Yohann Coulier

Dissociation Constants of Protonated Amines in Water at Temperatures from 293.15 K to 343.15 K

The dissociation constants of protonated 2-amino-1-ethanol (MEA), diethanol amine (DEA), triethanol amine (TEA), methyldiethanol amine (MDEA), 2-amino-2-methyl-1-propanol (AMP), 3-dimethylamino-1-propanol (DMAP), tris(hydromethyl)aminomethane (THAM), 2-[2-(dimethylamino)ethoxy]ethanol (DMAEOE) and, 1,2-bis(2-aminoethoxy)ethane (DiAEOE) were determined in the temperature range 293.15 to 343.15 K using a potentiometric titration method. The experimental technique was first validated using as reference the available literature data of MDEA. The dissociation enthalpies of amines were derived from their dissociation constants using the Van’t Hoff equation. Experimental dissociation constants and dissociation enthalpies were discussed in term of amine structure and compared with literature values when available.

Protonation of alkanolamines and cyclic amines in water at temperatures from 293.15 to 373.15 K

Abstract The protonation properties of amines are of particular interest for the development of thermodynamic models representative of CO2 dissolution in aqueous solutions. This paper reports experimental equilibrium constants of protonation of alkanolamines (2-aminoethanol, 2,2′-iminodiethanol, 2-[bis(2-hydroxyethyl)amino]ethanol, 2-amino-2-methylpropan-1-ol, 2,2′-(methylimino)diethanol and cyclic amines (morpholine, 4-methylmorpholine, pyridine, 1-methyl-piperidine, 2-methyl-piperidine, 2,6-dimethylpiperidine). The equilibrium constants of protonation were determined by potentiometric technique up to 353.15 K and extrapolated up to 373.15 K using experimental enthalpies of protonation.

Thermodynamic and Experimental Study of the Energetic Cost Involved in the Capture of Carbon Dioxide by Aqueous Mixtures of Commonly Used Primary and Tertiary Amines.

The capture of carbon dioxide with chemical solvents is one solution to mitigate greenhouse gas emissions from anthropogenic sources and thus tackle climate change. Recent research has been focused on optimizing new kinds of advanced absorbents including aqueous amine blends, but critical downsides such as the large energetic cost involved with the industrial process remain. To address this issue, a better understanding of the energetic interactions existing in solution is necessary. In this paper, we report direct experimental measurements of the energy cost involved in the solvation of CO2 in two aqueous amine blends at different temperatures. The chemical solvents were designed as aqueous mixtures of commonly used primary and tertiary amines to study the influence of the different chemical properties inferred by the amine class. We have also applied a thermodynamic model to represent the energetic effects that take place in solution during CO2 dissolution in these mixtures, where all parameters were taken from previous studies focused on single amine absorbents. The noteworthy agreement observed with the reported experimental heats of absorption and with literature vapor liquid equilibrium properties confirmed the relevance of the underlying molecular mechanisms considered in our model, and suggest that this model would prove useful to investigate CO2 dissolution in other amine blends.