Adsorption Processes for Seawater Desalination

Porous adsorbent materials (silica gel, zeolite, and metal-organic framework, etc.) have a high affinity to water molecules, which provides a strong driving force for desalination and water treatment. An adsorption desalination cycle is based on the interaction between adsorbents and water vapor. Compared with other water treatment technologies, adsorption desalination is able to treat various feed water sources using low-grade heat sources. This chapter presents a comprehensive overview of the adsorption process and its applications in desalination and water treatment. A universal adsorption isotherm model, which is capable of capturing the behavior of all adsorbent-adsorbate pairs, is firstly introduced to allow an in-depth understanding of the adsorption thermodynamics. Then various applications of the adsorption cycle are presented, including standalone adsorption desalination cycles (temperature-swing and pressure-swing) and their integration with other water treatment systems (multi-effect distillation and evaporative crystallizer). These applications demonstrate the great potential of the adsorption process in the water industry.