• A thorough review on the whole hydrogen energy chain to figure out the potential existence of phase transition and application of phase equilibrium studies. • A thermodynamically-consistent flash calculation scheme to calculate phase equilibrium states with physical meanings. • Predictions of phase equilibrium states in practical hydrogen production, storage and transportation applications. • Suggestions to the hydrogen industry for different engineering purposes based on the phase equilibrium calculations. In this paper, a thorough review of the current state of the hydrogen phase equilibrium approaches is presented. Potential applications of phase equilibrium calculations for the accurate simulation of the entire process are then identified. Based on the first and second laws of thermodynamics, an advanced constant (N), volume (V), and temperature (T) (NVT) flash calculation scheme is developed for fluid mixtures containing hydrogen, which can be used to calculate the phase equilibrium for various feed compositions. We produce reasonable predictions of the phase transition under various environmental conditions for a number of engineering scenarios during the hydrogen production and storage processes, thus demonstrating the effectiveness and robustness of the proposed phase equilibrium calculation scheme.