Saturday, April 5, 2008

Algae as feedstock for biodiesel

We all know biodiesel production and use is to be encouraged to reduce our diesel dependency –the clean burning biodiesel is also an attractive solution to reduce the pollution problems created by regular diesel. However, cost and availability of feedstocks such as vegetable oils and animal fats is an important limiting factor curbing the widespread production of biodiesel. Supplementing current feedstocks with alternative oil sources is a dire need for the renewable fuels industry – the important feature of course is that these feedstock oils should be low priced and readily available. They should not also trigger the Food vs Fuel debate—use of vegetable oils and animal fats for fuel does touch a raw nerve with the public in general. I had earlier blogged about the use of sorghum in my country as feedstock option, now I happened to read about another technology using algae for the same purpose –algae seems to be a very viable option from all perspectives.
The use of existing agricultural practices is being explored to grow specific algae species and develop methods for processing algae biomass that can be cost-effectively applied to commercial-scale biodiesel production. Algae can be a potential source of bio-oils suitable for biodiesel feedstock due to their rapid growth rates relative to traditional oil-seed plants and due to their lack of direct competition with food crops.
“The new technology, called Simgae™, uses common agriculture and irrigation components to produce algae at a reduced cost. The system uses unique thin walled polyethylene tubing, called Algae Biotape®, similar to conventional drip irrigation tubes.The patent pending biotape is laid out in parallel across a field. Under pressure, water containing the necessary nutrients and a small fraction of algae are slowly introduced into the biotape. Carbon dioxide is injected periodically and after roughly 24 hours the flow leaves the Algae Biotape with a markedly greater concentration of algae than was started. All the supporting hardware components and processes involved in Simgae are direct applications from the agriculture industry. Re-use of these practices avoids the need for expensive and complex hardware and costly installation and maintenance.The design is expected to provide an annual algae yield of 100 - 200 dry tons per acre. Capital costs are expected to be approximately $45k - $60k and profitable oil production costs are estimated at only $0.08 - $0.12/pound. These oil costs compare to recent market prices of feedstock oils anywhere from $0.25 - $0.44/pound.The team at Diversified Energy, is currently conducting a demonstration of the technology in Casa Grande, Arizona”.

Continued testing and system optimization is expected through 2008. I’ll be watching the space to know if Algae proves to be the perfect solution to the challenge of finding a suitable feedstock for renewable fuels.(source: Diversified Energy & XL Renewables Testing New Algae Technology (

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