Anhydrous tertiary alkanolamines as hybrid chemical and physical CO<sub>2</sub>capture reagents with pressure-swing regeneration

Rainbolt, James E.; Koech, Phillip K.; Yonker, Clement R.; Zheng, Feng; Main, Denise M.; Weaver, Matt L.; Linehan, John C.; Heldebrant, David J.

doi:10.1039/c0ee00506a

Cited by 63 publications

(53 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, CO 2 loading for AEDA/DMSO solution (Supplementary Material, Figs. S10.1, S10.3, top) is very similar to CO 2 loading for EEA/DMSO solution (Figure 9) over the broad concentration 30 range. Thus, reaction equilibrium appears primarily controlled by the DMSO solvent, and the acetyl group of AEDA is not providing the necessary properties to intramolecularly stabilize a product having 1 CO 2 per amine molecule.…”

Section: Scheme 15 Intramolecular Stabilization Of a Carbamic Acid Bsupporting

confidence: 56%

See 1 more Smart Citation

In Situ Nuclear Magnetic Resonance Mechanistic Studies of Carbon Dioxide Reactions with Liquid Amines in Non-aqueous Systems: Evidence for the Formation of Carbamic Acids and Zwitterionic Species

et al. 2015

View full text Add to dashboard Cite

In a previous study, we reported the use of in situ 1 H-and 13 C-NMR to elucidate mechanistic pathways for the reaction of carbon dioxide with a broad range of amines (pKa ~4.5-15.5), including alkanolamines of commercial interest, in water. In the aqueous systems of that study, water most importantly functions as a Brønsted acid/Lewis base and as the amine is consumed and pH decreases hydrolyzes the initially formed carbamate species (1:2 CO 2 :amine stoichiometry), into the alkyl ammonium bicarbonate with a more beneficial 1:1 CO 2 :amine stoichiometry. This study has been extended herein to amines, amidines and guanidines dissolved in non-aqueous solvent systems such as dimethylsulfoxide, sulfolane, toluene, 1-methyl-2-pyrrolidinone and the ionic liquid 1-ethyl-3-methyl-imidazolium acetate. The use of non-aqueous organic solvents shuts off some CO 2 reaction pathways available in aqueous solution. However, more importantly, it opens up new possibilities and reaction pathways for amine based carbon capture. Two important aqueous-system pathways are eliminated: the direct hydration of CO 2 with tertiary amines or guanidines to form bicarbonates, and the hydrolysis of carbamates at lower pH to form bicarbonates. In non-aqueous solution, the initial step for the reaction of primary and secondary amines with CO 2 is the same as in aqueous solution -nucleophilic attack by the amine nitrogen on CO 2 . However, additional mechanistic pathways are enabled in non-aqueous solvents, particularly the stabilization of carbamic acid(s) (rather than carbamates) products in certain organic solvents. The formation of carbamates requires no water and is favored by higher amine concentrations and basicities (higher amine pKa). In contrast, carbamic acid/zwitterion formation is favored by lower amine concentrations, higher CO 2 partial pressures, lower amine pKa, and selection of more polar organic solvents that promote hydrogen bonding. The new amine-CO 2 reaction pathways enabled here by the use of non-aqueous solvents introduce stabilizing interactions between the non-aqueous solvent and the amine-CO 2 reaction products, facilitating higher capacity and selectivity for carbon capture than in water solutions. The effects of temperature, amine basicity, solvent electronic structures, and concentration on amine-CO 2 reaction products (carbamic acid/zwitterion/carbamate and equilibria between neutral and ion-paired forms) are discussed in detail herein.

show abstract

Section: Scheme 15 Intramolecular Stabilization Of a Carbamic Acid Bsupporting

confidence: 56%

“…Recently developed NMR techniques have provided new fundamental insights into CO 2 -removal reaction mechanisms [27][28][29][30][31][32][33][34] . The use of titration 35,32 and FTIR for mechanistic studies has been reported 29,36-38 but quantification and real time / flow unit identification of unexpected species is cumbersome.…”

Section: Introductionmentioning

confidence: 99%

In Situ Nuclear Magnetic Resonance Mechanistic Studies of Carbon Dioxide Reactions with Liquid Amines in Non-aqueous Systems: Evidence for the Formation of Carbamic Acids and Zwitterionic Species

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Numerous sorbents have been developed for postcombustion CO 2 capture, which include alkanolamines (Rochelle, 2009;Rodriguez et al, 2011;Bishnoi and Rochelle, 2002;Rainbolt et al, 2011;Faramarzi et al, 2009), diamines (Zhou et al, 2010;Speyer et al, 2010), chilled ammonia (Peltier, 2008;Darde et al, 2010), CO 2 -binding organic liquids Zhang et al, 2013;Mathias et al, 2013), non-amine based solvents (Li et al, 2005;Chang et al, 2013), ionic liquids (Bates et al, 2002;Bara et al, 2009;Shannon et al, 2013), and phase-changing sorbents (Perry et al, 2010(Perry et al, , 2012. Monoethanolamine (MEA) has been the most extensively studied solvent for CO 2 capture applications (Rochelle, 2009;Liu et al, 1999;Freguia and Rochelle, 2003;Fan et al, 2009;Conway et al, 2011;Han et al, 2011;Zhu et al, 2012;Supap et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Aqueous hydrazine as a promising candidate for capturing carbon dioxide

Lee

You

et al. 2014

International Journal of Greenhouse Gas Control

View full text Add to dashboard Cite

“…For propargylic amines, the amino group is prone to activation by TEOA base, and CO 2 can also be activated by TEOA to form az witterionic ammonium carbonate adduct. [36][37][38] Therefore, the mechanisms for amino-activated and CO 2 -activated reaction pathways were investigated by DFT calculations, respectively. The amino-activated mechanism and its free energy profiles are depictedinS cheme 2and Figure2,respectively.The details for the optimized geometries of the transition states are shown in the Supporting Information.…”

Section: Possiblereaction Mechanismmentioning

confidence: 99%

An Experimental and Theoretical Study on the Unexpected Catalytic Activity of Triethanolamine for the Carboxylative Cyclization of Propargylic Amines with CO₂

Zhang

Qiu

et al. 2017

ChemSusChem

View full text Add to dashboard Cite

Chemical conversion of CO under atmospheric pressure and metal-free conditions remains a great challenge. In this work, a series of alkanolamines, low-cost and biodegradable bases, were used to catalyze the carboxylative cyclization of propargylic amines with CO . Among these alkanolamines, triethanolamine (TEOA) was found to be a highly efficient organocatalyst for this important transformation at atmospheric pressure, and a series of desired products were synthesized in good to excellent yields. After the reactions, TEOA could be easily recovered and reused without obvious reduction in the efficiency. DFT studies revealed that TEOA may activate CO to form a ring-shaped carbonate intermediate that plays an important role in the catalysis of the reaction. This finding provides an effective and environmentally friendly alternative route for the production of 2-oxazolidinones.

show abstract

Anhydrous tertiary alkanolamines as hybrid chemical and physical CO₂capture reagents with pressure-swing regeneration

Cited by 63 publications

References 14 publications

In Situ Nuclear Magnetic Resonance Mechanistic Studies of Carbon Dioxide Reactions with Liquid Amines in Non-aqueous Systems: Evidence for the Formation of Carbamic Acids and Zwitterionic Species

In Situ Nuclear Magnetic Resonance Mechanistic Studies of Carbon Dioxide Reactions with Liquid Amines in Non-aqueous Systems: Evidence for the Formation of Carbamic Acids and Zwitterionic Species

Aqueous hydrazine as a promising candidate for capturing carbon dioxide

An Experimental and Theoretical Study on the Unexpected Catalytic Activity of Triethanolamine for the Carboxylative Cyclization of Propargylic Amines with CO₂

Contact Info

Product

Resources

About

Anhydrous tertiary alkanolamines as hybrid chemical and physical CO2capture reagents with pressure-swing regeneration

Cited by 63 publications

References 14 publications

In Situ Nuclear Magnetic Resonance Mechanistic Studies of Carbon Dioxide Reactions with Liquid Amines in Non-aqueous Systems: Evidence for the Formation of Carbamic Acids and Zwitterionic Species

In Situ Nuclear Magnetic Resonance Mechanistic Studies of Carbon Dioxide Reactions with Liquid Amines in Non-aqueous Systems: Evidence for the Formation of Carbamic Acids and Zwitterionic Species

Aqueous hydrazine as a promising candidate for capturing carbon dioxide

An Experimental and Theoretical Study on the Unexpected Catalytic Activity of Triethanolamine for the Carboxylative Cyclization of Propargylic Amines with CO2

Contact Info

Product

Resources

About

Anhydrous tertiary alkanolamines as hybrid chemical and physical CO₂capture reagents with pressure-swing regeneration

An Experimental and Theoretical Study on the Unexpected Catalytic Activity of Triethanolamine for the Carboxylative Cyclization of Propargylic Amines with CO₂