Patent ID: 7378562
Filing Date: 2008-05-27
Classification: C07C,C10G,Y02P

Abstract:
1. A process for making a polyolefin product from an oxygenate feed stream, the process comprising the steps of: (a) contacting the oxygenate feed stream with a molecular sieve catalyst in an oxygenate-to-olefin reactor thereby producing a first olefin stream having olefins selected from the group comprising ethylene, propylene and mixtures thereof and byproducts selected from the group consisting of alkynes, dienes and mixtures thereof, wherein there is about 200 mppm or less of byproducts for every mole of olefins in the first product stream; (b) adding hydrogen to the first olefin stream, wherein the mole ratio of hydrogen to byproducts in the first product stream is about 1.05:1 or higher; (c) hydrogenating the byproducts in the first olefin stream the first olefin stream in the presence of a first hydrogenation catalyst producing a second olefin stream comprising prime olefins, second byproducts selected from the group consisting of alkynes, dienes and mixtures thereof, and unreacted hydrogen; (d) contacting the second byproducts in the second olefin stream with a second hydrogenation catalyst producing a third olefin stream, wherein the third olefin stream has about 10 mppm or less hydrogen based upon the composition of the third olefin stream; and (e) converting the prime olefins from the third olefin stream to the polyolefin product.