Liquid sulfur dioxide production method based on sulfur and oxygen. R&D of economically feasible method

The article shows the relevance of the industrial production of liquid sulfur dioxide, as well as the fields of its application. Herewith there is provided a brief description of the known methods for the production of liquid sulfur dioxide: the use of roast gas; sulfur-oleum method; multi-stage condensation; low temperature cryogenic process; oxidation of sulfur with oxygen under its stoichiometric deficiency. In the course of the analysis, the main shortcomings of the considered methods were identified, which made it possible to develop an innovative version of the process scheme. Based on the data obtained, JSC “NIUIF” has developed and patented a method for producing liquid sulfur dioxide, the main raw material of which is sulfur and oxygen under its stoichiometric deficiency. The principal difference of the proposed industrial scheme is the use of technical oxygen instead of air blast and the use of a sulfur furnace and a sulfur vapor condenser combined in one housing in the apparatus scheme. The proposed solution significantly reduces energy consumption and eliminates the possibility of liquid sulfur crystallizing inside the equipment. Therefore, this scheme can be considered more reliable and reasonable in comparison with the existing ones. Also, in the process scheme of the developed unit, the production of 1 ton of liquid sulfur dioxide consumes significantly less energy than in the existing technologies. To determine the design parameters of the equipment and master the processes, the article describes a lab unit for producing liquid sulfur dioxide, developed and already installed at JSC "NIUIF". At the moment, experiments are carried out at the facility for the purpose of adjusting the operation mode and collecting the physical and chemical process data.

Understanding Sulfur Redox Mechanisms in Different Electrolytes for Room-Temperature Na–S Batteries

This work reports influence of two different electrolytes, carbonate ester and ether electrolytes, on the sulfur redox reactions in room-temperature Na–S batteries. Two sulfur cathodes with different S loading ratio and status are investigated. A sulfur-rich composite with most sulfur dispersed on the surface of a carbon host can realize a high loading ratio (72% S). In contrast, a confined sulfur sample can encapsulate S into the pores of the carbon host with a low loading ratio (44% S). In carbonate ester electrolyte, only the sulfur trapped in porous structures is active via ‘solid–solid’ behavior during cycling. The S cathode with high surface sulfur shows poor reversible capacity because of the severe side reactions between the surface polysulfides and the carbonate ester solvents. To improve the capacity of the sulfur-rich cathode, ether electrolyte with NaNO3 additive is explored to realize a ‘solid–liquid’ sulfur redox process and confine the shuttle effect of the dissolved polysulfides. As a result, the sulfur-rich cathode achieved high reversible capacity (483 mAh g−1), corresponding to a specific energy of 362 Wh kg−1 after 200 cycles, shedding light on the use of ether electrolyte for high-loading sulfur cathode.

Eightfold Electrophilic Methylation of Octacyanotungstate [W(CN)8]4−/3−: Preparation of Homoleptic, Eight-coordinate Methylisocyanide Complexes [W(CNMe)8]4+/5+

Homoleptic eight-fold coordinated methylisocyanide complexes of W(IV) and W(V) have been prepared for the first time. The reaction of [NBu4]4[W(CN)8] with methyl triflate MeOTf gives [W(CNMe)8][OTf]4. The even stronger methylating mixture of methyl fluoride MeF and arsenic pentafluoride AsF5 in liquid sulfur dioxide SO2 is able to fully alkylate both [NBu4]4[W(CN)8] and [NBu4]3[W(CN)8]. The paramagnetic octakis(methylisocyanide)- tungsten(V) [W(CNMe)8][AsF6]5 is thermally highly unstable above −30 °C. All compounds have been characterized via single-crystal X-ray diffraction, IR and Raman, as well as NMR or EPR spectroscopy<br>

Eightfold Electrophilic Methylation of Octacyanotungstate [W(CN)8]4−/3−: Preparation of Homoleptic, Eight-coordinate Methylisocyanide Complexes [W(CNMe)8]4+/5+

Homoleptic eight-fold coordinated methylisocyanide complexes of W(IV) and W(V) have been prepared for the first time. The reaction of [NBu4]4[W(CN)8] with methyl triflate MeOTf gives [W(CNMe)8][OTf]4. The even stronger methylating mixture of methyl fluoride MeF and arsenic pentafluoride AsF5 in liquid sulfur dioxide SO2 is able to fully alkylate both [NBu4]4[W(CN)8] and [NBu4]3[W(CN)8]. The paramagnetic octakis(methylisocyanide)- tungsten(V) [W(CNMe)8][AsF6]5 is thermally highly unstable above −30 °C. All compounds have been characterized via single-crystal X-ray diffraction, IR and Raman, as well as NMR or EPR spectroscopy<br>

Electrochemically synthesized liquid-sulfur/sulfide composite materials for high-rate magnesium battery cathodes

Liquid S/sulfide composite cathodes can be spontaneously synthesized by electrochemically oxidizing sulfides, enabling high-rate magnesium rechargeable batteries.

Industrial and laboratory technologies of liquid sulphur dioxide based on sulfur and oxygen.

The article tells about the industrial unit for production of liquid sulfur dioxide based on sulfur and oxygen, which has been developed by Research Institute of Fertilizers and Insectofungicides(patent No. 2711642 dated 01/17/2020). The principal difference of the proposed industrial process is the use of technical oxygen instead of FDF and the use of a sulfur furnace and a sulfur vapor condenser combined in one housing. To determine the design parameters of equipment and to master the process, the article describes a lab unit for production of liquid sulfur dioxide, developed by and implemented at Research Instituteof Fertilizers and Insectofungicides. At the moment, the lab unit is run to adjust the operating mode.

An Another Protocol to Make Sulfur Embedded Ultrathin Sections of Extraterrestrial Small Samples

Another protocol to make sulfur embedded ultrathin sections was developed for STXM–XANES, AFM–IR and TEM analyses of organic materials in small extraterrestrial samples. Polymerized liquid sulfur—instead of low-viscosity liquid sulfur—is the embedding media in this protocol. Due to high viscosity of the polymerized sulfur, the embedded samples stay near the surface of polymerized liquid sulfur, which facilitates trimming of glassy sulfur and ultramicrotomy of tiny embedded samples. In addition, well-continued ribbons of ultramicrotomed sections can be obtained, which are suitable for the above mentioned analyses. Because there is no remarkable difference in Carbon XANES spectra of Murchison IOM prepared by this protocol and by the conventional protocol, this protocol gives another alternative to prepare sulfur embedded ultramicrotomed sections.

Chemical Weapons in the Iran-Iraq War (1980–1988). 4. The Destruction of Iraqi Chemical Weapons

After the defeat of Iraqi army in Kuwait in February 1991, on April 3, the UN Security Council (UN Security Council) adopted Resolution 687, that «decides that Iraq shall unconditionally accept the destruction, removal, or rendering harmless, under international supervision, of: (a) All chemical and biological weapons and all stocks of agents and all related subsystems and components and all research, development, support and manufacturing facilities». This UN operation was not the first forced disarmament of vanquished by victors, but it gave great impetus to the completion of the work on the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on Their Destruction, i.e. the destruction of an entire class of weapons of mass destruction. The aim of this article was to show the process of Iraqi`s chemical weapons destruction. The destruction of Iraqi chemical weapons included the formation of legal basis (United Nations Security Council Resolution 687); the establishment of the United Nations Special Commission (UNSCOM) to inspect and oversee the destruction or elimination of Iraq’s chemical weapons directly on Iraqi territory; certain measures of political, economic (UN sanctions) and military coercion (the US and the UK military operation «Desert Fox»). In summer 1991, UNSCOM formed a Destruction Advisory Panel to develop technologies for the destruction of chemical weapons, toxic substances and their precursors. Their destruction was carried out in the period October 1992 to May 1994 on the territory of the Muthanna State Establishment. Sarin, cyclosarin, tabun and their precursors were destroyed by hydrolysis in aqueous alkaline solution using a repurposed production facility. Thus 76 tons of sarin and sarin/cyclosarin mixture, as well as 40 tons of tabun were destroyed. For the sulfur mustard, the high-temperature direct burning method was used at the special factory, established under the project of the Destruction Advisory Panel. Thus were destroyed around 400 tons of liquid sulfur mustard. Chemical munitions and containers, after the extraction of poisonous agents, were destroyed using a specially developed technique of explosive ventilation and burning. 30 chemical warheads for Al-Hussein ballistic missiles, 12,8 thousand 155-mm mustard shells, 40,5 thousand 122 mm rockets for MLRS, filled with sarin/cyclosarin, were destroyed. In general, UNSCOM managed to solve the problem of chemical disarmament of Iraq. The article describes in details the Iraq’s chemical weapons destruction technologies