Fast Simulated Distillation Based on Agilent 6890N Gas Chromatograph

Significance of the Topic

Simulated distillation according to ASTM D2887 is a cornerstone technique in refining and quality control for determining boiling point distributions of complex petroleum fractions. Accelerating this process without compromising accuracy addresses the growing need for high-throughput analysis in industrial and research laboratories.

Objectives and Study Overview

This work aimed to develop and validate a rapid simulated distillation protocol on an Agilent 6890N gas chromatograph. Key goals included halving analysis time relative to conventional D2887, verifying agreement with ASTM consensus boiling points, and demonstrating robust performance on reference gas oil and cat cracker feed samples.

Methodology and Instrumentation

• Gas Chromatograph: Agilent 6890N with split/splitless inlet, flame ionization detector, electronic pneumatic control, and optional 220 V power for enhanced ramp rates
• Column and Oven: 3 m × 180 µm id × 0.4 µm DB-1 capillary column installed in a reduced-volume oven insert
• Oven Program: 35 °C to 350 °C at 30 °C/min, hold 0.5 min; helium carrier flow programmed for optimal separation
• Calibration: n-alkane standards C5–C40 to establish boiling point versus retention time correlation
• Software: Agilent SIMDIS application integrated with ChemStation for automated post-run boiling point calculations

Main Results and Discussion

• Calibration chromatograms achieved clear C5–C40 peak assignments with the fast method matching performance of the conventional 10 m column.
• Reference gas oil analysis (20 injections) showed boiling point averages within ASTM allowable windows and relative standard deviations below 0.3 percent.
• Comparison with conventional D2887 produced equivalent boiling point distributions across all percent-off cuts with a two-fold reduction in run time.
• Cat cracker feed analysis over 10 runs demonstrated repeatability with RSD values under 0.3 percent for all boiling cuts.

Benefits and Practical Applications

The optimized method offers significant throughput gains while maintaining compliance with ASTM D2887 guidelines. Its compatibility with existing GC hardware and automated software workflows makes it ideal for routine QA/QC, research laboratories, and industrial process monitoring.

Future Trends and Opportunities

• Implementation of 220 V GC systems and narrower columns to enable oven ramp rates up to 65 °C/min for further time savings
• Integration with high-temperature simulated distillation and mass spectrometric detection for extended boiling range analysis
• Application in emerging fields such as biofuel characterization and petrochemical process optimization
• Advances in software algorithms for automated quality checks and real-time data integration

Conclusion

The fast simulated distillation protocol on the Agilent 6890N GC delivers reliable boiling point distributions for petroleum fractions with a two-fold reduction in analysis time. Excellent reproducibility and agreement with ASTM consensus values make this approach a valuable tool for laboratories requiring rapid, high-throughput petroleum analysis.

References

1. ASTM D2887-97a Standard Test Method for Boiling Range Distribution of Petroleum Fractions by Gas Chromatography
2. Agilent Technologies Application Note 5989-2726EN Simulated Distillation System for ASTM D2887
3. Agilent Technologies Application Note 5989-2727EN High-Temperature Simulated Distillation System