Thx for your help @cgw
I changed my moisture_release function regarding dem-tests/evaporation. But I think I have a problem with CGS/SI problem. H2O released from Coal but this H2O doesn’t react with homogenous reactions (When I don’t use heterogeneous reactions, my homogenous reactions occur normally.)
I will study my case again. Your words give me good points.
Btw, If you need advice; I saw a lot of beginners need help with chemical reactions. Maybe you will add new tutorials about UDF-writing for chemistry.