Posted by: Prospector PJ21 AUG 2013
Seaweed may seem like an unlikely material to help save the planet, but it could prove a useful fuel without many of the disadvantages of existing biofuels.
Many biofuels are produced from food crops. But they drive up global prices and consume increasingly scarce fresh water. And some, such as palm oil, can produce more carbon dioxide than diesel does.
Seaweed has been shown to clean up pollution from fish farms. And it grows more quickly than land plants, turning sunlight into chemical energy five times more efficiently.
The potential is huge. The UK government already includes up to 4,700km2 of seaweed cultivation in its future energy scenarios. Seaweed can be used to produce ethanol, which can be mixed with petrol or methane, the main component of the natural gas used to heat UK homes.
The Scottish Association for Marine Science has recently harvested seaweed from the first open ocean cultivation trials using advanced textiles as a substrate. Mass harvesting of wild-growing seaweed is not economically viable in Europe, where labour costs are high. The SAMS project aims to make mass cultivation in inshore locations feasible by creating growth substrates that can withstand the constantly wet, salty and moving ocean environment.
Algae are another potential source of vast quantities of biofuel. The oil yield from algae is estimated to be 19,000–75,000 litres per acre per year, which is between seven and 31 times greater than that from palm oil, the next best crop in this context.
But efficient biofuel production from algae depends on finding a species with a high lipid and carbohydrate content and fast growth rate. The EU-funded Mabfuel (Marine Algae as Biomass for bioFuel) project uses the algae Nannochloropsis oculata and N salina because they have the highest oil content.