Process to make alpha olefins from ethanol

摘要

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/Al of at least about 100, a dealuminated crystalline silicate, and a phosphorus modified zeolite.

主权项

1. A process to make alpha olefins comprising:
a) providing a dehydration zone containing a dehydration catalyst, b) introducing a feedstock comprising ethanol, water, and an inert component into said dehydration zone and into contact with said dehydration catalyst, c) operating said dehydration zone at conditions effective to dehydrate at least a portion of the ethanol to an effluent consisting essentially of ethylene, water, unconverted ethanol if any, and the inert component, d) introducing said effluent into a first fractionation zone to recover an ethylene stream, e) introducing said ethylene stream into an oligomerization zone containing an oligomerization catalyst and into contact with said oligomerization catalyst, f) operating said oligomerization zone at conditions effective to produce an effluent consisting essentially of 1-butene, 1-hexene, heavier alpha olefins having 8 carbons or more, and unconverted ethylene if any, g) introducing the effluent from step h) into a second fractionation zone to recover a stream consisting essentially of 1-butene, a stream consisting essentially of 1-hexene, a stream consisting essentially of heavier alpha olefins having 8 carbons or more and a stream consisting essentially of ethylene, h) combining the 1-hexene and at least one heavier alpha olefin having 8 carbons or more recovered at step g) and isomerizing the combined stream to produce an internal olefin and i) converting the effluent recovered at step h) by metathesis with the ethylene into different alpha-olefins with an even or odd number of carbons.