New system could put dead seaweed to use as a source of power
By Ben Coxworth
May 6, 2013
Dead seaweed on a beach in the Spanish city of Alicante
When it’s alive and in the ocean, seaweed serves as a habitat, spawning ground and food source for marine life. Once it gets washed ashore, however, it pretty much just rots. Typically, along beaches in tourist areas, that dead seaweed is simply gathered and taken to a landfill. Now, however, researchers from Spain’s University of Alicante have conceived of a new seaweed-removal system that has less environmental impact, and that allows the seaweed to be used as an energy source.
Normally, when dead seaweed is gathered off Spanish beaches, a lot of sand and sea water is gathered with it. This makes it quite heavy and bulky to transport, and causes it to take up a lot of space in the landfills.
Additionally, the salt content of the water limits its potential uses, while the beach gradually loses sand with each new load of seaweed that’s taken away – in some cases, sand from outside sources needs to be periodically brought in to replace what’s been removed.
The new system, however, would reportedly reduce the weight and volume of the gathered seaweed by up to 80 percent, in the form of less sand and seawater.
It would consist of a flatbed trailer-like wheeled platform, containing three linked hoppers. As it was wheeled along the beach, human workers would deliver loads of wet, sandy seaweed into the first hopper, where it would be swirled with pumped-in seawater. As that water subsequently flowed back into the sea, it would take the bulk of the sand with it.
The seaweed would then proceed into the second hopper, where seawater that had been desalinated using a solar-powered device would be used to rinse much of its salt content away. It would then go into the third hopper, where air heated via solar power would be used to dry it.
Finally, it would be compressed into bales or pellets. Among other possible uses, it is hoped that it could then be used as a source of biomass in power plants.
The research was led by Prof. Irene Sentana Gadea.
Scientists from Germany’s Fraunhofer Institute for Chemical Technology have also developed a process for converting waste seaweed into building insulation.
Source: University of Alicante (Spanish)
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