Aqueous 2-amino-2-methyl-1-propanol Research Articles

Density and Viscosity of CO2-Loaded Aqueous 2-Amino-2-methyl-1-propanol (AMP) and Piperazine (PZ) Mixtures

Density and Viscosity of CO₂-Loaded Aqueous 2-Amino-2-methyl-1-propanol (AMP) and Piperazine (PZ) Mixtures

Effect of ammonia on the kinetics of sulfur dioxide absorption into aqueous 2-amino-2-methyl-1-propanol solutions

Abstract Rate constants for the reaction of aqueous 2-amino-2-methyl-1-propanol (AMP)/ammonia (NH3) solutions with SO2 were determined by measuring their SO2 absorption rates. The SO2 absorption characteristics of 30 wt% AMP solutions with added NH3(1, 3, and 5 wt%) were investigated using a stirred-cell reactor, and the rates of SO2 absorption into the aqueous blended amine solutions were measured. The addition of 5 wt% NH3 to AMP significantly increases the SO2 absorption rate, as well as the rate constant for the reaction of AMP with SO2 by 197%. The relevant Arrhenius expressions were found to be k A M P , S O 2 = 50.787 × 1 0 7 exp ( − 3880.47 / T ) , and k A M P + N H 3 , S O 2 = 377.168 × 1 0 7 exp ( − 4283.71 / T ) .

Experimental results of split flow process using AMP/PZ solution for post‐combustion CO2 capture

AbstractThe goal of reducing energy consumption of the CO2 removal process from flue gas may be pursued by developing new solvents as well as by modifying the technological process itself. This paper provides a discussion of the experimental results obtained from a process development unit (PDU) using an aqueous 2‐amino‐2‐methyl‐1‐propanol (AMP) solution activated with piperazine (PZ) for post‐combustion carbon capture located at the Clean Coal Technologies Centre in Poland. The results are compared for two distinct process setups, namely one with the lean amine stream being split – a solution referred to as split flow, and a system with standard configuration. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.

Real-Time Process Monitoring of CO2 Capture by Aqueous AMP-PZ Using Chemometrics: Pilot Plant Demonstration

A combination of analytical instrumentation and multivariate statistics is widely applied to improve in-line process monitoring. Currently, postcombustion CO2 capture (PCC) technology often involves the use of multiamine based chemical reagents for carbon dioxide removal from flue gas. The CO2 capture efficiency and overall process performance may be improved by introduction of the chemometrics analytical methods for flexible and reliable process monitoring. In this study, six variables were measured (conductivity, pH, density, speed of sound, refractive index, and near-infrared absorbance spectra). A compact data-collecting chemometric setup was constructed and installed at an industrial pilot plant for real-case testing. This setup was applied to the characterization of CO2 absorption into aqueous 2-amino-2-methyl-1-propanol (AMP) activated by piperazine (PZ) as the absorption agent. A partial least-squares (PLS) regression model was calibrated and validated based on the measurements conducted in the la...

Towards an understanding of the oxidative degradation pathways of AMP for post-combustion CO2 capture

Aqueous 2-amino-2-methyl-1-propanol (AMP) solution and the blends of AMP with other amines appear to be commercially attractive solvents for post-combustion CO2 capture by chemical absorption. To get an understanding of the chemistry of AMP oxidation, oxidative degradation of AMP was investigated in a closed-batch autoclave reactor at 80°C and in an open-batch photochemical reactor in the presence of UV radiation at 55°C. The degradation products were identified or quantified by ion chromatography (IC) and gas chromatography–mass spectrometry (GC–MS). The effect of temperature on final degradation product distribution was discussed based on the results of thermally accelerated AMP oxidation experiments. The degradation products of AMP oxidation in the presence of UV radiation were compared with that identified in the thermally accelerated AMP oxidation. A summarized scheme for AMP oxidation is proposed to account for the formation of all of the identified products.

A Reynolds Mass Flux Model for the Simulation of Chemical Absorption of CO2 into 2-Amino-2-methyl-1-propanol in a Packed Column

A Reynolds mass flux model is proposed for the simulation of CO2 absorption into aqueous 2-amino-2-methyl-1-propanol (AMP) solutions in a packed column. With the proposed model, distributions of concentration and temperature as well as velocity can be obtained. In the mathematical expression of the proposed model, the modeled Reynolds mass flux equation is used to close the turbulent mass transfer equation so that the generalized Boussinesq’s postulation is abandoned. The feature of the closure method is that the anisotropy of turbulent mass diffusion can be characterized. To validate the proposed model, a simulation is carried out for CO2-AMP absorption in a randomly packed column. The simulated results are compared with the experimental data in literature, and satisfactory agreement is found between them. Besides, the anisotropy of turbulent mass diffusion characterized by the proposed model is discussed and found to be consistent with that from experimental correlations. Finally, the simulations reveal...

On the origin of preferred bicarbonate production from carbon dioxide (CO₂) capture in aqueous 2-amino-2-methyl-1-propanol (AMP).

AMP and its blends are an attractive solvent for CO2 capture, but the underlying reaction mechanisms still remain uncertain. We attempt to elucidate the factors enhancing bicarbonate production in aqueous AMP as compared to MEA which, like most other primary amines, preferentially forms carbamate. According to our predicted reaction energies, AMP and MEA exhibit similar thermodynamic favorability for bicarbonate versus carbamate formation; moreover, the conversion of carbamate to bicarbonate also does not appear more favorable kinetically in aqueous AMP compared to MEA. Ab initio molecular dynamics simulations, however, demonstrate that bicarbonate formation tends to be kinetically more probable in aqueous AMP while carbamate is more likely to form in aqueous MEA. Analysis of the solvation structure and dynamics shows that the enhanced interaction between N and H2O may hinder CO2 accessibility while facilitating the AMP + H2O → AMPH(+) + OH(-) reaction, relative to the MEA case. This study highlights the importance of not only thermodynamic but also kinetic factors in describing CO2 capture by aqueous amines.

Study of corrosion of AISI 420 in the CO2 absorption process using 2-amino-2-methyl-1-propanol aqueous solutions

In this work, the corrosion behaviour of the stainless steel AISI 420 in the CO2 absorption systems using aqueous 2-amino-2-methyl-1-propanol (AMP) solutions is studied. Three process parameters were considered: temperature (293–323 K), amine concentration (0·1–2·0 kmol m−3) and CO2 flow (0·0–0·5 L min−1). Electrochemical techniques were used to determine the corrosion rate by means of a potentiostat. For each experiment, the electrochemical parameters (corrosion potential and current, anodic and cathodic slopes) were calculated, as well as the corrosion rate, using the Tafel method. At the same time, the pitting susceptibility was evaluated by potentiodynamic tests. According to the results, the influence of the studied variables and the steel characteristics on the polarisation curves and corrosion rate was analysed. Experimental results show that an increase in solution temperature and AMP concentration causes higher corrosion rate. The obtained results indicate that it is not likely to have pitting corrosion in these systems.

Binary and ternary VLE of the 2-amino-2-methyl-1-propanol (AMP)/piperazine (Pz)/water system

New VLE ebulliometric data for binary aqueous 2-amino-2-methyl-1-propanol (AMP) and piperazine (Pz) solutions and ternary aqueous AMP/Pz solutions are reported at different temperatures and concentrations. A proposed combination of titration and a 1H-NMR technique was developed and determination of the composition of the ternary system was successfully carried out. Results show that AMP is more volatile than commercial solvents such as MEA and MDEA whereas Pz is observed to be less volatile than that of MEA and MAPA. Three thermodynamic models (NRTL, Wilson and UNIQUAC) were used to correlate the data and the determined interaction parameters for both the binary and ternary VLE systems are given. New binary interaction parameters for (AMP(1) and Pz(2)) are also proposed. However, the parameters have no statistical significance which indicates that the activity coefficients for the species in the ternary system in general are similar to the activity coefficients obtained from the corresponding binary mixture. More data may be required for ternary VLE estimation, especially at higher amine concentrations.

Experimental and theoretical investigation of solubility of carbon dioxide in concentrated aqueous solution of 2-amino-2-methyl-1-propanol and piperazine

In this work, new experimental results for the (vapour+liquid) equilibrium (VLE) of CO2 in piperazine (PZ)-activated concentrated aqueous 2-amino-2-methyl-1-propanol (AMP) are presented for the temperature range of (303 to 328)K and PZ concentration range of (2 to 8)wt.%, keeping the total amine concentration in the solution at 40% and 50wt.%. The partial pressures of CO2 are in the range of (0.2 to 1500)kPa. The electrolyte non-random two-liquid (ENRTL) theory has been used to develop the VLE model for the quaternary system (CO2+AMP+PZ+H2O) to describe the equilibrium behaviour of the solution. The CO2 cyclic capacity of these solvents is determined between the rich and lean CO2 loadings. It is found that the CO2 cyclic capacity increases with the addition of PZ in aqueous AMP and also with the increase in AMP concentration in the aqueous solution. However, solid precipitation has been observed for 50wt.% total amine concentration below T=318K for all relative compositions of AMP and PZ in the solvent at higher CO2 loading. The model results of equilibrium composition, pH of the loaded solution and amine volatility of the mixed solvent system, are also presented.

Solubility of carbon dioxide in aqueous solution of 2-amino-2-methyl-1-propanol and piperazine

In this work, new experimental results of the vapour–liquid equilibrium (VLE) of CO 2 in aqueous 2-amino-2-methyl-1-propanol (AMP) and piperazine (PZ) have been presented in the temperature range of 298–328 K and PZ concentration range of 2–8 mass%, keeping the total amine concentration in the solution at 30 mass%. The partial pressures of CO 2 were in the range of 0.1–1450 kPa. A thermodynamic model was developed to correlate and predict the VLE of CO 2 in aqueous AMP + PZ. The electrolyte nonrandom two liquid (ENRTL) theory has been used to develop the VLE model for the quaternary system (CO 2 + AMP + PZ + H 2O) to describe the equilibrium behaviour of the solution. The experimental data from this work and data available in the literature were used to regress the ENRTL interaction parameters. The model predictions are in good agreement with the experimental data of CO 2 solubility in aqueous blends of this work as well as those reported in the literature. The current model can also predict speciation, heat of absorption, pH of the CO 2 loaded solution, and amine volatility.

Simultaneous Absorption of Carbon Dioxide and Nitrogen Dioxide into Aqueous 2-amino-2-methy-1-propanol

Carbon dioxide and nitrogen dioxide were simultaneously absorbed into aqueous 2-amino-2-methyl-1-propanol (AMP) in a stirred semi-batch tank with a planar gas-liquid interface within a range of 0–4.0 kmol/m3 of AMP, 0.03–0.3 atm of CO2, 0.005–0.2 atm of NO2, and 298–318 K. Absorption data of each gas in the CO2-AMP and NO2-AMP systems were obtained to verify their reaction regimes, based on film theory, respectively, which were then used to analyze the simultaneous absorption mechanisms of CO2 and NO2 in the CO2-NO2-AMP systems. The measured absorption rates of CO2 and NO2 were compared to those formulated by an approximate solution of the mass balances with simultaneous reactions.

(Vapour + liquid) equilibria (VLE) of CO 2 in aqueous solutions of 2-amino-2-methyl-1-propanol: New data and modelling using eNRTL-equation

This work presents new experimental results for carbon dioxide (CO 2) solubility in aqueous 2-amino-2-methyl-1-propanol (AMP) over the temperature range of (298 to 328) K and CO 2 partial pressure of about (0.4 to 1500) kPa. The concentrations of the aqueous AMP lie within the range of (2.2 to 4.9) mol · dm −3. A thermodynamic model based on electrolyte non-random two-liquid (eNRTL) theory has been developed to correlate and predict the (vapour + liquid) equilibrium (VLE) of CO 2 in aqueous AMP. The model predictions have been in good agreement with the experimental data of CO 2 solubility in aqueous blends of this work as well as those reported in the literature. The current model can also predict speciation, heat of absorption, enthalpy of CO 2 loaded aqueous AMP, pH of the loaded solution, and AMP volatility.

Simultaneous absorption of CO2 and SO2 into aqueous AMP/NH3 solutions in binary composite absorption system

To enhance the absorption rate for CO2 and SO2, aqueous ammonia (NH3) solution was added to an aque- ous 2-amino-2-methyl-1-propanol (AMP) solution. The simultaneous absorption rates of AMP and a blend of AMP+ NH3 for CO2 and SO2 were measured by using a stirred-cell reactor at 303 K. The process operating parameters of in- terest in this study were the solvent and concentration, and the partial pressures of CO2 and SO2. As a result, the addition of NH3 solution into aqueous AMP solution increased the reaction rate constants of CO2 and SO2 by 144 and 109%, respectively, compared to that of AMP solution alone. The simultaneous absorption rate of CO2/SO2 on the addition of 1 wt% NH3 into 10 wt% AMP at a pA1 of 15 kPa and pA2 of 1 kPa was 5.50×10 −6 kmol m −2 s −1 , with an increase of 15.5% compared to 10 wt% AMP alone. Consequently, the addition of NH3 solution into an aqueous AMP solution would be expected to be an excellent absorbent for the simultaneous removal of CO2/SO2 from the composition of flue gas emitted from thermoelectric power plants.

Effect of Ammonia on the Absorption Kinetics of Carbon Dioxide into Aqueous 2-Amino-2-methyl-1-propanol Solutions

Reaction rate constants of aqueous 2-amino-2-methyl-1-propanol (AMP)/ammonia (NH3) solutions with carbon dioxide (CO2) were determined by measuring their absorption rates. The CO2 absorption characteristics of an NH3 solution added to AMP were investigated using a stirred-cell reactor. The CO2 absorption rates into aqueous blended amine solutions were measured at different pressures (pA = 5, 10, and 15 kPa) and temperatures (293, 303, 313, and 323 K). Additive concentrations of 1, 3, and 5 wt % NH3 were added for each 30 wt % AMP solution. The results showed that the addition of NH3 to AMP significantly increased the CO2 absorption rates of AMP by 144%. In addition, the reaction rate constant for a blend of AMP and NH3 with CO2 as a function of temperature was 1.6- to 2.4-fold higher than that of AMP without NH3. The reaction rate constants were k2,AMP = 1.543 × 107 exp(−3019.92/T) and k2,NH3 = 1.847 × 1010 exp(−4954.25/T).

Simultaneous Absorption of Carbon Dioxide and Sulfur Dioxide into Aqueous 2-Amino-2-Methy-1-Propanol

Carbon dioxide and sulfur dioxide were simultaneously absorbed into aqueous 2-amino-2-methyl-1-propanol (AMP) in a stirred semi-batch tank with a planar gas-liquid interface within a range of 0–4.0 kmol/m3 of AMP, 0.03–0.3 mole fraction of CO2, 0.005–2 mole fraction of SO2, and 298–318 K. Absorption data of each gas in the CO2-AMP and SO2-AMP systems are obtained to verify their reaction regimes, based on film theory, respectively, which are used to analyze the simultaneous absorption mechanisms of CO2 and SO2 in the CO2-SO2-AMP systems. The measured absorption rates of CO2 and SO2 are compared to those formulated by an approximate solution of the mass balances with simultaneous reactions.

Kinetics region and model for mass transfer in carbon dioxide absorption into aqueous solution of 2-amino-2-methyl-1-propanol

A rigorous model for absorption of CO 2 into aqueous 2-amino-2-methyl-1-propanol (AMP) was investigated at a temperature of 303 K using a double stirred-cell absorber with a planar gas–liquid interface. It was demonstrated that the kinetics region of absorption CO 2 into aqueous AMP was the fast pseudo-first order reaction regime. The mass transfer-reaction kinetics equilibrium model according to the film theory is satisfactory to represent CO 2 absorption into aqueous AMP. The model predictions had been found to be in good agreement with the experimental results. And the proposed model could handle the prediction much more effectively when CO 2 loading was much smaller.

Experimental validation of a rate-based model for CO 2 capture using an AMP solution

Detailed experimental data, including temperature profiles over the absorber, for a carbon dioxide (CO 2) absorber with structured packing in an integrated laboratory pilot plant using an aqueous 2-amino-2-methyl-1-propanol (AMP) solution are presented. The experimental gas–liquid material balance was within an average of 3.5% for the experimental conditions presented. A predictive rate-based steady-state model for CO 2 absorption into an AMP solution, using an implicit expression for the enhancement factor, has been validated against the presented pilot plant data. Furthermore, a parameter sensitivity analysis for the proposed model has been carried out.

Rigorous Model for Predicting the Behavior of CO2 Absorption into AMP in Packed-Bed Absorption Columns

A rigorous computer model was developed for the simulation of the absorption of CO2 in aqueous 2-amino-2-methyl-1-propanol (AMP) solutions in a packed absorption column that takes into account the heat effects. This model predicts the concentration and the temperature profiles along the packed column for the CO2−AMP system. These profiles were compared with the experimental data that were obtained from two pilot-plant studies. The first study was with a column packed with 12.7-mm Berl Saddles, and the second study was with a high-efficiency structured packed absorber. The predicted results were found to be in close agreement with the measured values. For the experimental data from University of British Columbia, the average absolute deviations between the predicted and measured data in terms of concentration and temperature profiles are 9.7% and 2.3%, respectively. For the experimental data from University of Regina, the average absolute deviation between the predicted and measured concentration profiles is 13.8%. The model predictions could be improved by using more accurate physicochemical properties, when available.

Volumetric Properties and Viscosities for Aqueous AMP Solutions from 25 °C to 70 °C

This paper reports the density and viscosity of aqueous 2-amino-2-methyl-1-propanol (AMP) solutions at five temperatures in the range 25 °C to 70 °C over the whole concentration range. The results are compared with data published in the literature. The derived excess molar volumes, the partial molar volumes, the partial molar volumes at infinite dilution, and the viscosity deviations were correlated as a function of composition.