Biofuels - Algal farming: a new Agricultural Revolution?
Published: May 8, 2008
Source : Science Alert
The dilemma, biofuels or food, disappears as soon we turn our intention to the humble seawater algae. They are not only a potential source of biofuels. Algae are at the base of the marine food web and can also be used for human consumption or as animal fodder. And whatever we do not use can easily be converted into very good fertiliser. Growing algae on barren land may indeed offer a new agricultural revolution and Australia could be at its forefront, earning a good deal from carbon credits.
The world seems blinded by its desire for high-tech solutions. We may be better off adopting large volume, low-tech solutions which any farmer can understand and implement. If they grew algae for fuel, food, feed and fertiliser production farmers could become less dependent on fossil fuels, expensive fertilisers and dwindling fresh water sources. Farmers could also grow fish with the algae on barren land while continuing to grow food crops on fertile parts of their property. Australia’s salinity issue could also be addressed by providing salt water drainages and enabling targeted afforestation.
Unlike in the open sea, we have some control over what we grow in basins or ponds on barren land. This is the basis of my Greening Method (patent pending). As we grow the algae in saltwater ponds, the water will evaporate and this may offset soil humidity loss on nearby land sufficiently to enable vegetation growth. We can also use the grown algae to improve soil fertility and quality. And, once vegetation takes hold, we are ready to grow a new agroforestry mix.
Harvesting ocean algal blooms is also an option. Although we have yet to work out mechanisms that drive them, they too could also be managed as a source of algal oils and carbon credits. For example, existing oil spill containment technologies could easily be adapted for harvesting of algae on the open sea. The fishing industry may also benefit from this as seeding the seas may increase potential fish catches.
The public usually finds the thought of sewage treatment plants distasteful, but these too could play an important role in the envisioned agricultural revolution. Human waste provides primary nutrients to algae and since they are low in food chain we can be quite safe in using it to feed them. We can use the waste from sewage works in two ways: to grow algae for biofuels in specialised treatment plants or to fertilise algal blooms at sea.
People will inevitably raise the issue of the cost of algae-based fuels, but the answer is that political will always plays a key part in how much something costs – a point underlined by the Brazilian ethanol industry which would not have flourished without government support. Costs can be driven down not only by carbon credits, but also by our inventiveness and experience.
Our farmers were quite inventive in the past and they are likely to continue in the future. Algal farming experiences may also become valuable export products earning even more carbon credits.
Source
Science AlertRelated topics:
Recommend
Comment
Share
9 de mayo de 2008
Algae are a wonderful product. In our company we produce algae on a large-scale as a feed for aquaculture and for human food additives. Because of their very special and very concentrated composition algae or phytoplankton offer unique and powerfull food supplements. A number of Marine Algae posess Omega-3-fatty-acids, all kinds of pigments, sterols, anti-oxidants and so, and so on!
But something that isnt possible with algae or any biomass for that matter is to produce energy or biofuels with a positive energy balance. Here im not talking about waste-stream biomass but specially cultivated biomass for the purpose of producing energy (bio-fuels). Anyone who is able to make a realistic! life-cycle analisisys will concur with this. The problem is, that the amount of energy from the sun in the form of photons that can be used by plants (Algae equal) is limitid to 45% of the spectrum (so called PAR-light), than there is a quantum limitation in the photosynthesisapparatus (8-9 photons are needed to bind one CO2 molecule) This kicks back the amounth of sunlight that can tyheoreticly be used to produce biomass to a mere 10%. In open ponds only 1-2% of the suns energy can be converted into biomass and in some other systems 4-5% and the practical maximum will be around 7-8%. This means for example in the Netherlands were there is 100 Watt/m2 available (year round) that you can only produce between 1 and 7 Watts per m2. This is less than the Energy needed to grow the algae (stirring of the pond/substrate, pumping, harvesting, utilitys, personel, transportation etc etc) Leading to a negative Mass Balance. Now people will say, yeah the Netherlands its alway raining overthere and not so much sun as on the equator or other sunnier places. This doent work as well, because to much sun/light will kill the algae and like humans algae have a limit in how much they can eat ( if I asked one of you to eat one hamburer, this would not be a problem, but if I asked you to eat 100 hamburgers this wouldnt be possible) Other problems that cost a lot of energy in sunnier (warmer) places are cooling (above 40 C most algae will perish), need for water because of evaporation, higher transportation costs (in terms of energy) etc. etc.
So the bottom line is: It isnt possible to produce energy if the production process uses up more enegy than that it produces.
With kind regards,
Sander Hazewinkel
LGem bv
The Netherlands
Propierty owner of one of the world's highest efficientie algae systems.
Recommend
Reply
Would you like to discuss another topic? Create a new post to engage with experts in the community.
Featured users in Aquaculture
Chris Beattie
MSD - Merck Animal Health
Global Head of Aquaculture at Merck Animal Health
United States
United States
