Steric bulk controls CO(2) absorption: N-substituted amino acid salts in poly(ethylene glycol) reversibly absorb CO(2) in nearly 1:1 stoichiometry. Carbamic acid is thought to be the absorbed form of CO(2); this was supported by NMR and in situ IR spectroscopy, and DFT calculations. The captured CO(2) could be converted directly into oxazolidinones and thus CO(2) desorption could be sidestepped.

Equimolar CO2 Capture by N‐Substituted Amino Acid Salts and Subsequent Conversion

Phase change solvents for post-combustion CO2 capture: Principle, advances, and challenges

CO2 absorption studies in amino acid-anion based ionic liquids

Carbon capture and storage (CCS) is now known to be an effective way to reduce greenhouse gas emissions especially CO2 to the atmosphere. Amino acid salt (AAS) solutions are regarded as promising CO2 absorbents compared to traditional amine solutions, as they are environmentally being with lower evaporation as well as fewer degradation issues. This paper is intended to review recent developments in CO2 capture using AASs. The thermodynamics and kinetics of CO2 and different AASs are illustrated in detail. We will also discuss the blended solutions containing AASs in terms of applications and absorption or regeneration performance. Additionally, we will present specific directions for future research on CO2-AAS systems. This paper could provide a guideline for effective carbon capture by new absorbents.

Effectiveness of amino acid salt solutions in capturing CO2: A review

A review of chemical absorption of carbon dioxide for biogas upgrading

Aqueous solutions containing alkaline salts of carboxylic or sulfonic amino acids represent candidate solvents with good potential for carbon dioxide (CO2) capture. In the present work, the CO2 reactions with potassium salts of glycine (aminoacetic acid) and taurine (2-aminoethanesulfonic acid) in aqueous solutions are investigated using a stirred-cell reactor. The reaction pathways are comprehensively described using the zwitterion and the termolecular mechanism. The investigated reactions belong to the fast pseudo-first-order reaction regime systems. The second-order rate constant for the CO2 reaction with potassium glycinate is determined, and its value at 303 K is evaluated to be 6.29 m3/(mol s). The liquid-side mass-transfer coefficient is estimated, and its value (0.006 cm/s) is consistent with those typical for stirred-cell reactors. Finally, it is determined that potassium glycinate promotes the activity of tertiary amines (e.g., N,N-diethylethanolamine).

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Kinetics of Carbon Dioxide Removal by Aqueous Alkaline Amino Acid Salts

N,N-Diethylethanolamine (DEEA) is a very promising absorbent for CO2 removal from gaseous streams, as it can be prepared from renewable resources. Aqueous mixtures of DEEA and piperazine (PZ) are attractive for the enhancement of CO2 capture, due to the high CO2 loading capacity of DEEA and high reactivity of PZ. In the present work, for the first time, the equilibrium and kinetic characteristics of the CO2 reaction with such mixtures were considered. Kinetic data were obtained experimentally, by using a stirred cell reactor. These data were interpreted using a homogeneous activation mechanism, by which the investigated reaction was considered as a reaction between CO2 and DEEA in parallel with the reaction of CO2 with PZ. It is found that, in the studied range of temperatures, 298−308 K, and overall amine concentrations, 2.1−2.5 kmol/m3, this reaction system belongs to the fast pseudo-first-order reaction regime systems. The second-order rate constant for the CO2 reaction with PZ was determined from the ...

Kinetics of removal of carbon dioxide by aqueous solutions of N,N-diethylethanolamine and piperazine.

Publisher Summary CO 2 represents an undesirable component in a variety of industrial gases and it has to be removed down to very low concentrations to meet the required specifications. Although a number of different CO 2 separation technologies are available by now, chemisorption with alkanolamines represents the most feasible option, and it is commonly used in the gas processing industry. Industrially important alkanolamines for CO 2 removal are the primary amine, monoethanolamine (MEA), the secondary amine, diethanolamine (DEA), and the tertiary amine, methyldiethanolamine (MDEA). N,N-Diethylethanolamine (DEEA), which can be prepared from renewable resources, represents a candidate alkanolamine having good potential for the bulk removal of CO 2 from gaseous streams. A blend comprising DEEA, piperazine (PZ), and H2O, which combines the high CO 2 loading capacity of DEEA with the high reactivity of PZ, is attractive for the enhancement of CO 2 capture. The investigated reaction is considered as a reaction between CO 2 and DEEA in parallel with the reaction of CO 2 with PZ. The CO 2 –DEEA–PZ system belongs to the fast pseudo-first-order reaction systems.

Prashanti B. Konduru

Papers

Kinetics of Carbon Dioxide Removal by Aqueous Alkaline Amino Acid Salts

Kinetics of removal of carbon dioxide by aqueous solutions of N,N-diethylethanolamine and piperazine.

Activated DEEA Process for CO2 Capture