C4 to C18+ Linear Alpha Olefins Production

The process under analysis comprises three major sections: (1) Ethylene Oligomerization; (2) Alpha Olefins Fractionation; and (3) Internal Olefins Formation and Fractionation.

Ethylene Oligomerization. Fresh ethylene and unreacted ethylene recovered downstream are compressed and fed, along with a catalyst mixture, to a plug-flow reactor, where oligomerization takes place. The reactor effluent is sent to Olefins Separation, where unreacted ethylene is recovered to the compressor upstream, and an alpha olefin stream is sent to the C4 Column downstream. Also, a stream is routed to Solvent Recovery, where solvent is removed and returned to the reactor.

Alpha Olefins Fractionation. The alpha olefins are sent to subsequent columns, starting at C4 Column. Each column removes the lightest olefin as an overhead stream, which is condensed and stored. The bottom stream from each column, containing heavier olefins, is routed to the next column. The overhead of the C4 Column is partially sent to storage, with the remainder being sent to Isomerization reactor downstream. The column bottom is sent to a section where a C20+ stream is obtained and sent to Isomerization reactor, and a C6+ is routed to C6 Column. In this section, 1-hexene, 1-octene, 1-decene, 1-dodecene and a mix of heavy alpha olefins are also obtained.

Internal Olefins Formation and Fractionation. The 1-butene stream from the C4 Column is mixed with a C20+ stream from upstream and fed to the Isomerization Reactor, where alpha olefins are converted into internal olefins. The isomerization products are sent to a Disproportionation reactor, where lower molecular weight olefins react with higher molecular weight olefins, yielding olefins of intermediate molecular weight which are routed to Heavy Ends Column. This column separates C15+ olefins, which are returned to isomerization, from C11-C14 olefins, which are routed to a splitter and divided in a C11/C12 and a C13/C14 streams, which are directed to storage.