That we are increasingly demanding in terms of electricity consumption is a fact. As certain as hydrogen is found in 75% of the planet's matter. The estimates of the International Energy Agency (IEA), published at the end of 2019, announce an increase in energy demand between 25 to 30% until 2040. Taking into account our current dependence on sources of fossil origin such as coal, gas and oil, this greater demand would translate into a clear increase of carbon emissions. Point contrary to the purpose set by the European Comission for the years to come.
With all this, we are forced to look for sustainable alternative energies that seek to put an end to the era of fossil fuels.
THE PROPHECY OF JULES VERNE
In its book 'The Mysterious Island', written in 1814, the French writer spoke of the potential of water as a source of energy: “Electricity has allowed water to be broken down into its primitive elements, which will make it become a powerful and manageable force […]. Yes, my friends, I believe that one day water will be used as fuel, that the hydrogen and oxygen of which it is formed, used separately or together, will provide an inexhaustible source of light and heat, of an intensity of which coal is not capable […]. Water will be the carbon of the future…”
HYDROGEN AS AN ENERGY VECTOR
Hydrogen is the most abundant element on the planet, it is found in a 75% in matter, but the problem is that it does not exist in an individual state but is always forming compounds with other chemical elements. Examples of this are water, where it is found allied with oxygen and in organic compounds joining carbon.
Therefore, since it is not found in nature in its pure state, it is necessary to resort to chemical processes for its extraction and, depending on how sustainable its obtaining process has been, there is a color scale.
Green: It is extracted from the electrolysis of water, a process in which the molecule is broken, resulting in Hydrogen and water vapor. All of the energy used in the process comes from renewable sources and does not generate any type of contaminant to the atmosphere, seeing a long-term reduction in carbon dioxide emissions and significantly affecting the carbon footprint.
Blue: It is obtained from fossil fuels, but with techniques that can trap and store the carbon dioxide emissions that are produced, it is less polluting than gray hydrogen. The drawback is that there are greenhouse gas residues that are not completely eliminated.
Grey: It is obtained by reforming fossil fuels, natural gas being the most common, it is the cheapest to produce, but it emits a large amount of CO2 into the atmosphere and It is the one that is most used currently.
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HYDROGEN OBTAINING PROCESSES
Currently there are three processes to obtain hydrogen:
gasification: This is made from coal or biomass, using a reactor that burns the components at high temperatures, the result is dihydrogen and carbon monoxide.
The molecular transformation: It occurs through chemical reactions, the most used is from the reforming of natural gas from oil fields, water vapor is used at high temperatures to separate the carbon from the hydrogen that makes up natural gas, the result obtained is dihydrogen and dioxide. carbon, this is the most used currently.
Water electrolysis: Consists of the breakage of the water molecule into molecular oxygen and molecular hydrogen by the action of a direct electric current that is connected to water through electrodes. When electrolysis is used with renewable energies, it is the most sustainable production method.
HOW HYDROGEN WORKS AS ENERGY
The hydrogen is stored in specific tanks and channeled to a fuel cell, where oxygen from the air is injected and electrical energy is obtained and is the water residue, a clean, sustainable system that does not emit any pollutants.
