Olefins get cracking

UOP and Atofina have developed a new process for converting C4 to C8 olefins to propylene and ethylene.

Atofina started developing the technology in the mid-1990s and UOP joined the development in 2000. These activities included the successful operation of the technology in a demonstration unit, completion of the process design, and catalyst manufacturing development. The demonstration unit began operating in 1998 processing commercial feedstocks at Atofina's Antwerp, Belgium industrial facility. The unit includes feed pretreatment and internal recycle capabilities.

The Atofina /UOP Olefin Cracking Process was developed to use streams containing C4 to C8 olefins from steam crackers, FCC units (refineries) and methanol-to-olefins (MTO) units. When combined with a liquids steam cracker, the process increases propylene/ethylene ratios to help meet the growing gap between propylene demand and supply from conventional steam cracking plants.

For FCC units, the process uses FCC C4s and light gasoline streams to increase propylene and ethylene production while reducing the olefin content of gasoline streams with little or no loss of octane. When combined with an MTO unit, the process increases the yields of light olefins and reduces the amount of C4+ by-product.

The Atofina /UOP Olefin Cracking Process features fixed-bed reactors operating at temperatures between 500 and 600 degrees C and pressures between 1 to 5 barg.The process uses a proprietary zeolitic catalyst, which provides high yields of propylene. The catalyst allows the process design to minimise the reactor size and operating costs by operating at high space velocities and not requiring any diluent stream. A swing reactor system is used for catalyst regeneration.