Technology

History

In 1999, BP Chemicals acquired Amoco Chemicals and has since restructured its polypropylene and polyethylene businesses. As part of this restructuring, Amoco's and BP Chemicals'™ licensing businesses were combined. The polypropylene technology originally developed by Amoco was rebranded Innovene PP and was licensed by INEOS.

INEOS does no longer license its petrochemical and polymerisation technologies.

Reactor Technology and Process

The Innovene™ PP gas phase polymerization technology uses a horizontal stirred bed reactor (Fig. 1) operating at 2,200 kPa.

Figure 1 - Innovene PP Horizontal Stirred Bed Reactor^[3].

Ethylene is introduced into the liquid phase reactor where it is currently evaporating, which keeps the system cool. The unique reactor reportedly allows near plug flow (a linear flow of the propylene/polypropylene through the reactor, versus a random removal with recycling). The near plug flow, in turn, provides a much narrower molecular weight distribution than a back mixed reactor, as the residence time of each molecule is very nearly the same.

Process conditions are: 20-40 bar of pressure and 65°C reaction temperature. The catalyst employed is Ti/Mg/Ethylbenzoate + Tri-isobutyl aluminium. 

Only one reactor is used to produce homopolymers and random copolymers; two gas phase reactors in series are used to produce impact copolymers.

Figure 2 - Innovene™ PP Process Flow Diagram
1 - reactor, 2 - capacitor, 3 - pump for powder transport, 4 - impact reactor, 5 - separator of unreacted gas, 6 - deck for deactivation and separation of residual propylene directed to regeneration or to torch, 7 - extruder.

References

1. Townsend Solutions, 22^nd May 2016, Polypropylene: Technology Review.
2. Ketin, Sonja & Andrejic, Marko & Lutovac, Mitar & Biočanin, Rade. (2020). Future of technology of polymerization production (Polypropylene).
3. Sanath Kumar, An Overview of Polymer Plants at Dahej Petrochemical Complex, ONGC Petro additions Limited (OPaL), Uploaded on 2^nd May 2023 on Slideshare.