Liquefied petroleum gases (LPG)
Liquefied Petroleum Gases (LPG) are also fuels derived from petroleum. They exist in a gaseous state at room temperature and pressure, unlike liquid fuels such as gasoline and diesel.
LPG includes propane and butane, as well as specific-purpose mixtures like autogas. These products are supplied to end consumers in bottles, through piped distribution networks, or, in the case of autogas, at petrol stations for sale to the general public. LPG can also be supplied in bulk by tanker trucks to large customers in industries, commerce, services, and more.LPG contributes to improving the quality of life for the population through various applications, including cooking food, heating water and indoor/outdoor spaces, among others. The industrial sector also benefits from LPG, and there are essential applications where its use is fundamental, alongside natural gas, such as in ceramics and glass industries. The LPG value chain begins with crude oil production and refining and includes storage, bottling, transportation by road, rail, sea, and inland waterways in tanks or bottles, as well as transport and distribution through pipeline networks. The supply of LPG bottles (butane and propane) is currently the most widely available form of fuel gas outside major urban centers, and it is particularly important in geographically remote areas of Portugal.
For more information, please visit LPG: How does it work?
Import
Crude oil is found in large natural underground reservoirs, often beneath the seabed, as a thick, dark, flammable liquid composed of hydrocarbons mixed with sulphur, nitrogen, and other elements in varying proportions.
As extracted from natural reservoirs, crude oil has little use. However, as a raw material, it can be refined into fuels used for heating, electricity generation, powering vehicle engines, and more.
As Portugal is not an oil-producing country, it depends on crude oil imports as raw material for national refineries or, alternatively, on already-refined petroleum-derived fuels.
Refining
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.
Storage
Liquefied Petroleum Gases (LPG) are stored in liquid form in spherical or cylindrical pressure vessels, enabling the storage of large amounts of energy in relatively small volumes.
Large facilities have storage capacities of tens of thousands of cubic meters, distributed across multiple tanks. These facilities facilitate the receipt and shipment of the product through various means, including pipelines, propane ships, tankers, rail tanks, and even on-site filling of LPG bottles.
In Portugal, three LPG storage facilities have been designated as 'Public Interest Facilities' due to their size, location, and relevance to the National Petroleum System.
- The facilities of Companhia Logística de Combustíveis, in Aveiras de Cima, which store LPG and liquid fuels, and provide bottle filling services and tanker refuelling islands
- The Pergás facilities at Perafita, which have a storage capacity of approximately 14 000 cubic metres, and provide bottle filling services and tanker refuelling islands
- The Sigás propane storage cavern, located near the port of Sines, which consists of a rock cavern at a depth of just over 120 m, with a storage capacity of approximately 83 000 cubic metres of LPG
Transport and distribution
Liquefied petroleum gases (LPG) are transported in propane ships, in road and rail tanks and in various types of bottles.
In mainland Portugal, transportation from large storage facilities to LPG depots supplying large consumers or distribution networks is generally carried out by tanker trucks. Road transport of LPG is subject to strict safety standards, as stipulated in the European Agreement concerning the International Carriage of Dangerous Goods by Road.
Transportation of LPG from the mainland to the autonomous regions is typically done by propane tankers. For smaller quantities, it can also be transported by sea using tank-containers on ships designed for containerized cargo.
Supply
Liquefied Petroleum Gases (LPG) are supplied in several ways: in bottles of various types, through piped distribution networks, in bulk through delivery in tanker trucks to large consumers, or at petrol stations in the form of autogas.
Bottled LPG
Liquefied Petroleum Gases (LPG) can be supplied to consumers in propane and butane bottles. These two products are interchangeable, meaning that appliances can operate with either gas without the need to adapt the appliance or the gas installation. As butane is less volatile than propane, its use is recommended indoors under conditions of relative thermal comfort, especially in winter and cold areas.
There is a wide range of LPG bottles available, from large propane bottles (45 kg) to very small ones suitable for small cookers and camping lanterns. The most common bottles are made of metal with a capacity of 26 liters or lighter bottles made of composite materials with a capacity of around 22 liters.
LPG bottles are sold through retail outlets, including traditional shops, petrol stations for the general public, supermarkets, and even through call centers or internet applications with home delivery and bottle collection services. The bottled LPG market is liberalized, and the retail price is determined by competition.
There are approximately 50 thousand points of sale for bottled LPG in Portugal. The characteristics of gas bottles sold in Portugal can be found in the ERSE Catalogue.
Piped LPG
Liquefied Petroleum Gases (LPG), particularly propane, can be supplied through piped distribution networks from tanks located at LPG depots close to areas of concentrated consumption.
At these depots, propane is received from tankers and stored in liquid form. It is then vaporized and fed into the distribution networks, which deliver the gas conveniently and safely to end users.
Distribution networks are made of polyethylene or steel and are generally buried in public areas. The networks are connected to consumers' premises through branches, and supply is measured by individual meters for each customer on the network.
The supply of propane through pipelines is a versatile form of supply, suitable for different market segments, including the domestic, tertiary, and industrial sectors.