PEP Review 77-1-1
Propylene Oxide from Propylene Glycol Monoacetate
Published: January 1978
Propylene oxide can be made by pyrolysis of propylene glycol monoacetate. The problem with this process is that the monoacetate as produced from propylene, acetic acid, and oxygen always contains propylene glycol diacetate and propylene glycol, which are difficult to separate from the monoacetate because of the proximity of the respective boiling points. A recent Chem systems patent claims that the diacetate and propylene glycol are almost inert during pyrolysis when they are mixed with the monoacetate. Furthermore, the accumulation of the diacetate in this system can be prevented by hydrolysis. The selectivity of monoacetate to propylene oxide also can be improved by reducing the monoacetate partial pressure in the reaction mixture.
Evaluation of the process based on these claims shows that this process may be developed to become competitive with the isobutane process with recycle, but not with other commercial processes.