coc - marine fuel oils

7/30/2019 CoC - Marine Fuel Oils

1/64

Marine Fuel Oils

By S Premanathan


2/64

Standards

CIMAC International Council on

Combustion Engines

ISO International Standardisation

Organisation


3/64

For Exams & Orals

We will only use ISO 8217 : 2005 3rd Edition

and MARPOL Annex VI regulations


4/64

Main Changes Under ISO 8217-2005

Number of residual fuel grades has been

reduced from 15 to 10

Tests for used lub oil

Viscosity is measure at 50o

C instea o 100o

C Unit for viscosity is mm2/s or cSt


5/64

Major Bunker Testers

DNV Petroleum Services operated by Det

Norske Veritas

FOBAS Fuel Oil Bunker Analysis and Advisory

Viswa Labs


6/64

Charterer Agreement

Most charter party agreements state that in

the event of fuel oil quality dispute, thementioned oil testers result will be final.

mentioned


7/64

Density

Fuel is delivered by volume and sold by mass

Density = mass / volume

Unit is kg/m3

Reference temperature is 15oC

Density is one of the empirical measure forboth energy content and ignition performance


8/64

Density For fuel treatment systems containing a

centrifuge with a water seal, knowledge of thefuel density is necessary so that the correct

water interface, and hence efficient

treatment.


9/64

Fuel Purifiers

MOPX with gravity discMax 0.991 density limit

ALCAP without gravity discMax 1.010 density limit


10/64

Kinematic Viscosity Measured at 50oC and the unit is mm2/s

Knowledge of viscosity is necessary for theestimation of the required temperatures for

, . Necessary for the determination of heating

required for transfer purposes.


11/64

Flash Point For marine fuel storage, minimum

temperature is 60oC as per SOLAS

Most Classes recommend maximum heating

be 10oC less than measured flash point

For emergency outside the machinery spaces,

the flash point must be greater than 43oC


12/64

Pour Point Winter pour point is of importance if your ship

has no heating tanks

Below this pour point, the fuel become like

Most ship operators maintain bunkers at least

5oC above pour point

This is mostly for the purpose of bunkertransfer


13/64

Carbon Residue

Measured in % m/m

Indication of deposit forming tendency of fuel

Indication of fouling factor

causes increased fouling of the gasways,

necess tat ng more requent c ean ng,especially of the turbocharger and exhaust gas

boiler

Fuels with a high carbon residue value maycause problems in engines under low load

running conditions


14/64

Ash Measured in % m/m

Residue other than carbonaceous matter

In crude oils, mostly found as sand, dirt and

rust sca es Even after fuel treatment, still maybe present

mostly as mixture of aluminium, silicon,

calcium, zinc, phosphor, iron, nickel, sodiumand vanadium, etc (in soluble form)


15/64

Water

Measured in % v/v

Why we need to test for water?

Encourages sludge formation Corrosion of tanks and pipelines

Disruption of the atomising spray pattern

Retardation in the speed of combustion

resulting in still burning particles striking thecylinder wall and crown

Dilution of the cylinder liner oil film


16/64

Sulphur Found in natural form

Not separated by centrifuging

Dew point is directly proportional to the

su p ur content an t e ex aust gas pressure


17/64

Vanadium and Sodium Vanadium is present in the fuel in soluble

compounds and, consequently, cannot be removed.

Vanadium, in combination with sodium, may lead toexhaust valve corrosion and turbocharger deposits.

sodium to vanadium exceeds 1:3, and especially inthe case of a high vanadium content.

Vanadium deposits can be so hard that they cancause extensive damage to the TC nozzle ring andturbine wheel.

The only way to remove vanadium depositsis todisassemble the components and remove the

deposits mechanically.


18/64

Vanadium Found in natural form

Known for its high temperature corrosion

Combines with sodium to form a a molten

paste at temperatures aroun 500o

C


19/64


20/64


21/64


22/64


23/64

Aluminium + Silicon Refinery product in the form of catalyst fines

Can be reduced by centrifuging


24/64

Catalytic fines embedded in piston ring

Catalytic fines embeddedin piston ring

Abrasive wear of liner


25/64

Total Sediment, Potential Sludge forming tendency of fuel


26/64

Asphaltenes precipitationStable

Unstable


27/64

Used Lubricating Oil (ULO) Test for calcium, phosphorus and zinc


28/64

Zinc, Phosphorus & Calcium A Fuel is considered to be free of ULO if one or

more of the elements Zinc, Phosphorus &Calcium are below the limits. All three

deemed to contain ULO.


29/64

Is this considered having ULO? Calcium.25 mg/kg

Phosphorous20 mg/kg

Zinc20 mg/kg


30/64


Phosphorous12 mg/kg

Zinc12 mg/kg


31/64


Phosphorous20 mg/kg

Zinc20 mg/kg


32/64

Total Acid Number Indication of the presence of acids

No limit mentioned in ISO 8217 or MARPOLAnnex VI

Most repute supp iers c aim t ey supp y essthan TAN 3


33/64

CCAI

Calculated Carbon Aromacity Index

Determined from the density and viscosity

Mostly used to indicate ignition qualityalthough scientifically not proven

CCAI values790 to 830 : very good to good

830 to 850 : good to satisfactory

850 to 870 : satisfactory to bad

870 to 970 : bad to unacceptable


34/64

CCAI- measure of Aromaticity of fuel to know itsignition quality

Ignition quality can bemeasured by Aromaticity of

fuel. The ignition quality of a fuel

is a measure of the relativeease y w c t w gn te

There is accepted empiricalequations based on thedensity and viscosity of thefuel. These are theCalculated CarbonAromaticity Index (CCAI)range 800-870

Better methods areavailable


35/64

CCAI- Effect on engine type 4 stroke engines

800

810

820

830

840

CCAI

1 2 31Engine type old-1970

2 Engine Type mid-19803 Engine type modern-1990

850860

870

880

890

900

910

920

Normal operating condition

Difficulties may be encountered

May cause engine damage


36/64

Net Specific Energy Also known as lower calorific value

Measured in MJ/kg The energy released by a unit of fuel

Density and the sulphur content play a part While water content is to be considered, it is

presumed water is removed by centrifuging or

treatment


37/64

Question Study the specifications as specified by a

major engine manufacturer Propose the most economical fuel grade for


38/64

Major Engine Specs

Property Units Value

Density @ 15oC kg/m3 991*

Kinematic Viscosity @ 50

o

C cSt 700Flash Point oC 60

Pour Point oC 30

Carbon Residue % m/m 22

Ash % m/m 0.15

Total Sediment Potential % m/m 0.10

Water % v/v 1.0

Sulphur % m/m 5.0

Vanadium mg/kg 600

Aluminium + Silicon mg/kg 80


39/64

Centrifuges *Centrifuges capable of handling fuels up to

1010 kg/m3

Alfa LavalALCAP

West a ia.Unitro MitsubishiE-Hidens II


40/64


41/64

Recommended Book A Practical Guide to Marine Fuel Oil handling

By Chris Leigh-Jones IMAREST publication


42/64

1. Paraffins The paraffinic can be either

straight chains (normal) or

branched chains (isomers)of carbon atoms.

Gas.

Lower Boiling Point

methane CH4

ethane C2H6

propane C3Hs

butane C4H10

Lower Boiling

Point

C

HH

H

H


43/64

2. Aromatics general formula: C6H5 - Y (Y

is a longer, straight

molecule that connects tothe benzene ring)

ringed structures with oneor more rin s

rings contain six carbonatoms, with alternatingdouble and single bondsbetween the carbons

typically liquids examples: benzene,

napthalene Benzene


44/64

3. Naphthalenes general formula: CnH2n (n

is a whole number usually

from 1 to 20) ringed structures with one

or more rings

rings contain only singlebonds between the carbonatoms

typically liquids at room

temperature examples: cyclohexane,

methyl cyclopentane


45/64

Asphaltenes Bunker fuel oil consists of Asphaltene

particles suspended in oily medium.

These are large heavy aromatichydrocarbon molecules with highCarbon/Hydrogen ratio,

Slow burning and tend to obstruct thecombustion process. They are

responsible for increasing oil viscosity,causing ignition delay and producingCarbon deposit on injector nozzles,Piston crown etc

Percentage of Asphaltenes present infuel affects its Compatibility with otherfuels


46/64

Asphaltenes precipitationStable

Unstable


47/64

Need for refining The problem with crude oil is that it contains

hundreds of different types of hydrocarbonsall mixed together.

hydrocarbons to have anything useful.

Fortunately there is an easy way to separate

things, and this is what oil refining is all about.


48/64

Refinery Process


49/64

Bunker fuel- residue from different processes


50/64

Orals

What action would you take if your fuel oil

settling tank spring-loaded drain valve ischoked?

Answer


51/64

Answer

Put FO transfer pump to manual mode and

stop

Lower settling tank as low as possible tooverflow/spill tank using manual drain valve

s ng ange a r s eam connec on, ow

choked pipe, gently tapping with hammer

Never use sinuous wire to clear choke!!!!!


52/64

Orals

What action would you take if your fuel oil

service tank spring-loaded drain valve ischoked?

Answer


53/64

Answer

Change-over m/e suction to high suction Manually lower service tank level as much as

possible by draining to overflow/spill tank Using flanged air/steam connection, blow

,


54/64

Orals

If for some reason, you are unable to clear

choked service tank spring loaded valve, howwould you continue voyage taking all the

.

Answer


55/64

Answer

Service tank must be manually drained to

overflow tank as frequently as possible

Purifier throughput to be about 5~10% abovemain engine consumption

All fuel line filters including auto backflush

must cleaned often and at least one set ready

for exchange at all times

Drain from the mixing column if possible

O l Q i


56/64

Orals - Question

What is the maximum bunkers liftable on a

ship? Japan to Singapore to Durban

Bun ering in Singapore

What is the minimum bunkers for arrival

Durban?


57/64

JapanAt Sea

All units in cubic metres

Take Sounding of all tanks and calculate ROB = X

Calculate ROB at Singapore as

Z = X Y (Y = remaining voyage consumption to

Singapore)

Singapore

keep as many empty tanks as possible

- consolidate fuel tanks of same grade- in port Singapore, settling and service tanks to be full

When ordering bunkers in Singapore, order as

85% x full tank capacity unpumpables for each tank

Note No mixing bunkers of different gradesOrdering / Consumption of bunkers must be done in

consultation with Master/Chief Officer

O l A


58/64

Orals - Answer

85% for normal safe loading

Bunkering Plan to be briefed Usual shipboard settings

- 92% high level alarm- 95~98% for high-high level alarm

or with overflow arrangement


59/64

Singapore

ur an

Arrival Durban should be such:ROB departure Singapore voyage

consumption - unpumpables in empty

tanks

+ 3~5 days extra daily consumption or

20% more than voyage consumption,

the more, the better

Gross Tonnage


60/64

Gross Tonnage


61/64

Nett Tonnage

Orals


62/64

Orals

What are the SOLAS regulations pertaining to

service tank requirement?

Answer


63/64

Answer

Refer to SOLAS Chapter II-1,

Part C Machinery Installation,

Regulation 26 General,

Item 11.

Answer


64/64

Answer

Location & arrangement of vent pipes for fuel

service, settling and lubricating oil tanks

should be such that in the event of a brokenpipe, there is no risk of ingress of seawater

.

Fuel oil service tank for each type of fuel usedonboard should have a capacity of at least 8

hours at maximum sea speed with diesel

generators running.

coc - marine fuel oils

Documents