Fast Refinery Gas Analysis Using the Agilent 490 Micro GC QUAD

Importance of the Topic

Refinery gas streams vary widely in composition and pressure, demanding rapid and accurate analytical methods for process control, safety and product quality. High‐throughput gas analysis supports real‐time decision making in fluid coking, ethylene recovery, fuel gas management and environmental monitoring.

Objectives and Study Overview

This study demonstrates the capability of a portable four‐channel micro gas chromatograph to perform complete refinery gas analysis in approximately two minutes. The goal is to achieve precise quantification of permanent gases, C2–C4 hydrocarbons and heavier C5+ fractions with excellent repeatability and long‐term stability.

Methodology and Instrumentation

The instrument under evaluation is the Agilent 490 Micro GC QUAD, equipped with four parallel channels:

• Channel 1: CP‐Molsieve column for permanent gases (H₂, He, O₂, N₂, CH₄, CO).
• Channel 2: PoraPLOT U column for C2 hydrocarbons, CO₂ and H₂S.
• Channel 3: Aluminum oxide column with in‐line filters for C3 and C4 hydrocarbons.
• Channel 4: CP‐Sil 5 CB column for C5+ hydrocarbons.

Key chromatographic conditions include injector and column temperatures of 110 °C, argon or helium carrier gas, programmed backflush intervals to vent late‐eluting compounds, and column lengths of 8–10 m. A standard refinery gas mixture featuring 25 components was used to evaluate performance.

Key Results and Discussion

The micro GC resolved all target compounds within two minutes on the CP‐Molsieve channel and under five minutes across other channels. Retention time repeatability for C3–C4 analytes showed relative standard deviations below 0.11 %. Day‐to‐day reproducibility over ten days remained under 0.20 %, with no observable retention time drift due to the use of backflush and moisture/CO₂ traps. Chromatograms demonstrated clear peak separation and stable baselines across all channels.

Benefits and Practical Applications

• Rapid, on‐site analysis accelerates process optimization and troubleshooting.
• Portable format reduces installation footprint and enables point‐of‐use monitoring.
• High precision and stability support quality assurance and regulatory compliance.
• Automated operation with minimal maintenance extends column lifetime.

Future Trends and Opportunities

Upcoming developments may include integration with process control networks, advanced detectors for trace contaminants, AI‐driven data interpretation and further miniaturization. Expanding the micro GC’s analyte range and coupling with ambient sampling techniques will broaden its industrial and environmental applications.

Conclusion

The Agilent 490 Micro GC QUAD offers a powerful solution for fast and reliable refinery gas analysis. Its multi‐channel design, combined with backflush and filtration, ensures comprehensive component separation, excellent precision and long‐term stability in under two minutes.

Reference

• Duvekot C. Fast Refinery Gas Analysis Using the Agilent 490 Micro GC QUAD. Agilent Technologies Application Note SI-02233; 2012.