C2 hydrocarbons - Analysis of light hydrocarbons

Significance of the Topic

• Light C2 hydrocarbons such as ethylene, ethane and acetylene are key feedstocks and environmental indicators in petrochemical and fuel industries.
• Reliable separation and quantification of these isomers under varying moisture conditions is essential for process control, quality assurance and regulatory compliance.

Objectives and Study Overview

The application note demonstrates the capabilities of a novel bonded porous polymer column for achieving baseline separation of C2 hydrocarbon isomers. The work highlights its performance under isothermal, moisture-rich conditions relevant to routine industrial and laboratory analyses.

Methodology

Analyses were performed using gas chromatography in capillary mode. Gas samples at percentage‐level concentrations were injected in split mode. The column was operated isothermally at 30 °C with helium carrier gas at 50 kPa. Both injector and detector zones were maintained at 250 °C, and a pulsed discharge detector in HeD mode D-4-1 was used for detection.

Instrumentation Used

• GC-capillary system
• Agilent PoraBOND U column (0.32 mm × 25 m, 7 μm porous polymer)
• Helium carrier gas at 0.5 bar (7 psi)
• Split injector at 250 °C
• Pulsed discharge detector (HeD mode D-4-1) at 250 °C

Key Results and Discussion

The PoraBOND U column delivered baseline resolution of ethylene, ethane and acetylene at a low isothermal temperature of 30 °C. Moisture presence did not affect retention, confirming the column’s inert and hydrophobic nature. Retention stability was observed even at elevated temperatures up to 300 °C with minimal bleed. Peak identification included ambient air and CO₂ as matrix components, followed by the three target hydrocarbons.

Benefits and Practical Applications

• Direct analysis of humid gas samples without the need for moisture removal.
• Isothermal, low-temperature operation reduces energy consumption and thermal degradation risks.
• High stability and low bleed support extended column life and consistent performance in QA/QC, petrochemical and environmental laboratories.

Future Trends and Applications

Emerging directions include coupling the PoraBOND U column with mass spectrometry for enhanced selectivity and quantitation, deployment in portable micro-GC systems for in-field monitoring, and integration into automated process control platforms. Continued material innovation could broaden its applicability to higher hydrocarbons and diverse volatile organic compounds.

Conclusion

The Agilent PoraBOND U porous polymer column offers a robust and moisture-tolerant solution for precise separation of C2 hydrocarbons under isothermal conditions. Its combination of stability, inertness and low bleed makes it well suited for routine use in industrial, environmental and research settings.