Extended Refinery Gas Analyzer Nexis GC-2030ERGA1 GC-2014ERGA1

Significance of the Topic

Accurate determination of natural gas composition is vital for estimating heating value, relative density and ensuring process safety in petrochemical and energy industries. Extended refinery gas analysis supports quality control, custody transfer, and environmental monitoring by providing detailed component profiles from hydrogen to C13 hydrocarbons.

Objectives and Study Overview

This method outlines a comprehensive gas chromatographic procedure for quantifying major and minor constituents in natural gas and refinery streams. The protocol aims to deliver complete compositional data in a single 30-minute cycle, enabling calculation of physical properties and real-time monitoring of critical gas components.

Methodology and Used Instrumentation

The analytical sequence integrates four multiport valves and nine separation columns arranged across two ovens. Key steps include:

• Sample introduction via four loops with split/splitless injector.
• Pre-column back-flush to group C6+ hydrocarbons, separated later in a secondary oven.
• Alumina capillary column for C3–C5 separation with flame ionization detection (FID).
• MS-5A molecular sieve column for permanent gases (H2, O2, N2, CH4, CO) and a plot column for CO2, C2, H2S, detected by thermal conductivity detectors (TCD).
• Secondary Rtx-1 column in the second oven for detailed C6–C13 hydrocarbon profiling with FID.
• Shimadzu LabSolution workstation software with built-in BTU and specific gravity calculators.

Main Results and Discussion

Typical chromatograms demonstrate baseline resolution of hydrogen and helium within two minutes, clear separation of light hydrocarbons (CH4 through C5 isomers) by 5 minutes, and extended C6–C13 profiles completed by 25 minutes. Dual FID channels and dual TCD detectors provide simultaneous quantitation across a broad concentration range (0.001–50%). Detector sensitivity supports ppm-level detection for trace components, while robust valve timing ensures reproducible peak shape and retention times.

Benefits and Practical Applications

The described system affords several operational advantages:

• Comprehensive one-run analysis from permanent gases to C13 hydrocarbons.
• High throughput with 30-minute cycle time, suitable for on-line monitoring.
• Dual-detector configuration enhances dynamic range and selectivity.
• Flexible injector allows liquid hydrocarbon analysis without additional hardware.
• User-friendly software simplifies dual-oven control and property calculations.

Future Trends and Potential Applications

Advances in miniaturized columns, faster oven heating, and integration with mass spectrometry are expected to reduce analysis time and expand compound coverage. Machine-learning algorithms for automated peak identification and real-time quality assurance promise further efficiency gains. The methodology may be adapted for hydrogen-rich fuels, biomethane blends, and carbon capture monitoring.

Conclusion

This extended refinery gas analysis method offers a robust, high-resolution solution for complete compositional profiling of natural gas. Leveraging multiple columns, dual detectors, and intuitive software, it meets industry standards (ASTM-D1945, D1946, D3588, GPA-2261) and supports critical physical property calculations. The approach balances speed, sensitivity, and versatility, making it a valuable asset for research labs, process control and custody transfer applications.

Reference

• Shimadzu Corporation. SGC-ADS-0045B System Gas Chromatograph Extended Refinery Gas Analyzer Nexis GC-2030ERGA1/GC-2014ERGA1, First Edition, November 2017.
• ASTM D1945, ASTM D1946, ASTM D3588, GPA 2261.