International Science and Technology Journal

Producing fresh water from seawater by using RO desalination plants is known to be expensive due to its high energy requirements, so the main subject of desalination companies is to reduce the cost of producing water, one way to reduce the cost of water production is done by reducing the specific energy consumption (SEC) which is the most determinant factor in operation cost of seawater reverse osmosis (SWRO) desalination plants. The energy consumption is reduced by using the energy recovery devices (ERDs), these devices exploit the waste energy in the concentrated brine and return it to the feeding line. This paper aims to study the possibility of reducing the SEC of the Tajoura SWRO desalination plant by replacing the ancient ERD (reverse running pump) by a modern efficient ERD, therefore, the SEC by using a different types of ERDs has been calculated and compared with the reverse running pump. The results confirmed that the lowest value of SEC was when using the pressure exchanger (PX) with value of 2.12 kWh/m3, while it was 3.89 kWh/m3 by using the currently device. The PX device saved 61.7% of the energy compared with 29.7% saving in the reverse running pump. In general, for all studied ERDs, it was found that the energy savings in the positive displacement devices are greater than the saving in centrifugal devices.