Solubility of N2O in alkanolamines and in mixed solvents

Impact of thermodynamics and kinetics on the carbon capture performance of the amine-based CO2 capture system

Solvent-based CO2 capture is a commonly employed post-combustion technique in processes involving absorber-stripper columns. This study focused on computer simulations with equilibrium- and rate-based modeling of CO2 capture using the amine solvents 2-amino-2-methyl-1-propanol (AMP), diethanolamine (DEA), and methyl diethanolamine (MDEA) and thermodynamic methods involving electrolyte NRTL models. The objective of this study was to understand the impacts of rate-based modeling, the type of amine, and thermodynamic methods on carbon capture. Within this study, the amine-based CO2 capture process from coal-power plant flue gas was studied using Aspen Plus modeling. Simulations were also conducted to determine the impact of thermodynamics and kinetics on the CO2 capture performance of the system. The results were analyzed on the basis of captured CO2 according to the solvents and models. The equilibrium approach was mostly invalid because of the oversimplified ideal stage assumptions through the column. The lowest carbon capture capacity was obtained with MDEA, while DEA yielded the best results. A sensitivity analysis with rate-based modeling showed the significant impact of the inlet CO2 composition. The amine-based CO2 capture process simulation included solution chemistry, electrolyte thermodynamics, rigorous transport property modeling, reaction kinetics, and rate-based multistage simulation, which could be applicable to different solvent systems.

Hydrodynamic and Mass Transfer in the Desorption Process of CO2 Gas in a Packed-Bed Stripper

A lab-scale packed-bed stripper containing Dixon rings was used to explore the effects of the process variables on the hydrodynamics and mass-transfer in a stripper using a mixed solvent loaded CO2. The variables are the liquid flow rate, reboiler temperature, and amine concentration, and the hydrodynamic and mass-transfer data can be determined using different models. In the case of hydrodynamics, the dimensionless pressure drop at the flooding point and the total pressure drop were explored first. In the case of mass-transfer, the correlation of the mass-transfer coefficient and the parameter importance were also observed. In addition, the number of plates per meter can be compared with the Dixon rings manufacturer. Finally, the performances of a mixed solvent and monoethanolamine (MEA) solvent were also discussed.

Experimental and theoretical studies on efficient carbon dioxide capture using novel bis(3-aminopropyl)amine (APA)-activated aqueous 2-amino-2-methyl-1-propanol (AMP) solutions

The present study investigates the absorption of CO₂, into novel bis(3-aminopropyl)amine (APA)-activated aqueous solutions of 2-amino-2-methyl-1-propanol (AMP), using a wetted-wall column absorber.

Physical Absorption of Green House Gases in Amines: The Influence of Functionality, Structure, and Cross-Interactions

Monte Carlo simulations were performed in the isothermal-isobaric ensemble (NPT) to calculate the Henry constants of methane (CH₄), nitrous oxide (N₂O), and carbon dioxide (CO₂) in pure H₂O, amines, and alkanolamines using the classical Lorentz-Berthelot combining rules (L-B). The Henry constants of N₂O and CO₂ in water are highly overestimated and motivated us to propose a new set of unlike interactions. Contrarily, the Henry constant of N₂O in MEA is underestimated by around 40%, and again, a new reoptimized cross unlike parameter is able to reproduce the constant to within 10%. An analysis is given of the relationship between the physical absorption of these gases and the chemical structure or functionality of 12 molecules including amines and alkanolamines using the anisotropic united atom intermolecular potential (AUA4). Finally, the solubility of N₂O in an aqueous solution of monoethanolamine (MEA) at 30% (wt) was also studied. A Henry constant within 7% of the experimental value was found by using the reoptimized parameters along with L-B to account for the MEA + H₂O unlike interactions. This very good agreement without additional adjustments for the MEA + H₂O system may be attributed to the good excess properties predictions found in previous works for the binary mixture (MEA + H₂O). However, further work, including additional alkanolamines in aqueous solutions at several concentrations, is required to verify this particular point.

A review of CO2 capture by absorption in ionic liquid-based solvents

Concern has increased about climate change caused by carbon dioxide (CO