TECHNOLOGY FOR THE PRODUCTION OF PROPYLENE OXIDE
PROCESS FEATURES
The CONSER propylene oxide process is based on the chlorohydrination route using propylene, chlorine and milk of lime as feedstocks.
This route may be considered the most economic for plants of average capacity and in all cases where the massive production of co-products (e.g. styrene), as required by other technologies, is not justified.
Being a leader in design of chlorohydrination plants, CONSER is in position to offer a valid and modern propylene oxide technology, characterized by improved efficiencies, easy, safe and reliable operation and very high purity of the product (greater than 99.9%).
REFERENCES
(1) Revamping
Location SIR Italy MONTEDISON Italy TECHCORP Iraq MONTEDISON Italy
PROCESS DESCRIPTION
The propylene oxide technology of CONSER consists of the following main steps:
Chlorohydrination
Dehydrochlorination
Propylene oxide purificationChlorohydrination
Propylene, chlorine and water are fed to the chlorohydrin reactor, where the following main reaction occurs:
C3H6 + Cl2 + H2O ----> C3H6Cl -OH + HCl
(Chlorohydrin)
Other side or subsequent reactions are the following:
C3H6 + Cl2 ----> C3H6Cl2
(Propylene dichloride)
C3H6 + Cl2 + C3H6Cl-OH ----> ClC3H6-O-C3H6Cl
(Dichloroisopropylether)
Dehydrochlorination
The chlorohydrin solution is treated with milk of lime to produce propylene oxide, according to the following reaction:
C3H6Cl-OH + HCl + Ca(OH)2 ----> C3H6O + 2H2O + CaCl2
(Chlorohydrin) (Propylene oxide)
The reaction is accomplished in a distillation tower where propylene oxide is stripped by live steam injected to the bottom of the tower.
Waste water is taken off from the bottom of the stripper, while a raw propylene oxide stream is separated overhead.
Purification
Crude propylene oxide is purified in a distillation section.
By-products can be disposed to an incinerator, or distilled to recover a good quality solvent.