With only steam and ethane fed into the reactor, hydrogen is the main product. A small amount of methane is also formed. All the ethane is consumed by the reaction , but one does not get the full yield of hydrogen. The rest of the hydrogen fed into the reactor is converted into water by the reaction .

It is worth noting that no prior knowledge of the reactions (i.e., which products are formed) is required to perform the free-energy minimization. The ideal-gas contributions to the total Gibbs free energy are obtained from experimental data [1]. We compute the residual Gibbs free energy using the Peng–Robinson equation of state [2]. This determines the equilibrium composition for pressures much higher than 1 bar. It is clear that the ethane steam cracking produces no methane at high temperatures and low pressures. However, a significant amount of is obtained at high pressures (see Snapshot 3).