Computer simulation of carbonization and graphitization of coal.

Area of Science:

• Materials Science
• Computational Chemistry
• Chemical Engineering

Background:

• Carbonization and graphitization are crucial processes in materials science.
• Understanding the influence of impurities on these transformations is vital for material property control.
• Existing simulation methods may not fully capture the complexities of volatile outgassing and intermediate material changes.

Purpose of the Study:

• To simulate carbonization and graphite formation, including the effects of common impurities (H, N, O, S).
• To introduce and utilize a novel simulation technique, Simulation of Thermal Emission of Atoms and Molecules (STEAM), for detailed analysis.
• To investigate the impact of impurities, particularly nitrogen, on the physical, vibrational, and electronic properties of graphitic materials.

Main Methods:

• Development and application of the 'Simulation of Thermal Emission of Atoms and Molecules (STEAM)' technique.
• Computer simulations of carbonization and graphitization processes under varying impurity conditions.
• Analysis of functional group stability during high-temperature carbonization.
• Characterization of the physical, vibrational, and electronic attributes of impure amorphous graphite.

Main Results:

• The study elucidates volatile outgassing and density variations during carbonization using the STEAM method.
• Identification of functional groups that persist through high-temperature carbonization.
• Analysis of graphitization in carbon-rich materials with non-carbon impurities.
• Detailed examination of the physical, vibrational, and electronic properties of impure amorphous graphite, including nitrogen's effect on electronic conduction.

Conclusions:

• The novel STEAM technique provides valuable insights into the intermediate stages of carbonization.
• Impurities significantly influence the graphitization process and the resulting material properties.
• Nitrogen, in particular, has a notable impact on the electronic conductivity of amorphous graphite, suggesting potential for tailored material design.