Invention Reference Number
Direct capture of carbon dioxide from the air, as well as in scrubbing carbon dioxide from industrial exhausts, has an important role in climate change mitigation. One promising technology for carbon capture at the gigaton scale is mineral looping, but this has challenges. In a looping process, the sorbent is calcined to separate carbon dioxide and regenerates the sorbent. However, the sorbent can sinter or partially recrystallize during calcining, leading to a reduction in its surface area and thus its carbon dioxide capture capacity. This technology is a method to increase the surface area of sorbent magnesium oxide to overcome sintering impacts and increase the rate of carbon capture.
Description
This technology for carbon capture is a treatment of magnesium oxide with water vapor under pressure at an elevated temperature to increase the surface area and thus, increase the carbonation efficiency. Existing carbon capture technologies are expensive and require the use an air contactor-like fans or scrubbers that pass a large amount of carbon dioxide in the air past a solvent or sorbent. This generates a significant capital cost, and potentially additional run-time expenses. Mineral looping can, however, also be envisioned as a passive technology where no air contactor is required, as long as the carbon-capture process is suitably fast. After capture, however, carbon dioxide must be separated from the sorbent by calcining. However, during this calcining step, sintering of the sorbent can occur which reduces the surface area, thus decreases the carbon dioxide capture capacity, and shortening the lifetime of the sorbent. This technology is a method to increase the surface area of magnesium oxide to overcome sintering impacts by pretreating magnesium oxide. This increases the amount of carbon captured and extends the lifetime of the sorbent. Surface area increases of up to 1,300% were observed using this technology. The magnesium oxide is pretreated with water vapor under pressure. This dramatically decreases the carbon dioxide sorption time, and requires a lower temperature, and thus less energy, to regenerate magnesium oxide, and greatly improves the efficiency of carbon capture.
Industries and Applications
- Direct air capture of carbon dioxide
- Any industry that needs to scrub carbon dioxide from its systems
- Low carbon cements
- Beverage companies
Benefits
- More efficient process
- Less costly
- Less energy required
- Contributes to net-zero carbon goals
Contact
To learn more about this technology, email partnerships@ornl.gov or call 865-574-1051.
