Descripción

An optimal thermal seawater desalination proc-ess is disclosed, which combines two or more substan-tially different water pretreatment processes in a unique manner and in a special configuration, hereto unknown to prior desalination arts, to produce a high yield of high quality fresh water, including potable water. In this proc-ess a two stage NF membrane pretreatment unit (NF2) with an energy recovery turbo charger (TC) device in between the stages or equipped with an energy recovery pressure exchanger (PX) is synerglstlcally comblned with at least one thermal desalination unit to form a dual hybrid of NF2 - Thermal, or alternatively the two stage NF2 unit is synergistically combined with a two stage SWRO unit (SWR02) with an energy recovery TC in between the stages or combined with one stage SWRO (SWRO.,) equipped with an energy recovery TC or PX system and the reject from the SWR02 or SWRO., unit ¡s made make-up to a thermal unit to form a trihybrid of NF2 - SWR02 reject - Thermal. In both the cases of di- or trihybrids the thermal unit is equivalent to a multistage flash distillation (MSFD) or multieffect distillation (MED) orvaporcompression distillation (VCD) orthermal reheat (RH) evaporator.