Determination of Carbon, Hydrogen, and Nitrogen in Coal (CHN828)

Importance of the Topic

Ultimate analysis of coal fuels through carbon hydrogen and nitrogen determination is essential for characterizing material properties energy output and emission potential This information supports process control and optimization in combustion gasification and liquefaction applications

Objectives and Study Overview

This application note outlines a validated procedure per ASTM D5373 for accurate measurement of carbon hydrogen and nitrogen in coal samples using the LECO CHN828 system It covers sample preparation calibration drift correction and routine analysis workflows to ensure reliable results

Methodology

Coal samples are prepared to uniform particle size and analyzed as received with moisture correction per ASTM D2013 and D5373 Each sample is weighed in a tin foil cup and combusted in a pure oxygen environment within a vertical quartz furnace Combustion gases pass through an afterburner to remove sulfur compounds then collect in a ballast for equilibration A defined aliquot is directed through a helium or argon carrier stream Infrared detection quantifies carbon as CO2 and hydrogen as H2O A thermal conductivity detector measures nitrogen as N2 Calibration employs certified reference materials with full regression for carbon and zero-intercept linear fits for hydrogen and nitrogen Drift correction involves repeated analyses of reference material replicates and blank checks

Instrument Used

The LECO CHN828 features a vertical quartz combustion furnace at 950 degrees C and an afterburner at 850 degrees C Carrier gas options include helium for maximum sensitivity or argon for cost efficiency Infrared cells detect CO2 and H2O signals while a thermal conductivity detector measures N2 Accessories include tin foil cups and sample handling tools

Main Results and Discussion

Using helium carrier gas average results for coal reference materials yielded approximately 82.4% carbon 4.26% hydrogen and 1.19% nitrogen with standard deviations below 0.1% Argon produced comparable averages with slightly higher variability The data demonstrate robust repeatability across different coal lots and highlight the influence of carrier gas choice on sensitivity and precision

Benefits and Practical Applications

This method provides a rapid standardized approach to ultimate coal analysis enabling reliable feedstock characterization process optimization and emission estimation Compliance with ASTM D5373 supports quality assurance regulatory reporting and industrial laboratory workflows

Future Trends and Opportunities

Emerging developments may include automated sample preparation robotic handling real-time data analytics and machine learning for predictive maintenance Advances in detector technology and adoption of greener carrier gases could further enhance throughput precision and sustainability

Conclusion

The LECO CHN828 methodology delivers precise accurate carbon hydrogen and nitrogen determinations in coal samples Alignment with ASTM D5373 and use of certified reference materials ensure traceable results supporting quality control process development and regulatory compliance in energy applications

References

• ASTM D5373 Standard Test Methods for Determination of Carbon Hydrogen and Nitrogen in Analysis Samples of Coal
• LECO CHN828 Series Operator Instruction Manual
• LECO Certified Reference Materials LCRM and LRM and NIST standards