Glossary letter F


The conversion of certain organic compounds by enzymes secreted by microorganisms. These oxidation-reduction (redox) reactions take place in the absence of air or free oxygen (anaerobiosis). The type of fermentation depends on the nature of the reaction product — alcohol or ethanol, acetic acid, lactic acid, malic acid, propionic acid or butyric acid. Very little energy is released by fermentation. It is useful in biofuels, and the process for converting plant carbohydrates into ethanol is based on alcoholic fermentation.

Firedamp Explosion

Firedamp is methane and other gases naturally released by coal in mines. It is explosive at concentrations between 5 and 10% in the air. Firedamp explosions often result in numerous fatalities.

Fischer-Tropsch Process

Chemical process invented in Germany in 1923 in which a mixture of carbon monoxide and hydrogen — derived from coal or gas — is converted into liquid fuel through gasification. It was used by Germany in World War II when the country was cut off from oil resources and by South Africa during international sanctions imposed in response to apartheid. The process is rarely used today due to its high cost.

Flag of Convenience

Means of registration granted by some countries to any type of merchant vessel, including oil tankers. The vessel's country of ownership and control is different from the country in which it is registered. Ship owners that have been granted a flag of convenience therefore pay low or no taxes and, in the least scrupulous countries, are subject to less stringent inspections. The International Transport Workers' Federation (ITF) calculated the number of countries issuing flags of convenience at 35 in 2013.

Flat-Plate Collector (Solar)

Device in which the surface of the heat absorber plate is flat. Flat-plate collectors are either unglazed or glazed. In glazed flat-plate collectors, the heat generated by infrared radiation is trapped under a glass cover instead of being released to the atmosphere, thereby heating the heat transfer fluid.

Floating Liquefied Natural Gas (FLNG)

Intended for the development of offshore gas deposits, Floating Liquefied Natural Gas (FLNG) facilities are designed to produce, liquefy and transfer extracted gas to carriers at sea. These extremely complex and expensive facilities have been under consideration since the early 1970s, but advanced development only began in the mid-1990s.

Floating Production Storage and Offloading (FPSO) Vessel


A self-contained floating vessel that can process crude oil and store until it is transferred (offloaded) to a tanker. FPSOs are used when it would not be cost-effective to export oil to land over a long distance via a pipeline. FPSOs house units to process the crude oil (gas/liquid separation; removal of solids, water and impurities) and stabilize it, as well as pumps, generators, storage tanks and a seawater treatment unit.


Process in which the contrasting behavior of solid particles is used to selectively separate them in a water-filled vessel or tank known as a flotation cell. Hydrophobic particles float and can be collected from the surface, while hydrophilic particles sink to the bottom. Flotation is used to treat coal and metal ores. Various chemical reagents are employed to increase the movement of hydrophobic particles to the surface and hold them there.

Fractional Distillation

The first step in refining. The crude oil is heated until it evaporates, and the vapor fed into the bottom of a 60-meter distillation column, where it gradually cools as it rises. The vapor condenses into different liquids (petroleum cuts or fractions). From the heaviest oil molecules to the lighter hydrocarbons, the products are collected on trays located at different heights in the column (asphalt and wax at the bottom, then heavy fuel oil, fuel oil, diesel, kerosene, gasoline, naphtha and, at the top, LPG, mainly propane and butane).

French Thermal Regulations

Set energy consumption requirements for new and renovated buildings in such areas as heating, hot water and lighting. The 2012 Thermal Regulation stipulates that new buildings must be rated "low-energy", in other words must not consume over 50 kilowatt-hours of primary energy per square meter per year. The even more ambitious 2020 target is for buildings to produce more energy than they consume (positive energy buildings).


Fuel is any solid, liquid or gaseous substance or material that can be combined with an oxidant (also known as an oxidizer or combustion agent) during combustion reactions. This reaction generates large amounts of heat. The oxidant is usually the oxygen in the air. By extension and although it is in no way a combustion reaction, the term "nuclear fuel" is used to designate the fissile materials used to produce fission energy in nuclear power plants.

Fuel Assembly

Fuel assemblies are installed in the core of nuclear reactors, where fission occurs and energy is released. An assembly is made up of 264 fuel rods, each of which is 4.5 meters long and comprises a number of fuel pellets made of uranium oxide or mixed uranium-plutonium oxide. The core of a nuclear reactor contains between 120 and 250 assemblies, depending on the type of plant.

Fuel Cell

Pile a combustible

A device that produces electricity by oxidizing a reducing agent (fuel) in one electrode (the anode) and reducing an oxidizing agent in another (the cathode). The most common type of fuel cell is the hydrogen cell, which uses hydrogen as the fuel and oxygen from the air as the oxidant. Hydrogen fuel cells only emit water and are therefore non-polluting.

Fuel Rod (Nuclear)

A long metal tube containing pellets of fuel (enriched uranium or MOX) for nuclear reactors.

Futures Market

A financial market where traders can buy and sell quantities of oil that do not exist yet ("paper barrels"). This mechanism was initially developed so that operators could protect themselves against financial risks stemming from oil price fluctuations. Nowadays it has become an instrument of speculation.