Analysis of Boiling Point Distributions in Petroleum Fractions using Simulated Distillation (ASTM D2887A)

Importance of the Topic

Analysis of boiling point distribution in petroleum fractions underpins refining control, product specification and valuation. Simulated distillation by gas chromatography provides faster turnaround, improved precision, smaller sample requirement and greater safety compared to conventional physical distillation. It is widely adopted in quality control laboratories and research, supporting regulatory compliance and process optimization.

Objectives and Study Overview

This application note demonstrates a validated procedure for ASTM D2887A (procedure A) using a GC‐based simulated distillation (SimDist) system. The goals are to measure boiling point distribution from 36 °C to 545 °C in petroleum fractions, verify method performance against consensus reference values for a gas oil sample, and illustrate compliance with acceptance criteria.

Methodology

Samples and Calibration Mixture

• Normal paraffins C5–C44 at 1 % wt each in carbon disulfide for calibration of retention time vs boiling point.
• Petroleum fractions diluted in CS₂ according to ASTM D2887‐18.

Chromatographic Conditions

• Cool‐on‐column injector at 350 °C.
• 10 m × 0.53 mm × 2.65 µm inert steel SimDist column.
• Oven program: –20 °C initial, ramp at 10 °C/min to 350 °C, hold 2 min.
• Helium carrier at 20 mL/min, FID at 350 °C, injection volume 1 µL.

Used Instrumentation

The analysis was performed on a Scion SIMDIST system composed of a Scion 456-GC (or 436-GC) equipped with cool‐on‐column injector, SimDist column and flame ionization detector. Data acquisition and processing used Eclipse SIMDIST software.

Main Results and Discussion

Five replicate injections of a reference gas oil showed excellent agreement with ASTM consensus boiling point values. For each 10 % weight fraction, observed deviations were generally below 2 °C, meeting method requirements. The final boiling point (FBP) deviation was slightly higher but remained within the allowable limit. Calibration with n-paraffin mixture yielded a linear retention time vs boiling point relationship across the full range.

Benefits and Practical Applications

SimDist offers

• High precision and reproducibility.
• Rapid analysis with minimal hands-on time.
• Lower sample volume and chemical consumption.
• Enhanced safety versus large‐scale distillation.
• Equivalence to true boiling point (TBP) methods (ASTM D2892) for refining control.

Future Trends and Potential Uses

Advances may include coupling SimDist with mass spectrometry for compositional profiling, miniaturized GC systems for field or onboard monitoring, and integration with machine learning algorithms for predictive quality control. Expanding standards for bio-based and unconventional feedstocks will further broaden application scope.

Conclusion

The Scion SimDist solution reliably meets ASTM D2887A criteria for boiling point distribution analysis of petroleum fractions. The method delivers precision, efficiency and safety advantages, making it a robust alternative to conventional distillation for refining operations and product specification.

Reference

ASTM D2887-18. Standard Test Method for Boiling Range Distribution of Petroleum Fractions by Gas Chromatography. ASTM International.