Propylene Process by Kellogg Brown & Root LLC

To produce propylene and ethylene from low-value, light (C4 to C10) hydrocarbon olefins-containing streams from ethylene plants and refineries. Suitable feeds include C4/C5 streams from a steam cracker, light cat-cracker C4s and naphtha and coker gasolines.

Propylene

The SUPERFLEX process is a proprietary technology patented by ARCO Chemical Technology, Inc. (now LyondellBasell) and exclusively offered worldwide for license by KBR. It uses a fluidized catalytic reactor system with a proprietary catalyst to convert low-value feedstocks to predominantly propylene and ethylene products. The catalyst is very robust; thus, no feed pretreatment is required for typical contaminants such as sulfur, water, oxygenates or nitrogen. Attractive feedstocks include C4 and C5 olefin-rich streams from ethylene plants, FCC naphthas or C4s, thermally cracked naphthas from visbreakers or cokers, BTX or MTBE raffinates, C5 olefin-rich streams removed from motor gasolines, and Fischer-Tropsch light liquids.

The fluidized reactor system is similar to a refinery FCC unit and consists of a fluidized reactor/regenerator vessel, air compression, catalyst handling, flue-gas handling, and feed and effluent heat recovery. Using this reactor system with continuous catalyst regeneration allows higher operating temperatures than with competing fixed-bed reactors so that a substantial portion of the paraffins, as well as olefins, are converted. This allows for flexibility in the amounts of paraffins in the feeds to SUPERFLEX and the ability to recycle unconverted feed to extinction. Because this is a catalytic process, the CO2 footprint per ton of product is lower than conventional steam cracking.

The cooled reactor effluent can be processed for the ultimate production of polymer-grade olefins. Several design options are available, including fully dedicated recovery facilities; recovery in a nearby, existing ethylene plant recovery section to minimize capital investment; or processing in a partial recovery unit to recover recycle streams and concentrate olefin-rich streams for further processing in nearby plants. Depending on the final use of the ethylene byproduct, the recovery section costs may be reduced via use of an absorption process to produce dilute ethylene product rather than polymer grade.

Licensor: Kellogg Brown & Root LLC

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