Ethylene glycol

Basic information

  • Product Name:Ethylene glycol
  • CasNo.:107-21-1
  • MF:C2H6O2
  • MW:

Physical and Chemical Properties

  • Purity:99%
  • Boiling Point:
  • Packing:liquid
  • Throughput:
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Product Details

CasNo: 107-21-1

MF: C2H6O2

Appearance: liquid

Packing: 220kg/drum

Purity: 99%

1. Product Overview​

Ethylene glycol, also known as glycol or 1,2-ethanediol, has the chemical formula ​

C2​H6​O2​

. It is the simplest aliphatic diol and is a crucial organic chemical raw material and intermediate.​

2. Physical and Chemical Properties​

2.1 Physical Properties​

  • Appearance: Colorless, odorless, and viscous liquid at room temperature, with a sweet taste.​
  • Molecular Weight: 62.07​
  • Melting Point: -13 °C​
  • Boiling Point: 197.3 °C (760 mmHg)​
  • Density: 1.1135 g/mL (20 °C)​
  • Solubility: Miscible with water in any proportion, slightly soluble in ether, and soluble in most common solvents.​

2.2 Chemical Properties​

  • Oxidation Reaction: The oxidation products vary depending on the oxidizing agent used. For example, when oxidized with sodium (potassium) dichromate and sulfuric acid, a series of products with different oxidation degrees are formed.​
  • Esterification Reaction: Can react with oxygen-containing inorganic acids to form esters. For instance, it reacts with nitric acid to produce corresponding esters.​
  • Polycondensation Reaction: Can undergo polycondensation reactions. For example, when mixed with phthalic anhydride and some glycerol, it can be polycondensed into a network polyester (alkyd resin).​
  • Dehydration Reaction: Under sulfuric acid conditions, it can dehydrate to form acetaldehyde.​

3. Production Methods​

3.1 Petrochemical Route​

  • Direct Hydration of Ethylene Oxide: This is the dominant process in ethylene glycol production. Ethylene oxide directly reacts with water under high temperature to produce ethylene glycol, accompanied by by-products such as diethylene glycol (DEG), triethylene glycol (TEG), and other ethylene glycol homologues. However, this process has disadvantages such as a long process flow, high water consumption, difficult separation, and high production costs.​
  • Catalytic Hydration of Ethylene Oxide: Based on the direct hydration method, a highly efficient catalyst is added to improve the conversion rate of ethylene oxide and the selectivity of ethylene glycol. This method significantly reduces water consumption, energy consumption, and production costs.​
  • Ethylene Carbonate Method: The synthesis of ethylene glycol by the ethylene carbonate (EC) method involves three steps. First, ethylene oxide is obtained through the oxidation of ethylene. Then, ethylene oxide reacts with carbon dioxide to form ethylene carbonate. Finally, ethylene glycol is produced by hydrolysis or transesterification of ethylene carbonate. This method has advantages such as high selectivity, high yield, and environmental friendliness, but the acidic catalyst used can cause serious equipment corrosion.​

3.2 Coal - based Route​

  • Direct Method: The direct synthesis of ethylene glycol from syngas is a process that directly converts syngas (CO and ​

    H2​

    ) into ethylene glycol in one step under high temperature, high pressure, and the action of a catalyst.​
  • Indirect Method: Indirect methods first use syngas to generate intermediate products such as methanol and formaldehyde, and then produce ethylene glycol through catalytic hydrogenation. According to different intermediate products, indirect methods can be divided into formaldehyde carbonylation method, dimethyl oxalate hydrogenation method, formaldehyde hydroformylation method, etc.​

3.3 Bio - based Route​

Cellulose, sugars, plant straws, glycerol, etc. can also be used to produce ethylene glycol. For example, in the process of producing ethylene glycol from cellulose, cellulose is hydrolyzed into glucose, which is then further processed to obtain ethylene glycol. This route has the advantage of inexpensive and easily available raw materials.​

4. Applications​

4.1 Polyester Industry​

  • Polyester Fiber and Plastic: Ethylene glycol is a raw material for the production of polyester fibers and polyester plastics, such as polyvinyl succinate and polyurethane. The most important application is in the synthesis of polyethylene terephthalate (PET), which can be used as raw materials for polyester fibers, coatings, and polyester plastics.​
  • Alkyd Resin: Reaction of maleic acid, fumaric acid, and other polybasic acids with ethylene glycol can prepare alkyd resins. In the textile industry, ethylene glycol is mainly used to produce polyester fibers (polyester), and it is also used in the production of polyester films.​

4.2 Antifreeze and Deicing Agent​

Ethylene glycol has a freezing point of -13 °C and can be miscible with water in any proportion. The freezing point of its aqueous solution decreases with the increase of ethylene glycol concentration, and the boiling point increases. When the ethylene glycol concentration is 66%, the lowest freezing point is -68 °C. Due to its low specific heat capacity and heat transfer efficiency, it is used as an antifreeze and deicing agent for aircraft, automobiles, and instruments. Most of the antifreeze on the market is water - based antifreeze containing ethylene glycol.​

4.3 Hydrate Inhibitor​

In the process of natural gas mining and storage and transportation, natural gas hydrates often cause blockages in pipelines, valves, and equipment, affecting the normal operation of natural gas mining, gathering, transportation, and processing. Ethylene glycol can be used as a hydrate inhibitor for natural gas. It can remove water and inhibit the formation of natural gas hydrates by changing the thermodynamic equilibrium of natural gas molecules and water molecules and reducing the formation temperature of natural gas hydrates. Ethylene glycol is non - toxic, has a high boiling point, small evaporation loss, and a low freezing point of its aqueous solution, making it suitable for occasions with a large amount of natural gas treatment and can be reused after purification.​

4.4 Fuel Cell​

Ethylene glycol can be used as a new type of liquid fuel in the development of fuel cells. Under standard conditions, the Gibbs free energy of ethylene glycol is -1181 kJ/mol, the specific energy is 5.27 kW/h·kg, and the theoretical efficiency of the battery is 98.9%. It has a high theoretical capacity (4.8 Ah/m·L) and a high boiling point.​

5. Safety Information​

Ethylene glycol is of low toxicity, but it can produce toxic metabolites in the human body. Even a small amount of intake can cause irreversible damage to the human central nervous system and various organs. When using ethylene glycol, avoid contact with the skin and eyes. In case of accidental contact, rinse immediately with plenty of water. Keep it away from open flames, high heat, and oxidizing agents to prevent the risk of combustion and explosion.​

6. Packaging and Storage​

  • Packaging: Usually packaged in galvanized iron drums, with each drum containing 100 Kg or 200 Kg. For large - scale transportation, it can be transported in railway tank cars or ship cabins made of aluminum or stainless steel, and should be marked as "MEG special".​
  • Storage: Should be stored in a sealed manner. For long - term storage, nitrogen sealing, moisture prevention, fire prevention, and freezing prevention measures should be taken. Store in a cool, ventilated warehouse, away from fire and heat sources.​