The reaction of gaseous a-propylene chlorohydrin with Ca(OH)2 pellets in a fixed bed reactor was investigated at 160-250 Deg. A reaction model, which was derived on the basis of the reaction products propylene oxide, acetone, and propionaldehyde, is discussed. Reaction of the HCl formed is shown to be the rate detg. step over almost the entire temp. range investigated. A kinetic model for the variation of reaction rate with the duration of the expt. and with the amt. of converted solid reactant could be established which permits a quant. description of the exptl. results. It is also possible with this model to give a qual. explanation of the observed changes in selectivity with reaction time regarding the above mentioned products. [on SciFinder (R)]