Conversion of a double‐tetranuclear cluster silver helicate into a dihelicate via a rare desulfurization process

We present the first example of a silver double‐tetranuclear cluster helicate [Ag4L2]2 obtained from a bisthiosemicarbazone ligand using electrochemical synthesis. This cluster helicate undergoes a rare desulfurization process in chloroform...

Modern view on steel desulfurization

Modern technological schemes of steel production do not allow to achieve low (< 0.01 % S) and ultra-low (<0.005 % S) sulfur content on the production of in the metal directly. That is why out-of-furnace steel treatment is often used to remove sulfur. Desulfurization process of steel depends on the chemical composition of the slag, the time of its formation in the ladle, metal oxidation, conditions of mixing of steel in a ladle, additional technological operations and ladle metal processing. Methods are widely used for desulfurization of steel treatment of steel with solid slag-forming mixtures, synthetic slag, lime-aluminous slag, silico-calcium and other powdered materials. Modern approaches to the process of steel desulfurization in conditions steel production are analyzed in the Study. In particular, the Ukrainian (on the example of PJSC ‘Azovstal Iron & Steel Works’ and PJSC ‘Dneprovsky Integrated Iron & Steel Works named after Dzershinsky’) and foreign (on the example of PJSC ‘Severstal’ and PJSC ‘Magnitogorsk Iron & Steel Works’) experience of desulfurization under oxygen converter production. The use of technological complexes ‘Installation of pig iron desulfurization steel making unit’ and ‘Cast iron desulfurization installation steel making unit is ‘oven-bucket’ installation’ provides a deeper desulfurization of steel, the possibility of optimizing the cost of steel production, expands range of scarce products and eliminates a number of restrictive conditions that complicate current production. The analysis of steel C80D desulfurization process is given in the conditions of JSC ‘Moldova Steel Works’, in which partial sulfur removal occurs in an arc steel making furnace, and the ultra-low content is achieved by creating a highly basic refining slag in the process out-of-furnace processing of steel. The study of the kinetics of the desulfurization process of 20GL steel in the conditions of JSC ‘Tashkent Mechanical Plant’ with the use of solid slag-forming mixtures and modification of steel with rare-earth metals is analyzed. The issue of desulfurization of electric steel in the conditions of OJSC ‘Byelorussian Steel Works’ with injection of powdered materials through the installation ‘Velko’ during out-of-furnace processing of steel is considered. Keywords: steel desulfurization, desulfurizer reagent, degree of desulfurization, cast iron desulfurization installation, out-of-furnace processing of steel, ‘‘oven-bucket’’ installation.

Facile Construction of Magnetic Ionic Liquid Supported Silica for Aerobic Oxidative Desulfurization in Fuel

With the rapid growth in fuel demand, deep desulfurization of fuel oil is vitally necessary for the sake of health and environmental protection. In this work, a kind of magnetic ionic liquid supported silica is prepared by a facile ball milling method, and applied in the aerobic oxidative desulfurization of organosulfurs in fuel. The experimental results indicated that ball milling procedure can increase the specific surface area of samples, which is beneficial to oxidative desulfurization process. Under the optimal reaction conditions, the prepared materials can have an entire removal of aromatic sulfur compounds as well as a good recycling ability. Moreover, the introduction of Fe3O4 did not decline the desulfurization performance, but help the catalyst to be easily separated after reaction.

The Use of Limestones Built of Carbonate Phases with Increased Mg Content in Processes of Flue Gas Desulfurization

The purpose of this article was to present the theory of the possibility of using limestone sorbents containing carbonate minerals with increased Mg content in processes of flue gas desulfurization in power stations. Data obtained as a result of the conducted research show that the analyzed Triassic (Muschelkalk) limestones of the south-west part of Poland are built of the following carbonate minerals: low magnesium calcite, high magnesium calcite, dolomite and huntite. These carbonate minerals are characterized by various magnesium contents. The increased content of magnesium in the sorbent has a positive effect on the technological process of flue gas desulfurization using the dry method, especially in the case of desulfurization with the application of Fluidized Bed Reactors. The positive influence of magnesium’s presence in sorbent in the desulfurization process is connected with the decarbonization of carbonate phases with magnesium at temperatures similar to the dolomite decarbonization temperatures, which are, thus, lower than typical for low magnesium calcite. The process would be easier because the structure of a solid solution containing magnesium ions, with a smaller ion radius to calcium ions, is unstable and the decomposition of these phases runs easier and faster. Therefore, the desulfurization process starts earlier and is more effective.

ZnO-Activated Carbon Blended as a Catalyst for Oxidative Desulfurization of Dibenzothiophene

The problem of sulfur content in heavy oil is a challenge for researchers to meet the needs of environmentally friendly fuels. The catalyst preparation plays an important role in the desulfurization process. The synthesis of ZnO-activated carbon as a catalyst and its activity in oxidative desulfurization (ODS) reaction has been successfully carried out. In this work, the ZnO and activated carbon (AC) were blended by a solid-solid reaction. The ZnO, AC, and ZnO-AC were then characterized using acidity test with pyridine vapor adsorption, Fourier Transform Infra-Red (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX), and Surface Area Analyzer (SAA). ODS of dibenzothiophene (DBT) reaction was performed by using H2O2 under variation of the reaction time (30, 60, 120, and 150 min) for the ZnO-AC catalyst. The efficiency of ODS-DBT was analyzed by a UV-Visible spectrophotometer. The XRD analysis result showed that ZnO-AC blended displays new crystal peaks of Zn in the AC diffractogram. The surface area (734.351 m2/g) and acidity (4.8780 mmol/g) of ZnO-AC were higher than ZnO and AC themselves. ZnO-AC produced the highest efficiency of ODS-DBT which was 93.83% in the reaction time of 120 min. Therefore, the simple procedure of this physical blending was proved effective to homogenize between ZnO and AC into ZnO-AC so that it has good physicochemical properties as an ODS-DBT catalyst. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Theoretical and Experimental Studies of Sulfur and Boron Distribution between the Slag of the CaO-SiO2-B2O3-MgO-Al2O3 System and the Metal

The equilibrium interfacial distribution of sulfur and boron was estimated using the HSC 6.1 Chemistry software package (Outokumpu) and the simplex-lattice planning method. Adequate mathematical models have been constructed in the form of III degree polynomial, which describe the effect of the composition of the studied oxide system on the equilibrium distribution of sulfur and boron between the slag and the metal. Generalization of the results of experimental studies and thermodynamic modeling made it possible to obtain new data on the influence of the basicity and content of B2O3 in the slag of the CaO-SiO2-B2O3-MgO-Al2O3 system on the interphase distribution of sulfur and boron. It was found that in the range of boron oxide concentration of 1.0-10%, an increase in slag basicity from 2 to 5 at 1600°C leads to an increase in the sulfur distribution coefficient from 1 to 20 and, as a consequence, a decrease in the sulfur content in the metal from 0.02 to 0.0014 %, i.e. an increase in slag basicity favorably affects the development of the metal desulfurization process. An increase in the B2O3 content from 2.0 to 10.0% in slags formed in the region of moderate basicity, not exceeding 2-3, is accompanied at 1600°C by a decrease in the boron interphase distribution coefficient from 450 to 150 and an increase in the boron concentration in the metal from 0.006 to 0.021 %, which indicates the progress of boron reduction from slag to metal. The shift of the formed slags to the area of ​​increased basicity up to 5.0 shows a high degree of boron reduction from slag to metal. The results of the laboratory experiment confirmed the results of thermodynamic modeling.