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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)
OPERATING CONDITION:
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
OPERATING CONDITION:
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
OPERATING CONDITION:
TOP TEMP = 55- 65 DEG C
BOTTOM TEMP = 95-110 DEG C
FEED TEMP= 60-70 DEG C
PRESSURE = 20.0- 21.0 KG/CM2 (g)
DEPROPANISER
PURPOSE:
TO SEPARATE C3 FRACTION FROM FROM LPG
OPERATING CONDITION:
TOP TEMP = 40- 45 DEG C
BOTTOM TEMP = 85-90 DEG C
FEED TEMP= 55-60 DEG C
PRESSURE = 12.0- 13.0 KG/CM2 (g)
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
CATALYTIC REFORMING UNIT
• 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
CATALYTIC REFORMING UNIT
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