I have considered previously the possibilities of making biodiesel from algae, which can in principle be achieved on an amount per hectare some 100 or more times that derived from common "bio-crops". Against the backdrop of conventional oil supplies running short within a decade and the serious compromise that would exist between growing crops to produce either food or fuel - and still nowhere near meet current demand for the latter - this is a most attractive prospect. I remain optimistic about the technology, albeit noting that there remain many problems to be overcome before it might be used reliably on the large scale. In what can be thought of as an adaptation of the strategy, a company in Israel have used an undisclosed "green technology" to make biofuel from seaweed. The connection with algae may not appear immediately obvious, but seaweed are in fact macrocolonies of algae. It is reported that 1 litre of fuel can be made from 5 kilograms of dried algae.
Seaweed is a common name for all the large complex multicellular algae, and have the most complex anatomy of any algae. Some seaweeds have tissues and organs that resemble those of higher land plants, and yet they are more closely related to the unicellular algae we are more familiar with in using the term. Hence it seems that their anatomical complexity evolved independently. The seaweed body form is called "thallus" and usually the entity has a root-like holdfast which anchors the plant to the substrate (seabed or rock), a stem-like "stipe" and a leaf-like "blade" - the collection of which provides most of the photosynthetic apparatus for the algae.
The Israeli company, Seambiotic Ltd., have unveiled a new technology they say for "efficiently extracting fuel from seaweed", which involves the absorption of CO2 from fossil-fuel fired power plants. Rather than simply allowing the gas to escape into the atmosphere, it is passed through a filtration system in which it enters a pool to feed "microscopic seaweed", so the report describes it. The technology was developed by Seambiotic Ltd. three years ago on an experimental farm located on the site of the Ashkelon power plant, with the support of the Israeli Electric Corporation. The seaweed pools are located several hundred metres from the plant smokestacks, and are filled with seawater that has been used to cool the electric turbines. The seaweed employed grows naturally in the Mediterranean sea in small amounts, but in the pools the forcing conditions of elevated CO2 concentrations increase its growth by a factor of one million.
I think it is more likely that Seambiotic are cultivating unicellular algae, not seaweed as we usually think of it. I understand also that they are currently doing well in the highly profitable Food Supplements market, so this may represent a branching-out of their business interests. The essential premise is particularly fortuitous for Israel given that both land and freshwater are highly costly there. So, seawater is used as the bulk medium, and introduced in relatively small area, shallow ponds, or mainly vertical flow-systems made of light-transparent plastic tubes to maximize the solar energy input. Taking unwanted and highly undesirable (global warming!) CO2 from otherwise "polluting" power stations to actually enhance the algal growth is a wonderful bonus. The one remaining component is "fertilizer". Will this be supplied in the form of seawater "naturally" polluted by sewage, or in some other way? If waste CO2, sewage and seawater are all that is required to provide the necessary culture-medium for the project, it looks like a winner!
Amnon Bachar, who is the director of Seambiotic, said: "In the scientific literature it is stated that it is impossible to grow seaweed through the use of carbon dioxide from power plants, because of large quantities of pollutants released from the smokestacks. But it appears that whoever wrote that does not know how to grow seaweed. We have found that seaweed can grow on the basis of the carbon dioxide being emitted from power plants. We get the carbon dioxide for free, and the power plant produces less pollution."
There are about 30,000 species of micro-algae known, most of which have not been researched into in regard to fuel production. Since they exist or can be grown in large amounts it is an exciting outlook if algae can be substituted as the new "crude oil", for the production of both fuel and chemical feedstocks for making pharmaceuticals, plastics, textiles, soap etc. etc. Algae might even form a significant proportion of the world's staple food in the future, as its population rises. Consequently, it is important to invest in finding the best algal strains to work with and exploit the benefits of.
(1) "Israeli firm: seaweed could be used to solve energy crisis", by Ofri Ilan, Haaretz: http://www.haaretz.com/hasen/spages/837175.html
(2) "Israeli technology derives bio-fuel from algae", by Stephanie Field, ISRAEL21c: http:/www.israel21c.org/bin/en.jsp?enScript