Distillation or Reverse Osmosis? An updated comparison of current technology for seawater desalination

Recent advances in membrane technology have consequently enhanced the feasibility of Reverse Osmosis (RO) for seawater desalination in many applications. Membrane advancements have contributed to greater fluxes, elevated membrane service life and reduced energy requirements, all of which translate into lower production costs. Additionally, improved operational schemes for energy supply and recovery have contributed to lower overall system energy consumption. On the other hand, Multi-Effect (MED) and Mechanical Vapor Compression (MVC) distillation technology have also advanced as a result of improved mechanical design, greater thermal efficiency, and operational schemes exploiting the benefits of cogeneration or waste heat. Whereas today, both Reverse Osmosis and Thermal Distillation have relative benefits in specific applications, this paper will analyze the current performance of each technology and compare their technical and economic feasibility in various current seawater applications.