Technical progress and market situation of methanethiol

The poster wants to know information about methyl sulfide, not methanol； Read carefully before replying. Chinese name: Methyl mercaptan; English name: methyl mercaptan; Alternative Chinese name: Methanethiol; English name 2: methanethiol. CAS No.: 74-93-1; Molecular formula: CH4S; Molecular weight: 48.10. Physical and chemical properties: The main component is pure substance; Appearance and characteristics: Colorless gas with an unpleasant odor. Melting point (°C): -123.1 Boiling point (°C): 7.6 Relative density (water=1): 0.87 Relative vapor density (air=1): 1.66 Saturated vapor pressure (kPa): 53.32 at -7.9°C Heat of combustion (kJ/mol): 1244.0 Critical temperature (°C): 197 Critical pressure (MPa): 7.23 Flash point (°C): -17.8 Upper explosive limit (%/V): 21.8 Lower explosive limit (%/V): 3.9 Solubility: Insoluble in water; soluble in ethanol, ether, etc. Primary uses: Used in organic synthesis as well as in jet engine additives, pesticides, catalysts, etc. Health hazards: Inhaling it can cause headaches, nausea, and **effects of varying severity ； Inhalation of high concentrations can cause respiratory paralysis and death. Environmental hazards: It is harmful to the environment and can pollute water bodies. Fire and explosion hazard: This product is flammable and has ** properties. Hazardous properties: Flammable; its vapors can form explosive mixtures with air, and it poses a risk of combustion and explosion in the presence of heat sources, open flames, or oxidizing agents. Reacts with water, water vapor, and acids to produce toxic and flammable gases. Reacts violently upon contact with oxidizers. Methanethiol, also known as hydrogen sulfide or methyl mercaptan, is an important organic intermediate primarily used in the synthesis of materials, pesticides, pharmaceuticals, and more. Such as methionine, phosmet, benzylpyrethrin, imidacloprid, prometryn, etc., which are also used in the production of intermediates such as methanesulfonyl chloride and methylthiopropanol. Especially for the synthesis of methionine, in recent years, with the development and growth of the feed additive industry, the demand for methionine has been increasing, which in turn has spurred the development of methyl mercaptan production. Economic benefit analysis of the market: Due to the rapid development of the feed industry, demand for methionine – one of the key amino acids used to supplement synthetic proteins in poultry and livestock – has remained high. In 2005, China produced 80,000 tons of methionine, requiring 32,000 tons of methyl mercaptan. Coupled with the increasing demand from other industries such as pharmaceuticals and agriculture, China’s demand for methyl mercaptan in 2005 was approximately 40,500 tons. However, only a few companies in China produce this substance, and their output is insufficient to meet market demands. The total estimated investment for the project is 100 million yuan, with an annual total profit and tax amount of 30 million yuan, resulting in good economic benefits. Remarks: The Anqing Branch of Sinopec Corporation, which is located adjacent to the industrial park, can provide this project with inexpensive and reliable raw materials – hydrogen sulfide – as well as utilities such as water, electricity, and gas. There are many synthetic routes for methanethiol, including the thiourea-dimethyl sulfate synthesis method, the carbon disulfide-methanol catalytic synthesis method, the hydrogen sulfide-methanol synthesis method, and the carbon monoxide (or carbon dioxide)–hydrogen sulfide catalytic synthesis method. This project utilizes the mature domestic gas-phase synthesis technology for methanol and hydrogen sulfide in its production. This method involves the continuous reaction of hydrogen sulfide with methanol under the catalysis of potassium tungstate supported on active gamma-alumina to directly produce methanethiol. This method features high yield and good product quality; the methanol conversion rate can exceed 90%, while the methyl mercaptan yield can reach 98%. Scientific and Technological Achievements of East China University of Science and Technology – Research on the Preparation of Methylmercaptan and Dimethyl sulfide from Off-gases Generated in the Liquefaction of High-sulfur Coal. Date: 2007-7-19; Source unknown or not specified. Number of clicks: 49. Text font size: Large, Medium, Small. -------------------------------------------------------------------------------- Author: Unknown or not specified. Article entered by: Country boy. Methylmercaptan synthesized from hydrogen sulfide off-gases obtained through the indirect liquefaction of high-sulfur coal, together with methanol, and dimethyl sulfide produced as a by-product, are important intermediates in organic synthesis, primarily used in the production of methionine. The global annual demand for methionine is around 500,000 tons; the main production sites are currently France, the United States, Germany, and Japan ； In domestic industry, the thiourea-dimethyl sulfate method is primarily used for the production of methanethiol; however, the high toxicity of the solvents and high operating costs result in a severe shortage of methanethiol production in China, forcing the country to rely on imports. Based on the characteristics of high-sulfur coal, this study investigates the absorption and enrichment of H2S gas using solvents during indirect liquefaction, as well as its reaction with methanol in a multi-tube reactor to produce methyl mercaptan and dimethyl sulfide. H2S + CH3OH → CH3SH + H2O; CH3SH + CH3OH → CH3SCH3 + H2O; CH3SCH3 + H2S → 2CH3SH. This research project carries a low risk, building on the existing achievements at East China University of Science and Technology in areas such as water-coal slurry gasification (indirect liquefaction), the one-step production of dimethyl ether, and the two-step process involving first producing methanol and then synthesizing dimethyl ether. Developing liquefaction technologies for the resource utilization of high-sulfur coal in a manner tailored to local conditions helps to curb environmental pollution arising from coal conversion at its source. This is of great significance for alleviating the supply and demand imbalance of oil, ensuring energy security, and promoting the national economy. Currently, preliminary synthesis experiments have been carried out in a single-tube reactor (bubble reactor) in the laboratory to compare the effects of r-alumina and zirconia composite catalysts on the synthesis reaction. On this basis, further improvements will be made to enhance the selectivity and yield of the product as well as the catalyst lifespan ； Meanwhile, analytical methods for thiols and thioethers in C5-C6 light oil have been established. Based on the pilot tests, and in line with the requirements for multi-product production via indirect liquefaction, a pilot-scale production facility for methanethiol and dimethyl sulfide was established, achieving a conversion rate of 75–80% based on methanol. The methyl mercaptan and methyl sulfide products developed meet the corresponding national or industry standards. Required equipment and investment estimate: H2S absorption and enrichment unit ； Multi-tube reactor ( Appendix: multi-tube catalyst bed, multi-tube heat exchanger) ； Thiomethane and dimethyl sulfide cooling, separation, and distillation unit. The pilot plant investment is estimated to be around 3 million yuan. Application areas and market prospects: 1) Economic benefits: The raw materials used for liquefying high-sulfur coal are inexpensive; hydrogen sulfide waste gas and methanol can be utilized to produce methyl mercaptan, with dimethyl sulfide as a by-product. Thus, the economic efficiency in terms of input-output ratio is significant (the current market price of methanol in China is 3200–3500 yuan per ton) ； The price of methanethiol is around 11,000–12,000 yuan per ton, while the market price of dimethyl sulfide is about 16,500 yuan per ton. The market price of methionine ranges from 25,000 to 26,000 yuan per ton, and there is a demand that exceeds the supply. ) 2) Social benefits: As high-quality fossil fuel resources become increasingly scarce and environmental regulations become stricter, fuel prices keep rising. Given the characteristics of high-sulfur coal, it is particularly important to find new methods for coal liquefaction and integrated production. 3) Environmental benefits: In the green process of coal indirect liquefaction, while producing gasoline and diesel from coal, new fine chemical products such as methanethiol and dimethyl sulfide are developed; in addition to economic and social benefits, the environmental benefits are clearly more significant. Methanethiol, also known as hydrogen sulfide or methyl mercaptan, is a colorless gas that serves as an important intermediate and is primarily used in the synthesis of materials, pesticides, and pharmaceuticals. The reaction of methanethiol with acraldehyde can yield methionine, which is a raw material widely used in the feed industry, pharmaceutical industry, health products, and food industry ； Methanethiol can be converted into methyl sulfonic chloride (CH3SO2Cl) through wet oxidation; it serves as a catalyst for the methylation of phthalic anhydride, a catalyst for the copolymerization of aromatic tertiary amines with acrylonitrile, and a stabilizer for liquid sulfur trioxide ； Furthermore, methyl phosphoryl chloride can be further obtained through hydrolysis, and it can be used as an esterification catalyst, a raw material for pharmaceuticals, an additive and stabilizer in plating solutions, as well as a raw material for pharmaceuticals and pesticides. The main methods for producing methanethiol include the hydrogen sulfide-methanol method, the thiourea-dimethyl sulfate method, the chloromethane-alkaline sulfide method, and the methanol-dioxide sulfide method. The hydrogen sulfide-methanol method was the earliest approach used for synthesizing methanethiol. This method generates the byproduct dimethyl sulfide (DMS), has high production costs and low yields, and causes environmental pollution; it is suitable for small-scale production ； The thiourea-dimethyl sulfate method for producing methanethiol not only features high yields and low pollution, but it can also be used to produce sulfuric acid compounds with higher molecular weights, making it the most ideal method for large-scale industrial production. In recent years, China’s feed industry has developed rapidly, and the market demand for methionine has also increased sharply. It is estimated that China’s demand for methionine will reach 50,000 tons in the year 2000. Between 2001 and 2010, this figure is expected to rise to 70,000 tons per year, and between 2010 and 2020 it will reach 90,000 tons per year. At present, only companies such as Tianjin Methionine Factory, Hunan Changde Dongting Pharmaceutical Factory, Shanghai Chemical Reagents General Factory’s Third Plant, Nanning Organic Glass Factory in Guangxi, Tianjin Bohai Chemical Group’s Tianjin Chemical Plant, and Tianjin Hebei Pharmaceutical Factory produce methionine. The total production capacity of these facilities is around 30,000 tons per year, while actual output is only about 10,000 tons per year – far from sufficient to meet the needs of China’s feed industry. As a result, the country relies heavily on imports. Methanethiol is the main raw material for producing methionine; assuming a consumption of 400 kg of methanethiol per ton, the demand for this substance is at least 20,000 tons per year. Taking into account its other applications as well, China’s demand for methanethiol currently exceeds 25,000 tons per year. However, at present, only a few manufacturers in China produce methanethiol, such as Dandong Pharmaceutical Factory, Hebei Pharmaceutical Factory, Xinxiang Solvent Factory in Henan Province, and Ningyang Pesticide Factory, with production volumes of less than 1,000 tons – far from sufficient to meet domestic market demands. Therefore, relevant domestic enterprises should seize this opportunity to increase efforts in the development of methanethiol and its downstream products in order to meet the needs of actual domestic production.