Repsol YPF

All of them are obtained from a reaction between a water molecule and one (MPG), two (DPG) or three (TPG) molecules of propylene oxide, without using any additional solvent. At present, industrial production is carried out using propylene oxide, which reacts rapidly with water. At the reaction temperature (between 120 and 180 ºC) and without need for a catalyst, the three glycols are produced in differing proportions, proportions which vary according to the water/PO ration which feeds the reactor. The rest of the process consists of separating each of the glycols produced and the excess of added water, via successive distillations.

In general, the physical characteristics of the three glycols are similar: all are clear, transparent liquids, virtually odourless and low in volatility. They are hygroscopic, although this hygroscopic quality diminishes as molecular weight increases. They are totally soluble in water. In addition, all glycols have a strong capacity for dissolving many organic compounds, which enables them to be used as a vehicle for carrying aromas, colourings and so forth. All glycols have a molecule which possesses two hydroxyl groups. This means that although they are very stable products from the point of view of reactivity, in the right conditions they are capable of taking part in reactions typical of any other diol, for example, the reactions that form esters and ethers. For more information visit www.propylene-glycol.com

Repsol owns two plants in Spain, located at Puertollano and Tarragona, which have the following capacities:

Puertollano (t/year) Tarragona (t/year)
PG (MPG) 21,750 40,250
DPG 3,100 8,850
TPG 150 900

Both plants have received the UNE-EN ISO 9001-2000 quality management certification and the UNE-EN ISO 14001: 1996 environmental management certifications.