Clarity Extension NATURAL GAS ANALYSIS

Significance of the topic

Natural gas and liquefied petroleum gases represent key energy carriers in industry, power generation and transport. Accurate determination of their physical and chemical properties—such as calorific value, density, compressibility and Wobbe index—is critical for custody transfer, quality assurance and process control. Software tools that integrate chromatographic analysis with standards‐compliant calculations streamline workflows and reduce manual errors, ensuring compliance with international norms.

Objectives and Overview of the Manual

This document introduces the Natural Gas Analysis (NGA) Extension for the Clarity Chromatography Software. It aims to guide users through installation, configuration and routine use of the NGA Extension for processing gas chromatograms, performing calculations in accordance with ISO, ASTM and GPA standards, and generating reports and data exports.

Methodology and Instrumentation

The NGA Extension integrates into both online and offline Clarity environments, extending any configured GC system. Key methodological steps include:

• Calibration using multi‐signal peak tables with predefined compound names linked to supported norms or custom names via a link table.
• Selection of the desired calculation norm (ISO 6976-16/95, ASTM D3588/GPA 2172, ASTM D2421/2598 or ISO 8973/EN 589) and adjustment of parameters such as metering and combustion conditions, basis (ideal vs. real gas) and inclusion of water vapor.
• Automated computation of gas properties upon chromatogram loading or norm changes, with interactive result tables.
• Summary views for batch comparison in overlay mode, customizable report layouts, and exportable data tables.

Instrument Used

The extension operates within the Clarity Chromatography Software connected to GC instrumentation. A GC instrument type must be enabled in the System Configuration, and the NGA Extension activated by user code. All peak integration and calibration follow standard Clarity workflows.

Key Results and Discussion

Results are presented in two linked tables: NGA Amounts lists calibrated component fractions and custom‐norm links; NGA Results displays calculated properties per chromatogram, including:

• Compression factor, mean molecular weight and density (ideal and real gas)
• Gross and net calorific values (molar, mass and volumetric bases)
• Relative density and Wobbe index
• Additional LPG parameters: vapor pressure, motor octane and methane numbers

Warnings flag unmatched compounds or multi‐signal calibrations, resolved via link table or calibration settings.

Benefits and Practical Applications

The NGA Extension offers:

• Seamless compliance with multiple international standards in a single interface
• Centralized management of calibration, norm methods and link tables
• Automated, error‐flagged calculations to improve reliability
• Flexible reporting and data‐export options for QC, regulatory and contractual documentation

Future Trends and Potential Applications

Advancements may include integration with laboratory information management systems (LIMS), cloud‐based data processing, real‐time analytics driven by AI for anomaly detection, and expansion to emerging fuel blends and hydrogen admixtures. Adoption of new or revised standards will be facilitated through updatable norm tables and automated signature validation.

Conclusion

The Clarity NGA Extension enhances gas chromatographic workflows by embedding comprehensive, norm-compliant property calculations directly into data processing. It reduces manual post-processing, ensures consistency with international standards and provides flexible reporting—benefits essential for modern analytical laboratories handling natural and liquefied gas samples.

References

• Kubesh J., King S. R., Liss W. E.: Effect of Gas Composition on Octane Number of Natural Gas Fuels. SAE Technical Paper, 1992.