Adsorption Of Monoethanolamine Research Articles

Density Functional Theory Study of Monoethanolamine Adsorption on Hydroxylated Cr2O3Surfaces

The adsorption of monoethanolamine (MEA), a well-known CO2 capture amine, on the hydroxylated (0001)-Cr2O3 surface was investigated by periodic density functional theory calculations and complementary ab initio molecular dynamics. Two different adsorption modes were investigated: adsorption of MEA above the hydroxylated surface and substitution of a surface water molecule by MEA. Several MEA coverages were studied from 0.25 to 1 monolayer. An atomistic thermodynamic approach was used to take into account the effects of temperature and solvation on the MEA adsorption process in aqueous solution. MEA can adsorb on the surface in a parallel orientation, and H-bonds are formed between amine and alcohol groups and different (H)OH groups at the surface. In the gas phase at 0 K, the formation of a monolayer (ML) of MEA above the surface is the most favorable adsorption mode. In aqueous solution at 298.15K, calculations have suggested that MEA adsorbs above the hydroxylated Cr2O3 surface with a density of 2.37 ME...

Time-dependent electrochemical behavior of carbon steel in MEA-based CO2 capture process

Time-dependent electrochemical behavior of carbon steel was evaluated in CO2-loaded monoethanolamine (MEA) solutions in simulated carbon capture environments. Tests were conducted in 30wt.% MEA solution with different combinations of controlling factors (oxygen [O2], heat stable salts [HSS], flow and temperature) for 7 days. Corrosion behavior of carbon steel was evaluated by using electrochemical techniques (linear polarization resistance [LPR] and potentiodynamic polarization measurements), weight loss method and surface analytical techniques. Solution pH and ferrous/ferric ion concentration were also measured to monitor the change of water chemistry with time. The results showed that the corrosion rate of carbon steel decreased with time and then stabilized to very low values in the MEA/CO2 condition. XPS characterization revealed formation of a very thin protective FeCO3 layer on the surface, as well as adsorption of MEA. However, when O2 was present in the system, the corrosion rates remained at relatively high values, further increasing with flow. The presence of HSS resulted in a higher corrosion rate at the initial stage, but had a minimal effect on the corrosion rate for longer time exposure. Temperature had a slight effect on the corrosion rate because the solubility of CO2 and O2 decreases with increasing temperature.

Monoethanolamine Adsorption on TiO2(110): Bonding, Structure, and Implications for Use as a Model Solid-Supported CO2 Capture Material

We have studied the adsorption of monoethanolamine (MEA, HO(CH2)2NH2), a well-known CO2 capture molecule, on the rutile TiO2(110) surface using a combined experimental and theoretical approach. X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure spectroscopy, and scanning tunneling microscopy measurements indicate that MEA adsorbs with the oxygen atom of the hydroxyl group and the nitrogen atom of the amine group bonded to adjacent 5-fold coordinated Ti-sites (Ti(5f)) in the Ti-troughs, leading to a saturation coverage of 0.5 ML at room temperature. Density functional theory calculations confirm that this adsorption configuration is the most stable one with an adsorption energy of 2.33 eV per MEA molecule. The bonding of MEA to TiO2(110) is dominated by local donor–acceptor bonds between the oxygen and nitrogen atoms of the MEA molecule and surface Ti(5f) sites. Hydrogen bonds between adjacent MEA molecules stabilize the adsorption structure at saturation coverage. The implications of this bonding configuration for the use of MEA/TiO2(110) as a model CO2 capture material will be discussed.

Copper monoethanolamine adsorption in wood and its relation with cation exchange capacity (CEC)

Abstract To investigate the chemical adsorption capacity of copper-monoethanolamine (Cu-Mea) components on wood, the Na+ cation exchange capacity (CEC) of red pine (Pinus resinosa Ait.) was determined and compared with the adsorption capacity of free Mea, Cu2+ and Cu-Mea complexes. Red pine showed higher CEC as pH increased. Free Mea adsorption as a function of pH followed the Na adsorption curve except at pH over 9, when it exceeded the CEC. Below pH 5, where Cu-Mea complexes do not form, divalent Cu2+ was adsorbed as if it were monovalent. Cu-Mea adsorbed up to the CEC at pH 9.0–9.5 apparently as [CuMea]+, whereas the complex in solution is predominantly of the form [Cu(Mea)2]+. FTIR analysis showed that the same sites of wood are related to Mea, Na, and Cu adsorption.

Rate and extent of adsorption of ACQ preservative components in wood

Abstract The adsorption of copper, [as Cu(II)], monoethanolamine (MEA) and didecyldimethyl ammonium chloride (DDAC) components of CuMEA and alkaline copper quaternary (ACQ) solutions impregnated into wood was followed by measuring the changes in solution concentrations in the wood over time. The rate and extent of copper and MEA adsorption were highly dependent on the solution strength and the conditioning temperature. Both copper and MEA were adsorbed by the wood structure with a rapid initial reaction, with higher relative amounts sorbed from lower concentration solutions. This was followed by a slower adsorption that still had not equilibrated after 7 weeks at 22°C. Generally, the adsorption pattern was similar for copper and MEA, suggesting that they were adsorbed as a copper MEA complex, with an MEA/copper molar ratio close to the theoretical maximum of 4. At a higher conditioning temperature of 50°C the reaction time was greatly reduced, with the adsorption after 1 week higher than after 7 weeks at 22°C, suggesting faster and more complete reaction at higher temperatures. DDAC was adsorbed more quickly and to a higher degree than Cu(II) for all treatment solutions and should be preferentially removed from such solutions, especially if empty-cell treatments are used. There appeared to be higher Cu adsorption from the higher concentration solutions of CuMEA than from corresponding ACQ solutions, likely due to DDAC competition with copper for the same reaction sites.

Adsorption of monoethanolamine on clean, oxidized and hydroxylated aluminium surfaces: a model for amine-cured epoxy/aluminium interfaces

The interaction of 1-amino-2-hydroxyethane (monoethanolamine) with clean Al(100), in-situ oxidized Al(100) and in-situ hydroxylated Al(100) has been investigated using Auger electron spectroscopy (AES) and high-resolution electron energy-loss spectroscopy (HREELS). It has been shown that, on all these surfaces, adsorption of monoethanolamine can be interpreted in the framework of the Hard and Soft Acid Base (HSAB) principle. However, the detailed mechanism differs for each surface: (i) monoethanolamine interacts with clean Al(100) through its amine termination via a Lewis-like acid-base reaction; (ii) monoethanolamine interacts with oxidized Al(100) through its alcohol termination via a Lewis-like acid-base reaction; (iii) monoethanolamine interacts with hydroxylated Al(100) through its alcohol termination via a Brönsted-like acid-base reaction.