In order to understand what blue hydrogen is, it is necessary to delve into the subject of hydrogen in general and why this fascinates all those involved in the search for renewable energy sources.
This very statement of ours already deserves a fist caution, which we will address shortly.
In concrete terms, we are not just talking about blue hydrogen, but several other colours, each with its own peculiarities.
Of course, associating different types of colour with hydrogen is simply a taxonomy because we are basically talking about an element that, in its nature, is not only colourless but, when in a gaseous state, also invisible.
The different colours, therefore, refer to the different ways in which it is extracted from molecules and the different possible combinations thereof.
Returning however to the subject of our article, blue hydrogen refers to low-carbon hydrogen.
Let us see together what this is all about.
Hydrogen as an energy vector
Calling hydrogen an energy vector means to remember and recognise that we are not really talking about an energy source, but as mentioned in the title, a vector.
Energy vectors in general are compounds that transfer energy from one form to another; this transfer is possible precisely because of their physical and chemical characteristics.
The energy coming from an external energy source is stored and then released at the right time, also considering that it does not necessarily have to be made available immediately; this is why we also talk about storage.
The difference therefore between an energy carrier, such as hydrogen, and a primary energy source (such as oil, wind, or solar energy) is substantial:
an energy carrier must literally be produced, primary energy on the other hand is present in nature and does not have to undergo any transformative process.
Two elements contribute to distinguishing the different nature of hydrogen:
the type of energy, which we could call the source and the process by which it is produced.
Blue hydrogen therefore means hydrogen produced from natural fossil fuels, such as gas, but not only…, the production plant, in fact, includes a system for capturing and storing all the CO2 produced during the process.
Blue hydrogen is produced without climate-damaging emissions; in fact, natural gas is split into hydrogen and CO2 via a process called SMR (Steam Methane Reforming) or ATR (Auto Thermal Reforming).
Carbon dioxide, on the other hand, is ‘captured’ through a process called Carbon Capture Usage and Storage (CCUS).
Hydrogen as fuel
Hydrogen as a fuel is very much in favour of the ecological transition, because it is the only fuel that, regardless of how it is used, produces no polluting emissions.
Decidedly abundant in the universe (it is present at a rate of 90%), the hydrogen molecule in the presence of oxygen originates part water and part energy.
It therefore burns like a fuel, but without giving rise to substances that are harmful to the environment; moreover, it differs from other fuels in that it contains the highest energy content per unit of weight, in fact when compared to gasoline, its energy density proves to be three times higher.
Using it as a fuel does not seem to pose any particular problems, because as already pointed out, its emissions are less polluting than other known fuels.
The fact that the automotive sector has long been interested in hydrogen is not new, but research and experimentation is also quite lively in other contexts such as, for example, the domestic sector and in particular boilers.
Thinking of hydrogen as a fuel would in fact mean:
- producing energy while avoiding emissions of harmful substances
- improving any other fuel as mixing it with hydrogen would increase its efficiency.
Another interesting way to use hydrogen is to power combustion cells (some cars are already equipped with them) or to power devices that provide electricity to the crew on board spaceships, if as liquid fuel.
In order to support high-tech applications Tubiflex has long been active in hydrogen applications to support a global transformation process towards Carbon Neutrality.
Having said all this, the question is rather obvious: why is it not a real energy panacea?
Because its production is not so simple and in nature it is only found combined with other elements such as:
The process then of separating the hydrogen molecule (H2) alone requires not only more energy, but also a significant economic and environmental cost.
Fortunately, however, research into the application and benefits of hydrogen is quite active and responsive, and this will certainly enable suitable and useful solutions to be found so that its use will be increasingly widespread.
Hydrogen as an energy source
Hydrogen as an energy source could be a misleading title, because as mentioned in the first lines of this article, it cannot be considered a source of energy, but a vector of it.
It could be compared to electricity both for its versatility and possible applications, but unlike electricity it is a chemical energy carrier, i.e. characterised both by molecules than by electrons.
The are substantially two ways through which hydrogen can supply energy:
- thanks to combustion
- in combination with oxygen
If in the first case the process can be defined eco-sustainable only in part, in the second case the ecological soul of hydrogen is universally recognized.
Since this is chemical energy, unlike electricity, it can be transported in a stable way, just as it happens with other sources such as: oil, coal or natural gas.
Also due to this molecular nature, hydrogen can be combined with elements such as carbon and nitrogen, so as to produce fuels that can be used as raw materials for different types of industries, helping to reduce emissions of pollutants.
Hydrogen energy of the future
Can we consider hydrogen as the energy of the future?
Undoubtedly it can be considered a fuel in favor of the energy transition and certainly attentive to the theme of climate change, but the current framework cannot overlook the difficulties of its production cycle.
Some of the current technologies to produce it in fact have rather high costs and others are not today “eco-sustainable”.
What is certain is that it is an eclectic resource that could, in the not-too-distant future, support several sectors.
An ambitious project is that of zero emissions by 2050 and to achieve this goal, it is estimated that hydrogen-based fuels (extracted from renewable sources) will have to feed between 10 and 12% of global energy consumption.
Our country has therefore planned a series of investments for the development of hydrogen and certainly a new energy culture is emerging.
The chemical and refining industries have already worked on the use of fossil hydrogen, but other sectors, on the other hand, still require very high costs for their decarbonisation.
Another aspect to consider is the adaptation of production facilities or the need for a restyling of existing ones, so that they can work with hydrogen; this would involve, on the one hand, a more complicated technical management and, on the other hand, huge investments.
However, it remains an opportunity to discover and know, because regardless of what today can still be considered nodes to be solved, the next decades will be significant to consider the hydrogen energy of the future.
The industrial and transport sectors in general are likely to be among the first to benefit from hydrogen. The latter in particular, if electrification is not really a viable alternative, could thanks to hydrogen face a bright future… After all, we have not yet remembered, hydrogen is mainly the fuel of stars.