a) You can take a look at the manner in which the E-L framework handles this. If you have wet combustion on, a droplet material is included in your mixture, which is also defined by the moisture content of your PA. There's mass transfer from liquid to gaseous phase through evaporation. However I haven't used the EE framework, somehow you'll need to indicate a mass transfer mechanism to do the same as in EL. (Maybe define a liquid phase to represent moisture and then use mass transfer,)nCoal-volatiles is a gaseous species, and hence is just transfer from gas to gas phase.nnb) Maybe try using single Kinetic model first? Kobayashi Is useful when you have both fast/slow devolatilization. Look at your system and check which mode dominates, otherwise maybe look at the C3M software (free access) and review the devolatilization reaction there. It automatically creates UDF ready to be implemented in Fluent, but I'm not sure if the kobayashi model is employed there.nnc) Can you specify more about this? What is the input for KTGF? volatiles, tar and moisture are part of the full gasifiction reaction, so you need to define tar as well, and tar cracking reaction. d) I have the same question. I just know that some models represent Volatiles as a CHONS and do mass balance from here. Stoichiometric models based on equilibrium are useful to balance the devolatilization. For tar cracking and tar oxidation, look at C3M.nn