Petroleum-based fuels include gasoline, diesel, aviation fuels (kerosene) and marine fuels, among others. They are primarily used in the transportation sector, but can also have industrial and domestic applications.

Most of these fuels are made available to consumers at public retail fuel stations.. In cases where the fuels are not intended for road transport, large quantities are supplied in bulk (for example, at airports, seaports, or industrial facilities).

The fuels we are familiar with are generally obtained through the refining of crude oil, which is extracted from natural deposits, making them non-renewable resources derived from a raw material with limited reserves.

In addition to crude oil production and refining, the value chain of petroleum-based fuels includes activities such as storage, transportation and distribution to the locations where they are sold and used.

Energy from petroleum-based fuels is obtained through combustion and currently accounts for approximately 40% of the world’s energy needs.

Crude oil, or raw oil, is found in large natural underground reservoirs, often beneath the seabed, in the form of a thick, dark, flammable liquid consisting of hydrocarbons mixed with sulphur, nitrogen and other elements in varying proportions.

As extracted from natural reservoirs, crude oil has limited utility. However, as a raw material, it can be refined into fuels used for heating, electricity generation, vehicle propulsion, and more.

As Portugal is not an oil-producing country, it depends on imports of crude oil as a raw material for its domestic refineries or, alternatively, on already-refined petroleum-based fuels.

Refineries are designed to convert crude oil into petroleum products such as, liquefied petroleum gas (LPG), gasoline, diesel, paraffin, lubricating oils, fuel oil, bitumen and asphalt, and various  raw materials for the petrochemical industry.

Refineries separate the components of crude oil through distillation processes based on the difference in their boiling points. As the oil is heated in the distillation columns and boils, its vapors rise and cool, with different fractions condensing at different temperatures and heights within the columns. This is how the final and intermediate petroleum products are obtained.

Modern refineries have conversion units that enable the conversion of heavier fractions with lower economic and environmental value (such as fuel oil) into products with higher added value (such as gasolines and diesel).

Modern refineries also have treatment units to remove undesirable elements and compounds, from both intermediate and final products.

There is one refinery in Portugal, in Sines, owned and operated by Petrogal.

The storage of liquid fuels plays a crucial role in the value chain. On one hand, it supports logistics and supply operations to the retail market for end consumers. On the other hand, it ensures the existence of reserves that allow for emergency situations, energy crises, or significant disruptions in the supply of petroleum and petroleum products.

Storage facilities for liquid fuels receive products through liquid bulk terminals at the main Portuguese ports, including Leixões, Aveiro, Lisbon, Setúbal, and Sines. Alternatively, they can receive products through an oil pipeline from the Sines refinery, in the case of the Aveiras de Cima facility owned by Companhia Logística de Combustíveis (CLC).

Major oil companies operate liquid fuel storage facilities or have ownership stakes in companies engaged in this activity. This is the case with CLC, in which Galp, Repsol, BP and Rubis are shareholders. CLC has been granted the status of a ‘Public Interest Facility’, due to its size and importance.

Liquid fuel storage facilities have tanker truck loading islands, which facilitate the delivery of the product to large consumers and petrol stations for sale to the general public.

After storage, liquid fuels are primarily transported to petrol stations for sale to the general public, while the remaining portion is used by industries, other sectors, or exported. This transportation and distribution activity can be conducted through various means:

• Pipelines, for transporting products between storage facilities or from storage facilities to port terminals, refineries, and the petrochemical industry.
• Road or rail tankers (though rail transportation is practically non-existent in Portugal).
• Maritime transportation, for moving large quantities between port terminals

Liquid fuels are sold at petrol stations for the general public, where road fuels (such as  gasoline, diesel, and autogas) are available.

Some petrol stations also offer heating diesel and coloured diesel. Heating diesel is used for heating swimming pools, greenhouses, indoor and outdoor spaces, while  coloured diesel, also known as agricultural diesel, has a green colour for  easy identification. It is intended for consumption by certain economic activities and benefits from a reduced tax rate on petroleum products.

In Portugal, petrol stations for the general public are usually associated with the brand of the oil company that supplies them. Of the more than 3,000 stations comprising the national retail network, around 70% are owned or operated by oil company brands, with the remaining stations operated by independent brands. More recently, large shopping centres (hypermarkets) have developed their own petrol stations, often located in adjacent areas.

Liquid fuel consumption in road transport, including private cars, is quite significant. In 2017, sales in Portugal amounted to EUR 5.5 billion, with road diesel accounting for 75% of this figure.

The supply of liquid fuels also includes bulk fuel deliveries to airports, port terminals, industrial customers, and other entities.