Ionic Liquid Extraction Research Articles

Methane sulfonic acid ionic liquid extraction of gasoline desulfurization process and enhancement of microchannel technology

Methane sulfonic acid (MSA) was used as anion to synthesize a series of ionic liquids and its desulfurization performance was evaluated by extraction. The basic physical properties and structural properties of the ionic liquids were evaluated, and it was proved that the ionic liquids could be used and separated well in liquid–liquid extraction desulfurization (EDS) system. The liquid–liquid extraction desulfurization system was enhanced by microchannel technology. The effects of microchannel diameter, extraction temperature, residence time and extraction stage on extraction efficiency were discussed. In the microchannel extraction system, this extraction equilibrium time can be reduced to 60 s from more than 10–15 min or longer in the conventional intermittent extraction techniques, which effectively reduces the synthesis and production cost. This finding may provide some reference for the further study of the micro-reaction technology in the deep removal of sulfur compounds from gasoline by ionic liquid, and further optimize the operating conditions.

Design and optimization of an integrated process for the purification of propylene oxide and the separation of propylene glycol by-product

It is difficult to separate the methanol and hydrocarbons in the propylene oxide (PO) purification process due to their forming azeotrope. As for this, a novel PO separation process, in that the deionized water is employed as extractant and 1,2-propylene glycol (MPG) that is formed from the PO hydrolysis reaction is recovered, is presented in this work. The salient feature of this process is that both the non-catalyzed reactions of PO hydrolysis to form MPG and dipropylene glycol (DPG) are simultaneously considered and MPG by-product with high purity is obtained in virtue of the deionized water as reflux liquid and side take-off in MPG column. In addition, the ionic liquid (IL) extractant is screened through the conductor-like screening model for segment activity coefficient (COSMO-SAC) and the comparisons of separation efficiency between the IL and normal octane (nC8) extractant for the separation of PO and 2-methylpentane are made. With the non-random two-liquid (NRTL) thermodynamic model, the simulation and optimization design for the full flow sheet are performed and the effects of the key operation parameters such as solvent ratio, theoretical stages, feeding stage etc. on separation efficiency are detailedly discussed. The results show that the mass purity and the mass yield of PO can be up to 99.99% and 99.0%, and the condenser duty, reboiler duty and PO loss in the process with IL extractant can be decreased by 69.66%, 30.21% and 78.86% compared to ones with nC8. The total annual cost (TAC) calculation also suggests that the TAC would be significantly reduced if using IL in replace of nC8 for the investigated process. The presented results would provide a useful guide for improving the quality of PO product and the economic efficiency of industrial plant.

Manganese in the source of groundwater in Malaysia and the method for the removal process: A review on the adsorption and membrane separation processes

In Malaysia, the quality of groundwater as one of the main sources drinking water is deteriorated due to the presence of a high level of manganese, which exceeds the allowable values for drinking water consumption. Manganese at concentration higher than 0.1 mg/L causes staining, high turbidity and bad taste problem in drinking water, and eventually can cause a depletion of brain dopamine and a syndrome of motor dysfunction and memory loss resembling Parkinson disease. Several methods have been used to eliminate manganese from the groundwater, which include precipitation, coagulation, ion exchange, oxidation and filtration, aeration, activated carbon adsorption, ionic liquid extraction and biosorption. Among those methods, adsorption is the most efficient and cheaper method to remove heavy metal as the operation is easily be controlled and the reversible adsorbents can be regenerated through a suitable process. Membrane filtration on the other hand particularly reverse osmosis and nanofiltration have been found to be a very effective and economical way to isolate components that are suspended or dissolved in a liquid. In addition to that, the combination of adsorption and membrane filtration process such as polymer enhanced ultrafiltration and adsorptive membrane respectively are currently attracted attentions. This paper provides a review on the adsorption process and membrane filtration process for manganese removal, with subsequently outlining the potential adsorbents to be incorporated in the fabrication of adsorptive membrane.

Efficient extraction and theoretical insights for separating o‐, m‐, and p‐cresol from model coal tar by an ionic liquid [Emim][DCA

AbstractCresols are valuable phenolic chemicals which are mainly separated from coal tar. The separation of cresols using sustainable technology is of importance for comprehensive utilization of coal tar. In this work, for extracting o‐, m‐, and p‐cresol from the model coal tar, an ionic liquid 1‐ethyl‐3‐methylimidazolium dicyanamide ([Emim][DCA]) was prepared. The influence of ionic liquid dosage, extraction time, and temperature on separating o‐, m‐, and p‐cresol was explored. The extraction efficiency was determined from the experimental results to assess the extraction ability of [Emim][DCA]. With the optimal conditions, o‐, m‐, and p‐cresol were extracted efficiently from the model coal tar and the extraction efficiencies of o‐cresol, m‐cresol, and p‐cresol were up to 99.50%, 99.65%, 98.38%, respectively. In the meantime, the extraction mechanism was determined by calculation of σ‐profile, interaction energy, and electron density. The results showed that [Emim][DCA] and cresols formed the complexes by hydrogen bond. The formation of hydrogen bond was verified by the FTIR spectra, which is helpful for designing the related ionic liquids for recovering the phenolic compounds from coal tar. In addition, the recyclability of the [Emim][DCA] was explored.

Efficient selective separation of yttrium from holmium and erbium using carboxyl functionalized ionic liquids

The efficient extraction separation of yttrium (Y) from holmium (Ho) and erbium (Er) is always difficult because of their similar physical and chemical properties. In this work, three pyridine carboxylic acid ionic liquids were synthesized and used to extraction of Y. The effects of aqueous phase acidity, extraction time, extractant concentration, temperature and alkyl chain length of ionic liquids on extraction of Y were investigated systematically. The extraction efficiency of [(CH2)7COOHpyr][NTf2] for Y increased with an increase in pH, and could reach 99.3% at a pH of 2.5. Meanwhile, the extraction process could achieve equilibrium completely within 5 min. In addition, both the separation coefficients of Ho/Y and Er/Y were greater than 2, which were higher than other ionic liquid extractants. At last, 98.5% of Y could be stripped from the loaded ionic liquid phase with a single step using 0.04 mol/L HCl, and the extraction efficiency of the [(CH2)7COOHpyr][NTf2] for Y still maintained about 98% after 8 cycles. A possible cation exchange extraction mechanism was proposed by slope analysis and FTIR spectroscopy.

Ultrasonic‐Assisted Ionic Liquid Extraction of Four Biflavonoids from Ginkgo biloba L.

AbstractIn the study, four main biflavonoids (bilobetin (BIL), ginkgetin (GIN), isoginkgetin (IGIN) and sciadopitysin (SCI)) were extracted from Ginkgo biloba L. by ultrasonic‐assisted ionic liquid extraction (UAILE). The above four biflavonoids from Ginkgo biloba L. were simultaneously determined by the established high performance liquid chromatography (HPLC) approach. Next, three novel ionic liquids (ILs) were synthesized by one‐step method from benzoxazole and three acids or salts. The structure of ILs were characterized by elemental analysis, infrared spectroscopy and nuclear magnetic resonance. Moreover, the thermal stability of ILs was evaluated by thermogravimetric analysis. Through screening the extraction effect of 9 different ILs, [EPy]BF4 was screened as the optimal extraction agent. Through single factor and response surface analysis, the optimum extraction conditions of the four kinds of biflavonoids from Ginkgo biloba L. were further investigated. The optimum conditions were as follows: 0.148 mol/L IL concentration, 25 min extraction time, 1 : 14 g/ml solid‐liquid ratio, and 280 W ultrasonic power. The extraction rates of BIL, GIN, IGIN and SCI in Ginkgo biloba L. were 2.44 mg/g, 4.33 mg/g, 6.50 mg/g and 13.97 mg/g, respectively. Compared with ethanol‐UAE, infiltration extraction (IE) and percolation extraction (PE), UAILE not only could obtain more biflavonoids, but also could save the extraction time. In addition, the results of recovery test indicated that the recovered IL could be repeatedly extracted for 6 times. In general, three novel ILs were first synthesized in this study. The UAILE was first applied to extract the four biflavonoids in G. biloba L. This study provided a valuable reference for further investigation on G. biloba L.

Investigation on the Mass Distribution and Chemical Compositions of Various Ionic Liquids-Extracted Coal Fragments and Their Effects on the Electrochemical Performance of Coal-Derived Carbon Nanofibers (CCNFs).

Coal-derived carbon nanofibers (CCNFs) have been recently found to be a promising and low-cost electrode material for high-performance supercapacitors. However, the knowledge gap still exists between holistic understanding of coal precursors derived from different solvents and resulting CCNFs’ properties, prohibiting further optimization of their electrochemical performance. In this paper, assisted by laser desorption/ionization (LDI) and gas chromatography–mass spectrometry (GC–MS) technologies, a systematic study was performed to holistically characterize mass distribution and chemical composition of coal precursors derived from various ionic liquids (ILs) as extractants. Sequentially, X-ray photoelectron spectroscopy (XPS) revealed that the differences in chemical properties of various coal products significantly affected the surface oxygen concentrations and certain species distributions on the CCNFs, which, in turn, determined the electrochemical performances of CCNFs as electrode materials. We report that the CCNF that was produced by an oxygen-rich coal fragment from C6mimCl ionic liquid extraction showed the highest concentrations of quinone and ester groups on the surface. Consequentially, C6mimCl-CCNF achieved the highest specific capacitance and lowest ion diffusion resistance. Finally, a symmetric carbon/carbon supercapacitor fabricated with such CCNF as electrode delivered an energy density of 21.1 Wh/kg at the power density of 0.6 kW/kg, which is comparable to commercial active carbon supercapacitors.

Study dearomatization of kerosene by IR and UV spectral analysis

This work is devoted to study the extraction dearomatization of the kerosene fraction using ionic liquids synthesized on the basis of formic acid and morpholine, as well as acetic acid and diethylamine as a selective solvent. The influence of various factors on the selective purification process has been investigated and the conditions for dearomatization of kerosene have been determined. The group hydrocarbon composition of the dearomatized kerosene raffinate samples by ion-liquid extraction was determined by IR and UV spectral analysis.

Solvent Dependency of Sorghum Bran Phytochemicals Acting as Potential Antioxidants and Antibacterial Agents.

SUMMARYResearch backgroundSorghum bran, although considered as an agricultural waste, is an abundant source of various bioactive compounds. These bioactive compounds require specific extraction with particular solvents and therefore ionic liquid and three different conventional solvents, viz. anhydrous methanol, acidified methanol and water were used in this work.Experimental approachTo evaluate the phytochemicals in the different sorghum bran extracts, total phenol content, flavonoids, condensed tannins and anthocyanins were determined as per standard protocols. Liquid chromatography with tandem mass spectrometryanalysis of extracts was also performed for their phenolic profiling. The antioxidant activity of the extracts was estimated via three assays: 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation decolourization assay and Cu2+ reducing antioxidant capacity (CUPRAC) method. The antibacterial activity against two most opportunistic foodborne pathogens: Escherichia coli and Staphylococcus aureus was measured by agar well diffusion assay and minimum inhibitory concentration (MIC) was determined by serial dilution method.Results and conclusionsIonic liquid extract of sorghum bran gave the highest yield ((14.9±0.7) %), which indicated that various possible interactions like Van der Waals forces, H-bonding, hydrophobic and cation-π bonding can occur when ionic liquid is used as an extractant compared to other conventional solvents, although total phenol mass fraction expressed as gallic acid equivalents on dry mass basis was only (7.4±0.7) mg/g. The hydrophobicity of the ionic liquid also helped in efficient extraction of condensed tannins ((63.2±2.1) mg/g expressed on dry mass basis), which resulted in significant antioxidant activity of the ionic liquid extract ((85.2±1.2) µmol/g in DPPH assay, (100.8±0.9) µmol/g in ABTS assay and (63.2±1.9) µmol/g in CUPRAC). An interesting revelation reported in this work is the inability of DPPH assay to evaluate the antioxidant activity in acidic environment. The anhydrous methanolic extract of sorghum bran displayed pH sensitivity, making the extract beneficial for certain applications. Qualitative analysis of extracts revealed greater number of phenolic compounds to be present in methanol and distilled water extracts. Moreover, various derivatives of apigenin and luteolin were also observed in all four extracts. In addition, the acidified methanol extract of the sorghum bran exhibited antimicrobial property at a concentration of 12 mg/mL. A larger inhibition zone was observed against Escherichia coli than Staphylococcus aureus, while the MIC against these two bacteria was 2.2 and 1.1 mg/mL, respectively.Novelty and scientific contributionThis paper presents the first information on the application of ionic liquids as extracting phase for sorghum bran polyphenols and the quantification of such extracts. As evident from the study, each solvent has its own role in the extraction of bioactive compounds. This work also proves that sorghum bran imparts antibacterial activity against foodborne pathogens.

Ionic liquid extraction of silkworm pupa protein and its biological characteristics

• A novel extraction method for silkworm pupa protein has been demonstrated. • The CH-IL extraction increased protein content by 12.14%. • The solubility, emulsification, and foaming capacity of the CH-IL extracted protein were enhanced. Silkworm ( Bombyx mori ) pupa protein (SPP) is a high-quality source of animal protein with substantial nutritional benefits and health value. To develop an efficient extraction method for SPP that is environmentally friendly, we selected choline hydroxide ionic liquid (CH-IL) as the extraction solvent and performed orthogonal experiments to optimize the extraction conditions. We demonstrated that 3% CH-IL, a solid-to-liquid ratio (g/mL) of 1:30, an extraction temperature of 40 °C, and an extraction time of 1 h facilitated the most efficient extraction. Compared to the conventional alkali solubilization–acid precipitation method, the CH-IL extraction increased protein content by 12.14%. Protein structure analysis showed that the β-sheet content increased by 10.98% and that of disulfide bonds reduced by 16.4%. The processing properties of the CH-IL extracted protein showed that the solubility, emulsification, and foaming capacity were enhanced by 82.87%, 15.44%, and 18.97%, respectively. The physical properties of SPP remarkably improved relative to the increased stretching of the polypeptide chains. The findings of this study provide technical knowledge that will enhance the processing performance of pupal proteins.

Tentative Confinement of Ionic Liquids in Nylon 6 Fibers: A Bridge between Structural Developments and High-Performance Properties

A reversible confinement of ionic liquid (IL) among the amide segments has been carried out for the preparation of high-modulus and high-strength aliphatic semicrystalline nylon 6 fibers. In this research work, the suppression or the weakening of the hydrogen bonds during the conventional low-speed melt spinning process is followed by a hot-drawing stage and a subsequent IL extraction of the IL out of the 2% wt IL-confined fibers and an immediate thermal stabilization process for the improvement of the properties of the pristine nylon 6 fibers. The resulted crystal structural developments of the IL-confined fibers are attributed to ultimate molecular orientations, which have contributed to the developments of the overall fiber properties. Here, the influences of the IL on the γ and the α crystal phases, the γ-α transition, the morphological properties, and the tensile properties are investigated. The FTIR reported, experimentally, additional peaks at 1237 cm–1 for the γ crystal phase and at 1417 and 1476 cm–1 for the α crystal phase, in conformity with the theoretical computations. The XRD demonstrated that the conventional low-speed melt spinning can successfully be used to prepare as-spun IL-confined fibers having highly improved properties. The so prepared as-spun IL-confined fibers are found to have a γ phase structure that has a small crystal size and high crystal perfections. Fortunately, the γ-to-α crystal phase transition for the IL-confined nylon 6 fibers can be acquired during the hot-drawing stage (stress-induced phase transformation). Furthermore, the IL extraction process followed by a thermal stabilization process, interestingly, has led to significant increases in both of the tensile strengths and the tensile moduli of the reverted nylon 6 fibers. The values that are found are 8.46 cN/dtex for the tensile strength and 39.09 cN/dtex for the tensile modulus. The structure–property relationships between the IL-confined and the reverted nylon 6 fibers have also been discussed.

Ultrasonic-Assisted Ionic Liquid Extraction of Two Biflavonoids from Selaginella tamariscina.

Selaginella tamariscina, a traditional Chinese medicine, contains a variety of bioactive components, among which biflavonoids are the main active ingredients and have antioxidant, antitumor, and anti-inflammatory properties. In this study, ultrasonic-assisted ionic liquid extraction (UAILE) is used for the first time to extract two main biflavonoids (amentoflavone (AME) and hinokiflavone (HIN)) from S. tamariscina. A high-performance liquid chromatography method is used for the simultaneous determination of AME and HIN in S. tamariscina. Then, three novel ILs are synthesized for the first time by a one-step method using benzoxazole and three acids or acid salts as raw materials, and the structures of the synthesized ILs are characterized by elemental analysis, infrared spectroscopy, and NMR spectroscopy, as well as the thermal stability of the ILs is evaluated by thermogravimetric analysis. After screening the extraction effects of three benzoxazole ILs, three pyridine ILs, and three imidazole ILs, it is found that [Bpy]BF4 is the best and therefore selected as the extractant. The optimal extraction process is explored in terms of the yields of AME and HIN from S. tamariscina by a single-factor experiments and response surface analysis. Under the optimal level of each influencing factor (IL concentration of 0.15 mol/L, solid–liquid ratio of 1:12 g/mL, ultrasonic power of 280 W, ultrasonic time of 30 min, and three extraction cycles), the extraction rates of AME and HIN from S. tamariscina are 13.51 and 6.74 mg/g, respectively. Moreover, the recovery experiment of [Bpy]BF4 on the extraction of biflavonoids shows that the recovered IL can repeatedly extract targets six times and the extraction rate is about 90%, which indicates that the IL can be effectively reused. UAILE can effectively and selectively extract AME and HIN, laying the foundation for the application of S. tamariscina.

Mechanism analysis and sustainability evaluation of imidazole ionic liquid extraction based on molecular dynamics

Liquid-liquid extraction is often used in industry because of its advantages of low energy consumption and low cost. In this study, ionic liquids were used to separate ethyl acetate / n-hexane system. Molecular dynamics simulation was used to study the extraction mechanism of ionic liquid / n-hexane / ethyl acetate from a microscopic point of view. The results showed that the extraction capacity of ionic liquids for n-hexane-ethyl acetate mixture was [HMIM][PF6] > [HMIM][NTF2] > [HMIM][OTF] > [OMIM][PF6]. Anion plays a more important role in the extraction of ethyl acetate. The results showed that [HMIM][PF6] had better extraction effect. However, [PF6]− is easily hydrolyzed to produce HF, which causing great harm to the environment and equipment. Therefore, [HMIM][NTF2] is more suitable for the separation of ethyl acetate-n-hexane mixed system. In addition, Aspen Plus was used to simulate industrial processes to separate the ethyl acetate-n-hexane azeotropic system and recover the ionic liquid. The recovery rate of ionic liquid is 99.98%, and the mass fraction of purified n-hexane is 99.32%. In addition, the recovery rate, economical evaluation and environmental impact of [HMIM][NTF2] and acetonitrile as extractants were compared.

Recent Progress in Ionic Liquid Extraction for the Separation of Rare Earth Elements.

This review summarizes recent progress in solvent extraction of rare earth elements (REEs) using an ionic liquid (IL) as the extraction solvent. These IL extraction systems are advantageous owing to the affinity of ILs for both charged and neutral hydrophobic species, in contrast to conventional organic solvent extraction systems. Herein, REE extraction studies using ILs are detailed and classified based on the type of extraction system, namely extraction using anionic ligands, extraction using neutral ligands, synergistic extraction, extraction without extractants, and a specific system using task-specific ionic liquids (TSILs). In IL extraction systems, the extracted complexes are often different from those in organic solvent systems, and the REE extraction and separation efficiencies are often significantly enhanced. Synergistic IL extraction is an effective approach to improving the extractability and separability of REEs. The development of novel TSILs suitable for IL extraction systems is also effective for REE separation.

A review of the recovery of precious metals using ionic liquid extractants in hydrometallurgical processes

A large amount of industrial waste containing precious metals (PMs) has become a significant issue for the recovery of PMs. The success of PM extractions via hydrometallurgical processes using various types of ionic liquid (IL) extractants has been widely reported. An understanding of their extraction mechanisms and influencing factors is advantageous for further development and design, especially future utilization in industries. This review focuses on the extraction mechanisms of PMs using ILs as extractants in the liquid-liquid extraction or solvent extraction process. Factors influencing their extraction mechanisms and efficiency are described. Different types of ILs used in the extractions of gold (Au(III)), silver (Ag(I)), palladium (Pd(II)) and platinum (Pt(IV)) have been promoted. Moreover, the correlation of calculating parameters with the PM extractions is presented. Finally, their future aspects are recommended.

Ionic liquid assisted the extraction of cellulose from de-oiled Calophyllum inophyllum cake and its characterization

The present work reports the ionic liquid, 1-butyl-3-methylimidazolium chloride [BMIM] Cl, assisted extraction, and characterization of cellulose from the Calophyllum inophyllum de-oiled cake. The yield of the cellulose from the ionic liquid extraction was approximately 23.81 ± 1.72% w/w of the de-oiled cake, which is almost equal to any other fractionation. SEM imaging revealed the swollen nature of cellulose fibers. The results of FTIR affirmed the presence of cellulose functional groups and the absence of hemicellulose and lignin. XRD analysis revealed 81% crystallinity of the cellulose. The dominant carbon peaks from 60 to 106 ppm from CP/MAS 13C NMR also confirmed the presence and purity of cellulose. The thermal degradation pattern of extracted cellulose in between 200 and 350 °C was in good agreement with the literature. Overall, the present results confirmed that a high-quality cellulose fraction could be produced from the lignocellulosic biomass by employing a competent and green approach using the ionic liquid [BMIM] Cl.

Solvent extraction of lithium ions using benzoyltrifluoroacetone in new solvents

This work studies the solvent extraction of lithium ions from alkaline aqueous solutions by chelating agent 3-benzoyl-1,1,1-trifluoroacetone (HBTA). To develop a more eco-friendly extraction system for lithium than currently used, various hydrophobic room-temperature ionic liquids were investigated as diluents. The influence of several experimental parameters on lithium extraction was examined, including aqueous phase pH, the nature of lithium counter-ion, extractant concentration, the addition of electrically neutral co-extractant.It was found that contrary to the traditional extraction systems with molecular diluents, HBTA alone dissolved in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquid extracts efficiently lithium ions from the aqueous solution. The addition of co-extractant, tri(n-octyl)phosphine oxide (TOPO) to HBTA did not result in a synergetic effect. To confirm the mechanism of lithium extraction by HBTA dissolved in ionic liquid (IL), the measurements of IL constituent ions and deprotonated HBTA concentrations in the equilibrium aqueous phase were carried out. Analysis of the results suggests that an electrically neutral lithium-HBTA extractant complex is extracted into the IL phase.The system combining HBTA extractant and 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquid has high selectivity for lithium over sodium but poor selectivity over calcium. We have shown also that a high stripping ratio can be obtained using relatively concentrated aqueous solutions of hydrochloric acid. Finally, it was found that the use of some deep eutectic solvents as diluents is much less efficient compared with ILs.

Extraction Mechanism of Lithium from the Alkali Solution with Diketonate-Based Ionic Liquid Extractants

Four diketonate-based functional ionic liquids (ILs) with trialkylmethylammonium ([A336]+) cation were synthesized, and the synergistic extraction systems containing IL and thetrialkylphosphineoxid...

Separation of cobalt and lithium from spent lithium-ion battery leach liquors by ionic liquid extraction using Cyphos IL-101

The eventual fading and scrapping of lithium (Li)-ion batteries will result in the formation of a huge urban mine of spent batteries. Hydrometallurgy and further extraction/separation are effective ways in which to recover the valuable metal ions from such batteries. Herein, extraction and recovery of spent lithium cobalt oxide (LiCoO2) battery leach liquors using Cyphos IL-101 is proposed. Based on the optimization of extraction conditions, continuous circulating extraction, and thermodynamic analysis, Cyphos IL-101 effectively extracted cobalt (Co) ions with excellent stability and high extraction capacity (35.25 g/L). The separation factor of Co and Li (βCo/Li) was 102.11 in 0.5 M HCl at 60 °C under the optimal operation condition. Moreover, an increase in temperature increased Co extraction in the spent Li-ion battery leach liquors. The extractants before and after use were characterized using ultraviolet-visible (UV–Vis) absorption spectra, Fourier transform infrared (FTIR) spectra, and nuclear magnetic resonance (NMR) spectra. The extraction mechanism of cobalt ions by Cyphos IL-101 was suggested as that cobalt transferred to the organic phase from the aqueous phase in the form of [CoCl4]2−. 90.5% of Co and 86.2% of Li were recovered by precipitation after extraction separation in the forms of cobalt oxalate and lithium carbonate with the purity 87.4% and 74.2%. This suggested method might provide a promising strategy for recycling spent lithium cobalt oxide batteries.

Quantum chemical calculation, molecular dynamics simulation and process design for separation of heptane - butanol using ionic liquids extraction

Investigating energy-saving and environmentally friendly green solvents is an inevitable requirement for the sustainable development of liquid-liquid extraction. In this work, σ- profiles were drawn using COSMO-SAC model according to the extraction mechanism. Based on quantum chemistry method, the interaction energy, total charge density, deformed charge density and bond length of ionic liquids and butanol were calculated. According to the absolute value of the interaction energy, the hydrogen bond of the total charge density and the deformed charge density, the extractant with good extraction effect can be determined. The radial distribution function of ionic liquids was calculated at the molecular level through molecular dynamics simulation, and the extraction ability of ionic liquids were analyzed. According to the binary interaction parameters obtained from the liquid-liquid equilibrium data of 298.15 K ternary system, the extraction process was simulated. The minimum total annual cost was calculated when the required butanol recovery and heptane purity were achieved. Combining quantum chemical calculation and molecular dynamics simulation to select the best extractant, and verifying the feasibility of ionic liquids as extractant through the simulation process, is of great significance for the industrial application of ionic liquids.