Technology

The ExxonMobil autoclave technology also exists with a tubular tail connected to the primary autoclave reactor. Therefore, a tubular tail unit is available in the list of units when such a tubular tail technology is designed.

Characteristics of the ExxonMobil high-pressure polymerisation of ethylene processes are:

• The tubular reactors operate at pressure up to 3,000 bar, whereas autoclave reactor operates below 2,000 bar.
• MI range: 0.2 – 150
• Density range: 0.912 – 0.935
• Reactor turn down ratio: 50%
• Short residence times
• Reactor conversion up to 40%
• Ability to switch from homo-polymers to copolymers
• Product from the tubular process is typically higher in molecular weight and has more short chain branches than LDPE from the autoclave process .
• Produce LDPE homo-polymers and ethylene vinyl acetate (EVA) copolymers

Source: Echem Enppi, Apr 2013, Polyethylene Production Technologies, via the Internet Archive.