On social networks more and more stories and videos appear referred to one interesting invention: a system of size similar to an “American” fridge, composed of a minimum of 3 hexagonal structures, capable of capture carbon dioxide from the air to convert it into petrol. The idea of the startup Air based in New York uses a Process already known For the production of synthetic fuels, the so-called e-fuels: in short, the technique is not an absolute novelty, what is honestly admitted also by the startup. The novelties of the proposed system would be in the small and adaptable dimensions and in the fact that it only needs electricity and one water reserve to produce petrol usable from cars. It could therefore operate everywherefrom the home courtyard to remote contexts, without the need for an industrial infrastructure. The first public demonstration, which took place on the roof of a New York building, obviously aroused great interest and sensational titles on many newspapers: the same company, however, declares to not to be able to compete with the cost of petrol from fossil sources. While There are no official indicationssome online newspapers such as The Autopianhypothesize that the cost of the structure could be between $ 15 and 20,000!
How the production of e-Fuels works
Produce fuels starting from carbon dioxide (CO2) And possiblewhether it is simpler compounds such as methanol (the simplest alcohol, ch3Oh) or of More complex mixtures Like modern towel (a mix of 4 to 12 carbon atoms). The process used by Aircela and other similar proposals typically provides for three stadiums:
- Stadium 1: capture of the co2 atmospheric in a liquid solution of reusable potassium hydroxide (KOH)
- Stadium 2: generation of gaseous hydrogen (H2) on site through hydrolysis, to avoid the management and transport of compressed gases
- Stadium 3: Reduction of carbon atom (that is, enriched with electrons) of the carbon dioxide, to allow him to form links with the hydrogen atoms. With a controlled temperature system And metal catalysts is obtained, with which more complex hydrocarbons can be summarized.
The innovation of Activela
The founders of the startup they therefore did not revolutionize the science behind e-fuels: not surprisingly, Aircela’s site underlines the contribution of the “Senior Science Adviser” Klaus LacknerProfessor of Arizona State University who already in 1999 He studied methods to capture carbon dioxide from the air.
What distinguishes the proposal from the plants already in operation in various parts of the world, from South America to Norway, is the idea of reduce size of the system, making it modular and with dimensions adaptable also at needs of private citizens: a transportable product and also usable in remote placesfar from complex infrastructures, to which simply serves a source of electricity (like a series of solar panels) and water.
The structure is divided into Three “Celle A Eragon”: the first includes the CO capture system2while in the second hexagon production takes place hydrogen, which will be used in the summary synthesis reaction, inside the third block.
How sustainable the petrol of Aircela is
The problem of e-fuels is not like producing them, but what they are the economic and energy costs processes. Produce fuelwhatever it is, requires energybut not all the energy used then becomes available to “make the car move” or for other uses: a part is irreparably lost in the processing. We can talk about energy efficiencyin general, as the relationship between a result and how much energy we wanted to obtain it: in the case of a fuel, in particular, how much energy produce a fuel compared to what has been expense To produce it.
There company declares that at the moment the goal is to achieve the 75 kWh per day of electricity used to produce a gallon (approximately 3.8 liters) of petrol, then reaching the 50% efficiency: this means that synthesized petrol can generate half of the energy used to summarize ita value of about 33.7 kWh.
Let’s try to do two calculations with the hypothesis that the company manages to achieve this goal of energy efficiency. If we were to use this petrol in a car, we should also take into account theefficiency of the thermal enginethat is, its ability to transform the chemical energy of fuel into kinetic energy (movement). In modern engines, this can reach a maximum of 40%, but in real conditions it is on average of the 20-25%: the rest of the energy is dispersed in heat and noisedue to the moving parts.
We said that the E-Fuel produced by Aircela would provide 33, 7 kWh of energy, but the engine uses only 25%. In practice, We spent 75 kWh initial and we only get 9.4 kWh to make the car move (50% of production efficiency × 25% engine efficiency = 12.5%)
Even fuel sources “waste” energy, but but to a lesser: the process of oil refining petrol, in the USA, has in fact aefficiency of about 88%. This means that, despite the various refining processes, to which the transport costs between infrastructure and petrol pumps, a fuel from a fossil source should be added It still has 88% of its original energy It is possible to “provide the engine”, instead of 50% that it is the objective.
The theme of energy efficiency is one of the most important ones a favor of electric motorswhich could Use “directly” The 75 kWh with efficiency above 80%: in the case of an electric vehicle, however, the amount of energy lost in batteries storage or distribution on the networkoften neglected losses in counting absolute efficiency.
How much does the petrol produced with the Active system costs
Beyond the efficiency of the process, which could be justified using “green” energy in moments of productive peak as in the case of the sun, it is the cost of energy and production systems to make the petrol synthetic again Too dear.
The Aircela website does not indicate an official estimate of the cost of the structurebut only the goal of reducing it with an industrial production. According to some online newspapers in the automotive sector, the price would oscillate Between 15 and 20 thousand dollars: an investment high at the moment, but that it could already be justified in Remote, Where the possibility of generating fuel on the site without depending on external supplies certainly has a greater attraction.
