Biogas Analyser

Significance of the Topic

Biogas is an increasingly important renewable energy source produced by the anaerobic digestion of organic matter. Its composition of methane, carbon dioxide and trace components such as hydrocarbons, sulfur species, terpenes and siloxanes affects energy yield, combustion properties and equipment integrity. Reliable, rapid and comprehensive gas analysis is essential for plant optimization, compliance with industry standards and prevention of downstream equipment damage.

Objectives and Study Overview

This application note presents a suite of gas chromatography solutions tailored for biogas analysis. The goals are to demonstrate compliance with accepted industry methods (GPA, ISO, ASTM), to showcase different instrument configurations for target analytes and to highlight performance metrics including analysis time, sensitivity, repeatability and dynamic range.

Methodology

The analytical approach combines multiple detection techniques and column types to cover a broad spectrum of biogas constituents. A thermal conductivity detector (TCD) channel resolves permanent gases and light hydrocarbons, while a flame ionization detector (FID) channel extends hydrocarbon range up to C20. Fast screening of major components is achieved on a compact GC platform, and trace-level analysis of sulfur species employs a pulsed flame photometric detector (PFPD). Low-level terpenes and siloxanes are quantified using GC-MS.

Used Instrumentation

• Thermo TRACE 1300 GC with multi-channel manifold and heated valve oven
• CompactGC 4.0 platform for sub-minute analysis
• InstantConnect injector and detector modules
• Detectors: TCD, FID, PFPD and single quadrupole mass spectrometer
• Columns: micro-packed columns for TCD, capillary columns for FID and MS
• Sulfinert® sample tubing and robust diaphragm valves for inert sample path
• Software: Chromeleon, OpenLab, EZChrom Elite and ChromCard

Key Results and Discussion

• Main gas components (CO2, CH4, N2, H2S, O2, CO, H2) resolved in 9 minutes on TRACE 1300-TCD with detection limits better than 0.01%
• Extended hydrocarbon range (C1–C20) achieved in 20 minutes on FID channel, repeatability <0.1 % RSD for methane
• Rapid screening of six primary constituents completed in 80 seconds on CompactGC 4.0
• PPB-level sulfur analysis (H2S, COS, mercaptans) demonstrated with PFPD, detection <100 ppb
• Low-level terpenes and siloxanes quantified by GC-MS with high selectivity and sensitivity

Benefits and Practical Applications

These GC-based analyzers offer modularity to adapt to varying biogas compositions and regulatory requirements. Key advantages include robust operation in process environments, high throughput for frequent monitoring, broad dynamic range for major and trace analytes, and compliance with GPA, ISO and ASTM standards. Applications span biogas upgrading, grid injection quality control, flare gas monitoring and environmental emissions analysis.

Future Trends and Opportunities

Emerging trends in biogas analytics include real-time online monitoring with networked GC systems, miniaturized and portable gas chromatographs for field use, integration of machine learning for predictive maintenance and data interpretation, and expanded detector technologies for ultra-trace contaminants. These developments will further enhance process control, reduce operational costs and support the transition to sustainable energy.

Conclusion

Customized GC solutions from G.A.S deliver comprehensive, accurate and efficient analysis of biogas across a wide component spectrum. By combining proven column and detector technologies with flexible hardware configurations, these systems meet global industry standards while supporting rapid decision-making in renewable energy production.

References

• GPA Standards 2261, 2177, 2186, 2286
• ISO Standards 6974, 6975
• ASTM Standards D1945, D1946, D6228