{"id":11533,"date":"2021-12-09T15:47:08","date_gmt":"2021-12-09T14:47:08","guid":{"rendered":"http:\/\/h2sys.fr\/technology\/hydrogen\/"},"modified":"2022-01-10T17:40:50","modified_gmt":"2022-01-10T16:40:50","slug":"hydrogen","status":"publish","type":"page","link":"https:\/\/h2sys.fr\/en\/technology\/hydrogen\/","title":{"rendered":"Hydrogen"},"content":{"rendered":"

What is\u00a0hydrogen ?<\/strong><\/span><\/h2><\/div>

Hydrogen is the most common element in the universe. That is the main component of gaseous planets and stars, but it is rarely found in free state on Earth.
\nHydrogen bonds with other elements. With oxygen it forms water\u00a0(H2<\/sub>O) and combined with carbon it produces hydrocarbon\u00a0(CH4<\/sub>, C2<\/sub>H6<\/sub>, \u2026).<\/p>\n

A hydrogen atom is mostly combined with another hydrogen atom to create the \u201cdihydrogen molecule\u201d (H2<\/sub>). This one can be found in a gas state or in a liquid state \u2013 represented by the acronym LH2<\/sub> \u2013 by cooling the gas at -252.87\u00b0C.<\/p>\n<\/div><\/div><\/div>

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Where can we find hydrogen?<\/h2>
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Hydrogen is a natural element that can be extracted from other molecules such as water. For example by electrolysis of water using renewable energy sources, or by reforming other energy sources such as natural gas or oil.<\/p>\n<\/div>

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How is hydrogen produced?<\/h2><\/div>

The world of science debates on potential natural hydrogen sources in Russia and others places. Nevertheless these sources are not industrialized and two main methods are used to industrially produce hydrogen:<\/p>\n<\/div>

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Water electrolysis<\/h3><\/div>
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This process allows to separate elements of the water molecule by an electric current through a fluid.
\nThe water molecule is composed of two elements, two hydrogen cations and one oxygen anion. An electromagnetic attraction between the ions allows the element to hold together to create the molecule.When the electric current flows between the electrodes the ions are attracted to the opposite charged electrode and the water molecule is split into Hydrogen and Oxygen.
\nAs a result, hydrogen gas and oxygen gas could be collected separately, Hydrogen cations gathered around the anode (negative electrode) and Oxygen anions coming together around the cathode (positive electrode).<\/p>\n<\/div>

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Steam reforming<\/h3><\/div>
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Process based on the use of hydrocarbon gas, in which high temperature steam (700\u00b0C-1000\u00b0C) is used to produce hydrogen.
\nThe most common process is steam-methane reforming which consists of three main stages:
\nFirstly, methane (CH4<\/sub>) is cleaned from Sulfur by a catalytic chemical process called hydrodesulphurization.
\nIn a secondary step, methane is mixed with steam to produce Hydrogen and Carbon Monoxide during the steam-methane reforming reaction. The Carbon Monoxide is combined again with water, during the water-gas shift reaction, to create Hydrogen and Carbon Dioxide.
\nLastly, during the final stage, Hydrogen and Carbon Dioxide are separated and removed from the gas steam.
\nThe reactions could be summed-up by the following equations:
\nCH4<\/sub><\/strong>\u00a0+ 2 H2<\/sub>O\u00a0\u2192 CO + 3 H2<\/sub> + H2<\/sub>O \u2192 CO2 <\/sub>+ 4 H2<\/sub><\/strong><\/p>\n<\/div>

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Benefits<\/strong><\/span> of using hydrogen<\/h2><\/div>

The H2 molecule of hydrogen (commonly known as hydrogen) consists of two hydrogen atoms. It presents an interesting energy density (per unit fuel mass) that can be exploited through technological and scientific research<\/p>\n<\/div>

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The hydrogen combustion generates a high amount of energy (which can be exploited to produce heat or electricity)<\/p>\n<\/div><\/div><\/div>

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Hydrogen can be produced by hydrolysis from green and renewable energy (wind, solar, hydraulic, \u2026) which reduces greenhouse gas emissions.<\/p>\n<\/div><\/div><\/div>

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Hydrogen combustion is totally decarbonized, which makes it an alternative to fossil fuels with high CO2 emissions<\/p>\n<\/div><\/div><\/div>

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Hydrogen can be stored in a gaseous state in a \u00a0bottle or in a solid forms with metal hydrides. The hydrogen tanks can be stored easily.<\/p>\n<\/div><\/div><\/div>

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Progress expected for the \u00a0democratization of hydrogen<\/strong><\/span><\/h2><\/div>

Hydrogen technology has largely been developed during the last few years thanks to scientific and technological achievements. Nevertheless, there is still room for innovation and a lot of research efforts have been committed to overcome various barriers:<\/p>\n<\/div>

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Hydrogen production requires a lot of energy, especially in electrolysis that ensures \u201cgreen\u201d hydrogen production<\/p>\n<\/div><\/div><\/div>

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Its storage in large quantities is difficult due to its low density and requires a large amount of energy for its compression (high pressure gas cylinders), liquefaction or solid storage (metal hydrides)<\/p>\n<\/div><\/div><\/div>

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The cost of carbon free production is high, and its use by the public requires the implementation of major investments<\/p>\n<\/div><\/div><\/div>

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Hydrogen is a flammable gas and requires precautions during storage and use<\/p>\n<\/div><\/div><\/div>

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The widespread use of hydrogen requires working proactively on the hydrogen sector <\/strong>to improve technology, to increase efficiency and to embed hydrogen into existing technologies to make the most of its advantages<\/p>\n<\/div><\/div><\/div><\/div><\/div>

The place of hydrogen in the\u00a0energy transition<\/b><\/span><\/h2><\/div>

Hydrogen was at the heart of the debate at COP 21 held in Paris in December 2015. Hydrogen will play an important role in the energy transition in addition to renewable energy.<\/p>\n

Renewables are intermittent and may produce more energy by the time that the network can absorb or even does not produce enough energy to meet network demands.<\/p>\n

This phenomenon is observed with photovoltaic solar panels that produce an energy surplus between 10h and 16h but do not cover a home\u2019s needs in the morning or in the evening.<\/p>\n

Hydrogen allows, in particular, to store a surplus of energy compared to intermittent energies as it overcomes the constraints of decentralized production and finally its use can significantly reduce emissions of greenhouse gases.<\/p>\n

Hydrogen thus has a relevant role in the energy transition, though its industrial operation still requires a lot of investment.<\/p>\n<\/div><\/div><\/div>

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How to use<\/b><\/span>\u00a0hydrogen ?<\/h2><\/div>

As an energy carrier, hydrogen can be converted to electricity, heat or kinetic energy and can be used:<\/p>\n<\/div>