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Title: CO 2 Capture from Ambient Air by Crystallization with a Guanidine Sorbent

Carbon capture and storage is an important strategy for stabilizing the increasing concentration of atmospheric CO 2 and the global temperature. A possible approach toward reversing this trend and decreasing the atmospheric CO 2 concentration is to remove the CO 2 directly from air (direct air capture). In this paper, we report a simple aqueous guanidine sorbent that captures CO 2 from ambient air and binds it as a crystalline carbonate salt by guanidinium hydrogen bonding. The resulting solid has very low aqueous solubility (K sp=1.0(4)×10 -8), which facilitates its separation from solution by filtration. The bound CO 2 can be released by relatively mild heating of the crystals at 80–120 °C, which regenerates the guanidine sorbent quantitatively. Finally and thus, this crystallization-based approach to CO 2 separation from air requires minimal energy and chemical input, and offers the prospect for low-cost direct air capture technologies.
 [1] ;  [2] ;  [1] ;  [2] ;  [1] ;  [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division
  2. (United States). Dept. of Chemistry
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Angewandte Chemie (International Edition)
Additional Journal Information:
Journal Name: Angewandte Chemie (International Edition); Journal Volume: 56; Journal Issue: 4; Journal ID: ISSN 1433-7851
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Contributing Orgs:
Univ. of Tennessee, Knoxville, TN (United States); Univ. of Texas, Austin, TX (United States)
Country of Publication:
United States
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; carbon capture; crystallization; guanidines; hydrogen bonding; sustainable chemistry
OSTI Identifier: