Reaction-Diffusion Model for Gasification of a Shrinking Single Carbon-Anode Particle

Area of Science:

• Chemical Engineering
• Materials Science
• Thermodynamics

Background:

• Carbon anodes are crucial in industrial processes.
• Understanding anode gasification kinetics is vital for process optimization.
• Existing models require refinement for accurate prediction.

Purpose of the Study:

• To develop and validate a detailed reaction-transport model for single carbon anode particle gasification with CO2.
• To compare the performance of five kinetic models for describing carbon particle gasification.
• To investigate the influence of particle size on reaction kinetics and transport phenomena.

Main Methods:

• A detailed reaction-transport model incorporating mass conservation equations for gas and solid phases.
• Numerical solution of nonlinear partial differential equations.
• Validation against experimental data from thermogravimetric analysis (TGA) at 1233 K.
• Application of the Langmuir-Hinshelwood model to account for product inhibition.

Main Results:

• The random pore model (RPM) accurately described anode particle reactivity and predicted particle shrinkage.
• The model successfully quantified gas generation rate, gas composition, and carbon consumption rate.
• Good agreement between model predictions and experimental results validated the approach.
• Simulated effectiveness factors and Thiele moduli revealed the interplay between diffusion and chemical reactions.

Conclusions:

• The developed reaction-transport model provides a robust method for quantifying carbon anode gasification kinetics.
• The random pore model is highly effective for describing the gasification behavior of carbon anode particles.
• The study offers insights into the dominant reaction mechanisms and transport limitations during gasification.