Yellow hydrogen can be a clean energy source, but it depends on the production process
Yellow hydrogen It is an ambiguous term, and has different meanings depending on the literary source. But, in general, this hydrogen color refers to the color that is produced by electrolysis of water, exclusively with a solar energy source.
However, other sources, such as Energy Research (EPE), linked to the Ministry of Mines and Energy (MME), specify that Yellow hydrogen It is extracted using a mix up From energy sources. According to EPE, the Yellow hydrogen “It is produced using backup energy from the grid, mainly wind and solar energy.” In this case, the electrolysis process can operate using electricity from renewable, low-carbon sources and burning fossil fuels.
Hydrogen is the most abundant element in the universe, and has become increasingly attractive in research and development of projects focused on clean energy. Its adoption has the potential to significantly reduce pollutants from energy production and use, but it is necessary to consider the entire H2(1) life cycle.
How is yellow hydrogen produced?
Hey Yellow hydrogen It is produced through a process called water electrolysis. In it, a device called an electrolyzer separates a water molecule (H2O) into hydrogen (H2) and oxygen (O). This is caused by an electric current applied to two electrodes, which causes the atoms that make up the water to separate (2).
The electrolysis process does not directly produce atmospheric pollutants, making it a more environmentally friendly way to obtain hydrogen compared to other technologies. However, if powered by electricity from fossil and non-renewable sources, it can generate unsustainable hydrogen with a polluting life cycle (1).
What are the advantages of yellow hydrogen?
There are different technologies and raw materials that can be used in hydrogen production, and these differences are used as a parameter to classify it into different hydrogen colours. These colors are not related to the element itself, but rather specifically identify its origin.
Black and brown hydrogen is produced from metallurgical coal, a non-renewable and polluting energy source. Likewise, gray hydrogen is extracted from methane, found in natural gas, through a process that generates carbon dioxide (CO2). As an alternative, one could choose blue hydrogen, which differs from gray in that it captures and stores the carbon generated, but still relies on a non-renewable source (natural gas) to be produced.
In this sense Yellow hydrogenWhen produced by solar-powered electrolysis, it has an important advantage over the colors mentioned above. Its process relies on a renewable source of energy and does not generate carbon dioxide, which significantly reduces the potential environmental impact of its production chain.
In addition, hydrogen does not produce polluting gases when it undergoes combustion or when converted into energy within fuel cells, making it a clean source of energy when produced in an environmentally friendly manner (3).
What are the disadvantages of yellow hydrogen?
On the other hand, if Yellow hydrogen The dependent is that described by the EPE, which includes renewable and non-renewable energy sources, and this can contribute to perpetuating the environmental impacts of fossil fuel exploitation, such as atmospheric pollution, acid rain, and public health problems (4).
Furthermore, the release of carbon dioxide resulting from the extraction, production and burning of fossil fuels exacerbates global warming and global warming, highlighting the major drawback of this energy alternative. Yellow hydrogen.
Therefore, in order to mitigate the effects of climate change, as well as reduce global dependence on fossil fuels, it is better to Yellow hydrogen The ones used are those that are produced exclusively with solar energy.
What other colors of hydrogen might be sustainable?
When produced using raw materials and renewable energy sources, as well as through processes that prevent the spread of pollutants into the environment, hydrogen can be considered sustainable.
Green hydrogen is one of the main alternatives, as it is generated by water electrolysis with solar, wind or hydroelectric power, both of which are renewable. It is worth noting that energy production infrastructure, even green hydrogen, still relies on raw materials and non-renewable energy to be built, but its adoption tends to contribute in the long term to the decarbonization of energy systems.
Another option that can boost the energy transition is pink hydrogen. It is also produced by electrolysis, but nuclear energy powers the entire process. The uranium used to generate nuclear power is a non-renewable energy source, but both this type of energy and electrolysis do not generate carbon dioxide, making pink hydrogen an interesting option in the short to medium term.
Yellow hydrogen or green hydrogen
The two colors of hydrogen, yellow and green, represent H2 produced by water electrolysis using renewable energy. Hey Yellow hydrogen, when generated specifically by solar energy, is a subclass of green hydrogen. In this regard, Yellow hydrogen It would just be a more specific classification of hydrogen production technology, with green being the color that defines a broader path in terms of energy sources.
On the other hand, when hydrogen is produced with surplus energy from the electrical grid, which may be of fossil origin, according to the EPE classification, it is different from the green variant. This method of obtaining hydrogen is neither clean nor renewable, and tends to become extinct in the long term due to the limited nature of energy resources such as oil, natural gas, and metallurgical coal.
So, Yellow hydrogen It can be a promising source of low-carbon energy, if its production chain relies on non-polluting materials and processes. This color represents a range of technologies that are increasingly important for the energy transition towards sustainability, but the use of a mix up Renewable and non-renewable energy could take humanity in the opposite direction.
