Diethylaminoethanol Research Articles

Insight and assessment of CO2 capture using diethylenetriamine/2-(diethylamino)ethanol/n-propanol water-lean biphasic solvent: Experimental and quantum chemical calculation

Biphasic solvents hold immense promise for CO2 capture, but often struggle to maintain stable performance over long-term cyclic use. Alcohols possess low dielectric constants, which can provide protons for amine-CO2 reaction products, enhancing the regeneration performance of absorbents while maintaining stability. In this study, diethylenetriamine (DETA) + 2-(diethylamino)ethanol (DEEA) + H2O was used as the biphasic solvent, with n-propanol (PrOH) serving as the regulator to develop the DETA + DEEA + PrOH water-lean biphasic solvent. Replacing half of the water with PrOH improved the cyclic stability of the absorbent, reduced the rich phase ratio (46 %) and energy consumption (2.05 GJ·ton−1 CO2), while effectively enhanced corrosion resistance and thermal stability, confirming the feasibility of PrOH as the regulator. The detailed reaction mechanism of the absorbent for CO2 absorption was elucidated through 13C NMR and DFT calculations. Quantum chemical calculations have provided the first compelling evidence for PrOH’s involvement in the absorption reaction: PrOH stores the reaction products in the form of PrOCOOH/PrOCOO−. By regenerating DETA, it restores its CO2 absorption capacity. Through polarity and hydrogen bonding, the reaction products aggregate in one phase, enhancing CO2 loading. In summary the PrOH regulated water-lean biphasic solvent presents a highly promising absorbent for industrial use.

Bipolar membrane electrodialysis for amine regeneration from amine chloride stream: Closing the amine utilization loop

The amine-based CO2 capture & mineral carbonation (CCMC) using alkaline slag emerges as a decarbonation means. However, being the most costly component in the process, amine is consumed in large quantity yet its regeneration is overlooked. Thus, to close the material utilization loop, this work proposed the bipolar membrane electrodialysis (BMED) technology for amine regeneration from its chloride streams. With customized BMED configurations, the recovery of two different amines(monoethanolamine (MEA) & 2-(Diethylamino)ethanol (DEAE)) was investigated respectively to reveal the separation mechanisms. This novel concept was firstly proved with a three-compartment configuration, where the cations (MEA+ or DEAE+) can pass through the cation exchange membrane and react with OH− generated by the bipolar membrane thus producing pure amine. The respective MEA and DEAE regeneration reached up to 95.1 % and 92.4 % within 10 h; while the yield of a useful byproduct 1.8 wt% HCl reached ∼ 71 %, which can be reused in CCMC. The results showed that the membrane played a key role: with standard anion exchange membrane (AEM), the Cl− transfer rate decreased with increasing feed concentration. Although the proton blocking AEM avoided H+ cross-over, the Cl− transfer was stable but exhibited up to 2.5-times lower transfer rate. Via a comprehensive parametric study, a modest current density (150 A/m2) was chosen to avoid significant energy penalty, corresponding to a power consumption of 10.3 kWh/(kg amine). Compared to the acid model, the base model of two-compartment configuration, had 2x higher amine yield and higher energy efficiency. This study revealed the performance-limiting factors in BMED, inspiring future design of efficient amine regeneration system for closed-loop CCMC process and contributing to sustainable processing towards carbon neutrality.

Amino acids to reduce the escape of organic amines in the CO2 capture process

Carbon neutrality and carbon peaking are important strategic policies for our country. Carbon dioxide capture technology is the bottom of the realization of this strategy, in which amine escape is an important issue for the development of this technology. Herein, the proposal to utilize amino acids for reducing volatilization of organic amines was introduced for the first time. Diethylaminoethanol (DEEA), widely applied and highly volatile, was selected as the primary target for volatility reduction, while hydroxyethyl ethylenediamine (AEEA) and piperazine (PZ) were chosen as the main absorbents for absorption and desorption processes. The effects of DEEA addition on the main absorbent, different types of amino acid additives on volatility, and amino acids on absorption and desorption performance were investigated, respectively. Glutamine (Tyr) demonstrated significant potential in reducing the volatilization of organic amines; when 2% Tyr was added during gas–liquid equilibrium experiments, it resulted in a 74.5% decrease in DEEA volatilization within the absorbent system. Simulated gas–liquid entrainment escape showed that CO2 loading reduced volatilization by 42.31%, with a further reduction of 53.93% achieved when loaded with 0.5 molCO2/mol amine; this loading also had a promotional effect on absorption and desorption processes. Moreover, Tyr exhibited excellent stability without generating any degradation products, thereby prolonging absorber lifespan and minimizing economic cost losses.

Industrial test of post combustion CO2 capture by reactive absorption with two new solvents in natural gas power plant

The post-combustion chemical decarbonization process is one of the key technology selections for the low-carbon development of natural gas power plants. The high energy consumption of amine regeneration is hindering its commercial application. In this paper, two new mixed amines solvent 15%Diethylaminoethanol (DEEA) +9% Piperazine (PZ)+ 6% Monoethanolamine (MEA) named DT01-3 and 22% 1,4-butanediamine (BDA)+ 4% N-Methyldiethanolamine (MDEA) + 4% 2-Amino-2-methyl-1-propanol (AMP) named DT02-2 are verified by the 3000Nm3/h industrial demonstration system. The steady state condition was gradually established by adjusting the main parameters such as flue gas flow rate, absorber inlet flue gas temperature, solvent circulation flow rate, regeneration tower operation pressure, steam flow rate and so on with the goal of maintaining ≥90% of the capture efficiency. The results show that the CO2 capture efficiency of DT01-3 and DT02-2 is 91.23% and 90.81% respectively. The regeneration heat consumption is 3.65 GJ/tCO2 and 3.73 GJ/tCO2. The amines consumption is 0.95kg/tCO2,1.1kg/tCO2. The operating cost of DT01-3 and DT02-2 is 336.37 CNY/t,346.04 CNY/t, which is 20.94%,18.68% lower compared with MEA.

The Role of the Geometric Configuration of Diethylaminoethanol Derivative in the Pharmaceutical Development of a Dosage Form Based on It

Introduction. A comprehensive study of the active pharmaceutical ingredient (API) molecule is one of the defining criteria for pharmaceutical development according to the Quality by Design (QbD) concept and the ICH Q8 framework. The spatial arrangement of atoms in the molecule often has a significant impact on the physicochemical and technological properties of API, and hence on the method of producing dosage form based on it.Aim. To study some properties of substances, geometrical isomers of the molecule, which is a derivative of diethylaminoethanol (DEAE), as well as to compare the selected technologies for the preparation of dosage form.Materials and methods. The objects of the study were two substances, spatial isomers of the molecule, a derivative of DEAE, possessing neuroprotective, antiastenic and antioxidant effects. The study of properties of API and the obtained tablets was carried out in accordance with the requirements of the State Pharmacopoeia of the Russian Federation XIV edition, the Pharmacopoeia of the Eurasian Economic Union, as well as the European Pharmacopoeia 9.0 edition. In this research were used substances that have not expired at the time of the study, as well as authorized for medical use.Results and discussion. The geometrical configuration of the DEAE derivative influences the properties of the API, which has an impact on the stages of pharmaceutical development, especially on the development of the technology and formulation of dosage form. The use of cis-DEAE significantly simplifies the technological process and improves the quality of the resulting drug, and as a consequence, better stability and longer shelf life of dosage form may be achieved.Conclusion. In the course of the study, some properties of cis-DEAE API were studied and compared with similar properties of trans-DEAE. A comparison of tablet preparation technologies based on the two mentioned configurations of the DEAE derivative molecule has been carried out. It was found that the isomers have different technological properties and also differ significantly in moisture adsorption capacity. This property determines the approach to tablet preparation. The technology of tablets based on cis-DEAE appears to be simpler, and dosage form based on it is more stable.

A facile synthesized robust catalyst for efficient regeneration of biphasic solvent in CO2 capture: characterization, performance, and mechanism

Amine-based technology is promising for CO2 capture from the flue gas. However, it encounters high energy penalty and thus hampers its industrial application. Currently, the catalytic solvent regeneration is developing to lower down regeneration temperature, accelerate regeneration rate, and cut down energy consumption for monoethanolamine (MEA)-based process. However, the information on catalytic regeneration of biphasic solvent is seldom available. This work develops a facile synthesized robust catalyst, α-Fe2O3, to promote the biphasic solvent regeneration such as triethylenetetramine (TETA) and 2-(diethylamino) ethanol (DEEA) blend. Experimental results revealed that, with the aid of α-Fe2O3, the efficient regeneration of TETA-DEEA occurred at 94 °C, which is far below the conventional MEA-based process (110–120 °C). The corresponding CO2 stripping rate increased by 2.4 times compared with uncatalytic scenario. Furthermore, the relative energy consumption was furtherly decreased by 41.6%. Different from MEA regeneration, the biphasic solvent regeneration with α-Fe2O3 depended on the enhancement of water molecules proton donation rather than the abundant Brønsted acid and Lewis acid of the catalyst. Based on DFT calculation and 13C NMR spectra analysis, the water molecules on α-Fe2O3 surface and the protonated DEEA were parallel served as proton donors for carbamate decomposition. Consequently, a novel proton transfer mechanism was proposed for the biphasic solvent TETA-DEEA regeneration. The water molecules adsorbed on α-Fe2O3 surface generated oxyhydrogen groups and thus donate protons for the carbamate decomposition. This work proposes a novel proton transfer mechanism for solvent regeneration and advances its industrial application with a low energy penalty.

Probing molecular interactions in the system {water + 2-(diethylamino) ethanol} using solvatochromic dyes and excess partial molar enthalpies, at 298.15 K

The polarity of the binary {water + 2-(diethylamino)ethanol (DEEA)} mixtures was investigated, across the whole composition range using solvatochromic dyes, expressed in terms of the Kamlet-Abboud-Taft (π*, α, β) and ETN Reichardt parameters, at 298.15 K. The preferential solvation model of Bosch and co-workers was applied to each solvatochromic dye. Direct excess partial molar enthalpies, HiE, for the same system, at the same temperature and atmospheric pressure, were obtained at both ends of the composition range using a semi-adiabatic isoperibol solution calorimeter and an expeditious method pioneered by Yoshikata Koga. Infinite dilution values of this same thermodynamic property were calculated for the DEEA in water and for the water in DEEA and compared with the literature values for the systems {water + 2-(dimethylamino)ethanol (DMAE)} and {water + 2-(ethylamino)ethanol (EEA)}, to infer the effect of branching and chain length on this property. Values for the interaction enthalpy between pairs of molecules of the same species, HiiE, were also estimated, in the same composition ranges studied, revealing endothermic processes, at both ends. A successful multiparametric correlation between excess partial molar enthalpy of DEEA and the solvent polarity parameters, π*, α and β allowed to quantitatively discriminate the relative relevance of the different types of the DEEA-solvent interactions.

Investigation of viscosity, activation energy and CO2 diffusion coefficient for N-methyl-1,3-propane-diamine, N-(2-aminoethyl)ethanolamine and 1,4-butanediamine activated 2- diethylaminoethanol aqueous solutions

The viscosities of N-(2-aminoethyl)ethanolamine (AEEA), 1,4-butanediamine (BDA) and N-methyl- 1,3-propane- diamine (MAPA) activated 2- diethylaminoethanol (DEAE) aqueous solutions were measured at temperatures (T) from 303.2 K to 323.2 K, respectively. The DEAE mass fractions (wDEAE) and the other three amines (wAEEA/wBDA/wMAPA) are 0.300 to 0.500 and 0.050 to 0.150 respectively. The Weiland equation was used to calculate the viscosity of these three solutions, and the calculation results were satisfied with data of the experimental results. With the aid of experimentally determined viscosity data, the activation energy (Ea) of these three solutions was predicted through the Arrhenius formula. With the help of the viscosity data and the diffusion coefficient model of CO2 in water, the CO2 diffusion coefficient (DCO2) in these three solutions was calculated. The quantitative relationship between the calculated values (viscosity, activation energy and diffusion coefficient) and the operation conditions (solution mass fraction and temperature) was analyzed. Our results show that the DEAE-BDA absorbent has better application potential due to its lower viscosity, higher CO2 diffusion coefficient and lower activation energy.

The Kinetics Investigation of CO2 Absorption into TEA and DEEA Amine Solutions Containing Carbonic Anhydrase

Tertiary amines have been used as alternative absorbents for traditional primary and secondary amines in the process of carbon capture. However, the carbon dioxide (CO2) absorption rates in these kinds of amine are relatively slow, which implies greater investment and construction costs and limits the large-scale application of carbon capture. Carbonic anhydrase (CA) is considered to be an ideal homogeneous catalyst for accelerating the rate of CO2 into aqueous amine solution. In this work, CO2 absorption combining CA with two single aqueous tertiary amines, namely triethanolamine (TEA) and 2-(diethylamino)ethanol (DEEA), was studied by use of the stopped-flow apparatus over temperature ranging from 293 to 313 K. The concentrations of selected aqueous amine solution and CA used in the experiment were ranging among 0.1–0.5 kmol/m3 and 0–50 g/m3 , respectively. Compared to the solution without the addition of CA, the pseudo first-order reaction rate in the presence of CA (k0,withCA) is significantly increased. The values of k0,withCA have been calculated by a new kinetics model. The results of experimental and calculated k0,amine and k0,withCA in CO2-amine-H2O solutions were also investigated,respectively.

Evaluation on water balance and amine emission in CO2 capture

CO2 capture using amine-based solvent is now available for large scale deployment. Water balance and amine emission are drawing more and more attention as they have significant impacts on operation stability, economic cost and environmental pollution. However, experimentally investigating a new amine solvent in a demonstration test platform is time-consuming and costly. In this paper, a shortcut method was developed based on volatility data of a solvent to evaluate water balance and amine emission in CO2 capture system. Water balance can be achieved by employing a simple water wash after absorber and regulating water wash temperature according to flue gas temperature, CO2 concentration, and CO2 removal efficiency. Simple water wash reduces monoethanolamine (MEA) emission from absorber (215–425 mg/m3) to a level below 5 mg/m3. With constant water wash temperature, increasing absorber temperature condenses more water which is beneficial for reducing amine emission. Variable amines and configurations are also evaluated. Simple water wash is not efficient for those volatile solvents such as 40% 2-amino-2-methyl-1-propanol (AMP), piperazine (PZ)/1-(2-Hydroxyethyl)piperidine (HEPD), MEA/N-methylpyrrolidone (NMP) water-lean solvent, and 2-(diethylamino)ethanol (DEEA)/2-((2-aminoethyl) amino) ethanol (AEEA) biphasic solvent as their amine emissions after simple water wash are still higher than 100 mg/m3. For those solvents with moderate volatility, such as 30%MEA and 30–40%AMP, a second water wash is effective to reduce amine emission below 1 mg/m3. While for those highly volatile solvents, such as PZ/HEPD and DEEA blended biphasic solvents, acid wash for further amine emission reduction may be more competitive in view of capital cost and operation cost.

Inhibition of carbon steel corrosion in HCl solution using N-oleyl-1,3-propanediamine based formulation

The relatively environmentally benign ingredient diethyl-aminoethanol (DEAE) was introduced into the film forming amine (FFA) formulation based on the unsaturated diamine N-oleyl-1,3-propanediamine (NOPDA). The optimal FFA formulation was determined by orthogonal experiment. The high corrosion inhibition efficiency of 92.1% and the images of scanning electron microscopy (SEM) and atomic force microscopy (AFM) confirmed the excellent corrosion inhibition effect of the improved FFA formulation in 1.0 M HCl acidic environment. The results proved that DEAE could promote the emulsification and dissolution of NOPDA in aqueous solution and therefore facilitate its adsorption onto carbon steel surface. The weight loss experimental results showed that the adsorption of the FFA inhibitor onto metal surface was endothermic and conformed to Langmuir isotherm model. Electrochemical impedance spectroscopy (EIS) analysis proved that a protective film was formed on the surface of carbon steel to prevent the transfer of charge. Contact angle measurements indicated that the film formed on the surface of the carbon steel was hydrophobic. According to X-ray photoelectron spectroscopy (XPS) analyses and thermodynamic calculation, it is inferred that the adsorption mechanisms mainly involved chemisorption, electrostatic attraction and hydrogen bonding. The results of this study provide a good reference for the application of unsaturated fatty diamine. • Weight loss and EIS experiments were carried out to investigate the anti-corrosion performance. • The emulsification and dissolution of NOPDA in water could be promoted by DEAE. • NOPDA-based formulation exhibited excellent corrosion inhibition performance in HCl. • FFA adsorption isotherm and thermodynamics were studied. • SEM, AFM and XPS analyses were performed and anti-corrosion mechanisms were inferred.

Volatility of 2-(diethylamino)-ethanol and 2-((2-aminoethyl) amino) ethanol, a biphasic solvent for CO2 capture

Amine volatility may be a critical problem with biphasic solvent for CO2 capture such as the blend of 2-(diethylamino)-ethanol (DEEA) and 2-((2-aminoethyl) amino) ethanol (AEEA). The Henry’s law constant (Ham) of DEEA and AEEA in water at 40 and 50 °C was measured using a hot gas FTIR. DEEA is 20–30 times more volatile than monoethanolamine (MEA) while AEEA is nearly non-volatile. At lean loading, the amine volatility is 327 ppm in 12 m DEEA and 1.1 ppm in 2.5 m AEEA at 40 °C. The NRTL model shows good consistency with the DEEA-H2O data for amine and water activity coefficients. Amine volatility in 12 m DEEA with 0 to 0.4 mol CO2/mol DEEA and in 2.5 m AEEA with 0 to 0.9 mol CO2/mol AEEA at 40 and 50 °C was also measured. DEEA partial pressure (PDEEA) increases with CO2 loading even though there is less free DEEA in the loaded solutions. The ionic reaction products of DEEA and CO2 increase the ionic strength and DEEA activity coefficient. The effect of ionic strength on the DEEA activity coefficient was confirmed with data for 12 m DEEA-H2O-KNO3 and 12 m DEEA-H2O-H2SO4. AEEA partial pressure (PAEEA) decreases with CO2 loading as AEEA is converted by the reaction with CO2 to other non-volatile species.

Profiling of Cholinesterase Extracted from The Brain Tissue of Diodon hystrix and Its Inhibition Reaction Towards Carbamates

Diodon hystrix, commonly known as spot-fin porcupine fish is a salt-water fish belonging to the Diodontidae family. It is widely distributed in Sabah wet market due to its commercial value. This study exploits the effectiveness of Cholinesterase (ChE) obtained from the brain tissue of D. hystrix in detecting carbamates inhibitory activities. Carbamate pesticides known to inhibit ChE and toxic towards living organisms can contaminate the water bodies. By using diethylaminoethanol (DEAE) Sepharose ion exchange chromatography, a total of 40% recovery yield of ChE was obtained with a 165.77 purification fold. Furthermore, the ChE showed a high affinity towards acetylthiocholine iodide (ATC) with an optimum activity at pH 7.45 and temperature ranging from 20 to 40℃. Among five different types of carbamates, methomyl was found to have the highest percentage of inhibition analyzed using ChE inhibitory assay, followed by carbofuran, bendiocarb, carbaryl and propoxur with >85% inhibition rate. The results concluded that ChEs extracted from the brain tissue of D. hystrix are applicable to be used as a bioindicator in detecting the presence of carbamates.

Purification and antioxidant and anti-Inflammatory activity of extracellular polysaccharopeptide from sanghuang mushroom, Sanghuangporus lonicericola.

Sanghuang mushrooms are medicinal fungi widely used in eastern Asia. In this study, the antioxidant and anti-inflammatory activity of a novel extracellular polysaccharopeptide, sanghuang extracellular polysaccharopeptide (SePSP) was investigated. The SePSP was purified from the submerged fermentation broth of a sanghuang mycelium, Sanghuangporus lonicericola strain CBS17, which was isolated from a wild sanghuang fruiting body. The SePSP was extracted using an ethanol precipitation procedure, followed by diethylaminoethanol (DEAE) anion-exchange and size-exclusion chromatography. The mass ratio of the polysaccharide and peptide components in the purified SePSP was approximately 4.87:1. By determining its free radical scavenging abilities using 2,2-diphenyl-1-picrylhydrazyl (DPPH), the hydroxyl free radical, and the superoxide anion free radical, as well as its total reducing power, SePSP was shown to have strong concentration-dependent antioxidant activity in vitro. Further, SePSP effectively alleviated dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) in mice. Administration of 200 mg kg-1 SePSP by gavage for 7 days prevented body weight loss; significantly reduced the mRNA levels of proinflammatory cytokines, including TNF-α and IL-1β; increased mRNA level of the anti-inflammatory cytokine IL-10 in the colon, and decreased the malondialdehyde concentration from 6.42 to 4.82 μmol L-1 in the blood in UC mice. The SePSP had strong concentration-dependent antioxidant activity in vitro and effectively alleviated DSS-induced UC in mice. The in vivo therapeutic efficacy in DSS-induced UC may be mediated by modulating the expression of inflammatory cytokines and inhibiting oxidative stress. The findings provide a scientific rationale for the use of bioactive nutraceuticals from sanghuang mushrooms to develop functional foods for the prevention and treatment of UC. © 2020 Society of Chemical Industry.

Effects of compound growth regulators on the anatomy of Jujube Leaf and Fruit.

Effects of three compound growth regulators formulated with hypersensitivity protein, spermidine, salicylic acid and DA-6 (diethyl aminoethanol hexanoate) were tested on Xinjiang Jun Jujube. The doses of compound growth regulators were named as A (Hypersensitivity protein + spermidine + salicylic acid at the rate of 30 mg/L, 0.1 mmol/L and 0.25 mmol/L, respectively), B (Hypersensitive protein + spermidine + DA-6 at the rate of 30 mg/L, 0.1 mmol/L and 30 mg/L, respectively) and C (Spermidine + salicylic acid + DA-6 at the rate of 0.1 mmol/L, 0.25 mmol/L and 30 mg/L, respectively) versus a control group CK (contained only water). Fruit anatomical structures were compared after spraying. The results indicated that after spraying, the thickness of the upper and lower epidermal cells and the stratum corneum were increased. However, the upper epidermal stratum corneum became significantly thicker than the lower epidermis. Spraying with A improved the thickness of upper and lower epidermal cells, stratum corneum, the central vein and mesophyll. The cumulative effects of all these changes in leaf and fruit anatomical structures provided the resistance of the experimental fruit plant to stress. While the B and C regulators had inhibitory effects. So, the results obtained after spraying A category were beneficial to improve the stress resistance of the fruits. The length and cell area of pericarp and sarcocarp cells in the treatment groups were not changed significantly. But the length, number of sarcocarp cells and number of gaps were lower than those in the CK. This study can provide new measures for improving plant resistance in jujube production.

Selection of efficient absorbent for CO2 capture from gases containing low CO2

Amine-based absorption processes are widely used in natural gas processing, but recently they have been considered for CO2 capture from flue gas emitted from thermal power plants. The main issue of amine used in the CO2 capture process is the high cost of solvent regeneration. So, this issue can be solved by using efficient amine absorbent. The amine type absorbents employed in the experimentation were an aqueous blend of 2-(Diethylamino)ethanol (DEEA) with different types of diamine activators such as piperazine (PZ), 2-(2-aminoethylamino)ethanol (AEEA), hexamethylenediamine (HMDA), ethylenediamine (EDA), and 3-(Dimethylamino)-1-propylamine (DMAPA). An absorption experiment was performed to evaluate the CO2 absorption performance in terms of CO2 loading, absorption capacity, and absorption rate. The experiment was performed to assess the CO2 desorption performance in terms of desorption capacity, desorption rate, cyclic capacity, and regeneration efficiency. From the results of absorption-desorption and comparison with benchmark amine absorbent MEA, the aqueous blend of DEEA and HMDA indicated the best performance for CO2 capture applications among all the tested amine blends.

Equilibrium Solubility Measurement and Modeling of CO2 Absorption in Aqueous Blend of 2-(Diethyl amino) Ethanol and Ethylenediamine

The equilibrium CO2 solubility in an aqueous blend of 2-(diethyl amino) ethanol (DEEA) and ethylenediamine (EDA) was performed at atmospheric pressure with the use of a laboratory scale bubbling absorber. The total concentration of amine blend solution in the range of 1.13–4.90 mol·kg–1 and the EDA mole fraction in the total amine blend in the range of 0.05–0.20 were taken. The experiments for the measurement of CO2 solubility were performed at a temperature range of 303.15–333.15 K and CO2 partial pressure range of 10.13–20.27 kPa. The analysis of CO2 in the liquid phase was accomplished by a direct titration method using HCl solution. The solubility data of CO2 in DEEA+EDA solution of the present study were compared with data available in the literature. The experimental results were applied to develop an empirical mathematical model with an average absolute deviation of 7.03% to predict the CO2 equilibrium solubility in DEEA+EDA solution within the specified range of operating conditions. In addition, ...

Kinetics of CO2 absorption into aqueous solutions of 3-dimethylamino-1-propanol and 1-(2-hydroxyethyl)pyrrolidine in the blend with 3-(methylamino)propylamine

The kinetics of CO2 absorption into unloaded aqueous solutions of 3-dimethylamino-1-propanol (3DMA1P) and 1-(2-hydroxyethyl)pyrrolidine (1-(2HE)PRLD) blended with 3-(methylamino)propylamine (MAPA) were studied in the temperature range of 29–63 °C using a string of discs contactor. In addition, density and viscosity of the blended amines were measured in the temperature range of 25–80 °C, and N2O solubility was measured in the temperature range of 30–90 °C. The obtained results were compared with blends of 2-(diethylamino)ethanol (DEEA) and MAPA.The present study indicated that the blended amines, with varying solvent concentration, obtained comparable values for the overall mass transfer coefficient due to competing effects between solubility, diffusivity and reaction kinetics. The solubility of CO2 was higher in DEEA/MAPA than in the other blended amines, while the calculated values for the pseudo-first order kinetic constant were higher for the 3DMA1P/MAPA and 1-(2HE)PRLD/MAPA solutions than for the DEEA/MAPA solution. The pseudo-first order kinetic constants were correlated to the direct mechanism with reasonable accuracy. The contribution of the tertiary amine as a proton receiver for the MAPA-CO2 reaction represented between 53 and 70% of the pseudo-first order kinetic constant.

Volumetric and viscometric properties of binary and ternary mixtures of monoethanolamine, 2-(diethylamino) ethanol and water from (293.15 to 333.15) K

The densities and viscosities of binary mixtures monoethanolamine (MEA) + H2O, 2-(Diethylamino)ethanol (DEEA) + H2O, MEA + DEEA and ternary mixtures MEA + DEEA + H2O were measured over the entire composition at temperatures ranging from (293.15 to 333.15) K and atmospheric pressure. The volumetric and viscometric properties such as excess molar volume, partial molar volume, partial molar volume at infinite dilution, apparent molar volume, viscosity deviation, molar enthalpy, molar entropy and the molar Gibbs energy of activation for viscous flow of mixtures were calculated in terms of experimental data, respectively. Furthermore, excess molar volumes were fitted by the Redlich–Kister equation for binary mixture and by Cibulka equation for ternary solution. The volumetric and viscometric properties were analyzed through the molecular structure and intermolecular interactions.

Vapour-liquid equilibrium study of tertiary amines, single and in blend with 3-(methylamino)propylamine, for post-combustion CO2 capture

This work studies the potential of using the tertiary amines 3-dimethylamino-1-propanol (3DMA1P), 3-diethylamino-1-propanol (3DEA1P) and 1-(2-hydroxyethyl)pyrrolidine (1-(2HE)PRLD) as an alternative to 2-(diethylamino)ethanol (DEEA) in the blend with 3-(methylamino)propylamine (MAPA). Vapour pressure of the three tertiary amines and vapour-liquid equilibrium (VLE) of the binary mixtures 3DMA1P/H2O, 3DEA1P/H2O and 1-(2HE)PRLD/H2O at T = (353, 363 and 373) K were measured in a modified Swietoslawski ebulliometer. The vapour pressure of the pure amines was fitted to the Antoine equation, and the P-T-x-y data were fitted to NRTL equations. VLE of the CO2 loaded blended amines were measured in the temperature range of T = 313 to 393 K, and speciation data of equilibrated samples at different CO2 loadings were obtained by NMR spectroscopy.The study showed that the tertiary amines 3DMA1P, 3DEA1P and 1-(2HE)PRLD in the binary amine/H2O system were less volatile than DEEA in aqueous solution. The CO2 loaded blended amines showed comparable VLE behaviour, as well as speciation, and obtained a cyclic capacity higher than that of 30 wt% MEA but similar to most of the blended amines studied in the literature. The overall results indicated that the tertiary amines studied in this work can be used as an alternative to DEEA.