Diethylene glycol is derived as a co-product with ethylene glycol (MEG) and triethylene glycol. The industry generally operates to maximize MEG production. Ethylene glycol is by far the largest volume of the glycol products in a variety of applications. Availability of DEG will depend on demand for derivatives of the primary product, ethylene glycol, rather than on DEG market requirements.
DEG is produced by the partial hydrolysis of ethylene oxide. Depending on the conditions, varying amounts of DEG and related glycols are produced. The resulting product is two ethylene glycol molecules joined by an ether bond.
Specifications of DEG
The hydroxyl groups on glycols undergo alcohol chemistry, thus providing opportunities for production of a wide variety of derivatives. Hydroxyls can be converted to aldehydes, alkyl halides, amines, azides, carboxylic acids, ethers, mercaptans, nitrate esters, nitriles, nitrite esters, organic esters, peroxides, phosphate esters and sulfate esters.
|Property (Unit)||Typical Value|
|Apprearance||Essentially free of suspended matter|
|Diethylene glycol, wt. % max.||100.0|
|Color ( APHA ) max.||8|
|Acidity [ as acetic acid ], wt. % max.||0.005|
|Chlorides ( as CI ), ppm max.||0.1|
|Iron, ppm max.||0.10|
|Water, wt. % max.||0.10|
|Water solubility at 25°C||Miscible in all proportions|
|Boiling point at 760 mm Hg, °C||245.3|
|Freezing point, °C||-9|
|Flash point ( PMCC ), °C||154|
|Specific gravity at 20/20 °C||1.1182|
|Specific heat at 20 °C, cal/g/ °C||0.56|
|Absolute viscosity at 20 °C, cP||35.7|
|Refractive index at 20 °C||1.4472|
|Autoignition Temperature °C||364|
|Critical Pressure Kpa||4.605|
|Dielectric Constant at 25°C||31.69|