Product

C₈ raffinate is the para-xylene depleted aromatic hydrocarbon stream recovered from xylene separation units, consisting primarily of a mixture of C₈ aromatic isomers that remain after the selective removal of para-xylene. This stream contains the non-adsorbed or rejected aromatic compounds from the para-xylene recovery process.

Key Characteristics and Composition

Primary Components:

• Meta-xylene (m-xylene): Typically 40-60% of the C8 raffinate composition
• Ortho-xylene (o-xylene): Generally 15-25% of the stream
• Ethylbenzene: Usually 15-25% of the composition
• Para-xylene (residual): Less than 1.0% and preferably less than 0.5% in properly operating systems

Physical Properties:

• Molecular formula: Mixture of C₈H₁₀ isomers
• Boiling range: Approximately 136-144°C (covering the boiling points of individual C8 aromatic isomers)
• Appearance: Clear, colorless liquid with aromatic odor
• Density: Similar to other C₈ aromatics, approximately 0.86-0.88 g/cm³

References

1. UOP, Capturing Opportunities in Para-Xylene Production
2. Justia Patents, Process and apparatus for para-xylene production
3. Google Patents, Apparatus for separating para-xylene from aromatics
4. GCC Patent Office, Process for producing para-xylene using simulated moving bed