There are several types of marine fuels used in the shipping industry, with varying compositions and properties.
Marine Distillate Fuels
Distillate fuels are a type of refined petroleum product that are produced by the distillation of crude oil. During the refining process, crude oil is heated and separated into various fractions based on their boiling points. Distillate fuels are produced from the middle distillate fraction, which has a boiling range of approximately 150 to 350 degrees Celsius.
There are several types of distillate marine fuels that are commonly used in the shipping industry:
- Marine Gas Oil (MGO): This is a low-sulfur distillate fuel that is used in smaller vessels or as an auxiliary fuel in larger engines. MGO has a lower viscosity and higher density than marine diesel oil (MDO) and is more expensive.
- Marine Diesel Oil (MDO): This is a heavier distillate fuel that is typically used in larger marine engines. MDO contains more sulfur than MGO and has a higher viscosity.
- Ultra-Low Sulfur Diesel (ULSD): This is a type of distillate fuel that is used in diesel engines, including marine engines. ULSD has a sulfur content of 15 parts per million (ppm) or less, compared to traditional diesel fuel, which can contain up to 5,000 ppm of sulfur.
- Marine Distillate Fuel (MDF): This is a type of distillate fuel that is used in marine engines. MDF has a lower viscosity than MDO and a higher flash point than heavy fuel oil (HFO).
- Marine Gasoline (MAG): This is a type of distillate fuel that is used in smaller vessels or as an auxiliary fuel in larger engines. MAG has a higher octane rating than MGO and is typically used in gasoline engines.
Heavy Fuel Oils
Heavy Fuel Oil (HFO) is a type of fuel that is commonly used in large marine engines, such as those found on cargo ships, tankers, and container ships. HFO is a residual fuel, which means that it is produced from the leftover heavier components of crude oil after the lighter distillate fuels (like diesel and gasoline) have been extracted. HFO is popular in the shipping industry because it is cheaper than other types of marine fuel, and it has a high energy density, which means that it can provide more power per unit of fuel.
There are several types of Heavy Fuel Oil (HFO) that are commonly used in the shipping industry. These include HFO180 / 380 / 500 / 700 / 1000, the number indicating a maximum viscosity (cSt) at 50 degrees Celsius. It is also known as IFO (Intermediate Fuel Oil). RFO (Residual Fuel Oil) or LSFO (Low-Sulfur Fuel Oil).
Very Low Sulfur Oils
Very Low Sulfur Oils (VLSO) are a type of marine fuel that is designed to meet the International Maritime Organization's (IMO) regulations to reduce sulfur emissions from ships. These regulations were introduced in 2020 and require ships to use fuels with a sulfur content of 0.5% or less by weight, compared to the previous limit of 3.5%.
VLSO is a type of heavy fuel oil (HFO) that has been treated to remove most of the sulfur. It is also known as Ultra Low Sulfur Fuel Oil (ULSFO) or Very Low Sulfur Fuel Oil (VLSFO).
Besides conventional marine fuels, there are some types of cleaner, alternative fuels used in shipping:
- Liquefied Natural Gas (LNG): This is a cryogenic liquid that is stored and transported in insulated tanks and is vaporized to a gas before being used in ship engines. LNG is becoming increasingly popular due to its low emissions and low sulfur content.
- Biofuels: These are renewable fuels that are derived from biomass, such as plant-based oils or animal fats. They are used as an alternative to fossil fuels and can have a lower carbon footprint and emissions than traditional fuels.
- Hydrogen: This is a clean-burning fuel that can be used in fuel cells to produce electricity for ship propulsion. Hydrogen can be produced from renewable sources, such as solar or wind power, and has the potential to be a zero-emissions fuel.
- Methanol: This is a liquid fuel that can be produced from a variety of feedstocks, including natural gas, coal, or biomass. Methanol can be used as a marine fuel and has lower emissions of particulate matter and sulfur than traditional fuels.
- Ammonia: This is a hydrogen-rich fuel that can be produced from renewable sources, such as wind or solar power, and has the potential to be a zero-emissions fuel. Ammonia can be used as a marine fuel and has a high energy density, but it also has some safety concerns due to its toxicity and flammability.
- Electric batteries: This is a clean and efficient way to power ships, especially for short distances and smaller vessels. The batteries can be charged from shore power or renewable sources, and can power electric motors for propulsion.