AC8612 - Double D86 Distillation Productivity and Reduce Product Giveaway

Significance of the Topic

Accurate determination of boiling point ranges in gasoline, naphtha and related streams is essential for process monitoring, product specification and regulatory compliance. Traditional ASTM D86 physical distillation methods are reliable but slow, labor-intensive and carry safety hazards. Implementing a rapid, automated simulated distillation approach enhances lab productivity, reduces risk and preserves alignment with established standards.

Objectives and Overview of the Study/Article

This application note introduces the AC8612 analyzer from AC Analytical Controls. It demonstrates how the system:

• Generates ASTM D86-equivalent boiling range data for D86 groups 0, 1 and 2
• Produces a full True Boiling Point (TBP) report including hydrocarbon class distribution
• Completes analyses in eight minutes versus two analyses per hour on conventional units
• Minimizes operator involvement and reduces overall costs

Methodology and Instrumentation Used

The AC8612 system is built around an Agilent 6850 gas chromatograph equipped with a flame ionization detector (FID), split/splitless inlet and an automatic liquid sampler. Key methodological features include:

• Simulated distillation based on the Film Fugacity Model for reliable correlation to ASTM D86 results
• Continuous, high-throughput operation with unattended sample runs
• Software algorithms for boiling point calculations and TBP curve generation

Main Results and Discussion

Side-by-side comparisons with classical D86 physical distillation demonstrate that the AC8612 delivers excellent agreement and superior precision:

• Repeatability within ±5 °C and reproducibility within ±8 °C, matching or exceeding D86 specifications
• Correlation plots show nearly linear agreement across C5–C44 cuts (n=29 samples, 425 analyses)
• Precision testing (n=38 samples) confirms reduced variability and potential for product giveaway optimization

Benefits and Practical Applications

The AC8612 approach provides laboratories and refineries with significant advantages:

• Eight-fold increase in sample throughput compared to two analyses per hour
• Up to 75% reduction in labor and operational costs
• Elimination of open-flame hazards, enhancing safety
• Comprehensive boiling range and PIONA-type hydrocarbon analysis in one sequence
• Applicability to gasoline, naphtha, reformate, FCC, alkylate and isomerate streams

Future Trends and Applications

Emerging developments will further enhance simulated distillation workflows:

• Integration with laboratory information management systems (LIMS) and real-time data analytics
• Machine-learning algorithms for anomaly detection and method optimization
• Extension of simulated distillation to heavier cuts (D86 groups 3 and 4) via complementary AC8634 modules
• Miniaturized, field-deployable GC platforms for on-site quality control

Conclusion

The AC8612 simulated distillation system offers a validated, high-speed alternative to conventional ASTM D86 physical distillation. By leveraging film fugacity modeling and advanced GC automation, it achieves full compliance with boiling range specifications, enhances lab throughput and reduces both cost and safety risks.

Reference

Journal of Chromatographic Science, vol. 36, September 1998, pp. 467–475
ASTM International, ASTM D86 Standard Test Method for Distillation of Petroleum Products at Atmospheric Pressure