[Chemical Knowledge]：Properties, uses, upstream and downstream raw materials, storage methods, application of dimethyl carbonate

Properties of dimethyl carbonate

dimethyl carbonate (DMC) is a colorless and transparent liquid with a faint aromatic odor. Its chemical formula is C3H6O3 and its molecular weight is 90.08g/mol. DMC has a boiling point of about 90°C, a melting point of 4°C and a density of 1.069g/cm³. It has low viscosity and high volatility, soluble in a variety of organic solvents, such as alcohols, ketones and esters, and limited solubility in water. DMC is an environmentally friendly solvent that does not contain chlorine and does not cause damage to the ozone layer, so it is considered to be one of the important raw materials for green chemistry.

Use of dimethyl carbonate

dimethyl carbonate has a wide range of applications in the chemical industry, including the following aspects:

1. solvent because of its good solubility and low toxicity, DMC is widely used in coatings, inks, adhesives and other fields to replace traditional harmful solvents.

2. organic synthesis DMC is an important methylation reagent and carbonylation reagent, which is widely used in the synthesis of pharmaceutical intermediates, pesticide intermediates and dyes. For example, DMC can be used to produce antibiotics such as amoxicillin and penicillin, as well as some herbicides and pesticides.

3. Battery electrolyte in lithium-ion batteries, DMC is an important part of the electrolyte. Because of its excellent electrochemical stability and low viscosity, it can significantly improve the performance and service life of the battery.

4. fuel additive: DMC can be used as a fuel additive to improve the combustion performance of fuel and reduce pollutant emissions.

Upstream and downstream raw materials of dimethyl carbonate

the production of dimethyl carbonate involves a variety of raw materials and processes, and its upstream and downstream industry chain includes the following parts:

1. upstream raw materials:

• methanol: Methanol is one of the main raw materials for the production of DMC. DMC is produced by reaction with carbon dioxide or carbon monoxide.
• Carbon Dioxide part of the production process through the reaction of methanol and carbon dioxide to prepare DMC, the use of carbon dioxide in the exhaust gas, to achieve green production.
• phosgene: In the traditional process, DMC can be prepared by the reaction of methanol and phosgene, but due to the high toxicity and high risk of phosgene, it is gradually eliminated.

1. Downstream Products:

• electrolyte: For the electrolyte of lithium-ion batteries, DMC is used together with ethylene carbonate as one of the important components.
• organic synthesis intermediate DMC is used as an intermediate to further synthesize various pharmaceutical and pesticide products.
• Polycarbonate DMC is one of the important raw materials for the production of polycarbonate, which is widely used in the fields of electronics, electrical appliances, automobiles and construction.

Production Process of Dimethyl Carbonate

the production process of dimethyl carbonate mainly includes methanol carbonylation, methanol and carbon dioxide reaction and direct oxidation.

1. methanol carbonylation process: This process uses methanol and carbon monoxide to react with a catalyst to generate dimethyl carbonate. This method has mild reaction conditions and wide sources of raw materials, and is a relatively mature production process in industry at present.

2. methanol and carbon dioxide reaction method the method generates DMC through the reaction of methanol and carbon dioxide, and uses CO2 as raw material to realize the resource utilization of carbon dioxide, which has the advantage of environmental protection.

3. direct oxidation method this process directly oxidizes methanol and oxygen to produce DMC, which is simple and low cost, but it requires high reaction conditions and still needs further optimization and research.

Storage method of dimethyl carbonate

dimethyl carbonate has a certain degree of volatility and flammability, so special attention should be paid during storage and transportation:

1. storage Environment: DMC should be stored in a cool, well-ventilated warehouse, away from fire and heat sources. The storage temperature should be controlled below room temperature and avoid direct sunlight.

2. Container Requirements store in a closed container made of stainless steel or corrosion-resistant material to avoid contact with oxidants, acids and alkalis.

3. Fire Prevention Measures the warehouse shall be equipped with appropriate fire extinguishing equipment, such as dry powder fire extinguisher, foam fire extinguisher, etc. Operators shall wear protective equipment to avoid direct contact with DMC.

4. Transportation safety the transportation of DMC shall comply with the relevant regulations on the transportation of dangerous chemicals, and special vehicles for the transportation of dangerous goods shall be used, and the vehicles shall be equipped with safety facilities such as leakage prevention, fire prevention and explosion prevention.

Environmental and safety issues

dimethyl carbonate is regarded as a representative substance of green chemistry, but it is still necessary to pay attention to environmental protection and safety issues during its production, use and disposal:

1. production process: Adopt clean production process to reduce the discharge of waste gas, waste water and solid waste. In particular, it is necessary to control the leakage of methanol and carbon monoxide to avoid environmental pollution and safety hazards.

2. Use process: Operators should receive professional training and be familiar with the nature and safe use of DMC to avoid accidents caused by improper operation.

3. Waste Disposal: DMC waste should be treated in accordance with the relevant regulations on hazardous waste to avoid pollution of soil and water. Recycle as much as possible to reduce the burden on the environment.

Market Prospect and Development Trend

with the increasingly stringent environmental regulations and the promotion of the concept of green chemistry, the market demand for dimethyl carbonate is on the rise. In the future, DMC has broad development prospects in the following areas:

1. new energy: With the wide application of lithium-ion batteries, especially in the field of electric vehicles, DMC is an important component of the electrolyte, and the market demand will continue to grow.

2. Green solvent because of its low toxicity and good solubility, DMC will gradually replace the traditional harmful solvents and is widely used in coatings, inks and other industries.

3. carbon emission reduction the production of DMC through the utilization of carbon dioxide resources will become one of the important ways to reduce carbon emissions and help to realize the green transformation of the industrial field.

As an important chemical raw material, dimethyl carbonate occupies an important position in modern industry because of its excellent properties and wide range of uses. With the progress of technology and the increase of market demand, the application prospect of DMC will be broader and become an important driving force for the development of green chemistry.