This work presents the thermodynamic and techno-economic assessment of a forward osmosis – multi-effect distillation (FO-MED) system able to improve the thermal performance of the MED seawater desalination process and reduce its environmental impact. Energy, exergy and techno-economic analyses have been carried out to identify the best boundary conditions that enhance the process efficiency and water cost, predicting the scale formation with the Ryznar index. Results show that using FO pretreatment in a 100 m³/d MED plant of 8 effects at 65 °C allows increasing the heating steam temperature up to 100 °C and the number of effects to 16 without increasing the risk of scaling. This results in 44 % reduction of the specific thermal energy consumption and 21 % decrease in the specific heat transfer area. The volume of saline water rejected to the sea is reduced 40 % and the water footprint 36 %. The exergy analysis reveals that the MED is the component with the highest exergy destruction. Finally, the levelized cost of water of the FO-MED is higher (7.6 $/m³) than the standalone MED process (4.6 $/m³). If high-performing and cost-effective membranes are used, the product cost could be reduced 33 % (5.1 $/m³).

这项工作介绍了正向渗透 - 多效蒸馏 (FO-MED) 系统的热力学和技术经济评估，该系统能够改善 MED 海水淡化过程的热性能并减少其对环境的影响。已经进行了能源、火用和技术经济分析，以确定提高工艺效率和水成本的最佳边界条件，并使用 Ryznar 指数预测结垢。结果表明，使用 FO 预处理在 100 m ³/d MED 装置在 65 °C 下具有 8 个效果，允许将加热蒸汽温度提高到 100 °C，并将效果数量增加到 16 个，而不会增加结垢的风险。这导致比热能消耗减少 44%，比热传递面积减少 21%。排入大海的咸水量减少了 40%，水足迹减少了 36%。火用分析表明，MED 是火用破坏最高的组件。最后，FO-MED 的平准化水成本（7.6 $/m ³）高于独立的 MED 工艺（4.6 $/m ³）。如果使用高性能且具有成本效益的膜，产品成本可降低 33%（5.1 美元/m ³）。