Reinventing Design Principles for Developing Low-Viscosity Carbon Dioxide-Binding Organic Liquids for Flue Gas Clean Up

Journal Article · Wed Jan 11 00:00:00 EST 2017 · ChemSusChem

DOI:https://doi.org/10.1002/cssc.201601622· OSTI ID:1344632

Anthropogenic carbon dioxide (CO₂) emission from point sources, such as coal fired-power plants, account for the majority of the green houses gasses in the atmosphere. Capture, storage and utilization are required to mitigate adverse environmental effects. Aqueous amine-based CO₂ capture solvents are currently considered the industry standard, but deployment to market is limited by their high regeneration energy demand. In that context, energy efficient and less-viscous water-lean transformational solvent systems known as CO₂ Binding Organic Liquids (CO₂BOLs) are being developed in our group to advance this technology to commercialization. Herein, we present a logical design approach based on fundamental concepts of organic chemistry and computer simulations aimed at lowering solvent viscosity. Conceptually, viscosity reduction would be achieved by systemmatic methods such as introduction of steric hindrance on the anion to minimize the intermolecular cation-anion interactions, fine tuning the electronics, hydrogen bonding orientation and strength, and charge solvation. Conventional standard trial-and-error approaches while effective, are time consuming and economically expensive. Herein, we rethink the metrics and design principles of low-viscosity CO₂ capture solvents using a combined synthesis and computational modeling approach. We critically study the impacts of modyfying factors such as as orientation of hydrogen bonding, introduction of higher degrees of freedom and cation or anion charge solvation and assess if or how each factor impacts viscosity of CO₂BOL CO₂ capture solvents. Ultimately, we found that hydrogen bond orientation and strength is predominantly influencing the viscosity in CO₂BOL solvents. With this knowledge, a new 1-MEIPADM-2-BOL CO₂BOL variant was synthesized and tested, resulting in a solvent that is approximately 60% less viscous at 25 mol% CO₂ loading with respect to our base compound 1-IPADM-2-BOL. The insights gained from the current study redefines the fundamental concepts and understanding of what influences viscosity in concentrated organic CO₂ capture solvents.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1344632
• Report Number(s): PNNL-SA-121959; AA6510000
• Journal Information: ChemSusChem, Vol. 10, Issue 3; ISSN 1864-5631
• Publisher: ChemPubSoc Europe
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES