Techno-economic assessment of gas turbine combined cycles with multi-stage ammonia decomposition

More attention has been paid for transition from hydrocarbon fuels to zero‑carbon fuels on power generation. Partial ammonia cracking has emerged as an effective solution that leverages superior hydrogen combustion characteristics while retaining ammonia storage advantages. To overcome the challenges of thermal integration and thermochemical reaction limitations incorporating conventional thermal/catalytic ammonia cracking, a multi-stage decomposition concept on reciprocating heat is proposed and assessed from a techno-economic perspective. The results indicate that multi-stage reciprocating heat decomposition configurations reduce cracker scale and catalyst usage by nearly 90 %, with the adiabatic packed column configuration achieving the highest system exergy efficiency of 55.9 % and lowest levelized cost of electricity (LCOE) at €210.6/MWh. Increasing the ammonia cracking ratio from 10 % to 40 % leads to a 2.2 % gain in exergy efficiency and a 1.4 % reduction in LCOE, but also raises ammonia fuel supply equipment costs by 35.0 %. Ammonia price remains a critical barrier to the development of partially cracked ammonia combine cycles (PCACCs). The LCOE for PCACCs ranges from €210.6 to €222.8/MWh, with fuel costs accounting for 68.2 % to 70.1 % of the total—substantially higher than the 29.2 % observed in the natural gas combined cycle. Scaling up PCACCs from 50 MW to 830 MW leads to a reduction in the LCOE of 23.4 %. As green ammonia prices decrease to about €180/t, PCACCs are expected to become increasingly competitive with traditional carbon capture technologies.