Analysis of Petroleum Fractions by ASTM D2887

Significance of the Topic

Simulated distillation by gas chromatography is a cornerstone technique for determining the boiling point distribution of complex petroleum mixtures. It enables rapid, reproducible characterization of hydrocarbon fractions, essential for quality control, process optimization, and regulatory compliance in the petroleum industry.

Objectives and Study Overview

This study evaluates the performance of the Thermo Scientific TRACE TR-SimDist GC column under the conditions specified in ASTM D2887. The aim is to demonstrate adequate separation of n-alkanes from C5 to C44 within 20 minutes and to validate calibration linearity and resolution criteria.

Methodology and Instrumentation

• Calibration standard: n-alkane mixture (C5–C44) at 800 µg/mL in carbon disulfide.
• Sample: Reference gas oil diluted 1:20 in carbon disulfide.
• Instrument: Thermo Scientific TRACE GC equipped with TRACE TR-SimDist column (10 m × 0.53 mm ID, 2.65 µm film thickness).
• Injection: Programmable temperature vaporizer (PTV) in simulated on-column mode, 1 µL volume, temperature ramp from 40 °C to 370 °C.
• Carrier gas: Helium at 12 mL/min (constant flow).
• Oven temperature program: 40 °C hold 1 min, ramp 20 °C/min to 370 °C, hold 5 min.
• Detector: Flame ionization detector (FID) at 370 °C.

Main Results and Discussion

The 2.65 µm film provided enhanced retention and resolution of low-boiling C5–C12 components, achieving full separation in under 20 minutes. Resolution between C16 and C18 peaks exceeded 6.1, surpassing the ASTM D2887 minimum of 3. Calibration of retention time versus boiling point yielded an R² greater than 0.99, confirming linearity. Application to the reference gas oil sample identified compounds with boiling points from 36 °C to 475 °C.

Benefits and Practical Applications

• High throughput: complete boiling range distribution in less than 20 minutes.
• Wide boiling range coverage (55.5–538 °C) with robust peak shapes and reproducibility.
• Meets ASTM D2887 requirements, supporting routine quality control and process monitoring in refineries and laboratories.

Future Trends and Opportunities

Future developments may include coupling simulated distillation with mass spectrometry for enhanced component identification, advanced high-temperature stationary phases for improved stability, automated calibration protocols, and integration with real-time process control systems. Data analytics and miniaturization of GC platforms could further streamline petroleum fraction analysis.

Conclusion

The Thermo Scientific TRACE TR-SimDist column reliably fulfills ASTM D2887 criteria, delivering rapid, high-resolution simulated distillation of petroleum fractions. Its performance supports efficient quality assurance and research applications in the petroleum sector.

Reference

• ASTM Standard D2887-08, “Standard Test Method for Boiling Range Distribution of Petroleum Fractions by Gas Chromatography,” ASTM International, 2008.