Molecular Physics Longuet-Higgins Young Author’s Prize 2011 Winner Profile

摘要

Uncontrolled mixing of salty seawater with river water is an irreversible process, since a huge amount of entropy is created when the salt ions from the seawater redistribute themselves over a larger volume. However, these ions can also be made to perform work while they redistribute. In such a ‘controlled’ way of mixing, energy can be collected. The maximal power that can be gained from a river that flows into the sea is the same as from a waterfall of 200 metre altitude difference. In the paper we theoretically investigate a relatively new method that relies on cyclically charging and discharging highly porous electrodes that can be brought into contact with fresh and saline streams. We found a four-step cycle that has many analogies with the Carnot cycle. It therefore has maximal efficiency in gaining energy from the mixing process.