[Chemical Knowledge]：Properties, uses, upstream and downstream raw materials, storage methods of dichloromethane, main uses of dichloromethane

Properties of Dichloromethane

Dichloromethane (Dichloromethane, DCM), chemical formula CH₂ Cl₂, is a colorless, transparent, volatile liquid with an aromatic sweetness. It has a molecular weight of 84.93g/mol, a density of 1.33g/cm³, a boiling point of 39.6°C and a melting point of -96.7°C. Dichloromethane has a high vapor pressure and is easily volatilized at room temperature. Its solubility shows that it can be miscible with ethanol, ether and other organic solvents, but its solubility in water is low, only 13g/L. Because of its physical properties, dichloromethane is commonly used as a solvent and extractant in organic chemical reactions.

Dichloromethane Uses

Dichloromethane has a wide range of industrial and laboratory uses. In chemical synthesis, methylene chloride is often used as a reaction solvent, especially in the field of pharmaceutical synthesis and fine chemical industry. Its low boiling point and good solubility make it particularly important in the separation and purification process. In the coatings and paint industry, methylene chloride is used as a paint remover and cleaning agent because it can effectively dissolve a variety of resins and oils. Dichloromethane is also a common extraction solvent, which is widely used in the decaffeination of food and beverage and the extraction of natural products.

Methylene chloride upstream raw material

Methylene chloride is produced mainly by chlorination of methane or methanol with chlorine. Upstream feedstocks include methane (or methanol) and chlorine. Among them, methane can be obtained by natural gas separation, and methanol is synthesized by natural gas. The production of chlorine gas usually relies on electrolysis in the chlor-alkali industry, which is produced from common salt. These raw materials are chlorinated under specific reaction conditions (such as temperature, pressure and catalyst) to produce dichloromethane, as well as by-products such as chloroform and carbon tetrachloride. Therefore, the supply of upstream raw materials directly affects the production cost and market supply of dichloromethane.

Dichloromethane Downstream Products

Dichloromethane, as an intermediate, plays an important role in the chemical industry chain. Its main downstream products include pharmaceutical intermediates, pesticide intermediates and coating solvents. Especially in drug synthesis, methylene chloride is used to produce many important pharmaceutical ingredients, such as antibiotics, anticancer drugs, etc. In the field of agricultural chemicals, methylene chloride is an important raw material for the synthesis of certain herbicides and pesticides. In the coatings and paints industry, methylene chloride is used as a solvent and cleaning agent to help produce high-quality coating products.

Dichloromethane Storage Methods

Due to the volatile, flammable and harmful properties of methylene chloride, its storage requires special attention. Dichloromethane should be stored in a cool, dry, well-ventilated place, away from direct sunlight and high temperature environment to prevent its volatilization and spontaneous combustion. Storage containers should use special corrosion-resistant materials, such as glass or special plastic containers, and ensure good sealing to prevent leakage. The storage area should also be equipped with necessary fire fighting equipment, such as fire extinguishers and sandboxes, to deal with emergencies. Places where methylene chloride is stored and used should be equipped with an appropriate ventilation system to ensure air circulation and prevent gas accumulation.

Environmental and Safety Considerations

Dichloromethane is harmful to the environment and human health. Long-term exposure to methylene chloride vapor may cause damage to the central nervous system, liver, and cardiovascular system. Therefore, the use and handling of methylene chloride must follow strict safety procedures and wear suitable protective equipment such as gloves, goggles and gas masks. The disposal of dichloromethane waste must comply with environmental regulations and avoid direct discharge into water and soil to prevent pollution. Dichloromethane in industrial waste gas needs to be treated to ensure that emissions meet environmental standards.

Market and Development Trend

The market demand for methylene chloride mainly comes from industries such as pharmaceuticals, agricultural chemicals and coatings. With the continuous development of these industries, the market demand for methylene chloride is also showing an increasing trend. The use of methylene chloride has been restricted due to the increasing environmental and health problems. In the future, the development of green chemistry technology and increasingly stringent environmental regulations may drive the industry's transition to greener and safer alternatives. The improvement of production process and the optimization of raw material supply chain will help to reduce the production cost of dichloromethane and improve the market competitiveness.

Conclusion

Dichloromethane, as an important organic chemical raw material, has attracted much attention because of its unique physical and chemical properties and a wide range of applications. Its upstream raw material supply, production process and downstream market demand together determine its market performance. Despite the environmental and safety challenges, the economic value of methylene chloride can be realized while ensuring safety by improving storage methods, optimizing production processes and following environmental regulations. In the future, with the advancement of technology and the enhancement of environmental awareness, the dichloromethane industry is expected to achieve sustainable development.