Beyond conventional desalination: A critical review of multigeneration systems and emerging pathways for sustainable water production

Desalination is increasingly expected to contribute not only to freshwater supply, but also to the broader transition toward integrated and sustainable energy–water systems. This review critically examines desalination within multigeneration frameworks, with emphasis on the progression from conventional thermal and membrane-based technologies to emerging pathways that improve resource efficiency and environmental performance. Using a structured and critically integrative review approach, the study synthesizes advances in desalination technologies, thermodynamic integration strategies, zero liquid discharge, supercritical water desalination, artificial intelligence-assisted optimization, and life-cycle environmental assessment. The analysis shows that integrating desalination with multigeneration systems can substantially enhance waste-heat utilization, improve overall thermodynamic performance, and support the simultaneous production of electricity, freshwater, and other useful outputs. Emerging approaches, particularly zero liquid discharge and supercritical water desalination, further expand the role of desalination by enabling brine minimization, resource recovery, and more circular process configurations. At the same time, the literature reveals persistent barriers to large-scale deployment, including limited long-term validation, high thermal and capital requirements in advanced systems, insufficient evaluation under realistic brine conditions, fragmented digitalization, and inconsistent sustainability assessment frameworks. Overall, the review demonstrates that the future of desalination depends on a shift from isolated process optimization toward integrated system design supported by intelligent control, realistic experimental validation, and harmonized techno-economic and environmental evaluation. This perspective provides a more comprehensive basis for advancing resilient, low-impact, and resource-efficient desalination systems for future water and energy security.