•Carbon dioxide and methane binary adsorption equilibrium data were measured.•Adsorption selectivity was measured at different temperatures and pressures.•Experimental data were compared against ...results of thermodynamic models.
A static, volumetric method has been used to determine the adsorption equilibrium of CH4 and CO2 and their binary mixtures on 13X molecular sieves at various temperatures between 273 and 343K. Pressures for the pure component data extend up to 10bar, while all binary data were obtained at 4bar and 6bar. The measured pure isotherms were regressed using different isotherm equations and the regressed parameters were applied to different thermodynamic models such as ideal adsorbed solution theory (IAST), vacancy solution theory (VST) and real adsorbed solution theory (RAST). CH4/CO2 system that deviate from ideality is not well represented by IAST and VST, whereas RAST which include activity coefficient in the adsorbed phase as characterizing parameter for non-ideality, show a much better representation of the binary equilibria. Experimental selectivities CO2/CH4 range from 26 to 2 at different pressure and temperatures. It is concluded that zeolite 13X suitable for natural gas industrial separation with yCO2<0.2 at 303K and 4bar. For landfill gas upgrading, where yCO2<0.45, zeolite 13X can be successfully applied at 303K, 4bar and 303K, 6bar and 323K, 4bar.
In this study, the heat transfer performance of MMIDMP ionic liquid solution (20 vol% IL + 80 vol% deionized water) in the presence of Mxene nanoparticle is investigated based on computational fluid ...dynamics numerical method considering temperature-dependent properties. It should be noted that the thermophysical properties of IoNanofluid were experimentally measured in our previous published study. The modeling results are validated with numerical and experimental works, and the validation results indicate good agreement between them. The effect of adding Mxene nanoparticle to the base liquid was carried out in a horizontal tube with 1–50 range of Reynolds number. The results found that the heat transfer coefficient increased by increasing the Reynolds number and also the nanofluids’ concentration. Moreover, it raises by increasing the fluid inlet temperature while the Nu number decreases. This is because the Nusselt number is in a reverse relationship with the heat transfer coefficient. The maximum heat transfer coefficient observed for 0.2 mass% INf at 308 K fluid inlet temperature and Reynolds number of 50 was 2207.83 W m
2
K
−1
. However, the maximum Nusselt number detected for pure base fluid at 298.15 K fluid inlet temperature and Reynolds number of 50 was 13.22. Furthermore, the maximum heat transfer enhancement was observed for 0.2 mass% INf at Reynolds number of 50 and 308.15 K fluid inlet temperature (43.6%). Finally, a novel correlation is proposed to estimate the Nusselt number of nanofluids with R
2
= 0.992 and AREP = 2.8%.
A study was conducted to examine the effects of calcination temperature and acid used for synthesis on the performance of Nickel catalyst in dry reforming of methane under various experimental ...conditions. The characterization of catalysts supported on a cubic-ordered mesoporous alumina was carried out by using powder XRD, N
2
sorption, TPR, TPO, FTIR, XPS, high-resolution TEM, and thermogravimetric analyses. The catalyst synthesized by nitric acid and calcined at 500 °C demonstrated the best catalytic performance, achieving conversions of CH
4
= 92% and H
2
/CO = 0.8 at 800 °C. During the long-term reaction of the catalyst, deactivation was observed after 100 h at 700 ℃, and GHSV = 27,200 mL/(h g
catalyst
) due to the carbon deposition = 4.9%.
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•CO2 and CH4 binary adsorption equilibrium data on zeolite 5A were measured.•Adsorption selectivity was measured over a wide range of pressure and composition.•Experimental data were ...validated by predicted results of some thermodynamic models.•The x–y phase diagram of the system was studied experimentally and theoretically.•The binary selectivity data indicate that zeolite 5A is very selective to CO2.
Pure gas adsorption isotherms of carbon dioxide at (273, 283, 303, 323, 343)K and binary adsorption isotherms of carbon dioxide and methane at (303, 323)K and pressures up to 10bar on Zeochem Co. Zeolite 5A were measured using a volumetric method. Equilibrium gas phase compositions have been determined using a gas chromatograph (GC). The experimental binary equilibrium data were compared with equilibrium data calculated by ideal adsorbed solution theory (IAST), and vacancy solution model (VSM). A model analysis of the experimental data has been performed with real adsorbed solution theory (RAST) owing to not satisfactory prediction of multi-component behavior with IAST and VSM. For this purpose, activity coefficients, accounting for the non-ideality of the adsorbed mixture, were calculated from the experimental data. The results of the pure experimental data showed that, the heat of adsorption for methane is approximately independent of loading (about 20kJ/mol), and for carbon dioxide decreases by increasing loading when q<0.5mol/kg. Subsequently, by increasing loading, the heat of adsorption increases up to q=2mol/kg. The selectivity of both simulated landfill and biogas mixtures have been also measured experimentally. These data indicated that zeolite 5A can be successfully applied in CO2/CH4 separation for landfill gas and biogas upgrading.
In this work, solubility of hydrogen in some alkenes was investigated at different temperatures and pressures. Solubility values were calculated using the Peng–Robinson equation of state. Binary ...interaction parameters were calculated using fitting the equation of state on experimental data, Group contribution method and Moysan correlations and total average absolute deviation for these methods was 3.90, 17.60 and 13.62, respectively. Because hydrogen solubility in Alkenes is low, Henry’s law for these solutions were investigated, too. Results of calculation showed with increasing temperature, Henry’s constant was decreased. The temperature dependency of Henry’s constants of hydrogen in ethylene and propylene was higher than to other alkenes. In addition, using Van’t Hoff equation, the thermodynamic parameters for dissolution of hydrogen in various alkenes were calculated. Results indicated that the dissolution of hydrogen was spontaneous and endothermic. The total average of dissolution enthalpy (
Δ
H
∘
) and Gibbs free energy (
Δ
G
∘
) for these systems was 3.867 kJ/mol and 6.361 kJ/mol, respectively. But dissolution of hydrogen in almost of alkenes was not an entropy-driven process.
The gas-phase volumetric overall mass transfer coefficient (
K
G
a
V
) plays a key role in the assessment of an absorption packed column's performance since it determines the height of an absorber ...column. The effective and useable data provided by
K
G
a
V
is necessary for designing and scaling up absorption packed columns. This study provides the first comprehensive review of mass transfer performance in terms of
K
G
a
V
for CO
2
(
K
GCO
2
a
V
) absorption into amine solutions for absorber columns with random and structured packing. To date, researchers associated with the
K
GCO
2
a
V
parameter have focused on two main fields: experimental works and developing empirical correlations. For experimental works,
K
GCO
2
a
V
has been evaluated in the literature for a large number of conventional and improved amines over a range of operating parameters in laboratory-scale packed columns. In addition, researchers have developed empirical correlations for
K
GCO
2
a
V
based on operating parameters affecting
K
GCO
2
a
V
and physical properties. The details of research determining the
K
GCO
2
a
V
have been reviewed for low- and high-pressure absorption packed columns. Finally, directions for future research of the mass transfer performance for absorber packed columns in the CO
2
capture process have been discussed.
An overview on the experimental works for obtaining
K
GCO
2
a
V
for low- and high-pressure absorption packed columns.
Natural amino acid salt solutions (NAASs) are paving the way for greener carbon capture. This study developed simple and precise methods for the viscosity modeling of NAASs. Two approaches, namely, ...empirical correlations and artificial intelligence, were assessed using a large databank (16 NAAs, 3 alkaline compounds, 25 NAASs, and 1582 data points). Two general correlations and a global equation were suggested. Benefitting from the input of single reference-point data, the modified global equation yielded the best results with a 2.28% deviation. The other empirical models represented viscosities with less than a 7.20% error. The second approach, employing artificial neural networks (ANNs) with different algorithms, was also proposed. The best ANNs were a single-layer perceptron network with tansig + trainlm functions, a double-layer perceptron network with logsig + tansig + trainlm functions, and a radial basis function network with the maximum neurons. They managed to calculate the viscosities with errors of 2.82%, 1.82%, and 0.47%, respectively.
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•Simple correlations were developed to estimate the viscosities of liquids comprise of amino acid salt solutions.•Different schemes of artificial neural networks were assessed.•The global correlations reflected the effects of temperature, concentration, and the types of amino acid and alkaline compounds.•A large databank (25 solutions and 1582 data points) was assessed with remarkable accuracy for viscosity estimation.•Artificial neural networks could model viscosity data precisely with less than 3% error in their best structure.
In this study, new experimental data of CO2 equilibrium solubility for an aqueous solution of 1DMA2P, a novel ternary amine, are presented over a CO2 partial pressure range of 3–168 kPa, at different ...concentrations of 1DMA2P (2, 3 and 4 M), and in a temperature range of 298.15–333.15 K. Besides, new experimental data of viscosity and density are reported in a concentration range from 20 wt% up to pure 1DMA2P, in a temperature range of 298.15–333.15 K, and in atmospheric pressure. CO2 equilibrium solubility data were predicted by Deshmukh–Mather (D-M) thermodynamic model. From the experimental data of density and viscosity, thermodynamic properties including the thermal expansion coefficient (αp), excess molar volume (VE), viscosity deviation (Δη), activation molar enthalpy (ΔH), activation molar entropy (ΔS), and activation molar Gibbs free energy (ΔG) were obtained. We have modeled and predicted the experimental data of viscosity based on Eyring's theory and nonrandom two-liquid (NRTL) and Wilson models. The results showed that the Eyring-Wilson model predicts the experimental viscosity data better than Eyring-NRTL. For CO2 equilibrium solubility, D-M model gave a good prediction with an absolute average relative deviation of 2.64%.
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•We done experiments for density, viscosity and CO2 solubility of 1DMA2P solution.•Thermal expansion coefficient and activation properties were calculated.•Excess properties were modeled by using the Redlich–Kister equation.•Prediction of viscosity data for the 1DMA2P solution was done by Eyring's theory.•CO2 solubility data were predicted by thermodynamic model called Deshmukh-Mather.
In this study, a modeling-optimization framework was developed to assess absorption capacity of CO2 by four promising tertiary amines in CO2 capture, namely, 1-dimethylamino-2-propanol (1DMA2P), ...1-diethylamino-2-propanol (1DEA2P), 2-(diethylamino)ethanol (DEEA), and 4-diethylamino-2-butanol (DEAB). The purpose of this developed framework is to study the simultaneous effect of all solubility parameters including CO2 partial pressure, temperature, and amine concentration on the absorption capacity in terms of CO2 loading. In this framework, an orthogonal array design (OAD) method (a statistical method) was used for optimization, and Kent-Eisenberg (K-E), modified Kent-Eisenberg (M-K-E), and Deshmukh-Mather (D-M) models (thermodynamic models) were applied to predict CO2 loading of amine solutions. In addition, the back-propagation neural network model was applied and the results were compared with thermodynamic models. The D-M model was used to predict the response values (CO2 loading) in the OAD method. The results showed that the D-M model was superior to other thermodynamic models in the prediction of CO2 loading data with average absolute relative deviations (AARDs) of 2.89%, 3.59%, 1.76%, and 2.3% for DEEA, 1DMA2P, DEAB, and 1DEA2P solutions, respectively. The OAD results showed that all solubility parameters had significant effects on CO2 loading, and the statistically significant order of parameters affecting absorption capacity was CO2 partial pressure > amine concentration > temperature.
•A modeling-optimization framework was developed to assess the CO2 absorption capacity for novel amine solutions.•Different thermodynamic models such as Kent-Eisenberg modified Kent-Eisenberg, and Deshmukh–Mather were applied.•A Back-propagation neural network model and an orthogonal array design (OAD) method were developed.•The Deshmukh–Mather model predicted the CO2 loading data of four amine solutions with an AARD% of 2.63.•The satisfactory error for a modeling-optimization framework calculated to be less than 4%.
•Rate-based and equilibrium-stage models are developed and compared for CO2 capture by AMP solution.•The developed models are accurately validated by simulating a number of literature data.•The ...rate-based model of a packed absorption column is preferred in post-combustion CO2 capture process.•Comparison of the absorption performance between the CO2-MEA and CO2-AMP system is performed.
In this study, two mathematical models including rate-based and equilibrium-stage were applied and compared for CO2 absorption by 2-amino-2-methyl-1-propanol (AMP) solution in a packed column. In the rate-based model, process of simultaneous mass and energy transfer across the interface was modeled by means of rate equation and mass transfer coefficients. The rate-based model was based on the two-film theory. In contrast, the equilibrium-stage model was based on the theory of theoretical number stages combined with the concept of Murphree efficiency. In this model, different values of Murphree efficiencies were used along the absorption column. The two modeling approaches were validated by comparison of obtained results with published experimental data. The simulation of the absorber column shows the rate-based model gives a better prediction of the temperature and concentration profiles compared to the equilibrium-stage model. As a result, for a detailed process design the rate-based model should be applied. Also, comparison of the absorption performance between the CO2-MEA and CO2-AMP system in a bench-scale absorber packed with high efficiency packing was performed. Finally, The effect of important process parameters such as CO2 partial pressure, CO2 loading of amine solution, flow rate of amine solution, concentration of amine solution and solution temperature on the CO2 removal efficiency were analyzed. The results of this analysis showed that CO2 removal efficiency increases with the increase of solution flow rate, solution concentration and solution temperature (in the CO2 loading of more than 0.15) and decreases with the increase of the CO2 loading of AMP solution (in the CO2 loading of more than 0.15) and CO2 partial pressure.
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