Equilibrium Total Pressure and CO₂ Solubility in Binary and Ternary Aqueous Solutions of 2-(Diethylamino)ethanol (DEEA) and 3-(Methylamino)propylamine (MAPA)

Abstract

Equilibrium total pressures were measured and equilibrium CO 2 partial pressures were calculated from the measured total pressure data in binary and ternary aqueous solutions of 2-(diethylamino)ethanol (DEEA) and 3-(methylamino)propylamine (MAPA). The measurements were carried out in a commercially available calorimeter used as an equilibrium cell. The examined systems were the binary aqueous solutions of 5 M DEEA, 2 M MAPA, and 1 M MAPA and the ternary aqueous mixtures of 5 M DEEA + 2 M MAPA (5D2M) and 5 M DEEA + 1 M MAPA (5D1M), which gave liquid−liquid phase split upon CO 2 absorption. The total pressures were measured and the CO 2 partial pressures were calculated as a function of CO 2 loading at three different temperatures 40 °C, 80 °C, and 120 °C. All experiments were reproduced with good repeatability. The measurements were carried out for 30 mass % MEA solutions to validate the experimental method. All the measured data were also compared with the results of 30 mass % MEA as a reference case. 5 M DEEA has shown high cyclic capacity. Both 2 M and 1 M MAPA showed high loading capacities at 40 °C and 120 °C. The aqueous amine mixtures, 5D2M and 5D1M, gave fairly good cyclic capacities and their results depend on the concentration of the promoter (MAPA) in the mixture. Approximate enthalpies of absorption of CO 2 in all the tested aqueous amine systems were estimated from the CO 2 solubility data. The measured total pressure and the estimated CO 2 solubility data can be useful in thermodynamic modeling of the capture systems when aqueous DEEA−MAPA solutions are used as capture solvents.

Vapour-liquid equilibrium study of tertiary amines, single and in blend with 3-(methylamino)propylamine, for post-combustion CO2 capture

“…In Fig. 1, the cyclic capacity of 17 blended amines and the benchmark solvent 30 wt % MEA are compared [3][4][5][6][7][8][9][10]. The cyclic capacity was estimated as given in Eq.…”

Emerging New Types of Absorbents for Postcombustion Carbon Capture

“…In their pilot plant trials at a scale of 80-90 m 3 /h flue gas with CO 2 -rich/CO 2 -lean phase separation and CO 2 -rich phase regeneration, their system was shown to be superior to aqueous MEA, which was tested in the pilot plant as well [33,34]. This finding was supported by modeling the biphasic absorbent with an energy consumption of 2.2-2.4GJ/tCO 2 and compared to 3.7GL/tCO 2 using 30wt% aqueous MEA [32,35]. Table 6.…”

“…Table 6. Phase compositions of DEEA/MAPA (5M/2M) [31,32]. In summary, up to now, researchers and developers have achieved encouraging results in the area of liquid-liquid biphasic CO 2 absorbents, and some biphasic absorbents can be regenerated at lower temperatures with deeper regenerability than the bench mark aqueous MEA ( Table 7).…”

“…They found that DMMEA/PZ (3M/1M, 5M/2M), especially 3M/1M, and DMMEA/MEA (5M/2M), had high CO 2 absorption rate and characteristics of deep regeneration at low temperature, almost doubling the cyclic loading of the MEA. Further, these researchers developed biphasic absorbents of DEEA/MAPA, tertiary alkanolamine and lipophilic amine [31,32]. They examined the vapor liquid equilibrium (VLE) of CO 2 -DEEA-MAPA-H 2 O system at 40, 60, and 80°C, from which the CO 2 absorption loading, absorption phase split ratio, and phase compositions were derived as presented in Table 6.…”

Artificial neural network models for the prediction of CO2 solubility in aqueous amine solutions

“…Monoethanolamine (MEA), diethanolmine (DEA) and methyldiethanolamine (MDEA) are the mostly studied amines and have been researched for decades (Jones et al, 1959;Lawson and Garst, 1976;Jou et al, 1982;Kennard and Meisen, 1984;Shen and Li, 1992;Ermatchkov et al, 2006a;Aronu et al, 2011). Recently, some novel amine solvents (such as 2-amino-2-methyl-1-propanol (AMP), piperazine (PZ), 4-(diethylamino)-2-butanol (DEAB), and 2-(Diethylamino) ethanol (DEEA)) have been experimentally investigated (Tontiwachwuthikul et al, 1991;Kamps et al, 2003;Daneshvar et al, 2004b;Dong et al, 2010;Bougie and Iliuta, 2011;Rebolledo-Morales et al, 2011;Sema et al, 2011;Dash et al, 2012;Kumar and Kundu, 2012;Arshad et al, 2014). All of those studies determined the CO 2 solubility at various conditions such as amine concentrations (C), operation temperatures (T) and CO 2 partial pressures (P CO2 ), and have achieved high measurement accuracies with good repeatability.…”