Seaweed can be broadly termed as marine macroalgae, and belongs to one of the many groups of multicellular red, green and brown algae. Seaweed is widely used to produce vitamin supplements, cosmetics, plastics and animal feed in many parts of the world.
The importance of seaweed has skyrocketed ever since researchers managed to create a biofuel, ethanol, from it. Researchers believe that producing seaweed-based biofuel in the sea will take care of numerous issues caused by conventional fuels. Although seaweed farming has been in practice for 100s of years in Asia, researchers are focused on newer methods to grow seaweed.
Seaweed Farm Projects
Small-scale seaweed farms for the purpose of producing biofuel have started operating around the world. The traditional method of seaweed farming is labor-intensive, where twines have to be impregnated with millimetre-sized seaweed embryos, which are then wound around ropes and left in the water to grow. The seaweed has to be harvested by hand.
The Scottish Association for Marine Science operates a seaweed farm in a sea fjord, near Oban in Argyll. The environment is conducive for seaweed growth with natural water currents to flow over the blades of the seaweed, enabling the seaweed to absorb nutrients. The seaweeds are grown on a carpet placed over the water surface and held by moorings. Carpets with their rough surfaces are ideal growth substrates.
The AT~SEA project is a major European research program comprising many countries working towards mass cultivation of seaweeds along Europe's shores. The research team plans to use a technically and economically practical textile substrate for growing seaweed, such that it will be able to endure marine conditions. At the moment different textiles such as meshes used in gardening and fine fabrics, are being tested.
Seaweed Energy Solutions (SES), based in Trondheim, Norway, is headed by Paal Bakken who firmly believes that there is potential to make biofuels from seaweed. They have been working on cultivation technology since 2008. Currently, their production capacity is about 100,000 t of seaweed. According to Bakken, a particular type of seaweed called sugar Kelp can produce about 50 litres of ethanol and 20m3 of biomethane per wet ton. SES has successfully produced both ethanol and biomethane fuel during the test phase.
University of Victoria researcher, Aaron Philippsen recently presented a probable solution for British Columbia’s fuel supply which is currently being imported from other places. Philippsen has proposed farming seaweed along the length of British Columbia’s coastline for the production of ethanol, which would suffice for the fuel needs of the province. He wants to float large rafts in the ocean along the coastline to grow the seaweed.
For seaweed farming, neither irrigation nor farmland is required. Another plus point is that manufacturing seaweed-based ethanol produces less greenhouse gases than the conventional ethanol procured from corn or wheat. Thus seaweed farming is an environmentally friendly way to produce fuels in the coming years.
Researchers are looking to mechanize the process for large-scale seaweed production. They will also have to find cost-effective renewable energy processes for drying seaweed or else the overall costs will shoot up. Success in large-scale production of seaweed-based biofuels would mean reduction of our excessive dependence on oil in the future.
Athough large-scale seaweed biofuel production is not yet a reality, millions of dollars are being invested in seaweed research around the world and there is hope that this novel technology will be widely used for biofuel production in the future.