서강대학교

초록/요약

Water shortage and pollution are growing problems in many countries around the world. The need to alleviate water scarcity and ensure good water quality is a major challenge for the scientists and engineers in the coming century. The seawater desalination gets more attention as an alternative water supply source. There are several of methods for removing salt from seawater, among the many desalination methods, the forward osmosis process has recently received considerable attention. This is because it does not require any external energy for separation such as hydraulic pressure in reverse osmosis process and sensible heating energy in membrane distillation process. In this work presents energy, exergy analysis for a thermal and membrane desalination processes. FO desalination plant is compared to the energy requirements of the RO plant fitted with energy recovery turbines, and multi stage flash distillation process, for typical operating conditions. The main target of this analysis is to compare the energy efficiency and features of each desalination process. The analysis results show that the FO desalination process offers significant lowest value in energy consumption (1.4 kWh/m3) than RO (3.8 kWh/m3) and MSF plant (5.4 kWh/m3). Moreover exergy efficiency is also higher than other desalination methods. This is in part due to the ability of the FO process to use very low temperature heat, with correspondingly low thermal energy cost, in its solute separation process, an additional benefit found in the FO is low electrical energy consumption of the process. And we also discuss the concept of continuous FO desalination plant and hybrid plants in which the solute rejected by using nanofiltration process can be partly used to support a forward osmosis desalination plant.