Integrating desalination with carbon capture in multi-generation energy systems: a comprehensive review of efficiency and environmental impacts

Water scarcity and the urgent need to decarbonize energy systems are two critical global challenges of this century. Conventional thermal and membrane-based desalination remains constrained by high energy consumption, greenhouse gas emissions, and brine discharges. This review provides a system-level synthesis of integrating desalination with power generation and carbon capture and storage (CCS) within co-generation and multi-generation energy frameworks, based on a systematic analysis of peer-reviewed literature from the past two decades using thermodynamic, environmental, and techno-economic metrics. Five thematic areas are examined: (i) operating principles and efficiency limits of major desalination technologies and their waste-heat compatibility; (ii) pre-combustion, post-combustion, and oxy-fuel CCS approaches and their multi-generation suitability; (iii) thermodynamic coupling mechanisms demonstrating up to 2.5 times higher exergy recovery versus standalone configurations; (iv) life-cycle environmental impacts including carbon footprint and brine management; and (v) techno-economic drivers including levelized cost of water and technology readiness levels (TRL 4–9). Key findings show that oxy-fuel multigeneration systems, particularly the Allam cycle and supercritical CO₂ Brayton configurations, achieve 40–86% energy efficiency with near-zero emissions. Solar-assisted CCS-Multi Effect Desalination (MED) integration raises overall efficiency from 28% to 81%, capturing over 1.5 million tonnes of CO₂ annually. Persistent barriers including thermal mismatch, high-temperature scaling, and high capital costs must be addressed for large-scale deployment. A strategic decision-support framework aligning TRL constraints, regional resources, and sustainability targets is introduced, with priority research gaps identified in experimental validation and brine valorization.