Paraffins, Iso-Paraffins, Naphthenes and Aromatics (PINA) in Hydrocarbon Streams

Significance of the Topic

Spark ignition fuels are complex mixtures whose performance and emissions characteristics depend on their detailed hydrocarbon composition. Accurate quantification of paraffins, iso-paraffins, naphthenes and aromatics (PINA) by carbon number is critical for quality control, regulatory compliance and optimizing engine performance.

Objectives and Overview of the Study

This application note presents a multi-dimensional gas chromatography (GC) approach to quantify PINA compounds in spark ignition fuels using the Bruker PIONA+ Analyzer. The goals are to demonstrate method flexibility, separation efficiency and generation of comprehensive mass and volume percent profiles according to industry standard protocols.

Methodology and Instrumentation

The analysis employs a Bruker PIONA+ Analyzer configured with:

• Multi-dimensional GC setup combining a polar OV-275 column with a non-polar column
• CompassCDS chromatography software enhanced by the PIONA+ plug-in for automated data processing

Elution is controlled via timed fraction transfers and back-flushing steps to achieve clear separation of:

• Normal and iso-paraffins
• Naphthenes (cyclic paraffins)
• Aromatics

The system operates in predefined time windows, isolating fractions (e.g., C1–C12, C6–C8) and directing them to appropriate columns for further resolution.

Main Results and Discussion

Calibration sample analysis yielded well-resolved chromatographic groupings, enabling precise integration and quantification. The PIONA+ software automatically generated:

• Weight percent profiles by carbon number and compound class
• Volume percent profiles by carbon number and compound class

For a reformer feed sample (C6–C11 hydrocarbons), similar weight and volume percent reports were produced, summarizing group totals and individual carbon-number contributions in a single overview.

Benefits and Practical Applications of the Method

The described GC method offers:

• Robust separation of closely eluting hydrocarbon classes
• Automated reporting for fast turnaround in QA/QC laboratories
• Flexibility to adjust time windows for different fuel streams
• Compliance with industry standards for fuel composition analysis

Future Trends and Applications

Potential developments include:

• Integration of high-resolution mass spectrometry for compound confirmation
• Expansion of carbon-number range to cover heavier fractions and biofuel blends
• Real-time process monitoring via on-line GC sampling systems
• Advanced software algorithms leveraging machine learning for peak deconvolution

Conclusion

The Bruker PIONA+ Analyzer delivers comprehensive, reproducible quantification of paraffins, iso-paraffins, naphthenes and aromatics in spark ignition fuels. Its multi-dimensional GC approach, coupled with dedicated software, ensures clear group separation, efficient data processing and detailed mass/volume percent profiling.

Reference

Bruker Daltonics. Application Note #CA-270380, 2013. PINA Analysis in Hydrocarbon Streams using the PIONA+ Analyzer.