The challenges of hydrogen transportation and storage can be addressed using ammonia as a chemical carrier. In this context, enhancing the efficiency of ammonia decomposition is a key step toward enabling this solution. In this study, high- and low-pressure ammonia decomposition plants were proposed and compared based on techno-economic and environmental criteria. Rigorous process simulations were developed in Aspen Plus and Aspen Adsorption, incorporating model validation against experimental data. A detailed dynamic model for hydrogen purification by PSA is developed, in contrast to the black box approaches commonly adopted in the literature. Results indicated that the high-pressure plant exhibited superior performance in economic, environmental, and energy criteria. Although the reaction is favored at low pressure, hydrogen recompression leads to substantial electricity consumption. The estimated levelized cost of hydrogen (LCOH) for the high-pressure plant is 9.45 USD per kg, decreasing to 4.16 USD per kg by 2050, driven by the reduction in renewable energy costs. • A rigorous large-scale PSA model based on conservation equations was developed. • The estimated LCOH for the high- and low-pressure plants 9.45 and 9.84 USD∙kg −1 . • High-pressure operation improved performance, reducing energy use by 18.4%. • In 2050, the high-pressure route may reach an LCOH of 4.16 USD∙kg −1 .
Avilez et al. (Wed,) studied this question.