Effect of Blending Ratio and Temperature on CO₂ Solubility in Blended Aqueous Solution of Monoethanolamine and 2-Amino-2-methyl-propanol: Experimental and Modeling Study Using the Electrolyte Nonrandom Two-Liquid Model

Abstract

This paper reports the newly measured experimental data for CO2 solubility in a blended aqueous solution of monoethanolamine (MEA) and 2-amino-2-methyl-propanol (AMP) at different amine mixing ratios (MEA/AMP/H2O = 9:21:70, 15:15:70, and 21:9:70 wt %) and working temperatures (323.15, 373.15, and 383.15 K). The successive substitution method was used for calculating the mole fractions of all molecules (four molecules) and electrolytes (three cations and four anions) from the equilibrium along with the material and charge balance equations (11 equations). The electrolyte nonrandom two-liquid (e-NRTL) model was used to investigate nonideality in the liquid phase. Using the abovementioned thermodynamic models, the partial pressures of CO2 in the gas phase, mole fractions of all components in the liquid phase, pH variations, heats of absorption, and cyclic capacities of CO2 according to the absorption/desorption temperature and the blending ratio of MEA/AMP were estimated.

Electrochemical reduction of CO2 in the captured state using aqueous or nonaqueous amines

“…Temperature also affects the solubility of CO 2 , and thus the pH of the capture solution and the proportion of ionic species ( Hamborg and Versteeg, 2009 ; Rajan and Muraleedharan, 2017 ). We note that speciations are also sensitive to partial pressure and amine concentration, which further complicate the above considerations; we refer to readers to discussions elsewhere ( Böttinger et al., 2008 ; Choi et al., 2020 ). Overall, the amine speciation is far from straightforward and requires careful analysis for a given electrochemical system, especially if the elevated temperature is to be used to facilitate kinetics and/or transport.…”

Capture of CO2 Using Mixed Amines and Solvent Regeneration in a Lab-Scale Continuous Bubble-Column Scrubber

“…Generally speaking, a double-unit process including a combination of scrubb stripper is required when using the absorption method, in which the alkanol solutions were proposed as the absorption solvents for CO2 capture before 2030 [ However, the capture cost in the stripping step in CCS is about 60-70%, makin selection of strippers and solvents pivotal. Due to this, several solvents have adopted, such as amines [11][12][13][14][15], amino salts [16,17], ammonia water [18,19], so hydroxide [20], potassium carbonate [21], piperazines [22], ionic liquids, and ph solvents [10], with amines being the most popular solvents in these capture proc The drawbacks of a single solvent, such as loading, corrosion rate, degradation rat regeneration energy, were improved by adopting new solvents, including mixed a and non-aqueous solvents [23][24][25][26][27][28]. There are four kinds of amines, basically classi primary amines (such as monoethanolamine, MEA) [29,30], secondary amines (s diisopropanolamine, DIPA) [31][32][33], tertiary amines (such as triethanolamine, TEA 36], and steric amine (such as 2-amino-2-methyl-1-propanol, AMP) [37][38][39].…”