TECHNOLOGY FOR THE PRODUCTION OF PROPYLENE GLYCOLS

PROCESS FEATURES

Propylene glycols are prepared by the liquid phase hydration of propylene oxide. The purity of the products is dependent on the grade of propylene oxide used.
CONSER’s integrated process produces propylene oxide of high purity and, consequently, the purest grades of propylene glycols at a competitive cost of production.

REFERENCES

Company	Location	Capacity T/y
SIR	Italy	10000
TECHCORP	Iraq	8000

PROCESS DESCRIPTION

The propylene oxide technology of CONSER consists of the following main steps:

Hydration
Concentration
Purification

Hydration

Propylene, oxide and water are fed to a plug flow reactor, where the following
reactions occurs:

C3H6O + H2O ----> C3H6(OH)2

(Propylene oxyde) (Monopropylene glyco)

C3H6(OH)2 + C3H6O ----> C3H6-O-C3H6(OH)2

(MPG) (PO) (Dipropylene glycol)

C3H6-O-C3H6(OH)2 + C3H6O ----> C3H6-O-C3H6-O-CH6(OH)2

(DPG) (PO) (Tripropylene glycol)

Further propylene oxide addition gives minor amounts of polypropylene glycols.

Concentration and purification

Mono, di and tri propylene glycols are first concentrated in a multiple effect evaporator where the excess water is recovered and recycled to the reaction section.
The glycols are finally recovered and purified in a distillation section.