Simulated Distillation Analysis of Middle Distillates Using the Accelerated ASTM D2887 Method

Significance of the Topic

Simulated distillation is a critical technique for determining the boiling point distribution of middle distillates such as kerosene, aviation fuel, diesel, and light oils. Faster analytical methods support rapid quality control and compliance with industry standards. The accelerated ASTM D2887B method reduces analysis time from 30 to 9 minutes, enhancing laboratory productivity while maintaining accuracy and precision.

Objectives and Study Overview

The study aimed to evaluate the performance of the Agilent 8890 gas chromatograph configured for ASTM D2887B using three different capillary columns. Key goals included verifying peak symmetry, resolution, and boiling point cut-point accuracy against reference standards and real samples.

Methodology and Instrumentation

The experimental setup included:

• Agilent 8890 gas chromatograph with cool-on-column (COC) inlet and flame ionization detector (FID)
• Agilent 7650 automatic liquid sampler and 5 μL syringe
• Three capillary columns: HP-1 10 m × 0.53 mm × 0.88 μm, HP-1 5 m × 0.53 mm × 2.65 μm, DB-1 7.5 m × 0.53 mm × 1.5 μm
• Operating conditions: initial temperature 40–100 °C, ramp rate 35 °C/min to 350–360 °C, helium carrier flow 26–37 mL/min, FID gases (H₂, air, N₂)
• Calibration standard: n-alkanes C5–C44 in carbon disulfide

Main Results and Discussion

Key findings included:

• Chromatographic separation of C5–C8 normal alkanes with average peak skewness ~1.1 across all columns
• Resolution >4 for n-C16/n-C18 on every column
• Calibration curves demonstrated linear boiling point distribution using Agilent SimDis software
• Reference Gas Oil (RGO) cut-point temperatures were within ASTM limits for all columns
• Three middle distillate samples (Jet A, Diesel, Waxy distillate) yielded nearly identical boiling point profiles on each column

Benefits and Practical Applications of the Method

The accelerated simulated distillation method offers:

• Rapid 9-minute analysis, increasing sample throughput
• Flexibility to use any of three specified columns without compromising performance
• Reliable quality control for fuel production, refining, and regulatory compliance
• Compatibility with standard GC hardware and SimDis software tools

Future Trends and Opportunities

Potential developments include:

• Integration of automated data evaluation and artificial intelligence for streamlined interpretation
• Coupling with mass spectrometry for enhanced compound identification
• Extension to heavier and more complex petroleum fractions
• Real-time monitoring and process control in refining operations

Conclusion

The Agilent 8890 GC successfully met all performance criteria of the accelerated ASTM D2887B method using three different capillary columns. The approach delivers accurate boiling point distributions for middle distillates in a significantly reduced analysis time, supporting efficient and reliable fuel analysis.

Reference

• ASTM International. ASTM D2887-16a, Standard Test Method for Boiling Range Distribution of Petroleum Fractions by Gas Chromatography; West Conshohocken, PA, 2016.