Hydrocarbons, C1 – C4 - Analysis of impurities in 1,2,-butadiene

Importance of the Topic

Analysis of C1–C4 hydrocarbon impurities in 1,2-butadiene is critical for industrial quality control and safety. 1,2-butadiene is widely used as a monomer in polymer production and as a chemical intermediate, where trace contaminants can affect product performance, catalyst life, and operational safety.

Objectives and Study Overview

The purpose of this study was to establish a rapid, reliable gas chromatographic method capable of separating and quantifying 16 light hydrocarbon impurities (C1–C4) in 1,2-butadiene within a 20-minute analysis time.

Methodology

Separation was performed on a fused-silica capillary column coated with Al2O3/Na2SO4. Key parameters included:

• Column: 0.32 mm i.d. × 50 m, film thickness 5 µm
• Isothermal oven temperature: 110 °C
• Carrier gas: nitrogen at 110 kPa (1.1 bar)
• Injector: split mode, 20 mL/min, 150 °C
• Detector: flame ionization detector at 200 °C
• Sample volume: 100 µL; concentration range: 5–1000 ppm

Instrumentation Used

• Gas chromatograph with CP-Al2O3/Na2SO4 WCOT column (Agilent CP7565)
• Split injector assembly
• Flame ionization detector (FID)

Main Results and Discussion

The method achieved baseline separation of all 16 target compounds—including methane, ethane, ethylene, various C3 and C4 alkanes, alkenes, cycloalkanes, and dienes—within 20 minutes. The calibration was linear across 5–1000 ppm, demonstrating high sensitivity and reproducibility. Structurally similar isomers, such as cis- and trans-2-butene, were clearly resolved.

Benefits and Practical Applications

This GC-FID approach provides a fast, robust, and sensitive tool for routine quality assurance and process monitoring in petrochemical and polymer manufacturing. Precise quantitation of light hydrocarbon impurities enhances product purity assessment and helps maintain safety standards.

Future Trends and Opportunities

• Coupling with mass spectrometry for improved selectivity and identification of unknowns
• Development of temperature-programmed or faster columns to reduce analysis time further
• Miniaturized or portable GC systems for field or on-line monitoring
• Integration of automation and advanced data analytics for real-time quality control

Conclusion

The described gas chromatographic method offers a comprehensive, efficient, and reproducible solution for the analysis of C1–C4 impurities in 1,2-butadiene, supporting stringent quality control and safety requirements.