Analysis of Paraffins, Naphthenes and Aromatics (PNA) in Hydrocarbon Streams using Reformulyzer® M4

Importance of the Topic

Group-type analysis of hydrocarbons—paraffins, naphthenes and aromatics (PNA)—is fundamental for quality control, regulatory compliance and process optimization in petroleum refining and downstream applications. Rapid and reliable PNA profiling supports formulation of gasoline, bio-fuels and petrochemical feedstocks while meeting industry standards such as EN ISO 22854 and ASTM D6839.

Study Objectives and Overview

This application note demonstrates the capabilities of the 4th generation AC Analytical Controls Reformulyzer® M4 for PNA determination in hydrocarbon streams. The primary goals are:

• To achieve full compliance with EN ISO 22854 and ASTM D6839 methods.
• To shorten runtime and improve throughput for routine gasoline and blend analyses.
• To present performance data for certified reference materials (CRMs) and gravimetric blends.

Methodology and Instrumentation

The Reformulyzer M4 employs a combination of capillary and micropacked columns together with multiple traps and valve configurations. Key features include:

• Polar and boiling-point columns for sequential separation of saturates and aromatics.
• A 13X column for carbon number distribution of paraffins and naphthenes.
• Dedicated traps (olefin, A/E-trap, 5A) and backflush routines for detailed fractionation.
• Individual heater controls for simultaneous temperature programming of traps and columns.
• Analysis time of 25 minutes in PNA mode.

Key Results and Discussion

Analysis of a gravimetric blend and a reformer feed CRM demonstrated:

• Clear chromatographic separation among paraffins, naphthenes and aromatics.
• Accurate determination of Weight% and Volume% distributions by carbon number (C4–C11).
• Agreement with certified values: total weight and volume percentages of saturates (~49–52%), aromatics (~15–17%) and naphthenes (~33%).

Table 1 from the application note ranks multiple analysis modes versus hydrocarbon stream types, confirming versatility across naphthas, reformates, FCC streams and gasoline blends.

Benefits and Practical Applications

The Reformulyzer M4 offers:

• High throughput—25-minute runtime reduces bottlenecks in QC labs.
• Full compliance with international PNA group-type standards.
• Robust performance across diverse feedstocks and gasoline blends (including oxygenated fuels like E10–E85).
• Detailed carbon number profiles to guide refining and blending decisions.

Future Trends and Potential Applications

Ongoing developments in hydrocarbon analysis include integration with advanced data analytics and real-time monitoring. Potential directions:

• Automated sample handling and on-line process control for continuous PNA monitoring.
• Coupling with mass spectrometry or alternative detectors to enhance compound identification.
• Adaptation to bio-derived feedstocks and emerging renewable blends.

Conclusion

The AC Reformulyzer M4 delivers rapid, precise and standards-compliant PNA group-type analysis for a wide range of hydrocarbon streams. Its modular design, fast runtime and robust separation capabilities make it an effective solution for refining labs, fuel producers and QA/QC environments.

References

• ASTM D6839: Standard Test Method for Separation and Quantitation of Saturates, Aromatics, and Polycyclic Aromatic Compounds in Middle Distillate Fuels by Supercritical Fluid Chromatography.
• EN ISO 22854: Petroleum products — Instrumental determination of PONA content — Separation and quantification of paraffins, olefins, naphthenes and aromatics by comprehensive two-dimensional gas chromatography.