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

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. In this work, 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 specificmore » 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.« less

Authors:

Banuelos, Jose L. ^[1]; Lee, Mal-Soon  ^[2];

• Search DOE PAGES for author "Lee, Mal-Soon"
• Search DOE PAGES for ORCID "0000-0001-6851-177X"

Nguyen, Manh-Thuong ^[2]; Zhang, Difan ^[2]; Malhotra, Deepika ^[2]; Cantu Cantu, David ^[2]; Glezakou, Vassiliki-Alexandra  ^[2];

• Search DOE PAGES for author "Glezakou, Vassiliki-Alexandra"
• Search DOE PAGES for ORCID "0000-0001-6028-7021"

Rousseau, Roger J. ^[2]; Headen, Thomas F. ^[3]; Dalgliesh, Robert ^[3]; Heldebrant, David J.  ^[2];

• Search DOE PAGES for author "Heldebrant, David J."
• Search DOE PAGES for ORCID "0000-0002-5529-526X"

Graham, Trenton R.  ^[4];

• Search DOE PAGES for author "Graham, Trenton R."
• Search DOE PAGES for ORCID "0000-0001-8907-8004"

Han, Kee Sung ^[2]; Saunders, Steven R. ^[5]

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+ Show Author Affiliations

1. Univ. of Texas at El Paso, TX (United States)
2. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
3. Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab., ISIS Neutron Source
4. Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Washington State Univ., Pullman, WA (United States)
5. Washington State Univ., Pullman, WA (United States)

Publication Date:

Thu Aug 13 00:00:00 EDT 2020

Research Org.:

Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF)

OSTI Identifier:

1673419

Alternate Identifier(s):

OSTI ID: 1647882

Report Number(s):

PNNL-SA-153262
Journal ID: ISSN 1463-9076

Grant/Contract Number:  

AC05-76RL01830; FWP 67038; DMR-0520547; AC02-05CH11231

Resource Type:

Accepted Manuscript

Journal Name:

Physical Chemistry Chemical Physics. PCCP

Additional Journal Information:

Journal Volume: 22; Journal Issue: 34; Journal ID: ISSN 1463-9076

Publisher:

Royal Society of Chemistry

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY