Fast Refinery Gas Analyser

Importance of the Topic

The analysis of refinery gas streams is critical for process optimization, quality control, safety and compliance in the oil and gas industry. Rapid, accurate determination of permanent gases, light hydrocarbons and trace components such as H2S enables efficient plant operation, product specification verification and emission monitoring.

Objectives and Overview

This application note presents the configuration and performance of a fast, three-channel gas chromatograph system designed for comprehensive refinery gas analysis according to ASTM, UOP, DIN and ISO standards. It aims to demonstrate rapid cycle times, high uptime, low detection limits and flexibility for additional analytical requirements.

Methodology and Instrumentation

The analyser integrates two thermal conductivity detectors (TCD) and one flame ionisation detector (FID) on a Thermo Trace 1300 GC platform, with an auxiliary valve/column oven for multidimensional separations. Channels are configured as follows:

• Channel 1: He/H2 analysis on TCD (N2 carrier), targeting N2, O2, H2.
• Channel 2: Permanent gases (He carrier) on TCD for CH4, CO, CO2, H2S.
• Channel 3: C1–C6 hydrocarbons on FID (He or H2 carrier), using capillary columns.

The system supports optional fourth-channel expansion for sulfur, high purity gases, extended hydrocarbons or LPG components. Sulfinert® tubing ensures inert sample paths for H2S analysis. Injection is via fixed-loop gas sampling valves, with optional vaporiser or liquid sampling valve (LSV) for LPG samples. Data integration and control are provided by Chromeleon, ChromCard, OpenLab or EZChrom Elite.

Main Results and Discussion

The analyser delivers full component profiles in five minutes (seven minutes including H2S), with minimum detectability below 0.01% and a dynamic range spanning four decades on TCD and seven on FID. Repeatability is better than 1% RSD at 1% concentration over 20 consecutive runs. Uptime exceeds 99%, attributed to InstantConnect detectors and robust diaphragm valve technology.

Benefits and Practical Applications

• Fast cycle times improve plant throughput and decision-making.
• High sensitivity and broad dynamic range cover trace impurities to bulk components.
• Modular channels permit tailored analyses: sulfur, LPG, high-purity streams.
• Low carrier gas consumption and durable components reduce operating costs.

Future Trends and Applications

Emerging needs in refinery gas analysis include inline process monitoring, integration with digital twins and advanced calculation modules for real-time density, calorific value and Wobbe index. Expanding multidimensional GC and hybrid detector configurations will enhance speciation of complex hydrocarbons and trace contaminants.

Conclusion

The presented fast refinery gas analyser offers reliable, high-throughput performance in accordance with major international standards. Its flexible architecture and rapid analysis time support a wide range of refinery and petrochemical applications, delivering actionable data with minimal downtime.

Instrumentation Used

• Thermo Trace 1300 GC with auxiliary valve/column oven
• 2 × TCD detectors, 1 × FID detector (optional 4th channel)
• Micropacked and capillary columns
• Sulfinert® sample tubing
• Gas sampling valves and optional vaporiser/LSV