Life cycle analysis of ammonia-driven calcium looping processes for post-combustion CO₂ capture in NGCC power plants

Integrating calcium looping (CaL) based carbon capture and storage (CCS) technology with an existing natural gas combined cycle (NGCC) power plants offers a promising solution for low-carbon energy production. This work introduces a novel NH₃-driven CaL process for retrofitting NGCC plants. The economic performance and environmental impacts of the process were analyzed through life cycle analysis and compared with those of conventional oxy-fuel CaL and solar-driven CaL technologies. Results indicate that, the NH₃-driven CaL demonstrates with a very low energy penalty of only 2.6 points, while the solar-driven CaL method faces a 14-points energy penalty. From an environmental perspective, the NH₃-driven CaL method, with considering various ammonia sources, significantly impacts the environment more than oxy-fuel and solar-driven methods, with global warming potential values of 207.7 (oxy-fuel), 170.7 (solar), and 197.6-258.8 g CO₂-eq/kWh (green NH₃). Economically, based on an annual operation time of 4000 h of NGCC, the solar-driven CaL system has the lowest Life Cycle Cost of GHG Removed (LCOR) at 247.7 $/t CO₂. With anticipated reductions in ammonia prices to 240 $/t in 2050, the NH₃-driven CaL system is expected to gain a significant advantage in economic at 46.5 $/t CO₂ when natural gas price is 0.6 $/Nm³. And it is important to pay attention the clean production process of ammonia to reduce its impact on the environment.