Gross Heat in Petroleum Coke

Significance of the Topic

Fuel-grade petroleum coke represents a major industrial fuel source due to its high carbon content and energy density. Accurate determination of gross calorific value is essential for fuel quality assessment, cost calculation, and regulatory compliance.

Objectives and Study Overview

The primary goal was to develop and validate a reliable protocol for measuring the gross calorific value of petroleum coke using the LECO AC600 oxygen bomb calorimeter. The study follows ASTM D5865 for calorimetry and ASTM D346 for sample preparation to ensure industry-standard accuracy.

Methodology and Instrumentation

• Sample Preparation: Grinding to pass a 250 µm sieve in accordance with ASTM D346
• Standard Methods: ASTM D5865 for gross calorific value determination
• Instrumentation: LECO AC600 oxygen bomb calorimeter operated in TruSpeed mode
• Calibration: Benzoic acid pellets (LECO 774-208) analyzed multiple times to establish instrument response
• Analysis Sequence: Oxygen pressurization, ignition via a cotton fuse, heat release measurement, followed by nitrogen wash titration for correction
• Key Parameters: Analysis time 5.0 minutes, equilibrate time 1.5 minutes, fuse heat value 0.006255562 BTU per cm, results reported in BTU per pound

Main Results and Discussion

Reference material yielded an average gross calorific value of 15 232 BTU per pound with a standard deviation of 12, demonstrating method precision. Petroleum coke samples showed an average of 14 059 BTU per pound (s = 12), confirming reproducible performance and suitability for fuel evaluation.

Advantages and Practical Applications

• High precision using small sample masses (~0.75 g)
• Rapid analysis enabled by TruSpeed method
• Integrated sulfur and moisture corrections enhance result accuracy
• Compliance with regulatory requirements for industrial fuel quality

Future Trends and Applications

Advancements in automation and digital data management are expected to streamline calorimetric workflows. Emerging bomb calorimeter designs may offer faster turnaround and lower detection limits. The method could be extended to biofuels, alternative fuels, and waste-derived energy feedstocks.

Conclusion

The outlined procedure provides a robust, standardized approach for determining gross calorific value of petroleum coke. The LECO AC600 in TruSpeed mode delivers consistent, accurate results, meeting the needs of industrial laboratories and regulatory bodies.

Reference

• LECO Corporation. Organic Application Note, Form No. 203-821-467, 2014.