摘要 |
<p>The present invention relates to a process to make alpha olefins comprising: dehydrating ethanol to recover an ethylene stream, introducing said ethylene stream into an oligomerization zone containing an oligomerization catalyst and into contact with said oligomerization catalyst, operating said oligomerization zone at conditions effective to produce an effluent consisting essentially of 1-butene, 1-hexene, optionally heavier alpha olefins and unconverted ethylene if any, introducing the above effluent into a fractionation zone to recover a stream consisting essentially of 1-butene, a stream consisting essentially of 1-hexene, optionally a stream consisting essentially of heavier alpha olefins and an optional ethylene stream. In an advantageous embodiment the 1-hexene or at least one heavier alpha olefins, if any, are isomerized to an internal olefin and subsequently transformed by metathesis with the aid of additional ethylene into different alpha-olefins with even or odd number of carbons. By way of example 1-hexene is isomerized into 2-hexene and by methathesis with ethylene converted to 1-pentene and propylene. In another embodiment the oligomerization zone is only a dimerization zone and butene is produced. 1-butene is isomerized to 2-butene and sent to a methathesis zone in the presence of ethylene to be converted to propylene. In said embodiment the dehydration catalyst is selected in the group consisting of a crystalline silicate having a ratio Si/AI of at least about 100, a dealuminated crystalline silicate, and a phosphorus modified zeolite.</p> |