Verdox Captures Carbon Through Quinone Carboxylation

DACC (Direct Air Carbon Capture) is an area getting huge attention, and the IPCC’s Sixth Assessment Report states explicitly that it is “not an option — targets cannot be met without DACC.”

However, existing technologies (Climeworks, for example) require massive plants, need temperature and pressure swings for adsorption and release (with a large energy load as well), and carry very high costs, among many other challenges.

Verdox, introduced here, is technology out of MIT that holds the potential to solve many of the challenges above.

The YouTube video is below.

This Is CDR Ep. 30: Verdox’s Electrochemical DAC - with Dr. Sahag Voskian and Jonte Boysen

A related paper by CTO Dr. Sahag Voskian.

https://pubs.rsc.org/en/content/articlehtml/2019/ee/c9ee02412c

He has also done research on amine-based approaches elsewhere.

https://pubs.acs.org/doi/abs/10.1021/acssuschemeng.0c02172

There was also an article on this in Japanese.

MIT develops new method for removing low-concentration CO2 from the air

ESA looks like an extension of battery technology

ESA (Electro-Swing Adsorption) is a technology that drives adsorption through an electrical swing (charging and discharging) rather than through temperature or pressure.

It appears to have originated from research on battery electrodes, where a method for fixing gas emerged along the way, which then led to the idea of applying it to carbon capture.

The mechanism is straightforward: charging the device adsorbs CO2, and discharging it releases the CO2.

How quinone fixes CO2

The diagram below makes this easy to understand.

Quinone is essentially a benzene ring with two oxygen atoms attached, and it captures carbon dioxide by undergoing the change shown below.

https://pubs.rsc.org/image/article/2019/EE/c9ee02412c/c9ee02412c-f1_hi-res.gif

Here is a diagram that breaks the process down in a bit more detail.

https://pubs.rsc.org/image/article/2019/EE/c9ee02412c/c9ee02412c-s3_hi-res.gif

Anthraquinone itself turns up elsewhere as a substance that reduces carbon dioxide, including in research on artificial photosynthesis.

https://kaken.nii.ac.jp/ja/file/KAKENHI-PROJECT-25410102/25410102seika.pdf

Concentration

Compared with membrane-based approaches, the key advantage seems to be flexibility across concentration levels. Membrane-based approaches work well within a certain density range, but below that they require vast surface areas and large equipment. Verdox’s quinone-based solution, by contrast, appears to operate stably at any concentration.

The promise of electrical capture (ESA)

Most of the “already realized” solutions in the DACC space use amine-based absorbents: CO2 is adsorbed, then heated inside a chamber to be released and recovered, then compressed into liquid and sent to a pipeline.

This is simply because technological maturation takes time, and because in this space it is more or less common sense that practical application means building a plant (gigaton-scale capture demands nothing less), which inevitably pulls everything toward something plant-like.

Electrical capture needs no large heater, so the equipment stays compact, power consumption stays low, and I can imagine it running here and there off something as small as a solar panel.

I want to push back against the DACC-equals-giant-plant mindset myself (plant engineering isn’t my specialty), and on that point ESA stuck strongly in my mind as one idea worth watching.

Originally published in Japanese at https://clazytech.com/2022/07/910/. Translated with LLM assistance and reviewed before publication.