Many support the idea that hydrogen can save the world from the traps of the energy crisis and the climate dilemma, but implementing this solution is not easy, given that storing this substance is expensive. Which raises the following question: Is hydrogen can achieve a revolution in the energy field or is this just an illusion?
In this report, which was published by the French magazine “Marianne”, writer Pierre Vandegenesti said that France intends to adopt hydrogen for power generation, as the government has allocated a delicate program with a significant budget to encourage research and industry in this field over a period of 10 years.
Where is the complexity?
The complexity lies in how to obtain hydrogen, as it is known to be the most common chemical element in the universe, as its atoms are included in the composition of water and fossil fuels, similar to coal, oil and natural gas.
Hydrogen is extracted either from molecules containing hydrogen and carbon, such as methane, which is the main component of natural gas. Or from water by separating hydrogen from oxygen with the help of electricity in what is known as electrolysis.
This electricity is not mostly from clean energy sources, but rather from low-carbon energy sources: like dams, geothermal energy, wind turbines, solar energy, marine energies and nuclear energy. But the goal is to produce “green” hydrogen without producing harmful and polluting gases.
The writer explained that the generation of energy with hydrogen is through the interaction of hydrogen with oxygen, and that occurs either in the traditional way during the combustion process that produces heat that can be converted into energy, or by the modern method through a “fuel cell” that produces less heat in exchange for a greater amount of electricity.
A significant weakness of electrical energy generated by hydrogen is the way it is stored. The most reliable method is battery storage.
However, this poses many problems, such as the low “energy density”, especially in terms of weight, as replacing a car tank with a capacity of a few tens of liters of gasoline requires a battery weighing hundreds of kilograms. And making these batteries requires large amounts of metals.
Hydrogen itself has a high energy density by weight, since 3 kilograms of gasoline can be replaced by one kilogram of hydrogen. Using one kilogram of hydrogen, a car can travel 100 kilometers.
But things get complicated when we analyze the energy density in terms of volume, hydrogen is the lightest gas at all, as it weighs one liter of it at normal pressure and normal temperature only 90 milligrams, and a kilogram of it occupies only 11 cubic meters.
And we can store hydrogen because we know how to change its density in different ways through the use of pressure, but the hydrogen storage process, in turn, consumes a lot of energy. The process of liquefying hydrogen is more complicated, as it requires more energy consumption and a lower temperature (-253 ° C). Storage of hydrogen at normal temperature and pressure requires certain solids or liquids.
One of the shortcomings of some new sources of renewable energy is that they are intermittent, and we need to store the energy that they generate when there is wind, sun, current or waves, to be used at a later time when needed. And this requires huge storage resources.
Therefore, hydrogen is the most appropriate solution because its large tanks are a good alternative to the bulky batteries that cause a lot of problems.
The downsides of hydrogen production
France consumes 900,000 tons of hydrogen annually, 95% of which is extracted from natural gas. According to Philip Buckley, president of France Hydrogene, “extracting one kilogram of hydrogen from natural gas produces 9 or 10 kilograms of carbon dioxide.”
Xavier Vigor, Head of Hydrogen Technologies at Air Liquide Group, explains, “There are 3 methods for producing hydrogen by electrolysis of water, two of which require low temperature which are alkaline electrolysis and electrolysis by proton exchange membrane, while The third requires a high temperature (between 700 and 800 degrees Celsius). “
“The oldest process – and still the cheapest – is alkaline electrolysis. The largest units of hydrogen production still adopt this practical chemical principle that requires a continuous current between two electrodes immersed in water. Under the influence of electricity, water decomposes into hydrogen and oxygen,” Vigor adds.
According to Vigor, “the main disadvantage of this method remains in the use of expensive metals such as platinum and iridium, so research aims to reduce their quantity during the production process,” stressing that “the largest plant for the production of hydrogen electrolysis in the world is currently being built in Quebec.”
Hydrogen is cleaner
There are many ways to produce cleaner hydrogen. “Green hydrogen would be welcome to replace the polluting hydrogen that has long been used in some industrial sectors,” said Philippe Buckley, general manager of the company that manages the French network of natural gas transportation.
Not long ago, an article on hydrogen energy included a tip that denies the existence of natural hydrogen mines. But is this information correct?
Isabel Moretti, a researcher at Universite de Pau et des Pays de I’Adour, says, “In the small village of Boracaybougou, about 60 kilometers from Bamako, it was found while digging for water at a depth of 100 meters. Contains 96% pure hydrogen, which supplies the village with electricity at the moment. “
“It is not unlikely that subsoil contains native hydrogen,” she adds. Moretti continues, “Water immersion of rocks that contain minerals, including iron and magnesium, leads to their oxidation and thus the release of hydrogen.”
Moretti said, “Some sites where a similar phenomenon occurs have been identified in regions such as Kansas, Australia and Brazil. But the most interesting sites are in the sea, and exploration there is very expensive. However, it is necessary to study these phenomena in the beginning and determine the appropriate geological conditions.”