Simulated Distillation System for ASTM D2887, Based on the Agilent 6890N GC

Importance of the Topic

Simulated distillation of petroleum fractions provides critical insights into feedstock composition and product quality in refinery operations. Unlike classical physical distillation, GC-based SIMDIS offers rapid, automated boiling point distribution analysis with enhanced precision and reproducibility, supporting process optimization and regulatory compliance.

Objectives and Study Overview

This study details the implementation of ASTM D2887 using an Agilent 6890N GC equipped with a programmable temperature vaporizer (PTV) inlet and SIMDIS software. It demonstrates the system setup, calibration, validation with reference gases, and sample analysis for boiling range distribution of petroleum cuts up to 538 °C.

Methodology and Instrumentation

The analytical configuration includes:

• Agilent 6890N GC with electronic pneumatics control and flame ionization detector (FID)
• High-temperature PTV inlet (HT PTV) operating in split/hot injection mode
• DB-1 capillary column, 10 m × 530 µm × 2.65 µm
• Agilent 7683B autosampler with 0.5 µL or 5 µL syringe
• SIMDIS software integrated into ChemStation for blank correction, BP–RT calibration (C5–C40 or C5–C44), and automated data processing

Analytical workflow comprises blank runs in CS₂, calibration with n-alkane mixtures, validation using ASTM reference gas oil, and routine sample measurements.

Main Results and Discussion

Blank analysis confirmed baseline stability after multiple injections. Calibration established a robust linear BP–RT correlation. Reference gas oil (RGO) analyses over 10 replicates showed boiling point values within ASTM D2887 tolerances and less than 3% run-to-run variation. Simulated distillation of cracked gas oil displayed excellent repeatability (standard deviation < 0.2 °C) across all distillation cutpoints.

Benefits and Practical Applications

The Agilent SIMDIS system streamlines boiling point distribution analysis with:

• Accelerated runtimes compared to physical distillation
• Reduced operator intervention and higher throughput
• Automated data treatment and customizable reporting (e.g., cutpoint tables, yield percentages, D2887–D86 correlation)
• Compliance with ASTM D2887 and capability for extended methods (D2887x, D6352)

The method supports quality control, process monitoring, and regulatory compliance in petroleum refining.

Future Trends and Potential Applications

Emerging directions include high-temperature GC columns for extended boiling ranges, enhanced data analytics for predictive process control, and integration with real-time process analyzers. Broader applications may extend to biofuel fractions, petrochemical intermediates, and advanced feedstock blends.

Conclusion

The described SIMDIS system delivers reliable, fast, and reproducible boiling point distribution analysis in accordance with ASTM D2887. Its modular software and robust hardware enable routine QC and process development in petroleum refineries.

References

1. ASTM D2887-97a, Standard Test Method for Boiling Range Distribution of Petroleum Fractions by Gas Chromatography, ASTM International.
2. Wang, C.; Firor, R. High-Temperature Simulated Distillation System Based on the 6890N GC, Agilent Technologies, publication 5989-2727EN.