Fast Refinery Gas Analyzer Nexis GC-2030FRGA1 GC-2014FRGA1

Importance of the topic

Accurate characterization of natural gas and refinery gas mixtures is essential for energy accounting, safety, quality control and process optimization. Detailed compositional data enable calculation of physical properties such as heating value and relative density, support compliance with industry standards and inform operational decisions in upstream, mid-stream and downstream sectors.

Objectives and study overview

This application note presents a rapid gas chromatography method using a Shimadzu fast refinery gas analyzer (GC-2030FRGA1 or GC-2014FRGA1) to determine concentrations of major and trace components in natural and refinery gases. The goal is to demonstrate a complete analysis of He, H₂, O₂, N₂, CO, CO₂, H₂S, C1–C5 hydrocarbons and C6+ as a lumped fraction, within a ten-minute runtime, in accordance with ASTM D1945, D3588 and GPA-2261.

Methodology

The system employs four switching valves and eight capillary or packed columns arranged in three parallel paths:

• Pre-column back-flush of C6+ as a single peak.
• Alumina capillary column separation of C3–C5 hydrocarbons, detected by FID.
• MS-5A column for permanent gases (H₂, He, O₂, N₂, CH₄, CO) with TCD detection.
• Rtx-Q plot column for CO₂, C₂ and H₂S analysis using TCD with N₂ carrier gas.

The sample is introduced via four loops. Valve timing ensures sequential routing to achieve full separation and detection in under ten minutes.

Instrumentation

Key components of the system include:

• Shimadzu GC-2030FRGA1 or GC-2014FRGA1 fast gas chromatograph.
• Four multi-position switching valves.
• Eight capillary and packed columns (Alumina, MS-5A, Rtx-Q plot).
• Dual thermal conductivity detectors and a flame ionization detector.
• LabSolutions GC workstation and BTU/Specific Gravity calculation software.

Main results and discussion

Typical chromatograms demonstrate baseline separation of all targeted components:

• C3–C5 peaks resolved on FID within 3–7 minutes.
• Permanent gases and CO separated on TCD-1, with CO₂ and H₂S peaks clearly distinguished.
• H₂ and He resolved on TCD-2 within 2.5 minutes.

Detection limits span from 0.001 % for key hydrocarbons to 0.010 % for permanent gases, matching or exceeding standardized method requirements. Back-flush of heavier hydrocarbons reduces column fouling and cycle time.

Benefits and practical applications

This method offers:

• Fast analysis (<10 min) for real-time process monitoring.
• Comprehensive coverage of light and permanent gas components.
• High sensitivity and reproducibility suitable for QA/QC and regulatory compliance.
• Integrated software for property calculation (BTU, specific gravity).

Future trends and potential applications

Advances may include integration of mass spectrometric detection for isotopic or trace species, automation with online sampling interfaces, and expanded calibration libraries for non-hydrocarbon impurities. Coupling with digital twins or AI-driven data analysis could further enhance process control and predictive maintenance.

Conclusion

The Shimadzu fast refinery gas analyzer provides a robust, rapid and accurate solution for compositional analysis of natural and refinery gases. Compliance with ASTM and GPA standards, combined with short cycle times and multi-detector capability, makes it an effective tool for energy measurement, process optimization and quality assurance.

References

• ASTM D1945 Standard Test Method for Analysis of Natural Gas by Gas Chromatography.
• ASTM D3588 Standard Test Method for Analysis of Natural Gas Liquids by Gas Chromatography.
• GPA 2261 Gas Processors Association Standard for Gas Chromatography.