Search

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Electroseparation of zinc(II) from a solution of uranium(III) generated by the reduction of uranium(IV) triflate (U(OTf)4) with zinc amalgam (Zn(Hg)) was studied to establish a convenient route to the precursors of organic uranium(III) compounds. Specifically, the electrode reactions of U(OTf)4 in N,N-dimethylformamide on mercury (Hg) and Zn(Hg) electrodes were probed by voltammetry and bulk electrolysis measurements. The voltammograms recorded on the former electrode showed three cathodic waves assigned to the reduction of a uranium(IV) solvate complex (− 1.48 V), the reduction of [U(OTf)]3+ (− 1.81 V), and uranium amalgamation (− 2.65 V). On the latter electrode, the first cathodic wave was masked, as it was located at the potential of zinc amalgamation. Bulk electrolysis experiments revealed that for both Hg and Zn(Hg), the working electrode potential featured a plateau around − 2.3 V, which was not observed in the corresponding voltammograms and was related to the degradation of uranium(III) based on spectroscopic observations. The Electroseparation of zinc(II) from the uranium(III) solution on Zn(Hg) was successfully (highest coulombic efficiency = 0.81, final zinc(II) separation ratio = 93.4%) carried out after the reduction of U(OTf)4 by Zn(Hg). [ABSTRACT FROM AUTHOR]

Zinc electrodeposition is currently a hot topic because of its widespread use in rechargeable zinc‐air batteries. However, Zn deposition has received little attention in organic solvents with much higher ionic conductivity and current efficiency. In this study, a Zn‐betaine complex is synthesized by using ZnO and betainium bis[(trifluoromethyl)sulfonyl]imide and its electrochemical behavior for six organic solvents and electrodeposited morphology are studied. Acetonitrile allowed dendrite‐free Zn electrodeposition at room temperature with current efficiencies of up to 86 %. From acetonitrile solutions in which Zn, Pb, and Cu complexes are dissolved in high concentrations, Zn and Pb/Cu are efficiently separated electrolytically under potentiostatic control, allowing the purification of solutions prepared directly from natural ores. Additionally, a highly flexible Zn anode with excellent kinetics is obtained by using a carbon fabric substrate. A rechargeable zinc‐air battery with these electrodes shows an open‐circuit voltage of 1.63 V, is stable for at least 75 cycles at 0.5 mA cm−2 or 33 cycles at 20 mA cm−2, and allows intermediate cycling at 100 mA cm−2. [ABSTRACT FROM AUTHOR]

Separation process of LYZ by electrodialysis with ultrafiltration membrane. [Display omitted] • Separation lysozyme from ovalbumine with an EDUF process was demonstrated for the first time. • Effects of EDUF process parameters on the separation performance were investigated. • The purity of lysozyme isolated by EDUF could reach 100%. • The maximum yield of recovered LYZ by EDUF process was 32.2%. Lysozyme (LYZ) is a vital bioactive protein due to its chemical stability, non-toxicity, and biological functions including antibacterial, antiviral and anti-inflammatory activities. LYZ's separation and purification processes are essential for its applications in the food, pharmaceutical and some other fields. Electrodialysis with ultrafiltration membrane (EDUF) is a recently developed technique that has been proven to have a high selectivity in fractionating natural biologically active compounds. This study was conducted to isolate and purify LYZ from a model solution containing ovalbumin (OVA) and LYZ using an EDUF process, and to evaluate the effects of the operational parameters on its separation performances. Results showed that an excessive or inadequate applied voltage or solution flow rate was not conducive to the migration of LYZ. Additionally, the volume ratio of feed to permeate solution was inversely related to the amount of LYZ recovered. Under the most favorable conditions, with a voltage of 5 V, solution flow rate of 50 mL/min and volume ratio of 1:1.5, LYZ was recovered with a total yield of 32.2% and a purity of 100% after 240 min of running, with a relative energy consumption of 1.52 kW•h/g. This study demonstrated that LYZ could be successfully separated from the mixtures of OVA and LYZ by an EDUF process. EDUF technology provides an effective and innovative method for the active protein separation in the egg product-related industry. [ABSTRACT FROM AUTHOR]

[Display omitted] • Application of Tafel and LP to judge the kinetic properties of Eu and Gd on liquid Pb and LBE cathodes. • The effects of PE, GA, and PPE on separation factor, extraction efficiency, and crystal size were investigated and compared. • The reduction mechanism of Eu from Gd on liquid LBE alloy cathodes was systematically investigated. • The separation factors SF Gd/Eu of Gd/Eu and the extraction efficiency of Gd reached up to 759 and 99.1 %, respectively. The highly effective separation of two adjacent rare earth is significant to the rare earth and nuclear industries. This paper investigates the highly effective separation of Gd over Eu using liquid lead–bismuth eutectic (LBE) alloy cathode in molten LiCl-KCl-EuCl 3 -GdCl 3 by pulse potential electrolysis (PPE). Underpotential deposition of Eu and Gd is observed on the LBE alloy, with a depolarization value far greater than that of the liquid Pb electrode. Furthermore, the higher exchange current density and the lower activation energy of the electrode reaction indicate that the LBE alloy cathode has higher kinetic performance than the liquid Pb. Then, the practical electro-separation in LiCl-KCl-EuCl 3 -GdCl 3 systems is carried out by applying different electrolysis technology. The effects of varying electrolysis methods and parameters on separation factor (SF), extraction efficiency, cathode product morphology, and crystal size are studied and compared. The results show that both the extraction efficiency and the separation factor obtained by the PPE are the largest. The calculated extraction efficiency of Gd and the actual separation factor SF Gd/Eu of Gd/Eu could be up to 99.1 % and 759, respectively. [ABSTRACT FROM AUTHOR]

• Zn is directly separated from ZnS in choline chloride-urea-malonic acid (ChCl-urea-MA) deep eutectic solvent. • This process achieves the current efficiency of 86.5 % with the energy consumption of 2621.8 kW·h·t−1. • MA causes 0.13 mol·L-1 ZnS being dissolved to form stable MA-based ligands. • This study initiatively simplifies Zn separation from ZnS in green solution with hazardous waste minimization. Zinc sulfide (ZnS), one of the main ingredients of zinc ore and emerging materials, partly processes environmental risk. Deep eutectic solvents (DESs) are green solvents to efficiently separate metals with less emission. In this study, a novel route for direct electroseparation of Zn from ZnS in eco-friendly choline chloride-urea DES with the addition of malonic acid (MA) is studied for the first time. The role of MA and the reduction behavior of Zn(II) are systematically analyzed by cyclic voltammetry. The reduction of Zn(II) is quasi-reversible and follows one-step two-electron transfer process. Pure Zn with nanostructure is obtained with the current efficiency of 86.5 % and energy consumption of 2621.8 kW·h·t−1 at the optimized parameters of 10 mA·cm−2, 353 K and 100 mM·L-1 ZnS. Mechanisms analyses indicate that in the presence of 60 mM·L-1 MA, besides [ZnCl− 3 ]- and [ZnCl− 5 ]3-, some ZnS are dissolved to form stable [Zn(MA)2-Cl− 2 ]4-, [Zn(MA)2-Cl-]3- and other MA based ligands, which causes a higher Zn ion solubility of 0.13 mol·L-1 and may promote the subsequent electroseparation of ZnS. Results from this study are expected to propose a simplified route to directly separate Zn from ZnS without oxidation pretreatment to achieve hazardous waste minimization. [ABSTRACT FROM AUTHOR]