CO emissions₂ are a real enemy for the climate and ecology. They are constantly climbing around the world. This is why numerous methods are being sought in order to reduce emissions of greenhouse gases.

In the European Union, the objective is to reach climate neutrality by 2050. It is therefore necessary to accelerate in order to capture CO₂ and store it. However, Is it possible to turn carbon dioxide into fuel? SirEnergies tells you more.

How to capture CO₂ ?

Numerous techniques exist for capture CO₂ already present in the atmosphere. Even if it is not the most present particle (nitrogen dominates in the atmosphere), it is essential to reduce the presence of carbon dioxide because it retains heat. It is therefore an issue of fight against climate change.

Direct CO capture₂ In the air

Known under the acronym DAC, this device requires a very significant amount of energy. Because of the low presence of CO₂ compared to nitrogen, it is difficult to absorb all the particles in the atmosphere.

That is why important machines have been put in place. They consist of suck up the ambient air through large fans and pass this air through a filter that contains chemicals. Thanks to these, it is possible to preserve CO₂ concentrate and then put it into storage underground after mixing with water.

However, these installations have a certain cost and are very few in number at present. Even though the largest CO capture plant₂ was created in Iceland, near the Fagradalsfjall volcano last September, there are only 19 installations of this kind all over the world.

Hope is still allowed with this new factory called Orca. By capturing CO₂ of the air, the latter will then transfer it to a neighboring installation so that the latter stores it in a basalt layer. The CO₂ will then be kept for many years.

CO capture and storage₂

This technique is very popular with manufacturers, who see in it an advantage of reduce their CO emissions₂. Called CCS (Carbon Capture) And Storage), this device has existed for many years, but is tending to be developed in the future. Two techniques can be applied in order to capture CO₂ :

• “post-combustion” smoke capture: by this method, it is possible to recover CO₂ by cleaning the smoke created by combustion using chemical products;
• oxycombustion capture: through more concentrated smoke, CO₂ is extracted more easily from combustion carried out with pure oxygen.

There is a third technique that can be very useful for CO transformation₂ In fuel. This is CCUS (Carbon Capture, Utilization and Storage). This method is still in the laboratory stage.

How to store CO₂ to keep it?

In order to store CO₂, some methods can be very simple. By recovering the gas emitted by thermal power plants or factory chimneys, it is possible to conserve CO₂ with some appliances and then to separate it from the other gases.

A chemical reaction will then be created during compression in order to liquefy it and keep it in the rock for several thousand years. However, this can have a cost and create certain risks for the population. In particular, we can fear the occurrence of earthquakes due to the conservation of CO₂ underground. Massive leaks could also cause human asphyxiation.

This is why two devices are being studied in order to safely store this gas.

Deep saline aquifers

It's a great storage solution. Located at great depths, these water tanks have a capacity of up to 10,000 Gt. Well distributed all over the planet, it is now necessary know the sustainability of storage in these aquifers.

Depleted hydrocarbon deposits

Researchers who have studied the subject are familiar with these structures. They were very practices for conserving CO₂ and can be reused later. However, their storage capacity is limited compared to saline aquifers.

How to transform CO₂ In fuel?

Because of its harmful effects on the environment, CO₂ needs to be changed to a safer product. This is why many researchers are trying to find solutions in order to transform CO₂ into a fuel. This is particularly useful in order to Replace the fossil resources By renewables.

The creation of DME

This is particularly the case for the production of DME (dimethylether). Very useful for heavy vehicles, this fuel is trying to be obtained by CO conversion₂. Two steps are necessary in order to obtain this fuel:

• the gas is hydrogenated in order to obtain methanol;
• the methanol obtained is then dehydrated to constitute DME.

In order to perform these two steps, the researchers tried to design a hybrid catalyst which allows both hydrogenation and dehydration to be carried out. However, they had to resolve to keep a catalyst for each stage to get the most out of their liquid fuel. The development of catalytic systems is under way in order to obtain a perfect conversion of CO₂ in DME, with the absorption of water formed during the chemical reaction.

The photosynthesis of a plant

French researchers are also looking for a way to create fuel with carbon dioxide. They were able to photosynthesize a plant.

The latter in fact makes it possible to capture CO₂ In order to produce organic matter. Thanks to this photosynthesis, it was possible to produce ethylene. Ethanol could also be possible to make. However, it is necessary to see how it is possible to properly store and then transform CO₂ on a larger scale.

Alternative engines for airplanes

Other researchers have thought of a much more revolutionary idea: to recover the carbon dioxide emitted by airplanes to transform it into jet fuel, all in mid-flight.

This team of English researchers succeeded in their endeavor by creating this system. The latter allows create carbon neutral fuel. Canadian researchers had the idea of capturing CO₂ air to transform it into synthetic fuel.

There are therefore many ideas to transform CO₂ in fuel. For the most part, they are at the project stage. Even though many businesses support these ideas, it's going to be many more years before any of these projects take shape on a large scale.

Do not hesitate to read our article which answers another question: Is it possible to supply an entire country with renewable energy?