Using CH4 and steam as a source of H2 for NH3 synthesis require high temperature. Rather than burning CH4 separately to heat the mixture, it is more efficient to inject some O 2 into the reaction mixture. All of the H2 is thus released for the synthesis, and the heat of reaction for the combustion of CH4 helps maintain the required temperature. Imagine the reaction occurring in two steps:
2CH4(g) + O2(g) ⥫⥬ 2CO(g) + 4H2(g) Kp = 9.34×1028 at 1000. K
CO(g) + H2O(g) ⥫⥬ CO2(g) + H2(g) Kp = 1.374 at 1000. K
(b) What is Kp for the overall reaction?