Marine Fuel Oil and Fuel Oil Bunkering

Prepared By

Last Modified On: January 09, 2015

Md. Moynul Islam Chemical Engineer Expertise on Marine Fuels and Lubricants Contact Email : [email protected] Mobile : +8801816449869 Web : www.moynulislam.com

Content

PART-A: Marine Fuel Oil and Fuel Oil Specifications PART-B: Fuel Oil Delivery and Loss Prevention

Introduction As a buyer, you are not buying just fuels for your power plant, you are buying the energy which is the base of your business. Every year you are spending millions of dollars behind fuels. And your business profit is directly related to the quality fuels. Proper monitoring in your fuel management system is vitally needed to run your power business profitably. So, you have the right to know about the fuel specifications and also have the right to receive actual quantity that you have ordered to the supplier. Receiving off spec fuel or less quantity (from your ordered quantity) will ultimately impart on loss in energy. Loss in energy means loss in generation followed by loss in revenue. Your fuel supplier may settle your ordered quantity by manipulating some digits but the problem arises later when you will use this fuel in your engines. The engines are very rude to you about fuel consumption. To generate your desired power they will never compromise even a single drop in their consumption. They will consume exactly the required amount of fuel to generate your ordered power to them. They will consume fuels according to your fuel quality. If the calorific value of supplied fuel is high than the fuel consumption will be low and if the calorific value is low than the fuel consumption will be high. So, you need to understand about bunker and bunkering procedure before entering in this world. If you supply them any off spec fuel, it may be complicated to operate them smoothly or there may be severe damage to engine component following breakdown maintenance. Ultimately interruption in smooth engine operation.

Origin of Marine Fuel Oils (MFO) Crude oil refining and stocks for marine fuel blending: Crude oil is a mixture of many different hydrocarbons and small amounts of impurities. The composition of crude oil can vary significantly depending on its source. Crude oils from the same geographical area can be very different due to different petroleum formation strata. In subsequent slides, we will see different crude oil refining process , production of marine fuel oils and how the quality of marine fuels affected by different processing methods . Types of crudes: • Paraffinic crudes • Naphtenic crudes • Asphaltenic (aromatic) crudes Each crude oil contains the three different types of hydrocarbons, but the relative percentage may vary depending on sources.

Straight run refinery: Atmospheric crude distillation

Origin of Marine Fuel Oils (MFO)

Straight run refinery : Atmospheric crude distillation Diesel refers here to specific atmospheric distillation cuts, and this is not relevant for automotive engine application

Straight run stocks used for marine fuel blending: Light diesel, heavy diesel, and straight run residue Straight run marine gasoil and distillate marine diesel (MDO): Marine gasoil and distillate marine diesel oil (MDO) are manufactured from kero, light, and heavy gasoil fractions. For DMC distillate marine diesel up to 10–15%, residual fuel can be added. Straight run IFO 380 mm2/s (at 50°C): This grade is obtained by blending the atmospheric residue fraction (typical viscosity of about 800 mm2/s at 50°C) with a gasoil fraction. Straight run lower viscosity grade IFOs: Blending to lower grade IFOs is done from the IFO 380 mm2/s (at 50°C) using a gasoil cutter stock or with marine diesel. All IFOs have good ignition characteristics, due to the high percentage of paraffinic material still present in the atmospheric residue, and the paraffinic nature of the cutter-stocks used. The high amount of paraffinic hydrocarbons in the straight run marine fuels leads to relatively low densities for these products, ensuring easy and efficient onboard fuel purification. The product slate of a straight run refinery, with its heavy fuel production of approximately 50% of the crude feed, does not correspond to the product demand in industrialized countries where the ever-growing demand for light products (jet fuel, gasoline, and gasoil) coincides with a strong reduction in the demand for heavy fuel (10 to 15% of the crude oil). This results in the need to Convert the residue fraction into lighter, hence, more valuable, fractions and to the construction of Complex Refineries. Source: Everything You Need To Know About Marine Fuel

Origin of Marine Fuel Oils (MFO) Complex Refinery: A complex refinery processing scheme can be separated into two parts: 1. Crude oil distillation (atmospheric and vacuum distillation) 2. Streams from the vacuum distillation unit are converted through Catalytic (FCC) and Thermal Cracking processes.

Complex refinery : ADU, VDU, FCCU, VIS-BREAKING UNIT Source: Everything You Need To Know About Marine Fuel

Origin of Marine Fuel Oils (MFO) The main marine fuel blending components from a Fluidized bed Catalytic Cracking (FCC) refinery with Vis-breaker are the same distillates as those from a Straight run refinery (light and heavy diesel) as well as Light Cycle (gas) Oil (LCO) and Heavy Cycle Oil (HCO) from the Cat-Cracker and vis-broken residue from the Vis-breaker unit. Atmospheric residue is used as feedstock for the vacuum unit and will seldom be available for fuel blending. Marine fuels produced from a catalytic cracking/ vis-breaking refinery have a composition that is markedly different from that of an atmospheric refinery.

Light Sour Crude Refining Process

Origin of Marine Fuel Oils (MFO) Marine Gas Oil (MGO/DMA) : A new blend component Light Cycle Oil (LCO) which contains about 60% aromatics. Because of the high aromatic content in LCO, the density of a marine gasoil blended with LCO will be higher than when using gasoil from a Straight run refinery. The density will typically be close to 860 kg/m3 (at 15°C). No performance or handling differences with atmospheric gasoil are to be expected. Distillate marine diesel (MDO/DMB): Distillate marine diesel typically has a lower Cetane Index than MGO, and has a higher density. With the production slate of a Catalytic Cracking refinery, distillate marine diesel can therefore contain a higher percentage of LC(G)O than MGO.

Blended marine diesel (MDO/DMC): With atmospheric refining, blended marine diesel (MDO/ DMC) can contain up to 10% IFO with either marine gasoil (MGO/DMA) or distillate marine diesel (MD)/DMB). With complex refining, MDO/DMC no longer corresponds to a specific composition and extreme care must be used when blending this grade to prevent stability and/or combustion problems.

Medium/Heavy Sour Crude Refining Process

Origin of Marine Fuel Oils (MFO) IFO-380 Production: This grade is usually manufactured at the refinery and contains visbroken residue, HCO and LC(G)O. These three components influence the characteristics of the visbroken IF-380. Vacuum distillation reduces the residue yield to about 20% of the crude feed, unavoidably leading to a concentration of the heaviest molecules in this fraction. Visbreaking converts about 25% of its vacuum residue feed into distillate fractions. This means that about 15% of the original crude remains as vis-broken residue. The asphaltenes1, sulphur and metal content in visbroken residue are 3 to 3.5 times higher than in atmospheric residue. Visbreaking affects the molecular structure: Molecules are broken thermally, and this can deteriorate the stability of the asphaltenes. HCO (typical viscosity at 50°C: 130 mm2/s) contains approximately 60% aromatics, and is a high-density fraction: the density at 15°C is above 1 kg/l (typically 1.02). It is the bottom fraction of the FCC unit. The catalytic process of this unit is based on an aluminum silicate. Some mechanical deterioration of the catalyst occurs in the FCC process, and the resulting cat fines are removed from the HCO in the refinery. This removal, however, is not 100% efficient and a certain amount (ppm level) of cat fines remains in the HCO. From there they end up in heavy fuel blended with HCO. The aromaticity of HCO assists in ensuring optimum stability for the visbroken fuel blend. LC(G)O (typical viscosity at 50°C: 2.5 mm2/s) has the same aromaticity as HCO, but is a distillate fraction of the FCC unit, with a distillation range comparable to that of gasoil. With a typical density of 0.94 kg/l at 15°C, it is used to fine-tune the marine heavy fuel oil blending where generally a density maximum limit of 0.9910 kg/l has to be observed.

Source: Everything You Need To Know About Marine Fuel

Origin of Marine Fuel Oils (MFO) IFOs < 380 mm2/s Production: These grades are generally blended starting from 380 mm2/s IFOs (at 50°C), by using a suitable cutterstock (marine diesel, gasoil, LC(G)O, or a mixture of these). The blend composition has to be construed in such a way that the product stability is safeguarded, while at the same time direct or indirect density limits are fulfilled

Summary of Crude Oil Conversion Step01: Separation of Lighter Fractions: In this step, the crude oil is heated up to approx. 350 oC and enter to the Atmospheric Distillation Unit (ADU) where lighters fractions are recovered via distillation at atmospheric pressure. The bottom residue of ADU is further heated up and sends to the Vacuum Distillation Unit (VDU) where all of the volatile components are recovered via distillation at low pressure.

Step-02: Production of Marine Fuel Oil The viscosity of heavy residue of VDU is very high. To produce MFO, the heavy residue required further processing like cracking with FCC , and Vis-breaker where a cutter stocks (fuel oil heaving low viscosity) is used to reduce viscosity to the desired level.

Classification of Marine Fuel Oil Conventional Classification System In maritime industry the most commonly used fuel oil classification system is as follows MGO (Marine Gas Oil)

- Roughly equivalent to No. 2 fuel oil, made from distillate

MDO (Marine Diesel Oil)

- A blend of heavy gasoil that may contain very small amount of black refinery feed stocks, but has a low viscosity up to 12 cSt and it need not be heated for use in IC engines

IFO (Intermediate Fuel Oil) - A blend of HFO with less gasoil than MDO. MFO (Marine Fuel Oil)

- Same as HFO (just another name)

HFO(Heavy Fuel Oil)

- Pure or nearly pure residual fuel oil, roughly equivalent to No. 6 fuel oil

Another classification system popular in maritime industry for fuel oil is based on their maximum viscosity in cSt at 50oC IFO-380

-Intermediate Fuel Oil with max viscosity of 380 cSt at 50 oC

IFO-180

-Intermediate Fuel Oil with max viscosity of 180 cSt at 50 oC

LS-380

-Los Sulfur ( 20 % High and may be problematic and cause increased fouling 10 - 12 % Straight run fuels 15 - 16 % Average and acceptable in modern engines

Comment: Injector nozzles can become fouled using high MCR fuel. Careful control of nozzle cooling temperature can help reduce this.

Necessary Terms and Documents Used In Bunker Industry 4.0 Aluminum + Silicon (Catalytic Fines, CatFines) : Hard, abrasive particles, such as alumina/silica catalyst carry-over, originate in the refinery when this powdered catalyst is added to the charge stock of a fluidic catalytic cracking (F.C.C.) unit. Due to erosion and fracture, some of the catalyst is not recovered but is carried over with the bottoms from the F.C.C. unit. Larger sized catalyst particles, >10 microns, also can be carried over if there is a defect in the catalyst removal equipment (such as cyclone separators), if there is an upset in the operation of the F.C.C. unit, or if the heavy (low API gravity) bottoms (containing catalyst particles) are not permitted sufficient time to settleout in heated storage (when this method is used to control catalyst carry-over). It is also possible to contaminate a clean marine residual fuel oil with catalyst particles during transport. For example, if steamship fuel (frequently containing catalyst particles) has been transported by barge prior to moving a clean heavy fuel oil for a diesel powered ship, the barge bottom sediment will be mixed with the clean fuel oil and will contaminate it. Because cat-fines are generally small, very hard, and quite abrasive to fuel pumps, atomizers/injectors, piston rings and liners, a number of major diesel engine builders have concluded that 30 ppm of alumina in the bunkered fuel oil is the upper limit for successful treatment and engine operation. The average particle size, as well as the concentration, greatly impacts the wear rate of engine components. Small sized catalyst particles, in the one to ten (1-10) micron range, typically cause accelerated wear in injection pumps and injectors and only moderate increases in cylinder assembly wear, such as piston rings, piston grooves, and liners. The larger sized catalyst particles, in the ten to seventy (10-70) micron range, typically cause very accelerated wear rates in the cylinder assembly area. Accelerated damage can also be expected on injection pump inlet valves, exhaust valve seating areas, and turbocharger turbine blades. These larger sized particles have been associated with catastrophic wear rates.

Necessary Terms and Documents Used In Bunker Industry 5.0 Sodium(Na): Sodium is an alkaline, chemically extremely active metallic element. The sodium found in fuel can come from several sources. But most of it is a direct result of storing and handling procedures from the time the fuel leaves the refinery until it is delivered to bunkers. Salt water contamination in barges used to transport the fuel is not uncommon. To some extent, even salt air condensation in fuel tanks contributes to the overall sodium content. Sodium acts as a paste (flux) for vanadium slag. When unfavorable quantities of vanadium and sodium are present in a fuel they react at combustion temperatures to form (eutectic) compounds with ash melting points within operating temperatures. In molten form sodium/vanadium ash can corrode alloy steels, and when this condition is allowed to persist unchecked, high temperature corrosion, overheating, and eventual burning away of exhaust valves, valve faces, and piston crowns is not uncommon. The chief corrosive constituents in heavy fuel, oil ash formed during combustion are vanadium pentoxide, sodium sulphate, and other complex forms of these primary compounds. The chemical nature of these compounds and their interaction with steel surfaces on exhaust valve seats are of real concern, as the relatively low melting points of most of these compounds make them very corrosive at normal engine exhaust temperatures. The thickness of the various oxide layers depends on the temperature and the exhaust gas composition. In their molten states, the vanadium-sodium-sulfur compounds also act to dissolve the exhaust valve surface ferric oxide (Fe203) layer, thus exposing the underlying steel surface to further oxidation attack and subsequent erosion. The oxidation attack takes place by two mechanisms: gas phase oxidation and liquid phase oxidation. In the gas phase oxidation, the high temperature oxygen-containing exhaust gases react with steel to form oxides. Liquid phase oxidation (corrosion) takes place when molten sulfates and pyrosulfates in the exhaust gases deposit on valve surfaces. In extreme situations, similar sodium/vanadium ash corrosion attack can also occur downstream of the exhaust valves in the turbocharger exhaust gas turbine and blades.

Sodium -Vanadium Phase Diagram Vanadium present in fuel can form low melting compounds V2O5 which melts at 691 oC and which causes severe corrossive attack on all high temperature alloys used for gas turbine blades, valves. However, if sufficient magnesium is present in fuel, it will combine with the vanadium and forms a self-spalling compounds with higher melting points and thus reduce the corrosion rate to an acceptable level. Sodium and Potassium can combine with vanadium to form eutectics compounds which melt at temperatures as low as 565 oC and with sulfur in the fuel to yield sulfates with melting points in the operating range of the gas turbine. See the V2O5-Na2O phase diagram in Figure 07. See also the melting temperature of different oxides of vanadium also in figure 08

Necessary Terms and Documents Used In Bunker Industry Regardless of the manner of contamination, sodium in fuel is usually water soluble and can, therefore, be removed with the centrifugal separator. 6.0 Ash The ash contained in heavy fuel oil includes the (inorganic) metallic content, other non-combustibles and solid contamination. The ash content after combustion of a fuel oil takes into account solid foreign material (sand, rust, catalyst particles) and dispersed and dissolved inorganic materials, such as vanadium, nickel, iron, sodium, potassium or calcium. Ash deposits can cause localized overheating of metal surfaces to which they adhere and lead to the corrosion of the exhaust valves. Excessive ash may also result in abrasive wear of cylinder liners, piston rings, valve seats and injection pumps, and deposits which can clog fuel nozzles and injectors. In heavy fuel oil, soluble and dispersed metal compounds cannot be removed by centrifuging. They can form hard deposits on piston crowns, cylinder heads around exhaust valves, valve faces and valve seats and in turbocharger gas sides. High temperature corrosion caused by the metallic ash content can be minimized by taking these engine design factors into consideration; (1) hardened atomizers to minimize erosion and corrosion and (2) reduction of valve seat temperatures by better cooling. 7.0 Vanadium Vanadium is a metallic element that chemically combines with sodium to produce very aggressive low melting point compounds responsible for accelerated deposit formation and high temperature corrosion of engine components. Vanadium itself is responsible for forming slag on exhaust valves and seats on 4-cycle engines, and piston crowns on both 2- and 4-cycle engines, causing localized hot spots leading eventually to burning away of exhaust valves, seats and piston crowns. When combined with sodium, this occurs at lower temperatures and reduces exhaust valve life. As the vanadium content (ppm) increases, so does the relative corrosion rate.

Necessary Terms and Documents Used In Bunker Industry Vanadium is oil soluble. It can be neutralized during combustion by the use of chemical inhibitors (such as magnesium or silicon). Cooling exhaust valves and/or exhaust valve seats will extend valve and seat life. Raising fuel/air ratios also prolongs component life. Other measures which can be used to extend component life are the use of heat resistant material, rotating exhaust valves, and the provisions of sufficient cooling for the high temperature parts.

Vanadium content varies widely in heavy fuel oils depending on the crude oil source or crude oil mixes used by the refinery. The vanadium levels of future heavy fuel oils generally will be higher than today’s. This is particularly true of fuel oils produced from Venezuelan and Mexican crude. Vanadium cannot presently be economically reduced or removed by the refinery or the ship’s systems. The burden of coping with high vanadium levels will continue to remain with engine builders and ship operators. This tolerance must be achieved through advances in materials and cooling techniques and through the use of onboard treatment methods such as chemical additives. In general, fuel when delivered contains a small amount of sodium which is typically below 50 mg/kg. The presence of sea water increases this value by approximately 100 mg/kg for each per cent sea water. If not removed in the fuel treatment process, a high level of sodium will give rise to post-combustion deposits in the turbocharger. Although potentially harmful, these can normally be removed by water washing. High temperature corrosion and fouling can be attributed to vanadium and sodium in the fuel. During combustion, these elements oxidize and form semi-liquid and low melting salts which adhere to exhaust valves and turbochargers. In practice, the extent of hot corrosion and fouling are generally maintained at an acceptable level by employing the correct design and operation of the diesel engine. Temperature control and material selection are the principal means of minimizing hot corrosion. It is essential to ensure exhaust valve temperatures are maintained below the temperatures at which liquid sodium and vanadium complexes are formed and for this reason valve face and seat temperatures are usually limited to below 450°C.

Necessary Terms and Documents Used In Bunker Industry When a fuel is bunkered with a vanadium level greater than that recommended by the engine designer, there is a risk that hot corrosion and fouling may occur. One operational solution is by the use of a fuel additive, and numerous ash-modifying compounds are available. They should be used with care as situations can arise where the effect of the ashmodifier, by incorrect application, can cause further problems in the downstream postcombustion phase. Comment: Do not run on V levels above spec for extended intervals. Watch for Na:V of 1:3 ratio. Vanadium, Sodium and Ash will cause fouling in the Turbocharger.

8.0 CCAI The most common method of assessing this aspect is by an empirical equation involving density and viscosity, known as the Calculated Carbon Aromaticity Index (CCAI). Of the two parameters, density has the major effect. The incidence of fuels with a CCAI exceeding 870 is in the order of 0.2% , whilst those in the range 870-860 are less than 3%.

Necessary Terms and Documents Used In Bunker Industry Combustion

of a residual fuel is a multi-stage process of which one part is the ignition quality of the fuel. 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 vapor 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. The second phase or “diffusion burning” phase of combustion is controlled by how rapidly the oxygen and remaining vaporized fuel can be mixed as the initial supply of oxygen near the fuel droplets has been used during the pre-mixed combustion. 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. Ignition performance requirements of residual fuels in large diesel engines are primarily determined by engine type and, more significantly, engine operating conditions. Fuel factors influence ignition characteristics to a much lesser extent. It is for this reason that no general limits for ignition quality can be applied, since a value which may be problematical to one engine under adverse conditions may perform quite satisfactorily in many other circumstances. Engine operation under part load conditions using high CCAI fuel should be avoided. CCAI and CII are empirical attempts to estimate how long the fuel will take from injection to ignition and by implication the likelihood of engine damage. After calculating the CCAI or CII of a fuel, the operator must then judge the acceptability of that fuel for effective operation in the engine. Variations of engine load, rated speed and design affect the likelihood of poor combustion, hence it is impossible to give precise figures that apply to all engines. The figure above gives guidance in relation to CCAI for a number of engine types. This data is derived from the results of engine simulations and published performance criteria.

PART-B

Fuel Oil Delivery and Loss Prevention

Quantity only Think about the Discrepancy in Quality also Do not think for Discrepancy in

PART-B: Fuel Oil Delivery and Loss Prevention Fuel Oil Bunkering is a fuel oil transfer process, where a large quantity of fuel is transferred from one vessel (supplier vessel) to another vessel (receiver tank or vessel) in a systematic way. In bunker industry the well established trading unit of bunker fuel is metric tones(MT). There has some technical advantages to use this unit in purchasing bunker.(1) MT is a unit of mass which is not dependent on temperature, (2) All types of energy calculations are directly related to the mass of fuel rather than volume. For the sellers, you are selling fuels, and you have to be clean and reliable in your business by supplying actual information and technical data about the fuel which you are supplying/delivering to your customer. Due to the complexity in calculation procedure and limitation of time standard procedure of bunkering is rarely followed. But without a standard measurement system, attaining accurate result is quite impossible. This is the main reason of discrepancies in bunkering. 1. 2. 3. 4. 5. 6.

The key objectives of this effort: To automate the bunker calculation processes using computer. To establish IBIA standard procedure in bunkering in Bangladesh. To visualize the sources of error in bunkering in Bangladesh To minimize discrepancies in bunkering by removing erroneous procedures in bunkering Enhancing the fuel system monitoring in HFO/LFO based power plant

Necessary Terms and Documents Used In Bunker Industry

Density :

We know that volume is an extensive properties which is dependent on the temperature and the pressure. So, to measure density of fuel oil, the temperature and pressure must consider. In maritime industry the density of fuel oil is expressed at 15 oC called density at standard temperature. The standard density (density at 15 oC) is more meaningful rather than density in any other temperature. Because this density is used to calculate following parameters of fuel; 1. 2. 3. 4. 5. 6. 7. 8.

Shell Calculated Carbon Aromaticity Index (CCAI) BP Calculated Ignition Index(CII) Higher Heating/Calorific Value (HHV) Lower Heating/Calorific Value (LHV) Volume Correction Factor(VCF) by ASTM 54B Weight Correction Factor(WCF) by ASTM 56D Volume Conversion Density Conversion and so on…

Be careful!

In your fuel specification contract, the maximum density is specified 991 Kg/m3 at 15 oC. If you receive a fuel having observed density 989 at 30 oC temperature. Do not think that your fuel is within your specification. Actually this fuel is out of specification and actual density at 15 oC is 999.14 TABLE ASTM 53B is used for density correction from observed density to standard density

Necessary Terms and Documents Used In Bunker Industry Use of Density, API Gravity and Specific Gravity in Bunker Survey: Density, API Gravity and Specific Gravity (Also called Relative Density R.D) all are used by the bunker surveyor to calculate VCF and WCF. VCF Calculation: Table 54B is specified for Density, Table 6B is specified for API Gravity and Table 24B is specified for S.G. to calculate VCF. WCF Calculation: Again Table 56 is specified for Density and Table 13 is specified for API Gravity to calculate WCF. Comments: Sometimes the surveyors convert the density at 15 oC kg/m3 expressed in BDR in to Specific Gravity (S.G) to facilitate it with Table 54B and Table 56 to calculate VCF and WCF. Suppose, 978  0.978

Are they actually converting from Density at 15 oC in to Specific Gravity? They are not converting the Density in to S.G. They are actually converting the density unit from kg/m3 to kg/L. Because, some version of VCF and WCF tables are calculated based on the density expressed in kg/L unit rather than kg/m3. That is the reason for conversion of density unit from kg/m3 to kg/L.

So be careful about the use of Density and Specific Gravity. Do not mess up with density in kg/L with S.G To avoid all kinds of conversion problems in bunker survey, a specialized software is available which will automate your bunker quantity calculation. Visit author’s website www.moynulislam.com and see the demo

Purchase Bunker by Mass rather than by Volume Observe the pictures below, fuel oil is being shipped from a hotter region to a cooler region. The volume is different but the mass is remaining the same. So trading fuel by mass is more convenient rather than by volume. As a large volume of fuel is involved in bunkering and its quite impossible to measure the fuel quantity by mass using a weight measuring machine. That’s why the mass (an intensive properties) of fuel is measured indirectly from volume and density (two extensive properties of fuel). Converting fuel volume into mass is not an easy job just by multiplying the observed volume with observed density. It’s a critical job. Mass should be calculated following standard procedure. Accuracy in calculation procedure is important as fuel oil is not a low valued product like water. Hence, care should be taken before calculating the mass. The cost of small error in calculation procedure is much more higher than spending small effort in standard measurement.

Purchase Bunker by Mass rather than by Volume Observe the column chart below, an oil tanker carrying fuel oil from one location to another location.

Location 01: Temperature in Location 01 Quantity by Mass in Location 01 Quantity by Volume in Location 01

= 50 oC = 1413.09 MT = 1500 m3

Location 02: Temperature in Location 02 Quantity by Mass in Location 02 Quantity by Volume in Location 02

= 30 oC = 1413.09 MT = 1478.48 m3

Location 03: Temperature in Location 03 Quantity by Mass in Location 03 Quantity by Volume in Location 03

= 15 oC = 1413.09 MT = 1462.85 m3

1550 1500

1500

1478.48

1450

1462.85

1413.09

1413.09

1413.09

1400 1350 50

30 Volume(m^3)

Mass (MT)

15

Sounding Tape How To Take Sounding? Follow the steps mentioned below to take sounding on a ship using the sounding tape. 1.) Make sure the bob is tightly held with the tape using a strap hook. Ensure that the tape is not damaged anywhere in between to avoid dropping of bob or tape inside the pipe. 2.) Know the last reading (reference height) of the tank in order to have a rough idea whether to take sounding or ullage. 3.) Apply water/ oil finding paste to get exact readings. 4.) Drop the tape inside the pipe and make sure it strikes the striker plate. 5.) Coil up the tape and check for impression of paste and then note the sounding. 6.) Check the trim and list of the ship to read the correct reading for volumetric content of the ship. 7.) Note down the sounding in the record book with signature of the officer in charge.

Sounding Measuring Tape  For Manual measurement of sounding, a measuring tape normally made up of brass and steel with a weighted bob attached at the end of the tape is used.  Sounding pastes are also available for both water and gas oil which highlights the level of fluid in tape.

Reading Draft Marks Procedure for Reading Draft Marks: Draft marks are numbers marked on each side of the bow and stern of the vessel. Draft marks show the distance from the bottom of the keel to the waterline. Use the small boat to go around the ship and get as near as possible to the draft mark for best viewing. This process is hard to do and involves many rules of conduct to gain the correctness and accuracy of Draft Survey itself

Why accuracy in drafts reading is important? The reason is that, the tanks of a tanker is calibrated based on précised measurement. The capacity table is generated by using accurately measured drafts. Your unintentional mistakes in drafts measurement will affect your entire calculation. So, try to collect data as accurate as possible by avoiding common error in measurement.

Types of Hydrometers Hydrometers for Oil: A hydrometer is an instrument used to measure the specific gravity(or relative density) of liquids. Hydrometers for oils are specifically designed for the testing of oil and petroleum products, and are made in accordance with national and international standards. They can be supplied with calibration certificates, or certificates showing traceability to national NAMAS standards. Hydrometers varies depending on the scales and field of applications. The common types of hydrometers are as follows:  Specific Gravity Hydrometers (spgr 60/60 oF) calibrated at 60 oF  Density Hydrometers calibrated at 20 oC (at 68 oF)  API/ASTM Hydrometers  Baume Hydrometers  Brix Hydrometers  Twaddle Hydrometers  Plain Form Hydrometers How to use a hydrometer: Before using the hydrometer  Make sure both the hydrometer and hydrometer jar are clean.  If the liquid to be tested is not at room temperature, allow it to reach room temperature before testing.  Pour the liquid carefully into the hydrometer jar to avoid the formation of air bubbles. Do this by pouring it slowly down the side of the jar.  Stir the liquid gently, avoiding the formation of air bubbles.

Comment:

Visually, Density Hydrometer and Specific Gravity Hydrometer are same but differ in scale and calibration temperatures. Before using the hydrometer be sure about the type so that you can select right ASTM tables for density/specific gravity correction. Because the ASTM tables for density and specific gravity correction are different. For density hydrometer ASTM53B and for specific gravity hydrometer ASTM 23B are used.

How to take reading from a hydrometer? How to take reading from a hydrometer:  Carefully insert the hydrometer into the liquid, holding it at the top of the stem, and release it when it is approximately at its position of equilibrium.  Note the reading approximately, and then by pressing on the top of the stem push the hydrometer into the liquid a few millimetres and no more beyond its equilibrium position. Do not grip the stem, but allow it to rest lightly between finger and thumb. Excess liquid on the stem above the surface can affect the reading.  Release the hydrometer; it should rise steadily and after a few oscillations settle down to its position of equilibrium.  If during these oscillations the meniscus is crinkled or dragged out of shape by the motion of the hydrometer, this indicates that either the hydrometer or the surface of the liquid is not clean. Carefully clean the hydrometer stem. If the meniscus remains unchanged as the hydrometer rises and falls, then the hydrometer and liquid surface are clean, and a reading can be taken.  The correct scale reading is that corresponding to the plane of intersection of the horizontal liquid surface and the stem. This is not the point where the surface of the liquid actually touches the hydrometer stem. Take the reading by viewing the scale through the liquid, and adjusting your line of sight until it is in the plane of the horizontal liquid surface. Do not take a reading if the hydrometer is touching the side of the hydrometer jar.

Measuring The Temperature

Measuring The Temperature:  Using a suitable thermometer, take the temperature of the liquid immediately after taking the hydrometer reading.  If there is any chance of a change in the temperature of the liquid it is safer to take the temperature both before and after the hydrometer reading. A difference of more than

1°C means that the temperature is not stable, and the liquid should be left to reach room temperature.  If the temperature of the liquid is not the same as that on the hydrometer scale, the hydrometer reading should have a correction due to temperature applied.

Handling the Hydrometer  The hydrometer should never be held by the stem, except when it is being held vertically.  When holding the stem, always hold it by the top, as finger-marks lower down can affect the accuracy of the instrument.  Always handle with care.

Necessary Terms and Documents Used In Bunker Industry LIST and TRIM Correction Table: A certified calibration table for LIST and TRIM correction table.

Calibration Tables: A certified capacity table derived from the tank dimension to measure the bulk volume by providing tank sounding/ullage data. Make sure that the calibration table is original and accurate. It is not unknown for duplicate barge tables to be used. At first sight they appear in order but have, in fact, been modified to the advantage of the supplier. Inserted pages, photocopies, corrections, different print and paper types are all indications of tampering.

Meter Readings: If fuel oil delivery is determined by a meter reading, air may be pumped which will reduce the amount actually delivered. Meter readings record a volume which has to be converted to weight by knowledge of the density.

Ullage: The delivery barge contends that seals on sounding pipes cannot be broken. The statement is usually backed by excuses such as customs seals or a seized sounding cock. As an alternative to gauging the tanks.

fuel oil is delivered by meter and air is pumped through the meter to increase the measured delivery displayed Counter measures - don’t agree to meter only fuel oil deliveries.

ASTM D1250: Standard Guide for Use of the Petroleum Measurement Tables ASTM D1250: This guide explains in detail about use of the following petroleum measurement tables TABLE

VOLUME

NAME

5A

VOLUME I

GENERALIZED CRUDE OILS CORRECTION OF OBSERVED API GRAVITY TO API GRAVITY AT 60 oF

5B

VOLUME II

GENERALIZED PRODUCTS CORECTION OF OBSERVED API GRAVITY TO API GRAVITY AT 60 oF

6A

VOLUME I

GENERALIZED CRUDE OILS CORRECTION OF VOLUME TO 60oF AGAINST API GRAVITY AT 60oF

6B

VOLUME II

GENERALIZED PRODUCTS CORRECTION OF VOLUME TO 60oF AGAINST API GRAVITY AT 60oF

6C

VOLUME III

VOLUME CORRECTION FACTORS FOR INDIVIDUAL AND SPECIAL APPLICATIONS VOLUME CORRECTION TO 60 oF AGAINST THERMAL COEFFICIENTS A 60oF

23A

VOLUME IV

GENERALIZED CRUDE OILS CORRECTION OF OBSERVED RELATIVE DENSITY TO RELATIVE DENSITY AT 60/60oF

23B

VOLUME V

GENERALIZED PRODUCTS CORRECTION OF OBSERVED RELATIVE DENSITY TO RELATIVE DENSITY AT 60/60oF

24A

VOLUME IV

GENERALIZED CRUDE OILS CORRECTION OF VOLUME TO 60oF AGAINST RELATIVE DENSITY 60/60oF

24B

VOLUME V

GENERALIZED PRODUCTS CORRECTION OF VOLUME TO 60oF AGAINST RELATIVE DENSITY 60/60oF

24C

VOLUME VI

VOLUME CORRECTION FACTORS FOR INDIVIDUAL AND SPECIAL APPLICATIONS VOLUME CORRECTION TO 60oF AGAINST THERMAL COEFFICIENTS A 60oF

53A

VOLUME VII

GENERALIZED CRUDE OILS CORRECTION OF OBSERVED DENSITY TO DENSITY AT 15oC

53B

VOLUME VIII

GENERALIZED PRODUCTS CORRECTION OF OBSERVED DENSITY TO DENSITY AT 15oC

54A

VOLUME VII

GENERALIZED CRUDE OILS CORRECTION OF VOLUME TO 15oC AGAINST DENSITY AT 15oC

54B

VOLUME VIII

GENERALIZED PRODUCTS CORRECTION OF VOLUME TO 15oC AGAINST DENSITY AT 15oC

54C

VOLUME IX

VOLUME CORRECTION FACTORS FOR INDIVIDUAL AND SPECIAL APPLICATIONS VOLUME CORRECTION TO 15 oC AGAINST THERMAL COEFFICIENTS A T 15oC

56D

WEIGHT CORRECTION FACTOR AGAINST DENSITY AT 15oC

Petroleum Measurement Tables 23A TEMP ˚F 90 90.5 91 91.5 92 92.5

24A

0.9863 0.9858 0.9853 0.9849 0.9844 0.984

53A

929.1 929.2 929.4 929.5 929.7 929.9

54A

RELATIVE DENSITY 60/60˚F 0.614 0.616 0.618 0.62 CORRESPONDING RELATIVE DENSITY 60/60˚F 0.9863 0.9864 0.9865 0.9866 0.9859 0.986 0.9861 0.9862 0.9854 0.9855 0.9856 0.9857 0.985 0.9851 0.9852 0.9853 0.9845 0.9846 0.9847 0.9848 0.9841 0.9842 0.9843 0.9844

DENSITY AT OBSERVED TEMPERATURE 952.0 954.0 956.0 958.0 CORRESPONDING DENSITY AT 15˚C 931.1 933.1 935.2 937.3 931.3 933.3 935.4 937.4 931.4 933.5 935.5 937.6 931.6 933.6 935.7 937.7 931.7 933.8 935.8 937.9 931.9 934 936 938

1.0006 1.0005 1.0003 1.0002 1 0.9998

DENSITY AT 15 ˚C 992.0 994.0 996.0 998.0 FACTOR FOR CORRECTING VOLUME TO 15 ˚C 1.0006 1.0006 1.0006 1.0006 1.0005 1.0005 1.0005 1.0005 1.0003 1.0003 1.0003 1.0003 1.0002 1.0002 1.0002 1.0002 1 1 1 1 0.9998 0.9998 0.9998 0.9998

TEMP ˚F 195 195.5 196 196.5 197 197.5

OIL PRODUCTS RELATIVE DENSITY AT OBSERVED TEMPERATURE 0.941 0.943 0.945 0.947 0.949 CORRESPONDING RELATIVE DENSITY 60/60˚F 0.9906 0.9926 0.9946 0.9965 0.9985 0.9908 0.9928 0.9948 0.9967 0.9987 0.991 0.993 0.995 0.9969 0.9989 0.9912 0.9932 0.9951 0.9971 0.9991 0.9914 0.9933 0.9953 0.9973 0.9992 0.9916 0.0035 0.9955 0.9975 0.9994

24B 0.622 0.9867 0.9863 0.9858 0.9854 0.9849 0.9845

0.89 TEMP ˚F 135 135.5 136 136.5 137 137.5

960.0

0.9671 0.9668 0.9666 0.9664 0.9662 0.966

939.3 939.5 939.6 939.8 939.9 940.1

986.9 987.1 987.2 987.4 987.6 987.7

54B 1000.0 1.0006 1.0005 1.0003 1.0002 1 0.9998

RELATIVE DENSITY 60/60˚F 0.892 0.894 0.896 0.898 FACTOR FOR CORRECTING VOLUME TO 60˚F 0.9672 0.9673 0.9674 0.9675 0.9669 0.967 0.9671 0.9672 0.9667 0.9668 0.9669 0.967 0.9665 0.9666 0.9667 0.9668 0.9663 0.9664 0.9665 0.9666 0.9661 0.9662 0.9663 0.9664

0.9 0.9675 0.9673 0.9671 0.9669 0.9667 0.9665

DENSITY AT OBSERVED TEMPERATURE 999.0 1001.0 1003.0 1005.0 CORRESPONDING DENSITY AT 15˚C 988.9 990.9 992.9 994.9 989.1 991.1 993.1 995.1 989.2 991.2 993.3 995.3 989.4 991.4 993.4 995.4 989.6 991.6 993.6 995.6 989.7 991.7 993.7 995.8

1007.0 996.9 997.1 997.3 997.4 997.6 997.8

OIL PRODUCTS 730

TEMP ˚C 40 40.25 40.5 40.75 41 41.25

1.0005 1.0007 1.0008 1.001 1.0012 1.0014

OIL PRODUCTS 997

TEMP ˚C -0.5 -0.25 0 0.25 0.5 0.75

0.951

OIL PRODUCTS

53B

CRUDE OILS 990

TEMP ˚C 14 14.25 14.5 14.75 15 15.25

0.8488 0.849 0.8492 0.8494 0.8496 0.8498

CRUDE OILS 950.0

TEMP ˚C -18 -17.75 -17.5 -17.25 -17 -16.75

0.837

CRUDE OILS 0.612

TEMP ˚F 75 75.5 76 76.5 77 77.5

23B

CRUDE OILS RELATIVE DENSITY AT OBSERVED TEMPERATURE 0.827 0.829 0.831 0.833 0.835 CORRESPONDING RELATIVE DENSITY 60/60˚F 0.8389 0.8409 0.8429 0.8449 0.8468 0.8391 0.8411 0.8431 0.8451 0.847 0.8393 0.8413 0.8433 0.8453 0.8472 0.8395 0.8415 0.8435 0.8455 0.8474 0.8397 0.8417 0.8437 0.8456 0.8476 0.8399 0.8419 0.8439 0.8458 0.8478

0.9684 0.9681 0.9678 0.9675 0.9672 0.9669

DENSITY AT 15 ˚C 732.0 734.0 736.0 738.0 CORRESPONDING DENSITY AT 15˚C 0.9686 0.9687 0.9688 0.969 0.9683 0.9684 0.9685 0.9687 0.9679 0.9681 0.9682 0.9683 0.9676 0.9678 0.9679 0.968 0.9673 0.9674 0.9676 0.9677 0.967 0.9671 0.9673 0.9674

740.0 0.9691 0.9688 0.9685 0.9682 0.9679 0.9675

Bunker Delivery Receipt/Bunker Delivery Note: Bunker Delivery Receipt/Bunker Delivery Note: This a standard document originated from the fuel supplier for the purchaser containing necessary and most important information regarding the fuel that has been purchased. The purpose of the Bunker Delivery Receipt (BDR) is to record what has been transferred. Various factors are recorded in this document including:  Location and time of transfer  Details of product delivered  Temperature of product delivered  Product density at standard reference temperature  Sample seal numbers

Care should be taken before signing the BDR. For example, the bunkers should not be signed for in weight form, only for volume at observed temperature. The actual weight can only be calculated after a representative sample of the delivery has been tested for density.

IBIA Standard Bunker Delivery Note/Receipt

IBIA Standard Bunker Delivery Note/Receipt

An Existing Bunker Delivery Note/Receipt

Extracted from IBIA Standard Form for comparison

Bunker Checklist Bunker Checklist: Bunkering is often carried out when the engineering staff are under pressure in both time and manpower. Key checks are often missed and only come to light when it is too late. A few relevant points are detailed below: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.

The purchaser should obtain specification acceptance from the supplier. Purchaser needs to advise ship’s Staffs what grade of fuel will be delivered and how transferred. Fuels from different deliveries should be segregated as far as practical. All receiving tanks need to be gauged prior to taking fuel. Don’t sign any documentation unless you have witnessed the actual event. Always take up witness offers made by the supplier If the suppliers sampling method is unknown, then sign adding the words “for receipt only - source unknown”. Always take a fuel sample using a continuous drip method. Take one sample per barge/ delivery Sign the BDR for volume only, if necessary adding the words “for volume only - weight to be determined after density tests”. Ensure good records are kept throughout the bunkering. Keep accurate engine logs in the event of any subsequent problems Keep fuel samples for at least 12 months. Test all fuel on delivery for Viscosity, Density, Water,Stability, Pour Point and Salt (if water present). Use a laboratory to check results in the event of any discrepancies being indicated by on-site test equipment.

MARPOL Annex VI Summery: MARPOL: MARPOL 73/78 is the International Convention for the Prevention of Pollution From Ships, 1973

as modified by the Protocol of 1978. (MARPOL is short form of Marine Pollution and 73/78 short for the years 1973 and 1978) MARPOL Annex VI Summery:

 Fuel oil purchasers need to advise the ship’s staff what grade of fuel they will receive and how it will be transferred.  Fuels from different deliveries should be segregated as far as is practicable  All receiving fuel oil tanks need to be gauged and the results recorded prior to taking delivery of fuel  Don’t sign any documentation before you have witnessed the actual event  Always take up witness offers made by the supplier’s representatives.  If the origin and method by which the supplier’s sample was obtained is unknown then sign for it adding the words “for receipt only - source unknown”  Fuel oil samples should always be taken by continuous-drip method throughout the bunkering.  If the fuel oil delivered is supplied by more than one barge, a sample should be taken of each fuel oil from the supplying barges.  Sign the bunker delivery receipt only for volume delivered. If the supplier insists on a signature for weight add “for volume only - weight to be determined after density testing of representative sample”. Comment : Make sure that what you sign for is what you get. Be certain that the bunker receipt reflects the facts as witnessed. Do not sign anything unless you have witnessed it. Always take a representative sample.

Guidelines for the Sampling of Fuel Oil for Determination of Compliance with ANNEX VI of MARPOL 73/78 Definitions: Supplier’s representative: Supplier’s representative is the individual from the bunker tanker who is responsible for the delivery and documentation or, in the case of deliveries direct from the shore to the ship, the person who is responsible for the delivery and documentation. Ship’s representative: Ship’s representative is the ship’s master or officer in charge who is responsible for receiving bunkers and documentation. Representative Sample: Representative sample is a product specimen having its physical and chemical characteristics identical to the average characteristics of the total volume being sampled. Primary Sample: Primary Sample is the representative sample of the fuel delivered to the ship collected throughout the bunkering period obtained by the sampling equipment positioned at the bunker manifold of the receiving ship. Retained sample: Retained sample is the representative sample in accordance with regulation 18(6) of Annex VI to MARPOL 73/78, of the fuel delivered to the ship derived from the primary sample.

Sampling Method: The primary sample should be obtained by one of the following methods. 1. Manual valve-setting continuous-drip sampler 2. Time-Proportional automatic sampler 3. Flow-Proportional automatic sampler Sampling equipment should be used in accordance with manufacturer’s instructions or guidelines as appropriate.

Guidelines for the Sampling of Fuel Oil for Determination of Compliance with ANNEX VI of MARPOL 73/78 Manual Continuous Drip Sampler

AUTOMATIC SAMPLER

Sampling and Sample Integrity: 1. 2.

3.

A means should be provided to seal the sampling equipment throughout the period of supply. Attention should be given to: a) The form of set up of the sampler b) The form of primary sample container c) The cleanliness and dryness of the sampler and the primary sample container prior to use d) The setting of the means used to control the flow to the sample container e) The method to be used to secure the sample from tampering or contamination during the bunker operation The primary sample receiving container should be attached to the sampling equipment and sealed so as to prevent tampering or contamination of the sample throughout the bunker delivery period.

Sampling location: For the purpose of these guidelines a sample of the fuel delivered to the ship should be obtained at the receiving ship’s inlet bunker manifold and should be drawn continuously throughout the bunker delivery period.

Guidelines for the Sampling of Fuel Oil for Determination of Compliance with ANNEX VI of MARPOL 73/78 Retained sample handling: 1. 2. 3.

The retained sample container should be clean and dry Immediately prior to filling the retained sample container, the primary sample quantity should be thoroughly agitated to ensure that it is homogenous The retained sample should be sufficient quantity to perform the tests required but should not be less than 400 ml. The container should be filled to 90% +/-5% capacity and sealed.

Sealing of the retained sample: Immediately following collection of the retained sample, a tamper proof security seal with a unique means of identification should be installed by the supplier’s representative in the presence of ship’s representative. A label containing the following information should be secured

To the retained sample. 1. 2. 3. 4. 5. 6. 7.

Location at which, and the method by which the sample was drawn Date of commencement of delivery Name of bunker tanker/installation Name and IMO number of the receiving ship Signature over the printed name of supplier’s and ship’s representative Details of seal identification, and The bunker grade

Retained sample storage: 1. The retained sample should be kept in a safe storage location. 2. The retained sample should be stored in a sheltered location where it will not be subject to elevated temperatures, preferably at a cool/ambient temperature, and where it will not be exposed direct sunlight. 3. Pursuant to regulation 18(6) of Annex VI of MARPOL 73/78, the retained sample should be retained under the ship’s control until the fuel oil is substantially consumed, but in any case for a period of not less than 12 months from the date of delivery

Dubious Practices Summery Dubious Practices Summery:  Fuel oil purchasers need to advise the ship’s staff what grade of fuel they will receive and how it will be transferred.  Fuels from different deliveries should be segregated as far as is practicable  All receiving fuel oil tanks need to be gauged and the results recorded prior to taking delivery of fuel  Don’t sign any documentation before you have witnessed the actual event  Always take up witness offers made by the supplier’s representatives.  If the origin and method by which the supplier’s sample was obtained is unknown then sign for it adding the words “for receipt only - source unknown”  Fuel oil samples should always be taken by continuous-drip method throughout the bunkering.  If the fuel oil delivered is supplied by more than one barge, a sample should be taken of each fuel oil from the supplying barges.  Sign the bunker delivery receipt only for volume delivered. If the supplier insists on a signature for weight add “for volume only - weight to be determined after density testing of representative sample”.

Comment : Make sure that what you sign for is what you get. Be certain that the bunker receipt reflects the facts as witnessed. Do not sign anything unless you have witnessed it. Always take a representative sample.

Necessary Tools/Documents Required for Bunker Calculation

 Sounding Tape  Thermometer  Density Hydrometer  Water Finding Paste(For MDO)  Bunker Delivery Notes (BDN)  ASTM 53B table for density correction  ASTM 54B table for VCF calculation

 ASTM 56D table for weight correction  Calculator  Sample bottles

Pre-Bunker Data Collection in Existing Bunkering Measuring The Density: To measure the density, a fuel sample is drawn from randomly selected tank of the tanker. Sometimes average density of multiple tanks are used. Measuring The Temperature: The Temperature is measured using a mercury thermometer. Pre-bunker Tank Gauging/Sounding: Using a suitable sounding tape the soundings of associated tanks of the tanker are taken and calculate the corresponding volumes from the tank capacity/calibration tables.

Existing Calculation Sheet: Tank No 1P 1S 2P 2S 3P 3S 4P 4S

Tank Sounding cm

301 299 333.9 339 337 338 320 323 Total Obs. Vol : Observed Density: Quantity in MT(obs vol. x obs density/1000):

Observed Volume in m3 115.471 116.723 195.201 198.752 117.175 118.89 129.295 132.376 1123.883 977.4 1098.48

Observed Density Kg/m3

Observed Temp. o C

977.4

26.25

m3 oC

MT

Existing Bunker Quantity Calculation Flow Chart

Sounding of Desired Tanks Tank Calibration/Capacity Tables

Observed Temperature (oC)

Observed Volume (m3)

Observed Density (Kg/m3)

Quantity in (Kg) 1000

Quantity in Metric Tones (MT)

Observed Density of Representative Sample (Kg/m3)

Observed Temperature of Representative Sample oC

ASTM 53B

IBIA Standard Procedure for Bunker Quantity Calculation Flow Chart Actually, the density of a representative sample at 15oC should be specified in Bunker Delivery Receipt (BDR). If not specified, then use this method to calculate standard density.

Density at 15oC (Kg/m3) ASTM 54B Tank Temperature oC

Sounding of Desired Tanks

Tank Calibration/Capacity Tables

Observed Volume (m3)

Volume Correction Factor (VCF)

Standard Volume at 15 oC (m3)

Weight Correction Factor (WCF)

Quantity in Metric Tones (MT)

ASTM 56D

Case Study 01: Basic Information Supplied in the Bunker Delivery Receipt. Product Name : Heavy Fuel Oil Density in BDN at 15oC : 989.999 Kg/m3 Density of Representative Sample after Bunkering at 15oC = 980.019 Kg/m3

Case Study 01 (Cont’d): Basic Information Supplied in the Bunker Delivery Receipt. Product Name : Heavy Fuel Oil Density in BDN at 15oC : 989.999 Kg/m3 Density of Representative Sample after Bunkering at 15oC = 980.019 Kg/m3

Case Study 01 (Cont’d): Density of Representative Sample after Bunkering at 15oC = 984.994 Kg/m3 Opening Observed Volume (m3) = 1236.76 Opening Standard Volume (m3) = 1208.75 (VCF calculated from ASTM 54B) Closing Observed Volume (m3) = 144.949 Closing Standard Volume (m3) = 141.826 (VCF calculated from ASTM 54B) Observed Volume Transferred = 1236.76 – 144.949 = 1091.81 m3 Standard Volume Transferred = 1208.75 – 141.867 = 1066.88 m3 The theoretical weight transferred in air: = Density (kg/m3) * Standard volume at 15°C(m3) x Factor = kg * kg/1000 = 990.0*1066.88*0.988899/1000 (MT) (The Factor is calculated from ASTM 56D) = 1055.04 MT

The transferred weight of the fuel based on the density provided in Bunker Delivery Receipt(BDR) is = 1055.04 MT

As the density determined from a representative sample of the bunkering is 984.994 kg/m3; the actual weight transferred in air = 980.019 * 1066.88/1000 * 0.978919 = 1044.07 MT If the density is not determined from a representative sample, the BDR should be signed only for volume. If the supplier insists on a signature for weight, add “for volume only - weight to be determined after density testing of a representative sample”.

Comment: The example calculation given for a fuel delivery changed the actual delivery from: 1055.04 Changes to 1044.07 MT a savings of 10.97 MT or $8776 at $800/MT

Bunker Quantity Determination Software Package This is the software Package designed to automate entire bunker calculation process without compromising with any standard. All of the petroleum measurement tables required to work with Density, API Gravity or Specific Gravity are embedded in this software. This is light weight and can be used without installation in any windows based system. To download a demo visit author’s personal website www.moynulislam.com and see under “Application “ tab. Applicability: Crude Oils, Gasolenes, Transition Zone, Jet Fuels, Fuel Oils and Lubricants The main feature of this software is interactive conversion capabilities. With a single click one can switch from one measurement standard (say, Density based measurement to APIG based measurement) to another standard without changing the existing values. The accuracy of the calculation has been tested by comparing with DNVPS software “Bunker Master 2.0” and with Shell’s “BunkerCalc”. This software can be used universally to calculate the actual fuel quantity. Additionally this software contains energy calculation tools, density conversion tools, VCF calculation tools, WCF calculation tools, MT calculation tools etc. and much more.

The VB based software is featured with OFF HIRE BUNKER SURVEY, BUNKER ROB SURVEY, ULLAGE REPORT GENERATION, and BUNKER STEM SURVEY To try it out please visit www.moynulislam.com under Applications tab

Bunker Quantity Determination Software Package SN

Description

Version

Database Availability Yes Yes Yes

01 02 03

Bunker ROB Survey + Bunker Detective Survey (221B survey) Workbook Bunker Stem Survey Workbook ON-OFF-HIRE Survey Workbook

DENS/M3/oC DENS/M3/oC DENS/M3/oC

04 05 06

Bunker ROB Survey + Bunker Detective Survey (221B survey) Workbook Bunker Stem Survey Workbook ON-OFF-HIRE Workbook

APIG/US, bbl/oF APIG/US, bbl/oF APIG/US, bbl/oF

Yes Yes Yes

07 08 09

Bunker ROB Survey + Bunker Detective Survey (221B survey) Workbook Bunker Stem Survey Workbook ON-OFF-HIRE Survey Workbook

DENS/M3/oC DENS/M3/oC DENS/M3/oC

No No No

10 11 12

Bunker ROB Survey + Bunker Detective Survey (221B survey) Workbook Bunker Stem Survey Workbook ON-OFF-HIRE Survey Workbook

APIG/US, bbl/oF APIG/US, bbl/oF APIG/US, bbl/oF

No No No

Above workbooks are designed for HSFO, LSFO, MDO, LSMDO, MGO and LSMGO. But it is possible to customize for other refined products like Gasolenes, Naphtha, Jet Fuels and Lube Oils and also for Crude Oil. 13 14

Draught Survey Workbook and Wedge Volume Calculation Workbook with necessary tools (1D, 2D Interpolation, Density APIG SG conversion, Blended Density Calculation, Temperature Conversion etc and much more) required by bunker surveyors

PIFMS | BUNKER MANAGER – ROB+221B SURVEY This is a database embedded customized workbook for Bunker ROB and Bunker Detective Survey (221B Survey) where a surveyor can store his all survey related information in a built-in database which one can retrieve for further processing.

This program is designed, considering Bunker ROB Surveyor’s requirements. With a single click you can generate your all survey reports like VESSEL GAUGING REPORT, BUNKER ROB CERTIFICATE, 221B REPORT, TIME LOG, SURVEYOR’S COMMENTS etc in excel or pdf format. You can directly print or email reports from the program. To download the demo, visit author’s webpage www.moynulislam.com and you will get it under Applications tab.

PIFMS | BUNKER MANAGER

generated Vessel gauging report

PIFMS | BUNKER MANAGER

generated Vessel gauging report

PIFMS | BUNKER MANAGER – BUNKER STEM SURVEY This is a database embedded customized workbook for Bunker STEM SURVEY where a surveyor can store his all survey related information in a built-in database which one can retrieve for further processing. It has also built-in report generation capabilities like ROB SURVEY program. You can generate SUPPLY VESSEL and RECEIVING VESSEL GAUGING REPORTS, FINAL SURVEY SUMMARY , COQ, TIME LOG, TEMPERATURE LOG, DOCUMENTS CHECKLIST, FUEL SAMPLE INFO, SURVEYOR COMMENTS etc.

To try the demo, visit author’s webpage www.moynulislam.com and you will get it under Applications tab.

PIFMS | BUNKER MANAGER

generated receiving vessel gauging report

PIFMS | BUNKER MANAGER

generated Final Survey Summary Report

PIFMS | BUNKER MANAGER

generated Final Survey Summary Report

PIFMS | BUNKER MANAGER

generated COQ report

PIFMS | BUNKER MANAGER

generated document checklist

PIFMS | BUNKER MANAGER

Print Panel and fuel sample information

PIFMS | BUNKER MANAGER

ON-HIRE SURVEY CERTIFICATE

PIFMS | DRAUGHTS MASTER

PIFMS | DRAUGHTS MASTER

PIFMS | DRAUGHTS MASTER –

Certificate of draughts survey

Shore Based Fuel Storage System 3D layout of a shore based power station fuel storage system. This software can be customized for any tank firm/terminal to automate fuel calculation process.

Shore Based Fuel Storage System Monitoring This is also another semi-automatic fuel storage monitoring system designed to observe the content of individual storage tanks. You will need to put the dip and tank temperature manually. This is customizable for any liquid storage system. Using data acquisition system, it can be made completely automatic (no human operator is required to show the fuel quantity).

Bunker Delivery in Shore Tanks It seems that, bunkering in a shore tank is much easier than that of a ship/barge. The transferred fuel volume (observed volume) is determined from the initial and final tank sounding. The initial and final tank temperatures are not being considered. But the temperature differences influences the entire calculation process. In the software below we will estimate, how the differences in temperature participates on transferred quantity. Bunker delivery in a shore based storage tank

Effect of Temperature Variation in Bunkering Effect of Temperature Variation in Bunkering : Average temperature of Shore based fuel storage tanks are maintained around 45 to 50 oC to keep the fuel temperature above their pour point. Another reason of heating is to enhance the transfer process by lowering the viscosity of the oil. Hence, elevated temperature will greatly impart on received quantity during bunkering if the temperature correction is not considered. As the capacities of shore based storage tanks are normally high compared to other storage tanks (like in barge/oil tanker), So the variation in temperature by few degrees will change the entire scenario of bunkering. Please see the subsequent slides regarding volumetric expansion or volumetric shrinkage due to the variation in temperature during bunkering.

Bunker Handling in Shore Based Storage Tank

This is another useful tool for bunker handling in shore tanks. It consider all factors related to bunker quantity and use dynamic material balance to determine the volume shrinkage/expansion due to the temperature difference of incoming and receiving vessel. The above picture showing an oil tanker delivering bunker in a shore tank possessing temperature 30oC and after delivery the tank temperature increases to say 40 oC. According to the calculation, the receiving vessel will pay for 13.83 MT (Expanded quantity) that they have not received if they ignore the temperature correction.

Bunker Handling in Shore Based Storage Tank

The above picture showing an oil tanker delivering bunker in a shore tank possessing temperature 40oC and after delivery the tank temperature drops to say 30 oC. According to the calculation, the incoming vessel won’t find 13.73 MT (Shrinkage quantity) oil if they ignore the temperature correction.

Quick Volume

Inventory Control

Bunker Manager

Tools

Prepared By

Md. Moynul Islam Chemical Engineer Expertise on Marine Fuels and Lubricants Contact: Cell : +8801816449869 Email : [email protected] Web : www.moynulislam.com

How BargeCalc Works? Input Variables

•Barge Drafts •Tank Sounding •Tank Temperature •Density at 15oC

LOAD DATABASE Select TRIM Correction Table Select LIST Correction Table

Run 2D-Linear Interpolation For Given Sounding, TRIM and LIST Values

LIST and TRIM Corrected Volume

Call ASTM 54B Table For VCF Calculation

You can customize this application for your own vessel by integrating your own vessel calibration tables. It will definitely reduce your time to manage your OBQ and also to monitor your fuel consumption. To customize it for your own vessel, please contact with the author.

Call ASTM 56D For WCF Calculation

Calculate Quantity in Metric Tones

Using Flow Meters in Bunkering An worrying comment made in the Control Engineering article ”Flow meter selection: Right size, right design” that “Worlds 70% of installed flow meters are either the wrong technology or the

wrong size ”.

There are three types of flow meters are commonly used in oil and gas industry. They are the PD (Positive Displacement) flow meter, Ultrasonic Flow meter, and Coriolis Flow meter. None of the above are universal. All of them have some advantages and disadvantages depending on the field of application.

Ultrasonic Flow Meter

Ultrasonic Flow Meter

Ultrasonic Flow Meter Measurement Technology

The Coriolis Mass Flow meter Among the above flow meters, Coriolis Mass Flow Meter is the best choice in bunker industry. The main reason is its accuracy in mass measurement and entrained air compensation technology made it unique in flow measurement. It can measure the density, volumetric flow rate and the mass flow rate.

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