► Prediction of solubilities and selectivities of C3H6/C3H8 into ionic liquids. ► Screening of several ionic liquids using COSMO-RS for C3H6/C3H8 separation. ► Calculation of excess enthalpy to ...select the most suitable of silver salt.
The quantum chemical COSMO-RS method was applied to analyze the equilibrium solubility of gaseous propane and propylene in a set of different room temperature ionic liquids in order to contribute to the design of olefin/paraffin separation technologies based on reactive absorption onto ionic liquids with dissolved silver salts media. First of all, the predictive capability of COSMO-RS was evaluated through a comparison of estimated values with a wide range of solubility experimental data; next a further optimization step based on the comparative analysis of predicted and experimental values of the Henry’s law constant of each solute in different ILs was developed to improve the accuracy of the calculations. Afterwards, the optimized COSMO-RS approach was applied to select the most suitable RTILs for C3H6/C3H8 separation based on driving a computational screening of 696 RTILs. Results highlighted that small and symmetric fluorinated inorganic anions such as PF6- or BF4- provide lower solubilities for both hydrocarbons, but on a whole this results in higher separation selectivities. With regard to the structure of the cation, ILs based on imidazolium, pyridinium and pyrrolidinium cations provide similar properties. However ILs based on monosubstituted butyl ammonium have much lower solubilities for both gases and at the same time higher equilibrium selectivities for propylene. Also it was gathered that less and shorter alkyl chains in the cation also improve the selective separation of these mixtures. Finally, as the separation process is enhanced by the presence of Ag+ cations into the ionic liquid, the solubility of 8 commercially available silver salts was qualitatively related to the excess enthalpy of Ag+-IL in solution predicted by COSMO-RS in order to select a silver salt suitable to be dissolved in the selected RTIL. Thus, this work reports for the first time the use of a predictive tool in order to facilitate the design of innovative separation processes by reactive absorption in a Ag+-IL media.
The evaluation of sustainable solvents as alternatives to more harmful conventional solvents combined with intensification techniques to recover phenolic compounds from agri-food waste is in the ...spotlight. The wine industry generates large amounts of waste as a consequence of grape processing operations, which can be revalued by solvent extraction of valuable antioxidants for food and fine chemical applications. Therefore, the present study focuses on the use of natural eutectic solvents (NAESs) with benign environmental, health, and safety profiles, for valorization of grape waste in the context of a circular economy. Herein, up to 15 NAESs consisting of combinations of three hydrogen bond acceptors (choline chloride, L-proline, and betaine) and four hydrogen bond donors (1,2-propanediol, glycerol, and 1,2- and 1,3-butanediol) were evaluated for antioxidant recovery. After an initial screening of the performance of NAESs by conventional extraction, the process was intensified by microwave-assisted extraction (MAE). The extracts were analyzed by UV/VIS spectrophotometric and HPLC methods. Promising results were obtained with the solvent betaine, 1,2-butanediol 1:4, using MAE at 100 °C for 3 min. Overall, the proposed NAESs-based MAE method was successfully applied to recover target compounds from grape waste, with great prospects for the antioxidants market and sustainable development for the winery sector.
The valorization of orange peel waste (OPW) through the extraction of bioactive compounds is a clear example of the circular economy. OPW contains many value-added compounds, among which bioactive ...phenolic compounds (flavonoids and phenolic acids) could be extracted and used for industrial applications, such as pharmaceuticals or cosmetics.
In this work, the extraction of phenolic compounds from orange peel was carried out by conventional (orbital shaker) and assisted (ultrasound and microwave) extraction techniques using deionized water, 80% (v/v) ethanol in water, and ethyl acetate as solvents. The effect of temperature, extraction time, and type of technique was evaluated and discussed following spectrophotometric (total phenolic content and total flavonoid content) and high-performance liquid chromatography (HPLC) analyses of the extracts.
The most effective extraction in terms of efficiency was achieved by microwave-assisted extraction using 80% (v/v) ethanol in water as the extraction solvent, at 373 K for 6 min, which obtained 7.2 ± 0.1 mg gallic acid equivalent (GAE)/g OPW and 13.3 ± 0.1 mg quercetin equivalent (QE)/g OPW, with the main bioactive compound extracted being hesperidin (58.2 ± 0.2 mg/g OPW). The most effective extraction in terms of energy consumption was achieved using ultrasound-probe-assisted extraction, yielding 8.8 ± 0.0 mg GAE/g OPW; 17.1 ± 0.1 mg QE/g OPW; 40.0 ± 0.2 mg hesperidin/g OPW, with an energy consumption of 18 kJ.
Ultrasound and microwave-assisted extractions can be considered efficient extraction technologies for the valorization of OPW as they reduce extraction time and energy consumption and increase extraction yield.
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•Biorenewable DES efficiently extract polyphenolic antioxidants from orange waste.•ChCl:EG 1:4 provides the highest polyphenolic content and antioxidant potential.•Ferulic acid is the ...main antioxidant present in the polyphenolic extracts.•Structural analysis suggests DES efficient solvent for biomass pretreatment.•Novel orange waste valorization strategies can be developed based on sustainable DES.
Extraction of polyphenolic compounds from orange peel (OP) via solid-liquid extraction (SLE) using deep eutectic solvents (DES) was investigated in this work as a means to develop sustainable separation processes to recover natural antioxidants from food waste biomass. In particular, choline chloride-based DES paired with glycerol and ethylene glycol were explored as potential extractants to evaluate the effect of the solvent structure (i.e. number of hydroxyl groups and hydrogen bond acceptor/donor ratio) on the polyphenol extraction efficiency. Afterwards, the effect of different operating parameters (i.e. solvent concentration, temperature, time and solid/liquid ratio) were further evaluated to determine the optimal extraction conditions for polyphenols recovery in terms of total phenolic content (TPC) and antioxidant activity based on DPPH radical scavenging method. Under optimum conditions (DES 10 wt.% water, temperature of 333.15 K, 1:10 solid/liquid ratio and extraction time of 100 min), choline chloride-based DES outperformed the benchmark solvent (aqueous (aq.) ethanol 30 wt.% water) for the extraction of polyphenolic compounds from OP, with ChCl:EG 1:4 providing the highest TPC (3.61 mg gallic acid equivalent per gram of orange peel (GAE/g OP) and antioxidant potential (30.6 µg/ml). Although ethylene glycol (EG) has provided the highest TPC (5.84 mg GAE/g OP), DES have proved more selective towards target polyphenolic compounds. Additionally, Scanning Electron Microscopy (SEM) was performed to illustrate the structural modifications occurred on the biomass before and after the extraction process, supporting DES as efficient solvents for cell wall dissolution. Lastly, characterization and quantification of individual polyphenolic profiles in the extracts were completed via high performance liquid chromatography (HPLC), displaying ferulic acid as the most abundant compound followed by ρ-coumaric acid and gallic acid.
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•Natural antioxidants as phenolic compounds are present in food by-products.•Extraction of phenolic compounds promotes food processing waste valorization.•Neoteric solvents can ...replace conventional organic solvents for extraction.•Ionic liquids, eutectic solvents and bio-solvents are promising extractants.
The loss and waste of food is a matter of great concern, leading to a multifaceted problem with negative economic, social, and environmental impacts as addressed in the UN Sustainable Development Goals number 2: zero hunger. The wine, fruit juice and vegetable oil processing industries generate significant amounts of wastes and side streams containing potentially valuable bioactive compounds. Some of them are plant secondary phenolic metabolites that offer remarkable health benefits (as antioxidants and anti-inflammatory compounds). One of the current challenges is the recovery of such bioactive compounds from residual matrices for further applications in food, pharmaceutical and cosmetic industries. Within this framework and in the scope of the Green Chemistry concept, one of the current challenges is to find eco-efficient techniques for the recovery of bioactive compounds. In this context, neoteric solvents are considered a greener alternative to traditional solvents, as the latter are more harmful to human and animal health, and environment. This overview focuses on recent advances in the use of hydrophobic neoteric solvents, i.e. ionic liquids, eutectic solvents, and bio-based solvents, for liquid–liquid extraction of phenolic compounds from liquid agri-food matrices.
Extraction processes are widely used in biorefinery applications to recover target products from biomass, and their comprehensive evaluation is key to improving their economic and environmental ...sustainability. This paper applies a systematic methodology that combines a rigorous process design, techno-economic analysis, and life cycle assessment to evaluate the sustainability performance of solvent extraction-based processes, with a focus on downstream activities. The methodology, which consists of seven iterative steps that combine process simulation and economic and environmental sustainability assessment tools, is demonstrated using a biodiesel production process from algae biomass, with hexane as the lipid extraction solvent. The minimum biodiesel selling price is estimated at U.S. $8.95 per U.S. gal, using the discounted cash flow rate of return. This is 3.5 times the average price of fossil diesel, mostly due to the cost of algae biomass and lipid recovery capacity of the solvent. Eighteen environmental impact categories are estimated from cradle to grave using the ReCiPe v1.1 method. For example, the climate change and primary energy demand are calculated at 95 g CO2 eq./MJ and 1.52 MJ/MJ biodiesel, which are 5 and 24% higher compared to fossil diesel, respectively. Lipid extraction is identified as the hotspot of the downstream processing stages for all impact categories (52–97%) and an opportunity for improving the overall sustainability performance of algae biodiesel, e.g., solvent selection. These findings provide a benchmark for future improvements to biodiesel production from algae biomass, with focus on the interactions between biomass and the solvent, e.g., phase equilibrium thermodynamics.
Solvents play a primary role in the chemical industry, with an increasing regulatory pressure urging to find more benign replacements for conventional fossil-derived solvents. Efficient methods for ...rational screening, considering the wide variety of green solvent alternatives, are key to promote sustainable processes based on neoteric solvents. This paper summarizes recent advances on green solvent screening using computer-aided methods focused on macroscale modeling of phase equilibrium properties. Particular attention is paid to quantum chemistry methods based on Conductor-like Screening Model (COSMO) as a tool for guiding solvent selection from thermodynamic performance indicators. Integrated methods based on COSMO-derived molecular descriptors combined with molecular and large data-based methods are revised as significant approaches for multiobjective problems. Relevant solvent screening applications for separation operations, reactive systems, and environmental and health properties estimation are reviewed. Future prospects for the design of sustainable industrial systems based on green solvents using in silico strategies are discussed.
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•Hydrophobic eutectic solvents with ammonium salts and natural compounds were formed.•Liquid-liquid extraction of wine-derived phenolic antioxidants was optimized.•Extraction ...efficiencies were determined by spectrophotometric methods and HPLC.•N8881Cl-based HESs can efficiently recover wine-derived phenolic antioxidants.•Hydrophobic eutectic solvents are promising for winery wastewater treatment.
Global food waste is a far-reaching problem, where the recovery of high-value compounds from agri-food effluents using green solvents is an attractive valorisation strategy. Wine industry is an important business sector which generates significant volumes of wastewater, with negative economic and environmental implications. However, winery wastewater can be exploited as a rich source of phenolic antioxidants for food and fine chemical applications. For that purpose, the main goal of this work is the recovery of wine-derived phenolic compounds from liquid effluents using hydrophobic eutectic solvents (HESs). In particular, HESs composed of ammonium salts, DL-menthol and fatty acids, were prepared and evaluated for liquid–liquid extraction of phenolic compounds from synthetic winery wastewater. To achieve optimum extraction performance, the experimental conditions were optimized, including extraction time, solvent to feed volume ratio, dilution factor and type of HESs. The extraction method developed was used for the efficient extraction of natural antioxidants from wine-derived samples and gallic acid from aqueous solutions. The extracted phenolic compounds were quantified and determined by spectrophotometric methods and high-performance liquid chromatography (HPLC). The experimental results showed satisfactory recoveries of the target compounds within the range of 64.14–84.10% from winery wastewater and recoveries between 74.86 and 92.31% from gallic acid solutions. Chloride ammonium salts-based HESs, especially N8881Cl-DL-Menthol and N8881Cl-Octanoic acid, proved the highest potential for phenolic compounds recovery from winery wastewater matrices and aqueous solutions. Finally, the antioxidant capacity of the extracts was confirmed.
Lipid extraction and biodiesel production from algae biomass rely on volatile organic solvents obtained from fossil resources such as hexane, whose use involves high energy consumption for recovery ...and negative environmental impacts due to their volatile and hazardous nature. This study presents a techno-economic and environmental analysis of using alternative lipid extraction solvents in algae biodiesel production in an effort to understand how they may affect the performance of the process. Lipid recovery (LR), minimum biodiesel selling price (MBSP), solvent intensity (SI), energy intensity (EI), and water consumption (WC) are considered here as performance indicators at process and downstream processing levels. The studied solvents are limonene, ethyl tert-butyl ether (ETBE), and cyclohexane, which were screened in a previous study by the authors, and hexane for reference. The assessment is carried out using data sourced from the literature (upstream processing), while downstream processing data is generated in this study using the COnductor-like Screening MOdel for Real Solvents (COSMO-RS) method and process simulation tools in the absence of experimental data for the solvents. The results indicate that while there is no single candidate solvent that outperforms hexane in every criteria considered here, ETBE and limonene are promising alternative solvents for lipid extraction and should be explored further. For example, ETBE presented the highest LR (95.5%) and lowest MBSP (8.58 $/US gal), while limonene has a SI that is 35% lower than hexane. In terms of EI and WC, ETBE is the best performing solvent after hexane with a 4% difference. The MBSP of ETBE is still around 3.5 times the selling price of fossil diesel, and further efforts to improving the economic viability of algae biodiesel production are still needed. Besides from decreasing algae biomass costs (upstream processing), other improvement opportunities worth exploring in downstream processing includes alternative cell disruption technologies, as this is the most energy intensive stage in lipid extraction. While the use of biobased and less hazardous solvents can help improve the environmental performance of downstream processing in algae biodiesel production, it is recommended that their environmental impacts are quantified on a life cycle basis, i.e., solvent production and disposal.
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