Hydrogen, the energy of the future?

Fanny Trifilieff: Why do you call hydrogen an "energy carrier" rather than an "energy source"?

Audrey Soric : An energy source exists in its natural state, such as oil, solar energy or wind power. An energy carrier, on the other hand, is an energy carrier produced from energy sources. Hydrogen (H2) is sometimes mistakenly referred to as an energy carrier. It is not available in its natural state, but can be produced from natural gas, water electrolysis or biomass.

F.T: Can hydrogen be produced sustainably?

A.S: Historically, hydrogen was produced from natural gas and oil. For ecological reasons, and in order to decarbonize industry and production sources for energy carriers such as hydrogen, other processes are being developed. Much is said about water electrolysis, which separates the H2O molecule into hydrogen and oxygen, but hydrogen can also be produced via biomass. There are bacterial species that have the ability to transform carbonaceous organic matter into hydrogen and CO2 under specific conditions. Wastewater contains a high concentration of these organic carbon molecules. These can serve as nutrients for the bacteria, which in turn produce hydrogen. This way of converting biomass into hydrogen is less efficient than using fossil fuels, but it is part of a circular economy and sustainable development approach. In terms of environmental protection, this waste and wastewater is already treated via biological processes. By modifying the biological process, this could kill two birds with one stone: using bacteria to produce hydrogen, while treating waste and wastewater.

F.T: What are the possible applications for hydrogen?

A.S : One of the uses most people are familiar with is transport. Hydrogen can be used as a direct-combustion fuel, thanks to its high energy capacity. It can also be used to power fuel cells and act as an energy carrier, which would then be transformed into electricity, again in the context of transport. But hydrogen is also a raw material used extensively in industry. Its production, in H2 form, for industrial purposes is essentially based on fossil fuels. The challenge is therefore twofold: to develop hydrogen production for transport, but also to replace fossil fuel production for industrial needs. One possibility would be to use wastewater and waste produced on industrial sites to extract hydrogen, which would then be reinjected into the industrial process as part of a circular economy approach. This could lead, for example, to wastewater treatment plants which, instead of consuming energy, would produce it in the form of hydrogen.