Advanced optimization of a biogas-based multigeneration multi effect distillation system integrated with desalination process for enhancing sustainable energy resource efficiency: CatBoost-supported multi objective multi-verse optimization

The increasing global demand for sustainable energy and water resources highlights the need for integrated systems capable of delivering multiple utilities with high efficiency and reduced environmental impact. Conventional single-generation systems are often limited by low efficiency and high emissions, underscoring the urgency of developing advanced multigeneration solutions. To address this challenge, this study introduces an innovative biogas-fueled multigeneration system that couples a supercritical CO₂ cycle, ammonia Rankine cycle, Kalina cycle, multi-effect desalination, refrigeration, and liquefied natural gas (LNG) regasification into a thermally integrated configuration so as to simultaneously produce electricity, hot water, chilled water, and freshwater. A CatBoost-assisted multi-objective Multi-Verse Optimization (MVO) framework is employed to identify optimal operational conditions. Simulation results reveal that the proposed system achieves energy and exergy efficiencies of 46.96 % and 21.85 %, respectively, while environmental assessment shows a 56.21 % reduction in CO₂ emissions compared to single power generation, with a low carbon footprint of just 0.367 kg/kWh. Economic evaluation further indicates a competitive levelized cost of energy (0.12 $/kWh) and an exergo-economic cost of 67.63 $/GJ, with optimization yielding an optimal Case II configuration characterized by 29.06 % exergy efficiency, 50.84 $/GJ cost, and 0.317 kg/kWh footprint. These outcomes demonstrate the feasibility of the system for real-world deployment, offering sustainable, efficient, and cost-effective energy-water co-production.