Possible Pathways for Oxidative Degradation of β-hydroxyl Alkanolamine for Post-combustion CO2 Capture

Abstract

Solvent degradation due to the presence of oxygen is an important issue for amine-based absorption/stripping process for postcombustion carbon dioxide capture from flue gas streams. There are still some knowledge gaps in the understanding of alkanolamine oxidation so far. To explore possible degradation mechanism of alkanolamines, oxidative degradation of aqueous -hydroxyl alkanolamine solutions without CO 2 loading was investigated in the presence of 250 kPa O 2 at 120 °C. The alkanolamines include monoethanolamine (MEA), 2-amino-2-methyl-1-propanol (AMP), 2-amino-1-propanol (APN), and 2-amino-1-butanol (ABN). The anionic oxidation products were identified by anion chromatography. A possible degradation pathway for the oxidative degradation of the investigated amines is proposed to account for the formation of the carboxylic acid products.

Recent progress and new developments in post-combustion carbon-capture technology with amine based solvents

“…This mechanism has helped in further investigation of the same study to understand the role of MEA in protecting AMP from oxidative degradation when the amines are used together as a blended solvent. This mechanism work has been continued to account for formation of carboxylic acids identified in MEA, AMP, 2-amino-1-propanol (APN), and 2-amino-1-butanol (ABN) during the test (Wang and Jens, 2014). The mechanism of oxidation proposed for these amines was based on radical formation leading to generation of formate, acetate, glycolate, oxalate, and pyruvate.…”

Microwave Regeneration and Thermal and Oxidative Stability of Imidazolium Cyanopyrrolide Ionic Liquid for Direct Air Capture of Carbon Dioxide

“…Made mostly of bulky organic ions, ILs have almost infinite structural and chemical tunability. They are often referred to as “green solvents” or “designer solvents” for their intrinsic physiochemical properties, such as negligible volatility, non‐flammability, good thermal stability, as well as wide electrochemical window [1–5] . ILs demonstrate unique features for a broad spectrum of applications, such as media for synthesis, electrolytes, lubricants, as well as gas separations [5–11] .…”

“…[12] Furthermore, ILs can be functionalized with nucleophilic functionalities that chemically bind with CO 2 . [13] IL based sorbents, with amine, [14][15][16][17][18][19][20] strong base, [21,22] and multiple site cooperative interactions, [23,24] have been extensively studied for post combustion carbon capture and more recently considered for direct air capture (DAC). The distinct environmental difference in DAC from post combustion capture is the presence of significant amount of O 2 in air.…”

“…They are often referred to as "green solvents" or "designer solvents" for their intrinsic physiochemical properties, such as negligible volatility, non-flammability, good thermal stability, as well as wide electrochemical window. [1][2][3][4][5] ILs demonstrate unique features for a broad spectrum of applications, such as media for synthesis, electrolytes, lubricants, as well as gas separations. [5][6][7][8][9][10][11] Specifically, the low volatility and high CO 2 solubility of ILs are appealing in CO 2 separations.…”

Development of a Predictive Model to Correlate the Chemical Structure of Amines with Their Oxidative Degradation Rate in a Post-Combustion Amine-Based CO2 Capture Process Using Multiple Linear Regression and Machine Learning Regression Approaches

“…The hydrolysis of the imine radical then further occurs to produce an aldehyde. , In hydrogen abstraction, the hydrogen is likely extracted from an α- and/or β-carbon to the nitrogen atom and also from the nitrogen itself. Then, an internal and external amine radical transfer is performed to produce ammonium aldehydes and aldehyde radicals as the main degradation products. ,− Figure shows a simplified initial step of the radical-based oxidative degradation pathway of the amine.…”