Improved High Temperature Simulated Distillation (ASTM D6352 and D7169) Using Zebron™ ZB-1XT SimDist Metal GC Columns

Importance of the Topic

The precise characterization of heavy hydrocarbon fractions is essential for modern refinery operations, quality control, and process optimization. Traditional high-temperature simulated distillation methods (ASTM D6352 and D7169) are generally limited to C90–C100 range, constraining the ability to profile heavier boiling components in crude and fuel streams. Extending analytical range and enhancing column stability directly supports improved process planning, reduced downtime, and increased product yields.

Objectives and Overview of the Study

This work evaluates the performance of the Zebron ZB-1XT SimDist metal GC column featuring Glass Infusion™ Technology for high-temperature simulated distillation. The primary goals were to:

• Extend the boiling range analysis from C100 to C120 while complying with ASTM D6352/D7169 suitability criteria.
• Assess column-to-column reproducibility and chromatographic efficiency.
• Compare thermal stability and lifetime against competitive columns.

Used Instrumentation and Methodology

The study employed a GC system equipped with a flame ionization detector (FID). Key parameters included:

• Column: Zebron ZB-1XT SimDist, 5 m × 0.53 mm i.d. × 0.09 µm film thickness.
• Carrier gas: Hydrogen at 1.93 mL/min or helium at 30–34 mL/min constant flow.
• Injection: 1.0 µL split 100:1 or on-column at 38–53 °C.
• Temperature program: Initial hold at 35–53 °C, ramp to 430–450 °C at 9–10 °C/min, final hold for 10–20 min; FID at 325–450 °C.
• Active test mix: Polar and nonpolar probes (e.g., 4-chlorophenol, dicyclohexylamine) to evaluate surface interactions.
• Lifetime test: Repeated Polywax® 1000 injections at 400 °C over 90 h, monitoring C50/C52 resolution.

Main Results and Discussion

Glass Infusion™ Technology produced a smooth, uniform glass coating on the internal metal surface, eliminating exposed metal sites and ensuring consistent stationary phase bonding. Comparative data showed:

• Sharp, symmetrical peaks for acidic and basic probes on Zebron ZB-1XT versus tailing and adsorption on non-infused columns.
• Sustained resolution above 2.3 for C50/C52 over 90 h at 400 °C, well above the ASTM D6352 minimum of 2.0. Competing columns dropped near failure zones after 70–80 h.
• Successful elution of hydrocarbons up to C120 within the temperature program, meeting D7169 criteria (resolution ≥ 1.8, skew factors within 0.8–1.2 range).
• Chromatographic profiling of Yeates crude oil demonstrated elution of species beyond C120 at 450 °C, reducing residue buildup and carryover risks.

Benefits and Practical Applications of the Method

The Zebron ZB-1XT SimDist column offers:

• Extended boiling-point range analysis for comprehensive crude and fuel characterization.
• Superior column-to-column reproducibility from individual QC testing.
• Enhanced thermal stability and longer operational lifetime, lowering maintenance and replacement costs.
• Improved process data for refinery cracking optimization, yield improvement, and QA/QC.

Future Trends and Potential Applications

Potential developments include:

• Pushing simulated distillation beyond C120 with further material innovations.
• Integration with advanced detectors (MS, IR) for structural assignment of heavy ends.
• Real-time refinery process monitoring with on-line GC systems.
• Utilization of machine learning models to predict feedstock performance and optimize separation conditions.

Conclusion

The Zebron ZB-1XT SimDist metal GC column, leveraging Glass Infusion Technology, significantly enhances high-temperature simulated distillation by extending analysis to C120, assuring robust column performance, and increasing operational efficiency. This solution addresses critical needs in refinery analytics and quality control, delivering reliable data, longer column life, and reduced total cost of ownership.

Reference

• Kelly K, Countryman S, Fernandez C, Nguyen N. Improved High Temperature Simulated Distillation (ASTM D6352 and D7169) Using Zebron™ ZB-1XT SimDist Metal GC Columns. Phenomenex Application Note TN-2043, 2010.