Abstract
The need to reduce greenhouse gas emissions and diversify energy sources has driven the development of hydrogen (H2) as a leading carbon-free energy vector with high gravimetric energy density (33.3 kWh/kg) for stationary and transport applications. However, its storage and transportation remain challenging. Therefore, ammonia emerges as a promising hydrogen carrier due to its high energy density and ease of liquefaction and transport. This work presents the development of a phenomenological based mathematical model for an ammonia electrolysis cell operating in a zero-gap configuration with an anion exchange membrane. The model considers the contributions of different overpotentials (activation, ohmic, concentration) and incorporates empirical and semi-phenomenological expressions adjusted to experimental data from Zhang et al [1]. The model shows both qualitative and quantitative agreement with experimental measurements, achieving a determination coefficient (R2) of 0.9874. Beyond electrochemical modeling, the cell model is integrated into a nonlinear programming (NLP) optimization framework to minimize the total annualized cost (TAC) of the system. For hydrogen production of 1250 kg/h, the optimal solution corresponds to 353 K, 0.82 A/cm2, and 1302 cells, yielding a TAC of about 45.0 MUSD/year.