additives (BCA) DeSOx additives Metal traps Gasolene Sulphur Reduction (GSR) additives

PROCESS DESCRIPTION

Products to Main Column

UOP Side by Side Fluid Catalytic Cracking Unit

Reactor Flue Gas

Flue Gas Slide Valve

Stripping Steam Regenerator

Spent Catalyst Slide Valve

Air

Regenerated Catalyst Slide Valve

Raw Oil

Regenerated Catalyst Slide Valve Control

Reactor TIC High Temperature Closes Slide Valve

Low Signal Selector < Low Differential Pressure Signal Closes Slide Valve PDIC PDI
(readable from slide valve)

PDT PI PI Regenerated Catalyst from Upper Regenerator

Regenerated Slide Valve
FC

DA Handwheel Actuator

ZI

DG

Selector Switch

Process Flow and Control

32

Reactor

Spent Catalyst Slide Valve Control

Low Level Signal Closes Slide Valve

LIC LIC
DG (LAHL) LT DG

LT

Low Differential Pressure Signal Closes Slide Valve

DG DI DG DG DG DT

Low Signal Selector > PI LI

PDIC PDT PI

PDI

ZI DG FC

Readable from Slide Valve Actuator

Actuator Selector Switch

DA

Process Flow and Control

Spent Catalyst to Regenerator

33

Conventional FCC Flue Gas System

(without Power Recovery)
HSS >

PIC

PDIC

Signal from Reactor Pressure Tap

Flue Gas Slide Valves

Flue Gas

Orifice Chamber Steam

CO Boiler Air Air Water

Electrostatic Precipitator

FCC-PC002

Process Flow and Control

34

Main Column Bottoms Circulation

Reactor Product Vapor

FIC

FIC

LIC

HCN Stripper Reboiler

Debutanizer Reboiler

Torch Oil Pump Flushing Oil

MCB Quench

FIC

Disc and Donut Minimum Flow

Steam
FIC FI

LIC

Raw Oil

FIC

BFW
FIC FIC

MCB Product
CW

Raw Oil

FCC-PC401

Process Flow and Control

35

PROCESS VARIABLES

Process Variable Effects

Regenerator Temp Cyclone Efficiency Aromatic Content Reqd Stripping Steam Rate 37 LCO Aromatic Content Olefin Content

Affected Variable
Conversion LPG Yield Gas Yield

Gasoline

Adjusted Variable
Increased Combined Feed Temperature Increased Recycle Rate Increased Reactor Temperature Increased Reactor Pressure Increased Regenerator Pressure Increased Catalyst Circulation Rate at Constant Reactor Temperature (Increased Cat Cooler Duty)

Change in Affected Variable:

increases;

decreases

Process Variables

Catalyst Entrainment

Catalyst/Oil

Coke Yield

Octane

CRACKER EQUIPMENT

HARDWARE SUBSYSTEMS FOR FCC Feed distributor Riser termination device Stripper with efficient internals Catalyst & air distributors in regenerator Catalyst cooler Cyclones Flue gas scrubber
HARDWARES PLAY MAJOR ROLE IN FCC

Feed Distributor Historical Development

Bayonet Showerhead Premix Lift Gas Optimix

Equipment

40

Reactor Riser Feed Distributor

Jet Nozzle Type

Abrasion Resistant Lining

Abrasion Resistant Lining

FCC/DS-R00-98

Drain and Vacuum Connection

Equipment 41

Elevated Optimix Feed Distributor

Equipment

42

Optimix Feed Distributor

Work Point High Density Refractory Lining

Abrasion Resistant Lining

Welding Neck Flange Steam Connection

Ceramic Fiber Blanket Insulation Reactor Riser Feed Distributor

Equipment

Feed Connection
43

Reactor Riser Disengager Designs

Down-Turned Arms Vented Riser Direct-Connected Cyclones Suspended Catalyst Separation Vortex Disengager System and Vortex Separation System
Equipment 44

Reactor Riser Disengaging Devices

T-Type Disengager

Down Turned Arm

Equipment

Vented Riser

Direct-Connected Cyclones
45

Modern Reactor Riser Disengaging Devices

Vortex Disengager Stripper

Equipment

Vortex Separation System

46

Reactor WYE Section

Hot Wall vs. Cold Wall Cold Wall Advantages

Less Thermal Expansion No High Temperature Metallurgy Metal Temperature Out of Creep Range No Stress Relief Increased Operating Life

Equipment

47

Hot Wall WYE

Regenerated Catalyst Riser 304H SS 3/4 Abrasion Resistant Lining External Insulation

Blast Steam

Charge
Equipment 48

Cold Wall WYE

Regenerated Catalyst Riser Carbon Steel 5 Refractory Cement Lining

Blast Steam

Charge
Equipment 49

Catalyst Stripper

Insulation Riser Stripper Shell

Stripping Steam Abrasion Resistant Lining

Stripping Steam

Fluffing Steam
FCC-E005

Equipment

50

Bubbling Bed Regenerator

THERMOCOUPLES (1each cyclone) CYCLONE SUPPORTS REGENERATOR PLENUM

REFRACTORY LINING

MANWAYS

LEVEL AND PRESSURE TAPS TIs FIRST STAGE CYCLONES REFRACTORY LINING

SECOND STAGE CYCLONES

SPENT CATALYST DEFLECTOR

EXTERNAL LINING TRICKLE VALVES TORCH OIL MANWAY OPEN PRIMARY CYCLONE DIPLEG TERMINATIONS

SPENT CATALYST STANDPIPE LEVEL AND DENSITY PRESSURE TAPS

AIR DISTRIBUTOR REGENERATED CATALYST STANDPIPE

CATALYST WITHDRAWAL

FCC-E003

Pipe Air Grid

Equipment

52

Plan of Air Grid

PLAN (Total Number of Arm Jets Required: 1024) = Open Jets: 850 = Plugged Jets: 174
Equipment

53

Jet Detail

FCC/DS-R00-65

Equipment

54

Cyclone-Catalyst Fines Collector

Gas Out Catalyst-Free Gas Outlet

Catalyst-Laden Gas Inlet Catalyst-Laden Gas Inlet

Disengaging Hopper Catalyst Outlet Dip Pipe

Equipment

Stream Pattern-Lower Portion Stream Pattern-Upper Portion (Principally Finer Particles)

55

Regenerator Cyclones

First Stage

Inlet Velocity Shall Not Exceed 65 ft/sec (19.8 m/sec) Outlet Velocity Shall Not Exceed 80 ft/sec (24.4 m/sec) Ratio of Barrel Area to Inlet Area Shall be 3.7 Minimum

Equipment

56

Regenerator Cyclones (continued)

Second Stage

Inlet Velocity Shall Not Exceed 75 ft/sec (22.9 m/sec) Outlet Velocity Shall Not Exceed 120 ft/sec (39.6 m/sec) Ratio of Barrel Area to Inlet Area Shall be 4.3 Minimum Minimum Barrel Diameter is Equal to First Stage Barrel Diameter

Equipment

57

Regenerator Cyclones (continued)

Both Stages

Ratio of Cyclone Length to Barrel Diameter Shall be 5.0 Minimum Projected Apex of Main Cone Shall be a Minimum Distance of 0.3 Times Barrel Diameter Above the Outlet of the Dust Hopper

Equipment

58

Cyclone Dipleg Termination

Trickle Valve Counterweighted Flapper Valve Submerged

Equipment

59

Trickle Valve
Hinge

Flapper Plate Stop

3-5 From Vertical

Equipment

60

Weighted Flapper Valve

Equipment

61

UOP Plenum Chamber Designs

External Plenum

Internal Plenum

External Manifold

Equipment

62 FCC/DS-R00-104

Orifice Chamber
Flow Internal Manways

304H Internals Hexmesh

Carbon Steel Shell Refractory

Equipment

63

Orifice Chamber

Used When Regenerator Pressure is Controlled by Flue Gas Slide Valve Reduces Pressure Drop Across the Slide Valve Grid Hole Erosion

Equipment

64

Grid Section of Orifice Chamber

Grid Holes Rings

Plan of Grid C Grid L 1 Ring #1 Ring #2 Ring #3 Ring #4

C Grid L

3/4 Abrasion Resistant Lining

Grid Section
Equipment

65

Orifice Chamber Grids

First Grid: Last Grid:

Equipment

66

Electrostatic Precipitator

Equipment

67

ESP Fines Collection Equipment

Equipment

68