Entropy Identity inducing Non-Equilibrium Thermodynamics of Relativistic Multi-Component Systems and their Newtonian Limits

Non-equilibrium and equilibrium thermodynamics of an interacting component in a special-relativistic multi-component system is discussed by use of an entropy identity. The special case of the corresponding free component is considered. Equilibrium conditions and especially the multi-component Killing relation of the 4-temperature are discussed. Two axioms characterize the mixture: additivity of the energy momentum tensors and of the 4-entropies of the components generating those of the mixture. The resulting quantities of a component and of the mixture, energy, energy flux, momentum flux, stress tensor, entropy, entropy flux, supply and production and their Newtonian limits in zeroth approximation are derived.