One-Minute Natural Gas Analysis Using the Agilent 990 Micro GC Backflush-to-Detector Option

Importance of the Topic

Natural gas analysis is critical for quality control and process optimization in energy and chemical industries. Rapid, accurate determination of gas composition ensures compliance with regulatory standards and supports efficient resource management.

Objectives and Study Overview

This application note demonstrates a one-minute natural gas analysis using the Agilent 990 Micro GC with a backflush-to-detector (BF2D) option. The goal is to resolve C1 to C5 hydrocarbons individually while bundling C6+ components, achieving significant time savings without compromising data quality.

Methodology and Instrumentation

• Two-channel configuration:
  
  • Channel 1: 40 cm HayeSep A, 80 °C, helium carrier gas, 280 kPa
  • Channel 2: 8 m CP-Sil 5CB with BF2D, 72 °C, helium, 150 kPa, 7 s backflush
• Sample: Simulated natural gas containing N₂, O₂, CO₂, and hydrocarbons C1–C9
• Detection: Thermal Conductivity Detector (TCD) with real-time inversion of negative peaks for C6+ bundle

Used Instrumentation

• Agilent 990 Micro GC platform
• OpenLab CDS and ChemStation software for BF2D control and data analysis

Main Results and Discussion

Channel 1 achieved baseline separation of air, methane, carbon dioxide, ethane, and propane within one minute, with propane eluting at 53 s. Channel 2 resolved C3–C5 hydrocarbons and produced a bundled C6+ peak detected via backflush. Total analysis time remained under 60 s. Repeatability over 20 injections showed retention time RSDs below 0.1 % and area RSDs between 0.1 % and 3.1 %, confirming method reliability. Compared to the standard NGA A extended analyzer (75 s), the BF2D solution delivered a 20 % faster analysis for heavier hydrocarbons.

Benefits and Practical Applications

• Rapid turnaround (<1 min) for natural gas quality control
• Efficient quantitation of C6+ components using a single response factor
• Enhanced laboratory throughput and reduced cycle times

Future Trends and Potential Applications

Further optimization of precolumn and backflush timing may allow even shorter run times. Integration with advanced data analytics and remote monitoring could enable decentralized, real-time gas analysis in distributed networks. Adaptation to other gas matrices (e.g., biogas, syngas) offers additional industrial applications.

Conclusion

The one-minute natural gas analysis method using Agilent 990 Micro GC with a BF2D channel provides reliable, fast separation and quantitation of key gas components. The approach enhances analytical throughput while maintaining high precision, making it suitable for modern energy and chemical industry requirements.

References

1. Zhang J. Fast Analysis of Natural Gas Using the Agilent 990 Micro GC Natural Gas Analyzer. Agilent Technologies Application Note 5994-1040EN, 2019.
2. Agilent Technologies. One-Minute NGA Analysis Based on a Backflush-to-Detector Channel. Application Note 5991-9401EN, 2018.