Integration of pressure retarded osmosis in the solar ponds for desalination and photo-assisted chloralkali processes: Energy and exergy analysis

摘要

The proposed system uses the thermal energy storage characteristic of the solar pond to power a multi-effect desalination (MED) process with a total fresh water production of approximately 14,000 m(3) annually. Pressure retarded osmosis (PRO) alongside photo-assisted chloralkali reactor are employed to utilize the brine rejected from the desalination process. The inclusion of PRO is proposed to take advantage of the salinity difference that occurs as a result of the preparation of the solar pond and desalination process. The quest for zero salt discharge in the proposed energy system configuration is undertaken through the introduction of a photo-assisted chloralkali reactor, which is conducted utilizing the power generated from PRO, and solar pond storage arrangement. This solar pond and desalination coupling system will achieve independence from conventional energy sources, which will lead to a significant contribution to the reduction of greenhouse gas emissions caused by fossil-fuel driven desalination. At solar irradiation of 600 W/m(2), the overall energy and exergy efficiencies can reach 16.4% and 1.40/0, respectively. The annual average overall energy efficiency of 11.4% is achieved utilizing the integrated system, whereas the average overall exergy efficiency is about 0.9%. Parametric studies are performed to examine the impacts of ambient conditions, irradiance, solar pond geometry, brine salinity, and the total number of MED effects on the performance of the overall integrated system. In addition to the sensitivity analysis, the potential to improve overall energy and exergy efficiencies and fresh water production of the proposed system is demonstrated.