Aminoethylethanolamine Research Articles

Design of blend-amine solid adsorbents for CO2 capture: Enhances adsorption- equilibrium cycle strategies and mechanism

Blend amine-functionalized absorbents show great potential in the field of amine scrubbing for CO2, as they harness the absorption benefits of various monomer amines in combination. However, there is a lack of research on the application of the emerging concept of blend amines to solid amine adsorbents. Building upon this foundation, this study firstly incorporated Aminoethylethanolamine (AEEA) into Polyethyleneimine (PEI) of varying molecular weights to create a range of new binary solid amine adsorbents. The research then compared the adsorption performance differences between these binary adsorbents and pure PEI adsorbents. The enhanced dispersion of PEI by AEEA results in an increase in the effective active sites available. The amine efficiency and CO2 adsorption capacity of the AEEA-PEI blend amine system were maximally increased by 92.0% and 84.6%, respectively, compared to the pure PEI system. Furthermore, through DFT calculations, it is clear that the presence of AEEA lowers the overall activation energy of the reaction due to its superior proton acceptance compared to PEI. However, the AEEA-PEI system exhibits weak cycling stability attributed to the limited regeneration capacity of AEEA. Fortunately, this issue can be successfully addressed by introducing a strong base, N,N,N',N'',N''-pentamethyl diethylenetriamine (PMDETA). The CO2 adsorption cycling stability for AEEA-PEI-PMDETA system maximally improved by up to 17.1% compared to the AEEA-PEI system. The mechanism behind the effectively suppression of cycling losses by PMDETA was further elucidated through DFT calculations. Consequently, the novel ternary amine solid adsorbent introduced in this study, aimed at enhancing the CO2 adsorption performance of monomer amine solid adsorbents, offers a fresh strategy for fundamental theoretical investigations into CO2 adsorption.

Adjusting the phase transition time node of a solid–liquid biphasic solvent based on 2-amino-2-methyl-1-propanol for efficient CO2 capture: Insight into the regulatory effect of aminoethylethanolamine

Solid-liquid biphasic solvents (SLBSs) hold promise as energy-efficient candidates for CO2 capture. Nevertheless, the premature phase transition of current SLBSs leads to inopportune solid precipitation, posing operational challenges for the CO2 capture system. This study proposed a promising strategy that using aminoethylethanolamine (AEEA) as a regulator to fine-tune the phase transition time node of the 2-amino-2-methyl-1-propanol (AMP)/N-methylpyrrolidone (NMP) SLBS, enabling the phase transition to occur precisely as desired. Experimental results showed that the AEEA/AMP/NMP (A/A/N) SLBS exhibited tunable phase transition time nodes, modulated by the concentration of AEEA. Specifically, with the addition of 0.2 mol·L−1 AEEA, the CO2 loading associated with the phase transition increased significantly, from 0.19 to 0.54 mol·mol−1, approaching the saturation loading of 0.57 mol·mol−1. The delayed phase transition would facilitate the CO2 absorption operation. The regulatory mechanism of AEEA on the phase transition were thoroughly studied via 13C NMR and quantum calculations. AMP reacted with CO2 to produce AMPCOO− and AMPH+, which had a significantly stronger affinity for each other than for the solvent NMP, mediated by strong hydrogen bond interactions. Consequently, the continuous and fast aggregation of AMPCOO− and AMPH+ caused their swift precipitation from NMP. With the introduction of AEEA, the derived product AEEAH+(S)COO–(P) acted as a bridge-builder, connecting AMPCOO− or AMPH+ and NMP via hydrogen bonds, increasing the solubility of the AMP-derived products in NMP, thus effectively delaying the phase transition. Thermodynamic analysis revealed that the A/A/N SLBS exhibited a total regeneration energy consumption of 1.94 GJ·ton−1 CO2, representing a significant reduction of 48.9 % compared to that of 30 wt% MEA. This study provided a novel idea for designing SLBSs with controllable phase transition behavior, and offered a promising A/A/N SLBS for energy-efficient CO2 capture.

Inhibiting effect of 2-amino-2-methyl-1-propanol on gelatinous product formation in non-aqueous CO2 absorbents: Experimental study and molecular understanding

Diamines or polyamines with two or more amino groups are suitable for formulating non-aqueous absorbents (NAAs) with high CO2 loading capacity and low regeneration energy consumption. However, these two types of amines in NAAs are prone to produce insoluble gelatinous products after absorbing CO2, resulting in difficult operation of the CO2 capture system. In this study, by using 2-amino-2-methyl-1-propanol (AMP) as an inhibitor, the insoluble gelatinous products of the aminoethylethanolamine (AEEA)-N-methyl-2-pyrrolidone (NMP) (A-A-N) and 3-(methylamino)propylamine (MAPA)-NMP (M-A-N) NAAs were successfully eliminated. The experimental results showed that the AMP-regulated NAAs possessed a high absorption rate, high CO2 loading capacity, excellent desorption efficiency, and stable recyclability. The reaction mechanism of CO2 absorption and the inhibitory mechanism of AMP on the formation of gelatinous products were comprehensively elucidated. Taking the A-A-N system as a representative, AEEA reacted with CO2 to form zwitterionic protonated carbamate species (AEEACO2−(P)H+(S)), which tended to self-aggregate via hydrogen-bond interaction, resulting in the formation of insoluble gelatinous products. With the introduction of AMP, the AMP-derived products could combine easily with AEEACO2−(P)H+(S) via strong electrostatic attraction to form ion pairs, preventing the AEEACO2−(P)H+(S) molecules from self-aggregating to form insoluble gelatinous products. The regeneration heat duty of the A-A-N system was 1.89 GJ∙ton−1 CO2, which was 49.9 % lower than that of the benchmark 30 wt% MEA. Overall, introducing AMP as a gelatinous product inhibitor was beneficial for the development of NNAs with high CO2 absorption capacity and low-energy consumption.

Bi-amine functionalized mesostructured silica nanospheres for enhanced CO2 adsorption performance and fast desorption kinetics

A novel solid bi-amine adsorbent was synthesized by simultaneously impregnating pentaethylenehexamine (PEHA) and aminoethylethanolamine (AEEA) on the surfaces of mesoporous MCM–41 nanospheres. AEEA and PEHA had a synergistic effect during the CO2 adsorption of the bi-amine adsorbent and the highest CO2 adsorption capacity was 4.03 mmol·g−1. The bi-amine adsorbent exhibited the favorable recyclability because its saturated CO2 adsorption capacity decreased by 6.20 % after the initial eight adsorption/desorption cycles while by only 2.23 % in the following seven cycles. The adsorption activation energy and the desorption activation energy were determined to be 12.53 and 16.81 kJ·mol−1, respectively. The low value of the desorption activation energy suggested an inconsiderable energy requirement in the multicycles of the adsorbent. The characterization results indicated that hydrogen bonds were formed between the hydrogen atom in hydroxyl groups of AEEA and the oxygen atom in carbonyl groups of the carbamate. The synergistic effect between AEEA and PEHA was unveiled on the CO2 adsorption of the bi-amine adsorbent. The formed hydrogen bonds facilitated the release of protons from carbamic acids, enhanced the stability of the produced carbamate anions, and thus boosted the CO2 adsorption performance.

Simulation of Natural Gas Treatment for Acid Gas Removal Using the Ternary Blend of MDEA, AEEA, and NMP

Natural gas (NG) requires treatment to eliminate sulphur compounds and acid gases, including carbon dioxide (CO2) and hydrogen sulphide (H2S), to ensure that it meets the sale and transportation specifications. Depending on the region the gas is obtained from, the concentrations of acid gases could reach up to 90%. Different technologies are available to capture CO2 and H2S from NG and absorb them with chemical or physical solvents; occasionally, a mixture of physical and chemical solvents is employed to achieve the desired results. Nonetheless, chemical absorption is the most reliable and utilised technology worldwide. Unfortunately, the high energy demand for solvent regeneration in stripping columns presents an obstacle. Consequently, the present study proposes a novel, ternary-hybrid mixture of N-methyl diethanolamine (MDEA), amino ethyl ethanol amine (AEEA), and N-methyl 2-pyrrolidone (NMP) to overcome the issue and reduce the reboiler duty. The study employed high levels of CO2 (45%) and H2S (1%) as the base case, while the simulation was performed with the Aspen HYSYS® V12.1 software to evaluate different parameters that affect the reboiler duty in the acid gas removal unit (AGRU). The simulation was first validated, and the parameters recorded errors below 5%. As the temperature increased from 35 °C to 70 °C, the molar flow of the CO2 and H2S in sweet gas also rose. Nevertheless, the pressure demonstrated an opposite trend, where elevating the pressure from 1000 kPa to 8000 kPa diminished the molar flow of acid gases in the sweet gas. Furthermore, a lower flow rate was required to achieve the desired specification of sweet gas using a ternary-hybrid blend, due to the presence of a higher physical solvent concentration in the hybrid solvent, thus necessitating 64.2% and 76.8%, respectively, less reboiler energy than the MDEA and MDEA + AEEA.

INVESTIGATION OF ANTI-CORROSION PROPERTIES OF NEW MULTIFUNCTIONAL REAGENTS AGAINST INTERNAL CORROSION IN MAIN GAS PIPELINES

Compositions of amide synthesized based on oleic acid and aminoethylethanolamine (AEEA) with cis-1-((4-(-(benzoyloxymethyl)-1,3-dioxolan-2-yl) methyl)-1H-benzo[d][1,2,3]triazol-1-ium acetate synthesized based on benzotriazole were prepared (Reag – A, B, C, D), and their properties against hydrogen sulfide and microbiological corrosion were studied in various concentrations. It has been determined that the ratio of the components contained in the Reag-C is optimum since the reagent completely kills bacteria and shows 95.2% inhibition efficiency against hydrogen sulfide corrosion

Modeling the solubility of carbon dioxide in the MDEA + AEEA aqueous solution using the SAFT-HR equation of state and extended UNIQUAC model

In this study, a thermodynamic model has been used to determine the solubility of carbon dioxide in an aqueous solution which is the combination of methyldiethanolamine (MDEA) and aminoethylethanolamine (AEEA). The physical equilibriums have been considered between the liquid and vapor phases and chemical equilibrium in the liquid phase. The SAFT-HR equation of state has been used to specify the fugacity coefficients of the components in the vapor phase. The liquid phase is considered as an electrolyte solution besides; the extended UNIQUAC has been applied to figure out the activity coefficients. The bubble point calculation has been used in this research. This method includes two main loops. Calculations related to chemical equilibrium are performed in the interior loop and the ones associated with phase equilibrium are done in the exterior loop. The solubility of carbon dioxide has been predicted by the optimized parameters of the model in the temperature range of 308.2–368.2 K. It has been calculated that the absolute average relative deviations of the model are 16.65, 19.33, 28.91 and 19.99 in the calculation of partial pressure of carbon dioxide in various loadings at the temperatures of 308.2, 328.2, 343.2 and 368.2 K.

Experimental data and modeling for density and viscosity of carbon dioxide (CO2)-loaded and -unloaded aqueous blend of 2-(ethylamino)ethanol (EAE) and aminoethylethanolamine (AEEA) for post-combustion CO2 capture

Amine based chemical absorption is the most developed technique for post-combustion CO2 capture from flue gases of low CO2 partial pressure. Density and viscosity data of CO2 – loaded and –unloaded absorbent are important in kinetics study and design the absorption column. Density and viscosity of CO2 loaded and –unloaded aqueous blend of 2-(ethylamino)ethanol (EAE) + aminoethylethanolamine (AEEA) were obtained experimentally in the temperature range of 293.15 to 323.15 K with 5 K temperature interval at atmospheric pressure. Concentration of aqueous EAE + AEEA blend was 10 wt%, 20 wt%, and 30 wt% with 7/3 weight ratio of EAE/AEEA. Excess volume was calculated by using experimental density data and correlated with Redlich-Kister type equation. Correlations were developed to calculate density and viscosity. For CO2-loaded and –unloaded aqueous EAE + AEEA blend, correlations predicted data were with average absolute deviation percentage (AAD %) of 0.1286, 0.0208, respectively for density while with AAD % 4.744, 4.433, respectively for viscosity. Wieland model was also correlated to CO2-loaded viscosity data and AAD % was 2.852 for this model. Moreover, diffusivity of CO2 into the aqueous EAE + AEEA blend was calculated using modified Stokes-Einstein equation.

Measurement of vapour-liquid equilibrium and e-NRTL model development of CO2 absorption in aqueous dipropylenetriamine.

Vapour-liquid equilibrium (VLE) of CO2 in aqueous dipropylenetriamine (DPTA) is investigated experimentally using a stirred equilibrium cell setup. Equilibrium solubility of CO2 is measured in the temperature and pressure range of (313-333) K and (1-100) kPa respectively. Composition of aqueous DPTA solvent used for the absorption study is in the range of (5-15) mass%. Experimental data shows higher CO2 loading capacity of this solvent compared to conventional solvents like monoethanolamine (MEA), 2-amino-2-methyl-1-propanol (AMP), and N-methyldiethanolamine (MDEA) as well as recently developed polyamine solvents like aminoethylethanolamine (AEEA), piperazine (PZ), and hexamethylenediamine (HMDA). Experimental VLE data is then correlated using the electrolyte non-random two-liquid (e-NRTL) theory which is an activity coefficient-based model for the electrolyte system. Data regression system (DRS) in Aspen Plus® (V8.8) is employed to fit the e-NRTL model equation with the experimental data by regressing the model parameters. Model-predicted data is found to be in good agreement with the experimental VLE data with an average absolute deviation of 22.3%. Performance of aqueous DPTA solvent is also analysed by predicting solvent capacity, equilibrium liquid-phase speciation, and heat of CO2 absorption using the newly developed e-NRTL model for the investigated system.

CO2 absorption rate in biphasic solvent of aminoethylethanolamine and diethylethanolamine

Amine scrubbing is currently the most promising technology for CO2 capture from gas turbine and coal-fired flue gas. It is hindered by high regeneration energy and high capital cost. Biphasic solvent of 25% aminoethylethanolamine (AEEA)/50% diethylethanolamine (DEEA) could be a potential solution as it may achieve significant reduction in regeneration energy. A fast CO2 absorption rate is preferred to reduce the capital cost of the absorber. In this work, the CO2 absorption rate (kg′) of the biphasic solvent was measured in a wetted wall column at 40 °C and at the loading conditions in the absorber. At CO2 equilibrium partial pressure (PCO2*) lower than 100 Pa, 25% AEEA/50% DEEA is homogeneous. The CO2 absorption rate, kg′, is as fast as 30% PZ (3 times faster than 30% MEA). When PCO2* is greater than 100 Pa, 25% AEEA/50% DEEA forms aqueous and organic phases after CO2 absorption. It was first found that the organic phase of 25% AEEA/50% DEEA absorbs CO2 2–7 times faster than the aqueous phase because of greater physical CO2 solubility at the same PCO2* and physical mass transfer coefficient. The kg′ of the organic phase is much faster than 30% MEA and 25% AEEA at lean and rich loading and even greater than 30% PZ at lean loading. The instantaneous reaction mechanism fits the kinetics of CO2 absorption in the organic phase at low PCO2*. The slow kg′ of the aqueous phase results from greater viscosity which significantly reduces the physical mass transfer coefficient. The CO2 capacity of the aqueous phase is 2.9 times, 1.8 times, and 5.3 times greater than that of 30% MEA, 30% PZ, and the organic phase, respectively.

Equilibrium CO2 solubility in the aqueous mixture of MAE and AEEA: Experimental study and development of modified thermodynamic model

In the present study, equilibrium solubility of CO2 was studied in the aqueous blend of 2-(methylamino)ethanol (MAE) and aminoethylethanolamine (AEEA). Total concentration of blend solution, weight fraction of AEEA in aqueous (MAE+AEEA) blend, temperature, and partial pressure of CO2 was varied from 10 to 30 wt %, 0.10 to 0.30, 298.15 to 323.15 K, and 8.11 to 20.67 kPa, respectively. Maximum loading 0.944 mol CO2/mol amine was occurred at 298.15 K, 20.27 kPa of CO2 partial pressure, 10 wt % total concentration with 0.30 wt fraction AEEA. The Kent-Eisenberg thermodynamic model was modified by incorporating newly introduced correction factor (Fk) to predict CO2 solubility in the aqueous blend of MAE+AEEA. Experimental data and model predicted data was in good agreement with each other. In addition, heat of CO2 absorption was also calculated for this amine blend and reported as -73.43 kJ/mol.

An Electrochemically Mediated Amine Regeneration Process with a Mixed Absorbent for Postcombustion CO2 Capture.

Electrochemically mediated amine regeneration (EMAR) was recently developed to avoid the use of thermal means to release CO2 captured from postcombustion flue gas in the benchmark amine process. To address concerns related to the high vapor pressure of ethylenediamine (EDA) as the primary amine used in EMAR, a mixture of EDA and aminoethylethanolamine (AEEA) was investigated. The properties of the mixed amine systems, including the absorption rates, electrolyte pH and conductivity, and CO2 capacity, were evaluated in comparison with those of solely EDA. The mixed amine system had similar properties to that of EDA, indicating no significant changes would be necessary for the future implementation of the EMAR process with mixed amines as opposed to that with just EDA. The electrochemical performance of the mixed amines in terms of the cell voltage, gas desorption rate, electron utilization, and energetics was also investigated. A 50/50 mixture of EDA and AEEA displayed the lowest energetics: ∼10% lower than that of 100% EDA. With this mixture, a continuous EMAR process, in which the absorption column was connected to the electrochemical cell as the desorption stage, was tested over 100 h. The cell voltage was very stable and there was a steady gas output close to theoretical values. The desorbed gas was further analyzed and found to be 100% CO2, confirming no evaporation of the amine. The mixed absorbent composition was also characterized using titration and nuclear magnetic resonance (NMR) spectroscopy, and the results showed no amine degradation. These findings that demonstrate a stable, low vapor pressure absorbent with improved energetics are promising and could be a guideline for the future development of EMAR for CO2 capture from flue gas and other sources.

Anion Modulated Structural Variations in Copper(II) Complexes with a Flexidentate Ligand Derived from 2-((2-aminoethyl)amino)ethan-1-ol: Synthesis and Spectroscopic and X-ray Structural Characterization

Flexidentate ligand, HL has been prepared by the condensation of aminoethylethanolamine (AEEA) with benzoylacetone (bezac). On reaction with copper(II) salts it gives complexes CuLClO4.H2O (1), CuLN3 (2) and [Cu3L3Br]Br2.H2O (3). All complexes have been characterized by X-ray crystallography. The results show that the hydroxyl group of the flexidentate ligand can coordinate to the Cu(II) center or remain as an uncoordinated group. In (1), the coordination number around the copper(II) ion is five coordinated and the ligand is tetradentate with the OH group coordinated to the copper(II) ion. Complex (2) has a square planar geometry and the L- ligand is tridentate with the hydroxyl group left uncoordinated. The X-ray diffraction analysis of the trinuclear complex (3) shows that the copper(II) centers are five-coordinate and L- is a tetradentate ligand with the hydroxyl group being both terminal and bridging. The Hirshfeld surface analysis and the 2D fingerprint plot were used to analyze all of the intermolecular contacts in the crystal structures.

Experimental Data and Modeling for Viscosity and Refractive Index of Aqueous Mixtures with 2-(Methylamino)ethanol (MAE) and Aminoethylethanolamine (AEEA)

In the present study, the viscosity and refractive index of pure and aqueous 2-(methylamino)ethanol (MAE) and aminoethylethanolamine (AEEA) and an aqueous blend of MAE and AEEA were measured in the...

Potential of different additives to improve performance of potassium carbonate for CO2 absorption

The performance of potassium carbonate (K2CO3) solution promoted by three amines, potassium alaninate (K-Ala), potassium serinate (K-Ser) and aminoethylethanolamine (AEEA), in terms of heat of absorption, absorption capacity and rate was studied experimentally. The experiments were performed using a batch reactor, and the results were compared to pure monoethanolamine (MEA) and K2CO3 solutions. The heat of absorption of K2CO3+additive solution was calculated using the Gibbs-Helmholtz equation. In addition, a correlation for prediction of CO2 loading was presented. The results indicated that absorption heat, absorption rate and loading capacity of CO2 increase as the concentration of additive increases. The blend solutions have higher CO2 loading capacity and absorption rate when compared to pure K2CO3. The heat of CO2 absorption for K2CO3+additive solutions was found to be lower than that of the pure MEA. Among the additives, AEEA showed the highest CO2 absorption capacity and absorption rate with K2CO3. In conclusion, the K2CO3+AEEA solution with high absorption performance can be a potential solvent to replace the existing amines for CO2 absorption.

Absorption performance of carbon dioxide in 4-Hydroxy-1-methylpiperidine + aminoethylethanolamine aqueous solutions: Experimental measurement and modeling

In this study, new experimental data was obtained for the solubility and absorption rate of carbon dioxide in 2, 3 and 4 M of 4-Hydroxy-1-methylpiperidine (HMPD) aqueous solution and the effect of addition of 0.5 and 1.5 M aminoethylethanolamine (AEEA) on it. Experimental data was measured in a bath reactor within the temperature range of 303.15–373.15 K and pressure range of 28.3–1980.3 kPa. The solution viscosity was measured at different temperature and concentration conditions. Response surface methodology (RSM) was used for modeling and optimization of the CO2 loading and absorption rate.The results of RSM showed that AEEA concentration and partial pressure of CO2 have the maximum impact on absorption rate and CO2 loading, respectively. The maximum absorption rate and CO2 loading occurred at 2M HMPD+1.35M AEEA in 320.15K and 1980.3 kPa. The measured experimental values revealed that HMPD + AEEA solution has a more desirable absorption rate, CO2 loading and oxidative degradation in comparison to methylediethanolamine(MDEA) + piperazine(PZ) aqueous solution.

Amine-impregnated silicic acid composite as an efficient adsorbent for CO2 capture

A new high efficiency inorganic–organic composite solid sorbent was developed by the simple impregnation of aminoethylethanolamine (AEEA) on the nanoporous silicic acid (SiO(OH)2) for CO2 capture from flue gas. Experimental results revealed that amine loading amount, adsorption temperature, and moisture addition could greatly affect the CO2 adsorption capacity. At the optimal AEEA loading of 55 wt%, the CO2 sorption capacity reached a maximum value of 4.54 mmol/g at 25 °C under 10 vol% CO2and 10 vol% H2O. To the best of our knowledge, this is the first time that an AEEA based adsorbent has been reported as an efficient adsorbent for CO2 capture. The AEEA impregnated SiO(OH)2 also had good stability and reusability during cyclic adsorption/desorption tests, and the sorption capacity loss may be recovered by mixing condensed AEEA with cyclic sorbents. The Avrami’s fractional order kinetic model was applied for the kinetic analysis of CO2 adsorption and desorption on the optimized sorbent. The obtained activation energy for CO2 desorption was 33.5 kJ/mol. The estimated regeneration heat duty on the optimized AEEA sorbent was 53.29 kJ/mol CO2, a great energy penalty reduction compared to that of a typical aqueous monoethanolamine system.

Non-ideal behavior of ethanol + amines mixtures, modeling using the Peng-Robinson and PC-SAFT equation of state

In this paper, experimental measurements of densities and viscosities of Ethanol + Diethylenetriamine (DETA) or Aminoethylethanolamine (AEEA) binary liquid mixtures are reported at temperatures of 298.15, 303.15 and 308.15K and atmospheric pressure over the whole composition range. From the experimental data, excess molar volume, excess coefficient of thermal expansion, excess partial molar volume, isothermal coefficient of excess molar enthalpy, excess Gibbs free energy of activation and excess viscosity were calculated. The sign and magnitude of excess quantities were used to discuss about the nature and strength of molecular interactions in these solutions. The obtained excess molar volumes were correlated with Redlich-Kister polynomial equation. Moreover, the measured values of densities were predicted with Peng-Robinson and PC-SAFT equation of states and the experimental values of viscosities were correlated and predicted by different semi-empirical equations.

Facile synthesis of nitrogen-doped carbon dots from COOH-functional ionic liquid and their sensing application in selective detection of free chlorine

Heteroatom doped carbon dots (CDs) possess many unique properties and have attracted increasing attention. The precursor is vital for the preparation of highly fluorescent heteroatom doped CDs. Herein, 1, 3-bis(carboxymethyl)imidazolium chloride ([Im(AH)2]Cl, a COOH-functional ionic liquid) and aminoethylethanolamine (AEEA) were firstly used as precursors to prepare nitrogen-doped carbon dots (N-CDs) by a simple one-step pyrolysis approach. The effects of reaction time, temperature, and mass ratio of precursors on the quantum yield (QY) of N-CDs were investigated. The prepared N-CDs are spherical morphology with an average diameter of 2.4 nm, and have blue fluorescence with a QY of 23.2% and excitation-dependent emission behavior. They also possess good water solubility and fluorescent stability. In addition, based on the obtained N-CDs, a sensing method of free chlorine detection in acidic water system was introduced. The proposed method has good sensitivity and selectivity to free chlorine, and exhibits a nice linear response in the concentration range from 0.2 to 22 μM with a detection limit of 0.15 μM. Furthermore, this sensing method was successfully applied to detect free chlorine of tap water with satisfactory recovery (97%–103%), suggesting it has the potential application in water quality monitoring.

Multicriterial Analysis of Simulated Process of Post-Combustion Capture of Pure H2S and Mixtures of H2S and CO2 Using Single and Blended Aqueous Alkanolamines

The paper evaluates the performance of the nine selected alkanolamines, namely, monoethanolamine (MEA), diethanolamine (DEA), monomethylethanolamine (MMEA), aminoethylethanolamine (AEEA), diisopropanolamine (DIPA), triethanolamine (TEA), dimethylethanolamine (DMEA), N-methyldiethanolamine (MDEA), and piperazine (PZ) for post-combustion capture of pure hydrogen sulfide (H2S) and mixtures of hydrogen sulfide and carbon dioxide (CO2) at different solvent mass flows: 500, 750, and 1000 kg/h using Aspen Plus® Version 7.2. The objective of the paper is to select the best chemical absorbent for each different criterion: percent H2S removal, percent H2S solvent carrying capacity, percent H2S retained in the lean solvent, percent CO2 and H2S removal, percent CO2 and H2S solvent carrying capacity, percent CO2 and H2S retained in the lean solvent. Based from the obtained results, piperazine is an absorbent that has a good potential for use as a single amine or in mixtures with other amines for capture of pure H2S and mixtures of H2S and CO2.