Dehydration. Isopropyl alcohol can be dehydrated by combining with hydroxyl groups to produce isopropylene. The reaction needs to be carried out at a certain temperature and under the action of catalyst. In this process, the hydrogen atom on the hydroxyl group is removed, and at the same time, the hydroxyl group and isopropyl group on the isopropanol molecule combine to form a C=C double bond, resulting in isopropylene.