Hydrogen: the eternal promise of alternative fuels
Hydrogen is the eternal promise of alternative fuels to fossil fuels and that emit greenhouse gases. Despite its enormous potential, it is a difficult fuel to obtain, since it is not found in isolation in nature. Is an energy model based on this element feasible?
The panacea of alternative fuels
Hydrogen can be stored in a gaseous or liquid state and distributed through gas pipelines, and can be a substitute for natural gas, and does not emit greenhouse gases during combustion. So how is it possible that it has not already become the star alternative on our path to a sustainable energy model?
The problem must be found in the cost and in the difficulty of production. To begin with, despite being one of the most abundant elements on Earth, hydrogen is not easy to obtain, since it is not found in isolation in nature, but is generated from other substances that contain it, including water, carbon and natural gas.
The ideal way to produce it would be to obtain it directly from water, for which it would be necessary to carry out a process called electrolysis, which consists of the decomposition of water molecules (H2O), in oxygen (O2) and hydrogen (H2). However, this is generally a costly process that requires a lot of electrical energy — which in most cases does not come from renewable sources — to power the electrolyzers.
The difficulty in obtaining 100% clean hydrogen has led producers to classify the resulting product based on its sustainable value. Thus, “gray” hydrogen, the most used today, is the least environmentally friendly, since its generation continues to require fossil fuels.
Alternatively, “blue” or low-carbon hydrogen still requires fossil fuels, but emits less carbon, as it is removed with a method called 'capture and storage'.
The greenest option is “green” hydrogen, produced from renewable energies, a 100% sustainable alternative that, however, is the least common on the market.
