scholarly journals Tetraethylammonium Acetate and Tetraethylammonium Bromide-Based Deep Eutectic Solvents as Thermodynamic CO2 Gas Hydrate Inhibitors

2020 ◽  
Vol 10 (19) ◽  
pp. 6794
Author(s):  
Vinayagam Sivabalan ◽  
Nurasyikin Hasnor ◽  
Bhajan Lal ◽  
Zamzila Kassim ◽  
Abdulhalim Shah Maulud

The thermodynamic gas hydrate suppression behavior of four Deep Eutectic Solvents (DESs) was evaluated in this paper. The mixtures of Hydrogen Bond Acceptors (HBA), Tetraethylammonium Acetate (TEAAC), and Tetraethylammonium Bromide (TEAB) with Hydrogen Bond Donors (HBD), Mono-Ethylene Glycol (MEG), and Glycerol were used to make the DES. The DESs were made at a 1:7 molar ratio for the combinations of TEAAC:MEG, TEAAC:Glycerol, TEAB:MEG, and TEAB:Glycerol. The Hydrate Liquid-Vapor Equilibrium (HLVE) data for CO2 were evaluated through the T-cycle method at different temperature (273.15–283.15 K) and pressure (2–4 MPa) conditions in the presence and absence of 5 wt % aqueous DES solutions. The inhibition effects showed by the DESs, including average suppression temperature (ΔŦ) and gas hydrate dissociation enthalpies (ΔHdiss), were also calculated. The average suppression temperature values of the DESs ranged between 0.4 and 2.4, with the highest inhibition to lowest inhibition order being TEAB:Glycerol > TEAB:MEG > TEAAC:Glycerol > TEAAC:MEG. A comparison of the DES with conventional Thermodynamic Hydrate Inhibitors (THIs) showed that studied Deep Eutectic Solvents had better gas hydrate inhibition. The results proved that DES has the potential to be one of the promising alternatives in gas hydrate inhibition.

2019 ◽  
Vol 964 ◽  
pp. 109-114 ◽  
Author(s):  
Siti Zullaikah ◽  
Nizar Dwi Wibowo ◽  
I Made Gede Eris Dwi Wahyudi ◽  
M. Rachimoellah

High content of free fatty acids (FFA) in crude rice bran oil (CRBO) needs to be separated through deacidification. Generally, deacidification process that is widely used are chemical and physical processes which causes the loss of bioactive compounds (γ-oryzanol) and un-environmentally friendly. The liquid-liquid extraction (LLE) using deep eutectic solvents (DES) to remove FFA and preserve g-oryzanol would be implemented in this study. DES with different hydrogen bond donor (HBD) and hydrogen bond acceptor (HBA) with certain molar ratio such as Choline Chloride (ChCl)-Ethylene glycol 1:2 (DES I), ChCl-Glycerol 1:1 (DES II), ChCl-Urea 1:2 (DES III), ChCl-Oxalic acid 1:2 (DES IV), and Betaine Monohydrate-Glycerol 1:8 (NADES) were used as solvent to extract FFA from dewaxed/degummed RBO (DDRBO) for certain extraction time (30, 60, 120, 180, and 240 min) and extraction temperature (30°C, 40°C, 50°C, 60°C, and 70°C) under stirring (200 rpm). Deacidification using DES I for 240 min. and temperature of 50 °C was the optimum solvent to remove FFA (19.03 ± 2.33 %) and preserve g-oryzanol (recovery of g-oryzanol was 51.30 ± 1.77 %). The results also revealed that the longer time of extraction would be increased removal of FFA and decreased recovery of g-oryzanol. The higher temperature of extraction would be increased removal of FFA. In this work, temperature of 50 °C was the best extraction temperature of FFA since DES has highest solubility at this temperature.


2020 ◽  
Vol 10 (3) ◽  
pp. 125-137
Author(s):  
Mohammed Awwalu Usman ◽  
Olumide Kayode Fagoroye ◽  
Toluwalase Olufunmilayo Ajayi ◽  
Abiola John Kehinde

Abstract In this study, deep eutectic solvents (DESs) were prepared using choline chloride as hydrogen bond acceptor (HBA) and ethylene glycol (EG) or glycerol (GLY) or urea (U) as hydrogen bond donor (HBD) and were evaluated as solvents in the extraction of benzene from n-hexane. Six of such solvents were prepared using different molar ratios of HBA: HBD and code named DES1, DES2, DES3, DES4, DES5 and DES6. Liquid–liquid equilibria (LLE) data for the ternary systems of n-hexane-benzene-DESs were measured at 303 K and 101.3 kPa. Solubility data and mutual solubilities between n-hexane and DES were measured using the traditional cloud point method. The tie lines were obtained using titration and refractive index measurements on both phases (n-hexane phase and DES-phases). The ternary systems exhibit type-1 phase behavior. The Othmer-Tobias and Hands equations were applied to examine the reliability of the LLE data. The tie-line data were correlated using the nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) thermodynamic models, and their corresponding binary interaction parameters were determined. The results show that the maximum separation factors were 31.24, 462.00, 15.24, 37.83, 174.60 and 126.00 for DES1, DES2, DES3, DES4, DES5 and DES6, respectively. The glycerol based DES (DES2 and DES5) show the highest separation factors and thus considered the most suitable for separating benzene from hexane. The regression coefficient for both Othmer-Tobias and Hand equations are higher than 0.99 for all DESs, indicating the reliability and consistency of the data. Both NRTL and UNIQUAC models adequately capture the experimental data.


Author(s):  
Edyta Słupek ◽  
Patrycja Makoś

The paper presents a synthesis of deep eutectic solvents (DESs) based on choline chloride (ChCl) as hydrogen bond acceptor and phenol (Ph), glycol ethylene (EG), and levulinic acid (Lev) as hydrogen bond donors in 1:2 molar ratio. DESs were successfully used as absorption solvents for removal of dimethyl disulfide from (DMDS) from model biogas steam. Several parameters affecting the absorption capacity and absorption rate has been optimized including kind of DES, temperature, the volume of absorbent, model biogas flow rate, and initial concentration of DMDS. Furthermore, reusability and regeneration of DESs by means of adsorption and nitrogen barbotage followed by the mechanism of absorptive desulfurization by means of density functional theory (DFT) as well as FT-IR analysis were investigated. Experimental results indicate that the most promising DES for biogas purification is ChCl:Ph, due to high absorption capacity, relatively long absorption rate, and easy regeneration. The research on the absorption mechanism revealed that van der Waal interaction is the main driving force for DMDS removal from model biogas.


Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2157 ◽  
Author(s):  
Paulo Torres ◽  
Mercè Balcells ◽  
Enrique Cequier ◽  
Ramon Canela-Garayoa

Using the basic principle of construction between a hydrogen bond acceptor (HBA) and a hydrogen bond donor (HBD), four bio-based deep eutectic solvents (DESs) were prepared in a 1:2 molar ratio of HBA:HBD. 2,3-Dihydroxypropyl-1-triethylammonium chloride ([C9H22N+O2]Cl−) was synthesized from raw glycerol and used as an HBA. Lactic acid, urea, pure glycerol, and ethylene glycol were selected as HBD. Attempts to prepare DESs, using citric acid and benzoic acid as HBDs, were unsuccessful. All these DESs were characterized using FTIR and NMR techniques. Besides, physicochemical parameters such as pH, viscosity, density, and melting point were determined. The behavior of these DES to fractionate olive pomace was studied. Lignin recovery yields spanned between 27% and 39% (w/w) of the available lignin in olive pomace. The best DES, in terms of lignin yield ([C9H22N+O2]Cl− -lactic acid), was selected to perform a scale-up lignin extraction using 40 g of olive pomace. Lignin recovery on the multigram scale was similar to the mg scale (38% w/w). Similarly, for the holocellulose-rich fractions, recovery yields were 34% and 45% for mg and multi-gram scale, respectively. Finally, this DES was used to fractionate four fruit pruning samples. These results show that our novel DESs are alternative approaches to the ionic liquid:triethylammonium hydrogen sulfate and the widely used DES: choline chloride:lactic acid (1:10 molar ratio) for biomass processing.


2020 ◽  
Vol 10 (14) ◽  
pp. 4774
Author(s):  
Spyros Grigorakis ◽  
Abedalghani Halahlah ◽  
Dimitris P. Makris

A series of citrate salts were tested as hydrogen bond acceptors to synthesize deep eutectic solvents (DES) based on lactic acid and glycerol, used as hydrogen bond donors. The DES produced were then screened to identify the highest performing system for the effective extraction of polyphenolic phytochemicals from the medicinal plant Salvia fruticosa Mill. (Greek sage). The most efficacious DES was the one composed of lactic acid and sodium citrate dibasic, at a molar ratio of 15:1 (LA-SCDB15). Furthermore, for the first time there has been evidence concerning DES pH and extraction efficiency. Using this solvent, a batch, stirred-tank extraction process was developed, by employing ultrasonication pretreatment and response surface methodology. The optimal settings determined were stirring speed 900 rpm, proportion of DES/water 77% (w/v), and ultrasonication pretreatment time 15 min. By adjusting these optimal settings, the predicted maximum total polyphenol yield was calculated to be 79.93 ± 1.92 mg gallic acid equivalents g−1 dry mass. The examination of temperature effects demonstrated that the batch, stirred-tank extraction stage was very energy-efficient, with a barrier of 7.64 kJ mol−1. Comparison of the extraction of Salvia fruticosa polyphenols with other green processes previously developed, illustrated the high extraction capacity of LA-SCDB15. The major polyphenols identified in the extracts produced under optimized settings were chlorogenic acid, luteolin 7-O-glucuronide and rosmarinic acid.


Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 655
Author(s):  
Chiara Allegretti ◽  
Francesco G. Gatti ◽  
Stefano Marzorati ◽  
Letizia Anna Maria Rossato ◽  
Stefano Serra ◽  
...  

The use of Reactive Deep Eutectic Solvents (RDESs) in the preparation of polar head modified phospholipids (PLs) with phospholipase D (PLD)-catalyzed biotransformations has been investigated. Natural phosphatidylcholine (PC) has been submitted to PLD-catalyzed transphosphatidylations using a new reaction medium composed by a mixture of RDES/buffer. Instead of exploiting deep eutectic solvents conventionally, just as the reaction media, these solvents have been designed here in order to contribute actively to the synthetic processes by participating as reagents. RDESs were prepared using choline chloride or trimethyl glycine as hydrogen-bond acceptors and glycerol or ethylene glycol, as hydrogen-bond donors as well as nucleophiles for choline substitution. Specifically designed RDES/buffer reaction media allowed the obtainment of PLs with optimized yields in the perspective of a sustainable process implementation.


Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 438
Author(s):  
Kyle McGaughy ◽  
M. Toufiq Reza

In this study, CO2 and SO2 captures from post-combustion flue gas from a pulverized coal-fired power plant were evaluated using deep eutectic solvents (DES) to replace existing mono-ethanol amine (MEA) and CanSolv technologies. The system design of the DES-based CO2 and SO2 capture was based on the National Energy Technology Laboratory’s (NETL) 550 MWe pulverized coal-fired power plant model using Illinois #06 coal. Two of the most studied DES (choline chloride and urea at a 1:2 molar ratio and methyltriphenylphosphonium bromide (METPB) and ethylene glycol at a 1:3 molar ratio) for CO2 and SO2 capture were evaluated for this system analysis. Physical properties of DES were evaluated using both density functional theory (DFT)-based modeling as well as with documented properties from the literature. A technoeconomic assessment (TEA) was completed to assess DES ability to capture CO2 and SO2. Both solvents were able to fully dissolve and capture all SO2 present in the flue gas. It was also found from the system analyses that choline chloride and urea outperformed METPB and ethylene glycol (had a lower final cost) when assessed at 10–30% CO2 capture at high operating pressures (greater than 10 bar). At high system sizes (flow rate of greater than 50,000 kmoles DES per hour), choline chloride:urea was more cost effective than METPB:ethylene glycol. This study also establishes a modeling framework to evaluate future DES for physical absorption systems by both thermophysical and economic objectives. This framework can be used to greatly expedite DES candidate screening in future studies.


2022 ◽  
Vol 52 (1) ◽  
pp. 27-33
Author(s):  
Naciye Kutlu ◽  
Merve Sılanur Yılmaz ◽  
Gizem Melissa Erdem ◽  
Ozge Sakiyan ◽  
Aslı Isci

In this study, deep eutectic solvents (DESs) were prepared using choline-chloride as the hydrogen-bond acceptor and glycerol, formic acid and acetic acid as the hydrogen-bond donor. The effect of different process parameters such as molar ratio (1:2, 1:3 and 1:4), water content (15%, 30% and 45%), temperature (25, 50 and 75 °C) and frequency on dielectric properties of the DESs were examined. In conclusion, the highest dielectric constant value was detected at 25 °C for all DESs. Moreover, for all DESs, it was found that a decrease in water content resulted in a decrease in both dielectric constant and loss factor values. This can be explained by the absence of free water molecules which are responsible from dipole rotation mechanism. In light of the results, if DES will be used in microwave extraction, formic or acetic acid containing DESs might give more successful results compared to the one with glycerol.


2021 ◽  
Vol 3 (2) ◽  
pp. 490-502
Author(s):  
Thomas Quaid ◽  
M. Toufiq Reza

Deep eutectic solvents (DES) are compounds of a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA) that contain a depressed melting point compared to their individual constituents. DES have been studied for their use as carbon capture media and biogas upgrading. However, contaminants’ presence in biogas might affect the carbon capture by DES. In this study, conductor-like screening model for real solvents (COSMO-RS) was used to determine the effect of temperature, pressure, and selective contaminants on five DES’ namely, choline chloride-urea, choline chloride-ethylene glycol, tetra butyl ammonium chloride-ethylene glycol, tetra butyl ammonium bromide-decanoic acid, and tetra octyl ammonium chloride-decanoic acid. Impurities studied in this paper are hydrogen sulfide, ammonia, water, nitrogen, octamethyltrisiloxane, and decamethylcyclopentasiloxane. At infinite dilution, CO2 solubility dependence upon temperature in each DES was examined by means of Henry’s Law constants. Next, the systems were modeled from infinite dilution to equilibrium using the modified Raoults’ Law, where CO2 solubility dependence upon pressure was examined. Finally, solubility of CO2 and CH4 in the various DES were explored with the presence of varying mole percent of selective contaminants. Among the parameters studied, it was found that the HBD of the solvent is the most determinant factor for the effectiveness of CO2 solubility. Other factors affecting the solubility are alkyl chain length of the HBA, the associated halogen, and the resulting polarity of the DES. It was also found that choline chloride-urea is the most selective to CO2, but has the lowest CO2 solubility, and is the most polar among other solvents. On the other hand, tetraoctylammonium chloride-decanoic acid is the least selective, has the highest maximum CO2 solubility, is the least polar, and is the least affected by its environment.


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