Simulated Distillation of Crude Oil According to ASTM D 5307

Significance of the topic

Petroleum boiling point distribution is a critical quality attribute for crude oil evaluation, refinery feedstock selection, and product specification. Simulated distillation by gas chromatography offers an efficient, reproducible alternative to classical distillation methods, enabling rapid screening of complex hydrocarbon mixtures up to 538 °C.

Objectives and Study Overview

This study demonstrates the application of the ASTM D 5307 method using a capillary column–based simulated distillation system. Key objectives include establishing calibration procedures, verifying system performance, and generating boiling range profiles for water-free crude oil.

Methodology and Sample Preparation

• Calibration: A series of n-paraffins dissolved in carbon disulfide, covering C5–C40, was used to correlate retention time with boiling point.
• Sample preparation: Approximately 10 g of dry crude oil was weighed, spiked with ~1 g internal standard, and diluted in carbon disulfide. A separate unspiked aliquot was prepared for recovery assessment.
• Chromatographic conditions: On-column injection with temperature programming from 100 °C to 350 °C, a high-temperature FID at 350 °C, helium carrier at 20 mL/min, and an oven gradient of 35 °C to 350 °C at 10 °C/min.

Used Instrumentation

• Varian 450-GC SimDist Analyzer with on-column injector (Varian 1093) and high-temperature FID
• Varian CP-SimDist UltiMetal™ capillary column (10 m × 0.53 mm × 0.88 µm)
• Galaxie™ software with SimDist plug-in for data handling and report generation
• Varian CP-8400 autosampler

Main Results and Discussion

A smooth calibration curve confirmed accurate correlation between elution times and paraffin boiling points. Duplicate injections of crude oil yielded a recovery of 60.6% at 545 °C, with the remainder reported as residue. The software automatically produced the initial boiling point (28.6 °C), boiling percentiles (1%–60%), and temperature profile up to 538 °C.

Benefits and Practical Applications

• Rapid, high-throughput assessment of crude oil boiling distributions
• Enhanced reproducibility compared to classical distillation
• Integrated data processing and reporting streamlines QA/QC workflows

Future Trends and Possibilities

• Expansion of column chemistries for heavier distillation cuts
• Coupling with mass spectrometric detectors for compositional analysis
• Automated data interpretation using machine learning algorithms
• Miniaturized systems for field or on-stream monitoring

Conclusion

The described capillary-column simulated distillation setup fully complies with ASTM D 5307, delivering reliable boiling point distributions for crude oil. Its integrated design ensures robust performance, streamlined operation, and comprehensive reporting.

Reference

ASTM D 5307-97(2007), Determination of Boiling Range Distribution of Crude Petroleum by Gas Chromatography, ASTM International