In the area of environmental preservation, the main use of hydrogen is to remove the sulfur that is naturally contained in oil to produce cleaner fuels.
Hydrogen is a reagent used in many industrial sectors, including chemicals, textile fiber manufacturing, glass, electronics and metallurgy.
It is also used as fuel for rocket launchers.
Hydrogen, combined with a fuel cell, is also a great vector of clean energy, since it makes it possible to produce electricity directly onboard electric vehicles or in remote areas that are cut off from the power grid.
From the beginning of the space industry, hydrogen has played an important role as a rocket fuel. This is because it is the fuel that concentrates the most energy: 1 kg of hydrogen contains 3 times more energy than 1 kg of gasoline. This is a critical criterion considering that a launcher must be as light as possible.
Currently, liquid hydrogen and liquid oxygen are still combined and used to launch the European rocket Ariane 5. In the main cryo-technical stage of Ariane 5, the combustion of hydrogen produces an enormous quantity of steam, which is blown down at very high speed through the tail pipe of the Vulcain engine. It is the ejection of gas at high speed that propels the rocket, in accordance with the action-reaction principal.
Hydrogen burns upon contact with oxygen, but the latter is not present in space. It is for this reason that Ariane 5 carries an enormous central tank containing 162 tons of liquid oxygen at a temperature of -183°C and 28 tons of liquid hydrogen at -252,87°C.
Hydrogen is used to produce clean and silent energy for a variety of applications where doing so meets an immediate need and also offers a genuine benefit. This is the case for power supply to isolated regions that are not connected to the power grid, sensitive sites that require reliable back-up energy systems, captive fleets (forklift trucks and buses), and portable power generators used for outdoor events.
Hydrogen used in a fuel cell allows us to produce electricity directly onboard a vehicle with an electric engine. These "zero-emission" vehicles release only water.
Producing hydrogen requires energy. For this reason, hydrogen is referred to as a vector of energy, such as electricity and not as primary energy. Examples of primary energy include oil, carbon or coal, natural gas and some renewable energy sources.
The use of hydrogen now extends to other sectors like the aerospace and maritime transport industries. Air Liquide is involved in two major projects whose purpose is to find clean and sustainable alternative energies.
In partnership with Zodiac Aerospace, Dassault Aviation and the CEA, Air Liquide is working on Hycarus, a European project that aims to show that fuel cells can be used on aircraft. Fuel cells will be used to power the non-vital parts of the aircraft, like the galley (kitchen). Air Liquide has designed on-board hydrogen storage to power the fuel cell while the aircraft is in flight.
The first zero-emission energy self-sufficient hydrogen vessel powered by renewable energy, Energy Observer has just set out on six-year world tour with more than 100 ports of call. Energy Observer is the first ship in the world capable of producing its own hydrogen from sea water thanks to the energy mix: 120m2 of photovoltaic panels, 2 vertical axis wind turbines, and 1 intelligent traction kite that will power two electrical motors that double as hydrogenerators.
Hydrogen, a highly reactive gas, is widely used in many industrial applications to produce different materials.
In electronics, hydrogen is used as a carrier gas (a gas that transports active gases) for diverse applications such as the manufacture of electronic components. It offers excellent protection against impurities and oxidation.
It is used in the field of industrial chemistry, where it has numerous applications. For example, it can be combined with nitrogen to produce ammoniac, a base for fertilizers. It is a reagent that enters into the composition of textile fibers such as nylon, polyurethane foam and a number of plastic materials
In the glass industry, it is essential to the manufacture of the flat glass used for flat screens. Most flat glass uses the float process, for which high purity hydrogen constitutes a protective atmosphere.
Hydrogen is used in metallurgy for heat treatment atmospheres that enable to produce mechanical parts (the sintering of molded parts) or to alter their properties (annealing of metallic parts).
Today, the most important current use of hydrogen (nearly 2/3rd of the quantity sold by Air Liquide) is the desulfurization of hydrocarbons to produce sulfur-free fuels.
Sources of fossil energies such as crude oil naturally contain sulfur. The combustion of fuels containing sulfur produces sulfur oxides: SOx. These irritating gases cause a number of serious respiratory ailments. They trigger episodes of asthma and cause respiratory illnesses to which children are often prone. They also contribute to atmospheric pollution: the formation of smog above cities, acid rains, etc. In addition, sulfur interferes with the functioning of catalytic exhaust systems.
Hydrogen is used during fuel refining to remove this sulfur via a process of desulfurization or softening. Hydrogen is introduced at a high temperature (over 350°C) and high pressure (60 Bar) during the refining process. It reacts with the sulfur contained in the hydrocarbon molecules to form new compound— hydrogen sulfur (H2S)—which is removed. This hydrogen sulfur can then react with oxygen to yield sulfur, forming a yellow compound that is sometimes seen in refineries. This sulfur is then used as a raw material in industry.
© 2005 ESA - CNES - ARIANESPACE - JP.Mesguen - J.Bidon - L.Lelong