System and method for desalination of water

Abstract

A system for producing desalinated water from seawater or other saline water, wherein the system comprises the following equipment features or equipment items, in a typical direction of flow: a subsea seawater inlet, a subsea pretreatment stage, at least comprising one or more of a subsea filter and/or a subsea seawater pre-treatment unit and/or a subsea coarse screen unit, and/or a hydrocyclone, a subsea feed pump, fluidly coupled to, a subsea RO unit, a subsea product pump fluidly coupled to a RO unit product outlet, a product line fluidly coupled to the subsea product pump, and a RO unit reject outlet, preferably coupled to a reject line. The system is distinctive in that: the subsea seawater inlet is at a depth below or within the thermocline layer of the seawater, that is below the epipelagic zone, or as close as feasible if the local depth is insufficient to reach the thermocline layer, and wherein the system preferably is without any barrier fluid supply to the subsea pumps.