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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]

With the rapid development of the semiconductor industry, the demand for ultraclean and high‐purity electronic chemicals, especially ultrapure water as a general solvent for cleaning semiconductor chips, has increased dramatically. The distillation process is a good choice for large‐scale production of ultrapure water that can be used to clean semiconductor chips, but there is a lack of basic thermodynamic theory for removing ionic impurities. In this work, the temperature and vapor–liquid phase composition of sodium and potassium salts aqueous solutions at vapor–liquid equilibrium (VLE) were investigated by experiments. The microstructure of each inorganic salt aqueous solution was explored by molecular dynamics simulation and quantum chemical calculation, and the interaction between each ion and water molecule was analyzed. A volatilization mechanism of inorganic salts was proposed, and it was found that the volatilization of inorganic salts in an aqueous solution was affected by the strength of interaction between the dissociated anions and cations and water molecules. Finally, the conductor‐like screening model segment activity coefficient (COSMO‐SAC) model predicted the VLE values of inorganic salt aqueous solutions. The prediction at low concentrations (xs < 0.06) was in good agreement with the experimental data. [ABSTRACT FROM AUTHOR]

A new methyl chloride (CH3Cl) capture and dehydration process using two ionic liquids (ILs) was designed and systematically studied. ILs [EMIM][Ac] and [EMIM][BF4] were screened out as CH3Cl capture and drying absorbents through the COSMO‐RS model. The result of solubility experiment suggests [EMIM][Ac] has an excellent solvent capacity for CH3Cl at mild operation conditions. The bench‐scale CH3Cl absorption experiments further confirmed the outstanding CH3Cl capture ability of [EMIM][Ac]. Besides, the water content of outlet gas can be decreased to 452 ppm (mass fraction) using [EMIM][BF4] in the dehydration experiment. The industrial‐scale CH3Cl capture and dehydration process was simulated and optimized. Compared to the benchmarked triethylene glycol process, IL process has higher product purity (99.99 wt%), and lower energy consumption. The quantum chemical calculations clearly revealed the relationship between hydrogen bond and separation performance. This study provides a decision‐making basis for designing green process associated with volatile organic compounds. [ABSTRACT FROM AUTHOR]

Recovering the iron (Fe) and phosphorus (P) contained in steelmaking slags not only reduces the environmental burden caused by the accumulated slag, but also is the way to develop a circular economy and achieve sustainable development in the steel industry. We had previously found the possibility of recovering Fe and P resources, i.e., magnetite (Fe3O4) and calcium phosphate (Ca10P6O25), contained in steelmaking slags by adjusting oxygen partial pressure and adding modifier B2O3. As a fundamental study for efficiently recovering Fe and P from steelmaking slag, in this study, the crystallization behavior of the CaO—SiO2—FeO—P2O5—B2O3 melt has been observed in situ, using a confocal scanning laser microscope (CLSM). The kinetics of nucleation and growth of Fe- and P-rich phases have been calculated using a classical crystallization kinetic theory. During cooling, a Fe3O4 phase with faceted morphology was observed as the 1st precipitated phase in the isothermal interval of 1300–1150°C, while Ca10P6O25, with rod-shaped morphology, was found to be the 2nd phase to precipitate in the interval of 1150—1000°C. The crystallization abilities of Fe3O4 and Ca10P6O25 phases in the CaO—SiO2—FeO—P2O5—B2O3 melt were quantified with the index of (TU − TI)/TI (where TI represents the peak temperature of the nucleation rate and TU stands for that of growth rate), and the crystallization ability of Fe3O4 was found to be larger than that of Ca10P6O25 phase. The range of crystallization temperature for Fe3O4 and Ca10P6O25 phases was optimized subsequently. The Fe3O4 and Ca10P6O25 phases are the potential sources for ferrous feedstock and phosphate fertilizer, respectively. [ABSTRACT FROM AUTHOR]

To help maintain the sustainability of the steel industry by improving slag utilization, we are developing a novel process to recover P and Fe from steelmaking slag by controlling oxygen partial pressure and adding slag modifier B2O3, to control the precipitation of targeted phases. In this paper, the precipitated phases of the molten synthetic CaO–SiO2–FeO–P2O5(–B2O3) slags were predicted through thermodynamic calculations using FactSage 8.1. A confocal laser scanning microscope (CLSM) was used to in situ observe the crystallization behavior of the targeted metal oxides in the slags. It was found that iron and phosphorus could be recovered in the form of magnetite (Fe3O4) and calcium phosphate (Ca10P6O25) phases by controlling oxygen partial pressure and adding slag modifier B2O3. By changing oxygen partial pressure from 0.21 to 10–6 atm, the iron-containing phase transformed from Ca2Fe2O5 to magnetite (Fe3O4). Through the introduction of B2O3 from 2 to 8 pct, the amount of calcium phosphate (Ca10P6O25) first increased and then decreased, with the maximum of 28 pct (e.g. 28/100 g slag studied) at 6 pct B2O3. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) as promising green solvents were first proposed to extract polycyclic aromatic hydrocarbons (PAHs) from fluid catalytic cracking (FCC) diesel. The COSMO‐RS model was used for preliminary screening of IL extractants. The liquid–liquid equilibrium (LLE) experiments were performed to show that the IL [BMIM][BF4] has a high selectivity for the model oil system. Further, the LLE experimental results show that the solubility of 1‐methylnaphthalene in [BMIM][BF4] is relatively low, while the IL exhibits a high selectivity of n‐hexadecane to 1‐methylnaphthalene. This means that the use of [BMIM][BF4] can obtain the high‐purity products when considering the almost nonvolatility of IL. Compared to the benchmark process, the multistage countercurrent–reflux extraction process can improve the PAHs purity by about 2% at the expense of 5.06% total annual cost and 6.42% energy consumption, rendering the use of IL to extract PAHs from FCC diesel more feasible in industry. [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 drying agents were first proposed to natural gas (NG) dehydration. In this work, choline chloride (ChCl)‐based DESs were prepared using ChCl as hydrogen bond acceptor (HBA) and triethylene glycol (TEG), ethylene glycol (EG) or Urea as hydrogen bond donors (HBDs). To explore the potential application, methane (CH4) dehydration experiment was conducted to verify the dehydration performance using prepared DESs. The thermodynamic properties were predicted by COSMO‐RS model (Conductor‐like screening model for real solvents). The quantum chemistry calculation was applied to understand the separation mechanism at the molecular level. The absorption performance of H2O in DESs depends on the weak interaction between Cl atom (or N and O atom) of ChCl and H atom of H2O as well as the free volume of DESs. Molecular dynamics (MD) simulation discloses the intermolecular interaction between HBA and HBD. This work makes the first multi‐scale analysis on NG dehydration using DESs. [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]

In order to make a sound joint of TC4 titanium alloy and 316 L stainless steel, Ti-Zr-Hf-Cu-Ni amorphous filler metal was used to braze the two alloys in this paper. The effects of brazing temperature on the interfacial microstructure and mechanical property were investigated. The results showed that the maximum shear strength of 205 MPa was obtained at 960 °C/10 min. The cross section of brazed joint could be divided into five distinctive reaction zones namely: 316L, diffuson layer I, weld seam center structure H, diffuson layer &, TC4. The typical interfadal rmcrostructure of the joint was phases formed around the diffusion kyer I close to 316L stainless steel substrate, whcti was the weak part of the brazed joints. Fracture analysss idcated that cracks imtiated at the diffusion layer I . [ABSTRACT FROM AUTHOR]

The microstructures and properties of TC4 titanium alloy prepared via TIG arc additive manufacturing were studied. The results show that the microstructure of the arc additive manufacturing TC4 titanium alloy is different from the as-cast characteristics of the arc additive manufacturing steel material, which has significant heat-treated characteristics. It is a basketweave structure composed of α and β phases. Analyzing the formation process, it can be found that the primary structure of the additive body is dendrites, which has obvious orientation at this time; with the action of multiple reheating in the subsequent additive process, since the low thermal conductivity of titanium, the additive body maintains a higher temperature, the dendrite composition gradually becomes uniform and transforms into anisotropic slender β crystal grains; then the temperature decreases and transforms into a two-phase basketweave structure of α and β, and the a phase is in a supersaturated state, the β-phase precipitated with nano-scale dots can be observed, the structure and performance is close to isotropic at this time, the tensile strength and the elongation after fracture at room temperature can reach up to 998 MPa and 8.7%, respectively. [ABSTRACT FROM AUTHOR]

The traditional approach to solvent selection in the extractive distillation process strictly focuses on the change in the relative volatility of light-heavy components induced by the solvent. However, the total annual cost of the process may not be minimal when the solvent induces the largest change in relative volatility. This work presents a heuristic method for selecting the optimal solvent to minimize the total annual cost. The functional relationship between the relative volatility and the total annual cost is established, where the main factors, such as the relative volatility of the light-heavy components and the relative volatility of the heavy-component solvent, are taken into account. Binary azeotropic mixtures of methanol-toluene and methanol-acetone are separated to verify the feasibility of the model. The results show that using the solvent with the minimal two-column extractive distillation index, the process achieves a minimal total annual cost. The method is conducive for sustainable advancements in chemistry and engineering because a suitable solvent can be selected without simulation verification. [ABSTRACT FROM AUTHOR]

This paper proposes a novel coupled and active (CA) grasping mode for robot finger. While coupled grasping mode enables the phalanges of the finger to rotate in an anthropomorphic way, the active grasping mode enables the finger to adapt to the object's shape automatically. Combination of these grasping modes can greatly reduce the controlling complexity and enlarge the application of coupled hands. The CA finger is developed based on the pulley-belt mechanism. It is composed of a finger base and two mobile phalanges. The control process of the finger is also introduced in this paper. Grasping capabilities is validated by experiments. Theoretical and experimental results show that the CA grasping mode is effective. [ABSTRACT FROM AUTHOR]

A novel indirectly self-adaptive (ISA) underactuated hand with block-linkage mechanism is developed in this paper. There are two basic requirements for design of a humanoid robot hand. Firstly, regarding the function of the hand, the hand should be able to stably grasp common objects with different shapes and sizes. Secondly, regarding the structure of the hand, the hand should be similar to a human hand in its appearance and joint degrees of freedom (DOFs). The ISA Hand reaches the balance point in meeting both of requirements. The ISA Hand has 5 fingers, 14 joint DOFs and only 5 motors. There are nine ISA joints in the ISA Hand. All fingers are similar in structure. The thumb has two joints, one in which is the ISA joint. Four fingers in the ISA hand have three joints, two in which are the ISA joint. The reacting force from objects in grasping process can be used to drive the ISA joint. The architecture, grasping process and force analysis of the ISA finger are given in detail. Experimental results show that the ISA Hand can grasp different objects stably. [ABSTRACT FROM AUTHOR]

This paper presents a coupled and directly self-adaptive underactuated (CDSA) grasp mode, which has hybrid functions: coupled grasp and directly self-adaptive grasp. A novel multi-pulley-belt finger mechanism with springs is designed based on CDSA grasp mode. Compared with traditional coupled underactuated fingers or directly self-adaptive underactuated fingers, the grasp process of the new finger is more humanoid and its stability is better. Force analysis and size optimization rules of the finger are given. A multi-fingered robotic hand, CDSA hand, based on the CDSA finger is developed, whose control system adopts a digital signal processor (DSP) circuit module with a keyboard as its communication interface. The CDSA hand has five fingers, six DC motors, and 15 joint DOF, nine of which are CDSA joint DOF. The appearance and actions of CDSA hand imitate human hand, whose size is 1.5 times of human hand. CDSA hand weighs 1.6 kg and can grasp objects up to 0.5 kg. Simulation and experimental results show that CDSA hand is able to realize CDSA grasp mode effectively. [ABSTRACT FROM AUTHOR]