MIT Combines Carbon Foam and Graphite Flakes For Efficient Solar Steam Generati 110
rtoz (2530056) writes Researchers at MIT have developed a new spongelike material structure which can use 85% of incoming solar energy for converting water into steam. This spongelike structure has a layer of graphite flakes and an underlying carbon foam. This structure has many small pores. It can float on the water, and it will act as an insulator for preventing heat from escaping to the underlying liquid. As sunlight hits the structure, it creates a hotspot in the graphite layer, generating a pressure gradient that draws water up through the carbon foam. As water seeps into the graphite layer, the heat concentrated in the graphite turns the water into steam. This structure works much like a sponge. It is a significant improvement over recent approaches to solar-powered steam generation. And, this setup loses very little heat in the process, and can produce steam at relatively low solar intensity. If scaled up, this setup will not require complex, costly systems to highly concentrate sunlight.
The next generation of MIT? (Score:4, Insightful)
costly concentration (Score:5, Insightful)
> if scaled up, this setup will not require complex, costly systems to highly concentrate sunlight.
So, mirrors are costly now - does that imply that this carbon foam stuff is cheaper to produce than a sheet of polished stainless steel? If so that *is* promising.
Re:De-salination? (Score:4, Insightful)
Oh, now *there's* an idea. I suspect you'd have issues using saltwater though - when the water is boiled the salt would be left behind within the foam. In a closed-loop system that might not be an issue as the distilled water would be reintroduced to the reservoir preventing excessive concentration of salts, but otherwise you'd almost certainly end up with salt crystals completely coating the foam, Which would either render it immediately ineffective or eventually build up to such a level that it dies as a solid block of salt with an embedded carbon lattice.
Of course desalination isn't cheap, so it might be cost-effective to replace the foam regularly. You might even be able to rinse the crystals away with filtered seawater in order to reuse the foam.
Re:De-salination? (Score:5, Insightful)
You wouldn't boil the saltwater in foam, genius. Use properly prepared and recycled water as a heat transfer fluid and use that heat to distill seawater in tanks built for that process.