Sulfur and Carbon in Coal and Coke

Significance of the Topic

Total sulfur and carbon analyses are critical components of the ultimate analysis of coal and coke, providing essential data for assessing fuel quality, predicting combustion emissions, and optimizing processing efficiency. Accurate sulfur determination supports environmental compliance and process control, while precise carbon quantification is indispensable for carbon balance calculations and CO2 emissions estimates.

Aims and Study Overview

The application note presents a validated procedure for simultaneous determination of total sulfur and carbon in coal and coke samples using the SC832 Series analyzer. Key objectives include:

• Establishing reproducible analytical conditions for diverse fuel matrices
• Demonstrating instrument calibration and drift correction protocols
• Evaluating method precision and accuracy with certified reference materials

Methodology and Instrumentation

Sample preparation follows ASTM D2013, ensuring representative, homogeneous specimens. Moisture is measured per ASTM D3173/D7582 or ISO 11722 for dry-basis correction. The SC832 Series furnace operates at 1350 °C with a 20 s lance delay. Sulfur and carbon analyses employ a single-sample manual or automated mode. Calibration uses LECO and NIST reference materials; blanks and standards are run in triplicate. Key parameters:

• Baseline stability wait: 2 s
• Integration time: 90–360 s
• Comparator sensitivity: 0.30 V

Used Instrumentation

SC832 Series sulfur/carbon analyzer (LECO Corporation).

Main Results and Discussion

Typical results for bituminous coal, foundry coke, metallurgical coke, and several NIST/LECO standards reveal:

• Carbon recoveries within ±0.5% (dry basis)
• Sulfur recoveries within ±0.08% absolute
• Precision (standard deviation) generally <0.02% for sulfur and <0.2% for carbon

Comparison between manual and automated analyses shows negligible bias. Data confirm suitability across a broad range of matrices and concentrations.

Benefits and Practical Applications

• High throughput with reliable repeatability for QA/QC laboratories
• Robust calibration strategies minimize drift and maintenance needs
• Comprehensive ultimate analysis supporting regulatory reporting and process optimization

Future Trends and Opportunities

• Integration with automated sample preparation and robotics to boost throughput
• Advanced chemometric models for real-time data correction and feedback control
• Expansion to other solid fuels and waste-derived feedstocks

Conclusion

The SC832 Series method delivers accurate, precise sulfur and carbon determinations in coal and coke, meeting industry standards with minimal operator intervention. Its flexibility and performance make it a valuable tool for fuel characterization and environmental monitoring.

Reference

• ASTM D2013 – Preparation of Coal and Coke Samples for Analysis
• ASTM D4239 Method A – Total Sulfur in Coal and Coke
• ASTM D3173/D7582, ISO 11722 – Moisture in Coal and Coke