OxyTracer™ - Determination of individual oxygenates from 0.1 ppm to 2000 ppm in light hydrocarbon streams according to ASTM D7754 and ASTM D7423

Importance of the Topic

Monitoring trace levels of oxygen-containing compounds in light hydrocarbon streams is essential to prevent catalyst deactivation in hydrotreating and hydroprocessing operations. Even concentrations as low as parts per million can shorten catalyst lifetime and compromise downstream processes. At the same time, stricter environmental regulations mandate the use of oxygenates in fuels, making reliable detection of both intentional and impurity oxygenates critical for quality control and regulatory compliance.

Objectives and Study Overview

This work presents the AC OxyTracer™ solution for rapid, sensitive quantification of individual oxygenates in naphtha, LPG and gasoline streams. The method covers a concentration range from 0.1 ppm up to 2000 ppm and fully complies with ASTM D7754 and D7423 standards. Key goals include achieving low detection limits, broad compound coverage, fast analysis time (25–30 minutes) and seamless automation for high-throughput laboratories.

Methodology and Instrumentation Used

The OxyTracer platform is built on an Agilent 8890 gas chromatograph equipped with AC proprietary Deans switching technology. Liquid Sampling Valves (LSV) and heated Gas Sampling Valves (GSV) allow injection of pressurized or ambient samples in liquid or gas form. An optional second FID channel enhances flexibility. Automated Liquid Sampler (ALS) integration and dedicated software handle calibration, data acquisition and reporting, while a backpressure regulator preserves sample integrity for pressurized streams.

Main Results and Discussion

Chromatographic separation of up to 24 oxygenates (ASTM D7423) or 14 compounds (ASTM D7754) was achieved in under 30 minutes. The system demonstrated a lower detection limit of 0.1 ppm for key analytes with a linear response extending to 2000 ppm, method-dependent. Repeatability was better than 1% for MTBE and under 2% for other oxygenates. Representative chromatograms confirm clean baseline separation between oxygenates and the hydrocarbon matrix, validating the robustness of the Deans switching approach.

Benefits and Practical Applications

• Fast analysis in 25–30 minutes reduces turnaround time for QC and process monitoring.
• High sensitivity (0.1 ppm) and wide dynamic range enable detection of trace and elevated oxygenates.
• Comprehensive scope covers C2-C5 gases, LPG, naphtha and gasoline streams, including ethanol-blended fuels (up to 15%).
• Full automation of sampling, calibration and reporting minimizes operator intervention and error.
• Modular configuration supports multiple standard methods and customized analyte lists.

Future Trends and Opportunities

Advances in microfluidic GC technology and enhanced detector sensitivity may further reduce analysis time and detection limits. Integration of real-time data analytics and cloud-based reporting will support predictive maintenance and process control. Expanding the analyte library to emerging bio-derived oxygenates and refining-grade contaminants will meet evolving industry and regulatory demands.

Conclusion

The AC OxyTracer system offers a robust, standardized solution for rapid trace analysis of oxygenates in light hydrocarbon streams. By combining Deans switching technology with automated sampling and data handling, it delivers reliable, reproducible results that support catalyst protection, product quality and compliance with ASTM D7754 and D7423.