Effect of Bed Diffusion and Operating Parameters on Char Combustion in the Context of Underground Coal Gasification

S. Mahajani, and G. Samdani
Indian Institute of Technology Bombay
Mumbai, India

Char combustion is one of the most important reactions in the process of Underground Coal Gasification (UCG). Experiments are performed in a boat reactor under near isothermal condition to demonstrate effects of heat and mass transfer and bed diffusion through ash layer. To obtain a complete overview of boat experiments and to further get insights, CFD analysis of boat reactor is performed using COMSOL Multiphysics.

The features of the model are: Navier-Stokes equation for flow through cavity, diffusion through char bed, mass balance for oxygen and carbon dioxide and convective mass transfer in cavity. This model and the experimental study in together can show the effect of inlet temperate, flow rate and gas composition under the UCG conditions.