Syamalendu S. Bandyopadhyay

Kinetics of absorption of CO2 into aqueous solutions of 2-amino-2-methyl-1-propanol

The mechanism and kinetics of the reaction between CO2 and aqueous solution of sterically hindered amine, 2-amino-2-methyl-1-propanol (AMP), were investigated at 294–318 K by gas absorption studies using a wetted wall column. The reaction was found to be first order with respect to both CO2 and AMP. The values of the second order rate constant were found to be 439, 687, 1179 and 1650 m3/(kmols) at 294, 301.5, 311.5 and 318 K, respectively, in the amine concentration range 0.5−2.0 kmol/m3. These results agree closely with those of Alper (1990, Ind. Engng Chem. Res.29, 1725–1728), who adopted a completely different methodology, the stopped flow technique, for investigating the kinetics of CO2-AMP.

Absorption of carbon dioxide into aqueous blends of 2-amino-2-methyl-1-propanol and diethanolamine

Abstract This work presents an experimental and theoretical investigation of CO2 absorption into aqueous blends of 2-amino-2-methyl-1-propanol (AMP) and diethanolamine (DEA). The CO2 absorption into the amine blends is described by a combined mass transfer–reaction kinetics–equilibrium model, developed according to Higbies penetration theory. The model predictions have been found to be in good agreement with the experimental rates of absorption of CO2 into (AMP+DEA+H2O). The good agreement between the model predicted rates and enhancement factors and the experimental results indicate that the combined mass transfer–reaction kinetics–equilibrium model with the appropriate use of model parameters can effectively represent CO2 mass transfer for the aqueous amine blends AMP/DEA.

Removal of carbon dioxide by absorption in mixed amines: modelling of absorption in aqueous MDEA/MEA and AMP/MEA solutions

This work presents an investigation of CO 2 absorption into aqueous blends of methyldiethanolamine (MDEA) and monoethanolamine (MEA), as well as 2-amino-2-methyl-1-propanol (AMP) and monoethanolamine (MEA). The combined mass transfer-reaction kinetics-equilibrium model to describe CO 2 absorption into the amine blends has been developed according to Higbies penetration theory following the work of Hagewiesche et al. (Chem. Eng. Sci. 50 (1995) 1071). The model predictions have been found to be in good agreement with the experimental rates of absorption of CO 2 into (MDEA + MEA + H 2 O) of this work and into (AMP + MEA + H 2 O) reported by Xiao et al. (Chem. Eng. Sci. 55 (2000) 161), measured at higher contact times using wetted wall contactor. The good agreement between the model predicted rates and enhancement factors and the experimental results indicate that the combined mass transfer-reaction kinetics-equilibrium model with the appropriate use of model parameters can effectively represent CO 2 mass transfer for the aqueous amine blends MDEA/MEA and AMP/MEA.

Selective absorption of H2S from gas streams containing H2S and CO2 into aqueous solutions of N-methyldiethanolamine and 2-amino-2-methyl-1-propanol

Selective absorption of H2S from N2 streams containing H2S and CO2 into aqueous solutions of 2-amino-2-methyl-1-propanol (AMP) as well as N-methyldiethanolamine (MDEA) was investigated in a 2.81×10−2 m o.d. stainless steel wetted-wall column at atmospheric pressure and constant feed gas ratio. In the range of gas flow rates studied (90–180×10−6 m3/s), the effect of gas-phase resistance on the absorption of H2S was significant. The rates of absorption of H2S and the selectivity factor decreased with the contact time for both alkanolamine solutions. With increasing amine concentration in the range 2.0–3.0 kmol/m3, the rates of absorption of both CO2 and H2S increased, but relatively more for CO2, resulting in a consequent decrease in the selectivity factor. In the temperature range 293–313 K, the rates of absorption of CO2 increased marginally with the increase in temperature while the rates of absorption of H2S and the selectivity factor decreased. The maximum selectivity observed in this work was 17.57 and 23.02 for AMP and MDEA, respectively. The acid gas mass transfer has been modelled using equilibrium-mass-transfer-kinetics-based combined model for CO2 and gas-phase transport equation-based approximate model for H2S considering negligible interaction between CO2 and H2S in the liquid phase. The experimental and model results have been found to be in good agreement.

Carbon Dioxide Capture: Absorption of Carbon Dioxide in Piperazine Activated Concentrated Aqueous 2-Amino-2-Methyl-1-Propanol

Abstrac t—In this work new experimental data on the rate of absorption of CO2 into PZ activated concentrated aqueous AMP in the temperature range of (323–333) K are presented. Rate activator PZ is used with a concentration of (2–8) wt%, keeping the total amine concentration in the solution at 50 wt%. The vapour-liquid equilibrium (VLE) of CO2 into aque ous solutions of (AMP+PZ) have also been measured and modeled in order to determine the liquid phase speciation of (AMP+PZ+CO2+H2O) s ystem and equilibrium CO2 loading. Th e theoretical absorption-rate model used to interpret the experimental kinetic data is based on all possible chemical reactions in the liquid phase. The average absolute deviation between the experimental and model results is about 6.8 %. Index Terms—CO2 capture, 2-Amino-2-methyl-1-propanol,

THERMODYNAMICS OF ALKANOLAMINE + WATER SYSTEM

Design of gas treating processes requires knowledge of the vapor-liquid equilibrium behavior of the (acid gas + aqueous alkanolamine) system. The present study is focused on thermodynamics and associated nonideal behavior of binary MEA + H2O, DEA + H2O, and MDEA + H2O systems, which is required to predict the vapor-liquid equilibrium of acid gases such as CO2 and H2S over aqueous alkanolamine solutions. Determination of binary interaction parameters and analytical prediction of infinite dilution activity coefficient, heats of solution at infinite dilution, the excess Gibbs free energy, and excess enthalpy for nonideal alkanolamine-water systems are the objectives of this study.

Post-Combustion CO2 Capture with Sulfolane Based Activated Alkanolamine Solvent

Abstract In this work, new experimental data on vapour-liquid equilibrium (VLE) of CO 2 in piperazine (PZ) activated aqueous solutions of n-methyldiethylamine (MDEA) and hybrid solvents containing sulfolane as physical solvent along with aqueous (MDEA+PZ) have been reported over the temperature range of (313-333) K and CO 2 partial pressure range of (1-1400) kPa. PZ is used as a rate activator with a concentration range of 2 to 8 mass% and the total amine concentration in the aqueous solution of (MDEA+PZ) has been kept within 50 mass%, while the concentration of physical solvent sulfolane has been maintained at 10 mass%. Electrolyte non random two-liquid (ENRTL) theory has been used to model the VLE. A simulation work has been carried out using Aspen Plus (V7.1) to evaluate the energy requirements on % CO 2 removal. The hybrid solvent showed higher % CO 2 removal when compared with those of PZ-activated aqueous MDEA.