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Title: Reversible zwitterionic liquids, the reaction of alkanol guanidines, alkanol amidines, and diamines with CO2

Journal Article · · Green Chemistry, 12(4):713-721
DOI:https://doi.org/10.1039/b924790d· OSTI ID:978938

Carbon dioxide chemistry is increasingly relevant to real-world issues, thanks to global warming. Key chemistry issues currently being studied are the capture, storage, and utilization of CO2. While the relevance of capture and storage are obvious, the relevance of CO2 utilization is less clear. Although CO2 utilization is unlikely to consume significant quantities of CO2, it can be an significant strategy for the development of sustainable processes. As part of our research efforts towards CO2 utilization, some of us invented switchable solvents, meaning solvents that can switch reversibly from one version to another.1Our original version was a mixture of an amidine and an alcohol (equation 1, where B is a liquid amidine), but since then we and others have developed others such as guanidine/alcohol mixtures (equation 1, where B is a liquid guanidine),2 amidine/primary amine mixtures,3 and secondary amines (equation 2).4Switchable solvents of these types all convert from a low-polarity to a high-polarity ionic liquid form upon exposure to an atmosphere of CO2 and revert back to the low polarity form when the CO2 is removed by heat or flushing with inert gas. We also demonstrated that these switchable solvents can be used as reversible CO2-binding organic liquids (CO2BOLs) for CO2 capture, and are more energy-efficient in that role than aqueous solutions of ethanolamine.

Research Organization:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
AC05-76RL01830
OSTI ID:
978938
Report Number(s):
PNNL-SA-69761; TRN: US201010%%288
Journal Information:
Green Chemistry, 12(4):713-721, Vol. 12, Issue 4
Country of Publication:
United States
Language:
English