Char Reactions

A A S

Dear reacting flow specialists,

I am modeling coal combustion and gasification. I have been having some difficulty getting any surface reactions to take. Specifically, the following reaction will not work for some reason:

C<s> + O2 â€"> CO2

I have only two reactions in my current case, the first being a volumetric reaction: hv_vol + 1.598 O2 --> CO2 + 1.417 H2O I made certain that both reactions were included in the reaction-mechanism and I also tried using multiple-surface-reactions for the combustion model and set the specie mass fraction of C<s> to 1 but did not have any luck. I also tried lowering the activation energy and increasing the diffusion rate. Any suggestions on what I might be doing wrong would be welcome.