Ethyleneglycol (also known as glycol or 1, 2 - ethyl glycol) is a significant basic organiccompound. It is the simplest and most commonly used dihydric alcohol, includingethylene glycol, diethylene glycol and triethylene glycol.
Ethyleneglycol is usually referred to as Mono Ethylene Glycol (MEG). It is an odorless,colorless, sweet-tasting syrup at room temperature and atmospheric pressure. Itis moderately toxic, with human lethal doseofabout 1.6 g/kg. It is low volatility, high lightning, easy to be preserved andtransported. The density is 1.11g/cm3, the melting point is -12.6 ℃, the boiling point is 197.2 ℃. Hygroscopicity of ethyleneglycol is higher than glycerol (glycerol). Ethylene glycol can be miscible withwater or acetone, can greatly reduce the freezing point of water, but thesolubility in ether is low.
Ethyleneglycol can participate in dehydration, esterification, oxidation,polymerization and other reactions, and is primarily used to produce polyesterfiber, unsaturated polyester resin, antifreezing agent, lubricant, plasticizer,softening agent, nonionic surfactant and explosive, etc. In addition, it canalso be used in coatings, photographic developer, brake fluid, ink and otherindustries. Polyethylene glycol (PEG), the polymer of ethylene glycol is a kindof phase transfer catalyst and also used for cell fusion. Its nitrate is anexplosive.
Atpresent, the annual output of ethylene glycol is nearly 30 million tons in theworld. Most of ethylene glycol production is through the method of usingethylene oxide reacting with water, and producing ethylene oxide (EO) at thesame time. So the production device is called EO/EG device. Nowadays, there are43 sets of EO/EG production equipments in China. In the ethylene industry, ethyleneglycol is the second important only next to polyethylene.
Afteryears of research and development in China, the production technology of coal toglycol has gradually matured. A new process for synthesizing ethylene glycol isdeveloped. The production process with coal as raw material, synthesis gas(carbon monoxide and hydrogen) were obtained through gasification,transformation, purification and separation and purification. In the process,oxalate is produced from carbon monoxide by catalytic coupling and refining,and ethylene glycol is obtained from the hydrogenation of it. At present, thesuccessful working and operation coal-made ethylene glycol production plants amountto 10 units in China, and about 30 sets will be put into operation in 2020. Thetechnical route has become another important source of ethylene glycol products.