In recent days the Propeller Club - Port of Genoa has held a meeting centered on the applications of hydrogen for the decarbonization of the marine-portal sector, theme that has been widely treated by the secretary advisor Ezio Palmisani, executive president of Duferco Engineering, who has talked about the advantages of its application, the problems still to be solved and how it can become a real fuel for transport and for industry.

Palmisani explained that hydrogen is the most abundant element of the universe and on Earth is not free because it is very light and tends to combine with other elements and to disperse easily, but it is an extremely energetic element: a kilogram of hydrogen contains about three times more energy than a kilogram of oil and, if used in a fuel cell, does not produce CO2 emissions but only water. Moreover, it is already a familiar element to the industry, used for years in the steel industry and petrochemical. So there is a consolidated ability to manage security. The real problem is to extend its use as a widespread fuel, which still requires technological and infrastructural development.

The rapporteur explained that hydrogen can be used in two main ways: can be used in combustion in heat engines suitably adapted, or can be converted into electricity and heat via fuel cell. Today fuel cells are the most promising solution in many areas, because they allow to transform hydrogen into electricity at the point and the moment it serves, making it a flexible and usable energy carrier in different sectors. Palmisani also spoke of practical difficulties: Today the hydrogen used in the industry is mainly produced by steam reforming natural gas, with CO2 emissions. To obtain green hydrogen, water electrolysis is used, which requires a considerable amount of electricity to break chemical bonds; so that it is truly sustainable, this energy must come from renewable sources (FER), which entails high costs and constraints linked to the availability of space and plants. Moreover, hydrogen has a very low atmospheric pressure density: It occupies large volumes, so it is necessary to compress it (typically 350-700 bar), liquefy it or use innovative solutions such as metal sprays to make it possible storage and transport. Another aspect to consider is the consumption of water, about nine kg to produce a kilogram of hydrogen. Finally, the infrastructure is still limited, so production and distribution are complex and often hydrogen is produced directly on the site. In the face of these criticisms, however, it has a fundamental advantage over fossil sources: the possibility of zeroing direct emissions.

Palmisani then compared a diesel vehicle with a hydrogen powered by fuel cell. The overall efficiency "from the tank to the wheel" of a medium with gasoline thermal engine - it has explained - is around 29.6%, while an electric medium powered by hydrogen fuel cell reaches about 46.5%, thanks also to the recovery of the braking energy and to a more efficient management of the electric traction. In energy terms, this results in a significantly higher availability of useful energy by means of hydrogen. On the cost level, however, today the oil is even cheaper, about four times compared to green hydrogen. However, considering the future costs of CO2 emissions and ETS mechanisms, the gap tends to decline. Moreover, the margins of technological improvement are all in favour of hydrogen, which can become progressively more competitive.

Palmisani believes that hydrogen is an energy carrier with great potential, able to contribute in a concrete way to the energy transition, but that it still has to overcome some important barriers for a wide-scale diffusion, in particular the lack of infrastructure and current production costs. The current projects show that, with industrial vision and experimentation, these potentials can already be translated into real solutions.