Solar Thermal-Based Sustainable Desalination Technology:\nValidation and Optimal Process Configuration

In\nthis contribution, a novel multieffect distillation (MED) system\nintegrated with a heat pump-assisted vapor recompressor (VRC) for\na feed preheating system is proposed for the first time for seawater\ndesalination. For this, the dynamic model of the base MED-ejector-assisted\nthermal vapor compression (MED-TVC) unit is formulated. Having satisfactory\npredictability of plant data and outperformance over an existing model,\nthis work introduces VRC by replacing TVC to employ it for feed preheating\nin the condenser coupled to the last effect of MED. To acquire the\nbenefits associated with this heat pump system along with optimal\ndesigning of the proposed MED-VRC configuration, the multiobjective\noptimization strategy is developed with three conflicting objectives,\nnamely, total distillate (freshwater) production, freshwater production\ncost, and CO<sub>2</sub> emission, under the framework of a genetic\nalgorithm. Securing better performance of this proposed MED-VRC over\nthe standalone MED-TVC system, an attempt is made to make this industrial-scale\nMED-VRC process carbon-neutral by introducing a solar system for steam\ngeneration and electricity to run the VRC. This sustainable process\ntechnology secures zero-emission at the same productivity but with\nfreshwater production costs on a higher side over the existing MED-TVC\nplant scenario.