摘要 |
<p>Olefinically unsaturated aliphatic or cycloaliphatic hydrocarbons are manufactured by bringing alkanecarboxylic acids of 3 to 20 carbon atoms, alkanedicarboxylic acids of 4 to 20 carbon atoms or 5-membered or 6-membered cycloalkanecarboxylic acids or their alkyl, cycloalkyl, aralkyl or phenyl esters, in the gas phase, at from 250 DEG to 800 DEG C., into contact with catalysts in which the active composition consists of boron trioxide, boric acid and/or boron nitride, together with one or more of the oxides of aluminum, silicon, tin, lead, titanium and zirconium.</p> |