C4 to C30+ Linear Alpha Olefins Production

The process under analysis comprises four major sections: (1) Ethylene Oligomerization; (2) Transalkylation; (3) Product Treatment; and (4) Product Fractionation.

Ethylene Oligomerization. Fresh ethylene feed and unreacted ethylene recovered downstream are compressed in a multi-stage centrifugal compressor. The compressed ethylene stream is then fed to the Oligomerization Reactor, along with a trialkyl aluminum catalyst solution. The ethylene is rapidly dissolved in this solution, and the oligomerization proceeds rapidly.

Transalkylation. The, effluent of the oligomerization is subjected to a transalkylation reaction, using a nickel octanoate catalyst solution, that promotes the transalkylation of all residual trialkyl aluminum compounds from the oligomerization to triethylaluminum.

Product Treatment. The effluent stream from the Transalkylation Reactor undergoes a High-Pressure Flash to separate the linear olefins from unreacted ethylene gas, which is recycled to the compressor upstream. The linear olefins-rich stream is routed to Catalyst Deactivation, where it is washed with a caustic soda solution to hydrolyze the triethylaluminum. The bottom stream from this wash is fed to a decanter to separate an aqueous phase from an organic phase, containing all linear alpha olefins, which is then treated to remove impurities.

Product Fractionation. The treated alpha olefins process stream is sent to subsequent columns. Each column removes the lighest olefin remaining in the feed as an overhead stream, which is condensed and stored. The bottom stream from each column, containing heavier olefins, is routed to the next column.