Abstract
Desalination plants consume considerable amounts of energy for producing fresh water from seawater. Multistage flash (MSF) desalination plants require as high as 193-290 KJ per Kg of fresh water produced depending on the maximum operation temperature. Reverse osmosis (RO) for seawater only consume about 43 KJ per Kg of fresh water produced. This energy requirements of RO plants can be reduced approximately by 40% if the energy of the pressurized rejected water is recovered. There are four possible systems for energy recovery in RO plants. These include Pelton turbine, reaction turbine, hydraulic power recovery turbine and reverse running centrifugal pump. This paper will evaluate the feasibility of using these systems in RO plants for obtaining lower water production cost.