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FUELS
REFINERY PROCESSES
TYPICAL PRODUCTS
PRODUCT WT%
• GAS 0.1
• LPG 1.0
• NAPHTHA 9.7
• ATF / KEROSENE 10.8
• HSD 24.3
PRODUCT WT%
• LDO 4.8
• FUEL OILS 17.8
• ASPHALT 9.7
• VACCUM DISTILLATES 18.5
• FUEL & LOSSES 3.0
REFINERY FUELS PRODUCTS
• PROPANE• LPG• GASOLINE (NORMAL)• GASOLINE (PREMIUM)• LOW AROMATIC NAPHTHA• HIGH AROMATIC NAPHTHA• AVIATION TURBO FUEL DEFENCE / COMMERCIAL• HIGH SPEED DIESEL• LIGHT DIESEL OIL• KEROSENE• FUEL OIL (NORMAL)• FUEL OIL (DEFENCE)• LSHS
GASOLINE - SPECIFICATIONSWHERE ARE WE GOING ?
• LEAD• BENZENE• SULFUR• VOLATILITY
– VLI– E 70, E 100, E 180– FBP– RESIDUE
• OXYGENATES• GUM CONTENT• OLEFINS• DENSITY• ANTI KNOCK INDEX• ENGINE TESTS
DIESEL - SPECIFICATIONSWHERE ARE WE GOING ?
• AROMATICS• POLY AROMATICS• CARBON RESIDUE• SULFUR• WATER CONTENT• OLEFINS• VISCOSITY• VOLATILITY (T 95) • HEATING VALUE• COMPONENT COMPATIBILITY• STABILITY • CETANE INDEX• LUBRICITY• OXIDATION STABILITY• ENGINE / RIG TESTS
WHY BEING DONE
• TIGHTER EMISSION NORMS
• CHANGES IN ENGINE DESIGNS
• CHANGES IN METALLURGY OF THE ENGINE
• USE OF CAT CONVERTORS
• FUEL EFFICIENCY
• INCREASED POWER
ALL THIS HAS LED TO
• DECREASED FUEL STABILITY
• DECREASED COMPATIBILITY
• INCREASED OCTANE REQUIREMENTS
• POOR DRIVEABILITY AND DURABILITY
• EXTENDED REFINERIES AND TECHNOLOGY OF REFINING TO MAXIMUM
SOLUTION ?
FUEL ADDITIVE
“HP DIESEL PLUS”&
“HP PETROL PLUS”
BENEFITS
• IMPROVED FUEL ECONOMY• FUEL INJECTION CLEANLINESS• IMPROVED FUEL STABILITY• REDUCED EXHAUST EMISSIONS• DISPERSANCY FOR INSOLUBLE GUM• IMPROVED LUBRICITY• CORROSION PROTECTION • PREVENTION OF STABLE FUEL WATER
EMULSIONS• REDUCTION IN FOAM
DIESEL SPECS
PROPERTY LI MI TS
CETANE NUMBER 48 MI N
CETANE I NDEX 45 MI N
DENSI TY @ 15°C 820 – 860
VI SCOSI TY @ 40°C 2 – 4.5
SULPHUR, % WT 0.25 MAX
LURI CITY 400 MAX
T 95, °C 370 MAX
DIESEL SPECSPROPERTY LI MI TS
FLASH POI NT, °C 32 MI N
CARBON RESI DUE 0.03 MAX
CFPP *
WATER CONTENT 0.50 MAX
OXI DATI ON STABI LI TY 25 MAX
ASH CONTENT 0.01 MAX
COPPER CORRI SI ON 1 MAX
* LOWER THAN LOWEST AMBIENT
HEAVY FUEL OIL SPECS
CHARACTERI STI C I S DG SET
ACI DI TY I NORG NI L -
ASPHALTENES, % WT 10 & 14 14 MAX
ASH CONTENT, % WT 0.1 MAX 0.2 MAX
CCR, % WT 15 & 20 22 MAX
POTENT SED, % WT - 0.1 MAX
WATER, % WT 1 MAX 1 MAX
Al + Si 80 MAX 80 MAX
CCAI - 850 MAX
HEAVY FUEL OIL SPECSCHARACTERI STI C I S DGSET
FLASH POI NT, °C 66 MI N 60 MI N
KI N VI SC @ 50°C 180 MAX 55 @ 100
TOTAL SED 0.25 MAX -
POUR POI NT, °C 30 MAX -
TOTAL SULPHUR 4 MAX 5 MAX
DENSI TY, 15°C 0.991 MAX 0.991 MAX
VANADI UM, ppm 300 MAX 50 - 600
SODI UM, ppm 50 MAX 20 - 50
TEST PROCEDURES
PROPERTY METHODS
CETANE NUMBER D 613
CETANE I NDEX D 4737
DENSI TY @ 15°C D4052
VI SCOSI TY @ 40°C D 445
SULPHUR, % WT D 2622 / 5453
LURI CITY D 6079
T 95, °C D 86
TEST PROCEDURESPROPERTY METHODS
FLASH POI NT, °C D 93
CARBON RESI DUE D 4530
CFPP I P 309
WATER CONTENT D 1744
OXI DATI ON STABI LI TY D 2274
ASH CONTENT D 482
COPPER CORRI SI ON D 130
TEST PROCEDURESPROPERTY METHODS
TOTAL AROMATI C D 5186
POLY AROMATI C D 2425
LOW TEMP. FLOW TEST D 4539
FOAM NF M 07 - 075
BI OLOGI CAL GROWTH NF M 07 - 070
TOTAL ACI D NUMBER D 974
I NJ ECTOR CLEANI NESS CEC / CUMMI NS L 10
CORRI SI ON PERFOR. D 665
TEST SIGNIFICANCE
• DENISTY - ESSENTIAL FOR QUNTITY CALCULATIONS, SETTING PURIFIER, INDICATES SPECIFIC ENERGY AND IGNITION QULAITY
• API GRAVITY ° = (141.5 / RELATIVE DENSITY @ 60 / 60°F) - 131.5
• FLASH POINT - LEGAL REQUIREMENT
• POUR POINT - FUEL MUST BE MAINTAINED ABOVE POUR POINT
TEST SIGNIFICANCE
• CARBON RESIDUE - HIGH VALUES MAY GIVE DEPOSIT PROBLEMS
• ASH - IF EXCESSIVE CAN GIVE FOULING DEPOSITS
• WATER - CAN CAUSE SLUDGE AND COMBUSTION PROBLEMS
• VANADIUM AND SODIUM - POTENTIAL HIGH TEMPERATURE CORROSION CAN BE MINIMISED BY TEMPERATURE CONTROL AND MATERIALS SELECTION
TEST SIGNIFICANCE
• ALUMINIUM AND SILICON - USUALLY PRESENT AS CATALYST FINES WHICH ARE ABRASIVE, CAN NORMALLY BE REDUCED TO AN ACCEPTABLE LEVEL BY A CENTRIFUGE
• SULPHUR
• SEDIMENT & STABILITY - FUEL IS STABLE IF IT DOES NOT BREAK DOWN GIVING HEAVY SEDIMENT
• COMPATIBILITY - THE ABILITY OF TWO FUELS WHEN MIXED TO REMAIN STABLE
TEST SIGNIFICANCE
• SPECIFIC ENERGY - NET VALUE FOR DIESEL AND GROSS VALUE FOR BOILERS, USUALLY CALCULATED FROM EMPIRICAL EQUATIONS
• IGNITION QULAITY - RELATES TO PART OF THE COMBUSTION PROCESS
– FOR RESIDUAL FUELS EMPIRICAL EQUATION FOR CCAI IS
– CCAI = d - 81-141 log log (VK + 0.85)
d = DENSITYVK = VISCOSITY
TEST SIGNIFICANCE
• VISCOSITY - DETERMINES INJECTION AND TRANSFER TEMPERATURES
FUEL INJ VISC INJ VISC 13 CST 17 CST
120 100 91160 112 104
170 115 107 180 119 109 200 121 111 220 123 113
COMPARISON OF FUELS
CHARACTERI STI C NAPHTHA HSD
FLASH POI NT, °C - 12 32
KI N VI SCOSI TY 0.55 3.55
TOTAL SED, mg/100ml NI L 5
GCV, cal/g 11400 10900
TOTAL SULPHUR 0.0048 0.25
DENSI TY, 15°C 0.72 0.84
VANADI UM, ppb 1 200
SODI UM, ppm 0.018 0.2
COMPARISON OF FUELS
CHARACTERI STI C NAPHTHA HSD
ACI DI TY I NORG NI L NI L
ACI DI TY TOTAL NI L NI L
ASH CONTENT, % WT NI L NI L
RCR, % WT NI L 0.034
CETANE NUMBER - 48
POUR POI NT, °C <- 54 6
CU STRI P CORROSI ON 1A 1A
RECOVERY @ 366°C - 97
CASE STUDY
• NAPHTHA
• DIESEL
• FUEL OIL
NAPHTHAFLUE GAS ANALYSI S A B
CARBON DI OXI DE 12.8 9.1
CARBON MONOXI DE 1.4 0
HYDROGEN 0.7 0
OXYGEN 2.1 7.4
HYDROCARBON 0.2 0
NI TROGEN 82.8 83.5
REACTIONS FOR BURNING
• CO + 1/2 O2 = CO2
• H2 + 1/2 O2 = H2O
• CnH n+x + (n+1)/2O2 = nCO2 + yH2O
EXCESS AIR NEEDED = (1.4+0.7+0.2)/2 = 1.15
SOOT CONTROL• FAULTY INJECTORS
– DEGREE OF ENRICHMENT– AIR REQUIREMENT– VOLUME OF COMBUSTION PRODUCTS– FLAME TEMPERATURE– ATOMISATION / OVERFUELING
• RESTRICTED AIR INTAKE
• EXCESSIVE EXHAUST BACK PRESSURE
• INTAKE AIR HOT
• LEAKAGE OF AIR THRU GASKETS
• PREIGNITION
• WRONG FUEL
ADDITIVES FOR HEAVY FUEL OILS
• CRUDE OILS AND FUEL OILS
• HEAVY FUEL OILS
• COMBUSTION MECHANISM
• POTENTIAL PROBLEMS AND SOLUTIONS
– ADDITIVE A & B
Viscosity,20°C
% asphaltenes
Gasoline (C5-80°)
Heavy gasoline (80-160°)
Kerosene (160-250°)
Middle distillate (250-300°)
Heavy distillate (300-400°)
Residue (400 +)
35.8
5.8
4.09
9.05
12.58
14.12
7.51
50.42
10.2
0.93
5.56
12.02
15.5
17.19
8.72
38.71
ARABIANHEAVY
ARABIANLIGHT
NIGERIANBONNY
11.2
0.08
5.06
15.0
9.32
25.2
44.6
FRACTIONS FROM 3 DIFFERENT CRUDES
CHARACTERISTICS OF SOME CRUDE OILS
Viscosity,20 °C,cSt
Sulfur,%
Vanadium, ppm
Nickel, ppm
Asphaltenes, %
Conradson carbon,%
Arabianlight
9.2
1.8
15
5
0.7
5.1
Arabianheavy
40
2.8
30
10
2.7
Ekofisk
10
0.12
< 1
1.4
0.88
Nigerialight
6.7
0.11
2
6
0.08
0.86
Basrahheavy
57
3.58
54
22
8.3
Boscan
250000
5.2
1200
100
10.8
16.4
Ural
12.5
1.8
65
20
2.7
Gas
AD
VD
Reforming
Visbreak.
Hydrocr.
Coking
FCC
DA
NaphtaGasolinesKeroseneDiesel oils
Heavy fuels SR1
2
3
Gasolines
GasolinesKero,Diesel
Heavy fuels
H2, no HeavyFuels
4
AsphaltsHeavy fuels
REFINERY SCHEMES
CHEMICAL COMPOSITION RESIDUE OR HEAVY FUEL OILRESIDUE OR HEAVY FUEL OIL
ASPHALTENESASPHALTENESMALTENESMALTENES
"OIL""OIL""RESINS""RESINS"
SATURATED SATURATED AROMATICAROMATIC
MODEL OF ASPHALTENE MOLECULE
S
CH2
CH3
CH2
CH3
CH3
CH
CH2
CH2
CH3
CH2CH2CH3
CH2CH2
S
S
CH2
CH2
CH3
CH2
S
CH
CH2
CH2
CH3
CH2
CH2
CH3
CH
CH2
CH2
CH3
CH2 CH2CH3
N
CH3
CH2
CH3
CH3
CH2
CH3
CH3
CH3
CH2CH2
O
CH2
S
CH2
CH2
CH2
CH
CH2
CH2
CH3CH3
CH2CH3
CH3
CH3
ASPHALTENES CHARACTERISTICS
• Polycondensed aromatic structures with few alkyl chains
• Contains hetero-atoms: S, N, O
• Contains metals: V, Ni, Na
• Not soluble in oil
• Size of the micellar unit: 8 - 20 A
• Cannot boil even under reduced pressure
• Molecular structure depends on crude oil origin
RESINS CHARACTERISTICS
• Chemical structure close to asphaltenes structure but:
• LONGER ALKYL CHAINS
• LESS CONDENSED RINGS
• MORE SOLUBLE IN OIL
• Molecular structure depends on crude oil origin
• Presence necessary to provide a good stability to the
fuel
HEAVY FUEL OILS
DISPERSED AND STABLE FLOCULATED
Resins ensure seperation of heavy asphaltene molecules. Flocculated Asphaltene molecules tend to form sludge and settle at the bottom of the tank.
COMBUSTION MECHANISM
Atomisation Vaporization
Combustion
Viscosity Distillate cuts
Distillate cutsDensityMetalsConradson Carbon
C/H Ratio
Ignition
SOOT
UNBURNT PARTICLES
FLAME FRONT
FUELDROPLET
CENOSPHERE
EMISSIONS OF PARTICLES
0.02 m
1 to 100 m
LIGHT GASEOUS FRACTIONS
Simple droplet combustion model
SOLID ACCUMULATION
CENOSPHERES
PARTICULATE EMISSIONS
• SOOT (Soot number from 0 to 9 Bacharach)
– GAS PHASE COMBUSTION
– OH* increases the rate of oxidation of soot precursors
• UNBURNT PARTICLES (mg/Nm3)
– HETEROGENEOUS COMBUSTION (CENOSPHERES)
2 H2O H2 + 2 OH*Catalyst M
CO + H2
Catalyst M ’Cenospheres + H 2 Ov
POTENTIAL PROBLEMS
• STORAGE STABILITY AND COMPATIBILITY
• UNBURNT PARTICLES
STORAGE• PROBLEMS
– ASPHALTENES PRECIPITATION – CLOGGING OF FILTERS AND PIPES– SATURATION OF SEPARATORS– CLOGGING OF INJECTION SYSTEM
• ORIGIN– ASPHALTENES PRECIPITATION
• BLEND OF NON-COMPATIBLE FUELS• STORAGE TEMPERATURE
• SOLUTION– ADDITIVES
ADDITIVE A
• Preventive action
• Curative action
Fuel without additive Fuel with additive A
ADDITVE A• DOSING RATE
– 1 LITRE FOR 2000 TO 5000 LITRES OF FUEL.
• IMPROVES HEAVY FUEL OIL STABILITY
• PREVENTS ASPHALTENE PRECIPITATION
• AVOIDS COMPATIBILITY PROBLEMS
• NON TOXIC PRODUCT
• NON TOXIC COMBUSTION PRODUCTS
UNBURNT PARTICLES• PROBLEM
– EMISSIONS OF UNBURNT PARTICLES– HEATING SURFACES FOULING– FREQUENT BOILER CLEANING– COST OF EMISSION LIMITATIONS
• ORIGIN– NEED OF COMBUSTION IMPROVER– VERY LOW METAL CONTENT
• SOLUTION– ADDITIVE B
EFFICIENCY OF ELF ADDITIVE B
AB
C
FUEL
12
1 : + ELF AC 13 S (1/3000 l)
2 : + ELF AC 13 S (1/2000 l)
Unburnt HC
mg/th
Excess of air%
400
300
200
100
10 200
ADDITIVE B• DOSING RATE:
– 1 LITRE FOR 2000 TO 4000 LITRES OF FUEL.
• REDUCES EMISSIONS OF UNBURNT PARTICLES – MORE THAN 50 %
• ALLOWS TO REDUCE EXCESS OF AIR.• REDUCES FOULING• ACHIEVES A MORE STABLE COMBUSTION YIELD.• REDUCES DEPOSITS ON HEAT TRANSFERS.• NON TOXIC PRODUCT• NON TOXIC COMBUSTION PRODUCTS
THANK YOU