Rob
Ansys Employee
You posted what looked like the same question twice. Normally we'd delete one, but as the text wasn't identical I copied it into this thread. There were some issues overnight so we have more duplicate posts than normal: we usually don't like people posting the same thing more than once. nLooking at the questions, yes, you need to add the moisture etc to the solid phase. However, you can then use a mass transfer to move the moisture from the solid to gas phase. nVolatiles will need to be included as a species of some sort, that's for you to define, but again as it's a computer model there's nothing stopping you making up a material to balance with the evolved gases. You can also have multiple evolved gases if you include the cracking energy in the reaction/phase transition.