Advanced Materials for Solar Photomolecular Desalination
Water scarcity is a great challenge facing humanity and Morocco lies in a water-stressed region projected to become even more arid over the coming decades of climate change. Desalination of seawater and brackish groundwater via reverse osmosis and thermal distillation already provide critical sources of potable water at competitive prices in many areas, but only at significant scale and large upfront capital expenditure in limited locations. At small scale and off-grid locations, the costs and feasibility of these proven desalination technologies are prohibitive.
In response to these challenges, we have been developing direct solar thermal technologies to efficiently generate steam using floating and suspending structures. This effort recently led to our discovery of an unexpected and potentially game-changing phenomenon—the photomolecular effect. This involves the direct cleavage of larger water clusters by photons in the visible range of light from the water-vapor interface, despite bulk water being only weakly absorbing in this wavelength range. Our discovery explains the experimental observation that solar evaporation from nanoporous materials can exceed the thermal evaporation limit. Our preliminary results indicate that the rate of photomolecular evaporation can exceed that of thermal evaporation by an order of magnitude or more. This exciting discovery opens up the prospect of developing a cheap and efficient desalination technology at modest scale. However, currently nanoporous materials are not yet proven to be feasible for low-cost water production. In this project, we aim to develop and optimize materials that will make direct solar photomolecular desalination technology a competitive reality, with working prototypes developed and deployed at UM6P’s Green Energy Park.
UM6P project team
Professor Mohamed Chaker Necibi