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•Experimental investigation of CO2 solubility in novel solvents has been done.•KE model inclusive of gas phase non-ideality was used to correlate solubility.•Reversible ionic liquids ...formation TESA-CO2 reaction is confirmed by 13C NMR.•Bond formations/shifts studied by FTIR analysis of loaded and unloaded solvents.
The quest of energy efficient post combustion CO2 capture through an integrated process approach leads to the development of various novel solvents which can yield the necessary outputs. In line with this, the current work explores the experimental and simulation analysis of vapor liquid equilibrium of CO2 in novel aqueous 3-aminoproyl triethoxysilane (TESA) solvent blends enhanced by amine activators. Specific amine activators, viz. 1-(2-aminoethyl) piperazine (AEP) and bis (3-aminopropyl) amine (APA) were considered. The experiments were carried out over the temperature range of (303.2–323.2) K and pressure of (4–350) kPa. In order to realize the effect of activator, AEP/ APA concentration was gradually increased from 0.5 to 1.0 mol/kg with a total solvent concentration of ≈3 mol/kg. Along with this, qualitative 13C NMR and FTIR analysis were also performed to assess the proposed reaction scheme. The experimental vapour liquid equilibrium data (VLE) were correlated by modified Kent-Eisenberg equilibrium model considering gas phase non-ideality as well as non-rigorous statistical non-linear model. The equilibrium constants associated to deprotonation of protonated TESA, AEP and APA as well as carbamate formation reactions of these amines with CO2 are function of solvent concentration, temperature and CO2 partial pressure. These are regressed to fit the experimental VLE data. The modified KE model is further prolonged to estimate the concentration profiles of various molecular and ionic species involved in the reactive system.
•Thermophysical properties of six novel hybrid solvent blends were investigated.•Redlich-Kister and Grunberg-Nissan Model were used to correlate density & viscosity.•Statistical correlations used to ...model sound velocity, surface tension & RI.•Important thermodynamic and transport properties were derived from viscosity data.
The surge in energy demand globally has resulted in high level of CO2 emissions through large industrial point sources. Chemical or physical absorption is one of the widely used methods utilized for large scale CO2 capture. The utility of any solvent in CO2 absorption system requires the detail fundamental understanding of physicochemical properties associated with the solvent. In the present work, physicochemical properties of six different aqueous blends of hybrid solvents of (3-aminopropyl) triethoxysilane (TESA), N-methyldiethanolamine (MDEA), sulfolane (TMSO2), 1-butyl-3-methyl-imidazolium acetate (bmimAc) activated by 1-(2-aminoethyl) piperazine (AEP), bis-(3-aminopropyl)amine (APA) and 2-methyl piperazine (2-MPZ) are studied. Various important physiochemical properties needed for process design viz. density, viscosity, surface tension, refractive index and sound velocity are measured over a broad range of temperature (298.15–333.15) K and concentration. Redlich-Kister and Grunberg-Nissan models have been used for correlating density and viscosity. Statistical regression have been applied for correlating sound velocity, refractive index and surface tension. Important derived properties of the proposed solvents have been also evaluated through empirical correlations.
Novel aqueous (aq) blends
of
N
-methyldiethanolamine (MDEA), sulfolane (TMSO
2
), and 1-butyl-3-methyl-imidazolium acetate (bmimAc) with
amine activator 2-methylpiperazine (2-MPZ) are analyzed ...through conductor-like
screening model for real solvents (COSMO-RS) for possible application
in the chemisorption of CO
2
. The molecules associated are
analyzed for their ground-state energy, σ potential, and σ
surface. Thermodynamic and physicochemical properties have been assessed
and paralleled with the experimental data. Vapor pressure of the blended
systems and pure component density and viscosity have been compared
successfully with the experimental data. Important binary interaction
parameters for the aqueous blends over a wide temperature, pressure,
and concentration range have been estimated for NRTL, WILSON, and
UNIQUAC 4 models. The COSMO-RS theory is further applied in calculating
the expected CO
2
solubility over a pressure range of 1.0–3.0
bar and temperature range of 303.15–323.15 K. Henry’s
constant and free energy of solvation to realize the physical absorption
through intermolecular interaction offered by the proposed solvents.
Perceptive molecular learning from the behavior of chemical constituents
involved indicated that the best suitable solvent is aq (MDEA + 2-MPZ).
One of the ever-demanding research fields is the development of new solvents with better properties for mitigation of CO2 compared to existing solvents. This work reports the measurement and modeling ...of CO2 solubility in newly proposed aqueous solvent blends of 2-methyl piperazine with N-methyldiethanolamine (MDEA), sulfolane (TMSO2), and 1-butyl-3-methyl-imidazolium acetate (bmim Ac). The operating temperature and CO2 partial pressure conditions chosen were 303.2–323.2 K and 2–370 kPa, respectively. Along with this, qualitative 13C NMR and FTIR analysis were also performed to consider the proposed reaction scheme. The experimental vapor–liquid equilibrium data were modeled by a modified Kent–Eisenberg equilibrium model. The equilibrium constants associated with 2-methyl piperazine (2-MPZ) and bmim Ac deprotonation and carbamate formation reactions were regressed to fit the experimental CO2 solubility data. In addition, the CO2 cyclic capacity and heat of absorption were evaluated for the aq (MDEA + 2-MPZ) blend.
The present work demonstrates the experimental and theoretical study of equilibrium CO2 solubility in a potential absorbent, aqueous 1-(2-aminoethyl) piperazine (AEP) and its blend with ...2-amino-2-methyl-2-propanol (AMP). The measurements have been conducted at 303.2 to 323.2 K and within the CO2 partial pressure range of 2 to 250 kPa. The experimental data are modeled using modified Kent-Eisenberg (KE) equilibrium model for all the concentration range. Carbamate hydrolysis and AEP deprotonation constants are expressed as a function of pressure, temperature and amine concentration from the modified KE model. The developed model is used to predict the equilibrium liquid phase speciation in the CO2 loaded amine solution. An artificial neural network (ANN) model is also developed to predict the CO2 solubility in the understudy solvent system. The feed forward ANN model provides very good prediction with respect to the experimental solubility data having an average absolute deviation (% AAD) of 0.16. Qualitative 13C NMR and FTIR-ATR analysis have been performed for CO2 loaded solvent to understand the reaction scheme and identify the various important reaction products. Further, physicochemical properties such as density and viscosity of both the binary and ternary solvent system were also determined and correlated using Redlich-Kister and Grunberg-Nissan models.
•Equilibrium CO2 solubility measured in novel solvents•Modified Kent-Eisenberg and ANN model were used to correlate the solubility data.•FTIR-ATR and 13C NMR investigation carried out to assess the reaction scheme•pH and cyclic capacity of the loaded solvent were estimated.•Modified RK and GN models were used to correlate density and viscosity.
Organic acid-based bioleaching has attracted significant research interest for the recovery of rare earth elements (REEs) and other critical metals. Utilizing biologically produced leaching agents, ...known as biolixiviants, derived from waste materials holds great promise for enhancing the economic viability and environmental sustainability of bioleaching processes. This study focuses on the modeling and optimization of biolixiviant production using corn stover (CS), date palm clippings (DP), and nonrecyclable paper (NP). Techno-economic analysis revealed that gluconic acid production from NP is more cost-effective than that from CS and DP, with respective costs of $0.04/kg, $0.06–0.08/kg, and $0.06–0.09/kg of the biolixiviant, yielding gluconic acid concentrations of 135.39, 172.90, and 176.87 mM, respectively. Life cycle assessment demonstrated that biolixiviant production from NP exerts the lowest environmental impact compared with the other evaluated substrates. When applied to the bioleaching of a neodymium–iron–boron magnet swarf, the biolixiviant derived from NP exhibits the highest leaching efficiencies, confirming its cost and environmental competitiveness in comparison to CS and DP.
The non-linearity in the CO2 absorption process in the novel aqueous blends of TESA and amine activators AEP and APA is studied through COSMO-RS method. The energy associated with each molecule is ...estimated using Turbomole. Analysis of the chemical compounds for suitable CO2 absorption is carried out using the trends of sigma potential and sigma surface. Various significant thermodynamic properties (activity coefficient, chemical potential, excess enthalpy and excess Gibbs free energy, infinite dilution activity coefficient) and thermophysical (vapor pressure, density, viscosity) properties of the blends are estimated and compared with the experimental data. The binary interaction parameters for the systems under study using NRTL, WILSON and UNIQUAC 4 models is carried out. All the interaction parameters are functional to temperature and molecular properties of the constituents involved. CO2 solubility of three blended solvents at various concentration and temperatures is reported at (1.0–3.0) bar solute partial pressure. Important chemical reaction parameter pKa of the amine activators in various solvents is estimated at room temperature. An insightful study for the studied systems indicate their possible usage for CO2 absorption and of the many systems studied, the best suitable solvent being aq. (TESA + APA).
•aq. (TESA + AEP/APA) are explored for CO2 solubility using COSMO-RS theory.•p(σ) &μ(σ) have been analysed functional to σ for hydrogen bond acceptor/donors.•pKa, ln(γ∞), ln(γ), μi, GE &HE of studied systems are investigated.•NRTL, WILSON & UNIQUAC 4 interaction parameters are estimated for studied systems.•ρ, η, Pv, xCO2 &HCO2 are estimated and studied for CO2 solubility.
Equilibrium CO2 solubility data plays a pivotal role in the process design of the post-combustion CO2 capture Unit. In the current study, statistical non-rigorous models are developed to predict the ...solubility of carbon dioxide (CO2) in different aqueous blends of ionic liquids (ILs) and blends of ILs with alkanolamines, ethanol, etc. These correlations are utilized to estimate the liquid phase CO2 loading as a function of CO2 partial pressure at different temperature conditions. The correlations can predict CO2 solubility in the liquid phase of different (ILs + alkanolamine + water/ethanol) in the temperature and CO2 partial pressure range of (298–353) K and (50–6200) kPa respectively. The CO2 mole fraction in the liquid phase pertaining to 19 different solvent formulations is considered in the range of (0–0.487). It has been found that there is a good agreement between the results of the proposed models and reported experimental data of CO2 solubility. In addition to this, the predictability of artificial neural network (ANN) for CO2 solubility is also tested for 22 systems of ionic liquid blends with amines. The main advantages associated with these proposed models are their underlying simplicity and minimal input data, namely temperature and pressure.
•Statistical non-rigorous models are developed to predict the solubility of CO2 in different aqueous blended system•The predictability of ANN for CO2 solubility is also tested for 22 systems of ionic liquid blends with amines.•Good agreement between the results of the proposed models and reported experimental CO2 solubility data has been inferred.
The mean surface temperature has increased considerably over the past few decades primarily due to the huge contribution of CO2, a greenhouse gas. Hence, the reduction of CO2 majorly from the point ...sources of emission has been a thrust domain of research. This work reports the measurements and modeling of CO2 solubility in newly proposed aqueous solvent blends of 1-butyl-3-methyl-imidazolium acetate (bmim Ac) and amine activators. Various amine activators viz. 1-(2-aminoethyl) piperazine (AEP) and bis (3-aminopropyl) amine (APA) have been employed in aqueous bmim Ac over the wide operating temperature and CO2 partial pressure range of (303.15˗323.15) K and (1–390) kPa, respectively. Along with this, qualitative 13C NMR and FTIR analysis have been also performed to assess the proposed reaction scheme. The experimental vapor liquid equilibrium data (VLE) were modeled by modified Kent-Eisenberg equilibrium model including the gas phase non-ideality and Feed forward neural network model. The equilibrium constants associated with bmim Ac, AEP and APA deprotonation, and carbamate formation reactions are regressed to fit the experimental CO2 solubility data. Various important thermophysical properties such as surface tension, viscosity, sound velocity, refractive index and density have also been measured and correlated using established as well as newly proposed models.
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•CO2 solubility in aq. bmimAc, its two novel blends with AEP and APA were reported.•Modified KE model with gas phase non-ideality was used to correlate the solubility.•Reactions of solvents with CO2 is confirmed through 13C NMR and FTIR analysis.•Various physical properties were measured and modeled through first principle.
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•An innovative semi-automated stirred-cell apparatus developed for CO2 absorption.•CO2 solubility was examined in novel blends of aq. (TAEA + MDEA/AMP)•VLE data was correlated using ...Modified Kent-Eisenberg and ANN models.•Reaction scheme was analyzed using 13C NMR and FTIR-ATR.•Speciation and pH of CO2 absorbed solution were estimated.
This study involves the experimental measurements and theoretical analysis of equilibrium CO2 solubility in a novel activator (tris(2-aminoethyl) amine, TAEA) and its blend with commercial solvents like (N-methyldiethanol amine, MDEA) and (2-amino-2-methyl-1-propanol, AMP). All the measurements have been conducted at a fixed total amine concentration of 3 M (M) by varying the promoter concentration to (0.1–0.7) in an interval of 0.2 M, and temperatures range from (293.15–323.15) K at different CO2 partial pressures in the range of 2–500 kPa. The experimental data are modeled using a modified Kent-Eisenberg (KE) equilibrium model and feed forward neural network model. The equilibrium constants linked to TAEA deprotonation and carbamate formation reactions are regressed as a function of CO2 partial pressure, amine concentration, and temperature to fit the equilibrium CO2 solubility data using a modified KE model. To know the reaction scheme and recognize the various essential reaction products in the CO2-loaded solvents 13C NMR and FTIR-ATR analysis have been performed.
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