Extended Analysis for Refinery Gas and Similar Gaseous Mixtures on the AC HiSpeed RGA

Importance of the Topic

The analysis of light refinery gases and complex hydrocarbon mixtures up to C9 aromatics plays a vital role in process monitoring, quality control and environmental compliance in petrochemical and refining industries. Rapid and comprehensive profiling of gaseous streams enables operators to optimize production, prevent upsets and meet stringent regulatory limits.

Objectives and Study Overview

This work demonstrates an extended method for the AC HiSpeed RGA system, enabling separation and quantification of hydrocarbons from C1 through C9 aromatics in a single automated sequence. The goal is to maintain high throughput (28 min extended run) while preserving the integrity of existing channels for permanent gases (H2, He, O2, N2, CO, CO2).

Methodology and Instrumentation

Using the standard six-column AC HiSpeed RGA configuration, one channel was optimized for hydrocarbons by raising the PLOT capillary column temperature. The other two channels remained dedicated to permanent gases. Sample detection employed a flame ionization detector (FID) for organic compounds. Chromatographic conditions:

• Column group: PLOT capillary for C1–C9 hydrocarbons
• Temperature program: elevated final temperature to elute C9 aromatics
• Detector: FID for hydrocarbons; thermal conductivity detectors for permanent gases

Used Instrumentation

• AC HiSpeed RGA analyzer with three independent analytical channels
• Six capillary columns (including PLOT column for hydrocarbons)
• Flame ionization detector (FID)
• Thermal conductivity detectors for H2, He, O2, N2, CO, CO2
• AC GASXLNC software for calibration, peak grouping and reporting

Main Results and Discussion

The modified method achieved baseline resolution of C1–C9 hydrocarbons, including aromatics (benzene, toluene, xylenes), within a 28-minute cycle. Chromatograms showed clear separation of olefins and paraffins in the C4–C5 range and distinct aromatic peaks. The extended hydrocarbon channel did not impact the analysis time or separation quality of permanent gases in the other channels. The GASXLNC software facilitated both direct and indirect calibrations with absolute or relative response factors and provided grouping functions for reporting by carbon number.

Benefits and Practical Applications

• Automated switching between standard (5 min) and extended (28 min) methods without hardware changes or manual recalibration
• Comprehensive C1–C9 profiling supports process optimization, feedstock characterization and compliance monitoring
• Flexible software calibration and grouping streamline data management and reporting

Future Trends and Opportunities

Advances may include further extension to higher hydrocarbons, integration with process control systems and real-time data analytics. Enhanced detector technologies and machine-learning algorithms for peak identification could improve sensitivity and reduce analysis time. Cloud-based reporting and remote diagnostics will support decentralized monitoring and predictive maintenance.

Conclusion

The extended AC HiSpeed RGA method provides a robust, fully automated solution for simultaneous analysis of permanent gases and hydrocarbons up to C9 aromatics. By leveraging existing hardware and flexible software, laboratories can achieve detailed gas mixture characterization without compromising throughput or chromatographic performance.

Reference

AC Analytical Controls Application Note AC1004: Extended Analysis for Refinery Gas and Similar Gaseous Mixtures on the AC HiSpeed RGA.