Delayed Coker 3s1n2

DELAYED COKER UNIT

Prepared By: Neha OGH

TOPICS TO BE COVERED 1. Introduction 2. Where does Coker Unit fits in a refinery? 3. Residue Conversion/Up-gradation process 4. Coker Unit 5. Delayed Coker Unit 5.1 5.2 5.3 5.4

Schematic Diagram Process flow inside Delayed Coker Unit Products Obtained Use in Industries

1. INTRODUCTION

Crude Oil  “Unprocessed Oil” = Petroleum  Composition : Carbon, Hydrogen, Sulphur, Nitrogen, Oxygen, Metals & Salts

REFINING

The Bottom of the Barrel Residual Fuel Oil •

"scraps" at the refinery dinner table

•

Residual fuel oil is essentially what is left over, along with petroleum coke

•

"Resid" fuels are a large part of the heavy, residual leftovers from a barrel of petroleum after refiners have squeezed out every last drop of higher value products.

2. WHERE DOES COKER UNIT FIT IN A REFINERY ? REFINERY PROCESS

SEPARATI ON

CD U

CONVERSI ON

VD U Distillation Unit

RESI DS

PURIFICAT ION

COKE R UN IT

3. RESIDUE CONVERSION/UP-GRADATION PROCESS

Cracking: Conversion of heavier hydrocarbons into lighter hydrocarbons in or absence of a catalyst THERM AL CRACKI NG

Coking Vis breaker

CATALY TIC CRACKI NG

Residue FCC Hydrocracki ng

4. COKER UNIT Coking Process: Thermal Conversion of heaviest low value residues obtained from bottom of VDU in to valuable distillates

TYPES OF COKER UNITS

Delay ed Coker Unit

Fluid Coker Unit

Flexi Coker Unit

5. Delayed Coker Unit Converts petroleum residuum ( bottoms from CDU & VDU ) into liquid & gas products leaving petroleum coke behind Short residence time in furnace tubes, coking of feed “delayed” until it reached drums

5.1 DELAYED COKER SCHEMATIC FRACTIONATER: receives the feedstock from the refinery vacuum unit

FURNACE: heats the heavy liquid material from the bottom of the Fractionator to about 900 to 945o F

COKER DRU MS : Two or more drums where thermal cracking of hot feed occurs

5.2 PROCESS FLOW INSIDE DELAYED COKER UNIT

Cycle step 1 Overhead gas sent to fractionator to preheat feed Warm up period + steam supplie d

Feed pumped to furnace

Heated feed routed to D2

@end of cycle

Cycle step 2 Hot vapour diverted to fractionator

Hot vapour from D2 re-routed to D1

D2 Temp. dec

Cycle step 3 Vapours rises through T2; products separated D1 – cokin g begin s

Feed pumped to furnace

D2 purge d with steam

Heated feed routed to D1

Cycle step 4 Steam & oil vapours formed routed to T2

D1 – coking continue s

Water added to D2

After D2 cooled ; water drained to coke pad ; drum unheaded

Cycle step 5

D1 – coking continue s

Drill stem lowered ; cutting begins

Cycle step 6

D1 – coking continue s

Coke & water emptied onto coke pad

Cycle step 7

Vapour routed to T2 D1 – coke cycle ending

Steam applie d to D2

Cycle step 8 Hot vapour from D1 routed to D2 Hot vapour diverted to fractionator

D1 Temp. dec

5.3 Products Obtained Typical Yields & Dispositions PRODUCTS

YIELD, Wt% of FEED

DISPOSITION

Light Ends

12.5 – 20

LPG

Naptha

10 – 15

Naptha hydrotreating

Light Coker Gas Oil

18 – 24

Distillate Hydrotreating

Heavy Coker Gas Oil

30-40

Fluid Catalytic Cracking Sponge – Carbon anodes

Pet Coke

20 – 35

Needle – Graphite electrodes Shot Coke – Power generation

5.4 Uses of Petroleum Coke Fuel grade pet coke used as a source of fuel for cement kilns and electric power plants  Calcined pet coke is used in aluminium, graphite electrode, steel, titanium dioxide and other carbon consuming industries.

REFERENCES www.afrpm.org THE DELAYED COKING PROCESS – Thomas E. Wolf www.howstuffworks.com www.processEngrs.com

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