A comparative prospective life cycle assessment of coal-fired power plants in the US with MEA/MOF-based carbon capture

Abstract

The adoption of carbon capture technology in coal-fired power plants is expected to play a pivotal role in the energy transition. This study conducted consequential life cycle assessments (CLCAs) of coal-fired power generation in the United States using policy-level accounting. Monoethanolamine (MEA)-based and Mg-MOF-74-based carbon capture have been introduced, with a comparative analysis conducted on the emissions reduction potential of these two materials through their respective mechanisms of absorption and adsorption. The results indicate that carbon capture based on MEA or Mg-MOF-74 can significantly reduce emissions from coal-fired power generation, decreasing from 779.5 Mt CO2e to 50.1 Mt CO2e and 61.1 Mt CO2e in 2050, respectively. The introduction of ultra-supercritical power plants and carbon capture reduced direct emissions from 92% to 51%. MEA outperforms Mg-MOF-74 slightly, with lower emissions due to solvents and cleaning processes. Deviations in Mg-MOF-74's adsorption capacity and degradation rate could lead to 4%–6% model outcome variations. It is also concluded that the stability of MEA's marginal emissions depends on a steady expansion of existing production capacity, while the marginal emissions of Mg-MOF-74 are anticipated to remain unchanged. This study emphasizes carbon capture's potential but stresses the need for prompt implementation and comprehensive assessments before deployment decisions.