Self-Powered Desalination of Geothermal Saline Groundwater: Technical Feasibility

Water

Philip A. Davies¹  Jamel Orfi² 

[1] Sustainable Environment Research Group, School of Engineering and Applied Science, Aston University, Birmingham B4 7ET, UK;Department of Mechanical Engineering, College of Engineering, King Saud University, PO Box 800, Riyadh 11421, Saudi Arabia; E-Mail:

关键词: desalination;    brackish water;    organic Rankine cycle;    geothermal;    reverse osmosis;    exergy;    self-powered;    high recovery;   

DOI  :  10.3390/w6113409

来源: mdpi

【 摘 要 】

This theoretical study shows the technical feasibility of self-powered geothermal desalination of groundwater sources at <100 °C. A general method and framework are developed and then applied to specific case studies. First, the analysis considers an ideal limit to performance based on exergy analysis using generalised idealised assumptions. This thermodynamic limit applies to any type of process technology. Then, the analysis focuses specifically on the Organic Rankine Cycle (ORC) driving Reverse Osmosis (RO), as these are among the most mature and efficient applicable technologies. Important dimensionless parameters are calculated for the ideal case of the self-powered arrangement and semi-ideal case where only essential losses dependent on the RO system configuration are considered. These parameters are used to compare the performance of desalination systems using ORC-RO under ideal, semi-ideal and real assumptions for four case studies relating to geothermal sources located in India, Saudi Arabia, Tunisia and Turkey. The overall system recovery ratio (the key performance measure for the self-powered process) depends strongly on the geothermal source temperature. It can be as high as 91.5% for a hot spring emerging at 96 °C with a salinity of 1830 mg/kg.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.