MEG, by far the largest volume glycol, is produced by the direct hydration of ethylene oxide (EO). Smaller amounts of DEG and TEG are co-produced in this process, although additional quantities of DEG and TEG can be produced by further reacting MEG with additional EO.
The three ethylene glycols are colourless, essentially odourless stable liquids with low viscosities and high boiling points and have many similar chemical properties. Differences in their applications are due mainly to variations in physical properties such as viscosity, hygroscopicity and boiling point.
Glycols are widely used in industry because of their high boiling points, hygroscopicity, non-corrosiveness, freeze point depression, lubricating, plasticising and solvent properties. Additionally, their ease of chemical reaction, due to their alcohol end groups, makes them popular intermediates in the formation of numerous esters.
Most MEG is reacted with para-terephthalic acid (PTA) to produce polyester fibres for textiles and garments and polyethylene terephthalate (PET) plastics for food and drink packaging. Engine coolant in automobile antifreeze is another smaller but important application area, while the excellent humectant (hygroscopicity) property of MEG also makes it ideal for use in fibres treatment, paper, adhesives, printing inks, leather and cellophane films.
The exacting requirements of the polyester fibre market demand high purity MEG and a specific fibre-grade glycol is made for this purpose. Other applications are served by an industrial grade.
DEG is used in the manufacture of unsaturated polyester resins, polyurethanes and plasticisers. Other uses for DEG depend largely on its hygroscopic properties. In natural gas processing, DEG serves as a dehydration agent. It is also used in the treatment of corks, glue, paper and cellophane films.
The main uses for TEG depend upon its hygroscopic properties. It is employed as a liquid desiccant for the dehydration of natural gas and as a dehumidifier in air conditioning systems. TEG also finds use as a vinyl plasticiser, as an intermediate in the manufacture of polyester resins and polyols, and as a solvent in many miscellaneous applications.
Our key strengths in ethylene glycols
- World scale plants in key markets around the world
- Leading position in ethylene oxide/glycol process technology
- Global logistics capability