The critical temperature increases with pressure, ranging from 23 K at 100 GPa to 150 K at 200 GPa. When cooled below a critical temperature this high-pressure phase exhibits superconductivity. Īt pressures above 90 GPa ( gigapascal), hydrogen sulfide becomes a metallic conductor of electricity. Hydrogen sulfide is also responsible for tarnishing on various metals including copper and silver the chemical responsible for black toning found on silver coins is silver sulfide ( Ag 2S), which is produced when the silver on the surface of the coin reacts with atmospheric hydrogen sulfide. Treating metal sulfides with strong acid or electrolysis often liberates hydrogen sulfide. Lead(II) acetate paper is used to detect hydrogen sulfide because it readily converts to lead(II) sulfide, which is black. Hydrogen sulfide reacts with metal ions to form metal sulfides, which are insoluble, often dark colored solids. The sulfide anion S 2− is not formed in aqueous solution. When exposed to air, it slowly oxidizes to form elemental sulfur, which is not soluble in water. Hydrogen sulfide and its solutions are colorless. Hydrogen sulfide is slightly soluble in water and acts as a weak acid ( p K a = 6.9 in 0.01–0.1 mol/litre solutions at 18 ☌), giving the hydrosulfide ion HS − (also written SH −). This reaction is exploited in the Claus process, an important industrial method to dispose of hydrogen sulfide. If an excess of oxygen is present, sulfur trioxide ( SO 3) is formed, which quickly hydrates to sulfuric acid:Īt high temperatures or in the presence of catalysts, sulfur dioxide reacts with hydrogen sulfide to form elemental sulfur and water. Hydrogen sulfide burns in oxygen with a blue flame to form sulfur dioxide ( SO 2) and water: In general, hydrogen sulfide acts as a reducing agent, although in the presence of a base, it can act as an acid by donating a proton and forming SH −. A mixture of H 2S and air can be explosive. Hydrogen sulfide is slightly denser than air. It also occurs in volcanic gases, natural gas deposits, and sometimes in well-drawn water. Hydrogen sulfide is often produced from the microbial breakdown of organic matter in the absence of oxygen, such as in swamps and sewers this process is commonly known as anaerobic digestion, which is done by sulfate-reducing microorganisms. Despite this, the human body produces small amounts of this sulfide and its mineral salts, and uses it as a signalling molecule. When it is inhaled or its salts are ingested in high amounts, damage to organs occurs rapidly with symptoms ranging from breathing difficulties to convulsions and death. Hydrogen sulfide is toxic to humans and most other animals by inhibiting cellular respiration in a manner similar to hydrogen cyanide. The British English spelling of this compound is hydrogen sulphide, a spelling no longer recommended by the Royal Society of Chemistry or the International Union of Pure and Applied Chemistry. Swedish chemist Carl Wilhelm Scheele is credited with having discovered the chemical composition of purified hydrogen sulfide in 1777. The underground mine gas term for foul-smelling hydrogen sulfide-rich gas mixtures is stinkdamp. It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The three mechanisms of adsorption including π-complexation, acid–base interaction, and metal–sulfur interaction provide useful information for the subsequent development of BFG desulfurization technology.Hydrogen sulfide is a chemical compound with the formula H 2S. At the same time, commonly used adsorbent materials such as activated carbon, molecular sieves, metal–organic frameworks (MOFs), and layered hydroxide adsorbents (LDHs) are introduced. The adsorption method is simple in operation, economical, and rich in types of adsorbents and has become a major focus of current research. The sources of COS in BFG are reviewed, and the commonly used removal methods for COS are summarized, including the types of adsorbents commonly used in adsorption methods and the adsorption mechanism of COS. Carbonyl sulfide (COS) has become a significant and difficult issue in the BFG treatment due to its unique physical and chemical properties. However, with the introduction of energy-saving and emission reduction policies, desulfurization of blast furnace gas (BFG) is also necessary for further sulfur control in the iron and steel industry. The iron and steel industry is one of the foundational industries in China.
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