Invention Reference Number
Direct air carbon capture (DAC) is needed to reduce atmospheric carbon dioxide concentrations. DAC can be performed using sorbents, which need to be continuously regenerated and recycled. Regeneration requires thermal energy. Based on direct steam stripping, this technology is a cost-effective and energy-efficient regeneration process for solid sorbents used for DAC. Steam regeneration is expected to avoid sorbent degradation. Furthermore, this system will significantly increase the regeneration rate, simplify the overall carbon dioxide capture process, and reduce energy costs compared to conventional conductive thermal regeneration. The technology consists of a direct-steam sorbent regeneration reactor that could efficiently regenerate the CO2 sorbent with up to 99% release of CO2 through direct steam exposure.
Description
Direct steam stripping for sorbent regeneration involves using superheated steam from a turbine in the desorption column for CO2 stripping. This approach significantly increases the regeneration rate, simplifies the overall carbon dioxide capture process, and reduces energy costs compared to conventional conductive thermal regeneration. This is more efficient and cost effective compared to conventional boiler stripping. In this technology, the processes are conducive to facilitating the transport and recycling of the sorbent, thereby achieving process intensification. This direct-steam sorbent regeneration reactor shows that solid bis(iminoguanidines) (BIGs), specifically methylglyoxal-bis(iminoguanidine) (MGBIG), could be efficiently regenerated with up to ~99% carbon dioxide recovery through direct steam exposure. With low-temperature direct steam heating, this system can achieve 3.5 times faster regeneration rate of the sorbent compared to the time needed for conductive heating regeneration. Further, fully regenerated MGBIG can be converted into an aqueous MGBIG solution when the steam condenses onto the solid surface. This condensed steam, aqueous solution, can be easily recycled into the contactor upstream to achieve a continuous-flow direct-air-capture process.
Applications and Industries
- Carbon capture and use
Benefits
- Faster, less expensive, more efficient carbon capture and recycling
Contact
To learn more about this technology, email partnerships@ornl.gov or call 865-574-1051.
