Saturday, December 31, 2011

Fuel Of The Future?

Many NZ waterways suffer from nutrient-rich farm effluent run-off.
Because cows produce an awful lot of poo, many farmers spray it as fertiliser. Those poo nutrients leach into streams, rivers and lakes. The water becomes nutrient-rich, whereas most water plants have adapted themselves to nutrient-poor waters. So other plant species start to develop and the original plant species die. The water becomes foggy, which leads to a lower oxygen production in the water and the fish die, all due to effluent run-off.
Here in NZ, duckweed is being used for wastewater treatment, as it's able to digest nutrients at tremendous speeds, but overseas research indicates it can then be harvested for biofuel processing. Duckweed can store at least four times more starch per surface unit then regular crops, thus making it a good candidate for biofuel.
Biofuels have grown in popularity over the last few years with viable options now in production. However they're also surrounded by some controversy, because the biofuel crops are grown on land that could be producing food. This wouldn’t occur with duckweed, coz it grows on water and it’s four times more efficient!
University of North Carolina researchers have conducted lab-scale tests to convert duckweed starch to ethanol, using the technologies used for corn ethanol. They're now moving to a pilot-scale operation on a commercial farm.
Of course, there's still the issue of duckweed blocking sunlight to the water below. But if that can be resolved, perhaps by cropping duckweed in commercial-scale ponds on non-productive land, it may be a viable part of our fuel future.
For more info: [1], [2], [3].

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