To produce the full range of polypropylene (PP), including homopolymer, random copolymer and impact copolymer PP, using the ExxonMobil PP Process.
Description: The ExxonMobil PP process utilizes series, bulk-liquid loop reactors (1) for the production of homopolymer and random copolymer PP, plus a gas phase reactor (2) in combination with the loop reactors to production impact copolymer PP. The use of series loop reactors allows the production of different products, as necessary, in each reactor to tailor the final product properties for specific end-use applications. Advancements in the design, chemistry and operation of the gas-phase reactor, in combination with ExxonMobil proprietary catalyst system technology, allows the production of impact copolymer PP with industry leading impact/stiffness balance properties with excellent operational reliability. Additionally, the design allows production of impact copolymer PP with a broad range of impact resistance, including very highimpact resistance grades in a single gas-phase reactor.
The ExxonMobil PP Process has been demonstrated to handle a wide range of supported catalyst solids, which permits the manufacturer to select a catalyst solid that delivers the optimum in product performance and economics.
A unique feature of the ExxonMobil PP Process is the monomer recovery system (3) that utilizes indirect heating and residence time to remove the remaining unreacted monomer without exposing the granules directly to a large steam flow. The result is no mixing of hydrocarbon and steam, which then requires additional equipment for separation
and recovery of the hydrocarbon. This approach lowers the capital investment as well as significantly reducing steam and electricity consumption vs. other PP technologies.
The ExxonMobil PP process lines are in operation using both chemical-grade and polymerization-grade propylene as feed. PP granules plus the final product additive package are finished in a twin screw extrusion system (4) including any post-reactor modification of the polymer molecular weight and molecular weight distribution required by the specific product application, typically referred to as controlled rheology (CR) technology.
Products: The ExxonMobil commercial grade slate covers a wide range of homopolymer, random copolymer and impact copolymer PP for volume and specialty applications. ExxonMobil PP products are known for their quality and lot-to-lot consistency. Key consumers of PP products consider ExxonMobil PP products to be the industry’s leader in many important applications including OPP film; nonwoven fiber; durable goods including automotive and appliance applications; consumer products; rigid packaging; and materials handling applications.
Licensor: ExxonMobil Chemical Technology Licensing LLC