Hydrocarbons, C1 – C6 - Separation of light hydrocarbons on a medium polar porous polymer

Significance of the Topic

Gas chromatography separation of light hydrocarbons ranging from C1 to C6 is essential in energy, petrochemical, and environmental analysis. It enables accurate quantification of key gaseous components in natural gas, refinery streams, and air quality monitoring applications.

Objectives and Overview of the Study

This application note demonstrates the rapid separation of 21 light hydrocarbons using a medium-polar porous polymer GC column. The study aims to achieve baseline resolution within a 25-minute runtime and to illustrate the method's suitability for routine analysis.

Methodology

The method employs a wide-bore gas chromatography configuration with the following conditions:

• Column temperature held isothermally at 75 °C
• Carrier gas hydrogen at a linear velocity of 40 cm/s
• Direct injection of a 6 µL sample (0.1 % in nitrogen)
• Inject and detect at controlled temperatures to maintain consistent volatilization and detection

Instrumentation Used

• GC system configured for wide-bore operation
• Agilent PoraPLOT S porous polymer column (0.53 mm × 25 m, 20 µm film thickness)
• Flame ionization detector (FID) set at 150 °C
• Injector maintained at 100 °C for direct sample introduction

Main Results and Discussion

The method successfully resolved 21 light hydrocarbons, including methane, ethylene, propadiene, and neopentane, within a 25-minute run. Peak identification was achieved based on retention order. The medium-polar PLOT column provided sharp peaks and reliable separation of isomers such as cis-2-butene and trans-2-butene without coelution.

Benefits and Practical Applications of the Method

• Rapid analysis suitable for high-throughput laboratories
• Robust separation of C1 to C6 hydrocarbons and their isomers
• Minimal sample preparation with direct injection
• Applicability to natural gas quality control, refinery gas monitoring, and environmental testing

Future Trends and Potential Applications

Advancements may include coupling with mass spectrometry for confirmatory analysis, faster temperature programming techniques for even shorter runtimes, and integration into automated process control systems for real-time monitoring in industrial plants.

Conclusion

The described GC method using a medium-polar porous polymer column offers a fast, reliable, and efficient solution for the separation of light hydrocarbons from C1 to C6. Its strong resolution power and ease of use render it valuable for routine analyses in various sectors.