Substantial Emerging Impact of Amine-Based Carbon Capture on Atmospheric Particle Formation under Carbon Neutrality

Abstract Carbon capture (CC) is indispensable to carbon neutrality, and amine-based absorption using monoethanolamine (MEA) is among the most mature CC technologies. MEA can enhance atmospheric new particle formation (NPF), the primary source of atmospheric particles. However, the atmospheric impacts of MEA escaping from future large-scale CC deployment remain unknown. Here, we develop a three-dimensional model that represents MEA sources, sinks, and H2SO4-MEA nucleation based on quantum chemical and cluster dynamics calculations, to evaluate atmospheric MEA and its impacts from CC deployment at China’s coal-fired power plants under carbon-neutrality scenarios. By 2060, even moderate CC deployment raises atmospheric MEA concentrations to tens of pptv, exceeding dimethylamine (DMA), the canonical urban NPF agent. H2SO4-MEA nucleation consequently overtakes H2SO4-DMA nucleation across extensive CC-deployment regions (∼1 million km2) and is more than 10 times stronger within the CC-intensive core (∼0.2 million km2), raising particle number concentrations by 50–187% and exposing ∼430 million people to levels exceeding the WHO high-exposure benchmark. The associated rise in ultrafine particles is estimated to cause ∼34,800 additional deaths across China in 2060. We reveal that CC deployment may deliver climate benefits while inadvertently worsening particulate pollution and public-health burdens, warranting proactive and early preventive action.