Thermodynamics in the limit of irreversible reactions

► Thermodynamics has no limit for systems with irreversible reactions whereas the kinetic equations have. ► We describe the multiscale limit of systems of reversible reactions when some of equilibrium concentrations tend to zero. ► We prove the extended principle of detailed balance for systems with some irreversible reactions. ► We find the dynamical consequences of the extended principle of detailed balance. ► We constructively describe the limit points for the closed systems with some irreversible reactions.