INEOS Technologies is offering a slurry high-density polyethylene (HDPE) process (INNOVENE S) for license. This technology is based on a process developed by Solvay. The technology was used by the BP/Solvay joint venture in 2002 and acquired by BP when they bought out Solvay’s share of their joint venture company in early 2005. It became part of INEOS’s portfolio through its acquisition of Innovene at the end of 2005. INNOVENE S is now the most successful HDPE technology in the market with more than 2.3 million metric tons sold since this entry in the licensing arena.
The INNOVENE S process utilizes a proprietary vertical slurry-loop reactor, as shown in the flow diagram. Two reactors are used for bimodal capability. Isobutane is normally used as the hydrocarbon diluent in the process, although hexane may be used as an alternative. The diluent is used as a catalyst carrier and as the polymerization reactor suspension and heat transfer medium. Hexene-1 and/or butene-1 can be used as a comonomer. Hydrogen is used for molecular weight control when using the Zieglerg catalyst platform. Titaniumbased and chromium-based catalysts are both used.
The polymerization reactor is made of large diameter pipes assembled in a long vertical loop configuration. Early designs consisted of four- or six-leg loops. The reactor walls are made of carbon steel and are equipped with water jackets to control temperature in the isothermal reactor. Ethylene is polymerized under a total pressure of about 25 bars to 40 bars and at a temperature between 75°C and 110°C (167°F and 230°F). The recycle diluent, fresh monomer, comonomer, hydrogen, catalyst and co-catalyst (when required), are fed to the reactor. Polyethylene is formed as discrete particles in a rapidly circulating diluentpolymer slurry. On average, 98% of the ethylene is polymerized.
The concentrated withdrawn polymer slurry is flashed to separate the powder from the diluent and unreacted monomers. The polymer flows from the bottom of the flash tank, with the condensed overheads being recycled directly to the reaction system. Residual hydrocarbons are removed from the polymer using a countercurrent nitrogen purge flow. The polymer is then pneumatically transferred to either the extruder feed tank or storage silos.
Product coverage: INNOVENE S technology is capable of producing a full MDPE/HDPE product coverage with Ziegler or chromium catalyst, using monomodal and bimodal configuration with market leading products such PE100.
High added-value products, in addition to the lowest investment and operational costs allow INNOVENE S technology to make a winning MDPE/HDPE business.
Process advantages:
• Low investment costs (low equipment count)
• Operating costs
• Proven two-reactor bimodal technology
• High onstream times with no reactor fouling or cleaning
• No wax generation and no oligomers
• Safe and environmentally clean operation
Product advantages:
• Broad MDPE and HDPE product range based
• Monomodal and biomodal capability
• Chromium and Ziegler product coverage with demonstrated catalyst transitions
• Easy product transitions
• Proprietary technology to achieve outstanding bimodal products Properties
Licensor: INEOS Technologies
