Research Progress on Modified Amines for Carbon Dioxide Absorption: Bibliometric Insights and Pathways for Process Enhancement

Abstract Existing reviews on amine-based CO2 capture cover solvent chemistry, regeneration, and process development, but evidence remains distributed across solvent, process, and system scales. Here, we combine bibliometric mapping with a critical thematic review of modified amine absorbents for CO2 capture. A total of 2084 eligible publications indexed in the Web of Science Core Collection from 2015 to 2025 were analyzed using CiteSpace and VOSviewer; selected 2026 studies were used only qualitatively. The results show initial expansion (2015–2018), a high-output consolidation period (2019–2022), and renewed acceleration (2023–2025). Recent themes increasingly emphasize regeneration energy, phase-change absorbents, mass-transfer enhancement, stability, process design, and techno-economic analysis, indicating a shift toward coupled solvent–process evaluation. The technical synthesis organizes the evidence into five recurrent pathways: chemical structure modification, blended amine systems, phase-change absorbents, ionic-liquid-functionalized systems, and deep-eutectic-solvent-based systems. Across these pathways, engineering viability depends on tradeoffs among reaction kinetics, cyclic capacity, viscosity, degradation and corrosion, regeneration demand, and phase behavior. Accordingly, this review develops a three-tier framework─modification strategies–process intensification–system integration─that links solvent properties to dominant bottlenecks, compatible process-intensification options, and system-level screening through scaleup, techno-economic, and life-cycle considerations.