Negative emissions: New process converts CO2 back into coal briquettes

The simulation games to reduce global warming are usually based on two pillars. On the one hand, the international community committed to reducing CO2 emissions in the Paris climate agreement. At the same time, so-called negative emissions are also regularly planned. Specifically, this means: CO2 that has already been emitted should be captured and stored again. How this is to be achieved is currently being tested at various locations. There is a commercial facility in Switzerland that markets the CO2 - for example to beverage manufacturers and greenhouse operators. In Iceland, scientists have also succeeded in turning greenhouse gas underground into solid rock. An international working group is now treading a new path: it plans to convert the CO2 back into solid carbon.
The liquid alloy brought the breakthrough
The end product of the process would then be briquettes, which could be stored underground in old coal tunnels, for example. The process is based on the so-called electro-catalysis. Specifically, a CO2-containing liquid is provided with two rods. One is made of platinum and one is made of a liquid alloy. If you now apply voltage to the two wires, air bubbles rise on the one hand. So the oxygen is separated. But much more important: Small black flakes form on the liquid alloy. The carbon collects there and can be used later. The special feature of the process is the liquid alloy. In the past, solid substances were used here, but the catalysis process stopped after a few minutes - which is no longer the case.
So far, the technology has only been tested in the laboratory
The scientists have already been able to demonstrate in the laboratory that their approach actually works. The small amounts of CO2 that were drawn from the air there are unlikely to have any impact on the future climate. To really become a weapon in the fight against climate change, the technology has to be implemented on a large scale. From a purely technical point of view, this should be possible. But it is also clear that the conversion of CO2 comes at a price. Because electricity is actually converted into chemical energy. So you would need large amounts of energy to achieve the negative emissions. The prerequisite for this is the expansion of renewable energies. Because there would be little point in burning coal to filter CO2 from the air and convert it back into coal.