Measurement of CO2 Solubility in Amine Based Deep Eutectic Solvents (original) (raw)
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Experimental Investigation of CO2 Solubility in New Amine-Based Deep Eutectic Solvents
Tikrit Journal of Engineering Sciences, 2024
The growing concern about global warming and climate has raised the research field dedicated to finding solutions. One area that has received considerable attention is the exponential increase of carbon dioxide emissions from the atmosphere from the petroleum and gas industries. So, to solve this problem, researchers investigated new ways to collect CO2 from the air depending on the fact that CO2 is soluble in water because using aqueous amine absorbents to collect CO2 has a lot of drawbacks, such as the need for tremendous energy to recycle the solvent and high operational costs. In this study, a specific type of deep eutectic solvent (DES), namely Choline chloride + monoethanolamine (ChCl-MEA), was used as a promising solvent in the CO2 capture process. Solubility measurements were conducted at 1:6 molar ratios. The amines chosen are typical of basic amines. Experiment absorption data were investigated at various parameters, including a concentration range of 0-3 mol/L, temperatures ranging from 25 to 45 °C, and absorption durations ranging from 60 to 120 minutes, to get the best conditions for high-loading CO2 uptake. The study found that amine-based DESs had a significantly greater absorption capacity than monoethanolamine-based and conventional DESs. The study examined what happened when water was added to a deep eutectic solvent made of choline chloride and monoethanolamine (ChCl-MEA DES). The most effective way to absorb CO2 was physical absorption, which can hold 276.13 mol CO2 per gram of DES at 1 bar and 29.025 °C when mixed with water. The deep eutectic was mixed with water to increase the absorption efficiency. 10 ml of aqueous solution (DESs + water) was taken. The combination of DES and water significantly increased CO2's low solubility. The modified Design-Expert model satisfactorily represents the experimental solubility of CO2 in the solvent. The average percent differences between experimental and projected values were 10.7% and 6.8% for binary and ternary systems, respectively. The optimal conditions for maximum absorption rate were 29.025°C, 2.233 mol/L, and 101 minutes, with an absorption ratio of 0.0734 mol/kg.min and efficiency of absorption of 85.3% for solution DESs and water.
Deep eutectic solvents (DESs) have drawn a growing research interest for applications in a wide range of scientific and industrial arenas. However, a limited effort has been reported in the area of gas separation processes and particularly the carbon dioxide capture. This study introduces a novel set of DESs that were prepared by complexing ethylenediamine (EDA), monoethanolamine (MEA), tetraethylenepentamine (TEPA), triethylenetetramine (TETA) and diethylenetriamine (DETA) as hydrogen bond donors to monoethanolamide hydrochloride (EAHC) salt as a hydrogen bond acceptor. The absorption capacity of CO 2 was evaluated by exploiting a method based on measuring the pressure drop during the absorption process. The solubility of different DESs was studied at a temperature of 313.15 K and initial pressure of 0.8 MPa. The DES systems 1EAHC:9DETA, 1EAHC:9TETA and 1EAHC:9TEPA achieved the highest CO 2 solubility of 0.6611, 0.6572 and 0.7017 mol CO 2 •(mole DES) −1 respectively. The results showed that CO 2 solubility in the DESs increased with increasing the molar ratio of hydrogen bond donor. In addition, the CO 2 solubility increased as the number of amine groups in the solvent increases, therefore, increasing the alkyl chain length in the DESs, resulted in increasing the CO 2 solubility. FTIR analysis confirms the DES synthesis since no new functional group was identified. The FTIR spectra also revealed the carbamate formation in DES-CO 2 mixtures. In addition, the densities and viscosities of the synthesized DESs were also measured. The CO 2 initial investigation of reported DESs shows that these can be potential alternative for conventional solvents in CO 2 capture processes.
Novel Green Solvents for CO2 Capture
Energy Procedia, 2017
This study investigates the viability of novel green solvents for carbon capture. Three different types of amine based deep eutectic solvents were synthesized at three different molar ratio. The selected amines represent the primary (monoethanolamine), secondary (diethanolamine) and tertiary (methyldiethanolamine) amines, respectively. The CO2 absorption was conducted with a solvent screening setup (SSS) and the CO2 loading was measured with an 'Elementar' total organic carbon (TOC) analyzer. Thereafter, FTIR of the samples was conducted in order to determine the qualitative analysis for tracking the appearance, disappearance and stability of different functional groups (400-1600 cm-1). The solubility experiments were performed based on the conditions of the absorber in the post-combustion capture process (PCO2 = 15kPa and T = 40 o C). Results revealed that aminebased DESs have absorption capacity that is much higher than both 30wt% aqueous amine solutions and conventional DESs. The FTIR broadening of the O-H and N-H stretching of MEA and ChCl individual components, indicates the formation of hydrogen bonds between the two of them in the ChCl-MEA 1:6 before CO2 absorption.
Molecules, 2021
Amine absorption (or amine scrubbing) is currently the most established method for CO2 capture; however, it has environmental shortcomings and is energy-intensive. Deep eutectic solvents (DESs) are an interesting alternative to conventional amines. Due to their biodegradability, lower toxicity and lower prices, DESs are considered to be “more benign” absorbents for CO2 capture than ionic liquids. In this work, the CO2 absorption capacity of choline-chloride/levulinic-acid-based (ChCl:LvAc) DESs was measured at different temperatures, pressures and stirring speeds using a vapour–liquid equilibrium rig. DES regeneration was performed using a heat treatment method. The DES compositions studied had ChCl:LvAc molar ratios of 1:2 and 1:3 and water contents of 0, 2.5 and 5 mol%. The experimental results showed that the CO2 absorption capacity of the ChCl:LvAc DESs is strongly affected by the operating pressure and stirring speed, moderately affected by the temperature and minimally affecte...
Improved Eutectic Based Solvents for Capturing Carbon Dioxide (CO2)
Energy Procedia, 2017
Deep eutectic solvents are based upon environmentally benign moieties and have the potential to capture CO2 from flue gases. In this study, guanidine carbonate, malic acid, ethylene glycol, arginine and water were mixed in certain molar ratios to produce eutectic solvents. Their viscosities were determined in a temperature range of 303.2-330.2 K, while Henry's law constants of CO2 for these solvents were obtained at 313.2 K. The results have been compared with some other water-lean solvents and showed a compromise exists between the viscosity and CO2 solubility of eutectic based solvents for potential use in carbon capture applications.
Journal of Molecular Liquids, 2020
Physicochemical properties Design of experiment CO 2 solubility To study CO 2 capture potential, three types of transition-temperature mixtures (TTMs) were prepared by mixing ethyltriphenylphosphonium bromide (MTPPB) as a hydrogen bond acceptor (HBA) and n-methyl diethanolamine (MDEA) as a hydrogen bond donor (HBD) in different molar ratios (1:7, 1:10 and 1:16). Fourier transform infrared spectroscopy (FT-IR) results showed that TTMs have almost similar spectra to their HBD (MDEA) with different levels of transmittance and exhibit similar behavior. From the experimental results, it was found that the thermal stability, viscosity and surface tension of TTMs decreased as the concentration of MDEA in the mixture increased. According to response surface methodology (RSM) models and analysis of variance (ANOVA), temperature and molar ratio had a great effect on the viscosity and surface tension of TTMs. Finally, it was found that CO 2 solubility in TTMs (at 303.15 K at pressure up to 1.35 MPa) was enhanced as the MDEA quantity increased in the mixture up to 1:10 mol ratio. However, by increasing MDEA concentration to 16:1 mol ratio, there was a decreasing trend in the CO 2 solubility data. Also, all TTMs, particularly TTM containing 10:1 mol MDEA (MTPPB-MDEA 1:10) exhibited an equilibrium loading capacity approaching 1 mol CO 2 per mole solvent at high pressure, revealing their high potential for CO 2 capture. A comparison showed that the CO 2 solubility in the studied solvents was higher than that of existing deep eutectic solvents (DESs) and other TTMs as well as several ionic liquids (ILs) to date. To the best of our knowledge, this is the first study to report the CO 2 solubility in phosphonium-base TTMs containing MDEA.
Deep eutectic solvents for CO2 capture in post-combustion processes
Studia Universitatis Babe?-Bolyai Chemia, 2021
CO2 emissions represent an actual problem for the environment. Additionally, the new demands for all chemical and physical processes request to be more eco-friendly. In this work, deep eutectic solvents (DESs), a relatively new class of solvents, were used for CO2 capture and desorption. DESs are more environmentally friendly than classical solvents. Two choline chloride-based DES-ethaline (ChCl:EG, 1:2 molar ratio) and reline (ChCl:U, 1:2 molar ratio) were prepared and characterized before studying their CO2 absorption-desorption capacity. The formation of eutectics was confirmed by FT-IR analysis and DESs were characterized in terms of pH, density, viscosity, refractive index, and electrical conductivity. The tests showed that ethaline had better CO2 absorption and desorption capacity than reline, which could be explained by several parameters.
In this research, experiments have been carried out to evaluate the suitable absorbent for CO2 gas separation. The absorption of carbon dioxide in various alkanolamines in aqueous and deep eutectic solvent medium (DES) was assessed. The amines employed in this study are monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), 2-amino-2-methyl-1-propanol (AMP) and 2-methylamino ethanol (MAE). Choline chloride and urea (ChCl:U) mixture was employed as DES medium. The molar ratio of DES was optimized to get maximum absorption of CO2 gas. The absorption of CO2 in alkanolamines in DES medium was found to be higher than in aqueous medium. Among the various alkanolamines in DES medium, 2-amino-2-methyl-1-propanol in DES shows higher absorption capacity for CO2 gas. Thus alkanolamines in DES medium could be effectively used as an absorbent for CO2 capture.
Ternary Deep Eutectic Solvents Tasked for Carbon Dioxide Capture
ACS Sustainable Chemistry & Engineering, 2014
Task-specific ternary deep eutectic solvent (DES) systems comprising choline chloride, glycerol, and one of three different superbases were investigated for their ability to capture and release carbon dioxide on demand. The highest-performing systems were found to capture CO 2 at a capacity of ∼10% by weight, equivalent to 2.3−2.4 mmol of CO 2 captured per gram of DES sorbent. Of the superbases studied, 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) gave the best overall performance in terms of CO 2 capture capacity, facility of release, and low sorbent cost. Interestingly, we found that only a fraction of the theoretical CO 2 capture potential of the system was utilized, offering potential pathways forward for further design and optimization of superbasederived DES systems for further improved reversible CO 2 sequestration. Finally, the shear rate-dependent viscosities indicate non-Newtonian behavior which, when coupled to the competitive CO 2 capture performance of these task-specific DESs despite a 1 to 2 orders of magnitude higher viscosity, suggest that the Stokes−Einstein−Debye relation may not be a valid predictor of performance for these structurally and dynamically complex fluids.
Journal of physics, 2019
Deep eutectic solvents (DESs) are known as alternative green solvents due to their ease of synthesis, availability, biodegradability and negligible volatility. DESs consisted of betaine as the hydrogen bond acceptor with 1,2-propanediol, levulinic acid and methyl diethanolamine (MDEA) as the hydrogen bond donors, were prepared in 1:3 and 1:6 molar ratios. The carbon dioxide solubilities in these DESs were determined using a volumetric apparatus at 313.15 K and 6 bar. The results show that CO2 solubilities in betaine-based DESs are higher than the reported CO2 solubilities in choline chloride-based DESs, for DESs having the same hydrogen bonding donor and an identical or similar composition. The viscosity and polarity of hydrogen bond donors affected the ability of deep eutectic solvent to absorb carbon dioxide. The betaine-MDEA deep eutectic solvent, with molar ratio of 1:6, has the highest absorption capacity of 0.0814 mol CO2/mol DES, measured at 313.15 K and 6 bar.