Comparison of spacer-less and spacer-filled reverse electrodialysis

초록

Reverse electrodialysis (RED) is a renewable energy technology used to recover dissipated chemical energy in river estuaries globally. This technology has recently attracted significant attention owing to its great reliability and scalability. In this study, we propose the use of a spacer-less RED (i.e., a system in which a woven mesh is excluded from the flow channel). The performance of spacer-less RED, including its gross power density, internal resistance, and hydraulic loss, is compared with that of the spacer-filled RED, in relation to the variation in the inlet flow rate. The mixing enhancement is more important than the spacer shadow effect when considering power generation. The spacer-filled RED has uniform internal resistance over the whole range of flow rates, while the spacer-less RED shows a dramatic decrease in resistance with the increasing flow rate. The hydraulic loss is much lower in the spacer-less RED. The maximal net power, accordingly, is generated at the flow rate of 3 ml/min (for spacer-filled RED) and 12.5 ml/min (for spacer-less RED). In the end, a maximal net power density of 0.62W/m(2) was obtained in both structures. Published by AIP Publishing.

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