Thermodynamic Performance and Exergy Analysis of an Integrated Solar–Flared Gas Hybrid System for Water Desalination and Power Generation

ABSTRACT Flared gas and produced water represent two of the largest underutilized waste streams in the petroleum industry, while freshwater scarcity continues to challenge sustainable oil production. This study proposes a novel hybrid desalination–energy system that simultaneously utilizes flare‐gas thermal energy and solar energy through thermodynamic coupling between a combustion‐assisted high‐pressure evaporator and a vacuum‐assisted solar evaporation unit. An ejector generates subatmospheric pressure to enhance evaporation, while phase change material containing 4 wt% graphene quantum dots improves thermal storage and heat transfer. Experimental results showed that freshwater productivity increased from 2.1 to 6.5 kg m −2 day −1 , representing more than a threefold improvement compared with the conventional solar configuration. COMSOL simulations demonstrated approximately 35% faster thermal charging and nearly 60% longer effective heat release, with numerical predictions agreeing with experimental measurements within 3%. Energy and exergy analyses confirmed improved utilization of hybrid energy inputs despite localized irreversibilities in the combustion chamber and ejector. The evaporation–condensation process produced low‐salinity water suitable for reinjection into oil reservoirs, thereby reducing freshwater consumption and supporting sustainable produced‐water management. By integrating flare‐gas utilization, thermal energy storage, desalination, heat recovery, and partial power generation within a circular economy framework, the proposed system offers an energy‐efficient and environmentally sustainable solution for remote oil‐producing regions.