Analysis of Iso- and n-Paraffins, Naphthenes, Iso- and n-Olefins and Aromatics (PIONA) using Reformulyzer® M4

Importance of the Topic

Accurate and rapid determination of hydrocarbon group types in gasoline and naphtha streams is essential for refinery process control, blend optimization, regulatory compliance and engine performance. PIONA analysis—separating and quantifying iso- and n-paraffins, naphthenes, iso- and n-olefins and aromatics—provides critical compositional data for quality assurance and product specification.

Objectives and Study Overview

This application note presents the AC Analytical Controls Reformulyzer® M4, a fourth-generation system for PIONA analysis. The objectives are:

• Demonstrate compliance with EN ISO 22854 and ASTM D6839 methods.
• Illustrate the speed and precision of the Reformulyzer M4 in PIONA mode (55 minutes runtime).
• Report results from gravimetric blends and a certified reformate reference material.

Methodology and Instrumentation

The PIONA method uses a series of traps and columns under programmed temperature control and valve switching to fractionate hydrocarbons by class and carbon number. The flow path includes:

• A polar capillary column to separate paraffins and naphthenes from aromatics.
• Olefin and 5Å molecular-sieve traps to capture olefins and n-paraffins.
• A 13X column for carbon-number distribution of saturates and olefins.
• Boiling-point columns and additional traps for two aromatic fractions (C6–C8, C8–C10) and n-olefin analysis.

Used Instrumentation

• Reformulyzer M4 system with capillary and micropacked trap modules
• Flame ionization detector (FID)
• Independent heater elements for traps and columns
• Carrier gases: hydrogen and nitrogen

Main Results and Discussion

Chromatograms of a gravimetric blend and a certified reformate sample show clear separation of saturates, naphthenes, olefins and aromatics. Weight-percent and volume-percent distributions by carbon number (C4–C11) are reported. Results for the reference material fall within specification limits, demonstrating method precision and accuracy.

Benefits and Practical Applications

The Reformulyzer M4 offers:

• High throughput: complete PIONA analysis in 55 minutes
• Full compliance with international standard methods
• Wide analytical range covering C4–C11 hydrocarbons and oxygenates
• Excellent precision and carbon-number resolution
• Streamlined workflow for refinery QC, blend control and regulatory reporting

Future Trends and Potential Applications

Emerging developments may include integration of mass spectrometric detection for isomer identification, advanced column chemistries for improved resolution of complex biofuels and oxygenates, automated data handling for remote monitoring, and expansion of the methodology to heavier streams or alternative fuels.

Conclusion

The AC Reformulyzer M4 delivers reliable, fast PIONA group-type analysis in full accordance with EN ISO 22854 and ASTM D6839. Its flexible trap-and-column configuration and short runtime make it an ideal tool for refinery quality control, blend optimization and compliance with product specifications.