Techno-economic analysis of ammonia cracking for large scale power generation

Abstract

The increasing interest in leveraging green ammonia to mitigate carbon emissions in fertilizer production is paralleled by an expanding acknowledgment of its potential as a fuel for decarbonizing the electricity sector, particularly in high-efficiency gas turbine power plants. Co-firing ammonia with hydrogen presents a promising method for integrating ammonia into existing infrastructures. Within this context, the development of efficient technology for ammonia cracking presents a potential avenue for deploying ammonia in gas turbines. The objective of this study is to conduct a preliminary techno-economic evaluation and uncertainty analysis of two cracking technologies namely a membrane reactor and a conventional FTR (Fired Tubular Reactor) for the co-firing of ammonia with hydrogen in a CCGT (Combined Cycle Gas Turbine) plant. The integration of a membrane reactor during the cracking stage demonstrates a remarkable improvement in the system's thermal efficiency, surpassing traditional approaches by over 25%. Additionally, it brings about an approximate 10% reduction in the levelized cost of hydrogen (LCOH), despite a higher initial capital expenditure (CAPEX). At the CCGT level, the discrepancy in levelized cost of electricity (LCOE) narrows, as it is strongly influenced by the cost of ammonia constituting 80% of the LCOE. Beyond LCOE, the widespread adoption of these systems also faces challenges due to material scarcity. Analysis reveals that revamping just 1 GWe of CCGT assets using membrane reactors would for example necessitate approximately 0.11% of the global palladium supply, and 10% of the global ruthenium production. Considering the limited availability of these resources, coupled with their high demand across multiple sectors and the possibility of external factors such as geopolitical tensions, this strategy seems unfeasible. To tap into this market, future research should prioritize the exploration of alternative membrane materials, such as carbon molecular sieves, and catalysts, like nickel.