Analysis of Iso- and n-Paraffins, Naphthenes and Aromatics (PIPNA) in Naphtha , Reformate and Reformer feeds using Reformulyzer® M4

Importance of the Topic

Group-type analysis of paraffins, naphthenes and aromatics is essential for petroleum refining, fuel quality control and compliance with international standards. Rapid and precise PIPNA (Paraffins, Iso-paraffins, Naphthenes, Aromatics) profiling supports process optimization, blend verification and ensures product specifications are met.

Objectives and Study Overview

This application note evaluates the performance of the AC Reformulyzer® M4 in PIPNA mode for naphtha, reformate and reformer feed streams. Key aims include:

• Assessing analysis speed and throughput
• Verifying compliance with EN ISO 22854 and ASTM D6839
• Demonstrating group separation quality and reporting capability

Methodology

The PIPNA method on the Reformulyzer M4 employs a sequence of capillary and micropacked columns plus selective traps. Samples undergo:

• Initial separation on a polar column to isolate saturates and aromatics
• 5Å molecular-sieve trap to retain n-paraffins
• 13X column to resolve carbon number distribution of saturates
• Boiling-point column analysis for two aromatic fractions

The total run time is 30 minutes, and multiple valve configurations enable simultaneous heating and cooling for maximum speed.

Used Instrumentation

The analysis was performed on the AC Reformulyzer® M4 equipped with:

• Polar capillary column and micropacked pre-column
• 5Å molecular-sieve trap for n-paraffins
• 13X micropacked column for saturate carbon distribution
• Boiling-point column for aromatic fractions
• A/E trap and olefin trap modules
• Flame ionization detector (FID)

Main Results and Discussion

Representative chromatograms of a gravimetric blend and a certified reformer feed CRM show clear separation of PIPNA groups. Quantitative results for the CRM fall within specified tolerances:

• Weight percent distributions: saturates (~32 %), iso-paraffins (~30 %), n-paraffins (~20 %), aromatics (~17 %)
• Volume percent distributions closely match weight profiles
• Carbon number breakdown (C4–C11) exhibits consistent group totals

The method delivers high precision and repeatability, meeting method criteria under EN ISO 22854 and ASTM D6839.

Benefits and Practical Applications

The Reformulyzer M4 PIPNA mode offers:

• Rapid turnaround (30 min) for high-throughput laboratories
• Accurate group-type data for naphtha, reformate and feed streams
• Regulatory compliance for fuel specifications
• Enhanced decision support for blending, process control and product release

Future Trends and Opportunities

Advances in group-type analysis may include:

• Integration with laboratory information management systems for automated data flow
• Enhanced detector technologies for trace component detection
• Expanded application to heavier fractions and bio-derived fuels
• Machine-learning algorithms for pattern recognition and predictive maintenance

Conclusion

The AC Reformulyzer® M4 delivers fast, reliable and compliant PIPNA analysis in 30 minutes, enabling refiners and laboratories to obtain detailed hydrocarbon group data across a wide range of gasoline-related streams.

References

• EN ISO 22854
• ASTM D6839
• ASTM D5443
• IP 566
• SH/T 0741
• GB/T 28768-2012