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The synthesis of 2,5-furandicarboxylic acid (FDCA) for the production of the sustainable bioplastic polyethylenefuroate (PEF) represents a topic of strong scientific and commercial interest. However, despite extensive research, the development of an efficient process for the synthesis of FDCA still faces difficult challenges. The principle cause is the strong dependence of the reactions involved on the solvent employed and difficulties in isolating the intermediate 5-HMF, leading to issues in performing the oxidation step which is favoured only in water, while 5-HMF formation is promoted in ionic liquids and other organic solvents. In this study we exploited ionic liquids as efficient solvents for the synthesis of HMF from sugars with MnO2 as catalysts for the in situ oxidation of HMF into a dialkylimidazolium furan carboxylate ([dbmim]-FDC). The advantage in forming the imidazolium salt instead of the diacid form lies in the easier separation of this compound from the reaction mixture at low concentration (<2%) through antisolvent addition (ethanol) and its conversion into FDCA through acidification. This process represents a new efficient methodology to isolate FDCA directly from sugars such as glucose and fructose at isolated yield higher than 80% from these substrates, representing a step forward for the development of a technoeconomically efficient process for the production of biobased plastics. [ABSTRACT FROM AUTHOR]

Millions of tons of solvents are consumed annually in various industrial sectors, such as pharmaceuticals, chemical synthesis, textiles, coatings, paints, and others. Ionic liquids (ILs) are pairs of ions in the liquid form synthesized at temperatures below 100 °C that meet specific demands of processes, replacing organic solvents that are harmful to the environment. They offer exceptional prospects as advanced solvents owing to their unique attributes and remarkable recyclability. However, alkyl imidazolium-based ILs have proven to be flammable when exposed to heat, and cytotoxicity and phytotoxicity were observed for many traditional ILs. Therefore, with a focus on negligible toxicity, biocompatibility, straightforward preparation, and sustainability, biocompatible ionic liquids (Bio-ILs) have emerged with huge potential in many different fields of chemistry. These solvents are specifically designed to be derived from naturally occurring compounds. Their physical–chemical properties, modulated according to the application, make them an attractive green technology. Therefore, this review addresses the recent advances in Bio-ILs that include the production of renewable commodities and approaches in catalysis and the pharmaceutical field. Likewise, patents and future perspectives are discussed, demonstrating the great potential of Bio-ILs as green and sustainable compounds. [ABSTRACT FROM AUTHOR]

• Plant sterols can be precipitated from fatty acid based ionic liquids. • Over 80% of plant sterols recovery and over 90% purity can be obtained. • Plant sterol precipitation is only slightly affected by the fatty acid used. • Plant sterol precipitation is strongly inhibited by other molecules. • Recovery of 79.4% and purity of 991% plant sterols are reached from tall oil. Plant sterols and stanols are bio-derived compounds used in functional foods because of their hypocholesterolemic effect. Currently, plant sterols and stanols are recovered from tall oil and vegetable oil waste streams by using high vacuum distillation and crystallization. The aim of this work was to explore the recovery and purification of plant sterols and stanols using ionic liquids. Particularly, in-situ protic ionic liquids were synthesized by mixing an amine and fatty/resin acids as a model system of tall oil and vegetable oil waste streams, then an anti-solvent precipitation was performed using alcohols and water. Precipitation temperature, alcohol concentration, water concentration, type of alcohol (methanol and ethanol) and structure of amine (triethylamine, butylamine, and methyldiethanolamine) strongly affect the precipitation from model systems. On the other hand, precipitation time (3–12 h) and type of fatty/resin acid (myristic acid, oleic acid, abietic acid) only slightly influence the precipitation. Results show that when myristic acid was used, the best combination of recovery and purity is reached using triethylamine and methanol with maximum experimental values of 79.9 % of purity and 99.4 % of recovery at 5 °C, 120 % alcohol, 30 % water, and 12 h. Unfortunately, the precipitation performance of plant sterols and stanols from tall oil (5.3 %) using triethylamine and methanol is significantly worse than the performance observed in model systems, achieving maximum experimental values of 70.5 % of recovery of and 76.5 % of purity. However, it was found that saponifying the tall oil before the precipitation significantly improve plant sterols and stanols recovery and purity. [ABSTRACT FROM AUTHOR]

• Proton transfer is highly dependent on the amine structure in mixtures of fatty acids and amines. • Mixtures between fatty acids and amines exhibit high volatility; even mixtures with high proton transfer. • Mixtures between fatty acids and amines exhibit high hydrogen bond acceptor capacity and low dipolarity-polarizability. Fatty acids are long chain carboxylic acids naturally and abundantly found in oils and fats; therefore, they are interesting candidates for protic ionic liquids (PILs) synthesis. Mixtures of carboxylic acids and amines should lead to intermediate proton transfer from the acid to the amine to form PILs, with both ionic molecules (PIL) and non-ionic molecules observed in these mixtures, depending on the nature of the amine. This work studied the physicochemical properties of mixtures between fatty acids and amines, with phase transitions, thermal stability, viscosity, solvation (Kamlet-Taft parameters) and proton transfer evaluated. Our results show that like other carboxylic acids the proton transfer is highly dependent on the structure of the amine, being much higher for primary amines than for tertiary amines. Also, hydroxyl groups on tertiary amines increase the proton transfer. The extent of the proton transfer strongly influences the physicochemical properties of the mixtures, where a larger proton transfer leads to a higher melting point and higher viscosity. Also, mixtures based on highly volatile amines decomposed at low temperatures even when a high degree of proton transfer was observed. Surprisingly, mixtures based on butylamine or triethylamine exhibited high hydrogen bond acceptor capacity and low dipolarity-polarizability which is an unusual characteristics of ionic liquids, potentially opening new solvent application space for ionic liquids. [ABSTRACT FROM AUTHOR]

Nonaqueous biocatalysis is rapidly becoming a desirable tool for chemical and fuel synthesis in both the laboratory and industry. Similarly, ionic liquids are increasingly popular anhydrous reaction media for a number of industrial processes. Consequently, the use of enzymes in ionic liquids as efficient, environment-friendly, commercial biocatalysts is highly attractive. However, issues surrounding the poor solubility and low stability of enzymes in truly anhydrous media remain a significant challenge. Here, we demonstrate for the first time that engineering the surface of a protein to yield protein-polymer surfactant nanoconstructs allows for dissolution of dry protein into dry ionic liquids. Using myoglobin as a model protein, we show that this method can deliver protein molecules with near native structure into both hydrophilic and hydrophobic anhydrous ionic liquids. Remarkably, using temperature-dependent synchrotron radiation circular dichroism spectroscopy to measure half-denaturation temperatures, our results show that protein stability increases by 55 °C in the ionic liquid as compared to aqueous solution, pushing the solution thermal denaturation beyond the boiling point of water. Therefore, the work presented herein could provide a platform for the realization of biocatalysis at high temperatures or in anhydrous solvent systems. [ABSTRACT FROM AUTHOR]

Tracerdiffusion coefficients of CO2in several brineswere measured by 13C pulsed-field gradient NMR at a temperatureof 298 K and at salt molalities of up to 5 mol·kg–1. The brines studied were NaCl(aq), CaCl2(aq), Na2SO4(aq), and a mixed brine prepared from sevensalts: NaCl, CaCl2, MgCl2, KCl, Na2SO4, SrCl2, NaHCO3. The experimentalresults are compared with the predictions of a modified Stokes–Einsteinrelation in which the Stokes–Einstein number is 4 and the hydrodynamicradius of the CO2molecule in aqueous solution is takento be 168 pm, as determined in an earlier study of the (CO2+ H2O) binary system at the same temperature (Cadoganet al. J. Chem. Eng. Data2014, 59, 519−525). This comparison shows agreement to withinthe experimental uncertainty, independent of salt type and molality.We conclude that the modified Stokes–Einstein relation providesa reliable means of estimating the tracer diffusion coefficient ofCO2in aqueous electrolyte solutions, based on knowledgeof the brine viscosity and the hydrodynamic radius of CO2in pure water at the same temperature. [ABSTRACT FROM AUTHOR]

Introduced here is a quick, simple, robust method to measure acidity in ionic liquid (IL) systems by the use of the NMR-probe mesityl oxide. Acidity corresponding to a Hammett acidity of - 1 to - 9 can be measured reliably using this technique, a range that vastly exceeds that of any single UV-vis probe. [ABSTRACT FROM AUTHOR]

The microscopic features of binary solvent systems formed by molecular solvents (methanol, ethanol, 2-methylpropan-2-ol, water, pyridine, acetonitrile, 1-propanol, 2-propanol, dimethylformamide) and the ionic liquid ([bmim]BF4) as cosolvent were used to select mixed solvents with particular characteristics. Molecular-microscopic solvent parameters corresponding to these binary mixtures were utilised to study the kinetics of the nucleophilic substitution reaction between 2-chloro-3,5-dinitropyridine and aniline to investigate and compare the effects of the solvents on a model chemical reaction. For these mixtures, the solvation behaviour is dominated by both the dipolarity/ polarisability and hydrogen bonding interactions of the media. In these solutions, the rate constants of the reaction decrease with the mole fraction of ionic liquid. [ABSTRACT FROM AUTHOR]

The article presents a review of the study which describes the solvent-solute interactions in room temperature ionic liquids. It focuses on the benefits of using solvents in synthesis and catalysis in ionic liquids on transition metals. The authors contend s that the catalyst determines the outcomes of transition-metal-catalyzed reaction that even the small changes to a ligand can greatly impact catalysis performance.

The application of liquids that are salts at room temperature to chemical synthesis has become a hugely exciting field of study. The greatest promise that these ionic liquids hold is that they might offer process advantages, even novel behaviors that cannot be achieved in molecular solvents. We report here that the SN2 reaction of the trifluoromethanesulfonate and bis(trifluoromethanesulfonyl)imide salts of dimethyl-4-nitrophenylsulfonium ([p-NO2PhS(CH3)2]+[X]-; [X]- = [CF3SO3]-, [N(CF3SO2)2]-) with chloride ion follow a fundamentally different pathway to when the same salts react in molecular solvents. [ABSTRACT FROM AUTHOR]

The second-order rate constant (k2) for the esterification of methoxyacetic acid with benzyl alcohol is reported in a range of ionic and molecular solvents. The solvent effects on esterification rate are examined by using a linear solvation energy relationship based on the Kamlet-Taft solvent scales (α, β, and π*). It is shown that the hydrogen bond basicity of the solvent is the dominant parameter in determining the esterification rate and that the best rates are achieved in low basicity solvents. [ABSTRACT FROM AUTHOR]

Abstract: Liquid–liquid equilibria at ambient temperature and pressure were measured for four ternary systems: n-hexane+THF+water, n-hexane+acetonitrile+water, n-hexane+1,4-dioxane+water, and ethyl ether+1,4-dioxane+water. Partitioning of 1-octene and 1-nonanal in these systems was also measured. The results were modeled with the UNIQUAC and NRTL g E models. The experiments showed an aqueous phase in the n-hexane–THF–water system that was 90% water on average, and an organic n-hexane phase in the n-hexane–acetonitrile–water system that was 96% n-hexane on average. 1,4-Dioxane distributes fairly equally to both phases in the n-hexane–1,4-dioxane–water and ethyl ether–1,4-dioxane–water systems. [Copyright &y& Elsevier]

Abstract: Homogeneous catalysts offer many advantages over heterogeneous catalysts, such as higher activities and selectivities. However, recovery of homogeneous catalysts is often complicated by difficulties in separating these complexes from the reaction products. The use of gaseous carbon dioxide (CO2) as miscibility switch for organic and fluorous phases has been proposed to overcome this limitation. By using CO2 as a cosolvent, polar organic reactants can be homogenized with catalysts immobilized in a fluorous phase without using elevated temperatures. The phase behavior underlying this concept is investigated. High-pressure phase equilibria for the systems containing carbon dioxide, an organic (methanol, toluene, or acetone), and perfluoro-n-hexane were measured using a variable-volume view cell, by a method capable of rapid and facile measurement of compositions and density in both phases with no sampling or calibration. [Copyright &y& Elsevier]

Deep eutectic solvents (DESs) and ionic liquids (ILs) are potential solvents for lignocellulosic biomass fractionation. In this study, the rice straw pretreatment efficiency of four cholinium-based solvents (DESs and ILs) prepared from the same sources (lactic acid and lysine) were comparatively investigated at 110 °C for 4 h. The lignin removal rate correlated well with the saccharification efficiency of the pulps. Quantum chemical (QC) calculations and molecular dynamics (MD) simulations focused on the microscopic structure and non-covalent interactions of the solvents and lignin model molecules (guaiacylglycerol-β-guaiacyl ether, GG) were carried out, and the results indicate that anions of the solvent systems play a leading role (through strong hydrogen bonds or electrostatic interactions) in establishing interactions with GG, supported by cations (via van der Waals interactions). There were clear positive relationships between the total interaction energies (IEs) and lignin removal, cellulose digestibility and glucose yields. In particular, [Ch][Lys] with a low self-interaction energy is able to free some active sites to form strong hydrogen bonds and electrostatic interactions with lignin, thus resulting in lignin dissolution and excellent delignification. For cholinium cations, an ideal partner system provides low self-IEs for solvent molecules and strong IEs between solvents and lignin, which are determined by the type and number of functional groups and the alkyl chain length of the partner components. This work provides ideas about tailoring suitable partner systems for cholinium cations to build solvents for efficient biomass deconstruction. [ABSTRACT FROM AUTHOR]

The effects are reported of electrolyte composition on the electrochemistry of PbII and electrodeposition morphology of Pb in aqueous methanesulfonic acid (MSA) and two methanesulfonate-based ionic liquids: 1-butyl-3-methylimidazolium methanesulfonate and N,N -dimethylbutylammonium methanesulfonate. Cyclic voltammetry and chronoamperometry indicated that the reduction of PbII ions to Pb was a diffusion-controlled process proceeding via an overall two-electron transfer process at −0.67 V vs. Ag (1 M MSA) and involved 3-D progressive nucleation. Scanning electron microscopy showed a strong influence of deposition potential and electrolyte composition on the morphology of Pb deposits. Experimental data was used to model predictions of the specific electrical energy consumption for cathodic PbII electrodeposition coupled with either anodic oxygen evolution or PbO 2 electrodeposition. Image 1 [ABSTRACT FROM AUTHOR]

Coconut husks and shells are underutilised agricultural feedstocks in the bio-based industry. These biomass wastes have a higher lignin content than other woody biomass and have excellent potential as raw materials for the production of lignin-based materials. This work demonstrates the performance of a low-cost protic ionic liquid, N,N,N-dimethylbutylammonium hydrogen sulfate ([DMBA][HSO4]), for ionoSolv pretreatment of coconut husk and shell at 150 °C for 45–90 min and 170 °C for 15–60 min. Optimum pretreatment conditions were observed at 170 °C and 45 min for both feedstocks. At these conditions, [DMBA][HSO4] was able to remove almost 77 wt% of the lignin from the husk; leaving a cellulosic rich pulp behind, which released 82 % of the theoretical maximum glucose after enzymatic saccharification. The pretreated shell, by comparison, achieved 82 wt% lignin removal and 89 % glucose yield and these higher values could be attributed to the highly porous structure of coconut shell cell walls. The cleavage of the β-O-4 aryl ether linkages of lignin followed by extensive C–C condensation in the lignin at longer pretreatment times was shown by HSQC NMR analysis. This extensive condensation was evidenced by molecular weights > 10,000 g/mol exhibited by lignin precipitated after pretreatment at high temperature and long times. The high degree of lignin removal and high glucose release from both feedstocks demonstrate that [DMBA][HSO4] is an excellent ionic liquid for fractionation of very lignin-rich biomass. [ABSTRACT FROM AUTHOR]

We report on the pretreatment of poplar wood with three different 1-ethyl-3-methylimidazolium ionic liquids, [EMim][OAc], [EMim][MeSO3], and [EMim][HSO4], at varying water contents from 0–40 wt% at 100 °C. The performance was evaluated by observing the lignin and hemicellulose removal, as well as enzymatic saccharification and lignin yield. The mechanism of pretreatment varied between the ionic liquids studied, with the hydrogen sulfate ionic liquid performing delignification and hemicellulose hydrolysis more effectively than the other solvents across the investigated water content range. The acetate ionic liquid produced superior glucose yield at low water contents, while the hydrogen sulfate ionic liquid performed better at higher water contents and produced a recoverable lignin. The methanesulfonate ionic liquid did not introduce significant fractionation or enhancement of saccharification yield under the conditions used. These findings help distinguish the roles of anion hydrogen bonding, solvent acidity, and water content on ionic liquid pretreatment and can aid with anion and water content selections for different applications. [ABSTRACT FROM AUTHOR]

The synthesis of the molecule 2,5-furandicarboxylic acid (FDCA) from sugars is key to unlocking the potential for the replacement of the oil derivative PET (polyethylene terephthalate) by polyethylene furanoate (PEF). Although much research and investment has been dedicated to the synthesis of FDCA, there remains limited commercial activity in this area due to the challenges related to the stability and isolation of the FDCA precursor, 5-hydroxymethylfurfural (HMF). High yields of HMF can be obtained from fructose at high loadings in water–organic solvent mixtures (methyl isobutyl ketone, MIBK; γ-valerolactone, GVL), dimethyl sulfoxide (DMSO) or ionic liquids. Each of these approaches suffers from various drawbacks in terms of catalyst development, product separation and environmental impact. It is therefore necessary to understand which of these processes has the potential for scale-up, while ensuring low environmental impact and a competitive selling price. In this study, a process simulation (rather than a life cycle assessment) was performed to evaluate the associated emissions and selling price of FDCA based on its production using different solvents. It was determined that the cost and CO2 emissions associated with the isolation of HMF undermine the economic and environmental viability of the transformation of sugars to FDCA. In contrast, a two-step, one-pot reaction represents an ideal solution to reduce both cost and environmental impact, making FDCA competitive with terephthalic acid (the corresponding precursor for PET). The choice of solvent and the process were then evaluated and ranked based on safety, CO2 emissions, selling price and state of development though a scoring methodology. A system based on a water/GVL mixture is closer to commercial applicability but the process is limited by extensive formation of humins, which reduces the overall yield of the process, increasing the minimum selling price of FDCA. Using DMSO or ionic liquids minimises emissions and leads to the lowest cost of FDCA but further study is needed to improve the oxidation step. This investigation analyses the possible routes to FDCA from sugars based on the current literature, placing the emphasis on process economics but also considering the CO2 emissions from processing the sugars. [ABSTRACT FROM AUTHOR]

This study investigates the effects of temperature and period on the pretreatment of OPEFB using the low-cost N,N,N-dimethylbutylammonium hydrogen sulfate ionic liquid ([DMBA][HSO4] IL) with 20 wt% of water. The results demonstrate that higher pretreatment temperatures (120, 150, and 170 °C) and longer periods (0.5, 1, and 2 h) enhanced lignin recovery, resulting in increased purity of the recovered pulp and subsequently enhanced glucose released during enzymatic hydrolysis. However, at 170 °C, prolonging the period led to cellulose degradation and the formation of pseudo-lignin deposited on the pulps, resulting in a decreasing-trend in glucose released. Finally, the analysis of extracted lignin reveals that increasing pretreatment severity intensified lignin depolymerisation and condensation, leading to a decrease in number average molecular weight (Mn), weight average molecular weight (Mw) and polydispersity index (Đ) values. [ABSTRACT FROM AUTHOR]

Here, we demonstrate a chemical modification strategy to create biomaterials of the M13 bacteriophage with extraordinary thermal stability, and high compatibility with non-aqueous ionic liquids. The results provide a blueprint for developing soft materials with well-defined architectures that may find broad applicability in the next generation of flexible devices. [ABSTRACT FROM AUTHOR]

Keratin is a biopolymer with high potential for biomaterial production, being principally investigated in hydrogel and film forms for use in tissue-engineering applications. Aiming to find sustainable solvents and develop an efficient keratin recovery process, this work used an aqueous solution of bio-based ionic liquid (IL) for the dissolution of chicken feathers. Complete dissolution of chicken feathers in an aqueous solution of cholinium acetate ([N111(2OH)][C1CO2]) was conducted at a solid : liquid weight ratio of 1 : 20 w/w, 100 °C for 4 h. An experimental design was carried out to optimize the keratin recovery conditions, investigating coagulant solvent, solution : coagulant weight ratio, and time. Under the optimal conditions (20.25 wt% of ethanol in water, 5 h, and solution : coagulant ratio of 1 : 1.45 w/w), 93 wt% of keratin was recovered. The IL was shown to be reusable in four successive cycles, with a yield of around 95 wt% and no significant losses in the efficiency of keratin recovery. These results demonstrate that an aqueous solution of [N111(2OH)][C1CO2] can lead to effective keratin recovery, serving as the basis for the development of a more effective and environmentally friendly process to recover biopolymers from waste. Due to the relevance of the developed process, techno-economic assessment through a comprehensive sensitivity analysis was carried out, evaluating a virtual operating biorefinery and showing a pathway that can enable the commercialization of produced keratin by the developed process. According to the process simulation, the minimum selling price for keratin is 22 $ per kg, with a small positive CO2 emission (4.04 kgCO2 kgkeratin−1), making this process suitable for biomedical and cosmetic applications. [ABSTRACT FROM AUTHOR]

Review: ca. 200 refs. [ABSTRACT FROM AUTHOR]

Halometallate ionic liquids provide new opportunities for industrial catalytic processes because of their unique blend of physical and chemical properties. Tunability underpins the success of ionic liquids because small structural changes can have drastic effects on either property. Catalysis can be optimised by adjusting structures to target properties such as Lewis basicity and acidity, but the structural changes have simultaneous impacts on physical properties. In this work, we provide a thorough, methodical, and reliable list of thermal parameters to help define temperature limits to prevent catalyst poisoning and limit the need to replace costly and environmentally demanding solvents. Mechanistic insights show that decomposition is particularly detrimental for halometallate ionic liquids, and life cycle analysis highlights that lower levels of organic cations are better for economic and environmental sustainability. [ABSTRACT FROM AUTHOR]

Organic azides are widely used in organic synthesis. Continuous flow processing can be used to bypass their isolation, and can therefore be useful in mitigating the hazards associated with these potentially toxic and explosive reagents. Nonaflyl azide has been reported as an effective, bench-stable, and relatively safe diazo transfer reagent that can be useful in the preparation of azides from amines and so avoid the use of alkyl halides. Here we demonstrate the synthesis and purification of nonaflyl azide in continuous flow with isolation of the neat, pure reagent by membrane filtration. The neat reagent was used in the preparation of organic azides from primary amines, and then applied to the synthesis of triazoles. A variety of triazoles, including the antiseizure drug Rufinamide, were prepared from primary amines and alkynes via the CuAAC click reaction in a semi-batch parallel array without isolation of alkyl azide intermediates. A telescoped two-stage continuous flow process was also designed and demonstrated to form triazoles via the same CuAAC reaction, which avoids the handling of the intermediate reactive azides. [ABSTRACT FROM AUTHOR]

Thermoresponsive polymers have attracted much scientific attention due to their capacity for temperature-driven hydrogel formation. For biomedical applications, such as drug delivery, this transition should be tuned below body temperature to facilitate controlled and targeted drug release. We have recently developed a thermoresponsive polymer that forms gel at low concentrations (2 w/w%) in aqueous media and offers a cost-effective alternative to thermoresponsive systems currently being applied in clinics. This polymer is an ABC triblock terpolymer, where A, B, and C correspond to oligo(ethylene glycol) methyl ether methacrylate with average M n 300 g mol−1 (OEGMA300), n -butyl methacrylate (BuMA), and di(ethylene glycol) methyl ether methacrylate (DEGMA). To investigate the self-assembly and the gelation mechanism in diluted solutions, we used small-angle neutron scattering (SANS) on 1 w/w% (below the gelation concentration) and 5 w/w% solutions (above the gelation concentration). As a comparison, we also investigated the solutions of the most studied thermoresponsive polymer, namely, Pluronic F127, an ABA triblock bipolymer made of ethylene glycol (A) and propylene glycol (B) blocks. SANS revealed that the in-house synthesised polymer forms elliptical cylinders, whose length increases significantly with temperature. In contrast, Pluronic F127 solutions form core-shell spherical micelles, which slightly elongate with temperature. Transmission electron microscopy images support the SANS findings, with tubular/worm structures being present. Variable-temperature circular dichroism (CD) and proton nuclear magnetic resonance (1H NMR) spectroscopy experiments reveal insights on the tacticity, structural changes, and molecular origin of the self-assembly. [Display omitted] • Worm like micelles versus spherical micelles self-assembly and gelation. • Differences between the thermoresponsive behaviour of an ABC and an ABA triblock copolymer. • Tubular/worm like micelles can induce gelation at lower concentrations than spherical micelles. [ABSTRACT FROM AUTHOR]

The application of the protic ionic liquid 1-butylimidazolium hydrogen sulfate in the deconstruction (aka pretreatment) and fractionation of lignocellulosic biomass has been investigated. A cellulose rich pulp and a lignin fraction were produced. The pulp was subjected to enzymatic saccharification which allowed recovery of up to 90% of the glucan as fermentable glucose. The influence of the solution acidity on the deconstruction of Miscanthus giganteus was examined by varying the 1-butylimidazole to sulfuric acid ratio. Increased acidity led to shorter pretreatment times and resulted in reduced hemicellulose content in the pulp. Addition of water to the ionic liquid resulted in enhanced saccharification yields. The ability to tune acidity through the use of protic ionic liquids offers a significant advantage in flexibility over dialkylimidazolium analogues. [ABSTRACT FROM AUTHOR]

This paper reviews the application of ionic liquids to the deconstruction and fractionation of lignocellulosic biomass, in a process step that is commonly called pretreatment. It is divided into four parts: the first gives background information on lignocellulosic biomass and ionic liquids; the second focuses on the solubility of lignocellulosic biomass (and the individual biopolymers within it) in ionic liquids; the third emphasises the deconstruction effects brought about by the use of ionic liquids as a solvent; the fourth part deals with practical considerations regarding the design of ionic liquid based deconstruction processes. [ABSTRACT FROM AUTHOR]

Abstract: The acetylacetonate complexes of oxovanadium(IV): VO(X-acac)2 (X=Cl, CH3 and CH3CH2) were structurally characterized in several alkylimidazolium ionic liquids by visible absorption and EPR spectroscopies. VO(Me-acac)2 and VO(Et-acac)2 showed solvatochromism in the selected ionic liquids (a λ 1 shift of ca. 120nm was observed) and most complexes showed two species in the anisotropic EPR spectra in several ionic liquids. It was shown that the ionic liquids anions have coordinating ability and the basicity order found was: NTf2 − 95% conversion to sulfone. The ionic liquid that showed the best performance with all substrates was bmimNTf2. In bmimOTf and bmimBF4 the activity of all catalysts in the ECODS system was low to moderate, which is probably due to the higher coordinating ability of these anions. [Copyright &y& Elsevier]

Ionic liquids are of great interest as potential solvents/catalysts for the production of fuels and chemicals from lignocellulosic biomass. Attention has focused particularly on the pretreatment of lignocellulose to make the cellulose more accessible to enzymatic hydrolysis. Any biomass processing requires a reduction in the size of the harvested biomass by chipping and/or grinding to make it more amenable to chemical and biological treatments. This paper demonstrates that significant energy savings can be achieved in the grinding of pine wood chips when the ionic liquid is added before the grinding operation. We show that this is due to the lubricating properties of the ionic liquids and not to physico-chemical modifications of the biomass. A brief impregnation of the chipped biomass results in higher savings than a longer treatment. [ABSTRACT FROM AUTHOR]

Abstract: A number of ionic liquids have been used as co-solvents for the N-alkyl-3,4-dihyroisoquinoliunium catalyzed epoxidation of alkenes. Water miscible ionic liquids gave systems with similar reactivities to the conventional acetonitrile based systems. Attempts to produce an aqueous/ionic liquid biphasic system that could be used to recycle the catalyst failed due to a lack of phase transfer between the aqueous and ionic liquid phases. [Copyright &y& Elsevier]

The ionoSolv process is one of the most promising technologies for biomass pretreatment in a biorefinery context. In order to evaluate the transition of the ionoSolv pretreatment of biomass from bench-scale experiments to commercial scale, there is a need to get better insight in process intensification. In this work, the effects of biomass loading, particle size, pulp washing protocols and 100-fold scale up for the pretreatment of the grassy biomass Miscanthus giganteus with the IL triethylammonium hydrogen sulfate, [TEA][HSO4], are presented as a necessary step in that direction. At the bench scale, increasing biomass loading from 10 to 50 wt% reduced glucose yields from 68 to 23% due to re-precipitation of lignin onto the pulp surface. Omitting the pulp air-drying step maintained saccharification yields at 66% at 50 wt% loading due to reduced fiber hornification. 100-fold scale-up (from 10 mL to 1 L) improved the efficacy of ionoSolv pretreatment and increasing loadings from 10 to 20 wt% reduced lignin reprecipitation and led to higher glucose yields due to the improved heat and mass transfer caused by efficient slurry mixing in the reactor. Pretreatment of particle sizes of 1–3 mm was more effective than fine powders (0.18–0.85 mm) giving higher glucose yields due to reduced surface area available for lignin re-precipitation while reducing grinding energy needs. Stirred ionoSolv pretreatment showed great potential for industrialization and further process intensification after optimization of the pretreatment conditions (temperature, residence time, stirring speed), particle size and biomass loading. Pulp washing protocols need further improvement to reduce the incidence of lignin precipitation and the water requirements of lignin washing. [ABSTRACT FROM AUTHOR]

• PbII solubilities of 0.9 M were measured in [DMBA][MS] • Molar conductivities exceeded those of a Walden plot's KCl reference line • Cyclic voltammograms implied fast Pb deposition • Morphologies of Pb electrodeposits were potential-dependent Physicochemical and electrochemical properties of N,N,N -dimethylbutylammonium methanesulfonate, [DMBA][MS], ionic liquid (IL) have been determined, and the potential application for electrochemical recovery of lead from lead-acid batteries is discussed. To optimise the transport properties of the IL, the dependences were measured of conductivity, density and viscosity with varying amounts of excess acid with water as a diluent in the electrolyte mixture. Molar conductivities obtained from the molar concentration and ionic conductivity measurements were used to quantify the ionicities of these IL mixtures. The solubility of PbII from PbCO 3 was also shown to depend strongly on the IL composition. Preliminary results of the electrochemical kinetics of PbII reduction showed fast Pb deposition and potential-controlled electrodeposition morphologies of Pb, which may be advantageous for the design of up-scaled lead electrowinning processes. [ABSTRACT FROM AUTHOR]

Differential scanning calorimetry (DSC) is increasingly used as evidence to support a favourable safety profile of novel chemistry, or to highlight the need for caution. DSC enables preliminary assessment of the thermal hazards of a potentially energetic compound. However, unlike other standard characterisation methods, which have well defined formats for reporting data, the current reporting of DSC results for thermal hazard assessment has shown concerning trends. Around half of all results in 2019 did not include experimental details required to replicate the procedure. Furthermore, analysis for thermal hazard assessment is often only conducted in unsealed crucibles, which could lead to misleading results and dangerously incorrect conclusions. We highlight the specific issues with DSC analysis of hazardous compounds currently in the organic chemistry literature and provide simple "best practice" guidelines which will give chemists confidence in reported DSC results and the conclusions drawn from them. [ABSTRACT FROM AUTHOR]

Differential scanning calorimetry (DSC) is increasingly used as evidence to support a favourable safety profile of novel chemistry, or to highlight the need for caution. DSC enables preliminary assessment of the thermal hazards of a potentially energetic compound. However, unlike other standard characterisation methods, which have well defined formats for reporting data, the current reporting of DSC results for thermal hazard assessment has shown concerning trends. Around half of all results in 2019 did not include experimental details required to replicate the procedure. Furthermore, analysis for thermal hazard assessment is often only conducted in unsealed crucibles, which could lead to misleading results and dangerously incorrect conclusions. We highlight the specific issues with DSC analysis of hazardous compounds currently in the organic chemistry literature and provide simple "best practice" guidelines which will give chemists confidence in reported DSC results and the conclusions drawn from them. [ABSTRACT FROM AUTHOR]

In the present study, we used a low-cost protic ionic liquid, 1-methylimidazolium chloride, to simultaneously fractionate heavy metal contaminated wood and extract the metals from the wood at elevated temperature and short reaction time. This treatment selectively dissolves the lignin and hemicellulose in the biomass, leaving a solid cellulose-rich pulp, while coordinating and extracting 80–100% of the metal species present in the wood in a one-pot process. The lignin stream was recovered from the liquor and the cellulose was hydrolysed and then fermented into ethanol. The ionic liquid was recycled 6 times and the metals were recovered from the liquor via electrodeposition. This is the first time that highly contaminated waste wood has been integrated into a process which does not produce a contaminated waste stream, but instead valorises the wood as a feedstock for renewable chemicals, materials and fuels, while efficiently recovering the metals, converting a toxic environmental hazard into a rich source of biorenewables. We have therefore used an otherwise problematic waste as a low-cost lignocellulsoic feedstock for a circular bioeconomy concept. [ABSTRACT FROM AUTHOR]

IonoSolv pretreatment using protic ionic liquids has shown impressive biomass fractionation performance and ionic liquid recyclability. Lignin condensation during ionoSolov pretreatment can lower its economic value and potentially limit the valorisation of lignin to produce high value materials. Organosolv pretreatment is known for generating a high-quality lignin fraction with a large potential for value-added applications. In this study, a hybrid fractionation process was designed based on ionoSolv and organosolv pretreatments, and was tested on two representative feedstocks, Miscanthus and pine. Compared to ionoSolv processing, the hybrid pretreatment displayed an improved fractionation performance by generating a cellulose-rich pulp which was more enzyme-accessible, and by removing a higher proportion of lignin. Saccharification yields reached 89% and 74% for Miscanthus and pine, respectively. The process was also able to maintain its high fractionation performance up to 50 wt% biomass loading. HSQC spectroscopy and GPC were used to characterise the isolated lignin. Alcohol induced α-alkoxylation took place during lignin fractionation and obstructed the lignin condensation, resulting in an improved quality lignin. A technoeconomic analysis was conducted for this new hybrid pretreatment, showing lower energy consumption for the IL regeneration step at a high organic solvent concentration, suggesting lower environmental impact and higher economic potential. This ionoSolv-organosolv pretreatment could be a milestone for the development of the current ionoSolv pretreatment at commercial scale. [ABSTRACT FROM AUTHOR]

As the costs of solar PV continuously decrease and pollution legislation imposes less burning of agricultural residues, decentralized renewable energy is increasingly affordable for providing electricity to one billion people lacking access to a power grid. This paper presents a techno-economic feasibility case study of biomass gasification in off-grid and grid-connected mini-grids for community-scale energy application in rural Uttar Pradesh, India. Energy demand data was collected through surveys in a village with irrigation and agro-processing loads and off-grid households and used to construct a seasonal load profile based on statistical methods. This was used to simulate single-source and hybrid mini-grids based on solar PV, biomass gasification and diesel generation using HOMER Pro. Hybrid PV-biomass or PV-diesel systems were found to offer the highest reliability for off-grid power at the lowest cost. Single-source PV was cheaper than biomass gasification, though the cost of electricity is highly sensitive to biomass supply and gasifier maintenance. Both renewable options were around half the cost of diesel generation. The findings held across grid-connected systems with weak, moderate and strong reliability of grid supply. This suggests that biomass gasification-based mini-grids are not cost-competitive with PV unless the two generation sources are combined in a hybrid system, though they require operational testing prior to implementation. Image 1 • Hybrid PV–biomass or PV–diesel systems offer higher reliability at lower cost. • PV is cheaper than biomass gasification mini-grids for productive energy provision. • Grid-connected PV offers lowest LCOE over 20 years for strong and weak grid supply. • LCOE of biomass systems is highly sensitive to biomass requirement and maintenance. • PV–biomass systems appear resilient to operating parameters but lack field testing. [ABSTRACT FROM AUTHOR]

Ionic liquids have found their way into many applications where they show a high potential to replace traditional chemicals. But concerns over their ecological impacts (toxicity and biodegradability) and high cost have limited their use so far. The outcome of existing techno-economic and life-cycle assessments comparing ionic liquids with existing solvents has proven hard to interpret due to the many metrics used and trade-offs between them. For the first time, this paper couples the concept of monetization with detailed process simulation and life-cycle assessment to estimate the true cost of ionic liquids. A comparative case study on four solvents used in lignocellulosic biomass pretreatment is conducted: triethylammonium hydrogen sulfate [TEA][HSO4], 1-methylimidazolium hydrogen sulfate [HMIM][HSO4], acetone from fossil sources, and glycerol from renewable sources. The results show that the total monetized cost of production accounting for externalities can be more than double the direct costs estimated using conventional economic assessment methods. [TEA][HSO4] is found to have the lowest total cost, while glycerol presents the highest total cost. We expect this methodology to provide a starting point for future research and development in sustainable ionic liquids. [ABSTRACT FROM AUTHOR]

Ionic liquids offer exciting possibilities for biocatalysis as solvent properties provide rare opportunities for customizable, energy-efficient bioprocessing. Unfortunately, proteins and enzymes are generally unstable in ionic liquids and several attempts have been made to explain why; however, a comprehensive understanding of the ionic liquid–protein interactions remains elusive. Here, we present an analytical framework (circular dichroism (CD), fluorescence, ultraviolet-visible (UV/Vis) and nuclear magnetic resonance (NMR) spectroscopies, and small-angle X-ray scattering (SAXS)) to probe the interactions, structure, and stability of a model protein (green fluorescent protein (GFP)) in a range (acetate, chloride, triflate) of pyrrolidinium and imidazolium salts. We demonstrate that measuring protein stability requires a similar holistic analytical framework, as opposed to single-technique assessments that provide misleading conclusions. We reveal information on site-specific ionic liquid–protein interactions, revealing that triflate (the least interacting anion) induces a contraction in the protein size that reduces the barrier to unfolding. Robust frameworks such as this are critical to advancing non-aqueous biocatalysis and avoiding pitfalls associated with single-technique investigations. Ionic liquids are used as solvents in biocatalysis but how they interact with the structures of proteins is imperfectly understood. Here the effect of three common ionic liquids on the structure of green fluorescent protein is studied using a suite of experimental techniques, finding a complex relationship which is poorly captured by any single technique. [ABSTRACT FROM AUTHOR]

Softwood is an abundantly available feedstock for the bio-based industry. However, achieving cost-effective sugar release is particularly challenging, owing to its guaiacyl-only lignin. Here, we report the highly effective pretreatment of the softwood pine (Pinus sylvestris) using ionoSolv pretreatment, a novel ionic liquid-based lignocellulose fractionation technology. Three protic, low-cost ionic liquids, 1-butylimidazolium hydrogen sulfate, triethylammonium hydrogen sulfate and N,N-dimethylbutylammonium hydrogen sulfate, were used to fractionate the biomass into a carbohydrate-rich pulp and a lignin. The carbohydrate-rich pulp was hydrolysed into fermentable sugars by enzymatic saccharification. Under the most successful pretreatment conditions, quantitative glucose release from the pulp was achieved, which equates to a projected glucose release of 464 mg per gram of pine wood entering the process. We further intensified the process by increasing the solid to solvent ratio up to 1 : 2 g g−1 while maintaining saccharification yields of 75% of the theoretical maximum. We also demonstrate for the first time that N,N-dimethylbutylammonium hydrogen sulfate, [DMBA][HSO4], is an excellent low-cost pretreatment solvent, surpassing the pretreatment effectiveness of its symmetrically substituted analogue triethylammonium hydrogen sulfate. This shows that ionoSolv pretreatment with protic hydrogen sulfate ionic liquids is a truly feedstock-independent pretreatment option, further increasing the commercial potential of this pretreatment technology. [ABSTRACT FROM AUTHOR]

Deconstruction with low-cost ionic liquids (ionoSolv) is a promising method to pre-condition lignocellulosic biomass for the production of renewable fuels, materials and chemicals. This study investigated process intensification strategies for ionoSolv pretreatment of Miscanthus×giganteus with the low-cost ionic liquid triethylammonium hydrogen sulfate ([TEA][HSO4]) in the presence of 20 wt% water, using high temperatures and a high solid to solvent loading of 1 : 5 g/g. The temperatures investigated were 150, 160, 170 and 180 °C. We discuss the effect of pretreatment temperature on lignin and hemicellulose removal, cellulose degradation and enzymatic saccharification yields. We report that very good fractionation can be achieved across all investigated temperatures, including an enzymatic saccharification yield exceeding 75% of the theoretical maximum after only 15 min of treatment at 180 °C. We further characterised the recovered lignins, which established some tunability of the hydroxyl group content, subunit composition, connectivity and molecular weight distribution in the isolated lignin while maintaining maximum saccharification yield. This drastic reduction of pretreatment time at increased biomass loading without a yield penalty is promising for the development of a commercial ionoSolv pretreatment process. [ABSTRACT FROM AUTHOR]

Sustainable solvents are a topic of growing interest in both the research community and the chemical industry due to a growing awareness of the impact of solvents on pollution, energy usage, and contributions to air quality and climate change. Solvent losses represent a major portion of organic pollution, and solvent removal represents a large proportion of process energy consumption. To counter these issues, a range of greener or more sustainable solvents have been proposed and developed over the past three decades. Much of the focus has been on the environmental credentials of the solvent itself, although how a substance is deployed is as important to sustainability as what it is made from. In this Review, we consider several aspects of the most prominent sustainable organic solvents in use today, ionic liquids, deep eutectic solvents, supercritical fluids, switchable solvents, liquid polymers, and renewable solvents. We examine not only the performance of each class of solvent within the context of the reactions or extractions for which it is employed, but also give consideration to the wider context of the process and system within which the solvent is deployed. A wide range of technical, economic, and environmental factors are considered, giving a more complete picture of the current status of sustainable solvent research and development. [ABSTRACT FROM AUTHOR]

Cost-effective fractionation (pretreatment) of lignocellulosic biomass is necessary to enable its large-scale use as a source of liquid fuels, bio-based materials and bio-derived chemicals. While a number of ionic liquids (ILs) have proven capable of highly effective pretreatment, their high cost presents a barrier to commercial viability. In this study, we investigate in detail the application of the low-cost (ca. $1 kg−1) ionic liquid triethylammonium hydrogen sulfate for the fractionation of the grass Miscanthus x giganteus into a cellulose rich pulp, a lignin and a distillate. We found that up to 85% of the lignin and up to 100% of the hemicellulose were solubilized into the IL solution. The hemicellulose dissolved mainly in monomeric form, and pentoses were partially converted into furfural. Up to 77% of the glucose contained in the biomass could be released by enzymatic saccharification of the pulp. The IL was successfully recovered and reused four times. A 99% IL recovery was achieved each time. Effective lignin removal and high saccharification yields were maintained during recycling, representing the first demonstration that repeated IL use is feasible due to the self-cleaning properties of the non-distillable solvent. We further demonstrate that furfural and acetic acid can be separated quantitatively from the non-volatile IL by simple distillation, providing an easily recoverable, valuable co-product stream, while IL degradation products were not detected. We further include detailed mass balances for glucose, hemicellulose and lignin, and a preliminary techno-economic estimate for the fractionation process. This is the first demonstration of an efficient and repeated lignocellulose fractionation with a truly low-cost IL, and opens a path to an economically viable IL-based pretreatment process. [ABSTRACT FROM AUTHOR]

Acidic anions of ionic liquids have been demonstrated as efficient catalysts for the cleavage of the β-O-4 ether linkage prevalent in the lignin superstructure. Through the use of lignin model compounds with varying functionality and by monitoring reaction kinetics, a full mechanistic investigation into the hydrolysis of the β-O-4 linkage in acidic ionic liquid solutions is reported. Hammett acidities are reported for different 1-butyl-3-methylimidazolium hydrogen sulfate [C4C1im][HSO4] ionic liquid systems with varying acid and water concentrations and were correlated to substrate reactivity. Results show that the rate of ether cleavage increases with an increase in acidity and the initial dehydration of the model compound is the rate-determining step of the reaction. The Eyring activation parameters of the reaction in hydrogen sulfate ionic liquids with a variety of cations are reported, indicating a consistent E1 dehydration mechanism. Hydrogen bonding in protic ionic liquids was shown to significantly influence anion–cation interactions, consequently altering the solvation of the protonated starting material and therefore the overall rate of reaction. Comparison of reaction rates in these ionic liquids with results within aqueous or aqueous/organic media indicate that the ionic liquids facilitate more rapid cleavage of the β-O-4 ether linkage even under less acidic conditions. All the reported results give a complete overview of both the mechanistic and solvation effects of acidic ionic liquids on lignin model compounds and provide scope for the appropriate selection and design of ionic liquids for lignin processing. [ABSTRACT FROM AUTHOR]

A number of ionic liquids have been shown to be excellent solvents for lignocellulosic biomass processing, and some of these are particularly effective in the production of the versatile chemical building block 5-hydroxymethylfurfural (HMF). In this study, the production of HMF from the simple sugar glucose in ionic liquid media is discussed. Several aspects of the selective catalytic formation of HMF from glucose have been elucidated using metal halide salts in two distinct ionic liquids, 1-butyl-3-methylimidazolium chloride and 1-butyl-3-methylimidazolium hydrogen sulfate as well as mixtures of these, revealing key features for accelerating the desired reaction and suppressing byproduct formation. The choice of ionic liquid anion is revealed to be of particular importance, with low HMF yields in the case of hydrogen sulfate-based salts, which are reported to be effective for HMF production from fructose. The most successful system investigated in this study led to almost quantitative conversion of glucose to HMF (90% in only 30 minutes using 7 mol% catalyst loading at 120°C) in a system which is selective for the desired product, has low energy intensity and is environmentally benign. [ABSTRACT FROM AUTHOR]

Phthalic anhydride is used worldwide for an extremely broad range of applications spanning from the plastics industry to the synthesis of resins, agricultural fungicides and amines. This work proposes a conceptual design of a process for the production of phthalic anhydride from an agricultural residue (i.e. corn stover), energy integration alternatives as well as water consumption and life cycle greenhouse emissions assessment. The techno-economic and financial appraisal of the flowsheet proposed is performed. Results show how the valorization of all the carbohydrate-rich fractions present in the biomass as well as energy savings and integration is crucial to obtain an economically viable process and that it is in principle possible to produce renewable phthalic anhydride in a cost-competitive fashion with a lower impact on climate change compared to the traditional synthetic route. [ABSTRACT FROM AUTHOR]

Recently, acidic ionic liquid water mixtures based on the hydrogen sulfate anion have been shown to effectively extract lignin from lignocellulosic biomass. This study analyses Miscanthus giganteus lignin isolated after extraction with the protic ionic liquid 1-butylimidazolium hydrogen sulfate ([HC4im][HSO4]) followed by precipitation with the antisolvent water. Several analytical techniques were employed, such as quantitative 13C-NMR, 1H–13C HSQC NMR, 31P-NMR, Py-GC-MS, GPC and elemental analysis. The analysis shows that the ionic liquid pretreatment breaks lignin-hemicellulose linkages and depolymerizes the lignin through the cleavage of glycosidic, ester and β-O-4 ether bonds. This is accompanied by solubilization of the newly generated lignin fragments. At longer pretreatment times, repolymerization of lignin fragments through condensation reactions occurs. The isolated lignins were carbohydrate-free, had low sulfur contents, low molecular weights. Early stage lignins were structurally similar to ball-milled lignin, while more treated lignins were enriched in p-hydroxyphenyl and guaiacyl units and had a high phenolic hydroxyl group content. We conclude that, depending on the treatment conditions, lignins with a variety of characteristics can be isolated using this type of ionic liquid solution. [ABSTRACT FROM AUTHOR]

The cost of ionic liquids (ILs) is one of the main impediments to IL utilization in the cellulosic biorefinery, especially in the pretreatment step. In this study, a number of ionic liquids were synthesized with the goal of optimizing solvent cost and stability whilst demonstrating promising processing potential. To achieve this, inexpensive feedstocks such as sulfuric acid and simple amines were combined into a range of protic ionic liquids containing the hydrogen sulfate [HSO4]− anion. The performance of these ionic liquids was compared to a benchmark system containing the IL 1-ethyl-3-methylimidazolium acetate [C2C1im][OAc]. The highest saccharification yields were observed for the triethylammonium hydrogen sulfate IL, which was 75% as effective as the benchmark system. Techno-economic modeling revealed that this promising and yet to be optimized yield was achieved at a fraction of the processing cost. This study demonstrates that some ILs can compete with the cheapest pretreatment chemicals, such as ammonia, in terms of effectiveness and process cost, removing IL cost as a barrier to the economic viability of IL-based biorefineries. [ABSTRACT FROM AUTHOR]

Textile dyeing processes are known for their negative environmental impacts due to the production of aqueous effluents containing toxic dyes. Therefore, new wastewater treatment processes need to be developed to treat such effluents, including Liquid-Liquid Extraction (LLE) process using Ionic Liquids (IL). This work aimed to evaluate the application of the hydrophobic IL trihexyltetradecylphosphonium decanoate to extract black, navy, and royal reactive dyes from water and evaluate the toxicological aspects of the resulting water stream. We investigated the effect of selected parameters, such as pH (2–12), temperature (20–50 °C), salt effects, dye concentration (0.5–50 mg/L), and phase volume ratio (900–9000) on the dye extraction. The results showed extraction yields as high as 97% for the three dyes and an extraction capacity of approximately 300 mg/g for black and navy dyes and 400 mg/g for royal. The toxicity tests involved Lactuca sativa , Triticum aestivium L , and Daphnia magna as bioindicators. The difference between the toxicity of the dye solutions before and after extraction was not statistically significant when L. sativa and Triticum aestivum L were used as bioindicators. However, the extracted solution showed increased toxicity towards D. magna due to traces of IL. Overall, the IL has a high extraction capacity for the black, navy, and royal dyes. Nevertheless, further studies on LLE associated with other processes must be carried out to reduce the risk linked to the toxicity of IL transferred to the water. [Display omitted] • We applied Trihexyltetradecylphosphonium decanoate to remove textile dyes in water. • Effect of phase volume ratio, temperature, salt, and dye concentration was studied. • The phosphonium-based IL showed an impressive extraction capacity of 620 mg/g. • Extractions were succeeded (>97%) and did not affect the phytotoxicity of water. • Phosphonium-base IL has the potential for dye extraction from textile wastewater. [ABSTRACT FROM AUTHOR]

The potential of perennial bioenergy Miscanthus feedstock grown on heavy metal contaminated land was evaluated for the production of clean renewable energy, chemicals, and recovered metals. Trace element analysis showed significant levels of metal contaminants from the harvested Miscanthus : 6.47 g of Pb per kg of biomass, 1.91 g kg−1 Fe, 0.35 g kg−1 Zn, 26.59 mg kg−1 of Cu; along with other metals including Cr, Ni, As and Cd. The protic ionic liquid, 1-methylimidazolium chloride [H 1 Cim]Cl, extracted 99.3% of Pb from the biomass along with 96–98% of Cu, Zn and Cd, and produced a clean cellulose pulp, which was successfully saccharified into glucose with an 81.5% yield. The behaviour of PbII in aqueous solutions of [H 1 Cim]Cl showed that this ionic liquid medium supported the electrochemical reduction of PbII to Pb0 using a voltage of − 0.9 V, depositing and recovering 91.5% of Pb from the solution onto the electrode after 1 h of electrolysis. Intensification of process conditions were studied with recycling of the solvent: after the 1st pretreatment, the ionic liquid liquor was recycled and Pb was electrodeposited to clean-up and manage the build-up of metals for a subsequent pretreatment. The electrodeposition step in the ionic liquid liquor did not have a negative impact on the performance of the pretreatment and metal extraction was enhanced by 20% compared to recycled ionic liquid, which had not gone through any electrodeposition beforehand. This study opens up new valorisation possibilities for the integration of highly metal contaminated biomass into biorefining, without the need to incinerate metal contaminated biomass. • Miscanthus was grown on heavy metal marginal contaminated land, an exposed mine site in Wales. • Trace element analysis revealed high levels of Pb, Zn and other metals contaminants in the biomass. • The ionoSolv pretreatment process was used to both fractionate the lignocellulosic biomass into clean chemicals and extract the metals from the feedstock using a protic ionic liquid. • Pb was able to be electrodeposited from the ionic liquid liquor and the solvent was recycled for a subsequent pretreatment. [ABSTRACT FROM AUTHOR]