The present invention relates to devices for maintaining a state of equilibrium, and process set-ups to perform equilibrium reactions using heterogeneous catalysts, in particular said reactions are equilibrium reactions where at least one reaction product is volatile. The invention is especially interesting for enzymatic reactions using immobilized enzymes, although it is also useful for pure chemical reactions. The invention is characterized by a combination of non-impact mixing of components and volatilization and/or removal of excess molecules, thereby maintaining a state of equilibrium or driving an equilibrium reaction. The present invention also relates to devices and/or process set-ups and materials made using said processes.