Life cycle environmental impact and economic analysis of post-combustion carbon capture technologies in supercritical coal-fired power plants

Abstract

Coal-fired power plants remain a major contributor to global CO₂ emissions, necessitating the urgent deployment of carbon capture technologies to mitigate climate impacts. This study evaluated four post-combustion carbon capture (PCC) systems – monoethanolamine (MEA)-based chemical absorption, ammonia-based absorption, membrane separation, and calcium looping (CaL) – through life cycle environmental and economic assessments at the power plant level, to assess the trade-offs between emission reductions and cost-effectiveness across technologies. The results showed that, compared with the baseline plant, PCC technologies reduced the global warming potential and acidification potential by 61.3–77.6 % and 66.2–83.5 %, respectively. Other environmental impact categories increased to varying degrees, in particular Abiotic Depletion Potential fossil (by 3.8–49.3 %) and the marine aquatic ecotoxicity potential (by 10.8–66.8 %), which account for more than 80 % of the total environmental impact. The total life cycle costs of PCC plants increased by 35–66 % compared with that of the baseline plant, with external costs decreasing by 66.5–78.1 % and internal costs increasing by 62.6–100.9 %. The CaL power plant had the lowest environmental impact of the PCC plants except for Abiotic Depletion Potential elements, which had the largest reduction in external costs (78.1 %) and an increase in internal costs (77.7 %). Membrane separation PCC plants had the lowest total life cycle cost, reducing external costs by 70.0 %, while increasing internal costs by only 62.6 % compared. Thus, we recommend deploying membrane separation as a PCC technology, which combines environmental and economic factors. Our findings provide a reference for companies to select and deploy carbon capture technology.