Biological research is in progress in regard of how to produce biofuels from algae.
Some algae can produce oil by photosynthesis twice as much, in volume, as itself per year. Typical annual rate of biofuel (oil) production by traditional oil crops per one hectare of land area are as follows: 0.4 kℓ for soybean, 2.1 kℓ for corn, 5.2 kℓ for sugarcane. Whereas rate of biofuel (oil) production of some algae range between 11 ~ 90 kℓ/hectare, which is some tens of times as much as that of the traditional oil crops. In addition, cultivation of algae does not hinder the production of traditional food crops.

On 18 March 2010, NEDO (New Energy and Industrial Technology Development Organization) and CRIEPI (Central Research Institute of Electric Power Industry) made an announcement that they have succeeded in developing a technology to extract oil from blue-green algae at low cost. Blue-green algae tend to grow on the surface of extra-enriched lakes and marshes, and consequently do harm to aqua-ecosystem, hinder fishing work, and generate bad smell. Therefore, a smart and profitable utilization of the algae has been long waited for.

The extraction of oil from blue-green algae can be done by using DME (dimethyl ether: CH3-O-CH3) . This method makes it possible to eliminate dehydration and drying of algae, and therefore makes biofuel production easier and cheaper. Traditional extraction method barely yielded oil as little as only 0.6 % of dried weight of blue-green algae, whereas by the new method using DME, extraction of oil can be raised up to 40 %, a great reap of productivity (70 times as much as ever), indeed.

DME has been known as a clean fuel because it is sulfur-free. Therefore it does not emit sulfur oxides nor particle materials (PM), when burnt. On 18 May 2010, a private association called DME Vehicle Promotion Committee announced that they made a proof experiment for running trucks by using diesel fuel containing 5 % of DME that was extracted from eucalyptus chips and that they found no trouble in the test runs.

Thus, it has been proven that DME extracted from woody biomass could not only be used as biofuel but also be used for extraction of oil from blue-green algae. Practical use of bio-DME seems to be widening from now on!

Table  Oil Productivity per Area of Typical Oil Crops

Kind of Oil Crop	Oil Productivity (kℓ/ha/yr)
Soybeans	0.4
Wheat	0.7
Barley	0.9
Sunflower Seeds	1.0
Rape Seeds	1.2
Rice	1.6
Jatropha	1.9
Corn	2.1
Sugarcane	5.2
Oil Palm	5.9
Algae X (TAG* 15% in weight)	11.2
Algae Y (TAG* 50% in weight)	93.5

* TAG (Tri-Acryl-Glycerols) is a molecule type of oil in the algae cells

Fig.  Oil Productivity per Unit Area of Typical Oil Crops

Source: 1)
“Production of Biofuel from Algae”, November 2008, Hiroshi Yamazaki, SCE-NET Energy Research Committee (http://www.sce-net.jp/enrgypdf/bioalga.pdf), 2) a Press release of NEDO, 3) website of DME Vehicle Promotion Committee, (http://www.dme-vehicle.org /event/2010/100518img.html) et al