摘要
Salinity gradient energy between the concentrated and diluted electrolyte solutions can be converted to electric energy by using reverse electrodialysis(RED) technology. Electrolyte solution is a vital factor that impacts the energy conversion efficiency. Potassium acetate(KAc) was chosen as solute, and water, ethanol, 2,2,2-trifluoroethanol(TFE), 2-propanol(IPA) and several of their binary mixtures were selected as solvents. Electric conductivity of these solutions were measured under varying conditions. KAc was easily ionized in water and possessed the maximum electric conductivity, following by KAc–H_2O–TFE and KAc–H_2O–ethanol, and then KAc in pure TFE, ethanol, and IPA respectively. For electric convertibility of these solutions working in a RED power generation system, it was found that the KAc–H_2O possessed the maximum power density, and the KAc–ethanol–H_2O possessed the larger open circuit voltage than aqueous KAc solution under the same working condition. Besides, it was observed that both the electric conductivity and electric convertibility were significantly influenced by the concentration and temperature of solution. With the increasing of concentration,electric conductivity of these solutions increased firstly and then reached to the peak, but later it decreased.Solution temperature took a positive impact role to the electric conductivity. Electric conductivity of these solutions can be estimated by using a modified amplitude version of Gaussian peak function.
Salinity gradient energy between the concentrated and diluted electrolyte solutions can be converted to electric energy by using reverse electrodialysis(RED) technology. Electrolyte solution is a vital factor that impacts the energy conversion efficiency. Potassium acetate(KAc) was chosen as solute, and water, ethanol, 2,2,2-trifluoroethanol(TFE), 2-propanol(IPA) and several of their binary mixtures were selected as solvents. Electric conductivity of these solutions were measured under varying conditions. KAc was easily ionized in water and possessed the maximum electric conductivity, following by KAc–H_2O–TFE and KAc–H_2O–ethanol, and then KAc in pure TFE, ethanol, and IPA respectively. For electric convertibility of these solutions working in a RED power generation system, it was found that the KAc–H_2O possessed the maximum power density, and the KAc–ethanol–H_2O possessed the larger open circuit voltage than aqueous KAc solution under the same working condition. Besides, it was observed that both the electric conductivity and electric convertibility were significantly influenced by the concentration and temperature of solution. With the increasing of concentration,electric conductivity of these solutions increased firstly and then reached to the peak, but later it decreased.Solution temperature took a positive impact role to the electric conductivity. Electric conductivity of these solutions can be estimated by using a modified amplitude version of Gaussian peak function.
基金
Supported by the National Natural Science Foundations of China(51606024,51776029)
the Fundamental Research Funds for Central Universities(DUT17JC31)
the China Scholarship Council(iCET2017 Program)
