Fast analysis of Boiling Point Distributions in Petroleum Fractions using Simulated Distillation (ASTM D2887 B)

Importance of Topic

The accurate determination of boiling point distributions in petroleum fractions is fundamental for understanding composition, optimizing refining operations, and ensuring product quality. Simulated distillation by gas chromatography (SIMDIST) provides a rapid, high-throughput alternative to traditional physical distillation, enabling efficient monitoring of feedstocks, fuels, and bio-based liquids while reducing sample consumption and operational costs.

Objectives and Study Overview

This application note evaluates the fast method (Procedure B) described in ASTM D2887 for simulated distillation of petroleum cuts with final boiling points up to 545 °C. The study aims to demonstrate that the SCION SIMDIST configuration, using a cold-on-column injector and a specialized column, meets the precision and accuracy requirements of the standard, while significantly reducing analysis time compared to the conventional Procedure A.

Methodology and Instrumentation

• Analyzer: SCION SIMDIST system based on a 456-GC or 436-GC platform.
• Injector: Cool-on-column (COC) for minimal sample discrimination.
• Column: 5 m × 0.53 mm ID × 2.65 μm film thickness SIMDIST capillary with retention gap.
• Detector: Flame ionization detector (FID) maintained at 350 °C.
• Carrier gas: Helium at 35 mL/min constant flow.
• Oven temperature program: Start at 40 °C, ramp at 35 °C/min to 350 °C, hold 1 minute.
• Injection volume: 0.1 μL.
• Calibration: Normal paraffin mixture from C5 to C44 (1% w/w each) in carbon disulfide to establish retention time versus boiling point correlation.
• Software: Compass CDS with Eclipse SIMDIST module for data acquisition and processing.

Main Results and Discussion

Repeated analysis (n=11) of Reference Gasoil No. 2 demonstrated that measured initial boiling point (IBP), final boiling point (FBP), and intermediate percentiles (10%, 20%, …, 90%) all fell within ASTM D2887 allowable deviations. Precision data (repeatability and reproducibility) conformed to the standard limits. The total analysis cycle was approximately one-quarter the duration required for Procedure A, validating the fast method’s suitability.

Benefits and Practical Application

• Four-fold reduction in analysis time accelerates quality control and process monitoring.
• High precision and accuracy comparable to true boiling point distillation (ASTM D2892).
• Lower sample volume requirements and reduced solvent consumption.
• Enhanced laboratory throughput with minimal hands-on intervention.
• Applicable to petroleum fractions, feedstocks, and biodiesel samples up to 545 °C.

Future Trends and Applications

Advances in GC column technology, detector sensitivity, and automation will further streamline simulated distillation workflows. Integration with real-time process analytical technology (PAT) platforms can enable continuous monitoring of refining streams. Machine learning algorithms applied to retention-time data may enhance prediction accuracy and method robustness across diverse sample matrices.

Conclusion

The SCION SIMDIST configuration for ASTM D2887 Procedure B reliably reproduces standardized boiling point distribution data with high precision and within allowable error limits. Its accelerated runtime and reduced resource demands make it an effective alternative to conventional distillation methods for routine petroleum analysis.