Recovery Of Ionic Liquid Research Articles

Ionic Liquid-Assisted Selective Extraction and Partitioning of Biomolecules from Macroalgae.

Macroalgae are a promising feedstock for several industries due to their large content of proteins and carbohydrates and the high biomass productivities. A novel extraction and fractionation concept based on ionic liquids (ILs) using Ulva lactuca as model organism is presented. Biomolecules are first extracted by means of IL-assisted mechanical shear, followed by two-phase partitioning or ultrafiltration in order to fractionate proteins and carbohydrates and to recover the IL. Ethyl methyl imidazolium dibutyl phosphate ([Emim][DBP]) is strongly selective to proteins, leading to extraction yields up to 80.4% for proteins and 30.7% for carbohydrates. The complete process, including extraction and ultrafiltration, allowed protein recovery of up to 64.6 and 15.4% of the carbohydrates in the retentate phase, while a maximum of 85.7% of the IL was recovered in the permeate phase. The native structure of the extracted proteins was preserved during extraction and fractionation as shown by gel electrophoresis. Selective extraction of proteins from macroalgae under non-denaturing conditions using ILs followed by the recovery of IL using ultrafiltration is for the first time reported. The proposed extraction-fractionation approach is simple and can be potentially applied for the biorefinery of macroalgae at the commercial scale.

Insight into membrane fouling mechanism and cleaning strategy during selective electrodialysis for metal ions removal from ionic liquid aqueous solutions

Selective electrodialysis (SED) method has been proved to be effective in the process of the removal of mental ions from the ionic liquid (IL) aqueous solution in our previous work. However, the membrane fouling and cleaning strategy have not yet been investigated in IL recovery process, which are essential issues concerning the membrane life and overall cost. Therefore, various operating parameters, i.e. operation time, metal ion concentration, IL concentration, pH and temperature were systematically investigated to reveal the formation of membrane fouling in this work. Then, basing on the analysis results of fouling formation, the ion exchange capacity (IEC), contact angle, resistance, XPS were further adopted to reveal the fouling mechanism. These results showed that the variation of physicochemical properties of membranes with the formation of membrane fouling, and the [Emim]+ cation combined with the fixed groups in MSCM through physical/chemical formation. The EIS further demonstrated that the ion migration path changed as for the formation of [Emim]+, Mg2+, Ca2+ fouling layer. Finally, inspired by this mechanism, a specific cleaning strategy with the order of H2O, 0.1 M HCl, and 0.1 M NaCl was proposed, and the membranes exhibited the steady separation performance and physicochemical properties within 6-times recycle.

Ionic liquids enhanced oil recovery from oily sludge-experiment and mechanism

The oily sludge would cause environment pollution, and would cause the heavy oil waste. Therefore, it was vital for us to find novel methods to obtain heavy oil from the oily sludges. In this study, the [C12mim][PF6] and [C12mim][Br] ionic liquids(ILs) were used to enhance the oil recovery. The toluene could obtain the highest oil recovery, and both the two ILs could increase the oil recovery. Toluene could obtain the highest oil recovery (89.4 wt%), and n-octane could obtain the lowest oil recovery (76.8 wt%). [C12mim] [PF6] could efficiently increase the heavy oil recovery to 91.2 wt%(by toluene). The [C12mim][Br] could increase the heavy oil recovery further. Both the [C12mim] [PF6] and the [C12mim][Br] ionic liquids could increase the heavy ois C/H ratio, decrease heavy oil viscosity and increase the sands hydrophilicity. The [C12mim][Br] ionic liquids showed better effect. In addition, the ionic liquids could increase the solvents recovery, and the ionic liquids recovery were high. Therefore, the ionic liquids enhanced oil recovery could be recycled to ten times. The two ionic liquids could effectively decrease the heavy oil interaction force, and when the ionic liquids increased to 200 ppm, the force remained stable. In the end, the ionic liquids enhancing solvent extraction mechanism was put forward.

Preconcentration of Superbase Ionic Liquid from Aqueous Solution by Membrane Filtration.

Certain organic superbase ionic liquids (ILs) have shown good cellulose dissolution and fiber regeneration performance, allowing us to obtain high-quality textile fibers. However, there is a lack regarding the IL recovery from the spinning bath and its purification, which is essential for the economic viability of the process. Aiming to understand methods to separate ILs from water for reuse/recycle, the use of pressure-driven membrane processes to recycle ionic liquids from aqueous solution was investigated. The recovery of two superbase ILs, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-enium acetate, [mTBDH][OAc], and 5-methyl-1,5,7-triaza-bicyclo[4.3.0]non-6-enium acetate, [mTBNH][OAc], were studied using different types of membranes (microfiltration, ultrafiltration, nanofiltration, and reverse osmosis, RO). Additionally, pressure, IL concentration, temperature, and multicycle effect were evaluated. Significant retentions (>45%) were obtained for the nanofiltration and RO membranes (NF270-NF and BW30LE-RO). The increase in pressure and temperature resulted in an increase in volumetric flux and a decrease in IL retention. On the other hand, IL concentration decreased the volumetric flow and rejection. For the serial filtration tests, a three-fold ionic liquid concentration was achieved, for a maximum concentration of 14 wt % of the ionic liquid. The membrane filtration methodology proved to be an efficient technique for carrying out the preconcentration of the IL from dilute solutions.

Design of energy-efficient ionic liquid-based extractive distillation systems for ethanol dehydration including alternatives for ionic liquid recovery

Designs of extractive distillation systems for ethanol-water separation using ionic liquids as entrainers are presented. Distillation sequences that integrate the extractive column with five options for ionic liquid recovery were designed. Two types of ionic liquids, namely, 1-butyl-3-methylimidazolium chloride [BMIM](Cl)] and 1-ethyl-3-methylimidazolium tetrafluoroborate [EMIM](BF₄)], were considered. Once initial designs were obtained, simulations using the Aspen Plus environment were conducted to identify the operating conditions of the separation sequences that minimize energy consumption. The designs were tested under two levels of IL flows, one with the minimum flow required for the separation and another one with the flows that minimized the total annual cost of the extractive column. From the total of 20 design options, it was found that the most energy efficient design was based on a low flow of [BMIM(Cl)] as entrainer, with an extractive column followed by a desorption column and a membrane unit for IL recovery.

Ionic Liquid Recovery of Rare-Earth Elements from Coal fly Ash: Process Efficiency and Sustainability Evaluations

Ionic Liquid Recovery of Rare-Earth Elements from Coal fly Ash: Process Efficiency and Sustainability Evaluations

Ionic Liquid-Assisted DLLME and SPME for the Determination of Contaminants in Food Samples

Developing effective and green methods for food analysis and separation has become an urgent issue regarding the ever-increasing concern of food quality and safety. Ionic liquids (ILs) are a new chemical medium and soft functional material developed under the framework of green chemistry and possess many unique properties, such as low melting points, low-to-negligible vapor pressures, excellent solubility, structural designability and high thermal stability. Combining ILs with extraction techniques not only takes advantage of ILs but also overcomes the disadvantages of traditional extraction methods. This subject has attracted intensive research efforts recently. Here, we present a brief review of the current research status and latest developments regarding the application of IL-assisted microextraction, including dispersive liquid–liquid microextraction (DLLME) and solid-phase microextraction (SPME), in food analysis and separation. The practical applications of ILs in determining toxic and harmful substances in food specimens with quite different natures are summarized and discussed. The critical function of ILs and the advantages of IL-based microextraction techniques over conventional extraction techniques are discussed in detail. Additionally, the recovery of ILs using different approaches is also presented to comply with green analytical chemistry requirements.

Recovery of lithium from high Mg/Li ratio salt-lake brines using ion-exchange with NaNTf2 and TBP

In view of the complex problems for the ionic liquids (ILs) recovery with the system containing ILs and TBP, this work proposed a NaNTf2-based synergistic extraction system, NaNTf2 + TBP, which could realize the effective reutilization of the extraction system without reducing the lithium separation ability. Under the optimal extraction parameters, the extraction efficiency of Li+ exceeded 98%, while that of Mg2+ was only ~1%. The results of mass spectrometry (ESI-MS) and slope analysis showed that two TBP molecules involved in the extraction process of Li+, and the Li+ extraction mechanism obeyed the cation-exchange process. According to the red shift of the FT − IR peak of PO in TBP and the chemical shift changes of P in 31P NMR, the interaction strength between TBP and different metal ion followed the sequence: ETBP−H >> ETBP−Li > ETBP−Mg > ETBP−K > ETBP−Na. It was also found that after a three−stage countercurrent extraction process, [Li+]org was 0.42 g L−1, and the total recovery efficiency of Li+ was about 98%. The saturated extraction capacity for Li+ could be as high as 5.4 g L−1, and Li+ could be stripped with the aqueous solution containing 0.2 mol L-1 HCl. In addition, the extraction efficiency of Li+ was almost not attenuated after 6 extraction cycles. This new extraction system shows a certain industrial application prospect for Li+ separation from the salt lake bine with high Mg/Li ratio.

Recovery of the N,N-Dibutylimidazolium Chloride Ionic Liquid from Aqueous Solutions by Electrodialysis Method.

Ionic liquids (ILs), named also as liquid salts, are compounds that have unique properties and molecular architecture. ILs are used in various industries; however, due to their toxicity, the ILs’ recovery from the postreaction solutions is also a very important issue. In this paper, the possibility of 1,3-dialkylimidazolium IL, especially the N,N-dibutylimidazolium chloride ([C4C4IM]Cl) recovery by using the electrodialysis (ED) method was investigated. The influence of [C4C4IM]Cl concentration in diluate solution on the ED efficiency was determined. Moreover, the influence of IL on the ion-exchange membranes’ morphology was examined. The recovery of [C4C4IM]Cl, the [C4C4IM]Cl flux across membranes, the [C4C4IM]Cl concentration degree, the energy consumption, and the current efficiency were determined. The results showed that the ED allows for the [C4C4IM]Cl recovery and concentration from dilute solutions. It was found that the [C4C4IM]Cl content in the concentrates after ED was above three times higher than in the initial diluate solutions. It was noted that the ED of solutions containing 5–20 g/L [C4C4IM]Cl allows for ILs recovery in the range of 73.77–92.45% with current efficiency from 68.66% to 92.99%. The [C4C4IM]Cl recovery depended upon the initial [C4C4IM]Cl concentration in the working solution. The highest [C4C4IM]Cl recovery (92.45%) and ED efficiency (92.99%) were obtained when the [C4C4IM]Cl content in the diluate solution was equal 20 g/L. Presented results proved that ED can be an interesting and effective method for the [C4C4IM]Cl recovery from the dilute aqueous solutions.

Recovery of dialkylimidazolium-based ionic liquids from their mixtures with acetone or water by flash distillation

In a number of applications for which novel processes based on ionic liquids have been proposed, the recovery of the ionic liquid from its mixture with a molecular solvent is a step of critical importance for the viability of the process. In this work, feasibility and conditions for such recovery by simple flash vapourisation have been explored for the particular case of three dialkylimidazolium-based ionic liquids (namely 1-ethyl-3-methylimidazolium thiocyanate ([C2mim][SCN]), 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]), and 1-butyl-3-methylimidazolium acetate ([C4mim][OAc])) and either acetone or water as representative molecular solvents of industrial relevance. The isobaric vapour-liquid equilibria of the binary systems acetone + ([C2mim][SCN] or [C4mim][OAc]) and water + ([C2mim][OAc] or [C4mim][OAc]) have been determined at three different pressures (101.32, 50.00, and 30.00 or 25.00 kPa), and the data have been suitably correlated by means of the NRTL thermodynamic model. These correlations have been used in the software Aspen Plus for the development of reliable simulations of a flash unit to perform the desired separations. The results indicate the difficulty in getting the ionic liquids recovered with high purity, even if operating the flash at a pressure as low as 5 kPa and at temperatures close to the range where the thermal stability of the ionic liquids starts to get compromised.

Liquid-liquid equilibria for (polypropylene glycol 400 based magnetic ionic liquids + inorganic salts) aqueous two-phase systems at 298.15 K

Two polypropylene glycol 400 (PPG400) based temperature-sensitive magnetic ionic liquids were successfully used to construct the temperature-sensitive magnetic ionic liquid aqueous two-phase systems (MILATPs). This temperature-sensitive MILATPs combined temperature-controlled recovery and the advantages of a MILATPs and is showing great potential in the field of extraction and separation. In this work, aqueous two-phase equilibrium data of the temperature-sensitive MILATPs ([HOPPG400BMIM][Tempo-OSO3] + K3PO4/K2CO3/ Na2CO3 + H2O systems and [BMIMPPG400BMIM][Tempo-OSO3]2 + K3PO4/K2CO3/ Na2CO3 + H2O systems) were determined at 298.15 K under 0.1 MPa. Three common empirical equations including Merchuk equation were adopted to fit the experimental binodal data with satisfactory correlation performances. Inorganic salts screening demonstrated that K3PO4 and K2CO3 have better phase-forming ability than Na2CO3. Morever, [HOPPG400BMIM][Tempo-OSO3] has a better phase-forming ability than [BMIMPPG400BMIM][Tempo-OSO3]2. Subsequently, tie line data for systems containing K3PO4 or K2CO3 were determined and correlated by two empirical equations with satisfactory correlation performances. Furthermore, the temperature- controlled recovery of temperature-sensitive magnetic ionic liquid was ideally realized simply by heating. All these experimentally measured liquid–liquid equilibrium data and the theoretical correlations can provide valuable reference for future application in the field of extraction and separation.

A successful method for phycocyanin extraction from Arthrospira platensis using [Emim] [EtSO4] ionic liquid

AbstractResearch into the extraction of phycobiliprotein from Arthrospira platensis is currently ongoing. Most traditional methods of phycobiliprotein extraction include the use of organic solvents, which negatively affect the sustainability of the process. Ionic liquids (ILs) are a promising alternative for phycobiliprotein extraction due to their properties as green solvents. In the present work an imidazolium‐based IL and sonication were studied for phycobiliprotein and carbohydrate extraction. A factorial experimental design was used to optimize the amount of extracted phycocyanin. The maximum extraction yield was achieved by using low biomass/solvent ratios combined with high IL/water ratios and sonication powers, and long operation times. The recovery of IL was studied under these conditions using a dialysis‐based process to separate the IL from the extracted phycobiliproteins. The results reveal the possibility of using the recovered IL for seven consecutive extraction cycles with an acceptable phycocyanin extraction amount, from 75 mg g−1 (fresh IL) to 60 mg g−1 (7 cycles of reused IL). The use of [Emim] [EtSO4] + ultrasound is a promising alternative for phycocyanin extraction, enhancing the results obtained with other IL in terms of extracted phycocyanin and the number of times the IL can be reused. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

Janus membranes for fast-mass-transfer separation of viscous ionic liquids from emulsions

Separation membranes are urgently desired for the efficient recovery of oil-like ionic liquids (ILs) from industrially applied emulsions. Conventional membranes with asymmetric porous structure and high tortuosity suffer from high trans-membrane resistance and low mass transfer efficiency for this application. Herein, Janus membranes (JMs) are constructed by the single-side modification of hydrophobic poly(vinylidene fluoride) (PVDF) membrane with vertically penetrative pores for the rapid-mass-transfer separation of viscous ILs. A charged and underwater IL-phobic thin layer is facilely co-deposited on one side of the PVDF membranes from polydopamine/poly(diallyldimethylammonium chloride) solution. This single-side modification endows the as-prepared JMs with a deemulsification function to IL-in-water emulsions and a unidirectional transportation ability to hydrophobic ILs. These JMs show an excellent IL recovery capacity with high permeation speed and stable flux during a long-term cyclic separation of IL-in-water emulsions because the vertically penetrative pores with low tortuosity allow to significantly reduce the trans-membrane resistance toward those viscous ILs. Overall, our vertically-channeled JMs provide an ideal material solution for recovering high-viscosity and value-added chemicals from their industrial water mixture in practice, especially from those aqueous emulsions.

Molecular interaction mechanism and performance evaluation in the liquid-liquid extraction process of ionic liquid-heptane-tertiary butanol based on molecular dynamics

Nowadays, organic solvents are more and more widely used in chemical industry, If the waste liquid is not recovered in time, this will also cause serious damage to the environment. In this work, [HMIM][OTF] and [BMIM][OTF], [OMIM][OTF] were used to separate n-heptane-t-butanol azeotropic system. From the molecular level, through the analysis of non-bonding interaction energy, spatial distribution function, radial distribution function and self-diffusion coefficient, explore [HMIM][OTF] and [BMIM][OTF], [OMIM][OTF] to separate n-heptane-tertiary butanol mixture Extraction mechanism. According to the MD simulation results, the non-bond interaction energy, radial distribution function, spatial distribution function and self-diffusion coefficient of different ionic liquid and different components were calculated and compared. The accuracy of force field parameters is verified by the density of each component. The results show that electrostatic energy plays a key role in the extraction process. The radial distribution function shows that [OTF]- plays a leading role in the extraction process. With the continuous growth of carbon chain, the extraction ability of ionic liquid is enhanced, but the solubility of raffinate is also enhanced. At the same time, ECOSAR toxicity analysis software also showed that [OMIM]+ had strong biological toxicity and was not suitable to be used as extractant. After comprehensive consideration, [HMIM][OTF] is selected as the best extractant. Finally, using [HMIM][OTF] as extractant, the process is designed and optimized. The final mole fraction of NHP is 99.73%, and the recovery of ionic liquid is 99.97%. This study provides certain guidance for the screening of ionic liquids as extractants.

Technoeconomic Assessment of a Biomass Pretreatment + Ionic Liquid Recovery Process with Aprotic and Choline Derived Ionic Liquids

Ionic liquids have shown promising results in biomass pretreatment; however, an extensive water washing step is necessary. This fact increases not only the processing costs but also those associated with the ionic liquid recovery step. In this work, Eucalyptus globulus wood pretreated with two acetate-based ionic liquids, namely 1-ethyl-3-methylimidazolium acetate and choline acetate, has been washed with increasing volumes of water in order to analyze the influence of the amount of washing water used on the subsequent enzymatic hydrolysis stage and on the IL recovery costs. Vapor–liquid equilibria data of recovered ionic liquid/water mixtures have been determined to simulate the IL recovery step with Aspen Plus, calculating the operating costs using the Aspen Plus Economics Analyzer afterward. [Emim][OAc] was more efficiently washed and more effective toward wood pretreatment than [Ch][OAc]. Both IL/water systems were successfully modeled, and simulation studies showed that incremental volumes of water led to higher operating costs in the IL recovery step that are compensated with less IL makeup costs. Therefore, this work offers a technoeconomical analysis of the IL recovery step in a real biorefinery pretreatment process as a function of the volume of water used in the pretreated wood washing stage.

Influence of ionic liquid pretreatment on coal desulfurization

ABSTRACT Combining ionic liquid pretreatment with H2O2 oxidation desulfurization to remove sulfur from coal is a very valuable subject. In this work, three different types of ionic liquid were used to pretreat coal samples, and then the pretreated coal was treated by 30% H2O2 with the assistance of ultrasound, which is compared with the desulfurization effect of raw coal with the same method. The swelling characteristics and contact angle changes of coal samples before and after pretreatment were measured, and the samples before and after pretreatment were characterized by BET, SEM, TG. And the form sulfur changes of coal samples before and after being treated were determined by chemical methods, FT-IR and XPS were used to determine the sulfur-containing functional groups and the sulfur morphological change of coal samples before and after treatment, and different types of ionic liquid recovery experiments were also carried out. The results show that the ionic liquid pretreatment had a swelling effect on the coal samples and improved the wettability of the coal samples. The ionic liquid pretreatment increased the specific surface area and average pore size of the coal sample, as well as the coal particle gap increases, cracks developed on the coal surface. The characterization of the desulfurized samples find that the desulfurization rate of the ionic liquid pretreated coal treated by H2O2 with the assistance of ultrasound was significantly increased compared to the raw coal under the same conditions. Ionic liquid pretreatment promoted coal desulfurization, and more sulfur in coal was removed. The ionic liquid recovery experiments reveal that ionic liquid could be stably recovered, the FT-IR characterization experiment of ionic liquids indicate that the recovered ionic liquid had no obvious change of structural properties compared to the fresh ionic liquid.

Quantitative recovery and regeneration of acidic ionic liquid 1-butyl-3-methylimidazolium hydrogen sulphate via industrial strategy for sustainable biomass processing

Quantitative recovery is necessary for scale-up application of acidic ionic liquids (AILs). Ultrafiltration and bipolar membrane electrodialysis (BMED) was employed for the recovery and regeneration of acidic ionic liquid 1-butyl-3-methylimidazolium hydrogen sulphate (Bmim[HSO4]) after biomass pretreatment. Ultrafiltration was designed for the purification of BMED feed solution. During BMED treatment, Bmim+ retention with OH− generation occurred in mixing section and SO42− immigration with H+ generation occurred in aciding section. Resulting aqueous Bmim[OH] in mixing section and H2SO4 in aciding section could be utilized for quantitative synthesis of Bmim[HSO4]. Influence of BMED operating mode and major parameters including BMED feed concentration and current density of BMED module were studied in detail. The highest recovery ratio for Bmim+ and SO42− reached 96.2% and 96.0%. And the lowest energy consumption of specific Bmim[HSO4] recovery approached 9.0 kw∙h/kg. Insight gained from this study suggested a sustainable biomass processing methodology using AILs.

Permeabilization of Haematococcus pluvialis and solid-liquid extraction of astaxanthin by CO2-based alkyl carbamate ionic liquids

Haematococcus pluvialis (H. pluvialis) microalgae are well known for their high content of astaxanthin, which is a super potent antioxidant with various remedial effects. Ionic liquids (ILs) have been proposed as a promising solvent to permeabilize the robust microalgal cell wall for an effective extraction of bioactive compounds. Nonetheless, the removal of ILs from the extracted compounds requires the additional treatment steps that complicate the overall extraction process and the recycling of ILs. To address these shortcomings, we demonstrated a sustainable extraction system that utilizes CO2-based alkyl carbamate ILs to permeate H. pluvialis cells and extract astaxanthin. This class of ILs is readily distillable for an easy recovery of ILs from the extraction medium. Among the tested CO2-based alkyl carbamate ILs [dimethylammonium dimethylcarbamate (DIMCARB), dipropylammonium dipropylcarbamate (DPCARB), dibutylammonium dibutylcarbamate (DBCARB) and diallyammonium diallycarbamate (DACARB)], DIMCARB gave the best performance of astaxanthin extraction. The optimized extraction conditions [100% (w/w) of DIMCARB, 75 min and 45 °C] resulted in the high yield of astaxanthin (27.99 mg/g). The capability of DIMCARB to permeabilize the amorphous trilayered structure of cell wall was verified by the presence of pores on the cell surface of H. pluvialis as shown in the microscope images. The performance and recyclability of DIMCARB extraction system were also evaluated by conducting three successive rounds of astaxanthin extraction with the recycled DIMCARB solutions. In addition, the antioxidant capacity of the extracted astaxanthin was well retained, showing that this type of distillable IL was suitable for the extraction of phytonutrients from algal source.

Ionic liquids as potential pretreatment agent for bioconversion of biomass to biofuels.

Ionic liquids (ILs) have been greatly exploited as a good solvent and/or reagent with various applications because of their green properties and also their physiochemical and biological properties. One of the applications is pretreatment of biomass such as lignocellulosic biomass precedent to enzymatic hydrolysis for bioenergy production and other biomaterial production. Generally, the method collected of an IL pretreatment or recovery forwarded by hydrolysis of lignocellulosic biomass. Another approach came in vision in which simultaneously pretreatment process and saccharification of lignocellulosic biomass were used. However, the employment of ILs during this integrated process, within which enzymatic hydrolysis is finished within the presence of IL applied for biomass pretreatment, will simply inactivate the enzymes. Cellulases emerged as one of the important enzymes which are used to catalyze the polysaccharide from biomass and showed a higher level of stability in various ILs. Also, numerous approaches were created together with the synthesis of enzyme-compatible ILs, screening ILs-tolerant enzymes, and media engineering to boost cellulases performance. This review highlights the advancement and use of IL for the pretreatment or hydrolysis of lignocellulosic biomass. The structure of ILs and cellulase stabilization approaches are also discussed. From this review, this tends to powerfully believe that IL-compatible cellulase systems would eliminate the requirement to recover the regenerated biomass and cause simple, saccharification of cellulosic materials, which might be helpful in developing integrated bioprocesses.

Ionic liquid-based salting-out extraction of bio-chemicals

Ionic liquids (ILs) are known as green solvents, and have been widely used in the dissolution and transformation of biopolymers, the extraction of bioactive compounds and metal ions, and the capture of SO2 or CO2. However, less attention was given to the separation of bio-based chemicals, such as diols and organic acids. Bio-based chemicals can be efficiently separated by organic solvent-based salting-out extraction (SOE) from fermentation broths, while organic solvents are normally unfriendly to environment and process safety in commercialized production due to their toxicity or/and flammability. In recent years, the IL-based SOE system has been explored in the separation of bio-based chemicals as an alternative of organic solvent-based SOE system. In this review, the progress of IL-based SOE of bio-based chemicals has been summarized, including the effect of ILs structure on the formation of aqueous two phases, and the influences of ILs structure and concentration, temperature and pH on the partition behaviors of target products and ILs as well as removal of impurities. Most of bio-based chemicals could be distributed into the IL-rich phase with high recovery, while the partition behaviors of bio-based chemicals are sometimes different from that in organic solvent-based SOE systems. Although the results of IL-based SOE are promising, further studies are still required in the increased selectivity of target products over by-products, recovery and recycling of ILs, and the separation between ILs and bio-based chemicals. Additionally, three kinds of integrated bioprocesses would be developed on basis of utilization of ILs as extractant for SOE, catalyst for condensation reaction and solvent for pretreatment of lignocellulose.