Table The parameter values obtained through the least-squares method. The values for KM1R and Ru/C are the same with our previous report. Catalyst First, to show reliable simulation results, the total cost was evaluated at 30 bar for Ru/Pr2O3 and 10 bar for Ru/Ba-Ca(NH2)2, near pressures to available experimental data. 0.0683 USD/kWh was utilized for the electricity cost. The total costs and their breakdown are shown in Figure . The operating conditions for each catalyst and pressure were optimized to achieve the lowest total cost (the case of 100 tonnes/day is shown in Table ). As Figure shows, the catalyst is the most expensive, even with 10-year catalyst durability. It is because the reported reaction rates under the mild conditions are not fast enough, and the reactor volume and the amount of catalyst required to fill it are too large. Considering the industrialization of ammonia synthesis catalysts, the reaction conditions published in the paper base should be a little closer to the industrial process.