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Ionic liquids (ILs) are promising solvents for separating aromatics from fuel oils. However, studies for separate polycyclic aromatics with ILs are rare and insufficient, and the impact of solute structure on extraction performance still needs to be determined. In this work, we use 1‐ethyl‐3‐methylimidazolium bis([trifluoromethyl]sulfonyl)imide ([EMIM][NTF2]) as an extractant to separate 1‐methylnaphthalene, quinoline, and benzothiophene from dodecane mixtures. Liquid–liquid equilibrium experiments identified the optimal operating conditions. Nine solute molecules, including five alkanes and four aromatic hydrocarbons, were used to study the relationship between extraction performance and solute structure. Molecular dynamics simulation and quantum chemistry calculations gave a deep insight and reasonable interpretation of the structure‐performance relationship at the molecular level. An industrial‐scale extraction process was proposed. The IL can be easily regenerated using heptane as a back‐extractive solvent. A high‐purity fuel oil with aromatic content below 0.5 wt% is obtained after 8‐stage extraction. [ABSTRACT FROM AUTHOR]

The quantitative research on swelling properties of bentonite considering the influence of salt ions under the effect of hydrothermo-mechanical coupling is relatively weak. Based on a calculation model for the swelling characteristics of bentonite from a fractal perspective, this work proposes a novel coupled multifield control equation for unsaturated bentonite considering the influence of salt ions. The numericalization of the coupling control equation was completed by secondary development of a numerical analysis platform. The new theoretical model's dependability and validity were validated by comparing it to experimental data. The evolution of the related-field quantities under the multifield coupled effect in salt-bearing environments was obtained, and the effect of salt ion concentration was analyzed. The calculation showed that the temperature of bentonite changed periodically with changing ambient temperature. Temperature gradient induces migratory movement of water from high to low temperature regions. The hollow axisymmetric soil sample gradually saturated from outside to inside with increasing water injection rate at the outer cylindrical surface. The swelling pressure of bentonite will increase with an increase in water content, whereas the presence of salt ions weakened the swelling behavior. Temperature and relative humidity were less affected by salt ion concentration. [ABSTRACT FROM AUTHOR]

In the liquid biofuel production process, free fatty acids are important precursors for biodiesel and bio-aviation fuel. Enzymatic hydrolysis to produce free fatty acids has attracted more and more attention. However, enzymatic hydrolysis requires ensuring efficient expression of lipase and high product yield. In the shaking flask, the optimal addition amount of citric acid was 3 g/L, and the composition of composite amino acids was: histidine 0.1 mol/L, aspartic acid 0.03 mol/L and lysine 0.03 mol/L. On the basis of the shaking flask optimization, a 5 L fermentation tank was scaled up to obtain 25,000 U/mL of lipase after multiple batches of stable fermentation. This was the first time to cultivate Y. lipolytica using composite amino acid medium to produce high enzyme-activity lipase, demonstrating the industrial value of this lipase fermentation process. Finally, soybean oil was hydrolyzed to produce free fatty acids on a self-made static reactor. The optimized reaction conditions were: material flow rate 2813 mL/min, reaction temperature 45 °C, water content 25 wt% and lipase consumption 3 wt%. The yield of free fatty acids was 80.63% after 12 h under optimal reaction conditions in the self-made static reactor, 11.95% higher than that in the stirred reactor, which showed its industrial potential in the production of free fatty acids. [ABSTRACT FROM AUTHOR]

A new predictive molecular thermodynamic model (i.e., modified COSMO‐SAC‐UNIFAC) was first proposed and extended to predict the solubility of CO2 in pure and mixed ionic liquids (ILs) at the temperatures down to 263.2 K. It is interesting to discover that with equimolar amounts, the solubility of CO2 in such 1:1 IL pairs, that is, [A1][B1] + [A2][B2] and [A1][B2] + [A2][B1], was consistent at the same temperature and pressure in the case of exchanging their respective cations and anions. The molecular dynamic (MD) simulation for CO2 + mixed ILs was performed to deeply analyze and explain this intriguing phenomenon. Not only the CO2 gas drying experiment with the ILs ([C2mim][OAc], [C2mim][dca], and [C2mim][OAc] + [C2mim][dca]) as absorbents but also the corresponding process simulation and optimization were made to stress the effectiveness and applicability of the new thermodynamic model. Thus, this work ranges from molecular level to systematic scale. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DESs) as promising green absorbents were first proposed to capture the condensable cyclohexane gas. Choline chloride–ethylene glycol (EG) (Ethaline) and choline chloride–urea (Reline) were prepared using choline chloride as the hydrogen‐bond acceptor (HBA) and urea or EG as the hydrogen‐bond donor (HBD). To explore the potential application of DESs in condensable gas capture, the COSMO‐RS model was used to predict the solubility of cyclohexane in Ethaline and Reline. The thermodynamic properties, that is, Henry's constant and excess enthalpy, were estimated by correlating solubility data with Henry's law equation. Quantum chemical (QC) calculation was applied to understand the absorption mechanism at the molecular level. The results showed that the absorption performance of cyclohexane in Ethaline and Reline was dependent on the weak interaction between O of EG (or N of urea) and H of cyclohexane as well as the free volume effect of DESs. [ABSTRACT FROM AUTHOR]