Carbon sponge could decarbonize desalination
Researchers in the US have unveiled a new device that could be used in a solar-powered, near-equivalent of flash distillation to improve the sustainability of seawater desalination.The sponge-like material developed at the Massachusetts Institute of Technology (MIT) consists of a 10 cm diameter disc comprising a layer of graphite flakes with a porous carbon foam attached beneath it. The device floats on water where, according to the researchers, it converts 85% of solar energy into heat to form steam.
It applies the heat to a small volume of water - a principle behind flash distillation: "Basically, if you heat up the whole volume of the water, you don't raise the temperature very much. However, if you only heat up a small amount of water, then the temperature rise could be high," explained MIT professor of mechanical engineering, Gang Chen. Chen explained that by floating the graphite on the surface of the water, the researchers were able to concentrate the maximum amount of incoming sunlight.
He went on: "In remote areas where the sun is the only source of energy, if you can generate steam with solar energy, it would be very useful." Chen said he was excited about the potential for the material in water treatment, desalination or treating wastewater. The potential, he said, could be huge for water treatment in isolated, impoverished areas.
He was careful to emphasize, however, that his team's recent breakthrough in the laboratory was just a first step.