Search

Low-grade heat energy is enormous and widely distributed around the world, but it cannot be effectively converted to electricity owing to the small temperature difference and fluctuating heat source. As a promising technology that can convert low-grade heat energy into electricity while obtaining additional freshwater, thermo-osmotic energy conversion has attracted attentions of numerous researchers. However, traditional thermo-osmotic energy conversion technologies lack the utilization of the accompanying variation in salinity gradients throughout the process. In this study, a hybrid system was presented to achieve simultaneous freshwater production and electricity generation by combining thermo-osmosis system with a salinity gradient power recovery module. Continuous operation of the thermo-osmosis system will naturally produce a range of salinity differences, which will then be converted into electricity by the salinity gradient power recovery module. Our results show that this hybrid system can optimally increase the electricity output by ∼0.99 W m−2 over the conventional thermo-osmotic energy conversion system. Overall, our research demonstrates a promising device to harvest low-grade waste heat for co-generation of electricity and freshwater. This innovative approach has the potential to broaden the application possibilities of thermo-osmosis technology. • Salinity gradient recovery combined thermal-osmosis hybrid system was proposed. • A theoretical model was developed to predict electricity output of the system. • Comparing to traditional TOEC, increasing electricity output by ∼0.99 W m−2. • Co-generation of freshwater and electricity was achieved under real seawater. [ABSTRACT FROM AUTHOR]

Currently, energy conversion methods in nanochannels have been developed for both fundamental sciences and technological applications. Graphene oxide membranes with excellent properties possess potential applications in numerous fields. Due to the confinement of nanocapillaries within graphene oxide membranes and the mobility difference of ions, an electricity generation process has been achieved using graphene oxide membranes. In this study, for the first time, the influence of source concentration, applied pressure and membrane thickness was investigated on electricity generation in aqueous environment. The results revealed that these three factors could successfully control the electricity generation with graphene oxide membranes. Electrical potential difference would become larger with increasing the source concentration and membrane thickness. In contrast, the applied pressure was not well-suited to capture energy from sources. This provided new insights into the design and utilization of graphene oxide films for highly efficient energy harvesting. [ABSTRACT FROM AUTHOR]