New system could put dead seaweed to use as a source of power
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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Washing out the sand and removing as much as the water as practical on the beach are good ideas but unless they are dumping fresh water into the sea, they are going to need a salt tolerant incinerator or anaerobic digester if they want to use it as a fuel source.
Further, salt water is more conductive than fresh, which would then raise the possibility of using solar electricity to split the water into hydrogen and oxygen, then recombine to give pure water, when some of the heat from the combustion could be harvested for another use, perhaps in drying the weed.
While reverse osmosis desalination can be less energy intensive than distillation there is no way that solar energy collected by that truck will produce enough fresh water for any meaningful reduction of salt content in the seaweed.
Your electricity to hydrogen to electricity and water idea is interesting but you will also be liberating chlorine which is rarely a good thing.
However by the nature of their construction photovoltaic panels pack flat and a fairly large area of collector surface could be transported to the site on a separate vehicle. Further, there is no reason why some solar collectors could not be assembled the previous day on site, and then when the day's work is finished, moved to the next site, and so forth. Maybe the vehicles themselves could have some electrical propulsion using electricity generated etc.
My main reason for commenting however was to show that there was more than one way of tackling the problem, not just solar distillation.
As for the chlorine problem, what is to stop the chlorine recombining with the sodium to give salt again? Surely the processes of splitting and recombining the components of NaCl won't BOTH consume more energy than they consume.
Additional vehicles means additional cost, and the illustration shows 3 tiny panels of solar collectors. Some of the sodium will combine with oxygen. I would say this needs to be cost effective but it is a green energy project.
You had me until you got to the taxes and force. The free market solves all problems. No force needed. No theft (tax) needed. For example, baby seals are clubbed to death because the govt. forbids ownership until the seals are dead and then awards ownership to the killer. If ownership of the live seals were allowed, they could be bought and protected.
The market is not an unexplained miracle. It's working is based on the fact that reason and voluntary interaction is superior to force and fraud.