Antoine Dechany

Université Catholique de Louvain - UCLouvain | UCLouvain · Institute of Mechanics, Materials and Civil Engineering

Hi all,

To set things clearly: I am a PhD student working on the process implications of electryfing the ammonia production by replacing conventional SMR with Water Electrolysis. A part of my preliminary work is to assess the difference in theoretical minimum energy consumption. To do so, I have calculated a first approximation by summing up the reactions (SMR, Water gas shift, Haber-Bosch,...) and calculating the enthalpy of the resulting "total" reaction. I have done this for the "Water Electrolysis + Haber-Bosch scenario" and validated the minimum with values from the literature.

However, for the conventional "SMR + Haber-Bosch scenario", values from the literature are different. To be more specific, here is the energy minimum calculated in the following conference paper:

(...) the theoretical minimum of energy consumption for the process itself (represented by LHV of methane) is 22.2 GJ/t NH3 (...)

So here is my question: Why use the LHV of methane (instead the enthalpy of reactions) to calculate the energy minimum ? I feel like this is incorrect as I do not take into account the synthesis of methane.

Thanks in advance for any answers,

Antoine