Fast NGA System with He/H2 Analysis Nexis GC-2030 FRGA-II1 GC-2014 FRGA-II1

Importance of Topic

Natural gas and related mixtures are key energy sources and raw materials in many industries. Accurate compositional analysis is critical for determining heating value, density, and ensuring quality control in production, distribution, and billing.

Goals and Overview of Study

This work describes a fast natural gas analysis (NGA) system using a Shimadzu GC-2030 FRGA-II1 or GC-2014 FRGA-II1. The aim is to separate and quantify permanent gases (H₂, He, O₂, N₂, CO, CO₂, H₂S) and hydrocarbons from methane up to C6+ within approximately ten minutes, following standards ASTM D1945, D3588, and GPA-2261.

Methodology

A modular gas chromatograph employs five pneumatic valves, three sample loops, eight columns (seven packed, one capillary), and dual detection (two TCD channels and one FID).

• Sample introduction via three loops.
• C6+ components back-flushed as a single peak.
• C3–C5 separation on an Alumina capillary column with FID detection.
• Light gases and unsaturates routed on P-N and packed MS-5A columns, with valve switching to a P-Q column for CO₂, C2, and H₂S, all detected by TCD.
• H₂ separated on MS-5A and measured by a second TCD using N₂ carrier gas.

Used Instrumentation

• Shimadzu Nexis GC-2030 FRGA-II1 or GC-2014 FRGA-II1 system
• Five pneumatic valves
• Seven packed columns and one capillary column
• Three sample loops
• Two thermal conductivity detectors (TCD-1, TCD-2)
• One flame ionization detector (FID)
• LabSolutions GC workstation software with BTU and specific gravity calculation modules

Main Results and Discussion

The system demonstrates:

• Detection limits down to 0.001% for most hydrocarbons and permanent gases.
• Linear concentration ranges up to 80% for CH₄ and up to 50% for N₂.
• Complete separation of 25 target compounds within ~10 minutes.
• Typical chromatograms show clear, resolved peaks for light gases, C2–C5 hydrocarbons, and a grouped C6+ peak.
• Repeatability and precision meet industrial QA/QC requirements.

Benefits and Practical Applications

This fast NGA system offers:

• Rapid turnaround for routine laboratory and online monitoring.
• Integrated calorific value and specific gravity calculations.
• Compliance with multiple international standards.
• Versatility for petrochemical, utility, and research settings.

Future Trends and Potential Applications

Ongoing developments may include:

• Further reduction of analysis time through microflow technology.
• Enhanced automation and remote operation for continuous monitoring.
• Integration with machine learning for predictive maintenance and data interpretation.
• Expansion to trace impurities and isotopic ratio analysis.

Conclusion

The described GC configuration provides a comprehensive, fast, and reliable solution for natural gas compositional analysis. Its robust design and software integration ensure accurate determination of heating value, density, and component concentrations, supporting diverse industrial and research applications.