Sulfur in Hydrocarbons* (SC832)

Significance of the Topic

Sulfur content in hydrocarbon fuels and materials critically affects performance, handling, processing and compliance with environmental regulations. Accurate sulfur quantification supports quality control, engine performance optimization and ensures compliance with stringent emission standards.

Objectives and Study Overview

The primary aim of this application note is to present a robust analytical procedure for determining total sulfur in hydrocarbons boiling above 177°C using the LECO SC832 Series sulfur analyzer. The procedure encompasses instrument setup, blank determination, calibration, drift correction and sample analysis workflows.

Instrumentation Used

• LECO SC832 Series sulfur analyzer
• Ceramic boats (528-203)
• Com-Cat catalyst (502-321)
• Comparator leveling for quantification
• Hydrocarbon reference materials (LECO or equivalent, including NIST SRM 2722)

Methodology

The analysis relies on high-temperature combustion at 1350°C with oxygen flow and a lance delay of 20 seconds. Key steps include:

• Instrument conditioning with multiple hydrocarbon replicates
• Blank determination using catalyst alone
• Calibration and drift correction with at least three standards across the target range
• Sample weighing (0.10–0.13 g) with catalyst layering and furnace loading
• Integration times between 90 and 120 seconds until baseline stability is achieved

Main Results and Discussion

Typical performance data demonstrate high precision and accuracy across different matrix types:

• Residual fuel oil: 3.00% S, RSD 0.1%
• Residual fuel oil: 1.00% S, RSD 0.6%
• Heavy sweet crude (NIST SRM 2722): 0.21% S, RSD 1.4%
• #2 Diesel fuel: 0.50% S, RSD 0.6%

Measured averages align closely with certified values, indicating reliable calibration and minimal matrix effects.

Benefits and Practical Applications

This method delivers rapid, reproducible sulfur determinations with minimal sample preparation. It is applicable in fuel quality control laboratories, environmental compliance testing, petrochemical research and regulatory monitoring of ultra-low sulfur fuel programs.

Future Trends and Opportunities

Advancements may include lower detection limits, automated sample handling, speciation of sulfur compounds by coupling with chromatographic techniques and integration with streamlined regulatory workflows. The rise of alternative fuels will drive demand for adaptable sulfur analysis methods.

Conclusion

The LECO SC832 Series method provides a robust and precise approach for total sulfur analysis in heavy hydrocarbons. Its ease of operation and strong agreement with certified reference materials make it a valuable tool for industrial and environmental laboratories.

Reference

• ASTM D1552: Standard Test Method for Sulfur in Petroleum Products (Rod-Type Furnace Methods)