Study On The Extraction And Application Of Salinity Energy

With the oil energy consumption,in today's world energy less and less.Explore clean and renewable energy to satisfy the demand of human society for enemy is of great significance for the survival and sustainable development of human civilization.Salinity gradient energy stored as the salinity difference between seawater and freshwater is a large-scale renewable resource that can be harvested and converted to electricity,but extracting it efficiently as a form of useful energy for current technology remains a challenge.With the development of membrane science and technology,membrane-based techniques for energy extraction from salinity gradient energy,such as reverse electrodialysis,have get tremendous development in recent years,but have not commercial.So we should continue to explore new materials and methods to improve the reverse electrodialysis technology and the application in other fields,aiming to lay a foundation for in-depth research and applications.Inthis paper,we mainly study energy extraction from salinity gradient energy and applications.The followings are our significant work.(1)The study on power generation from salinity gradient energy by reverse electrodialysis.First we assembled a 10 cell pairs RED stack with 0.9mm spacers and DF-120 ion exchange membranes and the maximum output power density of the stack is 0.695W/m~2.In order to optimize the performance of reverse electrodialysis system,two difference reverse electrodialysis stacks were also assembled with 0.5mm spacers,DF-120 membranes and Tianwei new membranes.And the results show that: the maximum output power density achieved in the stack with 0.5mm spacers and DF-120 membranes is 1.20W/m~2,while the maximum output power density achieved in the stack with 0.5mm spacers and Tianwei new membranes is 0.60W/m~2.Through the comparison and analysis of the three reverse electrodialysis stacks,we know that :reduce the spacer thickness is very helpful to improve the output power density of reverse electrodialysis;while the influence of difference ion exchange membranes on reverse electrodialysis is mainly lies on itself characteristic.(2)The application of salinity gradient energy.An energy self-sufficient desalination stack was designed(which is integrated RED-ED stacks),through the evaluation and analysis of reverse electrodialysis and electrodialysis experiment results.And experiments were carried out under the optimal conditions.The results show that;under the optimum flow velocity,the NaCl in fresh water produced by RED-ED system with electrodes is lower than 500 mg/L,which realized the purpose of self-desalination and the salinity of produced fresh water reached the standard of drinking water.While the NaCl in fresh water produced by RED-ED system without electrodes is 507 mg/L,which also achieved self-desalination purposes,but the effect of desalination is slightly worse than RED-ED system with electrodes,and the salinity of produced fresh water did not reach the standard of drinking water.