TOPIC 2.1 ICHEM

is defined as mass per unit volume of a fluid.

Is a state function and for a pure compound depends on both temperature and pressure and is shown by ρ. Liquid densities decrease as temperature increases but the effect of pressure on liquid densities at moderate pressures is usually negligible.

is more commonly and widely used than the European Baume gravity scale. But they essentially measure the density of a crude oil.

Crude oils characterized by high amount of dissolved gases, are less dense thus, light in weight and therefore, possess _____

Denser crude oils of low amount of dissolved gases are characterized by _____

It is heavier than air (2 to 3 times)

The ____ of oil is a measure of its resistance to internal flow and an indication of its oiliness in the lubrication of surfaces.

What are the two types of viscosity ?

It is said to have a viscosity of 1 poise when a tangential force of 1 dyne causes a plane surface of 1 square centimeter area; spaced 1 cm from a stationary plane surface to move with a constant velocity of 1 cm per second, the space being filled with the viscous fluid.

The viscosity of a crude oil is influenced by the amount of ______ at the prevailing temperature.

Is known by the Greek symbol η, eta.

It is sometimes also referred to as shear viscosity.

is obtained by reformulating Newton's Law.

Is obtained by dividing the Shear stress by the rate of shear strain

The units of dynamic viscosity are:

is used to describe pressure or stress = force per area

Sometimes viscosity is measured by timing the flow of a known volume of fluid from a viscosity measuring cup.

The timings can be used along with a formula to estimate the kinematic viscosity value of the fluid in ____

Is the temperature at which a crude oil will no longer flow, when a tube containing it is first heated in a bath, in order to dissolve all its wax content and then gradually cooled.

Slightly above this temperature of no-flow (the pour point), there might had been an appearance of cloudy substances in the crude: which is due to the settling out of the solid paraffin waxes contained in the crude oil. That temperature is called the ____

It may be yellow, green or blue. For example, when a paraffin base crude oil (gasoline-rich) is exposed to ultraviolet fluorescence light, it emits yellow color, while naphthenic oils emit brownish color This property is important in testing for cutting, core and drilling mud samples and in well-logging interpretation, for location of different oil horizons.

This is the light transmitted through crude oils. It is yellowish to red for light oils and dark or even opaque for heavy (or low A.P.I gravity) oils.

This varies greatly in crude oils. High content of light hydrocarbons (paraffins and naphthenes) in a crude gives rise to a gasoline-like odor. A pleasant odor is produced if the crude has abundant aromatic hydrocarbons. But with high amount of unsaturated hydrocarbon compounds, sulfur and nitrogen compounds in the oil, it produces a repugnant odor.

Is a highly complex mixture of paraffin, cycloparaffinic (naphthenic), and aromatic hydrocarbons, containing a low percentage of sulfur and trace amounts of nitrogen and oxygen compounds.

Are the most common environmental contaminant in most industrial countries.

Types: There are two basic types of fuel oil: Distillate fuel oil (lighter, thinner, better for cold start) and Residual fuel oil (heavier, thicker, more powerful, better lubrication). Often, some distillate is added to residual fuel oil to get a desired viscosity. They are only used for industrial and marine applications because, although fuel oil is cheaper than diesel oil, it is more difficult to handle (must be settled, pre-heated and filtered, and leave a sludge at the bottom of the tanks). Notice that, sometimes, particularly in the USA, the term 'fuel oil' also includes diesel and kerosene.

It is lighter, thinner, better for cold start

It is heavier, thicker, more powerful, better lubrication

It is the most widely used type of fuels for commercial vessels.

The amount of heat energy thus released is the specific energy of a fuel and is measured in ____

Having a density at 15ºC higher than 900 kg/m3

having either a density at 15ºC higher than 900 kg/ m3 or a kinematic viscosity at 50oC higher than 180 mm2 /s; and Bitumen, tar, and their emulsions

max. 3.5% SOx - Heavy fuel oils designated as high-sulfur fuel oils (HSFO), with a maximum sulfur content of 3.5% as permitted under ISO 8217.

Max 1.0% SOx - Usually these are marine fuel types IFO 180 or IFO 380, which have been desulfurized.

: max 0.1% SOx - Usually refers to marine gasoil. It is composed exclusively of distillates.

Post the refining process; mechanical catalyst particles (aluminum silicate) remain in the oil and are not easy to separate. If exceeded in number, this can damage parts of the fuel system such as an injector, fuel pumps etc. As they have very fine clearance. As per ISO 8217:2010, the maximum limit for Al+Si is 60 mg/kg for RMG and RMK category fuels.

Every matter, whether solid, liquid or gas has a specific density. The “fuel oil density” is an essential factor that indicates the ignition quality of a fuel and is also used for calculating the amount of fuel oil quantity delivered during the bunkering procedure.

Viscosity is the resistance within the fluid which acts against the flow. Kinematic viscosity represents the dynamic viscosity of a fluid per unit density. The viscosity of fuel is a highly significant parameter as it is used to determine the ease of atomization and convenience to pump the fuel within the system.

Is a calculation based on the density and viscosity of a given fuel. As per the formula, the CCAI number is inversely proportional to efficient combustion. This means that higher the CCAI number, the more inferior the ignition quality of the fuel.

helps in getting the ignition delay of the fuel and is used only for the residual fuel such as HFO. The maximum acceptable valve for HFO CCAI is 870.

The temperature at which the vapor of the heated fuel ignites is known as the fuel’s _____

This is done under specified test conditions, using a test flame. As per SOLAS, The flashpoint for all heavy fuel oil to be used onboard vessels is set at Pensky–Martens closed- cup 60°C minimum.

Is the temperature below which the fuel ceases to flow. Once the fuel oil temperature goes below the pour point, it forms wax which can lead to blockage of the filter. The wax formation will also build upon tank bottoms and heating coils, leading to a reduction in heat exchanging capabilities.

_____ in the fuel is one of the main factors for sulphur oxide pollution from ships – a pollutant which is currently under major scrutiny.

As per MARPOL, the current sulfur value for HFO are:

In fuel leads to a decrease in the efficiency of fuel oil and leads to energy loss. Heavy fuel oil mixed with water, if burnt, will lead to corrosion of internal parts.

A lab test of fuel can determine the carbon residue in the heavy fuel oil. The fuel tends to form carbon deposits on the surface of different parts involved in the combustion chamber under a high-temperature condition. More the amount of hydrocarbons, more difficult to burn the fuel efficiently.

The number of inorganic materials present in the fuel which remain as residue once the combustion process is over is called ____

The maximum limit of ash content in the fuel is ____

These deposits mainly consist of elements such as vanadium, sulfur, nickel, sodium, silicon, aluminum etc., which are already present in the fuel.

Heavy fuel oil (HFO) is the residue of crude oil distillation that still flows, the quasisolid residue is

A high viscosity leads to a thicker film but more power loss.

Is the force required to slide two wetted surfaces. It was first measured in Poise, but after SI units became popular Pascal-seconds became more common.

Is the ratio of dynamic viscosity to the fluid density

Were used before the SI system and meters squared per second were used afterwards.

Viscosity decreases as temperature increases.

Is the most accurate and needs the viscosity at three different temperatures to be calibrated.

Was used to create the ASTM chart.

Tells how much the viscosity will vary; a low number indicates large variation while a high number indicates low variation.

Liquid lubricants will behave like solids at very high pressures.

Is the most well-known equation describing this relationship and is accurate to 0.5 GPa.

Takes into account both pressure and temperature.

If shear stress and shear rate have a linear relationship, a fluid is____

Materials have shear thinning.

Is shear thickening.

Have negligible non-Newtonian effects. For this type of viscometer, the time required for the fluid to flow through a capillary tube is measured. It gives kinematic viscosity.

have significant non-Newtonian effects. For this type of viscometer, the viscosity is related to the force required to generate shear. This can be done by having a constant torque and measuring the change in speed or having a constant speed and measuring the change in torque. This viscometer gives dynamic viscosity.

The specific heat of lubricants is typically half that of water. They increase with temperature linearly. The range is 1800-3300 J/kg-K. Lubricants thermal conductivity will range from about 0.14 W/m-K at 0 C to 0.11 W/m-K at 400 C.

At high temperatures oils will ___

At low temperatures they become

Is the temperature at which oil stops flowing due to wax crystallization.

Is the temperature at wax begins to precipitate

Occurs when oil starts separating from a mixture and is used with refrigerants.

Is the temperature at which oil vapors will ignite.

Is the temperature at which enough vapor is released for sustained burning.

Lubricants break down at high temperatures through a complex chemical process. More highly refined oils are generally more stable. This is very important for extended life.

Above a certain temperature oil will decompose even without oxygen. Synthetic lubricants generally perform better than mineral oils. Oxidative stability defines the highest useable temperature; Thermal stability is even higher.

This determines how a lubricant will wet and spread over a surface. It is very sensitive to additives.

This term quantifies the amount of KOH needed to neutralize an acidic compound. The TAN or Total Acid Number is the amount of KOH needed for neutralization. The TBN or Total Base Number is the amount of KOH needed to neutralize the HCL needed to remove the basicity of a fluid. These values can be used to assess the changes in lubricant during operation.

Above 300 °C long molecular chains may decompose or crack. They recombine to form tarry deposits which are bad for machinery is. This is more important for mineral oils than synthetic oils.