Ethylene glycol, also known as "ethylene glycol" and "1, 2- ethylene glycol", is abbreviated as EG, and its chemical formula is (CH2OH)2, which is the simplest diol. Ethylene glycol is a colorless and odorless sweet liquid, which is toxic to animals. The lethal dose to human is about 1.6g/kg. Ethylene glycol is soluble in water and acetone, but insoluble in ether. Used as solvent, antifreeze and raw material for synthetic polyester. Polyethylene glycol (PEG) is a polymer of ethylene glycol, a phase transfer catalyst and also used for cell fusion. Its nitrate ester is an explosive.

2. Physical properties

Colorless, sweet and viscous liquid.

Vapor pressure: 0.06 mm Hg (0.06 mm Hg) /20℃

Viscosity: 25.66 MPa sec (16℃) [2]

Solubility: miscible with water/ethanol/acetone/glyceropyridine acetate, slightly soluble in ether, insoluble in petroleum hydrocarbons and oils, soluble in inorganic substances.

3. Chemical properties

Because of its low molecular weight and active properties, it can react with esterification, etherification, alcoholization, oxidation, acetalization and dehydration.

Figure 1 Structure of Ethylene Glycol

Similar to ethanol, it can mainly react with inorganic or organic acids to form esters. Generally, only one hydroxyl group reacts first, then the temperature is raised and the amount of acid is increased, and both hydroxyl groups can form esters.

Ethylene glycol is mainly used to make polyester, so its industry belongs to a part of the polyester industrial chain, and ethylene glycol mainly belongs to the upstream petrochemical industry of the polyester industrial chain. Of course, with the development of domestic coal chemical industry, coal-based ethylene glycol has also begun to enter the polyester market. According to incomplete statistics, the proportion of coal-based ethylene glycol used in polyester industry at present is 25-30%. The polyester industry is mainly fiber and bottle chips, and its terminal applications are mainly textiles and clothing, beverages and sheets, which are closely related to basic needs such as food, clothing, housing and transportation. So the periodicity of the two is not obvious, and the demand for ethylene glycol is relatively stable.

Figure 2 Schematic diagram of polyester industrial chain

2. Production technology and distribution of ethylene glycol

At present, the main synthetic routes of ethylene glycol can be divided into two types, one is ethylene route, and the other is oxalate route. Ethylene route: generally divided into ethane route ethylene glycol and naphtha route ethylene glycol according to gas head ethylene and oil head ethylene; Oxalate route: Because carbon monoxide in coal is needed as the main raw material, it is mainly the coal head route. Judging from the current global commercialization route, ethylene glycol synthesis process can be divided into three categories: coal head, gas head and oil head according to the main raw materials used. Among them, oil accounts for a large proportion, represented by the United States and Canada, and the output of 20 17 naphtha accounts for 67%; Gas heads mainly come from Middle Eastern countries, relying on rich natural gas resources, accounting for 27%. Coal head is mainly located in China, accounting for 6% at present. However, with the improvement of technology, new production capacity is constantly being released.

Fig. 3 Main production process of ethylene glycol

Figure 4 Source Distribution of Production Process

Geographically, by 20 16, the world's major ethylene glycol production capacity will also be concentrated in Asia, the Middle East and North America, in which Asia accounts for185.57 million tons, accounting for 50%, North America for 4.98 million tons, accounting for 13%, and the Middle East for10.86 million tons.

The Middle East is mainly gas head, while North America and Asia are mainly oil head. The largest company in the world is Saudi SABIC Company, with 6.64 million tons of ethylene glycol production capacity, and its main devices are distributed in Saudi Arabia. Followed by Dow, Sinopec, Formosa Plastics and Shell. The top five enterprises account for 46% of the production capacity.

Fig. 5 Regional distribution of ethylene glycol production

3. Major ethylene glycol producers

Table 1 Top Five Ethylene Glycol Manufacturers in the World

From the perspective of production enterprises, the concentration of ethylene glycol industry is relatively high, and the top five manufacturers in the world account for 46% of the industry's production capacity, and manufacturers have strong bargaining power. Saudi Arabia's Schabik accounts for the largest proportion, accounting for 17% of the global production capacity according to the data of 20 17. Sinopec ranks third in the world with a production capacity of 3.24 million tons.