title: CO2Capture from Ambient Air by Crystallization with a Guanidine Sorbent.
abstract: Carbon capture and storage is an important strategy for stabilizing the increasing concentration of atmospheric CO2and the global temperature. A possible approach toward reversing this trend and decreasing the atmospheric CO2concentration is to remove the CO2directly from air (direct air capture). Herein we report a simple aqueous guanidine sorbent that captures CO2from ambient air and binds it as a crystalline carbonate salt by guanidinium hydrogen bonding. The resulting solid has very low aqueous solubility (Ksp=1.0(4)×10-8), which facilitates its separation from solution by filtration. The bound CO2can be released by relatively mild heating of the crystals at 80-120 °C, which regenerates the guanidine sorbent quantitatively. Thus, this crystallization-based approach to CO2separation from air requires minimal energy and chemical input, and offers the prospect for low-cost direct air capture technologies.
authors.affiliation: Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831-6119, USA.|Department of Chemistry, The University of Texas at Austin, 1 University Station-A5300, Austin, TX, 78712-0165, USA.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Seipp
authors.affiliation: Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831-6119, USA.|Department of Chemistry, The University of Tennessee, Buehler Hall 1420 Circle Dr., Knoxville, TN, 37996-1600, USA.
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Williams
authors.affiliation: Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831-6119, USA.
authors.forename: Michelle K
authors.initials: MK
authors.lastname: Kidder
authors.affiliation: Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831-6119, USA.
authors.forename: Radu
authors.initials: R
authors.lastname: Custelcean
keywords: carbon capture; crystallization; guanidines; hydrogen bonding; sustainable chemistry