Economies of scale in ammonia synthesis loops embedded with iron- and ruthenium-based catalysts

The economies of scale were analyzed in ammonia synthesis loops embedded with ironbased catalysts (Fe) and ruthenium-based catalysts (Ru/C). Aspen Plus (c) was utilized to simulate the synthesis and separation processes with the product range from ammonia 0.1 -500 tonne/day. The detailed kinetic models, the Temkin equation and the modified one, were employed to evaluate catalytic activity in reactors precisely. The result shows the cost advantage of Ru/C on a small scale. Besides, on a small scale, the costs of heat exchangers and reactors are dominant, while the catalyst cost of Ru/C itself is not dominant on any scales. For the ammonia synthesis based on renewable energy, Ru/C catalyst under mild pressure, i.e., Ru/C-50 bar, is preferable. The direction of the future research on the catalyst of ammonia synthesis from the viewpoint of cost is also discussed. (c) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The paper analyzed the economies of scale in ammonia synthesis loops with iron-based and ruthenium-based catalysts, showing that ruthenium-based catalysts have cost advantages on a small scale. In addition to discussing catalytic activity and cost, the direction of future research on catalysts for ammonia synthesis is also highlighted.