• Home
  • Search Results
  • Subtle changes in hydrogen bond orientation result in glassification of carbon capture solvents.

Subtle changes in hydrogen bond orientation result in glassification of carbon capture solvents.

Physical chemistry chemical physics : PCCP (2020-08-19)
José Leobardo Bañuelos, Mal-Soon Lee, Manh-Thuong Ngyuen, Difan Zhang, Deepika Malhotra, David C Cantu, Vassiliki-Alexandra Glezakou, Roger Rousseau, Thomas F Headen, Robert M Dalgliesh, David J Heldebrant, Trent R Graham, Kee Sung Han, Steven R Saunders
ABSTRACT

Water-lean CO2 capture solvents show promise for more efficient and cost-effective CO2 capture, although their long-term behavior in operation has yet to be well studied. New observations of extended structure solvent behavior show that some solvent formulations transform into a glass-like phase upon aging at operating temperatures after contact with CO2. The glassification of a solvent would be detrimental to a carbon-capture process due to plugging of infrastructure, introducing a critical need to decipher the underlying principles of this phenomenon to prevent it from happening. We present the first integrated theoretical and experimental study to characterize the nano-structure of metastable and glassy states of an archetypal single-component alkanolguanidine carbon-capture solvent and assess how minute changes in atomic-level interactions convert the solvent between metastable and glass-like states. Small-angle neutron scattering and neutron diffraction coupled with small- and wide-angle X-ray scattering analysis demonstrate that minute structural changes in solution precipitae reversible aggregation of zwitterionic alkylcarbonate clusters in solution. Our findings indicate that our test system, an alkanolguanidine, exhibits a first-order phase transition, similar to a glass transition, at approximately 40 °C-close to the operating absorption temperature for post-combustion CO2 capture processes. We anticipate that these phenomena are not specific to this system, but are present in other classes of colvents as well. We discuss how molecular-level interactions can have vast implications for solvent-based carbon-capture technologies, concluding that fortunately in this case, glassification of water-lean solvents can be avoided as long as the solvent is run above its glass transition temperature.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Dehydroabietic acid, ≥95% (LC/MS-ELSD)