Capture and convert carbon dioxide? Doing this at the same time saves energy

In order to achieve climate goals, we can hardly use CO2₂– Pick up. Both seize carbon dioxide₂ However, converting to another substance requires a lot of energy. Combining operations then saves money.

Carbon dioxide capture is one of the weapons in the fight against global warming₂ From the air. Even if we succeed in reducing emissions significantly, we cannot achieve the goal of keeping warming below 1.5 degrees if we also reduce carbon dioxide emissions.₂ to ban. The gas can then be stored or converted into fuels or other chemicals. Both capture and convert carbon dioxide₂ However, it consumes a lot of energy.

If we connect the two processes, the whole thing becomes more energy efficient, writes a group of engineers from the California Institute of Technology (Caltech) in the US and TU Delft now in the scientific journal stimulating nature. This can be done in different ways, with energy gains being achieved in different parts of the process: CO2 transport savings can be achieved₂ From the capture site to the conversion plant, or to capture and release carbon dioxide₂ of the capture fluid.

because of CO₂ At the request of De Engineers. “But we didn’t account for that exactly in the article.”

How it works?

Carbon dioxide is captured conventionally₂ By allowing it to bind with an absorbent, for example with amines or other chemical compounds, and then releasing it again at a high temperature or voltage. After that, carbon monoxide was released₂ It is transformed by interaction with water, at an electrode through which a current flows.

Instead of these two separate processes, engineers suggest that the CO2 complex₂ The absorbent is brought into direct contact with the electrode that contains carbon dioxide₂ can convert, so that CO₂ It doesn’t need to scan first.

However, a lot of research is still needed, Vermas says. We do not yet know what catalysts we should use for the direct conversion of carbon dioxide₂complex, so in practice the reaction rate is rather slow. Much lower than we expected based on CO₂-concentration. The combination of capture and conversion is still in its infancy, and it motivates me even more to investigate this matter.

Is it still necessary?

But is it still necessary to CO₂ Families, if we go to CO₂– Get a neutral power source? Vermaas, in a press release from TU Delft: At the moment, we still have processes that require hydrocarbons. For long-distance transportation, for example, or for materials such as cement and plastic. Although the world in 2050₂If we want to be neutral, we will continue to get ten to fifteen percent of our energy from conventional fuels.

Other research

Elsewhere, too, researchers are trying to devise the most efficient way to absorb carbon dioxide.₂ to get it out of the air. For example, 23 student teams were allowed to distribute $5 million from Elon Musk’s fund last week after winning a competition for the best CO.₂Relocation plan. Ideas ranged from growing seaweed on abandoned oil rigs to incorporating captured carbon dioxide₂ With mining waste, to be later disposed of as limestone.

point sources

To get enough carbon dioxide₂ To capture it, it wouldn’t be enough to focus on point sources – like factory chimneys, for example – but they would also take up carbon dioxide.₂ which are more widely distributed in the air or ocean waters. The best way to do this is to use CO₂ of ocean waters, the Vermaas team wrote earlier this year. Vermas: Contains five hundred times more carbon dioxide₂ Then in the air. You can read more about this in our back article at The engineer from last summer.

Opening image: TU Delft

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