ICHEM WEEK 5

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What is the fuel oil primarily used for?

For steam boilers in power plants, aboard ships, and in industrial plants.

Extraction

Step 1: Crude oil is taken from the ground or sea

Transport

Step 2: Crude oil is moved to refineries by ships or pipelines

Distillation

Step 3: Crude oil is heated and separated into fractions like gas, diesel, and fuel oil.

Blending

Step 4: Fractions are mixed to produce the desired fuel type

Storage and Delivery

Step 5: Finished fuel oil is stored in tanks and delivered to ships or industries

Heavy Fuel Oil (HFO)

High-viscosity oil used in large engines

Marine Gas Oil (MGO)

Very clean fuel oil and diesel; used where strict air emission rules apply

Marine Diesel Oil (MDO)

Blend of heavy fuel oil and diesel; used in smaller ship engines

Low Sulfur Fuel Oil (LSFO)

Requires heating due to viscosity; cleaner emissions than HFO.

Intermediate Fuel Oil (IFO)

Blend of residual heavy fuel oil and distillate marine gas oil; moderate sulfur, balance between cost and cleanliness

Biodiesel

Non-toxic fuel producing fewer air pollutants than petroleum diesel; higher cetane number and better lubrication.

Properties of biodiesel

Biodegradable, renewable, burns cleaner than diesel, lower energy content

Liquefied Natural Gas (LNG)

Natural gas cooled to liquid state for easier storage and transport

Properties of LNG

High energy content, almost zero sulfur, requires special cryogenic storage tanks

Alternative fuel: Hydrogen

In fuel cells to produce electricity with zero emissions; can be produced from renewable sources

Properties of Hydrogen

Zero emissions, high energy per kilogram but low per liter, expensive, requires advanced technology, not widely available

Alternative fuel: Methanol

Liquid at ambient temperature; can be produced from natural gas, biomass, or renewable electricity; burns cleaner than conventional marine fuels

Properties of Methanol

Burns clean, low sulfur content, easy to store, low energy content, toxic

Conventional Fuel

Also called fossil fuel; a non-renewable energy source derived from crude oil

Examples of conventional fuel

Heavy Fuel Oil (HFO), Marine Diesel Oil (MDO), Marine Gas Oil (MGO), Marine Diesel

Carbon Emission

The release of carbon dioxide into the atmosphere when fuel is burned

Importance of non-fossil fuels

They reduce carbon emissions by generating energy with little to no carbon dioxide production.

Possible effects of Oil Impurities

Damage to engine/machinery
Environmental impact
Reduced fuel efficiency
High maintenance costs

Causes of Oil Impurities

Poor maintenance
Environmental contamination
Erosion of pump impellers
Supply chain issues

Poor maintenance - effect?

Damage to engine/machinery

Environmental contamination - effect?

Environmental impact

Erosion of pump impellers - effect?

Reduced fuel efficiency

Supply chain issues - effect?

High maintenance costs

Correct parameters in a fuel oil system

Proper temperature, viscosity, and pressure

Importance of correct parameters

Ensures complete combustion - maximum power output
Prevent black smoke
Avoid engine damage
Maintain smooth fuel flow

Common impurities in fuel oil

Water, dirt, ash, sulfur, metals

Main sources of impurities

Dirty tanks
Sea water leaks
Rust in pipes
Poor handling

Effect of water in fuel oil?

Causes corrosion and rust

Effect of dirt and ash?

Block filters, cause wear

Effect of sulfur?

Forms acid that damages cylinders

Effect of metals?

Wear pumps and injectors

Main risk of mixing marine fuels during bunkering?

Dangerous reactions or performance issues if fuels are incompatible or mishandled

Key properties when mixing fuel

Compatibility
Stability
Density and viscosity
Sulfur content
Lubricity
Temperature sensitivity

Practices to avoid fuel incompatibility issues

Segregate new fuel until compatibility is confirmed
Use ASTM D4740 spot test
Record density, viscosity, and sulfur levels
Avoid mixing unless necessary
Change over fuel slowly for engine adaptation

Physical properties of fuel

Observable without changing chemical composition

Examples of physical properties

Density, viscosity, volatility

What is a chemical property of fuel?

It describes its potential to undergo chemical change

Examples of chemical properties

Flammability, heat of combustion, ignition temperature, reactivity, autoignition temperature

What are catalytic findings?

Observations related to catalysis — acceleration of a chemical reaction by a catalyst

How does a catalyst work?

Lowers activation energy without being consumed in the process

Define viscosity

A measure of a fluid’s internal resistance to flow

What is schematic viscosity?

A diagram or model showing viscosity-related concepts

What is the setting index?

A measure of how viscosity changes with temperature; also used as an estimate of diesel ignition quality

What is a flash point?

The lowest temperature at which a liquid's vapors ignite with an external ignition source, indicating its flammability hazard

What determines flash point?

The fuel’s chemical makeup and volatile components.

Effect of high flash point

Safer, less flammable

Effect of low flash point

Higher fire/explosion risk

Potential causes of flash point variation?

Volatile components, Impurities

What is pour point?

The lowest temperature at which a liquid will flow under its own weight, showing its cold-temperature performance

Causes of pour point limitation?

Formation of wax crystals/solids at low temperatures blocking flow

Effects of low pour point?

Fluid can flow in cold conditions, preventing blockages

Potential causes affecting pour point

Base fluid, Additives, Admixtures

What is sulfur content in marine fuel?

The amount of sulfur compounds present, measured in % by weight or parts per million (ppm).

Potential causes of high sulfur content?

Use of heavy fuel oil
Fuel contamination
Incomplete fuel refining
Non-compliance with fuel standards
Low-grade fuel

Effects of high sulfur content on engine?

Corrosion of cylinders, liners, piston rings, exhaust valves
Accelerated wear and deposit formation in combustion chamber
Shorter maintenance intervals
Engine part degradation
Reduced efficiency

Solutions for high sulfur content?

Use low-sulfur fuels
Refinery treatment
Blend fuels to lower sulfur percentage
Avoid contamination in tanks/pipes

What is the water content in fuel oil?

The amount of water present in fuel oil, usually from contamination or condensation; too much lowers fuel quality, causes poor combustion, and may damage engine

Potential causes of water content?

Condensation in tanks due to temperature changes at sea
Leaks during transfer or storage
Absorbing moisture from humid air
Improper handling of fuel
Contaminated supply from shore/bunkering

Effects of water content on engine?

Poor combustion, less power
Rust and corrosion in tanks, pipes, injectors
Increased fuel consumption, lower efficiency
 Microbial growth clogging filters and lines
Rough performance, more maintenance

Solutions for water content?

Use purifiers/separators
Drain tanks regularly
Frequent inspections
Prevent seawater ingress during bunkering

What is carbon residue?

The soild carbon left after fuel burns without enough air — the “leftover burnt material” inside the engine

Potential causes of carbon residue?

Incomplete combustion
Rich fuel-air mixture
Poor fuel quality
Overheating
Prolonged exposure to hot spots

Effects of carbon residue on engine?

Reduced efficiency, overheating risk
Restricted airflow, power loss
Fasten wear on liners/injectors
Injector fouling, nozzle blockage
Uneven fuel delivery, misfiring

Solutions for carbon residue?

Use cleaner, better-quality fuels
Blend/treat fuel to reduce residue
Maintain proper viscosity and temperature for atomization
Regular cleaning of injectors and chambers

What is Ash content in fuel oil?

The small amount of non-combustible, inorganic mineral residue left after combustion, indicating impurities in the fuel.

Importance of ash content in biofuels

It reflects the level of inorganic contamination, which affects engine wear, efficiency, and maintenance needs

Causes of high ash content?

Inorganic matter in fuel oil
Low-quality or impure feedstock
Soil, dust, or contamination during handling/storage
Incomplete combustion or inefficient processing

Effects of high ash content?

Wear on engine parts
Lower efficiency and power output
More frequent maintenance and treatment

Solutions for ash content?

Use cleaner, high-quality feedstock
Improve handling/storage to avoid contamination
Optimize combustion and processing efficiency

What is True Total Base Number (TBN)?

A measure of an engine oil’s capacity to neutralize acids formed during operation; higher TBN means better acid neutralization, longer oil life, and improved corrosion protection

Why is TBN important?

It protects engine components from acid corrosion, especially in extended drain intervals

Effects of TBN levels?

Correct TBN: Neutralizes acids, prevents corrosion, ensures smooth operation
Too high TBN: Causes deposits and abrasive wear
Too low TBN: Leads to acid corrosion, rapid liner/piston damage

Causes of TBN-related issues?

Ash deposits from fuel causing abrasion and fouling
Poor fuel quality increasing acid formation
Inefficient emission control systems leading to penalties or retrofits
Contamination and poor oil selection

Solutions for proper TBN management?

Regular oil analysis
Choose correct oil grade for engine and fuel type
Upgrade fuel quality
Monitor operational conditions
Address contamination promptly
Be cautious with high-mileage engines