A novel spiral wound module design for harvesting salinity gradient energy using pressure retarded osmosis

Abstract

Pressure retarded osmosis (PRO) is an evolving form of a renewable energy process which utilizes the salinity gradient energy from two solutions of different concentrations. One of the main problems limiting the application of PRO is the low performance of the commercially available spiral-wound modules which have poor flow distribution and high pressure drop. The present paper proposes a new spiral-wound module design for PRO application. The performance of the new module design was investigated numerically and compared with the available spiral-wound module. Compared to the available module, the power density of the new design was higher by 25% and 15% at draw concentrations of 35 g/kg and 60 g/kg respectively, while there was a 35% decrease in the pressure drop. The new spiral-wound module design presents an enhanced overall performance due to the better flow distribution and lower pressure drop, yielding a higher water flux and power density.