CDU PRESENTATION 13 07 2010.pptx

CRUDE DISTILLATION AND CATALYTIC REFORMING UNITS

HALDIA REFINERYPHALGUNI PAL, DMPN

Haldia Refinery – Block Flow DiagramC

rude

HSD (BS-II, Euro-III ,Export)

FO (2 GRADES)Bitumen(3GRADES)

CDU 1

CDU 2

Fuel GasLPG

SRN

Kero CutSt.Run G.O

JBO

RCO

ATU&ARUSweet Fuel Gas

SRU Sulphur

LPGNaphtha

NHDT&CRU MS(BS-II, Euro-III ,Export)

KHDS

MTORTF/ATFKerosene

DHDS

HGU-I

H2

JBO (2 GRADES)

VDU 1

VDU2

IFO

GOSO

LO / IO / HO

SR

PDA

DAO

FEUNMP

SDU HFU

FCCU

Extract

Slack Wax

LO

Asphalt

VBUBTU

CBFS

MCW MCW

CDWU

MSQ

FCC Gasoline

H2

H2

H2

Reformate

HC

N

Off Gas

H2

100N/150N/500N/850N/150BN GR-I LOBS

DC

O

Ext

ract 70N/100N/150N/500N/

850N/150BN GR-II LOBSH2

Bitumen Emulsion Bitumen Emulsion

VB Tar

Raffinate

Raffinate DWO

OHCUOHCU Bottoms

HGU-II

H2

FGSulphur

LPG

LCN

Kero

HS

D

ATU&SRU

HC

N

FUEL OIL BLOCK UNITS

Crude

CDU 1

CDU 2

SRN

Kero CutSt.Run G.O

JBO

LPG

Naphtha

CRU REFORMATE

KHDS

MTOATFKerosene

JBO

MSQH2

RCO

CRUDE DISTILLATION UNIT (CDU)

• CDU IS THE MOTHER UNIT OF ANY OIL REFINERY.

• PURPOSE OF THIS UNIT IS TO SEPARATE DIFFERENT FRACTIONS OF CRUDE BY DISTILLATION

INTRODUCTION TO CDU I

• DESIGNED FOR PROCESSING 2.5 MMTPA & COMMISIONED IN 1974.

• DEBOTTLENECKED IN DEC’84 TO 2.75 MMTPA.

• MAIN COLUMN INTERNAL REVAMP IN MAY’88 LEADING THE CAPACITY TO 3.16 MMTPA.

• INSTALLATION OF PREFRACTIONATOR IN MAY’96 LEADING THE CAPACITY TO 3.5 MMTPA.

INTRODUCTION TO CDU II• COMMISIONED IN 1997.

• INITIAL CAPACITY :2.5 MMTPA

• CAPACITY OF CDU-II AFTER REVAMP = 4.0 MMTPA

• TOTAL REFINING CAPACITY-7.5.

BASIC OPERATION

• CRUDE PREHEATING• DESALTING OF CRUDE• DESALTED CRUDE PREHEATING• PREFRACTIONATION• PREFRACTIONATED CRUDE PREHEATING• HEATING OF CUDE IN FURNACE• MULTI COMPONENT FRACTIONATION OF

CRUDE IN MAIN DISTILLATION COLUMN.

BASIC OPERATION

• NAPHTHA STABILISATION (REMOVAL OF LPG FROM NAPHTHA)

• NAPHTHA REDISTILLATION • DE-ETHANISER.• CAUSTIC WASH OF LPG & EXCESS

NAPHTHA.• DEPROPANISER.

DESALTER

PREFRACTIONATOR

MAIN FRACTIONATOR

FURNACE

IBP-140 TO 11 C04

KERO CUT

LGO

HGORCO

IBP-140 TO NAPHTHA STABILISER

PRE HEAT EXCHANGERS

PRE HEAT EXCHANGERS

PRE HEAT EXCHANGERS

PROCESS FLOW DIAGRAM OF CRUDE DISTILLATION UNIT

O/H REFLUX DRUM

REFLUX DRUM

IBP-140 EX PF AND MF

NAPHTHA STABILISER

LPG

DEETHANISER

LPG CAUSTIC WASH

LPG SETTLER

DEPROPANISER

NAPHTHA SPLITTER

NAPHTHA CAUSTIC AND WATER WASH

BUTANE

PROPANE

90-140 CUT NAPHTHA

C5-90 CUT NAPHTHA

DESALTERPURPOSE :

1. TO REDUCE SOLUBLE SALT CONTENT

2. TO REDUCE SUSPENDED SOLID

3. TO REDUCE RESIDUAL WATER

4. TO ACT AS SURGE DRUM FOR FRESH CRUDE

OPERATING CONDITION:

TEMP = 125 - 135 DEG C

PRESSURE = 7.0- 8.0 KG/CM2

WASH WATER = 5 % (V) OF CRUDE

PREFRACTIONATORPURPOSE:TO SEPARATE LIGHTER COMPONENT OF CRUDE AT RELATIVELY LOW TEMP SO AS TO

A. REDUCE HEAT LOAD FOR THE HEATER B. REDUCE MAIN FRACTIONATOR O/H VAP

LOADOPERATING CONDITION:

TOP TEMP = 115-135 DEG C BOTTOM TEMP = 180-210 DEG C

TOP PRESSURE = 2.5 – 3.0 KG/CM2(g)

MAIN FRACTIONATORPURPOSE:

TO SEPARATE PRETOPPED CRUDE INTO DIFFERENT FRACTIONS LIKE NAPHTHA,HY NAPHTHA, SK/ATF/MTO, GAS OIL,HY GAS OIL & RCO (REDUCED CRUDE OIL)


TOP TEMP = 115-135 DEG C

FEED TEMP = 350-360 DEG C

TOP PRESSURE = 2.0 – 2.5 KG/CM2(g)

NAPHTHA STABILISER PURPOSE :

TO STABILISE THE NAPHTHA (IBP-150 ) BY SEPERATING ITS FEED INTO LPG & STABILISED NAPHTHA


TOP TEMP = 65- 75 DEG C

BOTTOM TEMP = 155- 180 DEG C

FEED TEMP = 95- 110 DEG C

PRESSURE = 10.4- 10.6 KG/CM2 (g)

REFLUX RATIO = 3 - 5

NAPHTHA SPLITTERPURPOSE:

1. TO SPLIT THE STABILISED NAPHTHA FROM STABILISER INTO TWO FRACTIONS WHICH ARE CALLED (C5-90) & (90-140)

2. TOP FRACTION (C5-90) IS SENT TO EXCESS NAPHTHA POOL OR HGU FEED & BOTTOM FRACTION IS EITHER STORED FOR CRU FEED OR SENT TO EXCESS NAPHTAOPERATING CONDITION:TOP TEMP = 70- 80 DEG C

BOTTOM TEMP = 125-135 DEG C FEED TEMP = 90-100 DEG C PRESSURE = 0.1 – 0.4 KG/CM2 (g) REFLUX RATIO = 1

DE-ETHANISERPURPOSE:

1. TO REMOVE H2S & C2 FRACTION FROM LPG

2. LPG IS FURTHER WASHED WITH CAUSTIC TO MAKE IT FREE FROM RESIDUAL H2S AND LIGHT MERCAPTEN



BOTTOM TEMP = 95-110 DEG C

FEED TEMP= 60-70 DEG C


DEPROPANISER

PURPOSE:

TO SEPARATE C3 FRACTION FROM FROM LPG



BOTTOM TEMP = 85-90 DEG C

FEED TEMP= 55-60 DEG C


CHEMICALS USED IN CDU

DE-EMULSIFIER : USED TO BREAK THE EMULSION OF CRUDE OIL & WATER IN DESALTER.

• CAUSTIC : USED AT THE UPSTREAM OF DESALTER TO NEUTRALISE FREE ACIDS & AT THE DOWNSTREAM OF DESALTER TO CONVERT UNREACTED CALCIUM AND MAGNESIUM CHLORIDES INTO THEIR RESPECTIVE SODIUM SALT.

• AMMONIA : USED TO REDUCE CORROSIVE EFFECTS OF RESIDUAL ACIDS.

• CORROSION INHIBITOR : IT’S AMINE SOLUTION OF LONG CHAIN CYCLIC COMPOUND.IT PREVENTS METAL SURFACE CORROSION BY FORMING THIN PROTECTIVE LAYER

PRODUCTS AND THEIR SPECIFICATION

• LPG : WEATHERING = +3 DEG C (MAX) FOR NORMAL & +1 DEG C (MAX) FOR AUTO STRIP CORROSION-1A.

• EXCESS NAPHTHA : Cu- STRIP CORROSION-1A.• 90-140 CUT (CRU FEED) : IBP=90(MIN),FBP=155(MAX).• SRSK : FBP=285(MAX),FLASH=39(MIN) IF NOT

REPROCESSED.• SRATF: FBP=255(MAX)• SRMTO : FBP=240(MAX)• JBO(P): IBP=285(MIN)• JBO©: FBP=365(MAX)

NAPHTHA HYDROTREATING &

CATALYTIC REFORMING UNIT

INTRODUCTION

• BUILT BY M/S TECHNIP OF FRANCE• PROCESS LICENCER:IIP-DEHRADUN

& IFP-FRANCE.• UNIT CAPACITY: APPROX 37 M3/HR.• TYPICAL FEED CHATACTERISTICS

IBP: 110 FBP:160 CUT NAPHTHA

WHY NAPHTHA HYDROTREATER ? TO REMOVE SULPHUR,ORGANIC NITROGEN &

OXYGEN AND TO SATURATE OLEFINS FROM NAPHTHA WHICH ARE POISIONS FOR

DOWNSTREAM REFORMER CATALYST.

SULPHUR IN THE FORM OF MERCAPTANS, ALIPHATIC DISULPHIDES & CYCLIC SULPHIDES ARE CONVERTED TO H2S. ORGANIC NITROGEN IS CONVERTED INTO NH3.C-O BOND IS BROKEN TO FORM SATURATED ALIPHATIC/AROMATIC COMPOUND.

NHDT

Recycle GasCompressor

HP Separator

HP Purge GasTo Fuel Gas

DSN

Feed Heater

Reflux Drum

Stripper

Colum

n

HR

- 448HR-448

HR-945

Sulphur Guard

HY FCC GASOLINE

FEED 110-140 CUT NAPHTHA

MAKE UP HYDROGEN

REACTORS

MAX PERMISSIBLE LIMIT OF IMPURITIES IN REFORMER FEEDSULPHUR < 0.5 PPM

ORGANIC ‘N’ < 0.5 PPM

MOISTURE < 5 PPM

ARSENIC < 5 PPB

OLEFINS 0

DIOLEFINS 0

TOTAL HY METALS < 5 PPB

HALOGENS ( F,Cl) < 1 PPM

OPERATING CONDITIONS (PARAMETERS)

REACTOR OPERATING CONDITIONS

SECOND REACTOR O/L PR (KG/CM2,G) 23

FIRST REACTOR INLET TEMP (. C) 312

SECOND REACTOR O/L TEMP (.C) 330

RECYCLE RATIO 105


• REFORMING IS PROCESS TO REARRANGE NAPHTHA COMPONENTS TO AROMATICS & ISOPARRAFINS TO INCREASE OCTANE NO.

• UNIT CAPACITY = 216 TMT / YR

• OCTANE RATING IS A MEASURE OF THE AUTO IGNITION RESISTENCE OF GASOLINE USED IN SPARK-IGNITION IC ENGINES.IT IS A MEASURE OF ANTI-DETONATION OF A GASOLINE.THIS RATING WAS DEVELOPED BY A CHEMIST Russel Marker.

REFORMER CATALYST & REACTIONS

• Three Reactors in series filled with bimetallic (Pt-Re) catalyst.

• Main Reactions:

.Aromatization of Naphthenes & Paraffin

.Isomerization of Naphthenes & Paraffins

.Hydrocracking

.Hydrogenation of Olefins

Specifications BS-I BS-II BS-III BS-IV

DENSITY (KG/M3) 710-770 710-770 720-775 720-775

RON (MIN) - 88 91 91

BENZENE (%V, MAX) 5 3* & 5 1 1

OLEFINS (%V, MAX) - - 18 21

AROMATICS (%V, MAX) - - 42 35

SULFUR (ppmw, MAX) 1000 500 150 50

RVP (KPA) 35-60 35-60 60 (MAX)

M S QUALITY SPECIFICATION

DSN EX 21 C01PRE HEAT EXCHANGERS

22 F0122 R01

RECYCLE GAS COMPRESSOR

22 F20122 R02

22 F03

22 R201

EFFLUENT EXCHANGER AND COOLER

HP SEPARATOR

STABILISER

REFORMATE TO R/D

OFF GAS

MAKE UP TO NHDT/KHDS


FUNDAMENTAL REACTIONS IN CRU REACTORS

A.DESIRABLE RXN – (1) NAPHTHENES DEHYDROGENATION

• C H • 7 16

• + H • 2

• C H • 7 14

• CH2

• CH• 2 • CH• 2

• CH• 2 • CH• 2

• CH• 3 • CH• 3

• CH

• CH• 3 • CH• 3

• CH• 2 • CH• 2

• CH• 2 • CH

FNDAMENUTAL REACTIONS IN CRU REACTORSA.DESIRABLE RXN – (2) PARAFFINS DEHYDROCYCLISATION

Methylcyclohexane

CH2

CH2

CH CH2

CH3

CH3

CH

CH2

CH2

CH2

CH2

CHCH

3 H C

2

FUNDAMENTAL REACTIONS IN CRU REACTORSA.DESIRABLE RXN –

(3) PARAFFINS / NAPHTHENE ISOMERISATION

C H7 16 C H

7 16

FUNDAMENTAL REACTIONS IN CRU REACTORSB. ADVERSE RXN –

(1) CRACKING

+ H 2

(a) +

C H 4 8

C H 3 8

C H 7 14

FUNDAMENTAL REACTIONS IN CRU REACTORSB. ADVERSE RXN – (2) HYDROGENOLYSIS

+ H 2

C H 7

CH4

+ H 2

C H2

C H

or

+

+

16

C H 7 16

6

C H 6 14

5 12

OPERATING PARAMETERS OF CRU REACTORS

REACTOR AVG PR = 26.3 KG/CM2,(g)

REACTOR INLET TEMP = 497 – 512 deg c

H2 / HC (MOLE) RATIO = 4.5

SEPERATOR DRUM PRESSURE = 20 KG/CM2,(g)

OPERATING PARAMETERS OF CRU STRIPPER

TOP TEMP = 60-62 deg c

BOTTOM TEMP = 208-212 deg c.

TOP PRESSURE = 15 – 16 kg/cm2,g.

REFLUX / FEED RATIO = 0.16

REFORMING REACTIONS

• DEHYDROGENATION-METALLIC FUNCNTION• DEHYDROCYCLISATION-MET+ACID FUNCTION• ISOMERISATION- MET+ACID FUNCTION• HYDROGENOLYSIS(CRACKING OF C1&C2)-MET

FUNCTION• HYDRO CRACKING-MET+ACID FUNCTION

THANK

YOU

CDU PRESENTATION 13 07 2010.pptx

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