Thermodynamics Analysis of a Membrane Distillation Crystallization Ion Recovery System for Hydroponic Greenhouses Assisted with Renewable Energy

Sustaining agricultural demands is a typical problem, particularly in locations afflicted by the scarcity of fresh water, poor farming soil, and hot weather. The main goal of this study is to perform a thermodynamic analysis of an integrated multigeneration system containing a direct contact membrane distillation crystallization system that recovers beneficial hydroponic farming nutrients from seawater using renewable energy resources. A parametric study is carried out to determine the impacts of various factors on the system, such as changing the rate of mass flow rate, recovery ratio, and salinity. This study proposes a novel sustainable multigeneration system for seawater desalination and ions recovery using the direct contact membrane distillation crystallization system to provide the hydroponic solution and greenhouse ventilation using the dual evaporator vapor compression refrigeration system. With overall exergy efficiency and energy efficiency of 41.40%, and 39.80%, respectively, the system requires about 1182.69 kW and 5314.6 kW of electrical and thermal power in total, respectively, to desalinate 5 kg/s of seawater and recover 170 mg/s of Sulfate (SO₄), 81.28 mg/s of Magnesium (Mg), 25.48 mg/s of Calcium (Ca), and 24.16 mg/s of Potassium (K), yielding about 4.4 kg/s of a hydroponic solution, and ventilating 25 greenhouses with a volume of 600 m³ of single greenhouse.