| 摘要 |
<p>Prod. of propylene oxide from propylene chlorohydrin. M4-. Comprises reaction of aqueous solution of propylene chlorohydrin (contaminated with HCl and dichloropropane) with lime-water at atmospheric pressure and elevated temperature in a column (pref. bubble-cap of 5-10 plates) with heated input, containing a reaction zone and a concentration zone, above it, the column-head being heated to 78-96 degrees C, pref. 88-93 degrees C i.e. between B.pts. of azeotropes of dichloropropane/water (78 degrees C) and propylenechlorohydrin/water (96 degrees C). Mean time in reaction-zone 2-5 minutes. This procedure gives higher yield of purer product and uses less steam for heating than present methods.</p> |
