Hydrocarbons, C2 – C4 - Analysis of butenes in butane on an Agilent UltiMetal PLOT column

Importance of the Topic

Light olefins and paraffins in the C2–C4 range are fundamental feedstocks in petrochemical processes. Accurate analysis of butene isomers within butane streams is critical for process optimization, product quality control, and regulatory compliance.

Goals and Overview

This study demonstrates a rapid gas chromatographic method using an Agilent CP-Al2O3/Na2SO4 PLOT UltiMetal column to achieve baseline separation of light hydrocarbons, including all butene isomers, within a 22-minute run time.

Methodology

A GC-wide-bore technique was employed with a temperature program starting at 70 °C (5 min) rising to 170 °C at 10 °C/min. Nitrogen served as the carrier gas at 5 mL/min and 10 kPa. Injection was performed in split mode at 150 °C. Sample volumes of 100 µL covered concentration ranges from 50 ppm to 95% in gas form.

Used Instrumentation

• Agilent GC system equipped for wide-bore capillary columns
• CP-Al2O3/Na2SO4 PLOT UltiMetal column (0.53 mm × 50 m, df 10 µm)
• Split injector, 150 °C
• Flame ionization detector at 250 °C
• Nitrogen carrier gas flow 5 mL/min at 10 kPa

Main Results and Discussion

All C2–C4 hydrocarbons, including methane, ethane, ethylene, propane, cyclopropane, propene, isobutane, n-butane, dimethylcyclopropane, trans-2-butene, 1-butene, isobutene, cis-2-butene, 1,3-butadiene, and propyne, were baseline-resolved in under 22 minutes. Elevated column temperatures enhanced peak shapes and repeatability while maintaining selectivity among structurally similar isomers.

Benefits and Practical Applications

The method provides high throughput and reliable quality control for refinery and olefin plant operations. It enables precise monitoring of butene isomer distribution, supporting process adjustments and ensuring product conformity.

Future Trends and Possibilities

Emerging stationary phase coatings and advanced column designs may further shorten analysis time and improve resolution. Coupling with mass spectrometry detectors and automated sampling platforms could expand detection capabilities and streamline industrial analytics.

Conclusion

The Agilent PLOT UltiMetal GC-FID method offers a fast, robust solution for comprehensive C2–C4 hydrocarbon analysis in butane streams, meeting industrial demands for accuracy and efficiency.

References

No formal references were provided in the original document.