An alternative to steam cracking to crack straight run feeds such as light and full-range naphthas to produce greater quantities of propylene and total light olefins, but with much higher propylene/ethylene (P/E) ratio of 1.0.
The most predominant feed used to produce ethylene today is naphtha, as more than half of the world’s ethylene is currently derived from cracking naphtha feed. The Advanced Catalytic Olefins (ACO) process is an alternative process that catalytically converts naphtha feed and is thus able to produce higher ultimate yields of light olefins (propylene plus ethylene) and at a higher P/E production ratio relative to steam cracking, typically about 1:1.
ACO is a process co-developed by KBR and SK Energy in Korea and offered for license worldwide exclusively by KBR. SK Energy developed and patented the catalyst used in the process, which is geared specifically to cracking paraffinic streams such as naphthas and condensate. The fluidized reactor system is designed by KBR and is similar to a refinery
fluid catalytic cracking (FCC) unit consisting of a fluidized reactor/regenerator vessel, air compression, catalyst handling, flue-gas handling and feed and effluent heat recovery. Use of a catalytic system to crack the feed allows operating at much less severe conditions relative to a cracking furnace, and the system uses less fuel, meaning that the CO2 footprint is reduced.
The ACO recovery section is very similar to KBR’s ethylene plant recovery section design and is capable of production of polymer-grade olefins. Proprietary know-how is included to remove specific contaminants in the ACO process gas resulting from the FCC-type cracking process.
Yields: Light olefins yields are greater than in a steam cracker, and the P/E ratio is about 1:1 as opposed to 0.5. Fig. 2 is a comparison of steam cracker and ACO ultimate yields for a typical naphtha.
Energy: Fuel consumption is lower for the ACO process relative to a steam cracker. However, steam import is higher since there is less waste heat available for recovery. Overall cost of production is approximately US$90/ton ethylene lower for ACO due to the improved product slate.
Licensor: Kellogg Brown & Root LLC