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

Abstract

In this contribution, a novel multieffect distillation (MED) system integrated with a heat pump-assisted vapor recompressor (VRC) for a feed preheating system is proposed for the first time for seawater desalination. For this, the dynamic model of the base MED-ejector-assisted thermal vapor compression (MED-TVC) unit is formulated. Having satisfactory predictability of plant data and outperformance over an existing model, this work introduces VRC by replacing TVC to employ it for feed preheating in the condenser coupled to the last effect of MED. To acquire the benefits associated with this heat pump system along with optimal designing of the proposed MED-VRC configuration, the multiobjective optimization strategy is developed with three conflicting objectives, namely, total distillate (freshwater) production, freshwater production cost, and CO 2 emission, under the framework of a genetic algorithm. Securing better performance of this proposed MED-VRC over the standalone MED-TVC system, an attempt is made to make this industrial-scale MED-VRC process carbon-neutral by introducing a solar system for steam generation and electricity to run the VRC. This sustainable process technology secures zero-emission at the same productivity but with freshwater production costs on a higher side over the existing MED-TVC plant scenario.