Exceeding equilibrium limitations: Enhanced temperature control for sustainable decentralized green ammonia production − a techno-economic analysis
Hossein Asgharian, Valeria Pignataro, Florin Iov, Mads Pagh Nielsen, Vincenzo Liso
Abstract
The focus on green ammonia production has intensified due to its reduced power consumption, independence from fossil fuels, and elimination of carbon dioxide (CO2) emissions. Unlike conventional Haber-Bosch processes, which rely on hydrogen produced by fossil fuels and chillers to separate ammonia from unreacted gases and are constrained by equilibrium limitations, green ammonia production methods utilize hydrogen generated by water electrolysis. They typically employ metal halide materials for ammonia separation, enabling them to surpass equilibrium constraints. This study proposes a novel configuration for synthesis of green ammonia at elevated temperatures and facilitating its absorption at lower temperatures. Furthermore, it presents a comprehensive model of an alkaline electrolyser to supply the required hydrogen for green ammonia production. Additionally, this study proposes a novel method for cooling the electrolyte, leading to a 13.27% enhancement in the electrolysers system efficiency. Moreover, the analysis indicates that the proposed green ammonia production approach could reduce the power consumption by 46.2% compared to the green Haber-Bosch process. The economic analysis indicates that the proposed cooling method can reduce ammonia production costs by up to 19%, based on the electricity prices in 2023.