Methanol-

Introduction Methanol, also known as wood alcohol, is an organic compound and the simplest saturated monohydric alcohol. It appears as a colorless, transparent, flammable, volatile, and toxic liquid. Ingesting 5–10 milliliters can cause blindness, while larger quantities are fatal. Methanol is non-corrosive to metals at room temperature (except lead and aluminum) and possesses a faint alcohol-like odor. Its relative density is 0.792 (20/4°C), melting point is -97.8°C, boiling point is 64.5°C, flash point is 12.22°C, autoignition temperature is 463.89°C, vapor density 1.11, vapor pressure 13.33 kPa (100 mmHg at 21.2°C), vapor-air explosive limits 6–36.5% (by volume). It is miscible with water, ethanol, diethyl ether, benzene, ketones, halogenated hydrocarbons, and many other organic solvents. Commonly used as a solvent, antifreeze, fuel, or neutralizing agent.

Applications

Methanol has extensive applications as a fundamental organic chemical feedstock and high-quality fuel. It is primarily used in fine chemicals, plastics, and other sectors to produce various organic products such as formaldehyde, acetic acid, chloroform, methylamine, and dimethyl sulfate. It also serves as a key raw material for pesticides and pharmaceuticals. After deep processing, methanol can function as a new type of clean fuel and is blended with gasoline for combustion. Oxidation of Methanol to Formaldehyde Methanol is directly oxidized to formaldehyde at high temperatures in the presence of pumice silver, catalysts, or other solid catalysts. Currently, over 40% of global methanol production is used for formaldehyde synthesis, which is further processed into resins, plastics, and other chemical feedstocks. Polyoxymethylene (POM), a high-performance engineering plastic, finds extensive applications. Formaldehyde is also used to produce nearly one hundred downstream products, including butanediol and urotropine. Ammonia synthesis of methylamine involves mixing methanol and ammonia in specific proportions. At temperatures of 370–420°C and pressures of 5.0–20.0 MPa, using activated alumina as a catalyst, a mixture of methylamine, dimethylamine, and trimethylamine is synthesized. Distillation then yields pure methylamine, dimethylamine, or trimethylamine products. Methylamine, dimethylamine, and trimethylamine are used in pesticides, pharmaceuticals, dyes, or as organic raw material intermediates. Dehydration of methanol over metal silicon-aluminum catalysts or ZSM-5 molecular sieves yields dimethyl ether. Dehydrogenation of methanol produces methyl formate. Methyl formate serves as an organic synthesis feedstock for manufacturing methyl formamide, dimethylformamide, and others. Formamide serves as a raw material for pharmaceuticals, fragrances, and dyes, and is also used as a paper treatment agent, a softener in the fiber industry, and a polar solvent in organic synthesis. Dimethylformamide is an important organic chemical raw material and an excellent solvent, applicable in gas absorption, pesticides, polyurethane synthetic leather, polyacrylonitrile spinning, and butadiene extraction.