Kinetics of the reactive absorption of carbon dioxide in high CO2-loaded, concentrated aqueous monoethanolamine solutions

A predictive thermodynamic model for an aqueous blend of potassium carbonate, piperazine, and monoethanolamine for carbon dioxide capture from flue gas

Experimental densities, viscosities, and heat capacities at different temperatures were measured over the entire mole fraction range for the binary mixture of ethylene glycol + water. Density values were used in the determination of excess molar volumes, VE. The excess volumes, VE, are fitted as a function of the mole fraction to a polynomial. Δη was fitted to the Redlich−Kister equation. The excess volumes are negative over the entire composition at the lower temperatures. They show a U-shaped concentration dependence and decrease in absolute value with increasing temperature. At high temperatures, the excess molar volume shows an S-shaped dependence. Δη values are negative over the entire range of mole fraction and have a very similar trend to that for VE. The heat capacities of mixtures have the maximum values at x1= 0.0312.

Excess Molar Volumes, Viscosities, and Heat Capacities for the Mixtures of Ethylene Glycol + Water from 273.15 K to 353.15 K

The gas absorption process for CO2 separation from gas streams is of high interest in various applications in chemical, oil, and gas industries, as well as in environmental protection. The choice of a certain amine (single or blended amine) for CO2 capture is mainly based on the absorption capacity, reaction kinetics, and regenerative potential and facility. The application of sterically hindered amines in gas-treating technology offers absorption capacity, absorption rate, and degradation resistance advantages over conventional amines for CO2 removal from gases. The aim of this review is to bring an update of different aspects concerning several binary and multicomponent systems of CO2-sterically hindered amine-based absorbents essential for the design and operation of absorption equipment (physical properties like density, viscosity, vapor pressure, heat capacity and heat of absorption, CO2 and amine diffusivity, CO2 absorption capacity and kinetics, regeneration capability).

Sterically Hindered Amine-Based Absorbents for the Removal of CO2 from Gas Streams

Kinetics of the absorption of CO2 into monoethanolamine (MEA) + triethanolamine (TEA) + water were investigated at 30, 35, and 40 °C using a laboratory wetted wall column. Ten systems of which 0.5 and 1.0 kmol m-3 TEA mixed with various MEA concentrations (0.1, 0.2, 0.3, 0.4, and 0.5 kmol m-3) were studied. Densities and viscosities of 10 blended-amine systems and solubilities and diffusivities of N2O in the solutions were measured. The N2O analogy was applied to estimate the solubilities and diffusivities of CO2 in amine systems. On the basis of the fast pseudo-first-order rate for CO2 absorption, the overall pseudo-first-order reaction rate constants were determined from kinetic measurements. The addition of small amounts of MEA to TEA results in a significant enhancement of CO2 absorption rates. A hybrid reaction rate model, a zwitterion mechanism for MEA and a first-order reaction for TEA, was used to model the kinetic data. The model is satisfactory to represent CO2 absorption rates in TEA + MEA aque...

Kinetics of Absorption of Carbon Dioxide into Aqueous Solutions of Monoethanolamine + Triethanolamine

The diffusivities of nitrous oxide (N2O) in aqueous alkanolamine solutions have been measured at (30, 35, and 40) °C. The systems studied are aqueous monoethanolamine, diethanolamine, diisopropanolamine, triethanolamine, and 2-amino-2-methyl-1-propanol solutions. The concentration of amine for monoethanolamine ranges from (1 to 5) kmol·m-3 and for other amines from (0.5 to 2.5) kmol·m-3. The viscosities of diisopropanolamine and triethanolamine and the densities and viscosities of aqueous diisopropanolamine and triethanolamine solutions were also measured at (30, 35, and 40) °C. A simple correlation was used to correlate the diffusivity of N2O in amine solutions. The parameters of the correlation were determined from the measured diffusivity data and the available data in the open literature. The correlation has been shown to represent reasonably the diffusivity of N2O in six aqueous amine solutions:  MEA, DEA, DIPA, MDEA, TEA, and AMP. The correlations are, in general, satisfactory for estimating the dif...

Diffusivity of Nitrous Oxide in Aqueous Alkanolamine Solutions

The solubility of nitrous oxide (N2O) in alkanolamine aqueous solutions has been measured at (30, 35, and 40) °C. The systems studied are monoethanolamine, diethanolamine, diisopropanolamine, triethanolamine, and 2-amino-2-methyl-1-propanol aqueous solutions. The concentration of amine for monoethanolamine ranges from (1 to 6) kmol·m-3 and for other amines from (0.5 to 3) kmol·m-3. The accuracy of the measurement is estimated to be ± 2%. A semiempirical model of the excess Henry's constant proposed by Wang et al. (1992) was used to correlate the solubility of N2O in amine solutions. The parameters of the correlation were determined from the measured solubility data and the available data in the open literature. For a wide temperature range from (15 to 75) °C, the obtained correlation has been shown to represent reasonably the solubility of N2O in six amine aqueous solutions:  MEA, DEA, DIPA, TEA, MDEA, and AMP. For the purpose of process design, the obtained correlations are, in general, satisfactory for ...

Jiun-Jie Ko

Papers

Diffusivity of Nitrous Oxide in Aqueous Alkanolamine Solutions

Solubility of Nitrous Oxide in Alkanolamine Aqueous Solutions