Properties of Fuel Oil & Bunkering Procedure by Hanif Dewan


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Properties of Fuel Oil & Bunkering Procedure by Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh.

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Properties of Fuel Oil & Bunkering Procedure by Hanif Dewan

  1. 1. PROPERTIES OF FUEL OIL AND BUNKERING PROCEDURE -Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 1
  2. 2. Definition of Fuel: Each substance which gives energy after burning is called fuel. Fuels are classification by sources: a. Natural b. Artificial Fuels are classification by phases: a. Solid – coal, wood etc. b. Liquid – petroleum products, alcohol, biofuel etc. c. Gas – methane, butane, hydrogen, biogas etc. Generally Liquid fuels are preferential. 1. Energy per gram is too high 2. Fast conversion of chemical energy to thermal energy 3. Easy mix with oxygen 4. No ash after combustion 5. Easy transport and storage Every liquid substance which provides the sufficient thermal energy can be used as a fuel for internal combustion engines. PETROLEUM PRODUCTION: Petrolem = Petra + Oleum Rock + Oil Petroleum is often called crude oil, fossil fuel or oil. It is called a fossil fuel because it was formed from the remains of tiny sea plants and animals that died millions of years ago. When the plants and animals died, they sank to the bottom of the oceans. Here, they were buried by thousands of kms of sand and sediment, which turned into sedimentary rock. As the layers increased, they pressed harder and harder on the decayed remains at the bottom. The heat and pressure changed the remains and, eventually, petroleum was formed. Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 2
  3. 3. Petroleum is defined by 4 physical categories historically: 1. Boiling point 2. Density 3. Odour 4. Viscosity Light-heavy: Low boiling point and relative density Heavy-heavy: High boiling point, viscous. Because crude oil has Fe, Mg, Ca, P, V, S, Zn, Co, clay, water and other residuals, it has to distillate for internal combustion engines. Fractional Distillation Of Crude Oil Fractional distillation of crude oil is the first step in the production of many of the materials we have come to rely on in modern life. All our fossil fuels, virtually all our plastics, detergents and commercial alcohols are made from products of this process. In order to separate the different length chains in the crude mix, it is heated to a very high temperature. The temperature cannot be set higher than this as there is a risk that the lighter fractions will ignite. Distillation is the most common form of separation technology used in petroleum refineries, petrochemical and chemical plants, natural gas processing. Industrial distillation is typically performed in large, vertical cylindrical columns Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 3
  4. 4. known as "distillation or fractionation towers" or "distillation columns" with diameters ranging from about 65 centimetres to 6 metres and heights ranging from about 6 metres to 60 metres or more. The distillation towers have liquid outlets at intervals up the column which allow for the withdrawal of different fractions or products having different boiling points or boiling ranges. By increasing the temperature of the product inside the columns, the different hydrocarbons are separated. The "lightest" products (those with the lowest boiling point) exit from the top of the columns and the "heaviest" products (those with the highest boiling point) exit from the bottom of the column. Major products of oil refineries: • • • • • • • • • Liquid petroleum gas (LPG) Gasoline (also known as petrol) Naphtha Kerosene and related jet aircraft fuels Diesel fuel Fuel oils Lubricating oils Asphalt and Tar Petroleum coke Fractional distillation is used in oil refineries to separate crude oil into useful substances (or fractions) having different hydrocarbons of different boiling points Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 4
  5. 5. Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 5
  6. 6. Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 6
  7. 7. Product Definitions The products refined from the liquid fractions of crude oil can be placed into ten main categories: Asphalt Asphalt is commonly used to make roads. It is a colloid of asphaltenes and maltenes that is separated from the other components of crude oil by fractional distillation. Once asphalt is collected, it is processed in a de-asphalting unit, and then goes through a process called “blowing” where it is reacted with oxygen to make it harden. Asphalt is usually stored and transported at around 150 C. Diesel Diesel is any fuel that can be used in a diesel engine. Diesel is produced by fractional distillation between 250° Fahrenheit and 350° Fahrenheit. Diesel has a higher density than gasoline and is simpler to refine from crude oil. It is most commonly used in transportation. Fuel Oil Fuel oil is any liquid petroleum product that is burned in a furnace to generate heat. Fuel oil is also the heaviest commercial fuel that is produced from crude oil. Gasoline It is mainly used as fuel in internal combustion engines, like the engines in cars. Gasoline is a mixture of paraffins, naphthenes, and olefins, although the specific ratios of these parts depends on the refinery where the crude oil is processed. Gasoline refined beyond fractional distillation is often enhanced with iso-octane and ethanol so that it is usable in cars. Gasoline is called different things in different parts of the world. Some of these names are: petrol, petroleum spirit, gas, petrogasoline, and mogas. Kerosene Kerosene is collected through fractional distillation at temperatures between 150° Fahrenheit and 275° Fahrenheit. It is a combustible liquid that is thin and clear. Kerosene is most commonly used as jet fuel and as heating fuel. Liquefied Petroleum Gas Liquefied petroleum gas is a mixture of gases that are most often used in heating appliances, aerosol propellants, and refrigerants. Different kinds of liquefied petroleum gas, or LPG, are propane and butane. At normal atmospheric pressure, liquefied petroleum gas will evaporate, so it needs to be contained in pressurized steel bottles. Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 7
  8. 8. Lubricating Oil Lubricating oils consist of base oils and additives. Different lubricating oils are classified as paraffinic, naphthenic, or aromatic. Lubricating oils are used between two surfaces to reduce friction and wear. The most commonly-known lubricating oil is motor oil, which protects moving parts inside an internal combustion engine. Paraffin Wax Paraffin wax is a white, odorless, tasteless, waxy solid at room temperature. The melting point of paraffin wax is between 47° C and 65° C, depending on other factors. It is an excellent electrical insulator, second only to Teflon®, a specialized product of petroleum. Paraffin wax is used in drywall to insulate buildings. It is also an acceptable wax used to make candles. Bitumen Bitumen, commonly known as tar, is a thick, black, sticky material. Refined bitumen is the bottom fraction obtained by the fractional distillation of crude oil. This means that the boiling point of bitumen is very high, so it does not rise in the distillation chamber. The boiling point of bitumen is 525° C. Bitumen is used in paving roads and waterproofing roofs and boats. Bitumen is also made into thin plates and used to soundproof dishwashers and hard drives in computers. Fuel Properties Flash point  The flash point of a fuel is the temperature at which vapour given off will ignite when an external flame is applied under specified test conditions. A flash point is defined to minimise fire risk during normal storage and handling.  The minimum flash point for fuel in the machinery space of a merchant ship is governed by international legislation and the value is 60oC. For fuels used for emergency purposes, external to the machinery space, for example the lifeboats, the flash point must be greater than 43oC.  Residual fuels are capable of producing light hydrocarbons in the tank headspace, near to or within the flammable range. Hence all residual fuel oil headspaces should be considered to be potentially flammable. Fire Point The temperature at which the hydraulic fluid surface emits enough vapor to sustain a fire for five seconds in the presence of a flame. Cloud Point Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 8
  9. 9. The cloud point of a diesel fuel is the temperature at which the amount of precipitated wax crystals becomes large enough to make the fuel appear cloudy or hazy. Wax may form because normal paraffins occur naturally in diesel fuel. As the temperature of the fuel is lowered, these paraffins become less soluble in the fuel and precipitate out as wax crystals. Pour Point Pour point is the lowest temperature at which the fuel will flow and is used to predict the lowest temperature at which the fuel can be pumped. Flammability The ability or tendency to ignite and burn when exposed to an open flame. Fluidity A hydraulic fluid's ability to flow. As temperature increases, fluidity increases. SPECIFIC HEAT Specific heat is the amount of kCals needed to raise the temperature of 1 kg of oil by 1°C. The unit of specific heat is kcal/kg 0 C. It varies from 0.22 to 0.28 depending on the oil specific gravity. The specific heat determines how much steam or electrical energy it takes to heat oil to a desired temperature. Light oils have a low specific heat, whereas heavier oils have a higher specific heat. DENSITY: Density is the absolute relationship between mass and volume at a stated temperature. The SI unit is kg/m 3 at a reference temperature, typically 15°C. API: In the United States and some other countries, the density of petroleum products is defined in terms of API gravity. This is an arbitrary scale adopted by the American Petroleum Institute for expressing the relative density of oils. API= (141.5/RD at 60/60oF) – 131.5 Density in vacuum and in air The terms 'density in vacuo' or 'density in air' are sometimes used on fuel delivery or bunker receipt notes. As density is the absolute relationship between mass and volume and not its weight to volume, by definition density is in vacuo. Although often used, the term 'density in air' is incorrect and should be referred to as a 'weight factor'. This is because a substance weighed in air is supported to a small extent by the buoyancy of air acting on it. Thus the weight of a liquid in air is slightly less than the weight in Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 9
  10. 10. vacuo. There is no simple relationship between density and 'weight factor' but for bunker fuels the difference approximates to 1.1 kg/m 3 . To convert density at 15°C to the 'weight factor' at 15°C, 1.1 kg/m3 should be deducted. Density adjustment at temperatures other than 15oC: Densities are measured over a range of temperatures, usually for convenience, at the temperature at which the fuel is stored. The value is then corrected back in test equipment or by the use of standard tables to the reference temperature. EFFECT OF VARIATION IN DENSITY The effect of injecting heavy oil with increased density will result in increased compared to diesel oil:  Power - Increased power because of increase in heat energy being injected  Speed – Increase in speed of the engine.  Texh- Higher exhaust temperature because of more power being produced  Pcomp- because of increase in Turbocharger speed  Pmax- Increase because of increase in Pcomp and more heat energy being injected. Reduction in density will have the opposite effect. SPECIFIC GRAVITY This is defined as the ratio of the weight of a given volume of oil to the weight of the same volume of water at a given temperature. The density of fuel, relative to water, is called specific gravity. The specific gravity of water is defined as 1. Since specific gravity is a ratio, it has no units. The measurement of specific gravity is generally made by a hydrometer. Specific gravity is used in calculations involving weights and volumes. The specific gravity of various fuel oils are given in Table below: VISCOSITY The viscosity of a fluid is a measure of its internal resistance to flow. Viscosity depends on the temperature and decreases as the temperature increases. Any numerical value for viscosity has no meaning unless the temperature is also specified. Viscosity is measured in Stokes / Centistokes. Sometimes viscosity is also quoted in Engler, Saybolt or Redwood. Each type of oil has its own temperature - viscosity relationship. The measurement of viscosity is made with an instrument called a Viscometer. Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 10
  11. 11. Viscosity is the most important characteristic in the storage and use of fuel oil. It influences the degree of pre- heating required for handling, storage and satisfactory atomization. If the oil is too viscous, it may become difficult to pump, hard to light the burner, and difficult to handle. Poor atomization may result in the formation of carbon deposits on the burner tips or on the walls. Therefore pre-heating is necessary for proper atomization. DYNAMIC VISCOSITY Dynamic viscosity also termed as absolute viscosity, is the tangential force per unit area required to move one horizontal plane with respect to the other at unit velocity when maintained a unit distance apart by the fluid. When the fluid thickness is 1 cm, the force 1 dyne/cm2, the velocity 1cm/s the absolute viscosity is 1POISE. As the units are large it is more common to divide them by 100, resultant smaller units being CENTIPOISE. 1 centipoises= 1 milliPascal second . [Pascal= 1N/m2] The SI symbol is ‘ή’ and SI unit is N.s/m2. CENTISTOKE A unit of measurement for kinematic viscosity equal to the unit millimeters squared per second. The centistoke is the ratio of a liquid's absolute viscosity in centipoise to the density. KINEMATIC VISCOCITY: It is the ratio of viscosity to the density of fuel. Unit of kinematic viscosity is CENTISTOKE (cst) = centipoise / density It can be found out that 1 cSt =10-6m2/sec. VISCOSITY OF ORDERED FUEL Fuel may have been ordered to one of the grades in ISO 8217, frequently on delivery, only the viscosity grade is stated. For example IF 180 this means that the viscosity is a maximum of 180 cSt at 50°C. VISCOSITY TEMPERATURE RELATIONSHIP Because of the viscosity/temperature relationship, a few degrees change could make a big difference to the injection viscosity. In practical terms, this means that if the actual fuel viscosity is greater than that ordered, it is likely that the fuel oil heater can accommodate this. Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 11
  12. 12. VISCOSITY TEMPERATURE RELATIONSHIP Required viscosity for combustion in Engine: - Required viscosity for combustion of Heavy oil is about 13 to 17 cSt. - The viscosity of Diesel oil is about 7 cSt or less. INJECTION TEMPERATURE FOR VARIOUS GRADES OF VISCOSITY. Injection Temperatures for range of viscosities. Injection viscosity Fuel IF 180 IF 200 IF 220 IF 240 IF 380 IF 400 IF 420 IF 460 Injection viscosity 13 cSt 17 cSt O 119 C O 121 C O 123 C O 125 C O 134 C O 135 C O 136 C O 138 C O 109 C O 111 C O 113 C O 115 C O 124 C O 125 C O 126 C O 127 C Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 12
  13. 13. VISCOSITY INDEX: - It is a numerical value which measures the ability of the oil to resist viscosity change when the temperature changes. - A high viscosity index would refer to an oil capable of maintaining a fairly constant velocity value in spite of wide variation in the temperature. - The value of viscosity index is usually determined from a chart based on knowledge of the viscosity values at different temperatures. IGNITION QUALITY - Is a property related to distillated fuel and is that quality of combustibility during combustion process in a diesel engine, which causes ignition delay. - It is a relative value on a scale of 0 to 100, known as cetane number. Paraffin as non-combustible substance is taken for zero and Cetane (C16H34) a highly combustible substance is taken as 100. CCAI & CII CCAI and CII are empirical attempts to estimate how long the fuel will take from injection to ignition and they are also an implication of the likelihood of engine damage.  CCAI:  The ignition quality of a fuel is a measure of the relative ease by which it will ignite  There is accepted empirical equations based on the density and viscosity of the fuel. These are the Calculated Carbon Aromaticity Index (CCAI) range 800-870 Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 13
  14. 14.     CCAI- Effect on engine type 4 stroke engines Ignition quality- engine damage FIA-Fuel ignition analyser Ignition delay & Rate of heat release ROHR- New technology IGNITION QUALITY- ENGINE DAMAGE Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 14
  15. 15. EFFECT OF TIME BETWEEN INJECTION AND START OF INJECTION. - Fuel takes a finite time from the start of the injection to the start of combustion. - During this period, fuel is intimately mixed with the hot compressed air in the cylinder where it begins to vaporize. - After a short delay known as the ignition delay, the heat of compression causes spontaneous ignition to occur. - Rapid uncontrolled combustion follows as the accumulated vapour formed during the initial injection phase is vigorously burned. - The longer the ignition delay, the more fuel will have been injected and vaporized during this “pre-mixed” phase and the more explosive will be the initial combustion. EFFECT OF TIME BETWEEN INJECTION AND START OF INJECTION. - Rapid pre-mixed combustion causes very rapid rates of pressure rise in the cylinder resulting in shock waves, broken piston rings and overheating of metal surfaces. - Large diesel engines are designed to withstand a certain rate of pressure rise within the cylinder although the figure will vary between different designs. RATE OF PRESSURE RISE DUE TO IGNITION DELAY. Rate of pressure rise (bar/degree crank) Comments Below 10 No problem 10 - 12 Acceptable 12 - 16 May cause problem Over 16 Probably damaging This data is derived from the results of engine simulations and published performance criteria. Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 15
  16. 16. IGNITION QUALITY - The ignition quality of a fuel is a measure of the relative ease by which it will ignite. For distillate fuels, this is measured by the Cetane number. Cetane number is determined by testing in a special engine with a variable compression ratio. The higher the number, the more easily will the fuel ignite in the engine. - For residual fuel, there are two accepted empirical equations both based on the density and viscosity of the fuel. These are the Calculated Carbon Aromaticity Index (CCAI) and Calculated Ignition Index (CII). - The CCAI gives numbers in the range 800-870, while the CII gives values in the same order as the Cetane index for distillate fuels. Of the two equations, CCAI values are more frequently quoted. The figure is a nomogram which incorporates both CII and CCAI. If the viscosity is fixed and the density is raised, the CII value falls and the CCAI value is increased. Similarly, if the density is fixed and the viscosity lowered, the CII value falls and the CCAI value is increased. In general, values less than 30 for CII and greater than 870 for CCAI are considered problematical. If required, further guidance on acceptable ignition quality values should be obtained from the engine manufacturer. CCAI CCAI = d – 81- 141 log log(VK + 0.85) d = density kg/m^3, VK = viscosity in mm^2/s at 50oC Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 16
  17. 17. CETANE NUMBER - It is an indication of the ignition quality of the fuel. - In a compression ignition engine the time interval between fuel injection and firing, called ignition delay, must not be too long otherwise collected fuel will generate high pressures when it ignites and diesel knock results. - Paraffin hydrocarbons have the best ignition quality. CETANE NUMBER AND DENSITY - Density is often indicative of cetane number especially in the middle ranges, i.e., density 850 kg/m3, cetane number about 61, density 950 kg/cm3, cetane number about 37. - Acetone peroxide used as additives to improve cetane number. CALORIFIC VALUE The specific energy of a fuel expressed in MJ/kg depends on the composition. For residual fuel, the main constituents are carbon and hydrogen, both of which release energy on combustion. Sulphur also releases energy on combustion but to a lesser extent than carbon and hydrogen. CARBON RESIDUE: The carbon residue of a fuel is the tendency to form carbon deposits under high temperature conditions in an inert atmosphere. It may be expressed as Ramsbottom Carbon Residue (RCR), Conradson Carbon Residue (CCR) or Micro Carbon Residue (MCR). Numerically, the CCR value is the same as that of MCR. The carbon residue value is considered by some to give an approximate indication of the combustibility and deposit forming tendencies of the fuel. CARBON RESIDUE: The carbon residue value of a fuel depends upon the refinery processes employed in its manufacture. On a global basis, this is typically 15-16% m/m but in some areas can be as high as 20% m/m. SULPHUR  residual fuel the value is in the order or 1.5-4 % m/m.  marginal effect on the specific energy  The corrosive effect of sulphuric acid during combustion is counteracted by adequate lube oils and temperature control of the combustion chamber WATER  The ingress of water can come from a number of sources, which include tank condensation and tank leakage Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 17
  18. 18.  removed by centrifuging the fuel before use. This applies especially to salt water, the sodium content of which can result in deposits on valves and turbochargers.  If water cannot be removed, homogenizing after centrifuging is recommended. ASH  Ash represents solid contaminants as well as metals present in the fuel in soluble compounds (vanadium). Part of the ash could be catalyst particles from the refining process.  Such particles are highly abrasive.  Solid ash should be removed to the widest possible extent by centrifuging, and cleaning can be improved by installing a fine filter after the centrifuge e.g 5 – 10 microns. Vanadium and Sodium  Vanadium is present in the fuel in soluble compounds and, consequently, cannot be removed.  Vanadium, in combination with sodium, may lead to exhaust valve corrosion and turbocharger deposits.  This can occur especially if the weight ratio of sodium to vanadium exceeds 1:3, and especially in the case of a high vanadium content.  Vanadium deposits can be so hard that they can cause extensive damage to the TC nozzle ring and turbine wheel.  The only way to remove vanadium depositsis to disassemble the components and remove the deposits mechanically.  Vanadium & Sodium- High temperature corrosion  Sodium is normally present in the fuel as a salt water contamination and may, as such, be removed by centrifuging.  Sodium can also reach the engine in the form of airborne sea water mist. Aluminium and silicon  Aluminium and silicon limits content of catalytic fines, mainly Al 2O3 and SiO2, in the oil. 80 mg Al and Si corresponds to up to 170 mg Al 2O2 and SiO2.  Catalytic fines give rise to abrasive wear, reduced by centrifuging the fuel oil before it reaches the engine, and 5- 10 micron fine filter after the centrifuge  Catalytic fines imbedded in piston ring Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 18
  19. 19. IMPORTANCE OF FUEL PROPERTIES: Fuel’s Additive Functions Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 19
  20. 20. In the maritime field another type of classification is used for fuel oils: MGO (Marine gas oil) - roughly equivalent to No. 2 fuel oil, made from distillate only  MDO (Marine diesel oil) - A blend of heavy gasoil that may contain very small amounts of black refinery feed stocks, but has a low viscosity up to 12 cSt so it need not be heated for use in internal combustion engines  IFO (Intermediate fuel oil) A blend of gasoil and heavy fuel oil, with less gasoil than marine diesel oil  MFO (Marine fuel oil) - same as HFO (just another "naming")  HFO (Heavy fuel oil) - Pure or nearly pure residual oil, roughly equivalent to No. 6 fuel oil Marine diesel oil contains some heavy fuel oil, unlike regular diesels. Also, marine fuel oils sometimes contain waste products such as used motor oil.  CCAI and CII are two indexes which describe the ignition quality of residual fuel oil, and CCAI is especially often calculated for marine fuels. Despite this marine fuels are still quoted on the international bunker markets with their maximum viscosity (which is set by the ISO 8217 standard - see below) due to the fact that marine engines are designed to use different viscosities of fuel. The unit of viscosity used is the Centistoke and the fuels most frequently quoted are listed below in order of cost, the least expensive first        IFO 380 - Intermediate fuel oil with a maximum viscosity of 380 Centistokes (<3.5% sulphur) IFO 180 - Intermediate fuel oil with a maximum viscosity of 180 Centistokes (<3.5% sulphur) LS 380 - Low-sulphur (<1.0%) intermediate fuel oil with a maximum viscosity of 380 Centistokes LS 180 - Low-sulphur (<1.0%) intermediate fuel oil with a maximum viscosity of 180 Centistokes MDO - Marine diesel oil. MGO - Marine gasoil. LSMGO - Low-sulphur (<0.1%) Marine Gas Oil - The fuel is to be used in EU community Ports and Anchorages. EU Sulphur directive 2005/33/EC ULSMGO - Ultra Low Sulphur Marine Gas Oil - referred to as Ultra Low Sulfur Diesel (sulphur 0.0015% max) in the US and Auto Gas Oil (sulphur 0.001% max) in the EU. Maximum sulphur allowable in US territories and territorial waters (inland, marine and automotive) and in the EU for inland use. Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 20
  21. 21. Low Sulphur Fuels    Sulphur contained in the fuel forms metallic sulphides that coat the internal surfaces of the fuel injection equipment including the fuel pumps and the fuel injectors. These sulphides have low shear resistance and act as EP additives similar to that found in lubrication oils. Extremely low sulphur fuels in use on the automotive transport industry have led to the use of lubricity additives. In the marine environment the reduction in sulphur content has been less dramatic. Marpol Annex VI(regulation 14) and the creation of Sulphur Emission Control Area means it wil be a requirement to use only fuels with a certain maximum sulphur content. In the addition to the increased cost of these low sulphur fuels it is necessary to factor in the possibility of increased wear and tear on the engine components. Low sulphur fuels are normally low viscosity oils such as gas oil. Carefull planning has to be done both at the design level ( to ensure sufficient storage capacity) and at the operational and maintenance levels due to the known difficulties in changing over from a heated fuel to a non heated or one with reduced heating capacity. The first British standard for fuel oil came in 1982. The latest standard is ISO 8217 from 2005. The ISO standard describe four qualities of distillate fuels and 10 qualities of residual fuels. Over the years the standards have become stricter on environmentally important parameters such as sulfur content. The latest standard also banned the adding of used lubricating oil (ULO). MARINE DISTILLATE FUELS Parameter Unit Limit DMX DMA DMZ DMB Viscosity at 40°C mm /s ² Max 5.500 6.000 6.000 11.00 Viscosity at 40°C mm /s ² Min 1.400 2.000 3.000 2.000 Micro Carbon Residue at 10% Residue % m/m Max 0.30 0.30 0.30 - Density at 15°C kg/m Max - 890.0 890.0 900.0 Max - - - 0.30 Micro Carbon 3 % m/m Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 21
  22. 22. Residue Sulphur a % m/m Max 1.00 1.50 1.50 2.00 Water % V/V Max - - - 0.30 Total sediment by hot filtration % m/m Max - - - 0.10 Ash % m/m Max 0.010 0.010 0.010 0.010 Flash point 0°C Min 43.0 60.0 60.0 60.0 Pour point, Summer 0°C Max - 0 0 6 Pour point, Winter °C Max - -6 -6 0 Cloud point °C Max -16 - - - Min 45 40 40 35 Max 0.5 0.5 0.5 0.5 Max 25 25 25 25 Calculated Cetane Index b b Acid Number mgKOH/g Oxidation stability g/m Lubricity, corrected wear scar diameter d (wsd 1.4 at 60°C um Max 520 520 520 520 mg/kg Max 2.00 2.00 2.00 2.00 Hydrogen sulphide Appearance a e 3 Clear & Bright f c c b, c A sulphur limit of 1.00% m/m applies in the Emission Control Areas designated by the International Maritime Organization. As there may be local variations, the purchaser shall define the maximum sulphur content according to the relevant statutory requirements, notwithstanding the limits given in this table. b If the sample is not clear and bright, total sediment by hot filtration and water test shall be required. c Oxidation stability and lubricity tests are not applicable if the sample is not clear and bright. Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 22
  23. 23. d Applicable if sulphur is less than 0.050% m/m. e Effective only from 1 July 2012. f If the sample is dyed and not transparent, water test shall be required. The water content shall not exceed 200 mg/kg (0.02% m/m). MARINE RESIDUAL FUELS a RMA RMB RMD RME 10 30 80 180 180 380 500 700 380 500 700 Max 10.00 30.00 80.00 180.0 180.0 380.0 500.0 700.0 380.0 500.0 700.0 Max 920.0 960.0 975.0 991.0 991.0 1010.0 % m/m Max 2.50 10.00 14.00 15.00 18.00 20.00 mg/kg Max 25 mg/kg % m/m mg/kg % V/V Max Max Max Max Max 50 0.040 50 850 0.30 °C Max 6 30 °C Max 0 30 °C % m/m Min Max 60.0 Statutory requirements % m/m Max 0.10 mgKOH/g Max 2.5 Parameter Viscosity at 50°C Density at 15°C Micro Carbon Residue Aluminium + Silicon Sodium Ash Vanadium CCAI Water Pour point b (upper) , Summer Pour point b (upper) , Winter Flash point c Sulphur Total Sediment, aged Acid e Number Unit mm²/s kg/m 3 Limit Used 50 100 0.070 150 860 RMK 60 50 100 0.100 350 0.150 450 870 0.50 The fuel shall be free from ULO, and shall be considered to contain ULO when either lubricating oils (ULO): 40 RMG one of the following conditions is met: mg/kg Calcium > 30 and zinc >15; or Calcium and Calcium > 30 and phosphorus > 15. Zinc; or Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 23
  24. 24. Calcium and Phosphorus Hydrogen d sulphide mg/kg Max 2.00 a This residual marine fuel grade is formerly DMC distillate under ISO 8217:2005. b Purchasers shall ensure that this pour point is suitable for the equipment on board, especially in cold climates. c The purchaser shall define the maximum sulphur content according to the relevant statutory requirements. d Effective only from 1 July 2012. Strong acids are not acceptable, even at levels not detectable by the standard test methods for SAN. e As acid numbers below the values stated in the table do not guarantee that the fuels are free from problems associated with the presence of acidic compounds, it is the responsibility of the supplier and the purchaser to agree upon an acceptable acid number. Source: ISO 8217 Fourth Edition 2010-06-15 Petroleum products - Fuels (class F) - Specifications of marine fuels Marine Bunker Sampling Procedure: A good sampling location is one where a line sampler can be properly fitted at the manifold and where the crew can conduct the sampling process safely and monitor the progress conveniently during the bunkering operation. - Although many valid sampling methods and locations are available in the petroleum industry, DNVPS advocates continuous drip sampling at the point of custody transfer, i.e. ship manifold. - Ideally, only one sampling location should be adopted and a proper, continuousdrip line sampler used for every fuel delivery. - It would also help if both receiving vessel and supplier agree on one set of sample bottles for distribution. Each sample bottle should be sealed and have its label signed by both the receiving vessel and the supplier. - Wherever required, the seal numbers of the fuel samples should be entered on the BDN. Sampling Container: Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 24
  25. 25. 1. Sampling Device Procedures for sampling - step 1 Ensure that your vessel has a proper sampling device at the point of Custody Transfer, which is at the vessel's bunker manifold. Your sampling device and collection container should be clean and ready for use.If your vessel is not fitted with a proper sampling device, you will not be able to take a representative sample. We strongly recommend that you place an order for a DNVPS Line Sampler. 2 - Request to Witness Sampling Form Procedures for sampling - step 2 Sampling Form Complete a Request to Witness Sampling Form and give the top copy to the suppliers representative. Retain the blue copy for your file. Invite the supplier's representative to witness the sampling procedures. If the supplier declines to attend the witnessing of sampling, it is essential that you record this fact in the ship's log book at the time as contemporaneous evidence for future reference in case there is dispute. Ensure that full information about the barge, cargo officer, supplier, time, date, and circumstances etc. are recorded. These records will be important should a dispute Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 25
  26. 26. develop. 3 - Continuous Drip Sampling Procedures for sampling - step 3 Take a continuous drip sample by using the DNVPS Line Sampler. Continuous Adjust the needle valve to give a slow and continuous drip throughout the whole bunkering period. Secure the needle valve with a security Drip seal provided by DNVPS. Record the seal number to prevent any Sampling tampering. Collect approximately 5 liters of sample with the cubitainer provided in the DNVPS Sampling Kit.Check the amount of sample collected to ensure that you have about 5 liters by the end of the bunkering. If you need to break the seal on the needle valve to make adjustments, you should invite the bunker barge Cargo Officer or his representative to be present when you are adjusting the drip and replacing the security seal. Keep proper records in your ship's log if the invitation is declined and also when such adjustments took place. 4 - Dividing the Sample Evenly Procedures for sampling - step 4 Dividing the Sample Evenly Cap the cubitainer and shake the contents vigorously for about 10 minutes to mix the sample thoroughly. Fill 3 sample bottles 1/3 at a time. Make several passes to fill the bottles equally. This is to ensure the sample is more evenly distributed and that the contents in each bottle are similar. In some cases, both the ship owner and the charterer may be on the testing programme and will require separate samples to be sent. Four samples will be needed in such cases. Fill the bottles up to the indication on the bottle FILL TO THIS LINE. Stop at the line as shown in the diagram on the left. 5 - Sealing the Bottles Procedures for sampling - step 5 Close the bottles tightly using the screw caps provided. Seal all the bottles and record all seal numbers on the Chief Engineer's Sealing the Bottles Report form. It is important also to record this information in the ship's log book. Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 26
  27. 27. Complete three (or four) sample bottles labels and sign them in the presence of the supplier's representative. Do not sign any blank labels for the barge crew under any circumstances. Fix a label on each bottle. Caution: If you are offered a sample by the barge crew and have not witnessed correct sampling procedures, please use the rubber stamp provided to indicate a 'For receipt only, source unknown' message on the sample label. 6. Insert Sample into Ziplock Bag Procedures for sampling - step 6 Sample in Ziplock Bag Put the bottle to be sent for testing into the Ziplock bag to prevent spillage. Gently squeeze the Ziplock bag to minimize air content prior to sealing. This bottle will be sent ot the appropriate DNVPS laboratory by courier once the correct colour label has been used. See the DNVPS Air Courier Directory for details. 7. Sample for Supplier Procedures for sampling - step 7 Sample for Supplier Hand one bottle to the supplier's representative. If the supplier declines or discards the sample, make sure that this is recorded in the ship's log with full details of the person, barge, supplier, time, date, incident and sample seal number. This is essential for collecting contemporaneous evidence at the time of the event in case a quantity or quality dispute arises later. 8. Ship’s Retained Sample Procedures for sampling - step 8 Ship’s Retained Sample It is very important to retain one bottle of sample onboard as very often this will be the only one left which represents the fuel delivered to your ship. IMPORTANT If this sample is eventually sent for testing, please ensure Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 27
  28. 28. that all interested parties or their representatives are present to witness the breaking of the seal and the testing process. According to MARPOL Annex VI, Regulation 18, Fuel Oil Sampling: - A sealed sample meeting the requirements in associated guidelines has to supplied to the ship by the bunker supplier - For each individual BDN a sample has to be taken at the vessel’s bunker receiving manifold. - The sample label has to be signed by both the bunker supplier’s representative and the vessel’s Chief Engineer. - The sample size shall be not less than 400 mls - The sample is not to be used for any commercial purpose - The sample is to be retained on board for at least 1 year for inspection by PSC as required Bunkering Operations: Precautions, Checklists, Calculations & Corrections Explained An actual bunkering operation is carried out with bunker checklists. In this article, emphasis is made on the checklists, safety precautions, SOPEP locker and SOPEP equipment, temperature and density correction to calculate the quantity of oil bunkered. The formula for calculation has been included. Bunkering Oil All types of ships needs fuel oil, lube oil, etc. and hence it is important for everyone to understand the actual process of bunkering.  Pre-bunkering preparations. The most important aspect of bunkering operation are the "checklists", which form a part of company's safety management system (SMS) and I.S.M.,eliminating the possibility and negligence of human and other operational errors. The pre-bunkering checklist must be followed in-consultation with the Chief Engineer (C/E), as he is the person-in-charge for the bunkering operation. Before bunkering, usually it is 4th engineering officer, taking "soundings" of bunker tanks and calculates the volume of fuel oil available in every fuel oil tank of the ship. Then a Bunker-plan is made to plan the distribution of total quantity of bunker fuel oil.  Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 28
  29. 29.  Bunker Procurement Ordering of Bunker oil: The ship Managers (superintendents) monitor the performance of a fleet of ships. For example, on owning a car, we tend to keep a check on its fuel consumption widely called as "mileage." It is the distance travelled by the vehicle for a unit volume of fuel used. In the same way, as the ship consumes humungous quantity of fuel, whose costs are forming the major part of ship's operation. Managers tend to keep a check on it. This is measured in terms of specific fuel oil consumption of the main propulsion engine. Upon knowing the fuel oil consumption for a day and the next voyage plan, the quantity of fuel oil required is calculated and compared with the available bunker tank capacity. A requisition is placed through the C/E and Master of the vessel to the Managers. The requisition is processed and evaluated for the quality and quantity of fuel to be supplied for the particular ship. Planning is done for the delivery of bunker at a particular port where the oil is available at a comparitive lesser cost. On taking all these aspects into consideration, the Managers, deliver bunker to the vessel. Upon receiving the bunker, a sample collected during bunkering operation is sent for lab analysis to confirm the delivered oil meets the required standard for the safe and efficient operation of the auxiliary engines & main propulsion engine. Pre-Bunker Checklist 1. State of adjacent waters noticed  2. Vessel properly secured to dock 3. Check suppliers product corresponds to ordered product 4. Agree quantity to be supplied 5. Check valves open 6. Day tanks full and supply valves closed 7. Warning signs in position e.g. No Smoking 8. SOPEP plan available 9. Clean up material in place 10. Oil Boom in place 11. Foam fire extinguisher placed at bunker station 12. Alfa Laval and transfer pumps off Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 29
  30. 30. 13. Fuel tank supply valves open 14. Agree stop/start signals between vessel and barge/truck 15. Bravo flag flying/red light showing 16. Agree pumping/transfer rate 17. Agree emergency shut down procedure 18. Specification sheet received 19. Check hose and couplings are secure and in good order 20. Fuel nozzle and hose secured to vessel 21. Check barge/truck meters Reading: 22. Check on board meters Reading: 23. Bunker Valve open 24. Unused manifold connections blanked off 25. Master informed 26. Signal pumping to commence The above checklist has to be completely filled religiously by both the ship & barge personnel. SOPEP equipments At the bunker manifold and wherever necessary, as per the ships SOPEP plan, the SOPEP equipments should be kept in immediate readiness in order to avoid oil spill/pollution during bunkering operation.  SOPEP- Shipboard Oil Pollution Emergency Plan. The SOPEP Locker must have minimum of the below specified items: 1. Absorbent roll 2. Absorbent pads 3. Absorbent granules 4. Absorbent materials 5. Brooms 6. Shovels 7. Mops Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 30
  31. 31. 8. Scoops 9. Empty receptacles (200 ltrs capacity) 10. Portable air driven pumps 11. Oil boom 12. Oil spill dispersants. These items must be stowed in an easily accessible locker, clearly marked, and is to be brought on deck ready for immediate use, prior to all oil transfer operations. During Bunkering Procedures - Checklist 1. Witness taking and sealing of 2 representative product samples  2. Monitor fuel connections for leaks fuel flow and control tank levels 3. Change over of tanks whenever necessary. 4. Checking the rate at which bunkers are received. 5. Checking the tightness/slackness of mooring ropes. 6. Checking trim/list of the bunker barge & the ship. 7. Continuous monitoring/look outs for the vessel's position(when at anchor). During bunkering, the above checklist must be filled up and continuous monitoring of the above secified items are required till the bunkering operation is complete.  After Bunkering Procedures: On completion of the bunkering operations, with the ship-barge co-ordination, the line should be blown with air to make sure the line is not filled with oil. The after-bunker checklist is followed. After Bunker Checklist 1. Bunker Valve closed 2. Disconnect hose (drain before disconnecting) 3. Check barge/truck meter Reading: 4. Check ships meter Reading: 5. Sign Bunker Delivery Receipt BDR No.:(Bunker Delivery Report/Note). 6. Retain BDR with product sample Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 31
  32. 32. 7. SOPEP plan returned to bridge 8. Clean up gear stowed / Oil boom returned 9. Bravo Flag/Red light stowed/switched off 10. Remove and pack away warning/safety signs 11. Foam fire extinguisher placed back in correct location 12. Complete Oil Record Book 13. Master informed of completion 14. Confirm in Oil Record Book Bunkering checklist completed  Quantity Calculation & Temperature-Density Correction: After bunkering of various fuel oil tanks, the quantity in each bunkered tank must be calculated to cross-check whether the received quantity of oil matches the requisition. For calculating the quantity, "sounding" of the tanks which are "bunkered" must be taken. The "Density" of the fuel oil supplied vary from place to place. It also varies with the temperature. As a thumb rule, the density of fuel oil decreases with increase in temperature. So, when the oil is supplied at a higher temperature, then the volume of oil supplied is less than what is supplied at lesser temperature. Oil Temperature ----------------------------Density ------------------------------- Volume Of Oil Supplied Increases--------------------------------------Decreases------------------------------------Lesser Decreases--------------------------------- ---Increases -------------------------------------More Also the formula which is generally used for temperature-density correction is as follows: MT = (Temperature Corrected density * Actual Sounded Volume). Temperature Corrected Density can be calculated with the under-mentioned fomula: Temperature corrected Density = Density of Fuel Oil @ 15 degree Celsius * [1- {(t1-15) * 0.00064}] Where, t1 stands for temperature of oil in bunker tanks in degree Celsius, 0.00064 is the correction factor, volume of oil in m^3 (actual sounded volume), is obtained from the sounding table. Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 32
  33. 33.  Safeties of bunkering: General Safeties During Bunkering:  SOPEP locker,  Emergency shut-down arrangements,  Bunker line over-flow arrangements to overflow tank with audible & visual alarm,  Relief valve in the bunker line,  Containment trays.  Consistent & Continuous look outs. Thus bunkering operation is directly related to "MARPOL" annexes, i.e annex 1 and annex 6. When oil is spilled it causes marine pollution under annex 1. When the bunkered oil doesn't meet certain specifications, it causes pollution of air which comes under annex 6. MARPOL regulations regarding bunkering: Regulation 18 - Fuel Oil quality.  “Fuel oil shall be blends of hydrocarbons derived from petroleum refining”  “Fuel oil shall be free from inorganic acid”  “Fuel oil shall not include any added substance or chemical waste which either: o Jeopardises the safety of ships or adversely affects the performance of the machinery, or o Is harmful to personnel, or o Contributes overall to additional air pollution” Bunker Delivery Note (BDN): - Becomes a Statutory document - Must be kept on board for 3 years for inspection and a copy may be taken for further examination by PSC. - Must contain all data required by Appendix V - Name and IMO number of vessel Port - Date of Commencement of delivery - Details of fuel oil supplier - Product name, quantity , Density at 15 0C and Sulphur content % m/m - A declaration that fuel supplied meets Regulation 14 and 18 requirements Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 33
  34. 34. Shipboard Procedures for BDN and Samples  Adequate bunker manifold location for sampler attachment  External safe storage location for samples for 1 year period  Log book for sample retention and custody transfer  Safe storage for BDNs and other documents relating to bunkering onboard  Port/Flag State Control Guidelines  Proposed Guidelines from FSI 13 for MEPC 53 approval.  Initial inspections and Primary survey parameters – then “Clear Grounds” for indepth inspections  “In depth” inspection parameters Any Question? Thank you! Mohd. Hanif Dewan, Senior Engg. Lecturer, International Maritime Academy, Bangladesh. 34