Two types of fuels are used for different applications: bunker fuel and diesel fuel, which are usually used in the maritime and transportation sectors. Viscosity, usage, and preparation vary significantly from one to the other.
The main difference between bunker fuel and diesel is their refinement level: bunker fuel is a heavy, unrefined fuel used for large ships, while diesel is a lighter, refined fuel used for smaller engines and vehicles.
In this article, we will take you through some of the major differences between them, with some examples, applications, pros and cons, and a comparison of their cost.
What is Bunker Fuel?
Heavy fuel oil, or bunker and furnace fuel, is a thick, viscous oil mainly used in large ships. It has a high density and is prepared poorly, so it needs to be heated and filtered before use.
Example: Bunker fuel IFO 380 (Intermediate Fuel Oil) is a common fuel.
Main Types of Bunker Fuel
Different types of bunker fuel are used to power ships, and they have been designed to power particular vessels and meet particular regulatory requirements. Bunker fuel is chosen based on the engine’s type, environmental limits and requirements.
Marine Gas Oil (MGO)
It is similar to diesel; MGO is a light, refined bunker fuel. It is the most favoured fuel because it is easy to use and has a low sulphur level, making it ideal for usage in environmentally regulated areas.
Intermediate Fuel Oil (IFO)
Heavy Fuel Oil (HFO, sometimes referred to as IFO) is a blend of fuel oil and marine gas oil. You can use it on large ships; it comes in different grades of viscosities.
- IFO 180: Easy to handle with lower viscosity and is typically used in smaller or more efficient engines.
- IFO 380: Used in larger ships; requires heating and processing due to higher viscosity.
Heavy Fuel Oil (HFO)
The most common and thickest foreign fuel oil is known as HFO. To use in ship engines, it needs to be heated and filtered extensively.
- Standard HFO: High energy density but requires significant pre-treatment and is used in large tankers and bulk carriers.
- Low-Sulphur HFO: Low sulphur content variant of HFO suited to areas where environmental regulation are particularly important.
Alternative Bunker Fuels: ULSFO, VLSFO, LNG and Hybrid Fuels
Very Low Sulphur Fuel Oil (VLSFO)
It is intended to meet the 2020 International Maritime Organisation (IMO) sulphur cap regulation. VLSFO has less than 0.5% sulphur, making it a cleaner alternative to traditional heavy fuels.
Ultra-Low Sulphur Fuel Oil (ULSFO)
ULSFO also has lower sulphur content (0.1 % to below) than others, and it is perfect for use in Emission Control Areas (ECAs) where rules are strict.
Liquefied Natural Gas (LNG)
The lower emissions of LNG are attracting attention as a bunker fuel. That is a cleaner alternative, but it does have to be stored and handled using specialised systems.
Hybrid Fuels
Marine gas oil (MGO) and heavy fuel oil (HFO) are the types of hybrid fuels. These fuels are lower in sulphur and yet are as cost-effective and efficient as heavy fuels.
What is Diesel Fuel?
A lighter, low-viscosity fuel commonly used in vehicles and machinery is diesel fuel. Pumping of this fuel is easy as no preheating is required.
Example: Modern engines often use ultra-low sulphur diesel (ULSD), a common type of diesel fuel.
Diesel Fuel Types
Different types of diesel fuels are available to meet different engines and regulatory needs. The composition, performance, and environmental impact of each type are different.
Petroleum Diesel
Diesel fuel is mostly petroleum diesel. Due to its higher energy content, it is most commonly used in trucks, buses, and other heavy-duty vehicles.
Biodiesel
It can be produced from renewable sources such as vegetable oils and animal fats. B5 and B20 have different blending concentrations. B5 is commonly used in fleet vehicles and B20 is utilised in diesel vehicles without any engine modifications.
Synthetic Diesel
Natural gas, coal, or biomass is used in Fischer-Tropsch synthesis to create synthetic diesel. As it’s ultra-clean and provides better combustion with lower emissions than traditional diesel, it’s something to drive.
Renewable Diesel
This diesel is made from non-petrochemical sources such as animal fats and waste oils. It has chemically identical properties to petroleum diesel but with lower emissions and a lower environmental footprint.
Applications of Bunker Fuel vs Diesel
Bunker Fuel Applications
- Maritime Vessels: Mostly, large ships (container ships, oil tankers, bulk carriers) use bunker fuel. It’s good for long voyages thanks to its high energy density.
- Power Plants: Larger power plants are used in some regions of the world to generate electricity using bunker fuel as an alternative when other fuels are less economical.
- Industrial Boilers: Industrial boilers produce steam and heat for large manufacturing operations using bunker fuel.
- Backup Generators: The backup generators in some large-scale facilities, like hospitals or data centres, tend to use bunker fuel for continuous energy supply.
Diesel Fuel Applications
- Transportation: Vehicles such as trucks, buses, trains and personal cars with diesel engines use diesel fuel. It is known for its efficiency in power and torque for heavy-duty vehicles.
- Marine Engines: Because it doesn’t need the heating and filtration systems necessary for bunker fuel, smaller boats, yachts, and fishing vessels use diesel fuel.
- Equipment: Heavy machinery, such as excavators, bulldozers, and tractors, operate on diesel due to its ability to produce high torque at low speeds.
- Generators: Generators using diesel are commonly used for homes, businesses, and industrial work where grid power supply may be unreliable.
- Military Vehicles: Many military vehicles and equipment use diesel fuel for motive power because it delivers greater efficiency even in difficult conditions.
Cost and Efficiency Comparison
Bunker fuel is less expensive per unit of energy, but it requires additional investment in the infrastructure, heating, filtration and other costs related to those additional investments that will increase operational costs.
Although diesel fuel, in its pure form, is more expensive per unit, storage and use are easier, and its lower emissions may be an advantage for those areas with stringent environmental regulations.
Key Differences Between Bunker Fuel vs Diesel
Criteria | Bunker Fuel | Diesel |
What They Are? | Heavy fuel oil is primarily used in ships and is derived from crude oil residue. | A lighter, more refined fuel used in vehicles and machinery, derived from crude oil |
Types | Marine Bunker Fuel (IFO 180, IFO 380) | Synthetic or Clear Diesel |
# | Very Low Sulfur Fuel Oil (VLSFO) | Red Diesel |
# | Marine Gas Oil (MGO) | Biodiesel |
Applications | Commercial shipping | Transportation (trucks, cars) |
# | Power generation for marine vessels | Agriculture (tractors, equipment) |
# | Industrial uses in large machinery | Heating and generators |
Pros | Lower cost per unit than diesel | More efficient combustion |
# | Higher energy density | Cleaner burning, producing fewer emissions |
# | Readily available for shipping | Easier to handle and store |
Cons | High sulphur content, leading to emissions | Generally, a higher cost per unit |
# | Requires special handling and storage | Seasonal price fluctuations |
# | Potential for environmental regulations | Less energy density compared to bunker fuel |
Cost Comparison | Generally cheaper per barrel | More expensive per gallon |
# | Prices vary based on sulphur content and region | Prices influenced by crude oil prices and taxation |
Summary of the Guide
Bunker fuel and diesel fuel are both useful for different tiers of operation. Though cost-effective and energy-dense, bunker fuel is so complex that it can cause handling headaches. Diesel is versatile, easier to use, and environmentally friendly for smaller-scale applications.
Contact 123 Oil, UK’s one of the most reliable companies for certified and quality bunker fuel or diesel fuel supplies.
